Powered by Deep Web Technologies
Note: This page contains sample records for the topic "rf respirable fraction" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


1

Determination of respirable mass concentration using a high volume air sampler and a sedimentation method for fractionation  

SciTech Connect (OSTI)

A preliminary study of a new method for determining respirable mass concentration is described. This method uses a high volume air sampler and subsequent fractionation of the collected mass using a particle sedimentation technique. Side-by-side comparisons of this method with cyclones were made in the field and in the laboratory. There was good agreement among the samplers in the laboratory, but poor agreement in the field. The effect of wind on the samplers` capture efficiencies is the primary hypothesized source of error among the field results. The field test took place at the construction site of a hazardous waste landfill located on the Hanford Reservation.

Johnson, J.

1995-12-31T23:59:59.000Z

2

Fabrication of microfluidic devices for artificial respiration  

E-Print Network [OSTI]

We are developing elastomeric polydimethylsiloxane (PDMS) microfluidic devices incorporated with photoactive thin films to create an implantable artificial respiration platform. Whereas state-of-the-art respiration support ...

Park, Hyesung, Ph. D. Massachusetts Institute of Technology

2007-01-01T23:59:59.000Z

3

COMMERCIAL SNF ACCIDENT RELEASE FRACTIONS  

SciTech Connect (OSTI)

The purpose of this design analysis is to specify and document the total and respirable fractions for radioactive materials that are released from an accident event at the Monitored Geologic Repository (MGR) involving commercial spent nuclear fuel (CSNF) in a dry environment. The total and respirable release fractions will be used to support the preclosure licensing basis for the MGR. The total release fraction is defined as the fraction of total CSNF assembly inventory, typically expressed as an activity inventory (e.g., curies), of a given radionuclide that is released to the environment from a waste form. The radionuclides are released from the inside of breached fuel rods (or pins) and from the detachment of radioactive material (crud) from the outside surfaces of fuel rods and other components of fuel assemblies. The total release fraction accounts for several mechanisms that tend to retain, retard, or diminish the amount of radionuclides that are available for transport to dose receptors or otherwise can be shown to reduce exposure of receptors to radiological releases. The total release fraction includes a fraction of airborne material that is respirable and could result in inhalation doses. This subset of the total release fraction is referred to as the respirable release fraction. Potential accidents may involve waste forms that are characterized as either bare (unconfined) fuel assemblies or confined fuel assemblies. The confined CSNF assemblies at the MGR are contained in shipping casks, canisters, or disposal containers (waste packages). In contrast to the bare fuel assemblies, the container that confines the fuel assemblies has the potential of providing an additional barrier for diminishing the total release fraction should the fuel rod cladding breach during an accident. However, this analysis will not take credit for this additional bamer and will establish only the total release fractions for bare unconfined CSNF assemblies, which may however be conservatively applied to confined CSNF assemblies.

S.O. Bader

1999-10-18T23:59:59.000Z

4

Recycler barrier RF buckets  

SciTech Connect (OSTI)

The Recycler Ring at Fermilab uses a barrier rf systems for all of its rf manipulations. In this paper, I will give an overview of historical perspective on barrier rf system, the longitudinal beam dynamics issues, aspects of rf linearization to produce long flat bunches and methods used for emittance measurements of the beam in the RR barrier rf buckets. Current rf manipulation schemes used for antiproton beam stacking and longitudinal momentum mining of the RR beam for the Tevatron collider operation are explained along with their importance in spectacular success of the Tevatron luminosity performance.

Bhat, C.M.; /Fermilab

2011-03-01T23:59:59.000Z

5

Superconducting RF Cryomodule Demagnetization  

E-Print Network [OSTI]

This note presents measurements that support the proposition that it is feasible to demagnetize a fully assembled superconducting RF cryomodule.

Crawford, Anthony C

2015-01-01T23:59:59.000Z

6

Rf Feedback free electron laser  

DOE Patents [OSTI]

A free electron laser system and electron beam system for a free electron laser which use rf feedback to enhance efficiency. Rf energy is extracted from an electron beam by decelerating cavities and returned to accelerating cavities using rf returns such as rf waveguides, rf feedthroughs, etc. This rf energy is added to rf klystron energy to lower the required input energy and thereby enhance energy efficiency of the system.

Brau, Charles A. (Los Alamos, NM); Swenson, Donald A. (Los Alamos, NM); Boyd, Jr., Thomas J. (Los Alamos, NM)

1981-01-01T23:59:59.000Z

7

Commercial SNF Accident Release Fractions  

SciTech Connect (OSTI)

The purpose of this analysis is to specify and document the total and respirable fractions for radioactive materials that could be potentially released from an accident at the repository involving commercial spent nuclear fuel (SNF) in a dry environment. The total and respirable release fractions are used to support the preclosure licensing basis for the repository. The total release fraction is defined as the fraction of total commercial SNF assembly inventory, typically expressed as an activity inventory (e.g., curies), of a given radionuclide that is released to the environment from a waste form. Radionuclides are released from the inside of breached fuel rods (or pins) and from the detachment of radioactive material (crud) from the outside surfaces of fuel rods and other components of fuel assemblies. The total release fraction accounts for several mechanisms that tend to retain, retard, or diminish the amount of radionuclides that are available for transport to dose receptors or otherwise can be shown to reduce exposure of receptors to radiological releases. The total release fraction includes a fraction of airborne material that is respirable and could result in inhalation doses; this subset of the total release fraction is referred to as the respirable release fraction. Accidents may involve waste forms characterized as: (1) bare unconfined intact fuel assemblies, (2) confined intact fuel assemblies, or (3) canistered failed commercial SNF. Confined intact commercial SNF assemblies at the repository are contained in shipping casks, canisters, or waste packages. Four categories of failed commercial SNF are identified: (1) mechanically and cladding-penetration damaged commercial SNF, (2) consolidated/reconstituted assemblies, (3) fuel rods, pieces, and debris, and (4) nonfuel components. It is assumed that failed commercial SNF is placed into waste packages with a mesh screen at each end (CRWMS M&O 1999). In contrast to bare unconfined fuel assemblies, the container that confines the fuel assemblies could provide an additional barrier for diminishing the total release fraction should the fuel rod cladding breach during an accident. This analysis, however, does not take credit for the additional barrier and establishes only the total release fractions for bare unconfined intact commercial SNF assemblies, which may be conservatively applied to confined intact commercial I SNF assemblies.

J. Schulz

2004-11-05T23:59:59.000Z

8

anaerobic respiring bacteria: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

of locomotion, feeding and respiration (Weiss, 1950; von Holst, 1973; Hildebrand, 1980 Wainwright, Peter C. 55 Automated soil respiration measurements: new information,...

9

Can RF help CMOS processors?  

E-Print Network [OSTI]

FOR C OMMUNICATIONS Can RF Help CMOS Processors? Eran SocherRF communication can help increase the wired communicationaluminum and low-K dielectrics help reduce wire delay but do

Socher, Eran; Chang, Mau-Chung Frank

2007-01-01T23:59:59.000Z

10

RF test bench automation Description  

E-Print Network [OSTI]

RF test bench automation Description: Callisto would like to implement automated RF test bench. Three RF test benches have to be studied and automated: LNA noise temperature test bench LNA gain phase of the test benches and an implementation of the automation phase. Tasks: Noise temperature

Dobigeon, Nicolas

11

Airborne Release Fractions/Rates and Respirable Fractions for Nonreactor Nuclear Facilities, Volume 1  

Office of Environmental Management (EM)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) "of EnergyEnergy Cooperation |South42.2 (April 2012) 1 Documentation and Approval of TS NOT MEASUREMENT

12

Airborne Release Fractions/Rates and Respirable Fractions for Nonreactor Nuclear Facilities, Volume II  

Office of Environmental Management (EM)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) "of EnergyEnergy Cooperation |South42.2 (April 2012) 1 Documentation and Approval of TS NOT MEASUREMENT TS

13

Advances in Photosynthesis and Respiration Series Editor  

E-Print Network [OSTI]

Springer Advances in Photosynthesis and Respiration Series Editor: Govindjee, University of Illinois at Urbana-Champaign, USA Volume 29 Photosynthesis in silico Understanding Complexity from Molecules to Ecosystems Edited by; A. Laisk, L. Nedbal, and Govindjee Photosynthesis in silico

Govindjee "Gov"

14

RF power generation  

E-Print Network [OSTI]

This paper reviews the main types of r.f. power amplifiers which are, or may be, used for particle accelerators. It covers solid-state devices, tetrodes, inductive output tubes, klystrons, magnetrons, and gyrotrons with power outputs greater than 10 kW c.w. or 100 kW pulsed at frequencies from 50 MHz to 30 GHz. Factors affecting the satisfactory operation of amplifiers include cooling, matching and protection circuits are discussed. The paper concludes with a summary of the state of the art for the different technologies.

Carter, R G

2011-01-01T23:59:59.000Z

15

Plasma Acceleration from RF Discharge in Dielectric Capillary  

SciTech Connect (OSTI)

Plasma acceleration from rf discharge in dielectric capillary was demonstrated. Observed plasma flow had ion energies of approximately 100 eV and electron energies of approximately 20 eV. The discharge was powered by a MHz-range rf generator and fed by Ar. Experimental results indicate possible validity of assumptions about formation of a potential difference at the open end of the capillary and presence of hot electron fraction in the capillary discharge. Simplicity and small dimensions of the source are attractive for micro-propulsion applications.

A. Dunaevsky; Y. Raitses; N. J. Fisch

2005-08-09T23:59:59.000Z

16

LABORATORY #5 --BIOL 111 Photosynthesis and Respiration  

E-Print Network [OSTI]

!) Photosynthesis can be defined as the transfer and storage of solar energy to a chemical form called glucose (a the world of life go `round: photosynthesis and respiration. One is about converting solar energy the standpoint of chemistry, photosynthesis is written like this: solar energy 6CO2 + 6H2O C6H12O6 + 6O2 Carbon

17

Development of conformal respirator monitoring technology  

SciTech Connect (OSTI)

This report summarizes the results of a Small Business Innovative Research Phase II project to develop a modular, surface conforming respirator monitor to improve upon the manual survey techniques presently used by the nuclear industry. Research was performed with plastic scintillator and gas proportional modules in an effort to find the most conducive geometry for a surface conformal, position sensitive monitor. The respirator monitor prototype developed is a computer controlled, position-sensitive detection system employing 56 modular proportional counters mounted in molds conforming to the inner and outer surfaces of a commonly used respirator (Scott Model 801450-40). The molds are housed in separate enclosures and hinged to create a {open_quotes}waffle-iron{close_quotes} effect so that the closed monitor will simultaneously survey both surfaces of the respirator. The proportional counter prototype was also designed to incorporate Shonka Research Associates previously developed charge-division electronics. This research provided valuable experience into pixellated position sensitive detection systems. The technology developed can be adapted to other monitoring applications where there is a need for deployment of many traditional radiation detectors.

Shonka, J.J.; Weismann, J.J.; Logan, R.J. [and others

1997-04-01T23:59:59.000Z

18

Announcement Advances in Photosynthesis and Respiration: Focus on Plant  

E-Print Network [OSTI]

Announcement Advances in Photosynthesis and Respiration: Focus on Plant Respiration I am delighted to announce the publication, in the Advances in Photosynthesis and Respiration (AIPH) series, of two books, Michael T. Madigan and Carl E. Bauer, editors, 1995); 3. Biophysical Techniques in Photosynthesis (Jan

Govindjee "Gov"

19

Unbalanced field RF electron gun  

DOE Patents [OSTI]

A design for an RF electron gun having a gun cavity utilizing an unbalanced electric field arrangement. Essentially, the electric field in the first (partial) cell has higher field strength than the electric field in the second (full) cell of the electron gun. The accompanying method discloses the use of the unbalanced field arrangement in the operation of an RF electron gun in order to accelerate an electron beam.

Hofler, Alicia

2013-11-12T23:59:59.000Z

20

Diffusion in biofilms respiring on electrodes  

SciTech Connect (OSTI)

The goal of this study was to measure spatially and temporally resolved effective diffusion coefficients (De) in biofilms respiring on electrodes. Two model electrochemically active biofilms, Geobacter sulfurreducens PCA and Shewanella oneidensis MR-1, were investigated. A novel nuclear magnetic resonance microimaging perfusion probe capable of simultaneous electrochemical and pulsed-field gradient nuclear magnetic resonance (PFG-NMR) techniques was used. PFG-NMR allowed for noninvasive, nondestructive, high spatial resolution in situ De measurements in living biofilms respiring on electrodes. The electrodes were polarized so that they would act as the sole terminal electron acceptor for microbial metabolism. We present our results as both two-dimensional De heat maps and surface-averaged relative effective diffusion coefficient (Drs) depth profiles. We found that (1) Drs decreases with depth in G. sulfurreducens biofilms, following a sigmoid shape; (2) Drs at a given location decreases with G. sulfurreducens biofilm age; (3) average De and Drs profiles in G. sulfurreducens biofilms are lower than those in S. oneidensis biofilms—the G. sulfurreducens biofilms studied here were on average 10 times denser than the S. oneidensis biofilms; and (4) halting the respiration of a G. sulfurreducens biofilm decreases the De values. Density, reflected by De, plays a major role in the extracellular electron transfer strategies of electrochemically active biofilms.

Renslow, Ryan S.; Babauta, Jerome T.; Majors, Paul D.; Beyenal, Haluk

2013-02-15T23:59:59.000Z

Note: This page contains sample records for the topic "rf respirable fraction" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Cryogenic vacuumm RF feedthrough device  

DOE Patents [OSTI]

A cryogenic vacuum rf feedthrough device comprising: 1) a probe for insertion into a particle beam; 2) a coaxial cable comprising an inner conductor and an outer conductor, a dielectric/insulating layer surrounding the inner conductor, the latter being connected to the probe for the transmission of higher mode rf energy from the probe; and 3) a high thermal conductivity stub attached to the coaxial dielectric about and in thermal contact with the inner conductor which high thermal conductivity stub transmits heat generated in the vicinity of the probe efficiently and radially from the area of the probe and inner conductor all while maintaining useful rf transmission line characteristics between the inner and outer coaxial conductors.

Wu, Genfa (Yorktown, VA); Phillips, Harry Lawrence (Hayes, VA)

2008-12-30T23:59:59.000Z

22

The effect of temperature and humidity on respirator fit  

E-Print Network [OSTI]

Industry Standards. 2. ) ANSI 288. 2 (1980). 3. ) (NIOSH/MSHA) Title 3OCFR Part II. III. Respirator selection: 1. ) Proper device for the specific hazard. 2. ) Limitations of the device. IV. Fit test methods: 1. ) Negative Pressure. 2. ) Positive... respirator fit testing with isoamyl acetate (banana oil) is used extensively by industry to comply with current Federal safety and health standards. This test is required to help ensure that the respirator's integrity is not reduced by an improper fit...

Niekerk, Gary

1986-01-01T23:59:59.000Z

23

Note on RF Photo-Cathode Gun  

E-Print Network [OSTI]

Emittances in Laser-Driven RF Guns", Proc. 1988 Linear Acc.Palmer, "Preliminary Study of Gun Emittance Correction", BNLLaser-Driven RF Electron Guns", Nuc1. ln stt. Meth. , A275,

Kim, Kwang-Je

2010-01-01T23:59:59.000Z

24

Strengthening Line Management Oversight and Federal Monitoring...  

Office of Environmental Management (EM)

Safety Analysis iv PHA Preliminary Hazards Analysis PSDR Preliminary Safety Design Report PSVR Preliminary Safety Validation Report QA Quality Assurance RF Respirable Fraction...

25

Intelligent Radio Frequency (RF) Monitoring  

E-Print Network [OSTI]

? Intelligent Radio Frequency (RF) Monitoring ? 2009 Armstrong International, Inc. www.armstronginternational.com 2 ?Expect many enjoyable experiences!? David M. Armstrong Present Process Challenges ? Identifying a failure ? Procedure.... Armstrong Steam Trap Challenges ? Identifying a failure ? Manpower ? Location ? Magnitude of failure ? Energy loss ? Loss of heat transfer ? Justification for repair ? ?Speed of Implementation? ? Environmental concerns Manpower Location 4...

Kimbrough, B.

26

SPL RF Coupler Cooling Efficiency  

E-Print Network [OSTI]

Energy saving is an important challenge in accelerator design. In this framework, reduction of heat loads in a cryomodule is of fundamental importance due to the small thermodynamic efficiency of cooling at low temperatures. In particular, care must be taken during the design of its critical components (e.g. RF couplers, coldwarm transitions). In this framework, the main RF coupler of the Superconducting Proton Linac (SPL) cryomodule at CERN will not only be used for RF powering but also as the main mechanical support of the superconducting cavities. These two functions have to be accomplished while ensuring the lowest heat in-leak to the helium bath at 2 K. In the SPL design, the RF coupler outer conductor is composed of two walls and cooled by forced convection with helium gas at 4.5 K. Analytical, semi-analytical and numerical analyses are presented in order to defend the choice of gas cooling. Temperature profiles and thermal performance have been evaluated for different operating conditions; a sensitivit...

Bonomi, R; Montesinos, E; Parma, V; Vande Craen, A

2014-01-01T23:59:59.000Z

27

High-Power Rf Load  

DOE Patents [OSTI]

A compact high-power RF load comprises a series of very low Q resonators, or chokes [16], in a circular waveguide [10]. The sequence of chokes absorb the RF power gradually in a short distance while keeping the bandwidth relatively wide. A polarizer [12] at the input end of the load is provided to convert incoming TE.sub.10 mode signals to circularly polarized TE.sub.11 mode signals. Because the load operates in the circularly polarized mode, the energy is uniformly and efficiently absorbed and the load is more compact than a rectangular load. Using these techniques, a load having a bandwidth of 500 MHz can be produced with an average power dissipation level of 1.5 kW at X-band, and a peak power dissipation of 100 MW. The load can be made from common lossy materials, such as stainless steel, and is less than 15 cm in length. These techniques can also produce loads for use as an alternative to ordinary waveguide loads in small and medium RF accelerators, in radar systems, and in other microwave applications. The design is easily scalable to other RF frequencies and adaptable to the use of other lossy materials.

Tantawi, Sami G. (San Mateo, CA); Vlieks, Arnold E. (Livermore, CA)

1998-09-01T23:59:59.000Z

28

Josephson device with a matched rf source  

SciTech Connect (OSTI)

Analog simulation of a resistance-shunted ac Josephson junction coupled to an rf source with matching impedance reveals (1) added structure in the device's V-I curve even when the source is quiescent and (2) rf-induced steps with peak amplitudes between those produced by voltage and current rf sources. Both results are consistent with experimental data.

Longacre, A. Jr.

1980-03-01T23:59:59.000Z

29

A nonparametric method for separating photosynthesis and respiration components in CO2 flux measurements  

E-Print Network [OSTI]

A nonparametric method for separating photosynthesis and respiration components in CO2 flux dependence of photosynthesis and respiration. This observation provides empirical validation of efforts consideration of the temperature dependence of respiration and photosynthesis are likely to carry significant

30

Announcement Advances in Photosynthesis and Respiration, Volume 24  

E-Print Network [OSTI]

Announcement Advances in Photosynthesis and Respiration, Volume 24 (Photosystem I) I am delighted to announce, in Advances in Photosynthesis and Respiration (AIPH) Series, the publication of Volume 24; ISBN: 0-7923-3682-8); · Volume 3: Biophysical Techniques in Photosynthesis (24 chapters; 411 pages

Govindjee "Gov"

31

Announcement Advances in Photosynthesis and Respiration, Volume 19: `Chlorophyll a  

E-Print Network [OSTI]

Announcement Advances in Photosynthesis and Respiration, Volume 19: `Chlorophyll a Fluorescence: A Signature of Photosynthesis', edited by George C. Papageorgiou and Govindjee I am delighted to announce the publication, in the Advances in Photosynthesis and Respiration (AIPH) series, of the first book that focuses

Govindjee "Gov"

32

Coupling of Photosynthesis and Respiration Phloem Transport is  

E-Print Network [OSTI]

Coupling of Photosynthesis and Respiration ­ Phloem Transport is still a Mystery Arthur Gessler1 sources and sinks VanBel(2003) sugars water growth temperature nutrients photosynthesis light CO2 water #12;The coupling between photosynthesis and respiration 13C plant biomass and phloem 13C

Simon, Emmanuel

33

Low jitter RF distribution system  

DOE Patents [OSTI]

A timing signal distribution system includes an optical frequency stabilized laser signal amplitude modulated at an rf frequency. A transmitter box transmits a first portion of the laser signal and receive a modified optical signal, and outputs a second portion of the laser signal and a portion of the modified optical signal. A first optical fiber carries the first laser signal portion and the modified optical signal, and a second optical fiber carries the second portion of the laser signal and the returned modified optical signal. A receiver box receives the first laser signal portion, shifts the frequency of the first laser signal portion outputs the modified optical signal, and outputs an electrical signal on the basis of the laser signal. A detector at the end of the second optical fiber outputs a signal based on the modified optical signal. An optical delay sensing circuit outputs a data signal based on the detected modified optical signal. An rf phase detect and correct signal circuit outputs a signal corresponding to a phase stabilized rf signal based on the data signal and the frequency received from the receiver box.

Wilcox, Russell; Doolittle, Lawrence; Huang, Gang

2012-09-18T23:59:59.000Z

34

Single electron beam rf feedback free electron laser  

DOE Patents [OSTI]

A free electron laser system and electron beam system for a free electron laser which uses rf feedback to enhance efficiency are described. Rf energy is extracted from a single electron beam by decelerating cavities and energy is returned to accelerating cavities using rf returns, such as rf waveguides, rf feedthroughs, resonant feedthroughs, etc. This rf energy is added to rf klystron energy to reduce the required input energy and thereby enhance energy efficiency of the system.

Brau, C.A.; Stein, W.E.; Rockwood, S.D.

1981-02-11T23:59:59.000Z

35

DOE-HDBK-3010-94; Airborne Release Fractions/Rates and Respirable Fractions for Nonreactor Nuclear Facilities  

National Nuclear Security Administration (NNSA)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) "ofEarlyEnergyDepartmentNationalRestart of the Review of theOFFICEACME | NationalTbilisi08 to17

36

DOE-HDBK-3010-94; Airborne Release Fractions/Rates and Respirable Fractions for Nonreactor Nuclear Facilities, Volume II  

Broader source: Energy.gov (indexed) [DOE]

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) "ofEarly Career Scientists'Montana. DOCUMENTSofDATE M a y 9, 2005 REPLY TO530-98viii4-97 January 1997206-98

37

Molecular Characterization of Bacterial Respiration on Minerals  

SciTech Connect (OSTI)

The overall aim of this project was to contribute to our fundamental understanding of proteins and biological processes under extreme environmental conditions. We sought to define the biochemical and physiological mechanisms that underlie biodegradative and other cellular processes in normal, extreme, and engineered environments. Toward that end, we sought to understand the substrate oxidation pathways, the electron transport mechanisms, and the modes of energy conservation employed during respiration by bacteria on soluble iron and insoluble sulfide minerals. In accordance with these general aims, the specific aims were two-fold: To identify, separate, and characterize the extracellular biomolecules necessary for aerobic respiration on iron under strongly acidic conditions; and to elucidate the molecular principles whereby these bacteria recognize and adhere to their insoluble mineral substrates under harsh environmental conditions. The results of these studies were described in a total of nineteen manuscripts. Highlights include the following: 1. The complete genome of Acidithiobacillus ferrooxidans ATCC 23270 (type strain) was sequenced in collaboration with the DOE Joint Genome Institute; 2. Genomic and mass spectrometry-based proteomic methods were used to evaluate gene expression and in situ microbial activity in a low-complexity natural acid mine drainage microbial biofilm community. This was the first effort to successfully analyze a natural community using these techniques; 3. Detailed functional and structural studies were conducted on rusticyanin, an acid-stable electron transfer protein purified from cell-free extracts of At. ferrooxidans. The three-dimensional structure of reduced rusticyanin was determined from a combination of homonuclear proton and heteronuclear 15N- and 13C-edited NMR spectra. Concomitantly, the three-dimensional structure of oxidized rusticyanin was determined by X-ray crystallography to a resolution of 1.9 A by multiwavelength anomalous dispersion (MAD) phasing; 4. An acid-stable red cytochrome with a novel absorbance peak at 579 nm was purified from cell-free extracts of L. ferriphilum. Functional studies demonstrated that this cytochrome was an important component of the aerobic iron respiratory chain in this organism; 5. The specific adhesion of At. ferrooxidans to pyrite is mediated by an extracellular protein that was identified as aporusticyanin. The adhesion of At. ferrooxidans to minerals was characterized by high affinity binding that exhibited a high specificity for pyrite over other sulfide minerals. The principal biopolymer involved in this high-affinity adhesion to pyrite was isolated by mineral affinity chromatography and identified as aporusticyanin. The adhesion of purified aporusticyanin to minerals was observed to adhere to different mineral with a pattern of reactivity identical to that observed with the intact bacterium. Further, preincubation of pyrite with excess exogenous aporusticyanin served to inhibit the adherence of intact cells to the surface of the mineral, indicating that the protein and the cells adhered to the pyrite in a mutually exclusive manner. Taken together, these observations support a model where aporusticyanin located on the surface of the bacterial cell acts as a mineral-specific receptor for the initial adherence of At. ferrooxidans to solid pyrite; 6. The specific adhesion of L. ferriphilum to pyrite was mediated by a different acid-stable extracellular protein than aporusticyanin; and 7. A prototype integrating cavity absorption meter (ICAM) was assembled to determine whether this novel spectrophotometer could be used to study cellular respiration in situ.

Blake, Robert C.

2013-04-26T23:59:59.000Z

38

RF/optical shared aperture for high availability wideband communication RF/FSO links  

DOE Patents [OSTI]

An RF/Optical shared aperture is capable of transmitting and receiving optical signals and RF signals simultaneously. This technology enables compact wide bandwidth communications systems with 100% availability in clear air turbulence, rain and fog. The functions of an optical telescope and an RF reflector antenna are combined into a single compact package by installing an RF feed at either of the focal points of a modified Gregorian telescope.

Ruggiero, Anthony J; Pao, Hsueh-yuan; Sargis, Paul

2014-04-29T23:59:59.000Z

39

A 113 L/min ambient aerosol sampler for collection of thoracic and respirable fractions  

E-Print Network [OSTI]

oercent for the TTP filter and less than one percent for the RSP filter. DEDICATION This text is dedicated to Jamye, whose love made it all possible. ACKNOWLEDGMENTS This study was sponsored by the United States Environmental Protection Agency under... INTRODUCTION REVIEW OF PREVIOUS NORK METHODOLOGY Introduction Flow Splitter Tests w1th Oleic Acid Particles Tests with Polystyrene Particles Cyclone Mod1ficat1on RESULTS Data Analysis Discussion of Errors SUMMARY AND CONCLUSIONS Pa&ac 15 19 19...

Rue, Clayton Matthew

1981-01-01T23:59:59.000Z

40

RF power recovery feedback circulator  

DOE Patents [OSTI]

A device and method for improving the efficiency of RF systems having a Reflective Load. In the preferred embodiment, Reflected Energy from a superconducting resonator of a particle accelerator is reintroduced to the resonator after the phase of the Reflected Energy is aligned with the phase of the Supply Energy from a RF Energy Source. In one embodiment, a Circulator is used to transfer Reflected Energy from the Reflective Load into a Phase Adjuster which aligns the phase of the Reflected Energy with that of the Supply Energy. The phase-aligned energy is then combined with the Supply Energy, and reintroduced into the Reflective Load. In systems having a constant phase shift, the Phase Adjuster may be designed to shift the phase of the Reflected Energy by a constant amount using a Phase Shifter. In systems having a variety (variable) phase shifts, a Phase Shifter controlled by a phase feedback loop comprising a Phase Detector and a Feedback Controller to account for the various phase shifts is preferable.

Sharamentov, Sergey I. (Bolingbrook, IL)

2011-03-29T23:59:59.000Z

Note: This page contains sample records for the topic "rf respirable fraction" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Robust Diamond-Based RF Switch Yields Enhanced Communication...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Robust Diamond-Based RF Switch Yields Enhanced Communication Capabilities Technology available for licesning: A radio frequency (RF) microelectromechanical system (MEMS) switch...

42

Matching network for RF plasma source  

DOE Patents [OSTI]

A compact matching network couples an RF power supply to an RF antenna in a plasma generator. The simple and compact impedance matching network matches the plasma load to the impedance of a coaxial transmission line and the output impedance of an RF amplifier at radio frequencies. The matching network is formed of a resonantly tuned circuit formed of a variable capacitor and an inductor in a series resonance configuration, and a ferrite core transformer coupled to the resonantly tuned circuit. This matching network is compact enough to fit in existing compact focused ion beam systems.

Pickard, Daniel S. (Palo Alto, CA); Leung, Ka-Ngo (Hercules, CA)

2007-11-20T23:59:59.000Z

43

Simulations of Ion Migration in the LCLS RF Gun and Injector  

SciTech Connect (OSTI)

The motivation for this work was the observed surface contamination of the first LCLS RF gun copper cathode. We will present the results of simulations in regards to ion migration in the LCLS gun. Ions of residual gases will be created by interaction of molecular gas species with the UV drive laser beam and by the electron beam itself. The larger part of those ionized molecules remain in the vicinity of creation, are transported towards beam line walls or away from the cathode. However a small fraction gains enough kinetic energy, focused by RF and magnetic fields and propagates to the cathode, producing an undesirable increase of the cathode's surface work function. Although this fraction is small, during long term operation, this effect may become a significant factor limiting the source performance.

Brachmann, Axel; /SLAC; Dowell, David; /SLAC

2012-06-25T23:59:59.000Z

44

Samsung: ENERGY STAR Referral (RF26VAB)  

Broader source: Energy.gov [DOE]

DOE referred the matter of Samsung refrigerator-freezer model RF26VAB to the EPA for appropriate action after DOE testing showed that the model does not meet the ENERGY STAR specification.

45

Si-based RF MEMS components.  

SciTech Connect (OSTI)

Radio frequency microelectromechanical systems (RF MEMS) are an enabling technology for next-generation communications and radar systems in both military and commercial sectors. RF MEMS-based reconfigurable circuits outperform solid-state circuits in terms of insertion loss, linearity, and static power consumption and are advantageous in applications where high signal power and nanosecond switching speeds are not required. We have demonstrated a number of RF MEMS switches on high-resistivity silicon (high-R Si) that were fabricated by leveraging the volume manufacturing processes available in the Microelectronics Development Laboratory (MDL), a Class-1, radiation-hardened CMOS manufacturing facility. We describe novel tungsten and aluminum-based processes, and present results of switches developed in each of these processes. Series and shunt ohmic switches and shunt capacitive switches were successfully demonstrated. The implications of fabricating on high-R Si and suggested future directions for developing low-loss RF MEMS-based circuits are also discussed.

Stevens, James E.; Nordquist, Christopher Daniel; Baker, Michael Sean; Fleming, James Grant; Stewart, Harold D.; Dyck, Christopher William

2005-01-01T23:59:59.000Z

46

Deeply scaled CMOS for RF power applications  

E-Print Network [OSTI]

The microelectronics industry is striving to reduce the cost, complexity, and form factor of wireless systems through single-chip integration of analog, RF and digital functions. Driven by the requirements of the digital ...

Scholvin, Jörg, 1976-

2006-01-01T23:59:59.000Z

47

EXPERIMENTAL STUDIES OF RF BREAKDOWNS IN THE COUPLER OF THE TTF RF GUN  

E-Print Network [OSTI]

to han- dle 800 µs long RF pulses with 4.5 MW of peak power and at 10 Hz repetition rate. In this regime

48

Comparing nocturnal eddy covariance measurements to estimates of ecosystem respiration made by scaling chamber measurements at six coniferous boreal sites  

E-Print Network [OSTI]

construction respiration estimated as 0.25 times wood NPP [construction respiration estimated as 0.25 E times foliage NPP (construction respiration was 1.6-3.6 times greater than 0.25 times wood NPP

1997-01-01T23:59:59.000Z

49

Fraction Collector User Manual  

E-Print Network [OSTI]

Fraction Collector Frac-950 18-1139-56 User Manual #12;#12;Important user information All users Territories Hong Kong © Copyright Amersham Biosciences AB 2002 - All rights reserved Fraction Collector Frac Fraction Collector Frac-950 User Manual 18-1139-56 Edition AE v Contents 1 Introduction 1.1 General

Pawlowski, Wojtek

50

Conclusions Fractionated Space Systems  

E-Print Network [OSTI]

Conclusions Fractionated Space Systems There is a growing interest in fractionated space system design. Fractionated space systems are inherently flexible and modular. There are many key technologies of flexibility serves as a source of motivation for system designers to embed flexibility into a system design (i

de Weck, Olivier L.

51

ACCLIMATION OF PHOTOSYNTHESIS AND RESPIRATION TO INCREASING TEMPERATURES IN TREES  

E-Print Network [OSTI]

ACCLIMATION OF PHOTOSYNTHESIS AND RESPIRATION TO INCREASING TEMPERATURES IN TREES by JASON ERIC in mean growing season temperature. This allowed us to determine whether net photosynthesis and dark rates of net photosynthesis were similar among seedlings when compared to their respective mean site

Teskey, Robert O.

52

Ecosystem Respiration in a Cool Temperate Bog Depends on Peat  

E-Print Network [OSTI]

Ecosystem Respiration in a Cool Temperate Bog Depends on Peat Temperature But Not Water Table P-summer (July-August). As anticipated, there was a strong relationship between ER and peat temperatures (r2 = 0-table depth (r2 = 0.11). A laboratory incubation of peat cores at different moisture contents showed that CO2

Roulet, Nigel T.

53

Ris-R-1332(EN) Plant Respiration and Climate Change  

E-Print Network [OSTI]

Risø-R-1332(EN) Plant Respiration and Climate Change Effects Dan Bruhn Ph.D. thesis Plant Research, Roskilde April 2002 #12;Abstract The ongoing climate changes can affect many plant physiological processes. In turn, these effects on plants may result in a feedback between the climate change and the vegetation

54

Sediment Respiration and Nitrogen Cycling along a Eutrophic Gradient in a Shallow, Coastal Estuary  

E-Print Network [OSTI]

Sediment Respiration and Nitrogen Cycling along a Eutrophic Gradient in a Shallow, Coastal Estuary Respiration and Nitrogen Cycling along a Eutrophic Gradient in a Shallow, Coastal Estuary Semester and denitrification potentials. We found that the more eutrophic sites had higher respiration and ammonification. Our

Vallino, Joseph J.

55

Application of Kernel Principal Component Analysis for Single Lead ECG-Derived Respiration  

E-Print Network [OSTI]

1 Application of Kernel Principal Component Analysis for Single Lead ECG-Derived Respiration Devy signal from ECGs. In this study, an improved ECG-derived respiration (EDR) algorithm based on kernel PCA ECGs. Index Terms--ECG-derived respiration (EDR), kernel princi- pal component analysis (kPCA). I

56

Variations of the Respiration Signals for Respiratory-Gated Radiotherapy Using the Video Coached Respiration Guiding System  

E-Print Network [OSTI]

Respiratory-gated radiation therapy (RGRT) has been used to minimize the dose to normal tissue in lung-cancer radiotherapy. The present research aims to improve the regularity of respiration in RGRT using a video coached respiration guiding system. In the study, 16 patients with lung cancer were evaluated. The respiration signals of the patients were measured by a real-time position management (RPM) Respiratory Gating System (Varian, USA) and the patients were trained using the video coached respiration guiding system. The patients performed free breathing and guided breathing, and the respiratory cycles were acquired for ~5 min. Then, Microsoft Excel 2010 software was used to calculate the mean and standard deviation for each phase. The standard deviation was computed in order to analyze the improvement in the respiratory regularity with respect to the period and displacement. The standard deviation of the guided breathing decreased to 65.14% in the inhale peak and 71.04% in the exhale peak compared with the...

Lee, Hyun Jeong; Oh, Se An

2015-01-01T23:59:59.000Z

57

RF BREAKDOWN STUDIES USING PRESSURIZED CAVITIES  

SciTech Connect (OSTI)

Many present and future particle accelerators are limited by the maximum electric gradient and peak surface fields that can be realized in RF cavities. Despite considerable effort, a comprehensive theory of RF breakdown has not been achieved and mitigation techniques to improve practical maximum accelerating gradients have had only limited success. Part of the problem is that RF breakdown in an evacuated cavity involves a complex mixture of effects, which include the geometry, metallurgy, and surface preparation of the accelerating structures and the make-up and pressure of the residual gas in which plasmas form. Studies showed that high gradients can be achieved quickly in 805 MHz RF cavities pressurized with dense hydrogen gas, as needed for muon cooling channels, without the need for long conditioning times, even in the presence of strong external magnetic fields. This positive result was expected because the dense gas can practically eliminate dark currents and multipacting. In this project we used this high pressure technique to suppress effects of residual vacuum and geometry that are found in evacuated cavities in order to isolate and study the role of the metallic surfaces in RF cavity breakdown as a function of magnetic field, frequency, and surface preparation. One of the interesting and useful outcomes of this project was the unanticipated collaborations with LANL and Fermilab that led to new insights as to the operation of evacuated normal-conducting RF cavities in high external magnetic fields. Other accomplishments included: (1) RF breakdown experiments to test the effects of SF6 dopant in H2 and He gases with Sn, Al, and Cu electrodes were carried out in an 805 MHz cavity and compared to calculations and computer simulations. The heavy corrosion caused by the SF6 components led to the suggestion that a small admixture of oxygen, instead of SF6, to the hydrogen would allow the same advantages without the corrosion in a practical muon beam line. (2) A 1.3 GHz RF test cell capable of operating both at high pressure and in vacuum with replaceable electrodes was designed, built, and power tested in preparation for testing the frequency and geometry effects of RF breakdown at Argonne National Lab. At the time of this report this cavity is still waiting for the 1.3 GHz klystron to be available at the Wakefield Test Facility. (3) Under a contract with Los Alamos National Lab, an 805 MHz RF test cavity, known as the All-Seasons Cavity (ASC), was designed and built by Muons, Inc. to operate either at high pressure or under vacuum. The LANL project to use the (ASC) was cancelled and the testing of the cavity has been continued under the grant reported on here using the Fermilab Mucool Test Area (MTA). The ASC is a true pillbox cavity that has performed under vacuum in high external magnetic field better than any other and has demonstrated that the high required accelerating gradients for many muon cooling beam line designs are possible. (4) Under ongoing support from the Muon Acceleration Program, microscopic surface analysis and computer simulations have been used to develop models of RF breakdown that apply to both pressurized and vacuum cavities. The understanding of RF breakdown will lead to better designs of RF cavities for many applications. An increase in the operating accelerating gradient, improved reliability and shorter conditioning times can generate very significant cost savings in many accelerator projects.

Johnson, Rolland

2014-09-21T23:59:59.000Z

58

Wideband high efficiency CMOS envelope amplifiers for 4G LTE handset envelope tracking RF power amplifiers  

E-Print Network [OSTI]

RF power amplifier applications," IEEE Journal of Solid-RF power amplifier applications," IEEE Journal of Solid-RF power amplifier applications," IEEE Journal of Solid-

Hassan, Muhammad

2012-01-01T23:59:59.000Z

59

Fractional Electromagnetic Waves  

E-Print Network [OSTI]

In the present work we consider the electromagnetic wave equation in terms of the fractional derivative of the Caputo type. The order of the derivative being considered is 0 <\\gamma<1. A new parameter \\sigma, is introduced which characterizes the existence of the fractional components in the system. We analyze the fractional derivative with respect to time and space, for \\gamma = 1 and \\gamma = 1/2 cases.

J. F. Gómez; J. J. Rosales; J. J. Bernal; V. I. Tkach; M. Guía

2011-08-31T23:59:59.000Z

60

Fractions continues Michel Waldschmidt  

E-Print Network [OSTI]

´erentes oeuvres d'art, 2 appara^it aussi dans des oeuvres artistiques persanes. 2 #12;Figure 1. Fraction continue

Waldschmidt, Michel

Note: This page contains sample records for the topic "rf respirable fraction" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

X-Band RF Gun Development  

SciTech Connect (OSTI)

In support of the MEGa-ray program at LLNL and the High Gradient research program at SLAC, a new X-band multi-cell RF gun is being developed. This gun, similar to earlier guns developed at SLAC for Compton X-ray source program, will be a standing wave structure made of 5.5 cells operating in the pi mode with copper cathode. This gun was designed following criteria used to build SLAC X-band high gradient accelerating structures. It is anticipated that this gun will operate with surface electric fields on the cathode of 200 MeV/m with low breakdown rate. RF will be coupled into the structure through a final cell with symmetric duel feeds and with a shape optimized to minimize quadrupole field components. In addition, geometry changes to the original gun, operated with Compton X-ray source, will include a wider RF mode separation, reduced surface electric and magnetic fields.

Vlieks, Arnold; Dolgashev, Valery; Tantawi, Sami; /SLAC; Anderson, Scott; Hartemann, Fred; Marsh, Roark; /LLNL, Livermore

2012-06-22T23:59:59.000Z

62

Holographic fractional topological insulators  

SciTech Connect (OSTI)

We give a holographic realization of the recently proposed low-energy effective action describing a fractional topological insulator. In particular we verify that the surface of this hypothetical material supports a fractional quantum Hall current corresponding to half that of a Laughlin state.

Hoyos, Carlos; Jensen, Kristan; Karch, Andreas [Department of Physics, University of Washington, Seattle, Washington 98195-1560 (United States)

2010-10-15T23:59:59.000Z

63

Evaluation of respirator fit training by quantitative fit testing  

E-Print Network [OSTI]

that all respirator wearers be trained and f1t tested. In additiion, as part of a complete respiratory protection program, the effect1veness of resp1rator use training should be appraised at periodic 1ntervals. The purpose of this experiment... of trained individuals was able to significantly improve their measured protection factors when compared to the untrained control group. In addition, when fit tests were re- peated on the same day, the second test resulted in consistently higher scores...

Chute, Daniel Otis

2012-06-07T23:59:59.000Z

64

analog rf gap: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

LHC, particles not captured by the RF system at injection or leaking out of the RF bucket may quench the superconducting magnets during beam abort. The problem, common to other...

65

Novel rf mems tunable filters with adjustable spurious suppression  

E-Print Network [OSTI]

This thesis presents the theory and design of fixed and Radio Frequency (RF) Microelectromechanical Systems (MEMS) -based tunable microwave filters for RF and microwave applications. The methodology for the design of coupled resonator filters...

Sekar, Vikram

2009-05-15T23:59:59.000Z

66

A day in the life of the RF spectrum  

E-Print Network [OSTI]

There is a misguided perception that RF spectrum space is fully allocated and fully used though even a superficial study of actual spectrum usage by measuring local RF energy shows it largely empty of radiation. Traditional ...

Cooley, James E. (James Edward)

2005-01-01T23:59:59.000Z

67

Design and fabrication of an RF power LDMOSFET on SOI  

E-Print Network [OSTI]

This thesis studied thin-film Silicon-on-Insulator (SOI) LDMOSFET technology for RF power amplifier applications. To conduct this study, two generations of SOI RF power devices for portable wireless systems were designed ...

Fiorenza, James G. (James George), 1972-

2002-01-01T23:59:59.000Z

68

Advanced RF power sources for linacs  

SciTech Connect (OSTI)

In order to maintain a reasonable over-all length at high center-of-mass energy, the main linac of an electron-positron linear collider must operate at a high accelerating gradient. For copper (non-superconducting) accelerator structures, this implies a high peak power per unit length and a high peak power per RF source, assuming a limited number of discrete sources are used. To provide this power, a number of devices are currently under active development or conceptual consideration: conventional klystrons with multi-cavity output structures, gyroklystrons, magnicons, sheet-beam klystrons, multiple-beam klystrons and amplifiers based on the FEL principle. To enhance the peak power produced by an rf source, the SLED rf pulse compression scheme is currently in use on existing linacs, and new compression methods that produce a flatter output pulse are being considered for future linear colliders. This paper covers the present status and future outlook for the more important rf power sources and pulse compression systems. It should be noted that high gradient electron linacs have applications in addition to high-energy linear colliders; they can, for example, serve as compact injectors for FEL`s and storage rings.

Wilson, P.B.

1996-10-01T23:59:59.000Z

69

Configurations for short period rf undulators  

DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

Several configurations for rf undulators energized at millimeter wavelengths and designed to produce coherent nanometer radiation from sub-GeV electron beams are analyzed and compared with one another. These configurations include a traveling-wave resonant ring, a standing wave resonator, and a resonator operating close to cutoff.

Kuzikov, S. V.; Jiang, Y.; Marshall, T. C.; Sotnikov, G. V.; Hirshfield, J. L.

2013-07-01T23:59:59.000Z

70

Cw rf operation of the FMIT RFQ  

SciTech Connect (OSTI)

The 80-MHz RFQ for the Fusion Materials Irradiation Test Facility prototype accelerator has been rf conditioned for cw operation to the design field level of 17.5 MV/m (1.68 x Kilpatrick limit). Experimental results and operating experience will be discussed.

Fazio, M.V.; Brandeberry, F.E.

1985-01-01T23:59:59.000Z

71

Emittance control in rf cavities and solenoids  

E-Print Network [OSTI]

We study emittance growth for transport of uniform and Gaussian beams of particles in rf cavities and solenoids and show analytically its dependence on initial beam parameters. Analytical results are confirmed with simulation studies over a broad range of different initial beams.

Eshraqi, Mohammad; Lombardi, Alessandra M

2009-01-01T23:59:59.000Z

72

A discrete fractional random transform  

E-Print Network [OSTI]

We propose a discrete fractional random transform based on a generalization of the discrete fractional Fourier transform with an intrinsic randomness. Such discrete fractional random transform inheres excellent mathematical properties of the fractional Fourier transform along with some fantastic features of its own. As a primary application, the discrete fractional random transform has been used for image encryption and decryption.

Zhengjun Liu; Haifa Zhao; Shutian Liu

2006-05-20T23:59:59.000Z

73

Localized Plasticity in the Streamlined Genomes of Vinyl Chloride Respiring Dehalococcoides  

E-Print Network [OSTI]

2005) Genome sequence of the PCE-dechlorinating bacteriumlevels and pseudo-steady-state PCE respiration rates inreductive dehalogenases in a PCE-dechlorinating flow column.

McMurdie, Paul J.

2010-01-01T23:59:59.000Z

74

E-Print Network 3.0 - air-purifying respirator cartridges Sample...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

immediately wash skin... PRECAUTION(S) Wear respirator, chemical safety goggles, rubber boots, and heavy ... Source: Vakni, David - Ames Laboratory Collection: Materials Science 99...

75

E-Print Network 3.0 - air-purifying respirator performance Sample...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

immediately wash skin... PRECAUTION(S) Wear respirator, chemical safety goggles, rubber boots, and heavy ... Source: Vakni, David - Ames Laboratory Collection: Materials Science 99...

76

E-Print Network 3.0 - alkaline anaerobic respiration Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

2 3 4 5 > >> 1 The Effects of Benthic Organic Matter Quality on Aerobic and Anaerobic Sediment Metabolism in West Falmouth Harbor Summary: , respectively. Anaerobic respiration...

77

E-Print Network 3.0 - annual soil respiration Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Sciences and Ecology 4 Summary Soil respiration is controlled by soil temperature, soil water, fine roots, microbial activity, and soil physical and Summary: into the model; and...

