On the maximum pressure rise rate in boosted HCCI operation
Wildman, Craig B.
This paper explores the combined effects of boosting, intake air temperature, trapped residual gas fraction, and dilution on the Maximum Pressure Rise Rate (MPRR) in a boosted single cylinder gasoline HCCI engine with ...
Rapidly Solving an Online Sequence of Maximum Flow Problems
2008-02-29T23:59:59.000Z
... an interdictor allocates a finite amount of resources to remove arcs from a net- ... is, the next maximum flow problem in the sequence differs from the previous one by ..... the appropriate reoptimization case and then taking the appropriate action to ..... Our first set of computational experiments tested the performance of our ...
Smokeless Control of Flare Steam Flow Rate
Agar, J.; Balls, B. W.
1979-01-01T23:59:59.000Z
measurement of mass flow rate of flare gas, in spite of the hostile environment. Its use for initiating control of flare steam flow rate and the addition of molecular weight compensation, using specific gravity (relative density) measurement to achieve...
Position paper -- Tank ventilation system design air flow rates
Goolsby, G.K.
1995-01-04T23:59:59.000Z
The purpose of this paper is to document a project position on required ventilation system design air flow rates for the waste storage tanks currently being designed by project W-236A, the Multi-Function Waste Tank Facility (MWTF). The Title 1 design primary tank heat removal system consists of two systems: a primary tank vapor space ventilation system; and an annulus ventilation system. At the conclusion of Title 1 design, air flow rates for the primary and annulus ventilation systems were 960 scfm and 4,400 scfm, respectively, per tank. These design flow rates were capable of removing 1,250,000 Btu/hr from each tank. However, recently completed and ongoing studies have resulted in a design change to reduce the extreme case heat load to 700,000 Btu/hr. This revision of the extreme case heat load, coupled with results of scale model evaporative testing performed by WHC Thermal Hydraulics, allow for a reduction of the design air flow rates for both primary and annulus ventilation systems. Based on the preceding discussion, ICF Kaiser Hanford Co. concludes that the design should incorporate the following design air flow rates: Primary ventilation system--500 scfm maximum and Annulus ventilation system--1,100 scfm maximum. In addition, the minimum air flow rates in the primary and annulus ventilation systems will be investigated during Title 2 design. The results of the Title 2 investigation will determine the range of available temperature control using variable air flows to both ventilation systems.
The Maximum Flow Network Interdiction Problem: Valid Inequalities ...
2009-05-03T23:59:59.000Z
interdiction [12, 19], facility interdiction [6], and a variant of MFNIP where flow is routed before ..... A network interdiction model for hospital infection control.
Historical river flow rates for dose calculations
Carlton, W.H.
1991-06-10T23:59:59.000Z
Annual average river flow rates are required input to the LADTAP Computer Code for calculating offsite doses from liquid releases of radioactive materials to the Savannah River. The source of information on annual river flow rates used in dose calculations varies, depending on whether calculations are for retrospective releases or prospective releases. Examples of these types of releases are: Retrospective - releases from routine operations (annual environmental reports) and short term release incidents that have occurred. Prospective - releases that might be expected in the future from routine or abnormal operation of existing or new facilities (EIS`s, EID`S, SAR`S, etc.). This memorandum provides historical flow rates at the downstream gauging station at Highway 301 for use in retrospective dose calculations and derives flow rate data for the Beaufort-Jasper and Port Wentworth water treatment plants.
What is the maximum rate at which entropy of a string can increase?
Ropotenko, Kostyantyn [State Administration of Communications, Ministry of Transport and Communications of Ukraine 22, Khreschatyk, 01001, Kyiv (Ukraine)
2009-03-15T23:59:59.000Z
According to Susskind, a string falling toward a black hole spreads exponentially over the stretched horizon due to repulsive interactions of the string bits. In this paper such a string is modeled as a self-avoiding walk and the string entropy is found. It is shown that the rate at which information/entropy contained in the string spreads is the maximum rate allowed by quantum theory. The maximum rate at which the black hole entropy can increase when a string falls into a black hole is also discussed.
Control Strategies for Centrifugal Pumps with Variable Flow Rate...
Broader source: Energy.gov (indexed) [DOE]
Control Strategies for Centrifugal Pumps with Variable Flow Rate Requirements Control Strategies for Centrifugal Pumps with Variable Flow Rate Requirements This tip sheet discusses...
Solids flow rate measurement in dense slurries
Porges, K.G.; Doss, E.D.
1993-09-01T23:59:59.000Z
Accurate and rapid flow rate measurement of solids in dense slurries remains an unsolved technical problem, with important industrial applications in chemical processing plants and long-distance solids conveyance. In a hostile two-phase medium, such a measurement calls for two independent parameter determinations, both by non-intrusive means. Typically, dense slurries tend to flow in laminar, non-Newtonian mode, eliminating most conventional means that usually rely on calibration (which becomes more difficult and costly for high pressure and temperature media). These issues are reviewed, and specific solutions are recommended in this report. Detailed calculations that lead to improved measuring device designs are presented for both bulk density and average velocity measurements. Cross-correlation, chosen here for the latter task, has long been too inaccurate for practical applications. The cause and the cure of this deficiency are discussed using theory-supported modeling. Fluid Mechanics are used to develop the velocity profiles of laminar non-Newtonian flow in a rectangular duct. This geometry uniquely allows the design of highly accurate `capacitive` devices and also lends itself to gamma transmission densitometry on an absolute basis. An absolute readout, though of less accuracy, is also available from a capacitive densitometer and a pair of capacitive sensors yields signals suitable for cross-correlation velocity measurement.
Nolan, David S.
On the Vertical Decay Rate of the Maximum Tangential Winds in Tropical Cyclones DANIEL P. STERN independent of both the maximum wind speed and the radius of maximum winds (RMW). This can be seen winds change with height. Above 2-km height, vertical profiles of Vmaxnorm are nearly independent
Flow Rate Estimates Qs and As Q: What is the Flow Rate Technical Group?
Fleskes, Joe
to the BP oil spill in the Gulf of Mexico be stepped up as a result of the new flow rate estimates released their initial estimate. Â· The first approach analyzed how much oil is on the surface of the Gulf of Mexico using,000 and 270,000 barrels of oil are on the surface of the Gulf of Mexico and that a similar amount had already
VARIABLE FIRING RATE OIL BURNER USING PULSE FUEL FLOW CONTROL.
KRISHNA,C.R.; BUTCHER,T.A.; KAMATH,B.R.
2004-10-01T23:59:59.000Z
The residential oil burner market is currently dominated by the pressure-atomized retention head burner, which has an excellent reputation for reliability and efficiency. In this burner, oil is delivered to a fuel nozzle at pressures from 100 to 150 psi. In addition, to atomizing the fuel, the small, carefully controlled size of the nozzle exit orifice serves to control the burner firing rate. Burners of this type are currently available at firing rates of more than 0.5 gallons-per-hour (70,000 Btu/hr). Nozzles have been made for lower firing rates, but experience has shown that such nozzles suffer rapid fouling of the necessarily small passages, leading to bad spray patterns and poor combustion performance. Also, traditionally burners and the nozzles are oversized to exceed the maximum demand. Typically, this is figured as follows. The heating load of the house on the coldest day for the location is considered to define the maximum heat load. The contractor or installer adds to this to provide a safety margin and for future expansion of the house. If the unit is a boiler that provides domestic hot water through the use of a tankless heating coil, the burner capacity is further increased. On the contrary, for a majority of the time, the heating system is satisfying a much smaller load, as only rarely do all these demands add up. Consequently, the average output of the heating system has to be much less than the design capacity and this is accomplished by start and stop cycling operation of the system so that the time-averaged output equals the demand. However, this has been demonstrated to lead to overall efficiencies lower than the steady-state efficiency. Therefore, the two main reasons for the current practice of using oil burners much larger than necessary for space heating are the unavailability of reliable low firing rate oil burners and the desire to assure adequate input rate for short duration, high draw domestic hot water loads. One approach to solve this problem is to develop a burner, which can operate at two firing rates, with the lower rate being significantly lower than 0.5 gallons per hour. This paper describes the initial results of adopting this approach through a pulsed flow nozzle. It has been shown that the concept of flow modulation with a small solenoid valve is feasible. Especially in the second configuration tested, where the Lee valve was integrated with the nozzle, reasonable modulation in flow of the order of 1.7 could be achieved. For this first prototype, the combustion performance is still not quite satisfactory. Improvements in operation, for example by providing a sharp and positive shut-off so that there is no flow under low pressures with consequent poor atomization could lead to better combustion performance. This could be achieved by using nozzles that have shut off or check valves for example. It is recommended that more work in cooperation with the valve manufacturer could produce a technically viable system. Marketability is of course a far more complex problem to be addressed once a technically viable product is available.
Scaling of the magnetic reconnection rate with symmetric shear flow
Cassak, P. A. [Department of Physics, West Virginia University, Morgantown, West Virginia 26506 (United States); Otto, A. [Geophysical Institute, University of Alaska-Fairbanks, Fairbanks, Alaska 99775 (United States)
2011-07-15T23:59:59.000Z
The scaling of the reconnection rate during (fast) Hall magnetic reconnection in the presence of an oppositely directed bulk shear flow parallel to the reconnecting magnetic field is studied using two-dimensional numerical simulations of Hall reconnection with two different codes. Previous studies noted that the reconnection rate falls with increasing flow speed and shuts off entirely for super-Alfvenic flow, but no quantitative expression for the reconnection rate in sub-Alfvenic shear flows is known. An expression for the scaling of the reconnection rate is presented.
Structure of Turbulence in Katabatic Flows below and above the Wind-Speed Maximum
Grachev, Andrey A; Di Sabatino, Silvana; Fernando, Harindra J S; Pardyjak, Eric R; Fairall, Christopher W
2015-01-01T23:59:59.000Z
Measurements of small-scale turbulence made over the complex-terrain atmospheric boundary layer during the MATERHORN Program are used to describe the structure of turbulence in katabatic flows. Turbulent and mean meteorological data were continuously measured at multiple levels at four towers deployed along the East lower slope (2-4 deg) of Granite Mountain. The multi-level observations made during a 30-day long MATERHORN-Fall field campaign in September-October 2012 allowed studying of temporal and spatial structure of katabatic flows in detail, and herein we report turbulence and their variations in katabatic winds. Observed vertical profiles show steep gradients near the surface, but in the layer above the slope jet the vertical variability is smaller. It is found that the vertical (normal to the slope) momentum flux and horizontal (along the slope) heat flux in a slope-following coordinate system change their sign below and above the wind maximum of a katabatic flow. The vertical momentum flux is directed...
Effects of external pressure on the terminal lymphatic flow rate
Seale, James Lewis
1981-01-01T23:59:59.000Z
pressure applied to the skin of the canine cause the terminal lymphat- ic flow rate to increase until the external pressure reaches 60mm Hg. At an external pressure of 60mm Hg reduced lymphatic flow is observed in some of the test animals. At 75mm Hg... resulting from the external pressure begins to col- lapse the lymph vessels. External pressure between 60 and 75mm Hg restricts or completely occludes the terminal lymphatic flow rate. ACKNOWLEDGENENTS I would like to express my appreciation...
Some observations on Goldberg-Trajan's Maximum Flow algorithm on Bipartite Graphs
Yang, Bencai
1997-01-01T23:59:59.000Z
) is a direct graph with two distinguished vertices s (the source) and t (the sink). Each edge [u, v] in G is associated with a positive integer cap(u, v), called the capacity of the edge. If there is no edge from vertex u to vertex v. then we define... cap(u, v) = 0. Intuitively, a flow in a flow network should satisfy the following three conditions: (1) the amount of flow along an edge should not exceed the capacity of the edge (capacity constraint); (2) a flow from a vertex u to a vertex v can...
SHORT COMMUNICATION Flow rate-modified streaming effects in heterogeneous
Xuan, Xiangchun "Schwann"
the streaming potential (Norde and Rouwendal 1990; Elgersma et al. 1992; Werner et al. 1999) or streamingSHORT COMMUNICATION Flow rate-modified streaming effects in heterogeneous microchannels Junjie Zhu relations is developed to study the streaming potential and streaming current in heterogeneous micro
Prediction of Room Air Diffusion for Reduced Diffuser Flow Rates
Gangisetti, Kavita
2011-02-22T23:59:59.000Z
?, IEA Annex 20 project. The simulated results, in terms of maximum velocity, distribution of velocity and temperature in the room are validated against the experimental data. 3.1.1 Study the effect of various parameters on the CFD simulation. A study... and the walls of the room. The window is assumed to have a surface temperature of 30 0C.The diffuser used is a ?HESCO? type diffuser, which was used in the International Energy Agency (IEA) Annex 20 project (1993): ?Room air and contaminant flow, evaluation...
NONLINEAR DEVELOPMENT OF THE R-MODE INSTABILITY AND THE MAXIMUM ROTATION RATE OF NEUTRON STARS
Bondarescu, Ruxandra [Institute for Theoretical Physics, University of Zurich, CH-8057 Zurich (Switzerland); Wasserman, Ira, E-mail: ruxandra@physik.uzh.ch, E-mail: ira@astro.cornell.edu [Center for Radiophysics and Space Research, Cornell University, Ithaca, NY 14853 (United States)
2013-11-20T23:59:59.000Z
We describe how the nonlinear development of the R-mode instability of neutron stars influences spin up to millisecond periods via accretion. When nearly resonant interactions of the l = m = 2 R-mode with pairs of 'daughter modes' are included, the R-mode saturates at the lowest amplitude which leads to significant excitation of a pair of modes. The lower bound for this threshold amplitude is proportional to the damping rate of the particular daughter modes that are excited parametrically. We show that if dissipation occurs in a very thin boundary layer at the crust-core boundary, the R-mode saturation amplitude is too large for angular momentum gain from accretion to overcome loss to gravitational radiation. We find that lower dissipation is required to explain spin up to frequencies much higher than 300 Hz. We conjecture that if the transition from the fluid core to the crystalline crust occurs over a distance much longer than 1 cm, then a sharp viscous boundary layer fails to form. In this case, damping is due to shear viscosity dissipation integrated over the entire star. We estimate the lowest parametric instability threshold from first principles. The resulting saturation amplitude is low enough to permit spin up to higher frequencies. The requirement to allow continued spin up imposes an upper bound to the frequencies attained via accretion that plausibly may be about 750 Hz. Within this framework, the R-mode is unstable for all millisecond pulsars, whether accreting or not.
Multi-rate flowing Wellbore electric conductivity logging method
Tsang, Chin-Fu; Doughty, Christine
2003-04-22T23:59:59.000Z
The flowing wellbore electric conductivity logging method involves the replacement of wellbore water by de-ionized or constant-salinity water, followed by constant pumping with rate Q, during which a series of fluid electric conductivity logs are taken. The logs can be analyzed to identify depth locations of inflow, and evaluate the transmissivity and electric conductivity (salinity) of the fluid at each inflow point. The present paper proposes the use of the method with two or more pumping rates. In particular it is recommended that the method be applied three times with pumping rates Q, Q /2, and 2Q. Then a combined analysis of the multi-rate data allows an efficient means of determining transmissivity and salinity values of all inflow points along a well with a confidence measure, as well as their inherent or far-field pressure heads. The method is illustrated by a practical example.
DRAFT: Mass Balance Team, part of Flow Rate Technical Group, Completes Estimate of Oil Flow
Fleskes, Joe
with the reservoir will also be addressed by integration with the MMS team and by incorporation of some degree) The Department of Energy (DOE) was asked to conduct a nodal analysis to estimate flow rates from reservoir to release points. This effort will rely on input from a research team coordinated by the Minerals Management
Robert Felix Tournier
2014-04-25T23:59:59.000Z
An undercooled liquid is unstable. The driving force of the glass transition at Tg is a change of the undercooled-liquid Gibbs free energy. The classical Gibbs free energy change for a crystal formation is completed including an enthalpy saving. The crystal growth critical nucleus is used as a probe to observe the Laplace pressure change Dp accompanying the enthalpy change -Vm*Dp at Tg where Vm is the molar volume. A stable glass-liquid transition model predicts the specific heat jump of fragile liquids at temperatures smaller than Tg, the Kauzmann temperature TK where the liquid entropy excess with regard to crystal goes to zero, the equilibrium enthalpy between TK and Tg, the maximum nucleation rate at TK of superclusters containing magic atom numbers, and the equilibrium latent heats at Tg and TK. Strong-to-fragile and strong-to-strong liquid transitions at Tg are also described and all their thermodynamic parameters are determined from their specific heat jumps. The existence of fragile liquids quenched in the amorphous state, which do not undergo liquid-liquid transition during heating preceding their crystallization, is predicted. Long ageing times leading to the formation at TK of a stable glass composed of superclusters containing up to 147 atoms, touching and interpenetrating, are evaluated from nucleation rates.
Kawazura, Y.; Yoshida, Z. [Graduate School of Frontier Sciences, University of Tokyo, Kashiwa, Chiba 277-8561 (Japan)
2012-01-15T23:59:59.000Z
Two different types of self-organizing and sustaining ordered motion in fluids or plasmas--one is a Benard convection (or streamer) and the other is a zonal flow--have been compared by introducing a thermodynamic phenomenological model and evaluating the corresponding entropy production rates (EP). These two systems have different topologies in their equivalent circuits: the Benard convection is modeled by parallel connection of linear and nonlinear conductances, while the zonal flow is modeled by series connection. The ''power supply'' that drives the systems is also a determinant of operating modes. When the energy flux is a control parameter (as in usual plasma experiments), the driver is modeled by a constant-current power supply, and when the temperature difference between two separate boundaries is controlled (as in usual computational studies), the driver is modeled by a constant-voltage power supply. The parallel (series)-connection system tends to minimize (maximize) the total EP when a constant-current power supply drives the system. This minimum/maximum relation flips when a constant-voltage power supply is connected.
Flow Rate Dependence of Soil Hydraulic Characteristics D. Wildenschild,* J. W. Hopmans, J. Simunek
Wildenschild, Dorthe
Flow Rate Dependence of Soil Hydraulic Characteristics D. Wildenschild,* J. W. Hopmans, J. Simunek that some of the pores in theanalyzed using both steady state and transient flow analysis. One before their air-entry pres- loamy soil to evaluate the influence of flow rate on the calculated sure
Method and apparatus for controlling the flow rate of mercury in a flow system
Grossman, Mark W. (Belmont, MA); Speer, Richard (Reading, MA)
1991-01-01T23:59:59.000Z
A method for increasing the mercury flow rate to a photochemical mercury enrichment utilizing an entrainment system comprises the steps of passing a carrier gas over a pool of mercury maintained at a first temperature T1, wherein the carrier gas entrains mercury vapor; passing said mercury vapor entrained carrier gas to a second temperature zone T2 having temperature less than T1 to condense said entrained mercury vapor, thereby producing a saturated Hg condition in the carrier gas; and passing said saturated Hg carrier gas to said photochemical enrichment reactor.
Reidel, S.P.; Ledgerwood, R.K.; Myers, C.W.; Jones, M.G.; Landon, R.D.
1980-03-01T23:59:59.000Z
Detailed mapping of over 8000 square kilometers and logs from 20 core holes were used to determine the distribution and thickness of basalt flows and interbeds in the Pasco Basin. The data indicate the high-MgO Grande Ronde Basalt and Wanapum Basalt thicken from the northeast to the southwest. Deformation began in late Frenchman Springs time in the Saddle Mountains along a northwest-southeast trend and in Roza time along an east-west trend. By late Wanapum time, basalt flows were more restricted on the east side. Saddle Mountains Basalt flows spread out in the basin from narrow channels to the east. The Umatilla Member entered from the southeast and is confined to the south-central basin, while the Wilbur Creek, Asotin, Esquatzel, Pomona, and Elephant Mountain Members entered from the east and northeast. The distribution of these members is controlled by flow volume, boundaries of other flows, and developing ridges. The Wilbur Creek, Asotin, and Esquatzel flows exited from the basin in a channel along the northern margin of the Umatilla flow, while the Pomona and Elephant Mountain flows exited between Umtanum Ridge and Wallula Gap. The thickness of sedimentary interbeds and basalt flows indicated subsidence and/or uplift began in post-Grande Ronde time (14.5 million years before present) and continued through Saddle Mountains time (10.5 million years before present). Maximum subsidence occurred 40 kilometers (24 miles) north of Richland, Washington with an approximate rate of 25 meters (81 feet) per million years during the eruption of the basalt. Maximum uplift along the developing ridges was 70 meters (230 feet) per million years.
Variational bounds on the energy dissipation rate in body-forced shear flow
Petrov, Nikola
, the bulk (space and time averaged) dissipation rate per unit mass is proportional to the power required applied to many flows driven by boundary conditions, including shear flows and a variety of thermal
INSTALLATION CERTIFICATE CF-6R-MECH-27-HERS Maximum Rated Total Cooling Capacity (Page 1 of 2)
Conditioner is listed in the ARI database with a specified furnace or air handler and that furnace or air handler is to be installed. Otherwise, if the proposed Air Conditioner is listed in the ARI database (Watt) = ARI Rated Total Cooling Capacity (Btu/hr) / ARI Rated EER (Btu/Watt-hr) if the proposed Air
Maruyama, Shigeo
Effect of flow rate of ethanol on growth dynamics of VA-SWNT - Transition from no-flow CVD a growth model [2]. In this study, the flow rate of ethanol during the CVD was controlled precisely. Figure 1 shows the growth curve of VA-SWNT film for various ethanol flow rates. In the figure, "No
air flow rates: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 41 Overheat Instability in an Ascending Moist Air Flow as a Mechanism of Hurricane Formation...
air flow rate: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 41 Overheat Instability in an Ascending Moist Air Flow as a Mechanism of Hurricane Formation...
Momentum rate probe for use with two-phase flows S. G. Bush,a)
Panchagnula, Mahesh
of flows including nuclear reactor coolant streams, refrigerants in heating-ventilating air flow rates of these flows span a wide range of values, from those in nuclear power plant cooling systems, through supercritical diesel fuel injection, heating-ventilating and air-conditioning HVAC
Measurements of Film Flow Rate in Heated Tubes with Various Axial Power Distributions
Haviland, David
Measurements of Film Flow Rate in Heated Tubes with Various Axial Power Distributions by Carl, Measurements of Film Flow Rate in Heated Tubes with Various Axial Power Distributions KTH Nuclear Reactor power is limited by a phenomenon called critical heat flux (CHF). It appears as a sudden detoriation
Cocurrent gas - liquid flow at high rates in small particle beds
Wilemon, M.; Torrest, R.S. (Dept. of Chemical Engineering, Arizona State Univ., Tempe, AZ (US))
1988-01-01T23:59:59.000Z
Gas liquid cocurrent flow at high pressure drop often occurs near the well bore and in grabel filled perforations during production of oil and geothermal energy. Available studies have, however, emphasized large particles and low pressure drops. Here, results for air-water flows to high fluxes in beds of small glass spheres and in 0.44 mm sand, show the influence of particle size, and flow composition and rate, on pressure drop enhancement and flow regime extent.
Loading rate dependency of maximum nanoindentation depth in nano-grained NiTi shape memory alloy
Sun, Qing-Ping
of loading rate on nanoindentation depth for nano-grained polycrystalline superelastic (SE) NiTi SMA superelastic NiTi polycrystalline sheets were purchased from Memory Applications Inc. (USA). With X temperature (T=23 °C). To avoid plastic deformation under the tip, two spherical diamond tips with radii of R
High flow rate nozzle system with production of uniform size droplets
Stockel, Ivar H. (Bangor, ME)
1990-01-01T23:59:59.000Z
Method steps for production of substantially uniform size droplets from a flow of liquid include forming the flow of liquid, periodically modulating the momentum of the flow of liquid in the flow direction at controlled frequency, generating a cross flow direction component of momentum and modulation of the cross flow momentum of liquid at substantially the same frequency and phase as the modulation of flow direction momentum, and spraying the so formed modulated flow through a first nozzle outlet to form a desired spray configuration. A second modulated flow through a second nozzle outlet is formed according to the same steps, and the first and second modulated flows impinge upon each other generating a liquid sheet. Nozzle apparatus for modulating each flow includes rotating valving plates interposed in the annular flow of liquid. The plates are formed with radial slots. Rotation of the rotating plates is separably controlled at differential angular velocities for a selected modulating frequency to achieve the target droplet size and production rate for a given flow. The counter rotating plates are spaced to achieve a desired amplitude of modulation in the flow direction, and the angular velocity of the downstream rotating plate is controlled to achieve the desired amplitude of modulation of momentum in the cross flow direction. Amplitude of modulation is set according to liquid viscosity.
High flow rate nozzle system with production of uniform size droplets
Stockel, I.H.
1990-10-16T23:59:59.000Z
Method steps for production of substantially uniform size droplets from a flow of liquid include forming the flow of liquid, periodically modulating the momentum of the flow of liquid in the flow direction at controlled frequency, generating a cross flow direction component of momentum and modulation of the cross flow momentum of liquid at substantially the same frequency and phase as the modulation of flow direction momentum, and spraying the so formed modulated flow through a first nozzle outlet to form a desired spray configuration. A second modulated flow through a second nozzle outlet is formed according to the same steps, and the first and second modulated flows impinge upon each other generating a liquid sheet. Nozzle apparatus for modulating each flow includes rotating valving plates interposed in the annular flow of liquid. The plates are formed with radial slots. Rotation of the rotating plates is separably controlled at differential angular velocities for a selected modulating frequency to achieve the target droplet size and production rate for a given flow. The counter rotating plates are spaced to achieve a desired amplitude of modulation in the flow direction, and the angular velocity of the downstream rotating plate is controlled to achieve the desired amplitude of modulation of momentum in the cross flow direction. Amplitude of modulation is set according to liquid viscosity. 5 figs.
Acoustic measurement of the Deepwater Horizon Macondo well flow rate
Camilli, Richard
On May 31, 2010, a direct acoustic measurement method was used to quantify fluid leakage rate from the Deepwater Horizon Macondo well prior to removal of its broken riser. This method utilized an acoustic imaging sonar and ...
Does Water Content or Flow Rate Control Colloid Transport in Unsaturated Porous Media?
Thorsten Knappenberger; Markus Flury; Earl D. Mattson; James B. Harsh
2014-03-01T23:59:59.000Z
Mobile colloids can play an important role in contaminant transport in soils: many contaminants exist in colloidal form, and colloids can facilitate transport of otherwise immobile contaminants. In unsaturated soils, colloid transport is, among other factors, affected by water content and flow rate. Our objective was to determine whether water content or flow rate is more important for colloid transport. We passed negatively charged polystyrene colloids (220 nm diameter) through unsaturated sand-filled columns under steady-state flow at different water contents (effective water saturations Se ranging from 0.1 to 1.0, with Se = (? – ?r)/(?s – ?r)) and flow rates (pore water velocities v of 5 and 10 cm/min). Water content was the dominant factor in our experiments. Colloid transport decreased with decreasing water content, and below a critical water content (Se < 0.1), colloid transport was inhibited, and colloids were strained in water films. Pendular ring and water film thickness calculations indicated that colloids can move only when pendular rings are interconnected. The flow rate affected retention of colloids in the secondary energy minimum, with less colloids being trapped when the flow rate increased. These results confirm the importance of both water content and flow rate for colloid transport in unsaturated porous media and highlight the dominant role of water content.
Method and apparatus for measuring the mass flow rate of a fluid
Evans, Robert P. (Idaho Falls, ID); Wilkins, S. Curtis (Idaho Falls, ID); Goodrich, Lorenzo D. (Shelley, ID); Blotter, Jonathan D. (Pocatello, ID)
2002-01-01T23:59:59.000Z
A non invasive method and apparatus is provided to measure the mass flow rate of a multi-phase fluid. An accelerometer is attached to a pipe carrying a multi-phase fluid. Flow related measurements in pipes are sensitive to random velocity fluctuations whose magnitude is proportional to the mean mass flow rate. An analysis of the signal produced by the accelerometer shows a relationship between the mass flow of a fluid and the noise component of the signal of an accelerometer. The noise signal, as defined by the standard deviation of the accelerometer signal allows the method and apparatus of the present invention to non-intrusively measure the mass flow rate of a multi-phase fluid.
Global energy conversion rate from geostrophic flows into internal lee waves in the deep ocean
Nikurashin, Maxim
A global estimate of the energy conversion rate from geostrophic flows into internal lee waves in the ocean is presented. The estimate is based on a linear theory applied to bottom topography at O(1–10) km scales obtained ...
Coal flow aids reduce coke plant operating costs and improve production rates
Bedard, R.A.; Bradacs, D.J.; Kluck, R.W.; Roe, D.C.; Ventresca, B.P.
2005-06-01T23:59:59.000Z
Chemical coal flow aids can provide many benefits to coke plants, including improved production rates, reduced maintenance and lower cleaning costs. This article discusses the mechanisms by which coal flow aids function and analyzes several successful case histories. 2 refs., 10 figs., 1 tab.
RATE SENSITIVITY OF PLASTIC FLOW AND IMPLICATIONS FOR YIELD-SURFACE VERTICES
RATE SENSITIVITY OF PLASTIC FLOW AND IMPLICATIONS FOR YIELD-SURFACE VERTICES Jwo PAN Stress; in recked form 29 Norember 1982) &tract-When crystalline slip is considered as the micromechanism of plastic sensitivity of plastic flow may be central to understanding the ambiguous conclusions from experimental
Molecule-based approach for computing chemical-reaction rates in upper atmosphere hypersonic flows.
Gallis, Michail A.; Bond, Ryan Bomar; Torczynski, John Robert
2009-08-01T23:59:59.000Z
This report summarizes the work completed during FY2009 for the LDRD project 09-1332 'Molecule-Based Approach for Computing Chemical-Reaction Rates in Upper-Atmosphere Hypersonic Flows'. The goal of this project was to apply a recently proposed approach for the Direct Simulation Monte Carlo (DSMC) method to calculate chemical-reaction rates for high-temperature atmospheric species. The new DSMC model reproduces measured equilibrium reaction rates without using any macroscopic reaction-rate information. Since it uses only molecular properties, the new model is inherently able to predict reaction rates for arbitrary nonequilibrium conditions. DSMC non-equilibrium reaction rates are compared to Park's phenomenological non-equilibrium reaction-rate model, the predominant model for hypersonic-flow-field calculations. For near-equilibrium conditions, Park's model is in good agreement with the DSMC-calculated reaction rates. For far-from-equilibrium conditions, corresponding to a typical shock layer, the difference between the two models can exceed 10 orders of magnitude. The DSMC predictions are also found to be in very good agreement with measured and calculated non-equilibrium reaction rates. Extensions of the model to reactions typically found in combustion flows and ionizing reactions are also found to be in very good agreement with available measurements, offering strong evidence that this is a viable and reliable technique to predict chemical reaction rates.
Ellingson, William A. (Naperville, IL); Forster, George A. (Westmont, IL)
1999-11-02T23:59:59.000Z
Apparatus and a method for controlling the flow rate of viscous materials through a nozzle includes an apertured main body and an apertured end cap coupled together and having an elongated, linear flow channel extending the length thereof. An end of the main body is disposed within the end cap and includes a plurality of elongated slots concentrically disposed about and aligned with the flow channel. A generally flat cam plate having a center aperture is disposed between the main body and end cap and is rotatable about the flow channel. A plurality of flow control vane assemblies are concentrically disposed about the flow channel and are coupled to the cam plate. Each vane assembly includes a vane element disposed adjacent the end of the flow channel. Rotation of the cam plate in a first direction causes a corresponding rotation of each of the vane elements for positioning the individual vane elements over the aperture in the end cap blocking flow through the flow channel, while rotation in an opposite direction removes the vane elements from the aperture and positions them about the flow channel in a nested configuration in the full open position, with a continuous range of vane element positions available between the full open and closed positions.
Suyadal, Y. [Faculty of Engineering, Department of Chemical Engineering, Ankara University, 06100-Tandogan, Ankara (Turkey)
2006-07-15T23:59:59.000Z
Experimental work on estimation kinetic parameters for combustion was conducted in a bench-scale fluidised bed (FB: 105x200mm). Combustion medium was obtained by using an electrical heater immersed into the bed. The ratio of heating rate (kJ/s) to molar flow rate of air (mol/s) regulated by a rheostat so that the heat of combustion (kJ/mol) can be synthetically obtained by an electrical power supply for relevant O{sub 2}-feedstock concentration (C{sub 0}). O{sub 2}-restriction ratio ({beta}) was defined by the ratio of O{sub 2}-feedstock concentration to O{sub 2}-air concentration (C{sub O{sub 2}-AIR}) at prevailing heating rates. Compressed air at further atmospheric pressure ({approx_equal}102.7kPa) entered the bed that was alumina particles (250{mu}m). Experiments were carried out at different gas flow rates and heating rates. FB was operated with a single charge of (1300g) particles for obtaining the T/T{sub 0} curves, and than C/C{sub 0} curves. The mathematical relationships between temperature (T) and conversion ratio (X) were expressed by combining total energy balance and mass balance in FB. Observed surface reaction rate constants (k{sub S}) was obtained from the combined balances and proposed model was also tested for these kinetic parameters (frequency factor: k{sub 0}, activation energy: E{sub A}, and reaction order: n) obtained from air temperature measurements. It was found that the model curves allow a good description of the experimental data. Thus, reaction rate for combustion was sufficiently expressed. (author)
Maximum Entropy Correlated Equilibria
Ortiz, Luis E.
2006-03-20T23:59:59.000Z
We study maximum entropy correlated equilibria in (multi-player)games and provide two gradient-based algorithms that are guaranteedto converge to such equilibria. Although we do not provideconvergence rates for these ...
Schena, Emiliano; Saccomandi, Paola; Silvestri, Sergio [Center for Integrated Research, Unit of Measurements and Biomedical Instrumentation, Universita Campus Bio-Medico di Roma, Via Alvaro del Portillo, 21, 00128 Rome (Italy)
2013-02-15T23:59:59.000Z
A novel fiber optic macro-bend based gas flowmeter for low flow rates is presented. Theoretical analysis of the sensor working principle, design, and static calibration were performed. The measuring system consists of: an optical fiber, a light emitting diode (LED), a Quadrant position sensitive Detector (QD), and an analog electronic circuit for signal processing. The fiber tip undergoes a deflection in the flow, acting like a cantilever. The consequent displacement of light spot center is monitored by the QD generating four unbalanced photocurrents which are function of fiber tip position. The analog electronic circuit processes the photocurrents providing voltage signal proportional to light spot position. A circular target was placed on the fiber in order to increase the sensing surface. Sensor, tested in the measurement range up to 10 l min{sup -1}, shows a discrimination threshold of 2 l min{sup -1}, extremely low fluid dynamic resistance (0.17 Pa min l{sup -1}), and high sensitivity, also at low flow rates (i.e., 33 mV min l{sup -1} up to 4 l min{sup -1} and 98 mV min l{sup -1} from 4 l min{sup -1} up to 10 l min{sup -1}). Experimental results agree with the theoretical predictions. The high sensitivity, along with the reduced dimension and negligible pressure drop, makes the proposed transducer suitable for medical applications in neonatal ventilation.
Not Available
1993-07-01T23:59:59.000Z
This document provides an analysis of the potential impacts associated with the proposed action, which is continued operation of Naval Petroleum Reserve No. I (NPR-1) at the Maximum Efficient Rate (MER) as authorized by Public law 94-258, the Naval Petroleum Reserves Production Act of 1976 (Act). The document also provides a similar analysis of alternatives to the proposed action, which also involve continued operations, but under lower development scenarios and lower rates of production. NPR-1 is a large oil and gas field jointly owned and operated by the federal government and Chevron U.SA Inc. (CUSA) pursuant to a Unit Plan Contract that became effective in 1944; the government`s interest is approximately 78% and CUSA`s interest is approximately 22%. The government`s interest is under the jurisdiction of the United States Department of Energy (DOE). The facility is approximately 17,409 acres (74 square miles), and it is located in Kern County, California, about 25 miles southwest of Bakersfield and 100 miles north of Los Angeles in the south central portion of the state. The environmental analysis presented herein is a supplement to the NPR-1 Final Environmental Impact Statement of that was issued by DOE in 1979 (1979 EIS). As such, this document is a Supplemental Environmental Impact Statement (SEIS).
Robert Felix Tournier
2015-02-23T23:59:59.000Z
An undercooled liquid is unstable. The driving force of the glass transition at Tg is a change of the undercooled-liquid Gibbs free energy. The classical Gibbs free energy change for a crystal formation is completed including an enthalpy saving. The crystal growth critical nucleus is used as a probe to observe the Laplace pressure change Dp accompanying the enthalpy change -Vm *Dp at Tg where Vm is the molar volume. A stable glass-liquid transition model predicts the specific heat jump of fragile liquids at temperatures smaller than Tg, the Kauzmann temperature TK where the liquid entropy excess with regard to crystal goes to zero, the equilibrium enthalpy between TK and Tg, the maximum nucleation rate at TK of superclusters containing magic atom numbers, and the equilibrium latent heats at Tg and TK. Strong-to-fragile and strong-to-strong liquid transitions at Tg are also described and all their thermodynamic parameters are determined from their specific heat jumps. The existence of fragile liquids quenched in the amorphous state, which do not undergo liquid-liquid transition during heating preceding their crystallization, is predicted. Long ageing times leading to the formation at TK of a stable glass composed of superclusters containing up to 147 atoms, touching and interpenetrating, are evaluated from nucleation rates. A fragile-to-fragile liquid transition occurs at Tg without stable-glass formation while a strong glass is stable after transition.
GLOBAL OPTIMIZATION OF MULTIPHASE FLOW NETWORKS IN OIL AND GAS PRODUCTION SYSTEMS
Johansen, Tor Arne
1 GLOBAL OPTIMIZATION OF MULTIPHASE FLOW NETWORKS IN OIL AND GAS PRODUCTION SYSTEMS MSc. Hans in an oil production system is developed. Each well may be manipulated by injecting lift gas and adjusting in the maximum oil flow rate, water flow rate, liquid flow rate, and gas flow rate. The wells may also
Energy policy act transportation study: Interim report on natural gas flows and rates
NONE
1995-11-17T23:59:59.000Z
This report, Energy Policy Act Transportation Study: Interim Report on Natural Gas Flows and Rates, is the second in a series mandated by Title XIII, Section 1340, ``Establishment of Data Base and Study of Transportation Rates,`` of the Energy Policy Act of 1992 (P.L. 102--486). The first report Energy Policy Act Transportation Study: Availability of Data and Studies, was submitted to Congress in October 1993; it summarized data and studies that could be used to address the impact of legislative and regulatory actions on natural gas transportation rates and flow patterns. The current report presents an interim analysis of natural gas transportation rates and distribution patterns for the period from 1988 through 1994. A third and final report addressing the transportation rates and flows through 1997 is due to Congress in October 2000. This analysis relies on currently available data; no new data collection effort was undertaken. The need for the collection of additional data on transportation rates will be further addressed after this report, in consultation with the Congress, industry representatives, and in other public forums.
Sinskey, Anthony J.
Microfluidic chemostat and turbidostat with flow rate, oxygen, and temperature control for dynamic are not reasonable. Microfluidics offers a way to address the difficulties relating to conventional continuous.4 Integrating all of these microfluidic components into a working continuous culture system can
Utilizing Distributed Temperature Sensors in Predicting Flow Rates in Multilateral Wells
Al Mulla, Jassim Mohammed A.
2012-07-16T23:59:59.000Z
and pressure data to determine the flow rate in real time out of a multilateral well. Temperature and pressure changes are harder to predict in horizontal laterals compared with vertical wells because of the lack of variation in elevation and geothermal...
Effects of soil water repellency on infiltration rate and flow instability
Wang, Zhi "Luke"
. They are difficult to manage and pose negative effects on agricultural productivity and environmental sustain the contaminant transport to ground water. The purpose of this paper is to quantify the effects of soil waterEffects of soil water repellency on infiltration rate and flow instability Z. Wanga,*, Q.J. Wua,1
Toward compressed DMD: spectral analysis of fluid flows using sub-Nyquist-rate PIV data
Tu, Jonathan H; Kutz, J Nathan; Shang, Jessica K
2014-01-01T23:59:59.000Z
Dynamic mode decomposition (DMD) is a powerful and increasingly popular tool for performing spectral analysis of fluid flows. However, it requires data that satisfy the Nyquist-Shannon sampling criterion. In many fluid flow experiments, such data are impossible to capture. We propose a new approach that combines ideas from DMD and compressed sensing. Given a vector-valued signal, we take measurements randomly in time (at a sub-Nyquist rate) and project the data onto a low-dimensional subspace. We then use compressed sensing to identify the dominant frequencies in the signal and their corresponding modes. We demonstrate this method using two examples, analyzing both an artificially constructed test dataset and particle image velocimetry data collected from the flow past a cylinder. In each case, our method correctly identifies the characteristic frequencies and oscillatory modes dominating the signal, proving the proposed method to be a capable tool for spectral analysis using sub-Nyquist-rate sampling.
Elastic capsules in shear flow: Analytical solutions for constant and time-dependent shear rates
Steffen Kessler; Reimar Finken; Udo Seifert
2009-02-26T23:59:59.000Z
We investigate the dynamics of microcapsules in linear shear flow within a reduced model with two degrees of freedom. In previous work for steady shear flow, the dynamic phases of this model, i.e. swinging, tumbling and intermittent behaviour, have been identified using numerical methods. In this paper, we integrate the equations of motion in the quasi-spherical limit analytically for time-constant and time-dependent shear flow using matched asymptotic expansions. Using this method, we find analytical expressions for the mean tumbling rate in general time-dependent shear flow. The capsule dynamics is studied in more detail when the inverse shear rate is harmonically modulated around a constant mean value for which a dynamic phase diagram is constructed. By a judicious choice of both modulation frequency and phase, tumbling motion can be induced even if the mean shear rate corresponds to the swinging regime. We derive expressions for the amplitude and width of the resonance peaks as a function of the modulation frequency.
