WorldWideScience
1

Jet Noise Modeling for Suppressed and Unsuppressed Aircraft in - NASA  

Science.gov (United States)

Mechanisms, AGARD Conference Proceedings No. 131, 1974, Paper No. 11. ... Olsen, W. and Karchmer, A., Lip Noise Generated by Flow Separation From Nozzle ...

2

Experimental simulation of heat transfer augmentation by break-jets in passive containment cooling system  

International Nuclear Information System (INIS)

The studies of forced jet augmentation of natural convection heat transfer are introduced. It investigates experimentally mixed convection and heat transfer augmentation by forced jets in a large rectangular enclosure with a vertical cooling surface. The experiment is designed to measure the key parameters governing the heat transfer augmentation by a forced jet, and to investigate the effects of geometric factors, including the jet diameter, jet injection orientation, interior structures, and enclosure aspect ratio, on conditions simulating those of actual passive containment cooling systems and scales approaching those of actual containment buildings or compartments. The tests that cover a variety of injection modes will contribute to reveal the nature of mixing and stratification phenomena under accident conditions to a new generation of ...

2010-02-01

3

Experimental investigation of mixed convection heat transfer caused by forced-jets in large enclosure  

Energy Technology Data Exchange (ETDEWEB)

This research investigates experimentally mixed convection and heat transfer augmentation by forced jets in a large enclosure, at conditions simulating those of actual passive containment cooling systems and scales approaching those of actual containment buildings or compartments. The experiment was designed to measure the key parameters governing the heat transfer augmentation by forced jets and investigate the effects of geometric factors, including the jet diameter, jet injection orientation, interior structures, and enclosure aspect ratio. The tests cover a variety of injection modes leading to flow configurations of interest that contribute to reveal the nature of mixing and stratification phenomena in the containment under accident conditions of interest. The heat transfer of mixed convection can be predicted to be controlled by ...

2004-07-01

4

Investigation of mixed convection in a large rectangular enclosure  

Energy Technology Data Exchange (ETDEWEB)

This experimental research investigates mixed convection and heat transfer augmentation by gaseous forced jets in a large enclosure, at conditions simulating those of passive containment cooling systems for Gen III+ passively safe reactors. The experiment is designed to measure the key parameters governing heat transfer augmentation by forced jets, and to investigate the effects of geometric factors, including the jet diameter, jet injection orientation, interior structures, and enclosure aspect ratio. The tests cover a variety of injection modes leading to flow configurations of interest for mixing and stratification phenomena in containments under accident conditions. Correlations for heat transfer augmentation by forced jets are developed and compared with experimental data. The characteristic recirculation speed inside the enclosure is ...

2007-05-15

5

Investigation of mixed convection in a large rectangular enclosure  

International Nuclear Information System (INIS)

This experimental research investigates mixed convection and heat transfer augmentation by gaseous forced jets in a large enclosure, at conditions simulating those of passive containment cooling systems for Gen III+ passively safe reactors. The experiment is designed to measure the key parameters governing heat transfer augmentation by forced jets, and to investigate the effects of geometric factors, including the jet diameter, jet injection orientation, interior structures, and enclosure aspect ratio. The tests cover a variety of injection modes leading to flow configurations of interest for mixing and stratification phenomena in containments under accident conditions. Correlations for heat transfer augmentation by forced jets are developed and compared with experimental data. The characteristic recirculation speed inside the enclosure is ...

2007-05-01

6

NASA - A Cosmic Inkblot Test  

Science.gov (United States)

material may survive intact and mix back into interstellar gas clouds, helping to fuel the next generation of stars. NASA's Jet Propulsion Laboratory, Pasadena, Calif.,...

2011-08-10

7

A relativistic mixing-layer model for jets in low-luminosity radio galaxies  

CERN Document Server

We present an analytical model for jets in Fanaroff & Riley Class I (FRI) radio galaxies, in which an initially laminar, relativistic flow is surrounded by a shear layer. We apply the appropriate conservation laws to constrain the jet parameters, starting the model where the radio emission is observed to brighten abruptly. We assume that the laminar flow fills the jet there and that pressure balance with the surroundings is maintained from that point outwards. Entrainment continuously injects new material into the jet and forms a shear layer, which contains material from both the environment and the laminar core. The shear layer expands rapidly with distance until finally the core disappears, and all of the material is mixed into the shear layer. Beyond this point, the shear layer expands in a cone and decelerates smoothly. We apply our model to the well-observed FRI source 3C31 ...

2009-01-01

8

CAA broadband noise prediction for aeroacoustic design  

Science.gov (United States)

The current status of a computational aeroacoustics (CAA) approach to simulate broadband noise is reviewed. The method rests on the use of steady Reynolds averaged Navier-Stokes (RANS) simulation to describe the time-averaged motion of turbulent flow. By means of synthetic turbulence the steady one-point statistics (e.g. turbulence kinetic energy) and turbulent length- and time-scales of RANS are translated into fluctuations having statistics that very accurately reproduce the initial RANS target-setting. The synthetic fluctuations are used to prescribe sound sources which drive linear perturbation equations. The whole approach represents a methodology to solve statistical noise theory with state-of-the-art CAA tools in the time-domain. A brief overview of the synthetic turbulence model and its numerical discretization in terms of the random particle-mesh (RPM) and fast random particle-mesh (FRPM) method is given. Results are presented for ...

2011-08-01

9

Experimental assessment of the velocity and temperature distribution in an indoor displacement ventilation jet  

British Library Electronic Table of Contents (United Kingdom)

Displacement Ventilation (DV) offers a great opportunity to improve indoor air quality while reducing the energy consumption compared to mixing ventilation. A frequent problem with displacement ventilation is however the draft discomfort caused by the cold air movement at foot level and excessive temperature difference between head and ankle. Despite numerous past studies, there is still a lack of detailed data regarding the velocity and temperature distribution inside DV jets. In this experimental study, measurements of the air velocity and temperature are performed in the DV jet produced by a flat wall-mounted DV diffuser, using a fine mesh focused on the 0.00-0.20 m height range. Two supply conditions are studied. Three planes of measurements are covered: the vertical longitudinal plane...

2012-01-01

10

U.S. Department Of Energy's nuclear engineering education research: highlights of recent and current research-II. 4. Studies of Forced-Convection Heat Transfer Augmentation in Large Containment Enclosures  

International Nuclear Information System (INIS)

This paper provides information on heat transfer enhancement due to jet mixing inside a cylindrical enclosure. The work addresses conservative heat transfer assumptions regarding mixing and condensation that have typically been incorporated into passive containment design analyses. The current research presents an interesting possibility for increasing decay heat removal of passive containment systems under combined natural and forced convection. Eliminating these conservative assumptions could provide the basis for a change of containment design and reduce the construction cost. It is found that the ratio of forced- and free convection Nusselt numbers can be predicted as a function of the Archimedes number and a correlated factor accounting for jet orientation and enclosure geometry. To use the small-scale tests for large containment design, scale-up methods and criteria are important for matching the ...

2001-06-17

11

Multipass laser mass spectrometer with extreme jet-cooled pulsed gas  

International Nuclear Information System (INIS)

We have developed a photon accumulated laser mass spectrometer that enables us to identify isomers of polychlorinated dibenzo-p-dioxin and polychlorinated dibenzofuran. This system is comprised of a high temperature (230 deg. C) pulsed gas injector (PGI), multimirror multipath system (MMS), and the conventional time-of-flight mass spectrometer. The PGI induces the formation of a choked supersonic jet gas pulse that cools down to a temperature to restrain fragmentation and reduces vibrational and rotational thermal noises. The results suggest that the excited lifetime numbers and fragment dynamics of these species change completely with jet cooling of molecules. The MMS enhances the soft ionization efficiency (by a factor of 1000 over a single path system) through photon accumulation by extending the irradiation duration (to about 40 ns) and volume, and it further minimizes fragmentation by carefully controlling the laser ...

2006-09-01

12

Numerical study of inflow conditions on a turbulent isothermal or heated plane jet; Etude numerique des conditions d'emission sur un ecoulement de type jet plan turbulent isotherme ou chauffe  

Energy Technology Data Exchange (ETDEWEB)

We intend to solve equations governing turbulent plane-vertical isotherm and non isotherm jets by taking into account inflow conditions at the exit of the nozzle. The analysis is focused on the influence of these conditions on this type of flow. Two cases are considered (uniform and parabolic velocity and temperature profiles). A finite difference scheme is developed to solve the governing equations. This numeric model allows us to show that the region of fully developed regime begins much nearer the nozzle for the turbulent case than for the laminar flow case. Indeed, the turbulence increases the mixing between the incoming gas from the nozzle and the ambient fluid, and consequently the size of the potential core zone decreases. The results are compared to other works introducing mathematical variables based on the energy conservation for the case of the mixed convection and the momentum conservation for the forced ...

1999-11-01

13

Ultra-high pressure water jet: Baseline report  

International Nuclear Information System (INIS)

The ultra-high pressure waterjet technology was being evaluated at Florida International University (FIU) as a baseline technology. In conjunction with FIU's evaluation of efficiency and cost, this report covers the evaluation conducted for safety and health issues. It is a commercially available technology and has been used for various projects at locations throughout the country. The ultra-high pressure waterjet technology acts as a cutting tool for the removal of surface substrates. The Husky trademark pump feeds water to a lance that directs the high pressure water at the surface to be removed. The safety and health evaluation during the testing demonstration focused on two main areas of exposure. These were dust and noise. The dust exposure was found to be minimal, which would be expected due to the wet environment inherent in the technology, but noise exposure was at a significant level. Further testing for noise is ...

1997-07-01

14

Analysis of Computer Experiments with Multiple Noise Sources  

DEFF Research Database (Denmark)

In this paper we present a modeling framework for analyzing computer models with two types of variations. The paper is based on a case study of an orthopedic surgical unit, which has both controllable and uncontrollable factors. Our results show that this structure of variation can be modeled effectively with linear mixed effects models and generalized additive models. Copyright (C) 2009 John Wiley & Sons, Ltd.

2010-01-01

15

Nitrogen oxide abatement by distributed fuel addition. Quarterly report No. 8, May 1, 1989--July 31, 1989  

Energy Technology Data Exchange (ETDEWEB)

The performance of the new combustor was tested. Experiments showed that this combustor has superior insulating quality than the previous one. Measured radial concentrations indicated uniform distribution of the primary fuel (coal) inside the fire tube resulting in reasonably flat concentration profiles. However, measured radial concentrations after the addition of the reburn fuel showed uneven distribution of the fuel resulting in parabolic concentration profiles, an indication of insufficient mixing in the reburn zone. In order to study mechanisms of nitrogenous species destruction in the reburn zone, it is necessary to achieve adequate mixing if the assumption of one dimensional plug flow behavior is to be valid. Thus, it became necessary to modify the injector design and the injection mode of the reburn fuel to achieve an adequate level of mixing which is the focus of this report. The results show that a minimum reburn ...

1989-08-25

16

Computer simulations of reacting particle-laden jet mixing applied to SO_2 control by dry sorbent injection  

International Nuclear Information System (INIS)

A particle-laden turbulent reacting flow model is described and applied to in-furnace, dry SO_2 control in boilers. Sulfur capture by calcium-based sorbents is represented by a shrinking core model which accounts for surface areas loss and product layer diffusion. Sorbent particle trajectories and dispersion are followed with cloud statistics in a Lagrangian framework. The turbulent fluid mechanics and chemical reactions are coupled, and solutions obtained for mean and fluctuating velocity, composition, and particle position. Comparisons are made with data from an US EPA laboratory reactor. Practical implications for SO_2 control are examined including the effects of jet velocity, sorbent injection location, boiler load and thermal profiles.

1992-11-01

17

Washboard modes as ELM-related events in JET  

Energy Technology Data Exchange (ETDEWEB)

Washboard (WB) modes (Smeulders P et al 1999 Plasma Phys. Control. Fusion 41 1303) are a very common edge instability regularly observed in the H-mode regime in JET. They are detected as (normally several) bands of continuously fluctuating magnetic activity rotating in the direction of the electron diamagnetic drift with typical frequencies in the range of 10-90 kHz. The time evolution of the WB mode frequency is found to follow qualitatively the evolution of the electron temperature measured near the pedestal top, probably due to the strong diamagnetic drift associated with the large pedestal gradients. Evidence for their involvement in the pedestal and ELM dynamics will be presented. Increasing WB mode amplitude is correlated with an increase in the time between consecutive type-I ELMs. In situations in which a sudden increase (decrease) of WB mode activity is observed, the build-up of the pedestal temperature (and, linked to this, also of the pedestal pressure) ...

2004-01-01

18

Wind loss prevention for open cavity solar receivers  

Energy Technology Data Exchange (ETDEWEB)

Apparatus for minimizing thermal loss in a windowless, open cavity solar receiver due to airflow at the receiver aperture includes means for deflecting wind away from the cavity opening such that flow stream reattachment occurs away from the receiver aperture to provide a dead air zone at the cavity opening. This prevents turbulent-mixing airflow exchange between ambient air and heated air within the solar receiver. The wind deflector apparatus includes either a passive annular deflection foil at the receiver aperture, or an active device for producing an outwardly projected air jet at the receiver aperture.

1982-01-26

19

Development and use of localized arc filament plasma actuators for high-speed flow control  

International Nuclear Information System (INIS)

The paper discusses recent results on the development of localized arc filament plasma actuators and their use in controlling high-speed and high Reynolds number jet flows. Multiple plasma actuators (up to 8) are controlled using a custom-built 8-channel high-voltage pulsed plasma generator. The plasma generator independently controls pulse repetition rate (0-200 kHz), duty cycle and phase for each individual actuator. Current and voltage measurements demonstrated the power consumption of each actuator to be quite low (20 W at 20% duty cycle). Emission spectroscopy temperature measurements in the pulsed arc filament showed rapid temperature increase over the first 10-20 ?s of arc operation, from below 1000 deg. C to up to about 2000 deg. C. At longer discharge pulse durations, 20-100 ?s, the plasma temperature levels off at approximately 2000 deg. C. Modelling calculations using an unsteady, quasi-one-dimensional arc filament model showed that rapid localized ...

2007-02-07

20

Midwave infrared type-II InAs/GaSb superlattice detectors with mixed interfaces  

Science.gov (United States)

We report the growth and fabrication of midwave infrared InAs/GaSb strain layer superlattice (SLS) detectors. Growth of alternate interfaces leads to a reduced strain between the GaSb buffer and SLS ({delta}a{sub parallel}/a=-5x10{sup -4}), enabling the growth of active regions up to 3 {mu}m (625 periods). The structural, optical, and electrical properties of the active region were characterized using x-ray crystallography and photoluminescence, respectively. p-i-n detectors were grown using 625 periods of 8 ML (monolayer) InAs/8 ML GaSb as the active region. The {lambda}{sub cutoff} for the detectors was 4.6 {mu}m with a conversion efficiency of 32% at V{sub b}=-0.2 V. Detectivity was obtained using noise power spectral density measurements under 300 K 2{pi} field of view illumination and was equal to 5.2x10{sup 10} and 3x10{sup 10} cm Hz{sup 1/2}/W (V{sub b}=-0.02 V, T=80 K) in the white noise and 1/f noise limit (at 50 ...

2006-07-01

21

Cumulative Jets Interaction with Spent Nuclear Fuel  

International Science & Technology Center (ISTC)

Research of Cumulative Jets Interaction with Spent Nuclear Fuel

22

Stochastic combustion modeling of a direct injection diesel engine  

Energy Technology Data Exchange (ETDEWEB)

A mathematical model was developed to simulate the combustion process of a direct injection diesel engine. The model considers the key features of such a combustion process; namely fuel droplet evaporation, spray formation, mixing, ignition of heterogeneous burning of the fuel. To model mixing, great emphasis was placed on treating both large and small scale aspects of mixing, the model divides the combustion chamber into three distinct regions of air, fuel spray, and a turbulent plume that is formed once ignition occurs. The fuel spray itself is considered to be composed of multiple zones, which in turn are made of cells of equal mass and of different thermodynamic states. Micromixing of the fuel and air cells, within each zone of the jet and the turbulent plume, is then achieved by utilizing the concept of Monte Carlo stochastic coalescence dispersion technique. The frequency of such cell interactions ...

1984-01-01

23

Half-trek criterion for generic identifiability of linear structural equation models  

CERN Document Server

A linear structural equation model relates random variables of interest and corresponding Gaussian noise terms via a linear equation system. Each such model can be represented by a mixed graph in which directed edges encode the linear equations, and bidirected edges indicate possible correlations among noise terms. We study parameter identifiability in these models, that is, we ask for conditions that ensure that the edge coefficients and correlations appearing in a linear structural equation model can be uniquely recovered from the covariance matrix of the associated normal distribution. We treat the case of generic identifiability, where unique recovery is possible for almost every choice of parameters. We give a new graphical criterion that is sufficient for generic identifiability. It improves criteria from prior work and does not require the directed part of the graph to be acyclic. We also develop a related necessary ...

2011-01-01

28

DSN Radio Science ... - InterPlanetary Network (IPN) Progress Report  

Science.gov (United States)

tions, final noise-power spectral density measurements were made. These measurements of the noise-power spectral density were not the desired phase- noise ...

29

The effects of organosulfur compounds upon the storage stability of Jet A fuel  

Science.gov (United States)

This study examined the effect of sulfur-containing compounds on the storage stability of Jet A

1981-01-01

30

The Behavior of Water in Jet Fuels and the Clogging of ...  

Science.gov (United States)

... values and unless special precautions and equipment are used, it would be very difficult to service and maintain operational jet-fuel systems with ...

1950-01-11

31

Mais Tallinna-Helsingi laevaliinile Nordic Jet Line / Koit Luus  

Index Scriptorium Estoniae

AS Nordic Jet Line uus katamaraan Tallinna-Helsingi laevaliinil

1998-01-01

32

Fuel retention in H mode experiments in JET  

International Nuclear Information System (INIS)

... edge localized modes h-mode plasma confinement jet tokamak l-mode plasma

2007-07-02

34

Theoretical study on device efficiency of pulsed liquid jet pump  

International Nuclear Information System (INIS)

The influence of the main factors on device efficiency of pulsed liquid jet pump with gas-liquid piston is analysed, the theoretical equation and its time-averaged solution of pulsed liquid jet pump device efficiency are derived. The theoretical and experimental results show that the efficiency of transmission of energy and mass to use pulsed jet is greatly raised, compared with steady jet, in the same device of liquid jet pump. The calculating results of time-averaged efficiency of pulsed liquid jet pump are approximately in agreement with the experimental results in our and foreign countries

2001-03-01

35

The radio jet in NGC 6251  

International Nuclear Information System (INIS)

High-resolution observations are presented of the 300-kpc jet in the giant radio galaxy NGC 6251. The width of the jet is resolved over most of its length, and the axis of the jet wiggles with an amplitude increasing linearly with distance from the nucleus. Polarization data are used to derive densities of cold matter in the jet and, from the argument that the jet must form the lobe in a time equal to the age of the lobe, the speed of the jet is estimated as c/20. The energetics of the jet are then dominated by the bulk flow along it of cold matter at a rate of 1 solar mass yr"-"1. The jet appears to be confined; the wiggle of its axis is probably due to oscillations of the direction of the collimator with a period of about 6 x 10"6 yr. (author).

36

OPTIMIZED FUEL INJECTOR DESIGN FOR MAXIMUM IN-FURNACE NOx REDUCTION AND MINIMUM UNBURNED CARBON  

Energy Technology Data Exchange (ETDEWEB)

Reaction Engineering International (REI) has established a project team of experts to develop a technology for combustion systems which will minimize NO x emissions and minimize carbon in the fly ash. This much need technology will allow users to meet environmental compliance and produce a saleable by-product. This study is concerned with the NO x control technology of choice for pulverized coal fired boilers, ?in-furnace NO x control,? which includes: staged low-NO x burners, reburning, selective non-catalytic reduction (SNCR) and hybrid approaches (e.g., reburning with SNCR). The program has two primary objectives: 1) To improve the performance of ?in-furnace? NO x control processes. 2) To devise new, or improve existing, approaches for maximum ?in-furnace? NO x control and minimum unburned carbon. The program involves: 1) fundamental studies at laboratory- and bench-scale to define NO reduction mechanisms in flames and reburning jets; 2) laboratory experiments ...

1998-01-01

37

Jet cutting and cleaning bibliography  

Energy Technology Data Exchange (ETDEWEB)

This bibliography includes over 600 references (with abstracts) on all aspects of waterjet cutting and cleaning. The references are listed under the following chapter headings: fluid mechanics of jets; jet impact; equipment; jet cleaning; jet cutting; civil engineering; mining and tunnelling; precision cutting; underwater; safety; and bibliographies. Separate author and corporate source indexes are provided.

1988-01-01

38

Lockheed WP-3D Orion  

Science.gov (United States)

Approximately 62,000 lbs Fuel Load: 58,000 lbs. Type Fuel: JP4, JP5, JP8, JET A, JET A-1, JET B Standard Fuel Burn: 4500 - 6000 lbs/hr depending on altitude and airspeed Maximum...

2011-08-17

39

Gas Turbine Blade Heat Transfer Augmentation by Impingement of Air Jets Having Various Configurations.  

Science.gov (United States)

An experimental investigation of heat transfer characteristics for various configurations of air jets impinging on the leading edge inner surface of a gas turbine blade wall is presented. Three configurations were investigated, namely a slot jet, a round ...

1970-01-01

40

A novel method for quantifying scanner instability in fMRI  

British Library Electronic Table of Contents (United Kingdom)

Abstract A method was developed to quantify the effect of scanner instability on functional MRI data by comparing the instability noise to endogenous noise present when scanning a human. The instability noise was computed from agar phantom data collected with two flip angles, allowing for a separation of the instability from the background noise. This method was used on human data collected at four 3 T scanners, allowing the physiological noise level to be extracted from the data. In a -well-operating- scanner, the instability noise is generally less than 10% of physiological noise in white matter and only about 2% of physiological noise in cortex. This indicates that instability in a well-operating scanner adds very little noise to functional MRI results. This new method allows researcher...

2011-01-01

41

Experiments to investigate the effects of radiative cooling on plasma jet collimation  

CERN Document Server

Preliminary experiments have been performed to investigate the effects of radiative cooling on plasma jets. Thin (3 um - 5 um) conical shells were irradiated with an intense laser, driving jets with velocities > 100 km/s. Through use of different target materials - aluminium, copper and gold - the degree of radiative losses was altered, and their importance for jet collimation investigated. A number of temporally resoved optical diagnostics was used, providing information about the jet evolution. Gold jets were seen to be narrower than those from copper targets, while aluminium targets produced the least collimated flows.

2010-01-01

42

Measurement of audible noise from transmission lines  

Energy Technology Data Exchange (ETDEWEB)

The audible noise produced by corona on high-voltage transmission lines has several characteristics that differentiate it from other community noises. Transmission line noise is quite broadband and has a significant high frequency content. Special instrumentation designed to measure this type of noise pollution is described. All measuring systems have the same three basic elements: a transducer, a processing device, and an output device. Recorders, microphone devices, frequency analyzers, and meteorological instrumentation are discussed.

1981-03-01

43

Toxicity of Jet A (Aviation Fuel) Selected Aquatic Organisms  

Science.gov (United States)

... Descriptors : *JET ENGINE FUELS, *AQUATIC ORGANISMS, *AVIATION FUELS, *TOXICITY, HEALTH, SMOKE SCREENS, WIND, WATER ...

1989-03-01

44

Sorption of Selected Volatile Organic Constituents of Jet Fuels ...  

Science.gov (United States)

... TITLE (Include Security Classification) Sorption of Selected Volatile Organic Constituents of Jet Fuels and Solvents on Natural Sorbents from Gas ...

1988-08-01

45

Questions and Answers on Changes to the Renewable Fuel Standard...  

Science.gov (United States)

fuel obligation under the RFS2 program for the production or importation of conventional jet fuel, RINs can be generated for renewable jet fuel. Is that right? A: As described in...

2011-08-18

46

CRC literature survey on the thermal oxidation stability of jet fuel. [Coordinating Research Council  

Science.gov (United States)

Two hundred eleven references from the period 1951 to 1978 are reviewed in this survey of literature on the thermal stability of jet aircraft fuels.

1979-01-01

47

Briefing on the Latest Sanctions on Iran  

Science.gov (United States)

of refined petroleum and energy traders have stopped sales of refined product to Iran. Jet fuel suppliers are now refusing to supply jet fuel to Iran Air at most destinations in...

2011-08-28

48

ADVANCED INTERNAL COMBUSTION ENGINE USING JET FUELS ...  

Science.gov (United States)

NASA 1996 STTR Phase I. Proposal Number: 960022. Project Title: ADVANCED INTERNAL COMBUSTION ENGINE USING JET FUELS FOR LIGHT AIRCRAFT ...

49

Kinetic Modeling of Gasoline Surrogate Components and Mixtures under Engine Conditions  

Energy Technology Data Exchange (ETDEWEB)

Real fuels are complex mixtures of thousands of hydrocarbon compounds including linear and branched paraffins, naphthenes, olefins and aromatics. It is generally agreed that their behavior can be effectively reproduced by simpler fuel surrogates containing a limited number of components. In this work, an improved version of the kinetic model by the authors is used to analyze the combustion behavior of several components relevant to gasoline surrogate formulation. Particular attention is devoted to linear and branched saturated hydrocarbons (PRF mixtures), olefins (1-hexene) and aromatics (toluene). Model predictions for pure components, binary mixtures and multicomponent gasoline surrogates are compared with recent experimental information collected in rapid compression machine, shock tube and jet stirred reactors covering a wide range of conditions pertinent to internal combustion engines (3-50 atm, 650-1200K, stoichiometric fuel/air mixtures). Simulation results ...

2010-01-11

50

Jet initiation and penetration of explosives  

Energy Technology Data Exchange (ETDEWEB)

The two-dimensional Eulerian hydrodynamic code 2DE, with the shock initiation of heterogeneous explosive burn model called Forest Fire, is used to model numerically the interaction of jets of steel, copper, tantalum, aluminum, and water with steel, water, and explosive targets. The calculated and experimental critical condition for propagating detonation may be described by the Held V/sup 2/d expression (jet velocity squared times the jet diameter). In PBX 9502, jets initiate an overdriven detonation smaller than the critical diameter, which either fails or enlarges to greater than the critical diameter while the overdriven detonation decays to the C-J state. In PBX 9404, the jet initiates a detonation that propagates only if it is maintained by the jet for an interval sufficient to establish a stable curved detonation front. The calculated penetration ...

1983-01-01

51

Jet initiation and penetration of explosives  

Energy Technology Data Exchange (ETDEWEB)

The two-dimensional Eulerian hydrodynamic code 2DE with the shock initiation of heterogeneous explosive burn model called Forest Fire, is used to model numerically the interaction of jets of steel, copper, tantalum, aluminum, and water with steel, water, and explosive targets. The calculated and experimental critical condition for propagating detonation may be described by the Held V/sup 2/d expression (jet velocity squared times the jet diameter). In PBX 9502, jets initiate an overdriven detonation smaller than the critical diameter, which either fails or enlarges to greater than the critical diameter while the overdriven detonation decays to the C-J state. In PBX 9404, the jet initiates a detonation that propagates only if it is maintained by the jet for an interval sufficient to establish a stable curved detonation front. The calculated penetration velocities ...

1983-01-01

52

Hunting at the highway: traffic noise reduces foraging efficiency in acoustic predators  

UK PubMed Central (United Kingdom)

Noise pollution from human traffic networks and industrial activity impacts vast areas of our planet. While anthropogenic noise effects on animal communication are well documented, we have very limited...Full Text Available

2011-06-07

53

Comprehensive Quantification of Signal-to-Noise Ratio and g-Factor for Image-Based and k-Space-Based Parallel Imaging Reconstructions  

UK PubMed Central (United Kingdom)

Parallel imaging reconstructions result in spatially varying noise amplification characterized by the g-factor, precluding conventional measurements of noise from the final...Full Text Available

2008-10-01

54

Audiometric notch as a sign of noise induced hearing loss  

UK PubMed Central (United Kingdom)

OBJECTIVES—To investigate the relation between different types of exposure to noise and a classic sign of noise induced hearing loss (NIHL), the audiometric notch.
METHODS—The...Full Text Available

2001-01-01

55

Low power cross-flow atmospheric pressure Ar + He plasma jet  

International Nuclear Information System (INIS)

A cross-flow atmospheric plasma jet with distilled water or analyte solution nebulization has been investigated. The plasma gas flows perpendicularly to the RF powered electrode (11.21 MHz) and a grounded electrode was added for plasma stabilization. The working parameters of the plasma generator can be controlled in order to maximize either the plasma power (75 W) or the voltage on the RF powered electrode (plasma power, 40 W). The plasma gas, pure argon (0.4 l min-1) or a mixture of argon (0.3-0.4 l min-1) and helium (0-0.2 l min-1), was also used for liquid nebulization. Optical emission of the plasma, collected in the normal viewing mode, was used for plasma diagnostics and for evaluating its excitation capabilities. The influence of helium content in the mixed-gas plasma on the plasma characteristics and on the emission axial profiles of the plasma gas constituents and of the analytes originate from the wet aerosol was studied. The ...

2010-04-01

56

Noise spectral density measurements of a radiation hardened CMOS process in the weak and moderate inversion  

Energy Technology Data Exchange (ETDEWEB)

The authors have measured the noise of MOS transistors of the United Technology Microelectronics Center (UTMC) 1.2 [mu]m radiation hardened CMOS P-well process from the weak to moderate inversion region. The noise power spectral densities of both NMOS and PMOS devices were measured from 1 KHz to 50 MHz. The bandwidth was chosen such that the important components of the spectral densities such as the white thermal noise and the 1/f noise could be easily resolved and analyzed in detail. In this paper the effects of different device terminal DC biases and channel geometries on the noise are described.

1992-08-01

57

Tightly Integrating Optical And Inertial Sensors For Navigation ...  

Science.gov (United States)

... 13 2.4 Inertial Navigation Error Model . . . . . ... sources such as electrical noise, thermal noise, etc. 2.4 Inertial Navigation Error Model ...

2008-03-01

58

EFFECTS OF AMBIENT NOISE ON THE WHISTLES OF INDO-PACIFIC BOTTLENOSE DOLPHIN POPULATIONS  

Science.gov (United States)

... Characterizing the Relative Contributions of Large Vessels to Total Ocean Noise Fields: A Case Study Using the Gerry E. ... ...

59

Augmentation of heat transfer in heat conductive medium by electro-hydrodynamic effect  

Energy Technology Data Exchange (ETDEWEB)

A method of augmenting heat transfer in the interior of a fluid or from the interface of a solid in contact to a fluid by utilizing electro hydrodynamic (EHD) phenomena has the following advantages: the heat transfer can be effected by using a relatively small, light-weight high voltage source and some simple structural members; no vibration and noise are generated; the method has a control function to control heat transfer by adjustment of field and voltage; and this method is effective in cost-saving. It is mass transfer by the electric force caused by interaction between true charges or polarized charges in a fluid and external electric filed that plays an important role in most of such heat transfer augmentation methods by EHD. Examples of heat transfer augmentation by EHD phenomena include electricaly induced convection, contribution of EHD effect to heat transfer accompanied with boiling, heat transfer by corona wind accompanied with corona discharge, vapor ...

1988-04-20

60

Modelling of the wall jet in a direct injection diesel engine  

Energy Technology Data Exchange (ETDEWEB)

As a part of a phenomenological model, a method for simulating the wall/jet interaction in a direct injection diesel engine is proposed. The method is based on the application of the momentum conservation equation in the different directions in which the wall jet is spread, and takes into account both the interaction with the combustion chamber geometry and with swirl. It takes as initial conditions the results of calculating the free jet, which is divided into packages. The predictions provide good agreement with those by other researchers. (author).

1992-01-01

65

Coal liquefaction to increase jet fuel production  

Science.gov (United States)

Processing concept that increases supply of jet fuel has been developed as part of study on methods for converting coal to hydrogen, methane, and jet fuel. Concept takes advantage of high aromatic content of coal-derived liquids to make high-octane gasoline, instead of destroying aromatics to make jet fuel.

1979-01-01

67

Jet plume injection and combustion system for internal combustion engines  

Energy Technology Data Exchange (ETDEWEB)

This invention is comprised of an improved combustion system for an internal combustion engine is disclosed wherein a rich air/fuel mixture is furnished at high pressure to one or more jet plume generator cavities adjacent to a cylinder and then injected through one or more orifices from the cavities into the head space of the cylinder to form one or more turbulent jet plumes in the head space of the cylinder prior to ignition of the rich air/fuel mixture in the cavity of the jet plume generator. The portion of the rich air/fuel mixture remaining in the cavity of the generator is then ignited to provide a secondary jet, comprising incomplete combustion products which are injected into the cylinder to initiate combustion in the already formed turbulent jet plume. Formation of the turbulent jet plume in the head space of the cylinder prior to ignition has been ...

1992-12-31

68

Noise parameter forecasting and noise reduction design at working places in coal preparation plants  

Energy Technology Data Exchange (ETDEWEB)

Discusses the Methodological Directions for Expected Noise Calculation and Noise Reduction Design in Coal Preparation Plants developed at the Institute of Solid Fuel Preparation. Calculation of expected sound pressure levels is described. An exemplary chart of noise levels in the coal feed section of the coal preparation plant at the Taldinskii surface mine is presented. Procedures for planning noise pollution abatement measures and checking the expected noise levels are considered and explained on the example of the project of the coal crushing section in the Taldinskii plant (Kemerovugol' association) designed by Sibgiproshakht. A SMD-117 jaw crusher, 300 mm screen and a conveyor are to work in a space of 45,820 m{sup 3} with 30 m ceiling height. The expected noise level calculated for the working place of the crusher operator is 93-95 dBA without ...