78

Metabolic spatial variability in electrode-respiring Geobacter sulfurreducens biofilms  

SciTech Connect (OSTI)

Certain bacteria are capable of transferring electrons derived from respiratory metabolism to solid extracellular electron-accepting materials1-4. This ability allows the organisms to use conductive substrata as their sole electron sink, generating electricity that is available for practical applications5-7. Geobacter is a biofilm-forming genus capable of this extracellular electron transfer8-11. Evidence in the literature suggests that Geobacter cells produce a conductive matrix to gain access to electron-accepting surfaces12,13. It has been hypothesized that cells that are more than tens of microns from the electron-accepting surface cannot respire because of electrical resistance in the matrix and thus remain metabolically inactive14-16. To test this hypothesis, we sought to determine whether the entire biofilm remains metabolically active and able to respire on an electron-accepting surface as the biofilm thickness increases. We developed and used a novel electrochemical-nuclear magnetic resonance (EC-NMR) microimaging system capable of sustaining an electrochemically active biofilm on a polarized electrode inside a superconducting magnet, allowing for simultaneous NMR and electrochemical investigation of a biofilm for the first time. Here, we show that Geobacter biofilms can grow to several hundred microns thick while respiring on an electrode and that the top of the biofilm remains metabolically active. This is only possible if the cells near the top are able to transfer electrons through the initial biofilm matrix to the electrode. We used X-ray absorption spectroscopy to verify electron transfer to uranium ions by metabolically active cells near the top of the biofilm. Our results reveal that extracellular electron transfer is not prevented by electrical resistance, even when the biofilm is hundreds of microns thick. Furthermore, the electron donor may be the limiting factor for respiration and the base of the biofilm may be less active despite being in close proximity to the electrode. Long-range electron transfer across metabolically inactive regions within Geobacter biofilms adds a novel facet to our comprehension of electrochemically active biology.

Renslow, Ryan S.; Babauta, Jerome T.; Dohnalkova, Alice; Boyanov, Maxim I.; Kemner, Kenneth M.; Majors, Paul D.; Fredrickson, Jim K.; Beyenal, Haluk

2013-06-01T23:59:59.000Z

79

RUGGED CERAMIC WINDOW FOR RF APPLICATIONS  

SciTech Connect (OSTI)

High-current RF cavities that are needed for many accelerator applications are often limited by the power transmission capability of the pressure barriers (windows) that separate the cavity from the power source. Most efforts to improve RF window design have focused on alumina ceramic, the most popular historical choice, and have not taken advantage of new materials. Alternative window materials have been investigated using a novel Merit Factor comparison and likely candidates have been tested for the material properties which will enable construction in the self-matched window configuration. Window assemblies have also been modeled and fabricated using compressed window techniques which have proven to increase the power handling capability of waveguide windows. Candidate materials have been chosen to be used in fabricating a window for high power testing at Thomas Jefferson National Accelerator Facility.

MIKE NEUBAUER

2012-11-01T23:59:59.000Z

80

An Efficient RF Source for Jlab  

SciTech Connect (OSTI)

We propose the development of a highly reliable high efficiency RF source for JLAB with a lower lifetime cost operating at 80% efficiency with system operating costs of about 0.7M$/year for the 6 GeV machine. The design of the RF source will be based upon two injection locked magnetrons in a novel combining architecture for amplitude modulation and a cross field amplifier (CFA) as an output tube for the 12 GeV upgrade. A cost analysis including efficiency and reliability will be performed to determine the optimum system architecture. Several different system architectures will be designed and evaluated for a dual injection locked magnetron source using novel combining techniques and possibly a CFA as the output tube. A paper design for the 1497 MHz magnetron system will be completed. The optimum system architecture with all relevant specifications will be completed so that a prototype can be built.

Neubauer, M. [Muons, Inc.; Dudas, A. [Muons, Inc.; Rimmer, Robert A. [JLAB; Wang, Haipeng [JLAB

2013-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "rf respirable fraction" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

ILC RF System R and D  

SciTech Connect (OSTI)

The Linac Group at SLAC is actively pursuing a broad range of R&D to improve the reliability and reduce the cost of the L-band (1.3 GHz) rf system proposed for the ILC linacs. Current activities include the long-term evaluation of a 120 kV Marx Modulator driving a 10 MW Multi-Beam Klystron, design of a second-generation Marx Modulator, testing of a sheet-beam gun and beam transport system for a klystron, construction of an rf distribution system with remotely-adjustable power tapoffs, and development of a system to combine the power from many klystrons in low-loss circular waveguide where it would be tapped-off periodically to power groups of cavities. This paper surveys progress during the past few years.

Adolphsen, Chris; /SLAC

2012-07-03T23:59:59.000Z

82

The new RF sources for accelerators  

SciTech Connect (OSTI)

Several new RF sources are being developed for accelerator and collider applications. Assembly is nearing completion of a multiple beam inductive output tube at 352 MHz. An annular beam klystron is being developed to produce 10 MW pulses at 1.3 GHz. The annular beam approach provides significant cost reduction over similar multiple beam devices. Fabrication is underway on a 10 kW, periodic permanent magnet klystron at 2.815 GHz. Permanent magnets eliminate the solenoid and associated power supplies and cooling requirements to reduce operational cost. Investigations are beginning on a novel approach for driving accelerator cavities using pulse shaping to increase coupling efficiency and dramatically reduce RF power requirements.

Ives, Lawrence; Read, Michael; Ferguson, Patrick; Marsden, David; Collins, George; Jackson, R. H.; Bui, Thuc; Kimura, Takuji; Eisen, Edward [Calabazas Creek Research, Inc., 690 Port Drive, San Mateo, CA, 94404, (650) 312-9575 (United States); Communications and Power Industries, LLC., 811 Hansen Way, Palo Alto, CA94304 (United States)

2012-12-21T23:59:59.000Z

83

Radio frequency (RF) heated supersonic flow laboratory  

SciTech Connect (OSTI)

A unique supersonic flow apparatus which employs an inductively-coupled, radio frequency (RF) torch to supply high enthalpy source gas to the nozzle inlet is described. The main features of this system are the plasma tube, a cooled nozzle assembly, and a combustion/expansion chamber with a heat exchanger. A description of these components with current test data is presented. In addition, a discussion of anticipated experiments utilizing this system is included.

Wantuck, P.; Watanabe, H.

1990-01-01T23:59:59.000Z

84

RF Micro Devices | Open Energy Information  

Open Energy Info (EERE)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data CenterFranconia, Virginia:FAQ < RAPID Jump to: navigation, search RAPIDColoradosource History View New PagesElectron srlRF Micro Devices

85

RF Gun Photocathode Research at SLAC  

SciTech Connect (OSTI)

LCLS is presently operating with a third copper photocathode in the original rf gun, with a quantum efficiency (QE) of {approx}1 x 10{sup -4} and projected emittance {gamma}{var_epsilon}{sub x,y} = 0.45 {micro}m at 250 pC bunch charge. The spare LCLS gun is installed in the SLAC Accelerator Structure Test Area (ASTA), fully processed to high rf power. As part of a wider photocathode R and D program, a UV laser system and additional gun diagnostics are being installed at ASTA to measure QE, QE lifetime, and electron beam emittance under a variety of operating conditions. The near-term goals are to test and verify the spare photocathode production/installation sequence, including transfer from the final holding chamber to the rf gun. Mid- and longer-term goals include development of a rigorous understanding of plasma and laser-assisted surface conditioning and investigation of new, high-QE photocathode materials. In parallel, an x-ray photoemission spectroscopy station is nearing completion, to analyze Cu photocathode surface chemistry. In this paper we review the status and anticipated operating parameters of ASTA and the spectroscopy test chamber.

Jongewaard, E.; Akre, R.; Brachmann, A.; Corbett, J.; Gilevich, S.; Grouev, K.; Hering, P.; P.Krejcik,; Lewandowski, J.; Loos, H.; Montagne, T.; Sheppard, J.C.; Stefan, P.; Vlieks, A.; Weathersby, S.; Zhou, F.; /SLAC

2012-05-16T23:59:59.000Z

86

Fractional Standard Map  

E-Print Network [OSTI]

Properties of the phase space of the standard map with memory are investigated. This map was obtained from a kicked fractional differential equation. Depending on the value of the parameter of the map and the fractional order of the derivative in the original differential equation this nonlinear dynamical system demonstrates attractors (fixed points, stables periodic trajectories, slow converging and slow diverging trajectories, ballistic trajectories, and fractal-like structures) and/or chaotic trajectories. At least one type of fractal-like sticky attractors in the chaotic sea was observed.

Mark Edelman; Vasily E. Tarasov

2009-11-24T23:59:59.000Z

87

Fractionation, rearrangement, consolidation, reconstruction  

E-Print Network [OSTI]

is an innovation. WGD and fractionation are particularly prevalent in flowering plants [6], where the slow (tens itself does not add any new adjacencies or remove any; the pre-existing adjacencies simply continue or by pseudogenization. Even if xy and yz still exist in the homeologous region of the genome, the adjacency xz

El-Mabrouk, Nadia

88

Design and Manufacture of the RF Power Supply and RF Transmission Line for SANAEM Project Prometheus  

E-Print Network [OSTI]

A 1-5 MeV proton beamline is being built by the Turkish Atomic Energy Authority in collaboration with a number of graduate students from different universities. The most important aspect of the project, is to acquire the design ability and manufacturing capability of all the components locally. SPP will be an accelerator and beam diagnostics test facility and it will also serve the detector development community with its low beam current. This paper discusses the design and construction of the RF power supply and the RF transmission line components such as its waveguide converters and its circulator.

Turemen, G; Unel, G; Alacakir, A

2015-01-01T23:59:59.000Z

89

INTERANNUAL VARIABILITY IN GLOBAL SOIL RESPIRATION (1980-1994) Interannual Variability in Global Soil  

E-Print Network [OSTI]

INTERANNUAL VARIABILITY IN GLOBAL SOIL RESPIRATION (1980-1994) NDP-081 Interannual Variability in Global Soil Respiration on a 0.5 Degree Grid Cell Basis (1980-1994) Contributed by: James W. Raich 1, Tennessee 37831-6335. The ORNL is managed by UT-Battelle, LLC for the U.S. DEPARTMENT OF ENERGY under

90

A satellite-based biosphere parameterization for net ecosystem CO2 exchange: Vegetation Photosynthesis and Respiration  

E-Print Network [OSTI]

Photosynthesis and Respiration Model (VPRM) Pathmathevan Mahadevan,1 Steven C. Wofsy,1 Daniel M. Matross,1 12 April 2008. [1] We present the Vegetation Photosynthesis and Respiration Model (VPRM), a satellite of ecosystem photosynthesis, and annual sum of NEE at all eddy flux sites for which it is optimized

Lin, John Chun-Han

91

CO2 efflux from Amazonian headwater streams represents a significant fate for deep soil respiration  

E-Print Network [OSTI]

CO2 efflux from Amazonian headwater streams represents a significant fate for deep soil respiration amounts of CO2 to the atmosphere, while the magnitude of CO2 degassing from small streams remains a major was as terrestrially-respired CO2 dissolved within soils, over 90% of which evaded to the atmosphere within headwater

Lehmann, Johannes

92

Elevated CO2 stimulates grassland soil respiration by increasing carbon inputs rather than by enhancing soil  

E-Print Network [OSTI]

Elevated CO2 stimulates grassland soil respiration by increasing carbon inputs rather than It is not clear whether the consistent positive effect of elevated CO2 on soil respiration (soil carbon flux, SCF) results from increased plant and microbial activity due to (i) greater C availability through CO2-induced

Minnesota, University of

93

Physical controls on the isotopic composition of soil-respired CO2  

E-Print Network [OSTI]

Physical controls on the isotopic composition of soil-respired CO2 Nick Nickerson1 and Dave Risk1] Measurement of the isotopic composition of soil and soil-respired CO2 (d13 CO2) has become an invaluable tool in understanding the effects of diffusive transport on soil CO2 isotopic composition, it is crucial

94

Analysis of the effects of a proposed rule for the enforcement of respirable dust standards  

E-Print Network [OSTI]

The effects of a rule for the enforcement of respirable dust standards proposed by the Mine Safety and Health Administration (MSHA) has been evaluated. Respirable coal dust sample data collected over a three year period by a mining company were used...

Britton, Robert Grant

1996-01-01T23:59:59.000Z

95

An improved ECG-Derived Respiration Method using Kernel Principal Component Analysis  

E-Print Network [OSTI]

An improved ECG-Derived Respiration Method using Kernel Principal Component Analysis Devy Widjaja1) of heart beats generates well-performing ECG- derived respiratory signals (EDR). This study aims at im in the extraction of a respiratory signal from single lead ECGs. 1. Introduction Respiration is often jointly

96

A STATE VARIABLE DESCRIPTION OF THE RHIC RF CONTROL LOOPS.  

SciTech Connect (OSTI)

The beam transfer function changes during the RHIC ramp. The response of the RF control loops changes as a result. A state-variable description of the beam and the RF control loops was developed. This description was used to generate a set of feedback matrices that keeps the response of the RF control loops constant during the ramp. This paper describes the state-variable description and its use in determining the K matrices.

SCHULTHEISS,C.; BRENNAN,J.M.

2002-06-02T23:59:59.000Z

97

RF Gun cavities cooling regime study. K. Floettmann1  

E-Print Network [OSTI]

RF power of Pa 68kW corre- sponds to a heat load of 300kW m . To remove such a high heat value from of RF fields in the cavity at an operating frequency is calculated in the usual way. The temperature) with the boundary condition at the RF cavity surface: kc(ngradT) = Ps, (2) where kc = 391 W m·K is the heat

98

Multi-Physics Analysis of the Fermilab Booster RF Cavity  

SciTech Connect (OSTI)

After about 40 years of operation the RF accelerating cavities in Fermilab Booster need an upgrade to improve their reliability and to increase the repetition rate in order to support a future experimental program. An increase in the repetition rate from 7 to 15 Hz entails increasing the power dissipation in the RF cavities, their ferrite loaded tuners, and HOM dampers. The increased duty factor requires careful modelling for the RF heating effects in the cavity. A multi-physic analysis investigating both the RF and thermal properties of Booster cavity under various operating conditions is presented in this paper.

Awida, M.; Reid, J.; Yakovlev, V.; Lebedev, V.; Khabiboulline, T.; Champion, M.; /Fermilab

2012-05-14T23:59:59.000Z

99

Investigation of Microscopic Materials Limitations of Superconducting RF Cavities  

SciTech Connect (OSTI)

The high-field performance of SRF cavities is often limited by breakdown events below the intrinsic limiting surface fields of Nb, and there is abundant evidence that these breakdown events are localized in space inside the cavity. Also, there is a lack of detailed understanding of the causal links between surface treatments and ultimate RF performance at low temperatures. An understanding of these links would provide a clear roadmap for improvement of SRF cavity performance, and establish a cause-and-effect ‘RF materials science’ of Nb. We propose two specific microscopic approaches to addressing these issues. First is a spatially-resolved local microwave-microscope probe that operates at SRF frequencies and temperatures to discover the microscopic origins of breakdown, and produce quantitative measurements of RF critical fields of coatings and films. Second, RF Laser Scanning Microscopy (LSM) has allowed visualization of RF current flow and sources of nonlinear RF response in superconducting devices with micro-meter spatial resolution. The LSM will be used in conjunction with surface preparation and characterization techniques to create definitive links between physical and chemical processing steps and ultimate cryogenic microwave performance. We propose to develop RF laser scanning microscopy of small-sample Nb pieces to establish surface-processing / RF performance relations through measurement of RF current distributions on micron-length scales and low temperatures.

Anlage, Steven [University of Maryland

2014-07-23T23:59:59.000Z

100

Active high-power RF switch and pulse compression system  

DOE Patents [OSTI]

A high-power RF switching device employs a semiconductor wafer positioned in the third port of a three-port RF device. A controllable source of directed energy, such as a suitable laser or electron beam, is aimed at the semiconductor material. When the source is turned on, the energy incident on the wafer induces an electron-hole plasma layer on the wafer, changing the wafer's dielectric constant, turning the third port into a termination for incident RF signals, and. causing all incident RF signals to be reflected from the surface of the wafer. The propagation constant of RF signals through port 3, therefore, can be changed by controlling the beam. By making the RF coupling to the third port as small as necessary, one can reduce the peak electric field on the unexcited silicon surface for any level of input power from port 1, thereby reducing risk of damaging the wafer by RF with high peak power. The switch is useful to the construction of an improved pulse compression system to boost the peak power of microwave tubes driving linear accelerators. In this application, the high-power RF switch is placed at the coupling iris between the charging waveguide and the resonant storage line of a pulse compression system. This optically controlled high power RF pulse compression system can handle hundreds of Megawatts of power at X-band.

Tantawi, Sami G. (San Mateo, CA); Ruth, Ronald D. (Woodside, CA); Zolotorev, Max (Mountain View, CA)

1998-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "rf respirable fraction" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

A new microphonics measurement method for superconducting RF...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

new microphonics measurement method for superconducting RF cavities Re-direct Destination: Mechanical vibrations of the superconducting cavity, also known as microphonics, cause...

102

argon rf plasma: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

you for being so encouraging, for listening to and understanding the woes of RF plasma research, and for being so friendly at conferences and in the hallways. Professor...

103

Sandia National Laboratories: RF & Photonics  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 -theErik SpoerkeSolar Regional Test CenterCMCNational LaboratoriesRF &

104

DOE-HDBK-3010-94; DOE Handbook Airborne Release Fractions/Rates and Respirable Fractions for Nonreactor Nuclear Facilities, Volume 1  

Broader source: Energy.gov (indexed) [DOE]

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) "ofEarly Career Scientists'Montana. DOCUMENTSofDATE M a y 9, 2005 REPLY TO530-98viii4-97 January 1997206-9810-94

105

Extremely high frequency RF effects on electronics.  

SciTech Connect (OSTI)

The objective of this work was to understand the fundamental physics of extremely high frequency RF effects on electronics. To accomplish this objective, we produced models, conducted simulations, and performed measurements to identify the mechanisms of effects as frequency increases into the millimeter-wave regime. Our purpose was to answer the questions, 'What are the tradeoffs between coupling, transmission losses, and device responses as frequency increases?', and, 'How high in frequency do effects on electronic systems continue to occur?' Using full wave electromagnetics codes and a transmission-line/circuit code, we investigated how extremely high-frequency RF propagates on wires and printed circuit board traces. We investigated both field-to-wire coupling and direct illumination of printed circuit boards to determine the significant mechanisms for inducing currents at device terminals. We measured coupling to wires and attenuation along wires for comparison to the simulations, looking at plane-wave coupling as it launches modes onto single and multiconductor structures. We simulated the response of discrete and integrated circuit semiconductor devices to those high-frequency currents and voltages, using SGFramework, the open-source General-purpose Semiconductor Simulator (gss), and Sandia's Charon semiconductor device physics codes. This report documents our findings.

Loubriel, Guillermo Manuel; Vigliano, David; Coleman, Phillip Dale; Williams, Jeffery Thomas; Wouters, Gregg A.; Bacon, Larry Donald; Mar, Alan

2012-01-01T23:59:59.000Z

106

Fractional channel multichannel analyzer  

DOE Patents [OSTI]

A multichannel analyzer incorporating the features of the present invention obtains the effect of fractional channels thus greatly reducing the number of actual channels necessary to record complex line spectra. This is accomplished by using an analog-to-digital converter in the asynchronous mode, i.e., the gate pulse from the pulse height-to-pulse width converter is not synchronized with the signal from a clock oscillator. This saves power and reduces the number of components required on the board to achieve the effect of radically expanding the number of channels without changing the circuit board. 9 figs.

Brackenbush, L.W.; Anderson, G.A.

1994-08-23T23:59:59.000Z

107

Solvent Fractionation of Lignin  

SciTech Connect (OSTI)

Lignin is a highly abundant source of renewable carbon that can be considered as a valuable sustainable source of biobased materials. The major issues for the commercial production of value added high performance lignin products are lignin s physical and chemical heterogenities. To overcome these problems, a variety of procedures have been developed to produce pure lignin suitable for high performace applications such as lignin-derived carbon materials. However, most of the isolation procedures affect lignin s properties and structure. In this chapter, a short review of the effect of solvent fractionation on lignin s properties and structure is presented.

Chatterjee, Sabornie [ORNL; Saito, Tomonori [ORNL

2014-01-01T23:59:59.000Z

108

RF Thermal Plasma Synthesis of Ferrite Nanopowders from Metallurgical Wastes  

E-Print Network [OSTI]

RF Thermal Plasma Synthesis of Ferrite Nanopowders from Metallurgical Wastes J.Szépvölgyi1 , I Department of General Physics, Eötvös University H-1518 Budapest, P.O.B. 32 Hungary Keywords: zinc ferrite, thermal plasma, waste, XRD Abstract. RF thermal plasma synthesis of zinc-ferrite nanopowders has been

Gubicza, Jenõ

109

RF-MEMS capacitive switches with high reliability  

DOE Patents [OSTI]

A reliable long life RF-MEMS capacitive switch is provided with a dielectric layer comprising a "fast discharge diamond dielectric layer" and enabling rapid switch recovery, dielectric layer charging and discharging that is efficient and effective to enable RF-MEMS switch operation to greater than or equal to 100 billion cycles.

Goldsmith, Charles L.; Auciello, Orlando H.; Carlisle, John A.; Sampath, Suresh; Sumant, Anirudha V.; Carpick, Robert W.; Hwang, James; Mancini, Derrick C.; Gudeman, Chris

2013-09-03T23:59:59.000Z

110

Booster Synchrotron RF System Upgrade for SPEAR3  

SciTech Connect (OSTI)

Recent progress at the SPEAR3 includes the increase in stored current from 100 mA to 200 mA and top-off injection to allow beamlines to stay open during injection. Presently the booster injects 3.0 GeV beam to SPEAR3 three times a day. The stored beam decays to about 150 mA between the injections. The growing user demands are to increase the stored current to the design value of 500 mA, and to maintain it at a constant value within a percent or so. To achieve this goal the booster must inject once every few minutes. For improved injection efficiency, all RF systems at the linac, booster and SPEAR3 need to be phase-locked. The present booster RF system is basically a copy of the SPEAR2 RF system with 358.5 MHz and 40 kW peak RF power driving a 5-cell RF cavity for 1.0 MV gap voltage. These requirements entail a booster RF system upgrade to a scaled down version of the SPEAR3 RF system of 476.3 MHz with 1.2 MW cw klystron output power capabilities. We will analyze each subsystem option for their merits within budgetary and geometric space constraints. A substantial portion of the system will come from the decommissioned PEP-II RF stations.

Park, Sanghyun; /SLAC; Corbett, Jeff; /SLAC

2012-07-06T23:59:59.000Z

111

RF cavity using liquid dielectric for tuning and cooling  

DOE Patents [OSTI]

A system for accelerating particles includes an RF cavity that contains a ferrite core and a liquid dielectric. Characteristics of the ferrite core and the liquid dielectric, among other factors, determine the resonant frequency of the RF cavity. The liquid dielectric is circulated to cool the ferrite core during the operation of the system.

Popovic, Milorad (Warrenville, IL); Johnson, Rolland P. (Newport News, VA)

2012-04-17T23:59:59.000Z

112

Progress on a cryogenically cooled RF gun polarized electron source  

SciTech Connect (OSTI)

RF guns have proven useful in multiple accelerator applications. An RF gun capable of producing polarized electrons is an attractive electron source for the ILC or an electron-ion collider. Producing such a gun has proven elusive. The NEA GaAs photocathode needed for polarized electron production is damaged by the vacuum environment in an RF gun. Electron and ion back bombardment can also damage the cathode. These problems must be mitigated before producing an RF gun polarized electron source. In this paper we report continuing efforts to improve the vacuum environment in a normal conducting RF gun by cooling it with liquid nitrogen after a high temperature vacuum bake out. We also report on a design of a cathode preparation chamber to produce bulk GaAs photocathodes for testing in such a gun. Future directions are also discussed.

Fliller, R.P., III; Edwards, H.; /Fermilab

2006-08-01T23:59:59.000Z

113

The electrical and lumen output characteristics of an RF lamp  

SciTech Connect (OSTI)

Low pressure rf discharges have been studied for over a century. Their first practical application for lighting was proposed by Tesla in 1891. Since then hundreds of patents have been published attempting to implement rf lighting. However, progress in understanding rf discharge phenomena (mostly driven by plasma processing needs) and dramatic improvement in the performance/cost ratio of rf power sources have recently opened the door for development of rf light sources. Today commercial inductively coupled electrodeless lamps are offered by Matsuhita, Philips and GE. In this work the authors present measurements of the electrical characteristics and lumen output from a 2.65 MHz driven inductively coupled light source. Measurements were made on a spherical lamp of 3.125 inch diameter with a re-entrant cavity that houses a cylindrical ferrite core around which is wrapped the primary coil.

Alexandrovich, B.M.; Godyak, V.A.; Piejak, R.B. [Osram Sylvania Inc., Beverly, MA (United States)

1996-12-31T23:59:59.000Z

114

Upgrade of the cryogenic CERN RF test facility  

SciTech Connect (OSTI)

With the large number of superconducting radiofrequency (RF) cryomodules to be tested for the former LEP and the present LHC accelerator a RF test facility was erected early in the 1990’s in the largest cryogenic test facility at CERN located at Point 18. This facility consisted of four vertical test stands for single cavities and originally one and then two horizontal test benches for RF cryomodules operating at 4.5 K in saturated helium. CERN is presently working on the upgrade of its accelerator infrastructure, which requires new superconducting cavities operating below 2 K in saturated superfluid helium. Consequently, the RF test facility has been renewed in order to allow efficient cavity and cryomodule tests in superfluid helium and to improve its thermal performances. The new RF test facility is described and its performances are presented.

Pirotte, O.; Benda, V.; Brunner, O.; Inglese, V.; Maesen, P.; Vullierme, B. [CERN - European Organization for Nuclear Research, CH-1211 Geneva 23 (Switzerland); Koettig, T. [ESS - European Spallation Source, Box 176, 221 00 Lund (Sweden)

2014-01-29T23:59:59.000Z

115

SUPERCONDUCTING RF-DIPOLE DEFLECTING AND CRABBING CAVITIES  

SciTech Connect (OSTI)

Recent interests in designing compact deflecting and crabbing structures for future accelerators and colliders have initiated the development of novel rf structures. The superconducting rf-dipole cavity is one of the first compact designs with attractive properties such as higher gradients, higher shunt impedance, the absence of lower order modes and widely separated higher order modes. Two rf-dipole designs of 400 MHz and 499 MHz have been designed, fabricated and tested as proof-of-principle designs of compact deflecting and crabbing cavities for the LHC high luminosity upgrade and Jefferson Lab 12 GeV upgrade. The first rf tests have been performed on the rf-dipole geometries at 4.2 K and 2.0 K in a vertical test assembly with excellent results. The cavities have achieved high gradients with high intrinsic quality factors, and multipacting levels were easily processed.

Delayen, Jean [ODU, JLAB; De Silva, Paygalage Subashini [ODU, JLAB

2013-09-01T23:59:59.000Z

116

Hydrogen-filled RF Cavities for Muon Beam Cooling  

SciTech Connect (OSTI)

Ionization cooling requires low-Z energy absorbers immersed in a strong magnetic field and high-gradient, large-aperture RF cavities to be able to cool a muon beam as quickly as the short muon lifetime requires. RF cavities that operate in vacuum are vulnerable to dark-current- generated breakdown, which is exacerbated by strong magnetic fields, and they require extra safety windows that degrade cooling, to separate RF regions from hydrogen energy absorbers. RF cavities pressurized with dense hydrogen gas will be developed that use the same gas volume to provide the energy absorber and the RF acceleration needed for ionization cooling. The breakdown suppression by the dense gas will allow the cavities to operate in strong magnetic fields. Measurements of the operation of such a cavity will be made as functions of external magnetic field and charged particle beam intensity and compared with models to understand the characteristics of this technology and to develop mitigating strategies if necessary.

CHARLES, Ankenbrandt

2009-04-17T23:59:59.000Z

117

Traveling Wave RF Systems for Helical Cooling Channels  

SciTech Connect (OSTI)

The great advantage of the helical ionization cooling channel (HCC) is its compact structure that enables the fast cooling of muon beam 6-dimensional phase space. This compact aspect requires a high average RF gradient, with few places that do not have cavities. Also, the muon beam is diffuse and requires an RF system with large transverse and longitudinal acceptance. A traveling wave system can address these requirements. First, the number of RF power coupling ports can be significantly reduced compared with our previous pillbox concept. Secondly, by adding a nose on the cell iris, the presence of thin metal foils traversed by the muons can possibly be avoided. We show simulations of the cooling performance of a traveling wave RF system in a HCC, including cavity geometries with inter-cell RF power couplers needed for power propagation.

Yonehara, K.; Lunin, A.; Moretti, A.; Popovic, M.; Romanov, G.; /Fermilab; Neubauer, M.; Johnson, R.P.; /Muons Inc., Batavia; Thorndahl, L.; /CERN

2009-05-01T23:59:59.000Z

118

Wideband high efficiency CMOS envelope amplifiers for 4G LTE handset envelope tracking RF power amplifiers  

E-Print Network [OSTI]

addition, the small equivalent resistance of 8? of the RF PAor inefficient. The equivalent resistance of RF PA, R PA ,normalized equivalent load resistance (R PA ) representing

Hassan, Muhammad

2012-01-01T23:59:59.000Z

119

High-power RF testing of a 352-MHZ fast-ferrite RF cavity tuner at the Advanced Photon Source.  

SciTech Connect (OSTI)

A 352-MHz fast-ferrite rf cavity tuner, manufactured by Advanced Ferrite Technology, was high-power tested on a single-cell copper rf cavity at the Advanced Photon Source. These tests measured the fast-ferrite tuner performance in terms of power handling capability, tuning bandwidth, tuning speed, stability, and rf losses. The test system comprises a single-cell copper rf cavity fitted with two identical coupling loops, one for input rf power and the other for coupling the fast-ferrite tuner to the cavity fields. The fast-ferrite tuner rf circuit consists of a cavity coupling loop, a 6-1/8-inch EIA coaxial line system with directional couplers, and an adjustable 360{sup o} mechanical phase shifter in series with the fast-ferrite tuner. A bipolar DC bias supply, controlled by a low-level rf cavity tuning loop consisting of an rf phase detector and a PID amplifier, is used to provide a variable bias current to the tuner ferrite material to maintain the test cavity at resonance. Losses in the fast-ferrite tuner are calculated from cooling water calorimetry. Test data will be presented.

Horan, D.; Cherbak, E.; Accelerator Systems Division (APS)

2006-01-01T23:59:59.000Z

120

Soil respiration at mean annual temperature predicts annual total across vegetation types and biomes  

E-Print Network [OSTI]

3.0 License. Biogeosciences Soil respiration at mean annualI. L. , and Carvalho, J. E. M. : Effects of soil watercontent on soil res- piration in forests and cattle pastures

2010-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "rf respirable fraction" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

Soil organic matter stability and the temperature sensitivity of soil respiration   

E-Print Network [OSTI]

Soil respiration is an important source of atmospheric CO2, with the potential for large positive feedbacks with global warming. The size of these feedbacks will depend on the relative sensitivity to temperature of very ...

Burns, Nancy Rosalind

2012-11-29T23:59:59.000Z

122

RESPIRATION RATES AND LOW-OXYGEN TOLERANCE LIMITS IN SKIPJACK TUNA, KATSUWONUS PELAMIS  

E-Print Network [OSTI]

RESPIRATION RATES AND LOW-OXYGEN TOLERANCE LIMITS IN SKIPJACK TUNA, KATSUWONUS PELAMIS REGINALD M of voluntarily active skipjack tuna, Katsuwonus pelamis, at 23°_24° C were measured in the laboratory from

123

Extraction, Degradation, and Microbial Respiration Effects of Mesotrione in Selected Texas Soils  

E-Print Network [OSTI]

of atrazine on mesotrione degradation in soil; and 3) determine if mesotrione, mesotrione + atrazine treatments, and application rates had an impact on soil microbial activity (respiration). In the first experiment, mesotrione recoveries were...

Romero, Madahy B

2014-08-08T23:59:59.000Z

124

E-Print Network 3.0 - annual ecosystem respiration Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

9 CO2Exchange(umolCO2m2 duringdaytime) Summary: respiration. Ecosystem carbon and water exchange are not affected by the watering event. In April, however... carbon flux ...

125

Design studies for the LCLS 120 Hz RF gun  

SciTech Connect (OSTI)

A preliminary design studies were carried out at Brookhaven National Laboratory for a photocathode RF gun injection system for LCLS 120 Hz operation. The starting point for the design is 50 Hz BNL Gun IV developed by a BNL/KEK/SHI collaboration. The basic parameters of the 120 Hz gun is discussed in this report. The complete photocathode RF gun injection system is described for a 120 Hz operation. The injector system includes photocathode RF gun, emittance compensation solenoid magnet, laser system and laser beam delivery system, and electron beam diagnostics. The basic design parameters, mechanical modification and the performance will be presented in this report.

Wang, X.J.; Babzien, M.; Ben-Zvi, I.; Chang, X.Y.; Pjerov, S.; Woodle, M.

2000-11-01T23:59:59.000Z

126

An RF dosimeter for independent SAR measurement in MRI scanners  

SciTech Connect (OSTI)

Purpose: The monitoring and management of radio frequency (RF) exposure is critical for ensuring magnetic resonance imaging (MRI) safety. Commercial MRI scanners can overestimate specific absorption rates (SAR) and improperly restrict clinical MRI scans or the application of new MRI sequences, while underestimation of SAR can lead to tissue heating and thermal injury. Accurate scanner-independent RF dosimetry is essential for measuring actual exposure when SAR is critical for ensuring regulatory compliance and MRI safety, for establishing RF exposure while evaluating interventional leads and devices, and for routine MRI quality assessment by medical physicists. However, at present there are no scanner-independent SAR dosimeters. Methods: An SAR dosimeter with an RF transducer comprises two orthogonal, rectangular copper loops and a spherical MRI phantom. The transducer is placed in the magnet bore and calibrated to approximate the resistive loading of the scanner's whole-body birdcage RF coil for human subjects in Philips, GE and Siemens 3 tesla (3T) MRI scanners. The transducer loop reactances are adjusted to minimize interference with the transmit RF field (B{sub 1}) at the MRI frequency. Power from the RF transducer is sampled with a high dynamic range power monitor and recorded on a computer. The deposited power is calibrated and tested on eight different MRI scanners. Whole-body absorbed power vs weight and body mass index (BMI) is measured directly on 26 subjects. Results: A single linear calibration curve sufficed for RF dosimetry at 127.8 MHz on three different Philips and three GE 3T MRI scanners. An RF dosimeter operating at 123.2 MHz on two Siemens 3T scanners required a separate transducer and a slightly different calibration curve. Measurement accuracy was ?3%. With the torso landmarked at the xiphoid, human adult whole?body absorbed power varied approximately linearly with patient weight and BMI. This indicates that whole-body torso SAR is on average independent of the imaging subject, albeit with fluctuations. Conclusions: Our 3T RF dosimeter and transducers accurately measure RF exposure in body-equivalent loads and provide scanner-independent assessments of whole-body RF power deposition for establishing safety compliance useful for MRI sequence and device testing.

Qian, Di; Bottomley, Paul A. [Division of MR Research, Department of Radiology, Johns Hopkins School of Medicine, Baltimore, Maryland 21287 and Department of Electrical and Computer Engineering, Johns Hopkins University, Baltimore, Maryland 21218 (United States)] [Division of MR Research, Department of Radiology, Johns Hopkins School of Medicine, Baltimore, Maryland 21287 and Department of Electrical and Computer Engineering, Johns Hopkins University, Baltimore, Maryland 21218 (United States); El-Sharkawy, AbdEl-Monem M.; Edelstein, William A., E-mail: w.edelstein@gmail.com [Division of MR Research, Department of Radiology, Johns Hopkins School of Medicine, Baltimore, Maryland 21287 (United States)

2013-12-15T23:59:59.000Z

127

Incompressible Stars and Fractional Derivatives  

E-Print Network [OSTI]

Fractional calculus is an effective tool in incorporating the effects of non-locality and memory into physical models. In this regard, successful applications exist rang- ing from signal processing to anomalous diffusion and quantum mechanics. In this paper we investigate the fractional versions of the stellar structure equations for non radiating spherical objects. Using incompressible fluids as a comparison, we develop models for constant density Newtonian objects with fractional mass distributions or stress conditions. To better understand the fractional effects, we discuss effective values for the density, gravitational field and equation of state. The fractional ob- jects are smaller and less massive than integer models. The fractional parameters are related to a polytropic index for the models considered.

S. S. Bayin; J. P. Krisch

2014-08-21T23:59:59.000Z

128

Temperature-associated increases in the global soil respiration record  

SciTech Connect (OSTI)

Soil respiration (RS), the flux of CO2 from the soil surface to the atmosphere, comprises the second-largest terrestrial carbon flux, but its dynamics are incompletely understood, and the global flux remains poorly constrained. Ecosystem warming experiments, modelling analyses, and biokinetics all suggest that RS should change with climate. This has been difficult to confirm observationally because of the high spatial variability of RS, inaccessibility of the soil medium, and inability of remote sensing instruments to measure large-scale RS fluxes. Given these constraints, is it possible to discern climate-driven changes in regional or global RS fluxes in the extant four-decade record of RS chamber measurements? Here we use a database of worldwide RS observations, matched with high-resolution historical climate data, to show a previously unknown temporal trend in the RS record after accounting for mean annual climate, leaf area, nitrogen deposition, and changes in CO2 measurement technique. Air temperature anomaly (deviation from the 1961-1990 mean) is significantly and positively correlated with changes in RS fluxes; both temperature and precipitation anomalies exert effects in specific biomes. We estimate that the current (2008) annual global RS flux is 98±12 Pg and has increased 0.1 Pg yr-1 over the last 20 years, implying a global RS temperature response (Q10) of 1.5. An increasing global RS flux does not necessarily constitute a positive feedback loop to the atmosphere; nonetheless, the available data are consistent with an acceleration of the terrestrial carbon cycle in response to global climate change.

Bond-Lamberty, Benjamin; Thomson, Allison M.

2010-03-25T23:59:59.000Z

129

High performance RF and baseband building blocks for wireless receivers  

E-Print Network [OSTI]

market has suddenly expanded to unimaginable dimensions. Devices such as pagers, cellular and cordless phones, cable modems, and RF identification (RFID) tags are rapidly penetrating all aspects of our lives, evolving from luxury items to indispensable...

Bahmani, Faramarz

2007-09-17T23:59:59.000Z

130

CMOS RF Power Amplifier Design for Wireless Communications  

E-Print Network [OSTI]

conjugate (S22) match (solid curve) and power match (dashedSupply Linear RF Power Amplifier", IEEE J. Solid-State Circ.Fully-integrated CMOS Power Amplifiers", IEEE J. Solid-State

FANG, Qiang

2012-01-01T23:59:59.000Z

131

Progress on the Mice 201 MNz RF Cavity at LBNL  

E-Print Network [OSTI]

like to thank people at LBNL EH&S and Main Machine Shop forMICE 201 MHz RF CAVITY AT LBNL* Tianhuan Luol, Don Summers,Virostek, Michael Zisman, LBNL, Berkeley, CA 94720, USA

Luo, Tianhuan

2014-01-01T23:59:59.000Z

132

Electrodeless lighting RF power source development. Final report  

SciTech Connect (OSTI)

An efficient, solid state RF power source has been developed on this NICE project for exciting low power electrodeless lamp bulbs. This project takes full advantage of concurrent advances in electrodeless lamp technology. Electrodeless lamp lighting systems utilizing the sulfur based bulb type developed by Fusion Lighting, Inc., is an emerging technology which is based on generating light in a confined plasma created and sustained by RF excitation. The bulb for such a lamp is filled with a particular element and inert gas at low pressure when cold. RF power from the RF source creates a plasma within the bulb which reaches temperatures approaching those of high pressure discharge lamp plasmas. At these temperatures the plasma radiates substantial visible light with a spectrum similar to sunlight.

NONE

1996-08-30T23:59:59.000Z

133

Rf System Requirements for JLab’s MEIC Collider Ring  

SciTech Connect (OSTI)

The Medium-energy Electron Ion Collider (MEIC), proposed by Jefferson Lab, consists of a series of accelerators. At the top energy are the electron and ion collider rings. For the ion ring, it accelerates five long ion bunches to colliding energy and rebunches ions into a train of very short bunches before colliding. A set of low frequency RF system is needed for the long ion bunch energy ramping. Another set of high frequency RF cavities is needed to rebunch ions. For the electron ring, superconducting RF (SRF) cavities are needed to compensate the synchrotron radiation energy loss. The impedance of the SRF cavities must be low enough to keep the high current electron beam stable. The preliminary design requirements of these RF cavities are presented.

Wang, Shaoheng [JLAB; Li, Rui [JLAB; Rimmer, Robert A. [JLAB; Wang, Haipeng [JLAB; Zhang, Yuhong [JLAB

2013-06-01T23:59:59.000Z

134

Recent Progress of RF Cavity Study at Mucool Test Area  

SciTech Connect (OSTI)

Summar of presentation is: (1) MTA is a multi task working space to investigate RF cavities for R&D of muon beam cooling channel - (a) Intense 400 MeV H{sup -} beam, (b) Handle hydrogen (flammable) gas, (c) 5 Tesla SC solenoid magnet, (d) He cryogenic/recycling system; (2) Pillbox cavity has been refurbished to search better RF material - Beryllium button test will be happened soon; (3) E x B effect has been tested in a box cavity - Under study (result seems not to be desirable); (4) 201 MHz RF cavity with SRF cavity treatment has been tested at low magnetic field - (a) Observed some B field effect on maximum field gradient and (b) Further study is needed (large bore SC magnet will be delivered end of 2011); and (5) HPRF cavity beam test has started - (a) No RF breakdown observed and (b) Design a new HPRF cavity to investigate more plasma loading effect.

Yonehara, Katsuya; /Fermilab

2011-12-02T23:59:59.000Z

135

DESIGN OF A DC/RF PHOTOELECTRON GUN.  

SciTech Connect (OSTI)

An integrated dc/rf photoelectron gun produces a low-emittance beam by first rapidly accelerating electrons at a high gradient during a short ({approx}1 ns), high-voltage pulse, and then injecting the electrons into an rf cavity for subsequent acceleration. Simulations show that significant improvement of the emittance appears when a high field ({approx} 0.5-1 GV/m) is applied to the cathode surface. An adjustable dc gap ({le} 1 mm) which can be integrated with an rf cavity is designed for initial testing at the Injector Test Stand at Argonne National Laboratory using an existing 70-kV pulse generator. Plans for additional experiments of an integrated dc/rf gun with a 250-kV pulse generator are being made.

YU,D.NEWSHAM,Y.SMIRONOV,A.YU,J.SMEDLEY,J.SRINIVASAN RAU,T.LEWELLEN,J.ZHOLENTS,A.

2003-05-12T23:59:59.000Z

136

BN/Graphene/BN Transistors for RF Applications  

E-Print Network [OSTI]

In this letter, we demonstrate the first BN/graphene/BN field-effect transistor for RF applications. This device structure can preserve the high mobility and the high carrier velocity of graphene, even when it is sandwiched ...

Taychatanapat, Thiti

137

ANALYZING SURFACE ROUGHNESS DEPENDENCE OF LINEAR RF LOSSES  

SciTech Connect (OSTI)

Topographic structure on Superconductivity Radio Frequency (SRF) surfaces can contribute additional cavity RF losses describable in terms of surface RF reflectivity and absorption indices of wave scattering theory. At isotropic homogeneous extent, Power Spectrum Density (PSD) of roughness is introduced and quantifies the random surface topographic structure. PSD obtained from different surface treatments of niobium, such Buffered Chemical Polishing (BCP), Electropolishing (EP), Nano-Mechanical Polishing (NMP) and Barrel Centrifugal Polishing (CBP) are compared. A perturbation model is utilized to calculate the additional rough surface RF losses based on PSD statistical analysis. This model will not consider that superconductor becomes normal conducting at fields higher than transition field. One can calculate the RF power dissipation ratio between rough surface and ideal smooth surface within this field range from linear loss mechanisms.

Reece, Charles E. [JLAB; Kelley, Michael J. [JLAB, W& M College; Xu, Chen [JLAB, W& M College

2012-09-01T23:59:59.000Z

138

Test estructural i predictiu per a circuits RF CMOS.  

E-Print Network [OSTI]

??En aquesta tesi s'ha desenvolupat una tècnica de test que permet testar un LNA i un mesclador, situats en el capçal RF d'un receptor CMOS,… (more)

Suenaga Portugués, Kay

2008-01-01T23:59:59.000Z

139

Measurement of current distribution on RF coils using MR imaging  

E-Print Network [OSTI]

MEASUREMENT OF CURRENT DISTRIBUTION ON RF COILS USING MR IMAGING A Thesis by YU WU Submitted to the Office of Graduate Studies of Texas ARM University in partial fulfillment of the requirement for the degree of MASTER OF SCIENCE December... 1993 Major Subject' Electrical Engineering MEASUREMENT OF CURRENT DISTRIBUTION ON RF COILS USING MR IMAGING A Thesis by YU WU Submitted to Texas ASM University in partial fulfillment of the requirments for the degree of MASTER OF SCIENCE...

Wu, Yu

1993-01-01T23:59:59.000Z

140

RF-MEMS Switched Varactors for Medium Power Applications  

E-Print Network [OSTI]

In RF (Radio Frequency) domain, one of the limitations of using MEMS (Micro Electromechanical Systems) switching devices for medium power applications is RF power. Failure phenomena appear even for 500 mW. A design of MEMS switched capacitors with an enhanced topology is presented in this paper to prevent it. This kind of device and its promising performances will serve to fabricate a MEMS based phase shifter able to work under several watts.

Maury, F; Crunteanu, A; Conseil, F; Blondy, P

2008-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "rf respirable fraction" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

R&D ERL: High power RF systems  

SciTech Connect (OSTI)

The Energy Recovery Linac (ERL) project, now under construction at Brookhaven National Laboratory, requires two high power RF systems. The first RF system is for the 703.75 MHz superconducting electron gun. The RF power from this system is used to drive nearly half an Ampere of beam current to 2.5 MeV. There is no provision to recover any of this energy so the minimum amplifier power is 1 MW. It consists of 1 MW CW klystron, transmitter and power supplies, 1 MW circulator, 1 MW dummy load and a two-way power splitter. The second RF system is for the 703.75 MHz superconducting cavity. The system accelerates the beam to 54.7 MeV and recovers this energy. It will provide up to 50 kW of CW RF power to the cavity. It consists of 50 kW transmitter, circulator, and dummy load. This paper describes the two high power RF systems and presents the test data for both.

Zaltsman, A.

2010-01-15T23:59:59.000Z

142

High power RF systems for the BNL ERL project  

SciTech Connect (OSTI)

The Energy Recovery Linac (ERL) project, now under construction at Brookhaven National Laboratory, requires two high power RF systems. The first RF system is for the 703.75 MHz superconducting electron gun. The RF power from this system is used to drive nearly half an Ampere of beam current to 2 MeV. There is no provision to recover any of this energy so the minimum amplifier power is 1 MW. It consists of 1 MW CW klystron, transmitter and power supplies, 1 MW circulator, 1 MW dummy load and a two-way power splitter. The second RF system is for the 703.75 MHz superconducting cavity. The system accelerates the beam to 54.7 MeV and recovers this energy. It will provide up to 50 kW of CW RF power to the cavity. It consists of 50 kW transmitter, circulator, and dummy load. This paper describes the two high power RF systems and presents the test data for both.

Zaltsman, A.; Lambiase, R.

2011-03-28T23:59:59.000Z

143

COMPARISON OF RF CAVITY TRANSPORT MODELS FOR BBU SIMULATIONS  

SciTech Connect (OSTI)

The transverse focusing effect in RF cavities plays a considerable role in beam dynamics for low-energy beamline sections and can contribute to beam breakup (BBU) instability. The purpose of this analysis is to examine RF cavity models in simulation codes which will be used for BBU experiments at Jefferson Lab and improve BBU simulation results. We review two RF cavity models in the simulation codes elegant and TDBBU (a BBU simulation code developed at Jefferson Lab). elegant can include the Rosenzweig-Serafini (R-S) model for the RF focusing effect. Whereas TDBBU uses a model from the code TRANSPORT which considers the adiabatic damping effect, but not the RF focusing effect. Quantitative comparisons are discussed for the CEBAF beamline. We also compare the R-S model with the results from numerical simulations for a CEBAF-type 5-cell superconducting cavity to validate the use of the R-S model as an improved low-energy RF cavity transport model in TDBBU. We have implemented the R-S model in TDBBU. It will improve BBU simulation results to be more matched with analytic calculations and experimental results.

