Transport of LCLS-II 1.3 Ghz cryomodule to SLAC

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

McGee, M. W.; Arkan, T.; Peterson, T.

2016-06-30

In a partnership with SLAC National Accelerator Laboratory (SLAC) and Jefferson Lab, Fermilab will assemble and test 17 of the 35 total 1.3 GHz cryomodules for the Linac Coherent Light Source II (LCLS-II) Project. These include a prototype built and delivered by each Lab. Another two 3.9 GHz cryomodules will be built, tested and transported by Fermilab to SLAC. Each assembly will be transported over-the-road from Fermilab or Jefferson Lab using specific routes to SLAC. The transport system consists of a base frame, isolation fixture and upper protective truss. The strongback cryomodule lifting fixture is described along with other supportingmore » equipment used for both over-the-road transport and local (on-site) transport at Fermilab. Initially, analysis of fragile components and stability studies will be performed in order to assess the risk associated with over-the-road transport of a fully assembled cryomodule.« less

The ESS Superconducting RF Cavity and Cryomodule Cryogenic Processes

NASA Astrophysics Data System (ADS)

Darve, C.; Elias, N.; Molloy, S.; Bosland, P.; Renard, B.; Bousson, S.; Olivier, G.; Reynet, D.; Thermeau, J. P.

The European Spallation Source (ESS) is one of Europe's largest research infrastructures, tobring new insights to the grand challenges of science and innovation in fields as diverse as material and life sciences, energy, environmental technology, cultural heritage,solid-state and fundamental physics by the end of the decade. The collaborative project is funded by a collaboration of 17 European countries and is under design and construction in Lund, Sweden. A 5 MW, long pulse proton accelerator is used to reach this goal. The pulsed length is 2.86 ms and the repetition frequency is 14 Hz (4% duty cycle). The choice of SRF technology is a key element in the development of the ESS linear accelerator (linac). The superconducting linacis composed of one section of spoke cavity cryomodules(352.21 MHz) and two sections of elliptical cavity cryomodules (704.42 MHz). These cryomodules contain niobium SRF cavities operating at 2 K, cooled by the accelerator cryoplantthrough the cryogenic distribution system. This paper presents the superconducting RF cavity and cryomodule cryogenic processes, which are developed for the technology demonstrators and to be ultimately integrated for the ESS tunnel operation.

Hypernuclear Spectroscopy with Electron Beam at JLab Hall C

NASA Astrophysics Data System (ADS)

Fujii, Y.; Chiba, A.; Doi, D.; Gogami, T.; Hashimoto, O.; Kanda, H.; Kaneta, M.; Kawama, D.; Maeda, K.; Maruta, T.; Matsumura, A.; Nagao, S.; Nakamura, S. N.; Shichijo, A.; Tamura, H.; Taniya, N.; Yamamoto, T.; Yokota, K.; Kato, S.; Sato, Y.; Takahashi, T.; Noumi, H.; Motoba, T.; Hiyama, E.; Albayrak, I.; Ates, O.; Chen, C.; Christy, M.; Keppel, C.; Kohl, M.; Li, Y.; Liyanage, A.; Tang, L.; Walton, T.; Ye, Z.; Yuan, L.; Zhu, L.; Baturin, P.; Boeglin, W.; Dhamija, S.; Markowitz, P.; Raue, B.; Reinhold, J.; Hungerford, Ed. V.; Ent, R.; Fenker, H.; Gaskell, D.; Horn, T.; Jones, M.; Smith, G.; Vulcan, W.; Wood, S. A.; Johnston, C.; Simicevic, N.; Wells, S.; Samanta, C.; Hu, B.; Shen, J.; Wang, W.; Zhang, X.; Zhang, Y.; Feng, J.; Fu, Y.; Zhou, J.; Zhou, S.; Jiang, Y.; Lu, H.; Yan, X.; Ye, Y.; Gan, L.; Ahmidouch, A.; Danagoulian, S.; Gasparian, A.; Elaasar, M.; Wesselmann, F. R.; Asaturyan, A.; Margaryan, A.; Mkrtchyan, A.; Mkrtchyan, H.; Tadevosyan, V.; Androic, D.; Furic, M.; Petkovic, T.; Seva, T.; Niculescu, G.; Niculescu, I.; López, V. M. Rodríguez; Cisbani, E.; Cusanno, F.; Garibaldi, F.; Uuciuoli, G. M.; de Leo, R.; Maronne, S.