1989-02-01

69

JET contribution to ITER fuel cycle issues  

Energy Technology Data Exchange (ETDEWEB)

The Joint European Torus (JET) fusion machine is the only device capable of operation with tritium (as fuel) and Be (as plasma facing component), what makes it best suited to study ITER relevant issues. A large variety of activities are performed within the JET Fusion Technology Task Force. In this paper, some topics such as erosion/deposition and material transport, flakes characterization and detritiation techniques are highlighted. Recent results obtained using a pumping cryo-panel and on plasma facing component characterisation are given. Finally, issues that will be addressed in the forthcoming JET work-programme are presented, such as a beryllium main wall for JET and in-situ laser detritiation. (authors)

2005-07-01

70

Characterization of jet breakup mechanisms observed from simulant experiments of molten fuel penetrating coolant  

Science.gov (United States)

The goal of this research program has been to add to our understanding of the breakup of molten fuel jets penetrating reactor coolant. Easily handled working fluids are used to simulate fuel jet breakup, so that detailed observations may be obtained from a relatively large number of experiments. The tools used for observing this behavior are high speed notion picture photography, Flash X-radiography, and X-ray cine. Jet breakup lengths are determined from motion pictures; the mechanisms by which the jets are fragmented may be inferred from radiographs.

1992-01-01

71

Lifetime measurements of singlet ungerade states in isotopic molecular nitrogen  

International Nuclear Information System (INIS)

Full text: In the upper layers of the Earth's atmosphere, molecular nitrogen absorbs the extreme ultraviolet (XUV) solar radiation. The absorption is associated with dipole-allowed excitation of states of singlet ungerade symmetry ("1#SIGMA#"+_u and "1#PI#_u), which are known to undergo predissociation due to coupling with a mainfold of "1#PI#_u states. We determined new N_2 isotopic lifetimes of many "1#SIGMA#"+_u and "1#PI#_u states via line broadening measurements in the frequency domain. Ultrahigh resolution XUV + UV ionization spectra were recorded (bandwidth #approx# 250 MHz, resolving power 10"7), from which the natural linewidth, i.e. lifetime, was determined. These lifetimes provide new information about the predissociation of the singlet ungerade states in N_2. Tunable narrowband XUV radiation was produced by successively pulsed amplification of cw dye laser radiation, frequency doubling the pulsed visible laser beam into the UV and frequency tripling the UV in a xenon ...

2004-07-19

72

Noise Shielding Using Acoustic Metamaterials  

International Nuclear Information System (INIS)

We exploit theoretically a class of rectangular cylindrical devices for noise shielding by using acoustic metamaterials. The function of noise shielding is justified by both the far-field and near-field full-wave simulations based on the finite element method. The enlargement of equivalent acoustic scattering cross sections is revealed to be the physical mechanism for this function. This work makes it possible to design a window with both noise shielding and air flow. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

2010-03-15

76

Processing of multi-component crosshole reflection data by multi-mode crosshole migration (1): Theoretical study  

Energy Technology Data Exchange (ETDEWEB)

A theoretical background of crosshole reflection imaging with pre stack, multi-mode reverse time migration has been investigated. The crosshole migration has been carried out by solving two-way scalar wave equation with finite difference approximation. The wave field extrapolation was performed backward in time, with the imaging condition applied at each extrapolation time step to create partial image of the reflector. The complete migrated image was obtained by adding all the partial images from each time step. With multi-component crosshole data available, it is possible to separate the recorded data into primary P- and S-wave field. Separating wave field before migration is helpful in enhancing migrated image quality since only one wave mode can be dealt at a time with the scalar wave equation. It is possible to migrate mixed-mode primary reflections(P-S and S-P) as well as pure mode ones. These multi-mode migrations provide not only image data redundancy but ...

1993-08-31

77

Thermal Interaction Between Molten Metal Jet and Sodium Pool: Effect of Principal Factors Governing Fragmentation of the Jet  

International Nuclear Information System (INIS)

To clarify the effects of the principal factors that govern the thermal fragmentation of a molten metallic fuel jet in the course of fuel-coolant interaction, which is important in evaluating the sequence of core disruptive accidents (CDAs) for metallic fuel fast reactors, basic experiments were carried out using molten metallic fuel simulants (copper and silver) and a sodium pool.Fragmentation of a molten metal jet with a solid crust was caused by internal pressure produced by the boiling of sodium, which is locally entrapped inside the jet due to hydrodynamic motion between the jet and the coolant. The superheating and the latent heat of fusion of the jet are the principal factors governing this type of thermal fragmentation. On the other hand, the effect of the initial sodium temperature is regarded as negligible in the case of thermal conditions expected to result in CDAs for ...

2005-02-01

78

Segmentation and fragmentation of melt jets due to generation of large-scale structures. Observation in low subcooling conditions  

Energy Technology Data Exchange (ETDEWEB)

In order to clarify a mechanism of melt-jet breakup and fragmentation entirely different from the mechanism of stripping, a series of experiments were carried out by using molten tin jets of 100 grams with initial temperatures from 250degC to 900degC. Molten tin jets with a small kinematic viscosity and a large thermal diffusivity were used to observe breakup and fragmentation of melt jets enhanced thermally and hydrodynamically. We observed jet columns with second-stage large-scale structures generated by the coalescence of large-scale structures recognized in the field of fluid mechanics. At a greater depth, the segmentation of jet columns between second-stage large-scale structures and the fragmentation of the segmented jet columns were observed. It is reasonable to consider that the segmentation and the fragmentation of ...

1999-07-01

79

Modeling of thermal and hydrodynamic aspects of molten jet/water interactions  

Energy Technology Data Exchange (ETDEWEB)

In order to predict the effect of a fuel-coolant interaction after a hypothetical core-melt-down accident, a phenomenological model has been developed to describe the thermal and hydrodynamic behavior of a high-temperature molten jet when it interacts with saturated or subcooled water in a film boiling regime. The mechanisms of jet-material erosion were analyzed by Kelvin-Helmholtz instabilities on the coherent column and by boundary layer stripping on the leading edge. The heat transfer coefficient, vapor-film thickness, and net steam generation, all of which strongly affect the jet-breakup behavior, were solved analytically. It was found that the jet breakup (or erosion) depends strongly on the steam generation from the jet/water interaction. The jet-breakup length (i.e., penetration distance) was found to be sensitive to the initial jet ...

1989-01-01

80

Structural engineering and noise pollution abatement. Improvements that can be measured  

Energy Technology Data Exchange (ETDEWEB)

Structural engineering implies four factors particularly relevant to sonics: airborne noise abatement, insulation of plumbing, by-pass insulation and noise absorption (noise abatement). These are exemplified with special regard to methodical and/or product-specific noise pollution abatement measures. Besides, reference is made to DIN standards 4109 providing both engineers with practical advice and pipe fitters or plumbers with concrete examples for application. VDI recommendations 3733 convey essential knowledge of how to properly apply sonic principles in the planning, design and installation of pipes. (BR).

1985-06-01

81

Si-JFET devices and related noise behavior under irradiation  

Energy Technology Data Exchange (ETDEWEB)

Monolithic N-channel junction field effect transistors (NJFETs) dc characteristics, small signal parameters and noise have been studied from 300 K down to cryogenic temperatures before and after irradiation with {sup 60}Co {gamma}-rays and fast neutrons (1 MeV). Radiation induced effects on dc parameters and noise are reviewed. Noise spectral density measurements performed at various temperatures have shown that the radiation induces a noise increase which is temperature and frequency dependent. (orig.). 14 refs.

1998-02-01

82

Review of Subcritical Source-Driven Noise Analysis Measurements  

Energy Technology Data Exchange (ETDEWEB)

Subcritical source-driven noise measurements are simultaneous Rossia and randomly pulsed neutron measurements that provide measured quantities that can be related to the subcritical neutron multiplication factor. In fact, subcritical source-driven noise measurements should be performed in lieu of Rossia measurements because of the additional information that is obtained from noise measurements such as the spectral ratio and the coherence functions. The basic understanding of source-driven noise analysis measurements can be developed from a point reactor kinetics model to demonstrate how the measured quantities relate to the subcritical neutron multiplication factor.

1999-11-01

83

Detritiation of solid waste using superheated steam  

International Nuclear Information System (INIS)

Full text: During JET operations, tritium contaminated waste is generated principally but not exclusively from 'intervention' work and from removing or replacing redundant items. It is essential for JET and for any future fusion plant to have available a route for managing each waste stream however large or small, both during operation and decommissioning of the plant. The long term outcome is to have for each tritiated waste stream from JET a route for its management leading to its eventual disposal or recycling (and thus to be available for similar waste streams which will be produced by ITER operations). Since several years SCK#centre dot#CEN has been developing techniques for the treatment of tritiated waste. Amongst them, technologies for water detritiation, for the treatment of tritiated organic liquids and for the decontamination of several types of solid tritiated waste. Our R and D focuses on the development of a ...

2005-10-12

84

Photocurrent Noise in Quantum Dot Infrared Photodetectors  

Science.gov (United States)

Low-frequency current noise and current-voltage (I-V) characteristics have been studied in InAs/GaAs self-assembled Quantum Dot Infrared Photodetectors in dark conditions and under illumination, at T = 77K and T = 5K. The noise behavior is consistent with a generation-recombination fluctuation process mainly related to thermally excited charge carriers at T = 77K. At T = 5K the current noise is consistent with a mechanism of fluctuations driven by the electric field, related to tunneling rather than emission-capture of charge carriers from the Quantum Dots. A very effective noise suppression mechanism, related to the tunneling regime, determines a decrease of fluctuation intensity as a function of the voltage. At T = 5K, an interesting behavior is observed in the current-voltage and noise power spectra for some of nominally identical QDIP structures in the presence of irradiation. ...

2005-08-01

85

Performance of the gas-jet transport system coupled to the RIKEN gas-filled recoil ion separator GARIS for the 238U (22Ne, 5n)255No reaction  

International Nuclear Information System (INIS)

The performance of the gas-jet transport system coupled to the RIKEN gas-filled recoil ion separator GARIS was investigated using 255No produced in the 238U(22Ne, 5n)255No reaction. Alpha particles of 255No separated with GARIS and transported by the gas-jet system were measured with a rotating wheel apparatus for ? spectrometry under low background condition. The high gas-jet efficiencies of about 75% were independent of the recoil ranges of 255No in the gas-jet chamber. The present results suggest that the GARIS/gas-jet system is a promising tool for the next-generation superheavy element chemistry: (1) the background radioactivities of unwanted reaction products are strongly suppressed, (2) the intense beam is absent in the gas-jet chamber and hence the high gas-jet efficiency is achieved, and (3) the beam-free condition also allows for ...

2008-08-01

86

Multi-Stream Saline-Jet Dissection Using a Simple Irrigation System Defines Difficult Tissue Planes  

UK PubMed Central (United Kingdom)

Introduction:Single-stream hydro-jet dissection is increasingly used in various laparoscopic procedures, but its use requires special equipment. We describe a simple method for using...Full Text Available

2010-01-01

87

Heat Transfer Augmentation in Turbulent Impinging Jets.  

Science.gov (United States)

Heating and cooling by impinging jets is widely used in various engineering applications, due to the high heat transfer rates prevailing in the vicinity of the stagnation point. The authors have been able to utilize acoustically excited turbulence for the...

1979-01-01

88

Some considerations about future interferometric GW detectors  

International Nuclear Information System (INIS)

The two most important issues in designing future gravitational wave interferometric detectors are, in our opinion, thermal and optical noise. In this paper we discuss some approaches for reducing these noises. About thermal noise we show a possible cryogenic solution. About optical noise (namely, the combined effect of shot noise and radiation pressure noise) we show that it is possible to apply a recently proposed reduction strategy based on a 'quantum feedback' (Courty et al 2003 Phys. Rev. Lett. 90 083601; Courty et al 2003 Preprint gr-qc/0301068) to a full Fabry-Perot cavity. This can be seen as a further step towards the practical realization of a detector which is able to evade the standard quantum limit.

2004-03-07

89

Noise in Josephson mm-wave mixers  

International Nuclear Information System (INIS)

Point contact Josephson junctions can function as millimeter wave heterodyne mixers with conversion gain. The best results achieved thus far show a single sideband conversion gain of 1.3 and a mixer contribution to the system noise temperature of 54"0K. Both of these results are approximately 5 times better than the best published figures for cooled Schottky barrier diode mixers operated at the same frequency. The measured noise for a variety of junctions can be expressed as a universal function of the normalized rf frequency #OMEGA# = h#omega#/2eI/sub c/R. It is about a factor 2 larger than the calculated noise arising from the thermal noise in the junction shunt resistance, R. The noise calculation was done for the resistively shunted junction model using an analog junction simulator.

1974-09-30

90

Control of linear accelerator noise in the Los Alamos free-electron laser (FEL)  

International Nuclear Information System (INIS)

FELs require tight control of the amplitudes and phase of the fields in two linear accelerator tanks to obtain stable lasing. The accelerator control loops must establish constant, stable, repeatable amplitudes and phases of the rf fields and must have excellent bandwidth to control high-frequency noise components. A model of the feedback loops has been developed that agrees well with measurements and allows easy substitution of components and circuits, thus reducing breadboarding requirements. The model permits both frequency and time-domain analysis. The accelerator control scheme and model are described and the control of noise in feedback loops is discussed, showing how low-frequency-noise components (errors) can be corrected, but high-frequency-noise components (errors) are actually amplified by the feedback circuit. Measurements of noise in both open- and closed-loop modes is ...

1986-09-01

91

Theoretical Calculation of Jet Fuel Thermochemistry  

Science.gov (United States)

High-level ab initio calculations have been performed on the exo and endo isomers of gas-phase

2010-01-01

92

Experimental investigation of the length of a free diffusion jet of fuel gases diluted with inert gases  

Science.gov (United States)

Experimental investigation of the length of single burning jets of methane and hydrogen previously diluted with an inert gas (nitrogen or helium) was carried out. Efflux of fuel gases into the atmosphere occurred through cylindrical extension pieces 4 and 8 mm in diameter. The Reynolds numbers at the cut of a piece varied in the range from 400 to 12,000. A clearly defined dependence of the jet length on the quality of the added inert gas is obtained. The correlation of experimental data made it possible to recommend formulas for engineering calculations of free laminar and turbulent jets.

2010-05-01

93

Energy and Water Conservation  

Science.gov (United States)

Jet Propulsion Laboratory. California Institute of Technology. Pasadena, California. Energy and Water Conservation. Steve Rigdon. Facilities Energy Manager ...

94

Aerosol spectral optical depths - Jet fuel and forest fire smokes  

Science.gov (United States)

The Ames autotracking airborne sun photometer was used to investigate the spectral depth between 380

1990-01-01

95

The JET (Joint European Torus) multipellet launcher and fueling of JET plasmas by multipellet injection  

Energy Technology Data Exchange (ETDEWEB)

A new multipellet long-pulse plasma fueling system is in operation on JET. In the initial experimental phase, a variety of plasma density profile shapes have been produced with peak to average values ranging up to 2.5 and peak plasma density up to 1.2 )times) 10/sup 20/m/sup )minus/3). 7 refs., 4 figs

1988-01-01

96

Physical Modelling of Axisymmetric Turbulent Impinging Jets as used within the Nuclear Industry for Mobilisation of Sludges  

Energy Technology Data Exchange (ETDEWEB)

The impingement of a fluid jet onto a surface has broad applications across many industries. Within the UK nuclear industry, during the final stages of fuel reprocessing, impinging fluid jets are utilised to mobilise settled sludge material within storage tanks and ponds in preparation for transfer and ultimate immobilisation through vitrification. Despite the extensive applications of impinging jets within the nuclear and other industries, the study of two-phase, solid loaded, impinging jets is limited, and generally restricted to computational modelling. Surprisingly, very little fundamental understanding of the turbulence structure within such fluid flows through experimental investigation is found within the literature. The physical modelling of impinging jet systems could successfully serve to aid computer model validation, determine operating requirements, evaluate plant ...

2008-07-01

97

Photon final states at the Tevatron  

Energy Technology Data Exchange (ETDEWEB)

The authors present here several recent measurements involving associate production of photons and jets at the Tevatron. In particular, inclusive photon + met from D0, and photon + b-jets and photon + b-jet + leptons + MET from CDF are described in some detail. These measurements offer a good test of QCD predictions in rather complex final states.

2008-04-01

98

Influence of the jet pressure ratio on the performance of an AGARD single flow afterbody in the 0.60-0.95 Mach range  

Science.gov (United States)

The synthesis of experimental data concerning the effect of jet stagnation conditions on the drag of various afterbodies is presented. Jet pressure ratio effect on boattail pressure and on boundary layer separation is analyzed. This study is made for several values of the boundary layer thickness, taking into account the fact that some test rigs make its control possible by means of tangential blowing.

1975-10-01

99

Gas-temperature-dependent generation of cryoplasma jet under atmospheric pressure  

International Nuclear Information System (INIS)

Plasma with a gas temperature below room temperature is not yet fully understood although it is expected to be an attractive tool for applications to material processing. In the present work, gas-temperature-dependent generation of a cryoplasma jet was studied. So far, we have generated a helium cryoplasma jet (296-5 K) under atmospheric pressure. At gas temperatures below 20 K, the helium excimer, He2, was observed clearly from by optical emission spectroscopy.

2008-09-08

100

Effects of Chronic JP-8 Jet Fuel Exposure on Lung Function.  

Science.gov (United States)

The past three years of work for the Air Force Office of Scientific Research has resulted in the development of a congenic mouse model of JP-8 jet fuel exposure, the role of substance P in the JP-8 jet fuel-induced lung injury process, and development of ...

1997-01-01

101

Development of a new secondary beam separator and a new gas-jet target at Kyushu University  

International Nuclear Information System (INIS)

In order to facilitate observations of low energy nuclear reactions, a new type recoil mass-separator together with a new gas-jet target system is being developed at the tandem accelerator facility in Kyushu University. The expected mass-resolving power of the separator is 220 for a solid angle of 10 msr and the practical thickness of the gas-jet target will exceed 0.1 atm#centre dot#cm for the light elements of H and He. (author).

1994-06-01

102

Acute Toxicity Evaluation of JP-8 Jet Fuel and JP-8 Jet Fuel Containing Additives.  

Science.gov (United States)

To reduce fuel fouling in current U.S Navy and Air Force aircraft systems and to provide additional heat sink and thermal stability for future systems, the Air Force is developing an improved JP-8 jet fuel (JP-8 + 100). Two companies (Betz and Mobil) have...

1996-01-01

103

Variability In Motor Learning: Relocating, Channeling and Reducing Noise  

UK PubMed Central (United Kingdom)

Variability in motor performance decreases with practice but is never entirely eliminated, due in part to inherent motor noise. The present study develops a method that quantifies how performers...Full Text Available

2009-02-01

104

Standardization of clinical decision making for the conduct of credible clinical research in complicated medical environments.  

UK PubMed Central (United Kingdom)

The likelihood that past experience will produce correct guides to current practice depends on the signal-to-noise ratio for the clinical problem of interest. If the signal-to-noise ratio is high, the...Full Text Available

1996-01-01

105

Noise Characterization of Polycrystalline Silicon Thin Film Transistors for X-ray Imagers Based on Active Pixel Architectures  

UK PubMed Central (United Kingdom)

An examination of the noise of polycrystalline silicon thin film transistors, in the context of flat panel x-ray imager development, is reported. The study was conducted in the spirit of exploring...Full Text Available

2008-01-01

106

Measuring properties of impulsive low frequency noise by different measuring set up. Shogekisei teishuhaon no keisokuki ni tsuite no kento  

Energy Technology Data Exchange (ETDEWEB)

Pollution abatement measures against impulsive low frequency noises including mine blasting noise require precise measurement of sound waveforms, but no instruments have been designed for that purpose, nor commercially available. This paper describes investigations on such instruments as noise level meters currently available commercially on their instrumental characteristics using indoor experiments and field measurements. The following matters were clarified: An instrument combining a microphone with an amplifier can not determine the response from the measuring system from the respective frequency characteristics alone, and requires a discussion on the overall response from the measuring system. A preferred noise level meter would be an instrument that has the lower limit for the frequency characteristics of the microphone extended to several hertz, and measures noises without ...

1991-11-25

107

A new analysis for membrane noise. The integral spectrum.  

UK PubMed Central (United Kingdom)

A new method of random data analysis has been developed with special implications for membrane noise. The integral spectrometer uses overlapping broad-band filters of simple design, whose bandwidth...Full Text Available

1976-07-01

108

What can we learn about extragalactic radio jets from X-ray data?  

CERN Document Server

We review the current status of resolved X-ray emission associated with extragalactic radio jets and hotspots. The primary question for any particular jet is to decide if the X-rays come from the synchrotron process or from inverse Compton scattering. There is considerable evidence supporting synchrotron emission for knots in the jets of FRI galaxies. For FRII terminal hotspots detected in the X-ray band, synchrotron self-Compton emission continues to provide viable models with one possible exception (so far). Inverse Compton scattering on photons of the cosmic microwave background is indicated for a few powerful jets, and is expected to be an important contributor if not the dominating mechanism for higher redshift objects. The application of a model generally yields physical parameters and in many cases, these include the Doppler boosting factor.

2003-01-01

109

Quasi-stationary and transient patterns in jets  

Science.gov (United States)

Apparent evolution of relativistic flows as traced by radio emission results from a combination of several factors related to propagation of relativistic blobs or shocks, velocity, density and pressure stratification of the underlying flow, plasma instability and (possibly also) phase and time travel effect. This combination can create an intricate and chaotic patterns of the observed morphological changes in radio emission, which complicates the analysis and interpretation of kinematic and physical properties of the jet plasma. Recent studies have indicated that slow and quasi-stationary patterns in jets are most likely formed by plasma instabilities while faster, superluminally moving patterns are related to highly relativistic plasma condensations produced by the nuclear flares. Some of the stationary patterns may also be related to recollimation shocks or locations where strong non-thermal continuum is produced in jets. ...

2011-01-01

110

Measurement of dijet cross sections for events with a leading neutron in photoproduction at HERA  

Energy Technology Data Exchange (ETDEWEB)

Differential cross sections for dijet photoproduction in association with a leading neutron using the reaction e{sup +}+p{yields}e{sup +}+n+jet+jet+X{sub r} have been measured with the ZEUS detector at HERA using an integrated luminosity of 6.4 pb{sup -1}. The fraction of dijet events with a leading neutron in the final state was studied as a function of the jet kinematic variables. The cross sections were measured for jet transverse energies E{sub T}{sup jet}>6 GeV, neutron energy E{sub n}>400 GeV, and neutron production angle {theta}{sub n}<0.8 mrad. The data are broadly consistent with factorization of the lepton and hadron vertices and with a simple one-pion-exchange model.

2001-02-26

111

A pump-probe XFEL particle injector for hydrated samples  

CERN Document Server

We have developed a liquid jet injector system that can be used for hydrated sample delivery at X-ray Free Electron Laser (XFEL) sources and 3rd generation synchrotron sources. The injector is based on the Gas Dynamic Virtual Nozzle (GDVN), which generates a liquid jet with diameter ranging from 300 nm to 20 {\\mu}m without the clogging problems associated with conventional Rayleigh jets. An improved nozzle design is presented here. A differential pumping system protects the vacuum chamber and an in-vacuum microscope allows observation of the liquid jet for diagnostics while it is being exposed to the X-ray beam. A fiber optically coupled pump laser illuminating the jet is incorporated for pump-probe experiments. First results with this injector system have been obtained at the LCLS.

2011-01-01

112

Predicting formula development of audible noise on a 765 kV AC transmission line 1  

Energy Technology Data Exchange (ETDEWEB)

Audible noise from corona discharge had been identified as one of the most important factors in the design of conductor configurations for high-voltage transmission lines. 500 kV and above. Therefore this paper describes audible noise characteristics of 6 X 480 mm{sup 2} conductor bundle in KEPRI 765 kV Test Line and Corona Cage. Prediction formula for audible(corona) noise on a 765 kV Transmission Line was developed using this results. (author). 4 refs., 4 figs., 4 tabs.

1996-04-01

113

MCNP-DSP calculations of the {sup 252}Cf-source-driven noise analysis measurements of highly enriched uranium metal cylinders  

Energy Technology Data Exchange (ETDEWEB)

This paper presents calculations of the {sup 252}Cf-source-driven noise analysis measurements for subcritical highly enriched uranium metal cylinders using the Monte Carlo code MCNP-DSP. This code directly calculates the noise analysis data from the {sup 252}Cf- source-driven noise analysis method for both neutron and gamma ray detectors. Direct calculation of experimental observables by the Monte Carlo method allows for the benchmarking of the calculational model and the cross sections and for determining the bias in the calculation.

1995-07-01

114

Enhanced Core Noise Modeling for Turbofan Engines  

Science.gov (United States)

This report describes work performed by MTC Technologies (MTCT) for NASA Glenn Research Center (GRC)

2011-01-01

115

Discrete simulation of power law noise  

CERN Document Server

A method for simulating power law noise in clocks and oscillators is presented based on modification of the spectrum of white phase noise, then Fourier transforming to the time domain. Symmetric real matrices are introduced whose traces--the sums of their eigenvalues--are equal to the Allan variances, in overlapping or non-overlapping forms, as well as for the corresponding forms of the modified Allan variance. Diagonalization of these matrices leads to expressions for the probability distributions for observing a variance at an arbitrary value of the sampling or averaging interval $\\tau$, and hence for estimating confidence in the measurements. A number of applications are presented for the common power-law noises.

2011-01-01

116

The Hannover thermal noise experiment  

International Nuclear Information System (INIS)

To analyse the thermal noise of the pendulum mode of a suspended mirror, we interferometrically detect the differential movement of two mirrors suspended as multiple-stage pendulums. We present the set-up of this experiment and the current sensitivity, and also the different steps that we took in the past to increase the sensitivity, which include an auto alignment of the laser beam into the resonator eigenmode, changes of the seismic isolation system to more damping stages and higher moments of inertia and an intensive noise hunting.

2004-03-07

117

On the buildup of laser oscillation from noise  

Science.gov (United States)

It is well known that laser oscillation is initiated by spontaneous radiation ''noise.'' Evidence for this is often based on the complete theory of laser oscillation, including the quantization of the electromagnetic field. In this article, the buildup of laser oscillation from quantum noise is demonstrated using the most elementary classical equation describing the amplification of laser intensity.

1989-02-01

118

Low-noise Josephson mixers at 115 GHz using recyclable point contacts  

International Nuclear Information System (INIS)

Thermally recyclable Nb point-contact Josephson junctions are investigated as low-noise mixers with an external local oscillator at 115 GHz. The best single sideband mixer noise temperature achieved is 140 ( +- 20) K with a (SSB) conversion loss of 2.4 ( +- 0.5) dB. Such rugged junctions are suitable for use in practical receivers and should give unprecedented sensitivity at the shorter millimeter wavelengths.

119

Fault prediction on high voltage transmission lines  

Energy Technology Data Exchange (ETDEWEB)

The prediction of faults on high voltage transmission lines requires the detection of incipient faults, which is implemented by detection of the radio noise due to contaminated insulators, insulation deterioration, and improver connections. It is shown that the radio noise due to incipient faults is separable and identifiable from normal transmission line radio noise, hence faults can be predicted.

1982-12-01

120

Assessment of audible noise from high voltage transmission lines and a high voltage transformer station  

Energy Technology Data Exchange (ETDEWEB)

The study of audible noise from high voltage transmission lines and a high voltage transformer station was conducted in three parts. Part 1 consisted of long-term measurement and statistical analysis by computer reduction of audible noise as a result of corona discharge from high voltage transmission lines and the associated weather conditions which contribute to this noise. Recommendations are given concerning further computer programming in order to improve the statistical reliability of corona noise presence and reduce the degree of background noise contamination of the present results. Part 2 consisted of categorizing and cataloguing of corona noise spectra from long-term measurements on 550, 735 and 765 kV transmission lines and to provide a library of such sounds on magnetic tape to be used in the ongoing study of corona noise. ...

1986-11-01

121

Analysis of log rate noise in Ontario's CANDU reactors  

Energy Technology Data Exchange (ETDEWEB)

In the fall of 2003, the operators noticed that in the recently-refurbished Bruce A Shutdown System no. 1 (SDS1) the noise level in Log Rate signals were much larger than before. At the request of the Canadian Nuclear Safety Commission (CNSC), all Canadian CANDU reactors took action to characterize their Log Rate noise. Staff of the Inspection and Maintenance Services division of Ontario Power Generation (OPG) has collected high-speed high-accuracy noise data from nearly all 16 Ontario reactors, either as part of routine measurements before planned outages or as a dedicated noise recording. This paper gives the results of examining a suitable subset of this data, with respect to the characteristics and possible causes of Log Rate noise. The reactor and instrumentation design is different at each station: the locations of the moderator injection nozzles, the location of the ion ...

2007-07-01

122

A comparison of methods for calculating audible noise of high voltage transmission lines  

Energy Technology Data Exchange (ETDEWEB)

During the last several years, audible noise produced by high voltage transmission lines in corona has emerged as an important design consideration. In this same time frame a number of different methods for calculating audible noise levels have been proposed. The methods currently available, for both ac and dc lines, are described in this paper and are compared through application to practical line geometries for which data from long-term measurements are available.

1982-10-01

123

X-ray and HeI 1.0830 mu emission from protostellar jets  

CERN Document Server

Context. The high energies of protostellar jets, implied by recent observations of X-rays from such flows, came very much as a surprise. Inferred shock velocities are considerably higher than what was previously known, hence putting even larger energy demands on the driving sources of the jets. The statistics of X-ray emitting jets are still poor, yet a few cases exist which seem to imply a correlation between the presence of HeI 1.0830 mu emission and X-ray radiation in a given source. Aims. This tentative correlation needs confirmation and explanation. If the jet regions of HeI 1.0830 mu emission are closely associated with those producing X-rays, high resolution infared spectroscopy can be used to observationally study the velocity fields in the hot plasma regions of the jets. This would provide the necessary evidence to test and further develop theoretical models of ...

2006-01-01

124

Structure and evolution of the stabilization point of a lifted reacting jet  

Energy Technology Data Exchange (ETDEWEB)

In this work the authors study the stabilization point of a lifted, reacting jet of nitrogen diluted methane in co-flowing air. The jet flow is acoustically forced so as to organize the large scale vortical structures. The validation of the numerical results is possible through a concurrent experimental investigation of a similar planar jet. The use of an acoustically forced planar jet allows for significant savings by the restriction of the computation to two dimensions; the model is otherwise applicable in three dimensions. The authors based their study on the following parameters, which are derived from the experimental setup: a jet width of 1.16 cm, a mean jet velocity of 0.8 m/s, and a coflow velocity of 0.1 m/s. The acoustical forcing is studied at frequencies of 7.5 MHz and 90 MHz, which have been established experimentally as being characteristic of two ...

1997-11-01

125

Quark and Gluon Tagging at the LHC  

CERN Document Server

Being able to distinguish light-quark jets from gluon jets on an event-by-event basis could significantly enhance the reach for many new physics searches at the Large Hadron Collider. Through an exhaustive search of existing and novel jet substructure observables, we find that a multivariate approach can filter out over 95% of the gluon jets while keeping more than half of the light-quark jets. Moreover, a combination of two simple variables, the charge track multiplicity and the pT-weighted linear radial moment (girth), can achieve similar results. While this pair appears very promising, our study is only Monte Carlo based, and other discriminants may work better with real data in a realistic experimental environment. To that end, we explore many other observables constructed using different jet sizes and parameters, and highlight those that deserve further ...

2011-01-01

126

Fluid dynamics of jet-forming elements of contact devices with directional gas stream injection  

International Nuclear Information System (INIS)

One way to intensify heat and mass transfer processes in column-type equipment is through use of contact devices with directional gas phase injection into a liquid. Making the perforations at an angle to the tray plane permits a rise in the permissible gas velocity in the column, since inertial force adds to gravity during separation. Different arrangements of the jet-forming elements relative to one another and to partitions and baffle-type contacts installed on the trays can improve phase contact conditions and intensify heat and mass transfer. Design of jet-type trays for a specific purpose requires that the influence of jet-forming, element design parameters on at least the fluid dynamic situation on the tray be known. In this work, the authors evaluate the influence of tab bend-up angle on jet tray working characteristics. These investigations demonstrate that the jet ...

127

Computational study of jet interaction flow field with and without incidence  

International Nuclear Information System (INIS)

The objective was to study the interaction of a side jet with the incoming supersonic flow and hypersonic flow. Qualitatively same Cp trends have been obtained as found experimentally. Also in aerodynamic coefficients side jet interaction results in additional pitching moment which is because of the high pressure region in upstream of the jet and a low pressure region in the downstream of the jet. Also jet interaction results in the rise in the lift coefficient. Whereas in the incidence case, simulation has been performed for the hypersonic flows over a biconic body with supersonic lateral jet at Mach 9.7 and incidence of 0"o to incidence of -12"o and 12"o. The results obtained were compared with the experimental and CFD code CFL3D results. PAK-3D over predicts the surface pressure as compared to the CFL3D and experimental results, whereas the qualitative trends ...

2004-05-09

130

The Last Unknown Neutrino Mixing Angle $\\theta_{13}$ and the Daya Bay Experiment  

CERN Document Server

The Last Unknown Neutrino Mixing Angle $\\theta_{13}$ and the Daya Bay Experiment

2006-01-01

131

Triggered instabilities in rocket motors and active combustion control for an incinerator afterburner  

Science.gov (United States)

Two branches of research are conducted in this thesis. The first deals with nonlinear combustion response as a mechanism for triggering combustion instabilities in solid rocket motors. A nonlinear wave equation is developed to study a wide class of combustion response functions to second-order in fluctuation amplitude. Conditions for triggering are derived from analysis of limit cycles, and regions of triggering are found in parametric space. Introduction of linear cross-coupling and quadratic self-coupling among the acoustic modes appears to be how the nonlinear combustion response produces triggering to a stable limit cycle. Regions of initial conditions corresponding to stable pulses were found, suggesting that stability depends on initial phase angle and harmonic content, as well as the composite amplitude, of the pulse. Also, dependence of nonlinear stability upon system parameters is considered. The second part of this thesis presents research for a controller to improve the ...

1999-01-01

132

Impedance Noise Identification for State-of-Health Prognostics  

Energy Technology Data Exchange (ETDEWEB)

Impedance Noise Identification is an in-situ method of measuring battery impedance as a function of frequency using a random small signal noise excitation source. Through a series of auto- and cross-correlations and Fast Fourier Transforms, the battery complex impedance as a function of frequency can be determined. The results are similar to those measured under a lab-scale electrochemical impedance spectroscopy measurement. The lab-scale measurements have been shown to correlate well with resistance and power data that are typically used to ascertain the remaining life of a battery. To this end, the Impedance Noise Identification system is designed to acquire the same type of data as an on-board tool. A prototype system is now under development, and results are being compared to standardized measurement techniques such as electrochemical impedance spectroscopy. A brief description of the Impedance ...