Ilkyoung Shin,Byung Yunn,Todd Satogata,Shahid Ahmed

2011-03-01T23:59:59.000Z

144

A Holographic Fractional Topological Insulator  

E-Print Network [OSTI]

We give a holographic realization of the recently proposed low energy effective action describing a fractional topological insulator. In particular we verify that the surface of this hypothetical material supports a fractional quantum Hall current corresponding to half that of a Laughlin state.

Carlos Hoyos-Badajoz; Kristan Jensen; Andreas Karch

2010-07-19T23:59:59.000Z

145

RF-Plasma Source Commissioning in Indian Negative Ion Facility  

SciTech Connect (OSTI)

The Indian program of the RF based negative ion source has started off with the commissioning of ROBIN, the inductively coupled RF based negative ion source facility under establishment at Institute for Plasma research (IPR), India. The facility is being developed under a technology transfer agreement with IPP Garching. It consists of a single RF driver based beam source (BATMAN replica) coupled to a 100 kW, 1 MHz RF generator with a self excited oscillator, through a matching network, for plasma production and ion extraction and acceleration. The delivery of the RF generator and the RF plasma source without the accelerator, has enabled initiation of plasma production experiments. The recent experimental campaign has established the matching circuit parameters that result in plasma production with density in the range of 0.5-1x10{sup 18}/m{sup 3}, at operational gas pressures ranging between 0.4-1 Pa. Various configurations of the matching network have been experimented upon to obtain a stable operation of the set up for RF powers ranging between 25-85 kW and pulse lengths ranging between 4-20 s. It has been observed that the range of the parameters of the matching circuit, over which the frequency of the power supply is stable, is narrow and further experiments with increased number of turns in the coil are in the pipeline to see if the range can be widened. In this paper, the description of the experimental system and the commissioning data related to the optimisation of the various parameters of the matching network, to obtain stable plasma of required density, are presented and discussed.

Singh, M. J.; Bandyopadhyay, M.; Yadava, Ratnakar; Chakraborty, A. K. [ITER- India, Institute for Plasma Research, A-29, Sector 25, GIDC, Gandhinagar, Gujrat (India); Bansal, G.; Gahlaut, A.; Soni, J.; Kumar, Sunil; Pandya, K.; Parmar, K. G.; Sonara, J. [Institute for Plasma Research, Bhat Gandhinagar, Gujrat (India); Kraus, W.; Heinemann, B.; Riedl, R.; Obermayer, S.; Martens, C.; Franzen, P.; Fantz, U. [Max-Planck-Institut fuer Plasmaphysik, Boltzmannstrasse 2, D-85748 Garching (Germany)

2011-09-26T23:59:59.000Z

146

Upgrading petroleum and petroleum fractions  

SciTech Connect (OSTI)

A method is described for neutralizing the organic naphthenic acids acidity present in petroleum and petroleum fractions to produce a neutralization number less than 1.0 whereby they are rendered suitable as lube oil feed stocks which consists essentially of treating the petroleum and petroleum fractions with a neutralizing amount of monoethanolamine to form an amine salt with the organic acids and then heating the thus-neutralized petroleum and petroleum fractions at a temperature at least about 25/sup 0/F greater than the boiling point of water and for a time sufficient to convert the amine salts to amides.

Ferguson, S.; Reese, D.D.

1988-06-21T23:59:59.000Z

147

Phase Stable RF-over-fiber Transmission using Heterodyne Interferometry  

SciTech Connect (OSTI)

New scientific applications require phase-stabilized RF distribution to multiple remote locations. These include phased-array radio telescopes and short pulse free electron lasers. RF modulated onto a CW optical carrier and transmitted via fiber is capable of low noise, but commercially available systems aren't long term stable enough for these applications. Typical requirements are for less than 50fs long term temporal stability between receivers, which is 0.05 degrees at 3GHz. Good results have been demonstrated for RF distribution schemes based on transmission of short pulses, but these require specialized free-space optics and high stability mechanical infrastructure. We report a method which uses only standard telecom optical and RF components, and achieves less than 20fs RMS error over 300m of standard single-mode fiber. We demonstrate stable transmission of 3GHz over 300m of fiber with less than 0.017 degree (17fs) RMS phase error. An interferometer measures optical phase delay, providing information to a feed-forward correction of RF phase.

Wilcox, R.; Byrd, J. M.; Doolittle, L.; Huang, G.; Staples, J. W.

2010-01-02T23:59:59.000Z

148

RF Power Upgrade for CEBAF at Jefferson Laboratory  

SciTech Connect (OSTI)

Jefferson Laboratory (JLab) is currently upgrading the 6GeV Continuous Electron Beam Accelerator Facility (CEBAF) to 12GeV. As part of the upgrade, RF systems will be added, bringing the total from 340 to 420. Existing RF systems can provide up to 6.5 kW of CW RF at 1497 MHZ. The 80 new systems will provide increased RF power of up to 13 kW CW each. Built around a newly designed and higher efficiency 13 kW klystron developed for JLab by L-3 Communications, each new RF chain is a completely revamped system using hardware different than our present installations. This paper will discuss the main components of the new systems including the 13 kW klystron, waveguide isolator, and HV power supply using switch-mode technology. Methodology for selection of the various components and results of initial testing will also be addressed. Notice: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. The U.S. Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce this manuscript for U.S. Government purposes.

Andrew Kimber,Richard Nelson

2011-03-01T23:59:59.000Z

149

805 MHz and 201 MHz RF cavity development for MUCOOL  

SciTech Connect (OSTI)

A muon cooling channel calls for very high acceleratinggradient RF structures to restore the energy lost by muons in theabsorbers. The RF structures have to be operated in a strong magneticfield and thus the use of superconducting RF cavities is excluded. Toachieve a high shunt impedance while maintaining a large enough apertureto accommodate a large transverse emittance muon beam, the cavity designadopted is a pillbox-like geometry with thin Be foils to terminate theelectromagnetic field at the cavity iris. The possibility of using gridsof thin-walled metallic tubes for the termination is also being explored.Many of the RF-related issues for muon cooling channels are being studiedboth theoretically and experimentally using an 805 MHz cavity that has apillbox-like geometry with thin Be windows to terminate the cavityaperture. The design and performance of this cavity are reported here.High-power RF tests of the 805 MHz cavity are in progress at Lab G inFermilab. The cavity has exceeded its design gradient of 30 MV/m,reaching 34 MV/m without external magnetic field. No surface damage wasobserved at this gradient. The cavity is currently under conditioning atLab G with an external magnetic field of 2.5 T. We also present here a201 MHz cavity design for muoncooling channels. The proposed cavitydesign is also suitable for use in a proof-of-principle Muon IonizationCooling Experiment (MICE).

DLi@lbl.gov

2002-10-10T23:59:59.000Z

150

Fractions: conceptual and didactic aspects  

E-Print Network [OSTI]

Fractions: conceptual and didactic aspects Martha Isabel Fandiño Pinilla NRD Department of transforming "Knowledge" into "knowledge to teach" is called didactic transposition and constitutes a moment

Spagnolo, Filippo

151

Microfluidic Devices for Blood Fractionation  

E-Print Network [OSTI]

Blood, a complex biological fluid, comprises 45% cellular components suspended in protein rich plasma. These different hematologic components perform distinct functions in vivo and thus the ability to efficiently fractionate ...

Hou, Han Wei

152

The effects of ferrochrome lignosulfonate on the respiration and excretion of the coral, Madracis mirabilis  

E-Print Network [OSTI]

THE EFFECTS OF FERROCHR(ME LIGNOSULFONATE ON THE RESPIRATION AHD EZGHE'ZZGH DZ THE GGHAZ, HADHAGZE HZHAI!ZZZE A Thesis by NARY JOANNE MESTERHAUS Submitted to the Graduate CoIIsge of Texas A&H University in partial fulfi13ment... and Odum 1955; Kohn and Helfrich 1957; Gordon and Kelly 1962; Kinsey and Kinsey 1967). Laboratory studies on respiration and production of single species of coral have been done by Kanwisher and Wainwright (1967) using Florida reef corals and by Roffman...

Westerhaus, Mary Joanne

1978-01-01T23:59:59.000Z

153

RF Pulse compression stabilization at the CTF3 CLIC test facility  

E-Print Network [OSTI]

In the CTF3 accelerator, the RF produced by each of ten 3 GHz klystrons goes through waveguides, RF pulse compressors and splitters. The RF phase and power transformation of these devices depend on their temperature. The quantitative effect of the room temperature variation on the RF was measured. It is the major source of undesired changes during the CTF3 operation. An RF phaseloop and a compressor temperature stabilization are developed to suppress the phase fluctuation and the power profile change due to the temperature variation. The implementation is transparent for operators, it does not limit anyhow the flexibility of RF manipulations. Expected and measured suppression characteristics will be given.

Dubrovskiy, Alexey

2010-01-01T23:59:59.000Z

154

PVDF microbelts for harvesting energy from respiration Chengliang Sun, Jian Shi, Dylan J. Bayerl and Xudong Wang*  

E-Print Network [OSTI]

PVDF microbelts for harvesting energy from respiration Chengliang Sun, Jian Shi, Dylan J. Bayerl operation of small elec- tronic devices. Their capability for harvesting energy from simulated respiration was also demonstrated. Harvesting energy from ambient mechanical energy sources has recently been shown

Wang, Xudong

155

Theory and Practice of Cavity RF Test Systems  

SciTech Connect (OSTI)

Over the years Jefferson Lab staff members have performed about 2500 cold cavity tests on about 500 different superconducting cavities. Most of these cavities were later installed in 73 different cryomodules, which were used in three different accelerators. All of the cavities were tested in our vertical test area. About 25% of the cryomodules were tested in our cryomodule test facility and later commissioned in an accelerator. The remainder of the cryomodules were tested and commissioned after they were installed in their respective accelerator. This paper is an overview which should provide a practical background in the RF systems used to test the cavities as well as provide the mathematics necessary to convert the raw pulsed or continuous wave RF signals into useful information such as gradient, quality factor, RF-heat loads and loaded Q?s. Additionally, I will provide the equations necessary for determining the measurement error associated with these values.

Tom Powers

2006-08-28T23:59:59.000Z

156

HOM Coupler Optimisation for the Superconducting RF Cavities in ESS  

E-Print Network [OSTI]

The European Spallation Source (ESS) will be the world’s most powerful next generation neutron source. It consists of a linear accelerator, target, and instruments for neutron experiments. The linac is designed to accelerate protons to a ?nal energy of 2.5 GeV, with an average design beam power of 5 MW, for collision with a target used to produce a high neutron ?ux. A section of the linac will contain Superconducting RF (SCRF) cavities designed at 704 MHz. Beam induced HOMs in these cavities may drive the beam unstable and increase the cryogenic load, therefore HOM couplers are installed to provide suf?cient damping. Previous studies have shown that these couplers are susceptible to multipacting, a resonant process which can absorb RF power and lead to heating effects. This paper will show how a coupler suffering from multipacting has been redesigned to limit this effect. Optimisation of the RF damping is also discussed.

Ainsworth, R; Calaga, R

2012-01-01T23:59:59.000Z

157

A computer program for HVDC converter station RF noise calculations  

SciTech Connect (OSTI)

HVDC converter station operations generate radio frequency (RF) electromagnetic (EM) noise which could interfere with adjacent communication and computer equipment, and carrier system operations. A generic Radio Frequency Computer Analysis Program (RAFCAP) for calculating the EM noise generated by valve ignition of a converter station has been developed as part of a larger project. The program calculates RF voltages, currents, complex power, ground level electric field strength and magnetic flux density in and around an HVDC converter station. The program requires the converter station network to be represented by frequency dependent impedance functions. Comparisons of calculated and measured values are given for an actual HVDC station to illustrate the validity of the program. RAFCAP is designed to be used by engineers for the purpose of calculating the RF noise produced by the igniting of HVDC converter valves.

Kasten, D.G.; Caldecott, R.; Sebo, S.A. (Ohio State Univ., Columbus, OH (United States). Dept. of Electrical Engineering); Liu, Y. (Virginia Polytechnic Inst. State Univ., Blacksburg, VA (United States). Bradley Dept. of Electrical Engineering)

1994-04-01T23:59:59.000Z

158

Warming and Intensified Summer Drought Influence Leaf Dark Respiration and Related Plant Traits in Three Dominant Species of the Southern Oak Savanna  

E-Print Network [OSTI]

. scoparium and Q. stellata but not J. virginiana. All three species showed evidence of reduced temperature acclimation of respiration with progressive summer drought. Redistributed rainfall in J. virginiana increased respiration in midsummer compared...

Lindgren, Kourtnee Marr

2011-08-08T23:59:59.000Z

159

The MuCool Test Area and RF Program  

SciTech Connect (OSTI)

The MuCool RF Program focuses on the study of normal conducting RF structures operating in high magnetic field for applications in muon ionization cooling for Neutrino Factories and Muon Colliders. This paper will give an overview of the program, which will include a description of the test facility and its capabilities, the current test program, and the status of a cavity that can be rotated in the magnetic field which allows for a more detailed study of the maximum stable operating gradient vs. magnetic field strength and angle.

Bross, A D; Jansson, A; Moretti, A; Yonehara, K; Huang, D; Torun, Y; Li, D; Norem, J; Palmer, R B; Stratakis, D

2010-05-01T23:59:59.000Z

160

The Los Alamos VXI-based modular RF control system  

SciTech Connect (OSTI)

This paper describes the design and implementation of the Los Alamos modular RF control system, which provides high-performance feedback and/or feedforward control of RF accelerator cavities. This is a flexible, modular control system which has been realized in the industry-standard VXI cardmodular format. A wide spectrum of system functionality can be accommodated simply by incorporating only those modules and features required for a particular application. The fundamental principles of the design approach are discussed. Details of the VXI implementation are given, including the system architecture and interfaces, performance capabilities, and available features.

Jachim, S.P.; Ziomek, C.; Natter, E.F.; Regan, A.H.; Hill, J.; Eaton, L.; Gutscher, W.D.; Curtin, M.; Denney, P.; Hansberry, E.; Brooks, T.

1993-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "rf respirable fraction" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

The Los Alamos VXI-based modular RF control system  

SciTech Connect (OSTI)

This paper describes the design and implementation of the Los Alamos modular RF control system, which provides high-performance feedback and/or feedforward control of RF accelerator cavities. This is a flexible, modular control system which has been realized in the industry-standard VXI cardmodular format. A wide spectrum of system functionality can be accommodated simply by incorporating only those modules and features required for a particular application. The fundamental principles of the design approach are discussed. Details of the VXI implementation are given, including the system architecture and interfaces, performance capabilities, and available features.

Jachim, S.P.; Ziomek, C.; Natter, E.F.; Regan, A.H.; Hill, J.; Eaton, L.; Gutscher, W.D.; Curtin, M.; Denney, P.; Hansberry, E.; Brooks, T.

1993-01-01T23:59:59.000Z

162

CONCEPTUAL DESIGN OF A BRIGHT ELECTRON INJECTOR BASED ON A LASER-DRIVEN PHOTOCATHODE RF ELECTRON GUN  

E-Print Network [OSTI]

Photocathode RF Electron Gun S. Chattopadhyay, Y.J. Chen, D.PHOTOCATHODE RF ELECTRON GUN' S. Chnttopndhyny. Y.J. Chen (Photocathode RF Electron Gun S. Chattopadhyay, Y.I. Chen, D.

Chattopadhyay, S.

2010-01-01T23:59:59.000Z

163

Fishery Bulletin, Vol. 79, No. 1 Gooding, Reginald M., William H. Neill, and Andrew E. Dizon, "Respiration rates and low-oxygen  

E-Print Network [OSTI]

, "Respiration rates and low-oxygen tolerance limits in skipjack tuna, Katsuwonus pelamis:' p. 31-48. 1) Page 31

164

Comparison of electromagnetic, thermal and mechanical calculations with rf test results in rf-dipole deflecting/crabbing cavities  

SciTech Connect (OSTI)

The current requirements of higher gradients and strict dimensional constraints in the emerging applications have required the designing of compact deflecting and crabbing rf structures. The superconducting rf-dipole cavity is one of the first novel compact designs with attractive properties such as higher gradients, higher shunt impedance and widely separated higher order modes. The recent tests performed on proof-of-principle designs of the rf-dipole geometry at 4.2 K and 2.0 K in the vertical test area at Jefferson Lab have proven the designs to achieve higher gradients with higher intrinsic quality factors and easily processed multipacting conditions. The cavity characteristics, such as pressure sensitivity and Lorentz force detuning, were studied using ANSYS before the fabrication. These characteristics were measured during the cavity test. The comparison between the simulation and the measurement provides insight how the simulation can be used for design and fabrication of future cavities.

Park, HyeKyoung [JLAB, ODU; De Silva, Subashini U. [ODU; Delayen, Jean R. [ODU, JLAB

2013-12-01T23:59:59.000Z

165

A deeper respired carbon pool in the glacial equatorial Pacific Ocean L.I. Bradtmiller a,  

E-Print Network [OSTI]

A deeper respired carbon pool in the glacial equatorial Pacific Ocean L.I. Bradtmiller a, , R in paleoceanography. We present evidence from ten equatorial Pacific Ocean sediment cores to show that the deep Pacific Ocean likely stored more carbon during the last glacial period than the Holocene

Sachs, Julian P.

166

Continuous measurements of soil respiration with and without roots in a ponderosa pine plantation in the  

E-Print Network [OSTI]

soil carbon www.elsevier.com/locate/agrformet Agricultural and Forest Meteorology 132 (2005) 212;sequestration and reduced CO2 efflux (Lal, 2004; Goh, 2004). Improved understanding of the mechanisms is necessary for evaluating the soil carbon budget on the global scale. Soil respiration has been extensively

Cohen, Ronald C.

167

I am delighted to announce the publication, in Ad-vances in Photosynthesis and Respiration (AIPH)  

E-Print Network [OSTI]

I am delighted to announce the publication, in Ad- vances in Photosynthesis and Respiration (AIPH-Clermont and Sabeeha Mer- chant); and Volume 14 (Photosynthesis in Algae, edited by Anthony Larkum, Susan Douglas-7923-3682-8); Volume 3: Biophysical Techniques in Photosynthesis (24 Chapters; 411 pages; 1996; edited by the late Jan

Govindjee "Gov"

168

Photosynthesis & Respiration 2009 1 Minority Science Programs School of Biological Sciences University of California, Irvine  

E-Print Network [OSTI]

Photosynthesis & Respiration 2009 1 Minority Science Programs ­ School of Biological Sciences" hetero = "another" 2. During photosynthesis, plants and phytoplankton use energy from the sun to combine: An anacharis plant in water produces oxygen when it photosynthesizes. 3. Photosynthesis takes place within

Rose, Michael R.

169

Photosynthesis Respiration CH2O + O2 CO2 + H2O  

E-Print Network [OSTI]

Energy and life Photosynthesis Respiration CH2O + O2 CO2 + H2O hv Biomass CO2 + H2O CH2O + O2 ASSOCIATED WITH PHOTOSYNTHESIS) #12;ATP*: the "energy currency" of the cell *Adenosine triphospahte) PHOTOSYNTHESIS Light provides the energy for high energy electrons. The source of electrons is water OXIDATIVE

170

Decomposition of peat from upland boreal forest: Temperature dependence and sources of respired carbon  

E-Print Network [OSTI]

Decomposition of peat from upland boreal forest: Temperature dependence and sources of respired boreal peat under black spruce forest with sphagnum and feather moss understory using incubation increments. At temperatures below 0°C, significant decomposition was observed in feather moss peat

Litvak, Marcy

171

Microbial Respiration and Its Consequences on Oxygen Availability in Peat Substrate  

E-Print Network [OSTI]

91 Microbial Respiration and Its Consequences on Oxygen Availability in Peat Substrate R. Naasz, J to Horticulture 2, rue Le Nôtre, F-49045 Angers Cedex 01 France Keywords: peat, oxygen uptake, microorganisms (Sphagnum peat) on oxygen transport and availability to the root. This is why, a one-dimensional transfer

Boyer, Edmond

172

Mine waste contamination limits soil respiration rates: a case study using quantile regression  

E-Print Network [OSTI]

, the toxicity of heavy metals depends on soil acidity and organic matter because these factors strongly an environmental gradient. We quantified in situ soil respiration, pH, and heavy metal concentrations across a mine was limited with respect to both heavy metals and pH, and that both increased metals and increased acidity

Rilli, Matthias C.

173

ECG-Derived Respiration: Comparison and New Measures for Respiratory Variability  

E-Print Network [OSTI]

ECG-Derived Respiration: Comparison and New Measures for Respiratory Variability Devy Widjaja1 During ECG recording, several methods can be applied to derive a respiratory signal from the ECG (EDR signal). In this paper 4 EDR methods, including ECG filtering, R and RS amplitude based techniques

174

Z .Geoderma 82 1998 83114 The isotopic composition of soil and soil-respired  

E-Print Network [OSTI]

investigated for the past three decades by earth2 scientists in a variety of disciplines. Carbon dioxide due to the magnitude of soil2 respiration on a global scale, and its role in the processes controlling.V. All rights reserved. Z .PII S0016-7061 97 00098-0 #12;( )R. Amundson et al.rGeoderma 82 1998 83

Amundson, Ronald

175

E-Print Network 3.0 - angle rf pulses Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

pulse operating on M: RFx pulse operating on FZ: RF pulses K-Space Scheffler 1999: PDF... " cos() 2 sin2 ( 2) 1st 1st RF pulse 12;E. Wong, BE278, UCSD Winter 2011...

176

Advances in Filter Miniaturization and Design/Analysis of RF MEMS Tunable Filters  

E-Print Network [OSTI]

The main purpose of this dissertation was to address key issues in the design and analysis of RF/microwave filters for wireless applications. Since RF/microwave filters are one of the bulkiest parts of communication systems, their miniaturization...

Sekar, Vikram

2012-10-19T23:59:59.000Z

177

Advances in Broadband RF Sensing for Real-time Control of Plasma-Based Semiconductor Processing  

E-Print Network [OSTI]

to standard RF metrology. The system uses an antenna in the glow discharge to excite the bulk plasma identification of process conditions for standard RF sensing, and 99:5 correct identification of process

Grizzle, Jessy W.

178

E-Print Network 3.0 - accelerating rf station Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

by a 1.25-T -decay channel with phase-rotation via rf (to compress... to beam tests; Test 70-MHz rf cavity (+ 1.25-T magnet) 3 m from target; Characterize ... Source:...

179

MEDIUM POWER 352 MHZ SOLID STATE PULSED RF AMPLIFIERS FOR THE CERN LINAC4 PROJECT  

E-Print Network [OSTI]

MEDIUM POWER 352 MHZ SOLID STATE PULSED RF AMPLIFIERS FOR THE CERN LINAC4 PROJECT J. Broere, J in the CERN Linac4. The amplifiers are water-cooled and can provide up to 33 kW pulsed RF Power, 1.5 ms pulse RF Power for the debuncher cavity. The concept is based on 1.2 kW RF power modules using the latest 6

Paris-Sud XI, Université de

180

Development of RF CMOS receiver front-ends for ultrawideband  

E-Print Network [OSTI]

demonstrates two different solutions for the RF front-end designs in the UWB receivers, one is distributed topology, and the other is based on traditional lumped element topology. The distributed amplifier is one of the attractive candidates for UWB Low Noise...

Guan, Xin

2009-05-15T23:59:59.000Z

Note: This page contains sample records for the topic "rf respirable fraction" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

Superfluid helium cryogenic systems for superconducting RF cavities at KEK  

SciTech Connect (OSTI)

Recent accelerator projects at KEK, such as the Superconducting RF Test Facility (STF) for R and D of the International Linear Collider (ILC) project and the compact Energy Recovery Linac (cERL), employ superconducting RF cavities made of pure niobium, which can generate high gradient acceleration field. Since the operation temperature of these cavities is selected to be 2 K, we have developed two 2 K superfluid helium cryogenic systems for stable operation of superconducting RF cavities for each of STF and cERL. These two 2 K superfluid helium cryogenic systems are identical in principle. Since the operation mode of the cavities is different for STF and cERL, i.e. the pulse mode for STF and the continuous wave mode for cERL, the heat loads from the cavities are quite different. The 2 K superfluid helium cryogenic systems mainly consists of ordinary helium liquefiers/refrigerators, 2 K refrigerator cold boxes, helium gas pumping systems and high-performance transfer lines. The 2 K refrigerators and the high-performance transfer lines are designed by KEK. Some superconducting RF cavity cryomodules have been already connected to the 2 K superfluid helium cryogenic systems for STF and cERL respectively, and cooled down to 2 K successfully.

Nakai, H.; Hara, K.; Honma, T.; Hosoyama, K.; Kojima, Y.; Nakanishi, K. [High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0033 (Japan); Kanekiyo, T. [Hitachi Plant Technologies, Ltd., Toshima-ku, Tokyo 170-8466 (Japan); Morita, S. [Hitachi Plant Mechanics Co., Ltd., Kudamatsu, Yamaguchi 744-0061 (Japan)

2014-01-29T23:59:59.000Z

182

COLLISIONLESS ELECTRON HEATING IN RF GAS DISCHARGES: I. QUASILINEAR THEORY  

E-Print Network [OSTI]

COLLISIONLESS ELECTRON HEATING IN RF GAS DISCHARGES: I. QUASILINEAR THEORY Yu.M. Aliev1 , I an interest in mechanisms of electron heating and power deposition in the plasma main- tained by radio parameters. Due to the large value of the mean free path (MFP) the main mechanism of electron heating turns

Kaganovich, Igor

183

Feedback Configuration Tools for LHC Low Level RF  

SciTech Connect (OSTI)

The LHC Low Level RF System (LLRF) is a complex multi-VME crate system which is used to regulate the superconductive cavity gap voltage as well as to lower the impedance as seen by the beam through low latency feedback. This system contains multiple loops with several parameters to be set before the loops can be closed. In this paper, we present a suite of MATLAB based tools developed to perform the preliminary alignment of the RF stations and the beginnings of a closed loop model based alignment routine. We briefly introduce the RF system and in particular the base band (time domain noise based) network analyzer system built into the LHC LLRF. The main focus of this paper is the methodology of the algorithms used by the routines within the context of the overall system. Measured results are presented that validate the technique. Because the RF systems are located in a cavern 120 m underground in a location which is relatively un-accessible without beam and completely un-accessible with beam present or magnets are energized, these remotely operated tools are a necessity for the CERN LLRF team to maintain and tune their LLRF systems in a similar fashion as to what was done very successfully in PEP-II at SLAC.

Van Winkle, D.; Fox, J.; Mastorides, T.; Rivetta, C.; /SLAC; Baudrenghien, P.; Butterworth, A.; Molendijk, J.; /CERN

2009-12-16T23:59:59.000Z

184

RF power potential of 45 nm CMOS technology  

E-Print Network [OSTI]

This paper presents the first measurements of the RF power performance of 45 nm CMOS devices with varying device widths and layouts. We find that 45 nm CMOS can deliver a peak output power density of around 140 mW/mm with ...

Putnam, Christopher

185

Novel Reactor Relevant RF Actuator Schemes for the Lower  

E-Print Network [OSTI]

location for RF launchers · Transport in tokamak sends heat and particles to low field side SOL: ­ Forces reactor is challenging: ­ Survivability is a major issue because of the harsh environment high heat solution that both mitigates PMI / coupling problems and improves core wave physics issues. #12;Reactor

186

Beyond ITER: RF Heating and Current Drive Issues for DEMO  

E-Print Network [OSTI]

control Need to operate reliably in a high power flux, high radiation, and "steady state" nuclear lose 10% or more power to edge / vessel ­ Minimal diagnostic support for RF edge interactions systems do not yet run for extended time periods #12;Facilities that provide a DEMO-relevant testing

Princeton Plasma Physics Laboratory

187

Multiband Antenna-Receiver Integration using an RF Multiplexer with Sensitivity-Constrained Design  

E-Print Network [OSTI]

S.M. Shajedul Hasan (hasan@vt.edu) Steven Ellingson (ellingson@vt.edu) RF Multiplexer Hasan be largely mitigated by: · Implementing design to be robust to variations RF Multiplexer Hasan / Ellingson #12;Motivation (2/2) Focus of this paper System Diagram of the prototype MMR RF Multiplexer Hasan

Ellingson, Steven W.

188

Multiband Antenna-Receiver Integration using an RF Multiplexer with Sensitivity-Constrained Design  

E-Print Network [OSTI]

S.M. Hasan and S. W. Ellingson Wireless at Virginia Tech RF Multiplexer Hasan / Ellingson ­ July 10 be largely mitigated by: 2/14 RF Multiplexer Hasan / Ellingson ­ July 10, 2008 RFIC from Motorola Research (2/2) Focus of this paper System Diagram of the prototype MMR 3/14 RF Multiplexer Hasan / Ellingson

Ellingson, Steven W.

189

Identification of Residual Stress State in an RF-MEMS Device  

E-Print Network [OSTI]

of wafer level tests. The membrane is part of an RF MEMS Switch man- ufactured by Raytheon Systems Co) and 3D numerical simulations. THE RAYTHEON'S RF MEMS SWITCH The RF MEMS switch technology developed by Raytheon Systems Co. provides advantageous characteristics for communication circuits by virtue of its

Espinosa, Horacio D.

190

Comparative Analysis of Carbon Plasma in Arc and RF Reactors  

SciTech Connect (OSTI)

Results on studies of molecular spectra emitted in the initial stages of fullerene formation during the processing of graphite powder in induction RF reactor and evaporation of graphite electrodes in arc reactor are presented in this paper. It was found that C2 radicals were dominant molecular species in both plasmas. C2 radicals have an important role in the process of fullerene synthesis. The rotational-vibrational temperatures of C2 and CN species were calculated by fitting the experimental spectra to the simulated ones. The results of optical emission study of C2 radicals generated in carbon arc plasma have shown that rotational temperature of C2 species depends on carbon concentration and current intensity significantly. The optical emission study of induction RF plasma and SEM analysis of graphite powder before and after plasma treatment have shown that evaporation of the processed graphite powder depends on feed rate and composition of gas phase significantly. Based on the obtained results, it was concluded that in the plasma region CN radicals could be formed by the reaction of C2 species with atomic nitrogen at smaller loads. At larger feed rate of graphite powder, CN species were produced by surface reaction of the hot carbon particles with nitrogen atoms. The presence of nitrogen in induction RF plasma reduces the fullerene yield significantly. The fullerene yield obtained in two different reactors was: 13% in arc reactor and 4.1% in induction RF reactor. However, the fullerene production rate was higher in induction RF reactor-6.4 g/h versus 1.7 g/h in arc reactor.

Todorovic-Markovic, B.; Markovic, Z. ['Vinca' Institute of Nuclear Sciences, P.O.B. 522, 11001 Belgrade (Serbia and Montenegro); Mohai, I.; Szepvolgyi, J. [Research Laboratory of Materials and Environmental Chemistry, Chemical Research Center, Hungarian Academy of Sciences H-1525 Budapest, POB 17 (Hungary)

2004-12-01T23:59:59.000Z

191

Listing Unique Fractional Factorial Designs  

E-Print Network [OSTI]

fractional factorial design. The defining contrast subgroup is {I, ABE, BCD, ACDE}. Suppose the 25?2 design is constructed by using defining words {BCD, ABE}. This design, shown in Fig. 4, has the runs {1,4,6,7,9,12,14,15} of Fig. 3. Taking the modulo-2 sum... in generating design catalogs . . . . . . . . . . . 5 I.2.1. Computational issues . . . . . . . . . . . . . . 5 I.2.2. Complicated designs . . . . . . . . . . . . . . 6 I.3. Research objectives and contributions . . . . . . . . . . 8 I.4. Organization...

Shrivastava, Abhishek Kumar

2011-02-22T23:59:59.000Z

192

Response of the carbon isotopic content of ecosystem, leaf, and soil respiration to meteorological and physiological driving factors in a  

E-Print Network [OSTI]

was negatively correlated with vpd (P CO2 exchange (NEE) was positively correlated with vpd (P CO2 uptake. Consistent temperatures cause isotopic enrichment of respired CO2. The significant driving parameters differed for d13 CR

Ehleringer, Jim

193

Induction heating of FeCo nanoparticles for rapid rf curing of epoxy K. J. Miller,1,a  

E-Print Network [OSTI]

, and cracking of the polymer. An alternative curing process involves remote, noncontact rf heating of MNP loadedInduction heating of FeCo nanoparticles for rapid rf curing of epoxy composites K. J. Miller,1,a K epoxy composites through radio-frequency rf heating. The rf response of functionalized FeCo MNPs

McHenry, Michael E.

194

Free electron laser using Rf coupled accelerating and decelerating structures  

DOE Patents [OSTI]

A free electron laser and free electron laser amplifier using beam transport devices for guiding an electron beam to a wiggler of a free electron laser and returning the electron beam to decelerating cavities disposed adjacent to the accelerating cavities of the free electron laser. Rf energy is generated from the energy depleted electron beam after it emerges from the wiggler by means of the decelerating cavities which are closely coupled to the accelerating cavities, or by means of a second bore within a single set of cavities. Rf energy generated from the decelerated electron beam is used to supplement energy provided by an external source, such as a klystron, to thereby enhance overall efficiency of the system.

Brau, Charles A. (Los Alamos, NM); Swenson, Donald A. (Los Alamos, NM); Boyd, Jr., Thomas J. (Los Alamos, NM)

1984-01-01T23:59:59.000Z

195

Performance of Magnesium Cathode in the S Band RF Gun  

SciTech Connect (OSTI)

In this paper, we present the preliminary results of the performance of magnesium cathode in a high frequency RF gun. The quantum efficiency of magnesium showed a dramatic improvement upon laser cleaning, increasing from 10{sup -5} to 4x10{sup -4} after two hours of cleaning. The spatial uniformity of emission also improved from a spot to spot variation of 10 to a variation of 2. Measurements with charges >1 nC indicate that the transient variation of the field due to the shielding effect of the electron in the vicinity of the cathode may play a critical role in the efficient extraction of electrons. Comprehensive theory that includes the electron emission in the presence of a time dependent Schottky effect and RF effects will be discussed.

Srinivasan-Rao, T.; /Brookhaven; Palmer, D.T.; /SLAC; Ben-Zvi, I.; /Brookhaven; Miller, R.H.; /SLAC; Wang, X.J.; Woodle, M.; /Brookhaven

2011-09-01T23:59:59.000Z

196

The effect of respiration heat of sorghum grain on the design of conditioned-air storage systems  

E-Print Network [OSTI]

THE EFFECT OF RESPIRATION HEAT OF SORGHUM GRAIN ON THE DESIGN OF CONDITIONED-AIR STORAGE SYSTEMS A Thesis by DANEL GENE HAILE Submitted to the Graduate College of Texas AIM University in partial fulfillment of the requirements for the degree... of MASTER OF SCIENCE January 1967 Major Subject: Agricultural Engineering THE EFFECT OF RESPIRATION HEAT OF SORGHUM GRAIN ON THE DESIGN OF CONDITIONED-AIR STORAGE SYSTEMS A Thesis by DANEL GENE HAILE Approved as to style and content by: C airman...

Haile, Danel Gene

1967-01-01T23:59:59.000Z

197

RF generation in the DARHT Axis-II beam dump  

SciTech Connect (OSTI)

We have occasionally observed radio-frequency (RF) electromagnetic signals in the downstream transport (DST) of the second axis linear induction accelerator (LIA) at the dual-axis radiographic hydrodynamic testing (DARHT) facility. We have identified and eliminated some of the sources by eliminating the offending cavities. However, we still observe strong RF in the range 1 GHz t0 2 GHz occurring late in the {approx}2-{micro}s pulse that can be excited or prevented by varying the downstream tune. The narrow frequency width (<0.5%) and near exponential growth at the dominant frequency is indicative of a beam-cavity interaction, and electro-magnetic simulations of cavity structure show a spectrum rich in resonances in the observed frequency range. However, the source of beam produced RF in the cavity resonance frequency range has not been identified, and it has been the subject of much speculation, ranging from beam-plasma or beam-ion instabilities to unstable cavity coupling.

Ekdahl, Carl A. Jr. [Los Alamos National Laboratory

2012-05-03T23:59:59.000Z

198

1 -SUBTIDAL 2 -INTERTIDAL RB ROCK UB UNCONSOLIDATED AB AQUATIC BED RF -REEF OW -OPEN WATER/ AB AQUATIC BED RF REEF RS ROCKY SHORE US -UNCONSOLIDATED  

E-Print Network [OSTI]

M - MARINE 1 - SUBTIDAL 2 - INTERTIDAL RB ­ ROCK UB ­ UNCONSOLIDATED AB ­ AQUATIC BED RF - REEF OW - OPEN WATER/ AB ­ AQUATIC BED RF­ REEF RS ­ ROCKY SHORE US - UNCONSOLIDATED BOTTOM BOTTOM Unknown Bottom ­ UNCONSOLIDATED AB ­ AQUATIC RF ­ REEF OW - OPEN WATER/ AB ­ AQUATIC RF­ REEF SB ­ STREAMBED RS - ROCKY US

Gray, Matthew

199

Understanding fractional equivalence and the differentiated effects on operations with fractions  

E-Print Network [OSTI]

This study compared two representations for teaching fraction equivalence. It traced the implications of both representations on the student?s comprehension of fractions as well as their ability to perform operations with fractions...

Naiser, Emilie Ann

2005-02-17T23:59:59.000Z

200

Fractional topological insulators in three dimensions  

E-Print Network [OSTI]

Topological insulators can be generally defined by a topological field theory with an axion angle theta of 0 or pi. In this work, we introduce the concept of fractional topological insulator defined by a fractional axion angle and show that it can be consistent with time reversal (T) invariance if ground state degeneracies are present. The fractional axion angle can be measured experimentally by the quantized fractional bulk magnetoelectric polarization P_3, and a `halved' fractional quantum Hall effect on the surface with Hall conductance of the form (p/q)(e^2/2h) with p,q odd. In the simplest of these states the electron behaves as a bound state of three fractionally charged `quarks' coupled to a deconfined non-Abelian SU(3) `color' gauge field, where the fractional charge of the quarks changes the quantization condition of P_3 and allows fractional values consistent with T-invariance.

Joseph Maciejko; Xiao-Liang Qi; Andreas Karch; Shou-Cheng Zhang

2010-11-14T23:59:59.000Z

Note: This page contains sample records for the topic "rf respirable fraction" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Fractional Topological Insulators in Three Dimensions  

SciTech Connect (OSTI)

Topological insulators can be generally defined by a topological field theory with an axion angle {theta} of 0 or {pi}. In this work, we introduce the concept of fractional topological insulator defined by a fractional axion angle and show that it can be consistent with time reversal T invariance if ground state degeneracies are present. The fractional axion angle can be measured experimentally by the quantized fractional bulk magnetoelectric polarization P{sub 3}, and a 'halved' fractional quantum Hall effect on the surface with Hall conductance of the form {sigma}{sub H}=(p/q)(e{sup 2}/2h) with p, q odd. In the simplest of these states the electron behaves as a bound state of three fractionally charged 'quarks' coupled to a deconfined non-Abelian SU(3) 'color' gauge field, where the fractional charge of the quarks changes the quantization condition of P{sub 3} and allows fractional values consistent with T invariance.

Maciejko, Joseph; Zhang Shoucheng [Department of Physics, Stanford University, Stanford, California 94305 (United States); Qi Xiaoliang [Microsoft Research, Station Q, Elings Hall, University of California, Santa Barbara, California 93106 (United States); Department of Physics, Stanford University, Stanford, California 94305 (United States); Karch, Andreas [Department of Physics, University of Washington, Seattle, Washington 98195-1560 (United States)

2010-12-10T23:59:59.000Z

202

Selecting Fractionators for Product Composition Control  

E-Print Network [OSTI]

are presented for selecting those fractionators where installations of product composition control systems will result in energy savings. Suggestions are included for a preliminary screening of all fractionators and for detailed evaluation of the promising...

Griffin, D. E.; Anderson, J. E.

1979-01-01T23:59:59.000Z

203

What is a Weber fraction? Justin Halberda  

E-Print Network [OSTI]

What is a Weber fraction? Justin Halberda Johns Hopkins University Corresponding Author: Justin System (ANS), discrimination within the ANS, and how to think about Weber fractions (w). What the ANS representations for numerosities 4-10 for an individual with Weber fraction = .125. You can think

Halberda, Justin

204

Original article Micronutrients in biomass fractions  

E-Print Network [OSTI]

Original article Micronutrients in biomass fractions of holm oak, beech and fir forests biomass fractions in individual monospecific stands of holm oak (Quercus ilex L), beech (Fagus sylvatica L in different biomass fractions of the holm oak forest studied. This can be related to the low soil pH values

Boyer, Edmond

205

Development of an RF Conditioning System for Charged-Particle Accelerators  

SciTech Connect (OSTI)

Charged-particle accelerators use various vacuum windows on their accelerating radio-frequency (RF) cavities to throughput very high RF power. Before being placed on the cavities, the windows should be cleaned, baked, and fully RF conditioned to prevent a poor vacuum from outgassing, as well as other forms of contamination. An example is the coaxial fundamental power coupler (FPC) with an annular alumina ceramic window for each of the 81 superconducting RF cavities in the Spallation Neutron Source (SNS) linear accelerator. The FPCs needed to be tested up to 650-kW peak in a traveling wave and 2.6 MW with standing wave peaks in 1.3 and 60 pulses/s at 805 MHz. In this paper, an Experimental-Physics-and-Industrial-Control-System-based RF conditioning system for the SNS RF test facility is presented. This paper summarizes the hardware and software design strategies, provides the results obtained, and describes the future research scope.

Kang, Yoon W [ORNL; Howlader, Mostofa [ORNL; Shajedul Hasan, Dr. S. M. [Virginia Polytechnic Institute and State University (Virginia Tech)

2008-01-01T23:59:59.000Z

206

Production and decay properties of the 1.9-s isomeric state in {sup 261}Rf  

SciTech Connect (OSTI)

The 1.9-s isomeric state ({sup 261}Rf{sup b}) in {sup 261}Rf was directly populated in the {sup 248}Cm({sup 18}O,5n){sup 261}Rf{sup b} reaction. Alpha and spontaneous fission (SF) decays of {sup 261}Rf{sup b}, as well as the 68-s state {sup 261}Rf{sup a}, was investigated with a rotating wheel apparatus under low background conditions attained by a gas-jet transport system coupled to the RIKEN gas-filled recoil ion separator. An identification of {sup 261}Rf{sup b} was based on {alpha}-{alpha} correlations linking {alpha} decays of {sup 261}Rf{sup b} and its daughter {sup 257}No. The {alpha}-particle energy of {sup 261}Rf{sup b} was measured to be 8.52 {+-} 0.05 MeV. The half-life was determined to be 1.9 {+-} 0.4 s based on both 8.52-MeV {alpha} and SF decays. The {alpha} and SF branches are 0.27 {+-} 0.06 and 0.73 {+-} 0.06, respectively. The cross section for the {sup 248}Cm({sup 18}O,5n){sup 261}Rf{sup b} reaction is {sigma}({sup 261}Rf{sup b}) = 11 {+-} 2 nb at 95.1 MeV, which gives a cross-section ratio of {sigma}({sup 261}Rf{sup a})/{sigma}({sup 261}Rf{sup b}) = 1.1 {+-} 0.2.

Haba, H.; Kaji, D.; Kikunaga, H.; Kudou, Y.; Morimoto, K.; Morita, K.; Ozeki, K.; Sumita, T.; Yoneda, A.; Kasamatsu, Y.; Komori, Y.; Ooe, K.; Shinohara, A. [Nishina Center for Accelerator-Based Science, RIKEN, Wako, Saitama 351-0198 (Japan); Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043 (Japan)

2011-03-15T23:59:59.000Z

207

New SLED 3 system for Multi-mega Watt RF compressor  

E-Print Network [OSTI]

A compact X band SLED is introduced for X band RF compressing application. This SLED compressor consists two major parts: a rectangular to circular waveguide converter and an overmoded spherical cavity. The RF compressor is designed to convert 50 magawatt X band RF power with pulse length 1.5 microseconds and deliver 200 megawatts with pulse length 106 nanoseconds to the X band accelerating structure.

Xu, Chen; Tantawi, Sami

2014-01-01T23:59:59.000Z

208

Ultrananocrystalline diamond films with optimized dielectric properties for advanced RF MEMS capacitive switches  

DOE Patents [OSTI]

An efficient deposition process is provided for fabricating reliable RF MEMS capacitive switches with multilayer ultrananocrystalline (UNCD) films for more rapid recovery, charging and discharging that is effective for more than a billion cycles of operation. Significantly, the deposition process is compatible for integration with CMOS electronics and thereby can provide monolithically integrated RF MEMS capacitive switches for use with CMOS electronic devices, such as for insertion into phase array antennas for radars and other RF communication systems.

Sumant, Anirudha V.; Auciello, Orlando H.; Mancini, Derrick C.

2013-01-15T23:59:59.000Z

209

RF heating systems evolution for the WEST project  

SciTech Connect (OSTI)

Tore Supra is dedicated to long pulse operation at high power, with a record in injected energy of 1 GJ (2.8 MW × 380 s) and an achieved capability of 12 MW injected power delivered by 3 RF systems: Lower Hybrid Current Drive (LHCD), Ion Cyclotron Resonance Heating (ICRH) and Electron Cyclotron Resonance Heating (ECRH). The new WEST project (W [tungsten] Environment in Steady-state Tokamak) aims at fitting Tore Supra with an actively cooled tungsten coated wall and a bulk tungsten divertor. This new device will offer to ITER a test bed for validating the relevant technologies for actively cooled metallic components, with D-shaped H-mode plasmas. For WEST operation, different scenarii able to reproduce ITER relevant conditions in terms of steady state heat loads have been identified, ranging from a high RF power scenario (15 MW, 30 s) to a high fluence scenario (10 MW, 1000 s). This paper will focus on the evolution of the RF systems required for WEST. For the ICRH system, the main issues are its ELM resilience and its CW compatibility, three new actively cooled antennas are being designed, with the aim of reducing their sensitivity to the load variations induced by ELMs. The LH system has been recently upgraded with new klystrons and the PAM antenna, the possible reshaping of the antenna mouths is presently studied for matching with the magnetic field line in the WEST configuration. For the ECRH system, the device for the poloidal movement of the mirrors of the antenna is being changed for higher accuracy and speed.

Magne, R.; Achard, J.; Armitano, A.; Argouarch, A.; Berger-By, G.; Bernard, J. M.; Bouquey, F.; Charabot, N.; Colas, L.; Corbel, E.; Delpech, L.; Ekedahl, A.; Goniche, M.; Guilhem, D.; Hillairet, J.; Jacquot, J.; Joffrin, E.; Litaudon, X.; Lombard, G.; Mollard, P. [CEA, IRFM, F-13108 Saint-Paul-lez-Durance (France); and others

2014-02-12T23:59:59.000Z

210

MHD simulation of RF current drive in MST  

SciTech Connect (OSTI)

Auxiliary heating and current drive using RF waves such as the electron Bernstein wave (EBW) promises to advance the performance of the reversed field pinch (RFP). In previous computational work [1], a hypothetical edge-localized current drive is shown to suppress the tearing activity which governs the macroscopic transport properties of the RFP. The ideal conditions for tearing stabilization include a reduced toroidal induction, and precise width and radial position of the Gaussian-shaped external current drive. In support of the EBW experiment on the Madison Symmetric Torus, an integrated modeling scheme now incorporates ray tracing and Fokker-Plank predictions of auxiliary current into single fluid MHD. Simulations at low Lundquist number (S ? 10{sup 4}) generally agree with the previous work; significantly more burdensome simulations at MST-like Lundquist number (S ? 3×10{sup 6}) show unexpected results. The effect on nonlinearly saturated current profile by a particular RF-driven external force decreases in magnitude and widens considerably as the Lundquist number increases toward experimental values. Simulations reproduce the periodic current profile relaxation events observed in experiment (sawteeth) in the absence of current profile control. Reduction of the tearing mode amplitudes is still observable; however, reduction is limited to periods between the large bursts of magnetic activity at each sawtooth. The sawtoothing pattern persists with up to 10 MW of externally applied RF power. Periods with prolonged low tearing amplitude are predicted with a combination of external current drive and a reduced toroidal loop voltage, consistent with previous conclusions. Finally, the resistivity profile is observed to have a strong effect on the optimal externally driven current profile for mode stabilization.