Effect of transpiration rate on internal plant resistance to water flow
Hailey, James Lester
1971-01-01T23:59:59.000Z
models for liquid water flow in plants. because it enables one to estimate leaf water potential from known or estimated transpiration rates. The predicted leaf water potential can be used for scheduling irrigation ~ The leaf diffusion resistance... OF LITERATURE Soil Resistance Internal Plant Resistance Ohm's Law Analogy Mathematical Models of Water Transport in the Soil-Plant- Atmosphere System . ~ Poiseuille's Law . ~ ~ ~ ~ Leaf Diffusion and Aerodynamic Resistances ~ Conclusions of Literature...
Lee, Hyo-Chang; Kim, Aram; Chung, Chin-Wook [Department of Electrical Engineering, Hanyang University, 17 Haengdang-dong, Seongdong-gu, Seoul 133-791 (Korea, Republic of); Moon, Se Youn [Solar Energy Group, LG Electronics Advanced Research Institute, 16 Woomyeon-Dong, Seocho-Gu, Seoul 137-724 (Korea, Republic of)
2011-02-15T23:59:59.000Z
In industrial plasma processes, flow rate has been known to a key to control plasma processing results and has been discussed with reactive radical density, gas residence time, and surface reaction. In this study, it was observed that the increase in the flow rate can also change plasma parameters (electron temperature and plasma density) and electron energy distribution function in plasma processing reactor. Based on the measurement of gas pressure between the discharge region and the pumping port region, the considerable differences in the gas pressure between the two regions were found with increasing flow rate. It was also observed that even in the discharge region, the pressure gradient occurs at the high gas flow rate. This result shows that increasing the flow rate results in the pressure gradient and causes the changes in the plasma parameters.
A numerical investigation of high-rate gas flow for gravel-packed completions
Forrest, James Kenyon
1983-01-01T23:59:59.000Z
OF SCIENCE December 1983 Major Subject: Petroleum Engineering A NUMERICAL INVESTIGATION OF HIGH-RATE GAS FLOW FOR GRAVEL-PACKED COMPLETIONS A Thesis by JAMES KENYON FORREST Approved as to style and content by: C. . WU ( Chairman of Coamittee) R... used a radius of 30rw. In order to investigate this, several runs were made with various model radii. Three runs were made to determine the effect of radial discretization and model radius on the simulation results. One run used a radius of 30r...
Paris-Sud XI, UniversitĂ© de
Piping flow erosion in water retaining structures: inferring erosion rates from hole erosion tests-en-Provence Cedex 5, France E-mail: stephane.bonelli@cemagref.fr Abstract The piping flow erosion process, involving structures. Such a pipe can be imputed to roots or burrows. The coefficient of erosion must be known in order
DeMuth, S.F.; Watson, J.S.
1985-01-01T23:59:59.000Z
A model of compressible flow through an orifice, in the region of transition from free molecular to isentropic expansion flow, has been developed and tested for accuracy. The transitional or slip regime is defined as the conditions where molecular interactions are too many for free molecular flow modeling, yet not great enough for isentropic expansion flow modeling. Due to a lack of literature establishing a well-accepted model for predicting transitional flow, it was felt such work would be beneficial. The model is nonlinear and cannot be satisfactorily linearized for a linear regression analysis. Consequently, a computer routine was developed which minimized the sum of the squares of the residual flow for the nonlinear model. The results indicate an average accuracy within 15% of the measured flow throughout the range of test conditions. Furthermore, the results of the regression analysis indicate that the transitional regime lies between Knudsen numbers of approximately 2 and 45. 4 refs., 3 figs., 1 tab.
Hamel, William R. (Farragut, TN)
1984-01-01T23:59:59.000Z
This invention relates to a new method and new apparatus for determining fluid mass flowrate and density. In one aspect of the invention, the fluid is passed through a straight cantilevered tube in which transient oscillation has been induced, thus generating Coriolis damping forces on the tube. The decay rate and frequency of the resulting damped oscillation are measured, and the fluid mass flowrate and density are determined therefrom. In another aspect of the invention, the fluid is passed through the cantilevered tube while an electrically powered device imparts steady-state harmonic excitation to the tube. This generates Coriolis tube-damping forces which are dependent on the mass flowrate of the fluid. Means are provided to respond to incipient flow-induced changes in the amplitude of vibration by changing the power input to the excitation device as required to sustain the original amplitude of vibration. The fluid mass flowrate and density are determined from the required change in power input. The invention provides stable, rapid, and accurate measurements. It does not require bending of the fluid flow.
Gallis, Michail A.; Bond, Ryan Bomar; Torczynski, John Robert
2010-06-01T23:59:59.000Z
A recently proposed approach for the Direct Simulation Monte Carlo (DSMC) method to calculate chemical-reaction rates is assessed for high-temperature atmospheric species. The new DSMC model reproduces measured equilibrium reaction rates without using any macroscopic reaction-rate information. Since it uses only molecular properties, the new model is inherently able to predict reaction rates for arbitrary non-equilibrium conditions. DSMC non-equilibrium reaction rates are compared to Park's phenomenological nonequilibrium reaction-rate model, the predominant model for hypersonic-flow-field calculations. For near-equilibrium conditions, Park's model is in good agreement with the DSMC-calculated reaction rates. For far-from-equilibrium conditions, corresponding to a typical shock layer, significant differences can be found. The DSMC predictions are also found to be in very good agreement with measured and calculated non-equilibrium reaction rates, offering strong evidence that this is a viable and reliable technique to predict chemical reaction rates.
Doughty, Christine; Takeuchi, Shinji; Amano, Kenji; Shimo, Michito; Tsang, Chin-Fu
2004-10-04T23:59:59.000Z
The flowing fluid electric conductivity (FEC) logging method, wellbore fluid is replaced with de-ionized water, following which FEC profiles in the wellbore are measured at a series of times while the well is pumped at a constant rate. Locations were fluid enters the wellbore show peaks in the FEC logs, which may be analyzed to infer inflow strengths and salinities of permeable features intersected by the wellbore. In multi-rate flowing FEC logging, the flowing FEC logging method is repeated using two or more pumping rates, which enables the transmissivities and inherent pressure heads of these features to be estimated as well. We perform multi-rate FEC logging on a deep borehole in fractured granitic rock, using three different pumping rates. Results identify 19 hydraulically conducting fractures and indicate that transmissivity, pressure head, and salinity vary significantly among them. By using three pumping rates rather than the minimum number of two, we obtain an internal consistency check on the analysis that provides a measure of the uncertainty of the results. Good comparisons against static FEC profiles and against independent chemical, geological, and hydrogeological data have further enhanced confidence in the results of the multi-rate flowing FEC logging method.
Gilmore, Peter Lee
2012-06-07T23:59:59.000Z
. ) the desorption of molecules from the inside surface of the material. ( Measuring the permeation rate of polymers exhibiting the activated diffusion process can be calculated by Pick's First Law of diffusion, calculated by the equation: A -E/RT q x '(p -p) P... e 1 2 o where, q = permeation rate (cm /sec) 3 A = area of membrane (cm ) 2 x = membrane thickness (cm) pl= solvent partial pressure on the outer surface of the membrane (Pa) p2= solvent partial pressure on the inner surface of the membrane (Pa...
California at Riverside, University of
The Effect of Flow Rate of Very Dilute Sulfuric Acid on Xylan, Lignin, and Total Mass Removal from mass, xylan, and lignin and increases cellulose digestibility compared to batch operations at otherwise at a constant residence time also significantly accelerated xylan solubilization. Although lignin removal
Olama, Mohammed M [ORNL; Allgood, Glenn O [ORNL; Kuruganti, Phani Teja [ORNL; Lake, Joe E [ORNL
2012-01-01T23:59:59.000Z
The US Congress has passed legislation dictating that all government agencies establish a plan and process for improving energy efficiencies at their sites. In response to this legislation, Oak Ridge National Laboratory (ORNL) has recently conducted a pilot study to explore the deployment of a wireless sensor system for a real-time measurement-based energy efficiency optimization framework within the steam distribution system within the ORNL campus. We make assessments on the real-time status of the distribution system by observing the state measurements of acoustic sensors mounted on the steam pipes/traps/valves. In this paper, we describe a spectral-based energy signature scheme that interprets acoustic vibration sensor data to estimate steam flow rates and assess steam traps health status. Experimental results show that the energy signature scheme has the potential to identify different steam trap health status and it has sufficient sensitivity to estimate steam flow rate. Moreover, results indicate a nearly quadratic relationship over the test region between the overall energy signature factor and flow rate in the pipe. The analysis based on estimated steam flow and steam trap status helps generate alerts that enable operators and maintenance personnel to take remedial action. The goal is to achieve significant energy-saving in steam lines by monitoring and acting on leaking steam pipes/traps/valves.
Ko, Hanseo
1994-01-01T23:59:59.000Z
diameter for Re = 5, 000, 10, 000, and 20, 000. 15 Figure 3 Figure 4. Comparison of different roughness factors (e, = 0, 0. 1, 1. 0, and 10 mm) for dimensionless deposition velocity. Correlation of dimensionless deposition velocity and dimensionless... time for flow rate = 57 I/min, Re = 5, 000, and tube diameter = 15. 8 mm. 17 19 Figure 5. Correlation of dimensionless deposition velocity including electric migration velocity ( Vz = 0. 01, 0. 05, and 0. 1 mm/s) and dimensionless time for flow...
Bahrami, Majid
and potential energy changes are zero. 3 Steam properties are used for geothermal water. Properties Using7-31 7-88 A geothermal power plant uses geothermal liquid water at 160ÂşC at a specified rate saturated liquid properties, the source and the sink state enthalpies of geothermal water are (Table A-4) k
Original article Flow and passage rate studies at the ileal level in the
Boyer, Edmond
based mainly on lucerne meal. Flow and transit measurements were carried out using two particulate markers : ytterbium (Yb) fixed on lucerne meal cell-walls by soaking, and chromium (Cr) fixed
Ambient aerosol sampling inlet for flow rates of 100 and 400 l/min
Baehl, Michael Matthew
2009-05-15T23:59:59.000Z
across the cross section of the wind tunnel. Downstream from that is a flow straightener that eliminates large-scale turbulence and flow swirl. A TSI VelociCalc thermal anemometer (TSI Inc., St. Paul, MN) is used to measure the wind speed in the wind... on the slide through use of a coefficient similar 7 to that of Olan-Figuroa et al. (1982), but with a value of 1.29, which is appropriate for the Nyebar K. An Aerodynamic Particle Sizer (APS, Model 3321, TSI Inc., St. Paul, MN) is used to monitor...
Using multi-layer models to forecast gas flow rates in tight gas reservoirs
Jerez Vera, Sergio Armando
2007-04-25T23:59:59.000Z
pressure at the inner boundary. He combined a back-pressure gas rate equation (Eq 2.9) with the materials balance equation Eq 2.10 onto a rate-time equation for gas wells as described in Eq 2.11, and then he generated the new set of type curves as shown.......................................................................................... 10 2.1 Introduction ...................................................................................................10 2.2 Decline Curve Analysis...
Incremental Network Design with Maximum Flows - Optimization ...
2013-12-21T23:59:59.000Z
Dec 21, 2013 ... for adding arcs to the network, (2) a performance measure, which prescribes ... network is evaluated (for instance by the shortest s-t path or by the ...... Smart grid design for efficient and flexible power networks operation and.
Moseley, J.; Miller, D.; Shah, Q.-U.-A. S. J.; Sakurai, K.; Kempe, M.; Tamizhmani, G.; Kurtz, S.
2011-10-01T23:59:59.000Z
Use of thermoplastic materials as encapsulants in photovoltaic (PV) modules presents a potential concern in terms of high temperature creep, which should be evaluated before thermoplastics are qualified for use in the field. Historically, the issue of creep has been avoided by using thermosetting polymers as encapsulants, such as crosslinked ethylene-co-vinyl acetate (EVA). Because they lack crosslinked networks, however, thermoplastics may be subject to phase transitions and visco-elastic flow at the temperatures and mechanical stresses encountered by modules in the field, creating the potential for a number of reliability and safety issues. Thermoplastic materials investigated in this study include PV-grade uncured-EVA (without curing agents and therefore not crosslinked); polyvinyl butyral (PVB); thermoplastic polyurethane (TPU); and three polyolefins (PO), which have been proposed for use as PV encapsulation. Two approaches were used to evaluate the performance of these materials as encapsulants: module-level testing and a material-level testing.
Anderson, D.C.
1994-11-01T23:59:59.000Z
Activities associated with oil and gas development under the Maximum Efficiency Rate (MER) from 1975 to 2025 will disturb approximately 3,354 acres. Based on 1976 aerial photographs and using a dot grid methodology, the amount of land disturbed prior to MER is estimated to be 3,603 acres. Disturbances on Naval Petroleum Reserve No. 1 (NPR-1) were mapped using 1988 aerial photography and a geographical information system. A total of 6,079 acres were classified as disturbed as of June, 1988. The overall objective of this document is to provide specific information relating to the on-site habitat restoration program at NPRC. The specific objectives, which relate to the terms and conditions that must be met by DOE as a means of protecting the San Joaquin kit fox from incidental take are to: (1) determine the amount and location of disturbed lands on NPR-1 and the number of acres disturbed as a result of MER activities, (2) develop a long term (10 year) program to restore an equivalent on-site acres to that lost from prior project-related actions, and (3) examine alternative means to offset kit fox habitat loss.
Kuan, W.; Abdou, M.A. [Univ. of California, Los Angeles, CA (United States); Willms, R.S. [Los Alamos National Lab., NM (United States)
1994-12-31T23:59:59.000Z
The dynamic behavior of the fuel cycle in a fusion reactor is of crucial importance due to the need to keep track of the large amount of tritium being constantly produced, transported, and processed in the reactor system. Because tritium is a source of radioactivity, loss and exhaust to the environment must be kept to a minimum. With ITER advancing to its Engineering Design phase, there is a need to accurately predict the dynamic tritium inventories and flow rates throughout the fuel cycle and to study design variations to meet the demands of low tritium inventory. In this paper, time-dependent inventories and flow rates for several components of the fuel cycle are modeled and studied through the use of a new modular-type model for the dynamic simulation of the fuel cycle in a fusion reactor. The complex dynamic behavior in the modeled subsystems is analyzed using this new model. Previous dynamic models focusing on the fuel cycle dealt primarily with a residence time parameter ({tau}{sub res}) defining each subsystem of the model. In this modular model, this residence time approach is avoided in favor of a more accurate and flexible model that utilizes real design parameters and operating schedules of the various subsystems modeled.
MELE: Maximum Entropy Leuven Estimators
Paris, Quirino
2001-01-01T23:59:59.000Z
of the Generalized Maximum Entropy Estimator of the Generaland Douglas Miller, Maximum Entropy Econometrics, Wiley andCalifornia Davis MELE: Maximum Entropy Leuven Estimators by
DEVELOPMENT OF A LOW COST INFERENTIAL NATURAL GAS ENERGY FLOW RATE PROTOTYPE RETROFIT MODULE
E. Kelner; D. George; T. Morrow; T. Owen; M. Nored; R. Burkey; A. Minachi
2005-05-01T23:59:59.000Z
In 1998, Southwest Research Institute began a multi-year project to develop a working prototype instrument module for natural gas energy measurement. The module will be used to retrofit a natural gas custody transfer flow meter for energy measurement, at a cost an order of magnitude lower than a gas chromatograph. Development and evaluation of the prototype energy meter in 2002-2003 included: (1) refinement of the algorithm used to infer properties of the natural gas stream, such as heating value; (2) evaluation of potential sensing technologies for nitrogen content, improvements in carbon dioxide measurements, and improvements in ultrasonic measurement technology and signal processing for improved speed of sound measurements; (3) design, fabrication and testing of a new prototype energy meter module incorporating these algorithm and sensor refinements; and (4) laboratory and field performance tests of the original and modified energy meter modules. Field tests of the original energy meter module have provided results in close agreement with an onsite gas chromatograph. The original algorithm has also been tested at a field site as a stand-alone application using measurements from in situ instruments, and has demonstrated its usefulness as a diagnostic tool. The algorithm has been revised to use measurement technologies existing in the module to measure the gas stream at multiple states and infer nitrogen content. The instrumentation module has also been modified to incorporate recent improvements in CO{sub 2} and sound speed sensing technology. Laboratory testing of the upgraded module has identified additional testing needed to attain the target accuracy in sound speed measurements and heating value.
Fleskes, Joe
Of Oil Flowing from BP Oil Wen Clarice E Ransom to: Barbara W Wainman, 8. Arlene Compher 05127 Provides Preliminary Best Estimate Of Oil Flowing from BP Oil Well "Tsai, Brian" Estimate Of Oil Flowing from BP Oil Well USGS Director Dr. Marcia McNutt today announced that the National
Nashawi, I.S. [Kuwait Univ. (Kuwait); Al-Mehaideb, R.A.
1995-10-01T23:59:59.000Z
Most of the problems associated with conventional gas well test are related to the nonlinearity of the equations describing real gas flow, the presence of the rate dependent (non-Darcy) skin, and the long shut-in time periods required to collect the data for the analysis in tight reservoirs in which the wellbore storage period can be excessively long. This paper presents a new pressure buildup technique that reduces the wellbore storage effects, eliminates the long shut-in periods experienced with conventional tests by using afterflow rate and pressure data, and most importantly provides a direct method to estimate non-Darcy skin. The proposed technique uses normalized pseudofunctions to avoid the nonlinearities of the governing equations and involves using two different plots. The formation permeability is obtained from the slope of the first plot. The mechanical and non-Darcy skin factors are obtained respectively from the slope and intercept of the second plot. A field example and two simulated cases are presented to illustrate the application of the new technique.
Craine, Roger; Martin, Vance L.
2009-01-01T23:59:59.000Z
Flows and US Interest Rates,” NBER Working Paper No 12560. [Working Paper # 2008 -03 The Interest Rate Conundrum Roger
Chen, Chuan-Hua
of applications including electrostatic spraying, spinning, and printing. In the most common setup, a working be justified on dimensional grounds as long as the liquid viscosity (l) drops out of the picture. Note viscosity in the minimum flow rate scaling Eq. (1) lacks a rigorous justification, which poses a severe
A Requirement for Significant Reduction in the Maximum BTU Input...
A Requirement for Significant Reduction in the Maximum BTU Input Rate of Decorative Vented Gas Fireplaces Would Impose Substantial Burdens on Manufacturers A Requirement for...
Role of viscoelasticity and non-linear rheology in flows of complex fluids at high deformation rates
Ober, Thomas J. (Thomas Joseph)
2013-01-01T23:59:59.000Z
We combine pressure, velocimetry and birefringence measurements to study three phenomena for which the fluid rheology plays a dominant role: 1) shear banding in micellar fluids, 2) extension-dominated flows in microfluidic ...
Flow conditions of fresh mortar and concrete in different pipes
Jacobsen, Stefan, E-mail: stefan.jacobsen@ntnu.n [Norwegian University of Science and Technology, Dept of Structural Engineering, Trondheim (Norway); Haugan, Lars; Hammer, Tor Arne [SINTEF Byggforsk AS Building and Infrastructure, Trondheim (Norway); Kalogiannidis, Evangelos [Norwegian University of Science and Technology, Dept of Structural Engineering, Trondheim (Norway)
2009-11-15T23:59:59.000Z
The variation in fresh concrete flow rate over the pipe cross section was investigated on differently coloured and highly flowable concrete mixes flowing through pipes of different materials (rubber, steel, acryl). First, uncoloured (gray) concrete was poured through the pipe and the pipe blocked. Similar but coloured (black) concrete was then poured into the pipe filled with gray concrete, flowing after the gray concrete for a while before being blocked and hardened. The advance of the colouring along the pipe wall (showing boundary flow rate) was observed on the moulded concrete surface appearing after removing the pipe from the hardened concrete. The shapes of the interfaces between uncoloured and coloured concrete (showing variation of flow rate over the pipe cross section) were observed on sawn surfaces of concrete half cylinders cut along the length axes of the concrete-filled pipe. Flow profiles over the pipe cross section were clearly seen with maximum flow rates near the centre of the pipe and low flow rate at the pipe wall (typically rubber pipe with reference concrete without silica fume and/or stabilizers). More plug-shaped profiles, with long slip layers and less variation of flow rate over the cross section, were also seen (typically in smooth acrylic pipes). Flow rate, amount of concrete sticking to the wall after flow and SEM-images of pipe surface roughness were observed, illustrating the problem of testing full scale pumping.
Ismagilov, Rustem F.
angle hysteresis, the presence or absence of a lubricating oil layer, and adsorption of surface between the plates of the SlipChip ("dead-end flow"). Rupture of the lubricating oil layer (reminiscent containing an aqueous droplet into contact with a slightly deeper channel filled with immiscible oil
Wilcock, William
of aque-21 ous fluids within mid-ocean ridge hydrothermal systems and mechanical processes22 between mid-35 ocean ridge hydrothermal fluid flow and mechanical processes, there have been no36 direct in a Black Smoker Hydrothermal1 Vent In Response to a Mid-Ocean Ridge Earthquake Swarm2 Timothy J. Crone
Navarre, Audrey
1999-01-01T23:59:59.000Z
min?ą under conditions of saturated flow. Column eluate was monitored for pH, carbonate alkalinity, and Na, Ca and Cl concentrations to evaluate the elution of SAR 10 solution, dissolution of CaCO? and exchange of Na by Ca on the cation...
Ober, Thomas J. (Thomas Joseph)
2010-01-01T23:59:59.000Z
Worm-like micellar solutions are model non-Newtonian systems on account of their well understood linear viscoelastic behavior. Their high deformation rate, non-linear rheological response, however, remains inadequately ...
Schwehr, K. A.; Santschi, P. H.; Moran, J. E.
2003-01-01T23:59:59.000Z
analogy to chloride ? Long term database Chloride: Analogy for Iodide y = 5.27x -0.32 R 2 = 0.53 R = 0.73 0 1 2 3 4 5 6 0 20 40 60 80 100 120 SARPD Monthly Flow m 3 s -1 S ARP D [ C l - ] m e q / L Monthly values INSET: Annual median values.... GW y = 0.46x + 1.27 R 2 = 0.96 -2 -1 0 1 2 -3 -2 -1 0 log [Cl - GW ] or log [Cl - SARPD ] meq/L lo g [ C l - PP T ] m e q/ L ...
Aldred, William H
1956-01-01T23:59:59.000Z
with the foot storage spoon use not availablo to hold their grain for s mors favorable market. Furthermore, only a limited amount of a~nial storage vss available at that time, These oonditions disolosed the need for infox- mstion consuming pxoesdurss.../ustment of the air flow to the desired rates was controlled bp two sliding gates in the latexal ss shown in Figure 5. Bzxcyle ports were installed in each bin at two levels ? one foot. from the bottom snd halfway between the bottom and the toy, This per- mitted...
Ferrari, Raffaele
, and to bottom velocity obtained from a global ocean model. The total energy flux into internal lee wavesGEOPHYSICAL RESEARCH LETTERS, VOL. ???, XXXX, DOI:10.1029/, Global energy conversion rate from distribution of the energy flux is largest in the Southern Ocean which accounts for half of the total energy
Single ion heat engine with maximum efficiency at maximum power
Obinna Abah; Johannes Rossnagel; Georg Jacob; Sebastian Deffner; Ferdinand Schmidt-Kaler; Kilian Singer; Eric Lutz
2012-05-07T23:59:59.000Z
We propose an experimental scheme to realize a nano heat engine with a single ion. An Otto cycle may be implemented by confining the ion in a linear Paul trap with tapered geometry and coupling it to engineered laser reservoirs. The quantum efficiency at maximum power is analytically determined in various regimes. Moreover, Monte Carlo simulations of the engine are performed that demonstrate its feasibility and its ability to operate at maximum efficiency of 30% under realistic conditions.
Magnotti, F.; Diskin, G.; Matulaitis, J.; Chinitz, W.
1984-01-01T23:59:59.000Z
The use of silane (SiH4) as an effective ignitor and flame stabilizing pilot fuel is well documented. A reliable chemical kinetic mechanism for prediction of its behavior at the conditions encountered in the combustor of a SCRAMJET engine was calculated. The effects of hydrogen addition on hydrocarbon ignition and flame stabilization as a means for reduction of lengthy ignition delays and reaction times were studied. The ranges of applicability of chemical kinetic models of hydrogen-air combustors were also investigated. The CHARNAL computer code was applied to the turbulent reaction rate modeling.
A maximum entropy-least squares estimator for elastic origin-destination trip matrix estimation
Kockelman, Kara M.
A maximum entropy-least squares estimator for elastic origin- destination trip matrix estimation propose a combined maximum entropy-least squares (ME-LS) estimator, by which O- D flows are distributed-destination trip table; elastic demand; maximum entropy; least squares; subnetwork analysis; convex combination
Enciso, Juan; Santistevan, Dean; Hla, Aung K.
2007-10-01T23:59:59.000Z
Propeller flow meters are commonly used to measure water flow rate. They can also be used to estimate irrigation water use. This publication explains how to select, install, read and maintain propeller flow meters....
Estimating a mixed strategy employing maximum entropy
Golan, Amos; Karp, Larry; Perloff, Jeffrey M.
1996-01-01T23:59:59.000Z
MIXED STRATEGY EMPLOYING MAXIMUM ENTROPY by Amos Golan LarryMixed Strategy Employing Maximum Entropy Amos Golan Larry S.Abstract Generalized maximum entropy may be used to estimate
Spiliotopoulos, Alexandros A.
2013-03-20T23:59:59.000Z
This document describes a systematic method to develop flow rate recommendations for Pump-and-Treat (P&T) extraction and injection wells in 100-KR-4 and 100-HR-3 Groundwater Operable Units (OU) of the Hanford Site. Flow rate recommendations are developed as part of ongoing performance monitoring and remedy optimization of the P&T interim actions to develop hydraulic contairnnent of the dissolved chromium plume in groundwater and protect the Columbia River from further discharges of groundwater from inland. This document details the methodology and data required to infer the influence of individual wells near the shoreline on hydraulic containment and river protection and develop flow rate recommendations to improve system performance and mitigate potential shortcomings of the system configuration in place.
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: VegetationEquipment Surfaces andMapping the Nanoscale LandscapeImportsBG NorthMauro9 Maximum Let-Through
Ebert, W. L.; Chemical Engineering
2006-02-28T23:59:59.000Z
An international interlaboratory study (ILS) was conducted to evaluate the precision with which single-pass flow-through (SPFT) tests can be conducted by following a method to be standardized by the American Society for Testing and Materials - International. Tests for the ILS were conducted with the low-activity reference material (LRM) glass developed previously for use as a glass test standard. Tests were conducted at 70 {+-} 2 C using a LiCl/LiOH solution as the leachant to impose an initial pH of about 10 (at 70 C). Participants were provided with LRM glass that had been crushed and sieved to isolate the -100 +200 mesh size fraction, and then washed to remove fines. Participants were asked to conduct a series of tests using different solution flow rate-to-sample mass ratios to generate a range of steady-state Si concentrations. The glass dissolution rate under each test condition was calculated using the steady-state Si concentration and solution flow rate that were measured in the test. The glass surface area was estimated from the mass of glass used in the test and the Si content of LRM glass was known. A linear relationship between the rate and the steady-state Si concentration (at Si concentrations less than 10 mg/L) was used to estimate the forward dissolution rate, which is the rate in the absence of dissolved Si. Participants were asked to sample the effluent solution at least five times after reaction times of between 3 and 14 days to measure the Si concentration and flow rate, and to verify that steady-state was achieved. Results were provided by seven participants and the data sets provided by five participants were sufficient to determine the forward rates independently.
Multiphase flow calculation software
Fincke, James R. (Idaho Falls, ID)
2003-04-15T23:59:59.000Z
Multiphase flow calculation software and computer-readable media carrying computer executable instructions for calculating liquid and gas phase mass flow rates of high void fraction multiphase flows. The multiphase flow calculation software employs various given, or experimentally determined, parameters in conjunction with a plurality of pressure differentials of a multiphase flow, preferably supplied by a differential pressure flowmeter or the like, to determine liquid and gas phase mass flow rates of the high void fraction multiphase flows. Embodiments of the multiphase flow calculation software are suitable for use in a variety of applications, including real-time management and control of an object system.
Meixler, Lewis D. (East Windsor, NJ)
1993-01-01T23:59:59.000Z
The low flow monitor provides a means for determining if a fluid flow meets a minimum threshold level of flow. The low flow monitor operates with a minimum of intrusion by the flow detection device into the flow. The electrical portion of the monitor is externally located with respect to the fluid stream which allows for repairs to the monitor without disrupting the flow. The electronics provide for the adjustment of the threshold level to meet the required conditions. The apparatus can be modified to provide an upper limit to the flow monitor by providing for a parallel electronic circuit which provides for a bracketing of the desired flow rate.
Maximum likelihood estimation of the equity Efstathios Avdis
Kahana, Michael J.
premium is usually estimated by taking the sample mean of stock returns and subtracting a measure the expected return on the aggregate stock market less the government bill rate, is of central importance an alternative esti- mator, based on maximum likelihood, that takes into account informa- tion contained
Some interesting consequences of the maximum entropy production principle
Martyushev, L. M. [Russian Academy of Sciences, Institute of Industrial Ecology, Ural Division (Russian Federation)], E-mail: mlm@ecko.uran.ru
2007-04-15T23:59:59.000Z
Two nonequilibrium phase transitions (morphological and hydrodynamic) are analyzed by applying the maximum entropy production principle. Quantitative analysis is for the first time compared with experiment. Nonequilibrium crystallization of ice and laminar-turbulent flow transition in a circular pipe are examined as examples of morphological and hydrodynamic transitions, respectively. For the latter transition, a minimum critical Reynolds number of 1200 is predicted. A discussion of this important and interesting result is presented.
Portable wastewater flow meter
Hunter, Robert M. (320 S. Wilson Ave., Bozeman, MT 59715)
1999-02-02T23:59:59.000Z
A portable wastewater flow meter particularly adapted for temporary use at a single location in measuring the rate of liquid flow in a circular entrance conduit of a sewer manhole both under free flow and submerged, open channel conditions and under fill pipe, surcharged conditions, comprising an apparatus having a cylindrical external surface and an inner surface that constricts the flow through the apparatus in such a manner that a relationship exists between (1) the difference between the static pressure head of liquid flowing through the entrance of the apparatus and the static pressure head of liquid flowing through the constriction, and (2) the rate of liquid flow through the apparatus.
Portable wastewater flow meter
Hunter, Robert M. (320 S. Wilson Ave., Bozeman, MT 59715)
1990-01-01T23:59:59.000Z
A portable wastewater flow meter particularly adapted for temporary use at a single location in measuring the rate of liquid flow in a circular entrance conduit of a sewer manhole both under free flow and submerged, open channel conditions and under full pipe, surcharged conditions, comprising an apparatus having a cylindrical external surface and an inner surface that constricts the flow through the apparatus in such a manner that a relationship exists between (1) the difference between the static pressure head of liquid flowing through the entrance of the apparatus and the static pressure head of liquid flowing through the constriction, and (2) the rate of liquid flow through the apparatus.
Delay Analysis of Maximum Weight Scheduling in Wireless Ad Hoc Networks
Modiano, Eytan H.
This paper studies delay properties of the well-known maximum weight scheduling algorithm in wireless ad hoc networks. We consider wireless networks with either one-hop or multihop flows. Specifically, this paper shows ...
Maximum entropy principal for transportation
Bilich, F. [University of Brasilia (Brazil); Da Silva, R. [National Research Council (Brazil)
2008-11-06T23:59:59.000Z
In this work we deal with modeling of the transportation phenomenon for use in the transportation planning process and policy-impact studies. The model developed is based on the dependence concept, i.e., the notion that the probability of a trip starting at origin i is dependent on the probability of a trip ending at destination j given that the factors (such as travel time, cost, etc.) which affect travel between origin i and destination j assume some specific values. The derivation of the solution of the model employs the maximum entropy principle combining a priori multinomial distribution with a trip utility concept. This model is utilized to forecast trip distributions under a variety of policy changes and scenarios. The dependence coefficients are obtained from a regression equation where the functional form is derived based on conditional probability and perception of factors from experimental psychology. The dependence coefficients encode all the information that was previously encoded in the form of constraints. In addition, the dependence coefficients encode information that cannot be expressed in the form of constraints for practical reasons, namely, computational tractability. The equivalence between the standard formulation (i.e., objective function with constraints) and the dependence formulation (i.e., without constraints) is demonstrated. The parameters of the dependence-based trip-distribution model are estimated, and the model is also validated using commercial air travel data in the U.S. In addition, policy impact analyses (such as allowance of supersonic flights inside the U.S. and user surcharge at noise-impacted airports) on air travel are performed.
Flow Split Venturi, Axially-Rotated Valve
Walrath, David E. (Laramie, WY); Lindberg, William R. (Laramie, WY); Burgess, Robert K. (Sheridan, WY); LaBelle, James (Murrieta, CA)
2000-02-22T23:59:59.000Z
The present invention provides an axially-rotated valve which permits increased flow rates and lower pressure drop (characterized by a lower loss coefficient) by using an axial eccentric split venturi with two portions where at least one portion is rotatable with respect to the other portion. The axially-rotated valve typically may be designed to avoid flow separation and/or cavitation at full flow under a variety of conditions. Similarly, the valve is designed, in some embodiments, to produce streamlined flow within the valve. An axially aligned outlet may also increase the flow efficiency. A typical cross section of the eccentric split venturi may be non-axisymmetric such as a semicircular cross section which may assist in both throttling capabilities and in maximum flow capacity using the design of the present invention. Such a design can include applications for freeze resistant axially-rotated valves and may be fully-opened and fully-closed in one-half of a complete rotation. An internal wide radius elbow typically connected to a rotatable portion of the eccentric venturi may assist in directing flow with lower friction losses. A valve actuator may actuate in an axial manner yet be uniquely located outside of the axial flow path to further reduce friction losses. A seal may be used between the two portions that may include a peripheral and diametrical seal in the same plane. A seal separator may increase the useful life of the seal between the fixed and rotatable portions.
Dansereau, Véronique
2012-01-01T23:59:59.000Z
Interactions between the ocean circulation in sub-ice shelf cavities and the overlying ice shelf have received considerable attention in the context of observed changes in flow speeds of marine ice sheets around Antarctica. ...
Pressure and flow characteristics of restrictive flow orifice devices.
Shrouf, Roger D.
2003-06-01T23:59:59.000Z
A Restrictive Flow Orifice (RFO) can be used to enhance the safe design of a pressure system in several ways. Pressure systems frequently incorporate a regulator and relief valve to protect the downstream equipment from accidental overpressure caused by regulator failure. Analysis frequently shows that in cases of high-flow regulator failure, the downstream pressure may rise significantly above the set pressure of the relief valve. This is due to limited flow capacity of the relief valve. A different regulator or relief valve may need to be selected. A more economical solution to this problem is to use an RFO to limit the maximum system flow to acceptable limits within the flow capacity of the relief valve, thereby enhancing the overpressure protection of laboratory equipment. An RFO can also be used to limit the uncontrolled release of system fluid (gas or liquid) upon component or line failure. As an example, potential asphyxiation hazards resultant from the release of large volumes of inert gas from a 'house' nitrogen system can be controlled by the use of an RFO. This report describes a versatile new Sandia-designed RFO available from the Swagelok Company and specifies the gas flow characteristics of this device. Two sizes, 0.010 and 0.020 inch diameter RFOs are available. These sizes will allow enhanced safety for many common applications. This new RFO design are now commercially available and provide advantages over existing RFOs: a high pressure rating (6600 psig); flow through the RFO is equal for either forward or reverse directions; they minimize the potential for leakage by incorporating the highest quality threaded connections; and can enhance the safety of pressure systems.
A thermodynamic hypothesis regarding optimality principles for flow processes in geosystems
Liu, Hui-Hai
2015-01-01T23:59:59.000Z
a review of the maximum entropy production principle. RevSeleznev VD (2006) Maximum entropy pro- duction principle inexpenditure rate Maximum entropy production Optimality
Measuring Outdoor Air Intake Rates into Existing Building
Fisk, William; Sullivan, Douglas; Cohen, Sebastian; Han, Hwataik
2009-04-16T23:59:59.000Z
Practical and accurate technologies are needed for continuously measuring and controlling outdoor air (OA) intake rates in commercial building heating, ventilating, and air conditioning (HVAC) systems. This project evaluated two new measurement approaches. Laboratory experiments determined that OA flow rates were measurable with errors generally less than 10 percent using electronic air velocity probes installed between OA intake louver blades or at the outlet face of louvers. High accuracy was maintained with OA flow rates as low as 15 percent of the maximum for the louvers. Thus, with this measurement approach HVAC systems do not need separate OA intakes for minimum OA supply. System calibration parameters are required for each unique combination of louver type and velocity sensor location but calibrations are not necessary for each system installation. The research also determined that the accuracy of measuring OA flow rates with velocity probes located in the duct downstream of the intake louver was not improved by installing honeycomb airflow straighteners upstream of the probes. Errors varied with type of upstream louver, were as high as 100 percent, and were often greater than 25 percent. In conclusion, use of electronic air velocity probes between the blades of OA intake louvers or at the outlet face of louvers is a highly promising means of accurately measuring rates of OA flow into HVAC systems. The use of electronic velocity probes downstream of airflow straighteners is less promising, at least with the relatively small OA HVAC inlet systems employed in this research.
Richard W. Johnson; Hiroyuki Sato
2010-10-01T23:59:59.000Z
Significant uncertainty exists about the effects of bypass flow in a prismatic gas-cooled very high temperature reactor (VHTR). Bypass flow is the flow in the gaps between prismatic graphite blocks in the core. The gaps are present because of variations in their construction, imperfect installation and expansion and shrinkage from thermal heating and neutron fluence. Calculations are performed using computational fluid dynamics (CFD) for flow of the helium coolant in the gap and coolant channels along with conjugate heat generation and heat transfer in the fuel compacts and graphite. A commercial CFD code is used for all of the computations. A one-twelfth sector of a standard hexagonal block column is used for the CFD model because of its symmetry. Various scenarios are computed by varying the gap width from zero to 5 mm, varying the total heat generation rate to examine average and peak radial generation rates and variation of the graphite block geometry to account for the effects of shrinkage caused by irradiation. The calculations are for a 350 MWth prismatic reactor. It is shown that the effect of increasing gap width, while maintaining the same total mass flow rate, causes increased maximum fuel temperature while providing significant cooling to the near-gap region. The maximum outlet coolant temperature variation is increased by the presence of gap flow and also by an increase in total heat generation with a gap present. The effect of block shrinkage is actually to decrease maximum fuel temperature compared to a similar reference case.
Richard W. Johnson; Hiroyuki Sato
2012-10-01T23:59:59.000Z
Significant uncertainty exists about the effects of bypass flow in a prismatic gas-cooled very high temperature reactor (VHTR). Bypass flow is the flow in the gaps between prismatic graphite blocks in the core. The gaps are present because of variations in their construction, imperfect installation and expansion and shrinkage from thermal heating and neutron fluence. Calculations are performed using computational fluid dynamics (CFD) for flow of the helium coolant in the gap and coolant channels along with conjugate heat generation and heat transfer in the fuel compacts and graphite. A commercial CFD code is used for all of the computations. A one-twelfth sector of a standard hexagonal block column is used for the CFD model because of its symmetry. Various scenarios are computed by varying the gap width from zero to 5 mm, varying the total heat generation rate to examine average and peak radial generation rates and variation of the graphite block geometry to account for the effects of shrinkage caused by irradiation. The calculations are for a 350 MWth prismatic reactor. It is shown that the effect of increasing gap width, while maintaining the same total mass flow rate, causes increased maximum fuel temperature while providing significant cooling to the near-gap region. The maximum outlet coolant temperature variation is increased by the presence of gap flow and also by an increase in total heat generation with a gap present. The effect of block shrinkage is actually to decrease maximum fuel temperature compared to a similar reference case.
McFarland, Andrew R. (College Station, TX); Rodgers, John C. (Santa Fe, NM); Ortiz, Carlos A. (Bryan, TX); Nelson, David C. (Santa Fe, NM)
1994-01-01T23:59:59.000Z
Elbow mass flow meter. The present invention includes a combination of an elbow pressure drop generator and a shunt-type mass flow sensor for providing an output which gives the mass flow rate of a gas that is nearly independent of the density of the gas. For air, the output is also approximately independent of humidity.
Maximum entropy segmentation of broadcast news
Christensen, Heidi; Kolluru, BalaKrishna; Gotoh, Yoshihiko; Renals, Steve
2005-01-01T23:59:59.000Z
speech recognizer and subsequently segmenting the text into utterances and topics. A maximum entropy approach is used to build statistical models for both utterance and topic segmentation. The experimental work addresses the effect on performance...