2008-07-01

133

Discriminating between a Stochastic Gravitational Wave Background and Instrument Noise  

CERN Document Server

The detection of a stochastic background of gravitational waves could significantly impact our understanding of the physical processes that shaped the early Universe. The challenge lies in separating the cosmological signal from other stochastic processes such as instrument noise and astrophysical foregrounds. One approach is to build two or more detectors and cross correlate their output, thereby enhancing the common gravitational wave signal relative to the uncorrelated instrument noise. When only one detector is available, as will likely be the case with the Laser Interferometer Space Antenna (LISA), alternative analysis techniques must be developed. Here we show that models of the noise and signal transfer functions can be used to tease apart the gravitational and instrument noise contributions. We discuss the role of gravitational wave insensitive "null channels" formed from particular combinations ...

2010-01-01

134

Assessment of noise levels generated by music shops in an urban city in Nigeria  

British Library Electronic Table of Contents (United Kingdom)

SummaryObjectiveTo assess the level of noise generated by music shops in an urban city in Nigeria. Study designCross-sectional, descriptive study. MethodologyThe study involved music shops in three out of eight identified clusters of market areas in Benin City. A semi-structured, researcher-administered questionnaire was also used to collect data from music shop owners. Noise levels generated by speakers in the music shops were measured using a sound level meter, and blood pressure measurements were taken with a mercury sphygmomanometer. ResultsOf the 250 music shops studied, more than 90.0% generated noise levels >85 dB, and 54.8% had a continuous pattern of noise. Longer duration of working years was significantly associated with decreased hearing (P = 0.01), shouting when talking (P = 0...

2011-01-01

135

A microscopic model of electronic field noise heating in ion traps  

CERN Document Server

Motional heating of ions in micro-fabricated traps is a challenge hindering experimental realization of large-scale quantum processing devices. Recently a series of measurements of the heating rates in surface-electrode ion traps characterized their frequency, distance, and temperature dependencies, but our understanding of the microscopic origin of this noise is still vague. In this work we develop a theoretical model for the electric field noise which is associated with a random distribution of adsorbed atoms on the trap electrode surface. By using first principle calculations of the fluctuating dipole moments of the adsorbed atoms we evaluate the distance, frequency and temperature dependence of the resulting electric field fluctuation spectrum.Our theory calculates the noise spectrum beyond the standard scenario of two-level fluctuators, by incorporating all the relevant vibrational states. The $1/f$ ...

2011-01-01

136

Equivalent magnetic noise in magnetoelectric Metglas/Pb(Mg1/3Nb2/3)O3-PbTiO3 laminate composites  

British Library Electronic Table of Contents (United Kingdom)

Abstract We have experimentally and theoretically investigated the equivalent magnetic noise in a magnetoelectric Metglas/ 0.7Pb(Mg1/3Nb2/3)O3-0.3PbTiO3 laminate sensor unit by considering the constituent noise sources of dielectric loss (NDE) and DC leakage resistance (NR). In the low frequency range (f = 1 Hz), theory predicts that NR dominates the noise charge (1.6 times larger than NDE), with a 1 Hz noise of 9.1\\;{\\rm pt}/\\sqrt {\\rm Hz}. The experimental equivalent magnetic noise was 10.8\\;{\\rm pt}/\\sqrt {\\rm Hz}. This observed value is slightly higher than the predicted one, which might be due to an oversimplification of the theoretical model in terms of electrical charge amplifier and external vibration noise sources. ( 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

2011-01-01

137

Database of air and noise pollution in Lebanon. Final report  

International Nuclear Information System (INIS)

The growing global public concern over deteriorating air quality and greenhouse gases emissions released from various combustion processes, and particularly power plants and transportation system, led governments and local authorities, especially in industrialised countries into taking these issues seriously and establishing standards to reduce air pollution down to acceptable levels, (clean air act, earth summit,...). The transportation sector has another unwanted product, noise pollution caused by different segments of this sector including the noise produced by the engine, tires noise and exhaust noise, in addition to the noise product by private standby generals operating during electricity cut-off periods. To be able to estimate the environmental impacts of the national power plants and the transportation sector, it is necessary to collect enough data (samples of lead ...

138

Search for new physics in the jets and missing transverse energy topology with the D0 detector at the Tevatron; Recherche de nouvelle physique dans la topologie a jets et energie transverse manquante avec le detecteur D0 au TeVatron  

Energy Technology Data Exchange (ETDEWEB)

Although the standard model of particle physics agrees perfectly with experimental data, it is unlikely the final theory describing particles and their interactions. New phenomena has been searched in the jets and missing transverse energy topology. Such phenomena may be due to the pair production of leptoquarks decaying into a quark and a neutrino or the pair production of stops decaying into a charm and a neutralino which is assumed to be the lightest supersymmetric particle. These searches have been performed with the Ddiamter detector at hadronic collider TeVatron with a center of mass energy of 1.96 TeV. This kind of searches needs a good understanding of the jet energy calibration. The determination of the relative jet energy scale has allowed us to reduce the systematic uncertainties on the jet energy measurement when comparing the data and the simulation. Moreover a new method has been developed ...

2006-05-15

139

The infrared-dominated jet of 3C401  

CERN Document Server

We present a Hubble Space Telescope image of the FRII radio galaxy 3C 401, obtained at 1.6 microns with the NICMOS camera in which we identify the infrared counterpart of the brightest region of the radio jet. The jet has a complex radio structure and brightens where bending occurs, most likely as a result of relativistic beaming. We analyze archival data in the radio, optical and X-ray bands and we derive its spectral energy distribution. Differently from all of the previously known optical extragalactic jets, the jet in 3C401 is not detected in the X-rays even in a long 48ksec X-ray Chandra exposure and the infrared emission dominates the overall SED. We propose that the dominant radiation mechanism of this jet is synchrotron. The low X-ray emission is then caused by two different effects: i) the lack of any strong external photon field and ii) the shape of the electron ...

2005-01-01

140

Suzaku and Optical Spectroscopic Observations of SS 433 in the 2006 April Multiwavelength Campaign  

CERN Document Server

We report results of the 2006 April multi-wavelengths campaign of SS 433, focusing on X-ray data observed with Suzaku at two orbital phases (in- and out-of- eclipse) and simultaneous optical spectroscopic observations. By analyzing the Fe25 K_alpha lines originating from the jets, we detect rapid variability of the Doppler shifts, dz/dt ~ 0.019/0.33 day^-1, which is larger than those expected from the precession and/or nodding motion. This phenomenon probably corresponding to "jitter" motions observed for the first time in X-rays, for which significant variability both in the jet angle and intrinsic speed is required. From the time lag of optical Doppler curves from those of X-rays, we estimate the distance of the optical jets from the base to be ~(3-4) \\times 10^14 cm. Based on the radiatively cooling jet model, we determine the innermost temperature of the jets to be T_0 = 13 +/- ...

2010-01-01

141

Modeling jet penetration in glass  

Energy Technology Data Exchange (ETDEWEB)

It is well known that composite armors, consisting of glass elements confined with metallic tampers, are extraordinarily effective against shaped charge attack. Early experiments showed that jets fired against glass targets appeared to be bombarded by tiny fragments that destroyed alignment and reduced residual jet penetration. This result was attributed to an elastic rebound effect in which the outward radial motion of the target around the jet periphery was supposed to be arrested by tensile hoop stresses which developed behind the divergent shock front. Glass fragments were then accelerated radially inward and these destabilized the jet. To sustain the large tensile hoop stresses required, the glass must not have been fractured by the initial shock, behind which the stress state is typically well above the Hugoniot elastic limit. Modeling the penetration of a jet into glass ...

1990-04-05

142

Interactions of Jet Fuels with Nitrile O-Rings: Petroleum-Derived versus Synthetic Fuels  

Energy Technology Data Exchange (ETDEWEB)

A transition from petroleum~derived jet fuels to blends with Fischer-Tropsch (F~T) fuels, and ultimately fully synthetic hydro-isomerized F-T fuels has raised concern about the fate of plasticizers in nitrile-butadiene rubber a-rings that are contacted by the fuels as this transition occurs. The partitioning of plasticizers and fuel molecules between nitrile a-rings and petroleum-derived, synthetic, and additized-synthetic jet fuels has been measured. Thermal desorption of o-rings soaked in the various jet fuels followed by gas chromatographic analysis with a mass spectrometric detector showed many of the plasticizer and stabilizer compounds were removed from the o-rings regardless of the contact fuel. Fuel molecules were observed to migrate into the o-rings for the petroleum-derived fuel as did both the fuel and additive for a synthetic F-T jet fuel additized with benzyl alcohol, but less for the ...

2009-01-01

143

Extended radio emission in MOJAVE Blazars: Challenges to Unification  

CERN Document Server

We present the results of a study on the 1.4 GHz kpc-scale radio emission in the complete flux density limited MOJAVE sample, comprising 135 radio-loud AGNs. While extended emission is detected in the majority of the sources, about 7% of the sources exhibit only radio core emission. Many BL Lacs exhibit extended radio power and kpc-scale morphology typical of powerful FRII jets, while a substantial number of quasars possess radio powers intermediate between FRIs and FRIIs. This poses challenges to the simple radio-loud unified scheme, which links BL Lacs to FRIs and quasars to FRIIs. We find a significant correlation between extended radio emission and pc-scale jet speeds: the more radio powerful sources possess faster jets. This indicates that the 1.4 GHz (or low frequency) radio emission is indeed related to jet kinetic power. Various properties such as extended radio power and apparent pc-scale ...

2010-01-01

144

Similarity between the primary and secondary air-assisted liquid jet breakup mechanism  

CERN Document Server

we report an ultrafast synchrotron x-ray phase contrast imaging study of the primary breakup mechanism of a coaxial air-assisted water jet. We demonstrate that there exist great similarities in the phenomenology of primary breakup with that of the secondary breakup. Especially, a membrane-mediated breakup mechanism dominates the breakup process for a wide range of air speeds. This finding reveals the intrinsic connections of these two breakup regimes and has deep implications on the unified theoretical approach in treating the breakup mechanism of high speed liquid jet.

2007-01-01

145

Operation of a high temperature ion source at the helium-jet on-line isotope separator facility HELIOS  

Energy Technology Data Exchange (ETDEWEB)

The performance of a high temperature ion source coupled to a helium gas-jet transport system for an efficient mass separation of neutron-rich alkaline earth and lanthanide isotopes is reported and the results of overall efficiency measurements using different cluster materials in the gas-jet are given. A fast, microprocessor controlled tape transport system for ..gamma..-spectroscopic studies on short-lived isotopes is described. Some results on the decay of 3.8sub(-s) /sup 152/Pr are presented. (orig.).

1985-02-01

146

Operation of a high temperature ion source at the helium-jet on-line isotope separator facility HELIOS  

Energy Technology Data Exchange (ETDEWEB)

The performance of a high temperature ion source coupled to a helium gas-jet transport system for an efficient mass separation of neutron-rich alkaline earth and lanthanide isotopes is reported and the results of overall efficiency measurements using different cluster materials in the gas-jet are given. A fast, microprocessor controlled tape transport system for ..gamma..-spectroscopic studies on short-lived isotopes is described. Some results on the decay of 3.8sub(-s) /sup 152/Pr are presented.

1985-02-01

147

Dependence of thermal plasma jet temperature on discharge power and gas flow rate  

International Nuclear Information System (INIS)

With the help of heat balance equation and high temperature thermodynamic function, the calibration relation of jet temperature with discharge power, gas flow rate was obtained for nitrogen thermal plasma. It was shown that the results were agreed with the principle of similarity. The jet temperature was a function of Peff/f, instead of a general two variables function of Peff and f, which were effective discharge power and working gas flow rate, respectively. A related discussion has been given; it will be referable to thermal plasma applications. (authors)

2008-03-01

148

Convective heat transfer under unsteady impinging jets: the effect of the shape of the unsteadiness  

Science.gov (United States)

Unsteady impinging jets are systematically controlled with respect to their time dependence in order to investigate the influence of unsteadiness on the heat transfer performance. This is achieved by a special mass flow control device, which allows almost arbitrary shapes of unsteadiness to be imposed onto the impinging jet. Three different standard signals (sinusoidal, triangular, rectangular) and two specially designed signals are applied and their influence on heat transfer is determined in terms of an enhancement factor. Heat transfer augmentation up to 30% was found and could be physically explained with the help of PIV and hot-wire measurements of the flow field.

2009-10-01

149

Wing-surface-jet interaction characteristics of an upper-surface ...  

Science.gov (United States)

Engine flow simulation was provided by four separately mounted air ejectors connected to a high-pressure air supply. The engine nacelle center lines were ...

150

View Record - NASA Jet Propulsion Laboratory  

Science.gov (United States)

Jan 13, 2011 ... This 360-degree mosaic of images from the navigation camera on ... The Radiation Assessment Detector, shown prior to its September 2010 ...

151

USDA Blog » 2009 » October  

Science.gov (United States)

or third generation fuels. These are biofuels that can directly substitute for gasoline, jet fuel, and diesel. Today more than 9 billion gallons of biofuels are produced annually...

2011-10-07

152

Time Characterization of High Density Gas Jet from a Pulsed Supersonic Nozzle via Laser Produced Plasma  

International Nuclear Information System (INIS)

A high-density gas jet supersonic nozzle is reported in this paper. The jitter and actuation time of the nozzle is determined by the pin discharge and laser spark radiation respectively. The jitter time of the nozzle is within 10 ?s with the backing pressure as high as 25 bar. With a nanosecond laser pulse focused on the gas jet about 1 mm below the nozzle, the actuation time is calculated to be about 15 ms by detecting the laser produced spark radiation, which reveals the existence of the gas jet and the relative gas density evolving with time. Consequently the gas density is estimated to be well above 1019 cm-3, compared with theoretical simulations from the nozzle parameters.

2006-07-01

153

The Nuclear Outflow in NGC 2110  

CERN Document Server

We present a HST/STIS spectroscopic and optical/radio imaging study of the Seyfert NGC 2110 aiming to measure the dynamics and understand the nature of the nuclear outflow in the galaxy. Previous HST studies have revealed the presence of a linear structure in the Narrow-Line Region (NLR) aligned with the radio jet. We show that this structure is strongly accelerated, probably by the jet, but is unlikely to be entrained in the jet flow. The ionisation properties of this structure are consistent with photoionisation of dusty, dense gas by the active nucleus. We present a plausible geometrical model for the NLR, bringing together various components of the nuclear environment of the galaxy. We highlight the importance of the circum-nuclear disc in determining the appearance of the emission line gas and the morphology of the jet. From the dynamics of the emission line gas, we place constraints on the ...

2010-01-01

154

State-of-the-Art in Improved Parts Programming for ...  

Science.gov (United States)

... ai jets used for chip removal. Control is normally effectd through the use of miscellaneous function M Codes on the postprocessor NC output. ...

1976-10-01

155

Space Images - NASA Jet Propulsion Laboratory  

Science.gov (United States)

Jan 18, 2011 ... The Radiation Assessment Detector, shown prior to its September 2010 ... This 360-degree panorama shows the vista from the location where ...

156

Smoothing of laser energy deposition by gas jets  

International Nuclear Information System (INIS)

Smoothing of laser beam non-uniformities using gas jets has been studied. The experiment has been performed with the PALS (Prague Asterix Laser System) laser working at 0.44 ?m with an intensity of about 1015 W/cm2. The laser beam has been split in two by a prism thus creating an artificial large-scale non-uniformity (? 90 ?m). We recorded time resolved and static images of laser-gas jet interaction with and without an Al target. Multi 1-dimensional and 2-dimensional simulations show that such interaction acts redistributing the over-intensities over larger surface. This effect has to be attributed to ionization processes with consequent laser beam refraction. Results show that Argon gas jet produces a strong refraction of the laser beam thus strongly reducing the initial two spots separation. (authors)

2009-08-01

157

RESEARCH MEMORANDUM - NASA Technical Report Server (NTRS)  

Science.gov (United States)

lytical Comparison of Turbine-Blade Cooling System Designed for a. TurboJet Engine Operat- at Supersonic Speed and Altitude. I1 -. Air-C~Oling Systems. ...

158

Profiles - NASA Jet Propulsion Laboratory  

Science.gov (United States)

Jun 30, 2003 ... He graduated from training with top honors and served as a parachute rigger and paratrooper for the 82nd airborne division at Fort Bragg, ...

159

Production of Jet Fuels from Coal-Derived Liquids. Volume 12. ...  

Science.gov (United States)

... The phenol and cresylic acid stream is flashed in a thin film evaporator over a concentrated sulfuric acid mixture to remove pyridine type substances ...

1989-12-01

160

PLASMA JET WELDING, COATING, AND CUTTING: AN ...  

Science.gov (United States)

... 31. New electric forming methods offer potentials for light metals; magnetic forming and plasma forming. ... 3, 25 Magnetic Forming ..... ...

1963-02-01

161

Opposed jet diffusion flames of nitrogen-diluted hydrogen vs air - Axial LDA and CARS surveys; fuel/air rates at extinction  

Science.gov (United States)

An experimental study of H-air counterflow diffusion flames (CFDFs) is reported. Coaxial tubular

1989-01-01

162
163

Numerical simulations of nucleate boiling in impinging jets: Applications in power electronics cooling  

Energy Technology Data Exchange (ETDEWEB)

Boiling jet impingement cooling is currently being explored to cool power electronics components. In hybrid vehicles, inverters are used for DC-AC conversion. These inverters involve a number of insulated-gate bipolar transistors (IGBTs), which are used as on/off switches. The heat dissipated in these transistors can result in heat fluxes of up to 200 W/cm{sup 2}, which makes the thermal management problem quite important. In this paper, turbulent jet impingement involving nucleate boiling is explored numerically. The framework for these computations is the CFD code FLUENT. For nucleate boiling, the Eulerian multiphase model is used. The numerical results for boiling water and R113 jets (submerged) are validated against existing experimental data in the literature. Some representative IGBT package simulations that use R134a as the cooling fluid are also presented. (author)

2008-01-15

164

Non-Intrusive, Laser-Based Imaging of Jet-A Fuel Injection and Combustion Species in High Pressure, Subsonic Flows  

Science.gov (United States)

The emphasis of combustion research efforts at NASA Glenn Research Center (GRC) is on collaborating

2000-01-01

165

NASA Jet Propulsion Laboratory - Lecture series  

Science.gov (United States)

A Self-Powered Underwater Robot for Ocean Exploration and Beyond ... first unmanned underwater vehicle (UUV) that is completely powered by renewable energy . ...

166

NASA - Spitzer Sees Spider Web of Stars  

Science.gov (United States)

star formation. To either side of the center, a small bar of dust and gas is helping to fuel the new stars. NASA's Jet Propulsion Laboratory, Pasadena, Calif., manages the...

2011-07-20

167

Live Web Chat: Earthquakes - How, Where and Why? - NASA Jet ...  

Science.gov (United States)

Mar 2, 2010 ... The NASA/JPL Education Office works with educators -- both classroom teachers and informal educators -- to provide tools, resources and ...

168

Jet flow analysis of liquid poison injection in a CANDU reactor using source term  

Energy Technology Data Exchange (ETDEWEB)

For the performance analysis of Canadian deuterium uranium (CANDU) reactor shutdown system number 2 (SDS2), a computational fluid dynamics model of poison jet flow has been developed to estimate the flow field and poison concentration formed inside the CANDU reactor calandria. As the ratio of calandria shell radius over injection nozzle hole diameter is so large (1055), it is impractical to develop a full-size model encompassing the whole calandria shell. In order to reduce the model to a manageable size, a quarter of one-pitch length segment of the shell was modeled using symmetric nature of the jet; and the injected jet was treated as a source term to avoid the modeling difficulty caused by the big difference of the hole sizes. For the analysis of an actual CANDU-6 SDS2 poison injection, the grid structure was determined based on the results of two-dimensional real- and source-jet simulations. The ...

2001-01-01

169

Integrated coke, asphalt and jet fuel production process and apparatus  

Science.gov (United States)

A process and apparatus for the production of coke, asphalt and jet fuel m a feed of fossil fuels containing volatile carbon compounds therein is disclosed. The process includes the steps of pyrolyzing the feed in an entrained bed pyrolyzing means, separating the volatile pyrolysis products from the solid pyrolysis products removing at least one coke from the solid pyrolysis products, fractionating the volatile pyrolysis products to produce an overhead stream and a bottom stream which is useful as asphalt for road pavement, condensing the overhead stream to produce a condensed liquid fraction and a noncondensable, gaseous fraction, and removing water from the condensed liquid fraction to produce a jet fuel-containing product. The disclosed apparatus is useful for practicing the foregoing process. the process provides a useful method of mass producing and jet fuels from materials such as coal, oil shale and tar sands.

1991-01-01

170

Infrared Thermometer - NASA Spinoff  

Science.gov (United States)

May 1, 2011 ... Abstract: Diatek Corporation, San Diego, CA and the Jet Propulsion Lab developed the Diatek Model 7000 aural thermometer which weighs ...

171

Greenversations » 2009 » October  

Science.gov (United States)

this, however, was a real environmental threat since various drums containing jet fuel, Bunker C, diesel and other petroleum derivatives were on fire. The CAPECO...

2011-10-07

172

GHG Inventories & Forecasts: National Inventories and Forecasts...  

Science.gov (United States)

of different transportation fuels (e.g., gasoline, diesel fuel, aviation gasoline, jet fuel, residual fuel oil). Subsequent calculations are performed to estimate the share...

2011-08-26

173

Frequent Questions - Emissions | Climate Change | U.S. EPA  

Science.gov (United States)

activities, including the combustion of diesel fuel in heavy-duty vehicles and jet fuel in aircrafts. Current details on emissions from the transportation and other...

2011-04-14

174

Force Required to Detach Conidia of Helminthosporium maydis  

UK PubMed Central (United Kingdom)

The force required to break the conidium-conidiophore attachment in Helminthosporium maydis was measured by centrifugation and by a small jet of air. The force which removed half the...Full Text Available

1975-01-01

175

Fifty years of jet in cross flow research  

Science.gov (United States)

The jet in cross flow (JICF) is a basic flowfield which is relevant to a wide variety of applications which are described to provide context for JICF investigations. Material consistent with the scope of topics presented at the 72nd AGARD Fluid Dynamics Panel Meeting and Symposium on Computational and Experimental Assessment of Jets in Cross Flow on 19-22 April 1993 in Winchester, U.K. is summarized. The JICF research was divided into three time periods: (1) early research - up to 1970, (2) research during the 1970's, and (3) research since 1980. The following areas of experimental activity are discussed; the definition of an effective correlation parameter; the jet flowfield including the jet trajectories, cross-section shape, and jet induced pressures; the effects of jet deflection angle, nozzle shape, pressure ratio, velocity decay, and temperature; and the ...

1993-11-01

176

FR Doc 2010-30296  

Science.gov (United States)

cellulosic biofuel volumes for consumption as transportation fuel, heating oil, or jet fuel in the U.S. in 2011. We also evaluated the production and import potential for...

2010-12-08

177

FR Doc 2010-24310  

Science.gov (United States)

and used to reduce or replace petroleum-based transportation fuel, heating oil or jet fuel). In addition, this rule includes a new regulatory provision establishing a...

2010-09-27

178

Does Your Class Have Questions About Earthquakes? - NASA Jet ...  

Science.gov (United States)

Mar 15, 2011 ... The NASA/JPL Education Office works with educators -- both classroom teachers and informal educators -- to provide tools, resources and ...

179

Bioremediation  

Science.gov (United States)

from a military fuel storage facility released about 80,000 gallons of kerosine-based jet fuel. Immediate and extensive recovery measures managed to contain the spill, but...

2011-10-08

180

Bioremediation  

Science.gov (United States)

from a military fuel storage facility released about 80,000 gallons of kerosine-based jet fuel. Immediate and extensive recovery measures managed to contain the spill, but...

2011-08-27

181

Attendees - MEPAG - NASA  

Science.gov (United States)

Barlow, Nadine Northern Arizona University, Flagstaff, AZ. 10. Barker, Don NASA Johnson Space Center, TX. 11. Beaty, David NASA Jet Propulsion Laboratory, ...

182

Application of Synthetic Jets to Reduce Stator Flow Separation in a ...  

Science.gov (United States)

Surface pressure measurements at mid span indicate that flow separation begins near ..... Turbomachinery Flows, AGARD Propulsion Energetics Panel, 1998. ...

183

A Great Day to Go Flying  

Science.gov (United States)

but one test point on the flight cards was achieved before we hit our "bingo," or minimal fuel remaining, and we had to land. The radar was developed by NASA's Jet Propulsion...

2011-10-07

184

49 CFR 130.11 - Communication requirements.  

Science.gov (United States)

...identified as oil when the shipment document accurately describes the material as: aviation fuel, diesel fuel, fuel oil, gasoline, jet fuel, kerosene, motor fuel, or...

2010-10-01

185

--No Title--  

Science.gov (United States)

Air Show. The exhibit will feature 16 fuel companies showcasing cutting-edge alternative jet fuel technologies. In addition to individual company exhibits, the Showcase will...

2011-08-28

186

+ September 2006 - NASA Jet Propulsion Laboratory  

Science.gov (United States)

Post-drive imaging included 360-degree view by the navigation camera and .... Sol 938: Opportunity completed another assessment of the clarity of the sky. ...

187

Investigation of computational aeroacoustic tools for noise predictions of wind turbine aerofoils  

International Nuclear Information System (INIS)

In this work trailing edge noise levels of a research aerofoil have been computed and compared to aeroacoustic measurements using two different approaches. On the other hand, aerodynamic and aeroacoustic calculations were performed with the full Navier-Stokes CFD code Fluent [Fluent Inc 2005 Fluent 6.2 Users Guide, Lebanon, NH, USA] on the basis of a steady RANS simulation. Aerodynamic characteristics were computed by the aid of various turbulence models. By the combined usage of implemented broadband noise source models, it was tried to isolate and determine the trailing edge noise level. Throughout this work two methods of different computational cost have been tested and quantitative and qualitative results obtained. On the one hand, the semi-empirical noise prediction tool NAFNoise [Moriarty P 2005 NAFNoise User's Guide. Golden, Colorado, July. http://wind.nrel.gov/designcodes/ simulators/NAFNoise] ...

2007-07-01

188

Improvement of PLL algorithm for the LEP Q-meter  

CERN Document Server

The PLL (Phase Locked Loop) has two modes: search mode and locking mode. The mode is determined by how far apart the internal frequency is from the external frequency. When the internal - and exter nal frequencies are close, the PLL is in locking mode. While locking on the external frequency, the PLL can largely be expressed as a linear term superimposed with a small "noise" term. We can t herefore calculate a transfer function that will completely describe the performance of the PLL apart from the precision, which is determined by the noise term. Two ideas are presented on how to re duce the noise term. The first idea is to compensate the noise term with an equal value of opposite sign. This completely removes the noise when the PLL locks on a steady frequency. Unfortunately it can not be used for the LEP Q-meter which is plagued by the presence of satellite frequencies. For other ...

1998-01-01

189

Control of linear accelerator noise in the Los Alamos free-electron laser (FEL)  

International Nuclear Information System (INIS)

The Los Alamos FEL requires tight control of the amplitudes and phases of the fields in two linear accelerator tanks to obtain stable lasing. The accelerator control loops must establish constant, stable, repeatable amplitudes and phases of the rf fields and must have excellent bandwidth to control high-frequency noise components. A model of the feedback loops has been developed that agrees well with measurements and allows easy substitution of components and circuits, thus reducing breadboarding requirements. The model permits both frequency and time-domain analysis. This paper describes the accelerator control scheme and our model and discusses the control of noise in feedback loops, showing how low-frequency-noise components (errors) can be corrected, but high-frequency-noise components (errors) are actually amplified by the feedback circuit. Measurements of noise in both open- ...

1986-06-02

190

Application and evaluation of processing methods of electrochemical noise generated during stress corrosion cracking  

Energy Technology Data Exchange (ETDEWEB)

Electrochemical noise generated during stress corrosion cracking (SCC) of type 304 stainless steel (UNS S30400) and {alpha}-brass were studied. Noise patterns showed common characteristics (i.e., a quick drop and slow recovery of the potential). The quick drop corresponded to the initiation of localized events where fresh metal was exposed. The slow recovery corresponded to the repassivation process of the exposed bare metal. The potential drop rate and recovery rate were almost constant during the SCC process for a given SCC system. For random noise, rates of potential rise and drop were similar. Frequency of the noise generated during SCC increased with an increase in applied stress. SCC initiation could be monitored and determined according to noise characteristics and distribution. Since the shift of background potentials had an obvious influence on characteristics of power ...

1999-09-01

191

iMAST Quarterly, Number 1, 1998  

Science.gov (United States)

... Airframe System Technoloqies Laser fabricated flooring Composite sandwich panels for noise control Spray formed HS aluminum alloys Protective ...

2011-05-14

192

Power spectral density measurements with "2"5"2Cf for a mockup of the FFTF  

International Nuclear Information System (INIS)

... californium 252 fftf reactor mockup power density reactor cores reactor noise

1975-06-08

193

Parallel MRI reconstruction using variance partitioning regularization  

British Library Electronic Table of Contents (United Kingdom)

Multiple receivers can be utilized to enhance the spatiotemporal resolution of MRI by employing the parallel imaging technique. Previously, we have reported the L-curve Tikhonov regularization technique to mitigate noise amplification resulting from the geometrical correlations between channels in a coil array. Nevertheless, one major disadvantage of regularized image reconstruction is lengthy computational time in regularization parameter estimation. At a fixed noise level, L-curve regularization parameter estimation was also found not to be robust across repetitive measurements, particularly for low signal-to-noise ratio (SNR) acquisitions. Here we report a computationally efficient and robust method to estimate the regularization parameter by partitioning the variance of the noise-white...

2007-01-01

194

Low frequency noise from MW wind turbines -- mechanisms of generation and its modeling  

Energy Technology Data Exchange (ETDEWEB)

During the present project the mechanisms of generation of low frequency noise (LFN) for upwind rotors has been investigated. A 3.6 MW turbine has been simulated with a noise prediction model from NASA in US. Running the model on this turbine a number of important turbine design parameters with influence on the LFN have been identified as well as other parameters not linked to the turbine design. Of important parameters can be mentioned 1) rotor rotational speed, 2) blade/tower clearance, 3) rotor configuration - upwind/downwind, 4) unsteadiness/turbulence in inflow. Further, the directivity characteristics of LFN has been computed as well as reduction in noise as function of distance from the turbine. In general low levels of LFN has been computed for the upwind rotor in standard configuration. (au)

2008-04-15

195

LAMBDA - IRAS Faint Source Survey Plates - LAMBDA - NASA  

Science.gov (United States)

Apr 18, 2008 ... The FSS was produced by point-source filtering the individual detector data ... a 1-sigma noise map; and a coverage map giving the count of ...

196

High Temperature Superconducting Compounds  

Science.gov (United States)

... Voltage noise power spectral density measurements as a function of temperature, frequency, current, and magnetic field on DyBa2Cu3O7.x (DBCO ...

1992-11-30

197

Femtosecond Laser Passivation of GaAs Detector Material  

Science.gov (United States)

... The approach is to perform noise spectral density measurements and selected materials structure measurements on GaAs detector materials, with ...

2008-06-07

199

Enhancing AIS to Improve Whale-Ship Collision Avoidance ...  

Science.gov (United States)

... 2008. Characterizing the relative contributions of large vessels to total ocean noise fields: a case study using the Gerry E. Studds Stellwagen Bank ...

2010-06-01

200

Drift- or Fluctuation-Induced Ordering and Self-Organization in Driven Many-Particle Systems  

CERN Document Server

According to empirical observations, some pattern formation phenomena in driven many-particle systems are more pronounced in the presence of a certain noise level. We investigate this phenomenon of fluctuation-driven ordering with a cellular automaton model of interactive motion in space and find an optimal noise strength, while order breaks down at high(er) fluctuation levels. Additionally, we discuss the phenomenon of noise- and drift-induced self-organization in systems that would show disorder in the absence of fluctuations. In the future, related studies may have applications to the control of many-particle systems such as the efficient separation of particles. The rather general formulation of our model in the spirit of game theory may allow to shed some light on several different kinds of noise-induced ordering phenomena observed in physical, chemical, biological, and socio-economic systems ...

2002-01-01

201

AERODYNAMIC NOISE TESTS ON X-20 SCALE MODELS. ...  

Science.gov (United States)

... 37 18 Power Spectral Density Measurements of Buffet Pressures for Two Different Microphone Positions Compared with PSD Values Inferred from ...

1965-11-01

202

Understanding and predicting soot generation in turbulent non-premixed jet flames.  

Energy Technology Data Exchange (ETDEWEB)

This report documents the results of a project funded by DoD's Strategic Environmental Research and Development Program (SERDP) on the science behind development of predictive models for soot emission from gas turbine engines. Measurements of soot formation were performed in laminar flat premixed flames and turbulent non-premixed jet flames at 1 atm pressure and in turbulent liquid spray flames under representative conditions for takeoff in a gas turbine engine. The laminar flames and open jet flames used both ethylene and a prevaporized JP-8 surrogate fuel composed of n-dodecane and m-xylene. The pressurized turbulent jet flame measurements used the JP-8 surrogate fuel and compared its combustion and sooting characteristics to a world-average JP-8 fuel sample. The pressurized jet flame measurements demonstrated that the surrogate was representative of JP-8, with a somewhat higher tendency to ...

2010-10-01

203

Software framework and jet energy scale calibration in the ATLAS experiment; Environnement logiciel et etalonnage de l'echelle en energie des jets dans l'experience ATLAS  

Energy Technology Data Exchange (ETDEWEB)

This thesis presents the work achieved to instrument the ATLAS software framework, ATHENA, with a library of tools and utensils for the physics analysis as well as the extraction of the jet energy scale using physics events (in-situ calibration). The software part presents the various components of the ATHENA framework which handles the simulated and reconstructed data flow as well as the different stages of this process, before and during the data taking. The building of a library of tools easing the reconstruction of physics objects, their association with Monte-Carlo particles and their API is then explained. The need for common language and collaboration-wide utensils is emphasised as it allows to share the workload of validating these tools and to get reproducible physics results. The analysis part deals with the implementation of a light jet energy scale calibration algorithm within the C++ framework. This calibration algorithm makes use ...