Hendries, E. R.; Anderson, J. K.; Forest, C. B.; Reusch, J. A.; Seltzman, A. H.; Sovinec, C. R. [University of Wisconsin, Madison WI (United States); Diem, S. [Oak Ridge National Laboratory, Oak Ridge TN (United States); Harvey, R. W. [CompX, Del Mar, CA (United States)

2014-02-12T23:59:59.000Z

211

Patterns of NPP, GPP, Respiration and NEP During Boreal Forest Succession  

SciTech Connect (OSTI)

We deployed a mesonet of year-round eddy covariance towers in boreal forest stands that last burned in ~1850, ~1930, 1964, 1981, 1989, 1998, and 2003 to understand how CO2 exchange changes during secondary succession.The strategy of using multiple methods, including biometry and micrometeorology, worked well. In particular, the three independent measures of NEP during succession gave similar results. A stratified and tiered approach to deploying eddy covariance systems that combines many lightweight and portable towers with a few permanent ones is likely to maximize the science return for a fixed investment. The existing conceptual models did a good job of capturing the dominant patterns of NPP, GPP, Respiration and NEP during succession. The initial loss of carbon following disturbance was neither as protracted nor large as predicted. This muted response reflects both the rapid regrowth of vegetation following fire and the prevalence of standing coarse woody debris following the fire, which is thought to decay slowly. In general, the patterns of forest recovery from disturbance should be expected to vary as a function of climate, ecosystem type and disturbance type. The NPP decline at the older stands appears related to increased Rauto rather than decreased GPP. The increase in Rauto in the older stands does not appear to be caused by accelerated maintenance respiration with increased biomass, and more likely involves increased allocation to fine root turnover, root metabolism, alternative forms of respiration, mycorrhizal relationships, or root exudates, possibly associated with progressive nutrient limitation. Several studies have now described a similar pattern of NEP following boreal fire, with 10-to-15 years of modest carbon loss followed by 50-to-100 years of modest carbon gain. This trend has been sufficiently replicated and evaluated using independent techniques that it can be used to quantify the likely effects of changes in boreal fire frequency and stand age structure on regional carbon balance.

Goulden, Michael L.; McMillan, Andrew; Winston, Greg; Rocha, Adrian; Manies, Kristen; Harden, Jennifer W.; Bond-Lamberty, Benjamin

2010-12-15T23:59:59.000Z

212

Study of AC/RF properties of SRF ingot niobium  

SciTech Connect (OSTI)

In an attempt to correlate the performance of superconducting radiofrequency cavities made of niobium with the superconducting properties, we present the results of the magnetization and ac susceptibility of the niobium used in the superconducting radiofrequency cavity fabrication. The samples were subjected to buffer chemical polishing (BCP) surface and high temperature heat treatments, typically applied to the cavities fabrications. The analysis of the results show the different surface and bulk ac conductivity for the samples subjected to BCP and heat treatment. Furthermore, the RF surface impedance is measured on the sample using a TE011 microwave cavity for a comparison to the low frequency measurements.

Dhakal, Pashupati; Tsindlekht, Menachem I.; Genkin, Valery M.; Ciovati, Gianluigi; Myneni, Ganapati Rao

2013-09-01T23:59:59.000Z

213

The modeling of RF stacking of protons in the Accumulator  

SciTech Connect (OSTI)

When the Run2 collider program is terminated in 2009, the present pbar source will be available for other usages. One possible application is to convert the Antiproton Accumulator to a proton accumulator so that the beam power from the Main Injector could be greatly enhanced [1]. The Accumulator has the unique feature of very large momentum acceptance. It is possible to stack 3-4 Booster batches in the longitudinal phase space before transferring them to the Main Injector or Recycler. This note shows the simulation of RF stacking using the code ESME [2].

Yoon, Phil S.; /Fermilab /Rochester U.; McGinnis, David P.; Chou, Weiren; /Fermilab

2005-06-01T23:59:59.000Z

214

Fabrication Processes for the PEP II RF Cavities  

SciTech Connect (OSTI)

This paper presents the major steps used in the fabrication of the 26 RF Cavities required for the PEP-II B-factory. Several unique applications of conventional processes have been developed and successfully implemented: electron beam welding (EBW), with minimal porosity, of .75 inch (19 mm) copper cross-sections; extensive 5-axis milling of water channels; electroplating of .37 inch (10 mm) thick OFE copper; tuning of the cavity by profiling beam noses prior to final joining with the cavity body; and machining of the cavity interior, are described here.

Franks, R.Mark; /LLNL, Livermore; Rimmer, Robert A.; /LBL, Berkeley; Schwarz, Heinz; /SLAC

2011-09-01T23:59:59.000Z

215

THERMAL MODELING OF ION EXCHANGE COLUMNS WITH SPHERICAL RF RESIN  

SciTech Connect (OSTI)

Models have been developed to simulate the thermal performance of RF columns fully loaded with radioactive cesium. Temperature distributions and maximum temperatures across the column were calculated during Small Column Ion Exchange (SCIX) process upset conditions with a focus on implementation at Hanford. A two-dimensional computational modeling approach was taken to include conservative, bounding estimates for key parameters such that the results will provide the maximum centerline temperatures achievable under the design configurations using a feed composition known to promote high cesium loading on RF. The current full-scale design for the SCIX system includes a central cooling tube, and one objective of these calculations was to examine its elimination to simplify the design. Results confirmed that a column design without a central cooling tube is feasible for RF, allowing for the possibility of significant design simplifications if it can be assumed that the columns are always filled with liquid. With active cooling through the four outer tubes, the maximum column diameter expected to maintain the temperature below the assumed media and safety limits is 26 inches, which is comparable to the current design diameter. Additional analysis was conducted to predict the maximum column temperatures for the previously unevaluated accident scenario involving inadvertent drainage of liquid from a cesium-saturated column, with retention of the ion exchange media and cesium in the column. As expected, much higher maximum temperatures are observed in this case due to the poor heat transfer properties of air versus liquid. For this hypothetical accident scenario involving inadvertent and complete drainage of liquid from a cesium-saturated column, the modeling results indicate that the maximum temperature within a 28 inch diameter RF column with external cooling is expected to exceed 250 C within 2 days, while the maximum temperature of a 12 inch column is maintained below 100 C. In addition, the calculation results demonstrate that the cooling tube system external to an air-filled column is not highly effective at reducing the maximum temperature, but the baseline design using a central cooling tube inside the column provides sufficient cooling to maintain the maximum temperature near the assumed safety limit.

Lee, S.; King, W.

2009-12-30T23:59:59.000Z

216

Beam dynamics studies for transverse electromagnetic mode type rf deflectors  

DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

We have performed three-dimensional simulations of beam dynamics for transverse electromagnetic mode (TEM) type rf deflectors: normal and superconducting. The compact size of these cavities as compared to the conventional TM110 type structures is more attractive particularly at low frequency. Highly concentrated electromagnetic fields between the parallel bars provide strong electrical stability to the beam for any mechanical disturbance. An array of six 2-cell normal conducting cavities or a single cell superconducting structure is enough to produce the required vertical displacement at the target point. Both the normal and superconducting structures show very small emittance dilution due to the vertical kick of the beam.

Ahmed, Shahid; Krafft, Geoffrey A.; Deitrick, Kirsten; De Silva, Subashini U.; Delayen, Jean R.; Spata, Mike; Tiefenback, Michael; Hofler, Alicia; Beard, Kevin

2012-02-01T23:59:59.000Z

217

Frequency and amplitude control for an experimental linac rf drive  

E-Print Network [OSTI]

, India Chair of Advisory Committee: Dr. S. P. Bhattacharyya, The Texas Accelerator Center (TAC) experimental linear accelerator uses a radio- frequency quadrupole (RFQ) to accelerate a 10 mA beam of H ions to 500 keV. It is to be used as an injector... to form a high-energy input beam for large circular accelerators. The pulsed beam will require 100 kW peak rf power at 473 MHz. To satisfy the beam dynamics requirements for particle acceleration and to minimize beam spill, the frequency of the source...

Atre, Mahesh Purushottam

1992-01-01T23:59:59.000Z

218

Optical Emission of Dusty RF Discharges: Experiment and Simulation  

SciTech Connect (OSTI)

The spectral emission of argon atoms in a dusty radio frequence (RF) discharge has been investigated experimentally and in simulations. It was observed that the spatially and temporally resolved emission of the argon atoms in the dusty discharge was increased compared to the dust-free case during sheath expansion. The corresponding simulations have revealed that the dust trapped in the sheath of the discharge leads to a small, but important, increase of the amount of high-energy electrons that in turn leads to an increased argon emission.

Melzer, A.; Lewerentz, L.; Schneider, R. [Institute of Physics, University Greifswald, Felix-Hausdorff-Str. 6, 17489 Greifswald (Germany); Huebner, S. [Institute of Physics, University Greifswald, Felix-Hausdorff-Str. 6, 17489 Greifswald (Germany); Department of Applied Physics, Technical University Eindhoven, NL-5600 MB Eindhoven (Netherlands); Matyash, K. [Max-Planck-Institute for Plasma Physics, EURATOM Association, D-17491 Greifswald (Germany); Ikkurthi, V. R. [Institute for Plasma Research, Bhat, Ghandinagar, Gujarat (India)

2011-11-29T23:59:59.000Z

219

Index of /research/alcator/facility/Procedures/RF  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsingFun withconfinementEtching.348ASSEMBLY [ICO] Name Last modifiedPOWER [ICO] NameRF

220

Microsoft PowerPoint - rf_5year_review  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: VegetationEquipment Surfaces andMapping RichlandScattering PropertiesTechniqueresultsReview March 11,7,RF

Note: This page contains sample records for the topic "rf respirable fraction" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

Influence of temperature on respiration of excised tissues from citrus seedlings  

E-Print Network [OSTI]

(C02 evolved and 02 absorbed, and the calculated RO and QIO) on tissues from sour orange seedlings revealed: 1) the relation between the amount of gas respired by hardened and unhardened plants and temperature was linear or slightly curvilinear... fluorescent and 12 100-w Modified nutrient solution: N (168 PPm N03 and 14 PPm NN4); Ca 200 ppm; K 78 ppm; P 31 ppm; Mg 48 ppm; 8 . 1 ppm; Mn 0. 5 ppm; Zn . 05 ppm; Cu . 02 ppm; Mo . 01 ppm; Fe 5 ppm (Chell 138). For specific control as the situations...

Peynado, Ascension

1970-01-01T23:59:59.000Z

222

System studies of rf current drive for MST  

SciTech Connect (OSTI)

Two rf schemes are being studied on the MST reversed field pinch for their potential in current profile control experiments. MHD modeling has shown that a substantial externally-driven off axis parallel current can improve stability of the dominant core tearing modes. A radially localized axisymmetric population of fast electrons has been observed by SXR emission during LH injection (100kW at 800MHz), and is consistent with CQL3D modeling which predicts a small driven current. Computational work suggests that doubling the input power will statistically improve the LH-induced SXR signal to background ratio, and that about 2MW of injected power (an order of magnitude increase) will drive enough current for stabilization of tearing modes. Additionally, a 1 MW 5.5 GHz electron Bernstein wave (EBW) experiment is under construction, which utilizes a very simple and compact antenna compatible with the demands of the RFP. EBW allows access to electron cyclotron heating and current drive in the overdense plasma. Coupling of the external electromagnetic wave to the EBW has been demonstrated, and initial tests at {approx}100kW power have produced a small, localized xray flux consistent with rf heating and high diffusivity of fast electrons. Computational work is currently underway to answer the very important questions of how much power is required, and what level of electron diffusivity is tolerable, to generate a consequential amount of EBW current.

Anderson, J. K.; Burke, D. R.; Forest, C. B.; Goetz, J. A.; Hendries, E. R.; Seltzman, A. H.; Thomas, M. A. [Department of Physics, University of Wisconsin, Madison, WI (United States); Diem, S. [Oak Ridge National Laboratory, Oak Ridge TN (United States); Harvey, R. W. [CompX, Del Mar, CA (United States); Kaufman, M. C. [Department of Physics, University of Wisconsin, Madison, WI (United States); Oak Ridge National Laboratory, Oak Ridge, TN (United States)

2011-12-23T23:59:59.000Z

223

Is it safe to wear contact lenses with a full-facepiece respirator  

SciTech Connect (OSTI)

The Federal OSHA regulation that prohibits the wearing of contact lenses while using a respirator is being challenged by users. We surveyed 9100 fire fighters around the US and Canada to determine if the wearing of contacts while using a self-contained breathing apparatus (SCBA) had caused any serious problems to warrant this strict regulation. Of the 1405 questionnaires returned, 403 fire fighters do wear contacts with SCBA, despite the regulation. Of these, only six responded that contact-lens related problems had caused them to remove the facepiece in an environment in which the facepiece would normally be worn. In contrast, the safety-related problems caused by eyeglasses in SCBA - which are legal - are proportionately higher. Over half of the supervisors returning the questionnaire admitted that some of their employees wear contacts with SCBA; however, these supervisors knew of only eight cases when contact-lens problems had caused the facepiece to be removed when it should not have been. Our investigation has indicated that these problems were not significantly hazardous. We believe that the use of contacts with a respirator should not be prohibited. 7 refs., 2 figs., 7 tabs.

Da Roza, R.A.; Weaver, C.

1985-08-16T23:59:59.000Z

224

Catalytic cracking of residual petroleum fractions  

SciTech Connect (OSTI)

This paper reports on Arabian Light crude oil vacuum bottoms fractionated into five high-boiling fractions by wiped film evaporation, and the fractions subjected to catalytic cracking in a fixed-fluidized bed using a commercial equilibrium cracking catalyst. Density, aromaticity, and heteroatom content generally increased with boiling point, as did metals content except for vanadium and iron which demonstrated possible bimodal distributions. The cracking response of these fractions showed increasing yields of dry gas and coke, with decreasing gasoline yields, as a function of increasing apparent boiling point as would normally be expected. Surprisingly, however, local maxima were observed for wet gas yield and total conversion, with local minima for cycle oil and slurry yields, in the region of the 1200-1263{degrees}F (650-680{degrees}C) middle fraction. All fractions showed significant response to cracking, with coke yields generally being the only negative factor observed.

Moore, H.F.; Mayo, S.L.; Goolsby, T.L. (Research and Development Dept., Ashland Petroleum Co., Ashland, KY (US))

1991-01-01T23:59:59.000Z

225

Green radio despite "Dirty RF" front-end Myriam Ariaudo*1  

E-Print Network [OSTI]

Green radio despite "Dirty RF" front-end Myriam Ariaudo*1 , Inbar Fijalkow1 , Jean-Luc Gautier1 in order to contribute in a Green radio development. In fact, the effects of typical RF imperfections, like algorithms are applied. Such algorithms enable Green applications (e.g., Orthogonal Frequency Division

Fijalkow, Inbar

226

Study of lithium diffusion in RF sputtered Nickel/Vanadium mixed oxides thin films  

E-Print Network [OSTI]

Study of lithium diffusion in RF sputtered NickelÁ/Vanadium mixed oxides thin films F. Artuso a lithium insertion inside RF sputtered Ni/V mixed oxides thin films have been investigated employing, showed three steps clearly involved in the intercalation mechanism of lithium in the oxide films: (i

Artuso, Florinda

227

High tunability barium strontium titanate thin films for rf circuit applications  

E-Print Network [OSTI]

High tunability barium strontium titanate thin films for rf circuit applications N. K. Pervez,a) P) Large variations in the permittivity of rf magnetron sputtered thin-film barium strontium titanate have/cm. © 2004 American Institute of Physics. [DOI: 10.1063/1.1818724] Barium strontium titanate (BST) is a solid

York, Robert A.

228

Ambient-RF-Energy-Harvesting Sensor Node with Capacitor-Leakage-Aware Duty Cycle Control  

E-Print Network [OSTI]

Ambient-RF-Energy-Harvesting Sensor Node with Capacitor-Leakage-Aware Duty Cycle Control Ryo (WSN) that are solely powered by ambient RF power. Different from all other energy harvesting WSN for an energy storage in the energy harvesting system because of its efficient charge and discharge performance

Tentzeris, Manos

229

Study of high pressure gas filled RF cavities for muon collider  

E-Print Network [OSTI]

Muon collider is a considerable candidate of the next-generation high-energy lepton collider machine. Operating an RF cavity in a multi-Tesla magnet is a critical requirement in a muon accelerator and a cooling channel. However, the maximum RF gradient in a vacuum RF cavity is strongly limited by an external magnetic field. Dense hydrogen gas filled RF cavity has been proposed since it is functional of generating a high RF accelerating gradient in a strong magnetic field and making an ionization cooling process at the same time. A critical issue of the cavity is a beam- induced plasma that consumes a considerable amount of RF power. The gas filled RF test cell was made and measured the RF loading due to a beam-induced plasma by using an intense proton beam at Fermilab. By doping an electronegative gas in dense hydrogen, the plasma loading effect is significantly mitigated. The result shows that the cavity is functional with a muon collider beam. Recent progress is shown in this presentation.

Yonehara, Katsuya

2015-01-01T23:59:59.000Z

230

RF propagation in an HVAC duct system: impulse response characteristics of the channel  

E-Print Network [OSTI]

RF propagation in an HVAC duct system: impulse response characteristics of the channel Pavel V, the heating, ventilation, and air conditioning (HVAC) duct system in buildings is a complex network of hollow at RF and microwave frequencies of com- mon interest. HVAC ducts can be used as a wireless communication

Stancil, Daniel D.

231

An All Metal High Power Circularly Polarized 100 MW RF Load  

SciTech Connect (OSTI)

A compact RF load has been designed using a cascaded array of lossy radial RF chokes to dissipate 100 MW peak and 8 kW average power uniformly along the length of the load. Operation in the circularly polarized Te{_}11 mode assures uniform dissipation azimuthally as well.

Fowkes, W.R.; Jongewaard, E.N.; Loewen, R.J.; Tantawi, S.G.; Vlieks, A.E.; /SLAC

2011-08-30T23:59:59.000Z

232

Power Reduction of CMP Communication Networks via RF-Interconnects M-C. Frank Chang  

E-Print Network [OSTI]

- alized via integration of Radio Frequency Interconnect (RF- I) through on-chip transmission lines of analog waves over on- chip transmission lines. These technologies include radio fre- quency interconnect latency and low energy consumption [5][7]. RF-I transmission lines provide single-cycle cross

Cong, Jason "Jingsheng"

233

Permanent-magnet helicon sources and arrays: a new type of rf plasma Francis F. Chena)  

E-Print Network [OSTI]

Permanent-magnet helicon sources and arrays: a new type of rf plasma Francis F. Chena) and Humberto mechanism of RF coupling. However, the requirement of a dc magnetic field has prevented their wide acceptance in industry. The use of permanent magnets greatly simplifies helicon sources, and arrays of small

Chen, Francis F.

234

Permanent-magnet helicon sources and arrays: A new type of rf plasmaa... Francis F. Chenb  

E-Print Network [OSTI]

Permanent-magnet helicon sources and arrays: A new type of rf plasmaa... Francis F. Chenb mechanism of rf coupling. However, the requirement of a dc magnetic field has prevented their wide acceptance in industry. The use of permanent magnets greatly simplifies helicon sources, and arrays of small

Chen, Francis F.

235

Nonlinear time-fractional dispersive equations  

E-Print Network [OSTI]

In this paper we study some cases of time-fractional nonlinear dispersive equations (NDEs) involving Caputo derivatives, by means of the invariant subspace method. This method allows to find exact solutions to nonlinear time-fractional partial differential equations by separating variables. We first consider a third order time-fractional NDE that admits a four-dimensional invariant subspace and we find a similarity solution. We also study a fifth order NDE. In this last case we find a solution involving Mittag-Leffler functions. We finally observe that the invariant subspace method permits to find explicit solutions for a wide class of nonlinear dispersive time-fractional equations.

P. Artale Harris; R. Garra

2014-10-29T23:59:59.000Z

236

Accelerator dynamics of a fractional kicked rotor  

E-Print Network [OSTI]

It is shown that the Weyl fractional derivative can quantize an open system. A fractional kicked rotor is studied in the framework of the fractional Schrodinger equation. The system is described by the non-Hermitian Hamiltonian by virtue of the Weyl fractional derivative. Violation of space symmetry leads to acceleration of the orbital momentum. Quantum localization saturates this acceleration, such that the average value of the orbital momentum can be a direct current and the system behaves like a ratchet. The classical counterpart is a nonlinear kicked rotor with absorbing boundary conditions.

A. Iomin

2006-09-14T23:59:59.000Z

237

Nuclear magnetic resonance apparatus having semitoroidal rf coil for use in topical NMR and NMR imaging  

DOE Patents [OSTI]

An improved nuclear magnetic resonance (NMR) apparatus for use in topical magnetic resonance (TMR) spectroscopy and other remote sensing NMR applications includes a semitoroidal radio-frequency (rf) coil. The semitoroidal rf coil produces an effective alternating magnetic field at a distance from the poles of the coil, so as to enable NMR measurements to be taken from selected regions inside an object, particularly including human and other living subjects. The semitoroidal rf coil is relatively insensitive to magnetic interference from metallic objects located behind the coil, thereby rendering the coil particularly suited for use in both conventional and superconducting NMR magnets. The semitoroidal NMR coil can be constructed so that it emits little or no excess rf electric field associated with the rf magnetic field, thus avoiding adverse effects due to dielectric heating of the sample or to any other interaction of the electric field with the sample.

Fukushima, Eiichi (Los Alamos, NM); Roeder, Stephen B. W. (La Mesa, CA); Assink, Roger A. (Albuquerque, NM); Gibson, Atholl A. V. (Bryan, TX)

1986-01-01T23:59:59.000Z

238

Dependence of nuclear spin singlet lifetimes on RF spin-locking power  

E-Print Network [OSTI]

We measure the lifetime of long-lived nuclear spin singlet states as a function of the strength of the RF spin-locking field and present a simple theoretical model that agrees well with our measurements, including the low-RF-power regime. We also measure the lifetime of a long-lived coherence between singlet and triplet states that does not require a spin-locking field for preservation. Our results indicate that for many molecules, singlet states can be created using weak RF spin-locking fields: more than two orders of magnitude lower RF power than in previous studies. Our findings suggest that in many biomolecules, singlets and related states with enhanced lifetimes might be achievable in vivo with safe levels of RF power.

Stephen J. DeVience; Ronald L. Walsworth; Matthew S. Rosen

2012-01-06T23:59:59.000Z

239

Structurefunction of the Na/H Exchanger Regulatory Factor (NHE-RF) 2199 The Journal of Clinical Investigation  

E-Print Network [OSTI]

, Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, North Carolina 27710 representing full-length NHE-RF as well as truncated and mutant forms of NHE-RF were deter- mined using/H exchanger activity that is not regulated by PKA. NHE-RF in the presence of ATP and Mg but not PKA, in

Hall, Randy A

240

Material Selection and Characterization for High Gradient RF Applications  

E-Print Network [OSTI]

The selection of candidate materials for the accelerating cavities of the Compact Linear Collider (CLIC) is carried out in parallel with high power RF testing. The maximum DC breakdown field of copper, copper alloys, refractory metals, aluminium and titanium have been measured with a dedicated setup. Higher maximum fields are obtained for refractory metals and for titanium, which exhibits, however, important damages after conditioning. Fatigue behaviour of copper alloys has been studied for surface and bulk by pulsed laser irradiation and ultrasonic excitation, respectively. The selected copper alloys show consistently higher fatigue resistance than copper in both experiments. In order to obtain the best local properties in the device a possible solution is a bi-metallic assembly. Junctions of molybdenum and copper-zirconium UNS C15000 alloy, achieved by HIP (Hot Isostatic Pressing) diffusion bonding or explosion bonding were evaluated for their mechanical strength. The reliability of the results obtained wit...

Arnau-Izquierdo, G; Heikkinen, S; Ramsvik, T; Sgobba, Stefano; Taborelli, M; Wuensch, W

2007-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "rf respirable fraction" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

RF Design Optimization for New Injector Cryounit at CEBAF  

SciTech Connect (OSTI)

A new injector superconducting RF (SRF) cryounit with one new 2-cell, B=0.6 cavity plus one refurbished 7-cell, B=0.97, C100 style cavity has been re-designed and optimized for the engineering compatibility of existing module for CEBAF operation. The optimization of 2-cell cavity shape for longitudinal beam dynamic of acceleration from 200keV to 533keV and the minimization of transverse kick due to the waveguide couplers to less than 1 mrad have been considered. Operating at 1497MHz, two cavities has been designed into a same footprint of CEBAF original quarter cryomodule to deliver an injection beam energy of 5MeV in less than 0.27{degree} rms bunch length and a maximum energy spread of 5keV.

Wang, Haipeng; Cheng, Guangfeng; Hannon, Fay E.; Hofler, Alicia S.; Kazimi, Reza; Preble, Joe; Rimmer, Robert A.

2013-06-01T23:59:59.000Z

242

A new microphonics measurement method for superconducting RF cavities  

SciTech Connect (OSTI)

Mechanical vibrations of the superconducting cavity, also known as microphonics, cause shifts in the resonant frequency of the cavity. In addition to requiring additional RF power, these frequency shifts can contribute to errors in the closed loop phase and amplitude regulation. In order to better understand these effects, a new microphonics measurement method was developed, and the method was successfully used to measure microphonics on the half-wave superconducting cavity when it was operated in a production style cryostat. The test cryostat held a single ?=0.1 half-wave cavity which was operated at 162.5 MHz [1] and [2]. It's the first time that the National Instruments PXIe-5641R intermediate frequency transceiver has been used for microphonics measurements in superconducting cavities. The new microphonics measurement method and results will be shown and analyzed in this paper.

Gao,Zheng; He,Yuan; Chang,Wei; Powers, Tom [JLAB; Yue,Wei-ming; Zhu,Zheng-long; Chen,Qi

2014-09-01T23:59:59.000Z

243

Results of a preliminary, high power RF thruster test  

SciTech Connect (OSTI)

The objective of this program was to demonstrate a high power electrodeless, RF electric propulsion concept. This was successfully accomplished. No attempt was made to optimize the design of the thruster with regard to physical dimensions, mass flow, nozzle shape, operational frequency, or power level. Measurements made were chamber pressure, total and static pressures at the nozzle exit plane and exhaust tank pressure. Mass flows range from about 0.4 to 1 gm/sec and, assuming perfect gas relationships, specific impulses up to 580 sec were obtained. Typical chamber pressure was 300 torr exhausting to a tank pressure of about 10 torr. Working fluids used were argon, helium and mixtures of the two. No degration of the device was detected after 12 start/stop cycles, about three hours of total run time, and a maximum input power of 70 kW. 10 refs.

Brewer, L.; Karras, T.; Frind, G.; Holmes, D.G.

1989-01-01T23:59:59.000Z

244

National RF Test Facility as a multipurpose development tool  

SciTech Connect (OSTI)

Additions and modifications to the National RF Test Facility design have been made that (1) focus its use for technology development for future large systems in the ion cyclotron range of frequencies (ICRF), (2) expand its applicability to technology development in the electron cyclotron range of frequencies (ECRF) at 60 GHz, (3) provide a facility for ELMO Bumpy Torus (EBT) 60-GHz ring physics studies, and (4) permit engineering studies of steady-state plasma systems, including superconducting magnet performance, vacuum vessel heat flux removal, and microwave protection. The facility will continue to function as a test bed for generic technology developments for ICRF and the lower hybrid range of frequencies (LHRF). The upgraded facility is also suitable for mirror halo physics experiments.

McManamy, T.J.; Becraft, W.R.; Berry, L.A.; Blue, C.W.; Gardner, W.L.; Haselton, H.H.; Hoffman, D.J.; Loring, C.M. Jr.; Moeller, F.A.; Ponte, N.S.

1983-01-01T23:59:59.000Z

245

Nanometer emittance ultralow charge beams from rf photoinjectors  

DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

In this paper we discuss the generation of a new class of high brightness relativistic electron beams, characterized by ultralow charge (0.1–1 pC) and ultralow normalized emittance (<50??nm ). These beams are created in rf photoinjectors when the laser is focused on the cathode to very small transverse sizes (<30???m rms). In this regime, the charge density at the cathode approaches the limit set by the extraction electric field. By shaping the laser pulse to have a cigarlike aspect ratio (the longitudinal dimension much larger than the transverse dimension) and a parabolic temporal profile, the resulting space charge dominated dynamics creates a uniformly filled ellipsoidal distribution and the emittance can be nearly preserved to its thermal value. We also present a new method, based on a variation of the pepper-pot technique, for single shot measurements of the ultralow emittances for this new class of beams.

Li, R. K.; Roberts, K. G.; Scoby, C. M.; To, H.; Musumeci, P.

2012-09-01T23:59:59.000Z

246

The Development of the Linac Coherent Light Source RF Gun  

E-Print Network [OSTI]

The Linac Coherent Light Source (LCLS) is the first x-ray laser user facility based upon a free electron laser (FEL). In addition to many other stringent requirements, the LCLS XFEL requires extraordinary beam quality to saturate at 1.5 angstroms within a 100 meter undulator.[1] This new light source is using the last kilometer of the three kilometer linac at SLAC to accelerate the beam to an energy as high as 13.6 GeV and required a new electron gun and injector to produce a very bright beam for acceleration. At the outset of the project it was recognized that existing RF guns had the potential to produce the desired beam but none had demonstrated it. This paper describes the analysis and design improvements of the BNL/SLAC/UCLA s-band gun leading to achievement of the LCLS performance goals.

Dowell, David H; Lewandowski, James; Limborg-Deprey, Cecile; Li, Zenghai; Schmerge, John; Vlieks, Arnold; Wang, Juwen; Xiao, Liling

2015-01-01T23:59:59.000Z

247

Fractional Exact Solutions and Solitons in Gravity  

E-Print Network [OSTI]

We survay our recent results on fractional gravity theory. It is also provided the Main Theorem on encoding of geometric data (metrics and connections in gravity and geometric mechanics) into solitonic hierarchies. Our approach is based on Caputo fractional derivative and nonlinear connection formalism.

Dumitru Baleanu; Sergiu I. Vacaru

2010-08-02T23:59:59.000Z

248

Void Fraction Instrument operation and maintenance manual  

SciTech Connect (OSTI)

This Operations and Maintenance Manual (O&MM) addresses riser installation, equipment and personnel hazards, operating instructions, calibration, maintenance, removal, and other pertinent information necessary to safely operate and store the Void Fraction Instrument. Final decontamination and decommissioning of the Void Fraction Instrument are not covered in this document.

Borgonovi, G.; Stokes, T.I.; Pearce, K.L.; Martin, J.D.; Gimera, M.; Graves, D.B.

1994-09-01T23:59:59.000Z

249

Inverse Problems for Fractional Diffusion Equations  

E-Print Network [OSTI]

. . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 1.5.3 Derivation of fractional difiusion equations . . . . . . . . . . . 12 1.6 Fractional calculus . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 1.7 Mittag-Le?er function . . . . . . . . . . . . . . . . . . . . . . . . . . 14 1... point theory . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 1.3 Volterra equation of the second kind . . . . . . . . . . . . . . . . . . 6 1.4 Classical difiusion equations . . . . . . . . . . . . . . . . . . . . . . . 6 1.4.1 Derivation...

Zuo, Lihua

2013-06-21T23:59:59.000Z

250

Fractional Zaslavsky and Henon Discrete Maps  

E-Print Network [OSTI]

This paper is devoted to the memory of Professor George M. Zaslavsky passed away on November 25, 2008. In the field of discrete maps, George M. Zaslavsky introduced a dissipative standard map which is called now the Zaslavsky map. G. Zaslavsky initialized many fundamental concepts and ideas in the fractional dynamics and kinetics. In this paper, starting from kicked damped equations with derivatives of non-integer orders we derive a fractional generalization of discrete maps. These fractional maps are generalizations of the Zaslavsky map and the Henon map. The main property of the fractional differential equations and the correspondent fractional maps is a long-term memory and dissipation. The memory is realized by the fact that their present state evolution depends on all past states with special forms of weights.

Vasily E. Tarasov

2011-07-26T23:59:59.000Z

251

Modulation and daily banding of Mg/Ca in Orbulina universa tests by symbiont photosynthesis and respiration: a complication for  

E-Print Network [OSTI]

of calcium carbonate tests (shells) secreted by planktonic foraminifera is increasingly being employed­respiration cycle of algal symbionts. The amplitude of Mg/Ca variation within individual tests and across many daily is strongly influenced by diurnal changes in the biological activity of algal symbionts and the host

252

Short-Term Effects of Experimental Burning and Thinning on Soil Respiration in an Old-Growth,  

E-Print Network [OSTI]

sustainability and CO2 sequestration, we evaluated the effects of burning and thin- ning treatments on soil application of these forest management practices. Soil respiration, including autotrophic and hetero- trophic and Schlesinger 1992), forest management activities, such as burning and thinning, can also change soil environ

North, Malcolm

253

Subarctic Pacific evidence for a glacial deepening of the oceanic respired carbon pool S.L. Jaccard a,d,  

E-Print Network [OSTI]

Subarctic Pacific evidence for a glacial deepening of the oceanic respired carbon pool S.L. Jaccard of the overturning circulation. Volumetrically the Pacific Ocean dominates the world ocean (it is three times larger of Atmospheric and Oceanic Sciences, Princeton University, Princeton, USA c Department of Geosciences, Princeton

Gilli, Adrian

254

Long-term effects of soil warming on labile carbon availability and microbial community respiration and composition  

E-Print Network [OSTI]

of a positive feedback loop if this carbon were to enter the atmosphere. Much of the carbon that entersLong-term effects of soil warming on labile carbon availability and microbial community respiration of warming on the microbial community and soil organic carbon pool. Soils were incubated at various

Vallino, Joseph J.

255

Production, oxygen respiration rates, and sinking velocity of copepod fecal pellets: Direct measurements of ballasting by opal and calcite  

E-Print Network [OSTI]

Production, oxygen respiration rates, and sinking velocity of copepod fecal pellets: Direct of copepod fecal pellets egested by Temora longicornis were measured using a nanoflagellate (Rhodomonas sp pellet production varied between 0.8 pellets ind21 h21 and 3.8 pellets ind21 h21 and was significantly

Matthews, Adrian

256

Aquatic respiration in many fishes is a mechanical ballet in which water is pumped from the oropharyngeal chamber,  

E-Print Network [OSTI]

pattern at the three openings into the respiratory system: (1) in through the spiracle only, (2Aquatic respiration in many fishes is a mechanical ballet in which water is pumped from of discontinuous flow into the mouth and out of the gill slit(s). The blood flow in the respiratory structures

Summers, Adam P.

257

Multi-Year Lags between Forest Browning and Soil Respiration at High Northern Latitudes  

SciTech Connect (OSTI)

High-latitude northern ecosystems are experiencing rapid climate changes, and represent a large potential climate feedback because of their high soil carbon densities and shifting disturbance regimes. A significant carbon flow from these ecosystems is soil respiration (RS, the flow of carbon dioxide, generated by plant roots and soil fauna, from the soil surface to atmosphere), and any change in the high-latitude carbon cycle might thus be reflected in RS observed in the field. This study used two variants of a machine-learning algorithm and least squares regression to examine how remotely-sensed canopy greenness (NDVI), climate, and other variables are coupled to annual RS based on 105 observations from 64 circumpolar sites in a global database. The addition of NDVI roughly doubled model performance, with the best-performing models explaining ~62% of observed RS variability

Bond-Lamberty, Benjamin; Bunn, Andrew G.; Thomson, Allison M.

2012-11-26T23:59:59.000Z

258

Exploring the biochemistry at the extracellular redox frontier of bacterial mineral Fe(III) respiration  

SciTech Connect (OSTI)

Many species of the bacterial Shewanella genus are notable for their ability to respire in anoxic environments utilizing insoluble minerals of Fe(III) and Mn(IV) as extracellular electron acceptors. In Shewanella oneidensis, the process is dependent on the decahaem electron-transport proteins that lie at the extracellular face of the outer membrane where they can contact the insoluble mineral substrates. These extracellular proteins are charged with electrons provided by an inter-membrane electron-transfer pathway that links the extracellular face of the outer membrane with the inner cytoplasmic membrane and thereby intracellular electron sources. In the present paper, we consider the common structural features of two of these outermembrane decahaem cytochromes, MtrC and MtrF, and bring this together with biochemical, spectroscopic and voltammetric data to identify common and distinct properties of these prototypical members of different clades of the outer-membrane decahaem cytochrome superfamily.

Richardson, David J.; Edwards, Marcus; White, Gaye F.; Baiden, Nanakow; Hartshorne, Robert S.; Fredrickson, Jim K.; Shi, Liang; Zachara, John M.; Gates, Andrew J.; Butt, Julea N.; Clarke, Thomas

2012-06-01T23:59:59.000Z

259

Next Generation Fast RF Interlock Module and ATCA Adapter for ILC High Availability RF Test Station Demonstration  

SciTech Connect (OSTI)

High availability interlocks and controls are required for the ILC (International Linear Collider) L-Band high power RF stations. A new F3 (Fast Fault Finder) VME module has been developed to process both fast and slow interlocks using FPGA logic to detect the interlock trip excursions. This combination eliminates the need for separate PLC (Programmable Logic Controller) control of slow interlocks. Modules are chained together to accommodate as many inputs as needed. In the next phase of development the F3's will be ported to the new industry standard ATCA (Advanced Telecom Computing Architecture) crate (shelf) via a specially designed VME adapter module with IPMI (Intelligent Platform Management Interface). The goal is to demonstrate auto-failover and hot-swap for future partially redundant systems.

Larsen, R

2009-10-17T23:59:59.000Z

260

On using an adaptive neural network to predict lung tumor motion during respiration for radiotherapy applications  

SciTech Connect (OSTI)

In this study we address the problem of predicting the position of a moving lung tumor during respiration on the basis of external breathing signals--a technique used for beam gating, tracking, and other dynamic motion management techniques in radiation therapy. We demonstrate the use of neural network filters to correlate tumor position with external surrogate markers while simultaneously predicting the motion ahead in time, for situations in which neither the breathing pattern nor the correlation between moving anatomical elements is constant in time. One pancreatic cancer patient and two lung cancer patients with mid/upper lobe tumors were fluoroscopically imaged to observe tumor motion synchronously with the movement of external chest markers during free breathing. The external marker position was provided as input to a feed-forward neural network that correlated the marker and tumor movement to predict the tumor position up to 800 ms in advance. The predicted tumor position was compared to its observed position to establish the accuracy with which the filter could dynamically track tumor motion under nonstationary conditions. These results were compared to simplified linear versions of the filter. The two lung cancer patients exhibited complex respiratory behavior in which the correlation between surrogate marker and tumor position changed with each cycle of breathing. By automatically and continuously adjusting its parameters to the observations, the neural network achieved better tracking accuracy than the fixed and adaptive linear filters. Variability and instability in human respiration complicate the task of predicting tumor position from surrogate breathing signals. Our results show that adaptive signal-processing filters can provide more accurate tumor position estimates than simpler stationary filters when presented with nonstationary breathing motion.

Isaksson, Marcus; Jalden, Joakim; Murphy, Martin J. [Department of Electrical Engineering, Stanford University, Stanford, California 94036 (United States); Department of Radiation Oncology, Virginia Commonwealth University, Richmond, Virginia 23298 (United States)

2005-12-15T23:59:59.000Z

Note: This page contains sample records for the topic "rf respirable fraction" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Pressurized H_{2} rf Cavities in Ionizing Beams and Magnetic Fields  

SciTech Connect (OSTI)

A major technological challenge in building a muon cooling channel is operating RF cavities in multi-tesla external magnetic fields. We report the first experimental characterization of a high pressure gas-filled 805 MHz RF cavity for use with intense ionizing beams and strong external magnetic fields. RF power consumption by beam-induced plasma was investigated with hydrogen and deuterium gases with pressures between 20 and 100 atm and peak RF gradients between 5 and 50 MV/m. The energy absorption per ion pair-RF cycle ranges from 10?18 to 10?16 J. The low pressure case agrees well with an analytical model based on electron and ion mobilities. Varying concentrations of oxygen gas were investigated to remove free electrons from the cavity and reduce the RF power consumption. Measurements of the electron attachment time to oxygen and rate of ion-ion recombination were also made. Additionally, we demonstrate the operation of the gas-filled RF cavity in a solenoidal field of up to 3 T, finding no major magnetic field dependence. These results indicate that a high pressure gas-filled cavity is potentially a viable technology for muon ionization cooling.

Chung, M.; et al.

2013-10-01T23:59:59.000Z

262

Responses of soil respiration to elevated CO2, air warming, and changing soil water availability in an old-field grassland  

SciTech Connect (OSTI)

Responses of soil respiration to atmospheric and climatic change will have profound impacts on ecosystem and global C cycling in the future. This study was conducted to examine effects on soil respiration of the concurrent driving factors of elevated atmospheric CO2 concentration, rising temperature, and changing precipitation in a constructed old-field grassland in eastern Tennessee, USA. Model ecosystems of seven old-field species in 12 open-top chambers (4 m in diameter) were treated with two CO2 (ambient and ambient plus 300 ppm) and two temperature (ambient and ambient plus 3 C) levels. Two split plots with each chamber were assigned with high and low soil moisture levels. During the 19-month experimental period from June 2003 to December 2004, higher CO2 concentration and soil water availability significantly increased mean soil respiration by 35.8% and 15.7%, respectively. The effects of air warming on soil respiration varied seasonally from small reductions to significant increases to no response, and there was no significant main effect. In the wet side of elevated CO2 chambers, air warming consistently caused increases in soil respiration, whereas in other three combinations of CO2 and water treatments, warming tended to decrease soil respiration over the growing season but increase it over the winter. There were no interactive effects on soil respiration among any two or three treatment factors irrespective of testing time period. Temperature sensitivity of soil respiration was reduced by air warming, lower in the wet than the dry side, and not affected by CO2 treatment. Variations of soil respiration responses with soil temperature and soil moisture ranges could be primarily attributable to the seasonal dynamics of plant growth and its responses to the three treatments. Using a conceptual model to interpret the significant relationships of treatment-induced changes in soil respiration with changes in soil temperature and moisture observed in this study, we conclude that elevated CO2, air warming, and changing soil water availability had both direct and indirect effects on soil respiration via changes in the three controlling factors: soil temperature, soil moisture, and C substrate. Our results demonstrate that the response of soil respiration to climatic warming should not be represented in models as a simple temperature response function. A more mechanistic understanding of the direct and indirect impacts of concurrent global change drivers on soil respiration is needed to facilitate the interpretation and projection of ecosystem and global C cycling in response to atmospheric and climate change.

Wan, Shiqiang [Chinese Academy of Sciences; Norby, Richard J [ORNL; Childs, Joanne [ORNL; Weltzin, Jake [University of Tennessee, Knoxville (UTK)

2007-01-01T23:59:59.000Z

263

Assessment of contrast enhanced respiration managed cone-beam CT for image guided radiotherapy of intrahepatic tumors  

SciTech Connect (OSTI)

Purpose: Contrast enhancement and respiration management are widely used during image acquisition for radiotherapy treatment planning of liver tumors along with respiration management at the treatment unit. However, neither respiration management nor intravenous contrast is commonly used during cone-beam CT (CBCT) image acquisition for alignment prior to radiotherapy. In this study, the authors investigate the potential gains of injecting an iodinated contrast agent in combination with respiration management during CBCT acquisition for liver tumor radiotherapy. Methods: Five rabbits with implanted liver tumors were subjected to CBCT with and without motion management and contrast injection. The acquired CBCT images were registered to the planning CT to determine alignment accuracy and dosimetric impact. The authors developed a simulation tool for simulating contrast-enhanced CBCT images from dynamic contrast enhanced CT imaging (DCE-CT) to determine optimal contrast injection protocols. The tool was validated against contrast-enhanced CBCT of the rabbit subjects and was used for five human patients diagnosed with hepatocellular carcinoma. Results: In the rabbit experiment, when neither motion management nor contrast was used, tumor centroid misalignment between planning image and CBCT was 9.2 mm. This was reduced to 2.8?mm when both techniques were employed. Tumors were not visualized in clinical CBCT images of human subjects. Simulated contrast-enhanced CBCT was found to improve tumor contrast in all subjects. Different patients were found to require different contrast injections to maximize tumor contrast. Conclusions: Based on the authors’ animal study, respiration managed contrast enhanced CBCT improves IGRT significantly. Contrast enhanced CBCT benefits from patient specific tracer kinetics determined from DCE-CT.

Jensen, Nikolaj K. G., E-mail: nkyj@regionsjaelland.dk [Physics and Engineering, London Regional Cancer Program, London, Ontario N6A3K7 (Canada)] [Physics and Engineering, London Regional Cancer Program, London, Ontario N6A3K7 (Canada); Stewart, Errol [Radiology, St. Joseph's Health Care, London, Ontario N6A 4V2 (Canada) [Radiology, St. Joseph's Health Care, London, Ontario N6A 4V2 (Canada); Imaging Research Lab, Robarts Research Institute, London, Ontario N6A 5B7 (Canada); Imaging Program, Lawson Health Research Institute, London, Ontario N6C 2R5 (Canada); Lock, Michael; Fisher, Barbara [Radiation Oncology, London Regional Cancer Program, London, Ontario N6A3K7 (Canada) [Radiation Oncology, London Regional Cancer Program, London, Ontario N6A3K7 (Canada); Department of Oncology, University of Western Ontario, London, Ontario N6A 4L6 (Canada); Kozak, Roman [Radiology, St. Joseph's Health Care, London, Ontario N6A 4V2 (Canada)] [Radiology, St. Joseph's Health Care, London, Ontario N6A 4V2 (Canada); Chen, Jeff [Physics and Engineering, London Regional Cancer Program, London, Ontario N6A3K7 (Canada) [Physics and Engineering, London Regional Cancer Program, London, Ontario N6A3K7 (Canada); Department of Oncology, University of Western Ontario, London, Ontario N6A 4L6 (Canada); Department of Medical Biophysics, University of Western Ontario, London, Ontario N6A 5C1 (Canada); Lee, Ting-Yim [Radiology, St. Joseph's Health Care, London, Ontario N6A 4V2 (Canada) [Radiology, St. Joseph's Health Care, London, Ontario N6A 4V2 (Canada); Imaging Research Lab, Robarts Research Institute, London, Ontario N6A 5B7 (Canada); Imaging Program, Lawson Health Research Institute, London, Ontario N6C 2R5 (Canada); Department of Oncology, University of Western Ontario, London, Ontario N6A 4L6 (Canada); Department of Medical Biophysics, University of Western Ontario, London, Ontario N6A 5C1 (Canada); Wong, Eugene [Physics and Engineering, London Regional Cancer Program, London, Ontario N6A3K7 (Canada) [Physics and Engineering, London Regional Cancer Program, London, Ontario N6A3K7 (Canada); Department of Oncology, University of Western Ontario, London, Ontario N6A 4L6 (Canada); Department of Medical Biophysics, University of Western Ontario, London, Ontario N6A 5C1 (Canada); Department of Physics and Astronomy, University of Western Ontario, London, Ontario N6A 3K7 (Canada)

2014-05-15T23:59:59.000Z

264

Solid state RF power: The route to 1W per euro cent  

SciTech Connect (OSTI)

In most particle accelerators RF power is a decisive design constraint due to high costs and relative inflexibility of current electron beam based RF sources, i.e. Klystrons, Magnetrons, Tetrodes etc. At VHF/UHF frequencies the transition to solid state devices promises to fundamentally change the situation. Recent progress brings 1 Watt per Euro cent installed cost within reach. We present a Silicon Carbide semiconductor solution utilising the Solid State Direct Drive technology at unprecedented efficiency, power levels and power densities. The proposed solution allows retrofitting of existing RF accelerators and opens the route to novel particle accelerator concepts.