2010-10-01

Hypernuclear spectroscopy with electron beam at JLab Hall C has been studied since 2000. The first experiment, JLab E89-009, demonstrated the possibility of the (e,e'K+) reaction for hypernuclear spectroscopy by achieving an energy resolution of better than 1 MeV (FWHM). The second experiment, JLab E01-011 employed a newly constructed high resolution kaon spectrometer and introduced a vertically tilted electron arm setup to avoid electrons from bremsstrahlung and Moeller scattering. The setup allowed us to have 10 times yield rate and 4 times better signal to accidental ratio with expected energy resolution of 400 keV (FWHM). The third experiment, JLab E05-11B will be performed in 2009 with employing newly constructed high resolution electron spectrometer and a new charge-separation magnet. With the fully customized third generation experimental setup, we can study a variety of targets up to medium-heavy ones such as 52Cr.

Hypernuclear Spectroscopy with Electron Beam at JLab Hall C

NASA Astrophysics Data System (ADS)

Fujii, Y.; Chiba, A.; Doi, D.; Gogami, T.; Hashimoto, O.; Kanda, H.; Kaneta, M.; Kawama, D.; Maeda, K.; Maruta, T.; Matsumura, A.; Nagao, S.; Nakamura, S. N.; Shichijo, A.; Tamura, H.; Taniya, N.; Yamamoto, T.; Yokota, K.; Kato, S.; Sato, Y.; Takahashi, T.; Noumi, H.; Motoba, T.; Hiyama, E.; Albayrak, I.; Ates, O.; Chen, C.; Christy, M.; Keppel, C.; Kohl, M.; Li, Y.; Liyanage, A.; Tang, L.; Walton, T.; Ye, Z.; Yuan, L.; Zhu, L.; Baturin, P.; Boeglin, W.; Dhamija, S.; Markowitz, P.; Raue, B.; Reinhold, J.; Hungerford, Ed. V.; Ent, R.; Fenker, H.; Gaskell, D.; Horn, T.; Jones, M.; Smith, G.; Vulcan, W.; Wood, S. A.; Johnston, C.; Simicevic, N.; Wells, S.; Samanta, C.; Hu, B.; Shen, J.; Wang, W.; Zhang, X.; Zhang, Y.; Feng, J.; Fu, Y.; Zhou, J.; Zhou, S.; Jiang, Y.; Lu, H.; Yan, X.; Ye, Y.; Gan, L.; Ahmidouch, A.; Danagoulian, S.; Gasparian, A.; Elaasar, M.; Wesselmann, F. R.; Asaturyan, A.; Margaryan, A.; Mkrtchyan, A.; Mkrtchyan, H.; Tadevosyan, V.; Androic, D.; Furic, M.; Petkovic, T.; Seva, T.; Niculescu, G.; Niculescu, I.; Rodríguez López, V. M.; Cisbani, E.; Cusanno, F.; Garibaldi, F.; Uuciuoli, G. M.; de Leo, R.; Maronne, S.

Hypernuclear spectroscopy with electron beam at JLab Hall C has been studied since 2000. The first experiment, JLab E89-009, demonstrated the possibility of the (e, e‧ K+) reaction for hypernuclear spectroscopy by achieving an energy resolution of better than 1 MeV (FWHM). The second experiment, JLab E01-011 employed a newly constructed high resolution kaon spectrometer and introduced a vertically tilted electron arm setup to avoid electrons from bremsstrahlung and Moeller scattering. The setup allowed us to have 10 times yield rate and 4 times better signal to accidental ratio with expected energy resolution of 400 keV (FWHM). The third experiment, JLab E05-115 will be performed in 2009 with employing newly constructed high resolution electron spectrometer and a new charge-separation magnet. With the fully customized third generation experimental setup, we can study a variety of targets up to medium-heavy ones such as 52Cr.