2006-07-01

204

Remote participation technical infrastructure for the JET facilities under EFDA  

Energy Technology Data Exchange (ETDEWEB)

The new collaborative exploitation of the JET Facilities requires suitable technical tools and infrastructure measures to enable the Remote Participation of scientists from all European Fusion labs. Such measures are being gradually introduced. They comprise of a toolkit for Remote Data Access, Remote Computer Access and for teleconferencing, and of infrastructure measures that address network connectivity, network security, shared documentation and technical support.

2001-10-01

205

PIV measurements of flow structures in a spray dryer  

DEFF Research Database (Denmark)

Stereoscopic Particle Image Velocimetry (PIV) measurements are made in horizontal planes in a simplified scale model of a spray dryer using water as fluid. The sample rate was sufficient to resolve phenomena at lower frequencies. Data reveal asymmetric velocity fields in both mean fields and dynamics. Data were analysed using Proper Orthogonal Decomposition (POD). An important periodic event is an elongation of the jet core cross section that results in a downstream displacement of the jet towards the chamber wall.

2011-01-01

206

Neutron detection techniques for plasma diagnostics at the Joint European Torus (JET)  

International Nuclear Information System (INIS)

The importance of neutron measurements both as a succinct measure of the progress to fusion ignition using the magnetic confinement route and also as a diagnostic of plasma conditions is discussed. The various neutron diagnostic systems that have been or are being constructed by AERE Harwell for JET are described. The properties to be measured by such diagnostics are clearly identified and some results obtained with the installed diagnostics during d-d plasmas are presented.

207

Concept of Plasma Spraying System for Solid Oxide Fuel Cell: Heating Studies of YSZ Particle in Plasma Jet  

International Nuclear Information System (INIS)

One of several methods to build YSZ electrolyte of SOFC is plasma spraying. This system heats particle to a melting point and then pushing them into target and forming a deposition. This paper presents heating studies of YSZ particle in plasma jet. By simple model it is shown that the required time such those YSZ particle with grain size of 50 ?m to be melt is around 12 x 10-4 second. (author)

2006-07-01

208

Analytical determination of the dimensions and evolution with current of the ion-emitting jet in liquid-metal ion sources  

Energy Technology Data Exchange (ETDEWEB)

The apex dimensions and length are calculated as a function of current for the ion-emitting jet in liquid-metal ion sources (LMIS). The results agree well with observations. Since the final expressions are analytical, they give more insight into the fundamental mechanisms involved than do numerical calculations. Some implications of the model are discussed concerning focused ion beam (FIB) systems employing LMIS. (author).

1991-12-14

209

Advanced thermally stable jet fuels: Technical progress report, October 1994--December 1994  

Science.gov (United States)

There are five tasks within this project on thermally stable coal-based jet fuels. Progress on each of the tasks is described. Task 1, Investigation of the quantitative degradation chemistry of fuels, has 5 subtasks which are described: Literature review on thermal stability of jet fuels; Pyrolytic and catalytic reactions of potential endothermic fuels: cis- and trans-decalin; Use of site specific {sup 13}C-labeling to examine the thermal stressing of 1-phenylhexane: A case study for the determination of reaction kinetics in complex fuel mixtures versus model compound studies; Estimation of critical temperatures of jet fuels; and Surface effects on deposit formation in a flow reactor system. Under Task 2, Investigation of incipient deposition, the subtask reported is Uncertainty analysis on growth and deposition of particles during heating of coal-derived aviation gas turbine fuels; under Task 3, Characterization of solid ...

1995-02-01

210

Mixed waste disposal facility at the Nevada Test Site  

Energy Technology Data Exchange (ETDEWEB)

This report provides a brief overview of the history and planning for a proposed mixed waste disposal site on the Nevada Test Site. 8 figs.

1987-01-01

211

The jet-powered optical nebula of Cygnus X-1  

CERN Document Server

We present H-alpha and [O III] (5007 Angstroms) images of the nebula powered by the jet of the black hole candidate and microquasar Cygnus X-1, observed with the 2.5m Isaac Newton Telescope (INT). The ring-like structure is luminous in [O III] and there exists a thin outer shell with a high [O III] / H-alpha flux ratio. This outer shell probably originates in the collisionally excited atoms close to the front of the bow shock. Its presence indicates that the gas is shock excited as opposed to photoionised, supporting the jet-powered scenario. The shock velocity was previously constrained at 20 = 100 km/s (1 sigma confidence) based on a comparison of the observed [O III] / H-alpha ratio in the bow shock with a number of radiative shock models. From this we further constrain the time-averaged power of the jet: P_Jet = (4 - 14)*10^36 erg/s. The H-alpha flux behind the shock front is typically 4*10^-15 ...

2007-01-01

212

Plasma nitriding of substrate by using supersonic nitrogen plasma jet; Cho onsoku chisso plasma jet wo mochiita Ti kizai no plasma chikka  

Energy Technology Data Exchange (ETDEWEB)

Plasma nitriding of a Ti substrate is carried out under a low ambient pressure below 3kPa, and a plasma torch is prepared on a trial basis which is provided with a supersonic expansion nozzle considered to expand plasma jet optimally and to be effective for suppressing the occurrence of shock wave. The system used for the study is provided with a specimen holder having the function of adjusting the distance between the nozzle outlet and the substrate inside the vacuum chamber which is provided with a plasma torch in the flange member. The plasma torch is so structured that a supersonic expansion nozzle can be installed at the tip of the plasma torch. In this process wherein plasma jet is employed, hard nitrided layer can be formed by plasma irradiation for a short time even under such low pressure as less than 3kPa by setting adequate experimental conditions. It is made clear that the use of a supersonic nozzle corresponding to the internal ...

1997-07-01

213

Modification of the sheet resistance of ink jet printed polymer conducting films by changing the plastic substrate  

Energy Technology Data Exchange (ETDEWEB)

The ink jet printing technology is a relatively novel technique in development of organic electronic devices. The technique consists of working out depositions of organic layers by a piezo-based ink jet printer. In this work polymer conducting films deposited by ink jet printing technique on different plastic substrates has been demonstrated. The poly(3,4-ethylenedioxythiofene)/poly(4-styrenesulfonate) [PEDOT/PSS] and glycerol-modified PEDOT/PSS [G-PEDOT/PSS] were used like conducting inks to be applied on polyester and polyethylene terephthalate (PET) substrates. By means of the change of substrate associated to the deposition number or type of polymer ink used for printing of the conducting films, the sheet resistance can be modified. Such a behavior suggests that plastic substrate fulfills an important role for the changing of sheet resistance of the PEDOT/PSS and G-PEDOT/PSS films made by ink jet ...

2005-09-25

214

A new method of heat transfer augmentation by means of foreign gas jet impingement in liquid bath  

International Nuclear Information System (INIS)

The authors discuss a two-phase two-component experimental system developed to study enhancement of heat transfer from a vertical chip size heater to surrounding liquid (Freon 113 or Ethanol) due to air jet impingement. Heat transfer coefficient was measured as function of jet velocity, heat flux and the distance between exit of jet tube and heated surface. The injector was placed very close to the hot surface. It was found that the heat transfer was notably enhanced with foreign gas impingement, especially in the cases of small temperature differences between wall and coolant. In fact for higher jet velocities the heat transfer coefficients tended to infinite while the temperature differences between wall and coolant were zero. The heat transfer coefficients decreased with the increasing of heat flux. High-speed camera was used to study the behaviour of the gas bubbles which play very important role in ...

1985-10-01

215

New injection equipment for high-speed Diesel engines  

Energy Technology Data Exchange (ETDEWEB)

A high-speed light-Diesel engine with direct injection has been developed by the Institute of Combustion Engines, Graz. Thanks to light construction throughout, exhaust gas supercharger and noise-reduced composition a Diesel engine could be built that is comparable to Otto-cycle engines as regards performance, weight, aggregate size and noise production but far superior to these with respect to fuel consumption and exhaust gas emission.

1982-09-01

216

Model of quantum noise of shadow radiation images  

International Nuclear Information System (INIS)

Correlation characteristics of quantum noise on the shadow radiation image (RI) of the object under nondestructive testing are studied. Mathematical model of RI occasional distortions is derived. The model takes into account the parameters of object under testing and of radiation beam by radiation quanta flux density. The results obtained can be used as a component in the process of investigation of various radiation testing systems

217

Experience with a digital noise analysis system in subcriticality measurements on a mockup of the FFTF  

Science.gov (United States)

From nuclear science symposium; San Francisco, California, USA (14 Nov 1973). A digital Fourier analyzer was programmed to perform reactor neutron noise analysis measurements and on-line processing of the data to obtain the steady-state reactivity. The system is suitable for recovering cross spectral density with low correlatedsignal component and for repetitive measurements with efficient use of reactor time. (auth)

1973-01-01

218

Asymptotic properties and simulations of a stochastic logistic model under regime switching  

British Library Electronic Table of Contents (United Kingdom)

Taking both white noise and colored environmental noise into account, a general stochastic logistic model under regime switching is proposed and studied. Sufficient conditions for extinction, nonpersistence in the mean, weak persistence, stochastic permanence and global attractivity are established. The critical number between weak persistence and extinction is obtained. Moreover, some simulation figures are introduced to illustrate the main results.

2011-01-01

219

Advances in noise analysis for nuclear plant surveillance and diagnostics  

Energy Technology Data Exchange (ETDEWEB)

An automated surveillance and baseline noise signature acquisition system is being demonstrated at Sequoyah-1. A nonperturbing method is also being developed for monitoring the subcritical reactivity during initial core loading in LWRs, in fuel storage and processing facilities, and during postaccident recovery operations such as Three Mile Island-2. (DLC)

1980-01-01

220

Study of exhaust and noise emissions reduction on a single spray direct injection diesel engine  

Energy Technology Data Exchange (ETDEWEB)

In order to materialize the automobile use small direct injection diesel engine (DI), the reduction in both exhaust emission and noise, as studied, was explained in summary. The DI, as excellent in fuel consumption characteristics, was studied to be adopted to the small automobile, with the materialization of small DI to be about 600cc in capacity per cylinder. However the further diminution in dimension had not been materialized yet, because of the aggravation in exhaust emission and vibration noise. Then a single spray DI, characterized by the approximate sphericity in shape of combustion chamber and adoption of cast iron made piston and two-stage spring nozzle, was prototypically made, with optimizing the combustion in characteristics, decreasing HC in exhaust quantity by modifying the injection system, doing also NOx in exhaust quantity by adopting the lag angle at injection time and EGR, modifying the structure to lower the ...

1989-04-01

221

Sensitivity of dual fuel engine combustion and knocking limits to gaseous fuel composition  

International Nuclear Information System (INIS)

Combustion noise, knock and ignition limits data are measured and presented for a dual fuel engine running on dual fuels of Diesel and three gaseous fuels separately. The gaseous fuels used are liquefied petroleum gas, pure methane and compressed natural gas mixture. The maximum pressure rise rate during combustion is presented as a measure of combustion noise, and the knocking and ignition limits are presented as torque output at the onset of knocking and ignition failure. Experimental investigation on the dual fuel engine revealed the noise generated from combustion, knocking and ignition limits for all gases at different design and operating conditions. A Ricardo E6 Diesel version engine is converted to run on dual fuel of Diesel and the tested gaseous fuel and is used throughout the work. The engine is fully computerized, and the cylinder pressure data, crank angle data and engine operating variables are stored in a PC ...

2004-02-01

222

Kepler Mission Stellar and Instrument Noise Properties  

CERN Document Server

Kepler Mission results are rapidly contributing to fundamentally new discoveries in both the exoplanet and asteroseismology fields. The data returned from Kepler are unique in terms of the number of stars observed, precision of photometry for time series observations, and the temporal extent of high duty cycle observations. As the first mission to provide extensive time series measurements on thousands of stars over months to years at a level hitherto possible only for the Sun, the results from Kepler will vastly increase our knowledge of stellar variability for quiet solar-type stars. Here we report on the stellar noise inferred on the timescale of a few hours of most interest for detection of exoplanets via transits. By design the data from moderately bright Kepler stars are expected to have roughly comparable levels of noise intrinsic to the stars and arising from a combination of fundamental limitations such as Poisson statistics and any ...

2011-01-01

223

Investigation of the frequency-dependence of the MTC noise estimator  

International Nuclear Information System (INIS)

The Moderator Temperature Coefficient of reactivity (MTC) was earlier proven to be properly determined via noise analysis when the neutron noise is measured locally and when the radial average of the moderator temperature noise is used. Nevertheless, measurements revealed that the MTC was correctly estimated on a much narrower frequency band (0.6 - 0.7 Hz) than expected (0.1 - 1.0 Hz). The present paper investigates the effect of the feedback on the MTC determination using this new MTC noise estimator (which could explain the deviation at low frequencies, i.e. between 0.1 - 0.5 Hz) and the effect of the detector time constants (which could explain the deviation at high frequencies, i.e. between 0.7 - 1.0 Hz). For that purpose, a coupled neutronic/thermalhydraulic model of the Ringhals-3 PWR is developed in the frequency-domain, based on a radial 2-dimensional heterogeneous representation of the core. ...

2005-09-12

224

Two-phase flow characteristic of inverted bubbly, slug and annular flow in post-critical heat flux region  

Energy Technology Data Exchange (ETDEWEB)

Inverted annular flow can be visualized as a liquid jet-like core surrounded by a vapor annulus. While many analytical and experimental studies of heat transfer in this regime have been performed, there is very little understanding of the basic hydrodynamics of the post-CHF flow field. However, a recent experimental study was done that was able to successfully investigate the effects of various steady-state inlet flow parameters on the post-CHF hydrodynamics of the film boiling of a single phase liquid jet. This study was carried out by means of a visual photographic analysis of an idealized single phase core inverted annular flow initial geometry (single phase liquid jet core surrounded by a coaxial annulus of gas). In order to extend this study, a subsequent flow visualization of an idealized two-phase core inverted annular flow geometry (two-phase central jet core, surrounded by a coaxial annulus of ...

1988-01-01

225

Production of jet fuel using heavy crude oil; Producao de combustiveis de aviacao a partir de petroleos pesados  

Energy Technology Data Exchange (ETDEWEB)

The production of heavy crude oils increased in the last years in the world. Crude oils with high density, viscosity, acidity and sulfur, nitrogen, metals and asphaltenes contents, by the others hand, low stability and low product quality. The challenger of many refiners is find solutions to refine the heavy crude oils, and produce fuels with certify quality, such as Jet Fuel. The principal aviation technique on the world work with gas turbines engines feted for jet fuel (JET A1). The quality specifications of this fuel are establish by International Norms: ASTM-1655, DEF STAN 91-91-3 (DERD 2494) and joint Fuelling System Check List. The world technologies to obtain jet fuel from mixtures of heavy crude oil with middle crude oils are: Atmospheric distillation, with a posterior hydrogenation and finally the additivation. Studies carried out have demonstrates that the Cubans heavy crude oils is ...

2004-07-01

226

Life Cycle Assessment of Potential Bio-jet Fuel Production in the United States.  

Science.gov (United States)

The objective of this paper is to reveal to what degree bio-based jet fuels (bio-jet) can reduce greenhouse gas (GHG) emissions from the US aviation sector. A model of the supply and demand chain of bio-jet involving farmers, bio-refineries, airlines, and policymakers is developed by considering factors that drive the decisions of actors (i.e. decision-makers and stakeholders) in the life cycle stages. Two kinds of feedstock are considered: oil-producing feedstock (i.e. camelina and algae) and lignocellulosic biomass (i.e. corn stover, switchgrass, and short rotation woody crops). By factoring in farmer/ feedstock producer and bio-refinery profitability requirements, land availability and suitability, as well as a time delay factor, a more realistic estimate of the level of bio-jet supply and emissions reduction can be developed under different oil price assumptions. Factors that drive ...

2011-09-29

229

Radioactive and mixed waste management plan for the Lawrence Berkeley Laboratory Hazardous Waste Handling Facility  

Energy Technology Data Exchange (ETDEWEB)

This Radioactive and Mixed Waste Management Plan for the Hazardous Waste Handling Facility at Lawrence Berkeley Laboratory is written to meet the requirements for an annual report of radioactive and mixed waste management activities outlined in DOE Order 5820.2A. Radioactive and mixed waste management activities during FY 1994 listed here include principal regulatory and environmental issues and the degree to which planned activities were accomplished.

1995-01-01

230

News from Smithers Rapra  

Wastenet

...of Mixing Sections 9 Interacting Rotor/Stator Mixers 10 Floating Ring Mixing Devices 11 Static (or Motionless) Mixers 12 Incorporation of Liquid Additives and Dispersions by Direct Addition 13 Dispersive Mixing of Fillers and Pigments 14 Dispersive Mixing Applied to Polymer Blending 15 Compounding with Single Screw Extruders Appendix - Preparation of Microtome Sections for Assessment of Dispersive In order to get a feel for this book, you can view Chapter 1 now, simply follow the link ...

237

Flavor Mixing of Quarks and Neutrinos  

CERN Document Server

The "texture zero mass matrices" for the quarks and leptons describe very well the flavor mixing of the quarks and leptons. We can calculate the angles of the unitarity triangle. We expect the angle alpha of the unitarity triangle to be 90 degrees. The masses of the neutrinos can be calculated - they are very small, the largest neutrino mass is 0.05 eV. We calculated the matrix element of the mixing matrix, relevant for the reactor mixing angle. It can be measured in the near future in the DAYA BAY experiment.

2011-01-01

247

Absolute values of three neutrino masses from atmospheric mixing and an ansatz for the mixing-matrix elements  

CERN Document Server

Using data from atmospheric neutrino mixing, and a simple functional form for mixing angles, the absolute values of three neutrino masses are calculated: $m_3\\cong 5.37\\times 10^{-2} eV$, $m_2\\cong 1.94\\times 10^{-2} eV$, $m_1\\cong 1.46\\times 10^{-2} eV$. The quantities relevant for solar neutrino mixing are calculated: $(m_2^2-m_1^2) \\cong 1.63\\times 10^{-4} eV^2$, with non-maximal mixing $\\tan^2\\theta_\\sol \\cong 0.56$. The analysis gives a suggestion of a dynamical origin for the empirical, large CP-violating phase associated with an intrinsically, very small mixing angle in the quark sector.

2003-01-01

248

The new JET phased ICRH array: first experiments and modelling  

Energy Technology Data Exchange (ETDEWEB)

New ICRH antennas on JET were designed to couple to the new JET divertor plasma configurations and to improve the Fast Wave Current Drive (FWCD) capabilities. The A2 antenna consists of 4 straps whose currents can be phased at arbitrary angles. The real time automatic tuning acts on frequency, line length (line phase shifters) and stub length. Provision is made for the coupling resistance/plasma position feedback to accommodate the fast changes in antenna loading. The first coupling, tuning and heating results are reported in 0{pi}0{pi}, 0000 and 00{pi}{pi} phasing. A new antenna model is described, which was developed to simulate the measured antenna loading in terms of plasma parameters and to provide a starting point for the real time automatic tuning. 5 refs., 4 figs.

1994-07-01

249

THE RADIO JET INTERACTION IN NGC 5929: DIRECT DETECTION OF SHOCKED GAS  

International Nuclear Information System (INIS)

We report on the discovery of kinematic shock signatures associated with a localized radio jet interaction in the merging Seyfert galaxy NGC 5929. We explore the velocity-dependent ionization structure of the gas and find that low-ionization gas at the interaction site is significantly more disturbed than high-ionization gas, which we attribute to a local enhancement of shock ionization due to the influence of the jet. The characteristic width of the broad low-ionization emission is consistent with shock velocities predicted from the ionization conditions of the gas. We interpret the relative prominence of shocks to the high density of gas in the nuclear environment of the galaxy and place some constraints of their importance as feedback mechanisms in Seyferts.

2010-03-10

250

Remotely sensing of excavation cavity during mining  

Energy Technology Data Exchange (ETDEWEB)

This patent describes a method of hydraulically mining a surface of a mining location comprising: a. determining the dimensions of the surface of the mining location from a fixed point at the location; b. constructing at a second location remote from the mining location a visual representation of the surface form the determined dimensions of the mining location with respect to the fixed point; c. jetting water under high pressure against a selected area on the surface of the mining location; d. determining changes in the dimensions of the selected area of the surface of the mining location; e. reconstructing at the second location a new visual representation of the surface from the determined changes of the location during the jetting of the water; and f. redirecting the jetted water under high pressure utilizing data from the reconstructed visual representation.

1987-11-24

251

Jets and accretion processes in Active Galactic Nuclei further clues  

CERN Document Server

We present evidence in favour of a link between the luminosity radiatively dissipated in the central engine of radio-loud Active Galactic Nuclei and the kinetic power in their jets. This piece of evidence is based on the relation we find between the luminosity in broad emission lines and the kinetic power in pc-scale radio jets, for a sample of radio-loud quasars for which suitable data are available in the literature. We find that the ionizing luminosity and the kinetic one are of the same order of magnitude, suggesting that the processes responsible for them are somehow related. A strong magnetic field in equipartition with the radiation field could be responsible for regulating both processes. BL Lac objects seem to follow a similar behaviour, but with comparatively fainter broad line emission.

1996-01-01

252

Gamma-Ray Burst jet dynamics and their interaction with the progenitor star  

CERN Document Server

The association of at least some long gamma-ray bursts with type Ic supernova explosions has been established beyond reasonable doubt. Theoretically, the challenge is to explain the presence of a light hyper-relativistic flow propagating through a massive stellar core without losing those properties. We discuss the role of the jet-star interaction in shaping the properties of the outflow emerging on the surface of the star. We show that the nature of the inner engine is hidden from the observer for most of the evolution, well beyond the time of the jet breakout on the stellar surface. The discussion is based on analytical considerations as well as high resolution numerical simulations. Finally, the observational consequences of the scenario are addressed in light of the present capabilities.

2006-01-01

253

Study on reactor building structures using ultrahigh strength materials - Part 8: Results of mixed structure tests  

International Nuclear Information System (INIS)

The mixed structure of a nuclear reactor building is composed of SC-columns, S-beams, S-joints and PCa-panels. Following the last report (Part 7)[1], the main test results of the mixed structure, that is, the deformation mode, strain distribution and shear strength, are described. The S-joints using ultrahigh strength materials had no buckling nor shear slipping. The proposed mixed structure resisted the external horizontal forces under integrated uniformity among SC-columns, S-joints and PCa-panels. It could be confirmed that the mixed structure can be established. (author)

1993-08-15

254

Waterjet Techniques for Composite Material Jet Engine ...  

Science.gov (United States)

Page 1. Page 2. Page 3. Page 4. Page 5. Page 6. Page 7. Page 8. Page 9. Page 10. Page 11. Page 12. Page 13. Page 14. Page 15. Page 16. Page ...

1996-06-01

255

Vehicle Technologies Program: Fact #676: May 23, 2011 U.S. Refiners...  

Science.gov (United States)

fuel are produced from a barrel of crude oil by U.S. refiners. Other products such as jet fuel and heating oil make up the remaining one third. Graphic of a barrel of oil...

2011-10-09

256

US Air Force Aircraft in Southeast Asia Tested by the Air Force ...  

Science.gov (United States)

... feet in length, and 26 feet 2 inches high. The AC-119G and AC-119K, are powered with two General Electric J85-17 jet engines pod-mounted ...

1970-03-01

257

The physics of automatic letter sorting  

Science.gov (United States)

The astronomical number of letters handled by the Post Office makes automatic sorting technology essential. Key roles are played by the postcode system and an ink-jet printer that has been developed to use phosphorescent inks.

1988-07-01

258

The Surface Water and Ocean Topography (SWOT) - NASA  

Science.gov (United States)

The ratio of particle velocity to translation speed exceeds 1 for 98% of .... The westward movement of the meandering jet and eddy system transports nutrient- rich ...... J. Hydrometeor., 4, 1044-1066. Gedney, N., P. M. Cox, H. Douville, ...

259

Swift panchromatic observations of the bright gamma-ray burst GRB050525a  

CERN Document Server

The bright gamma-ray burst GRB050525a has been detected with the Swift observatory, providing unique multiwavelength coverage from the very earliest phases of the burst. The X-ray and optical/UV afterglow decay light curves both exhibit a steeper slope ~0.15 days after the burst, indicative of a jet break. The timing of the jet break combined with the total gamma-ray energy of the burst constrains the opening angle of the jet to be 2.5 degrees. We derive an empirical `time-lag' redshift from the BAT data of z_hat = 0.69 +/- 0.02, in good agreement with the spectroscopic redshift of 0.61. Prior to the jet break, the X-ray data can be modelled by a simple power law with index alpha = -1.2. However after 300s the X-ray flux brightens by about 30% compared to the power-law fit. The optical/UV data have a more complex decay, with evidence of a rapidly falling reverse shock component that dominates in the ...

2006-01-01

260

Pressure driven spinning: A multifaceted approach for preparing nanoscaled functionalized fibers, scaffolds, and membranes with advanced materials  

UK PubMed Central (United Kingdom)

Electrospinning, a flexible jet-based fiber, scaffold, and membrane fabrication approach, has been elucidated as having significance to the heath sciences. Its capabilities have been most impressive...Full Text Available

261

Preliminary investigation of performance and starting characteristics of liquid fluorine : liquid oxygen mixtures with jet fuel  

Science.gov (United States)

The performance of jet fuel with an oxidant mixture containing 70 percent liquid fluorine and 30 percent liquid oxygen by weight was investigated in a 500-pound-thrust engine operating at a chamber pressure of 300 pounds per square inch absolute. A one-oxidant-on-one-fuel skewed-hole impinging-jet injector was evaluated in a chamber of characteristic length equal to 50 inches. A maximum experimental specific impulse of 268 pound-seconds per pound was obtained at 25 percent fuel, which corresponds to 96 percent of the maximum theoretical specific impulse based on frozen composition expansion. The maximum characteristic velocity obtained was 6050 feet per second at 23 percent fuel, or 94 percent of the theoretical maximum. The average thrust coefficient was 1.38 for the 500-pound thrust combustion-chamber nozzle used, which was 99 percent of the theoretical (frozen) maximum. Mixtures of fluorine and oxygen were found to be self-igniting with ...

1954-01-01

262

PNNL: News Center - Archives  

Science.gov (United States)

million for advanced energy projects Thu, Sep 29, 2011 - Project Aims to Bring Bio-based Jet Fuel Production to the Northwest Mon, Sep 12, 2011 - Drive like the wind Thu, Aug 25,...

2011-10-09

263

Making Clean Gasoline: The Effect on Jet Fuels.  

Science.gov (United States)

Persistently high concentrations of carbon monoxide and low-altitude ozone in the air of the Nation's major urban centers led Congress in the 1990 Clean Air Act Amendments to mandate changes to the composition of gasoline and diesel fuel. Those gasoline c...

1992-01-01

264

Fragmentation mechanisms of a single molten copper jet penetrating a sodium pool. Transition from thermal to hydrodynamic fragmentation in instantaneous contract interface temperatures below its freezing point  

International Nuclear Information System (INIS)

To clarify the fragmentation mechanism of a molten metallic fuel jet in a sodium pool under high-ejection-velocity conditions that correspond to the medium- and high-burnup conditions in the metallic fuel core of liquid-metal-cooled fast breeder reactors, a series of experiments with molten copper as a metallic fuel simulant and a sodium pool was carried out. Under low-ejection-velocity conditions in the range of an ambient Weber number (Wea) a ? 200, the size of the fragments is confirmed to be almost independent of the initial superheating of the jet. Furthermore, the size of the fragments agrees well with that evaluated using the Rayleigh-Taylor instability model, in which the fragment size is assumed to be equal to half the fastest growing wavelength. This result is qualitatively consistent with the characteristics that the molten jet column with large inertia force owing to the high ejection velocity, which transports ...

2010-03-01

265

FS-1037C Appendix A  

Science.gov (United States)

Telecommunication Union IVDT integrated voice data terminal IXC interexchange carrier JANAP Joint Army-Navy-Air Force Publication(s) JCS Joint Chiefs of Staff JPL Jet Propulsion...

2007-05-31

266

Evaluation of two commercial jet nebulisers and three compressors for the nebulisation of antibiotics.  

UK PubMed Central (United Kingdom)

Nebulised antibiotics have been shown to be beneficial in the treatment of lung infections in cystic fibrosis. Studies on the efficiency of nebuliser systems are constantly required in view of the large...Full Text Available

1994-10-01

267

EPA On-line Tools for Site Assessment Calculation | Ecosystems...  

Science.gov (United States)

MWo = average molecular weight of fuel est. 105 g/mole for gasoline est. 165 g/mole for Jet fuel est. 230 g/mole for diesel fuel MWX = molecular weight of selected chemical...

2011-01-19

268

Department of Natural Resources  

Science.gov (United States)

to end statewide burn ban 09/28/2011 - Commissioner's statement on $80 million biomass to jet fuel award to UW and WSU Media Center | View All News Meetings & Events Saturday Oct...

2011-10-08

269

Circadian Rhythm Sleep Disorders: Part I, Basic Principles, Shift Work and Jet Lag DisordersAn American Academy of Sleep Medicine Review  

UK PubMed Central (United Kingdom)

Objective:This the first of two articles reviewing the scientific literature on the evaluation and treatment of circadian rhythm sleep disorders (CRSDs), employing the methodology...Full Text Available

2007-11-01

270

CFD Approaches for Modelling Bubble Entrainment by an Impinging Jet  

International Nuclear Information System (INIS)

This contribution presents different approaches for the modeling of gas entrainment under water by a plunging jet. Since the generation of bubbles happens on a scale which is smaller than the bubbles, this process cannot be resolved in meso-scale simulations, which include the full length of the jet and its environment. This is why the gas entrainment has to be modeled in meso-scale simulations. In the frame of a Euler-Euler simulation, the local morphology of the phases has to be considered in the drag model. For example, the gas is a continuous phase above the water level but bubbly below the water level. Various drag models are tested and their influence on the gas void fraction below the water level is discussed. The algebraic interface area density (AIAD) model applies a drag coefficient for bubbles and a different drag coefficient for the free surface. If the AIAD model is used for the simulation of impinging jets, ...

5101-01-01

271

BEACON eSpace at Jet Propulsion Laboratory: Estimating the Cost of ...  

Science.gov (United States)

Jan 22, 2011 ... dc.subject.other, Cost cost estimating budgets budget estimating ... dc.title, Estimating the Cost of Doing a Cost Estimate, en_US ...

272

ASME proceedings of the 31. national heat transfer conference: Volume 2. HTD-Volume 324  

Energy Technology Data Exchange (ETDEWEB)

This volume is divided into the following sections: (1) fundamentals of convection heat transfer; (2) fundamentals of heat transfer with impinging jets; and (3) fundamentals of heat transfer augmentation. Separate abstracts were prepared for most papers in this volume.

1996-12-31

273

A study on heat-transfer enhancement by a square-rod array in an impinging jet system  

Energy Technology Data Exchange (ETDEWEB)

An impinging jet is a widely used technique for realizing high heat-transfer rates between a fluid and a surface. However, the area of enhanced heat transfer is limited to the neighborhood of the stagnation point. In this study, heat transfer is augmented remote from the stagnation point in an impinging plane jet system by a rod array located near the wall. Each square rod in the array was positioned normal to the flow direction and parallel to the flat plate surface. The distance between the nozzle and the flat plate (H) and the spacing between the rods and the flat plate surface (C) were changed to find the optimum values. The largest heat-transfer augmentation was obtained for C = 1 mm, H/B = 10, where the jet nozzle width is B. In this case, the heat-transfer coefficient averaged over an area 2B from the stagnation point is about 1.6 times greater compared to that without a rod array.

1996-07-01

274

A study of kerf characteristics in abrasive waterjet machining of graphite/epoxy composite  

Energy Technology Data Exchange (ETDEWEB)

Kerf geometry, kerf wall features, and cutting front characteristics of an Abrasive Waterjet (AWJ) machined Graphite/Epoxy (Gr/Ep) laminate were studied. A macroscopic analyses suggests that geometrical features associated with AWJ machining of Gr/Ep laminates are influenced by three macro regions along the cutting depth. The presence of these regions, including initial damage at jet entry, smooth cutting, and rough cutting near the jet exit, depends on the operating conditions. Design of experiments and analysis of variance were used to determine the effect of cutting parameters on kerf characteristics and to develop empirical models for kerf profile and features of the three distinct macroscopic regions. Cutting front analysis revealed that the mechanisms of material removal in AWJ machining of Gr/Ep do not change over the jet penetration depth. In general, high quality uniform cuts may be obtained by minimizing initial ...

1996-04-01

275

A numerical simulation of the evolution and fate of a FRI jet. The case of 3C 31  

CERN Document Server

The evolution of FRI jets has been long studied in the framework of the FRI-FRII dichotomy. In this paper, we test the present theoretical and observational models via a relativistic numerical simulation of the jets in the radio galaxy 3C 31. We use the parameters derived from the modelling presented by \\cite{lb02a,lb02b} as input parameters for the simulation of the evolution of the source, thus assuming that they have not varied over the lifetime of the source. We simulate about 10 % of the total lifetime of the jets in 3C 31. Realistic density and pressure gradients for the atmosphere are used. The simulation includes an equation of state for a two-component relativistic gas that allows a separate treatment of leptonic and baryonic matter. We compare our results with the modelling of the observational data of the source. Our results show that the bow shock evolves self-similarly at a quasi-constant speed, with slight ...

2007-01-01

276

Effect of co- and counter-swirl on the isothermal flow- and mixture field of a double-airflow burner; Einfluss gleich- und gegensinniger Verdrallung auf das isotherme Stroemungs- und Mischungsfeld eines luftseitig zweiflutigen Brenners  

Energy Technology Data Exchange (ETDEWEB)

Atomization of liquid fuel in aircraft engines requires application of airblast atomizers, where the kerosene is supplied into the shear layer between two swirling airstreams. The transfer of this functional principle towards gaseous fuel, as illustrated in Fig. 1, yielded a strong influence of the swirl arrangement of the airflows on flame stability and homogeneity of the fuel/air-mixture. Compared to the co-swirl configuration the flow field of the counter-swirl arrangement exhibits a marked increase of the mass flow recirculated in the internal recirculation zone and a reduction of its length in axial direction. This is attributed to the faster decay of tangential velocity maxima in case of counter-rotating airflows. This generates a stronger positive axial pressure gradient dp/dx, thus enhancing the internal recirculation zone. Analysis of local turbulence quantities yields a restriction of turbulent exchange to smaller radial sections and lower maximum values in the ...