Cell development obeys maximum Fisher information
B. R. Frieden; R. A. Gatenby
2014-04-29T23:59:59.000Z
Eukaryotic cell development has been optimized by natural selection to obey maximal intracellular flux of messenger proteins. This, in turn, implies maximum Fisher information on angular position about a target nuclear pore complex (NPR). The cell is simply modeled as spherical, with cell membrane (CM) diameter 10 micron and concentric nuclear membrane (NM) diameter 6 micron. The NM contains about 3000 nuclear pore complexes (NPCs). Development requires messenger ligands to travel from the CM-NPC-DNA target binding sites. Ligands acquire negative charge by phosphorylation, passing through the cytoplasm over Newtonian trajectories toward positively charged NPCs (utilizing positive nuclear localization sequences). The CM-NPC channel obeys maximized mean protein flux F and Fisher information I at the NPC, with first-order delta I = 0 and approximate 2nd-order delta I = 0 stability to environmental perturbations. Many of its predictions are confirmed, including the dominance of protein pathways of from 1-4 proteins, a 4nm size for the EGFR protein and the approximate flux value F =10^16 proteins/m2-s. After entering the nucleus, each protein ultimately delivers its ligand information to a DNA target site with maximum probability, i.e. maximum Kullback-Liebler entropy HKL. In a smoothness limit HKL approaches IDNA/2, so that the total CM-NPC-DNA channel obeys maximum Fisher I. Thus maximum information approaches non-equilibrium, one condition for life.
Improving predictability of time series using maximum entropy methods
Gregor Chliamovitch; Alexandre Dupuis; Bastien Chopard; Anton Golub
2014-11-28T23:59:59.000Z
We discuss how maximum entropy methods may be applied to the reconstruction of Markov processes underlying empirical time series and compare this approach to usual frequency sampling. It is shown that, at least in low dimension, there exists a subset of the space of stochastic matrices for which the MaxEnt method is more efficient than sampling, in the sense that shorter historical samples have to be considered to reach the same accuracy. Considering short samples is of particular interest when modelling smoothly non-stationary processes, for then it provides, under some conditions, a powerful forecasting tool. The method is illustrated for a discretized empirical series of exchange rates.
Improving predictability of time series using maximum entropy methods
Chliamovitch, Gregor; Chopard, Bastien; Golub, Anton
2014-01-01T23:59:59.000Z
We discuss how maximum entropy methods may be applied to the reconstruction of Markov processes underlying empirical time series and compare this approach to usual frequency sampling. It is shown that, at least in low dimension, there exists a subset of the space of stochastic matrices for which the MaxEnt method is more efficient than sampling, in the sense that shorter historical samples have to be considered to reach the same accuracy. Considering short samples is of particular interest when modelling smoothly non-stationary processes, for then it provides, under some conditions, a powerful forecasting tool. The method is illustrated for a discretized empirical series of exchange rates.
Weak Scale From the Maximum Entropy Principle
Yuta Hamada; Hikaru Kawai; Kiyoharu Kawana
2014-09-23T23:59:59.000Z
The theory of multiverse and wormholes suggests that the parameters of the Standard Model are fixed in such a way that the radiation of the $S^{3}$ universe at the final stage $S_{rad}$ becomes maximum, which we call the maximum entropy principle. Although it is difficult to confirm this principle generally, for a few parameters of the Standard Model, we can check whether $S_{rad}$ actually becomes maximum at the observed values. In this paper, we regard $S_{rad}$ at the final stage as a function of the weak scale ( the Higgs expectation value ) $v_{h}$, and show that it becomes maximum around $v_{h}={\\cal{O}}(300\\text{GeV})$ when the dimensionless couplings in the Standard Model, that is, the Higgs self coupling, the gauge couplings, and the Yukawa couplings are fixed. Roughly speaking, we find that the weak scale is given by \\begin{equation} v_{h}\\sim\\frac{T_{BBN}^{2}}{M_{pl}y_{e}^{5}},\
Weak Scale From the Maximum Entropy Principle
Hamada, Yuta; Kawana, Kiyoharu
2014-01-01T23:59:59.000Z
The theory of multiverse and wormholes suggests that the parameters of the Standard Model are fixed in such a way that the radiation of the $S^{3}$ universe at the final stage $S_{rad}$ becomes maximum, which we call the maximum entropy principle. Although it is difficult to confirm this principle generally, for a few parameters of the Standard Model, we can check whether $S_{rad}$ actually becomes maximum at the observed values. In this paper, we regard $S_{rad}$ at the final stage as a function of the weak scale ( the Higgs expectation value ) $v_{h}$, and show that it becomes maximum around $v_{h}={\\cal{O}}(300\\text{GeV})$ when the dimensionless couplings in the Standard Model, that is, the Higgs self coupling, the gauge couplings, and the Yukawa couplings are fixed. Roughly speaking, we find that the weak scale is given by \\begin{equation} v_{h}\\sim\\frac{T_{BBN}^{2}}{M_{pl}y_{e}^{5}},\
Integrating Correlated Bayesian Networks Using Maximum Entropy
Jarman, Kenneth D.; Whitney, Paul D.
2011-08-30T23:59:59.000Z
We consider the problem of generating a joint distribution for a pair of Bayesian networks that preserves the multivariate marginal distribution of each network and satisfies prescribed correlation between pairs of nodes taken from both networks. We derive the maximum entropy distribution for any pair of multivariate random vectors and prescribed correlations and demonstrate numerical results for an example integration of Bayesian networks.
Systematic characterization of degas-driven flow for poly(dimethylsiloxane) microfluidic devices
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Lee, Luke P.; Liang, David Y.; Tentori, Augusto M.; Dimov, Ivan K. [Universidad de Valparaiso (Chile)
2011-06-02T23:59:59.000Z
Degas-driven flow is a novel phenomenon used to propel fluids in poly(dimethylsiloxane) (PDMS)-based microfluidic devices without requiring any external power. This method takes advantage of the inherently high porosity and air solubility of PDMS by removing air molecules from the bulk PDMS before initiating the flow. The dynamics of degas-driven flow are dependent on the channel and device geometries and are highly sensitive to temporal parameters. These dependencies have not been fully characterized, hindering broad use of degas-driven flow as a microfluidic pumping mechanism. Here, we characterize, for the first time, the effect of various parameters on the dynamics of degas-driven flow, including channel geometry, PDMS thickness, PDMS exposure area, vacuum degassing time, and idle time at atmospheric pressure before loading. We investigate the effect of these parameters on flow velocity as well as channel fill time for the degas-driven flow process. Using our devices, we achieved reproducible flow with a standard deviation of less than 8% for flow velocity, as well as maximum flow rates of up to 3 nL/s and mean flow rates of approximately 1-1.5 nL/s. Parameters such as channel surface area and PDMS chip exposure area were found to have negligible impact on degas-driven flow dynamics, whereas channel cross-sectional area, degas time, PDMS thickness, and idle time were found to have a larger impact. In addition, we develop a physical model that can predict mean flow velocities within 6% of experimental values and can be used as a tool for future design of PDMS-based microfluidic devices that utilize degas-driven flow.
QCD Level Density from Maximum Entropy Method
Shinji Ejiri; Tetsuo Hatsuda
2005-09-24T23:59:59.000Z
We propose a method to calculate the QCD level density directly from the thermodynamic quantities obtained by lattice QCD simulations with the use of the maximum entropy method (MEM). Understanding QCD thermodynamics from QCD spectral properties has its own importance. Also it has a close connection to phenomenological analyses of the lattice data as well as experimental data on the basis of hadronic resonances. Our feasibility study shows that the MEM can provide a useful tool to study QCD level density.
Tissue Radiation Response with Maximum Tsallis Entropy
Sotolongo-Grau, O.; Rodriguez-Perez, D.; Antoranz, J. C.; Sotolongo-Costa, Oscar [UNED, Departamento de Fisica Matematica y de Fluidos, 28040 Madrid (Spain); UNED, Departamento de Fisica Matematica y de Fluidos, 28040 Madrid (Spain) and University of Havana, Catedra de Sistemas Complejos Henri Poincare, Havana 10400 (Cuba); University of Havana, Catedra de Sistemas Complejos Henri Poincare, Havana 10400 (Cuba)
2010-10-08T23:59:59.000Z
The expression of survival factors for radiation damaged cells is currently based on probabilistic assumptions and experimentally fitted for each tumor, radiation, and conditions. Here, we show how the simplest of these radiobiological models can be derived from the maximum entropy principle of the classical Boltzmann-Gibbs expression. We extend this derivation using the Tsallis entropy and a cutoff hypothesis, motivated by clinical observations. The obtained expression shows a remarkable agreement with the experimental data found in the literature.
Broader source: Energy.gov [DOE]
This simple spreadsheet model estimates either the flow rate required to produce a specified level of power output, or the power output that can be produced from a specified flow rate.
Su-Jong Yoon; Piyush Sabharwall
2014-07-01T23:59:59.000Z
The operation temperature of advanced nuclear reactors is generally higher than commercial light water reactors and thermal energy from advanced nuclear reactor can be used for various purposes such as district heating, desalination, hydrogen production and other process heat applications, etc. The process heat industry/facilities will be located outside the nuclear island due to safety measures. This thermal energy from the reactor has to be transported a fair distance. In this study, analytical analysis was conducted to identify the maximum distance that thermal energy could be transported using various coolants such as molten-salts, helium and water by varying the pipe diameter and mass flow rate. The cost required to transport each coolant was also analyzed. The coolants analyzed are molten salts (such as: KClMgCl2, LiF-NaF-KF (FLiNaK) and KF-ZrF4), helium and water. Fluoride salts are superior because of better heat transport characteristics but chloride salts are most economical for higher temperature transportation purposes. For lower temperature water is a possible alternative when compared with He, because low pressure He requires higher pumping power which makes the process very inefficient and economically not viable for both low and high temperature application.
Broader source: Energy.gov [DOE]
One of the major responsibilities of Southeastern is to design, formulate, and justify rate schedules. Repayment studies prepared by the agency determine revenue requirements and appropriate rate...
A global maximum power point tracking DC-DC converter
Duncan, Joseph, 1981-
2005-01-01T23:59:59.000Z
This thesis describes the design, and validation of a maximum power point tracking DC-DC converter capable of following the true global maximum power point in the presence of other local maximum. It does this without the ...
McFarland, A.R.; Rodgers, J.C.; Ortiz, C.A.; Nelson, D.C.
1994-08-16T23:59:59.000Z
The present invention includes a combination of an elbow pressure drop generator and a shunt-type mass flow sensor for providing an output which gives the mass flow rate of a gas that is nearly independent of the density of the gas. For air, the output is also approximately independent of humidity. 3 figs.
Colloidal particle deposition in turbulent flow
Morton, D.S.
1994-05-01T23:59:59.000Z
A theoretical analysis is presented which describes the initial deposition of monodispersed spherical colloidal particles from a steady fully developed turbulent flow onto conduit walls. When the net particle-conduit electrical interaction potential is attractive, particle deposition is shown to be often governed by turbulent hydrodynamics. When the net particle-conduit electrical interaction potential possess a repulsive maximum, particle deposition to first order is uniform and depends solely on electrical interaction effects. The developed theoretical model specialized to orifice deposition with the use of Harwell Flow3D turbulence modelling software qualitatively described the deposition of 0.5 {mu}m silica particles onto glass orifices from an aqueous suspension. The effect of the electrical double layer on the rate of colloidal particle deposition in laminar flow has been described by Spielman and Friedlander (1), Dahneke (2), Bowen et al. (3) and Bowen and Epstein (4). This article describes the extension of their work to colloidal particle deposition under steady fully developed turbulent flow conditions. This article also reports the results of orifice particle deposition experiments which were conducted to qualitatively investigate the developed theoretical model.
Accelerated maximum likelihood parameter estimation for stochastic biochemical systems
Daigle, Bernie J; Roh, Min K; Petzold, Linda R; Niemi, Jarad
2012-01-01T23:59:59.000Z
as: Daigle et al. : Accelerated maximum likelihood parame-Gillespie DT: Approximate accelerated stochastic simulationARTICLE Open Access Accelerated maximum likelihood parameter
articulatorily constrained maximum: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
weight spanning forests. Amitabha Bagchi; Ankur Bhargava; Torsten Suel 2005-01-01 27 Maximum Entropy Correlated Equilibria MIT - DSpace Summary: We study maximum entropy...
Droplet sizes, dynamics and deposition in vertical annular flow
Lopes, J C.B.; Dukler, A E
1985-10-01T23:59:59.000Z
The role of droplets in vertical upwards annular flow is investigated, focusing on the droplet size distributions, dynamics, and deposition phenomena. An experimental program was performed based on a new laser optical technique developed in these laboratories and implemented here for annular flow. This permitted the simultaneous measurement of droplet size, axial and radial velocity. The dependence of droplet size distributions on flow conditions is analyzed. The Upper-Log Normal function proves to be a good model for the size distribution. The mechanism controlling the maximum stable drop size was found to result from the interaction of the pressure fluctuations of the turbulent flow of the gas core with the droplet. The average axial droplet velocity showed a weak dependence on gas rates. This can be explained once the droplet size distribution and droplet size-velocity relationship are analyzed simultaneously. The surprising result from the droplet conditional analysis is that larger droplet travel faster than smaller ones. This dependence cannot be explained if the drag curves used do not take into account the high levels of turbulence present in the gas core in annular flow. If these are considered, then interesting new situations of multiplicity and stability of droplet terminal velocities are encountered. Also, the observed size-velocity relationship can be explained. A droplet deposition is formulated based on the particle inertia control. This permitted the calculation of rates of drop deposition directly from the droplet size and velocities data.
Investigation of Turbulent transition in plane Couette flows Using Energy Gradient Method
Hua-Shu Dou; Boo Cheong Khoo
2010-06-07T23:59:59.000Z
The energy gradient method has been proposed with the aim of better understanding the mechanism of flow transition from laminar flow to turbulent flow. In this method, it is demonstrated that the transition to turbulence depends on the relative magnitudes of the transverse gradient of the total mechanical energy which amplifies the disturbance and the energy loss from viscous friction which damps the disturbance, for given imposed disturbance. For a given flow geometry and fluid properties, when the maximum of the function K (a function standing for the ratio of the gradient of total mechanical energy in the transverse direction to the rate of energy loss due to viscous friction in the streamwise direction) in the flow field is larger than a certain critical value, it is expected that instability would occur for some initial disturbances. In this paper, using the energy gradient analysis, the equation for calculating the energy gradient function K for plane Couette flow is derived. The result indicates that K reaches the maximum at the moving walls. Thus, the fluid layer near the moving wall is the most dangerous position to generate initial oscillation at sufficient high Re for given same level of normalized perturbation in the domain. The critical value of K at turbulent transition, which is observed from experiments, is about 370 for plane Couette flow when two walls move in opposite directions (anti-symmetry). This value is about the same as that for plane Poiseuille flow and pipe Poiseuille flow (385-389). Therefore, it is concluded that the critical value of K at turbulent transition is about 370-389 for wall-bounded parallel shear flows which include both pressure (symmetrical case) and shear driven flows (anti-symmetrical case).
In-Situ Calibration for Feedwater Flow Measurement
Peyvan, David [Entergy Nuclear Generating Company (United States); Gurevich, Yuri [Advanced Measurement and Analysis Group, Mississauga, ON (Canada); French, Charles T. [Westinghouse Electric Company (United States)
2002-07-01T23:59:59.000Z
With the approval by the Nuclear Regulatory Commission (NRC), of the Appendix K power up-rates, it has become important to provide an accurate measurement of the feedwater flow. Failure to meet documented requirements can now more easily lead to plant operations above their analyzed safety limits. Thus, the objective of flow instrumentation used in Appendix K up-rates, becomes one of providing precise measurements of the feedwater mass flow that will not allow the plant to be overpowered, but will still assure that maximum licensed thermal output is achieved. The NRC has licensed two technologies that meet these standards. Both are based on ultrasonic measurements of the flow. The first of these technologies, which is referred to as transit-time, relies on the measurement of differences in time for multiple ultrasonic beams to pass up and downstream in the fluid stream. These measurements are then coupled with a numerical integration scheme to compensate for distortions in the velocity profile due to upstream flow disturbances. This technology is implemented using a spool piece that is inserted into the feedwater pipe. The second technology relies on the measurement of the velocity of eddies within the fluid using a numerical process called cross-correlation. This technology is implemented by attaching the ultrasonic flow meter to the external surface of the pipe. Because of the ease in installation, for atypical situations, distortions in the velocity profile can be accounted for by attaching a second ultrasonic flow meter to the same pipe or multiple meters to a similar piping configuration, where the flow is fully developed. The additional meter readings are then used for the calibration of the initial set-up. Thus, it becomes possible to provide an in-situ calibration under actual operating conditions that requires no extrapolation of laboratory calibrations to compensate for distortions in the velocity profile. This paper will focus on the cross-correlation method of flow measurement, starting with the theoretical bases for the velocity profile correction factor and its reliance on only the Reynolds number to produce an accurate measurement of the flow, when the flow is fully developed. The method of laboratory calibration and the verification of these calibrations under actual plant operating conditions will be discussed. This will be followed by a discussion of how this technology is being used today to support the Appendix K up-rates. Various examples will be presented of piping configurations, where in-situ calibrations have or will be used to provide an accurate measurement of the feedwater flow at a specific location. (authors)
LANDFILL OPERATION FOR CARBON SEQUESTRATION AND MAXIMUM METHANE EMISSION CONTROL
Don Augenstein
2001-02-01T23:59:59.000Z
The work described in this report, to demonstrate and advance this technology, has used two demonstration-scale cells of size (8000 metric tons [tonnes]), sufficient to replicate many heat and compaction characteristics of larger ''full-scale'' landfills. An enhanced demonstration cell has received moisture supplementation to field capacity. This is the maximum moisture waste can hold while still limiting liquid drainage rate to minimal and safely manageable levels. The enhanced landfill module was compared to a parallel control landfill module receiving no moisture additions. Gas recovery has continued for a period of over 4 years. It is quite encouraging that the enhanced cell methane recovery has been close to 10-fold that experienced with conventional landfills. This is the highest methane recovery rate per unit waste, and thus progress toward stabilization, documented anywhere for such a large waste mass. This high recovery rate is attributed to moisture, and elevated temperature attained inexpensively during startup. Economic analyses performed under Phase I of this NETL contract indicate ''greenhouse cost effectiveness'' to be excellent. Other benefits include substantial waste volume loss (over 30%) which translates to extended landfill life. Other environmental benefits include rapidly improved quality and stabilization (lowered pollutant levels) in liquid leachate which drains from the waste.
Maximum mass of magnetic white dwarfs
Paret, D Manreza; Horvath, J E
2015-01-01T23:59:59.000Z
We revisit in this work the problem of the maximum masses of magnetized White Dwarfs (WD). The impact of a strong magnetic field onto the structure equations is addressed. The pressures become anisotropic due to the presence of the magnetic field and split into a parallel and perpendicular components. We first construct stable solutions of TOV equations for the parallel pressures, and found that physical solutions vanish for the perpendicular pressure when $B \\gtrsim 10^{13}$ G. This fact establishes an upper bound for a magnetic field and the stability of the configurations in the (quasi) spherical approximation. Our findings also indicate that it is not possible to obtain stable magnetized WD with super Chandrasekhar masses because the values of the magnetic field needed for them are higher than this bound. To proceed into the anisotropic regime, we derived structure equations appropriated for a cylindrical metric with anisotropic pressures. From the solutions of the structure equations in cylindrical symme...
Maximum screening fields of superconducting multilayer structures
Gurevich, Alex
2015-01-01T23:59:59.000Z
It is shown that a multilayer comprised of alternating thin superconducting and insulating layers on a thick substrate can fully screen the applied magnetic field exceeding the superheating fields $H_s$ of both the superconducting layers and the substrate, the maximum Meissner field is achieved at an optimum multilayer thickness. For instance, a dirty layer of thickness $\\sim 0.1\\; \\mu$m at the Nb surface could increase $H_s\\simeq 240$ mT of a clean Nb up to $H_s\\simeq 290$ mT. Optimized multilayers of Nb$_3$Sn, NbN, some of the iron pnictides, or alloyed Nb deposited onto the surface of the Nb resonator cavities could potentially double the rf breakdown field, pushing the peak accelerating electric fields above 100 MV/m while protecting the cavity from dendritic thermomagnetic avalanches caused by local penetration of vortices.
Cabec Conference; Rashid Mir P. E
2009-01-01T23:59:59.000Z
Consistent, accurate, and uniform ratings based on a single statewide rating scale Reasonable estimates of potential utility bill savings and reliable recommendations on cost-effective measures to improve energy efficiency Training and certification procedures for home raters and quality assurance procedures to promote accurate ratings and to protect consumers Labeling procedures that will meet the needs of home buyers, homeowners, renters, the real estate industry, and mortgage lenders with an interest in home energy ratings
Ali Ulas Ozgur Kisisel; Ozgur Sarioglu; Bayram Tekin
2008-06-17T23:59:59.000Z
Using the conformally invariant Cotton tensor, we define a geometric flow, the "Cotton flow", which is exclusive to three dimensions. This flow tends to evolve the initial metrics into conformally flat ones, and is somewhat orthogonal to the Yamabe flow, the latter being a flow within a conformal class. We define an entropy functional, and study the flow of nine homogeneous spaces both numerically and analytically. In particular, we show that the arbitrarily deformed homogeneous 3-sphere flows into the round 3-sphere. Two of the nine homogeneous geometries, which are degenerated by the Ricci flow, are left intact by the Cotton flow.
Maximum Entropy Method Approach to $?$ Term
Masahiro Imachi; Yasuhiko Shinno; Hiroshi Yoneyama
2004-06-09T23:59:59.000Z
In Monte Carlo simulations of lattice field theory with a $\\theta$ term, one confronts the complex weight problem, or the sign problem. This is circumvented by performing the Fourier transform of the topological charge distribution $P(Q)$. This procedure, however, causes flattening phenomenon of the free energy $f(\\theta)$, which makes study of the phase structure unfeasible. In order to treat this problem, we apply the maximum entropy method (MEM) to a Gaussian form of $P(Q)$, which serves as a good example to test whether the MEM can be applied effectively to the $\\theta$ term. We study the case with flattening as well as that without flattening. In the latter case, the results of the MEM agree with those obtained from the direct application of the Fourier transform. For the former, the MEM gives a smoother $f(\\theta)$ than that of the Fourier transform. Among various default models investigated, the images which yield the least error do not show flattening, although some others cannot be excluded given the uncertainty related to statistical error.
Wang, Yuqing
0 Energy Production, Frictional Dissipation, and Maximum Intensity of a Numerically Simulated) viewed as a heat engine converts heat energy extracted from the ocean to kinetic energy of the TC, which is eventually dissipated due to surface friction. Since the energy production rate is a linear function while
Wang, Yuqing
Energy Production, Frictional Dissipation, and Maximum Intensity of a Numerically Simulated as a heat engine converts heat energy extracted from the ocean into the kinetic energy of the TC, which is eventually dissipated due to surface friction. Since the energy production rate is a linear function while
A Distributed Approach to Maximum Power Point Tracking for Photovoltaic Sub-Module Differential
Liberzon, Daniel
of the proposed distributed algorithm. I. INTRODUCTION IN photovoltaic (PV) energy systems, PV modules are often of the system, small size and low power ratings of the power electronics circuit components. Due1 A Distributed Approach to Maximum Power Point Tracking for Photovoltaic Sub-Module Differential
Computation of the maximum loadability of a power system using nonlinear optimization
Khabirov, Abdufarrukh
2001-01-01T23:59:59.000Z
Between Generator and Load. . . . . . . . . 34 E. Flowchart for Optimization Program F. Tutorial Example G. Conclusion. . 35 36 44 V SIMULATION RESULTS. 45 A. Introduction. B. Results of Simulation for Maximum Loadability of the Total System. I... of this work starting from the basics. Chapter III will cover concepts of power flow and loadability along with tutorial example. The literature survey over this topic and previous work as well as problem statement and solution method will be covered...
Fisk, William; Sullivan, Douglas; Cohen, Sebastian; Han, Hwataik
2008-10-01T23:59:59.000Z
Practical and accurate technologies are needed for continuously measuring and controlling outdoor air (OA) intake rates in commercial building heating, ventilating, and air conditioning (HVAC) systems. This project evaluated two new measurement approaches. Laboratory experiments determined that OA flow rates were measurable with errors generally less than 10percent using electronic air velocity probes installed between OA intake louver blades or at the outlet face of louvers. High accuracy was maintained with OA flow rates as low as 15percent of the maximum for the louvers. Thus, with this measurement approach HVAC systems do not need separate OA intakes for minimum OA supply. System calibration parameters are required for each unique combination of louver type and velocity sensor location but calibrations are not necessary for each system installation. The research also determined that the accuracy of measuring OA flow rates with velocity probes located in the duct downstream of the intake louver was not improved by installing honeycomb airflow straighteners upstream of the probes. Errors varied with type of upstream louver, were as high as 100percent, and were often greater than 25percent. In conclusion, use of electronic air velocity probes between the blades of OA intake louvers or at the outlet face of louvers is a highly promising means of accurately measuring rates of OA flow into HVAC systems. The use of electronic velocity probes downstream of airflow straighteners is less promising, at least with the relatively small OA HVAC inlet systems employed in this research.
Rates of maximum food intake in young northern fur seals (Callorhinus ursinus) and the seasonal
- ports body growth and energy storage, which ultimately af- fect survival and reproductive success to compensate by further increasing their levels of consumption on subsequent feeding days. Absolute levels, the fur seals did not appear to efficiently convert this additional energy into mass growth, particularly
The use of maximum rate of dissipation criterion to model beams with internal dissipation
Ko, Min Seok
2004-09-30T23:59:59.000Z
This thesis deals with a systematic procedure for the derivation of exact expression for the frequency equation of composite beams undergoing forced vibration with damping. The governing differential equations of motion of the composite beam...
A Requirement for Significant Reduction in the Maximum BTU Input Rate of
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious RankCombustion |Energyon ArmedWaste and Materials2014 Chief FreedomServices Â» ProgramDecorative Vented Gas
GMM Estimation of a Maximum Entropy Distribution with Interval Data
Perloff, Jeffrey M.
GMM Estimation of a Maximum Entropy Distribution with Interval Data Ximing Wu* and Jeffrey M estimate it using a simple yet flexible maximum entropy density. Our Monte Carlo simulations show that the proposed maximum entropy density is able to approximate various distributions extremely well. The two
Flow Duration Curve Load Duration Curve
Flow Duration Curve Load Duration Curve 1. Develop Flow Duration Curve 2. Estimate load given flow and concentration data--select appropriate conversion factors 3. Develop Load Duration Curve 4. Plot observed data with Load Duration Curve What are they? How do you make one? Describes the percent of time a flow rate
On the "viscosity maximum" during the uniaxial extension of a low density polyethylene
Teodor I. Burghelea; Zdenek Stary; Helmut Muenstedt
2010-01-13T23:59:59.000Z
An experimental investigation of the viscosity overshoot phenomenon observed during uniaxial extension of a low density polyethylene is pre- sented. For this purpose, traditional integral viscosity measurements on a Muenstedt type extensional rheometer are combined with local mea- surements based on the in-situ visualization of the sample under exten- sion. For elongational experiments at constant strain rates within a wide range of Weissenberg numbers (Wi), three distinct deformation regimes are identified. Corresponding to low values of Wi (regime I), the tensile stress displays a broad maximum. This maximum can be explained by simple mathematical arguments as a result of low deformation rates and it should not be confused with the viscosity overshoot phenomenon. Corre- sponding to intermediate values of Wi (regime II), a local maximum of the integral extensional viscosity is systematically observed. However, within this regime, the local viscosity measurements reveal no maximum, but a plateau. Careful inspection of the images of samples within this regime shows that, corresponding to the maximum of the integral viscosity, sec- ondary necks develop along the sample. The emergence of a maximum of the integral elongational viscosity is thus related to the distinct in- homogeneity of deformation states and is not related to the rheological properties of the material. In the fast stretching limit (high Wi, regime III), the overall geometric uniformity of the sample is well preserved, no secondary necks are observed and both the integral and the local transient elongational viscosity show no maximum. A detailed comparison of the experimental findings with results from literature is presented.
Microelectromechanical flow control apparatus
Okandan, Murat (NE Albuquerque, NM)
2009-06-02T23:59:59.000Z
A microelectromechanical (MEM) flow control apparatus is disclosed which includes a fluid channel formed on a substrate from a first layer of a nonconducting material (e.g. silicon nitride). A first electrode is provided on the first layer of the nonconducting material outside the flow channel; and a second electrode is located on a second layer of the nonconducting material above the first layer. A voltage applied between the first and second electrodes deforms the fluid channel to increase its cross-sectional size and thereby increase a flow of a fluid through the channel. In certain embodiments of the present invention, the fluid flow can be decreased or stopped by applying a voltage between the first electrode and the substrate. A peristaltic pumping of the fluid through the channel is also possible when the voltage is applied in turn between a plurality of first electrodes and the substrate. A MEM flow control assembly can also be formed by providing one or more MEM flow control devices on a common substrate together with a submicron filter. The MEM flow control assembly can optionally include a plurality of pressure sensors for monitoring fluid pressure and determining flow rates through the assembly.
Control Volume Analysis, Entropy Balance and the Entropy Production in Flow Systems
Robert K. Niven; Bernd R. Noack
2014-07-21T23:59:59.000Z
This chapter concerns "control volume analysis", the standard engineering tool for the analysis of flow systems, and its application to entropy balance calculations. Firstly, the principles of control volume analysis are enunciated and applied to flows of conserved quantities (e.g. mass, momentum, energy) through a control volume, giving integral (Reynolds transport theorem) and differential forms of the conservation equations. Several definitions of steady state are discussed. The concept of "entropy" is then established using Jaynes' maximum entropy method, both in general and in equilibrium thermodynamics. The thermodynamic entropy then gives the "entropy production" concept. Equations for the entropy production are then derived for simple, integral and infinitesimal flow systems. Some technical aspects are examined, including discrete and continuum representations of volume elements, the effect of radiation, and the analysis of systems subdivided into compartments. A Reynolds decomposition of the entropy production equation then reveals an "entropy production closure problem" in fluctuating dissipative systems: even at steady state, the entropy production based on mean flow rates and gradients is not necessarily in balance with the outward entropy fluxes based on mean quantities. Finally, a direct analysis of an infinitesimal element by Jaynes' maximum entropy method yields a theoretical framework with which to predict the steady state of a flow system. This is cast in terms of a "minimum flux potential" principle, which reduces, in different circumstances, to maximum or minimum entropy production (MaxEP or MinEP) principles. It is hoped that this chapter inspires others to attain a deeper understanding and higher technical rigour in the calculation and extremisation of the entropy production in flow systems of all types.
THE MAXIMUM ENERGY OF ACCELERATED PARTICLES IN RELATIVISTIC COLLISIONLESS SHOCKS
Sironi, Lorenzo [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Spitkovsky, Anatoly [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544-1001 (United States); Arons, Jonathan, E-mail: lsironi@cfa.harvard.edu [Department of Astronomy, Department of Physics, and Theoretical Astrophysics Center, University of California, Berkeley, CA 94720 (United States)
2013-07-01T23:59:59.000Z
The afterglow emission from gamma-ray bursts (GRBs) is usually interpreted as synchrotron radiation from electrons accelerated at the GRB external shock that propagates with relativistic velocities into the magnetized interstellar medium. By means of multi-dimensional particle-in-cell simulations, we investigate the acceleration performance of weakly magnetized relativistic shocks, in the magnetization range 0 {approx}< {sigma} {approx}< 10{sup -1}. The pre-shock magnetic field is orthogonal to the flow, as generically expected for relativistic shocks. We find that relativistic perpendicular shocks propagating in electron-positron plasmas are efficient particle accelerators if the magnetization is {sigma} {approx}< 10{sup -3}. For electron-ion plasmas, the transition to efficient acceleration occurs for {sigma} {approx}< 3 Multiplication-Sign 10{sup -5}. Here, the acceleration process proceeds similarly for the two species, since the electrons enter the shock nearly in equipartition with the ions, as a result of strong pre-heating in the self-generated upstream turbulence. In both electron-positron and electron-ion shocks, we find that the maximum energy of the accelerated particles scales in time as {epsilon}{sub max}{proportional_to}t {sup 1/2}. This scaling is shallower than the so-called (and commonly assumed) Bohm limit {epsilon}{sub max}{proportional_to}t, and it naturally results from the small-scale nature of the Weibel turbulence generated in the shock layer. In magnetized plasmas, the energy of the accelerated particles increases until it reaches a saturation value {epsilon}{sub sat}/{gamma}{sub 0} m{sub i}c {sup 2} {approx} {sigma}{sup -1/4}, where {gamma}{sub 0} m{sub i}c {sup 2} is the mean energy per particle in the upstream bulk flow. Further energization is prevented by the fact that the self-generated turbulence is confined within a finite region of thickness {proportional_to}{sigma}{sup -1/2} around the shock. Our results can provide physically grounded inputs for models of non-thermal emission from a variety of astrophysical sources, with particular relevance to GRB afterglows.
Self-regulating flow control device
Humphreys, Duane A. (Pittsburgh, PA)
1984-01-01T23:59:59.000Z
A variable, self-regulating valve having a hydraulic loss coefficient proportional to a positive exponential power of the flow rate. The device includes two objects in a flow channel and structure which assures that the distance between the two objects is an increasing function of the flow rate. The range of spacing between the objects is such that the hydraulic resistance of the valve is an increasing function of the distance between the two objects so that the desired hydraulic loss coefficient as a function of flow rate is obtained without variation in the flow area.
Pinkel, Daniel (Walnut Creek, CA)
1991-01-01T23:59:59.000Z
An obstruction across the flow chamber creates a one dimensional convergence of a sheath fluid. A passageway in the construction directs flat cells near to the area of one dimensional convergence in the sheath fluid to provide proper orientation of flat cells at fast rates.
A Near Maximum Likelihood Decoding Algorithm for MIMO Systems ...
2005-10-05T23:59:59.000Z
Jul 30, 2005 ... the randomization procedure of [43], we bijectively map the .... ?1x are also in the integer grid. ... in a Maximum A Posteriori (MAP) decoder by.
Solving Maximum-Entropy Sampling Problems Using Factored Masks
Samuel Burer
2005-03-02T23:59:59.000Z
Mar 2, 2005 ... Abstract: We present a practical approach to Anstreicher and Lee's masked spectral bound for maximum-entropy sampling, and we describe ...
A masked spectral bound for maximum-entropy sampling
Kurt Anstreicher
2003-09-16T23:59:59.000Z
Sep 16, 2003 ... Abstract: We introduce a new masked spectral bound for the maximum-entropy sampling problem. This bound is a continuous generalization of ...
Maximum entropy generation in open systems: the Fourth Law?
Umberto Lucia
2010-11-17T23:59:59.000Z
This paper develops an analytical and rigorous formulation of the maximum entropy generation principle. The result is suggested as the Fourth Law of Thermodynamics.
analog fixed maximum: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
state for given entanglement which can be viewed as an analogue of the Jaynes maximum entropy principle. Pawel Horodecki; Ryszard Horodecki; Michal Horodecki 1998-05-22...
IBM Research Report Solving Maximum-Entropy Sampling ...
2005-02-28T23:59:59.000Z
Feb 28, 2005 ... Solving Maximum-Entropy Sampling Problems Using. Factored Masks. Samuel Burer. Department of Management Sciences. University of Iowa.
LANDFILL OPERATION FOR CARBON SEQUESTRATION AND MAXIMUM METHANE EMISSION CONTROL
Don Augenstein; Ramin Yazdani; Rick Moore; Michelle Byars; Jeff Kieffer; Professor Morton Barlaz; Rinav Mehta
2000-02-26T23:59:59.000Z
Controlled landfilling is an approach to manage solid waste landfills, so as to rapidly complete methane generation, while maximizing gas capture and minimizing the usual emissions of methane to the atmosphere. With controlled landfilling, methane generation is accelerated to more rapid and earlier completion to full potential by improving conditions (principally moisture, but also temperature) to optimize biological processes occurring within the landfill. Gas is contained through use of surface membrane cover. Gas is captured via porous layers, under the cover, operated at slight vacuum. A field demonstration project has been ongoing under NETL sponsorship for the past several years near Davis, CA. Results have been extremely encouraging. Two major benefits of the technology are reduction of landfill methane emissions to minuscule levels, and the recovery of greater amounts of landfill methane energy in much shorter times, more predictably, than with conventional landfill practice. With the large amount of US landfill methane generated, and greenhouse potency of methane, better landfill methane control can play a substantial role both in reduction of US greenhouse gas emissions and in US renewable energy. The work described in this report, to demonstrate and advance this technology, has used two demonstration-scale cells of size (8000 metric tons [tonnes]), sufficient to replicate many heat and compaction characteristics of larger ''full-scale'' landfills. An enhanced demonstration cell has received moisture supplementation to field capacity. This is the maximum moisture waste can hold while still limiting liquid drainage rate to minimal and safely manageable levels. The enhanced landfill module was compared to a parallel control landfill module receiving no moisture additions. Gas recovery has continued for a period of over 4 years. It is quite encouraging that the enhanced cell methane recovery has been close to 10-fold that experienced with conventional landfills. This is the highest methane recovery rate per unit waste, and thus progress toward stabilization, documented anywhere for such a large waste mass. This high recovery rate is attributed to moisture, and elevated temperature attained inexpensively during startup. Economic analyses performed under Phase I of this NETL contract indicate ''greenhouse cost effectiveness'' to be excellent. Other benefits include substantial waste volume loss (over 30%) which translates to extended landfill life. Other environmental benefits include rapidly improved quality and stabilization (lowered pollutant levels) in liquid leachate which drains from the waste.
Farrell, Anthony P.
, skipjack tuna (Katsuwonus pelamis) have maximum heart rates of 154Â191 beats min-1 (Brill, 1987; Farrell et
Chemical response of methane/air diffusion flames to unsteady strain rate
Im, H.G.; Chen, J.H. [Sandia National Labs., Livermore, CA (United States); Chen, J.Y. [Univ. of California, Berkeley, CA (United States). Dept. of Mechanical Engineering
1998-03-01T23:59:59.000Z
Effects of unsteady strain rate on the response of methane/air diffusion flames are studied. The authors use the finite-domain opposed flow configuration in which the nozzle exit velocity is imposed as a function of time. The GRI mechanism v2.11 is used for the detailed methane/air chemistry. The response of individual species to monochromatic oscillation in strain rate with various frequencies reveals that the fluctuation of slow species, such as CO and NO{sub x}, is more rapidly suppressed as the flow time scale decreases. It is also observed that the maximum CO concentration is very insensitive to the variation in the scalar dissipation rate. An extinction event due to an abrupt imposition of high strain rates is also simulated by an impulsive velocity with various frequencies. For a fast impulse, a substantial overshoot in NO{sub 2} concentration is observed after extinction. Finally, the overall fuel burning rate shows a nonmonotonic response to the variation in characteristic unsteady time scale, while the emission indices for NO{sub x} shows monotonic decay in response as frequency is increased.
Maximum Constant Boost Control of the Z-Source Inverter
Tolbert, Leon M.
Maximum Constant Boost Control of the Z-Source Inverter Miaosen Shen1 , Jin Wang1 , Alan Joseph1 Laboratory Abstract: This paper proposes two maximum constant boost control methods for the Z-source inverter to modulation index is analyzed in detail and verified by simulation and experiment. Keywords- Z-source inverter
Appendix 22 Draft Nutrient Management Plan and Total Maximum Daily
Appendix 22 Draft Nutrient Management Plan and Total Maximum Daily Load for Flathead Lake, Montana. #12;11/01/01 DRAFT i October 30, 2001 Draft Nutrient Management Plan and Total Maximum Daily Load..............................................................................................................................2-11 SECTION 3.0 APPLICABLE WATER QUALITY STANDARDS
Classification of Two-Phase Flow Patterns by Ultrasonic Sensing
Ray, Asok
in addition to several other factors such as the bulk flow rate, fluid properties, and flow boundary conditions [1]. Characterization of flow patterns and identification of the associ- ated flow regimes instrumentation, both for void fraction identification and flow pattern classification. High-speed photog- raphy
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AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 -the Mid-Infrared at 278, 298, andEpidermal Growth Factor. |INCIDENCET3PACI-T3Rate
The transition from the annular to the slug flow regime in two-phase flow
Haberstroh, Robert D.
1964-01-01T23:59:59.000Z
Experiments were conducted to determine the transition from annular to semiannular flow regimes for two-phase, gas-liquid upflow in vertical tubes. The influencesof liquid flow rate, tube diameter, liquid viscosity, surface ...
Flame-wall interaction simulation in a turbulent channel flow
Bruneaux, G.; Akselvoll, K.; Poinsot, T.; Ferziger, J.H.
1996-10-01T23:59:59.000Z
The interaction between turbulent premixed flames and channel walls is studied. Combustion is represented by a simple irreversible reaction with a large activation temperature. A low heat release assumption is used, but feedback to the flowfield can be allowed through viscosity changes. The effect of wall distance on local and global flame structure is investigated. Quenching distances and maximum wall heat fluxed computed in laminar cases are compared to DNS results. It is found that quenching distances decrease and maximum heat fluxes increase relative to laminar flame values, scaling with the turbulent strain rate. It is shown that these effects are due to large coherent structures which push flame elements towards the wall. The effect of wall strain in flame-wall interaction is studied in a stagnation line flow; this is used to explain the DNS results. The effects of the flame on the flow through viscosity changes is studied. It is also shown that remarkable flame events are produced by flame interaction with a horseshoe vortex: burned gases are pushed towards the wall at high speed and induce quenching and high wall heat flux while fresh gases are expelled from the wall region and form finger-like structures. Effects of the wall on flame surface density are investigated.