Qualification and cryogenic performance of cryomodule components at CEBAF

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

Heckman, J.; Macha, K.; Fischer, J.

1996-12-31

At CEBAF an electron beam is accelerated by superconducting resonant niobium cavities which are operated submerged in superfluid helium. The accelerator has 42 1/4 cryomodules, each containing eight cavities. The qualification and design of components for the cryomodules under went stringent testing and evaluation for acceptance. Indium wire seals are used between the cavity and helium vessel interface to make a superfluid helium leak tight seal. Each cavity is equipped with a mechanical tuner assembly designed to stretch and compress the cavities. Two rotary feedthroughs are used to operate each mechanical tuner assembly. Ceramic feedthroughs not designed for super-fluid weremore » qualified for tuner and cryogenic instrumentation. To ensure long term integrity of the machine special attention is required for material specifications and machine processes. The following is to share the qualification methods, design and performance of the cryogenic cryomodule components.« less

Spectroscopic Research of Lambda Hypdernuclei at JLab Hall C

NASA Astrophysics Data System (ADS)

Gogami, T.; Achenbach, P.; Ahmidouch, A.; Albayrak, I.; Androic, D.; Asaturyan, A.; Asaturyan, R.; Ates, O.; Baturin, P.; Badui, R.; Boeglin, W.; Bono, J.; Brash, E.; Carter, P.; Chen, C.; Chiba, A.; Christy, E.; Dalton, M.; Danagoulian, S.; De Leo, R.; Doi, D.; Elaasar, M.; Ent, R.; Fujii, Y.; Furic, M.; Gabrielyan, M.; Gan, L.; Garibaldi, F.; Gaskell, D.; Gasparian, A.; Hashimoto, O.; Horn, T.; Hu, B.; Hungerford, Ed. V.; Jones, M.; Kanda, H.; Kaneta, M.; Kato, S.; Kawai, M.; Kawama, D.; Khanal, H.; Kohl, M.; Liyanage, A.; Luo, W.; Maeda, K.; Margaryan, A.; Markowitz, P.; Maruta, T.; Matsumura, A.; Maxwell, V.; Mkrtchyan, A.; Mkrtchyan, H.; Nagao, S.; Nakamura, S. N.; Narayan, A.; Neville, C.; Niculescu, G.; Niculescu, M. I.; Nunez, A.; Nuruzzaman; Okayasu, Y.; Petkovic, T.; Pochodzalla, J.; Qiu, X.; Reinhold, J.; Rodriguez, V. M.; Samanta, C.; Sawatzky, B.; Seva, T.; Shichijo, A.; Tadevosyan, V.; Tang, L.; Taniya, N.; Tsukada, K.; Veilleux, M.; Vulcan, W.; Wesselmann, F. R.; Wood, S. A.; Yamamoto, T.; Ya, L.; Ye, Z.; Yokota, K.; Yuan, L.; Zhamkochyan, S.; Zhu, L.

A Λ hyperon which has a strangeness can be bound in deep inside of a nucleus since a Λ does not suffer from the Pauli exclusion principle from nucleons. Thus, a Λ could be a useful tool to investigate inside of a nucleus. Since 2000, Λ hypernuclear spectroscopic experiments by the (e,e'k) reaction have been performed at the experimental hall C in Thomas Jefferson National Accelerator Facility (JLab Hall C). An experiment, JLab E05-115 was carried out to investigate Λ hypernuclei with a wide mass range (the mass number, A = 7, 9, 10, 12, 52). The latest analysis status of JLab E05-115 experiment is discussed in the present article.

Demagnetization of a complete superconducting radiofrequency cryomodule: Theory and practice

DOE PAGES

Crawford, Anthony C.; Chandrasekaran, Saravan K.

2016-12-07

Here, a significant advance in magnetic field management in a fully assembled superconducting radiofrequency (SRF) cryomodule has been achieved and is reported here. Demagnetization of the entire cryomodule after assembly is a crucial step toward the goal of average magnetic flux density less than 0.5 μT at the location of the superconducting radio frequency cavities. An explanation of the physics of demagnetization and experimental results are presented.