2002-11-01

277

Radio and television interference caused by corona discharges from high-voltage transmission lines  

Energy Technology Data Exchange (ETDEWEB)

Increase in power utility loads in industrialized countries, as well as developing countries, demands a higher level of transmission line voltage. Radio interference (RI) problems have been determined to be a limiting factor in selecting the size of transmission line conductors. Transmission line noise is primarily caused by corona discharges in the immediate vicinity of the conductor. It has been observed that discharges occur during both half-cycles of the applied voltage, but positive corona is usually predominant at AM radio frequencies range with practical high-voltage and extra high-voltage transmission lines. The corona radio noise effect is highly dependent upon the presence of particles on the surface of the conductor and the increase of the electrical gradient beyond the breakdown value of the air. Therefore, corona radio noise varies significantly with the weather and atmospheric conditions and generally ...

1996-11-01

278

Radio and television interference caused by corona discharges from high-voltage transmission lines  

Energy Technology Data Exchange (ETDEWEB)

Increase in power utility loads in industrialized countries, as well as developing countries, demands a higher level of transmission line voltage. Radio interference (RI) problems have been determined to be a limiting factor in selecting the size of transmission line conductors. Transmission line noise is primarily caused by corona discharges in the immediate vicinity of the conductor. It has been observed that discharges occur during both half-cycles of the applied voltage, but positive corona is usually predominant at AM radio frequencies range with practical high-voltage and extra high-voltage transmission lines. The corona radio noise effect is highly dependent upon the presence of particles on the surface of the conductor and the increase of the electrical gradient beyond the breakdown value of the air. Therefore, corona radio noise varies significantly with the weather and atmospheric conditions and generally ...

1995-10-01

279

Radio and television interference caused by corona discharges from high-voltage transmission lines  

International Nuclear Information System (INIS)

Increase in power utility loads in industrialized countries, as well as developing countries, demands a higher level of transmission line voltage. Radio interference (RI) problems have been determined to be a limiting factor in selecting the size of transmission line conductors. Transmission line noise is primarily caused by corona discharges in the immediate vicinity of the conductor. It has been observed that discharges occur during both half-cycles of the applied voltage, but positive corona is usually predominant at AM radio frequencies range with practical high-voltage and extra high-voltage transmission lines. The corona radio noise effect is highly dependent upon the presence of particles on the surface of the conductor and the increase of the electrical gradient beyond the breakdown value of the air. Therefore, corona radio noise varies significantly with the weather and atmospheric conditions and generally ...

1996-04-09

280

Persistence and extinction of a stochastic single-species model under regime switching in a polluted environment II.  

Science.gov (United States)

This is a continuation of our paper [Liu, M., Wang, K., 2010. Persistence and extinction of a stochastic single-species model under regime switching in a polluted environment, J. Theor. Biol. 264, 934-944]. Taking both white noise and colored noise into account, a stochastic single-species model under regime switching in a polluted environment is studied. Sufficient conditions for extinction, stochastic nonpersistence in the mean, stochastic weak persistence and stochastic permanence are established. The threshold between stochastic weak persistence and extinction is obtained. The results show that a different type of noise has a different effect on the survival results. PMID:20816991

2010-09-08

281

Normalized noise power spectrum of full field digital mammography detector system  

International Nuclear Information System (INIS)

Full text: A method to measure noise power spectrum of a full field digital mammography system is presented. The effect of X-ray radiation dose, size and configuration of region of interest on normalized noise power spectrum (NNPS) was investigated. Flat field images were acquired using RQA-M2 beam quality technique (Mo/Mo anode-filter, 28 kV, 2 mm Al) with different clinical radiation doses. The images were cropped at about 4 cm from the edge of the breast wall and then divided into different size of non-overlapping or overlapping segments. NNPS was determined through de trending, 2-D fast Fourier transformation and normalization. Our measurement shows that high radiation dose gave lower NNPS at a specific beam quality. (author)

282

Normalized Noise Power Spectrum of Full Field Digital Mammography System  

International Nuclear Information System (INIS)

A method to measure noise power spectrum of a full field digital mammography system is presented. The effect of X-ray radiation dose, size and configuration of region of interest on normalized noise power spectrum (NNPS) was investigated. Flat field images were acquired using RQA-M2 beam quality technique (Mo/Mo anode-filter, 28 kV, 2 mm Al) with different clinical radiation doses. The images were cropped at about 4 cm from the edge of the breast wall and then divided into different size of non-overlapping or overlapping segments. NNPS was determined through detrending, 2-D fast Fourier transformation and normalization. Our measurement shows that high radiation dose gave lower NNPS at a specific beam quality.

2010-01-05

283

Noise and vibration control offshore towards an improved design procedure  

Energy Technology Data Exchange (ETDEWEB)

There is a clear incentive, therefore, for early consideration of the measures required to meet noise and vibration standards. The platform or rig owner and the operator are jointly responsible for agreeing a noise and vibration control policy and approach at the conceptual design stage, and for then passing on their requirements to the engineering design teams. The engineering design teams and acoustic and vibration specialists for their part need to use all their skill and judgement to apply that policy to the intensely complex job of designing and fabricating topsides facilities. With these concerns as background, UEG started, and has nearly completed, a two-phase study to provide detailed guidance to project managers and designers to assist them to develop appropriate policy and procedures and to help them put those procedures into practice. This paper describes the development of UEG's study, its application and benefits.

1983-09-01

284

Modeling the origins of combustion noise in the indirect injection diesel engine  

Energy Technology Data Exchange (ETDEWEB)

The Computational Fluid Dynamics (CFD) Code KIVA II has been applied to model combustion pressure oscillations in the Indirect Injection Diesel Engine. These oscillations are attenuated and transmitted by the engine structure to the surroundings as noise. The computational model was used to evaluate changes in design and operating characteristics of an engine, and the effect of these on the intensity of gas pressure oscillation. The results in general corroborate the trends of published experimental measurements of combustion noise. A 40% increase in grid resolution showed minor changes in the magnitude of cylinder pressure oscillation and approximately 0.5{degree} crank angle phase advance in the oscillation cycle compared with the grid used for the results presented here. 18 refs., 18 figs.

1995-12-31

285

Experimental study of neutron noise with criticality safety applications in mind  

Energy Technology Data Exchange (ETDEWEB)

A study has been conducted on the statistics of detected neutrons that leaked from four subcritical reflected, enriched-uranium assemblies, to explore the feasibility of developing a criticality warning system based on neutron noise analysis. Studies were conducted on three possible discriminators, i.e., three signatures that might be used to discriminate among assemblies of various multiplications. The noise analysis techniques studied performed well enough in deeply subcritical situations to deserve testing in an applications environment. They have a good chance of detecting changes in reactivity that are potentially dangerous. One can expect sharpest results when doing comparisons, i.e., when comparing two records, one taken in the past under circumstances known to be normal and one taken now to search for change.

1985-11-01

286

Electrochemical noise in corrosion  

International Nuclear Information System (INIS)

By varying different variables (potential, chloride content, surface pretreatment etc.) it is possible to show the effect of increasingly harsher corrosion conditions on passive-layer stability. These changes will not be detected by conventional methods e.g. measurement of passive current density, until a very late stage. Electrochemical noise measurement will allow the action of inhibitors to be detected in a rapid and effective manner. High-alloy steels and titanium claddings subjected to pitting corrosion in chloride-containing media demonstrate how to use this method for problem solutions and to open up new practical applications. The effect of mechanical stresses (natural, tensile) on the corrosion system can be detected by electrochemical noise which opens up new methods for crack corrosion studying and monitoring. (orig./DG).

1993-10-07

287

Efficient Global Optimization Under Conditions of Noise and Uncertainty - A Multi-Model Multi-Grid Windowing Approach  

Energy Technology Data Exchange (ETDEWEB)

Incomplete convergence in numerical simulation such as computational physics simulations and/or Monte Carlo simulations can enter into the calculation of the objective function in an optimization problem, producing noise, bias, and topo- graphical inaccuracy in the objective function. These affect accuracy and convergence rate in the optimization problem. This paper is concerned with global searching of a diverse parameter space, graduating to accelerated local convergence to a (hopefully) global optimum, in a framework that acknowledges convergence uncertainty and manages model resolu- tion to efficiently reduce uncertainty in the final optimum. In its own right, the global-to-local optimization engine employed here (devised for noise tolerance) performs better than other classical and contemporary optimization approaches tried individually and in combination on the "industrial" test problem to be presented.

1999-05-18

288

Eddy currents signal processing for steam generator inspection in PWR nuclear power plants  

International Nuclear Information System (INIS)

Steam generator tubes in nuclear power plants are periodically checked by means of eddy current probes. The output of a probe is composed of three types of signals: known events (rolling zone, support plates, U-bend part), noise (mainly metallurgical noise) and possible flaws. The latter are random transients, both in arrival time and in shape: they have to be detected and then estimated, before to be fed to the high level stages of a diagnostic system. The objective of the study presented is to develop a semi-automatic system, which could manage and process more than 1 M-bytes of data per tube and provide an operator with reliable diagnostics proposals within a few minutes. This can be achieved only by cooperation of several digital signal processing techniques: detection, segmentation, estimation, noise subtraction, adaptive filtering, modelization, pattern recognition. The paper describes some of these items.

1992-01-01

289

Compacting high voltage transmission lines in view of dielectric and corona noise constraints. Riduzione di ingombro delle linee di trasmissione nei confronti dei vincoli dielettrici e dei disturbi per effetto corona  

Energy Technology Data Exchange (ETDEWEB)

The paper reports the results of the studies performed at the Electric Research Center of ENEL (Italian National Electricity Board) in the field of compacting high voltage transmission lines, from the point of view of dielectric and corona noise constraints. The results of switching impulse withstand voltage tests, performed on typical compact line insulation configurations, are given and optimization criteria of such insulation configurations in relation to switching impulse are outlined. The constraints regarding surface withstand voltage in polluted conditions of the above insulations are analyzed and the possibility of reducing their dimensions by using unconventional insulation materials is considered. Finally, evaluations of corona noise in the case of optimization of the line encumbrance from the point of view of dielectric constraints are given.

1993-05-01

290

Characterisation of hole traps in GaAs Fets by DLTS, low frequency noise and g sub M dispersion methods  

International Nuclear Information System (INIS)

Deep level effects in GaAs MOSFET have been characterised in the ohmic channel using DLTS, low frequency excess noise and dispersion technique. An isothermal multi exponential curve fitting method has been devised and implanted into the DLTS system. Multi exponential curve fitting method used to decompose a multi exponential transient into its constituents so that the peak signature can be better characterised for the case whereas several peaks are closely spaced. Low frequency excess noise and dispersion techniques also confirm the trap in signature of the same traps observed in the DLTS measurements. (author)

291

Atmospheric Gravity Perturbations Measured by Ground-Based Interferometer with Suspended Mirrors  

CERN Document Server

A possibility of geophysical measurements using the large scale laser interferometrical gravitational wave antenna is discussed. An interferometer with suspended mirrors can be used as a gradiometer measuring variations of an angle between gravity force vectors acting on the spatially separated suspensions. We analyze restrictions imposed by the atmospheric noises on feasibility of such measurements. Two models of the atmosphere are invoked: a quiet atmosphere with a hydrostatic coupling of pressure and density and a dynamic model of moving region of the density anomaly (cyclone). Both models lead to similar conclusions up to numerical factors. Besides the hydrostatic approximation, we use a model of turbulent atmosphere with the pressure fluctuation spectrum f^{-7/3} to explore the Newtonian noise in a higher frequency domain (up to 10 Hz) predicting the gravitational noise background for modern gravitational wave ...

2003-01-01

292

An improved noise-robust voice activity detector based on hidden semi-Markov models  

British Library Electronic Table of Contents (United Kingdom)

To improve the performance of voice activity detector (VAD) in noisy environments, this paper concentrates on three critical aspects related to noise robustness including speech features, feature distributions and temporal dependence. Based on the statistic on TIMIT and NOIZEUS, Mel-frequency cepstrum coefficients (MFCCs) are selected as speech features, Gaussian Mixture distributions (GMD) are applied to associate the observations in MFCC domain with both speech and non-speech states, and Weibull and Gamma distributions are used to explicitly model noise and speech durations, respectively. To integrate these aspects into VAD, the hidden semi-Markov model (HSMM) as a generalized hidden Markov model (HMM) is introduced first. Then the VAD decision is made according to the likelihood ratio t...

2011-01-01

293

Surface roughening of superalloys by high pressure pure waterjet  

Energy Technology Data Exchange (ETDEWEB)

A high pressure waterjet has been used to study the surface roughening of superalloys as preparation for thermal spraying. Designed experiments for Mar-M 509 and Rene 80 were carried out for the effects of jet pressure and mass of water delivered per unit area. Comparisons were made of several superalloys in terms of erosion, surface roughness and topology. The mechanism of jet erosion of Rene 80 was studied in relation to its metallurgical microstructure. An MCrAlY coating by shrouded plasma spray was made over a waterjet prepared surface with excellent bonding and having an ideally clean interface.

1995-12-31

294

Service the Two-Piece Flo-Jet Carburetor. Fuel System. Student Manual 3. Small Engine Repair Series. First Edition.  

Science.gov (United States)

This student manual, part of a small-engine repair series on servicing fuel systems, is designed for use by special needs students in Texas. The manual explains in pictures and short sentences, written on a low reading level, the job of servicing two-piece flo-jet carburetors. Along with the steps of this repair job, specific safety and caution information is frequently noted. To reinforce consistency in material presented to the slow learners, the pictures and written words correspond exactly with the pictures and wording on a corresponding audiovisual presentation. A progress chart for rating the students is included in the manual. (KC)

1981-12-01

295

Radiant Energy Power Source for Jet Aircraft. Final performance report  

Energy Technology Data Exchange (ETDEWEB)

This report beings with a historical overview on the origin and early beginnings of Radiant Energy Power Source for Jet Aircraft. The report reviews the work done in Phase I (Grant DE-FG01-82CE-15144) and then gives a discussion of Phase II (Grant DE-FG01-86CE-15301). Included is a reasonably detailed discussion of photovoltaic cells and the research and development needed in this area. The report closes with a historical perspective and summary related to situations historically encountered on projects of this nature. 15 refs.

1992-02-01

296

Radiant Energy Power Source for Jet Aircraft  

Energy Technology Data Exchange (ETDEWEB)

This report beings with a historical overview on the origin and early beginnings of Radiant Energy Power Source for Jet Aircraft. The report reviews the work done in Phase I (Grant DE-FG01-82CE-15144) and then gives a discussion of Phase II (Grant DE-FG01-86CE-15301). Included is a reasonably detailed discussion of photovoltaic cells and the research and development needed in this area. The report closes with a historical perspective and summary related to situations historically encountered on projects of this nature. 15 refs.

1992-02-01

297

Post-mortem measurements of fuel retention at JET with MKII-SRP divertor  

International Nuclear Information System (INIS)

The deuterium inventory at JET after 2001-2004 operational campaign has been determined using nuclear reaction analysis (NRA) and secondary ion mass spectrometry (SIMS). A full poloidal set of divertor tiles and a set of outer poloidal limiter (OPL) tiles were analysed providing an estimation for the total deuterium retention of about 66 g. Deuterium is trapped mainly at the inner divertor on horizontal target tile and at the inner divertor louvre area where ?60% of the trapped D is found. The long-term D retention is ?4% of the total D input.

2009-06-15

298

Modification of a gas jet transport system for the supression of heavy-mass fission product homologues  

Energy Technology Data Exchange (ETDEWEB)

The uranium target of a gas jet transport system for fission products has been modified by the addition of an aluminum cover foil. The new modification allows fission fragments of low mass to enter a continuous chemistry system while heavier fragments are stopped in the aluminum. The elimination of the heavier homologues allows development of simpler and faster chemical separation procedures. In addition, since the lighter fragments are slowed down by the cover foil a smaller target chamber can be used. This leads to a reduction in system holdup time.

1987-04-15

299

Modification of a gas jet transport system for the supression of heavy-mass fission product homologues  

International Nuclear Information System (INIS)

The uranium target of a gas jet transport system for fission products has been modified by the addition of an aluminum cover foil. The new modification allows fission fragments of low mass to enter a continuous chemistry system while heavier fragments are stopped in the aluminum. The elimination of the heavier homologues allows development of simpler and faster chemical separation procedures. In addition, since the lighter fragments are slowed down by the cover foil a smaller target chamber can be used. This leads to a reduction in system holdup time. (orig.).

300

Exploring the structure of the proton through polarization observables in l p \\to jet X  

CERN Document Server

We present results for a complete set of polarization observables for jet production in lepton proton collision, where the final state lepton is not observed. The calculations are carried out in collinear factorization at the level of Born diagrams. For all the observables we also provide numerical estimates for typical kinematics of a potential future Electron Ion Collider. On the basis of this numerical study, the prospects for the transverse single target spin asymmetry are particularly promising. This observable is given by a certain quark-gluon correlation function, which has a direct relation to the transverse momentum dependent Sivers parton distribution.

2011-01-01

301

Development of an efficient, low-NOx domestic gas range cooktop. Phase 3. Final report, January 1986-December 1988. Technical report  

Science.gov (United States)

The objective of the program was to develop a domestic cooktop with low-NOx emissions and high efficiency. During the first two phases of the program, three design concepts were developed, and two versions of developmental prototypes using the IR-Jet approach were fabricated and tested. The third phase was initiated to address the design issues of a simmer setting, air/gas metering, and jet plate durability and to develop prototypes for interested manufacturers.

1989-10-01

302

Combining laser chemical processing and aerosol jet printing: a laboratory scale feasibility study  

British Library Electronic Table of Contents (United Kingdom)

Abstract First results showing the viability of combining laser chemical processing (LCP) and aerosol jet printing (AJP) technologies to produce a high-efficiency front side for silicon solar cells are presented. LCP simultaneously opens the anti-reflection coating (ARC) and highly dopes the underlying silicon to create a selective emitter, while AJP is the first in a two-step fine-line contact formation procedure. The electrical properties as well as the morphology of the resulting structures are presented. Performance similar to that achieved with evaporated TiPdAg metallization is demonstrated. Copyright 2010 John Wiley & Sons, Ltd.

2011-01-01

303

Beam lifetime and emittance growth in RHIC under normal operating conditions with the hydrogen gas jet, the cluster-jet and pellet targets  

International Nuclear Information System (INIS)

The inelastic scattering of the beam and the residual gas molecules in RHIC could represent one of the limitations on the beam life time and emittance growth. This report covers the dominant central nuclear collisions influence on the beam lifetime and transverse emittance growth. The cross sections for the beam-gas electron radiative captures are an order of magnitude smaller. The capture cross sections include the radiative and non-radiative capture, and the capture from the electron-positron pair creation from the 'vacuum capture'.

2010-09-01

304

Laser Raman scattering measurements of differential molecular diffusion in turbulent nonpremixed jet flames of H{sub 2}/CO{sub 2} fuel  

Science.gov (United States)

This paper explores effects of differential diffusion in nonpremixed turbulent jet flames. Pulsed Raman scattering spectroscopy is used to measure temperature and species concentrations in chemically reacting jets of H{sub 2}/CO{sub 2} into air, over a range of jet Reynolds numbers from 1,000 to 30,000 based on cold jet fluid properties. Results show significant effects of differential diffusion at all jet Reynolds numbers considered. Differential diffusion between H{sub 2} and C0{sub 2} produces differences between the hydrogen element mixture fraction ({xi}{sub H}) and the carbon element mixture fraction ({xi}{sub c}). The greatest effects occur on the rich side of stoichiometric, where {xi}{sub H} is observed to be smaller than {xi}{sub C} at all Reynolds numbers. Differential diffusion between H{sub 2} and H{sub 2}O creates a net flux of hydrogen element toward the ...

1994-01-01

305

Heat transfer augmentation of axisymmetric impinging jet using a perforated plate set in front of a target plate. 1st report effects of diameter and pitch of holes in a perforated plate  

Energy Technology Data Exchange (ETDEWEB)

Concerning heat transfer augmentation of an axisymmetric impinging jet using a perforated plate set, the bore of the hole in the plate for local and averge heat transfer rate, pitch, and effect of the distance between perforated plate and target plate were examined. Heat transfer augmentation was examined under the condition of 0.063 /ge/d/D /ge/0.200, 1.25 /ge/p/d /ge/4.00, Re is approximately equal to 18000, (where d is the bore of the hole in the plate, D is the axisymmetric nozzle outlet bore, p is the pitch of the perforated plate, and Re is the jet Reynolds number). The findings are as follows; The velocity of the small jet after passing the perforated plate is reduced, and resistance to disturbance is remarkably large. The small jet which is not at the center hole extends to the outside of the plate. The heat transfer rate at a stagnation point is high when the target plate is placed in the ...

1988-07-25

306

Dynamic behaviour of dc double anode plasma torch at atmospheric pressure  

International Nuclear Information System (INIS)

An original dc double anode plasma torch which provides a long-time and highly stable atmospheric plasma jet has been devised for the purpose of hazardous waste treatment. The arc fluctuations and dynamic behaviour of the argon and argon-nitrogen plasma jets under different operating conditions have been investigated by means of classical tools, such as the statistic method, fast Fourier transform (FFT) and correlation analysis. In our experiments, the takeover mode is identified as the fluctuation characteristic of the argon plasma jet while the restrike mode is typical in the argon-nitrogen plasma dynamic behaviour. In the case of pure argon, the FFT and correlation calculation results of electrical signals exhibit the only characteristic frequency of 150 Hz, which originates from the torch power and is independent of any change in the operating conditions. It indicates that the nature of fluctuations in an argon plasma ...

2007-07-07

307

VGB guidelines on the consideration of noise emission in ordering power plant equipment  

International Nuclear Information System (INIS)

The present guidelines supplement the 'VGB guidelines for the reduction of noise in thermal power plants' with indications for the ordering and quality assurance of the individual noise-producing machines and equipment of power plant operation. These guides are to simplify the commissioning and delivering for the orderer and deliverer. In addition, these guidelines are to lead to a successful cooperation of all parties in the reduction of the sound radiation. A precondition for this is an explanation of the sound technical demands which must be made on the single machines or mechanical equipment in power plant systems. A protection of the neighbourhood as well as operational personnel against noise according to the state of technology is to be achieved by a clear form of ordering and quality assurance. The ordering and assurance procedure for all aggregates in the region of the grounds of a power plant up to the ...

308

Tuning and controlling gene expression noise in synthetic gene networks  

UK PubMed Central (United Kingdom)

Synthetic gene networks can be used to control gene expression and cellular phenotypes in a variety of applications. In many instances, however, such networks can behave unreliably due to gene expression...Full Text Available

2010-05-01

309

Transduction noise induced by 4-hydroxy retinals in rod photoreceptors.  

UK PubMed Central (United Kingdom)

New visual pigments were formed with 4-hydroxy retinals in isolated vertebrate rod photoreceptors by exposing bleached rods from the tiger salamander, Ambystoma tigrinum, to lipid vesicles containing...Full Text Available

1990-01-01

310

The use of quartz patch pipettes for low noise single channel recording.  

UK PubMed Central (United Kingdom)

Quartz has a dissipation factor of approximately 10(-4), which is an order of magnitude less than that of the best glasses previously used to fabricate patch pipettes; it's dielectric constant of 3.8...Full Text Available

1993-10-01

311

Speech Communication in Noise  

Science.gov (United States)

... Un jeu de DVD créés à partir de boucles de bruit sur bande audionumérique ont été étalonnés de manière à produire le même spectre de bruit ...

2008-05-13

312

Robust principal axes determination for point-based shapes using least median of squares  

UK PubMed Central (United Kingdom)

A robust technique for determining the principal axes of a 3D shape represented by a point set, possibly with noise, is presented. We use techniques from robust statistics to guide the classical...Full Text Available

2009-04-01

313

Radio frequency noise from an MLC: a feasibility study of the use of an MLC for linac-MR systems  

UK PubMed Central (United Kingdom)

Currently several groups are actively researching the integration of a megavoltage teletherapy unit with magnetic resonance (MR) imaging for real-time image-guided radiotherapy. The use of a...Full Text Available

2010-02-21

314

Non-white noise in fMRI: does modelling have an impact?  

DEFF Research Database (Denmark)

The sources of non-white noise in Blood Oxygenation Level Dependent (BOLD) functional magnetic resonance imaging (fMRI) are many. Familiar sources include low-frequency drift due to hardware imperfections, oscillatory noise due to respiration and cardiac pulsation and residual movement artefacts not accounted for by rigid body registration. These contributions give rise to temporal autocorrelation in the residuals of the fMRI signal and invalidate the statistical analysis as the errors are no longer independent. The low-frequency drift is often removed by high-pass filtering, and other effects are typically modelled as an autoregressive (AR) process. In this paper, we propose an alternative approach: Nuisance Variable Regression (NVR). By inclusion of confounding effects in a general linear model (GLM), we first confirm that the spatial distribution of the various fMRI noise sources is similar to what has already been ...

2005-01-01

315

Non-white noise in fMRI: Does modelling have an impact?  

DEFF Research Database (Denmark)

The sources of non-white noise in Blood Oxygenation Level Dependent (BOLD) functional magnetic resonance imaging (fMRI) are many. Familiar sources include low-frequency drift due to hardware imperfections, oscillatory noise due to respiration and cardiac pulsation and residual movement artefacts not accounted for by rigid body registration. These contributions give rise to temporal autocorrelation in the residuals of the fMRI signal and invalidate the statistical analysis as the errors are no longer independent. The low-frequency drift is often removed by high-pass filtering, and other effects are typically modelled as an autoregressive (AR) process. In this paper, we propose an alternative approach: Nuisance Variable Regression (NVR). By inclusion of confounding effects in a general linear model (GLM), we first confirm that the spatial distribution of the various fMRI noise sources is similar to what has already been ...

2006-01-01

316

Noise suppression in scatter correction for cone-beam CT  

UK PubMed Central (United Kingdom)

Scatter correction is crucial to the quality of reconstructed images in x-ray cone-beam computed tomography (CBCT). Most of existing scatter correction methods assume smooth scatter distributions. The...Full Text Available

2009-03-01

317

Noise Susceptibility of Cochlear Implant Users: The Role of Spectral Resolution and Smearing  

UK PubMed Central (United Kingdom)

The latest-generation cochlear implant devices provide many deaf patients with good speech recognition in quiet listening conditions. However, speech recognition deteriorates rapidly as the level of...Full Text Available

2005-03-01

318

Light amplifier with filtering of spontaneous background  

Energy Technology Data Exchange (ETDEWEB)

A comparitive analysis is made of the principal characteristics of narrow-band and conventional semiconductor light amplifiers. It is shown that quasi-distributed filtering of the spontaneous radiation ensures a high gain and a low level of the spontaneous noise at the amplifier output.

1980-06-01

319

Environmental Assessment of Marine Geophysical Survey in the Commonwealth of the Northern Mariana Islands, April to ...  

Science.gov (United States)

... Southall et al. 2007). However, based on preliminary simulation modeling that attempted to allow for various uncertainties in ... 1986. Behavioral responses of gray whales to industrial noise:

320

Energy balance and environmental aspects of electric cars. Energiebilanz und Umweltaspekte von Elektroautomobilen  

Energy Technology Data Exchange (ETDEWEB)

The report deals with the energy consumption of traffic and its emissions of hazardous substances into the air, and stresses the advantages of the electric car with respect to energy consumption and noise generation. 5 figs., 3 refs.

1991-01-01

321

Effects of noise and electromagnetic fields on reproductive outcomes.  

UK PubMed Central (United Kingdom)

Much public health research has been directed to studies of cancer risks due to chemical agents. Recently, increasing attention has been given to adverse reproductive outcomes as another, shorter-term...Full Text Available

1989-05-01

322

Dual Energy and Low kVp CT in the Abdomen  

UK PubMed Central (United Kingdom)

Low kVp settings provide high conspicuity of contrast materials at CT but may result in high image noise, particularly in larger patients. Material decomposition at dual energy CT can differentiate...Full Text Available

2009-07-01

323

Discrimination of Schroeder-Phase Harmonic Complexes by Normal-Hearing and Cochlear-Implant Listeners  

UK PubMed Central (United Kingdom)

The temporal fine structure (TFS) of sound contributes significantly to the perception of music and speech in noise. The evaluation of new strategies to improve TFS delivery in cochlear implants (CIs)...Full Text Available

2008-03-01

324

Comparison of susceptibility to pitting corrosion of AA2024-T4, AA7075-T651 and AA7475-T761 aluminium alloys in neutral chloride solutions using electrochemical noise analysis  

Energy Technology Data Exchange (ETDEWEB)

The susceptibility to pitting corrosion of AA2024-T4, AA7075-T651 and AA7475-T761 aluminium alloys was investigated in aqueous neutral chloride solution for the purpose of comparison using electrochemical noise measurement. The experimentally measured electrochemical noises were analysed based upon the combined stochastic theory and shot-noise theory using the Weibull distribution function. From the occurrence of two linear regions on one Weibull probability plot, it was suggested that there existed two stochastic processes of uniform corrosion and pitting corrosion; pitting corrosion was distinguished from uniform corrosion in terms of the frequency of events in the stochastic analysis. Accordingly, the present analysis method allowed us to investigate pitting corrosion independently. The susceptibility to pitting corrosion was appropriately evaluated by determining pit embryo formation rate in the stochastic analysis. The ...

2008-01-15

325

Civil and Military Satellite Communications: A Systems ...  

Science.gov (United States)

... to-noise density than the uplink budget has (74.2 ... in heav:, point-to-point link applications with ... 11.7 Expanded bands allocated (Ku band) (500 MHz ...

1991-02-01

326

Cf-source-driven neutron-noise measurements of subcriticality for a 4. 95 wt% /sup 235/U-enriched uranyl fluoride solution cylinder  

Energy Technology Data Exchange (ETDEWEB)

A method for determining the reactivity of subcritical systems of fissile material, using neutron-noise power spectral density measurements in conjunction with a /sup 252/Cf source, has been tested in experiments with an aqueous solution containing uranium fluoride (4.95 wt% /sup 235/U). The kappasub(eff)-values obtained from the ratio of spectral densities G*/sub 12/G/sub 13//G/sub 11/G/sub 23/ agreed with those from break-frequency noise analysis and with bias-corrected transport theory calculations within the statistical uncertainty of the measurements. Corrections for the effects of spatial modes and source-detector locations appear to be well-understood, since measurements for a variety of source-detector positions resulted in essentially the same kappasub(eff)-values. Modal correction factors were such that ignoring them would result in higher values of kappasub(eff) than actually occur. The measurements have demonstrated the ...

1986-01-01

327

Air conditioning of future small urban electric cars by thermoelectricity  

Energy Technology Data Exchange (ETDEWEB)

Air conditioning of urban electric cars by Peltier effect is simulated. Advantages (noise, simplicity of construction and of regulation, good heating performances...) and disadvantages (cooling performances lower than actual compressors, actual costs...) are presented. (A.B.). 8 refs., 5 figs.

1994-01-01

328

AVISO and PODAAC User Handbook IGDR and GDR Jason Products - NASA  

Science.gov (United States)

An ascending node occurs when the subsatellite point crosses the earth's equator going from .... 11dB sigma-naught. This error budget includes the altimeter noise, ...... it is also recommended to filter the data as follows to ...

329

Shot-noise-limited measurement of sub-parts-per-trillion birefringence phase shift in a high-finesse cavity  

International Nuclear Information System (INIS)

We report on a promising approach to high-sensitivity anisotropy measurements using a high-finesse cavity locked by optical feedback to a diode laser. We provide a simple and effective way to decouple the weak anisotropy of interest from the inherent mirror's birefringence whose drift may be identified as the key limiting parameter in cavity-based techniques. We demonstrate a shot-noise-limited phase shift resolution previously inaccessible in an optical cavity, readily achieving the state-of-the-art level of 3x10"-"1"3 rad.

2010-09-01

330

Observation of stochastic resonance near a subcritical bifurcation  

Energy Technology Data Exchange (ETDEWEB)

A hysteretic subcritical period-doubling bifurcation is observed in the nonlinear strain dynamics of a magnetostrictive oscillator. The dynamic strain response of the magnetostrictive oscillator was observed with a high-resolution fiber optic interferometer. The effects of low-frequency modulation and band-limited stochastic fluctuations on such a bifurcation are investigated. Power spectral density measurements show that for an optimal value of externally injected noise the signal-to-noise ratio of a low-frequency modulation signal is enhanced by greater than 14 dB, thus indicating the first experimental observation of stochastic resonance near a bistable period-doubling bifurcation. 10 refs., 7 figs.

1993-01-01

331

Josephson effect mm-wave receivers  

International Nuclear Information System (INIS)

Josephson effect heterodyne mixers with external local oscillators are very promising low noise mm-wave receivers for applications such as radio astronomy. Experiments at 36 GHz have shown that both the noise and the conversion efficiency of mixers made using Nb point contacts are in quantitative agreement with values calculated from the resistively shunted junction (RSJ) model. Preliminary measurements at 140 GHz suggest that this agreement extends to higher frequencies. In this paper the theoretical limits to the sensitivity of such receivers are explored as a function of the signal frequency. (Auth.).

332

Application of wavelet analysis to signal processing methods for eddy-current test; ueburetto kaiseki no kadenryushinshoho heno tekiyo  

Energy Technology Data Exchange (ETDEWEB)

This study deals with the application of wavelet analysis to detection and characterization of defects from eddy-current and ultrasonic testing signals of a low signal-to-noise ratio. Presented in this paper are the methods for processing eddy-current testing signals of heat exchanger tubes of a steam generator in a nuclear power plant. The results of processing eddy-current testing signals of tube test pieces with artificial flaws show that the flaw signals corrupted by noise and/or non-defect signals can be effectively detected and characterized by using the wavelet methods. (author)

1998-12-15

333

A review of the probabilistic aspects of localized corrosion  

Energy Technology Data Exchange (ETDEWEB)

Localized corrosion has a stochastic character by nature. This character leads to an observed random behavior: fluctuations of the free potential, fluctuations of the current when a constant potential is maintained. This random signal, which is similar to an electric noise, can be analyzed either in the time domain by counting the events or in the frequency domain by measuring the power spectral density of the electrochemical noise. The experimental techniques developed for investigating the localized corrosion on the probabilistic point of view, i.e., statistical counting and power spectral density measurements, are discussed. Then the experimental results reported in the literature are reviewed in order to see what kind of parameters are accessible and how they can be related to the localized corrosion processes.