Heid, Oliver [Siemens AG, Mozartstrasse 57, Erlangen (Germany)

2013-04-19T23:59:59.000Z

265

RF-driven ion source with a back-streaming electron dump  

DOE Patents [OSTI]

A novel ion source is described having an improved lifetime. The ion source, in one embodiment, is a proton source, including an external RF antenna mounted to an RF window. To prevent backstreaming electrons formed in the beam column from striking the RF window, a back streaming electron dump is provided, which in one embodiment is formed of a cylindrical tube, open at one end to the ion source chamber and capped at its other end by a metal plug. The plug, maintained at the same electrical potential as the source, captures these backstreaming electrons, and thus prevents localized heating of the window, which due to said heating, might otherwise cause window damage.

Kwan, Joe; Ji, Qing

2014-05-20T23:59:59.000Z

266

RF-sheath heat flux estimates on Tore Supra and JET ICRF antennae. Extrapolation to ITER  

SciTech Connect (OSTI)

RF-sheath induced heat loads are identified from infrared thermography measurements on Tore Supra ITER-like prototype and JET A2 antennae, and are quantified by fitting thermal calculations. Using a simple scaling law assessed experimentally, the estimated heat fluxes are then extrapolated to the ITER ICRF launcher delivering 20 MW RF power for several plasma scenarios. Parallel heat fluxes up to 6.7 MW/m{sup 2} are expected very locally on ITER antenna front face. The role of edge density on operation is stressed as a trade-off between easy RF coupling and reasonable heat loads. Sources of uncertainty on the results are identified.

Colas, L.; Portafaix, C.; Goniche, M. [CEA, IRFM, F-13108 Saint-Paul-lez-Durance (France); Jacquet, Ph. [EURATOM/UKAEA Fusion Association, Culham, OX14 3DB (United Kingdom); Agarici, G. [Fusion for Energy, C/Josep Pla 2, E-08019 Barcelona (Spain)

2009-11-26T23:59:59.000Z

267

Arc Detection and Interlock Module for the PEP II Low Level RF System  

SciTech Connect (OSTI)

A new arc detection and interlock generating module for the SLAC PEP-II low-level RF VXI-based system has been developed. The system is required to turn off the RF drive and high voltage power supply in the event of arcing in the cavity windows, klystron window, or circulator. Infrared photodiodes receive arc signals through radiation resistant optical fibers. Gain and bandwidth are selectable for each channel to allow tailoring response. The module also responds to interlock requests from other modules in the VXI system and communicates with the programmable logic controller (PLC) responsible for much of the low-level RF system's interlock functionality.

Tighe, R.; /SLAC

2011-08-31T23:59:59.000Z

268

Bio-oil fractionation and condensation  

DOE Patents [OSTI]

A method of fractionating bio-oil vapors which involves providing bio-oil vapors comprising bio-oil constituents is described. The bio-oil vapors are cooled in a first stage which comprises a condenser having passages for the bio-oil separated by a heat conducting wall from passages for a coolant. The coolant in the condenser of the first stage is maintained at a substantially constant temperature, set at a temperature in the range of 75 to 100.degree. C., to condense a first liquid fraction of liquefied bio-oil constituents in the condenser of the first stage. The first liquid fraction of liquified bio-oil constituents from the condenser in the first stage is collected. Also described are steps for subsequently recovering further liquid fractions of liquefied bio-oil constituents. Particular compositions of bio-oil condensation products are also described.

Brown, Robert C; Jones, Samuel T; Pollard, Anthony

2013-07-02T23:59:59.000Z

269

Development of plutonium aerosol fractionation system  

E-Print Network [OSTI]

DEVELOPMENT OF A PLUTONIUM AEROSOL FRACTIONATION SYSTEM A Thesis by MALLA R. MEKALA Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE August... 1993 Major Subject: Mechanical Engineering DEVELOPMENT OP A PLUTONIUM AEROSOL FRACTIONATION SYSTEM A Thesis by MALLA R. MEKALA Approved as to style and content by: A. R. McFarland (Chair of Committee) N. K. Anand (Mer toer) (', & C. B...

Mekala, Malla R.

1993-01-01T23:59:59.000Z

270

Tunable Substrate Integrated Waveguide Filters Implemented with PIN Diodes and RF MEMS Switches  

E-Print Network [OSTI]

This thesis presents the first fully tunable substrate integrated waveguide (SIW) filter implemented with PIN diodes and RF MEMS switches. The methodology for tuning SIW filters is explained in detail and is used to create three separate designs...

Armendariz, Marcelino

2012-02-14T23:59:59.000Z

271

E-Print Network 3.0 - average current rf Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

management estimates the channel upon a frame recep- tion. MIMO... MHz bandwidth. 6.2 Simulation Results We compare the average energy per bit of RF chain management... measure...

272

A New First-Principles Calculation of Field-Dependent RF Surface Impedance of BCS Superconductor  

SciTech Connect (OSTI)

There is a need to understand the intrinsic limit of radiofrequency (RF) surface impedance that determines the performance of superconducting RF cavities in particle accelerators. Here we present a field-dependent derivation of Mattis-Bardeen theory of the RF surface impedance of BCS superconductors based on the shifted density of states resulting from coherently moving Cooper pairs. Our theoretical prediction of the effective BCS RF surface resistance (Rs) of niobium as a function of peak surface magnetic field amplitude agrees well with recently reported record low loss resonant cavity measurements from JLab and FNAL with carefully, yet differently, prepared niobium material. The surprising reduction in resistance with increasing field is explained to be an intrinsic effect.

Xiao, Binping [Brookhaven National Laboratory, Upton, New York (United States); Reece, Charles E. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)

2014-02-01T23:59:59.000Z

273

Design of RF/IF analog to digital converters for software radio communication receivers  

E-Print Network [OSTI]

Software radio architecture can support multiple standards by performing analogto- digital (A/D) conversion of the radio frequency (RF) signals and running reconfigurable software programs on the backend digital signal processor (DSP). A slight...

Thandri, Bharath Kumar

2007-09-17T23:59:59.000Z

274

Highly Parallel Magnetic Resonance Imaging with a Fourth Gradient Channel for Compensation of RF Phase Patterns  

E-Print Network [OSTI]

A fourth gradient channel was implemented to provide slice dependent RF coil phase compensation for arrays in dual-sided or "sandwich" configurations. The use of highly parallel arrays for single echo acquisition magnetic resonance imaging allows...

Bosshard, John 1983-

2012-08-20T23:59:59.000Z

275

E-Print Network 3.0 - atmospheric rf device Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

rf device Page: << < 1 2 3 4 5 > >> 1 Packaging of Ka-Band Patch Antenna and Optoelectronic Components for Dual-Mode Indoor Wireless Communication Summary: that the coupling...

276

Experimental evaluation of 350 MHz RF accelerator windows for the low energy demonstration accelerator  

SciTech Connect (OSTI)

Radio frequency (RF) windows are historically a point where failure occurs in input power couplers for accelerators. To obtain a reliable, high-power, 350 MHz RF window for the Low Energy Demonstration Accelerator (LEDA) project of the Accelerator Production of Tritium program, RF windows prototypes from different vendors were tested. Experiments were performed to evaluate the RF windows by the vendors to select a window for the LEDA project. The Communications and Power, Inc. (CPI) windows were conditioned to 445 kW in roughly 15 hours. At 445 kW a window failed, and the cause of the failure will be presented. The English Electronic Valve, Inc. (EEV) windows were conditioned to 944 kW in 26 hours and then tested at 944 kW for 4 hours with no indication of problems.

Cummings, K.; Rees, D.; Roybal, W. [and others

1997-09-01T23:59:59.000Z

277

PURDUE UNIVERSITY ULTRAFAST OPTICS & OPTICAL FIBER COMMUNICATIONS LABORATORY Photonic RF Waveform Synthesis,  

E-Print Network [OSTI]

PURDUE UNIVERSITY ULTRAFAST OPTICS & OPTICAL FIBER COMMUNICATIONS LABORATORY Photonic RF Waveform, Shijun Xiao Funding from ARO, DARPA, and NSF #12;PURDUE UNIVERSITY ULTRAFAST OPTICS & OPTICAL FIBER performance (spectral engineering, dispersion compensation) #12;PURDUE UNIVERSITY ULTRAFAST OPTICS & OPTICAL

Purdue University

278

Detection technique and front-end RF tunable filter for cognitive radio systems  

E-Print Network [OSTI]

dual-mode WiMAX/WLAN direct- conversion receiver,” in Proc.Hamilton, “Aspects of direct conversion receiver design,” inand M. Ismail, “A direct conversion WiMAX RF receiver front-

Park, Sanghoon

2010-01-01T23:59:59.000Z

279

High gain proportional rf control stability at TESLA cavities Elmar Vogel  

E-Print Network [OSTI]

High gain proportional rf control stability at TESLA cavities Elmar Vogel Deutsches Elektronen) based on TESLA technology. Additional control loops improve the field regulation by treating repetitive loops is desirable for the strong suppression of nonpredictive and nonrepetitive disturbances. TESLA

280

Thesis for the Degree of Licentiate of Engineering CTH-RF-190 Development and Investigation of  

E-Print Network [OSTI]

Thesis for the Degree of Licentiate of Engineering CTH-RF-190 Development and Investigation (ADS), Feynman-alpha formulae, source modulation method, point kinetics #12;#12;This licentiate thesis

Haviland, David

Note: This page contains sample records for the topic "rf respirable fraction" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

A CW normal-conductive RF gun for free electron laser and energy recovery linac applications  

E-Print Network [OSTI]

Todd, State-of-the art electron guns and injector de- signs,7] Summary of working group on guns and injectors, 41st Ad-A CW normal-conductive RF gun for free electron laser and

Baptiste, Kenneth

2009-01-01T23:59:59.000Z

282

A high-gradient high-duty-factor Rf photo-cathode electron gun  

E-Print Network [OSTI]

approximately 13 MV/m, but in the gun cell the fields couldBeam Radius [mm] End of rf gun Uncompensated Compensated 6preliminary analysis of the gun indicates that the fields in

Rimmer, Robert A.; Hartman, Neal; Lidia, Steven M.; Wang, Shaoheng

2002-01-01T23:59:59.000Z

283

Analysis of slice transverse emittance evolutioin in a photocathode RF gun  

E-Print Network [OSTI]

evolution at 1 nC for the LCLS gun including the solenoidevolution at 1 nC for the LCLS gun including the solenoidevolution in a photocathode RF gun Zhirong Huang, Yuantao

Huang, Zhirong

2009-01-01T23:59:59.000Z

284

High-power rf-pulsed modulators for the Los Alamos free-electron laser  

SciTech Connect (OSTI)

In the rf-driven free-electron laser (FEL) at the Los Alamos National Laboratory, there are two pulsed-power rf modulators as sources for two tandem, side-coupled 20-MeV linear accelerators. The rf power used to control the cavity fields is supplied by two 5.5-MW modulating anode klystrons operating at a center frequency of 1300.2 MHz. The modulation of the 125 kV klystron is achieved by using a triode switch tube that provides a pulse width up to 300 ..mu..s and a pulse repetition rate up to 10 Hz. This paper describes the present configuration of these two duplicate systems and presents plans for meeting the requirements of future rf FEL experiments at Los Alamos. 12 refs., 5 figs.

Johnson, W.J.D.; Lynch, M.T.; Tallerico, P.J.; Keffeler, D.R.; Hornkohl, J.O.

1987-09-01T23:59:59.000Z

285

Deeply-scaled GaN high electron mobility transistors for RF applications  

E-Print Network [OSTI]

Due to the unique combination of large critical breakdown field and high electron velocity, GaN-based high electron mobility transistors (HEMTs) have great potential for next generation high power RF amplifiers. The ...

Lee, Dong Seup

2014-01-01T23:59:59.000Z

286

E-Print Network 3.0 - active rf pulse Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

that the duty ratios of the pulse are kept large for small input. Then, an RF pulse train is generated by mixing... the modulated envelope with the phase modulated carrier. The...

287

Wide-Range Bolometer with RF Readout TES  

E-Print Network [OSTI]

To improve both scalability and noise-filtering capability of a Transition-Edge Sensor (TES), a new concept of a thin-film detector is suggested, which is based on embedding a microbridge TES into a high-Q planar GHz range resonator weakly coupled to a 50 Ohm-readout transmission line. Such a TES element is designed as a hot-electron microbolometer coupled to a THz range antenna and as a load of the resonator at the same time. A weak THz signal coupled to the antenna heats the microbridge TES, thus reducing the quality factor of the resonator and leading to a power increment in the readout line. The power-to-power conversion gain, an essential figure of merit, is estimated to be above 10. To demonstrate the basic concept, we fabricated and tested a few submicron sized devices from Nb thin films for operation temperature about 5 K. The dc and rf characterization of the new device is made at a resonator frequency about 5.8 GHz. A low-noise HEMT amplifier is used in our TES experiments without the need for a SQU...

Shitov, S V; Kuzmin, A A; Merker, M; Arndt, M; Wuensch, S H; Ilin, K S; Erhan, E; Ustinov, A; Siegel, M

2014-01-01T23:59:59.000Z

288

Superconducting RF Linac Technology for ERL Light Sources  

SciTech Connect (OSTI)

Energy Recovering Linacs (ERLs) offer an attractive alternative as drivers for light sources as they combine the desirable characteristics of both storage rings (high efficiency) and linear accelerators (superior beam quality). Using superconducting RF technology allows ERLs to operate more efficiently because of the inherent characteristics of SRF linacs, namely that they are high gradient-low impedance structures and their ability to operate in the long pulse or CW regime. We present an overview of the physics challenges encountered in the design and operation of ERL based light sources with particular emphasis on those issues related to SRF technology. These challenges include maximizing a cavity�������¢����������������s Qo to increase cryogenic efficiency, maintaining control of the cavity field in the presence of the highest feasible loaded Q and providing adequate damping of the higher-order modes (HOMs). If not sufficiently damped, dipole HOMs can drive the multipass beam breakup (BBU) instability which ERLs are particularly susceptible to. Another challenge involves efficiently extracting the potentially large amounts of HOM power that are generated when a bunch traverses the SRF cavities and which may extend over a high range of frequencies. We present experimental data from the Jefferson Lab FEL Upgrade, a 10 mA ERL light source presently in operation, aimed at addressing some of these issues. We conclude with an outlook towards the future of ERL based light sources.

Chris Tennant

2005-08-01T23:59:59.000Z

289

Comparison of the theory and the practice of rf current drive  

SciTech Connect (OSTI)

The theory of rf-driven plasma currents is applied to the lower-hybrid experiments on the PLT tokamak. Particular emphasis is placed on those experiments in which the plasma current was varying. The comparison between theory and experiment is made with respect to the efficiency with which rf energy was converted to poloidal magnetic field energy. Good agreement is found irrespective of whether the current was increasing, constant, or decreasing.

Karney, C.F.F.; Fisch, N.J.; Jobes, F.C.

1984-10-01T23:59:59.000Z

290

Laser cooling and sympathetic cooling in a linear quadrupole rf trap  

E-Print Network [OSTI]

LASER COOLING AND SYMPATHETIC COOLING IN A LINEAR QUADRUPOLE RF TRAP A Dissertation by VLADIMIR LEONIDOVICH RYJKOV Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree... of DOCTOR OF PHILOSOPHY December 2003 Major Subject: Physics LASER COOLING AND SYMPATHETIC COOLING IN A LINEAR QUADRUPOLE RF TRAP A Dissertation by VLADIMIR LEONIDOVICH RYJKOV Submitted to Texas A&M University in partial fulfillment of the requirements...

Ryjkov, Vladimir Leonidovich

2005-02-17T23:59:59.000Z

291

Respiration Induced Heart Motion and Indications of Gated Delivery for Left-Sided Breast Irradiation  

SciTech Connect (OSTI)

Purpose: To investigate respiration-induced heart motion for left-sided breast irradiation using a four-dimensional computed tomography (4DCT) technique and to determine novel indications to assess heart motion and identify breast patients who may benefit from a gated treatment. Methods and Materials: Images of 4DCT acquired during free breathing for 20 left-sided breast cancer patients, who underwent whole breast irradiation with or without regional nodal irradiation, were analyzed retrospectively. Dose distributions were reconstructed in the phases of 0%, 20%, and 50%. The intrafractional heart displacement was measured in three selected transverse CT slices using D{sub LAD} (the distance from left ascending aorta to a fixed line [connecting middle point of sternum and the body] drawn on each slice) and maximum heart depth (MHD, the distance of the forefront of the heart to the line). Linear regression analysis was used to correlate these indices with mean heart dose and heart dose volume at different breathing phases. Results: Respiration-induced heart displacement resulted in observable variations in dose delivered to the heart. During a normal free-breathing cycle, heart-induced motion D{sub LAD} and MHD changed up to 9 and 11 mm respectively, resulting in up to 38% and 39% increases of mean doses and V{sub 25.2} for the heart. MHD and D{sub LAD} were positively correlated with mean heart dose and heart dose volume. Respiratory-adapted gated treatment may better spare heart and ipsilateral-lung compared with the conventional non-gated plan in a subset of patients with large D{sub LAD} or MHD variations. Conclusion: Proposed indices offer novel assessment of heart displacement based on 4DCT images. MHD and D{sub LAD} can be used independently or jointly as selection criteria for respiratory gating procedure before treatment planning. Patients with great intrafractional MHD variations or tumor(s) close to the diaphragm may particularly benefit from the gated treatment.

Qi, X. Sharon, E-mail: xiangrong.qi@ucdenver.edu [Department of Radiation Oncology, University of Colorado Denver, Aurora, CO (United States); Hu, Angela [Department of Radiation Oncology, University of Colorado Denver, Aurora, CO (United States); Wang Kai [Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, WI (United States); Newman, Francis [Department of Radiation Oncology, University of Colorado Denver, Aurora, CO (United States); Crosby, Marcus; Hu Bin; White, Julia; Li, X. Allen [Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, WI (United States)

2012-04-01T23:59:59.000Z

292

Remote sensing of heart rate and patterns of respiration on a stationary subject using 94 GHz millimeter wave interferometry.  

SciTech Connect (OSTI)

Using continuous wave, 94-GHz millimeter-wave interferometry, a signal representing chest wall motion can be obtained that contains both the heart rate and respiration patterns of a human subject. These components have to be separated from each other in the received signal. Our method was to use the quadrature and in-phase components of the signal, after removing the mean of each, to find the phase, unwrap it, and convert it to a displacement measurement. Using this, the power spectrum was examined for peaks, which corresponded to the heart rate and respiration rate. The displacement waveform of the chest was also analyzed for discrete heartbeats using a novel wavelet decomposition technique.

Mikhelson, I. V.; Bakhtiari, S.; Elmer, T. W.; Sahakian, A. V. (Nuclear Engineering Division); (Northwestern University)

2011-06-01T23:59:59.000Z

293

On sampling fractions and electron shower shapes  

SciTech Connect (OSTI)

We study the usage of various definitions of sampling fractions in understanding electron shower shapes in a sampling multilayer electromagnetic calorimeter. We show that the sampling fractions obtained by the conventional definition (I) of (average observed energy in layer)/(average deposited energy in layer) will not give the best energy resolution for the calorimeter. The reason for this is shown to be the presence of layer by layer correlations in an electromagnetic shower. The best resolution is obtained by minimizing the deviation from the total input energy using a least squares algorithm. The 'sampling fractions' obtained by this method (II) are shown to give the best resolution for overall energy. We further show that the method (II) sampling fractions are obtained by summing the columns of a non-local {lambda} tensor that incorporates the correlations. We establish that the sampling fractions (II) cannot be used to predict the layer by layer energies and that one needs to employ the full {lambda} tensor for this purpose. This effect is again a result of the correlations.

Peryshkin, Alexander; Raja, Rajendran; /Fermilab

2011-12-01T23:59:59.000Z

294

Soil respiration in perennial grass and shrub ecosystems: Linking environmental controls with plant and microbial sources on seasonal and diel timescales  

E-Print Network [OSTI]

R. Vargas (2008), Automated soil respiration measure- ments:and J. M. Wraith (2007), Diurnal hysteresis between soil CO2 and soil temperature is controlled by soil water content,

Carbone, Mariah S; Winston, Gregory C; Trumbore, Susan E

2008-01-01T23:59:59.000Z

295

Effect of organic-vapor mixtures on the service life of respirator cartridges. Part 1  

SciTech Connect (OSTI)

We challenged pairs of MSA respirator cartridges with two compounds, isopropyl alcohol (IPA) and methyl ethyl ketone (MEK), to study the adsorption characteristics of organic vapors on cartridge performance. Each vapor was injected at three concentrations: (1) each at 10 times the respective Threshold Limit Value (TLV), (2) as a mixture at a concentration equal to the sum of the two single concentrations of item (1), and (3) each alone at a concentration equal to the total-mixture challenge concentration of item (2). The experiments were repeated at 20% and 85% relative humidities. One-percent and ten-percent breakthrough times were observed experimentally in every case, and breakthrough times of the mixture agreed with the single, high-concentration challenge. Experimental data were matched to a theoretical model derived from modified Wheeler-Robell equations and showed close correlations between adsorption-rate constants for the mixture and for the individual compounds. Based on these first experiments, we feel that an accurate mathematical model is possible, and further experiments are planned to verify this. 12 refs., 1 fig., 3 tabs.

Swearengen, P.M.; Weaver, S.C.

1985-01-01T23:59:59.000Z

296

Urinary 1-hydroxypyrene concentrations in Chinese coke oven workers relative to job category, respirator usage, and cigarette smoking  

SciTech Connect (OSTI)

1-Hydroxypyrene (1-OHP) is a biomarker of recent exposure to polycyclic aromatic hydrocarbons (PAHs). We investigated whether urinary 1-OHP concentrations in Chinese coke oven workers (COWs) are modulated by job category, respirator usage, and cigarette smoking. The present cross-sectional study measured urinary 1-OHP concentrations in 197 COWs from Coking plant I and 250 COWs from Coking plant II, as well as 220 unexposed referents from Control plant I and 56 referents from Control plant II. Urinary 1-OHP concentrations (geometric mean, {mu}mol/mol creatinine) were 5.18 and 4.21 in workers from Coking plants I and II, respectively. The highest 1-OHP levels in urine were found among topside workers including lidmen, tar chasers, and whistlers. Benchmen had higher 1-OHP levels than other workers at the sideoven. Above 75% of the COWs exceeded the recommended occupational exposure limit of 2.3 {mu}mol/mol creatinine. Respirator usage and increased body mass index (BMI) slightly reduced 1-OHP levels in COWs. Cigarette smoking significantly increased urinary 1-OHP levels in unexposed referents but had no effect in COWs. Chinese COWs, especially topside workers and benchmen, are exposed to high levels of PAHs. Urinary 1-OHP concentrations appear to be modulated by respirator usage and BMI in COWs, as well as by smoking in unexposed referents.

Bo Chen; Yunping Hu; Lixing Zheng; Qiangyi Wang; Yuanfen Zhou; Taiyi Jin [Fudan University, Shanghai (China). School of Public Health

2007-09-15T23:59:59.000Z

297

The evaluation of a valveless disposable respirator for use as respiratory protection against exposure to Halothane (2-Bromo-2-Chloro-1,1,1-Trifluoroethane)  

E-Print Network [OSTI]

and Health Administration (MSHA), and the V. S. Department of Health and Human Services' National Institute for Occupational Safety and Health (NIOSH). The 30CFR11 regulation does not address the testing of valveless organic vapor respirators. In 1975... no criteria by which a valveless organic vapor respirator can receive MSHA-NIOSH approval. The Bendix report , however, 3 produced very interesting performance data which is the basis of this thesis work. The concentra tion of challenge agent inside of a...

Gaudet, Glenn Lawrence

1980-01-01T23:59:59.000Z

298

RF properties of periodic accelerating structures for linear colliders  

SciTech Connect (OSTI)

With the advent of the SLAC electron-positron linear collider (SLC) in the 100 GeV center-of-mass energy range, research and development work on even higher energy machines of this type has started in several laboratories in the United States, Europe, the Soviet Union and Japan. These linear colliders appear to provide the only promising approach to studying e/sup /plus//e/sup /minus// physics at center-of-mass energies approaching 1 TeV. This thesis concerns itself with the study of radio frequency properties of periodic accelerating structures for linear colliders and their interaction with bunched beams. The topics that have been investigated are: experimental measurements of the energy loss of single bunches to longitudinal modes in two types of structures, using an equivalent signal on a coaxial wire to simulate the beam; a method of canceling the energy spread created within a single bunch by longitudinal wakefields, through appropriate shaping of the longitudinal charge distribution of the bunch; derivation of the complete transient beam-loading equation for a train of bunches passing through a constant-gradient accelerator section, with application to the calculation and minimization of multi-bunch energy spread; detailed study of field emission and radio frequency breakdown in disk-loaded structures at S-, C- and X-band frequencies under extremely high-gradient conditions, with special attention to thermal effects, radiation, sparking, emission of gases, surface damage through explosive emission and its possible control through RF-gas processing. 53 refs., 49 figs., 9 tabs.

Wang, J.W.

1989-07-01T23:59:59.000Z

299

Experimental Studies of Light Emission Phenomena in Superconducting RF Cavitites  

SciTech Connect (OSTI)

Experimental studies of light emission phenomena in superconducting RF cavities, which we categorize under the general heading of cavity lights, are described. The cavity lights data, which were obtained using a small CCD video camera, were collected in a series of nine experimental runs ranging from {approx} 1/2 to {approx} 2 h in duration. The video data were recorded on a standard VHS tape. As the runs progressed, additional instrumentation was added. For the last three runs a LabVIEW controlled data acquisition system was included. These runs furnish evidence for several, possibly related, light emission phenomena. The most intriguing of these is what appear to be small luminous objects {le} 1.5 mm in size, freely moving about in the vacuum space, generally without wall contact, as verified by reflections of the tracks in the cavity walls. In addition, on a number of occasions, these objects were observed to bounce off of the cavity walls. The wall-bounce aspect of most of these events was clearly confirmed by pre-bounce and post-bounce reflections concurrent with the tracks. In one of the later runs, a mode of behavior was observed that was qualitatively different from anything observed in the earlier runs. Perhaps the most perplexing aspect of this new mode was the observation of as many as seven luminous objects arrayed in what might be described as a macromolecular formation, coherently moving about in the interior of the cavity for extended periods of time, evidently without any wall contact. It is suggested that these mobile luminous objects are without explanation within the realm of established physics. Some remarks about more exotic theoretical possibilities are made, and future plans are discussed.

Anthony, P.L.; /SLAC; Delayen, J.R.; /Jefferson Lab; Fryberger, D.; /SLAC; Goree, W.S.; Mammosser, J.; /Jefferson Lab /SNS Project, Oak Ridge; Szalata, Z.M.; II, J.G.Weisend /SLAC

2009-08-04T23:59:59.000Z

300

Fractionation of Oxygen Isotopes in Phosphate during its Interactions...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Fractionation of Oxygen Isotopes in Phosphate during its Interactions with Iron Oxides. Fractionation of Oxygen Isotopes in Phosphate during its Interactions with Iron Oxides....

Note: This page contains sample records for the topic "rf respirable fraction" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

Comparison of Measured and Calculated Coupling between a Waveguide and an RF Cavity Using CST Microwave Studio  

SciTech Connect (OSTI)

Accurate predications of RF coupling between an RF cavity and ports attached to it have been an important study subject for years for RF coupler and higher order modes (HOM) damping design. We report recent progress and a method on the RF coupling simulations between waveguide ports and RF cavities using CST Microwave Studio in time domain (Transit Solver). Comparisons of the measured and calculated couplings are presented. The simulated couplings and frequencies agree within {approx} 10% and {approx} 0.1% with the measurements, respectively. We have simulated couplings with external Qs ranging from {approx} 100 to {approx} 100,000, and confirmed with measurements. The method should also work well for higher Qs, and can be easily applied in RF power coupler designs and HOM damping for normal-conducting and superconducting cavities.

J. Shi; H. Chen; S. Zheng; D. Li; R.A. Rimmer; H. Wang

2006-06-26T23:59:59.000Z

302

The Fractional Kinetic Equation and Thermonuclear Functions  

E-Print Network [OSTI]

The paper discusses the solution of a simple kinetic equation of the type used for the computation of the change of the chemical composition in stars like the Sun. Starting from the standard form of the kinetic equation it is generalized to a fractional kinetic equation and its solutions in terms of H-functions are obtained. The role of thermonuclear functions, which are also represented in terms of G- and H-functions, in such a fractional kinetic equation is emphasized. Results contained in this paper are related to recent investigations of possible astrophysical solutions of the solar neutrino problem.

H. J. Haubold; A. M. Mathai

2000-01-16T23:59:59.000Z

303

Application of new simulation algorithms for modeling rf diagnostics of electron clouds  

SciTech Connect (OSTI)

Traveling wave rf diagnostics of electron cloud build-up show promise as a non-destructive technique for measuring plasma density and the efficacy of mitigation techniques. However, it is very difficult to derive an absolute measure of plasma density from experimental measurements for a variety of technical reasons. Detailed numerical simulations are vital in order to understand experimental data, and have successfully modeled build-up. Such simulations are limited in their ability to reproduce experimental data due to the large separation of scales inherent to the problem. Namely, one must resolve both rf frequencies in the GHz range, as well as the plasma modulation frequency of tens of MHz, while running for very long simulations times, on the order of microseconds. The application of new numerical simulation techniques allow us to bridge the simulation scales in this problem and produce spectra that can be directly compared to experiments. The first method is to use a plasma dielectric model to measure plasma-induced phase shifts in the rf wave. The dielectric is modulated at a low frequency, simulating the effects of multiple bunch crossings. This allows simulations to be performed without kinetic particles representing the plasma, which both speeds up the simulations as well as reduces numerical noise from interpolation of particle charge and currents onto the computational grid. Secondly we utilize a port boundary condition model to simultaneously absorb rf at the simulation boundaries, and to launch the rf into the simulation. This method improves the accuracy of simulations by restricting rf frequencies better than adding an external (finite) current source to drive rf, and absorbing layers at the boundaries. We also explore the effects of non-uniform plasma densities on the simulated spectra.

Veitzer, Seth A.; Smithe, David N.; Stoltz, Peter H. [Tech-X Corporation, Boulder, CO, 80303 (United States)

2012-12-21T23:59:59.000Z

304

1Fractions and Chemistry Because molecules and  

E-Print Network [OSTI]

1Fractions and Chemistry Because molecules and atoms come in 'integer' packages, the ratios of gasoline (ethane) are combined with 7 molecules of oxygen you get 4 molecules of carbon dioxide and 6;1 Answer Key Problem 1 - What makes your car go: When 2 molecules of gasoline (ethane) are combined with 7

305

Measurement of the D -> pipi branching fractions  

E-Print Network [OSTI]

Using data from CLEO II at the Cornell Electron Storage Ring we provide a new measurement of the branching fraction for D0 --> pi+pi-, and we present the first measurements of D0 --> pi0pi0 and of D+ --> pi+pi0, which is ...

Ammar, Raymond G.; Ball, S.; Baringer, Philip S.; Coppage, Don; Copty, N.; Davis, Robin E. P.; Hancock, N.; Kelly, M.; Kwak, Nowhan; Lam, H.

1993-09-01T23:59:59.000Z

306

Measurement of the D*(2010) branching fractions  

E-Print Network [OSTI]

We report a measurement of the D*+ and D*0 decay branching fractions based on 780 pb-1 of data collected with the CLEO II detector. For radiative D*+ decay, we obtain an upper limit, B(D*+ --> D+ gamma) < 4.2% (90% confidence ...

Ammar, Raymond G.; Ball, S.; Baringer, Philip S.; Coppage, Don; Copty, N.; Davis, Robin E. P.; Hancock, N.; Kelly, M.; Kwak, Nowhan; Lam, H.

1992-10-01T23:59:59.000Z

307

Hamilton-Jacobi Fractional Sequential Mechanics  

E-Print Network [OSTI]

As a continuation of Rabei et al. work [11], the Hamilton- Jacobi partial differential equation is generalized to be applicable for systems containing fractional derivatives. The Hamilton- Jacobi function in configuration space is obtained in a similar manner to the usual mechanics. Two problems are considered to demonstrate the application of the formalism. The result found to be in exact agreement with Agrawal's formalism.

Eqab M. Rabei; Bashar S. Ababneh

2007-04-04T23:59:59.000Z

308

World Volume Action for Fractional Branes  

E-Print Network [OSTI]

We study the world volume action of fractional Dp-branes of type IIA string theory compactified on the orbifold T^4/Z_2. The geometric relation between these branes and wrapped branes is investigated using conformal techniques. In particular we examine in detail various scattering amplitudes and find that the leading low-energy interactions are consistent with the boundary action derived geometrically.

Merlatti, P

2001-01-01T23:59:59.000Z

309

World Volume Action for Fractional Branes  

E-Print Network [OSTI]

We study the world volume action of fractional Dp-branes of type IIA string theory compactified on the orbifold T^4/Z_2. The geometric relation between these branes and wrapped branes is investigated using conformal techniques. In particular we examine in detail various scattering amplitudes and find that the leading low-energy interactions are consistent with the boundary action derived geometrically.

P. Merlatti; G. Sabella

2001-01-11T23:59:59.000Z

310

Stabilizing effect of a double-harmonic RF system in the CERN PS  

SciTech Connect (OSTI)

Motivated by the discussions on scenarios for LHC upgrades, beam studies on the stability of flat bunches in a double-harmonic RF system have been conducted in the CERN Proton Synchrotron (PS). Injecting nearly nominal LHC beam intensity per cycle, 18 bunches are accelerated on harmonic h = 21 to 26GeV with the 10MHz RF system. On the flat-top, all bunches are then transformed to flat bunches by adiabatically adding RF voltage at h = 42 from a 20 MHz cavity in anti-phase to the h = 21 system. The voltage ratio V (h42)/V (h21) of about 0.5 was set according to simulations. For the next 140 ms, longitudinal profiles show stable bunches in the double-harmonic RF bucket until extraction. Without the second harmonic component, coupled-bunch oscillations are observed. The flatness of the bunches along the batch is analyzed as a measure of the relative phase error between the RF systems due to beam loading. The results of beam dynamics simulations and their comparison with the measured data are presented.

Bhat, C.; /Fermilab; Caspers, F.; Damerau, H.; Hancock, S.; Mahner, E.; Zimmermann, F.; /CERN

2009-04-01T23:59:59.000Z

311

Simulation of RF Cavity Dark Current In Presence of Helical Magnetic Field  

SciTech Connect (OSTI)

In order to produce muon beam of high enough quality to be used for a Muon Collider, its large phase space must be cooled several orders of magnitude. This task can be accomplished by ionization cooling. Ionization cooling consists of passing a high-emittance muon beam alternately through regions of low Z material, such as liquid hydrogen, and very high accelerating RF cavities within a multi-Tesla solenoidal focusing channel. But first high power tests of RF cavity with beryllium windows in solenoidal magnetic field showed a dramatic drop in accelerating gradient due to RF breakdowns. It has been concluded that external magnetic fields parallel to RF electric field significantly modifies the performance of RF cavities. However, magnetic field in Helical Cooling Channel has a strong dipole component in addition to solenoidal one. The dipole component essentially changes electron motion in a cavity compare to pure solenoidal case, making dark current less focused at field emission sites. The simulation of dark current dynamic in HCC performed with CST Studio Suit is presented in this paper.

Romanov, Gennady; Kashikhin, Vladimir; /Fermilab

2012-05-01T23:59:59.000Z

312

Combined Delta-Nabla Sum Operator in Discrete Fractional Calculus  

E-Print Network [OSTI]

We introduce a more general discrete fractional operator, given by convex linear combination of the delta and nabla fractional sums. Fundamental properties of the new fractional operator are proved. As particular cases, results on delta and nabla discrete fractional calculus are obtained.

Bastos, Nuno R O

2010-01-01T23:59:59.000Z

313

Infrared spectroscopy of diatomic molecules - a fractional calculus approach  

E-Print Network [OSTI]

The eigenvalue spectrum of the fractional quantum harmonic oscillator is calculated numerically solving the fractional Schr\\"odinger equation based on the Riemann and Caputo definition of a fractional derivative. The fractional approach allows a smooth transition between vibrational and rotational type spectra, which is shown to be an appropriate tool to analyze IR spectra of diatomic molecules.

Richard Herrmann

2012-12-12T23:59:59.000Z

314

Phase-resolved optical emission of dusty rf discharges: Experiment and simulation  

SciTech Connect (OSTI)

The spectral emission of atoms in a dusty radio frequence (rf) discharge plasma in argon and helium has been measured with a gated ICCD camera. The spatially and temporally resolved emission/excitation of the argon and helium atoms during the rf cycle in the dusty discharge was compared to the dust-free case. In the bulk plasma above the dust cloud, the emission is clearly enhanced in the dusty discharge with respect to the pure discharge, whereas in the sheath the emission is reduced. In addition, the emission of a dusty argon plasma is studied via particle-particle particle-mesh (P{sup 3}M) simulations. The rf dynamics with a single dust particle trapped in the sheath was calculated. Like in the experiment the dust modifies the atomic emission. The spatiotemporal excitation pattern of the experiment is reproduced and a detailed understanding of the difference in excitation of the discharge with and without dust is presented.

Melzer, Andre; Huebner, Simon; Lewerentz, Lars; Schneider, Ralf [Institut fuer Physik, Ernst-Moritz-Arndt-Universiaet, D-17489 Greifswald (Germany); Matyash, Konstantin [Max-Planck Institut fuer Plasmaphysik, EURATOM Association, D-17491 Greifswald (Germany); Ikkurthi, Ramana [Institute for Plasma Research, Bhat, Ghandinagar, Gujarat (India)

2011-03-15T23:59:59.000Z

315

RF transmission line and drill/pipe string switching technology for down-hole telemetry  

DOE Patents [OSTI]

A modulated reflectance well telemetry apparatus having an electrically conductive pipe extending from above a surface to a point below the surface inside a casing. An electrical conductor is located at a position a distance from the electrically conductive pipe and extending from above the surface to a point below the surface. Modulated reflectance apparatus is located below the surface for modulating well data into a RF carrier transmitted from the surface and reflecting the modulated carrier back to the surface. A RF transceiver is located at the surface and is connected between the electrically conductive pipe and the electrical conductor for transmitting a RF signal that is confined between the electrically conductive well pipe and the electrical conductor to the modulated reflectance apparatus, and for receiving reflected data on the well from the modulated reflectance apparatus.

Clark, David D. (Santa Fe, NM); Coates, Don M. (Santa Fe, NM)

2007-08-14T23:59:59.000Z

316

Precision Vector Control of a Superconducting RF Cavity driven by an Injection Locked Magnetron  

E-Print Network [OSTI]

The technique presented in this paper enables the regulation of both radio frequency amplitude and phase in narrow band devices such as a Superconducting RF (SRF) cavity driven by constant power output devices i.e. magnetrons. The ability to use low cost high efficiency magnetrons for accelerator RF power systems, with tight vector regulation, presents a substantial cost savings in both construction and operating costs compared to current RF power system technology. An operating CW system at 2.45 GHz has been experimentally developed. Vector control of an injection locked magnetron has been extensively tested and characterized with a SRF cavity as the load. Amplitude dynamic range of 30 dB, amplitude stability of 0.3% r.m.s, and phase stability of 0.26 degrees r.m.s. has been demonstrated.

Chase, Brian; Cullerton, Ed; Varghese, Philip

2015-01-01T23:59:59.000Z

317

Precision Vector Control of a Superconducting RF Cavity driven by an Injection Locked Magnetron  

E-Print Network [OSTI]

The technique presented in this paper enables the regulation of both radio frequency amplitude and phase in narrow band devices such as a Superconducting RF (SRF) cavity driven by constant power output devices i.e. magnetrons. The ability to use low cost high efficiency magnetrons for accelerator RF power systems, with tight vector regulation, presents a substantial cost savings in both construction and operating costs compared to current RF power system technology. An operating CW system at 2.45 GHz has been experimentally developed. Vector control of an injection locked magnetron has been extensively tested and characterized with a SRF cavity as the load. Amplitude dynamic range of 30 dB, amplitude stability of 0.3% r.m.s, and phase stability of 0.26 degrees r.m.s. has been demonstrated.

Brian Chase; Ralph Pasquinelli; Ed Cullerton; Philip Varghese

2014-11-21T23:59:59.000Z

318

Final Technical Report- Back-gate Field Emission-based Cathode RF Electron Gun  

SciTech Connect (OSTI)

The objective was to complete the design of an electron gun which utilizes a radio frequency (RF) power source to apply a voltage to a field emission (FE) cathode, a so called cold cathode, in order to produce an electron beam. The concept of the RF electron gun was originally conceived at Argonne National Laboratory but never reduced to practice. The research allowed the completion of the design based upon the integration of the FE electron source. Compared to other electron guns, the RF gun is very compact, less than one third the size of other comparable guns, and produces a high energy (to several MeV), high quality, high power electron beam with a long focal length with high repetition rates. The resultant electron gun may be used in welding, materials processing, analytical equipment and waste treatment.

McGuire, Gary; Martin, Allen; Noonan, John

2010-10-30T23:59:59.000Z

319

Fluid catalytic cracking of heavy petroleum fractions  

SciTech Connect (OSTI)

A process is claimed for fluid catalytic cracking of residuum and other heavy oils comprising of gas oil, petroleum residue, reduced and whole crudes and shale oil to produce gasoline and other liquid products which are separated in various streams in a fractionator and associated vapor recovery equipment. The heat from combustion of coke on the coked catalyst is removed by reacting sulfur-containing coke deposits with steam and oxygen in a separate stripper-gasifier to produce a low btu gas stream comprising of sulfur compounds, methane, carbon monoxide, hydrogen, and carbon dioxide at a temperature of from about 1100/sup 0/F. To about 2200/sup 0/F. The partially regenerated catalyst then undergoes complete carbon removal in a regeneration vessel. The regenerated catalyst is recycled for re-use in the cracking of heavy petroleum fractions. The liquid products are gasoline, distillates, heavy fuel oil, and light hydrocarbons.

McHenry, K.W.

1981-06-30T23:59:59.000Z

320

Effect of RF Gradient upon the Performance of the Wisconsin SRF Electron Gun  

SciTech Connect (OSTI)

The performance of the Wisconsin 200-MHz SRF electron gun is simulated for several values of the RF gradient. Bunches with charge of 200 pC are modeled for the case where emittance compensation is completed during post-acceleration to 85 MeV in a TESLA module. We first perform simulations in which the initial bunch radius is optimal for the design gradient of 41 MV/m. We then optimize the radius as a function of RF gradient to improve the performance for low gradients.

Bosch, Robert [SRC U. Wisconsin-Madison; Legg, Robert A. [JLAB

2013-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "rf respirable fraction" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

Method and apparatus for transferring and injecting rf energy from a generator to a resonant load  

DOE Patents [OSTI]

Improved apparatus and method are provided for the coherent amplification and injection of radio-frequency (rf) energy into a load cavity using a plurality of amplifier tubes. A plurality of strip line cavities (30, 32, 34, 36, 40, 42, 44) are laterally joined to define a continuous closed cavity (48), with an amplifier tube (50, 52, 54, 56, 58, 60, 62, 64) mounted within each resonant strip cavity. Rf energy is injected into the continuous cavity (48) from a single input (70) for coherent coupling to all of the amplifier tubes for amplification and injection into the load cavity (76).

Hoffert, William J. (Albuquerque, NM)

1987-01-01T23:59:59.000Z

322

Chiral anomaly, bosonization, and fractional charge  

SciTech Connect (OSTI)

We present a method to evaluate the Jacobian of chiral rotations, regulating determinants through the proper-time method and using Seeley's asymptotic expansion. With this method we compute easily the chiral anomaly for ..nu.. = 4,6 dimensions, discuss bosonization of some massless two-dimensional models, and handle the problem of charge fractionization. In addition, we comment on the general validity of Fujikawa's approach to regulate the Jacobian of chiral rotations with non-Hermitian operators.

Mignaco, J.A.; Monteiro, M.A.R.

1985-06-15T23:59:59.000Z

323

Fractional Quantum Hall States in Graphene  

E-Print Network [OSTI]

We quantum mechanically analyze the fractional quantum Hall effect in graphene. This will be done by building the corresponding states in terms of a potential governing the interactions and discussing other issues. More precisely, we consider a system of particles in the presence of an external magnetic field and take into account of a specific interaction that captures the basic features of the Laughlin series \

Ahmed Jellal; Bellati Malika

2008-05-15T23:59:59.000Z

324

Pyrolysis of shale oil residual fractions  

SciTech Connect (OSTI)

The freezing point of JP-5, the Navy jet fuel, has been related to the n-alkane content, specifically n-hexadecane. In general, jet fuels from shale oil have the highest n-alkanes. The formation of n-alkanes in the jet fuel distillation range can be explained if large n-alkanes are present in the crude oil source. Quantities of large n-alkanes are insufficient, however, to explain the amounts found - up to 37% n-alkanes in the jet fuel range. Other possible precursors to small straight chain molecules are substituted cyclic compounds. Attack in the side chain obviously afford a path to an n-alkane. Aromatic hydrocarbons, esters, acids, amines, and ethers also have the potential to form n-alkanes if an unbranched alkyl chain is present in the molecule. Investigations showed that the best yield of the JP-5 cut comes at different times for the various fractions, but a time in the 60 to 120 min range would appear to be the optimum time for good yield at 450/sup 0/C. The longer time would be preferred with respect to lower potential n-alkane yield. None of the fractions gave n-alkane yields approaching the 37% amount found in the Shale-I JP-5. A temperature different than the 450/sup 0/C used here might affect the conversion percentage. Further the combined saturate, aromatic, and polar fractions may interact under pyrolysis conditions to give higher potential n-alkane yields than the fractions stressed independently.

Hazlett, R.N.; Beal, E.; Vetter, T.; Sonntag, R.; Moniz, W.

1980-01-01T23:59:59.000Z

325

The Fractional London Equation and The Fractional Pippard Model For Superconductors  

E-Print Network [OSTI]

With the discovery of new superconductors there was a running to find the justifications for the new properties found in these materials. In order to describe these new effects some theories were adapted and some others have been tried. In this work we present an application of the fractional calculus to study the superconductor in the context of London theory. Here we investigated the linear London equation modified by fractional derivatives for non-differentiable functions, instead of integer ones, in a coarse grained scenario. We apply the fractional approach based in the modified Riemann-Liouville sense to improve the model in order to include possible non-local interactions and the media. It is argued that the e ects of non-locality and long memory, intrinsic to the formalism of the fractional calculus, are relevant to achieving a satisfactory phenomenological description. In order to compare the present results with the usual London theory, we calculated the magnetic field distribution for a mesoscopic superconductor system. Also, a fractional Pippard-like model is proposed to take into account the non-locality beside effects of interactions and the media. We propose that parameter alfa of fractionality can be used to create an alternative way to characterize superconductors.