Morozov, Victor (Manassas, VA)
2011-01-18T23:59:59.000Z
A flow chamber having a vacuum chamber and a specimen chamber. The specimen chamber may have an opening through which a fluid may be introduced and an opening through which the fluid may exit. The vacuum chamber may have an opening through which contents of the vacuum chamber may be evacuated. A portion of the flow chamber may be flexible, and a vacuum may be used to hold the components of the flow chamber together.
Yu. N. Bratkov
2008-11-19T23:59:59.000Z
In this paper geology and planetology are considered using new conceptual basis of high-speed flow dynamics. Recent photo technics allow to see all details of a flow, 'cause the flow is static during very short time interval. On the other hand, maps and images of many planets are accessible. Identity of geological flows and high-speed gas dynamics is demonstrated. There is another time scale, and no more. All results, as far as the concept, are new and belong to the author. No formulae, pictures only.
MSET modeling of Crystal River-3 venturi flow meters.
Bockhorst, F. K.; Gross, K. C.; Herzog, J. P.; Wegerich, S. W.
1998-01-05T23:59:59.000Z
The analysis of archived Crystal River-3 feedwater flow data reveals a slow and steady degradation of the flow meter measurements during the 1992/1993 operating cycle. MSET can reliably estimate the true flow rate and quantify the degree of departure between the indicated signal and the true flow rate with high accuracy. The MSET computed flow rate could, in principle, be used to provide an improved estimate of the reactor power and hence avoid the revenue loss associated with derating the reactor based on a faulty feedwater flow rate indication.
Maher, K.; Steefel, C. I.; White, A.F.; Stonestrom, D.A.
2009-02-25T23:59:59.000Z
In order to explore the reasons for the apparent discrepancy between laboratory and field weathering rates and to determine the extent to which weathering rates are controlled by the approach to thermodynamic equilibrium, secondary mineral precipitation and flow rates, a multicomponent reactive transport model (CrunchFlow) was used to interpret soil profile development and mineral precipitation and dissolution rates at the 226 ka marine terrace chronosequence near Santa Cruz, CA. Aqueous compositions, fluid chemistry, transport, and mineral abundances are well characterized (White et al., 2008, GCA) and were used to constrain the reaction rates for the weathering and precipitating minerals in the reactive transport modeling. When primary mineral weathering rates are calculated with either of two experimentally determined rate constants, the nonlinear, parallel rate law formulation of Hellmann and Tisser and [2006] or the aluminum inhibition model proposed by Oelkers et al. [1994], modeling results are consistent with field-scale observations when independently constrained clay precipitation rates are accounted for. Experimental and field rates, therefore, can be reconciled at the Santa Cruz site. Observed maximum clay abundances in the argillic horizons occur at the depth and time where the reaction fronts of the primary minerals overlap. The modeling indicates that the argillic horizon at Santa Cruz can be explained almost entirely by weathering of primary minerals and in situ clay precipitation accompanied by undersaturation of kaolinite at the top of the profile. The rate constant for kaolinite precipitation was also determined based on model simulations of mineral abundances and dissolved Al, SiO{sub 2}(aq) and pH in pore waters. Changes in the rate of kaolinite precipitation or the flow rate do not affect the gradient of the primary mineral weathering profiles, but instead control the rate of propagation of the primary mineral weathering fronts and thus total mass removed from the weathering profile. Our analysis suggests that secondary clay precipitation is as important as aqueous transport in governing the amount of dissolution that occurs within a profile because clay minerals exert a strong control over the reaction affinity of the dissolving primary minerals. The modeling also indicates that the weathering advance rate and the total mass of mineral dissolved is controlled by the thermodynamic saturation of the primary dissolving phases plagioclase and K-feldspar, as is evident from the difference in propagation rates of the reaction fronts for the two minerals despite their very similar kinetic rate laws.
Robinett, Rush D., III; Wilson, David Gerald
2010-05-01T23:59:59.000Z
In this paper, the swing equations for renewable generators are formulated as a natural Hamiltonian system with externally applied non-conservative forces. A two-step process referred to as Hamiltonian Surface Shaping and Power Flow Control (HSSPFC) is used to analyze and design feedback controllers for the renewable generator system. This formulation extends previous results on the analytical verification of the Potential Energy Boundary Surface (PEBS) method to nonlinear control analysis and design and justifies the decomposition of the system into conservative and non-conservative systems to enable a two-step, serial analysis and design procedure. In particular, this approach extends the work done by developing a formulation which applies to a larger set of Hamiltonian Systems that has Nearly Hamiltonian Systems as a subset. The results of this research include the determination of the required performance of a proposed Flexible AC Transmission System (FACTS)/storage device to enable the maximum power output of a wind turbine while meeting the power system constraints on frequency and phase. The FACTS/storage device is required to operate as both a generator and load (energy storage) on the power system in this design. The Second Law of Thermodynamics is applied to the power flow equations to determine the stability boundaries (limit cycles) of the renewable generator system and enable design of feedback controllers that meet stability requirements while maximizing the power generation and flow to the load. Necessary and sufficient conditions for stability of renewable generators systems are determined based on the concepts of Hamiltonian systems, power flow, exergy (the maximum work that can be extracted from an energy flow) rate, and entropy rate.
Liu, Jian
2008-01-01T23:59:59.000Z
1992). J. Skilling, in Maximum entropy and Bayesian methods,1989). S. F. Gull, in Maximum entropy and Bayesian methods,with the classical maximum entropy (CME) technique (MEAC-
Improved constraints on transit time distributions from argon 39: A maximum entropy approach
Holzer, Mark; Primeau, Francois W
2010-01-01T23:59:59.000Z
Gull (1991), Bayesian maximum entropy image reconstruction,Atlantic venti- lated? Maximum entropy inversions of bottlefrom argon 39: A maximum entropy approach Mark Holzer 1,2
Soffer, Bernard H; Kikuchi, Ryoichi
1994-01-01T23:59:59.000Z
of Confidence for Maximum Entropy Restoration and EstimationApril 3, 1992) The Maximum Entropy method, using physicalare discussed. Maximum Entropy (ME) estimation has been
Maximum Photovoltaic Penetration Levels on Typical Distribution Feeders: Preprint
Hoke, A.; Butler, R.; Hambrick, J.; Kroposki, B.
2012-07-01T23:59:59.000Z
This paper presents simulation results for a taxonomy of typical distribution feeders with various levels of photovoltaic (PV) penetration. For each of the 16 feeders simulated, the maximum PV penetration that did not result in steady-state voltage or current violation is presented for several PV location scenarios: clustered near the feeder source, clustered near the midpoint of the feeder, clustered near the end of the feeder, randomly located, and evenly distributed. In addition, the maximum level of PV is presented for single, large PV systems at each location. Maximum PV penetration was determined by requiring that feeder voltages stay within ANSI Range A and that feeder currents stay within the ranges determined by overcurrent protection devices. Simulations were run in GridLAB-D using hourly time steps over a year with randomized load profiles based on utility data and typical meteorological year weather data. For 86% of the cases simulated, maximum PV penetration was at least 30% of peak load.
Maximum containment : the most controversial labs in the world
Bruzek, Alison K. (Allison Kim)
2013-01-01T23:59:59.000Z
In 2002, following the September 11th attacks and the anthrax letters, the United States allocated money to build two maximum containment biology labs. Called Biosafety Level 4 (BSL-4) facilities, these labs were built to ...
Multichannel Blind Identification: From Subspace to Maximum Likelihood Methods
Tong, Lang
Multichannel Blind Identification: From Subspace to Maximum Likelihood Methods LANG TONG, MEMBER, IEEE, AND SYLVIE PERREAU Invited Paper A review of recent blind channel estimation algorithms is pre-- Blind equalization, parameter estimation, system identification. I. INTRODUCTION A. What Is Blind
Multi-Class Classification with Maximum Margin Multiple Kernel
Tomkins, Andrew
(named OBSCURE and UFO-MKL, respectively) are used to optimize primal versions of equivalent problems), the OBSCURE and UFO-MKL algorithms are compared against MCMKL #12;Multi-Class Classification with Maximum
Maximum entropy method and oscillations in the diffraction cone
O. Dumbrajs; J. Kontros; A. Lengyel
2000-07-15T23:59:59.000Z
The maximum entropy method has been applied to investigate the oscillating structure in the pbarp- and pp-elastic scattering differential cross-section at high energy and small momentum transfer. Oscillations satisfying quite realistic reliability criteria have been found.
Efficiency at maximum power of interacting molecular machines
N. Golubeva; A. Imparato
2012-10-22T23:59:59.000Z
We investigate the efficiency of systems of molecular motors operating at maximum power. We consider two models of kinesin motors on a microtubule: for both the simplified and the detailed model, we find that the many-body exclusion effect enhances the efficiency at maximum power of the many-motor system, with respect to the single motor case. Remarkably, we find that this effect occurs in a limited region of the system parameters, compatible with the biologically relevant range.
Filtering Additive Measurement Noise with Maximum Entropy in the Mean
Henryk Gzyl; Enrique ter Horst
2007-09-04T23:59:59.000Z
The purpose of this note is to show how the method of maximum entropy in the mean (MEM) may be used to improve parametric estimation when the measurements are corrupted by large level of noise. The method is developed in the context on a concrete example: that of estimation of the parameter in an exponential distribution. We compare the performance of our method with the bayesian and maximum likelihood approaches.
The maximum entropy tecniques and the statistical description of systems
B. Z. Belashev; M. K. Suleymanov
2001-10-19T23:59:59.000Z
The maximum entropy technique (MENT) is used to determine the distribution functions of physical values. MENT naturally combines required maximum entropy, the properties of a system and connection conditions in the form of restrictions imposed on the system. It can, therefore, be employed to statistically describe closed and open systems. Examples in which MENT is used to describe equilibrium and non-equilibrium states, as well as steady states that are far from being in thermodynamic equilibrium, are discussed.
Active combustion flow modulation valve
Hensel, John Peter; Black, Nathaniel; Thorton, Jimmy Dean; Vipperman, Jeffrey Stuart; Lambeth, David N; Clark, William W
2013-09-24T23:59:59.000Z
A flow modulation valve has a slidably translating hollow armature with at least one energizable coil wound around and fixably attached to the hollow armature. The energizable coil or coils are influenced by at least one permanent magnet surrounding the hollow armature and supported by an outer casing. Lorentz forces on the energizable coils which are translated to the hollow armature, increase or decrease the flow area to provide flow throttling action. The extent of hollow armature translation depends on the value of current supplied and the direction of translation depends on the direction of current flow. The compact nature of the flow modulation valve combined with the high forces afforded by the actuator design provide a flow modulation valve which is highly responsive to high-rate input control signals.
Povinelli, L.A.
1990-01-01T23:59:59.000Z
An overview is given of research activity on the application of computational fluid dynamics (CDF) for hypersonic propulsion systems. After the initial consideration of the highly integrated nature of air-breathing hypersonic engines and airframe, attention is directed toward computations carried out for the components of the engine. A generic inlet configuration is considered in order to demonstrate the highly three dimensional viscous flow behavior occurring within rectangular inlets. Reacting flow computations for simple jet injection as well as for more complex combustion chambers are then discussed in order to show the capability of viscous finite rate chemical reaction computer simulations. Finally, the nozzle flow fields are demonstrated, showing the existence of complex shear layers and shock structure in the exhaust plume. The general issues associated with code validation as well as the specific issue associated with the use of CFD for design are discussed. A prognosis for the success of CFD in the design of future propulsion systems is offered.
Y. Wu
2004-11-01T23:59:59.000Z
The purpose of this report is to document the unsaturated zone (UZ) flow models and submodels, as well as the flow fields that have been generated using the UZ flow model(s) of Yucca Mountain, Nevada. In this report, the term ''UZ model'' refers to the UZ flow model and the several submodels, which include tracer transport, temperature or ambient geothermal, pneumatic or gas flow, and geochemistry (chloride, calcite, and strontium) submodels. The term UZ flow model refers to the three-dimensional models used for calibration and simulation of UZ flow fields. This work was planned in the ''Technical Work Plan (TWP) for: Unsaturated Zone Flow Analysis and Model Report Integration'' (BSC 2004 [DIRS 169654], Section 1.2.7). The table of included Features, Events, and Processes (FEPs), Table 6.2-11, is different from the list of included FEPs assigned to this report in the ''Technical Work Plan for: Unsaturated Zone Flow Analysis and Model Report Integration'' (BSC 2004 [DIRS 169654], Table 2.1.5-1), as discussed in Section 6.2.6. The UZ model has revised, updated, and enhanced the previous UZ model (BSC 2001 [DIRS 158726]) by incorporating the repository design with new grids, recalibration of property sets, and more comprehensive validation effort. The flow fields describe fracture-fracture, matrix-matrix, and fracture-matrix liquid flow rates, and their spatial distributions as well as moisture conditions in the UZ system. These three-dimensional UZ flow fields are used directly by Total System Performance Assessment (TSPA). The model and submodels evaluate important hydrogeologic processes in the UZ as well as geochemistry and geothermal conditions. These provide the necessary framework to test hypotheses of flow and transport at different scales, and predict flow and transport behavior under a variety of climatic conditions. In addition, the limitations of the UZ model are discussed in Section 8.11.
Bahrami, Majid
7-11 7-29 A coal-burning power plant produces 300 MW of power. The amount of coal consumed during The heating value of the coal is given to be 28,000 kJ/kg. Analysis (a) The rate and the amount of heat inputs'tQQ The amount and rate of coal consumed during this period are kg/s48.33 s360024 kg10893.2 MJ/kg28 MJ101.8 6
Liquid metal Flow Meter - Final Report
Andersen C, Hoogendoom S, Hudson B, Prince J, Teichert K, Wood J, Chase K
2007-01-30T23:59:59.000Z
Measuring the flow of liquid metal presents serious challenges. Current commercially-available flow meters use ultrasonic, electromagnetic, and other technologies to measure flow, but are inadequate for liquid metal flow measurement because of the high temperatures required by most liquid metals. As a result of the reactivity and high temperatures of most liquid metals, corrosion and leakage become very serious safety concerns. The purpose of this project is to develop a flow meter for Lockheed Martin that measures the flow rate of molten metal in a conduit.
Initial test results from the RedFlow 5 kW, 10 kWh zinc-bromide module, phase 1.
Ferreira, Summer Rhodes; Rose, David Martin
2012-02-01T23:59:59.000Z
In this paper the performance results of the RedFlow zinc-bromide module (ZBM) Gen 2.0 are reported for Phase 1 of testing, which includes initial characterization of the module. This included physical measurement, efficiency as a function of charge and discharge rates, efficiency as a function of maximum charge capacity, duration of maximum power supplied, and limited cycling with skipped strip cycles. The goal of this first phase of testing was to verify manufacturer specifications of the zinc-bromide flow battery. Initial characterization tests have shown that the ZBM meets the manufacturer's specifications. Further testing, including testing as a function of temperature and life cycle testing, will be carried out during Phase 2 of the testing, and these results will be issued in the final report, after Phase 2 testing has concluded.
Optimization of well rates under gas coning conditions
Urbanczyk, Christopher Henry
1989-01-01T23:59:59.000Z
production rates under gas caning conditions. This new method applies to an oil reservoir overlain by a large gas cap containing multiple wells. The cases consider have a limit on the maximum field production rate for both oil and gas. It was found... that the optimal p~ion rates are achieved when Eq. 1 is satisfied for any pair of wells i and j: ) I = constant i = 1, . . . , n dqo This condition minimizes the f ield gas production rate when the maximum field production rate for oil is met, and maximizes...
Cooling Flows or Heating Flows?
James Binney
2003-10-08T23:59:59.000Z
It is now clear that AGN heat cooling flows, largely by driving winds. The winds may contain a relativistic component that generates powerful synchrotron radiation, but it is not clear that all winds do so. The spatial and temporal stability of the AGN/cooling flow interaction are discussed. Collimation of the winds probably provides spatial stability. Temporal stability may be possible only for black holes with masses above a critical value. Both the failure of cooling flows to have adiabatic cores and the existence of X-ray cavities confirm the importance of collimated outflows. I quantify the scale of the convective flow that the AGN Hydra would need to drive if it balanced radiative inward flow by outward flow parallel to the jets. At least in Virgo any such flow must be confined to r<~20 kpc. Hydrodynamical simulations suggest that AGN outbursts cannot last longer than ~25 Myr. Data for four clusters with well studied X-ray cavities suggests that heating associated with cavity formation approximately balances radiative cooling. The role of cosmic infall and the mechanism of filament formation are briefly touched on.
Yoshida, Z. [Graduate School of Frontier Sciences, University of Tokyo, Chiba 277-8561 (Japan); Mahajan, S. M. [Institute for Fusion Studies, University of Texas at Austin, Austin, Texas 78712 (United States)
2008-03-15T23:59:59.000Z
A thermodynamic model of a plasma boundary layer, characterized by enhanced temperature contrasts and ''maximum entropy production,'' is proposed. The system shows bifurcation if the heat flux entering through the inner boundary exceeds a critical value. The state with a larger temperature contrast (larger entropy production) sustains a self-organized flow. An inverse cascade of energy is proposed as the underlying physical mechanism for the realization of such a heat engine.
Radiant energy receiver having improved coolant flow control means
Hinterberger, H.
1980-10-29T23:59:59.000Z
An improved coolant flow control for use in radiant energy receivers of the type having parallel flow paths is disclosed. A coolant performs as a temperature dependent valve means, increasing flow in the warmer flow paths of the receiver, and impeding flow in the cooler paths of the receiver. The coolant has a negative temperature coefficient of viscosity which is high enough such that only an insignificant flow through the receiver is experienced at the minimum operating temperature of the receiver, and such that a maximum flow is experienced at the maximum operating temperature of the receiver. The valving is accomplished by changes in viscosity of the coolant in response to the coolant being heated and cooled. No remotely operated valves, comparators or the like are needed.
Yousefian, V.; Weinberg, M.H.; Haimes, R.
1980-02-01T23:59:59.000Z
The NASA CEC Code was the starting point for PACKAGE, whose function is to evaluate the composition of a multiphase combustion product mixture under the following chemical conditions: (1) total equilibrium with pure condensed species; (2) total equilibrium with ideal liquid solution; (3) partial equilibrium/partial finite rate chemistry; and (4) fully finite rate chemistry. The last three conditions were developed to treat the evolution of complex mixtures such as coal combustion products. The thermodynamic variable pairs considered are either pressure (P) and enthalpy, P and entropy, at P and temperature. Minimization of Gibbs free energy is used. This report gives detailed discussions of formulation and input/output information used in the code. Sample problems are given. The code development, description, and current programming constraints are discussed. (DLC)
Research Article Milli-free flow electrophoresis: I. Fast
Krylov, Sergey
, but has not yet been implemented due to an incompatibility of scale. Continuous purification, in FFE a term of milli-free flow electrophoresis (mFFE) to describe mid-scale FFE with flow rates intermediate reactors with product flow rates of $5 to 2000 mL/min, too small for macro-FFE but too large for m
Constraints on flow regimes in wide-aperture fractures
Ghezzehei, Teamrat A.
2004-02-28T23:59:59.000Z
In recent years, significant advances have been made in our understanding of the complex flow processes in individual fractures, aided by flow visualization experiments and conceptual modeling efforts. These advances have led to the recognition of several flow regimes in individual fractures subjected to different initial and boundary conditions. Of these, the most important regimes are film flow, rivulet flow, and sliding of droplets. The existence of such significantly dissimilar flow regimes has been a major hindrance in the development of self-consistent conceptual models of flow for single fractures that encompass all the flow regimes. The objective of this study is to delineate the existence of the different flow regimes in individual fractures. For steady-state flow conditions, we developed physical constraints on the different flow regimes that satisfy minimum energy configurations, which enabled us to segregate the wide range of fracture transmissivity (volumetric flow rate per fracture width) into several flow regimes. These are, in increasing order of flow rate, flow of adsorbed films, flow of sliding drops, rivulet flow, stable film flow, and unstable (turbulent) film flow. The scope of this study is limited to wide-aperture fractures with the flow on the opposing sides of fracture being independent.
NGC2613, 3198, 6503, 7184: Case studies against `maximum' disks
B. Fuchs
1998-12-02T23:59:59.000Z
Decompositions of the rotation curves of NGC2613, 3198, 6505, and 7184 are analysed. For these galaxies the radial velocity dispersions of the stars have been measured and their morphology is clearly discernible. If the parameters of the decompositions are chosen according to the `maximum' disk hypothesis, the Toomre Q stability parameter is systematically less than one and the multiplicities of the spiral arms as expected from density wave theory are inconsitent with the observed morphologies of the galaxies. The apparent Q<1 instability, in particular, is a strong argument against the `maximum' disk hypothesis.
Efficiency of autonomous soft nano-machines at maximum power
Udo Seifert
2010-11-11T23:59:59.000Z
We consider nano-sized artificial or biological machines working in steady state enforced by imposing non-equilibrium concentrations of solutes or by applying external forces, torques or electric fields. For unicyclic and strongly coupled multicyclic machines, efficiency at maximum power is not bounded by the linear response value 1/2. For strong driving, it can even approach the thermodynamic limit 1. Quite generally, such machines fall in three different classes characterized, respectively, as "strong and efficient", "strong and inefficient", and "balanced". For weakly coupled multicyclic machines, efficiency at maximum power has lost any universality even in the linear response regime.
When are microcircuits well-modeled by maximum entropy methods?
2010-07-20T23:59:59.000Z
POSTER PRESENTATION Open Access When are microcircuits well-modeled by maximum entropy methods? Andrea K Barreiro1*, Eric T Shea-Brown1, Fred M Rieke2,3, Julijana Gjorgjieva4 From Nineteenth Annual Computational Neuroscience Meeting: CNS*2010 San... Antonio, TX, USA. 24-30 July 2010 Recent experiments in retina and cortex have demon- strated that pairwise maximum entropy (PME) methods can approximate observed spiking patterns to a high degree of accuracy [1,2]. In this paper we examine...
Valence quark distributions of the proton from maximum entropy approach
Rong Wang; Xurong Chen
2014-10-14T23:59:59.000Z
We present an attempt of maximum entropy principle to determine valence quark distributions in the proton at very low resolution scale $Q_0^2$. The initial three valence quark distributions are obtained with limited dynamical information from quark model and QCD theory. Valence quark distributions from this method are compared to the lepton deep inelastic scattering data, and the widely used CT10 and MSTW08 data sets. The obtained valence quark distributions are consistent with experimental observations and the latest global fits of PDFs. Maximum entropy method is expected to be particularly useful in the case where relatively little information from QCD calculation is given.
Valence quark distributions of the proton from maximum entropy approach
Wang, Rong
2014-01-01T23:59:59.000Z
We present an attempt of maximum entropy principle to determine valence quark distributions in the proton at very low resolution scale $Q_0^2$. The initial three valence quark distributions are obtained with limited dynamical information from quark model and QCD theory. Valence quark distributions from this method are compared to the lepton deep inelastic scattering data, and the widely used CT10 and MSTW08 data sets. The obtained valence quark distributions are consistent with experimental observations and the latest global fits of PDFs. Maximum entropy method is expected to be particularly useful in the case where relatively little information from QCD calculation is given.
Assessing complexity by means of maximum entropy models
Chliamovitch, Gregor; Velasquez, Lino
2014-01-01T23:59:59.000Z
We discuss a characterization of complexity based on successive approximations of the probability density describing a system by means of maximum entropy methods, thereby quantifying the respective role played by different orders of interaction. This characterization is applied on simple cellular automata in order to put it in perspective with the usual notion of complexity for such systems based on Wolfram classes. The overlap is shown to be good, but not perfect. This suggests that complexity in the sense of Wolfram emerges as an intermediate regime of maximum entropy-based complexity, but also gives insights regarding the role of initial conditions in complexity-related issues.
Design and Fabrication of a Vertical Pump Multiphase Flow Loop
Kirkland, Klayton 1965-
2012-08-24T23:59:59.000Z
is supplied by separate air and water inlet flows that mix just before entering the pump. These flows can be controlled to give a desired gas volume fraction and overall flow rate. The pump outlet flows into a tank which separates the fluids allowing them...
Maximum power tracking control scheme for wind generator systems
Mena Lopez, Hugo Eduardo
2008-10-10T23:59:59.000Z
The purpose of this work is to develop a maximum power tracking control strategy for variable speed wind turbine systems. Modern wind turbine control systems are slow, and they depend on the design parameters of the turbine and use wind and/or rotor...
Maximum power tracking control scheme for wind generator systems
Mena, Hugo Eduardo
2009-05-15T23:59:59.000Z
The purpose of this work is to develop a maximum power tracking control strategy for variable speed wind turbine systems. Modern wind turbine control systems are slow, and they depend on the design parameters of the turbine and use wind and/or rotor...
Maximum-principle-satisfying and positivity-preserving high order ...
2011-04-01T23:59:59.000Z
conservation laws: Survey and new developments ..... Notice that in (2.10) we need to evaluate the maximum/minimum of a ..... total energy, p is the pressure, e is the internal energy, and ? > 1 is a constant ... under a standard CFL condition.
Maximum Entropy in Support of Semantically Annotated Datasets
Kreinovich, Vladik
Maximum Entropy in Support of Semantically Annotated Datasets Paulo Pinheiro da Silva, Vladik whether two datasets describe the same quantity. The existing solution to this problem is to use these datasets' ontologies to deduce that these datasets indeed represent the same quantity. However, even when
Performance of Civil Aviation Receivers during Maximum Solar Activity Events
Boyer, Edmond
Performance of Civil Aviation Receivers during Maximum Solar Activity Events Lina DEAMBROGIO on the fields of ionosphere scintillations, solar energetic particles and on the implementation of operational the upcoming period of high solar activity. Emilien ROBERT got his PhD in 2005 and started to work on behalf
THE MAXIMUM CAPACITY OF A LINE PLAN IS INAPPROXIMABLE
Nabben, Reinhard
THE MAXIMUM CAPACITY OF A LINE PLAN IS INAPPROXIMABLE CHRISTINA PUHL AND SEBASTIAN STILLER Abstract a network, upper arc-capacities and a line pool. E-mail: puhl@math.tu-berlin.de, stiller of the European Commission under contract no. FP6-021235-2. 1 #12;2 CHRISTINA PUHL AND SEBASTIAN STILLER We
O(1)-Approximations for Maximum Movement Piotr Berman1
Demaine, Erik
movement of the pebbles, motivated by minimizing either execution time or energy usage. Spe- cific problems the maximum movement made by pebbles on a graph to reach a configuration in which the pebbles form a connected. For example, in the connectivity goal, the proximity of the robots should form a connected graph. Two
Maximization of Recursive Utilities: A Dynamic Maximum Principle Approach
Di Girolami, Cristina
Maximization of Recursive Utilities: A Dynamic Maximum Principle Approach Wahid FAIDI LAMSIN, ENIT for a class of robust utility function introduced in Bordigoni, Matoussi et Schweizer (2005). Our method-investment strategy which is characterized as the unique solution of a forward-backward system. Key words : Utility
Maximum stellar mass versus cluster membership number revisited
Th. Maschberger; C. J. Clarke
2008-09-05T23:59:59.000Z
We have made a new compilation of observations of maximum stellar mass versus cluster membership number from the literature, which we analyse for consistency with the predictions of a simple random drawing hypothesis for stellar mass selection in clusters. Previously, Weidner and Kroupa have suggested that the maximum stellar mass is lower, in low mass clusters, than would be expected on the basis of random drawing, and have pointed out that this could have important implications for steepening the integrated initial mass function of the Galaxy (the IGIMF) at high masses. Our compilation demonstrates how the observed distribution in the plane of maximum stellar mass versus membership number is affected by the method of target selection; in particular, rather low n clusters with large maximum stellar masses are abundant in observational datasets that specifically seek clusters in the environs of high mass stars. Although we do not consider our compilation to be either complete or unbiased, we discuss the method by which such data should be statistically analysed. Our very provisional conclusion is that the data is not indicating any striking deviation from the expectations of random drawing.
Renewable Energy Scheduling for Fading Channels with Maximum Power Constraint
Greenberg, Albert
Renewable Energy Scheduling for Fading Channels with Maximum Power Constraint Zhe Wang Electrical--In this paper, we develop efficient algorithm to obtain the optimal energy schedule for fading channel with energy harvesting. We assume that the side information of both the channel states and energy harvesting
Retrocommissioning Case Study - Applying Building Selection Criteria for Maximum Results
Luskay, L.; Haasl, T.; Irvine, L.; Frey, D.
2002-01-01T23:59:59.000Z
RETROCOMMISSIONING CASE STUDY ?Applying Building Selection Criteria for Maximum Results? Larry Luskay, Tudi Haasl, Linda Irvine Portland Energy Conservation, Inc. Portland, Oregon Donald Frey Architectural Energy Corporation Boulder.... The building was retrocommissioned by Portland Energy Conservation, Inc. (PECI), in conjunction with Architectural Energy Corporation (AEC). The building-specific goals were: 1) Obtain cost-effective energy savings from optimizing operation...
A Flow Time Model for Melt-Cast Insensitive Explosive Process Guillemin Jean-Philippe*, Brunet Luc
Boyer, Edmond
and inserted in our flow time equations. De Larrard's model for the calculation of the maximum packing density The purpose of this article is to propose a predictive model of the flow time necessary for emptying a reactor
Van den Engh, G.
1995-11-07T23:59:59.000Z
A Faraday cage is described which encloses the flow chamber of a cytometer. Ground planes associated with each field deflection plate inhibit electric fields from varying the charge on designated events/droplets and further concentrates. They also increase forces applied to a passing charged event for accurate focus while concomitantly inhibiting a potential shock hazard. 4 figs.
Measuring rates of outdoor airflow into HVAC systems
Fisk, William J.; Faulkner, David; Sullivan, Douglas P.; Delp, Woody
2002-10-01T23:59:59.000Z
During the last few years, new technologies have been introduced for measuring the flow rates of outside air into HVAC systems. This document describes one particular technology for measuring these airflows, a system and a related protocol developed to evaluate this and similar measurement technologies under conditions without wind, and the results of our evaluations. We conclude that the measurement technology evaluated can provide a reasonably accurate measurement of OA flow rate over a broad range of flow, without significantly increasing airflow resistance.
Chemical preconcentrator with integral thermal flow sensor
Manginell, Ronald P. (Albuquerque, NM); Frye-Mason, Gregory C. (Cedar Crest, NM)
2003-01-01T23:59:59.000Z
A chemical preconcentrator with integral thermal flow sensor can be used to accurately measure fluid flow rate in a microanalytical system. The thermal flow sensor can be operated in either constant temperature or constant power mode and variants thereof. The chemical preconcentrator with integral thermal flow sensor can be fabricated with the same MEMS technology as the rest of the microanlaytical system. Because of its low heat capacity, low-loss, and small size, the chemical preconcentrator with integral thermal flow sensor is fast and efficient enough to be used in battery-powered, portable microanalytical systems.
Theoretical cosmic Type Ia supernova rates
R. Valiante; F. Matteucci; S. Recchi; F. Calura
2009-03-16T23:59:59.000Z
The aim of this work is the computation of the cosmic Type Ia supernova rates at very high redshifts (z>2). We adopt various progenitor models in order to predict the number of explosions in different scenarios for galaxy formation and to check whether it is possible to select the best delay time distribution model, on the basis of the available observations of Type Ia supernovae. We also computed the Type Ia supernova rate in typical elliptical galaxies of different initial luminous masses and the total amount of iron produced by Type Ia supernovae in each case. It emerges that: it is not easy to select the best delay time distribution scenario from the observational data and this is because the cosmic star formation rate dominates over the distribution function of the delay times; the monolithic collapse scenario predicts an increasing trend of the SN Ia rate at high redshifts whereas the predicted rate in the hierarchical scheme drops dramatically at high redshift; for the elliptical galaxies we note that the predicted maximum of the Type Ia supernova rate depends on the initial galactic mass. The maximum occurs earlier (at about 0.3 Gyr) in the most massive ellipticals, as a consequence of downsizing in star formation. We find that different delay time distributions predict different relations between the Type Ia supernova rate per unit mass at the present time and the color of the parent galaxies and that bluer ellipticals present higher supernova Type Ia rates at the present time.
Battista, L.; Sciuto, S. A.; Scorza, A. [Department of Engineering, ROMA TRE University, via della Vasca Navale 79/81, Rome (Italy)
2013-03-15T23:59:59.000Z
In this work, a simple and low-cost air flow sensor, based on a novel fiber-optic sensing technique has been developed for monitoring air flows rates supplied by a neonatal ventilator to support infants in intensive care units. The device is based on a fiber optic sensing technique allowing (a) the immunity to light intensity variations independent by measurand and (b) the reduction of typical shortcomings affecting all biomedical fields (electromagnetic interference and patient electrical safety). The sensing principle is based on the measurement of transversal displacement of an emitting fiber-optic cantilever due to action of air flow acting on it; the fiber tip displacement is measured by means of a photodiode linear array, placed in front of the entrance face of the emitting optical fiber in order to detect its light intensity profile. As the measurement system is based on a detection of the illumination pattern, and not on an intensity modulation technique, it results less sensitive to light intensity fluctuation independent by measurand than intensity-based sensors. The considered technique is here adopted in order to develop two different configurations for an air flow sensor suitable for the measurement of air flow rates typically occurring during mechanical ventilation of newborns: a mono-directional and a bi-directional transducer have been proposed. A mathematical model for the air flow sensor is here proposed and a static calibration of two different arrangements has been performed: a measurement range up to 3.00 Multiplication-Sign 10{sup -4} m{sup 3}/s (18.0 l/min) for the mono-directional sensor and a measurement range of {+-}3.00 Multiplication-Sign 10{sup -4} m{sup 3}/s ({+-}18.0 l/min) for the bi-directional sensor are experimentally evaluated, according to the air flow rates normally encountered during tidal breathing of infants with a mass lower than 10 kg. Experimental data of static calibration result in accordance with the proposed theoretical model: for the mono-directional configuration, the coefficient of determination r{sup 2} is equal to 0.997; for the bi-directional configuration, the coefficient of determination r{sup 2} is equal to 0.990 for positive flows (inspiration) and 0.988 for negative flows (expiration). Measurement uncertainty {delta}Q of air flow rate has been evaluated by means of the propagation of distributions and the percentage error in the arrangement of bi-directional sensor ranges from a minimum of about 0.5% at -18.0 l/min to a maximum of about 9% at -12.0 l/min.
Maximum Entropy Principle and the Higgs Boson Mass
Alves, Alexandre; da Silva, Roberto
2014-01-01T23:59:59.000Z
A successful connection between Higgs boson decays and the Maximum Entropy Principle is presented. Based on the information theory inference approach we determine the Higgs boson mass as $M_H= 125.04\\pm 0.25$ GeV, a value fully compatible to the LHC measurement. This is straightforwardly obtained by taking the Higgs boson branching ratios as the target probability distributions of the inference, without any extra assumptions beyond the Standard Model. Yet, the principle can be a powerful tool in the construction of any model affecting the Higgs sector. We give, as an example, the case where the Higgs boson has an extra invisible decay channel. Our findings suggest that a system of Higgs bosons undergoing a collective decay to Standard Model particles is among the most fundamental ones where the Maximum Entropy Principle applies.
Maximum Entropy Principle and the Higgs Boson Mass
Alexandre Alves; Alex G. Dias; Roberto da Silva
2014-11-18T23:59:59.000Z
A successful connection between Higgs boson decays and the Maximum Entropy Principle is presented. Based on the information theory inference approach we determine the Higgs boson mass as $M_H= 125.04\\pm 0.25$ GeV, a value fully compatible to the LHC measurement. This is straightforwardly obtained by taking the Higgs boson branching ratios as the target probability distributions of the inference, without any extra assumptions beyond the Standard Model. Yet, the principle can be a powerful tool in the construction of any model affecting the Higgs sector. We give, as an example, the case where the Higgs boson has an extra invisible decay channel. Our findings suggest that a system of Higgs bosons undergoing a collective decay to Standard Model particles is among the most fundamental ones where the Maximum Entropy Principle applies.
k - Version of Finite Element Method for Polymer flows using Giesekus Constitutive Model
Deshpande, Kedar M.
2008-01-31T23:59:59.000Z
and hence high Deborah number flows are invariably associated with higher flow rates and thus higher velocities. In many standard model problems such as couette flow, lid driven cavity, expansion, contraction etc, severe deborah number (De) limitations...
Maximum entanglement in squeezed boson and fermion states
Khanna, F. C. [Theoretical Physics Institute, University of Alberta, Edmonton, Alberta T6G 2J1 (Canada); TRIUMF, Vancouver, British Columbia V6T 2A3 (Canada); Malbouisson, J. M. C. [Instituto de Fisica, Universidade Federal da Bahia, 40210-340, Salvador, BA (Brazil); Theoretical Physics Institute, University of Alberta, Edmonton, Alberta T6G 2J1 (Canada); Santana, A. E. [Instituto de Fisica, Universidade de Brasilia, 70910-900, Brasilia, DF (Brazil); Theoretical Physics Institute, University of Alberta, Edmonton, Alberta T6G 2J1 (Canada); Santos, E. S. [Centro Federal de Educacao Tecnologica da Bahia, 40030-010, Salvador, BA (Brazil)
2007-08-15T23:59:59.000Z
A class of squeezed boson and fermion states is studied with particular emphasis on the nature of entanglement. We first investigate the case of bosons, considering two-mode squeezed states. Then we construct the fermion version to show that such states are maximum entangled, for both bosons and fermions. To achieve these results, we demonstrate some relations involving squeezed boson states. The generalization to the case of fermions is made by using Grassmann variables.
Maximum Entry and Mandatory Separation Ages for Certain Security Employees
Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]
2001-10-11T23:59:59.000Z
The policy establishes the DOE policy on maximum entry and mandatory separation ages for primary or secondary positions covered under special statutory retirement provisions and for those employees whose primary duties are the protection of officials of the United States against threats to personal safety or the investigation, apprehension, and detention of individuals suspected or convicted of offenses against the criminal laws of the United States. Admin Chg 1, dated 12-1-11, cancels DOE P 310.1.
Maximum entropy method for reconstruction of the CMB images
A. T. Bajkova
2002-05-21T23:59:59.000Z
We propose a new approach for the accurate reconstruction of cosmic microwave background distributions from observations containing in addition to the primary fluctuations the radiation from unresolved extragalactic point sources and pixel noise. The approach uses some effective realizations of the well-known maximum entropy method and principally takes into account {\\it a priori} information about finiteness and spherical symmetry of the power spectrum of the CMB satisfying the Gaussian statistics.
Occam's Razor Cuts Away the Maximum Entropy Principle
Rudnicki, ?ukasz
2014-01-01T23:59:59.000Z
I show that the maximum entropy principle can be replaced by a more natural assumption, that there exists a phenomenological function of entropy consistent with the microscopic model. The requirement of existence provides then a unique construction of the related probability density. I conclude the letter with an axiomatic formulation of the notion of entropy, which is suitable for exploration of the non-equilibrium phenomena.
PNNL: A Supervised Maximum Entropy Approach to Word Sense Disambiguation
Tratz, Stephen C.; Sanfilippo, Antonio P.; Gregory, Michelle L.; Chappell, Alan R.; Posse, Christian; Whitney, Paul D.
2007-06-23T23:59:59.000Z
In this paper, we described the PNNL Word Sense Disambiguation system as applied to the English All-Word task in Se-mEval 2007. We use a supervised learning approach, employing a large number of features and using Information Gain for dimension reduction. Our Maximum Entropy approach combined with a rich set of features produced results that are significantly better than baseline and are the highest F-score for the fined-grained English All-Words subtask.
Pressure-flow reducer for aerosol focusing devices
Gard, Eric (San Francisco, CA); Riot, Vincent (Oakland, CA); Coffee, Keith (Diablo Grande, CA); Woods, Bruce (Livermore, CA); Tobias, Herbert (Kensington, CA); Birch, Jim (Albany, CA); Weisgraber, Todd (Brentwood, CA)
2008-04-22T23:59:59.000Z
A pressure-flow reducer, and an aerosol focusing system incorporating such a pressure-flow reducer, for performing high-flow, atmosphere-pressure sampling while delivering a tightly focused particle beam in vacuum via an aerodynamic focusing lens stack. The pressure-flow reducer has an inlet nozzle for adjusting the sampling flow rate, a pressure-flow reduction region with a skimmer and pumping ports for reducing the pressure and flow to enable interfacing with low pressure, low flow aerosol focusing devices, and a relaxation chamber for slowing or stopping aerosol particles. In this manner, the pressure-flow reducer decouples pressure from flow, and enables aerosol sampling at atmospheric pressure and at rates greater than 1 liter per minute.
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Flow Cell EMSL's Subsurface Flow and Transport Experimental Laboratory offers several meter-scale flow cells and columns for research in saturated and unsaturated porous media....
Carroll, Susan
2013-07-01T23:59:59.000Z
Spreadsheets provides measured chlorite rate data from 100 to 300C at elevated CO2. Spreadsheet includes derived rate equation.
DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]
Carroll, Susan
Spreadsheets provides measured chlorite rate data from 100 to 300C at elevated CO2. Spreadsheet includes derived rate equation.