1990-04-01

334

The Cause of an Eddy Current Signal Noise from a Steam Generator Tube and its Effect on the Detectability of a Crack  

International Nuclear Information System (INIS)

An eddy current inspection has been applied for a pre-service and in-service examination of a steam generator in nuclear power plants. The experience from the inspection of steam generators showed that many plants had an excessive number of tubes with eddy current noise signals over several hundreds, which originated from manufacturing anomalies. The plants in U.S suffered significant downstream inspection costs, history reviews, and diagnostic testing because some signals resembled flaws and others masked a flaw. These lessens learned resulted in issuing the guidelines for steam generator tubing specifications and repair, in order to reduce the number of anomalous signals in the tubes and also to provide the requirement of a signal to noise ratio by applying a field type examination with bobbin coil eddy current probes at a manufacturing process. Besides the noise signals of a bobbin coil eddy current probe from ...

2008-05-01

335

Acoustic analysis of combustion engines; Die Akustikanalyse von Verbrennungsmotoren  

Energy Technology Data Exchange (ETDEWEB)

For millions of people general noise and especially traffic noise are the main sources of environmental pollution. The increasingly stricter noise pollution abatement limiting values laid down by the law call for motor vehicle noise pollution abatement measures. Within the framework of today`s cost- and performance-oriented automobile and engine development developing engineers are required to reduce noise levels. The present state of the art is described and future possibilities of combustion engine structure-borne noise calculation and optimization are discussed from the point of view of K + P Computerunterstuetzte Strukturanalysen GmbH. (orig.) [Deutsch] Laerm allgemein und dabei speziell wiederum der Verkehrslaerm steht fuer Millionen von Menschen an allererster Stelle der persoenlichen Belastung durch die Umwelt. Zur Minderung der Laermbelastung werden vom ...

1995-04-01

336

Separation of the bacterial species, Escherichia coli, from mixed-species microbial communities for transcriptome analysis  

UK PubMed Central (United Kingdom)

BackgroundThe study of bacterial species interactions in a mixed-species community can be facilitated by transcriptome analysis of one species in the community using cDNA microarray...Full Text Available

337

MELCOR analyses of NUPEC`s large-scale hydrogen mixing test-II  

Energy Technology Data Exchange (ETDEWEB)

NUPEC has carried out hydrogen mixing tests to investigate hydrogen distribution behavior within a model containment and to provide a set of experimental data for validation of severe accident analysis codes.

1995-12-31

338

Low-pressure degenerate four-wave mixing spectroscopy with flam atomization  

Energy Technology Data Exchange (ETDEWEB)

A combination of degenerate four-wave mixing spectroscopy and a low-pressure sampling technique has been studied for isotopic analysis in an air-acetylene flame. Hyperfine spectra of D lines of sodium and several mixtures of lithium isotopes obtained in this way are presented.

1988-08-01

339

Isolation of gram-positive rods that resemble but are clearly distinct from Actinomyces pyogenes from mixed wound infections.  

UK PubMed Central (United Kingdom)

Beginning in 1990, gram-positive rods resembling Actinomyces pyogenes were found with increasing frequency in mixed cultures from various infectious processes, most of them from patients with otitis,...Full Text Available

1993-05-01

340

Energy-momentum tensor of a spinor field in the mixed universe cosmological model  

International Nuclear Information System (INIS)

The energy-momentum tensor of a massless spinor field is constructed and studied based on the previously proposed interpretation of quantum effects of such a field in the anisotropic metric of Bianchi type IX. The characteristic properties of the energy-momentum tensor in the mixed universe model are discussed.

341

Dynamic Conditionally Linear Mixed Models for Longitudinal Data  

UK PubMed Central (United Kingdom)

SummaryWe develop a new class of models, dynamic conditionally linear mixed models, for longitudinal data by decomposing the within-subject covariance matrix using a special Cholesky...Full Text Available

2002-03-01

342

Characterization and catalytic oxidation activity of uranium-bismuth mixed oxides  

International Nuclear Information System (INIS)

Bi-U mixed oxides were synthesized by two methods and characterized by X-ray diffraction and X-ray photoelectron spectroscopy. The samples were tested for the catalytic oxidation of carbon monoxide by oxygen. A stepwise redox mechanism consistent with the kinetic results is proposed. (orig.).

344

Subsolutions of an Isaacs Equation and Efficient Schemes for ...  

Science.gov (United States)

... analyze importance sampling schemes for stochastic networks ... an interesting mixed open/closed queueing network ... with a suitable terminal condition ...

2005-08-08

345

Report: Mathematics and Science  

Science.gov (United States)

... and Security..........................13 Materials Science ... hybrid system theory, Internet analysis, materials science, mixing, physiology, iterative control ...

346

Nitrogen oxides decreasing combustion method  

Energy Technology Data Exchange (ETDEWEB)

A nitrogen oxides decreasing combustion method comprising: mixing a fuel and air with each other; bringing the mixture obtained into contact with a packed catalyst; and adding a fresh supply of the fuel to the stream obtained to form a mixed gas and causing the mixed gas to undergo non-catalytic thermal combustion, characterized in that only a catalytic reaction or combustion occurs at the packed catalyst; the temperature of the packed catalyst is kept lower than the ignition temperature of the mixture; the adiabatic flame temperature which is reached by the non-catalytic thermal combustion of the mixed gas is lower than the temperature at which the nitrogen oxides occur. 39 figs.

1988-10-19

347

Nitrogen oxides decreasing combustion method  

Energy Technology Data Exchange (ETDEWEB)

This patent describes a nitrogen oxides decreasing combustion method which comprises: a first step of mixing a fuel and air with each other; a second step of bringing the mixture obtained in the first step into contact with a packed catalyst such that only catalytic combustion occurs; and a third step of adding a fresh supply of the fuel to a stream obtained from the second step to form a mixed gas and causing the mixed gas to undergo non-catalytic thermal combustion. The temperature of the packed catalyst is lower than the ignition temperature of the mixture and the adiabatic flame temperature of the mixed gas is lower than a temperature at which the nitrogen oxides occur.

1988-03-22

348

New materials to manufacture casting molds  

International Nuclear Information System (INIS)

A report is given on an improved filler-binder mixing method in the manufacture of artificial graphite, the so-called coat-mix process. The individual graphite-filler grains are coated completely with uniform binder coatings (phenol formaldehyde resin) in a continuous process. Methanol is used as solvent for the resin. In a modified further development of the process, the use of organic solvents can be disregarded by dissolving the binder resin in caustic soda and injecting the slurry into water diluted acid. The manufacture of casting molds from coat-mix powders, their properties and industrial application are given. Finally, the advantages of using carbon bodies of coal-mix material for conversion to silicon carbide are indicated. (IHOE).

349

Multistep contributions in "8"8Sr(h,t)"8"8Y  

International Nuclear Information System (INIS)

... mixing coupled channel theory differential cross sections excited states helium

350

JENDL-4.0: A database on neutron-induced reactions for nuclear science and engineering  

International Nuclear Information System (INIS)

... compilation fission products j codes mixed oxide fuels neutron reactions

2010-12-01

351

Isospin mixing in the decay of the T/sub greater-than/ giant dipole state  

Energy Technology Data Exchange (ETDEWEB)

The magnitude of the isospin mixing in the decay of the T/sub greater-than/ giant dipole resonance has been estimated, using the (..gamma.., n) and (..gamma..,p) cross sections available for the medium-weight nuclei /sup 60/Ni, /sup 88/Sr, /sup 89/Y, /sup 90/Zr, and /sup 92/Mo. The deduced values show a fair correspondence with the existing data for mixing between compound states. From these results the mean mixing Coulomb matrix elements between compound states could also be derived.

1984-10-01

354

Cost sensitivity analysis for mixed-oxide fuel cycles  

International Nuclear Information System (INIS)

(1978). United States Quan, B. Becker, M. Harris, DR Rensselaer Polytechnic

355

Condensing curves for a number of mixed-hydrocarbon working fluids  

Energy Technology Data Exchange (ETDEWEB)

Condensing curves are presented for a number of two-component mixed hydrocarbon working fluids which are potentially usable in binary geothermal cycles. Performance of geothermal thermodynamic cycles incorporating these fluids has been evaluated under separate cover; two figures summarizing the results of those evaluations have been included here for continuity. The purpose of this report is: first, to document the condensing curves which were used in the mixed fluid cycle analyses, and second, to provide background useful in the preliminary evaluation of heat rejection systems for advanced geothermal electric power plants utilizing mixed hydrocarbon working fluids. Some concluding remarks are presented.

1981-07-01

356

Buoyancy effects in double-diffusive and mixed convection flows  

Science.gov (United States)

When induced by bottom heating in a horizontal fluid layer which is characterized by forced motion or solute stratification, buoyancy-driven flows may assume a variety of forms. The flows, which are examples of mixed or double-diffusive convection, can strongly influence heat tranfer or the entrainment of stratified fluid. General aspects of each form of convection are reviewed, and emphasis is placed on mixed convection in a horizontal rectangular channel and on double-diffusive convection due to thermally driven mixed-layer development in a solutally stratified fluids. Flow conditions are described, and experimental and theoretical results are presented for related heat-transfer and entrainment parameters.

1986-01-01

357

Analysis of tritium mission FMEF/FAA fuel handling accidents  

Energy Technology Data Exchange (ETDEWEB)

The Fuels Material Examination Facility/Fuel Assembly Area is proposed to be used for fabrication of mixed oxide fuel to support the Fast Flux Test Facility (FFTF) tritium/medical isotope mission. The plutonium isotope mix for the new mission is different than that analyzed in the FMEF safety analysis report. A reanalysis was performed of three representative accidents for the revised plutonium mix to determine the impact on the safety analysis. Current versions computer codes and meterology data files were used for the analysis. The revised accidents were a criticality, an explosion in a glovebox, and a tornado. The analysis concluded that risk guidelines were met with the revised plutonium mix.

1997-11-18

358

Kinetic dialysis as a method for determining mixed micelle composition  

Energy Technology Data Exchange (ETDEWEB)

A new method for the determination of the cmc using a dialysis technique which allows monometric species to diffuse through but no micelles has been applied for determining the mixed micelle composition. The method is based on determining the amount of surfactant that diffuses through at two different times which allows for the calculation of the cmc by use of the appropriate equation. This method requires the preparation of only one concentration of solution and lends itself particularly well to the determination of the composition of mixed micelles. (orig.)

1982-02-16

359

Device for laying cut peat in a drying formation  

Energy Technology Data Exchange (ETDEWEB)

A device for laying cut peat in drying formations is proposed consisting of separate compartments, reinforced on a common frame and with mechanisms for both vertical and horizontal mixing. In order to intensify the drying process, within the scope of laying cut peat, uniform clearances and spacing in formations is applied. The mixing compartments are joined in sections with capabilities for separate mixing in each unit. The compartments are joined together by hinges and can be turned 180 degrees on the hinges horizontal to the plane.

1980-06-17

360

Relative correlation of Jet-REMPI monitoring with adsorption tube sampling followed by TDS-CIS-GC/MS  

Energy Technology Data Exchange (ETDEWEB)

During earlier work rapid and highly sensitive Jet-REMPI (resonance-enhanced multiphoton ionization) mass spectrometry was applied for monitoring the effluent from thermal treatment of a filter dust during a de novo test under laboratory conditions. The sample, from ESP-Field 2 of an iron ore sintering plant, was already loaded with dioxins ({sigma}PCDD/F = 132 ng/g), their precursors (PCBz, PCPh) and other products of incomplete combustion. Heating filter dust in a temperature window 200-350 C under a flow of air results in further formation of these pollutants. As described elsewhere, on-line detection was mostly carried out using a non-selective ionization mode, to measure a wide range of compounds simultaneously. The changes of output suggest that the reaction products increase in chlorination level with time. Another explanation is that higherchlorinated compounds appear later as a consequence of lower volatility and stronger adsorption. However, due to mass ...

2004-09-15

361

Realistic Probability Estimates For Destructive Overpressure Events In Heated Center Wing Tanks Of Commercial Jet Aircraft  

Energy Technology Data Exchange (ETDEWEB)

The Federal Aviation Administration (FAA) identified 17 accidents that may have resulted from fuel tank explosions on commercial aircraft from 1959 to 2001. Seven events involved JP 4 or JP 4/Jet A mixtures that are no longer used for commercial aircraft fuel. The remaining 10 events involved Jet A or Jet A1 fuels that are in current use by the commercial aircraft industry. Four fuel tank explosions occurred in center wing tanks (CWTs) where on-board appliances can potentially transfer heat to the tank. These tanks are designated as ''Heated Center Wing Tanks'' (HCWT). Since 1996, the FAA has significantly increased the rate at which it has mandated airworthiness directives (ADs) directed at elimination of ignition sources. This effort includes the adoption, in 2001, of Special Federal Aviation Regulation 88 of 14 CFR part 21 (SFAR 88 ''Fuel Tank System Fault Tolerance ...

2007-02-07

362

Aspects of two-photon physics at linear e"+e"- colliders  

International Nuclear Information System (INIS)

We discuss various reactions at future e"+e"- and #gamma##gamma# colliders involving real (beamstrahlung or backscattered laser) or quasi-real (bremsstrahlung) photons in the initial state and hadrons in the final state. The production of two central jets with large transverse momentum p_T is described in some detail; we give distributions for the rapidity and p_T of the jets as well as the di-jet invariant mass, and discuss the relative importance of various initial state configurations and the uncertainties that arise from the at present rather poor knowledge of the parton content of the photon. We also present results for 'mono-jet' production where one jet goes down a beam pipe, for the production of charm, bottom and top quarks, and for single production of W and Z bosons. Where appropriate, the two-photon processes are compared with annihilation reactions leading to similar ...

363

Renormalization Group Running of Lepton Mixing Parameters in See-Saw Models with $S_4$ Flavor Symmetry  

CERN Document Server

We study the renormalization group running of the tri-bimaximal mixing predicted by the two typical $S_4$ flavor models at leading order. Although the textures of the mass matrices are completely different, the evolution of neutrino mass and mixing parameters is found to display approximately the same pattern. For both normal hierarchy and inverted hierarchy spectrum, the quantum corrections to both atmospheric and reactor neutrino mixing angles are so small that can be neglected. The evolution of solar mixing angle $\\theta_{12}$ depends on $\\tan\\beta$ and mass spectrum, the deviation from its tri-bimaximal value could be large. Taking into account the renormalization group running effect, the neutrino spectrum is constrained by experimental data on $\\theta_{12}$ and the inverted hierarchy spectrum is disfavored for large $\\tan\\beta$. The evolution of light neutrino masses is approximately ...

2010-01-01

364

Neutrino Oscillations: from Standard and Non-standard Viewpoints  

CERN Document Server

In the standard model of neutrino oscillations, the neutrino flavor states are mixtures of mass-eigenstates, and the phenomena are well described by the neutrino mixing matrix, i.e., the PMNS matrix. I review the recent progress on parametrization of the neutrino mixing matrix. Besides that I also discuss on the possibility to describe the neutrino oscillations by a non-standard model in which the neutrino mixing is caused by the Lorentz violation (LV) contribution in the effective field theory for LV. We assume that neutrinos are massless and that neutrino flavor states are mixing states of energy eigenstates. In our calculation the neutrino mixing parts depend on LV parameters and neutrino energy. The oscillation amplitude varies with the neutrino energy, thus neutrino experiments with energy dependence may test and constrain the Lorentz violation scenario for neutrino ...

2011-01-01

365

Flavor Mixing, Quark Masses, Neutrino Masses and Neutrino Oscillations  

CERN Document Server

We discuss first the flavor mixing of the quarks, using the texture zero mass matrices. Then we study a similar model for the mass matrices of the leptons. We are able to relate the mass eigenvalues of the charged leptons and of the neutrinos to the mixing angles and can predict the masses of the neutrinos. We find a normal hierarchy - the masses are 0.004 eV, 0.01 eV and 0.05 eV. The atmospheric mixing angle is given by the mass ratios of the charged leptons and the neutrinos. we find about 40 degrees, consistent with the experiments. The mixing element, connecting the first neutrino wit the electron, is predicted to be 0.05. This prediction can soon be checked by the Daya Bay experiment.

2009-01-01

366

Development of a petrographic technique for the quality control of concrete mixes used in mines. Final report; Mise au point d`une technique petrographique pour le controle de qualite des betons miniers. Rapport final  

Energy Technology Data Exchange (ETDEWEB)

Petrographical analysis is a microscopical analytical tool which allows definition of the exact nature of the components of different concrete mixes, as well as definition of internal structures and alteration processes. In order to improve the precision and the swiftness of the petrographical analysis, an automated image analysis system has been developed. In the next stage of this study, which consisted in the testing of new concrete mixes containing fluidised bed ashes, petrography has been used, not only to identify the nature of the mix components, but also assess the behaviour of these new concrete mixes when exposed to aggressive conditions.

1997-11-01

367

Synchrotron Self-Compton Analysis of TeV X-ray Selected BL Lacertae Objects  

CERN Document Server

We introduce a methodology for analysis of multiwavelength data from X-ray selected BL Lac (XBL) objects detected in the TeV regime. By assuming that the radio--through--X-ray flux from XBLs is nonthermal synchrotron radiation emitted by isotropically-distributed electrons in the randomly oriented magnetic field of a relativistic blazar jet, we obtain the electron spectrum. This spectrum is then used to deduce the synchrotron self-Compton (SSC) spectrum as a function of the Doppler factor, magnetic field, and variability timescale. The variability timescale is used to infer the comoving blob radius from light travel-time arguments, leaving only two parameters. With this approach, we accurately simulate the synchrotron and SSC spectrum of flaring XBLs in the Thomson through Klein-Nishina regimes. Photoabsorption by interactions with internal jet radiation and the intergalactic background light (IBL) is included. Doppler factors, magnetic fields, ...

2008-01-01

368

Results of reliability test program on light water reactor piping  

Energy Technology Data Exchange (ETDEWEB)

The Japan Atomic Energy Research Institute has conducted a piping reliability test program to demonstrate the safety and reliability of light water reactor primary piping. In this program, pipe fatigue test, leak-before-break (LBB) verification test and pipe rupture test were carried out to examine the integrity of piping, to verify the LBB and to demonstrate the effectiveness of protective measures against jet impingement and pipe whip loads under a pipe rupture event.In the pipe fatigue test, a procedure to predict the fatigue crack growth was developed, and the integrity of piping during the plant service life was evaluated. In the LBB verification test, the pipe fracture test and the leak rate test were performed to verify the LBB in the primary piping.In the pipe rupture test, the influence of jet impingement on the target disk and the deformation behavior of whipping pipe and restraint were investigated. Using the test results, the ...

1994-12-01

369

Quirks at the Tevatron and Beyond  

CERN Document Server

We consider the physics and collider phenomenology of quirks that transform nontrivially under QCD color, SU(2)_W as well as an SU(N)_{ic} infracolor group. Our main motivation is to show that the recent Wjj excess observed by CDF naturally arises in quirky models. The basic pattern is that several different quirky states can be produced, some of which beta-decay during or after spin-down, leaving the lightest electrically neutral quirks to hadronize into a meson that subsequently decays into gluon jets. We analyze LEP II, Tevatron, UA2, and electroweak precision constraints, identifying the simplest viable models: scalar quirks ("squirks") transforming as color triplets, SU(2)_W triplets and singlets, all with vanishing hypercharge. We calculate production cross sections, weak decay, spin-down, meson decay rates, and estimate efficiencies. The novel features of our quirky model includes: quirkonium decay proceeds into a pair of gluon jets, ...

2011-01-01

370

Overview of reliability test program on primary coolant piping of light water reactors  

Energy Technology Data Exchange (ETDEWEB)

Upon request by the Science and Technology Agency of Japanese Government, the Japan Atomic Energy Research Institute has conducted Piping Reliability Test Program to demonstrate the safety and reliability of light water reactor primary pipings. In this report, the results of the program are summarized. In the test program, pipe fatigue tests, Leak-Before-Break (LBB) verification tests and pipe rupture tests were carried out to examine the integrity of pipings, to verify the LBB concept and to demonstrate the effectiveness of the protective measures against jet impingement and pipe whip under pipe rupture event, respectively. In the pipe fatigue tests, a procedure to predict the fatigue crack growth was developed and the integrity of piping during plant service life was demonstrated. In the LBB verification tests, pipe fracture tests and leak rate tests were performed using cracked pipes. Based on the test results, LBB in the primary pipings was demonstrated. In the ...

1993-10-01

371

Development of an efficient, low-NOx domestic gas-range cooktop. Phase 3. Annual technical report, January 1986-December 1986  

Science.gov (United States)

The objective of the program is to develop a domestic cooktop with low-NOx emissions and high efficiency. During the first two phases of the program, three design concepts were developed, and two versions of developmental prototypes using the IR-Jet approach were fabricated and tested. The third phase was initiated to address the design issues of burner turndown and modulation and to conduct the field test of a prototype with one IR-Jet and three conventional burners. Two prototypes containing one IR-Jet and three conventional burners and utilizing blower speed control for air/gas modulation were fabricated. One unit employed a brushless dc motor and the other a 2-pole ac motor. The ac motor prototype was field tested. Field testing showed the need for a mechanical air/gas valve for modulation and for a 1500 Btu/hr simmer setting. A 4-inch-diameter stepped-tile configuration provided input rates from 1500 to 8000 Btu/hr. A ...

1987-06-01

372

Abrasion wear studies with abrasives from brown coal beneficiation  

Energy Technology Data Exchange (ETDEWEB)

This paper evaluates abrasive jet wear tests, carried out on the ZUK-3M abrasion apparatus according to the GOSF 23.201-78 industrial standard. As abrasive material, brown coal coke dust, brown coal dust, power plant fly ash and quartz sand (for the purpose of comparison) were employed. Seventeen types of materials were blasted with abrasive jets, including a selection of steels, glass, rubber, SYS-pur plastics, cast basalt, Kawenit and vitroceramics. The test apparatus produced abrasive jet velocities between 12 and 130 ms/SUP/-/SUP/1 at rotor revolutions of 1,000 to 10,000 min/SUP/-/SUP/1. Blasted material samples were arranged at angles between 15 and 90 degrees. Various tables and graphs present abrasivity results. These results were employed for technical modifications of dedusting equipment in briquetting and coking plants, which led to a threefold increase in service life of abrasion endangered equipment parts. (8 ...

1983-01-01

373

AGN Feedback: Does it work?  

CERN Document Server

While feedback is important in theoretical models, we do not really know if it works in reality. Feedback from jets appears to be sufficient to keep the cooling flows in clusters from cooling too much and it may be sufficient to regulate black hole growth in dominant cluster galaxies. Only about 10% of all quasars, however, have powerful radio jets, so jet-related feedback cannot be generic. The outflows could potentially be a more common form of AGN feedback, but measuring mass and energy outflow rates is a challenging task, the main unknown being the location and geometry of the absorbing medium. Using a novel technique, we made first such measurement in NGC 4051 using XMM data and found the mass and energy outflow rates to be 4 to 5 orders of magnitude below those required for efficient feedback. To test whether the outflow velocity in NGC 4051 is unusually low, we compared the ratio of outflow velocity to escape ...

2009-01-01

374

A gas-jet ECR ion source at TRIGA-SPEC  

International Nuclear Information System (INIS)

The TRIGA-SPEC experiment has been installed recently at the research reactor TRIGA Mainz. Ground state properties like masses, charge radii, spins, and moments of short-lived nuclides can be determined with very-high precision using the Penning trap mass spectrometer TRIGA-TRAP, and the collinear laser spectroscopy setup TRIGA-LASER. Short-lived neutron-rich radionuclides in the mass range 80 < A < 140 are produced by thermal neutron induced fission of e.g. U-235, Pu-239 or Cf-249, respectively. For the extraction and ionization of the fission products a gas-jet system is coupled to a 2.45-GHz ECR ion source for the production of singly charged ions. The gas-jet has been tested on-line and fission products have been extracted. First off-line tests of the ion source have been performed successfully with argon gas. The results of the commissioning test of the ion source and the on-line coupling of the experiments are presented.

2010-03-08

375

A Distinctive Disk-Jet Coupling in the Seyfert-1 AGN NGC 4051  

CERN Document Server

We report on the results of a simultaneous monitoring campaign employing eight Chandra X-ray (0.5-10 keV) and six VLA/EVLA (8.4 GHz) radio observations of NGC 4051 over seven months. Evidence for compact jets is observed in the 8.4 GHz radio band; This builds on mounting evidence that jet production may be prevalent even in radio-quiet Seyferts. Assuming comparatively negligible local diffuse emission in the nucleus, the results also demonstrate an inverse correlation of L_radio proportional to L_X-ray ^(-0.72+/-0.04) . Current research linking the mass of supermassive black holes and stellar-mass black holes in the "low/hard" state to X-ray luminosities and radio luminosities suggest a "fundamental plane of accretion onto black holes" that has a positive correlation of L_radio proportional to L_X-ray^(0.67+/-0.12) . Our simultaneous results differ from this relation by more than 11 sigma, indicating that a separate mode of accretion and ...

2010-01-01

376

Measurement of the charge asymmetry in top-antitop quark production with the CDF II experiment  

Energy Technology Data Exchange (ETDEWEB)

The Fermi National Laboratory (Fermilab) operates the Tevatron proton-antiproton collider at a center-of-mass energy of {radical}s = 1.96 TeV, the is therefore the only collider which is today able to produce the heaviest known particle, the top quark. The top quark was discovered at the Tevatron by the CDF and D0 collaborations in 1995. At the Tevatron, most top quarks are produced via the strong interaction, whereby quark-antiquark annihilation dominates with 85%, and gluon fusion contributes with 15%. Considering next-to-leading order (NLO) contributions in the cross section of top-antitop quark production, leads to a slight positive asymmetry in the differential distribution of the production angle {alpha} of the top quarks. This asymmetry is due to the interference of certain NLO contributions. The charge asymmetry A in the cosine of {alpha} is predicted [14] to amount to 4-6%. Information about the partonic rest frame, necessary for a measurement of A in the observable cos ...

2006-12-01

377

Electrochemical noise measurements of sustained microbially influenced pitting corrosion in a laboratory flow loop system.  

Energy Technology Data Exchange (ETDEWEB)

Because of the chaotic nature of the corrosion process and the complexity of the electrochemical noise signals that are generated, there is no generally accepted method of measuring and interpreting these signals that allows the consistent detection and identification of sustained localized pitting (SLP) as compared to general corrosion. We have reexamined electrochemical noise analysis (ENA) of localized corrosion using different hardware, signal collection, and signal processing designs than those used in conventional ENA techniques. The new data acquisition system was designed to identify and monitor the progress of SLP by analyzing the power spectral density (PSD) of the trend of the corrosion current noise level (CNL) and potential noise level (PNL). Each CNL and PNL data point was calculated from the root-mean- square value of the ac components of current and potential fluctuation signals, which ...

1999-01-13

378

Effect of earthquakes on ambient noise cross-correlation function  

Science.gov (United States)

Surface wave tomography method based on analysis of ambient noise is widely used during the last decade. It is assumed that correlated component of noise is composed of surface waves generated by sources distributed over the Earth's surface more or less uniformly. In such a case the cross-correlation function (CCF) at two stations may be considered as the Green's function of surface wave. This function should be symmetric relatively to zero time. However analysis of CCF at the stations located at the East-European Platform shows that as a rule CCF is characterized with a strong asymmetry. Since "purered noise cannot be extracted from seismic records due to superposition of earthquake signals, the method for calculation of CCF includes amplitude normalization for suppression of earthquakes that reduces signals from earthquakes to a noise level. The parts of records containing waves from earthquakes are ...

2011-09-01

379

Wavelength shift of lasing from a dye-doped asymmetrically deformed liquid jet  

International Nuclear Information System (INIS)

We examined the spectral behaviors of lasing from a asymmetrically deformed liquid jet (a ? 14 ?m) which is induced by a laterally flowing gas. Th liquid sample was methanols which contains DCM dye. When n distortion is induced, the lasing spectrum appears as two periodic peaks which are corresponding to the resonance modes of cylindrical cavity. As the distortion parameter exceeds about 4%, the lasing spectrum shifts continuously to short wavelength. When the distortion parameter reaches ? 10%, the amount of blue shift was ? 30 nm. The blue shift can be explained as the shift of optimum wavelength of threshold curves. From the absorption and fluorescence curve of liquid sample, we estimated the spoiled Q with the distortion parameter.

1997-11-01

380

The utility of naphthyl-keratin adducts as biomarkers for jet-fuel exposure.  

Science.gov (United States)

We investigated the association between biomarkers of dermal exposure, naphthyl-keratin adducts (NKA), and urine naphthalene biomarker levels in 105 workers routinely exposed to jet-fuel. A moderate correlation was observed between NKA and urine naphthalene levels (p?=?0.061). The NKA, post-exposure breath naphthalene, and male gender were associated with an increase, while CYP2E1*6 DD and GSTT1-plus (++/+-) genotypes were associated with a decrease in urine naphthalene level (p?

2011-09-30

381

The spatial distribution of argon clusters in gas jet  

International Nuclear Information System (INIS)

The spatial distribution of argon clusters in gas jet is tested using the Rayleigh scattering method. A pulsed laser is used to acquire the whole evolution of the cluster inside one event. The measured results at a fixed axial position show that the argon clusters grow in less than one millisecond after the nozzle is opened and the cluster size keeps constant during the whole open period of 20 ms. Further results show that the scattering signal along the radial direction is almost Gaussian-distributed and the full width half maximum (FWHM) increases almost linearly when the distance from nozzle increases. The scattering signal along the axial direction is Landau-distributed and the area near the nozzle is most effective for laser cluster interaction. (authors)

2010-02-01

382

The electron cyclotron absorption diagnostic for the JET pumped divertor plasma  

International Nuclear Information System (INIS)

We present the design of a diagnostic system to measure electron cyclotron absorption at the second harmonic E-mode resonance in the JET pumped divertor plasma. The diagnostic will measure transmission as a function of frequency along one or more sightlines from which the spatial profile of the n_eT_e product will be deduced. The divertor is briefly described, and the electron cyclotron resonance physics relevant to this measurement is reviewed. The problems of measuring transmission using an oversized transmission system are discussed and the chosen measurement technique, a swept frequency interferometer using a coherent radiation source, is described. A prototype of the instrument has been assembled to test the measurement technique. Some data demonstrating the instrument's characteristics are presented. The nonresonant losses, which may affect the interpretation of the measurement, are also discussed. (orig.).

1993-03-01

383

The Dynamical Interaction of AGN with their Galaxian Environments  

CERN Document Server

Jet-driven shocks are responsible for an important fraction of the emission of the narrow-line regions (NLRs) in many classes of AGN. However, this cannot explain all observations. It is clear that the remaining sources are photoionised by the active nucleus. The 2-d hydrodynamic models from the RSAA group support an evolutionary scenario whereby the shock-excited NLRs are initially jet-driven but later, ionizing photons from the central engine replace shocks as the main excitation mechanism and shock induced star formation may also become important. In their photoionized phase, dusty and radiation-pressure dominated evolution produces a self-regulated NLR spectrum. This model aso explains the coronal emission lines and fast (3000 km s$^{-1}$) outflows seen in some Seyferts.

2003-01-01

384

Overview of long-term fuel inventory and co-deposition in castellated beryllium limiters at JET  

International Nuclear Information System (INIS)

Morphology of castellated Be tiles from the belt limiter exposed to the JET plasma for 56,000 s was examined on both sides of castellated grooves, on plasma-facing and side surfaces of the tiles. The essential results are (i) deuterium retention in the castellated grooves and in other locations is associated with co-deposition of carbon; (ii) the decay length of deposition in the castellation is around 1.5 mm; (iii) no deuterium is detected in bulk Be; (iv) bridging of gaps by molten beryllium occurred but gaps were not filled with Be; (v) on side surfaces of the tiles the formation of BeO layer was detected at a distance of 20 mm and more from the plasma-facing surface. The consequences for a long-term operation of a reactor-class device with several different plasma-facing materials are addressed.

2009-04-30

385

Macro-Cellular Silicon carbide Reactors for Nonstationary Combustion Under Piston Engine-Like Conditions  

British Library Electronic Table of Contents (United Kingdom)

Strut lattice structures of reaction-bonded silicon infiltrated silicon carbide ceramics (RB-SiSiC) for air-fuel mixture formation and for nonstationary lean-burn under pressure applications were fabricated. The lattice design with a high porosity >80% was shaped by indirect three-dimensional printing. It was shown that pre-ignition processes in the porous reactor are much faster than in a free combustion, especially at lower temperatures. Interaction of high velocity diesel jets with cylindrical strut ligaments of the SiSiC lattice structure offers a new possibility for quick and efficient fuel distribution (multi-jet splitting) in space.

2011-01-01

386

Ion temperature anisotropy in high power helium neutral beam fuelling experiments in JET  

Energy Technology Data Exchange (ETDEWEB)

During helium beam fuelling experiments in JET, distinctive anisotropic features have been observed in the velocity distribution function describing both fast and thermal alpha particle populations. During the initial fuelling phase the central helium ion temperature observed perpendicular to the magnetic field is higher than the central electron temperature, while the central helium ion temperature observed parallel to the magnetic field is lower than or equal to the central electron temperature. In order to verify temperature measurements of both perpendicular and parallel lines of sight, other independent methods of deducing the ion temperature are investigated: deuterium ion temperature, deuterium density, comparison with neutron rates and profiles (influence of a possible metastable population of helium). 6 refs., 7 figs.