José Weberszpil

2012-07-23T23:59:59.000Z

326

Real-time imaging of the spatial distribution of rf-heating in NMR samples during broadband decoupling  

E-Print Network [OSTI]

by the temperature control system. Moreover, as the heating is spatially inhomogeneous, higher temperature increases of the numerical simulations. Since electric fields manifest themselves by rf-heating, the E-field distributionReal-time imaging of the spatial distribution of rf-heating in NMR samples during broadband

Wider, Gerhard

327

Open-Thru de-embedding for Graphene RF devices Giancarlo Vincenzi, George Deligeorgis, Fabio Coccetti and Patrick Pons  

E-Print Network [OSTI]

Open-Thru de-embedding for Graphene RF devices Giancarlo Vincenzi, George Deligeorgis, Fabio, LAAS, F-31400 Toulouse, France Abstract--The performances of graphene RF devices rely heavily-embedding technique adapted to the needs of microwave graphene devices is presented. Two standards and only one step

Boyer, Edmond

328

APS DPP Meeting, Quebec City Canada R V Budny 2327 October 2000 Comparison of RF-heated with  

E-Print Network [OSTI]

42 nd APS DPP Meeting, Quebec City Canada R V Budny 23­27 October 2000 JG00.293/1 Comparison of RF 2000 JG00.293/3 Conclusions Motivation ICRH ­ heated ELMy plasmas are suggested for reactor startup heated ELMy plasmas Heating power lower than desired (close to L-mode) VTor for RF in Co-Ip direction

Budny, Robert

329

Nano-fabricated superconducting radio-frequency composites, method for producing nano-fabricated superconducting rf composites  

DOE Patents [OSTI]

Superconducting rf is limited by a wide range of failure mechanisms inherent in the typical manufacture methods. This invention provides a method for fabricating superconducting rf structures comprising coating the structures with single atomic-layer thick films of alternating chemical composition. Also provided is a cavity defining the invented laminate structure.

Norem, James H.; Pellin, Michael J.

2013-06-11T23:59:59.000Z

330

Dependence of nuclear spin singlet lifetimes on RF spin-locking power Stephen J. DeVience a,  

E-Print Network [OSTI]

Dependence of nuclear spin singlet lifetimes on RF spin-locking power Stephen J. DeVience a: Received 6 January 2012 Revised 14 March 2012 Available online 28 March 2012 Keywords: Nuclear singlet of long-lived nuclear spin singlet states as a function of the strength of the RF spin-locking field

Rosen, Matthew S

331

2012 IEEE 30th VLSI Test Symposium (VTS) Towards a Fully Stand-Alone Analog/RF BIST: A  

E-Print Network [OSTI]

-effective analog/RF BIST solution must rely on low-cost measurements obtained through on-chip sensors, along to achieve a fully stand-alone analog/RF BIST solution that can be used for low-cost production test as well in the low-cost measure- ment multi-dimensional space. To investigate this approach, we have designed

Makris, Yiorgos

332

Particle-In-Cell/Monte Carlo Simulation of Ion Back BomBardment in a High Average Current RF Photo-Gun  

E-Print Network [OSTI]

High Average Current RF Photo-Gun J. Qiang Lawrence Berkeleyradio-frequency (RF) photo-gun using a particle-in-cell/ion motion inside the gun so that the ion power deposition

Qiang, J.

2010-01-01T23:59:59.000Z

333

Improved nuclear magnetic resonance apparatus having semitoroidal rf coil for use in topical NMR and NMR imaging  

DOE Patents [OSTI]

An improved nuclear magnetic resonance (NMR) apparatus for use in topical magnetic resonance (TMR) spectroscopy and other remote sensing NMR applications includes a semitoroidal radio frequency (rf) coil. The semitoroidal rf coil produces an effective alternating magnetic field at a distance from the poles of the coil, so as to enable NMR measurements to be taken from selected regions inside an object, particularly including human and other living subjects. The semitoroidal rf coil is relatively insensitive to magnetic interference from metallic objects located behind the coil, thereby rendering the coil particularly suited for use in both conventional and superconducting NMR magnets. The semitoroidal NMR coil can be constructed so that it emits little or no excess rf electric field associated with the rf magnetic field, thus avoiding adverse effects due to dielectric heating of the sample or to any other interaction of the electric field with the sample.

Fukushima, E.; Roeder, S.B.W.; Assink, R.A.; Gibson, A.A.V.

1984-01-01T23:59:59.000Z

334

Locating RF Emitters with Large UAV Teams Paul Scerri, Robin Glinton, Sean Owens and Katia Sycara  

E-Print Network [OSTI]

Locating RF Emitters with Large UAV Teams Paul Scerri, Robin Glinton, Sean Owens and Katia Sycara efficient way for a team of UAVs with Received Signal Strength Indicator (RSSI) sen- sors to locate radio locations requires integrating multiple signals from different UAVs into a Bayesian filter, hence requir

Scerri, Paul

335

Structure and magnetic properties of rf thermally plasma synthesized Mn and MnZn ferrite nanoparticles  

E-Print Network [OSTI]

Structure and magnetic properties of rf thermally plasma synthesized Mn and Mn­Zn ferrite has previously been shown to be a viable route to producing nanocrystalline magnetite and Ni ferrite nanoparticles. In this work nanocrystalline powders of Mn and Mn­Zn ferrites have been synthesized using a 50 k

McHenry, Michael E.

336

Optimization of High Tunability Barium Strontium Titanate Thin Films Grown by RF Magnetron  

E-Print Network [OSTI]

Optimization of High Tunability Barium Strontium Titanate Thin Films Grown by RF Magnetron Abstract-- Barium strontium titanate is a solid solution perovskite with a field-dependent permittivity.7 MV/cm. I. INTRODUCTION In recent years there has been much interest in thin-film barium strontium

York, Robert A.

337

Ion Crystals Produced by Laser and Sympathetic Cooling in a Linear RF Ion Trap  

E-Print Network [OSTI]

A detailed investigation of ion crystals produced by laser and sympathetic cooling in a linear RF trap has been conducted. The laser cooling methods were examined and applied to the trapped ^24Mg^(positive) ions. The crystals produced by the laser...

Zhu, Feng

2012-02-14T23:59:59.000Z

338

CMOS RF front-end design for terrestrial and mobile digital television systems  

E-Print Network [OSTI]

With the increasing demand for high quality TV service, digital television (DTV) is replacing the conventional analog television. DTV tuner is one of the most critical blocks of the DTV receiver system; it down-converts the desired DTV RF channel...

Xiao, Jianhong

2007-09-17T23:59:59.000Z

339

Thin crystalline silicon solar cells based on epitaxial films grown at 165C by RF PECVD  

E-Print Network [OSTI]

1 Thin crystalline silicon solar cells based on epitaxial films grown at 165°C by RF PECVD Romain temperatures. Keywords : Low temperature, epitaxy, PECVD, Si thin film, Solar cell hal-00749873,version1-25Nov shortage until 2010. Research on epitaxial growth for thin film crystalline silicon solar cells has gained

340

Thin crystalline silicon solar cells based on epitaxial films grown at 165C by RF PECVD  

E-Print Network [OSTI]

1 Thin crystalline silicon solar cells based on epitaxial films grown at 165°C by RF PECVD Romain temperatures. Keywords : Low temperature, epitaxy, PECVD, Si thin film, Solar cell #12;2 1. Introduction: martin.labrune@polytechnique.edu ABSTRACT We report on heterojunction solar cells whose thin intrinsic

Note: This page contains sample records for the topic "rf respirable fraction" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

International Conference on Microwave and RF Heating MODELING OF A CYLINDRICAL APPLICATOR WITH THE  

E-Print Network [OSTI]

by comprehensive modeling specifying appropriate parameters of the excitation system and monitoring the electric10th International Conference on Microwave and RF Heating and experimentally. It appears that because of the uniform electric field distribution along the axis of the cylinder

Yakovlev, Vadim

342

CMOS RF down-conversion mixer design for low-power wireless communications  

E-Print Network [OSTI]

and the digital building blocks on a single chip. Indeed, both the full integration and the low-voltage design, 1 building blocks This paper aims to study the design of an integrated single-balanced mixer in CMOS 0.18 !m for the design of RF integrated circuits. Indeed, in recent years the huge efforts, provided

Paris-Sud XI, Université de

343

Comparing the performance of plasma impedance probes and Langmuir probes for RF plasma diagnostics  

E-Print Network [OSTI]

Comparing the performance of plasma impedance probes and Langmuir probes for RF plasma diagnostics probing, a less developed technique, can possibly overcome these problems. Better plasma diagnostic tools Ethan Dale, Dr. Mitchell Walker High-Power Electric Propulsion Laboratory Objective Plasma is the most

Walker, Mitchell

344

Phase loop bandwidth measurements on the advanced photon source 352 MHz rf systems  

SciTech Connect (OSTI)

Phase loop bandwidth tests were performed on the Advanced Photon Source storage ring 352-MHz rf systems. These measurements were made using the HP3563A Control Systems Analyzer, with the rf systems running at 30 kilowatts into each of the storage ring cavities, without stored beam. An electronic phase shifter was used to inject approximately 14 degrees of stimulated phase shift into the low-level rf system, which produced measureable response voltage in the feedback loops without upsetting normal rf system operation. With the PID (proportional-integral-differential) amplifier settings at the values used during accelerator operation, the measurement data revealed that the 3-dB response for the cavity sum and klystron power-phase loops is approximately 7 kHz and 45 kHz, respectively, with the cavities the primary bandwidth-limiting factor in the cavity-sum loop. Data were taken at various PID settings until the loops became unstable. Crosstalk between the two phase loops was measured.

Horan, D.; Nassiri, A.; Schwartz, C.

1997-08-01T23:59:59.000Z

345

New low-level rf system for the Fermilab Booster synchrotron  

SciTech Connect (OSTI)

This paper describes the Booster low-level rf system that was constructed to meet these recently added requirements: (1) synthesizer controlled capture frequency at injection, (2) very low-phase noise over the machine cycle, (3) smooth phase-lock of beam to an external reference frequency and (4) ability to accelerate either a full turn or partial turn of beam.

Kerns, C.; Crisp, J.; Kerns, Q.; Miller, H.

1987-03-01T23:59:59.000Z

346

Optical Investigations of Dust Particles Distribution in RF and DC Discharges  

SciTech Connect (OSTI)

Optical emission spectroscopy is used to study dust particles movement and conditions of a formation of ordered plasma-dust structures in a capacitively coupled RF discharge. 3D binocular diagnostics of plasma-dust structures in dc discharge was made.

Ramazanov, T. S.; Dosbolayev, M. K.; Jumabekov, A. N.; Amangaliyeva, R. Zh. [Al-Farabi Kazakh National University, IETP, 96a Tole Bi St., Almaty 050012 (Kazakhstan); Filatova, I. I.; Azharonok, V. V. [B. I. Stepanov Institute of Physics NAS of Belarus, Nezavisimosti Ave., 68, 220072, Minsk (Belarus)

2008-09-07T23:59:59.000Z

347

Recombination time of an RF discharge plasma in the presence of water molecules  

SciTech Connect (OSTI)

The authors show that the introduction of water vapor into an electrodeless rf discharge noticeably reduces the excitation temperature and substantially increases the recombination time of the plasma. An attempt is made to explain the physical processes associated with these phenomena.

Protasevich, E.T.

1986-05-01T23:59:59.000Z

348

Conservation Biology (Biology 45300) An Ecology Course for the Fall of 2007 with RF Rockwell  

E-Print Network [OSTI]

Conservation Biology (Biology 45300) An Ecology Course for the Fall of 2007 with RF Rockwell Biology 45300 - Conservation Biology This undergraduate course provides an introduction to conservation biology with an emphasis on the interplay of various fields of biology in the mamangement and conservation

Lombardi, John R.

349

CRYOGENIC TESTING OF THE RF INPUT WAVEGUIDE FOR THE CEBAF UPGRADE CRYOMODULE*  

E-Print Network [OSTI]

CRYOGENIC TESTING OF THE RF INPUT WAVEGUIDE FOR THE CEBAF UPGRADE CRYOMODULE* T. Hiatt , M. Breth to support the planned CEBAF upgrade at the Jefferson Lab a new cryomodule has been designed. A key component original CEBAF waveguides. A series of tests were performed on the waveguide to include temperature

350

High Power RF Tests on WR650 Pre-Stressed Planar Windows  

SciTech Connect (OSTI)

A new planar, ceramic window intended to be used with WR650 waveguide fundamental power couplers at 1300 MHz or 1500 MHz has been developed. It is based on the pre-stressed planar window concept tested in PEP II and LEDA. A test stand that made use of the 100kW CW 1500 MHz RF system in the JLAB FEL was commissioned and used to apply up to 80 kW traveling wave (TW)to the windows. Two different types of RF windows (brazed and diffusion bonded ceramics) with design specification of 50 kW CW in TW mode were successfully tested both as a gas barrier (intended to operate up to 2 psi) and as a vacuum barrier. The vacuum windows were able to maintain UHV quality vacuum and were successfully operated in the 10{sup -9} mbar range. An overview of the pre-stressed power windows, RF test stand, procedures and RF power testing results will be presented.

Stirbet, Mircea [JLAB; Davis, G. Kirk [JLAB; Elliott, Thomas S. [JLAB; King, Larry [JLAB; Powers, Thomas J. [JLAB; Rimmer, Robert A. [JLAB; Walker, Richard L. [JLAB

2009-11-01T23:59:59.000Z

351

Development of fundamental power coupler for high-current superconducting RF cavity  

SciTech Connect (OSTI)

Brookhaven National Laboratory took a project of developing a 704 MHz five-cell superconducting RF cavity for high-current linacs, including Energy Recovery Linac (ERL) for planned electron-hadron collider eRHIC. The cavity will be fed by a high-power RF amplifier using a coaxial Fundamental Power Coupler (FPC), which delivers 20 kW of CW RF power to the cavity. The design of FPC is one of the important aspects as one has to take into account the heat losses dissipated on the surface of the conductor by RF fields along with that of the static heat load. Using a simple simulation model we show the temperature profile and the heat load dissipated along the coupler length. To minimize the heat load on FPC near the cavity end, a thermal intercept is required at an appropriate location on FPC. A 10 K intercept was chosen and its location optimized with our simulation code. The requirement on the helium gas flow rate for the effective heat removal from the thermal intercept is also discussed.

Jain P.; Belomestnykh, S.; Ben-Zvi, I.; Xu, W.

2012-05-20T23:59:59.000Z

352

A multichannel, real-time MRI RF power monitor for independent SAR determination  

SciTech Connect (OSTI)

Purpose: Accurate measurements of the RF power delivered during clinical MRI are essential for safety and regulatory compliance, avoiding inappropriate restrictions on clinical MRI sequences, and for testing the MRI safety of peripheral and interventional devices at known RF exposure levels. The goal is to make independent RF power measurements to test the accuracy of scanner-reported specific absorption rate (SAR) over the extraordinary range of operating conditions routinely encountered in MRI. Methods: A six channel, high dynamic range, real-time power profiling system was designed and built for monitoring power delivery during MRI up to 440 MHz. The system was calibrated and used in two 3 T scanners to measure power applied to human subjects during MRI scans. The results were compared with the scanner-reported SAR. Results: The new power measurement system has highly linear performance over a 90 dB dynamic range and a wide range of MRI duty cycles. It has about 0.1 dB insertion loss that does not interfere with scanner operation. The measurements of whole-body SAR in volunteers showed that scanner-reported SAR was significantly overestimated by up to about 2.2 fold. Conclusions: The new power monitor system can accurately and independently measure RF power deposition over the wide range of conditions routinely encountered during MRI. Scanner-reported SAR values are not appropriate for setting exposure limits during device or pulse sequence testing.

El-Sharkawy, AbdEl-Monem M.; Qian Di; Bottomley, Paul A.; Edelstein, William A. [Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins, University School of Medicine, Baltimore, Maryland 21287 (United States); Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins, University School of Medicine, Baltimore, Maryland 21287 (United States) and Department of Electrical and Computer Engineering, Johns Hopkins University, Baltimore, Maryland 21287 (United States); Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins, University School of Medicine, Baltimore, Maryland 21287 (United States)

2012-05-15T23:59:59.000Z

353

IEEE ELECTRON DEVICE LETTERS, VOL. 24, NO. 4, APRIL 2003 227 RF MEMS Switches Fabricated on  

E-Print Network [OSTI]

with superior performance over con- ventional semiconductor devices [4]­[7]. Typically, RF MEMS switches-resistivity silicon wafers, gallium arsenide (GaAs) wafers, and quartz substrates using semiconductor Manuscript and surface planarization of wide metal lines prior to deposition of a metal membrane bridge, which poses

Cetiner, Bedri A.

354

PERFORMANCE STATUS OF THE RF-GUN BASED INJECTOR OF THE TESLA TEST FACILITY LINAC  

E-Print Network [OSTI]

PERFORMANCE STATUS OF THE RF-GUN BASED INJECTOR OF THE TESLA TEST FACILITY LINAC S. Schreiber£ for the TESLA Collaboration, DESY, 22603 Hamburg, Germany Abstract The TESLA Test Facility Linac (TTFL) at DESY uses two modules with 8 TESLA superconducting accelerat- ing structures each to accelerate an electron

355

FIRST EXPERIMENTS WITH THE RF GUN BASED INJECTOR FOR THE TESLA TEST FACILITY LINAC  

E-Print Network [OSTI]

FIRST EXPERIMENTS WITH THE RF GUN BASED INJECTOR FOR THE TESLA TEST FACILITY LINAC S. Schreiber for the TESLA Collaboration, DESY, 22603 Hamburg, Germany Abstract During 1997 and 1998 a first accelerator module was tested successfully at the TESLA Test Facility Linac (TTFL) at DESY. Eight superconducting

356

Aluminum nitride for heatspreading in RF IC's L. La Spina a,*, E. Iborra b  

E-Print Network [OSTI]

phenomena Heatspreader Piezoelectric characteristics RF integration Thermal instabilities Thermal resistance that display a reduc- tion of more than 70% in the value of the thermal resistance. Ã? 2008 Elsevier Ltd. All lead to a very high thermal resistance. This has been demonstrated in our in-house silicon-on- glass

Technische Universiteit Delft

357

EUROPEAN ORGANIZATION FOR NUCLEAR RESEARCH CERN SL/98-060 (RF)  

E-Print Network [OSTI]

EUROPEAN ORGANIZATION FOR NUCLEAR RESEARCH CERN SL/98-060 (RF) A Recirculating Electron Accelerator will become available after the decommissioning of LEP. The major design features and subjects of further developments are discussed. Geneva, Switzerland October 9, 1998 #12;1 INTRODUCTION The European nuclear physics

Keil, Eberhard

358

ACP-OPLL Photonic Integrated Circuits for High Dynamic Range RF/Photonic links  

E-Print Network [OSTI]

the local optical phase modulators Laser source RF input ACP-OPLL Phase modulator PD PD Output PhaseB optical coupler and a feedback trace from the photodetector common electrode to the phase modulator common electrode. Through phase tracking the OPLL forces the optical phase of the local ACP phase modulator

Coldren, Larry A.

359

Experimental Studies of RF Interference and Upset in Devices and Gates  

E-Print Network [OSTI]

Xingzhi Wen #12;Goals · Start with the study of the effects on the fundamental units of IC circuits, ie and protecting elements. · Develop on-chip sensing, registration, and protection circuitry. #12;Effects. · Effective protection and RF hardened design will be developed #12;RFI Effect on Diode I-V Characteristics

Anlage, Steven

360

WTJ(S^rf7?\\ Ris-R-761p*  

E-Print Network [OSTI]

WTJ(S^rf7?\\ Risø-R-761£p*Thermonuclear Fusion September 1994 #12;ANNUAL PROGRESS _****ig*r REPORT 1993 Work in Controlled Thermonuclear Fusion Research Research Performed in The Fusion Research Unit underthe Contract ofAssociationbetween Euratom and Risø

Note: This page contains sample records for the topic "rf respirable fraction" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

RF Distribution System for High Power Test of the SNS Cryomodule  

SciTech Connect (OSTI)

A four-way waveguide RF power distribution system for testing the Spallation Neutron Source (SNS) multi-cavity cryomodule to investigate the collective behavior has been developed. A single klystron operating at 805MHz for 1.3 msec at 60Hz powers the 4-way waveguide splitter to deliver up to 400 kW to individual cavities. Each cavity is fed through a combination of waveguide splitters and vector modulators (VM) to provide independent magnitude and phase controls. The waveguide vector modulator consists of two quadrature hybrids and two motorized waveguide phase shifters. The phase shifters and the assembled waveguide vector modulators were individually tested and characterized for low power and high RF power in the SNS RF test facility. Precise calibrations of magnitude and phase were performed to generate the look up tables (LUTs) to provide operational references during the cryomodule test. An I-Q demodulator module was developed and utilized to measure relative phases in pulsed high RF power operation. PLC units were developed for mechanical control of the phase shifters. Initial low/high power measurements were made using LabVIEW. An operation algorithm has been implemented into EPICS control for the cryomodule test stand.

Lee, Sung-Woo [ORNL] [ORNL; Kang, Yoon W [ORNL] [ORNL; Broyles, Michael R [ORNL] [ORNL; Crofford, Mark T [ORNL] [ORNL; Geng, Xiaosong [ORNL] [ORNL; Kim, Sang-Ho [ORNL] [ORNL; Phibbs, Curtis L [ORNL] [ORNL; Strong, William Herb [ORNL] [ORNL; Peglow, Robert C [ORNL] [ORNL; Vassioutchenko, Alexandre V [ORNL] [ORNL

2012-01-01T23:59:59.000Z

362

Heterogeneous PLC-RF networking for LLNs Cdric Chauvenet*,** --Bernard Tourancheau*  

E-Print Network [OSTI]

Heterogeneous PLC-RF networking for LLNs Cédric Chauvenet*,** -- Bernard Tourancheau* * CITI INSA and city automation, our view of the future building networking infrastructure places PLC as the central point. Thanks to the design of converging IPv6 networking layers, we show that merging PLC with existing

Paris-Sud XI, Université de

363

Pyrolysis of shale oil vacuum distillate fractions  

SciTech Connect (OSTI)

The freezing point of US Navy jet fuel (JP-5) has been related to the amounts of large n-alkanes present in the fuel. This behavior applies to jet fuels derived from alternate fossil fuel resources, such as shale oil, coal, and tar sands, as well as those derived from petroleum. In general, jet fuels from shale oil have the highest and those from coal the lowest n-alkane content. The origin of these n-alkanes in the amounts observed, especially in shale-derived fuels, is not readily explained on the basis of literature information. Studies of the processes, particularly the ones involving thermal stress, used to produce these fuels are needed to define how the n-alkanes form from larger molecules. The information developed will significantly contribute to the selection of processes and refining techniques for future fuel production from shale oil. Carbon-13 nmr studies indicate that oil shale rock contains many long unbranched straight chain hydrocarbon groups. The shale oil derived from the rock also gives indication of considerable straight chain material with large peaks at 14, 23, 30, and 32 ppM in the C-13 nmr spectrum. Previous pyrolysis studies stressed fractions of shale crude oil residua, measured the yields of JP-5, and determined the content of potential n-alkanes in the JP-5 distillation range (4). In this work, a shale crude oil vacuum distillate (Paraho) was separated into three chemical fractions. The fractions were then subjected to nmr analysis to estimate the potential for n-alkane production and to pyrolysis studies to determine an experimental n-alkane yield.

Hazlett, R.N.; Beal, E.

1983-01-01T23:59:59.000Z

364

Pyrolysis of shale oil vacuum distillate fractions  

SciTech Connect (OSTI)

The freezing point of U.S. Navy jet fuel (JP-5) has been related to the amounts of large nalkanes present in the fuel. This behavior applies to jet fuels derived from alternate fossil fuel resources, such as shale oil, coal, and tar sands, as well as those derived from petroleum. In general, jet fuels from shale oil have the highest and those from coal the lowest n-alkane content. The origin of these n-alkanes in the amounts observed, especially in shale-derived fuels, is not readily explained on the basis of literature information. Studies of the processes, particularly the ones involving thermal stress, used to produce these fuels are needed to define how th n-alkanes form from larger molecules. The information developed will significantly contribute to the selection of processes and refining techniques for future fuel production from shale oil. Carbon-13 nmr studies indicate that oil shale rock contains many long unbranched straight chain hydrocarbon groups. The shale oil derived from the rock also gives indication of considerable straight chain material with large peaks at 14, 23, 30 and 32 ppm in the C-13 nmr spectrum. Previous pyrolysis studies stressed fractions of shale crude oil residua, measured the yields of JP-5, and determined the content of potential n-alkanes in the JP-5 distillation range (4). In this work, a shale crude oil vacuum distillate (Paraho) was separated into three chemical fractions. The fractions were then subjected to nmr analysis to estimate the potential for n-alkane production and to pyrolysis studies to determine an experimental n-alkane yield.

Hazlett, R.N.; Beal, E.

1983-02-01T23:59:59.000Z

365

Polyfunctional catalyst for processiing benzene fractions  

SciTech Connect (OSTI)

A by-product of the coke industry is a raw benzene fraction benzene- 1 which may serve as for catalytic processes. The paper reports a study on the influence of the composition and temperatures on the activity and selectivity of NiO-V{sub 2}O{sub 6}-MoO{sub 3}/{gamma}-Al{sub 2}O{sub 3} catalysts and the corresponding binary and tertiary subsystems are studied by a pulse method in model reactions; the hydrodealkylating of toluene and the hydrodesulfurizing of thioprhene. The optimal catalyst composition is established. The new catalyst is compared with industrial catalysts.

G. Byakov; B.D. Zubitskii; B.G. Tryasunov; I.Ya. Petrov [Kuznetsk Basin State Technical University, Kemerovo (Russian Federation)

2009-05-15T23:59:59.000Z

366

Hydrolysis and fractionation of lignocellulosic biomass  

DOE Patents [OSTI]

A multi-function process is described for the hydrolysis and fractionation of lignocellulosic biomass to separate hemicellulosic sugars from other biomass components such as extractives and proteins; a portion of the solubilized lignin; cellulose; glucose derived from cellulose; and insoluble lignin from said biomass comprising one or more of the following: optionally, as function 1, introducing a dilute acid of pH 1.0-5.0 into a continual shrinking bed reactor containing a lignocellulosic biomass material at a temperature of about 94 to about 160.degree. C. for a period of about 10 to about 120 minutes at a volumetric flow rate of about 1 to about 5 reactor volumes to effect solubilization of extractives, lignin, and protein by keeping the solid to liquid ratio constant throughout the solubilization process; as function 2, introducing a dilute acid of pH 1.0-5.0, either as virgin acid or an acidic stream from another function, into a continual shrinking bed reactor containing either fresh biomass or the partially fractionated lignocellulosic biomass material from function 1 at a temperature of about 94-220.degree. C. for a period of about 10 to about 60 minutes at a volumetric flow rate of about 1 to about 5 reactor volumes to effect solubilization of hemicellulosic sugars, semisoluble sugars and other compounds, and amorphous glucans by keeping the solid to liquid ratio constant throughout the solubilization process; as function 3, optionally, introducing a dilute acid of pH 1.0-5.0 either as virgin acid or an acidic stream from another function, into a continual shrinking bed reactor containing the partially fractionated lignocellulosic biomass material from function 2 at a temperature of about 180-280.degree. C. for a period of about 10 to about 60 minutes at a volumetric flow rate of 1 to about 5 reactor volumes to effect solubilization of cellulosic sugars by keeping the solid to liquid ratio constant throughout the solubilization process; and as function 4, optionally, introducing a dilute acid of pH 1.0-5.0 either as virgin acid or an acidic stream from another function, into a continual shrinking bed reactor containing the partially fractionated lignocellulosic biomass material from function 3 at a temperature of about 180-280.degree. C. for a period of about 10 to about 60 minutes at a volumetric flow rate of about 1 to about 5 reactor volumes to effect solubilization of cellulosic sugars by keeping the solid to liquid ratio constant throughout the solubilization process.

Torget, Robert W. (Littleton, CO); Padukone, Nandan (Denver, CO); Hatzis, Christos (Denver, CO); Wyman, Charles E. (Lakewood, CO)

2000-01-01T23:59:59.000Z

367

Fractional electric charge and quark confinement  

E-Print Network [OSTI]

Owing to their fractional electric charges, quarks are blind to transformations that combine a color center phase with an appropriate electromagnetic one. Such transformations are part of a global $Z_6$-like center symmetry of the Standard Model that is lost when quantum chromodynamics (QCD) is treated as an isolated theory. This symmetry and the corresponding topological defects may be relevant to non-perturbative phenomena such as quark confinement, much like center symmetry and ordinary center vortices are in pure SU($N$) gauge theories. Here we report on our investigations of an analogous symmetry in a 2-color model with dynamical Wilson quarks carrying half-integer electric charge.

Sam R. Edwards; André Sternbeck; Lorenz von Smekal

2012-02-07T23:59:59.000Z

368

Fractional revivals through Rényi uncertainty relations  

E-Print Network [OSTI]

We show that the R\\'enyi uncertainty relations give a good description of the dynamical behavior of wave packets and constitute a sound approach to revival phenomena by analyzing three model systems: the simple harmonic oscillator, the infinite square well, and the quantum bouncer. We prove the usefulness of entropic uncertainty relations as a tool for identifying fractional revivals by providing a comparison in different contexts with the usual Heisenberg uncertainty relation and with the common approach in terms of the autocorrelation function.

Elvira Romera; Francisco de los Santos

2014-09-19T23:59:59.000Z

369

Theoretical Predictions and Experimental Assessments of the Performance of Alumina RF Windows  

SciTech Connect (OSTI)

Radio frequency (RF) windows are the most likely place for catastrophic failure to occur in input power couplers for particle accelerators. Reliable RF windows are essential for the success of the Accelerator Production of Tritium (APT) program because there are over 1000 windows on the accelerator, and it takes more than one day to recover from a window failure. The goals of this research are to analytically predict the lifetime of the windows, to develop a conditioning procedure, and to evaluate the performance of the RF windows. The analytical goal is to predict the lifetime of the windows. The probability of failure is predicted by the combination of a finite element model of the window, Weibull probabilistic analysis, and fracture mechanics. The window assembly is modeled in a finite element electromagnetic code in order to calculate the electric fields in the window. The geometry (i.e. mesh) and electric fields are input into a translator program to generate the mesh and boundary conditions for a finite element thermal structural code. The temperatures and stresses are determined in the thermal/structural code. The geometry and thermal structural results are input into another translator program to generate an input file for the reliability code. Material, geometry and service data are also input into the reliability code. To obtain accurate Weibull and fatigue data for the analytical model, four point bend tests were done. The analytical model is validated by comparing the measurements to the calculations. The lifetime of the windows is then determined using the reliability code. The analytical model shows the window has a good thermal mechanical design and that fast fracture is unlikely to occur below a power level of 9 Mw. The experimental goal is to develop a conditioning procedure and evaluate the performance of RF windows. During the experimental evaluation, much was learned about processing of the windows to improve the RF performance. Methods of processing included grit blasting and using various coatings.

Karen Ann Cummings

1998-07-01T23:59:59.000Z

370

Hydrogen isotope fractionation during lipid biosynthesis by Haloarcula marismortui  

E-Print Network [OSTI]

Hydrogen isotope fractionation during lipid biosynthesis by Haloarcula marismortui Sitindra S studied the controls on the fractionation of hydrogen isotopes during lipid biosynthesis by Haloarcula marismortui, a halophilic archaea, in pure culture experiments by varying organic substrate, the hydrogen

371

Process for stabilization of coal liquid fractions  

DOE Patents [OSTI]

Coal liquid fractions to be used as fuels are stabilized against gum formation and viscosity increases during storage, permitting the fuel to be burned as is, without further expensive treatments to remove gums or gum-forming materials. Stabilization is accomplished by addition of cyclohexanol or other simple inexpensive secondary and tertiary alcohols, secondary and tertiary amines, and ketones to such coal liquids at levels of 5-25% by weight with respect to the coal liquid being treated. Cyclohexanol is a particularly effective and cost-efficient stabilizer. Other stabilizers are isopropanol, diphenylmethanol, tertiary butanol, dipropylamine, triethylamine, diphenylamine, ethylmethylketone, cyclohexanone, methylphenylketone, and benzophenone. Experimental data indicate that stabilization is achieved by breaking hydrogen bonds between phenols in the coal liquid, thereby preventing or retarding oxidative coupling. In addition, it has been found that coal liquid fractions stabilized according to the invention can be mixed with petroleum-derived liquid fuels to produce mixtures in which gum deposition is prevented or reduced relative to similar mixtures not containing stabilizer.

Davies, Geoffrey (Boston, MA); El-Toukhy, Ahmed (Alexandria, EG)

1987-01-01T23:59:59.000Z

372

Hamilton-Jacobi formulation of systems within Caputo's fractional derivative  

E-Print Network [OSTI]

In this paper we develop a fractional Hamilton-Jacobi formulation for discrete systems in terms of fractional Caputo derivatives. The fractional action function is obtained and the solutions of the equations of motion are recovered. An example is studied in details.

Eqab M. Rabei; Ibtesam Almayteh; Sami I. Muslih; Dumitru Baleanu

2007-03-26T23:59:59.000Z

373

Electron Spin Precession for the Time Fractional Pauli Equation  

E-Print Network [OSTI]

In this work, we aim to extend the application of the fractional calculus in the realm of quantum mechanics. We present a time fractional Pauli equation containing Caputo fractional derivative. By use of the new equation we study the electron spin precession problem in a homogeneous constant magnetic field.

Hosein Nasrolahpour

2011-04-05T23:59:59.000Z

374

An rf-carpet electrospray ion source to provide isobaric mass calibrants for trans-uranium elements  

E-Print Network [OSTI]

For trans-uranium elements, stable atomic isobars do not exist. In order to provide isobaric reference ions for the mass measurement of trans-uranium elements, an electrospray ion source (ESI) was combined with an rf-carpet to collect molecular ions efficiently. The rf-carpet allows for simplification of the pumping system to transport ions from the ESI to a precision mass analyzer. Molecular ions appropriate for isobaric references of trans-uranium elements were extracted from the rf-carpet and analyzed by a multi-reflection time-of-flight mass spectrograph (MRTOF-MS) with a resolving power of $\\rm{R_m} \\gtrsim100,000$.

S. Naimi; S. Nakamura; Y. Ito; H. Mita; K. Okada; A. Ozawa; P. Schury; T. Sonoda; A. Takamine; M. Wada; H. Wollnik

2012-12-16T23:59:59.000Z

375

Topological Current in Fractional Chern Insulators  

E-Print Network [OSTI]

We consider interacting fermions in a magnetic field on a two-dimensional lattice with the periodic boundary conditions. In order to measure the Hall current, we apply an electric potential with a compact support. Then, due to the Lorentz force, the Hall current appears along the equipotential line. Introducing a local current operator at the edge of the potential, we derive the Hall conductance as a linear response coefficient. For a wide class of the models, we prove that if there exists a spectral gap above the degenerate ground state, then the Hall conductance of the ground state is fractionally quantized without averaging over the fluxes. This is an extension of the topological argument for the integrally quantized Hall conductance in noninteracting fermion systems on lattices.

Koma, Tohru

2015-01-01T23:59:59.000Z

376

Topological Current in Fractional Chern Insulators  

E-Print Network [OSTI]

We consider interacting fermions in a magnetic field on a two-dimensional lattice with the periodic boundary conditions. In order to measure the Hall current, we apply an electric potential with a compact support. Then, due to the Lorentz force, the Hall current appears along the equipotential line. Introducing a local current operator at the edge of the potential, we derive the Hall conductance as a linear response coefficient. For a wide class of the models, we prove that if there exists a spectral gap above the degenerate ground state, then the Hall conductance of the ground state is fractionally quantized without averaging over the fluxes. This is an extension of the topological argument for the integrally quantized Hall conductance in noninteracting fermion systems on lattices.

Tohru Koma

2015-04-06T23:59:59.000Z

377

ABJ Fractional Brane from ABJM Wilson Loop  

E-Print Network [OSTI]

We present a new Fermi gas formalism for the ABJ matrix model. This formulation identifies the effect of the fractional M2-brane in the ABJ matrix model as that of a composite Wilson loop operator in the corresponding ABJM matrix model. Using this formalism, we study the phase part of the ABJ partition function numerically and find a simple expression for it. We further compute a few exact values of the partition function at some coupling constants. Fitting these exact values against the expected form of the grand potential, we can determine the grand potential with exact coefficients. The results at various coupling constants enable us to conjecture an explicit form of the grand potential for general coupling constants. The part of the conjectured grand potential from the perturbative sum, worldsheet instantons and bound states is regarded as a natural generalization of that in the ABJM matrix model, though the membrane instanton part contains a new contribution.

Sho Matsumoto; Sanefumi Moriyama

2014-03-03T23:59:59.000Z

378

Multidimensional optical fractionation with holographic verification  

E-Print Network [OSTI]

The trajectories of colloidal particles driven through a periodic potential energy landscape can become kinetically locked in to directions dictated by the landscape's symmetries. When the landscape is realized with forces exerted by a structured light field, the path a given particle follows has been predicted to depend exquisitely sensitively on such properties as the particle's size and refractive index These predictions, however, have not been tested experimentally. Here, we describe measurements of colloidal silica spheres' transport through arrays of holographic optical traps that use holographic video microscopy to track individual spheres' motions in three dimensions and simultaneously to measure each sphere's radius and refractive index with part-per-thousand resolution. These measurements confirm previously untested predictions for the threshold of kinetically locked-in transport, and demonstrate the ability of optical fractionation to sort colloidal spheres with part-per-thousand resolution on multiple characteristics simultaneously.

Ke Xiao; David G. Grier

2009-12-23T23:59:59.000Z

379

Anomalous Topological Pumps and Fractional Josephson Effects  

E-Print Network [OSTI]

We discover novel topological pumps in the Josephson effects for superconductors. The phase difference, which is odd under the chiral symmetry defined by the product of time-reversal and particle-hole symmetries, acts as an anomalous adiabatic parameter. These pumping cycles are different from those in the "periodic table", and are characterized by $Z\\times Z$ or $Z_2\\times Z_2$ strong invariants. We determine the general classifications in class AIII, and those in class DIII with a single anomalous parameter. For the $Z_2\\times Z_2$ topological pump in class DIII, one $Z_2$ invariant describes the coincidence of fermion parity and spin pumps whereas the other one reflects the non-Abelian statistics of Majorana Kramers pairs, leading to three distinct fractional Josephson effects.

Fan Zhang; C. L. Kane

2013-10-20T23:59:59.000Z

380

The effective delayed neutron fraction for bare-metal criticals  

SciTech Connect (OSTI)

Given sufficient material, a large number of actinides could be used to form bare-metal criticals. The effective delayed neutron fraction for a bare critical comprised of a fissile material is comparable with the absolute delayed neutron fraction. The effective delayed neutron fraction for a bare critical composed of a fissionable material is reduced by factors of 2 to 10 when compared with the absolute delayed neutron fraction. When the effective delayed neutron fraction is small, the difference between delayed and prompt criticality is small, and extreme caution must be used in critical assemblies of these materials. This study uses an approximate but realistic model to survey the actinide region to compare effective delayed neutron fractions with absolute delayed neutron fractions.

Pearlstein, S.

1999-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "rf respirable fraction" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

Fractional Calculus in Hydrologic Modeling: A Numerical Perspective  

SciTech Connect (OSTI)

Fractional derivatives can be viewed either as a handy extension of classical calculus or, more deeply, as mathematical operators defined by natural phenomena. This follows the view that the diffusion equation is defined as the governing equation of a Brownian motion. In this paper, we emphasize that fractional derivatives come from the governing equations of stable Levy motion, and that fractional integration is the corresponding inverse operator. Fractional integration, and its multi-dimensional extensions derived in this way, are intimately tied to fractional Brownian (and Levy) motions and noises. By following these general principles, we discuss the Eulerian and Lagrangian numerical solutions to fractional partial differential equations, and Eulerian methods for stochastic integrals. These numerical approximations illuminate the essential nature of the fractional calculus.

David A. Benson; Mark M. Meerschaert; Jordan Revielle

2012-01-01T23:59:59.000Z

382

ECG-Derived Respiration and Instantaneous Frequency based on the Synchrosqueezing Transform: Application to Patients with Atrial Fibrillation  

E-Print Network [OSTI]

The acquisition of information about respiratory patterns without directly recording the respiratory signals would be beneficial in many clinical settings. The electrocardiogram (ECG)-derived respiration (EDR) algorithm, which derives the respiratory pattern by using the information encoded in ECG signals, enables data acquisition in this manner. However, the traditional EDR algorithm cannot be used in patients with atrial fibrillation (AF) because they have highly irregular heart rates. In this paper, we first provide a definition of ideal instantaneous frequency (IIF) of respiratory signals and then describe how a novel time-frequency representation technique referred to as the Synchrosqueezing transform (SST) was used for the accurate estimation of the IIF of respiratory signals, i.e., SST-IF. Then, we introduce a new EDR algorithm based on the evaluation of the SST-IF. We tested the applicability of our new EDR algorithm in patients with comorbid cardiovascular diseases, most of which were complicated by ...

Yi-Hsin, Chan; Shu-Shya, Hseu; Chi-Tai, Kuo; Yung-Hsin, Yeh

2011-01-01T23:59:59.000Z

383

Tests of an RF Dipole Crabbing Cavity for an Electron-Ion Collider  

SciTech Connect (OSTI)

On the scheme of developing a medium energy electron-ion collider (MEIC) at Jefferson Lab, we have designed a compact superconducting rf dipole cavity at 750 MHz to crab both electron and ion bunches and increase luminosities at the interaction points (IP) of the machine. Following the design optimization and characterization of the electromagnetic properties such as peak surface fields and shunt impedance, along with field nonuniformities, multipole components content, higher order modes (HOM) and multipacting, a prototype cavity was built by Niowave Inc. The 750 MHz prototype crab cavity has been tested at 4 K and is ready for re-testing at 4 K and 2 K at Jefferson Lab. In this paper we present the detailed results of the rf tests performed on the 750 MHz crab cavity prototype.

Castilla Loeza, Alejandro [ODU, JLAB; Delayen, Jean R. [ODU, JLAB

2013-12-01T23:59:59.000Z

384

Elimination of Radio-Frequency Noise by Identifying and Diverting Large RF Ground Currents  

SciTech Connect (OSTI)

The problem of electromagnetic interference in scientific instruments is compounded for high-power plasma experiments by the large currents and voltages as well as by the broad bandwidths of the instruments. Ground loops are known to allow stray magnetic fields to drive large ground currents that can induce spurious signals and damage electronics. Furthermore, even when a ground loop is broken, capacitive coupling can still permit the flow of radio-frequency current, resulting in high-frequency spurious signals that can overwhelm the desired signal. We present the effects of RF ground loops on the output of vacuum photodiodes used in the Caltech Solar Loop Experiment and demonstrate the elimination of the spurious signals by diverting the ground currents away from the most vulnerable point of the signal line. Techniques for identifying the RF ground loops are also discussed. These techniques should be valuable in many high-power systems where interference from spurious coupling is an issue.

Perkins, R. J.; Bellan, P. M. [Applied Physics, California Institute of Technology (United States)

2011-12-23T23:59:59.000Z

385

Capture cavity cryomodule for quantum beam experiment at KEK superconducting RF test facility  

SciTech Connect (OSTI)

A capture cavity cryomodule was fabricated and used in a beam line for quantum beam experiments at the Superconducting RF Test Facility (STF) of the High Energy Accelerator Research Organization in Japan. The cryomodule is about 4 m long and contains two nine-cell cavities. The cross section is almost the same as that of the STF cryomodules that were fabricated to develop superconducting RF cavities for the International Linear Collider. An attempt was made to reduce the large deflection of the helium gas return pipe (GRP) that was observed in the STF cryomodules during cool-down and warm-up. This paper briefly describes the structure and cryogenic performance of the captures cavity cryomodule, and also reports the measured displacement of the GRP and the cavity-containing helium vessels during regular operation.

Tsuchiya, K.; Hara, K.; Hayano, H.; Kako, E.; Kojima, Y.; Kondo, Y.; Nakai, H.; Noguchi, S.; Ohuchi, N.; Terashima, A. [High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801 (Japan); Horikoshi, A.; Semba, T. [Hitachi, Ltd., Hitachi Works, Hitachi, Ibaraki 317-8511 (Japan)

2014-01-29T23:59:59.000Z

386

Options for an 11 GeV RF Beam Separator for the Jefferson Lab CEBAF Upgrade  

SciTech Connect (OSTI)

The CEBAF accelerator at Jefferson Lab has had, since first demonstration in 1996, the ability to deliver a 5-pass electron beam to experimental halls (A, B, and C) simultaneously. This capability was provided by a set of three, room temperature 499 MHz rf separators in the 5th pass beamline. The separator was two-rod, TEM mode type resonator, which has a high shunt impedance. The maximum rf power to deflect the 6 GeV beams was about 3.4kW. The 12 GeV baseline design does not preserve the capability of separating the 5th pass, 11 GeV beam for the 3 existing halls. Several options for restoring this capability, including extension of the present room temperature system or a new superconducting design in combination with magnetic systems, are under investigation and are presented.

Jean Delayen, Michael Spata, Haipeng Wang

2009-05-01T23:59:59.000Z

387

A new approach to calculate the transport matrix in RF cavities  

SciTech Connect (OSTI)

A realistic approach to calculate the transport matrix in RF cavities is developed. It is based on joint solution of equations of longitudinal and transverse motion of a charged particle in an electromagnetic field of the linac. This field is a given by distribution (measured or calculated) of the component of the longitudinal electric field on the axis of the linac. New approach is compared with other matrix methods to solve the same problem. The comparison with code ASTRA has been carried out. Complete agreement for tracking results for a TESLA-type cavity is achieved. A corresponding algorithm will be implemented into the MARS15 code. A realistic approach to calculate the transport matrix in RF cavities is developed. Complete agreement for tracking results with existed code ASTRA is achieved. New algorithm will be implemented into MARS15 code.

Eidelman, Yu.; /Novosibirsk, IYF; Mokhov, N.; Nagaitsev, S.; Solyak, N.; /Fermilab

2011-03-01T23:59:59.000Z

388

RF Surface Impedance Characterization of Potential New Materials for SRF-based Accelerators  

SciTech Connect (OSTI)

In the development of new superconducting materials for possible use in SRF-based accelerators, it is useful to work with small candidate samples rather than complete resonant cavities. The recently commissioned Jefferson Lab RF Surface Impedance Characterization (SIC) system can presently characterize the central region of 50 mm diameter disk samples of various materials from 2 to 40 K exposed to RF magnetic fields up to 14 mT at 7.4 GHz. We report the recent measurement results of bulk Nb, thin film Nb on Cu and sapphire substrates, Nb{sub 3}Sn sample, and thin film MgB{sub 2} on sapphire substrate provided by colleagues at JLab and Temple University.

Xiao, Binping [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States) and College of William and Mary, Williamsburg, VA (United States); Eremeev, Grigory V. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Reece, Charles E. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Phillips, H. Lawrence [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Kelley, Michael J. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)

2012-09-01T23:59:59.000Z

389

Permanent-magnet helicon sources and arrays: A new type of rf plasma  

SciTech Connect (OSTI)

Helicon discharges are known for their ability to produce high densities of partially ionized plasma, their efficiency arising from an unusual mechanism of rf coupling. However, the requirement of a dc magnetic field has prevented their wide acceptance in industry. The use of permanent magnets greatly simplifies helicon sources, and arrays of small sources extend the use of helicons to the processing of large substrates. An eight-tube array was designed and constructed, and its density uniformity measured in a 53x165 cm{sup 2} chamber. Three innovations involved (a) the remote field of ring magnets, (b) a low-field density peak, and (c) rf power distribution. High-density plasmas uniform over large areas requires compatibility in all three areas.