Oil Flow Rale Problem Behler, David D 0 McNutt, Marcia K 05/23/201001 :04 PM
Fleskes, Joe
Oil Flow Rale Problem t Behler, David D 0 McNutt, Marcia K 05/23/201001 :04 PM Marcia - just some thoughts on the oil flow rate problem. Over the past few weeks, it's become apparent that the oil flow rate it's best to frame a range of estimated oil flow rates and refine the range over time as the tools
Beyond Boltzmann-Gibbs statistics: Maximum entropy hyperensembles out-of-equilibrium
Crooks, Gavin E.
2006-01-01T23:59:59.000Z
1957). J. Skilling, in Maximum Entropy and Bayesian Methods,45–52. J. Skilling, in Maximum Entropy and Bayesian Methods,e C. C. Rodriguez, in Maximum Entropy and Bayesian Methods,
Deriving the continuity of maximum-entropy basis functions via variational analysis
Sukumar, N.; Wets, R. J. -B.
2007-01-01T23:59:59.000Z
and V. J. DellaPietra, A maximum entropy approach to naturalJ. and R. K. Bryan, Maximum entropy image reconstruction:Heidelberg, Continuity of maximum-entropy basis functions p
Capacitance-based prover for gas flow meters
Pipkins, Sean Patrick
1995-01-01T23:59:59.000Z
) Sunday . . . Stability Measurement: /tC vs. Time (21 Feb 95). . . . Capacitance vs. Time for Mass Flow Rate of 124. 7 g/s. . . . 41 41 42 23 Capacitance vs. Time for Mass Flow Rate of 124. 7 g/s (06 Apr 95). . . . . . . . . . . 43 24 25 Pressure... vs. Time for Mass Flow Rate of 124. 7 g/s (06 Apr 95). . . . Capacitance vs. Time for Mass Flow Rate of 209. 1 g/s. . . . 43 44 FIGURE 26 Capacitance vs. Time for Loading Phase 27 Pressure vs. Time for Loading Phase. 28 T; vs. Time...
Scaling bounds on dissipation in turbulent flows
Seis, Christian
2015-01-01T23:59:59.000Z
We present a new rigorous method for estimating statistical quantities in fluid dynamics such as the (average) energy dissipation rate directly from the equations of motion. The method is tested on shear flow, channel flow, Rayleigh--B\\'enard convection and porous medium convection.
CHARACTERISTICS OF SOLAR MERIDIONAL FLOWS DURING SOLAR CYCLE 23
Basu, Sarbani [Department of Astronomy, Yale University, P.O. Box 208101, New Haven, CT 06520-8101 (United States); Antia, H. M., E-mail: sarbani.basu@yale.ed, E-mail: antia@tifr.res.i [Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400005 (India)
2010-07-01T23:59:59.000Z
We have analyzed available full-disk data from the Michelson Doppler Imager on board SOHO using the 'ring diagram' technique to determine the behavior of solar meridional flows over solar cycle 23 in the outer 2% of the solar radius. We find that the dominant component of meridional flows during solar maximum was much lower than that during the minima at the beginning of cycles 23 and 24. There were differences in the flow velocities even between the two minima. The meridional flows show a migrating pattern with higher-velocity flows migrating toward the equator as activity increases. Additionally, we find that the migrating pattern of the meridional flow matches those of sunspot butterfly diagram and the zonal flows in the shallow layers. A high-latitude band in meridional flow appears around 2004, well before the current activity minimum. A Legendre polynomial decomposition of the meridional flows shows that the latitudinal pattern of the flow was also different during the maximum as compared to that during the two minima. The different components of the flow have different time dependences, and the dependence is different at different depths.
Letter Report: Borehole Flow and Horizontal Hydraulic Conductivity with Depth at Well ER-12-4
Phil L. Oberlander; Charles E. Russell
2005-12-31T23:59:59.000Z
Borehole flow and fluid temperature during pumping were measured at well ER-12-4 at the Nevada Test Site in Nye County, Nevada. This well was constructed to characterize the carbonate aquifer. The well is cased from land surface to the total depth at 1,132 m (3,713 ft bgs) below ground surface (bgs). The screened section of the well consists of alternating sections of slotted well screen and blank casing from 948 to 1,132 m bgs (3,111 to 3,713 ft bgs). Borehole flow velocity (LT-1) with depth was measured with an impeller flowmeter from the top of the screened section to the maximum accessible depth while the well was pumped and under ambient conditions. A complicating factor to data interpretation is that the well was not filter packed and there is upward and downward vertical flow in the open annulus under ambient and pumping conditions. The open annulus in the well casing likely causes the calculated borehole flow rates being highly nonrepresentative of inflow from the formation. Hydraulic conductivities calculated under these conditions would require unsupportable assumptions and would be subject to very large uncertainties. Borehole hydraulic conductivities are not presented under these conditions.
Maximum likelihood reconstruction for the Daya Bay Experiment
Xia Dongmei
2014-03-07T23:59:59.000Z
The Daya Bay Reactor Neutrino experiment is designed to precisely determine the neutrino mixing angle theta13. In this paper, we report a maximum likelihood (ML) method to reconstruct the vertex and energy of events in the anti-neutrino detector, based on a simplified optical model that describes light propagation. We calibrate the key paramters of the optical model with Co60 source, by comparing the predicted charges of the PMTs with the observed charges. With the optimized parameters, the resolution of the vertex reconstruction is about 25cm for Co60 gamma.
Better Nonlinear Models from Noisy Data: Attractors with Maximum Likelihood
Patrick E. McSharry; Leonard A. Smith
1999-11-30T23:59:59.000Z
A new approach to nonlinear modelling is presented which, by incorporating the global behaviour of the model, lifts shortcomings of both least squares and total least squares parameter estimates. Although ubiquitous in practice, a least squares approach is fundamentally flawed in that it assumes independent, normally distributed (IND) forecast errors: nonlinear models will not yield IND errors even if the noise is IND. A new cost function is obtained via the maximum likelihood principle; superior results are illustrated both for small data sets and infinitely long data streams.
Application of Maximum Entropy Method to Dynamical Fermions
Jonathan Clowser; Costas Strouthos
2001-10-16T23:59:59.000Z
The Maximum Entropy Method is applied to dynamical fermion simulations of the (2+1)-dimensional Nambu-Jona-Lasinio model. This model is particularly interesting because at T=0 it has a broken phase with a rich spectrum of mesonic bound states and a symmetric phase where there are resonances, and hence the simple pole assumption of traditional fitting procedures breaks down. We present results extracted from simulations on large lattices for the spectral functions of the elementary fermion, the pion, the sigma, the massive pseudoscalar meson and the symmetric phase resonances.
Reducing Degeneracy in Maximum Entropy Models of Networks
Horvát, Szabolcs; Toroczkai, Zoltán
2014-01-01T23:59:59.000Z
Based on Jaynes's maximum entropy principle, exponential random graphs provide a family of principled models that allow the prediction of network properties as constrained by empirical data. However, their use is often hindered by the degeneracy problem characterized by spontaneous symmetry-breaking, where predictions simply fail. Here we show that degeneracy appears when the corresponding density of states function is not log-concave. We propose a solution to the degeneracy problem for a large class of models by exploiting the nonlinear relationships between the constrained measures to convexify the domain of the density of states. We demonstrate the effectiveness of the method on examples, including on Zachary's karate club network data.
Excited nucleon spectrum from lattice QCD with maximum entropy method
K. Sasaki; S. Sasaki; T. Hatsuda; M. Asakawa
2003-09-29T23:59:59.000Z
We study excited states of the nucleon in quenched lattice QCD with the spectral analysis using the maximum entropy method. Our simulations are performed on three lattice sizes $16^3\\times 32$, $24^3\\times 32$ and $32^3\\times 32$, at $\\beta=6.0$ to address the finite volume issue. We find a significant finite volume effect on the mass of the Roper resonance for light quark masses. After removing this systematic error, its mass becomes considerably reduced toward the direction to solve the level order puzzle between the Roper resonance $N'(1440)$ and the negative-parity nucleon $N^*(1535)$.
Ionization and maximum energy of nuclei in shock acceleration theory
Morlino, Giovanni
2011-01-01T23:59:59.000Z
We study the acceleration of heavy nuclei at SNR shocks when the process of ionization is taken into account. Heavy atoms ($Z_N >$ few) in the interstellar medium which start the diffusive shock acceleration (DSA) are never fully ionized at the moment of injection. The ionization occurs during the acceleration process, when atoms already move relativistically. For typical environment around SNRs the photo-ionization due to the background galactic radiation dominates over Coulomb collisions. The main consequence of ionization is the reduction of the maximum energy which ions can achieve with respect to the standard result of the DSA. In fact the photo-ionization has a timescale comparable to the beginning of the Sedov-Taylor phase, hence the maximum energy is no more proportional to the nuclear charge, as predicted by standard DSA, but rather to the effective ions' charge during the acceleration process, which is smaller than the total nuclear charge $Z_N$. This result can have a direct consequence in the pred...
Maximum surface level and temperature histories for Hanford waste tanks
Flanagan, B.D.; Ha, N.D.; Huisingh, J.S.
1994-09-02T23:59:59.000Z
Radioactive defense waste resulting from the chemical processing of spent nuclear fuel has been accumulating at the Hanford Site since 1944. This waste is stored in underground waste-storage tanks. The Hanford Site Tank Farm Facilities Interim Safety Basis (ISB) provides a ready reference to the safety envelope for applicable tank farm facilities and installations. During preparation of the ISB, tank structural integrity concerns were identified as a key element in defining the safety envelope. These concerns, along with several deficiencies in the technical bases associated with the structural integrity issues and the corresponding operational limits/controls specified for conduct of normal tank farm operations are documented in the ISB. Consequently, a plan was initiated to upgrade the safety envelope technical bases by conducting Accelerated Safety Analyses-Phase 1 (ASA-Phase 1) sensitivity studies and additional structural evaluations. The purpose of this report is to facilitate the ASA-Phase 1 studies and future analyses of the single-shell tanks (SSTs) and double-shell tanks (DSTs) by compiling a quantitative summary of some of the past operating conditions the tanks have experienced during their existence. This report documents the available summaries of recorded maximum surface levels and maximum waste temperatures and references other sources for more specific data.
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
of the FY Mid-Year Change 10012013 - 03312014 04012014 - 09302014 Power Rates Annual Revenue Requirement Rate Schedule Power Revenue Requirement 73,441,557...
Reduction in maximum time uncertainty of paired time signals
Theodosiou, G.E.; Dawson, J.W.
1981-02-11T23:59:59.000Z
Reduction in the maximum time uncertainty (t/sub max/ - t/sub min/) of a series of paired time signals t/sub 1/ and t/sub 2/ varying between two input terminals and representative of a series of single events where t/sub 1/ less than or equal to t/sub 2/ and t/sub 1/ + t/sub 2/ equals a constant, is carried out with a circuit utilizing a combination of OR and AND gates as signal selecting means and one or more time delays to increase the minimum value (t/sub min/) of the first signal t/sub 1/ closer to t/sub max/ and thereby reduce the difference. The circuit may utilize a plurality of stages to reduce the uncertainty by factors of 20 to 800.
Probable maximum flood control; Yucca Mountain Site Characterization Project
DeGabriele, C.E.; Wu, C.L. [Bechtel National, Inc., San Francisco, CA (United States)
1991-11-01T23:59:59.000Z
This study proposes preliminary design concepts to protect the waste-handling facilities and all shaft and ramp entries to the underground from the probable maximum flood (PMF) in the current design configuration for the proposed Nevada Nuclear Waste Storage Investigation (NNWSI) repository protection provisions were furnished by the United States Bureau of Reclamation (USSR) or developed from USSR data. Proposed flood protection provisions include site grading, drainage channels, and diversion dikes. Figures are provided to show these proposed flood protection provisions at each area investigated. These areas are the central surface facilities (including the waste-handling building and waste treatment building), tuff ramp portal, waste ramp portal, men-and-materials shaft, emplacement exhaust shaft, and exploratory shafts facility.
Fracture Toughness and Maximum Stress in a Disordered Lattice System
Chiyori Urabe; Shinji Takesue
2008-12-29T23:59:59.000Z
Fracture in a disordered lattice system is studied. In our system, particles are initially arranged on the triangular lattice and each nearest-neighbor pair is connected with a randomly chosen soft or hard Hookean spring. Every spring has the common threshold of stress at which it is cut. We make an initial crack and expand the system perpendicularly to the crack. We find that the maximum stress in the stress-strain curve is larger than those in the systems with soft or hard springs only (uniform systems). Energy required to advance fracture is also larger in some disordered systems, which indicates that the fracture toughness improves. The increase of the energy is caused by the following two factors. One is that the soft spring is able to hold larger energy than the hard one. The other is that the number of cut springs increases as the fracture surface becomes tortuous in disordered systems.
Maximum Margin Clustering for State Decomposition of Metastable Systems
Wu, Hao
2015-01-01T23:59:59.000Z
When studying a metastable dynamical system, a prime concern is how to decompose the phase space into a set of metastable states. Unfortunately, the metastable state decomposition based on simulation or experimental data is still a challenge. The most popular and simplest approach is geometric clustering which is developed based on the classical clustering technique. However, the prerequisites of this approach are: (1) data are obtained from simulations or experiments which are in global equilibrium and (2) the coordinate system is appropriately selected. Recently, the kinetic clustering approach based on phase space discretization and transition probability estimation has drawn much attention due to its applicability to more general cases, but the choice of discretization policy is a difficult task. In this paper, a new decomposition method designated as maximum margin metastable clustering is proposed, which converts the problem of metastable state decomposition to a semi-supervised learning problem so that...
Improved Maximum Entropy Analysis with an Extended Search Space
Alexander Rothkopf
2013-01-07T23:59:59.000Z
The standard implementation of the Maximum Entropy Method (MEM) follows Bryan and deploys a Singular Value Decomposition (SVD) to limit the dimensionality of the underlying solution space apriori. Here we present arguments based on the shape of the SVD basis functions and numerical evidence from a mock data analysis, which show that the correct Bayesian solution is not in general recovered with this approach. As a remedy we propose to extend the search basis systematically, which will eventually recover the full solution space and the correct solution. In order to adequately approach problems where an exponentially damped kernel is used, we provide an open-source implementation, using the C/C++ language that utilizes high precision arithmetic adjustable at run-time. The LBFGS algorithm is included in the code in order to attack problems without the need to resort to a particular search space restriction.
Quantum maximum entropy principle for a system of identical particles
Trovato, M. [Dipartimento di Matematica, Universita di Catania, Viale A. Doria, 95125 Catania (Italy); Reggiani, L. [Dipartimento di Ingegneria dell' Innovazione and CNISM, Universita del Salento, Via Arnesano s/n, 73100 Lecce (Italy)
2010-02-15T23:59:59.000Z
By introducing a functional of the reduced density matrix, we generalize the definition of a quantum entropy which incorporates the indistinguishability principle of a system of identical particles. With the present definition, the principle of quantum maximum entropy permits us to solve the closure problem for a quantum hydrodynamic set of balance equations corresponding to an arbitrary number of moments in the framework of extended thermodynamics. The determination of the reduced Wigner function for equilibrium and nonequilibrium conditions is found to become possible only by assuming that the Lagrange multipliers can be expanded in powers of (Planck constant/2pi){sup 2}. Quantum contributions are expressed in powers of (Planck constant/2pi){sup 2} while classical results are recovered in the limit (Planck constant/2pi)->0.
Method and apparatus for controlling fluid flow
Miller, J.R.
1980-06-27T23:59:59.000Z
A method and apparatus for precisely controlling the rate (and hence amount) of fluid flow are given. The controlled flow rate is finely adjustable, can be extremely small (on the order of microliter-atmospheres per second), can be adjusted to zero (flow stopped), and is stable to better than 1% with time. The dead volume of the valve can be made arbitrarily small, in fact essentially zero. The valve employs no wearing mechanical parts (including springs, stems, or seals). The valve is finely adjustable, has a flow rate dynamic range of many decades, can be made compatible with any fluid, and is suitable for incorporation into an open or closed loop servo-control system.
Electroosmotic flow pumps with polymer frits Shulin Zenga,*
Santiago, Juan G.
Electroosmotic flow pumps with polymer frits Shulin Zenga,* , Chuan-Hua Chena , Juan G. Santiagoa 11 November 2001 Abstract Electroosmotic flow (EOF) pumps with flow rates on the order of 1 ml/min have been designed and fabricated. These pumps use EOF to propel liquid solutions in a compact system
The effects of flow rate on in vivo fluorescence measurements
Sweet, Stephen Thomas
1988-01-01T23:59:59.000Z
. 0 0 Te pe:lf 340 2 iZ 15 io I 4 Ti e (GMT) 2( 0 3 6 9 I 15 Io I 4 T [Gl I I I b. p(M 4. 0 3. 0 51 2. 5 'I 0 1. 5 0. 1 I. o 0$ 0. 0 21 4 3 6 9 12 15 Ti e (Ghrrl 10 21 24 0, 0 zr 0 3 6 9 12 )S 10 I Ti e (GI(IT) 150 100 fc ep... the ring ((36. 1 ppt) was lower than surrounding waters of the Gulf of Mexico (36. 4 to 36. 5 ppt). Lower surface salinities within the cyclonic eddy are consistent with previous work in the western Gulf of Mexico ( Elliott, 1979; Sweet and Guinasso...
Control Strategies for Centrifugal Pumps with Variable Flow Rate
Broader source: Energy.gov (indexed) [DOE]
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Property:FirstWellFlowRate | Open Energy Information
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A survey of air flow models for multizone structures
Feustel, H.E.; Dieris, J.
1991-03-01T23:59:59.000Z
Air flow models are used to simulate the rates of incoming and outgoing air flows for a building with known leakage under given weather and shielding conditions. Additional information about the flow paths and air-mass flows inside the building can only by using multizone air flow models. In order to obtain more information on multizone air flow models, a literature review was performed in 1984. A second literature review and a questionnaire survey performed in 1989, revealed the existence of 50 multizone air flow models, all developed since 1966, two of which are still under development. All these programs use similar flow equations for crack flow but differ in the versatility to describe the full range of flow phenomena and the algorithm provided for solving the set of nonlinear equations. This literature review was found that newer models are able to describe and simulate the ventilation systems and interrelation of mechanical and natural ventilation. 27 refs., 2 figs., 1 tab.
Bernstein, Hans C.; Konopka, Allan; Melnicki, Matthew R.; Hill, Eric A.; Kucek, Leo A.; Zhang, Shuyi; Shen, Gaozhong; Bryant, Donald A.; Beliaev, Alex S.
2014-08-30T23:59:59.000Z
Synechococcus sp. PCC 7002 was grown to steady state in optically thin turbidostat cultures under conditions for which light quantity and quality was systematically varied by modulating the output of narrow-band LEDs. Cells were provided photons absorbed primarily by chlorophyll (680 nm) or phycocyanin (630 nm) as the organism was subjected to four distinct mono- and dichromatic regimes. During cultivation with dichromatic light, growth rates displayed by Synechococcus sp. PCC 7002 were generally proportional to the total incident irradiance at values < 275 µmol photons m-2 s-1 and were not affected by the ratio of 630:680 nm wavelengths. Notably, under monochromatic light conditions, cultures exhibited similar growth rates only when they were irradiated with 630 nm light; cultures irradiated with only 680 nm light grew at rates that were 60 – 70% of those under other light quality regimes at equivalent irradiances. The functionality of photosystem II and associated processes such as maximum rate of photosynthetic electron transport, rate of cyclic electron flow, and rate of dark respiration generally increased as a function of growth rate. Nonetheless, some of the photophysiological parameters measured here displayed distinct patterns with respect to growth rate of cultures adapted to a single wavelength including phycobiliprotein content, which increased under severely light-limited growth conditions. Additionally, the ratio of photosystem II to photosystem I increased approximately 40% over the range of growth rates, although cells grown with 680 nm light only had the highest ratios. These results suggest the presence of effective mechanisms which allow acclimation of Synechococcus sp. PCC 7002 acclimation to different irradiance conditions.
Evolution of flow disturbances in cocurrent gas-liquid flows
McCready, M.J.
1992-10-01T23:59:59.000Z
Studies of interfacial waves in horizontal gas-liquid flows, close to neutral stability, suggest that the rate of evolution of the interface may be linked to nonlinear interactions between the fundamental mode and the subharmonic -- even if the subharmonic is linearly stable. The rate of evolution increases as the subharmonic becomes more unstable. A comparison of linear stability techniques used to predict the initial behavior of waves reveals similar predictions of growth rates and almost identical speeds between a two layer laminar Orr-Sommerfeld theory and an Orr-Sommerfeld theory when the effect of the (turbulent) gas flow enters as boundary conditions on the liquid layer. However, there is disagreement at small wavenumbers as to the point at which the growth curve crosses 0. This is a significant problem because longwave disturbances, in our case roll waves, form by growth of (initially) small amplitude waves that have frequencies which are 0.5 to 1 Hz, which is in the range where the two theories disagree about the sign of the growth rate. While nonlinear effects are probably involved in the formation of the peak (at least while its amplitude is small), the linear growth rate must play an important role when the amplitude is small.
Oldenburg, C.M.
2013-01-01T23:59:59.000Z
for estimates of the oil and gas flow rate from the Macondoteam and carried out oil and gas flow simulations using theoil-gas system. The flow of oil and gas was simulated using
Pressure Normalization of Production Rates Improves Forecasting Results
Lacayo Ortiz, Juan Manuel
2013-08-07T23:59:59.000Z
. However, these new decline curve analysis (DCA) methods are still based only on production rate data, relying on the assumption of stable flowing pressure. Since this stabilized state is not reached rapidly in most cases, the applicability of these methods...
Basal melt rates beneath Whillans Ice Stream, West Antarctica
Beem, Lucas H.; Jezek, Ken C.; Van Der Veen, C. J.
2010-08-05T23:59:59.000Z
Basal water lubricates and enables the fast flow of the West Antarctic ice streams which exist under low gravitational driving stress. Identification of sources and rates of basal meltwater production can provide insight into the dynamics of ice...
Yoder, Graydon L.
1980-01-01T23:59:59.000Z
Dispersed flow consists of small liquid droplets entrained in a flowing vapor. This flow regime can occur in cryogenic equipment, in steam generators, and during nuclear reactor loss of coolant accidents. A theoretical ...
Marcos, Ph.D. Massachusetts Institute of Technology
2011-01-01T23:59:59.000Z
Bacteria are ubiquitous and play a critical role in many contexts. Their environment is nearly always dynamic due to the prevalence of fluid flow: creeping flow in soil, highly sheared flow in bodily conduits, and turbulent ...
Savannah River Site radioiodine atmospheric releases and offsite maximum doses
Marter, W.L.
1990-11-01T23:59:59.000Z
Radioisotopes of iodine have been released to the atmosphere from the Savannah River Site since 1955. The releases, mostly from the 200-F and 200-H Chemical Separations areas, consist of the isotopes, I-129 and 1-131. Small amounts of 1-131 and 1-133 have also been released from reactor facilities and the Savannah River Laboratory. This reference memorandum was issued to summarize our current knowledge of releases of radioiodines and resultant maximum offsite doses. This memorandum supplements the reference memorandum by providing more detailed supporting technical information. Doses reported in this memorandum from consumption of the milk containing the highest I-131 concentration following the 1961 1-131 release incident are about 1% higher than reported in the reference memorandum. This is the result of using unrounded 1-131 concentrations of I-131 in milk in this memo. It is emphasized here that this technical report does not constitute a dose reconstruction in the same sense as the dose reconstruction effort currently underway at Hanford. This report uses existing published data for radioiodine releases and existing transport and dosimetry models.
Maximum Entropy Analysis of the Spectral Functions in Lattice QCD
M. Asakawa; T. Hatsuda; Y. Nakahara
2001-02-26T23:59:59.000Z
First principle calculation of the QCD spectral functions (SPFs) based on the lattice QCD simulations is reviewed. Special emphasis is placed on the Bayesian inference theory and the Maximum Entropy Method (MEM), which is a useful tool to extract SPFs from the imaginary-time correlation functions numerically obtained by the Monte Carlo method. Three important aspects of MEM are (i) it does not require a priori assumptions or parametrizations of SPFs, (ii) for given data, a unique solution is obtained if it exists, and (iii) the statistical significance of the solution can be quantitatively analyzed. The ability of MEM is explicitly demonstrated by using mock data as well as lattice QCD data. When applied to lattice data, MEM correctly reproduces the low-energy resonances and shows the existence of high-energy continuum in hadronic correlation functions. This opens up various possibilities for studying hadronic properties in QCD beyond the conventional way of analyzing the lattice data. Future problems to be studied by MEM in lattice QCD are also summarized.
Improved Maximum Entropy Method with an Extended Search Space
Alexander Rothkopf
2012-08-25T23:59:59.000Z
We report on an improvement to the implementation of the Maximum Entropy Method (MEM). It amounts to departing from the search space obtained through a singular value decomposition (SVD) of the Kernel. Based on the shape of the SVD basis functions we argue that the MEM spectrum for given $N_\\tau$ data-points $D(\\tau)$ and prior information $m(\\omega)$ does not in general lie in this $N_\\tau$ dimensional singular subspace. Systematically extending the search basis will eventually recover the full search space and the correct extremum. We illustrate this idea through a mock data analysis inspired by actual lattice spectra, to show where our improvement becomes essential for the success of the MEM. To remedy the shortcomings of Bryan's SVD prescription we propose to use the real Fourier basis, which consists of trigonometric functions. Not only does our approach lead to more stable numerical behavior, as the SVD is not required for the determination of the basis functions, but also the resolution of the MEM becomes independent from the position of the reconstructed peaks.
Maximum entropy detection of planets around active stars
Petit, P; Hébrard, E; Morin, J; Folsom, C P; Böhm, T; Boisse, I; Borgniet, S; Bouvier, J; Delfosse, X; Hussain, G; Jeffers, S V; Marsden, S C; Barnes, J R
2015-01-01T23:59:59.000Z
(shortened for arXiv) We aim to progress towards more efficient exoplanet detection around active stars by optimizing the use of Doppler Imaging in radial velocity measurements. We propose a simple method to simultaneously extract a brightness map and a set of orbital parameters through a tomographic inversion technique derived from classical Doppler mapping. Based on the maximum entropy principle, the underlying idea is to determine the set of orbital parameters that minimizes the information content of the resulting Doppler map. We carry out a set of numerical simulations to perform a preliminary assessment of the robustness of our method, using an actual Doppler map of the very active star HR 1099 to produce a realistic synthetic data set for various sets of orbital parameters of a single planet in a circular orbit. Using a simulated time-series of 50 line profiles affected by a peak-to-peak activity jitter of 2.5 km/s, we are able in most cases to recover the radial velocity amplitude, orbital phase and o...
Flow enhancement in nanotubes of different materials and lengths
Ritos, Konstantinos, E-mail: konstantinos.ritos@strath.ac.uk [James Weir Fluids Lab, Department of Mechanical and Aerospace Engineering, University of Strathclyde, Glasgow G1 1XJ (United Kingdom)] [James Weir Fluids Lab, Department of Mechanical and Aerospace Engineering, University of Strathclyde, Glasgow G1 1XJ (United Kingdom); Mattia, Davide [Department of Chemical Engineering, University of Bath, Bath BA2 7AY (United Kingdom)] [Department of Chemical Engineering, University of Bath, Bath BA2 7AY (United Kingdom); Calabrň, Francesco [DIEI, Universitŕ di Cassino e del Lazio Meridionale, 03043 Cassino (Italy)] [DIEI, Universitŕ di Cassino e del Lazio Meridionale, 03043 Cassino (Italy); Reese, Jason M. [School of Engineering, University of Edinburgh, Edinburgh EH9 3JL (United Kingdom)] [School of Engineering, University of Edinburgh, Edinburgh EH9 3JL (United Kingdom)
2014-01-07T23:59:59.000Z
The high water flow rates observed in carbon nanotubes (CNTs) have previously been attributed to the unfavorable energetic interaction between the liquid and the graphitic walls of the CNTs. This paper reports molecular dynamics simulations of water flow in carbon, boron nitride, and silicon carbide nanotubes that show the effect of the solid-liquid interactions on the fluid flow. Alongside an analytical model, these results show that the flow enhancement depends on the tube's geometric characteristics and the solid-liquid interactions.
Predicting the pressure driven flow of gases through micro-capillaries and micro-orifices
Anderson, B.L.; Carlson, R.W.; Fischer, L.E. [Lawrence Livermore National Lab., CA (United States)
1994-11-01T23:59:59.000Z
A large body of experimentally measured gas flow rates were obtained from the literature and then compared to the predictions obtained with constitutive flow equations. This was done to determine whether the equations apply to the predictions of gas flow rates from leaking containment vessels used to transport radioactive materials. The experiments consisted of measuring the volumetric pressure-driven flow of gases through micro-capillaries and micro-orifices. The experimental results were compared to the predictions obtained with the equations given in ANSI N14.5 the American National Standard for Radioactive Materials-Leakage Tests on Package for Shipment. The equations were applied to both (1) the data set according to the recommendations given in ANSI N14.5 and (2) globally to the complete data set. It was found that: The continuum and molecular flow equation provided good agreement between the experimental and calculated flow rates for flow rates less than about 1 atm{center_dot}cm{sup 3}/s. The choked flow equation resulted in over-prediction of the flow rates for flow rates less than about 1 atm-cm{sup 3}/s. For flow rates higher than 1 atm{center_dot}cm{sup 3}/s, the molecular and continuum flow equation over-predicted the measured flow rates and the predictions obtained with the choked flow equation agreed well with the experimental values. Since the flow rates of interest for packages used to transport radioactive materials are almost always less than 1 atm{center_dot}cm{sup 3}/s, it is suggested that the continuum and molecular flow equation be used for gas flow rate predictions related to these applications.
Interfacial stress balances in structured continua and free surface flows in ferrofluids
Chaves, Arlex [School of Chemical Engineering, Universidad Industrial de Santander, Calle 9 Cra. 27, Edificio 24, Bucaramanga, Santander (Colombia)] [School of Chemical Engineering, Universidad Industrial de Santander, Calle 9 Cra. 27, Edificio 24, Bucaramanga, Santander (Colombia); Rinaldi, Carlos, E-mail: carlos.rinaldi@bme.ufl.edu [J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, Florida 32611, USA and Department of Chemical Engineering, University of Florida, Gainesville, Florida 32611 (United States)] [J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, Florida 32611, USA and Department of Chemical Engineering, University of Florida, Gainesville, Florida 32611 (United States)
2014-04-15T23:59:59.000Z
Interfacial linear and internal angular momentum balances are obtained for a structured continuum and for the special case of a ferrofluid, a suspension of magnetic nanoparticles in a Newtonian fluid. The interfacial balance equations account for the effects of surface tension and surface tension gradient, magnetic surface excess forces, antisymmetric stresses, and couple stresses in driving interfacial flows in ferrofluids. Application of the interfacial balance equations is illustrated by obtaining analytical expressions for the translational and spin velocity profiles in a thin film of ferrofluid on an infinite flat plate when a rotating magnetic field is applied with axis of rotation parallel to the ferrofluid/air interface. The cases of zero and non-zero spin viscosity are considered for small applied magnetic field amplitude. Expressions for the maximum translational velocity, slope of the translational velocity profile at the ferrofluid/air interface, and volumetric flow rate are obtained and their use to test the relevance of spin viscosity and couple stresses in the flow situation under consideration is discussed.
Flow Distances on Open Flow Networks
Guo, Liangzhu; Shi, Peiteng; Wang, Jun; Huang, Xiaohan; Zhang, Jiang
2015-01-01T23:59:59.000Z
Open flow network is a weighted directed graph with a source and a sink, depicting flux distributions on networks in the steady state of an open flow system. Energetic food webs, economic input-output networks, and international trade networks, are open flow network models of energy flows between species, money or value flows between industrial sectors, and goods flows between countries, respectively. Flow distances (first-passage or total) between any given two nodes $i$ and $j$ are defined as the average number of transition steps of a random walker along the network from $i$ to $j$ under some conditions. They apparently deviate from the conventional random walk distance on a closed directed graph because they consider the openness of the flow network. Flow distances are explicitly expressed by underlying Markov matrix of a flow system in this paper. With this novel theoretical conception, we can visualize open flow networks, calculating centrality of each node, and clustering nodes into groups. We apply fl...
Bacteria Total Maximum Daily Load Task Force Final Report
Jones, C. Allan; Wagner, Kevin; Di Giovanni, George; Hauck, Larry; Mott, Joanna; Rifai, Hanadi; Srinivasan, Raghavan; Ward, George; Wythe, Kathy
for TMDL and Watershed Studies at Virginia Tech (http://www.tmdl.bse.vt.edu/outreach/C85/). Bacteria Indicator Tool (BIT) Another MB tool is the BIT provided by EPA (http://www.epa.gov/waterscience/ftp/basins/system/BASINS3/bit.htm). The BIT is a... spreadsheet that can be used to estimate the monthly accumulation rate of fecal coliform bacteria on four land uses (cropland, forested, built-up and pastureland). The tool also estimates the direct input of fecal coliform bacteria to streams from grazing...
A constitutive law for dense granular flows
Pierre Jop; Yoël Forterre; Olivier Pouliquen
2006-12-05T23:59:59.000Z
A continuum description of granular flows would be of considerable help in predicting natural geophysical hazards or in designing industrial processes. However, the constitutive equations for dry granular flows, which govern how the material moves under shear, are still a matter of debate. One difficulty is that grains can behave like a solid (in a sand pile), a liquid (when poured from a silo) or a gas (when strongly agitated). For the two extreme regimes, constitutive equations have been proposed based on kinetic theory for collisional rapid flows, and soil mechanics for slow plastic flows. However, the intermediate dense regime, where the granular material flows like a liquid, still lacks a unified view and has motivated many studies over the past decade. The main characteristics of granular liquids are: a yield criterion (a critical shear stress below which flow is not possible) and a complex dependence on shear rate when flowing. In this sense, granular matter shares similarities with classical visco-plastic fluids such as Bingham fluids. Here we propose a new constitutive relation for dense granular flows, inspired by this analogy and recent numerical and experimental work. We then test our three-dimensional (3D) model through experiments on granular flows on a pile between rough sidewalls, in which a complex 3D flow pattern develops. We show that, without any fitting parameter, the model gives quantitative predictions for the flow shape and velocity profiles. Our results support the idea that a simple visco-plastic approach can quantitatively capture granular flow properties, and could serve as a basic tool for modelling more complex flows in geophysical or industrial applications.
Shamir, Ron
of length r if there are i1 j1 r Center, 650 Harry Road, San Jose, CA 95120 ,USA and Sackler Faculty of Exact Sciences, Tel Aviv
Study of Different Implementation Approaches for a Maximum Power Point Florent Boico Brad Lehman
Lehman, Brad
will study the design of a maximum power point tracker for low power solar panels (10-50W). In the process weStudy of Different Implementation Approaches for a Maximum Power Point Tracker 1 Florent Boico Brad Lehman Northeastern University Abstract: This paper studies the design of a Maximum Power Point Tracker
A Maximum Entropy Algorithm for Rhythmic Analysis of Genome-Wide Expression Patterns
Richardson, David
A Maximum Entropy Algorithm for Rhythmic Analysis of Genome-Wide Expression Patterns Christopher James Langmead C. Robertson McClung Bruce Randall Donald ,,,Â§,Â¶ Abstract We introduce a maximum entropy-based spectral analysis, maximum entropy spectral reconstruction is well suited to signals of the type generated
1 A MAXIMUM ENTROPY METHOD FOR SUBNETWORK ORIGIN-DESTINATION 2 TRIP MATRIX ESTIMATION
Kockelman, Kara M.
1 A MAXIMUM ENTROPY METHOD FOR SUBNETWORK ORIGIN-DESTINATION 2 TRIP MATRIX ESTIMATION 3 4 Chi Xie 5, maximum entropy, linearization 36 algorithm, column generation 37 #12;C. Xie, K.M. Kockelman and S is the trip matrix of the simplified network. This paper discusses a5 maximum entropy method
Maximum entropy and Bayesian approaches to the ratio problem Edward Z. Shen*
Perloff, Jeffrey M.
Maximum entropy and Bayesian approaches to the ratio problem Edward Z. Shen* Jeffrey M. Perloff** January 2001 Abstract Maximum entropy and Bayesian approaches provide superior estimates of a ratio extra information in the supports for the underlying parameters for generalized maximum entropy (GME
Perloff, Jeffrey M.
Comparison of Maximum Entropy and Higher-Order Entropy Estimators Amos Golan* and Jeffrey M. Perloff** ABSTRACT We show that the generalized maximum entropy (GME) is the only estimation method- classes of estimators may outperform the GME estimation rule. Keywords: generalized entropy, maximum
GREENE,G.A.; FINFROCK,C.C.
2001-10-01T23:59:59.000Z
Experiments were conducted to measure the rates of oxidation and vaporization of pure tungsten rods in flowing air, steam and air-steam mixtures in laminar flow. Also measured were the downstream transport of tungsten-oxide condensation aerosols and their region of deposition, including plateout in the superheated flow tube, rainout in the condenser and ambient discharge which was collected on an array of sub-micron aerosol filters. The nominal conditions of the tests, with the exception of the first two tests, were tungsten temperatures of 1000 C, gas mixture temperatures of 200 C and wall temperatures of 150 C to 200 C. It was observed that the tungsten oxidation rates were greatest in all air and least in all steam, generally decreasing non-linearly with increasing steam mole fraction. The tungsten oxidation rates in all air were more than five times greater than the tungsten oxidation rates in all steam. The tungsten vaporization rate was zero in all air and increased with increasing steam mole fraction. The vaporization rate became maximum at a steam mole fraction of 0.85 and decreased thereafter as the steam mole fraction was increased to unity. The tungsten-oxide was transported downstream as condensation aerosols, initially flowing upwards from the tungsten rod through an 18-inch long, one-inch diameter quartz tube, around a 3.5-inch radius, 90{sup o} bend and laterally through a 24-inch horizontal run. The entire length of the quartz glass flow path was heated by electrical resistance clamshell heaters whose temperatures were individually controlled and measured. The tungsten-oxide plateout in the quartz tube was collected, nearly all of which was deposited at the end of the heated zone near the entrance to the condenser which was cold. The tungsten-oxide which rained out in the condenser as the steam condensed was collected with the condensate and weighed after being dried. The aerosol smoke which escaped the condenser was collected on the sub-micron filter assemblies. There was no aerosol generation for the case of all air, so the plateout, condensate and smoke were all zero. For the case of all steam, there was very little plateout in the superheated regions (several percent) and the rest of the aerosol was collected in the condensate from the condenser. There was no smoke discharge into the filters. For the experiments with intermediate air-steam fractions, there was some aerosol plateout, considerable aerosol in the condensate and aerosol smoke discharged from the condenser with the escaping air.
Theoretical uncertainty of orifice flow measurement
Husain, Z.D. [Daniel Flow Products, Inc., Houston, TX (United States)
1995-12-01T23:59:59.000Z
Orifice meters are the most common meters used for fluid flow measurement, especially for measuring hydrocarbons. Meters are rugged, mechanically simple, and well suited for field use under extreme weather conditions. Because of their long history of use and dominance in the fluid flow measurement, their designs, installation requirements, and equations for flow rate calculation have been standardized by different organizations in the United States and internationally. These standards provide the guideline for the users to achieve accurate flow measurement. and minimize measurement uncertainty. This paper discusses different factors that contribute to the measurement inaccuracy and provide an awareness to minimize or eliminate these errors. Many factors which influence the overall measurement uncertainty are associated with the orifice meter application. Major contributors to measurement uncertainty include the predictability of flow profile, fluid properties at flowing condition, precision of empirical equation for discharge coefficient, manufacturing tolerances in meter components, and the uncertainty associated with secondary devices monitoring the static line pressure, differential pressure across the orifice plate, flowing temperature, etc. Major factors contributing to the measurement uncertainty for a thin, concentric, square-edged orifice flowmeter are as follows: (a) Tolerances in prediction of coefficient of discharge, (b) Predictability in defining the physical properties of the flowing fluid, (c) Fluid flow condition, (d) Construction tolerances in meter components, (e) Uncertainty of secondary devices/instrumentation, and (f) Data reduction and computation. Different factors under each of the above areas are discussed with precautionary measures and installation procedures to minimize or eliminate measurement uncertainty.
Security Constrained Optimal Power Flow 1.0 Introduction and notation
McCalley, James D.
1 Security Constrained Optimal Power Flow 1.0 Introduction and notation Figure 1 below compares the optimal power flow (OPF) with the security-constrained optimal power flow (SCOPF). Fig. 1 Some comments normal flow moves from just 100% of continuous rating. SCOPF differs from an OPF solution
TRACKING ELEPHANT FLOWS IN INTERNET BACKBONE TRAFFIC WITH AN FPGA-BASED CACHE
Haddadi, Hamed
TRACKING ELEPHANT FLOWS IN INTERNET BACKBONE TRAFFIC WITH AN FPGA-BASED CACHE Martin Zadnik an FPGA-friendly approach to track- ing elephant flows in network traffic. Our approach, Single Step elephant flows: con- servatively promoting potential elephants and evicting low- rate flows in LRU manner
Heart Rate Artifact Suppression.
Dickson, Christopher
2012-01-01T23:59:59.000Z
??Motion artifact strongly corrupts heart rate measurements in current pulse oximetry systems. In many, almost any motion will greatly diminish the system’s ability to extract… (more)
Residential Solar Valuation Rates
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
Residential Solar Valuation Rates Karl R. Rbago Rbago Energy LLC 1 The Ideal Residential Solar Tariff Fair to the utility and non-solar customers Fair compensation to...