1994-07-01

387

Investigation of erosion-corrosion of 3003 aluminum alloy in ethylene glycol-water solution by impingement jet system  

British Library Electronic Table of Contents (United Kingdom)

Erosion-corrosion (E-C) of 3003 aluminum (Al) alloy in ethylene glycol-water solutions were studied by weight-loss and electrochemical measurements as well as surface characterization through an impingement jet system. Al alloy E-C is dominated by erosion components, i.e., pure erosion and corrosion-enhanced erosion, which account for 92-97% of the total E-C rate under the various conditions in this work. Contribution from corrosion components, including pure corrosion and erosion-enhanced corrosion, is slight. With the increase of fluid flow velocity and sand concentration, the total E-C rate increases. Compared with the significant increase of the rates of erosion components, the increase of the rate of corrosion component is negligible. Upon fluid flow, passivity of Al alloy that develo...

2009-01-01

388

Heat transfer augmentation in an axisymmetric impinging jet  

Science.gov (United States)

This paper presents the experimental results of heat transfer augmentation in an axisymmetric jet impinging normally on a flat plate surface without the requirement of additional pumping power. The present technique of augmentation utilizes only a punched plate with circular holes arranged in a triangular array, fixed parallel to, just in front of the heated target plate. Near the optimum conditions determined, the heat transfer coefficient at the geometrical stagnation point can be increased 4 times. Additional flow visualization study indicates that this augmentation mechanism creates an improved flow field where the punched plate acts as a detached fin, the conductivity of which may be exploited for further augmentation. Besides augmentation, the present investigation foresees the possibility of manipulating the distribution of local heat transfer rate by varying few parameters.

1982-01-01

389

Functional adaptation of microbial communities from jet fuel-contaminated soil under bioremediation treatment: simulation of pollutant rebound  

British Library Electronic Table of Contents (United Kingdom)

Abstract To investigate the link between the functionality and the diversity of microbial communities under strong selective pressure from pollutants, two types of mesocosms that simulate natural attenuation and phytoremediation were generated using soil from a site highly contaminated with jet fuel and under air-sparging treatment. An increase in the petroleum hydrocarbon concentration from 4900 to 18-500-mg-kg-1-dw soil simulated a pollutant rebound (postremediation pollutant reversal due to residual contamination). Analysis of soil bacterial communities by denaturing gradient gel electrophoresis of PCR-amplified 16S rRNA gene fragments showed stronger changes and selection for a phylogenetically diverse microbial population in the mesocosms with pollutant-tolerant willow trees. Enumerat...

2011-01-01

390

Experimental investigations of plasma bullets  

International Nuclear Information System (INIS)

Recently several investigators reported on various means of generating cold plasma jets at atmospheric pressure. More interestingly, these jets turned out to be not continuous plasmas but trains of small high velocity plasma packets/bullets. However, until now little is known of the nature of these 'bullets'. Here we present experimental insights into the physical and chemical characteristics of bullets. We show that their time of initiation, their velocity and the distance they travel are directly dependent on the value of the applied voltage. We also show that these bullets can be controlled by the application of an external electric field. Using an intensified charge coupled device camera we report on their geometrical shape, which was revealed to be 'donut' shaped, therefore giving an indication that solitary surface ionization waves may be responsible for the creation of these bullets. In addition, using emission spectroscopy, we follow ...

2009-03-07

391

Excitation of global Alfven Eigenmodes by RF heating in JET  

Energy Technology Data Exchange (ETDEWEB)

The alpha-particle confinement of future D-T experiments at JET can be severely degraded by Global Alfven Eigenmodes (AE). Scenarios for the excitation of Alfven Eigenmodes in usual (e.g. D-D) plasmas are proposed, which provide a MHD diagnostic and allow the study of the transport of super-Alfvenic ions. Active studies with separate control of TAE amplitude and energetic particle destabilization, measuring the plasma response, give more information than passive studies, in particular concerning the damping mechanisms. The TAE excitation can be achieved by means of the saddle coil and the ICRH antenna. The experimental method is introduced together with a theoretical model for RF excitation. (authors). 6 refs., 3 figs.

1994-07-01

392

Efficient, low emissions gas range cooktop  

Energy Technology Data Exchange (ETDEWEB)

Disclosed is a gas-fired cooktop for a range which provides high thermal efficiency and low emissions of air pollutants, particularly low levels of NO{sub x}. The cooktop includes a perforated tile burner which radiates infrared energy upward at a high flux rate to rapidly quench burner gas temperatures and inhibit the formation of NO{sub x}. A perforated glass-ceramic jet plate positioned between the burner and a cooking vessel transmits most of the radiant infrared energy from the burner to the vessel and also forms jets of combustion products which are directed against the bottom of the vessel fo convective heating. Thermal efficiencies of up to about 70% and NO{sub x} emissions as low as about 15ppM are achieved by the cooktop.

1990-01-09

393

Dependence of nitriding degree of Ti surface by non-LTE nitrogen plasma on various plasma parameters  

International Nuclear Information System (INIS)

Experiments of plasma nitriding of titanium are carried out by two plasma sources. One is a microwave discharge plasma source under several Torr, and the other is a nitrogen arc jet generated under atmospheric pressure followed by rapid expansion into a gas wind tunnel. The relationship between the surface density of nitrogen atoms in the #alpha#-Ti and various plasma parameters is systematically studied. For the microwave nitrogen plasma, it is found that the effect of the vibration temperature is the most essential for the surface nitriding, whereas the effect of electron temperature, density and rotation temperature is less remarkable. It is also found that the higher vibration temperature of the microwave discharge nitrogen plasma makes the target temperature higher, and consequently, the surface density of atomic nitrogen remarkably increased. However, the effect of target temperature is less remarkable for the arc jet nitrogen plasma.

2004-06-01

394

Definitive generic study for the effect of high lift airfoils on wind turbine effectiveness, executive summary  

Science.gov (United States)

The effect of high lift airfoils on the cost effectiveness of HAWT and VAWT (horizontal and vertical axis wind turbine) machines is studied. The scope involved first studying modern two dimensional airfoils, and developing a generalized formulation for their performance in terms of lift, drag, and thickness at appropriate Reynolds numbers. Single element, multi-element, symmetrical, extra thick airfoils and jet flap airfoils were analyzed. The jet flap airfoils were considered to be unacceptable because of excessive power requirements. Then the effect of using the above airfoils on the rotors of a variety of wind turbines was made. Qualitative representation of the type of airfoils studied is given.

1979-05-01

395

Chemistry of dense clumps near moving Herbig-Haro objects  

British Library Electronic Table of Contents (United Kingdom)

Abstract Localized regions of enhanced emission from HCO+, NH3 and other species near Herbig-Haro objects (HHOs) have been interpreted as arising in a photochemistry stimulated by the HHO radiation on high-density quiescent clumps in molecular clouds. Static models of this process have been successful in accounting for the variety of molecular species arising ahead of the jet; however, recent observations show that the enhanced molecular emission is widespread along the jet as well as ahead. Hence, a realistic model must take into account the movement of the radiation field past the clump. It was previously unclear as to whether the short interaction time between the clump and the HHO in a moving source model would allow molecules such as HCO+ to reach high enough levels, and to survive fo...

2011-01-01

396

Blowdown thrust force under pipe rupture accident. Pt. 1. Experimental evaluations of blowdown thrust force and decompression characteristics  

Energy Technology Data Exchange (ETDEWEB)

Blowdown thrust forces and decompression characteristics were evaluated concerning the jet discharge or pipe whip tests with a 4-inch or 6-inch diameter pipe under PWR LOCA or BWR LOCA conditions related to pipe rupture accidents in nuclear power plants. This paper presents experimental evaluations of time-dependent and maximum blowdown thrust forces, and evaluations of decompression characteristics under instantaneous pipe rupture conditions. The following items are discussed: the peak value of the blowdown thrust force, the jet thrust coefficient for the maximum blowdown thrust force, the pressure recovery after break, and the relationship between the pressure undershoot of the sudden decompression and the decompression rate.

1984-06-01

397

Beryllium coating on JET Inconel tiles  

International Nuclear Information System (INIS)

Full text: Institute for Nuclear Research, Pitesti-Mioveni, Romania in direct cooperation with the National Institute for Laser, Plasma and Radiation Physics, Magurele, Bucharest studied and prepared for coating more than 1000 tiles made of Inconel with 7-9 #mu#m of beryllium for nuclear fusion applications at JET, Culham, UK. The principles of manufacturing processes using thermal evaporation and plasma ignited in pure metal vapors as well as by Thermionic Vacuum Arc (TVA) method and the properties of the Ni and Be coatings are presented. The prepared beryllium layers were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy and atomic force microscopy. (authors)

2009-10-12

398

Analytical studies of four-inch pipe whip tests under BWR LOCA conditions  

Energy Technology Data Exchange (ETDEWEB)

The purpose of pipe rupture studies in JAERI is to perform model tests on pipe whip, restraint behavior, jet impingement and jet thrust force, and to establish a computational method for analyzing these phenomena. This report presents the analytical results of 4-inch pipe whip tests under BWR LOCA conditions. Dynamic response analyses were performed using the general-purpose finite element program ADINA. The test pipe was modelled by straight beam elements and the four restraints were modelled by a single truss element. The analytical results were compared with the experimental results. Impact time and maximum total restraint force showed good agreement with experimental results. On the other hand, pipe strain and pipe deflection could not be predicted so well. The reason for this is that the sliding of the restraint during the pipe whip movement cannot be considered in the analyses.

1985-01-01

399

Analysis of catalyst deactivation during steam reforming of jet fuel on Ni-(PdRh)/g-Al2O3 catalyst  

British Library Electronic Table of Contents (United Kingdom)

Catalyst deactivation during steam reforming of transportation fuels, primarily due to sulfur poisoning and carbon deposition, is a major hurdle in the commercialization of fuel cell technologies. In an attempt to better understand the phenomena, a previously formulated multi-component (Ni, Pd, Rh) catalyst supported on g-Al2O3 was studied under steam reforming of Jet A spiked with thiophene to achieve a total sulfur content of 1000ppm by weight. Analysis of fresh catalysts showed the presence of two groups of active metal particles, primarily distinguished by their size and composition; small particles (1-5nm) largely comprised of Rh and large particles (10-20nm) that were predominantly Ni, with or without the presence of Pd. Analysis of used catalysts showed sintering of crystallites con...

2011-01-01

400

Use of noise analysis methods in process monitoring of future fuel cycles  

Energy Technology Data Exchange (ETDEWEB)

The {sup 252}Cf-source-driven noise analysis method has been used in measurements for subcritical configurations of fissile systems for a variety of applications including a dynamic measurement that was the first step in applying this method to monitor fuel in a future reprocessing plant These measurements showed that this method has potential to monitor many dynamic situations in processing plants such as in a continuous dissolver or batch dissolvers either to obtain the neutron multiplication factor k or to be used as a signature to verify that various processes are occurring in a repeatable or bounded way. This verification of normal operation would be by comparing noise analysis signatures for the process with reference signatures. Abnormal operation could be ascertained if the signature deviates by some specified amount from the reference signatures from normal operation. The deviations from normal could be specified by measurement or by ...

1993-08-01

401

Subcritical measurements using the /sup 252/Cf source-driven neutron noise analysis method  

Energy Technology Data Exchange (ETDEWEB)

This paper describes recent measurements of the subcritical neutron multiplication factor using the /sup 252/Cf source-driven neutron noise analysis method. This work was supported by a program of collaboration between the United States Department of Energy and the Power Reactor and Nuclear Fuel Development Corporation of Japan related to the development of fast breeder technology. The experiment reported consists of a configuration of two interacting tanks of uranyl nitrate aqueous solution with different uranium concentrations in each tank. The /sup 252/Cf-source-driven neutron noise analysis method obtains the subcriticality from the signals of three detectors: the first, a parallel plate ionization chamber with /sup 252/Cf electroplated on one of its plates that is located in or near the system containing the fissile material, and produces an electrical pulse for every spontaneous fission that occurs and thereby serves as a timed source of ...

1985-01-01

402

Performance evaluation for ML sequence detection in ISI channels with Gauss Markov Noise  

CERN Document Server

Inter-symbol interference (ISI) channels with data dependent Gauss Markov noise have been used to model read channels in magnetic recording and other data storage systems. The Viterbi algorithm can be adapted for performing maximum likelihood sequence detection in such channels. However, the problem of finding an analytical upper bound on the bit error rate of the Viterbi detector in this case has not been fully investigated. Current techniques rely on an exhaustive enumeration of short error events and determine the BER using a union bound. In this work, we consider a subset of the class of ISI channels with data dependent Gauss-Markov noise. We derive an upper bound on the pairwise error probability (PEP) between the transmitted bit sequence and the decoded bit sequence that can be expressed as a product of functions depending on current and previous states in the (incorrect) decoded sequence and the (correct) transmitted sequence. In ...

2010-01-01

403

Noise bias in the refinement of structures derived from single particles  

Energy Technology Data Exchange (ETDEWEB)

One of the main goals in the determination of three-dimensional macromolecular structures from electron microscope images of individual molecules and complexes (single particles) is a sufficiently high spatial resolution, about 4 A, at which the interpretation with an atomic model becomes possible. To reach high resolution, an iterative refinement procedure using an expectation maximization algorithm is often used that leads to a more accurate alignment of the positional and orientational parameters for each particle. We show here the results of refinement algorithms that use a phase residual, a linear correlation coefficient, or a weighted correlation coefficient to align individual particles. The algorithms were applied to computer-generated data sets that contained projections from model structures, as well as noise. The algorithms show different degrees of over-fitting, especially at high resolution where the signal is weak. We demonstrate that the degree of ...

2004-12-15

404

Noise and microresonance of critical current in Josephson junction induced by Kondo trap states  

CERN Document Server

We analyze the impact of trap states in the oxide layer of a superconducting tunnel junctions, on the fluctuation of the Josephson critical current, thus on coherence in superconducting qubits. Two mechanisms are usually considered: the current blockage due to repulsion at the occupied trap states, and the noise from electrons hopping across a trap. We extend previous studies of noninteracting traps to the case where the traps have on-site electron repulsion inside one ballistic channel. The repulsion not only allows the appropriate temperature dependence of 1/f noise, but also is a control to the coupling between the computational qubit and the spurious two-level systems inside the oxide dielectric. We use second order perturbation theory which allows to obtain analytical formulae for the interacting bound states and spectral weights, limited to small and intermediate repulsions. Remarkably, it still reproduces the main features of the model ...

2011-01-01

405

Laboratory Evaluation of an Electrochemical Noise System for Detection of Localized and General Corrosion of Natural Gas Transmission Pipelines  

Energy Technology Data Exchange (ETDEWEB)

Gas transmission pipelines are susceptible to both internal (gas side) and external (soil side) corrosion attack. Internal corrosion is caused by the presence of salt laden moisture, CO{sub 2}, H{sub 2}S, and perhaps O{sub 2} in the natural gas. Internal corrosion usually manifests itself as general corrosion. However, the presence of chlorides in entrained water also can lead to pitting corrosion damage. The electrochemical noise technique can differentiate general from localized corrosion and provide estimates of corrosion rates without external perturbation of the corroding system. It is increasingly being applied to field and industrial installations for in situ corrosion monitoring. It has been used here to determine its suitability for monitoring internal and external corrosion damage on gas transmission pipelines. Corrosion measurements were made in three types of environments: (1) aqueous solutions typical of those found within gas pipelines in equilibrium ...

2003-03-16

406

Eddy currents signal processing for steam generator inspection in PWR nuclear power plants; Traitement des signaux de courants de Foucault pour le controle des tubes de generateurs de vapeur dans les centrales nucleaires REP  

Energy Technology Data Exchange (ETDEWEB)

Steam generator tubes in nuclear power plants are periodically checked by means of eddy current probes. The output of a probe is composed of three types of signals: known events (rolling zone, support plates, U-bend part), noise (mainly metallurgical noise) and possible flaws. The latter are random transients, both in arrival time and in shape: they have to be detected and then estimated, before to be fed to the high level stages of a diagnostics system. The objective of the study presented is to develop a semi-automatic system, which could manage and process more than 1 M-bytes of data per tube and provide an operator with reliable diagnostics proposals within a few minutes. This can be achieved only by cooperation of several digital signal processing techniques: detection, segmentation, estimation, noise subtraction, adaptive filtering, modelization, pattern recognition. The paper describes some of these items.

1991-07-01

407

Eddy currents signal processing for steam generator inspection in PWR nuclear power plants. Traitement des signaux courants de Foucault pour le controle des tubes de generateurs de vapeur dans les centrales nucleaires REP  

Energy Technology Data Exchange (ETDEWEB)

Steam generator tubes in nuclear power plants are periodically checked by means of eddy current probes. The output of a probe is composed of three types of signals: known events (rolling zone, support plates, U-bend part), noise (mainly metallurgical noise) and possible flaws. The latter are random transients, both in arrival time and in shape: they have to be detected and then estimated, before to be fed to the high level stages of a diagnostic system. The objective of the study presented is to develop a semi-automatic system, which could manage and process more than 1 M-bytes of data per tube and provide an operator with reliable diagnostics proposals within a few minutes. This can be achieved only by cooperation of several digital signal processing techniques: detection, segmentation, estimation, noise subtraction, adaptive filtering, modelization, pattern recognition. The paper describes some of these items.

1992-01-01

408

Analyzing the performance of probabilistic algorithm in noisy manets  

CERN Document Server

Probabilistic broadcast has been widely used as a flooding optimization mechanism to alleviate the effect of broadcast storm problem (BSP) in mobile ad hoc networks (MANETs). Many research studies have been carried-out to develop and evaluate the performance of this mechanism in an error-free (noiseless) environment. In reality, wireless communication channels in MANETs are an error-prone and suffer from high packet-loss due to presence of noise, i.e., noisy environment. In this paper, we propose a simulation model that can be used to evaluate the performance of probabilistic broadcast for flooding in noisy environment. In the proposed model, the noise-level is represented by a generic name, probability of reception (pc) (0<=pc<=1), where pc=1 for noiseless and <1 for noisy environment. The effect of noise is determined randomly by generating a random number \\zeta (0<=\\zeta<1); if \\zeta<=pc means the ...

2010-01-01

409

/sup 252/Cf-source-driven neutron noise analysis measurements for coupled uranium metal cylinders  

Energy Technology Data Exchange (ETDEWEB)

The /sup 252/Cf-source-driven neutron noise analysis method for obtaining the subcriticality of an assembly of fissile material from cross-power spectral densities (CPSDs) was developed to avoid some difficulties inherent in other measurement methods. This method requires measurement of frequency-dependent CPSD between a pair of detectors in or near the fissile assembly and CPSDs between these detectors and a source of correlated neutron noise from an ionization chamber containing /sup 252/Cf, also in or near the fissile assembly. Also, the auto-power spectral density of the source is required. The ratio of spectral densities is then formed and is related to the subcriticality. To date various measurements have been performed which demonstrate the usefulness of the method including measurements with single uranium metal cylinders. The experiments described here, which used coupled uranium (93.15 wt % /sup 235/U) metal cylinders separated by ...

1985-01-01

410

Tunable erbium-doped fiber ring laser for applications of infrared absorption spectroscopy  

British Library Electronic Table of Contents (United Kingdom)

We fabricate a low noise erbium-doped fiber ring laser that can be continuously tuned over 102nm by insertion of the fiber Fabry-Perot tunable filter (FFP-TF) in the ring cavity with a novel cavity structure and the optimal gain medium length. As an application of this fiber ring laser, we performed the absorption spectroscopy of acetylene (13C2H2) and hydrogen cyanide (H13C14N) and measure the absorption spectra of more than 50 transition lines of these gases with an excellent signal to noise ratio (SNR). The pressure broadening coefficients of four acetylene transition lines are obtained using this fiber ring laser and an external cavity laser diode.

2007-01-01

411

Thermal noise as a spectroscopic tool to determine transport properties  

British Library Electronic Table of Contents (United Kingdom)

The utilization of thermal fluctuations or Johnson/Nyquist noise as a spectroscopic method to determine transport properties in conductors or semiconductors is developed. The autocorrelation function is obtained from power spectral density measurements thus enabling electronic transport property calculation through the Green-Kubo formalism. This experimental approach is distinct from traditional numerical methods such as molecular dynamics simulations, which have been used to extract the autocorrelation function and directly related physics only. This work reports multi-transport property measurements consisting of the electronic relaxation time, resistivity, mobility, diffusion coefficient, electronic contribution to thermal conductivity and Lorenz number from experimental data. Double va...

2009-01-01

412

Speckle Reduction for LIDAR Using Optical Phase Conjugation  

Energy Technology Data Exchange (ETDEWEB)

Remote detection of chemicals using LIDAR (Light Detection and Ranging) utilizing DIAL (Differential Absorption LIDAR) is now a standard detection technique for both military and civilian activities. We have developed a novel nonlinear optical phase conjugation system that can reduce the effects of speckle noise and atmospheric turbulence on DIAL remote detection systems. We have shown numerically and experimentally that it is possible to increase the signal-to-noise (S/N) ratio for LIDAR systems under certain conditions using optical phase conjugation. This increase in S/N can result in more accurate detection of chemical effluents while simultaneously reducing the time necessary to acquire this information.

2001-02-26

413

Preliminary investigation of the /sup 252/Cf-source-driven noise analysis method of subcriticality measurement in LWR fuel storage and initial loading applications  

Energy Technology Data Exchange (ETDEWEB)

The ability of the /sup 252/Cf-source-driven neutron noise analysis method to measure subcriticality has been demonstrated in a variety of experimental configurations of fissile materials. Calculations for an approximately 4-m-dia configuration of light water reactor (LWR) fuel elements indicated the feasibility of measuring the subcriticality of large, loosely coupled arrays of LWR fuel elements by this same method. These analysis suggested application to the initial loading of both pressurized and boiling water reactors, zero-power testing of reactors (such as shutdown margin measurements after initial loading), light water reactor refueling, and safe storage of LWR spent fuel. In the fuel storage application, direct measurement of subcriticality in the actual fuel storage facilities provides the parameter which is directly related to criticality safety.

1984-01-01

414

Neural network and noise injection for the modeling of ozone pollution; Reseau de neurones et injection de bruit pour la modelisation de la pollution par l'ozone  

Energy Technology Data Exchange (ETDEWEB)

This study has been carried out in the framework of a collaboration between the laboratory of processes automation (LAP, Caen (France)), and Air Com, a monitoring network for the prevention of atmospheric pollution in Basse-Normandie. It aims at obtaining a medium and long term forecast of the ozone level above the Caen city. The expected goal is to foresee the pollution peaks exceeding the warning thresholds, but the rareness of such events make them more difficult to predict. In order to solve this kind of problem, a neural modeling method combined with a noise injection technique has been implemented in order to obtain a sufficiently performing model over the whole domain of operation. (J.S.)

2001-07-01

415

Moving average-based estimators of integrated variance  

DEFF Research Database (Denmark)

We examine moving average (MA) filters for estimating the integrated variance (IV) of a financial asset price in a framework where high-frequency price data are contaminated with market microstructure noise. We show that the sum of squared MA residuals must be scaled to enable a suitable estimator of IV. The scaled estimator is shown to be consistent, first-order efficient, and asymptotically Gaussian distributed about the integrated variance under restrictive assumptions. Under more plausible assumptions, such as time-varying volatility, the MA model is misspecified. This motivates an extensive simulation study of the merits of the MA-based estimator under misspecification. Specifically, we consider nonconstant volatility combined with rounding errors and various forms of dependence between the noise and efficient returns. We benchmark the scaled MA-based estimator to subsample and realized kernel estimators and find that the MA-based ...

2008-01-01

416

Modeling Credit Risk with Partial Information  

CERN Document Server

This paper provides an alternative approach to Duffie and Lando [Econometrica 69 (2001) 633-664] for obtaining a reduced form credit risk model from a structural model. Duffie and Lando obtain a reduced form model by constructing an economy where the market sees the manager's information set plus noise. The noise makes default a surprise to the market. In contrast, we obtain a reduced form model by constructing an economy where the market sees a reduction of the manager's information set. The reduced information makes default a surprise to the market. We provide an explicit formula for the default intensity based on an Azema martingale, and we use excursion theory of Brownian motions to price risky debt.

2008-01-01

417

IEA Annex 27. Assessment of air quality, comfort and sound of ventilation systems in houses; IEA Annex 27. Beoordeling van woningventilatiesystemen op luchtkwaliteit, comfort en geluid  

Energy Technology Data Exchange (ETDEWEB)

In the international study of IEA Annex 27 `Demonstration and evaluation of domestic ventilation systems` a number of simple tools to gain insight into the characteristics of ventilation systems for dwellings are presented. The assessment is made with respect to e.g. indoor air quality, comfort, noise, energy, costs and reliability. In three articles the results of Annex 27 will be discussed. In the first article background information of IEA Annex 27 was given as well as applications in the Netherlands. In this second article attention is paid to the assessment models (`simplified tools`) for indoor air quality, thermal comfort and noise. 6 refs.

1999-09-01

418

Generation of number-phase minimum uncertainty states  

Energy Technology Data Exchange (ETDEWEB)

The difference between the two nonclassical lights, i.e., the squeezed state and number-phase minimum uncertainty state (NUS) is discussed. The four different generation principles for NUS are described. They are: unitary evolution using self-phase modulation; nonunitary state reduction by the first kind measurement; controlled state reduction by quantum correlation measurement-feedback, and high saturated laser oscillation with suppressed-pump-noise. The constant current-driven semiconductor laser based on the last principle generated the NUS with photon number noise reduced below the standard quantum limit by 40 percent in the entire frequency region from dc to 1.1 GHz. Several applications of NUS including quantum communication, quantum mechanical computers and interferometric gravitational detection are discussed briefly. This presentation is represented by viewgraphs only.

1987-01-01

419

Combustion of jojoba methyl ester in an indirect injection diesel engine  

Energy Technology Data Exchange (ETDEWEB)

An experimental investigation has been carried out to examine for the first time the performance and combustion noise of an indirect injection diesel engine running with new fuel derived from pure jojoba oil, jojoba methyl ester, and its blends with gas oil. A Ricardo E6 compression swirl diesel engine was fully instrumented for the measurement of combustion pressure and its rise rate and other operating parameters. Test parameters included the percentage of jojoba methyl ester in the blend, engine speed, load, injection timing and engine compression ratio. Results showed that the new fuel derived from jojoba is generally comparable and a good replacement to gas oil in diesel engine at most engine operating conditions, in terms of performance parameters and combustion noise produced. (author)

2003-07-01

420

Analysis of heterogeneous cell populations: A density-based modeling and identification framework  

British Library Electronic Table of Contents (United Kingdom)

Abstract: In many biological processes heterogeneity within clonal cell populations is an important issue. One of the most striking examples is a population of cancer cells in which after a common, identical death signal some cells die whereas others survive. The reason for this heterogeneity is intrinsic and extrinsic noise. In this paper we present a mechanistic multi-scale modeling framework for cell populations, in which the dynamics of every individual cell is captured by a parameter dependent stochastic differential equation (SDE). Heterogeneity among individual cells is accounted for by differences in parameter values, modeling extrinsic influences. Based on the statistical properties of the extrinsic noise and the SDE model for the individual cell, a partial differential equation (...

2011-01-01

421

Advanced readout integrated circuit signal processing  

Science.gov (United States)

Readout integrated circuits (ROICs) for focal plane arrays (FPAs) have become increasingly complex to meet the needs of modern infrared systems. BAE Systems has pioneered a number of advanced signal processing architectures for FPA ROICs. Demonstrated signal processing capabilities of BAE Systems FPAs include analog-to-digital conversion, offset subtraction, individual pixel automatic gain compensation, transient noise suppression, on-FPA defect deselection, reconfigurable pixels, spatial neural network processing and subframe noise averaging. BAE Systems FPA advanced signal processing is not just for demonstrations, but is used in many of their deliverable FPAs, improving real system performance.

2006-06-01

422

Absolute subcriticality measurement without calibration and detection efficiency dependence by the /sup 252/Cf source-driven noise method  

Energy Technology Data Exchange (ETDEWEB)

The /sup 252/Cf-source-driven noise analysis method determines the subcriticality of a system containing fissionable material from the ratio of cross power spectral densities between the detectors that detect particles from the fission process and between these detectors and an ionization chamber containing a spontaneously fissioning neutron source which provides neutrons to induce fission in the system. This method has two advantages: (1) a calibration is not required and thus subcriticality can be determined from measurements only on the subcritical system of interest, and (2) the subcriticality is independent of the type of detector or its efficiency. These properties of this technique are illustrated by measurements.

1984-01-01

423

A hybrid time-frequency method based on improved Morlet wavelet and auto terms window  

British Library Electronic Table of Contents (United Kingdom)

In this paper, a hybrid time-frequency method (HTM) based on the improved Morlet wavelet and auto terms window (ATW) is presented. The Morlet wavelet, for its shape is similar to the mechanical shock signals, is added two parameters which decide the shape of the mother wavelet. The added parameters and the appropriate scale parameter for continuous wavelet transformation (CWT) are calculated using the cross validation method (CVM) and the minimum Shannon entropy method. The useless noise in the original signal can be filtered by the CWT filter de-noising process. An ATW based on the Smoothed Pseudo Wigner-Ville Distribution (SPWVD) spectrum is designed as a window function to suppress the cross terms in Wigner-Ville Distribution (WVD). The gear fault diagnosis experiment results show that ...

2011-01-01

424

A Quantum-Enhanced Prototype Gravitational-Wave Detector  

CERN Document Server

The quantum nature of the electromagnetic field imposes a fundamental limit on the sensitivity of optical precision measurements such as spectroscopy, microscopy, and interferometry. The so-called quantum limit is set by the zero-point fluctuations of the electromagnetic field, which constrain the precision with which optical signals can be measured. In the world of precision measurement, laser-interferometric gravitational wave (GW) detectors are the most sensitive position meters ever operated, capable of measuring distance changes on the order of 10^-18 m RMS over kilometer separations caused by GWs from astronomical sources. The sensitivity of currently operational and future GW detectors is limited by quantum optical noise. Here we demonstrate a 44% improvement in displacement sensitivity of a prototype GW detector with suspended quasi-free mirrors at frequencies where the sensitivity is shot-noise-limited, by injection of a squeezed state ...

2008-01-01

425

/sup 252/Cf-source-driven neutron noise measurements of subcriticality for a slab tank containing aqueous Pu-U nitrate  

Energy Technology Data Exchange (ETDEWEB)

In order to study nuclear criticality safety related to the development of fast breeder technology, /sup 252/Cf-source-driven neutron noise analysis measurements were performed with a Pu-U nitrate solution in a slab tank of various heights and thickness varying 11.43 cm to 19.05 cm. The results and conclusions of these experiments are (1) a capability to measure the subcriticality of a multiplying system of slab geometry to a k/sub eff/ as low as 0.7 was demonstrated, (2) calculated neutron multiplication factors agreed with those from the experiments within approx.0.02, and (3) the applicability of the method for plutonium solution systems was demonstrated. This paper describes measurements in which the height of the slab was varied for a fixed thickness and the thickness varied for a fixed height, which are the first applications of this measurement method to slab geometry.

1987-08-01

426

Turbulent mixing in the foot piece of a HPLWR fuel assembly  

International Nuclear Information System (INIS)

A homogeneous turbulent mixing of coolant flows with different temperatures at the fuel assembly inlets is an important requirement to minimize hot spots in a fuel assembly of a High Performance Light Water Reactor (HPLWR). Therefore, the mixing chamber between lower core plate, flow adjuster and the mixing chamber within the cluster foot piece diffuser have been investigated using the Computational Fluid Dynamics (CFD)-code Fluent 6.1 and its implemented k-#epsilon# model. The previously presented 3D-CAD-geometry has been simplified using Gambit 2.1.2 and consists of various inlet and outlet tubes or channels in the foot piece bottom plate, the lower core plate and the flow adjuster establishing the boundaries of two consecutive mixing chambers. The temperature distribution at the inlet of the sub-channels of the cluster fuel assemblies is presented. It reveals temperature variations at the coolant ...

2005-10-09

427

Solidification of radioactive waste effluents  

Energy Technology Data Exchange (ETDEWEB)

A process and apparatus for solidifying radioactive waste liquid containing dissolved and/or suspended solids is disclosed. The process includes chemically treating for pH adjustement and precipitation of solids, concentrating solids with a thin-film evaporator to provide liquid concentrate containing about 50% solids, and drying the concentrate with heated mixing apparatus. The heated mixing apparatus includes a heated wall and working means for shearing dried concentrate from internal surfaces and subdividing dry concentrate into dry, powdery particles. The working means includes a rotor and helical means for positively advancing the concentrate and resulting dry particles from inlet to outlet of the mixing apparatus. The dry particles may also be encapsulated in a matrix material. Entrained particles in the vapor stream from the evaporator and mixer are removed in an integral particle separator and the vapor is ...

1983-10-11

428

Numerical analysis of reaction-diffusion effects on species mixing rates in turbulent premixed methane-air combustion  

Energy Technology Data Exchange (ETDEWEB)

The scalar mixing time scale, a key quantity in many turbulent combustion models, is investigated for reactive scalars in premixed combustion. Direct numerical simulations (DNS) of three-dimensional, turbulent Bunsen flames with reduced methane-air chemistry have been analyzed in the thin reaction zones regime. Previous conclusions from single step chemistry DNS studies are confirmed regarding the role of dilatation and turbulence-chemistry interactions on the progress variable dissipation rate. Compared to the progress variable, the mixing rates of intermediate species is found to be several times greater. The variation of species mixing rates are explained with reference to the structure of one-dimensional premixed laminar flames. According to this analysis, mixing rates are governed by the strong gradients which are imposed by flamelet structures at high Damkoehler numbers. This suggests a modeling ...

2010-03-15

429

A study of turbulent heat transfer in the subchannel by the large scale secondary vortex flow  

International Nuclear Information System (INIS)

Experimental and computational studies were performed to confirm the enhancement of turbulent heat transfer performance in the 6x6 simulated rod bundle subchannel by generating the large scale secondary vortex flow. Experimental studies were carried out at Reynolds Number 10,000 with atmospheric condition. Axial variations of mean velocity and turbulent intensity in the rod bundle subchannel were measured by the 2-color LDV measurement system. Computational works were accomplished using the commercial CFD code, FLUENT. Normal operating condition of Uljin 3, 4 nuclear power plant is used in computation works as an initial condition. The LSSVF mixing vanes generate the most strong secondary flow vortices that maintain about 35 D_H after the spacer grid. The LSSVF mixing vane influences strongly to flow mixing in adjacent subchannels because large scale stream wise vortices in subchannel sustain two times more than that in ...