Chen, Francis F.; Torreblanca, Humberto [University of California, Los Angeles, California 90095-1594 (United States)

2009-05-15T23:59:59.000Z

390

A 201-MHz Normal Conducting RF Cavity for the International MICE Experiment  

SciTech Connect (OSTI)

MICE is a demonstration experiment for the ionization cooling of muon beams. Eight RF cavities are proposed to be used in the MICE cooling channel. These cavities will be operated in a strong magnetic field; therefore, they must be normal conducting. The cavity design and construction are based on the successful experience and techniques developed for a 201-MHz prototype cavity for the US MUCOOL program. Taking advantage of a muon beamâ s penetration property, the cavity employs a pair of curved thin beryllium windows to terminate conventional beam irises and achieve higher cavity shunt impedance. The cavity resembles a round, closed pillbox cavity. Two half-shells spun from copper sheets are joined by e-beam welding to form the cavity body. There are four ports on the cavity equator for RF couplers, vacuum pumping and field probes. The ports are formed by means of an extruding technique.

Li, D.; DeMello, A.J.; Virostek, Steve; S. Zisman, Michael; Rimmer, Robert

2008-07-01T23:59:59.000Z

391

Design methodologies for built-in testing of integrated RF transceivers with the on-chip loopback technique  

E-Print Network [OSTI]

Advances toward increased integration and complexity of radio frequency (RF) andmixed-signal integrated circuits reduce the effectiveness of contemporary testmethodologies and result in a rising cost of testing. The focus in this research...

Onabajo, Marvin Olufemi

2009-05-15T23:59:59.000Z

392

Design of a horizontal test cryostat for superconducting RF cavities for the FREIA facility at Uppsala University  

SciTech Connect (OSTI)

Uppsala University is constructing a large scale facility, called FREIA (Facility for Research Instrumentation and Accelerator Development). FREIA includes a helium liquefier and an accelerator test facility and has the capacity to test superconducting radio-frequency (RF) cavities with the same RF system and RF power level as in an accelerator. A central element of FREIA is a horizontal test cryostat connected in closed loop to a helium liquefier. This cryostat can house two fully equipped (tuners, piezo, power coupler, helium tank) superconducting cavities to perform full RF high power tests and operate at temperatures between 1.8 K and 4.2 K. The cryostat is designed to accommodate a large array of superconducting cavities and magnets, among which the European Spallation Source (ESS) type spoke and high-? elliptical cavities as well as TESLA/ILC type elliptical cavities. The present status of the project and the design of the cryostat are reported.

Chevalier, N. R.; Thermeau, J.-P.; Bujard, P.; Junquera, T. [Accelerators and Cryogenic Systems (ACS), 86 rue de Paris, 91400 Orsay (France); Hermansson, L.; Kern, R. Santiago; Ruber, R. [Uppsala University, Department of Physics and Astronomy, 75120 Uppsala (Sweden)

2014-01-29T23:59:59.000Z

393

A 900MHz RF Energy Harvesting Module TARIS Thierry, VIGNERAS Valrie  

E-Print Network [OSTI]

Abstract --This paper presents a guideline to design and optimize a RF energy harvester operating in ISM-the-shelf devices. The topology of the impedance transformation block is selected to reduce the losses which sensitivity of -22.5 dBm for a dc output voltage of 200 mV up to -11 dBm for 1.08 V. A wireless power

Paris-Sud XI, Université de

394

A PARAMETRIC STUDY OF BCS RF SURFACE IMPEDANCE WITH MAGNETIC FIELD USING THE XIAO CODE  

SciTech Connect (OSTI)

A recent new analysis of field-dependent BCS rf surface impedance based on moving Cooper pairs has been presented.[1] Using this analysis coded in Mathematica TM, survey calculations have been completed which examine the sensitivities of this surface impedance to variation of the BCS material parameters and temperature. The results present a refined description of the "best theoretical" performance available to potential applications with corresponding materials.

Reece, Charles E. [JLAB; Xiao, Binping [JLAB, BNL

2013-09-01T23:59:59.000Z

395

High Power Testing of RF Cavities for the PEP II B Factory  

SciTech Connect (OSTI)

We describe the process of conditioning and high-power testing of RF cavities for PEP-II. Procedures for vacuum assembly, bakeout and automated processing are described. Interlocks and safety precautions for protection of equipment and personnel are discussed and performance data of tested cavity assemblies are reported. Performance of ancillary components such as windows, couplers and tuners is also discussed. Comments are included on handling, alignment, installation and commissioning issues where appropriate.

Rimmer, R.A.; /LBL, Berkeley; Allen, M.; Fant, K.; Hill, A.; Hoyt, M.; Judkins, J.; Neubauer, Mark Stephen; Schwarz, H.; /SLAC

2011-09-01T23:59:59.000Z

396

Uniform longitudinal beam profiles in the Fermilab Recycler using adaptive rf correction  

SciTech Connect (OSTI)

The Fermilab Recycler Ring is a permanent magnet based 8 GeV anti-proton storage ring. A wideband RF system, driven with ARB's (ARBitrary waveform generators), allows the system to produce programmable barrier waveforms. Beam current profile distortion was observed, its origin verified both experimentally and theoretically, and an FPGA-based correction system was designed, tested and implemented to level the bunch profile.

Hu, Martin; Broemmelsiek, Daniel Robert; Chase, Brian; Crisp, James L.; Eddy, Nathan; Joireman, Paul W.; Ng, King Yuen; /Fermilab

2007-06-01T23:59:59.000Z

397

Structure of Velocity Distribution of Sheath-Accelerated Secondary Electrons in Asymmetric RF-DC Discharge  

E-Print Network [OSTI]

The ballistic population is thought to be responsible for alleviating the electron shading effect and the notching of the photoresist layer. We have performed test-particle simulations where the features in the EVDF of electrons impacting the RF electrode are fully resolved at all energies. An analytic model has been developed to predict existence of peaked and step-like structures in the EVDF.

Khrabrov, Alexander V; Ventzek, Peter L G; Ranjan, Alok; Chen, Lee

2015-01-01T23:59:59.000Z

398

The Development of RF Heating of Magnetically Confined Deuterium-Tritium Plasmas  

SciTech Connect (OSTI)

The experimental and theoretical development of ion cyclotron radiofrequency heating (ICRF) in toroidal magnetically-confined plasmas recently culminated with the demonstration of ICRF heating of D-T plasmas, first in the Tokamak Fusion Test Reactor (TFTR) and then in the Joint European Torus (JET). Various heating schemes based on the cyclotron resonances between the plasma ions and the applied ICRF waves have been used, including second harmonic tritium, minority deuterium, minority helium-3, mode conversion at the D-T ion-ion hybrid layer, and ion Bernstein wave heating. Second harmonic tritium heating was first shown to be effective in a reactor-grade plasma in TFTR. D-minority heating on JET has led to the achievement of Q = 0.22, the ratio of fusion power produced to RF power input, sustained over a few energy confinement times. In this paper, some of the key building blocks in the development of rf heating of plasmas are reviewed and prospects for the development of advanced methods of plasma control based on the application of rf waves are discussed.

B.P. LeBlanc; C.K. Phillips; J.C. Hosea; R. Majeski; S. Bernabei [and others

1999-06-01T23:59:59.000Z

399

rf system for the Los Alamos free-electron laser (FEL)  

SciTech Connect (OSTI)

The FEL electron linac consists of three buncher cavities: two accelerator cavities and a deflection cavity, each with its own phase-coherent rf source. All sources will be pulsed for 100 ..mu..s at a 1-pps rate. The phase and amplitude stability requirements are +-1/2/sup 0/, and +-1/2%. There are two subharmonic bunchers, each requiring 5 kW at 108.33 MHz. All remaining cavities operate at 1300 MHz. The fundamental buncher requires 5 kW, whereas each of the accelerating cavities requires at least 3 MW. The deflection cavity requires up to 100 kW, which is coupled from one of the accelerator cavity rf sources. Prominent features of the rf system are the phase and amplitude control circuits and the multimegawatt klystron amplifiers. Three L3707 klystrons were obtained from the AMRAD radar site at White Sands, which was decommissioned in the early 1970s. The tubes originally were designed to produce 10-MW, 10-..mu..s pulses. Each tube has delivered over 3.6-MW, 100-..mu..s pulses in the FEL system.

Friedrichs, C.C.; Tallerico, P.J.; Hoffert, W.J.

1983-01-01T23:59:59.000Z

400

Design of a new VHF RF power amplifier system for LANSCE  

SciTech Connect (OSTI)

A major upgrade is replacing much of the 40 year-old proton drift tube linac RF system with new components at the Los Alamos Neutron Science Center (LANSCE). When installed, the new system will reduce the total number of electron power tubes from twenty-four to eight in the RF powerplant. A new 200 MHz high power cavity amplifier has being developed at LANSCE. This 3.2 MW final power amplifier (FPA) uses a Thales TH628 Diacrode{reg_sign}, a state-of-the-art tetrode that eliminates the large anode modulator of the triode-based FPA that has been in use for four decades. Drive power for the FPA is provided by a new tetrode intermediate power amplifier (and a solid-state driver stage). The new system has sufficient duty-factor capability to allow LANSCE to return to 1 MW beam operation. Prototype RF power amplifiers have been designed, fabricated, and assembled, and are being tested. High voltage DC power became available through innovative re-engineering of an installed system. Details of the electrical and mechanical design of the FPA and ancillary systems are discussed.

Lyles, John T M [Los Alamos National Laboratory

2010-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "rf respirable fraction" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

HIGH POWER TEST OF RF SEPARATOR FOR 12 GEV UPGRADE OF CEBAF AT JLAB  

SciTech Connect (OSTI)

CEBAF at JLab is in the process of an energy upgrade from 6 GeV to 12 GeV. The existing setup of the RF separator cavities in the 5th pass will not be adequate to extract the highest energy (11 GeV) beam to any two existing halls (A, B or C) while simultaneously delivering to the new hall D in the case of the proposed 12 GeV upgrade of the machine. To restore this capability, we are exploring the possibility of extension of existing normal conducting 499 MHz TEM-type rf separator cavities. Detailed numerical studies suggest that six 2-cell normal conducting structures meet the requirements; each 2-cell structure will require up to 4 kW RF input power in contrast with the current nominal operating power of 1.0 to 2.0 kW. A high power test of 4 kW confirms that the cavity meet the requirement.

S. Ahmed, M. Wissmann, J. Mammosser, C. Hovater, M. Spata, G. Krafft, J. Delayen

2012-07-01T23:59:59.000Z

402

Optimizing RF gun cavity geometry within an automated injector design system  

SciTech Connect (OSTI)

RF guns play an integral role in the success of several light sources around the world, and properly designed and optimized cw superconducting RF (SRF) guns can provide a path to higher average brightness. As the need for these guns grows, it is important to have automated optimization software tools that vary the geometry of the gun cavity as part of the injector design process. This will allow designers to improve existing designs for present installations, extend the utility of these guns to other applications, and develop new designs. An evolutionary algorithm (EA) based system can provide this capability because EAs can search in parallel a large parameter space (often non-linear) and in a relatively short time identify promising regions of the space for more careful consideration. The injector designer can then evaluate more cavity design parameters during the injector optimization process against the beam performance requirements of the injector. This paper will describe an extension to the APISA software that allows the cavity geometry to be modified as part of the injector optimization and provide examples of its application to existing RF and SRF gun designs.

Alicia Hofler ,Pavel Evtushenko

2011-03-28T23:59:59.000Z

403

Synchronization of piece-wise continuous systems of fractional order  

E-Print Network [OSTI]

The aim of this study is to prove analytically that synchronization of a piece-wise continuous class of systems of fractional order can be achieved. Based on our knowledge, there are no numerical methods to integrate differential equations with discontinuous right hand side of fractional order which model these systems. Therefore, via Filippov's regularization [1] and Cellina's Theorem [2,3], we prove that the initial value problem can be converted into a continuous problem of fractional-order, to which numerical methods for fractional orders apply. In this way, the synchronization problem transforms into a standard problem for continuous systems of fractional order. Three examples of fractional-order piece-wise systems are considered: Sprott system, Chen and Shimizu-Morioka system.

Marius-F. Danca

2014-08-19T23:59:59.000Z

404

Power-law spatial dispersion from fractional Liouville equation  

SciTech Connect (OSTI)

A microscopic model in the framework of fractional kinetics to describe spatial dispersion of power-law type is suggested. The Liouville equation with the Caputo fractional derivatives is used to obtain the power-law dependence of the absolute permittivity on the wave vector. The fractional differential equations for electrostatic potential in the media with power-law spatial dispersion are derived. The particular solutions of these equations for the electric potential of point charge in this media are considered.

Tarasov, Vasily E. [Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, Moscow 119991 (Russian Federation)] [Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, Moscow 119991 (Russian Federation)

2013-10-15T23:59:59.000Z

405

Projective synchronization in fractional order chaotic systems and its control  

E-Print Network [OSTI]

The chaotic dynamics of fractional (non-integer) order systems have begun to attract much attention in recent years. In this paper, we study the projective synchronization in two coupled fractional order chaotic oscillators. It is shown that projective synchronization can also exist in coupled fractional order chaotic systems. A simple feedback control method for controlling the scaling factor onto a desired value is also presented.

Chunguang Li

2006-04-24T23:59:59.000Z

406

Fractional Equations of Kicked Systems and Discrete Maps  

E-Print Network [OSTI]

Starting from kicked equations of motion with derivatives of non-integer orders, we obtain "fractional" discrete maps. These maps are generalizations of well-known universal, standard, dissipative, kicked damped rotator maps. The main property of the suggested fractional maps is a long-term memory. The memory effects in the fractional discrete maps mean that their present state evolution depends on all past states with special forms of weights. These forms are represented by combinations of power-law functions.

Vasily E. Tarasov; George M. Zaslavsky

2011-07-20T23:59:59.000Z

407

Tunable fractional quantum Hall phases in bilayer graphene  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Coulomb interactions drive the existence of a correlated many-body state. Bilayer graphene represents a particularly interesting material in which to study the fractional...

408

Linear Stochastic Fractional Programming with Sum-of-Probabilistic ...  

E-Print Network [OSTI]

Fractional Programming Problem with Mixed Constraints”, Acta Ciencia Indica,. Vol. XXX M, No. 3, pp 497-506. 11. Charles, V., and Dutta, D., “Extremization of ...

2005-04-19T23:59:59.000Z

409

Non-Linear Stochastic Fractional Programming Model of Financial ...  

E-Print Network [OSTI]

2. Charles, V. and Dutta, D., A method for solving linear stochastic fractional programming problem with mixed constraints, Acta Ciencia Indica, Vol. XXX M,. No.

2005-04-19T23:59:59.000Z

410

Determination of Charm Hadronic Branching Fractions at CLEO-c  

E-Print Network [OSTI]

Recent results from CLEO-c on measurements of absolute hadronic branching fractions of D0, D+, and Ds+ mesons are presented.

A. Ryd

2007-11-24T23:59:59.000Z

411

amorphous volume fractions: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

are consistent with the boundary action derived geometrically. P. Merlatti; G. Sabella 2001-01-11 5 NORTHWESTERN UNIVERSITY Particle Coarsening in High Volume Fraction...

412

CT-guided Bipolar and Multipolar Radiofrequency Ablation (RF Ablation) of Renal Cell Carcinoma: Specific Technical Aspects and Clinical Results  

SciTech Connect (OSTI)

Purpose. This study was designed to evaluate the clinical efficacy of CT-guided bipolar and multipolar radiofrequency ablation (RF ablation) of renal cell carcinoma (RCC) and to analyze specific technical aspects between both technologies. Methods. We included 22 consecutive patients (3 women; age 74.2 {+-} 8.6 years) after 28 CT-guided bipolar or multipolar RF ablations of 28 RCCs (diameter 2.5 {+-} 0.8 cm). Procedures were performed with a commercially available RF system (Celon AG Olympus, Berlin, Germany). Technical aspects of RF ablation procedures (ablation mode [bipolar or multipolar], number of applicators and ablation cycles, overall ablation time and deployed energy, and technical success rate) were analyzed. Clinical results (local recurrence-free survival and local tumor control rate, renal function [glomerular filtration rate (GFR)]) and complication rates were evaluated. Results. Bipolar RF ablation was performed in 12 procedures and multipolar RF ablation in 16 procedures (2 applicators in 14 procedures and 3 applicators in 2 procedures). One ablation cycle was performed in 15 procedures and two ablation cycles in 13 procedures. Overall ablation time and deployed energy were 35.0 {+-} 13.6 min and 43.7 {+-} 17.9 kJ. Technical success rate was 100 %. Major and minor complication rates were 4 and 14 %. At an imaging follow-up of 15.2 {+-} 8.8 months, local recurrence-free survival was 14.4 {+-} 8.8 months and local tumor control rate was 93 %. GFR did not deteriorate after RF ablation (50.8 {+-} 16.6 ml/min/1.73 m{sup 2} before RF ablation vs. 47.2 {+-} 11.9 ml/min/1.73 m{sup 2} after RF ablation; not significant). Conclusions. CT-guided bipolar and multipolar RF ablation of RCC has a high rate of clinical success and low complication rates. At short-term follow-up, clinical efficacy is high without deterioration of the renal function.

Sommer, C. M., E-mail: christof.sommer@med.uni-heidelberg.de [University Hospital Heidelberg, INF 110, Department of Diagnostic and Interventional Radiology (Germany); Lemm, G.; Hohenstein, E. [Minimally Invasive Therapies and Nuclear Medicine, SLK Kliniken Heilbronn GmbH, Clinic for Radiology (Germany); Bellemann, N.; Stampfl, U. [University Hospital Heidelberg, INF 110, Department of Diagnostic and Interventional Radiology (Germany); Goezen, A. S.; Rassweiler, J. [Clinic for Urology, SLK Kliniken Heilbronn GmbH (Germany); Kauczor, H. U.; Radeleff, B. A. [University Hospital Heidelberg, INF 110, Department of Diagnostic and Interventional Radiology (Germany); Pereira, P. L. [Minimally Invasive Therapies and Nuclear Medicine, SLK Kliniken Heilbronn GmbH, Clinic for Radiology (Germany)

2013-06-15T23:59:59.000Z

413

Aggregation Behavior of Two Asphaltenic Fractions in Aromatic Solvents  

E-Print Network [OSTI]

Aggregation Behavior of Two Asphaltenic Fractions in Aromatic Solvents Rahoma S. Mohamed* and Anto. The results indicated possible asphaltene aggregation as well as the probable existence of critical micelle fraction. Average molecular areas for asphaltenes adsorbed at different interfaces estimated from surface

Loh, Watson

414

Correlated topological insulators and the fractional magnetoelectric effect  

SciTech Connect (OSTI)

Topological insulators are characterized by the presence of gapless surface modes protected by time-reversal symmetry. In three space dimensions the magnetoelectric response is described in terms of a bulk {theta} term for the electromagnetic field. Here we construct theoretical examples of such phases that cannot be smoothly connected to any band insulator. Such correlated topological insulators admit the possibility of fractional magnetoelectric response described by fractional {theta}/{pi}. We show that fractional {theta}/{pi} is only possible in a gapped time-reversal-invariant system of bosons or fermions if the system also has deconfined fractional excitations and associated degenerate ground states on topologically nontrivial spaces. We illustrate this result with a concrete example of a time-reversal-symmetric topological insulator of correlated bosons with {theta}=({pi}/4). Extensions to electronic fractional topological insulators are briefly described.

Swingle, B.; Barkeshli, M.; McGreevy, J.; Senthil, T. [Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

2011-05-15T23:59:59.000Z

415

Correlated Topological Insulators and the Fractional Magnetoelectric Effect  

E-Print Network [OSTI]

Topological insulators are characterized by the presence of gapless surface modes protected by time-reversal symmetry. In three space dimensions the magnetoelectric response is described in terms of a bulk theta term for the electromagnetic field. Here we construct theoretical examples of such phases that cannot be smoothly connected to any band insulator. Such correlated topological insulators admit the possibility of fractional magnetoelectric response described by fractional theta/pi. We show that fractional theta/pi is only possible in a gapped time reversal invariant system of bosons or fermions if the system also has deconfined fractional excitations and associated degenerate ground states on topologically non-trivial spaces. We illustrate this result with a concrete example of a time reversal symmetric topological insulator of correlated bosons with theta = pi/4. Extensions to electronic fractional topological insulators are briefly described.

Brian Swingle; Maissam Barkeshli; John McGreevy; T. Senthil

2010-05-06T23:59:59.000Z

416

A Survey of Pressure Vessel Code Compliance for Superconducting RF Cryomodules  

SciTech Connect (OSTI)

Superconducting radio frequency (SRF) cavities made from niobium and cooled with liquid helium are becoming key components of many particle accelerators. The helium vessels surrounding the RF cavities, portions of the niobium cavities themselves, and also possibly the vacuum vessels containing these assemblies, generally fall under the scope of local and national pressure vessel codes. In the U.S., Department of Energy rules require national laboratories to follow national consensus pressure vessel standards or to show ''a level of safety greater than or equal to'' that of the applicable standard. Thus, while used for its superconducting properties, niobium ends up being treated as a low-temperature pressure vessel material. Niobium material is not a code listed material and therefore requires the designer to understand the mechanical properties for material used in each pressure vessel fabrication; compliance with pressure vessel codes therefore becomes a problem. This report summarizes the approaches that various institutions have taken in order to bring superconducting RF cryomodules into compliance with pressure vessel codes. In Japan, Germany, and the U.S., institutions building superconducting RF cavities integrated in helium vessels or procuring them from vendors have had to deal with pressure vessel requirements being applied to SRF vessels, including the niobium and niobium-titanium components of the vessels. While niobium is not an approved pressure vessel material, data from tests of material samples provide information to set allowable stresses. By means of procedures which include adherence to code welding procedures, maintaining material and fabrication records, and detailed analyses of peak stresses in the vessels, or treatment of the vacuum vessel as the pressure boundary, research laboratories around the world have found methods to demonstrate and document a level of safety equivalent to the applicable pressure vessel codes.

Peterson, Thomas; Klebaner, Arkadiy; Nicol, Tom; Theilacker, Jay; /Fermilab; Hayano, Hitoshi; Kako, Eiji; Nakai, Hirotaka; Yamamoto, Akira; /KEK, Tsukuba; Jensch, Kay; Matheisen, Axel; /DESY; Mammosser, John; /Jefferson Lab

2011-06-07T23:59:59.000Z

417

Impact of dose size in single fraction spatially fractionated (grid) radiotherapy for melanoma  

SciTech Connect (OSTI)

Purpose: To evaluate the impact of dose size in single fraction, spatially fractionated (grid) radiotherapy for selectively killing infiltrated melanoma cancer cells of different tumor sizes, using different radiobiological models. Methods: A Monte Carlo technique was employed to calculate the 3D dose distribution of a commercially available megavoltage grid collimator in a 6 MV beam. The linear-quadratic (LQ) and modified linear quadratic (MLQ) models were used separately to evaluate the therapeutic outcome of a series of single fraction regimens that employed grid therapy to treat both acute and late responding melanomas of varying sizes. The dose prescription point was at the center of the tumor volume. Dose sizes ranging from 1 to 30 Gy at 100% dose line were modeled. Tumors were either touching the skin surface or having their centers at a depth of 3 cm. The equivalent uniform dose (EUD) to the melanoma cells and the therapeutic ratio (TR) were defined by comparing grid therapy with the traditional open debulking field. The clinical outcomes from recent reports were used to verify the authors’ model. Results: Dose profiles at different depths and 3D dose distributions in a series of 3D melanomas treated with grid therapy were obtained. The EUDs and TRs for all sizes of 3D tumors involved at different doses were derived through the LQ and MLQ models, and a practical equation was derived. The EUD was only one fifth of the prescribed dose. The TR was dependent on the prescribed dose and on the LQ parameters of both the interspersed cancer and normal tissue cells. The results from the LQ model were consistent with those of the MLQ model. At 20 Gy, the EUD and TR by the LQ model were 2.8% higher and 1% lower than by the MLQ, while at 10 Gy, the EUD and TR as defined by the LQ model were only 1.4% higher and 0.8% lower, respectively. The dose volume histograms of grid therapy for a 10 cm tumor showed different dosimetric characteristics from those of conventional radiotherapy. A significant portion of the tumor volume received a very large dose in grid therapy, which ensures significant tumor cell killing in these regions. Conversely, some areas received a relatively small dose, thereby sparing interspersed normal cells and increasing radiation tolerance. The radiobiology modeling results indicated that grid therapy could be useful for treating acutely responding melanomas infiltrating radiosensitive normal tissues. The theoretical model predictions were supported by the clinical outcomes. Conclusions: Grid therapy functions by selectively killing infiltrating tumor cells and concomitantly sparing interspersed normal cells. The TR depends on the radiosensitivity of the cell population, dose, tumor size, and location. Because the volumes of very high dose regions are small, the LQ model can be used safely to predict the clinical outcomes of grid therapy. When treating melanomas with a dose of 15 Gy or higher, single fraction grid therapy is clearly advantageous for sparing interspersed normal cells. The existence of a threshold fraction dose, which was found in the authors’ theoretical simulations, was confirmed by clinical observations.

Zhang, Hualin, E-mail: hualin.zhang@northwestern.edu, E-mail: hualinzhang@yahoo.com [Department of Radiation Oncology, Northwestern University Feinberg School of Medicine, Chicago, Illinois 60611 and Department of Radiation Oncology, Indiana University School of Medicine, Indianapolis, Indiana 46202 (United States)] [Department of Radiation Oncology, Northwestern University Feinberg School of Medicine, Chicago, Illinois 60611 and Department of Radiation Oncology, Indiana University School of Medicine, Indianapolis, Indiana 46202 (United States); Zhong, Hualiang [Department of Radiation Oncology, Henry Ford Health System, Detroit, Michigan 48202 (United States)] [Department of Radiation Oncology, Henry Ford Health System, Detroit, Michigan 48202 (United States); Barth, Rolf F. [Department of Pathology, The Ohio State University, Columbus, Ohio 43210 (United States)] [Department of Pathology, The Ohio State University, Columbus, Ohio 43210 (United States); Cao, Minsong; Das, Indra J. [Department of Radiation Oncology, Indiana University School of Medicine, Indianapolis, Indiana 46202 (United States)] [Department of Radiation Oncology, Indiana University School of Medicine, Indianapolis, Indiana 46202 (United States)

2014-02-15T23:59:59.000Z

418

RF study and simulations of a C-band Barrel Open Cavity (BOC) pulse compressor  

E-Print Network [OSTI]

This paper focuses on the RF study of a C-band(5712MHz) BOC pulse compressor. The operating principle of BOC is presented and the technical specifications are determined. The main components of BOC such as the cavity, the matching waveguide, the coupling slots and the tuning rings were numerically simulated by 3-D codes software HFSS and CST Microwave Studio(MWS). The "whispering gallery" mode TM6,1,1 with an unload Q of 100000 was chosen to oscillate in the cavity. An energy multiplication factor of 1.99 and a peak power gain of 6.34 were achieved theoretically.

Shu, Guan; He, Xiang

2014-01-01T23:59:59.000Z

419

Fabrication of super-hydrophobic surfaces on aluminum alloy substrates by RF-sputtered polytetrafluoroethylene coatings  

SciTech Connect (OSTI)

In this work, we present a method of fabricating super-hydrophobic surface on aluminum alloy substrate. The etching of aluminum surfaces has been performed using Beck's dislocation etchant for different time to create micrometer-sized irregular steps. An optimised etching time of 50 s is found to be essential before polytetrafluoroethylene (PTFE) coating, to obtain a highest water contact angle of 165±2° with a lowest contact angle hysteresis as low as 5±2°. The presence of patterned microstructure as revealed by scanning electron microscopy (SEM) together with the low surface energy ultrathin RF-sputtered PTFE films renders the aluminum alloy surfaces highly super-hydrophobic.

Wang, Yang; Liu, Xiao Wei; Zhang, Hai Feng, E-mail: wy3121685@163.com; Zhou, Zhi Ping [Department of Microelectronics, Harbin Institute of Technology, Harbin, Heilongjiang, 150001 (China)] [Department of Microelectronics, Harbin Institute of Technology, Harbin, Heilongjiang, 150001 (China)

2014-03-15T23:59:59.000Z

420

Rf-plasma synthesis of nanosize silicon carbide and nitride. Final report  

SciTech Connect (OSTI)

A pulsed rf plasma technique is capable of generating ceramic particles of 10 manometer dimension. Experiments using silane/ammonia and trimethylchlorosilane/hydrogen gas mixtures show that both silicon nitride and silicon carbide powders can be synthesized with control of the average particle diameter from 7 to 200 nm. Large size dispersion and much agglomeration appear characteristic of the method, in contrast to results reported by another research group. The as produced powders have a high hydrogen content and are air and moisture sensitive. Post-plasma treatment in a controlled atmosphere at elevated temperature (800{degrees}C) eliminates the hydrogen and stabilizes the powder with respect to oxidation or hydrolysis.

Buss, R.J.

1997-02-01T23:59:59.000Z

Note: This page contains sample records for the topic "rf respirable fraction" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Electromagnetic design of the RF cavity beam position monitor for the LCLS.  

SciTech Connect (OSTI)

A high-resolution X-band cavity BPM has been developed for the LCLS. A dipole mode cavity and a monopole mode reference cavity have been designed in order to achieve micron-level accuracy of the beam position. The rf properties of the BPM as well as beam interaction with the cavities will be discussed including output power and tuning. In addition, methods will be presented for improving the isolation of the output ports to differentiate between horizontal/vertical beam motion and to reject extraneous modes from affecting the output signal. The predicted simulation results will be compared to data collected from low-power experimental tests.

Waldschmidt, G.; Lill, B.; Morrison, L.

2008-01-01T23:59:59.000Z

422

Multi-MW 22.8 GHz Harmonic Multiplier - RF Power Source for High-Gradient Accelerator R&D  

SciTech Connect (OSTI)

Electrodynamic and particle simulation studies have been carried out to optimize design of a two-cavity harmonic frequency multiplier, in which a linear electron beam is energized by rotating fields near cyclotron resonance in a TE111 cavity in a uniform magnetic field, and in which the beam then radiates coherently at the nth harmonic into a TEn11 output cavity. Examples are worked out in detail for 7th and 2nd harmonic converters, showing RF-to-RF conversion efficiencies of 45% and 88%, respectively at 19.992 GHz (K-band) and 5.712 GHz (C-band), for a drive frequency of 2.856 GHz. Details are shown of RF infrastructure (S-band klystron, modulator) and harmonic converter components (drive cavity, output cavities, electron beam source and modulator, beam collector) for the two harmonic converters to be tested. Details are also given for the two-frequency (S- and C-band) coherent multi-MW test stand for RF breakdown and RF gun studies.

Jay L. Hirshfield

2012-07-26T23:59:59.000Z

423

Evaluation of the modified Anderson sampler for determining particle size distributions and respirable concentrations of particulate matter present in the working environment of cottonseed oil mills  

E-Print Network [OSTI]

EVALUATION OF THE MODIFIED ANDERSON SAMPLER FOR DETERMINING PARTICLE SIZE DISTRIBUTIONS AND RESPIRABLE CONCENTRATIONS OF PARTICULATE MATTER PRESENT IN THE WORKING ENVIRONMENT OF COTTONSEED OIL MILLS A Thesis by STANLEY WAYNE MATLOCK Submitted... to the Graduate College of Texas A&M University in partial fulfillment of the requirement for the degree of MASTER OF SCIENCE August 1976 Major Subject: Agricultural Engineering FVALUATION OF THE MODIFIED ANDERSON SAMPLER FOR DETERMINING PARTICLE SIZE...

Matlock, Stanley Wayne

1976-01-01T23:59:59.000Z

424

Phenolic compounds containing/neutral fractions extract and products derived therefrom from fractionated fast-pyrolysis oils  

DOE Patents [OSTI]

A process is described for preparing phenol-formaldehyde novolak resins and molding compositions in which portions of the phenol normally contained in said resins are replaced by a phenol/neutral fractions extract obtained from fractionating fast-pyrolysis oils. The fractionation consists of a neutralization stage which can be carried out with aqueous solutions of bases or appropriate bases in the dry state, followed by solvent extraction with an organic solvent having at least a moderate solubility parameter and good hydrogen bonding capacity. Phenolic compounds-containing/neutral fractions extracts obtained by fractionating fast-pyrolysis oils from a lignocellulosic material, is such that the oil is initially in the pH range of 2-4, being neutralized with an aqueous bicarbonate base, and extracted into a solvent having a solubility parameter of approximately 8.4-9.11 [cal/cm[sup 3

Chum, H.L.; Black, S.K.; Diebold, J.P.; Kreibich, R.E.

1993-06-29T23:59:59.000Z

425

Uncertainties analysis of fission fraction for reactor antineutrino experiments  

E-Print Network [OSTI]

Reactor antineutrino experiment are used to study neutrino oscillation, search for signatures of nonstandard neutrino interaction, and monitor reactor operation for safeguard application. Reactor simulation is an important source of uncertainties for a reactor neutrino experiment. Commercial code is used for reactor simulation to evaluate fission fraction in Daya Bay neutrino experiment, but the source code doesn't open to our researcher results from commercial secret. In this study, The open source code DRAGON was improved to calculate the fission rates of the four most important isotopes in fissions, $^{235}$U,$^{238}$U,$^{239}$Pu and $^{241}$Pu, and then was validated for PWRs using the Takahama-3 benchmark. The fission fraction results are consistent with those of MIT's results. Then, fission fraction of Daya Bay reactor core was calculated by using improved DRAGON code, and the fission fraction calculated by DRAGON agreed well with these calculated by SCIENCE. The average deviation less than 5\\% for all the four isotopes. The correlation coefficient matrix between $^{235}$U,$^{238}$U,$^{239}$Pu and $^{241}$Pu were also studied using DRAGON, and then the uncertainty of the antineutrino flux by the fission fraction was calculated by using the correlation coefficient matrix. The uncertainty of the antineutrino flux by the fission fraction simulation is 0.6\\% per core for Daya Bay antineutrino experiment. The uncertainties source of fission fraction calculation need further to be studied in the future.

X. B. Ma; F. Lu; L. Z. Wang; Y. X. Chen; W. L. Zhong; F. P. An

2015-03-17T23:59:59.000Z

426

Plasma processing of large curved surfaces for superconducting rf cavity modification  

SciTech Connect (OSTI)

Plasma based surface modification of niobium is a promising alternative to wet etching of superconducting radio frequency (SRF) cavities. The development of the technology based on Cl2/Ar plasma etching has to address several crucial parameters which influence the etching rate and surface roughness, and eventually, determine cavity performance. This includes dependence of the process on the frequency of the RF generator, gas pressure, power level, the driven (inner) electrode configuration, and the chlorine concentration in the gas mixture during plasma processing. To demonstrate surface layer removal in the asymmetric non-planar geometry, we are using a simple cylindrical cavity with 8 ports symmetrically distributed over the cylinder. The ports are used for diagnosing the plasma parameters and as holders for the samples to be etched. The etching rate is highly correlated with the shape of the inner electrode, radio-frequency (RF) circuit elements, chlorine concentration in the Cl2/Ar gas mixtures, residence time of reactive species and temperature of the cavity. Using cylindrical electrodes with variable radius, large-surface ring-shaped samples and d.c. bias implementation in the external circuit we have demonstrated substantial average etching rates and outlined the possibility to optimize plasma properties with respect to maximum surface processing effect.

Upadhyay, J.; Im, Do; Popovi??, S.; Valente-Feliciano, A.-M.; Phillips, L.; Vuskovic, L

2014-12-01T23:59:59.000Z

427

Ambipolar and non-ambipolar diffusion in an rf plasma source containing a magnetic filter  

SciTech Connect (OSTI)

By placing a magnetic filter across a rectangular plasma source (closed at one end with a ceramic plate and an rf antenna, and terminated at the opposite end by a grounded grid), we experimentally investigate the effect of conducting and insulating source walls on the nature of the plasma diffusion phenomena. The use of a magnetic filter creates a unique plasma, characterized by a high upstream electron temperature (T{sub e{sub u}}?5 eV) near the rf antenna and a low downstream electron temperature (T{sub e{sub d}}?1 eV) near the grid, which more clearly demonstrates the role of the source wall materials. For conducting walls a net ion current to ground is measured on the grid, and the plasma potential is determined by a mean electron temperature within the source. For insulating walls the plasma potential is determined by the downstream electron temperature (i.e., V{sub p}?5.2T{sub e{sub d}} in argon), and the net current to the grid is exactly zero. Furthermore, by inserting a small additional upstream conductor (that can be made floating or grounded through an external circuit switch), we demonstrate that the plasma potential can be controlled and set to a low (V{sub p}?5.2T{sub e{sub d}}), or high (V{sub p}?5.2T{sub e{sub u}}) value.

Lafleur, T., E-mail: trevor.lafleur@lpp.polytechnique.fr [Laboratoire de Physique des Plasmas, CNRS, Sorbonne Universités, UPMC Univ Paris 06, Univ Paris-Sud, Ecole Polytechnique, 91128 Palaiseau (France); ONERA-The French Aerospace Lab, 91120 Palaiseau (France); Aanesland, A. [Laboratoire de Physique des Plasmas, CNRS, Sorbonne Universités, UPMC Univ Paris 06, Univ Paris-Sud, Ecole Polytechnique, 91128 Palaiseau (France)

2014-06-15T23:59:59.000Z

428

Electromagnetic Design of RF Cavities for Accelerating Low-Energy Muons  

SciTech Connect (OSTI)

A high-gradient linear accelerator for accelerating low-energy muons and pions in a strong solenoidal magnetic field has been proposed for homeland defense and industrial applications. The acceleration starts immediately after collection of pions from a target in a solenoidal magnetic field and brings decay muons, which initially have kinetic energies mostly around 15-20 MeV, to 200 MeV over a distance of {approx}10 m. At this energy, both ionization cooling and further, more conventional acceleration of the muon beam become feasible. A normal-conducting linac with external-solenoid focusing can provide the required large beam acceptances. The linac consists of independently fed zero-mode (TM{sub 010}) RF cavities with wide beam apertures closed by thin conducting edge-cooled windows. Electromagnetic design of the cavity, including its RF coupler, tuning and vacuum elements, and field probes, has been developed with the CST MicroWave Studio, and is presented.

Kurennoy, Sergey S. [Los Alamos National Laboratory

2012-05-14T23:59:59.000Z

429

A Numerical Treatment of the Rf SQUID: I. General Properties andNoise Energy  

SciTech Connect (OSTI)

We investigate the characteristics and noise performance of rf Superconducting Quantum Interference Devices (SQUIDs) by solving the corresponding Langevin equations numerically and optimizing the model parameters with respect to noise energy. After introducing the basic concepts of the numerical simulations, we give a detailed discussion of the performance of the SQUID as a function of all relevant parameters. The best performance is obtained in the crossover region between the dispersive and dissipative regimes, characterized by an inductance parameter {beta}{prime}{sub L} {triple_bond} 2{pi}LI{sub 0}/{Phi}{sub 0} {approx} 1; L is the loop inductance, I{sub 0} the critical current of the Josephson junction, and {phi}{sub 0} the flux quantum. In this regime, which is not well explored by previous analytical approaches, the lowest (intrinsic) values of noise energy are a factor of about 2 above previous estimates based on analytical approaches. However, several other analytical predictions, such as the inverse proportionality of the noise energy on the tank circuit quality factor and the square of the coupling coefficient between the tank circuit and the SQUID loop, could not be well reproduced. The optimized intrinsic noise energy of the rf SQUID is superior to that of the dc SQUID at all temperatures. Although for technologically achievable parameters this advantage shrinks, particularly at low thermal fluctuation levels, we give an example for realistic parameters that leads to a noise energy comparable to that of the dc SQUID even in this regime.

Kleiner, Reinhold; Koelle, Dieter; Clarke, John

2007-01-15T23:59:59.000Z

430

Sunlight creates oxygenated species in water-soluble fractions...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Florida State University, 1800 East Paul Dirac Drive, Tallahassee, FL 32310-4005, United States h i g h l i g h t s * Oxidation seen in water-soluble oil fraction after exposure...

431

Dirac Quantization and Fractional Magnetoelectric Effect on Interacting Topological Insulators  

E-Print Network [OSTI]

We use Dirac quantization of flux to study fractional charges and axion angles \\theta in interacting topological insulators with gapless surface modes protected by time-reversal symmetry. In interacting topological insulators, there are two types of fractional axion angle due to conventional odd and nontrivial even flux quantization at the boundary. On even flux quantization in a gapped time reversal invariant system, we show that there is a halved quarter fractional quantum Hall effect on the surface with Hall conductance of p/4q e2/2h with p and q odd integers. The gapless surface modes can be characterized by a nontrivial Z2 anomaly emerged from the even flux quantization. It is suggested that the electron can be regarded as a bound state of fractionally charged quarks confined by a nonabelian color gauge field on the Dirac quantization of complex spinor fields.

K. -S. Park; H. Han

2010-10-10T23:59:59.000Z

432

Deriving emissions time series from sparse atmospheric mole fractions  

E-Print Network [OSTI]

A growth-based Bayesian inverse method is presented for deriving emissions of atmospheric trace species from temporally sparse measurements of their mole fractions. This work is motivated by many recent studies that have ...

Rigby, Matthew

433

acidic antigenic fractions: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

3 (> 170 o C). Each fraction was analyzed composition of fatty acid ethyl esters using gas chromatography (GC). The result showed that the yield medium chain fatty acid ethyl...

434

Measurement of the Topological Branching Fractions of the ? Lepton  

E-Print Network [OSTI]

We report new and precise measurements of the decay branching fractions of the ? lepton to one and three charged particles. The data, corresponding to an integrated luminosity of 176 pb(?1), were collected by the high ...

Baringer, Philip S.

1985-08-05T23:59:59.000Z

435

A fractional dispersion model for overland solute transport  

E-Print Network [OSTI]

Using the kinematic-wave overland flow equation and a fractional dispersion-advection equation, a process-oriented, physically-based model is developed for overland solute transport. Two scenarios, one consisting of downslope and the other...

Deng, Zhi-Qiang; de Lima, M. Isabel P.; Singh, Vijay P.; de Lima, Jo??o L. M. P.

2006-03-18T23:59:59.000Z

436

On fractional differential inclusions with the Jumarie derivative  

SciTech Connect (OSTI)

In the paper, fractional differential inclusions with the Jumarie derivative are studied. We discuss the existence and uniqueness of a solution to such problems. Our study relies on standard variational methods.

Kamocki, Rafa?, E-mail: rafkam@math.uni.lodz.pl [Faculty of Mathematics and Computer Science, Chair of Differential Equations and Computer Science, University of Lodz, Banacha 22, 90-238 Lodz (Poland)] [Faculty of Mathematics and Computer Science, Chair of Differential Equations and Computer Science, University of Lodz, Banacha 22, 90-238 Lodz (Poland); Obczy?ski, Cezary, E-mail: czacza@math.uni.lodz.pl [Faculty of Mathematics and Computer Science, Chair of Nonlinear Analysis, University of Lodz, Banacha 22, 90-238 Lodz (Poland)] [Faculty of Mathematics and Computer Science, Chair of Nonlinear Analysis, University of Lodz, Banacha 22, 90-238 Lodz (Poland)

2014-02-15T23:59:59.000Z

437

RESEARCH Open Access Gene expression and fractionation resistance  

E-Print Network [OSTI]

in Paramecium, Gout et al. [10] identify a clear relationship between high WGD duplicate gene retention rates for explaining variable resistance to fractionation. The Gout et al. paper [10] is the primary inspiration

Sankoff, David

438

A BIFURCATION RESULT FOR NON-LOCAL FRACTIONAL EQUATIONS  

E-Print Network [OSTI]

, minimal surfaces, materials science and water waves. This is one of the reason why, recently, non studied non-local fractional Laplacian equations with superlinear and subcritical or critical

439

Dynamic optimization of fractionation schedules in radiation therapy  

E-Print Network [OSTI]

In this thesis, we investigate the improvement in treatment effectiveness when dynamically optimizing the fractionation scheme in radiation therapy. In the first part of the thesis, we consider delivering a different dose ...

Ramakrishnan, Jagdish

2013-01-01T23:59:59.000Z

440

Electron absorption spectra of coal pitch and its fractions  

SciTech Connect (OSTI)

An investigation into the electron absorption spectra of coal pitch and its fractions was presented. The pitch tested had a softening point of 67 degrees C, volatile matter of 61.1 %, density of 1.308 g/cm/sup 3/, and an ash content of 0.17 %. The fractions tested were the ..gamma.., ..beta.., ..cap alpha../sub 2/, and ..cap alpha../sub 1/ fractions, and the fractional yield was 31.4, 43.6, 19.3, and 5.7%, respecively. The minimum absorption level in the electron spectrum of the pitch was found to be in the ultraviolet region indicating aromatic compounds. The aromatics of interest were anthracene, anthraquinone, and pyrene. (JMT)

Popov, V.K.; Rus'yanova, N.D.; Plastun, S.N.

1982-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "rf respirable fraction" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

Energy Efficiency in Cryogenic Fractionation Through Distributive Distillation  

E-Print Network [OSTI]

-down and cryogenic fractionation steps, the technology can significantly reduce refrigeration power requirements. ARS technology can be applied to revamps of existing plants as well as new plant designs. Additional applications are now being considered...

Carradine, C. R.; McCue, R. H.

442

acid oxidase fraction: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

are consistent with the boundary action derived geometrically. P. Merlatti; G. Sabella 2001-01-11 436 The Geometry of Fractional D1-branes HEP - Theory (arXiv) Summary: We...

443

Nanoparticle Doped Water -NeowaterTM The effects of the rf-treatments of water and aqueous solutions can be amplified and stabilized by  

E-Print Network [OSTI]

Nanoparticle Doped Water - NeowaterTM The effects of the rf-treatments of water and aqueous by the rf-treatment and cavitation is generated due to the injection of hot particles into water below solutions can be amplified and stabilized by doping the water with low density of insoluble nanoparticles [1

Jacob, Eshel Ben

444

RF CONTROL REQUIREMENTS FOR THE CEBAF ENERGY UPGRADE C. Hovater, J. Delayen, L. Merminga, T. Powers, C. Reece, Jefferson Lab, Newport News, VA  

E-Print Network [OSTI]

RF CONTROL REQUIREMENTS FOR THE CEBAF ENERGY UPGRADE CAVITIES* C. Hovater, J. Delayen, L. Merminga, T. Powers, C. Reece, Jefferson Lab, Newport News, VA Abstract The 6 GeV CEBAF accelerator superconducting cavity for the CEBAF and FEL upgrades. From the low-level RF (LLRF) controls perspective higher

445

Experimental observation of breakdowns in the Fermilab RF Gun G4 J.-P. Carneiro1, D. Edwards2, I. Gonin2, S. Schreiber1  

E-Print Network [OSTI]

Experimental observation of breakdowns in the Fermilab RF Gun G4 J.-P. Carneiro1, D. Edwards2, I Fermilab has developed and delivered to DESY Hamburg two RF guns for the operation of the phase I at the A0 photo-injector at Fermilab since January 1999 where it has been successfully conditioned at 1 Hz

446

Characterization and fractionation by ultrafiltration of guayule resin  

E-Print Network [OSTI]

Rubber Production. 2. Solute Flow Through GPC Column. 3. Comparison of UF, MF, and RO Processes. 4. Pressure Gradient in Tubular Membrane. 5. Flow Pattern for Hollow Tube Asymmetric UF Membranes. 6. Structure of an Asymmetric Tubular Membrane. 7... information from the GPC analysis, indicates which compounds were present in each fraction. Identification and separation of potentially valuable fractions in the resin would increase the overall market value of the guayule shrub. Ultrafiltration (UF...