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charges or credits associated with the creation, termination, or modification to any tariff, contract, or rate schedule accepted or approved by the Federal Energy Regulatory...
Broader source: Energy.gov [DOE]
Notepad text file provides the LCC guidance rates in a numbered format for the various regions throughout the U.S.
Initial advance of long lava flows in open channels Daisuke Takagi, Herbert E. Huppert
Huppert, Herbert
cooling-limited when it reaches a maximum length attainable for a given supply of lava from the vent to cooling become important. Theoretical results are applied to the study of long lava flows that descended the dynamic properties of the bulk flow. In contrast, effects due to cooling played a major role throughout
Investigating the stability of viscoelastic stagnation flows in T-shaped microchannels
Soulage, Johannes
We investigate the stability of steady planar stagnation flows of a dilute polyethylene oxide (PEO) solution using T-shaped microchannels. The precise flow rate control and well-defined geometries achievable with microfluidic ...
Energy Efficient Process Heating: Managing Air Flow Kevin Carpenter and Kelly Kissock
Kissock, Kelly
temperature and decreased combustion gas mass flow rate. The method for calculating savings from preheating flow include minimizing combustion air, preheating combustion air, minimizing ventilation air from minimizing combustion air accounts for improvement in efficiency from increased combustion
Molecular dynamics simulations of oscillatory Couette flows with slip boundary conditions
Nikolai V. Priezjev
2012-08-27T23:59:59.000Z
The effect of interfacial slip on steady-state and time-periodic flows of monatomic liquids is investigated using non-equilibrium molecular dynamics simulations. The fluid phase is confined between atomically smooth rigid walls, and the fluid flows are induced by moving one of the walls. In steady shear flows, the slip length increases almost linearly with shear rate. We found that the velocity profiles in oscillatory flows are well described by the Stokes flow solution with the slip length that depends on the local shear rate. Interestingly, the rate dependence of the slip length obtained in steady shear flows is recovered when the slip length in oscillatory flows is plotted as a function of the local shear rate magnitude. For both types of flows, the friction coefficient at the liquid-solid interface correlates well with the structure of the first fluid layer near the solid wall.
Previous Power Rates (rates/current)
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Power Rates Announcements (pbl/rates)
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AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 -the Mid-Infrared at 278, 298, andEpidermal Growth Factor. |INCIDENCET3PACI-T3Rate
Bowyer, Ted W. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Kephart, Rosara F.; Eslinger, Paul W. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Friese, Judah I. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Miley, Harry S. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Saey, Paul R. [Vienna University of Technology, Atomic Institute of the Austrian Universities, Vienna (Austria)
2013-01-01T23:59:59.000Z
Fission gases such as 133Xe are used extensively for monitoring the world for signs of nuclear testing in systems such as the International Monitoring System (IMS). These gases are also produced by nuclear reactors and by fission production of 99Mo for medical use. Recently, medical isotope production facilities have been identified as the major contributor to the background of radioactive xenon isotopes (radioxenon) in the atmosphere (Saey, et al., 2009). These releases pose a potential future problem for monitoring nuclear explosions if not addressed. As a starting point, a maximum acceptable daily xenon emission rate was calculated, that is both scientifically defendable as not adversely affecting the IMS, but also consistent with what is possible to achieve in an operational environment. This study concludes that an emission of 5×109 Bq/day from a medical isotope production facility would be both an acceptable upper limit from the perspective of minimal impact to monitoring stations, but also appears to be an achievable limit for large isotope producers.
Device and method for measuring multi-phase fluid flow in a conduit using an elbow flow meter
Ortiz, Marcos G. (Idaho Falls, ID); Boucher, Timothy J. (Helena, MT)
1997-01-01T23:59:59.000Z
A system for measuring fluid flow in a conduit. The system utilizes pressure transducers disposed generally in line upstream and downstream of the flow of fluid in a bend in the conduit. Data from the pressure transducers is transmitted to a microprocessor or computer. The pressure differential measured by the pressure transducers is then used to calculate the fluid flow rate in the conduit. Control signals may then be generated by the microprocessor or computer to control flow, total fluid dispersed, (in, for example, an irrigation system), area of dispersal or other desired effect based on the fluid flow in the conduit.
Device and method for measuring multi-phase fluid flow in a conduit using an elbow flow meter
Ortiz, M.G.; Boucher, T.J.
1997-06-24T23:59:59.000Z
A system is described for measuring fluid flow in a conduit. The system utilizes pressure transducers disposed generally in line upstream and downstream of the flow of fluid in a bend in the conduit. Data from the pressure transducers is transmitted to a microprocessor or computer. The pressure differential measured by the pressure transducers is then used to calculate the fluid flow rate in the conduit. Control signals may then be generated by the microprocessor or computer to control flow, total fluid dispersed, (in, for example, an irrigation system), area of dispersal or other desired effect based on the fluid flow in the conduit. 2 figs.
Ultrasonic flow metering system
Gomm, Tyler J. (Meridian, ID); Kraft, Nancy C. (Idaho Falls, ID); Mauseth, Jason A. (Pocatello, ID); Phelps, Larry D. (Pocatello, ID); Taylor, Steven C. (Idaho Falls, ID)
2002-01-01T23:59:59.000Z
A system for determining the density, flow velocity, and mass flow of a fluid comprising at least one sing-around circuit that determines the velocity of a signal in the fluid and that is correlatable to a database for the fluid. A system for determining flow velocity uses two of the inventive circuits with directional transmitters and receivers, one of which is set at an angle to the direction of flow that is different from the others.
On Thermonuclear Reaction Rates
H. J. Haubold; A. M. Mathai
1996-12-02T23:59:59.000Z
Nuclear reactions govern major aspects of the chemical evolution od galaxies and stars. Analytic study of the reaction rates and reaction probability integrals is attempted here. Exact expressions for the reaction rates and reaction probability integrals for nuclear reactions in the case of nonresonant, modified nonresonant, screened nonresonant and resonant cases are given. These are expressed in terms of H-functions, G-functions and in computable series forms. Computational aspects are also discussed.
Modelling macroeconomic flows related to large ensembles
Schellekens, Michel P.
, including, say, oil prices, interest rates, etc; dynamics of shares markets are governed by information are illustrated by flows of a liquid between interconnected reservoirs, where the heights of different reservoirs is changing with time, and movement of the liquid between the reservoirs is governed by gravity, see Figure 1
Air Flow Distribution in the Sales Area of a Supermarket
Fang, X.; Song, C.; Zhao, J.; Wang, Z.
2006-01-01T23:59:59.000Z
Many kinds of goods are displayed in a supermarket, which have their own particularities. The consumer flow rate is great and the type of shelved goods varies significantly, thereby influencing the objects that generate heat, and the demands of air...
Contraction/expansion flow of dilute elastic solutions in microchannels
Scott, Timothy Peter, 1980-
2004-01-01T23:59:59.000Z
An experimental study is conducted on the nature of extensional flows of mobile dilute polymer solutions in microchannel. By observing such fluids on the microscale it is possible to generate large strain rates ([approximately] ...
Composition Pulse Time-Of-Flight Mass Flow Sensor
Mosier, Bruce P. (San Francisco, CA); Crocker, Robert W. (Fremont, CA); Harnett, Cindy K. (Livermore, CA) l
2004-01-13T23:59:59.000Z
A device for measuring fluid flow rates over a wide range of flow rates (<1 nL/min to >10 .mu.L/min) and at pressures at least as great as 10,000 psi. The invention is particularly adapted for use in microfluidic systems. The device operates by producing compositional variations in the fluid, or pulses, that are subsequently detected downstream from the point of creation to derive a flow rate. Each pulse, comprising a small fluid volume, whose composition is different from the mean composition of the fluid, can be created by electrochemical means, such as by electrolysis of a solvent, electrolysis of a dissolved species, or electrodialysis of a dissolved ionic species. Measurements of the conductivity of the fluid can be used to detect the arrival time of the pulses, from which the fluid flow rate can be determined
A MEMS BODY FLUID FLOW SENSOR Ellis Meng1
Meng, Ellis
for its stability, accuracy, and high temperature coefficient of resistivity (TCR). Additional packaging the device using compressed air. The flow rate is adjusted by a metering valve and calibrated using
THE STATE OF THE ART OF NUMERICAL MODELING OF THERMOHYDROLOGIC FLOW IN FRACTURED ROCK MASSES
Wang, J.S.Y.
2013-01-01T23:59:59.000Z
At normal rates of geothermal wells, turbulent flow is fullyeffects in two- phase geothermal well tests were studied (of salt precipitation around geothermal wells and of methane
A New Approach to Computing Max Flows using Electrical Flows
Rajamani, Sriram K.
A New Approach to Computing Max Flows using Electrical Flows Yin Tat Lee (MIT) Satish Rao (UC-Kelner-Madry-Spielman-Teng'11]: approximate flow in time Uses electrical flows. 7 #12;Electrical Flows 3 1 S t 8 #12;Electrical Flows Identify Graph with Resistor Network R(e)=1/w(e) 1/3 S t 1 9 #12;Electrical Flows Electrical flow
Bell, Geoffrey C. (Pleasant Hill, CA); Feustel, Helmut E. (Albany, CA); Dickerhoff, Darryl J. (Berkeley, CA)
2002-01-01T23:59:59.000Z
A fume hood is provided having an adequate level of safety while reducing the amount of air exhausted from the hood. A displacement flow fume hood works on the principal of a displacement flow which displaces the volume currently present in the hood using a push-pull system. The displacement flow includes a plurality of air supplies which provide fresh air, preferably having laminar flow, to the fume hood. The displacement flow fume hood also includes an air exhaust which pulls air from the work chamber in a minimally turbulent manner. As the displacement flow produces a substantially consistent and minimally turbulent flow in the hood, inconsistent flow patterns associated with contaminant escape from the hood are minimized. The displacement flow fume hood largely reduces the need to exhaust large amounts of air from the hood. It has been shown that exhaust air flow reductions of up to 70% are possible without a decrease in the hood's containment performance. The fume hood also includes a number of structural adaptations which facilitate consistent and minimally turbulent flow within a fume hood.
Binary fish passage models for uniform and nonuniform flows
Neary, Vincent S [ORNL
2011-01-01T23:59:59.000Z
Binary fish passage models are considered by many fisheries managers to be the best 21 available practice for culvert inventory assessments and for fishway and barrier design. 22 Misunderstandings between different binary passage modeling approaches often arise, 23 however, due to differences in terminology, application and presentation. In this paper 24 one-dimensional binary fish passage models are reviewed and refined to clarify their 25 origins and applications. For uniform flow, a simple exhaustion-threshold (ET) model 26 equation is derived that predicts the flow speed threshold in a fishway or velocity barrier 27 that causes exhaustion at a given maximum distance of ascent. Flow speeds at or above 28 the threshold predict failure to pass (exclusion). Flow speeds below the threshold predict 29 passage. The binary ET model is therefore intuitive and easily applied to predict passage 30 or exclusion. It is also shown to be consistent with the distance-maximizing model. The 31 ET model s limitation to uniform flow is addressed by deriving a passage model that 32 accounts for nonuniform flow conditions more commonly found in the field, including 33 backwater profiles and drawdown curves. Comparison of these models with 34 experimental observations of volitional passage for Gambusia affinis in uniform and 35 nonuniform flows indicates reasonable prediction of binary outcomes (passage or 36 exclusion) if the flow speed is not near the threshold flow velocity. More research is 37 needed on fish behavior, passage strategies under nonuniform flow regimes and 38 stochastic methods that account for individual differences in swimming performance at or 39 near the threshold flow speed. Future experiments should track and measure ground 40 speeds of ascending fish to test nonuniform flow passage strategies and to improve model 41 predictions. Stochastic models, such as Monte-Carlo techniques, that account for 42 different passage performance among individuals and allow prediction of the percentage 43 of fish passing would be particularly useful near flow speed thresholds where binary 44 passage models are clearly limited.
Quantitative tomographic measurements of opaque multiphase flows
GEORGE,DARIN L.; TORCZYNSKI,JOHN R.; SHOLLENBERGER,KIM ANN; O'HERN,TIMOTHY J.; CECCIO,STEVEN L.
2000-03-01T23:59:59.000Z
An electrical-impedance tomography (EIT) system has been developed for quantitative measurements of radial phase distribution profiles in two-phase and three-phase vertical column flows. The EIT system is described along with the computer algorithm used for reconstructing phase volume fraction profiles. EIT measurements were validated by comparison with a gamma-densitometry tomography (GDT) system. The EIT system was used to accurately measure average solid volume fractions up to 0.05 in solid-liquid flows, and radial gas volume fraction profiles in gas-liquid flows with gas volume fractions up to 0.15. In both flows, average phase volume fractions and radial volume fraction profiles from GDT and EIT were in good agreement. A minor modification to the formula used to relate conductivity data to phase volume fractions was found to improve agreement between the methods. GDT and EIT were then applied together to simultaneously measure the solid, liquid, and gas radial distributions within several vertical three-phase flows. For average solid volume fractions up to 0.30, the gas distribution for each gas flow rate was approximately independent of the amount of solids in the column. Measurements made with this EIT system demonstrate that EIT may be used successfully for noninvasive, quantitative measurements of dispersed multiphase flows.
LANGMUIR WAVE ACTIVITY: COMPARING THE ULYSSES SOLAR MINIMUM AND SOLAR MAXIMUM ORBITS
California at Berkeley, University of
). The top three panels correspond to the southern segment of the solar minimum orbit; repeated passesLANGMUIR WAVE ACTIVITY: COMPARING THE ULYSSES SOLAR MINIMUM AND SOLAR MAXIMUM ORBITS R. J at the electron plasma frequency) during the solar minimum and solar maximum orbits of Ulysses. At high latitudes
Comparison of VLF Wave Activity in the Solar Wind During Solar Maximum and Minimum
California at Berkeley, University of
second fast latitude scan (near the solar maximum) with the wave observations during the first fast Experiments (URAP) of Ulysses during its first orbit, which occurred when the solar activity was approachingComparison of VLF Wave Activity in the Solar Wind During Solar Maximum and Minimum: Ulysses
On the duration of the Paleocene-Eocene thermal maximum Ursula Rohl and Thomas Westerhold
Zachos, James
On the duration of the Paleocene-Eocene thermal maximum (PETM) Ursula RoÂ¨hl and Thomas Westerhold of California, Santa Cruz, California 95064, USA [1] The Paleocene-Eocene thermal maximum (PETM) is one of global warming and a massive perturbation of the global carbon cycle from injection of isotopically light
An Optimal Randomized Algorithm for Maximum Tukey Depth Timothy M. Chan
Chan, Timothy M.
An Optimal Randomized Algorithm for Maximum Tukey Depth Timothy M. Chan Abstract We present the first optimal algorithm to compute the maximum Tukey depth (also known as location or halfspace depth , the Tukey depth of a point q IRd is defined as: min{|P | : over all halfspaces containing q}. We
Beating the maximum cooling limit with graded thermoelectric materials Zhixi Bian and Ali Shakouria
.1063/1.2396895 The maximum cooling temperature is one of the perfor- mance parameters for a thermoelectric module. ExcludingBeating the maximum cooling limit with graded thermoelectric materials Zhixi Bian and Ali Shakouria cooling of a single element thermoelectric material cannot be improved by changing its geometry.3
Maximum Power Transfer Tracking in a Solar USB Charger for Smartphones
Pedram, Massoud
chargers do not perform the maximum power point tracking [2], [3] of the solar panel. We excludeMaximum Power Transfer Tracking in a Solar USB Charger for Smartphones Abstract--Battery life poor capacity utilization during solar energy harvesting. In this paper, we propose and demonstrate
Maximum-Power-Point Tracking Method of Photovoltaic Using Only Single Current Sensor
Fujimoto, Hiroshi
» «Solar cell systems» Abstract This paper describes a novel strategy of maximum-power-point tracking point using only a single current sensor, i.e., a Hall-effect CT. Output power of the photovoltaic can-climbing method is employed to seek the maximum power point, using the output power obtained from only the current
Vegetation and Fire at the Last Glacial Maximum in Tropical South America
Binford, Michael W.
Chapter 4 Vegetation and Fire at the Last Glacial Maximum in Tropical South America Francis E temperatures. Keywords Charcoal Â· Last Glacial Maximum Â· pollen Â· Quaternary Â· tropical South America F-mail: Francis.Mayle@ed.ac.uk 89F. Vimeux et al. (eds.), Past Climate Variability in South America
A Basic Thermodynamic Derivation of the Maximum Overburden Pressure Generated in Frost Heave
Libbrecht, Kenneth G.
can derive the maximum overburden pressure. A similar argument can also produce the maximum Heave Engine Frost heave is a common environmental process in which the freezing of water into ice can produce forces large enough to seriously damage roads and bridges [1]. Contrary to common belief, frost
Frequency Moments Inverse Problem and Maximum (Shannon vs. R enyi-Tsallis) Entropy
) maximization of Shannon's entropy (MaxEnt), b) maximization of R#19;enyi-Tsallis entropy (maxTent). ConcerningEnt 4 1.2 Aims 5 2 Frequency moment constraints 5 2.1 Characteristics of MaxEnt choice 6 2.2 Maximum RFrequency Moments Inverse Problem and Maximum (Shannon vs. R#19;enyi-Tsallis) Entropy #3; A case
How Is the Maximum Entropy of a Quantized Surface Related to Its Area?
I. B. Khriplovich; R. V. Korkin
2001-12-27T23:59:59.000Z
The maximum entropy of a quantized surface is demonstrated to be proportional to the surface area in the classical limit. The result is valid in loop quantum gravity, and in a somewhat more general class of approaches to surface quantization. The maximum entropy is calculated explicitly for some specific cases.
Osterloh, Frank
, we show that the maximum conversion efficiency is limited further by the excited state entropyMaximum Theoretical Efficiency Limit of Photovoltaic Devices: Effect of Band Structure on Excited State Entropy Frank E. Osterloh* Department of Chemistry, University of CaliforniaDavis, One Shields
Experimental on two sensors combination used in horizontal pipe gas-water two-phase flow
Wu, Hao; Dong, Feng [Tianjin Key Laboratory of Process Measurement and Control, School of Electrical Engineering and Automation, Tianjin University, Tianjin (China)
2014-04-11T23:59:59.000Z
Gas-water two phase flow phenomenon widely exists in production and living and the measurement of it is meaningful. A new type of long-waist cone flow sensor has been designed to measure two-phase mass flow rate. Six rings structure of conductance probe is used to measure volume fraction and axial velocity. The calibration of them have been made. Two sensors have been combined in horizontal pipeline experiment to measure two-phase flow mass flow rate. Several model of gas-water two-phase flow has been discussed. The calculation errors of total mass flow rate measurement is less than 5% based on the revised homogeneous flow model.
Unification of Field Theory and Maximum Entropy Methods for Learning Probability Densities
Kinney, Justin B
2014-01-01T23:59:59.000Z
Bayesian field theory and maximum entropy are two methods for learning smooth probability distributions (a.k.a. probability densities) from finite sampled data. Both methods were inspired by statistical physics, but the relationship between them has remained unclear. Here I show that Bayesian field theory subsumes maximum entropy density estimation. In particular, the most common maximum entropy methods are shown to be limiting cases of Bayesian inference using field theory priors that impose no boundary conditions on candidate densities. This unification provides a natural way to test the validity of the maximum entropy assumption on one's data. It also provides a better-fitting nonparametric density estimate when the maximum entropy assumption is rejected.
Kaplan, Alexander
outside affect the situation. 4. , , , . 4. Incandescent Data Transfer Achieve a maximum data transfer rate using an incandescent bulb as a transmitter to modulate the optical signal
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 -the Mid-Infrared at 278, 298, andEpidermal Growth Factor.Tariff Rates FY 2015 Rates
Method and system for measuring multiphase flow using multiple pressure differentials
Fincke, James R. (Idaho Falls, ID)
2001-01-01T23:59:59.000Z
An improved method and system for measuring a multiphase flow in a pressure flow meter. An extended throat venturi is used and pressure of the multiphase flow is measured at three or more positions in the venturi, which define two or more pressure differentials in the flow conduit. The differential pressures are then used to calculate the mass flow of the gas phase, the total mass flow, and the liquid phase. The method for determining the mass flow of the high void fraction fluid flow and the gas flow includes certain steps. The first step is calculating a gas density for the gas flow. The next two steps are finding a normalized gas mass flow rate through the venturi and computing a gas mass flow rate. The following step is estimating the gas velocity in the venturi tube throat. The next step is calculating the pressure drop experienced by the gas-phase due to work performed by the gas phase in accelerating the liquid phase between the upstream pressure measuring point and the pressure measuring point in the venturi throat. Another step is estimating the liquid velocity in the venturi throat using the calculated pressure drop experienced by the gas-phase due to work performed by the gas phase. Then the friction is computed between the liquid phase and a wall in the venturi tube. Finally, the total mass flow rate based on measured pressure in the venturi throat is calculated, and the mass flow rate of the liquid phase is calculated from the difference of the total mass flow rate and the gas mass flow rate.
Flow and axial dispersion in a sinusoidal-walled tube: Effects of inertial and unsteady flows
Richmond, Marshall C.; Perkins, William A.; Scheibe, Timothy D.; Lambert, Adam; Wood, Brian D.
2013-12-01T23:59:59.000Z
Dispersion in porous media flows has been the subject of much experimental, theoretical and numerical study. Here we consider a wavy-walled tube (a three-dimensional tube with sinusoidally-varying diameter) as a simplified conceptualization of flow in porous media, where constrictions represent pore throats and expansions pore bodies. A theoretical model for effective (macroscopic) longitudinal dispersion in this system has been developed by volume averaging the microscale velocity field. Direct numerical simulation using computational fluid dynamics (CFD) methods was used to compute velocity fields by solving the Navier-Stokes equations, and also to numerically solve the volume averaging closure problem, for a range of Reynolds numbers (Re) spanning the low-Re to inertial flow regimes, including one simulation at Re = 449 for which unsteady flow was observed. Dispersion values were computed using both the volume averaging solution and a random walk particle tracking method, and results of the two methods were shown to be consistent. Our results are compared to experimental measurements of dispersion in porous media and to previous theoretical results for the low-Re, Stokes flow regime. In the steady inertial regime we observe an power-law increase in effective longitudinal dispersion (DL) with Re, consistent with previous results. This rapid rate of increase is caused by trapping of solute in expansions due to flow separation (eddies). For the unsteady case (Re = 449), the rate of increase of DL with Re was smaller than that observed at lower Re. Velocity fluctuations in this regime lead to increased rates of solute mass transfer between the core flow and separated flow regions, thus diminishing the amount of tailing caused by solute trapping in eddies and thereby reducing longitudinal dispersion.
Heating Rate Profiles in Galaxy Clusters
Edward C. D. Pope; Georgi Pavlovski; Christian R. Kaiser; Hans Fangohr
2006-01-05T23:59:59.000Z
In recent years evidence has accumulated suggesting that the gas in galaxy clusters is heated by non-gravitational processes. Here we calculate the heating rates required to maintain a physically motived mass flow rate, in a sample of seven galaxy clusters. We employ the spectroscopic mass deposition rates as an observational input along with temperature and density data for each cluster. On energetic grounds we find that thermal conduction could provide the necessary heating for A2199, Perseus, A1795 and A478. However, the suppression factor, of the clasical Spitzer value, is a different function of radius for each cluster. Based on the observations of plasma bubbles we also calculate the duty cycles for each AGN, in the absence of thermal conduction, which can provide the required energy input. With the exception of Hydra-A it appears that each of the other AGNs in our sample require duty cycles of roughly $10^{6}-10^{7}$ yrs to provide their steady-state heating requirements. If these duty cycles are unrealistic, this may imply that many galaxy clusters must be heated by very powerful Hydra-A type events interspersed between more frequent smaller-scale outbursts. The suppression factors for the thermal conductivity required for combined heating by AGN and thermal conduction are generally acceptable. However, these suppression factors still require `fine-tuning` of the thermal conductivity as a function of radius. As a consequence of this work we present the AGN duty cycle as a cooling flow diagnostic.
Taylor-Couette flow of unmagnetized plasma
Collins, C.; Cooper, C. M.; Flanagan, K.; Khalzov, I. V.; Nornberg, M. D.; Forest, C. B. [Department of Physics, University of Wisconsin, Madison, Wisconsin 53706 (United States) [Department of Physics, University of Wisconsin, Madison, Wisconsin 53706 (United States); Center for Magnetic Self Organization, University of Wisconsin, Madison, Wisconsin 53706 (United States); Clark, M.; Seidlitz, B.; Wallace, J. [Department of Physics, University of Wisconsin, Madison, Wisconsin 53706 (United States)] [Department of Physics, University of Wisconsin, Madison, Wisconsin 53706 (United States)
2014-04-15T23:59:59.000Z
Differentially rotating flows of unmagnetized, highly conducting plasmas have been created in the Plasma Couette Experiment. Previously, hot-cathodes have been used to control plasma rotation by a stirring technique [C. Collins et al., Phys. Rev. Lett. 108, 115001 (2012)] on the outer cylindrical boundary—these plasmas were nearly rigid rotors, modified only by the presence of a neutral particle drag. Experiments have now been extended to include stirring from an inner boundary, allowing for generalized circular Couette flow and opening a path for both hydrodynamic and magnetohydrodynamic experiments, as well as fundamental studies of plasma viscosity. Plasma is confined in a cylindrical, axisymmetric, multicusp magnetic field, with T{sub e}?flows (up to 12?km/s, M?=?V?c{sub s}???0.7) are driven by edge J?×?B torques in helium, neon, argon, and xenon plasmas, and the experiment has already achieved Rm???65 and Pm?0.2?12. We present measurements of a self-consistent, rotation-induced, species-dependent radial electric field, which acts together with pressure gradient to provide the centripetal acceleration for the ions. The maximum flow speeds scale with the Alfvén critical ionization velocity, which occurs in partially ionized plasma. A hydrodynamic stability analysis in the context of the experimental geometry and achievable parameters is also explored.
Kumar S. Gupta; Siddhartha Sen
2010-06-05T23:59:59.000Z
We demonstrate the possibility of a turbulent flow of electrons in graphene in the hydrodynamic region, by calculating the corresponding turbulent probability density function. This is used to calculate the contribution of the turbulent flow to the conductivity within a quantum Boltzmann approach. The dependence of the conductivity on the system parameters arising from the turbulent flow is very different from that due to scattering.
Nonlinear elasto-plastic model for dense granular flow
Ken Kamrin
2009-05-07T23:59:59.000Z
This work proposes a model for granular deformation that predicts the stress and velocity profiles in well-developed dense granular flows. Recent models for granular elasticity (Jiang and Liu 2003) and rate-sensitive plastic flow (Jop et al. 2006) are reformulated and combined into one universal granular continuum law, capable of predicting flowing regions and stagnant zones simultaneously in any arbitrary 3D flow geometry. The unification is performed by justifying and implementing a Kroner-Lee elasto-plastic decomposition, with care taken to ensure certain continuum physical principles are necessarily upheld. The model is then numerically implemented in multiple geometries and results are compared to experiments and discrete simulations.
Measurement of steam quality in two-phase critical flow
Sinclair, John William
2012-06-07T23:59:59.000Z
through a venturi for subczitical flow of steam-water 45 13 Steam quality as a function of vapor-phase Reynolds number for subczitical flow of steam-water 46 14 Steam quality as a function of Collins and Gacesa parameter for subcritical flow of steam... high degree of accuracy. He suggested that the following correlation may be used to calculate two-phase flow rates through orifices to within an error of 1. 5 percent 339 K 3 9 9' J 9 v v a v w f + [ 1. 26 (1-f ) K Y /K ] ~p p where V and L...
Flow and evaporation in single micrometer and nanometer scale pipes
Velasco, A. E.; Yang, C.; Siwy, Z. S.; Taborek, P. [Department of Physics and Astronomy, University of California, Irvine 92697 (United States); Toimil-Molares, M. E. [Department of Materials Science, GSI Helmholtzzentrum fur Schwerionenforschung GmbH, Darmstadt (Germany)
2014-07-21T23:59:59.000Z
We report measurements of pressure driven flow of fluids entering vacuum through a single pipe of micrometer or nanometer scale diameter. Nanopores were fabricated by etching a single ion track in polymer or mica foils. A calibrated mass spectrometer was used to measure the flow rates of nitrogen and helium through pipes with diameter ranging from 10??m to 31?nm. The flow of gaseous and liquid nitrogen was studied near 77?K, while the flow of helium was studied from the lambda point (2.18?K) to above the critical point (5.2?K). Flow rates were controlled by changing the pressure drop across the pipe in the range 0–31 atm. When the pressure in the pipe reached the saturated vapor pressure, an abrupt flow transition was observed. A simple viscous flow model is used to determine the position of the liquid/vapor interface in the pipe. The observed mass flow rates are consistent with no slip boundary conditions.
Investigation of the rate sensitivity of pseudo relative permeabilities
Brittain, Charles Finney
1986-01-01T23:59:59.000Z
of hypothetical reservoir stratifications were considered. Cross-sectional simulation runs were made using each stratification case for a range of waterflood injection rates and endpoint mobility ratios. Dynamic pseudo relative permeabilities were calculated... , These dynamic pseudo relative permeabilities were developed for those reservoirs that do not satisfy the assumptions of the vertical equilibrium or viscous-dominated pKr models. For waterflooding a stratified oil reservoir, fluid flow rate (velocity...
Nonlinear model-based control of two-phase flow in risers by feedback linearization
Skogestad, Sigurd
conditions at offshore oilfields. The slugging flow constitutes an unstable and highly nonlinear system and flow rates (Storkaas (2005), Storkaas and Skogestad (2007)). The oscillatory flow condition in offshore disturbances or plant changes. We aim to find a robust control solution for anti-slug control systems
Mitchell, Randall J.
1 Productivity & Energy Flow Ecosystem approach, focuses: on flow of energy, water, and nutrients (capture) of energy by autotrophs Gross (total) Net (total Â costs) Secondary productivity- capture of energy by herbivores http://sciencebitz.com/?page_id=204 What Controls the Primary Productivity
Microcontroller Servomotor for Maximum Effective Power Point for Solar Cell System
Al-Khalidy, M.; Al-Rawi, O.; Noaman, N.
2010-01-01T23:59:59.000Z
In this paper a Maximum Power point (MPP) tracking algorithm is developed using dual-axis servomotor feedback tracking control system. An efficient and accurate servomotor system is used to increase the system efficiency and reduces the solar cell...
Achieving Consistent Maximum Brake Torque with Varied Injection Timing in a DI Diesel Engine
Kroeger, Timothy H
2013-09-19T23:59:59.000Z
, the characteristics of combustion for swept injection timings along the maximum brake torque plateau are determined. The research is conducted by varying injection timing at constant engine speed and load while measuring engine emissions and in-cylinder pressure...
Tropical climate variability from the last glacial maximum to the present
Dahl, Kristina Ariel
2005-01-01T23:59:59.000Z
This thesis evaluates the nature and magnitude of tropical climate variability from the Last Glacial Maximum to the present. The temporal variability of two specific tropical climate phenomena is examined. The first is the ...
Dynamical Reconstruction of Upper-Ocean Conditions in the Last Glacial Maximum Atlantic
Wunsch, Carl
Proxies indicate that the Last Glacial Maximum (LGM) Atlantic Ocean was marked by increased meridional and zonal near sea surface temperature gradients relative to today. Using a least squares fit of a full general circulation ...
Atlantic Ocean circulation at the last glacial maximum : inferences from data and models
Dail, Holly Janine
2012-01-01T23:59:59.000Z
This thesis focuses on ocean circulation and atmospheric forcing in the Atlantic Ocean at the Last Glacial Maximum (LGM, 18-21 thousand years before present). Relative to the pre-industrial climate, LGM atmospheric CO? ...
Submodule Integrated Distributed Maximum Power Point Tracking for Solar Photovoltaic Applications
Pilawa-Podgurski, Robert C. N.
This paper explores the benefits of distributed power electronics in solar photovoltaic applications through the use of submodule integrated maximum power point trackers (MPPT). We propose a system architecture that provides ...
Acoustic Space Dimensionality Selection and Combination using the Maximum Entropy Principle
Abdel-Haleem, Yasser H; Renals, Steve; Lawrence, Neil D
2004-01-01T23:59:59.000Z
In this paper we propose a discriminative approach to acoustic space dimensionality selection based on maximum entropy modelling. We form a set of constraints by composing the acoustic space with the space of phone classes, and use a continuous...
Author's personal copy Unified behaviour of maximum soot yields of methane, ethane and propane
GĂĽlder, Ă?mer L.
Author's personal copy Unified behaviour of maximum soot yields of methane, ethane and propane the current study and the previous measurements in similar flames with methane, ethane, and propane flames
The planar X-junction flow: stability analysis and control
Lashgari, Iman; Tammisola, Outi; Citro, Vincenzo; Juniper, Matthew P.; Brandt, Luca
2014-07-29T23:59:59.000Z
and ? is the kinematic viscosity. The velocity ratio is defined as Vr = U2 U1 , (2.2) where U2 is the maximum inflow velocity of the side channels. In this paper, we study the stability of the X-junction flow in the Reynolds number regime 60 waves, and the lift-up effect. To determine the instability mechanism in our flow, we note that the present instability is stationary, the mode shape streamwise elon- gated, and the streamwise velocity component order of magnitude larger than...
The Modelling of Degenerate Neck Pinch Singularities in Ricci Flow by Bryant Solitons
David Garfinkle; James Isenberg
2007-09-04T23:59:59.000Z
In earlier work, carrying out numerical simulations of the Ricci flow of families of rotationally symmetric geometries on $S3$, we have found strong support for the contention that (at least in the rotationally symmetric case) the Ricci flow for a ``critical'' initial geometry - one which is at the transition point between initial geometries (on $S^3$) whose volume-normalized Ricci flows develop a singular neck pinch, and other initial geometries whose volume normalized Ricci flows converge to a round sphere - evolves into a ``degenerate neck pinch.'' That is, we have seen in this earlier work that the Ricci flows for the critical geometries become locally cylindrical in a neighborhood of the initial pinching, and have the maximum amount of curvature at one or both of the poles. Here, we explore the behavior of these flows at the poles, and find strong support for the conjecture that the Bryant steady solitons accurately model this polar flow.
A stochastic model for sediment yield using the Principle of Maximum Entropy
Singh, V. P.; Krstanovic, P. F.
WATER RESOURCES RESEARCH, VOL. 23, NO. 5, PAGES 781-793, MAY 1987 A Stochastic Model for Sediment Yield Using the Principle of Maximum Entropy V. P. SINGH AND P. F. KRSTANOVIC Department of Civil Engineering, Louisiana State University, Baton... Rouge The principle of maximum entropy was applied to derive a stochastic model for sediment yield from upland watersheds. By maximizing the conditional entropy subject to certain constraints, a probability distribution of sediment yield conditioned...
Heat transfer and flow characteristics of cooling channels in turbine blades
Saxena, Amit
1988-01-01T23:59:59.000Z
/mass transfer distributions were determined for straight flow' through a pin fin channel (H/D = 1, S/D = X/D = 2. 5) and a flow through the pin fin channel with trailing edge flow ejection. The overall friction factor and local pressure drop results were... obtained for various configurations and lengths (L/d = 2 and 20) of the trailing edge ejection holes, From the pressure drop data, the radial mass flow rate and the mass flow rates through trailing edge ejection holes were calculated. The results show...
Graduate Kentucky Metropolitan Rate Application
Franco, John
Graduate Kentucky Metropolitan Rate Application REGISTRAR'S OFFICE University of Cincinnati PO Box Kentucky counties are able to attend UC at an established metropolitan tuition rate. Non Kentucky residency, these students are not eligible for the graduate metropolitan rate. Kentucky counties
Simulations of ductile flow in brittle material processing
Luh, M.H.; Strenkowski, J.S.
1988-12-01T23:59:59.000Z
Research is continuing on the effects of thermal properties of the cutting tool and workpiece on the overall temperature distribution. Using an Eulerian finite element model, diamond and steel tools cutting aluminum have been simulated at various, speeds, and depths of cut. The relative magnitude of the thermal conductivity of the tool and the workpiece is believed to be a primary factor in the resulting temperature distribution in the workpiece. This effect is demonstrated in the change of maximum surface temperatures for diamond on aluminum vs. steel on aluminum. As a preliminary step toward the study of ductile flow in brittle materials, the relative thermal conductivities of diamond on polycarbonate is simulated. In this case, the maximum temperature shifts from the rake face of the tool to the surface of the machined workpiece, thus promoting ductile flow in the workpiece surface.
Couette flow regimes with heat transfer in rarefied gas
Abramov, A. A., E-mail: alabr54@mail.ru; Butkovskii, A. V., E-mail: albutkov@mail.ru [Zhukovski Central Aerohydrodynamics Institute (Russian Federation)
2013-06-15T23:59:59.000Z
Based on numerical solution of the Boltzmann equation by direct statistic simulation, the Couette flow with heat transfer is studied in a broad range of ratios of plate temperatures and Mach numbers of a moving plate. Flow regime classification by the form of the dependences of the energy flux and friction stress on the Knudsen number Kn is proposed. These dependences can be simultaneously monotonic and nonmonotonic and have maxima. Situations are possible in which the dependence of the energy flux transferred to a plate on Kn has a minimum, while the dependence of the friction stress is monotonic or even has a maximum. Also, regimes exist in which the dependence of the energy flux on Kn has a maximum, while the dependence of the friction stress is monotonic, and vice versa.
Solar rotation rate and its gradients during cycle 23
H. M. Antia; Sarbani Basu; S. M. Chitre
2008-05-22T23:59:59.000Z
Available helioseismic data now span almost the entire solar activity cycle 23 making it possible to study solar-cycle related changes of the solar rotation rate in detail. In this paper we study how the solar rotation rate, in particular, the zonal flows change with time. In addition to the zonal flows that show a well known pattern in the solar convection zone, we also study changes in the radial and latitudinal gradients of the rotation rate, particularly in the shear layer that is present in the immediate sub-surface layers of the Sun. In the case of the zonal-flow pattern, we find that the band indicating fast rotating region close to the equator seems to have bifurcated around 2005. Our investigation of the rotation-rate gradients show that the relative variation in the rotation-rate gradients is about 20% or more of their average values, which is much larger than the relative variation in the rotation rate itself. These results can be used to test predictions of various solar dynamo models.
Kim, Leonard, E-mail: kimlh@umdnj.edu [Department of Radiation Oncology, Cancer Institute of New Jersey, Robert Wood Johnson Medical School, University of Medicine and Dentistry of New Jersey, New Brunswick, NJ (United States); Narra, Venkat; Yue, Ning [Department of Radiation Oncology, Cancer Institute of New Jersey, Robert Wood Johnson Medical School, University of Medicine and Dentistry of New Jersey, New Brunswick, NJ (United States)
2013-07-01T23:59:59.000Z
Recent studies have reported potentially clinically meaningful dose differences when heterogeneity correction is used in breast balloon brachytherapy. In this study, we report on the relationship between heterogeneity-corrected and -uncorrected doses for 2 commonly used plan evaluation metrics: maximum point dose to skin surface and maximum point dose to ribs. Maximum point doses to skin surface and ribs were calculated using TG-43 and Varian Acuros for 20 patients treated with breast balloon brachytherapy. The results were plotted against each other and fit with a zero-intercept line. Max skin dose (Acuros) = max skin dose (TG-43) ? 0.930 (R{sup 2} = 0.995). The average magnitude of difference from this relationship was 1.1% (max 2.8%). Max rib dose (Acuros) = max rib dose (TG-43) ? 0.955 (R{sup 2} = 0.9995). The average magnitude of difference from this relationship was 0.7% (max 1.6%). Heterogeneity-corrected maximum point doses to the skin surface and ribs were proportional to TG-43-calculated doses. The average deviation from proportionality was 1%. The proportional relationship suggests that a different metric other than maximum point dose may be needed to obtain a clinical advantage from heterogeneity correction. Alternatively, if maximum point dose continues to be used in recommended limits while incorporating heterogeneity correction, institutions without this capability may be able to accurately estimate these doses by use of a scaling factor.
Fluid breakup during simultaneous two-phase flow through a three-dimensional porous medium
Sujit S. Datta; Jean-Baptiste Dupin; David A. Weitz
2014-06-26T23:59:59.000Z
We use confocal microscopy to directly visualize the simultaneous flow of both a wetting and a non-wetting fluid through a model three-dimensional (3D) porous medium. We find that, for small flow rates, both fluids flow through unchanging, distinct, connected 3D pathways; in stark contrast, at sufficiently large flow rates, the non-wetting fluid is broken up into discrete ganglia. By performing experiments over a range of flow rates, using fluids of different viscosities, and with porous media having different geometries, we show that this transition can be characterized by a state diagram that depends on the capillary numbers of both fluids, suggesting that it is controlled by the competition between the viscous forces exerted on the flowing oil and the capillary forces at the pore scale. Our results thus help elucidate the diverse range of behaviors that arise in two-phase flow through a 3D porous medium.