2002-11-17

430

[The study of the mixing layer by the point image method].  

Science.gov (United States)

The properties of the mixing layer in dynamic systems were studied by the example of a mathematical model of the cubic image type. Its role in the generation of information and the evolution of its significance was shown. At the moment of generation, information is of zero significance, and this significance then increases. A criterion of efficiency was proposed, and the optimum moment of making a decision in creative work was determined. It was shown that the increase in the variability of the parameters of a living system upon entry into the mixing layer and its decrease upon exit can serve as objective indicators of the transition of the system from one dynamic regime (attractor) to another. PMID:12723364

431

Study on reactor building structure using ultrahigh strength materials - Part 7: Outline of mixed structure tests  

International Nuclear Information System (INIS)

The objective of this study is to comprehend the basic structural characteristics of box shaped mixed structures proposed for a future nuclear reactor building structure. Specimens of reinforced concrete precast panel walls of the mixed structures were prepared using ultrahigh strength materials. Two bending shear tests were conducted with a parameter of the quantity of reinforcement bars. The results include: (1) Relationship of shear stress and the angle of the structure, and (2) Failure mode. (author)

1993-08-15

432

Non-Standard Interaction Effects at Reactor Neutrino Experiments  

CERN Document Server

We study non-standard interactions (NSIs) at reactor neutrino experiments, and in particular, the mimicking effects on \\theta_13. We present generic formulas for oscillation probabilities including NSIs from sources and detectors. Instructive mappings between the fundamental leptonic mixing parameters and the effective leptonic mixing parameters are established. In addition, NSI corrections to the mixing angles \\theta_13 and \\theta_12 are discussed in detailed. Finally, we show that, even for a vanishing \\theta_13, an oscillation phenomenon may still be observed in future short baseline reactor neutrino experiments, such as Double Chooz and Daya Bay, due to the existences of NSIs.

2008-01-01

433

Mixed-ligand tungsten-antipyrine-trihydroxyfluorone complexes and their use in analysis  

International Nuclear Information System (INIS)

In order to increase the sensitivity of photometric determination of tungsten and to find forms with high molar extinction coefficients, mixed-ligand complexes of tungsten with antipyrine and trihydroxyfluorone have been studied. The molar extinction coefficients have been determined for chloride associates of mixed-ligand complexes containing different trioxyfluorones: phenylfluorone, salicylflourone, p-bromphenylfluorone, anthrafluorone, dioxyfluorescein, and dioxyfluoroscein ethylate (DOFE). An associate formed by DOFE has the maximum molar extinction coefficient. It has been used for photometric determination of microgram amounts of tungsten impurity in vanadyl sulphate.

1977-01-01

434

Mixed structures in continuously cooled low-carbon automotive steels  

Energy Technology Data Exchange (ETDEWEB)

Mixed microstructures have been studied in low- carbon microalloyed steels suitable for automotive applications, after continuous cooling from the hot-rolled condition. Microstructural features such as polygonal ferrite, bainitic and acicular ferrite and microphase constituent are identified using transmission electron microscopy. The influence of these mixed structures on the tensile strength, impact toughness and fracture behaviour is examined. It is found that improvements in impact toughness as compared with microalloyed medium- carbon ferrite/pearlite steels can be achieved from these predominantly acicular structures developed by controlling alloy composition and continuous cooling of these lower carbon steels. (orig.).

1993-11-01

435

Mixed structures in continuously cooled low-carbon automotive steels  

International Nuclear Information System (INIS)

Mixed microstructures have been studied in low- carbon microalloyed steels suitable for automotive applications, after continuous cooling from the hot-rolled condition. Microstructural features such as polygonal ferrite, bainitic and acicular ferrite and microphase constituent are identified using transmission electron microscopy. The influence of these mixed structures on the tensile strength, impact toughness and fracture behaviour is examined. It is found that improvements in impact toughness as compared with microalloyed medium- carbon ferrite/pearlite steels can be achieved from these predominantly acicular structures developed by controlling alloy composition and continuous cooling of these lower carbon steels. (orig.).

1993-06-01

436

Characterization of Mixed Wettability at Different Scales and its Impact on Oil Recovery Efficiency  

Energy Technology Data Exchange (ETDEWEB)

The objectives of this project was to: (1) quantify the pore scale mechanisms that determine the wettability state of a reservoir, (2) study the effect of crude oil, brine and mineral compositions in the establishment of mixed wet states, (3) clarify the effect of mixed - wettability on oil displacement efficiency in waterfloods, (4) develop a new tracer technique to measure wettability, fluid distributions, residual saturation's and relative permeabilities, and (5) develop methods for properly incorporating wettability in up-scaling from pore to core to reservoir scales.

2002-01-28

437

A Geometrical Model for Non-Zero $\\theta_{13}$  

CERN Document Server

Based on Friedberg and Lee's geometric picture by which the tribimaximal PMNS leptonic mixing matrix is constructed, namely corresponding mixing angles correspond to the geometric angles among the sides of a cube. We suggest that the three realistic mixing angles which slightly deviate from the values determined for the cube, are due to a viable deformation from the perfectly cubic shape. Taking the best fitted results of $\\theta_{12}$ and $\\theta_{23}$ as inputs, we determine the central value of $\\sin^22\\theta_{13}$ should be 0.0238 with a relatively large error tolerance, this value lies in the range of measurement precision of the Daya Bay experiment.

2011-01-01

438

Testing and modification of a simple flow turbine; Messtechnische Untersuchung und Modifikation einer einfachen Durchstroemturbine  

Energy Technology Data Exchange (ETDEWEB)

A study conducted at the IHS had the aim to obtain basic information on whether it is possible to build flow turbines following the free jet principle that are on a par with, or superior to, the conventional design, especially in terms of performance and the efficiency curve. Several inflow contours with a ventilated free jet and a conventional flow turbine were studied. The direct comparison of these variants revealed a slightly enhanced peak load efficiency and a very distinct superiority of the free jet contour during partial load. But the efficiency of all variants failed to attain the values claimed by commercial manufacturers. As compared to the initial contour, peak load efficiency was enhanced by 5 per cent. During partial load, the variants studied showed a distinct superiority of the free jet concept over the contour of conventional flow turbines. (orig.) [Deutsch] Am IHS wurde eine ...

1997-12-31

439

Suspension and solution plasma spraying of finely structured layers: potential application to SOFCs  

International Nuclear Information System (INIS)

Suspension direct current plasma spraying allows achieving finely structured coatings whose thickness is between few tens and few hundreds of micrometres. Drops (200-300 ?m in diameter) or liquid jets are mechanically injected in the plasma jet. With radial injection they are rapidly (a few ?s) fragmented into droplets (a few ?m in diameter). The latter are vaporized (in a few ?s) and the solid particles contained in suspension droplets are accelerated and melted by the plasma jet. As in conventional plasma spraying (CPS), much smaller splats (with diameters between 0.2 and 3 ?m and thicknesses between 30 and 200 nm) are arranged in layers up to form the coating. The low inertia of particles requires spray distances between 40 and 60 mm which induces plasma heat fluxes up to 22 MW m-2 participating in coating densification. Even more than in CPS, the plasma jet fluctuations, particularly for plasmas ...

2007-04-21

440

RTD Info 21 - Key Action  

Wastenet

... Targeted fields of research Continuation of ongoing research - Finalising detailed design work on the ITER project; getting JET operational at full power; Improvement of the basic concepts of fusion devices - Fusion plasmas; theoretical studies; technology watch on research into inertial confinement; new experimental concepts and systems; etc.; Long-term technology - Preparations for building a demonstration reactor (development of tritium breeding blankets; prospective ...

441

Numerical study of the impingement of a supersonic, axisymmetric jet on a flat plate  

International Nuclear Information System (INIS)

A numerical method for studying the flow field of an under-expanded axis-symmetric jet created by a converging-diverging nozzle and impinging on a flat plate is presented. The calculation domain of interest is a region that contains all the features of the jet that leaves the nozzle and impinges onto the plate. Axial symmetry of the domain allows a reduced 2-dimensional model to be used. FLUENT software is utilized to solve the continuity, momentum and energy equations using a coupled implicit scheme. The ideal-gas law is used to determine the gas density along with a k-#epsilon# turbulence model with a special modification to account for compressibility effects. In addition, the temperature dependency of viscosity has been taken into consideration. A number of different modeling techniques are investigated including different approximations to account for the flow inside the nozzle. Performance of non-equilibrium wall functions for near-wall ...

442

NO{sub x} formation in lean premixed combustion of methane at high pressures  

Energy Technology Data Exchange (ETDEWEB)

High pressure experiments in a jet-stirred reactor have been performed to study the NO{sub x} formation in lean premixed combustion of methane/air mixtures. The experimental results are compared with numerical predictions using four well known reaction mechanisms and a model which consists of a series of two perfectly stirred reactors and a plug flow reactor. (author) 2 figs., 7 refs.

1999-08-01

443

Hydrocarbon fuels having one or more fullerenes therein as identification media  

Energy Technology Data Exchange (ETDEWEB)

An improved hydrocarbon fuel is described selected from the group consisting of gasoline, diesel fuel, kerosene, jet fuel, No. 1 heating oil, and No. 2 heating oil containing a detectable amount of one or more fullerene additives therein serving as identification means for said fuel wherein said fullerenes are present in an amount insufficient to alter any of the combustion properties of the fuel.

1993-08-10

444

Extratropical Forcing of Convectively Coupled Kelvin Waves during Austral Winter.  

Science.gov (United States)

Observations are presented that link extratropical Rossby wave disturbances excited in the Southern Hemisphere subtropical jet to the initiation of convectively coupled Kelvin waves in the Pacific intertropical convergence zone (ITCZ) during austral winter. A baroclinic, zonal wavenumber 6, eastward-propagating Rossby wave train in the subtropical jet turns northeastward in the vicinity of Australia, inducing upper tropospheric divergence and vertical motion fields that spread equatorward and induce cloudiness anomalies in the Tropics. Lower tropospheric pressure surges excited from the extratropics also induce Kelvin wave-like geopotential height and temperature anomalies at the surface, providing additional lower tropospheric convergence and vertical motion forcing. The tropical outgoing longwave radiation (OLR) and circulation fields propagate eastward in tandem with the extratropical Rossby wave train at approximately 17 m s-1. Kelvin wave ...

2003-02-01

445

Experimental studies of the turbulence structures of impinging reacting jets using time-resolved particle image velocimetry visualisation, hot wire anemometry and acoustic signal processing  

Energy Technology Data Exchange (ETDEWEB)

In this paper, the turbulence structures of premixed impinging jets are investigated by three different experimental techniques: time-resolved particle image velocimetry (TPIV) visualisation, hot wire anemometry (HWA) and acoustic signal processing. The focus is on the TPIV, with the other two techniques providing supplementary information. The 2-D velocities of the impinging jets were obtained by TPIV. The contour maps of velocity derivatives were computed to facilitate the visualisation of the turbulence structure of the reactant part of turbulent impinging flames. Particular attention was concentrated on the turbulence structures out of the burner nozzle and their interactions with the combustion process. It was found that the contour plots are effective in visualising time-dependent structures. It is demonstrated that the derivatives of the velocity field are able to reveal many otherwise hidden turbulence patterns. Test cases were designed ...

2000-12-01

446

Effect of esters on lubricity of hydrotreated jet fuel  

Energy Technology Data Exchange (ETDEWEB)

The authors synthesized a number of esters of stearic acid with polyhydric alcohols and ran comparative tests on aliphatic alcohols to determine their effects on the antiwear properties of the fuel. They conclude that the differences in effectiveness in improving the lubricity by the use of aliphatic alcohols and the full and partial esters of polyhydric alcohols and stearic acid can be explained by the presence of hydroxyl and ester groups close to each other in partial esters. This is reflected in the higher polarity of the partial esters, a higher rate of adsorption, and a stronger bonding of the adsorbed layer to the metal surface.

1985-07-01

447

Development of an efficient, low-NOx domestic gas-range cooktop. Phase 2. Annual report, January 1984-December 1984  

Science.gov (United States)

The objective of the program is to develop a domestic cooktop with low NOx emissions and higher efficiency. During the first phase of the program, a developmental prototype incorporating four IR-Jet burners was assembled. The report describes the work performed during the second phase of the program and covers optimization, and testing of the developmental prototype and design, fabrication and testing of the field-test prototype.

1985-02-01

448

Design basis for protection of light water nuclear power plants against effects of postulated pipe rupture  

Energy Technology Data Exchange (ETDEWEB)

This standard addresses the design bases for light water reactor, nuclear power plant structures and components essential for the protection of public health and safety from the potential adverse effects of pipe whip, jet impingement, pressurization of compartments outside containment, environmental conditions and flooding associated with a postulated pipe rupture. The design bases for missile protection and the design bases for containment pressurization are not within this standard.

1981-01-01

449

Corrosion studies of carbon steel under impinging jets of simulated slurries of neutralized current acid waste (NCAW) and neutralized cladding removal waste (NCRW)  

Energy Technology Data Exchange (ETDEWEB)

Plans for the disposal of radioactive liquid and solid wastes presently stored in double-shell tanks at the Hanford Site call for retrieval and processing of the waste to create forms suitable for permanent disposal. Waste will be retrieved from a tank using a submerged slurry pump in conjunction with one or more rotating slurry jet mixer pumps. Pacific Northwest Laboratory (PNL) has conducted tests using simulated waste slurries to assess the effects of a impinging slurry jet on the corrosion rate of the tank wall and floor, an action that could potentially compromise the tank's structural integrity. Corrosion processes were investigated on a laboratory scale with a simulated neutralized cladding removal waste (NCRW) slurry and in a subsequent test with simulated neutralized current acid waste (NCAW) slurry. The test slurries simulated the actual NCRW and NCAW both chemically and physically. The tests simulated those conditions ...

1992-01-01

450

Corrosion studies of carbon steel under impinging jets of simulated slurries of neutralized current acid waste (NCAW) and neutralized cladding removal waste (NCRW)  

Energy Technology Data Exchange (ETDEWEB)

Plans for the disposal of radioactive liquid and solid wastes presently stored in double-shell tanks at the Hanford Site call for retrieval and processing of the waste to create forms suitable for permanent disposal. Waste will be retrieved from a tank using a submerged slurry pump in conjunction with one or more rotating slurry jet mixer pumps. Pacific Northwest Laboratory (PNL) has conducted tests using simulated waste slurries to assess the effects of a impinging slurry jet on the corrosion rate of the tank wall and floor, an action that could potentially compromise the tank`s structural integrity. Corrosion processes were investigated on a laboratory scale with a simulated neutralized cladding removal waste (NCRW) slurry and in a subsequent test with simulated neutralized current acid waste (NCAW) slurry. The test slurries simulated the actual NCRW and NCAW both chemically and physically. The tests simulated those conditions expected to ...

1992-01-01

451

Composite vector leptoquarks in e"+e-, #gamma#e, and #gamma##gamma# colliders  

International Nuclear Information System (INIS)

We study the signals for composite vector leptoquarks in e"+e- colliders (CERN e"+e- collider LEP II, Next Linear Collider, and CERN Linear Collider) through their effects on the production of jet pairs, as well as their single and pair productions. We also analyze their production in #gamma#e and #gamma##gamma# collisions.

452

American National Standard: design basis for protection of light water nuclear power plants against effects of postulated pipe rupture  

Energy Technology Data Exchange (ETDEWEB)

This standard addresses the design bases for light water reactor, nuclear power plant structures and components essential for the protection of public health and safety from the potential adverse effects of pipe whip, jet impingement, pressurization of compartments outside containment, environmental conditions and flooding associated with a postulated pipe rupture. The design bases for missile protection and the design bases for containment pressurization are not within this standard.

1980-12-31

453

Three-Dimensional Mixed Convection Heat and Mass Transfer in a Rectangular Duct: Case of Longitudinal Rolls  

British Library Electronic Table of Contents (United Kingdom)

This article presents numerical study of 3-D thermosolutale mixed convection (TSMC) in horizontal rectangular channels. The contribution of this work is to characterize the travelling wave's appearance and to generalize the behavior of Poiseuille-Rayleigh-Benard (PRB) systems for a broad range of dimensionless parameters, which control the double diffusive mixed convection. The numerical results consist of analyzing the flow regimes of the steady longitudinal thermoconvectives rolls for the case of purely thermal mixed convection (TMC) and for both thermal and mass transfer (TSMC). The transition from opposed volume forces to cooperating ones at fixed Rayleigh (Ra), Reynolds (Re), and Lewis (Le) numbers, considerably affects the birth and the development of the longitudinal rolls (noted R/...

2011-01-01

454

Three generation vacuum oscillations and the solar neutrino problem  

CERN Document Server

We investigate the solar neutrino problem in the scenario of three generation neutrino oscillation hypothesis, taking into account other phenomenological constraints to the neutrino mixing and mass parameters.

1994-01-01

455

TECHNICAL REPORT - NASA Technical Reports Server  

Science.gov (United States)

VORTEX VALVE FLOW CHARACTERISTICS. 49. VENTED VORTEX VALVE. 50. VORTEX DIVERTER VALVE- ... 46 AND VORTEX MIXING VALVE FLOW CHARACTERISTICS ...

456

Soret and Dufour effect on double diffusion mixed convection from a vertical surface in a porous medium saturated with a non-Newtonian fluid  

British Library Electronic Table of Contents (United Kingdom)

A non-similar boundary layer analysis is presented to study the flow, heat and mass transfer characteristics of non-Darcian mixed convection of a non-Newtonian fluid from a vertical isothermal plate embedded in a homogeneous porous medium with the effect of Soret and Dufour and in the presence of either surface injection or suction. The value of the mixed-convection parameter lies between 0 and 1. In addition, the power-law model is used for non-Newtonian fluids with exponent n1 for dilatant fluids. Furthermore, the coordinates and dependent variables are transformed to yield computationally efficient numerical solutions that are valid over the entire range of mixed convection, from the pure forced-convection limit to the pure free-conve...

2010-01-01

457

Relevance of mixed layer scaling for daytime dispersion based on RAPS and other field programs  

Energy Technology Data Exchange (ETDEWEB)

A brief review and assessment of field measurement programs that provide data for mixed layer diffusion research is presented. The majority of programs emphasize either the meteorological aspects of the mixed layer or plume characterization. Few programs are available that provide the complimentary blend of plume and appropriate meteorological measurements needed to adequately validate mixed layer diffusion theory. Three major U.S. EPA (Environmental Protection Agency) field programs that provide data bases for model development and validation of mixed layer diffusion processes are described and discussed in more detail. The Regional Air Pollution Study (RAPS) focused on measurements of surface and mixed layer turbulent transport processes in the urban environment. The Tennessee Plume Study (TPS) obtained a database with coincident measurement of boundary layer turbulent structure ...

1983-01-01

458

Pattern Search Ranking and Selection Algorithms for Mixed ...  

Science.gov (United States)

... 5.12 Terminal Value for Performance Measure P ... As examples, a stochastic communication network containing a buffer queue at each ...

2004-09-01

459

On penetration effect in M1 component of 70.45 keV #gamma#-transition in "1"7"7Ta  

International Nuclear Information System (INIS)

... gamma radiation l conversion m conversion mev range 10-100 mixing ratio

1987-04-14

460

Model for predicting air-fuel mixing and combustion for direct injection diesel engine  

Energy Technology Data Exchange (ETDEWEB)

Based on a multi-zone spray-mixing approach, an air-fuel mixing and combustion model for a Direct Injection Diesel engine is presented. The predictions from the model show very good agreement with the experimental data for various engines under a wide range of operating conditions. Major physical processes are modeled and validated independently. The atomisation process is based on Binary Drop Division concept. Fuel droplets are considered randomly distributed in the spray. A spherico-symmetrical transient drop evaporation model is used for evaporation calculation. A 3-dimensional spray-swirl interaction is modeled on centreline velocity vector/continuum approach. Turbulent mixing is characterised considering all possible available energy sources in DI diesel engines.

1986-01-01

461

Mixed-ligand complexes of scandium with 4-(2-pyridylazo)resorcinol and monocarboxylic acids  

International Nuclear Information System (INIS)

Scandium reacts with 4-(2-pyridylazo)resorcinol in the presence of monocarboxylic acids (X) to form mixed-ligand complexes with a Sc:PAR:x ratio of 1:2:2. The chemical nature of this interaction has been established, and the extraction of these mixed-ligand complexes has also been investigated; stability constants and molar extinction coefficients have been calculated. The values of the latter decrease in the order CH_3COOH > CH_2ClCOOH > CCl_3COOH. The formation and extraction of mixed-ligand complexes in Sc-PAR-HX systems make it possible to increase the sensitivity and selectivity of scandium determination in comparison with the use of the Sc-PAR mono-ligand complex.

1987-09-01

462

Gutteral Pouch Mycosis and Mycotic Encephalitis in a Horse  

UK PubMed Central (United Kingdom)

A case of mycotic encephalitis in a horse with guttural pouch mycosis is described. A liquid pellet feed binder contaminated with Aspergillus sp. and erroneously mixed in a feed concentrate...Full Text Available

1986-03-01

464

Exploratory Temperature and Precipitation Reconstructions from the Qinling Mountains, North-Central China  

Science.gov (United States)

... to the north of the Qinling, through mixed deciduous broad-leaved forest at lower mountain elevations, and conifer forest at ... ...

468

Density: Sea Water Mixing and Sinking - Aquarius - NASA  

Science.gov (United States)

density is slightly higher, its electrical conductivity is much higher, and it is slightly ... Sea water has characteristic properties (e.g. density) that are independent of ...

469

BBC - Ethical Man blog: Think before you carve  

Wastenet

... And I am sure lots of us carnivores would be a lot less keen on our mixed grills if we had to look ...

470

Analysis of mixing in a Twin Cam mixer using smoothed particle hydrodynamics  

British Library Electronic Table of Contents (United Kingdom)

Smoothed Particle Hydrodynamics (SPH) is a Lagrangian, particle-based method that is well suited to industrial mixing simulations. Mass transport is simply the motion of the particles, and its grid-free nature means that it can easily accommodate complicated geometries involving moving parts and sharp corners. This article describes 2D SPH simulations of a Twin Cam mixer and compares the results against experimental data and results from two published finite element method (FEM) simulations. To analyze the mixing processes in the Twin Cam mixer, we present a method for calculating the Finite-Time Lyapunov Exponent (FTLE) using SPH particle data. The FTLEs can be used to locate the unstable and stable manifolds in the flow and indicate where mixing is either promoted or inhibited in the flo...

2008-01-01

471

Adaptive Pareto Set Estimation for Stochastic Mixed Variable ...  

Science.gov (United States)

... Direct Search (SMOMADS) and Paciencia's NMADS [45] based on Kim and de Weck's ... Todd Paciencia for his foundational contributions. ...

2009-03-01

472

A fuel treatment reduces fire severity and increases suppression efficiency in a mixed conifer forest  

Science.gov (United States)

Fuel treatments are being implemented on public and private lands across the western United States. Although scientists and managers have an understanding ... ...

474

"Paratrigeminal" paralysis of the oculopupillary sympathetic system  

UK PubMed Central (United Kingdom)

Raeder described five patients with mixed features of trigeminal nerve pathology and oculosympathetic impairment, with or without other cranial nerve lesions. This constellation of clinical features...Full Text Available

2002-03-01

475

Launching proton-dominated jets from accreting Kerr black holes: the case of M87  

Science.gov (United States)

A general relativistic model for the formation and acceleration of lowmass-loaded jets from systems containing accreting black holes is presented. The model is based on previous numerical results and theoretical studies in the Newtonian regime, but modified to include the effects of space-time curvature in the vicinity of the event horizon of a spinning black hole. It is argued that the boundary layer between the Keplerian accretion disk and the event horizon is best suited for the formation and acceleration of the accretion-powered jets in active galactic nuclei and micro-quasars. The model presented here is based on matching the solutions of three different regions: i- a weakly magnetized Keplerian accretion disk in the outer part, where the transport of angular momentum is mediated through the magentorotational instability, ii- a strongly magnetized, advection-dominated and turbulent-free boundary layer (BL) between the outer cold accretion ...

2011-07-01

476

{sup 252}Cf-source-driven noise analysis measurements for characterization of concrete highly enriched uranium (HEU) storage vaults  

Energy Technology Data Exchange (ETDEWEB)

The {sup 252}Cf-source-driven noise analysis method has been used in measurements for subcritical configurations of fissile systems for a variety of applications. Measurements of 25 fissile systems have been performed with a wide variety of materials and configurations. This method has been applied to measurements for (1) initial fuel loading of reactors, (2) quality assurance of reactor fuel elements, (3) fuel preparation facilities, (4) fuel processing facilities, (5) fuel storage facilities, (6) zero-power testing of reactors, and (7) verification of calculational methods for assemblies with the neutron k < l. These previous measurements, performed with a wide variety of multiplying systems, demonstrated the usefulness of the method. The high sensitivity of noise-measured parameters to small changes in fissile systems has been observed in several measurements. This high sensitivity has been evaluated using Monte Carlo neutron transport ...

1993-10-01

477

Visualization of liquid metal two-phase flow by a real time neutron radiography system  

Energy Technology Data Exchange (ETDEWEB)

In order to understand the detail transient two-phase flow structure, more advanced two-phase flow instrumentation is required. One advanced technique for flow visualization is real-time neutron radiography. Reconstruction method of visualized radiographic image of liquid metal two-phase flow generated by the real-time neutron radiography system is proposed in this paper. Image processing techniques for noise reduction and image enhancement are discussed in detail. (author).

1995-11-01

478

Visualization of liquid metal two-phase flow by a real time neutron radiography system  

International Nuclear Information System (INIS)

In order to understand the detail transient two-phase flow structure, more advanced two-phase flow instrumentation is required. One advanced technique for flow visualization is real-time neutron radiography. Reconstruction method of visualized radiographic image of liquid metal two-phase flow generated by the real-time neutron radiography system is proposed in this paper. Image processing techniques for noise reduction and image enhancement are discussed in detail. (author).

1995-01-01

479

The building tomorrow and after..; Le batiment demain et apres-demain..  

Energy Technology Data Exchange (ETDEWEB)

During its jubilee, the French building technical and scientific centre (CSTB) has organized a colloquium about the future tendencies of buildings evolution in the 20 forthcoming years: autonomy in energy production and wastes or effluents management, reduction of water consumption and management of water, hot water production and space heating, bio-sensors for the management of indoor air-quality, control of noise environment using active acoustic systems etc.. (J.S.)

1998-01-01

480

The analysis of coupled heat and particle transport in Tokamaks by means of Fourier transform  

Energy Technology Data Exchange (ETDEWEB)

A method to deduce the 2 x 2 transport matrix for coupled heat and particle transport in Tokamaks is proposed. The method applies to perturbative experiments, and is based on a Fourier transform of the measured signals of temperature and density. By analyzing different linear combinations of temperature and density, the eigenvectors and eigenvalues of the transport matrix are determined. The method is tested for a number of illustrative cases using simulated data, and the sensitivity to noise on the signals is evaluated. (author).

1992-04-01

481

Technique of high pressure injection with unit injector systems  

Energy Technology Data Exchange (ETDEWEB)

The multi-spray direct injection diesel engine has the best efficiency of all combustion systems. The optimization of the air-fuel mixture parameters, especially of the fuel injection, enables the forming of the combustion process in a way, that all requirements and legislative regulations concerning power output, noise and exhaust emissions can be fulfilled. Electronic controlled unit injector systems, as developed by Voest-Alpine Automotive GmbH, Linz, offer the necessary potential to meet the complex requirements.

1988-02-01

482

Single Atom Detection With Optical Cavities  

CERN Document Server

We present a thorough analysis of single atom detection using optical cavities. The large set of parameters that influence the signal-to-noise ratio for cavity detection is considered, with an emphasis on detunings, probe power, cavity finesse and photon detection schemes. Real device operating restrictions for single photon counting modules and standard photodiodes are included in our discussion, with heterodyne detection emerging as the clearly favourable technique, particularly for detuned detection at high power.

2008-01-01

483

Resonant-mass detectors of gravitational radiation  

International Nuclear Information System (INIS)

A network of second-generation low-temperature gravitational radiation detectors is nearing completion. These detectors, sensitive to mechanical strains of order 10"-"1"8, are possible because of a variety of technical innovations that have been made in cryogenics, low-noise superconducting instrumentation, and vibration isolation techniques. Another five orders of magnitude improvement in energy sensitivity of resonant-mass detectors is possible before the linear amplifier quantum limit is encountered. 33 references, 3 figures, 1 table.

1987-07-01

484

Quantum locking of mirrors in interferometric measurements  

International Nuclear Information System (INIS)

We discuss the use of active control to reduce mirror position fluctuations at the quantum level. We have shown in a recent experiment that it is possible to reduce the thermal noise of a mirror by measuring and controlling its motion with an optomechanical sensor based on a high-finesse optical cavity. This approach can be extended to lock the mirror motion at the quantum level, and to suppress the quantum effects of radiation pressure in interferometric measurements such as gravitational-wave detectors. The sensitivity improvement is furthermore independent of losses in the interferometer.

2004-03-07

485

On some problems caused by wavelet filtering in calculated spectra  

Energy Technology Data Exchange (ETDEWEB)

It is shown that de-noising a measured time signal by wavelet technique produces a rather good result in time domain, while it has unwanted consequences in spectrum estimation. Therefore it can be used for reconstruction of the picture of the physical process, but it should be avoided, when the aim is to reveal eigenfrequencies or transient behaviour of the spectra.

1999-08-01

486

Neutron radiography with the cyclotron, 6  

International Nuclear Information System (INIS)

The image processing system for the dynamic neutron radiography has been developed. It is based on the hardware subset, composed by the method of the pipe-line and use of algorithm of local statistics. The processing speed per one pixel is shorter than 100 n sec and video-rate processing can be executed on it. Some image processes for improving the quality of the real-time neutron image, noise reduction and contrast stretching would be attempted by the use of this system. (author).

1988-01-01

487

Josephson junctions as heterodyne detectors  

International Nuclear Information System (INIS)

Heterodyne detection with a point-contact Josephson junction has been investigated both experimentally and theoretically. The measured performance of the device at 36 GHz is in good agreement with the theory. By operating vanadium point contacts at 1.4 K, the authors have achieved a single-sideband (SSB) mixer noise temperature of 54 K with a conversion gain of 1.35 and a signal bandwidth on the order of 1 GHz. A potentially impressive performance for these devices at submillimeter wavelengths can be extrapolated from the results.

488

Installation of heat pumps  

Energy Technology Data Exchange (ETDEWEB)

Heat pumps can be installed indoors or outdoors. H. Klein investigates which site would be preferable for a one-family house. Advantages and disadvantages with regard to necessary space, noise, maintenance and repair are discussed; heat losses in both cases of installations are dealt with. Mathematic calculation shows that indoor installation is safer and more adequate in terms of energy savings.

1982-06-01

489

Engineering health and safety in coal mining  

Energy Technology Data Exchange (ETDEWEB)

This book presents the papers given at a symposium on occupational safety in coal mines. Topics considered at the symposium included human factors, causes and prevention of personal injuries, remote sensing for ground control, respirable dust generation by continuous miners, accident analysis, hazard analysis of mining equipment, coal mine blasting accidents, coal mine respirable dust sampling, and noise in the mining industry.

1986-01-01

490

Device for marking and searching for information on a magnetic carrier  

Science.gov (United States)

A device for marking and searching for information on a magnetic carrier is described. In order to increase the noise immunity and reliability of the data recording and reading paths, the recording head is included between the amplifier of the clock pulses for the master oscillator and through the amplifier of the code pulses for the logical element unit. The reproduction head is connected through the code pulse shaper-amplifier with a switch which is connected with the display unit, and through another analogous clock pulse amplifier with a multivibrator.

1984-03-01

491

Cross Entropy Approximation of Structured Covariance Matrices  

CERN Document Server

We apply two variations of the principle of Minimum Cross Entropy (the Kullback information measure) to fit parameterized probability density models to observed data densities. For an array beamforming problem with P incident narrowband point sources, N > P sensors, and colored noise, both approaches yield eigenvector fitting methods similar to that of the MUSIC algorithm[1]. Furthermore, the corresponding cross-entropies are related to the MDL model order selection criterion[2].

2006-01-01

492

Combined-cycle cogen plant a successful good neighbor  

Energy Technology Data Exchange (ETDEWEB)

This article describes a new natural-gas-fired combined cycle cogeneration plant in Bellingham, Washington. The topics of the article include community impact, siting constraints, natural gas fuel, the flexibility provided by the steam turbine, the cooling tower and pumps, air-quality, noise, and cooling water system constraints, and community relations program.

1993-04-01

493

Active RF filter for high voltage transmission lines  

Energy Technology Data Exchange (ETDEWEB)

A new technique is described in this paper for a general active radio frequency (RF) filter trap that can be used for suppressing noise or interference on high voltage (HV) transmission lines. The technique exploits the Miller effect of an RF amplifier in conjunction with a special sensing circuit, and is potentially far more economical to implement than conventional techniques that use passive HV filter components.

1993-07-01

494

Abundances of s-process elements in planetary nebulae: Br, Kr & Xe  

CERN Document Server

We identify emission lines of post-iron peak elements in very high signal-to-noise spectra of a sample of planetary nebulae. Analysis of lines from ions of Kr and Xe reveals enhancements in most of the PNe, in agreement with the theories of s-process in AGB star. Surprisingly, we did not detect lines from Br even though s-process calculations indicate that it should be produced with Kr at detectable levels.

2006-01-01

495

A solution for solid state detector and preamplifier protection, during HV application and removal transition periods  

International Nuclear Information System (INIS)

Surface barrier detectors may be damaged, because of microplasma breakdown, in rapid application of bias voltage. The high performance FETs of very low noise preamplifiers may also be damaged by rapid changes of the bias voltage. The electronic device described permits the gradual application and removal of the bias voltage, without any influence on the power supply specification. (Auth.).

496

Fragrance mix II in the baseline series contributes significantly to detection of fragrance allergy  

DEFF Research Database (Denmark)

Fragrance mix II (FM II) is a relatively new screening marker for fragrance contact allergy. It was introduced in the patch test baseline series in Denmark in 2005 and contains six different fragrance chemicals commonly present in cosmetic products and which are known allergens.

2010-01-01