Daly, Monica Ann

2012-06-07T23:59:59.000Z

447

Evaluating guayule resin fractions for mutagenicity and toxicity  

E-Print Network [OSTI]

EVALUATING GUAYULE RESIN FRACTIONS FOR NUTAGENICITY AND TOXICITY A Thesis by DONALD BAKER AVIRETT Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER... OF SCIENCE December 1992 Major Subject: Industrial Hygiene EVALUATING GUAYULE RESIN FRACTIONS FOR MUTAGENICITY AND TOXICITY A Thesis by DONALD BAKER AVIRETT Submitted to Texas A&M University in partial fulfillment of the requirements for the degree...

Avirett, Donald Baker

1992-01-01T23:59:59.000Z

448

Structural characterization of a family of cytochromes c{sub 7} involved in Fe(III) respiration by Geobacter sulfurreducens.  

SciTech Connect (OSTI)

Periplasmic cytochromes c{sub 7} are important in electron transfer pathway(s) in Fe(III) respiration by Geobacter sulfurreducens. The genome of G. sulfurreducens encodes a family of five 10-kDa, three-heme cytochromes c{sub 7}. The sequence identity between the five proteins (designated PpcA, PpcB, PpcC, PpcD, and PpcE) varies between 45% and 77%. Here, we report the high-resolution structures of PpcC, PpcD, and PpcE determined by X-ray diffraction. This new information made it possible to compare the sequences and structures of the entire family. The triheme cores are largely conserved but are not identical. We observed changes, due to different crystal packing, in the relative positions of the hemes between two molecules in the crystal. The overall protein fold of the cytochromes is similar. The structure of PpcD differs most from that of the other homologs, which is not obvious from the sequence comparisons of the family. Interestingly, PpcD is the only cytochrome c{sub 7} within the family that has higher abundance when G. sulfurreducens is grown on insoluble Fe(III) oxide compared to ferric citrate. The structures have the highest degree of conservation around 'heme IV'; the protein surface around this heme is positively charged in all of the proteins, and therefore all cytochromes c{sub 7} could interact with similar molecules involving this region. The structures and surface characteristics of the proteins near the other two hemes, 'heme I' and 'heme III', differ within the family. The above observations suggest that each of the five cytochromes c{sub 7} could interact with its own redox partner via an interface involving the regions of heme I and/or heme III; this provides a possible rationalization for the existence of five similar proteins in G. sulfurreducens.

Pokkuluri, P. R.; Londer, Y. Y.; Yang, X.; Duke, N. E. C.; Erickson, J.; Orshonsky, V.; Johnson, G.; Schiffer, M.; Biosciences Division

2010-02-01T23:59:59.000Z

449

A real-time respiration position based passive breath gating equipment for gated radiotherapy: A preclinical evaluation  

SciTech Connect (OSTI)

Purpose: To develop a passive gating system incorporating with the real-time position management (RPM) system for the gated radiotherapy. Methods: Passive breath gating (PBG) equipment, which consists of a breath-hold valve, a controller mechanism, a mouthpiece kit, and a supporting frame, was designed. A commercial real-time positioning management system was implemented to synchronize the target motion and radiation delivery on a linear accelerator with the patient's breathing cycle. The respiratory related target motion was investigated by using the RPM system for correlating the external markers with the internal target motion while using PBG for passively blocking patient's breathing. Six patients were enrolled in the preclinical feasibility and efficiency study of the PBG system. Results: PBG equipment was designed and fabricated. The PBG can be manually triggered or released to block or unblock patient's breathing. A clinical workflow was outlined to integrate the PBG with the RPM system. After implementing the RPM based PBG system, the breath-hold period can be prolonged to 15-25 s and the treatment delivery efficiency for each field can be improved by 200%-400%. The results from the six patients showed that the diaphragm motion caused by respiration was reduced to less than 3 mm and the position of the diaphragm was reproducible for difference gating periods. Conclusions: A RPM based PBG system was developed and implemented. With the new gating system, the patient's breath-hold time can be extended and a significant improvement in the treatment delivery efficiency can also be achieved.

Hu Weigang; Xu Anjie; Li Guichao; Zhang Zhen; Housley, Dave; Ye Jinsong [Department of Radiation Oncology, Fudan University Shanghai Cancer Center and Department of Oncology, Shanghai Medical College, Fudan University, Shanghai 200032 (China); Department of Radiation Oncology, Swedish Cancer Institute, Seattle, Washington 98104 (United States)

2012-03-15T23:59:59.000Z

450

Models of three-dimensional fractional topological insulators  

E-Print Network [OSTI]

Time-reversal invariant three-dimensional topological insulators can be defined fundamentally by a topological field theory with a quantized axion angle theta of zero or pi. It was recently shown that fractional quantized values of theta are consistent with time-reversal invariance if deconfined, gapped, fractionally charged bulk excitations appear in the low-energy spectrum due to strong correlation effects, leading to the concept of a fractional topological insulator. These fractionally charged excitations are coupled to emergent gauge fields which ensure that the microscopic degrees of freedom, the original electrons, are gauge-invariant objects. A first step towards the construction of microscopic models of fractional topological insulators is to understand the nature of these emergent gauge theories and their corresponding phases. In this work, we show that low-energy effective gauge theories of both Abelian or non-Abelian type are consistent with a fractional quantized axion angle if they admit a Coulomb phase or a Higgs phase with gauge group broken down to a discrete subgroup. The Coulomb phases support gapless but electrically neutral bulk excitations while the Higgs phases are fully gapped. The Higgs and non-Abelian Coulomb phases exhibit multiple ground states on boundaryless spatial 3-manifolds with nontrivial first homology, while the Abelian Coulomb phase has a unique ground state. The ground state degeneracy receives an additional contribution on manifolds with boundary due to the induced boundary Chern-Simons term.

Joseph Maciejko; Xiao-Liang Qi; Andreas Karch; Shou-Cheng Zhang

2012-12-20T23:59:59.000Z

451

Solids Fraction Measurement with a Reflective Fiber Optic Probe  

SciTech Connect (OSTI)

A method has been developed to extract solids fraction information from a reflective fiber optic probe. The commercially available reflective fiber optic probe was designed to measure axial particle velocity (both up and down directions). However, the reflected light intensity measured is related to particle size and particle concentration. A light reflection model is used to relate the reflected light intensity to solids fraction. In this model we assume that the reflected light intensity is a fixed fraction, K1, of the total light intensity lost in penetration of a solid layer. Also, the solids fraction is related to particle concentration, N, in the light path, by N = K2 (1- ?), where (1-?) is the solids fraction. The parameters K1 and K2 are determined through a calibration and curve fitting procedure. This paper describes this procedure and the steps taken to derive the values of K1 and K2. It is proposed that the reflective fiber optic can be used for real time measurement of solids fraction in a circulating fluid bed.

Seachman, S.M.; Yue, P.C.; Ludlow, J.C.; Shadle, L.J.

2006-11-01T23:59:59.000Z

452

Proc. of the workshop on pushing the limits of RF superconductivity.  

SciTech Connect (OSTI)

For three days in late September last year, some sixty experts in RF superconductivity from around the world came together at Argonne to discuss how to push the limits of RF superconductivity for particle accelerators. It was an intense workshop with in-depth presentations and ample discussions. There was added excitement due to the fact that, a few days before the workshop, the International Technology Recommendation Panel had decided in favor of superconducting technology for the International Linear Collider (ILC), the next major high-energy physics accelerator project. Superconducting RF technology is also important for other large accelerator projects that are either imminent or under active discussion at this time, such as the Rare Isotope Accelerator (RIA) for nuclear physics, energy recovery linacs (ERLs), and x-ray free-electron lasers. For these accelerators, the capability in maximum accelerating gradient and/or the Q value is essential to limit the length and/or operating cost of the accelerators. The technological progress of superconducting accelerators during the past two decades has been truly remarkable, both in low-frequency structures for acceleration of protons and ions as well as in high-frequency structures for electrons. The requirements of future accelerators demand an even higher level of performance. The topics of this workshop are therefore highly relevant and timely. The presentations given at the workshop contained authoritative reviews of the current state of the art as well as some original materials that previously had not been widely circulated. We therefore felt strongly that these materials should be put together in the form of a workshop proceeding. The outcome is this report, which consists of two parts: first, a collection of the scholarly papers prepared by some of the participants and second, copies of the viewgraphs of all presentations. The presentation viewgraphs, in full color, are also available from the Workshop Presentations link on the workshop's web page at http://www.aps.anl.gov/conferences/RFSCLimits/. I would like to thank all of the participants for their lively contributions to the workshop and to these proceedings, and Helen Edwards and Hasan Padamsee for their help in developing the workshop program. I also thank Cathy Eyberger, Kelly Jaje, and Renee Lanham for working very hard to take care of the administrative details, in particular Cathy for editing this report.

Kim, K-J., Eyberger, C., editors

2005-04-13T23:59:59.000Z

453

Publications in refereed journals 115. Krajnovic, D., ..., Peletier, R.F., et al. 2008, MNRAS, 390, 93  

E-Print Network [OSTI]

, R. F., Falc´on-Barroso, J., Bacon, R., et al. 2007, MNRAS, 379, 445 106. Cappellari, M. Falc´on-Barroso, J., Bacon, R., Bureau, M., ..., Peletier, R.F., et al. 2006, MNRAS, 369, 529 87., Falc´on-Barroso, J., Peletier, R. F., Cappellari, M., Emsellem, E., McDermid, R. M., de Zeeuw, P. T

Peletier, Reynier

454

Locating RF Emitters with Large UAV Teams Paul Scerri, Robin Glinton, Sean Owens, Steven Okamoto and Katia Sycara  

E-Print Network [OSTI]

Locating RF Emitters with Large UAV Teams Paul Scerri, Robin Glinton, Sean Owens, Steven Okamoto The rapidly improving availability of small, unmanned aerial vehicles (UAVs) and their ever reducing cost is leading to considerable interest in multi-UAV applications. How- ever, while UAVs have become smaller

Scerri, Paul

455

PROPELLER-EPI With Parallel Imaging Using a Circularly Symmetric Phased-Array RF Coil at 3.0 T  

E-Print Network [OSTI]

to EPI's relatively slow sam- pling rate along the phase-encoding direction, diffusion images generallyPROPELLER-EPI With Parallel Imaging Using a Circularly Symmetric Phased-Array RF Coil at 3.0 T: Application to High-Resolution Diffusion Tensor Imaging Tzu-Chao Chuang,1 Teng-Yi Huang,2 Fa-Hsuan Lin,3 Fu

456

Multi-walled carbon nanotubes on amorphous carbon films R.F. Klie a,*, D. Ciuparu b  

E-Print Network [OSTI]

Multi-walled carbon nanotubes on amorphous carbon films R.F. Klie a,*, D. Ciuparu b , L. Pfefferle, that are inherent to the production process of the amorphous carbon support films, used for both SEM and TEM studies appear in both commercial as well as homemade holey carbon support films on copper grids, and suggest

Harris, Peter J F

457

3-D Computational Modeling of RF MEMS Switches H. D. Espinosa, M. Fischer, Y. Zhu and S. Lee  

E-Print Network [OSTI]

in this work by means of wafer level experimental techniques. RF MEMS Switches manufactured by Raytheon Systems, Raytheon Systems Co. developed MEMS switches to operate in tunable filters and oscillators used by Raytheon Systems Co. (b) Top view of the "bow-tie" membrane mounted on posts. It is made of an aluminum

Espinosa, Horacio D.

458

Excitation and propagation of Electrostatic Ion Cyclotron waves in rf-sustained plasmas of interest to propulsion research  

E-Print Network [OSTI]

it is thus necessary to heat these ions considerably. Various types of electrodeless plasma heating provideExcitation and propagation of Electrostatic Ion Cyclotron waves in rf-sustained plasmas of interest to propulsion research Rostislav Spektor and Edgar Y. Choueiri Electric Propulsion and Plasma Dynamics

Choueiri, Edgar

459

In conventional accelerators, energy from RF electro-magnetic waves in vacuum is transformed into kinetic energy  

E-Print Network [OSTI]

In conventional accelerators, energy from RF electro- magnetic waves in vacuum is transformed for accelerating and storing countercirculating beams of 7-TeV protons, has a stored beam energy exceeding 300 MJ. Accelerator-based light sources rely on the fact that when beams of GeV electrons interact with magnetic

Geddes, Cameron Guy Robinson

460

COLLISIONLESS ELECTRON HEATING IN RF GAS DISCHARGES: II. THE ROLE OF COLLISIONS AND NON-LINEAR EFFECTS  

E-Print Network [OSTI]

COLLISIONLESS ELECTRON HEATING IN RF GAS DISCHARGES: II. THE ROLE OF COLLISIONS AND NON of electrons ( ) is large (comparable with discharge slab) and collisionless heating dominates Ohmic one. Being initially proposed for plasma heating in 1 , it was rst explored in gas discharge plasma for a capacitively

Kaganovich, Igor

Note: This page contains sample records for the topic "rf respirable fraction" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


461

in: "Density Functional Theory", edited by R.F. Nalewajski, Topics in Current Chemistry, Vol. 181, p. 81  

E-Print Network [OSTI]

in: "Density Functional Theory", edited by R.F. Nalewajski, Topics in Current Chemistry, Vol. 181, p. 81 Springer­Verlag Berlin Heidelberg 1996 Density functional theory of time­dependent phenomena E of density functional theory (DFT) is to describe an interacting many­particle system exclusively

Gross, E.K.U.

462

in: "Density Functional Theory", edited by R.F. Nalewajski, Topics in Current Chemistry, Vol. 181, p. 81  

E-Print Network [OSTI]

in: "Density Functional Theory", edited by R.F. Nalewajski, Topics in Current Chemistry, Vol. 181, p. 81 Springer-Verlag Berlin Heidelberg 1996 Density functional theory of time-dependent phenomena E of density functional theory (DFT) is to describe an interacting many-particle system exclusively

Gross, E.K.U.

463

D)TT(^!rf5\\\\ "bKtSOOO&i. Ris-R-793(EN) Optics and Fluid Dynamics  

E-Print Network [OSTI]

D)TT(^!rf5\\\\ "bKtSOOO&i. Risø-R-793(EN) Optics and Fluid Dynamics Department Annual Progress Report, Denmark January 1995 #12;Optics and Fluid Dynamics Department Annual Progress Report for 1994 Edited by S;Abstract Research in the Optics and Fiuid Dynamics Department is performed within the following two

464

Tailoring the Temperature Coefficient of Capacitance (TCC), Dielectric Loss and Capacitance Density with Ceramic-Polymer Nanocomposites for RF Applications  

E-Print Network [OSTI]

. The processes include (i) combining polymer-matrix and nano-ceramic-fillers, whose TCCs have different signs (ceramic-ceramic- polymer nanocomposite, CCPN) with negative and positive TCC in polymer-matrix thus making with Ceramic-Polymer Nanocomposites for RF Applications Isaac Robin Abothu, Baik-Woo Lee, P. Markondeya Raj

Swaminathan, Madhavan

465

1046 IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES, VOL. 62, NO. 4, APRIL 2014 Scalable RF Energy Harvesting  

E-Print Network [OSTI]

Energy Harvesting Zoya Popovi, Fellow, IEEE, Sean Korhummel, Student Member, IEEE, Steven Dunbar, Student1046 IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES, VOL. 62, NO. 4, APRIL 2014 Scalable RF--This paper discusses harvesting of low-power density incident plane waves for electronic devices

Popovic, Zoya

466

A Comparison of Magnesium and Beryllium Acceptors in GaN Grown by rf-Plasma Assisted Molecular Beam Epitaxy  

E-Print Network [OSTI]

A Comparison of Magnesium and Beryllium Acceptors in GaN Grown by rf-Plasma Assisted Molecular Beam Evans and Associates, Sunnyvale, CA 94086 ABSTRACT Step-doped structures of both magnesium and beryllium activation energy of approximately 100 meV. INTRODUCTION While magnesium is currently the most

Myers, Tom

467

300 MHz RF coils for MR studies of Macaca mulatta brain at 7 Tesla Hellmut Merkle2  

E-Print Network [OSTI]

300 MHz RF coils for MR studies of Macaca mulatta brain at 7 Tesla Hellmut Merkle2 , Josef Pfeuffer, customized for a vertical ultra high field 7 Tesla system develop for vision research in the alert, trained macaque. Methods A prototype primate chair was designed and built for the vertical 7-Tesla/60-cm BRUKER

Jegelka, Stefanie

468

Design Guidelines for Ferrite Absorbers Submitted to RF-induced Heating  

E-Print Network [OSTI]

The use of ferrite absorbers is one of the most effective means of damping potentially harmful high order RF modes, which may lead to beam instabilities and excessive power losses in accelerator devices. However, the power deposited on ferrite absorbers themselves maylead to ferrite exceeding its Curie temperature, losing its damping properties. An evaluation of the ferrite capability to dissipate deposited heat is hence of paramount importance for the safe design of particle accelerator devices. In this paper, figures of merit are proposed to assess the maximum specific power allowed on a generic ferrite tile, before it reaches its Curie temperature. Due to its inherent brittleness, sufficient contact pressure between ferrite and its housing, allowing heat transmission by conduction, can hardly be applied. A semi-analytical study is thus performed, assuming that ferrite is evacuating heat solely through radiation. The described method is then exemplified in the case of the BPM-embedded tertiary collimator (T...

Bertarelli, A

2013-01-01T23:59:59.000Z

469

An RF-only ion-funnel for extraction from high-pressure gases  

E-Print Network [OSTI]

An RF ion-funnel technique has been developed to extract ions from a high-pressure (10 bar) noble-gas environment into vacuum ($10^{-6}$ mbar). Detailed simulations have been performed and a prototype has been developed for the purpose of extracting $^{136}$Ba ions from Xe gas with high efficiency. With this prototype, ions have been extracted for the first time from high-pressure xenon gas and argon gas. Systematic studies have been carried out and compared to the simulations. This demonstration of extraction of ions with mass comparable to that of the gas generating the high-pressure into vacuum has applications to Ba tagging from a Xe-gas time-projection chamber (TPC) for double beta decay as well as to the general problem of recovering trace amounts of an ionized element in a heavy (m$>40$ u) carrier gas.

Thomas Brunner; Daniel Fudenberg; Victor Varentsov; Amanda Sabourov; Giorgio Gratta; Jens Dilling; Ralph DeVoe; David Sinclair; William Fairbank Jr.; Joshua B Albert; David J Auty; Phil S Barbeau; Douglas Beck; Cesar Benitez-Medina; Martin Breidenbach; Guofu F Cao; Christopher Chambers; Bruce Cleveland; Matthew Coon; Adam Craycraft; Timothy Daniels; Sean J Daugherty; Tamar Didberidze; Michelle J Dolinski; Matthew Dunford; Lorenzo Fabris; Jacques Farine; Wolfhart Feldmeier; Peter Fierlinger; Razvan Gornea; Kevin Graham; Mike Heffner; Mitchell Hughes; Michael Jewell; Xiaoshan S Jiang; Tessa N Johnson; Sereres Johnston; Alexander Karelin; Lisa J Kaufman; Ryan Killick; Thomas Koffas; Scott Kravitz; Reiner Kruecken; Alexey Kuchenkov; Krishna S Kumar; Douglas S Leonard; Francois Leonard; Caio Licciardi; Yi-Hsuan H Lin; Jiajie Ling; Ryan MacLellan; Michael G Marino; Brian Mong; David Moore; Allen Odian; Igor Ostrovskiy; Christian Ouellet; Andreas Piepke; Andrea Pocar; Fabrice Retiere; Peter C Rowson; Maria P Rozo; Alexis Schubert; Erica Smith; Victor Stekhanov; Michal Tarka; Tamer Tolba; Delia Tosi; Karl Twelker; Jean-Luc L Vuilleumier; Josiah Walton; Timothy Walton; Manuel Weber; Liangjian J Wen; Ubi Wichoski; Liang Yang; Yung-Ruey Yen

2014-12-03T23:59:59.000Z

470

A new methodology for determining recombination parameters using an RF photoconductance instrument  

SciTech Connect (OSTI)

Measurements of minority-carrier lifetime in silicon wafers provide an effective technique for process control and device-physics optimization. For example, detailed measurements of minority-carrier lifetime vs. injection level can allow a nearly complete experimental optimization of a solar cell design and process. This extended abstract describes a methodology that allows this fully characterization by using a relatively simple RF photoconductance-decay tool. By analyzing the quasi-steady-state photoconductance as a function of incident light intensity, information corresponding to an I{sub sc}-V{sub oc} curve can be obtained from a non-contacted silicon wafer. This information is available at various stages during the solar cell fabrication process. The use of steady-state photoconductance instead of transient photoconductance makes use of simple electronics and light sources, yet it has the capability to measure lifetimes down into the 100 ns range.

Sinton, R.A.; Cuevas, A. [Australian National Univ., Canberra (Australia)

1995-08-01T23:59:59.000Z

471

Multi-purpose 805 MHz Pillbox RF Cavity for Muon Acceleration Studies  

SciTech Connect (OSTI)

An 805 MHz RF pillbox cavity has been designed and constructed to investigate potential muon beam acceleration and cooling techniques. The cavity can operate at vacuum or under pressure to 100 atmospheres, at room temperature or in a liquid nitrogen bath at 77 K. The cavity is designed for easy assembly and disassembly with bolted construction using aluminum seals. The surfaces of the end walls of the cavity can be replaced with different materials such as copper, aluminum, beryllium, or molybdenum, and with different geometries such as shaped windows or grid structures. Different surface treatments such as electro polished, high-pressure water cleaned, and atomic layer deposition are being considered for testing. The cavity has been designed to fit inside the 5-Tesla solenoid in the MuCool Test Area at Fermilab. Current status of the cavity prepared for initial conditioning and operation in the external magnetic field is discussed.

Kurennoy, Sergey S. [Los Alamos National Laboratory; Chan, Kwok-Chi Dominic [Los Alamos National Laboratory; Jason, Andrew [Los Alamos National Laboratory; Miyadera, Haruo [Los Alamos National Laboratory; Turchi, Peter J. [Los Alamos National Laboratory

2011-01-01T23:59:59.000Z

472

Initial Testing of the Mark-0 X-Band RF Gun at SLAC  

SciTech Connect (OSTI)

A new X-band RF gun (Mark-0) has been assembled, tuned and was tested in the ASTA facility at SLAC. This gun has been improved from an earlier gun used in Compton-scattering experiments at SLAC by the introduction of a racetrack dual-input coupler to reduce quadrupole fields. Waveguide-to-coupler irises were also redesigned to reduce surface magnetic fields and therefore peak pulse surface heating. Tests of this photocathode gun will allow us to gain early operational experience for beam tests of a new gun with further improvements (Mark-1) being prepared for SLAC's X-Band Test Area (XTA) program and the LLNL MEGa-ray program. Results of current testing up to {approx} 200 MV/m peak surface Electric fields are presented.

Vlieks, Arnold; Adolphsen, C.; Dolgashev, V.; Lewandowski, J.; Limborg, Cecile; Weathersby, S.; /SLAC

2012-06-06T23:59:59.000Z

473

Simulation of non-linear rf losses derived from characteristic Nb topography  

SciTech Connect (OSTI)

A simplified model has been developed to simulate non-linear RF losses on Nb surfaces exclusively due to topographical enhancement of surface magnetic fields. If local sharp edges are small enough, at locations where local surface fields exceed Hc, small volumes of material may become normal conducting without thermal leading to quench. These small volumes of normal material yield increases in the effective surface resistance of the Nb. Using topographic data from typical BCP?d and EP?d fine grain niobium surfaces, we have simulated field-dependent losses and found that when extrapolated to resulting cavity performance, these losses correspond well to characteristic BCP/EP high field Q0 performance differences for fine grain Nb. We describe the structure of the model, its limitations, and the effects of this type of non-linear loss contribution on SRF cavities.

Reece, Charles E. [JLAB; Xu, Chen; Kelley, Michael [W& M. JLAB

2013-09-01T23:59:59.000Z

474

Physics-based statistical model and simulation method of RF propagation in urban environments  

DOE Patents [OSTI]

A physics-based statistical model and simulation/modeling method and system of electromagnetic wave propagation (wireless communication) in urban environments. In particular, the model is a computationally efficient close-formed parametric model of RF propagation in an urban environment which is extracted from a physics-based statistical wireless channel simulation method and system. The simulation divides the complex urban environment into a network of interconnected urban canyon waveguides which can be analyzed individually; calculates spectral coefficients of modal fields in the waveguides excited by the propagation using a database of statistical impedance boundary conditions which incorporates the complexity of building walls in the propagation model; determines statistical parameters of the calculated modal fields; and determines a parametric propagation model based on the statistical parameters of the calculated modal fields from which predictions of communications capability may be made.

Pao, Hsueh-Yuan (San Jose, CA); Dvorak, Steven L. (Tucson, AZ)

2010-09-14T23:59:59.000Z

475

Thin film deposition of barium strontium oxide by rf magnetron sputtering  

SciTech Connect (OSTI)

Barium strontium oxide [(BaSr)O] thin films approximately 1 {mu}m in thickness were deposited on tungsten substrates using rf magnetron sputter deposition for thermionic cathode applications. Three substrate temperatures ranging from 25 to 700 deg. C were used in the deposition processes to create oxide films with different surface morphologies and crystalline structures. The films were characterized with scanning electron microscopy and their surface morphologies were correlated to their thermionic emission properties. The results showed that the surface morphology and crystalline structure of the oxide films strongly affected the emission properties. The oxide film deposited at the lowest substrate temperature of 25 deg. C showed a rough surface and a crystalline structure consisting of nanograins. At higher substrate temperatures, the oxide films exhibited smooth surfaces and close-packed crystalline structures with larger grains. The work function of the oxide films was reduced and the emission current density increased as a result of the increase in the growth temperature. The (BaSr)O film made at 700 deg. C exhibited the lowest work function of 1.57 eV and the largest emission current density of 1.60 A/cm{sup 2} at 1198 K under an electrical field of 0.88 V/{mu}m. The emission current density and the work function of the (BaSr)O thin film cathodes were stable over the testing period of 8 h. Compared to the traditional cathode fabrication process, which involves the coating of carbonates followed by an activation process, rf magnetron sputtering has a greater ability to control the deposition parameters, which makes it a valuable alternative technique to fabricate oxide cathodes.

Liu Yan; Day, Christopher M.; Little, Scott A.; Jin, Feng [Department of Physics and Astronomy, Ball State University, Muncie, Indiana 47306 (United States)

2006-11-15T23:59:59.000Z

476

Evaluation of a RF-Based Approach for Tracking UF6 Cylinders at a Uranium Enrichment Plant  

SciTech Connect (OSTI)

Approved industry-standard cylinders are used globally to handle and store uranium hexafluoride (UF{sub 6}) feed, product, tails, and samples at uranium enrichment plants. The International Atomic Energy Agency (IAEA) relies on time-consuming physical inspections to verify operator declarations and detect possible diversion of UF{sub 6}. Development of a reliable, automated, and tamper-resistant system for near real-time tracking and monitoring UF{sub 6} cylinders (as they move within an enrichment facility) would greatly improve the inspector function. This type of system can reduce the risk of false or misreported cylinder tare weights, diversion of nuclear material, concealment of excess production, utilization of undeclared cylinders, and misrepresentation of the cylinders contents. This paper will describe a proof-of-concept approach that was designed to evaluate the feasibility of using radio frequency (RF)-based technologies to track individual UF{sub 6} cylinders throughout a portion of their life cycle, and thus demonstrate the potential for improved domestic accountability of materials, and a more effective and efficient method for application of site-level IAEA safeguards. The evaluation system incorporates RF-based identification devices (RFID) which provide a foundation for establishing a reliable, automated, and near real-time tracking system that can be set up to utilize site-specific, rules-based detection algorithms. This paper will report results from a proof-of-concept demonstration at a real enrichment facility that is specifically designed to evaluate both the feasibility of using RF to track cylinders and the durability of the RF equipment to survive the rigors of operational processing and handling. The paper also discusses methods for securely attaching RF devices and describes how the technology can effectively be layered with other safeguard systems and approaches to build a robust system for detecting cylinder diversion. Additionally, concepts for off-site tracking of cylinders are described.

Pickett, Chris A [ORNL] [ORNL; Younkin, James R [ORNL] [ORNL; Kovacic, Donald N [ORNL] [ORNL; Laughter, Mark D [ORNL] [ORNL; Hines, Jairus B [ORNL] [ORNL; Boyer, Brian [Los Alamos National Laboratory (LANL)] [Los Alamos National Laboratory (LANL); Martinez, B. [Los Alamos National Laboratory (LANL)] [Los Alamos National Laboratory (LANL)

2008-01-01T23:59:59.000Z

477

Model of Fractionalization of Faraday Lines in Compact Electrodynamics  

E-Print Network [OSTI]

Motivated by ideas of fractionalization and intrinsic topological order in bosonic models with short-range interactions, we consider similar phenomena in formal lattice gauge theory models. Specifically, we show that a compact quantum electrodynamics (CQED) can have, besides the familiar Coulomb and confined phases, additional unusual confined phases where excitations are quantum lines carrying fractions of the elementary unit of electric field strength. We construct a model that has $N$-tupled monopole condensation and realizes $1/N$ fractionalization of the quantum Faraday lines. This phase has another excitation which is a $Z_N$ quantum surface in spatial dimensions five and higher, but can be viewed as a quantum line or a quantum particle in four or three spatial dimensions respectively. These excitation have statistical interactions with the fractionalized Faraday lines; for example, in three spatial dimensions, the particle excitation picks up a Berry phase of $e^{i2\\pi/N}$ when going around the fractionalized Faraday line excitation. We demonstrate the existence of this phase by Monte Carlo simulations in (3+1) space-time dimensions.

Scott D. Geraedts; Olexei I. Motrunich

2014-08-13T23:59:59.000Z

478

Assimilation and respiration of radioactive ethylene glycol, in the presence of high sodium chloride concentrations, by a sodium chloride requiring bacterium  

E-Print Network [OSTI]

and the contents distilled over into 5 ml of a 2X boric acid solution containing 3 ml of a O. l%%d ethanolic solution of methyl red and 5. 7 ml of a 0. 1X ethanolic 29 solution of brom cresol green. The samples were titrated, with 0. 1N HC1 using a... limits. Sodium requirement Effect of pH on growth Utilization of carbon sources. Respiration studies. Quantitation of ethylene glycol carbon Disappearance of. glucose and ammonia-nitrogen from cultures of Bacterium T-52. Possible pathways...

Gonzalez, Carlos Francisco

1972-01-01T23:59:59.000Z

479

Pressurized water reactor fuel assembly subchannel void fraction measurement  

SciTech Connect (OSTI)

The void fraction measurement experiment of pressurized water reactor (PWR) fuel assemblies has been conducted since 1987 under the sponsorship of the Ministry of International Trade and Industry as a Japanese national project. Two types of test sections are used in this experiment. One is a 5 x 5 array rod bundle geometry, and the other is a single-channel geometry simulating one of the subchannels in the rod bundle. Wide gamma-ray beam scanners and narrow gamma-ray beam computed tomography scanners are used to measure the subchannel void fractions under various steady-state and transient conditions. The experimental data are expected to be used to develop a void fraction prediction model relevant to PWR fuel assemblies and also to verify or improve the subchannel analysis method. The first series of experiments was conducted in 1992, and a preliminary evaluation of the data has been performed. The preliminary results of these experiments are described.

Akiyama, Yoshiei [Mitsubishi Heavy Industries, Ltd., Yokohama (Japan). Nuclear Fuel and Core Engineering Dept.; Hori, Keiichi [Mitsubishi Heavy Industries, Ltd., Hyougo (Japan); Miyazaki, Keiji [Osaka Univ. (Japan). Faculty of Engineering; Mishima, Kaichiro [Kyoto Univ., Osaka (Japan). Research Reactor Inst.; Sugiyama, Shigekazu [Nuclear Power Engineering Corp., Tokyo (Japan). Nuclear Fuel Dept.

1995-12-01T23:59:59.000Z

480

Fractional power-law spatial dispersion in electrodynamics  

SciTech Connect (OSTI)

Electric fields in non-local media with power-law spatial dispersion are discussed. Equations involving a fractional Laplacian in the Riesz form that describe the electric fields in such non-local media are studied. The generalizations of Coulomb’s law and Debye’s screening for power-law non-local media are characterized. We consider simple models with anomalous behavior of plasma-like media with power-law spatial dispersions. The suggested fractional differential models for these plasma-like media are discussed to describe non-local properties of power-law type. -- Highlights: •Plasma-like non-local media with power-law spatial dispersion. •Fractional differential equations for electric fields in the media. •The generalizations of Coulomb’s law and Debye’s screening for the media.

Tarasov, Vasily E., E-mail: tarasov@theory.sinp.msu.ru [Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, Moscow 119991 (Russian Federation); Departamento de Análisis Matemático, Universidad de La Laguna, 38271 La Laguna, Tenerife (Spain); Trujillo, Juan J., E-mail: jtrujill@ullmat.es [Departamento de Análisis Matemático, Universidad de La Laguna, 38271 La Laguna, Tenerife (Spain)

2013-07-15T23:59:59.000Z

Note: This page contains sample records for the topic "rf respirable fraction" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


481

Boosting Deuteron Polarization in HD Targets: Experience of moving spins between H and D with RF methods during the E06-101 experiment at Jefferson Lab  

SciTech Connect (OSTI)

Solid HDice targets are polarized by bringing the HD crystal to thermal equilibrium at low temperature and high magnetic field, typically 10-20 mK and 15 Tesla, at Jefferson Lab. In this regime, due to its smaller magnetic moment, the resulting polarization for D is always at least three times smaller than for H. The controlled amount of polarizing catalysts, o-H2 and p-D2, used in the process of reaching a frozen-spin state, further limit the maximum achievable D polarization. Nonetheless, H and D polarizations can be transferred from one to the other by connecting the H and D sub-states of the HD system with RF. In a large target, the RF power needed for such transitions is effectively limited by non-uniformities in the RF field. High efficiency transfers can require substantial RF power levels, and a tuned-RF circuit is needed to prevent large temperature excursions of the holding cryostat. In this paper, we compare the advantages and limitations of two different RF transfer methods to increase D polarization, Forbidden Adiabatic and Saturated Forbidden RF Transitions. The experience with the HD targets used during the recently completed E06-101 experiment in Hall-B of Jefferson Lab is discussed.

Wei, Xiangdong; Bass, Christopher; D'Angelo, Annalisa; Deur, Alexandre; Dezern, Gary; Kageya, Tsuneo; Laine, Vivien; Lowry, Michael; Sandorfi, Andrew; Teachey, Robert; Wang, Haipeng; Whisnant, Charles

2014-06-01T23:59:59.000Z

482

E-Print Network 3.0 - aragonitic fraction essais Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Oxygen, Carbon, Strontium, Summary: , C.S., Grossman, E.L. and Morse, J.W. 1992. Carbon isotopic fractionation in synthetic aragonite... fractionation for sulfides with...

483

E-Print Network 3.0 - ameliorates fractionated whole-brain Sample...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

fractionated whole-brain Search Powered by Explorit Topic List Advanced Search Sample search results for: ameliorates fractionated whole-brain Page: << < 1 2 3 4 5 > >> 1...

484

Some topics on the fractional Brownian motion and stochastic partial differential equations  

E-Print Network [OSTI]

In this dissertation, we investigate some problems in fractional Brownian motion and stochastic partial differential partial differential equations driven by fractional Brownian motion and Hilbert space valued Wiener ...

Song, Jian

2010-04-25T23:59:59.000Z

485

THE PAIR FRACTION OF MASSIVE GALAXIES AT 0 {<=} z {<=} 3  

SciTech Connect (OSTI)

Using a mass-selected (M{sub *} {>=} 10{sup 11} M{sub Sun }) sample of 198 galaxies at 0 {<=} z {<=} 3.0 with Hubble Space Telescope/NICMOS H{sub 160}-band images from the COSMOS survey, we find evidence for the evolution of the pair fraction above z {approx} 2, an epoch in which massive galaxies are believed to undergo significant structural and mass evolution. We observe that the pair fraction of massive galaxies is 0.15 {+-} 0.08 at 1.7 {<=}z {<=} 3.0, where galaxy pairs are defined as massive galaxies having a companion of flux ratio from 1:1 to 1:4 within a projected separation of 30 kpc. This is slightly lower but still consistent with the pair fraction measured previously in other studies, and the merger fraction predicted in halo-occupation modeling. The redshift evolution of the pair fraction is described by a power law F(z) = (0.07 {+-} 0.04) Multiplication-Sign (1 + z){sup 0.6{+-}0.5}. The merger rate is consistent with no redshift evolution; however it is difficult to constrain due to the limited sample size and the high uncertainties in the merging timescale. Based on the merger rate calculation, we estimate that a massive galaxy undergoes on average 1.1 {+-} 0.5 major mergers from z = 3 to 0. The observed merger fraction is sufficient to explain the number density evolution of massive galaxies, but insufficient to explain the size evolution. This is a hint that mechanism(s) other than major merging may be required to increase the sizes of the massive, compact quiescent galaxies from z {approx} 2 to 0.

Man, Allison W. S.; Toft, Sune; Zirm, Andrew W. [Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen (Denmark); Wuyts, Stijn [Max-Planck-Institut fuer Extraterrestrische Physik, Garching bei Muenchen (Germany); Van der Wel, Arjen, E-mail: allison@dark-cosmology.dk, E-mail: sune@dark-cosmology.dk, E-mail: azirm@dark-cosmology.dk, E-mail: swuyts@mpe.mpg.de, E-mail: vdwel@mpia.de [Max-Planck-Institut fuer Astronomie, Heidelberg (Germany)

2012-01-10T23:59:59.000Z

486

Recommended plutonium release fractions from postulated fires. Final report  

SciTech Connect (OSTI)

This report was written at the request of EG&G Rocky Flats, Inc. in support of joint emergency planning for the Rocky Flats Plant (RFP) by EG&G and the State of Colorado. The intent of the report is to provide the State of Colorado with an independent assessment of any respirable plutonium releases that might occur in the event of a severe fire at the plant. Fire releases of plutonium are of interest because they have been used by EG&G to determine the RFP emergency planning zones. These zones are based on the maximum credible accident (MCA) described in the RFP Final Environmental Impact Statement (FEIS) of 1980, that MCA is assumed to be a large airplane crashing into a RFP plutonium building.The objective of this report was first, to perform a worldwide literature review of relevant release experiments from 1960 to the present and to summarize those findings, and second, to provide recommendations for application of the experimental data to fire release analyses at Rocky Flats. The latter step requires translation between experimental and expected RFP accident parameters, or ``scaling.`` The parameters of particular concern are: quantities of material, environmental parameters such as the intensity of a fire, and the physico-chemical forms of the plutonium. The latter include plutonium metal, bulk plutonium oxide powder, combustible and noncombustible wastes contaminated with plutonium oxide powder, and residues from plutonium extraction processes.

Kogan, V.; Schumacher, P.M.

1993-12-01T23:59:59.000Z

487

Fractional Power-Law Spatial Dispersion in Electrodynamics  

E-Print Network [OSTI]

Electric fields in non-local media with power-law spatial dispersion are discussed. Equations involving a fractional Laplacian in the Riesz form that describe the electric fields in such non-local media are studied. The generalizations of Coulomb's law and Debye's screening for power-law non-local media are characterized. We consider simple models with anomalous behavior of plasma-like media with power-law spatial dispersions. The suggested fractional differential models for these plasma-like media are discussed to describe non-local properties of power-law type.

Tarasov, Vasily E

2015-01-01T23:59:59.000Z

488

Fractional noise destroys or induces a stochastic bifurcation  

SciTech Connect (OSTI)

Little seems to be known about the stochastic bifurcation phenomena of non-Markovian systems. Our intention in this paper is to understand such complex dynamics by a simple system, namely, the Black-Scholes model driven by a mixed fractional Brownian motion. The most interesting finding is that the multiplicative fractional noise not only destroys but also induces a stochastic bifurcation under some suitable conditions. So it opens a possible way to explore the theory of stochastic bifurcation in the non-Markovian framework.

Yang, Qigui, E-mail: qgyang@scut.edu.cn [School of Sciences, South China University of Technology, Guangzhou 510640 (China)] [School of Sciences, South China University of Technology, Guangzhou 510640 (China); Zeng, Caibin, E-mail: zeng.cb@mail.scut.edu.cn [School of Sciences, South China University of Technology, Guangzhou 510640 (China) [School of Sciences, South China University of Technology, Guangzhou 510640 (China); School of Automation Science and Engineering, South China University of Technology, Guangzhou 510640 (China); Wang, Cong, E-mail: wangcong@scut.edu.cn [School of Automation Science and Engineering, South China University of Technology, Guangzhou 510640 (China)] [School of Automation Science and Engineering, South China University of Technology, Guangzhou 510640 (China)

2013-12-15T23:59:59.000Z

489

Separation of carbon nanotubes into chirally enriched fractions  

DOE Patents [OSTI]

A mixture of single-walled carbon nanotubes ("SWNTs") is separated into fractions of enriched chirality by preparing an aqueous suspension of a mixture of SWNTs and a surfactant, injecting a portion of the suspension on a column of separation medium having a density gradient, and centrifuging the column. In some embodiments, salt is added prior to centrifugation. In other embodiments, the centrifugation is performed at a temperature below room temperature. Fractions separate as colored bands in the column. The diameter of the separated SWNTs decreases with increasing density along the gradient of the column. The colored bands can be withdrawn separately from the column.

Doorn, Stephen K. (Los Alamos, NM); Niyogi, Sandip (Los Alamos, NM)

2012-04-10T23:59:59.000Z

490

Epidemiological-environmental study of diesel bus garage workers: acute effects of NO/sub 2/ and respirable particulate on the respiratory system  

SciTech Connect (OSTI)

Personal samples of nitrogen dioxide (NO/sub 2/) and respirable particulate (RP) were collected over the shift on 232 workers in four diesel bus garages. Response was assessed by an acute respiratory questionnaire and before and after shift spirometry. Measures of exposure to NO/sub 2/ and RP were associated with work-related symptoms of cough; itching, burning, or watering eyes; difficult or labored breathing; chest tightness; and wheeze. The prevalence of burning eyes, headaches, difficult or labored breathing, nausea, and wheeze experienced at work were higher in the diesel bus garage workers than in a comparison population of battery workers, while the prevalence of headaches was reduced. Mean reductions in forced vital capacity (FVC), forced expiratory volume in 1 sec (FEV1), peak flow, and flows at 50 and 75% of FVC were not obviously different from zero. There was no detectable association of exposure to NO/sub 2/ or respirable particulate and acute reductions in pulmonary function. Workers who often had respiratory work-related symptoms generally had a slightly greater mean acute reduction in FEV1 and FEF50 than did those who did not have these symptoms, but these differences were not statistically significant.

Gamble, J.; Jones, W.; Minshall, S.

1987-02-01T23:59:59.000Z

491

FRACTIONAL SKEW MONOID RINGS P. ARA, M.A. GONZ  

E-Print Network [OSTI]

FRACTIONAL SKEW MONOID RINGS P. ARA, M.A. GONZ â?? ALEZ­BARROSO, K.R. GOODEARL, AND E. PARDO FQM­298 of the Junta de Andalucâ??�a. 1 #12; 2 P. ARA, M.A. GONZ â?? ALEZ­BARROSO, K.R. GOODEARL, AND E

Bigelow, Stephen

492

Fractionation apparatus providing improved heat recovery from bottom stream  

SciTech Connect (OSTI)

An energy efficient design of fractionation column in which the liquid at the column bottom must be cooled to prevent thermal degradation, the column being provided with a perforated annular baffle through which liquid from the lowermost tray is channeled to the outlet of the column bottom, while a body of cooler recycled liquid is maintained in the column bottom outside of said baffle.

Farnham, R.A.

1981-10-20T23:59:59.000Z

493

Branch length distribution in TREF fractionated polyethylene Ramnath Ramachandran a  

E-Print Network [OSTI]

Branch length distribution in TREF fractionated polyethylene Ramnath Ramachandran a , Gregory Keywords: Polyethylene Branching Neutron scattering a b s t r a c t Commercial polyethylene is typically and catalyst activity. Further, processing of polyethylene after polymerization may also result in changes

Beaucage, Gregory

494

no switch: spontaneous actin polymerization (MINIMAL ACTIVTY) FractionActin  

E-Print Network [OSTI]

polymerization (MINIMAL ACTIVTY) FractionActin Polymerization relative activity = t1/2 / t1/2 max actin polymerization in presence of constitutively active output domain (VCA) (MAXIMAL ACTIVITY) experimental point: actin polymerization of switch in presence/absence of inputs (EXPERIMENTAL ACTIVITY) t1/2 = time

Lim, Wendell

495

Parameter Estimation Using Dual Fractional Power Filters Jason M. Kinser  

E-Print Network [OSTI]

discriminant functions (SDF) which are reviewed in ref. 9. Unlike the previous methods, the SDF class of the SDF class. These filters are Fractional Power Filters (FPFs) which will be reviewed in Section 2 is a superset of two standard SDF-class filters: the SDF and the MACE filter. This section will review the SDF

Kinser, Jason M.

496

General teleportation channel, singlet fraction and quasi-distillation  

E-Print Network [OSTI]

We prove a theorem on direct relation between the optimal fidelity $f_{max}$ of teleportation and the maximal singlet fraction $F_{max}$ attainable by means of trace-preserving LQCC action (local quantum and classical communication). For a given bipartite state acting on $C^d\\otimes C^d$ we have $f_{max}= {F_{max}d+1\\over d+1}$. We assume completely general teleportation scheme (trace preserving LQCC action over the pair and the third particle in unknown state). The proof involves the isomorphism between quantum channels and a class of bipartite states. We also exploit the technique of $U\\otimes U^*$ twirling states (random application of unitary transformation of the above form) and the introduced analogous twirling of channels. We illustrate the power of the theorem by showing that {\\it any} bound entangled state does not provide better fidelity of teleportation than for the purely classical channel. Subsequently, we apply our tools to the problem of the so-called conclusive teleportation, then reduced to the question of optimal conclusive increasing of singlet fraction. We provide an example of state for which Alice and Bob have no chance to obtain perfect singlet by LQCC action, but still singlet fraction arbitrarily close to unity can be obtained with nonzero probability. We show that a slight modification of the state has a threshold for singlet fraction which cannot be exceeded anymore.

Pawel Horodecki; Michal Horodecki; Ryszard Horodecki

1999-03-02T23:59:59.000Z

497

Effect of Number of Fractionating Trays on Reactive Distillation Performance  

E-Print Network [OSTI]

Effect of Number of Fractionating Trays on Reactive Distillation Performance Muhammad A. Al and rectifying sec- tions of a reacti®e distillation column can degrade performance. This effect, if true®e distillation columns cannot use conser®ati®e estimates of tray numbers, that is, we cannot simply add excess

Al-Arfaj, Muhammad A.

498

Process for removing polymer-forming impurities from naphtha fraction  

DOE Patents [OSTI]

Polymer precursor materials are vaporized without polymerization or are removed from a raw naphtha fraction by passing the raw naphtha to a vaporization zone and vaporizing the naphtha in the presence of a wash oil while stripping with hot hydrogen to prevent polymer deposits in the equipment. 2 figs.

Kowalczyk, D.C.; Bricklemyer, B.A.; Svoboda, J.J.

1983-12-27T23:59:59.000Z

499

Optical transformation from chirplet to fractional Fourier transformation kernel  

E-Print Network [OSTI]

We find a new integration transformation which can convert a chirplet function to fractional Fourier transformation kernel, this new transformation is invertible and obeys Parseval theorem. Under this transformation a new relationship between a phase space function and its Weyl-Wigner quantum correspondence operator is revealed.

Hong-yi Fan; Li-yun Hu

2009-02-11T23:59:59.000Z

500

Hydrogen isotope fractionation during lipid biosynthesis by Tetrahymena thermophila  

E-Print Network [OSTI]

Hydrogen isotope fractionation during lipid biosynthesis by Tetrahymena thermophila Sitindra S Accepted 7 September 2013 Available online 16 September 2013 a b s t r a c t Hydrogen isotope ratio values from recording the hydrogen isotope composition of ambient water, dD values of lipids also depend