Money versus Time: Evaluation of Flow Control in Terms of Energy Consumption and Convenience
Frohnapfel, Bettina; Quadrio, Maurizio
2012-01-01T23:59:59.000Z
Flow control with the goal of reducing the skin friction drag on the fluid-solid interface is an active fundamental research area, motivated by its potential for significant energy savings and reduced emissions in the transport sector. Customarily, the performance of drag reduction techniques in internal flows is evaluated under two alternative flow conditions, i.e. at constant mass flow rate or constant pressure gradient. Successful control leads to reduction of drag and pumping power within the former approach, whereas the latter leads to an increase of the mass flow rate and pumping power. In practical applications, however, money and time define the flow control challenge: a compromise between the energy expenditure (money) and the corresponding convenience (flow rate) achieved with that amount of energy has to be reached so as to accomplish a goal which in general depends on the specific application. Based on this idea, we derive two dimensionless parameters which quantify the total energy consumption an...
Elliptic flow phenomenon at ATLAS
Martin Spousta
2014-06-20T23:59:59.000Z
We summarize measurements of elliptic flow and higher order flow harmonics performed by the ATLAS experiment at the LHC. Results on event-averaged flow measurements and event-plane correlations in Pb+Pb collisions are discussed along with the event-by-event flow measurements. Further, we summarize results on flow in p+Pb collisions.
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Sustainable systems rating program: Marketing Green'' Building in Austin, Texas
Not Available
1991-12-01T23:59:59.000Z
Four major resource issues for home construction were identified: water, energy, materials, and waste. A systems flow model was then developed that tracked the resource issues through interactive matrices in the areas of sourcing, processing, using, and disposing or recycling. This model served as the basis for a rating system used in an educational and marketing tool called the Eco-Home Guide.
Sustainable systems rating program: Marketing ``Green`` Building in Austin, Texas
Not Available
1991-12-01T23:59:59.000Z
Four major resource issues for home construction were identified: water, energy, materials, and waste. A systems flow model was then developed that tracked the resource issues through interactive matrices in the areas of sourcing, processing, using, and disposing or recycling. This model served as the basis for a rating system used in an educational and marketing tool called the Eco-Home Guide.
Shroud leakage flow discouragers
Bailey, Jeremy Clyde (Middle Grove, NY); Bunker, Ronald Scott (Niskayuna, NY)
2002-01-01T23:59:59.000Z
A turbine assembly includes a plurality of rotor blades comprising a root portion, an airfoil having a pressure sidewall and a suction sidewall, and a top portion having a cap. An outer shroud is concentrically disposed about said rotor blades, said shroud in combination with said tip portions defining a clearance gap. At least one circumferential shroud leakage discourager is disposed within the shroud. The leakage discourager(s) increase the flow resistance and thus reduce the flow of hot gas flow leakage for a given pressure differential across the clearance gap to improve overall turbine efficiency.
Richard Schultz
2011-09-01T23:59:59.000Z
The purpose of the fluid dynamics experiments in the MIR (Matched Index of-Refraction) flow system at Idaho National Laboratory (INL) is to develop benchmark databases for the assessment of Computational Fluid Dynamics (CFD) solutions of the momentum equations, scalar mixing, and turbulence models for the flow ratios between coolant channels and bypass gaps in the interstitial regions of typical prismatic standard fuel element (SFE) or upper reflector block geometries of typical Modular High-temperature Gas-cooled Reactors (MHTGR) in the limiting case of negligible buoyancy and constant fluid properties. The experiments use Particle Image Velocimetry (PIV) to measure the velocity fields that will populate the bypass flow study database.
Magnetically stimulated fluid flow patterns
Martin, Jim; Solis, Kyle
2014-08-06T23:59:59.000Z
Sandia National Laboratories' Jim Martin and Kyle Solis explain research on the effects of magnetic fields on fluid flows and how they stimulate vigorous flows. Fluid flow is a necessary phenomenon in everything from reactors to cooling engines in cars.
Compensated count-rate circuit for radiation survey meter
Todd, Richard A. (Powell, TN)
1981-01-01T23:59:59.000Z
A count-rate compensating circuit is provided which may be used in a portable Geiger-Mueller (G-M) survey meter to ideally compensate for counting loss errors in the G-M tube detector. In a G-M survey meter, wherein the pulse rate from the G-M tube is converted into a pulse rate current applied to a current meter calibrated to indicate dose rate, the compensated circuit generates and controls a reference voltage in response to the rate of pulses from the detector. This reference voltage is gated to the current-generating circuit at a rate identical to the rate of pulses coming from the detector so that the current flowing through the meter is varied in accordance with both the frequency and amplitude of the reference voltage pulses applied thereto so that the count rate is compensated ideally to indicate a true count rate within 1% up to a 50% duty cycle for the detector. A positive feedback circuit is used to control the reference voltage so that the meter output tracks true count rate indicative of the radiation dose rate.
Compensated count-rate circuit for radiation survey meter
Todd, R.A.
1980-05-12T23:59:59.000Z
A count-rate compensating circuit is provided which may be used in a portable Geiger-Mueller (G-M) survey meter to ideally compensate for couting loss errors in the G-M tube detector. In a G-M survey meter, wherein the pulse rate from the G-M tube is converted into a pulse rate current applied to a current meter calibrated to indicate dose rate, the compensation circuit generates and controls a reference voltage in response to the rate of pulses from the detector. This reference voltage is gated to the current-generating circuit at a rate identical to the rate of pulses coming from the detector so that the current flowing through the meter is varied in accordance with both the frequency and amplitude of the reference voltage pulses applied thereto so that the count rate is compensated ideally to indicate a true count rate within 1% up to a 50% duty cycle for the detector. A positive feedback circuit is used to control the reference voltage so that the meter output tracks true count rate indicative of the radiation dose rate.
Energy Management Through Innovative Rates
Williams, M. L.
1982-01-01T23:59:59.000Z
of energy efficiency in the industrial sector and specific rate design alternatives for doing so....
Flow dynamics and solute transport in unsaturated rock fractures
Su, G. W.
1999-10-01T23:59:59.000Z
Rock fractures play an important role in flow and contaminant transport in fractured aquifers, production of oil from petroleum reservoirs, and steam generation from geothermal reservoirs. In this dissertation, phenomenological aspects of flow in unsaturated fractures were studied in visualization experiments conducted on a transparent replica of a natural, rough-walled rock fracture for inlet conditions of constant pressure and flow rate over a range of angles of inclination. The experiments demonstrated that infiltrating liquid proceeds through unsaturated rock fractures along non-uniform, localized preferential flow paths. Even in the presence of constant boundary conditions, intermittent flow was a persistent flow feature observed, where portions of the flow channel underwent cycles of snapping and reforming. Two modes of intermittent flow were observed, the pulsating blob mode and the rivulet snapping mode. A conceptual model for the rivulet snapping mode was proposed and examined using idealized, variable-aperture fractures. The frequency of intermittent flow events was measured in several experiments and related to the capillary and Bond numbers to characterize this flow behavior.
Liu, G.; Liu, M.
2006-01-01T23:59:59.000Z
. For example, the Venturi meter is commonly used for steam flow measurement, but it is less commonly used for water flow measurement because of the poor accuracy at low flow rates and high installation cost. 2) Displacement flow meter: The meter works... by using the fluid to rotate or displace a device inserted into the flow stream, e.g., a turbine flow meter, tangential paddlewheel meter, etc. It causes extra pressure drop. The bearing wears out and calibration is often needed to ensure accuracy...
Chan, Vincent W. S.
Present-day networks are being challenged by dramatic increases in bandwidth demand of emerging applications. We will explore a new transport, ldquooptical flow switchingrdquo, that will enable significant growth and ...
Neuenschwander, Ulrich
Handling hazardous multiphase reactions in flow brings not only safety advantages but also significantly improved performance, due to better mass transfer characteristics. In this paper, we present a continuous microreactor ...
Parallel flow diffusion battery
Yeh, H.C.; Cheng, Y.S.
1984-01-01T23:59:59.000Z
A parallel flow diffusion battery for determining the mass distribution of an aerosol has a plurality of diffusion cells mounted in parallel to an aerosol stream, each diffusion cell including a stack of mesh wire screens of different density.
Regression Model for Daily Maximum Stream Temperature David W. Neumann1
Balaji, Rajagopalan
U.S. river basins and elsewhere in the world is that water storage and use for mu- nicipal, industrial, agricultural, and power production purposes leaves river biota with insufficient flow to maintain more rapidly than higher flows. High stream tempera- tures reduce cold water fish populations
Period-luminosity and period-luminosity-colour relations for Mira variables at maximum light
S. M. Kanbur; M. A. Hendry; D. Clarke
1997-04-14T23:59:59.000Z
In this paper we confirm the existence of period-luminosity (PL) and period-luminosity-colour (PLC) relations at maximum light for O and C Mira variables in the LMC. We demonstrate that in the J and H bands the maximum light PL relations have a significantly smaller dispersion than their counterparts at mean light, while the K band and bolometric PL relations have a dispersion comparable to that at mean light. In the J, H and K bands the fitted PL relations for the O Miras are found to have smaller dispersion than those for the C Miras, at both mean and maximum light, while the converse is true for the relations based on bolometric magnitudes. The inclusion of a non-zero log period term is found to be highly significant in all cases except that of the C Miras in the J band, for which the data are found to be consistent with having constant absolute magnitude. This suggests the possibility of employing C Miras as standard candles. We suggest both a theoretical justification for the existence of Mira PL relations at maximum light and a possible explanation of why these relations should have a smaller dispersion than at mean light. The existence of such maximum light relations offers the possibility of extending the range and improving the accuracy of the Mira distance scale to Galactic globular clusters and to other galaxies.
On the maximum value of the cosmic abundance of oxygen and the oxygen yield
L. S. Pilyugin; T. X. Thuan; J. M. Vilchez
2007-01-11T23:59:59.000Z
We search for the maximum oxygen abundance in spiral galaxies. Because this maximum value is expected to occur in the centers of the most luminous galaxies, we have constructed the luminosity - central metallicity diagram for spiral galaxies, based on a large compilation of existing data on oxygen abundances of HII regions in spiral galaxies. We found that this diagram shows a plateau at high luminosities (-22.3 oxygen abundance 12+log(O/H) ~ 8.87. This provides strong evidence that the oxygen abundance in the centers of the most luminous metal-rich galaxies reaches the maximum attainable value of oxygen abundance. Since some fraction of the oxygen (about 0.08 dex) is expected to be locked into dust grains, the maximum value of the true gas+dust oxygen abundance in spiral galaxies is 12+log(O/H) ~ 8.95. This value is a factor of ~ 2 higher than the recently estimated solar value. Based on the derived maximum oxygen abundance in galaxies, we found the oxygen yield to be about 0.0035, depending on the fraction of oxygen incorporated into dust grains.
HFIR Vessel Maximum Permissible Pressures for Operating Period 26 to 50 EFPY (100 MW)
Cheverton, R.D.; Inger, J.R.
1999-01-01T23:59:59.000Z
Extending the life of the HFIR pressure vessel from 26 to 50 EFPY (100 MW) requires an updated calculation of the maximum permissible pressure for a range in vessel operating temperatures (40-120 F). The maximum permissible pressure is calculated using the equal-potential method, which takes advantage of knowledge gained from periodic hydrostatic proof tests and uses the test conditions (pressure, temperature, and frequency) as input. The maximum permissible pressure decreases with increasing time between hydro tests but is increased each time a test is conducted. The minimum values that occur just prior to a test either increase or decrease with time, depending on the vessel temperature. The minimum value of these minimums is presently specified as the maximum permissible pressure. For three vessel temperatures of particular interest (80, 88, and 110 F) and a nominal time of 3.0 EFPY(100 MVV)between hydro tests, these pressures are 677, 753, and 850 psi. For the lowest temperature of interest (40 F), the maximum permissible pressure is 295 psi.
Composition pulse time-of-flight mass flow sensor
Harnett, Cindy K. (Livermore, CA); Crocker, Robert W. (Fremont, CA); Mosier, Bruce P. (San Francisco, CA); Caton, Pamela F. (Berkeley, CA); Stamps, James F. (Livermore, CA)
2007-06-05T23:59:59.000Z
A device for measuring fluid flow rates over a wide range of flow rates (<1 nL/min to >10 .mu.L/min) and at pressures at least as great as 2,000 psi. The invention is particularly adapted for use in microfluidic systems. The device operates by producing compositional variations in the fluid, or pulses, that are subsequently detected downstream from the point of creation to derive a flow rate. Each pulse, comprising a small fluid volume, whose composition is different from the mean composition of the fluid, can be created by electrochemical means, such as by electrolysis of a solvent, electrolysis of a dissolved species, or electrodialysis of a dissolved ionic species. Measurements of the conductivity of the fluid can be used to detect the arrival time of the pulses, from which the fluid flow rate can be determined. A pair of spaced apart electrodes can be used to produce the electrochemical pulse. In those instances where it is desired to measure a wide range of fluid flow rates a three electrode configuration in which the electrodes are spaced at unequal distances has been found to be desirable.
New sensor for measurement of low air flow velocity. Phase I final report
Hashemian, H.M.; Hashemian, M.; Riggsbee, E.T. [Analysis and Measurement Services Corp., Knoxville, TN (United States)
1995-08-01T23:59:59.000Z
The project described here is the Phase I feasibility study of a two-phase program to integrate existing technologies to provide a system for determining air flow velocity and direction in radiation work areas. Basically, a low air flow sensor referred to as a thermocouple flow sensor has been developed. The sensor uses a thermocouple as its sensing element. The response time of the thermocouple is measured using an existing in-situ method called the Loop Current Step Response (LCSR) test. The response time results are then converted to a flow signal using a response time-versus-flow correlation. The Phase I effort has shown that a strong correlation exists between the response time of small diameter thermocouples and the ambient flow rate. As such, it has been demonstrated that thermocouple flow sensors can be used successfully to measure low air flow rates that can not be measured with conventional flow sensors. While the thermocouple flow sensor developed in this project was very successful in determining air flow velocity, determining air flow direction was beyond the scope of the Phase I project. Nevertheless, work was performed during Phase I to determine how the new flow sensor can be used to determine the direction, as well as the velocity, of ambient air movements. Basically, it is necessary to use either multiple flow sensors or move a single sensor in the monitoring area and make flow measurements at various locations sweeping the area from top to bottom and from left to right. The results can then be used with empirical or physical models, or in terms of directional vectors to estimate air flow patterns. The measurements can be made continuously or periodically to update the flow patterns as they change when people and objects are moved in the monitoring area. The potential for using multiple thermocouple flow sensors for determining air flow patterns will be examined in Phase II.
Viability of the diagonal implicit algorithm for hypersonic flowfields with finite rate chemistry
Roy, Christopher John
2012-06-07T23:59:59.000Z
The diagonal implicit algorithm has been examined for high speed, moderate density flows. In this flight regime, nonequilibrium thermal, chemical, and radiative effects are important and the determination of these finite rate processes, coupled...
A Novel Approach for the Rapid Estimation of Drainage Volume, Pressure and Well Rates
Gupta, Neha 1986-
2012-11-12T23:59:59.000Z
For effective reservoir management and production optimization, it is important to understand drained volumes, pressure depletion and reservoir well rates at all flow times. For conventional reservoirs, this behavior is based on the concepts...
Tables for solution of the heat-conduction equation with a time-dependent heating rate
Bergles A. E.
1962-01-01T23:59:59.000Z
Tables are presented for the solution of the transient onedimensional heat flow in a solid body of constant material properties with the heating rate at one boundary dependent on time. These tables allow convenient and ...
Isabelle Cantat; Renaud Delannay
2005-07-21T23:59:59.000Z
We analyze the flow of a liquid foam between two plates separated by a gap of the order of the bubble size (2D foam). We concentrate on the salient features of the flow that are induced by the presence, in an otherwise monodisperse foam, of a single large bubble whose size is one order of magnitude larger than the average size. We describe a model suited for numerical simulations of flows of 2D foams made up of a large number of bubbles. The numerical results are successfully compared to analytical predictions based on scaling arguments and on continuum medium approximations. When the foam is pushed inside the cell at a controlled rate, two basically different regimes occur: a plug flow is observed at low flux whereas, above a threshold, the large bubble migrates faster than the mean flow. The detailed characterization of the relative velocity of the large bubble is the essential aim of the present paper. The relative velocity values, predicted both from numerical and from analytical calculations that are discussed here in great detail, are found to be in fair agreement with experimental results.
Spectral Modeling of SNe Ia Near Maximum Light: Probing the Characteristics of Hydro Models
E. Baron; S. Bongard; David Branch; Peter H. Hauschildt
2006-03-03T23:59:59.000Z
We have performed detailed NLTE spectral synthesis modeling of 2 types of 1-D hydro models: the very highly parameterized deflagration model W7, and two delayed detonation models. We find that overall both models do about equally well at fitting well observed SNe Ia near to maximum light. However, the Si II 6150 feature of W7 is systematically too fast, whereas for the delayed detonation models it is also somewhat too fast, but significantly better than that of W7. We find that a parameterized mixed model does the best job of reproducing the Si II 6150 line near maximum light and we study the differences in the models that lead to better fits to normal SNe Ia. We discuss what is required of a hydro model to fit the spectra of observed SNe Ia near maximum light.
Fast singular value decomposition combined maximum entropy method for plasma tomography
Kim, Junghee; Choe, W. [Department of Physics, Korea Advanced Institute of Science and Technology, 373-1 Guseong-dong, Yuseong-gu, Daejeon 305-701(Korea, Republic of)
2006-02-15T23:59:59.000Z
The maximum entropy method (MEM) is a widely used reconstruction algorithm in plasma physics. Drawbacks of the conventional MEM are its heavy time-consuming process and possible generation of noisy reconstruction results. In this article, a modified maximum entropy algorithm is described which speeds up the calculation and shows better noise handling capability. Similar to the rapid minimum Fisher information method, the modified maximum entropy algorithm uses simple matrix operations instead of treating a fully nonlinear problem. The preprocess for rapid tomographic calculation is based on the vector operations and the singular value decomposition (SVD). The initial guess of the sought-for emissivity is calculated by SVD and this helped reconstruction about ten times faster than the conventional MEM. Therefore, the developed fast MEM can be used for intershot tomographic analyses of fusion plasmas.
Section 13: Flow control 1 Section 13: Flow control
Kohlenbach, Ulrich
Geometries for Energyefficient Flow Around Bodies Abstract 14:30 14:50: Elfriede Friedmann (Universität
Byrne, Raymond Harry; Silva Monroy, Cesar Augusto.
2012-12-01T23:59:59.000Z
The valuation of an electricity storage device is based on the expected future cash ow generated by the device. Two potential sources of income for an electricity storage system are energy arbitrage and participation in the frequency regulation market. Energy arbitrage refers to purchasing (stor- ing) energy when electricity prices are low, and selling (discharging) energy when electricity prices are high. Frequency regulation is an ancillary service geared towards maintaining system frequency, and is typically procured by the independent system operator in some type of market. This paper outlines the calculations required to estimate the maximum potential revenue from participating in these two activities. First, a mathematical model is presented for the state of charge as a function of the storage device parameters and the quantities of electricity purchased/sold as well as the quantities o ered into the regulation market. Using this mathematical model, we present a linear programming optimization approach to calculating the maximum potential revenue from an elec- tricity storage device. The calculation of the maximum potential revenue is critical in developing an upper bound on the value of storage, as a benchmark for evaluating potential trading strate- gies, and a tool for capital nance risk assessment. Then, we use historical California Independent System Operator (CAISO) data from 2010-2011 to evaluate the maximum potential revenue from the Tehachapi wind energy storage project, an American Recovery and Reinvestment Act of 2009 (ARRA) energy storage demonstration project. We investigate the maximum potential revenue from two di erent scenarios: arbitrage only and arbitrage combined with the regulation market. Our analysis shows that participation in the regulation market produces four times the revenue compared to arbitrage in the CAISO market using 2010 and 2011 data. Then we evaluate several trading strategies to illustrate how they compare to the maximum potential revenue benchmark. We conclude with a sensitivity analysis with respect to key parameters.
Study on Two Optimization Problems: Line Cover and Maximum Genus Embedding
Cao, Cheng
2012-07-16T23:59:59.000Z
STUDY ON TWO OPTIMIZATION PROBLEMS: LINE COVER AND MAXIMUM GENUS EMBEDDING A Thesis by CHENG CAO Submitted to the O ce of Graduate Studies of Texas A&M University in partial ful llment of the requirements for the degree of MASTER OF SCIENCE... May 2012 Major Subject: Computer Science STUDY ON TWO OPTIMIZATION PROBLEMS: LINE COVER AND MAXIMUM GENUS EMBEDDING A Thesis by CHENG CAO Submitted to the O ce of Graduate Studies of Texas A&M University in partial ful llment...
Hydrodynamic Relaxation of an Electron Plasma to a Near-Maximum Entropy State
Rodgers, D. J.; Servidio, S.; Matthaeus, W. H.; Mitchell, T. B.; Aziz, T. [Department of Physics and Astronomy, University of Delaware, Newark, Delaware 19716 (United States); Montgomery, D. C. [Department of Physics and Astronomy, Dartmouth College, Hanover, New Hampshire 03755 (United States)
2009-06-19T23:59:59.000Z
Dynamical relaxation of a pure electron plasma in a Malmberg-Penning trap is studied, comparing experiments, numerical simulations and statistical theories of weakly dissipative two-dimensional (2D) turbulence. Simulations confirm that the dynamics are approximated well by a 2D hydrodynamic model. Statistical analysis favors a theoretical picture of relaxation to a near-maximum entropy state with constrained energy, circulation, and angular momentum. This provides evidence that 2D electron fluid relaxation in a turbulent regime is governed by principles of maximum entropy.
Maximum-Entropy Closures for Kinetic Theories of Neuronal Network Dynamics
Rangan, Aaditya V.; Cai, David [Courant Institute of Mathematical Sciences, New York University, New York, New York 10012 (United States)
2006-05-05T23:59:59.000Z
We analyze (1+1)D kinetic equations for neuronal network dynamics, which are derived via an intuitive closure from a Boltzmann-like equation governing the evolution of a one-particle (i.e., one-neuron) probability density function. We demonstrate that this intuitive closure is a generalization of moment closures based on the maximum-entropy principle. By invoking maximum-entropy closures, we show how to systematically extend this kinetic theory to obtain higher-order (1+1)D kinetic equations and to include coupled networks of both excitatory and inhibitory neurons.
Maximum Entropy Models of Shortest Path and Outbreak Distributions in Networks
Bauckhage, Christian; Hadiji, Fabian
2015-01-01T23:59:59.000Z
Properties of networks are often characterized in terms of features such as node degree distributions, average path lengths, diameters, or clustering coefficients. Here, we study shortest path length distributions. On the one hand, average as well as maximum distances can be determined therefrom; on the other hand, they are closely related to the dynamics of network spreading processes. Because of the combinatorial nature of networks, we apply maximum entropy arguments to derive a general, physically plausible model. In particular, we establish the generalized Gamma distribution as a continuous characterization of shortest path length histograms of networks or arbitrary topology. Experimental evaluations corroborate our theoretical results.
Characterization of secondary collection system flows beneath synthetic composite liners
Groenleer, M.E. [Wenck Associates, Inc., Grand Rapids, MI (United States)
1995-12-31T23:59:59.000Z
Secondary liner systems for landfills are becoming more common. Subtitle D may be construed to require secondary liners to meet monitorability requirements for new units. Michigan requires secondary liners in many situations, most commonly at previously contaminated sites to allow for differential monitoring of the new cell(s). Much work has been done in characterizing the flow of liquids through FML/clay composite liners but less is known about flows through FML/geosynthetic clay liner (GCL) composite liners or through isolated FMLs. Flow and chemical data are examined from two Michigan landfills employing different configurations of all synthetic primary and secondary liners. The data is examined for apparent trends. Conclusions are drawn about the application of generic action flow rates as a regulatory standard to these systems and the chemical characteristics of the liquids in secondary systems. Calculations are presented to achieve a realistic action leakage rate for these systems.
Damage-induced nonassociated inelastic flow in rock salt
Chan, K.S.; Bodner, S.R. [Southwest Research Inst., San Antonio, TX (United States); Brodsky, N.S.; Fossum, A.F. [RE/SPEC, Inc., Rapid City, SD (United States); Munson, D.E. [Sandia National Labs., Albuquerque, NM (United States)
1993-06-01T23:59:59.000Z
The multi-mechanism deformation coupled fracture model recently developed by CHAN, et al. (1992), for describing time-dependent, pressure-sensitive inelastic flow and damage evolution in crystalline solids was evaluated against triaxial creep experiments on rock salt. Guided by experimental observations, the kinetic equation and the flow law for damage-induced inelastic flow in the model were modified to account for the development of damage and inelastic dilatation in the transient creep regime. The revised model was then utilized to obtain the creep response and damage evolution in rock salt as a function of confining pressure and stress difference. Comparison between model calculation and experiment revealed that damage-induced inelastic flow is nonassociated, dilatational, and contributes significantly to the macroscopic strain rate observed in rock salt deformed at low confining pressures. The inelastic strain rate and volumetric strain due to damage decrease with increasing confining pressures, and all are suppressed at sufficiently high confining pressures.
National Utility Rate Database: Preprint
Ong, S.; McKeel, R.
2012-08-01T23:59:59.000Z
When modeling solar energy technologies and other distributed energy systems, using high-quality expansive electricity rates is essential. The National Renewable Energy Laboratory (NREL) developed a utility rate platform for entering, storing, updating, and accessing a large collection of utility rates from around the United States. This utility rate platform lives on the Open Energy Information (OpenEI) website, OpenEI.org, allowing the data to be programmatically accessed from a web browser, using an application programming interface (API). The semantic-based utility rate platform currently has record of 1,885 utility rates and covers over 85% of the electricity consumption in the United States.
Energy Flow Energy Flow Energy Flow A.Ukleja, T.Tymieniecka, I.Skillicorn 1 Azimuthal asymmetry
Energy Flow Energy Flow Energy Flow A.Ukleja, T.Tymieniecka, I.Skillicorn 1 Azimuthal asymmetry using energy flow method Azimuthal angle distribution at Q2 >100 GeV2 Energy flow method.Ukleja on behalf of the ZEUS Collaboration #12; Energy Flow Energy Flow Energy Flow A.Ukleja, T.Tymieniecka, I
The Energy Transformation Limit Theorem for Gas Flow Systems
Volov, V T
2011-01-01T23:59:59.000Z
The limit energy theorem which determines the possibility of transformation the energy flow in power systems in the absence of technical work is investigated and proved for such systems as gas lasers and plasmatrons, chemical gas reactors, vortex tubes, gas-acoustic and other systems, as well as a system of close stars. In the case of the same name ideal gas in the system the maximum ratio of energy conversion effectiveness is linked to the Carnot theorem, which in its turn is connected with the Nernst theorem. However, numerical analyses show that the class of flow energy systems is non-carnot one. The ratio of energy conversion effectiveness depends on the properties of the working medium; a conventional cycle in open-circuit is essentially irreversible. The proved theorem gives a more strongly worded II law of thermodynamics for the selected class of flow energy systems. Implications for astrophysical thermodynamic systems and the theory of a strong shock wave are discussed.
Evaluation of flow hood measurements for residential register flows
Walker, I.S.; Wray, C.P.; Dickerhoff, D.J.; Sherman, M.H.
2001-09-01T23:59:59.000Z
Flow measurement at residential registers using flow hoods is becoming more common. These measurements are used to determine if the HVAC system is providing adequate comfort, appropriate flow over heat exchangers and in estimates of system energy losses. These HVAC system performance metrics are determined by using register measurements to find out if individual rooms are getting the correct airflow, and in estimates of total air handler flow and duct air leakage. The work discussed in this paper shows that commercially available flow hoods are poor at measuring flows in residential systems. There is also evidence in this and other studies that flow hoods can have significant errors even when used on the non-residential systems they were originally developed for. The measurement uncertainties arise from poor calibrations and the sensitivity of exiting flow hoods to non-uniformity of flows entering the device. The errors are usually large--on the order of 20% of measured flow, which is unacceptably high for most applications. Active flow hoods that have flow measurement devices that are insensitive to the entering airflow pattern were found to be clearly superior to commercially available flow hoods. In addition, it is clear that current calibration procedures for flow hoods may not take into account any field application problems and a new flow hood measurement standard should be developed to address this issue.
Piezoelectric axial flow microvalve
Gemmen, Randall; Thornton, Jimmy; Vipperman, Jeffrey S.; Clark, William W.
2007-01-09T23:59:59.000Z
This invention is directed to a fuel cell operable with a quantity of fuel and a quantity of an oxidizer to produce electrical power, the fuel cell including a fuel cell body including a labyrinth system structured to permit the fuel and the oxidizer to flow therethrough; at least a first catalyst in fluid communication with the labyrinth; and at least a first microvalve operably disposed within at least a portion of the labyrinth. The microvalve utilizes a deflectable member operable upon the application of a voltage from a voltage source. The microvalve includes an elongated flow channel formed therein and extending substantially longitudinally between the first and second ends to permit substantially longitudinal flow of the fluid therethrough and between the first and second ends; and the deflectable member disposed on the valve body, the deflectable member including at least a first piezoelectric portion that is piezoelectrically operable to deflect the deflectable member between an open position and a closed position upon the application of a voltage, the deflectable member in the closed position being operable to resist the flow of the fluid through the flow channel.
Pressurized tundish for controlling a continuous flow of molten metal
Lewis, T.W.; Hamill, P.E. Jr.; Ozgu, M.R.; Padfield, R.C.; Rego, D.N.; Brita, G.P.
1990-07-24T23:59:59.000Z
A pressurized tundish for controlling a continuous flow of molten metal is characterized by having a pair of principal compartments, one being essentially unpressurized and receiving molten metal introduced thereto, and the other being adapted for maintaining a controlled gaseous pressure over the surface of the fluid metal therein, whereby, by controlling the pressure within the pressurized chamber, metal exiting from the tundish is made to flow continually and at a controlled rate. 1 fig.
Pressurized tundish for controlling a continuous flow of molten metal
Lewis, Thomas W. (964 Cork Dr., Bethel Park, PA 15102); Hamill, Jr., Paul E. (R.D. #1, Box 173A1, Jeannette, PA 15644); Ozgu, Mustafa R. (790 Yorkshire Rd., Bethlehem, PA 18017); Padfield, Ralph C. (1918 Paul Ave., Bethlehem, PA 18018); Rego, Donovan N. (1703 W. Brown St., Allentown, PA 18104); Brita, Guido P. (3225 Edna Terrace Ave., Bethlehem, PA 18017)
1990-01-01T23:59:59.000Z
A pressurized tundish for controlling a continous flow of molten metal characterized by having a pair of principal compartments, one being essentially unpressurized and receiving molten metal introduced thereto, and the other being adapted for maintaining a controlled gaseous pressure over the surface of the fluid metal therein, whereby, by controlling the pressure within the pressurized chamber, metal exiting from the tundish is made to flow continually and at a controlled rate.
Exact Maximum Likelihood estimator for the BL-GARCH model under elliptical distributed
Paris-Sud XI, Université de
Exact Maximum Likelihood estimator for the BL-GARCH model under elliptical distributed innovations, Brisbane QLD 4001, Australia Abstract We are interested in the parametric class of Bilinear GARCH (BL-GARCH examine, in this paper, the BL-GARCH model in a general setting under some non-normal distributions. We
Stone, G. A.; DeVito, E. M.; Nease, N. H.
2002-01-01T23:59:59.000Z
Texas adopted in its residential building energy code a maximum 0.40 solar heat gain coefficient (SHGC) for fenestration (e.g., windows, glazed doors and skylights)-a critical driver of cooling energy use, comfort and peak demand. An analysis...
Ocean Circulation During the Last Glacial Maximum Simulated by PMIP3 Climate Models
Schmittner, Andreas
in the intensity of the Atlantic Overturning Circulation (distinguished by the local maximum at approximately 30 N %. In the plot corresponding to the World Ocean Circulation, an increase in the Deep Circulation, associated of the water masses as well as the impact on ocean carbon storage. References: [1] Godfrey J. S., Geophysics
The chronology of the Last Glacial Maximum and deglacial events in central Argentine Patagonia
The chronology of the Last Glacial Maximum and deglacial events in central Argentine Patagonia and deglaciation in the Lago PueyrredoÂ´n valley of central Patagonia, 47.5 S, Argentina. The valley was a major and the onset of deglaciation occurred broadly synchronously throughout Patagonia. Deglaciation resulted
Paris-Sud XI, UniversitĂ© de
periods often appear in industry due to a machine breakdown (stochastic) or preventive maintenance of machine unavailability. However, in some cases (e.g. preventive maintenance), the maintenance of a machineSingle-machine scheduling with periodic and exible periodic maintenance to minimize maximum
THE SECOND LAW OF THERMODYNAMICS AND THE GLOBAL CLIMATE SYSTEM: A REVIEW OF THE MAXIMUM
Lorenz, Ralph D.
to absorption of solar radiation in the climate system is found to be irrelevant to the maximized prop- erties from hot to cold places, thereby producing the kinetic energy of the fluid itself. His generalTHE SECOND LAW OF THERMODYNAMICS AND THE GLOBAL CLIMATE SYSTEM: A REVIEW OF THE MAXIMUM ENTROPY
Hydraulic limits on maximum plant transpiration and the emergence of the safetyefficiency trade-off
Jackson, Robert B.
Hydraulic limits on maximum plant transpiration and the emergence of the safetyefficiency trade.12126 Key words: hydraulic limitation, safety efficiency trade-off, soilplantatmosphere model, trait hydraulics constrain ecosystem productivity by setting physical limits to water transport and hence carbon
Performance of Photovoltaic Maximum Power Point Tracking Algorithms in the Presence of Noise
Odam, Kofi
Performance of Photovoltaic Maximum Power Point Tracking Algorithms in the Presence of Noise tracking (MPPT) algorithms for photovoltaic systems, including how noise affects both tracking speed-performance photovoltaic sys- tems. An intelligent controller adjusts the voltage, current, or impedance seen by a solar
Towards a frequency-dependent discrete maximum principle for the implicit Monte Carlo equations
Wollaber, Allan B [Los Alamos National Laboratory; Larsen, Edward W [Los Alamos National Laboratory; Densmore, Jeffery D [Los Alamos National Laboratory
2010-12-15T23:59:59.000Z
It has long been known that temperature solutions of the Implicit Monte Carlo (IMC) equations can exceed the external boundary temperatures, a so-called violation of the 'maximum principle.' Previous attempts at prescribing a maximum value of the time-step size {Delta}{sub t} that is sufficient to eliminate these violations have recommended a {Delta}{sub t} that is typically too small to be used in practice and that appeared to be much too conservative when compared to numerical solutions of the IMC equations for practical problems. In this paper, we derive a new estimator for the maximum time-step size that includes the spatial-grid size {Delta}{sub x}. This explicitly demonstrates that the effect of coarsening {Delta}{sub x} is to reduce the limitation on {Delta}{sub t}, which helps explain the overly conservative nature of the earlier, grid-independent results. We demonstrate that our new time-step restriction is a much more accurate means of predicting violations of the maximum principle. We discuss how the implications of the new, grid-dependent timestep restriction can impact IMC solution algorithms.
Hydroelastic analysis of the floating plate optimized for maximum radiation damping
Damaren, Christopher J.
Hydroelastic analysis of the floating plate optimized for maximum radiation damping Christopher J t In previous work, the problem of optimizing the shape of a thin floating plate to maximize radiation damping, incompressible ocean of infinite extent. For simplicity, only rigid heave motions were considered and the damping
Maximum late Holocene extent of the western Greenland Ice Sheet during the late 20th century
Briner, Jason P.
the 20th century. This suggests a lagged ice-margin response to prior cooling, such as the Little Ice AgeMaximum late Holocene extent of the western Greenland Ice Sheet during the late 20th century Samuel Keywords: Greenland Ice Sheet Little Ice Age 10 Be exposure dating Ice-dammed lake Lake sediment core a b
Maximum Likelihood Estimation of Mixture Densities for Binned and Truncated Multivariate
Smyth, Padhraic
Maximum Likelihood Estimation of Mixture Densities for Binned and Truncated Multivariate Data in data analysis and machine learning. This paper addresses the problem of fitting mixture densities to multivariate binned and truncated data. The EM approach proposed by McLachlan and Jones (1988
Design of wind farm layout for maximum wind energy capture Andrew Kusiak*, Zhe Song
Kusiak, Andrew
Design of wind farm layout for maximum wind energy capture Andrew Kusiak*, Zhe Song Intelligent Accepted 24 August 2009 Available online 22 September 2009 Keywords: Wind farm Wind turbine Layout design Optimization Evolutionary algorithms Operations research a b s t r a c t Wind is one of the most promising
Maximum Class Separability for Rough-Fuzzy C-Means Based Brain MR Image Segmentation
Pal, Sankar Kumar
Maximum Class Separability for Rough-Fuzzy C-Means Based Brain MR Image Segmentation Pradipta Maji of brain MR images. The RFCM algorithm comprises a judicious integration of the of rough sets, fuzzy sets with vagueness and incompleteness in class definition of brain MR images, the membership function of fuzzy sets
EXTENSION OF THE MAXIMUM POWER REGION OF DOUBLY-SALIENT VARIABLE RELUCTANCE MOTORS
Paris-Sud XI, UniversitĂ© de
-Salient Variable Reluctance Motors (DSVRM) has been investigated and developed for variable-speed drives during, variable-frequency generators, wind wheels, machine tools, etc.). In these applications, it is generally necessary to operate in a regime of a high speed ux-weakening (zone of maximum constant power), for a better
Sukumar, N.
the nonlinear system of equations. Maximum-entropy basis functions are used to discretize the two displacement control method is implemented to solve the nonlinear system of equations and to obtain tools in the field of structural engineering, Yaw and co-workers [1] presented a blended FE and meshfree
Maximum Utility Product Pricing Models and Algorithms Based on Reservation Prices
TunĂ§el, Levent
Maximum Utility Product Pricing Models and Algorithms Based on Reservation Prices R. Shioda L. Tun for pricing a product line with several customer segments under the assumption that customers' product choices utility model and formulate it as a mixed-integer programming problem, design heuristics and valid cuts
Self-Assembly for Maximum Yields Under Constraints Michael J. Fox and Jeff S. Shamma
Shamma, Jeff S.
Self-Assembly for Maximum Yields Under Constraints Michael J. Fox and Jeff S. Shamma Abstract-- We present an algorithm that, given any target tree, synthesizes reversible self-assembly rules that provide states that cannot be recovered from the unlabeled graph. I. INTRODUCTION Self-assembly is the phenomenon
Generalized Local Maximum Principles for Finite-Difference Operators Author(s): Achi Brandt
Generalized Local Maximum Principles for Finite-Difference Operators Author(s): Achi Brandt Source://www.jstor.org/action/showPublisher?publisherCode=ams. . Each copy of any part of a JSTOR transmission must contain the same copyright notice that appears on the screen or printed page of such transmission. JSTOR is a not-for-profit service that helps scholars
NOAA Technical Memorandum NWS HYDRO 39 PROBABLE MAXIMUM PRECIPITATION FOR THE UPPER
NOAA Technical Memorandum NWS HYDRO 39 PROBABLE MAXIMUM PRECIPITATION FOR THE UPPER DEERFIELD RIVER The Office of Hydrology (HYDRO) of the National Weather Service (NWS) develops procedures for making river agencies, and conducts pertinent research and development. NOAA Technical Memorandums in the NWS HYDRO
Pauly, Daniel
). In addition, average surface water pH of the ocean has dropped by 0.1 units since pre- industrial timesIntegrating ecophysiology and plankton dynamics into projected changes in maximum fisheries catch 7TJ, UK 2 Centre for Environment, Fisheries and Aquaculture Science, Pakefield Road, Lowestoft
Blind Equalization via Approximate Maximum Likelihood Source Seungjin CHOI x1 and Andrzej CICHOCKI y
Choi, Seungjin
Blind Equalization via Approximate Maximum Likelihood Source Separation Seungjin CHOI x1, RIKEN 2-1 Hirosawa, Wako-shi Saitama 351-0198, JAPAN Abstract Blind equalization of single input multiple output (SIMO) FIR channels can be refor- mulated as the problem of blind source separation
Mandelis, Andreas
Photothermoacoustic imaging of biological tissues: maximum depth characterization comparison for Advanced Diffusion-Wave Technologies Department of Mechanical and Industrial Engineering 5 King's College induced in light-absorbing materials can be observed either as a transient signal in time domain
Power and Sample Size Determination for a Stepwise Test Procedure for Finding the Maximum Safe Dose
Tamhane, Ajit C.
Power and Sample Size Determination for a Stepwise Test Procedure for Finding the Maximum Safe Dose This paper addresses the problem of power and sample size calculation for a stepwise multiple test procedure of a compound. A general expression for the power of this procedure is derived. It is used to find the minimum
Optimization of stomatal conductance for maximum carbon gain under dynamic soil moisture
Katul, Gabriel
Optimization of stomatal conductance for maximum carbon gain under dynamic soil moisture Stefano Accepted 26 September 2013 Available online 9 October 2013 Keywords: Optimization Photosynthesis Soil moisture Stomatal conductance Transpiration a b s t r a c t Optimization theories explain a variety
Uncorking the bottle: What triggered the Paleocene/Eocene thermal maximum methane release?
Uncorking the bottle: What triggered the Paleocene/Eocene thermal maximum methane release? Miriam E realms that has been attributed to a massive methane (CH4) release from marine gas hydrate reservoirs. Previously proposed mechanisms for this methane release rely on a change in deepwater source region
Electrical Estimation of Conditional Probability for Maximum-likelihood Based PMD Mitigation
Zweck, John
Xi, T¨ulay Adali, and John Zweck Department of Computer Science and Electrical Engineering UniversityElectrical Estimation of Conditional Probability for Maximum-likelihood Based PMD Mitigation Wenze probability density functions in the presence of both all-order PMD and ASE noise are estimated electronically
Turro, Nicholas J.
Hydrogen Molecules inside Fullerene C70: Quantum Dynamics, Energetics, Maximum Occupancy of Chemistry, New York UniVersity, New York, New York 10003, Department of Chemistry, Brown UniVersity, ProVidence, Rhode Island 02912, and Department of Chemistry, Columbia UniVersity, New York, New York 10027 Received
Maximum Power Point Tracking Control for Photovoltaic System Using Adaptive Neuro-Fuzzy
Paris-Sud XI, UniversitĂ© de
conventional controller like Adaptive Neuro-Fuzzy "ANFIS" and fuzzy logic controller is proposed and simulated power point tracking (MPPT) technique will be used. Fuzzy logic control "FLC" and adaptive neuro-fuzzyMaximum Power Point Tracking Control for Photovoltaic System Using Adaptive Neuro- Fuzzy "ANFIS
Magnetofossil spike during the Paleocene-Eocene thermal maximum: Ferromagnetic resonance, rock,2 Timothy D. Raub,3,4 Dirk Schumann,5 Hojatollah Vali,5 Alexei V. Smirnov,3,6 and Joseph L. Kirschvink1 controversial hypothesis that a cometary impact triggered the PETM. Here we present ferromagnetic resonance (FMR
Extraction of Spectral Functions from Dyson-Schwinger Studies via the Maximum Entropy Method
Dominik Nickel
2006-07-20T23:59:59.000Z
It is shown how to apply the Maximum Entropy Method (MEM) to numerical Dyson-Schwinger studies for the extraction of spectral functions of correlators from their corresponding Euclidean propagators. Differences to the application in lattice QCD are emphasized and, as an example, the spectral functions of massless quarks in cold and dense matter are presented.
Nasser, Hassan
2014-01-01T23:59:59.000Z
We propose a numerical method to learn Maximum Entropy (MaxEnt) distributions with spatio-temporal constraints from experimental spike trains. This is an extension of two papers [10] and [4] who proposed the estimation of parameters where only spatial constraints were taken into account. The extension we propose allows to properly handle memory effects in spike statistics, for large sized neural networks.
Beyond Boltzmann-Gibbs statistics: Maximum entropy hyperensembles out of equilibrium Gavin E at equilibrium? Here, we argue the most appropriate additional parameter is the nonequilibrium entropy of ways that the same system can be out of equilibrium. That the equilibrium entropy is maximized given
Extraction of spectral functions from Dyson-Schwinger studies via the maximum entropy method
Nickel, Dominik [Institut fuer Kernphysik, Technische Universitaet Darmstadt, D-64289 Darmstadt (Germany)]. E-mail: dominik.nickel@physik.tu-darmstadt.de
2007-08-15T23:59:59.000Z
It is shown how to apply the Maximum Entropy Method (MEM) to numerical Dyson-Schwinger studies for the extraction of spectral functions of correlators from their corresponding Euclidean propagators. Differences to the application in lattice QCD are emphasized and, as an example, the spectral functions of massless quarks in cold and dense matter are presented.
Lattice Field Theory with the Sign Problem and the Maximum Entropy Method
Masahiro Imachi; Yasuhiko Shinno; Hiroshi Yoneyama
2007-02-09T23:59:59.000Z
Although numerical simulation in lattice field theory is one of the most effective tools to study non-perturbative properties of field theories, it faces serious obstacles coming from the sign problem in some theories such as finite density QCD and lattice field theory with the $\\theta$ term. We reconsider this problem from the point of view of the maximum entropy method.
A PROXIMITY CONTROL ALGORITHM TO MINIMIZE NONSMOOTH AND NONCONVEX SEMI-INFINITE MAXIMUM
Noll, Dominikus
in the context of eigen- value optimization, and [8] gives an overview of the history. The bases for the presentA PROXIMITY CONTROL ALGORITHM TO MINIMIZE NONSMOOTH AND NONCONVEX SEMI-INFINITE MAXIMUM EIGENVALUE function, semi-infinite problem, H-norm. 1. Introduction. Proximity control for bundle methods has been
A PROXIMITY CONTROL ALGORITHM TO MINIMIZE NONSMOOTH AND NONCONVEX SEMI-INFINITE MAXIMUM
Noll, Dominikus
in the context of eigen- value optimization, and [9] gives an overview of the history. The bases for the presentA PROXIMITY CONTROL ALGORITHM TO MINIMIZE NONSMOOTH AND NONCONVEX SEMI-INFINITE MAXIMUM EIGENVALUE function, semi-infinite problem, H-norm. 1. Introduction. Proximity control for bundle methods has been
2007 Wholesale Power Rate Schedules : 2007 General Rate Schedule Provisions.
United States. Bonneville Power Administration.
2006-11-01T23:59:59.000Z
This schedule is available for the contract purchase of Firm Power to be used within the Pacific Northwest (PNW). Priority Firm (PF) Power may be purchased by public bodies, cooperatives, and Federal agencies for resale to ultimate consumers, for direct consumption, and for Construction, Test and Start-Up, and Station Service. Rates in this schedule are in effect beginning October 1, 2006, and apply to purchases under requirements Firm Power sales contracts for a three-year period. The Slice Product is only available for public bodies and cooperatives who have signed Slice contracts for the FY 2002-2011 period. Utilities participating in the Residential Exchange Program (REP) under Section 5(c) of the Northwest Power Act may purchase Priority Firm Power pursuant to the Residential Exchange Program. Rates under contracts that contain charges that escalate based on BPA's Priority Firm Power rates shall be based on the three-year rates listed in this rate schedule in addition to applicable transmission charges. This rate schedule supersedes the PF-02 rate schedule, which went into effect October 1, 2001. Sales under the PF-07 rate schedule are subject to BPA's 2007 General Rate Schedule Provisions (2007 GRSPs). Products available under this rate schedule are defined in the 2007 GRSPs. For sales under this rate schedule, bills shall be rendered and payments due pursuant to BPA's 2007 GRSPs and billing process.
Flow Characteristics Analysis of Widows' Creek Type Control Valve for Steam Turbine Control
Yoo, Yong H.; Sohn, Myoung S.; Suh, Kune Y. [PHILOSOPHIA, Inc., Seoul National University, San 56-1 Sillim-dong, Gwanak-gu, Seoul, 151-742 (Korea, Republic of)
2006-07-01T23:59:59.000Z
The steam turbine converts the kinetic energy of steam to mechanical energy of rotor blades in the power conversion system of fossil and nuclear power plants. The electric output from the generator of which the rotor is coupled with that of the steam turbine depends on the rotation velocity of the steam turbine bucket. The rotation velocity is proportional to the mass flow rate of steam entering the steam turbine through valves and nozzles. Thus, it is very important to control the steam mass flow rate for the load following operation of power plants. Among various valves that control the steam turbine, the control valve is most significant. The steam flow rate is determined by the area formed by the stem disk and the seat of the control valve. While the ideal control valve linearly controls the steam mass flow rate with its stem lift, the real control valve has various flow characteristic curves pursuant to the stem lift type. Thus, flow characteristic curves are needed to precisely design the control valves manufactured for the operating conditions of nuclear power plants. OMEGA (Optimized Multidimensional Experiment Geometric Apparatus) was built to experimentally study the flow characteristics of steam flowing inside the control valve. The Widows' Creek type control valve was selected for reference. Air was selected as the working fluid in the OMEGA loop to exclude the condensation effect in this simplified approach. Flow characteristic curves were plotted by calculating the ratio of the measured mass flow rate versus the theoretical mass flow rate of the air. The flow characteristic curves are expected to be utilized to accurately design and operate the control valve for fossil as well as nuclear plants. (authors)
Morozov, Victor (Manassas, VA)
2011-04-05T23:59:59.000Z
A flow cell for electrophoretically-assisted capturing analytes from a flow. The flow cell includes a specimen chamber, a first membrane, a second membrane, a first electrode chamber, and a second electrode chamber. The specimen chamber may have a sample inlet and a sample outlet. A first portion of the first membrane may be coupled to a first portion of the specimen chamber. A first portion of the second membrane may be coupled to a second portion of the specimen chamber. The first electrode chamber may be configured to accept a charge. A portion of the first electrode chamber may be coupled to a second portion of the first membrane. A second electrode chamber may be configured to accept an opposite charge. A portion of the second electrode chamber may be coupled to a second portion of the second membrane.
Dynamics on the Laminar-Turbulent Boundary and the Origin of the Maximum Drag Reduction Asymptote
Graham, Michael D.
Dynamical trajectories on the boundary in state space between laminar and turbulent plane channel flow—edge states—are computed for Newtonian and viscoelastic fluids. Viscoelasticity has a negligible effect on the properties ...
The magnetic flywheel flow meter: Theoretical and experimental contributions
Buchenau, D., E-mail: d.buchenau@hzdr.de; Galindo, V.; Eckert, S. [Helmholtz-Zentrum Dresden-Rossendorf, Institute of Fluid Dynamics, Bautzner Landstraße 400, 01328 Dresden (Germany)
2014-06-02T23:59:59.000Z
The development of contactless flow meters is an important issue for monitoring and controlling of processes in different application fields, like metallurgy, liquid metal casting, or cooling systems for nuclear reactors and transmutation machines. Shercliff described in his book “The Theory of Electromagnetic Flow Measurement, Cambridge University Press, 1962” a simple and robust device for contact-less measurements of liquid metal flow rates which is known as magnetic flywheel. The sensor consists of several permanent magnets attached on a rotatable soft iron plate. This arrangement will be placed closely to the liquid metal flow to be measured, so that the field of the permanent magnets penetrates into the fluid volume. The flywheel will be accelerated by a Lorentz force arising from the interaction between the magnetic field and the moving liquid. Steady rotation rates of the flywheel can be taken as a measure for the mean flow rate inside the fluid channel. The present paper provides a detailed theoretical description of the sensor in order to gain a better insight into the functional principle of the magnetic flywheel. Theoretical predictions are confirmed by corresponding laboratory experiments. For that purpose, a laboratory model of such a flow meter was built and tested on a GaInSn-loop under various test conditions.
Noninvasive Characterization Of A Flowing Multiphase Fluid Using Ultrasonic Interferometry
Sinha, Dipen N. (Los Alamos, NM)
2005-05-10T23:59:59.000Z
An apparatus for noninvasively monitoring the flow and/or the composition of a flowing liquid using ultrasound is described. The position of the resonance peaks for a fluid excited by a swept-frequency ultrasonic signal have been found to change frequency both in response to a change in composition and in response to a change in the flow velocity thereof. Additionally, the distance between successive resonance peaks does not change as a function of flow, but rather in response to a change in composition. Thus, a measurement of both parameters (resonance position and resonance spacing), once calibrated, permits the simultaneous determination of flow rate and composition using the apparatus and method of the present invention.
Noninvasive characterization of a flowing multiphase fluid using ultrasonic interferometry
Sinha, Dipen N.
2003-11-11T23:59:59.000Z
An apparatus for noninvasively monitoring the flow and/or the composition of a flowing liquid using ultrasound is described. The position of the resonance peaks for a fluid excited by a swept-frequency ultrasonic signal have been found to change frequency both in response to a change in composition and in response to a change in the flow velocity thereof. Additionally, the distance between successive resonance peaks does not change as a function of flow, but rather in response to a change in composition. Thus, a measurement of both parameters (resonance position and resonance spacing), once calibrated, permits the simultaneous determination of flow rate and composition using the apparatus and method of the present invention.
Noninvasive characterization of a flowing multiphase fluid using ultrasonic interferometry
Sinha, Dipen N. (Los Alamos, NM)
2007-06-12T23:59:59.000Z
An apparatus for noninvasively monitoring the flow and/or the composition of a flowing liquid using ultrasound is described. The position of the resonance peaks for a fluid excited by a swept-frequency ultrasonic signal have been found to change frequency both in response to a change in composition and in response to a change in the flow velocity thereof. Additionally, the distance between successive resonance peaks does not change as a function of flow, but rather in response to a change in composition. Thus, a measurement of both parameters (resonance position and resonance spacing), once calibrated, permits the simultaneous determination of flow rate and composition using the apparatus and method of the present invention.
SALTSTONE DISPOSAL FACILITY: DETERMINATION OF THE PROBABLE MAXIMUM WATER TABLE ELEVATION
Hiergesell, R
2005-04-01T23:59:59.000Z
A coverage depicting the configuration of the probable maximum water table elevation in the vicinity of the Saltstone Disposal Facility (SDF) was developed to support the Saltstone program. This coverage is needed to support the construction of saltstone vaults to assure that they remain above the maximum elevation of the water table during the Performance Assessment (PA) period of compliance. A previous investigation to calculate the historical high water table beneath the SDF (Cook, 1983) was built upon to incorporate new data that has since become available to refine that estimate and develop a coverage that could be extended to the perennial streams adjacent to the SDF. This investigation incorporated the method used in the Cook, 1983 report to develop an estimate of the probable maximum water table for a group of wells that either existed at one time at or near the SDF or which currently exist. Estimates of the probable maximum water table at these wells were used to construct 2D contour lines depicting this surface beneath the SDF and extend them to the nearby hydrologic boundaries at the perennial streams adjacent to the SDF. Although certain measures were implemented to assure that the contour lines depict a surface above which the water table will not rise, the exact elevation of this surface cannot be known with complete certainty. It is therefore recommended that the construction of saltstone vaults incorporate a vertical buffer of at least 5-feet between the base of the vaults and the depicted probable maximum water table elevation. This should provide assurance that the water table under the wet extreme climatic condition will never rise to intercept the base of a vault.
The Flow of Newtonian Fluids in Axisymmetric Corrugated Tubes
Taha Sochi
2010-06-08T23:59:59.000Z
This article deals with the flow of Newtonian fluids through axially-symmetric corrugated tubes. An analytical method to derive the relation between volumetric flow rate and pressure drop in laminar flow regimes is presented and applied to a number of simple tube geometries of converging-diverging nature. The method is general in terms of fluid and tube shape within the previous restrictions. Moreover, it can be used as a basis for numerical integration where analytical relations cannot be obtained due to mathematical difficulties.
Time-resolved fluorescence decay measurements for flowing particles
Deka, Chiranjit (Miami, FL); Steinkamp, John A. (Los Alamos, NM)
1999-01-01T23:59:59.000Z
Time-resolved fluorescence decay measurements for flowing particles. An apparatus and method for the measurement and analysis of fluorescence for individual cells and particles in flow are described, wherein the rapid measurement capabilities of flow cytometry and the robust measurement and analysis procedures of time-domain fluorescence lifetime spectroscopy are combined. A pulse-modulated cw laser is employed for excitation of the particles. The characteristics and the repetition rate of the excitation pulses can be readily adjusted to accommodate for fluorescence decays having a wide range of lifetimes.
Time-resolved fluorescence decay measurements for flowing particles
Deka, C.; Steinkamp, J.A.
1999-06-01T23:59:59.000Z
Time-resolved fluorescence decay measurements are disclosed for flowing particles. An apparatus and method for the measurement and analysis of fluorescence for individual cells and particles in flow are described, wherein the rapid measurement capabilities of flow cytometry and the robust measurement and analysis procedures of time-domain fluorescence lifetime spectroscopy are combined. A pulse-modulated CW laser is employed for excitation of the particles. The characteristics and the repetition rate of the excitation pulses can be readily adjusted to accommodate for fluorescence decays having a wide range of lifetimes. 12 figs.
Peter A. Thomas
1996-08-20T23:59:59.000Z
I discuss the multiphase nature of the intracluster medium whose neglect can lead to overestimates of the baryon fraction of clusters by up to a factor of two. The multiphase form of the cooling flow equations are derived and reduced to a simple form for a wide class of self-similar density distributions. It is shown that steady-state cooling flows are \\emph{not} consistent with all possible emissivity profiles which can therefore be used as a test of the theory. In combination, they provide strong constraints on the mass distribution within the cooling radius.
Kumar, Anand T.N.
, Massachusetts 02115 ReceiVed: December 31, 2000; In Final Form: April 27, 2001 We discuss the application distributions of protein conformational substates. As an experimental example, we present an MEM analysis
Broader source: Energy.gov [DOE]
The U.S. Department of Energy prepared this statement to evaluate the environmental impacts of increasing petroleum production, and of additional or expanded operational facilities, at Elk Hills from 160,000 barrels per day up to 240,000 barrels per day.
Air-flow regulation system for a coal gasifier
Fasching, George E. (Morgantown, WV)
1984-01-01T23:59:59.000Z
An improved air-flow regulator for a fixed-bed coal gasifier is provided which allows close air-flow regulation from a compressor source even though the pressure variations are too rapid for a single primary control loop to respond. The improved system includes a primary controller to control a valve in the main (large) air supply line to regulate large slow changes in flow. A secondary controller is used to control a smaller, faster acting valve in a secondary (small) air supply line parallel to the main line valve to regulate rapid cyclic deviations in air flow. A low-pass filter with a time constant of from 20 to 50 seconds couples the output of the secondary controller to the input of the primary controller so that the primary controller only responds to slow changes in the air-flow rate, the faster, cyclic deviations in flow rate sensed and corrected by the secondary controller loop do not reach the primary controller due to the high frequency rejection provided by the filter. This control arrangement provides at least a factor of 5 improvement in air-flow regulation for a coal gasifier in which air is supplied by a reciprocating compressor through a surge tank.
Qin, Wensheng
Catalytic conversion of glycerol to oxygenated fuel additive in a continuous flow reactor: Process optimization Malaya R. Nanda a , Zhongshun Yuan a , Wensheng Qin b , Hassan S. Ghaziaskar c , Marc for synthesis of solketal from glycerol was optimized. A maximum yield of 94 Â± 2% was obtained at optimum
Study of nuclear dynamics of neutron-rich colliding pair at energy of vanishing flow
Sakshi Gautam
2011-07-28T23:59:59.000Z
We study nuclear dynamics at the energy of vanishing flow of neutron-rich systems having N/Z ratio 1.0, 1.6 and 2.0 throughout the mass range at semi central colliding geometry. In particular we study the behavior of average and maximum density with N/Z dependence of the system.
High-latitude eruptions cast shadow over the African monsoon and the flow of the Nile
Stenchikov, Georgiy L.
the Sahel of Africa, thus producing the low Nile flow. Future high-latitude eruptions would significantly, p. 120]. By January 1785, 1/6 of the population of Egypt had either died or left the country of Asia and North America. Recon- structed summer temperatures using tree ring maximum latewood density
Modal and transient dynamics of jet flows X. Garnaud,1, a)
Paris-Sud XI, UniversitĂ© de
of incompressible and compressible isothermal jets are investigated by means of their optimal initial perturbations for a large variety of flow configurations in recent years; examples include vortex shedding in the cylinder frequency, and found maximum amplification to occur at a Strouhal number of 0.3. This approximate value
Assessments of fluid friction factors for use in leak rate calculations
Chivers, T.C. [Berkeley Technology Centre, Glos (United Kingdom)
1997-04-01T23:59:59.000Z
Leak before Break procedures require estimates of leakage, and these in turn need fluid friction to be assessed. In this paper available data on flow rates through idealized and real crack geometries are reviewed in terms of a single friction factor k It is shown that for {lambda} < 1 flow rates can be bounded using correlations in terms of surface R{sub a} values. For {lambda} > 1 the database is less precise, but {lambda} {approx} 4 is an upper bound, hence in this region flow calculations can be assessed using 1 < {lambda} < 4.
An analysis of an application of radioactive ionization for gas flow metering
Lam, Carroll Frank
2012-06-07T23:59:59.000Z
fulfillment of the requirements for ths legree of MASTER OF SC1ENCE May 1959 Major Subject: Electrical Engines x ing AN ANALYSIS OF AN APPLICATION OF RADIOACTIVE IONIZATION FOR l 1 '~, '1 1 ', '1 ' 1 1 "1 g 1 n \\ '& \\ GAS FLOW METERING A...'s Apparatus Z. An Ezperimental Flow Meter . 3. Mark I Meter and Test Equipment 4. Electrical Circuit 5. Current vs. Flow Rate Curve for Mark I Meter. . . . . . . . . . . . . 6. Current vs. Flow Rate for DifferentSource Spacings. . . . . . . . . . 7...
Rate constants for charge transfer across semiconductor-liquid interfaces
Fajardo, A.M.; Lewis, N.S. [California Institute of Technology, Pasadena, CA (United States)
1996-11-08T23:59:59.000Z
Interfacial charge-transfer rate constants have been measured for n-type Si electrodes in contact with a series of viologen-based redox couples in methanol through analyses of the behavior of these junctions with respect to their current density versus potential and differential capacitance versus potential properties. The data allow evaluation of the maximum rate constant (and therefore the electronic coupling) for majority carriers in the solid as well as of the dependence of the rate constant on the driving force for transfer of delocalized electrons from the n-Si semiconducting electrode into the localized molecular redox species in the solution phase. The data are in good agreement with existing models of this interfacial electron transfer process and provide insight into the fundamental kinetic events underlying the use of semiconducting photoelectrodes in applications such as solar energy conversion. 23 refs., 3 figs.
Hughes, Larry
The Inverted Block Rate:The Inverted Block Rate: An Alternative to Flat Rate BillingAn Alternative;Inverted Block RateInverted Block Rate 22 IntroductionIntroduction Â·Â· Modern societies rely on electrical collectionMetering and Rate Models facilitate collection #12;Inverted Block RateInverted Block Rate 33 Rate
Asymptotic Cellular Growth Rate as the Effective Information Utilization Rate
Pugatch, Rami; Tlusty, Tsvi
2013-01-01T23:59:59.000Z
We study the average asymptotic growth rate of cells in randomly fluctuating environments. Using a game-theoretic perspective, we show that any response strategy has an asymptotic growth rate, which is the sum of: (i) the maximal growth rate at the worst possible distribution of environments, (ii) relative information between the actual distribution of environments to the worst one, and (iii) information utilization rate which is the information rate of the sensory devices minus the "information dissipation rate", the amount of information not utilized by the cell for growth. In non-stationary environments, the optimal strategy is the time average of the instantaneous optimal strategy and the optimal switching times are evenly spaced in the statistical (Fisher) metric.
Schwartz, Stephen E.
ENERGY FLOWS FORCINGS CLIMATE CHANGE A REALLY TOUGH PROBLEM Stephen E. Schwartz, BNL, 7-20-11 www average temperature 15Â°C or 59Â°F #12;ATMOSPHERIC RADIATION Power per area Energy per time per area Unit" temperature to radiative flux. #12;GLOBAL ENERGY BALANCE Global and annual average energy fluxes in watts per
James Binney
2001-03-23T23:59:59.000Z
For two decades the steady-state cooling-flow model has dominated the literature of cluster and elliptical-galaxy X-ray sources. For ten years this model has been in severe difficulty from a theoretical point of view, and it is now coming under increasing pressure observationally. For two decades the steady-state cooling-flow model has dominated the literature of cluster and elliptical-galaxy X-ray sources. For ten years this model has been in severe difficulty from a theoretical point of view, and it is now coming under increasing pressure observationally. A small number of enthusiasts have argued for a radically different interpretation of the data, but had little impact on prevailing opinion because the unsteady heating picture that they advocate is extremely hard to work out in detail. Here I explain why it is difficult to extract robust observational predictions from the heating picture. Major problems include the variability of the sources, the different ways in which a bi-polar flow can impact on X-ray emission, the weakness of synchrotron emission from sub-relativistic flows, and the sensitivity of synchrotron emission to a magnetic field that is probably highly localized.
Nishi, Y.; Eguchi, Y.; Nishihara, T.; Kanai, T.; Kondo, M. [Central Research Inst. of Electric Power Industry CRIEPI, 2-11-1 Iwado Kita, Komae-shi, Tokyo 201-8511 (Japan)
2012-07-01T23:59:59.000Z
In orifice flowmeters used in nuclear power plants, requirements for the inner surface roughness of upstream piping and eccentric installation exist depending on certain standards. If these cannot be satisfied based on the installation condition, an appropriate error margin must be considered, although this remains to be clarified. In this research, quantitative data concerning the relative error of orifice flowmeters were obtained during experiments with the parameters of the inner surface roughness of upstream piping and the installation eccentricity of the orifice hole. The maximum Reynolds number of the experimental facility is about 1.6x10{sup 6}. In orifice flowmeters, the flow rate is calculated based on the differential pressure between upstream and downstream orifices and the peculiar discharge coefficient C. The latter value shows an upward trend with increasing roughness of piping, while change of 0.3% of C was observed in terms of roughness (case 2), which approaches the limits of the JIS standard. With significant roughness (Case 3) that exceeds five times the JIS standard, C is shown to have increased by about 1%. No influence was observed by varying the direction of eccentric installation, hence this was fixed and the amount of eccentricity was considered. Change in C of about 0.25% was observed when around twice the standard level of eccentricity was applied. The error margin data under conditions exceeding the JIS standard for the orifice flowmeter was obtained. (authors)
Daily air pollution effects on children's respiratory symptoms and peak expiratory flow
Vedal, S.; Schenker, M.B.; Munoz, A.; Samet, J.M.; Batterman, S.; Speizer, F.E.
1987-06-01T23:59:59.000Z
To identify acute respiratory health effects associated with air pollution due to coal combustion, a subgroup of elementary school-aged children was selected from a large cross-sectional study and followed daily for eight months. Children were selected to obtain three equal-sized groups: one without respiratory symptoms, one with symptoms of persistent wheeze, and one with cough or phlegm production but without persistent wheeze. Parents completed a daily diary of symptoms from which illness constellations of upper respiratory illness (URI) and lower respiratory illness (LRI) and the symptom of wheeze were derived. Peak expiratory flow rate (PEFR) was measured daily for nine consecutive weeks during the eight-month study period. Maximum hourly concentrations of sulfur dioxide, nitrogen dioxide, ozone, and coefficient of haze for each 24-hour period, as well as minimum hourly temperature, were correlated with daily URI, LRI, wheeze, and PEFR using multiple regression models adjusting for illness occurrence or level of PEFR on the immediately preceding day. Respiratory illness on the preceding day was the most important predictor of current illness. A drop in temperature was associated with increased URI and LRI but not with increased wheeze or with a decrease in level of PEFR. No air pollutant was strongly associated with respiratory illness or with level of PEFR, either in the group of children as a whole, or in either of the symptomatic subgroups; the pollutant concentrations observed, however, were uniformly lower than current ambient air quality standards.
Epstein, Irving R.
oxidase in a continuous flow stirred tank reactor Vladimir K. Vanag,a David G. MĂguez,b and Irving R as the flow rate is varied in a continuous flow stirred tank reactor. Oscillations in pH can be obtained
Two dimensional flow of a compressible gas in a thin passage
Desai, Anantkumar Ratanji
1971-01-01T23:59:59.000Z
with Experimental Results Nasa Flow Rates at 2 atm. Nasa Flow Rates at 3 atm. Temperature Profiles at 2 atm. Temperature Profiles at 3 atm. Pressure Profiles at U=+300 ft/sec. Pressure Profiles at U -300 ft/sec. Page 12 14 16 17 18 19 21 22 Various... Non-Isentropic -300 -200 -100 0 100 200 300 U ft/sec. FIGURE 4 MASS FLOW RATES AT 3 atm. 18 85o O T R 800 P ~ 2atm 1 T % 700' 1 U ft/sec. -300 T'R 750 700 -100 -10 650 +10 +300 600 10 Diatance x in 10 ft. -3 FIGURE 5 TEMPERATURE...
Quantum computing with nearest neighbor interactions and error rates over 1%
David S. Wang; Austin G. Fowler; Lloyd C. L. Hollenberg
2010-09-20T23:59:59.000Z
Large-scale quantum computation will only be achieved if experimentally implementable quantum error correction procedures are devised that can tolerate experimentally achievable error rates. We describe a quantum error correction procedure that requires only a 2-D square lattice of qubits that can interact with their nearest neighbors, yet can tolerate quantum gate error rates over 1%. The precise maximum tolerable error rate depends on the error model, and we calculate values in the range 1.1--1.4% for various physically reasonable models. Even the lowest value represents the highest threshold error rate calculated to date in a geometrically constrained setting, and a 50% improvement over the previous record.
Analysis of Refrigerant Flow and Deformation for a Flexible Short-Tube using a Finite Element Model
O'Neal, D.L.; Bassiouny, R.
reliability. Short-tubes have either a constant inner dia- meter flow channel or a tapered channel with a smallAbstract A finite element model was used to simulate single-phase flow of R-22 through flexible short-tubes. The numerical model included the fluid... in the flow area. The more flexible (5513 kPa) short-tube restricted the mass flow rate more than the most rigid (9889 kPa) short-tube used in this study. The mass flow rates estimated with the finite element model were as much as 14% higher than those from...
Boyer, Edmond
by microorganisms into biogas (methane and carbon dioxide) and digestate (natural manure) in the absence of oxygen digestion S. Diop1 and I. Simeonov2 Abstract-- The paper proposes an observability anal- ysis and estimation measured quantities Â the dilution rate and the flow rates of methane and carbon dioxide in the biogas
Tracer studies of pathways and rates of meltwater transport through Arctic summer sea ice
Eicken, Hajo
Tracer studies of pathways and rates of meltwater transport through Arctic summer sea ice H. Eicken) program's field site in the northern Chukchi Sea, snow and ice meltwater flow was found to have a strong impact on the heat and mass balance of sea ice during the summer of 1998. Pathways and rates of meltwater
Two-dimensional flows of foam: drag exerted on circular obstacles and dissipation
Benjamin Dollet; Florence Elias; Catherine Quilliet; Arnaud Huillier; Miguel Aubouy; Francois Graner
2004-11-22T23:59:59.000Z
A Stokes experiment for foams is proposed. It consists in a two-dimensional flow of a foam, confined between a water subphase and a top plate, around a fixed circular obstacle. We present systematic measurements of the drag exerted by the flowing foam on the obstacle, \\emph{versus} various separately controlled parameters: flow rate, bubble volume, solution viscosity, obstacle size and boundary conditions. We separate the drag into two contributions, an elastic one (yield drag) at vanishing flow rate, and a fluid one (viscous coefficient) increasing with flow rate. We quantify the influence of each control parameter on the drag. The results exhibit in particular a power-law dependence of the drag as a function of the solution viscosity and the flow rate with two different exponents. Moreover, we show that the drag decreases with bubble size, increases with obstacle size, and that the effect of boundary conditions is small. Measurements of the streamwise pressure gradient, associated to the dissipation along the flow of foam, are also presented: they show no dependence on the presence of an obstacle, and pressure gradient depends on flow rate, bubble volume and solution viscosity with three independent power laws.
On the minimum and maximum mass of neutron stars and the delayed collapse
Strobel, K; Strobel, Klaus; Weigel, Manfred K.
2001-01-01T23:59:59.000Z
The minimum and maximum mass of protoneutron stars and neutron stars are investigated. The hot dense matter is described by relativistic (including hyperons) and non-relativistic equations of state. We show that the minimum mass ($\\sim$ 0.88 - 1.28 $M_{\\sun}$) of a neutron star is determined by the earliest stage of its evolution and is nearly unaffected by the presence of hyperons. The maximum mass of a neutron star is limited by the protoneutron star or hot neutron star stage. Further we find that the delayed collapse of a neutron star into a black hole during deleptonization is not only possible for equations of state with softening components, as for instance, hyperons, meson condensates etc., but also for neutron stars with a pure nucleonic-leptonic equation of state.
On the minimum and maximum mass of neutron stars and the delayed collapse
Klaus Strobel; Manfred K. Weigel
2000-12-14T23:59:59.000Z
The minimum and maximum mass of protoneutron stars and neutron stars are investigated. The hot dense matter is described by relativistic (including hyperons) and non-relativistic equations of state. We show that the minimum mass ($\\sim$ 0.88 - 1.28 $M_{\\sun}$) of a neutron star is determined by the earliest stage of its evolution and is nearly unaffected by the presence of hyperons. The maximum mass of a neutron star is limited by the protoneutron star or hot neutron star stage. Further we find that the delayed collapse of a neutron star into a black hole during deleptonization is not only possible for equations of state with softening components, as for instance, hyperons, meson condensates etc., but also for neutron stars with a pure nucleonic-leptonic equation of state.
Beer, M.
1980-12-01T23:59:59.000Z
The maximum likelihood method for the multivariate normal distribution is applied to the case of several individual eigenvalues. Correlated Monte Carlo estimates of the eigenvalue are assumed to follow this prescription and aspects of the assumption are examined. Monte Carlo cell calculations using the SAM-CE and VIM codes for the TRX-1 and TRX-2 benchmark reactors, and SAM-CE full core results are analyzed with this method. Variance reductions of a few percent to a factor of 2 are obtained from maximum likelihood estimation as compared with the simple average and the minimum variance individual eigenvalue. The numerical results verify that the use of sample variances and correlation coefficients in place of the corresponding population statistics still leads to nearly minimum variance estimation for a sufficient number of histories and aggregates.
An Ad-Hoc Method for Obtaining chi**2 Values from Unbinned Maximum Likelihood Fits
M. Williams; C. A. Meyer
2008-06-30T23:59:59.000Z
A common goal in an experimental physics analysis is to extract information from a reaction with multi-dimensional kinematics. The preferred method for such a task is typically the unbinned maximum likelihood method. In fits using this method, the likelihood is a goodness-of-fit quantity in that it effectively discriminates between available hypotheses; however, it does not provide any information as to how well the best hypothesis describes the data. In this paper, we present an {\\em ad-hoc} procedure for obtaining chi**2/n.d.f. values from unbinned maximum likelihood fits. This method does not require binning the data, making it very applicable to multi-dimensional problems.
Maximum-Entropy Meshfree Method for Compressible and Near-Incompressible Elasticity
Ortiz, A; Puso, M A; Sukumar, N
2009-09-04T23:59:59.000Z
Numerical integration errors and volumetric locking in the near-incompressible limit are two outstanding issues in Galerkin-based meshfree computations. In this paper, we present a modified Gaussian integration scheme on background cells for meshfree methods that alleviates errors in numerical integration and ensures patch test satisfaction to machine precision. Secondly, a locking-free small-strain elasticity formulation for meshfree methods is proposed, which draws on developments in assumed strain methods and nodal integration techniques. In this study, maximum-entropy basis functions are used; however, the generality of our approach permits the use of any meshfree approximation. Various benchmark problems in two-dimensional compressible and near-incompressible small strain elasticity are presented to demonstrate the accuracy and optimal convergence in the energy norm of the maximum-entropy meshfree formulation.
Hanel, Rudolf; Gell-Mann, Murray
2014-01-01T23:59:59.000Z
The maximum entropy principle (MEP) is a method for obtaining the most likely distribution functions of observables from statistical systems, by maximizing entropy under constraints. The MEP has found hundreds of applications in ergodic and Markovian systems in statistical mechanics, information theory, and statistics. For several decades there exists an ongoing controversy whether the notion of the maximum entropy principle can be extended in a meaningful way to non-extensive, non-ergodic, and complex statistical systems and processes. In this paper we start by reviewing how Boltzmann-Gibbs-Shannon entropy is related to multiplicities of independent random processes. We then show how the relaxation of independence naturally leads to the most general entropies that are compatible with the first three Shannon-Khinchin axioms, the (c,d)-entropies. We demonstrate that the MEP is a perfectly consistent concept for non-ergodic and complex statistical systems if their relative entropy can be factored into a general...
Exact computation of the Maximum Entropy Potential of spiking neural networks models
Cofre, Rodrigo
2014-01-01T23:59:59.000Z
Understanding how stimuli and synaptic connectivity in uence the statistics of spike patterns in neural networks is a central question in computational neuroscience. Maximum Entropy approach has been successfully used to characterize the statistical response of simultaneously recorded spiking neurons responding to stimuli. But, in spite of good performance in terms of prediction, the ?tting parameters do not explain the underlying mechanistic causes of the observed correlations. On the other hand, mathematical models of spiking neurons (neuro-mimetic models) provide a probabilistic mapping between stimulus, network architecture and spike patterns in terms of conditional proba- bilities. In this paper we build an exact analytical mapping between neuro-mimetic and Maximum Entropy models.
Maximum-entropy principle for static and dynamic high-field transport in semiconductors
Trovato, M. [Dipartimento di Matematica, Universita di Catania, Viale A. Doria, 95125 Catania (Italy); Reggiani, L. [Dipartimento di Ingegneria dell' Innovazione e Nanotechnology National Laboratory of CNR-INFM, Universita di Lecce, Via Arnesano s/n, 73100 Lecce (Italy)
2006-06-15T23:59:59.000Z
Within the maximum entropy principle we present a general theory able to provide, in a dynamical context, the macroscopic relevant variables for carrier transport under electric fields of arbitrary strength. For the macroscopic variables the linearized maximum entropy approach is developed including full-band effects within a total energy scheme. Under spatially homogeneous conditions, we construct a closed set of hydrodynamic equations for the small-signal (dynamic) response of the macroscopic variables. The coupling between the driving field and the energy dissipation is analyzed quantitatively by using an arbitrary number of moments of the distribution function. The theoretical approach is applied to n-Si at 300 K and is validated by comparing numerical calculations with ensemble Monte Carlo simulations and with experimental data.
Theoretical and experimental studies of churn flow in vertical tubes. Final technical report
Not Available
1986-01-27T23:59:59.000Z
The pattern known as churn flow is a highly unsteady pattern with stochastic features and is extremely complex. However, calculations show that for many geothermal wells the condition of churn flow consists over much of the length of the two phase zone. Furthermore, it frequently exists at the surface so that design of separation equipment and surface piping depends on the accurate modelling of this type of flow. It has been the long term purpose of this project to develop physically based models for churn flow which can be used as a basis for predicting holdup, frictional loss and heat transfer rates for this flow pattern in geothermal systems. To achieve this end, it was necessary to develop new methods for measuring the time dependent characteristics of the flow and thus be able to uncover the basic physics of the flow. Models can then be developed based on this understanding which characterizes the flow and equations for holdup, friction and heat transfer evolved.
Evaluation of a CFD-model for simulation of simplified flow conditioners
Erdal, A. [Statoil/K-LAB, Haugesund (Norway); Torbergsen, L.E.; Rimestad, S.; Krogstad, P.A. [Norwegian Inst. of Technology, Trondheim (Norway)
1995-12-31T23:59:59.000Z
Perforated plate flow conditioners are used to generate a fully developed turbulent flow profile upstream of an orifice meter. It is very time-consuming to measure the effect of a flow conditioner for different upstream flow profiles. Therefore a project is initiated to evaluate the performance of a computational fluid computer code for this purpose. If the code correctly predicts the flow characteristics downstream of more complex flow conditioners. In this study a k-{var_epsilon} CFD-model was used to predict the flow downstream of obstruction plates having one large or nine small holes. Both mean velocity, turbulent kinetic energy, k, and the dissipation rate of turbulent kinetic energy, {var_epsilon}, were calculated and compared against measured data. The results indicate that it is possible to predict the mean velocity well and that the accuracy of the predicted k and {var_epsilon} depends on the complexity of the flow.
A simple model of gas flow in a porous powder compact
Shugard, Andrew D.; Robinson, David B.
2014-04-01T23:59:59.000Z
This report describes a simple model for ideal gas flow from a vessel through a bed of porous material into another vessel. It assumes constant temperature and uniform porosity. Transport is treated as a combination of viscous and molecular flow, with no inertial contribution (low Reynolds number). This model can be used to fit data to obtain permeability values, determine flow rates, understand the relative contributions of viscous and molecular flow, and verify volume calibrations. It draws upon the Dusty Gas Model and other detailed studies of gas flow through porous media.
An Analysis of Maximum Residential Energy Efficiency in Hot and Humid Climates
Malhotra, M.; Haberl, J. S.
2006-01-01T23:59:59.000Z
the high efficiency instantaneous water heater with electronic ignition. The largest equipment energy savings (20%) was achieved from the horizontal-axis clothes washer. Compact fluorescent lamps (CFLs) saved 75% lighting energy use. Among all...AN ANALYSIS OF MAXIMUM RESIDENTIAL ENERGY EFFICIENCY IN HOT AND HUMID CLIMATES Mini Malhotra Graduate Research Assistant Jeff Haberl, Ph.D., P.E. Professor/Associate Director Energy Systems Laboratory, Texas A&M University College...
A maximum entropy theorem with applications to the measurement of biodiversity
Leinster, Tom
2009-01-01T23:59:59.000Z
This is a preliminary article stating and proving a new maximum entropy theorem. The entropies that we consider can be used as measures of biodiversity. In that context, the question is: for a given collection of species, which frequency distribution(s) maximize the diversity? The theorem provides the answer. The chief surprise is that although we are dealing not just with a single entropy, but a one-parameter family of entropies, there is a single distribution maximizing all of them simultaneously.
Hydrodynamic equations for electrons in graphene obtained from the maximum entropy principle
Barletti, Luigi, E-mail: luigi.barletti@unifi.it [Dipartimento di Matematica e Informatica “Ulisse Dini”, Universitŕ degli Studi di Firenze, Viale Morgagni 67/A, 50134 Firenze (Italy)
2014-08-15T23:59:59.000Z
The maximum entropy principle is applied to the formal derivation of isothermal, Euler-like equations for semiclassical fermions (electrons and holes) in graphene. After proving general mathematical properties of the equations so obtained, their asymptotic form corresponding to significant physical regimes is investigated. In particular, the diffusive regime, the Maxwell-Boltzmann regime (high temperature), the collimation regime and the degenerate gas limit (vanishing temperature) are considered.