Commissioning and First Results from the Fermilab Cryomodule Test Stand

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

Harms, Elvin; et al.

2017-05-01

A new test stand dedicated to SRF cryomodule testing, CMTS1, has been commissioned and is now in operation at Fermilab. The first device to be cooled down and powered in this facility is the prototype 1.3 GHz cryomodule assembled at Fermilab for LCLS-II. We describe the demonstrated capabilities of CMTS1, report on steps taken during commissioning, provide an overview of first test results, and survey future plans.

Spectroscopic Research of Lambda Hypdernuclei at JLab Hall C

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

Gogami, Toshiyuki; et. al.,

2014-03-01

A Lambda hyperon which has a strangeness can be bound in deep inside of a nucleus since a Λ does not suffer from the Pauli exclusion principle from nucleons. Thus, a Λ could be a useful tool to investigate inside of a nucleus. Since 2000, Lambda hypernuclear spectroscopic experiments by the (e,e'k) reaction have been performed at the experimental hall C in Thomas Jefferson National Accelerator Facility (JLab Hall C). An experiment, JLab E05-115 was carried out to investigate Lambda hypernuclei with a wide mass range (the mass number, A = 7, 9, 10, 12, 52). The latest analysis statusmore » of JLab E05-115 experiment is discussed in the present article.« less

Intermediate quality control tests in the development of a superconducting RF cryomodule for CW operation

NASA Astrophysics Data System (ADS)

Pattalwar, Shrikant; Jones, Thomas; Strachan, John; Bate, Robert; Davies, Phil; McIntosh, Peter

2012-06-01

Through an international cryomodule collaboration, ASTeC at Daresbury Laboratory has taken the primary responsibility in leading the development of an optimised Superconducting RF (SRF) cryomodule, operating in CW mode for energy recovery facilities and other high duty cycle accelerators. For high beam current operation, Higher Order Mode (HOM) absorbers are critical components of the SRF Cryomodule, ensuring excessive heating of the accelerating structures and beam instabilities are effectively managed. This paper describes some of the cold tests conducted on the HOM absorbers and other critical components during the construction phase, to ensure that the quality and reliable cryomodule performance is maintained.

Impact of remanent magnetic field on the heat load of original CEBAF cryomodule

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

Ciovati, Gianluigi; Cheng, Guangfeng; Drury, Michael

The heat load of the original cryomodules for the CEBAF accelerator is ~50% higher than the target value of 100 W at 2.07 K for refurbished cavities operating at an accelerating gradient of 12.5 MV/m. This issue is due to the quality factor of the cavities being ~50% lower in the cryomodule than when tested in a vertical cryostat, even at low RF field. Previous studies were not conclusive about the origin of the additional losses. We present the results of a systematic study of the additional losses in a five-cell cavity from a decommissioned cryomodule after attaching components, whichmore » are part of the cryomodule, such as the cold tuner, the He tank and the cold magnetic shield, prior to cryogenic testing in a vertical cryostat. Flux-gate magnetometers and temperature sensors are used as diagnostic elements. Different cool-down procedures and tests in different residual magnetic fields were investigated during the study. Here, three flux-gate magnetometers attached to one of the cavities installed in the refurbished cryomodule C50-12 confirmed the hypothesis of high residual magnetic field as a major cause for the increased RF losses.« less

Impact of remanent magnetic field on the heat load of original CEBAF cryomodule

DOE PAGES

Ciovati, Gianluigi; Cheng, Guangfeng; Drury, Michael; ...

2016-11-22

The heat load of the original cryomodules for the CEBAF accelerator is ~50% higher than the target value of 100 W at 2.07 K for refurbished cavities operating at an accelerating gradient of 12.5 MV/m. This issue is due to the quality factor of the cavities being ~50% lower in the cryomodule than when tested in a vertical cryostat, even at low RF field. Previous studies were not conclusive about the origin of the additional losses. We present the results of a systematic study of the additional losses in a five-cell cavity from a decommissioned cryomodule after attaching components, whichmore » are part of the cryomodule, such as the cold tuner, the He tank and the cold magnetic shield, prior to cryogenic testing in a vertical cryostat. Flux-gate magnetometers and temperature sensors are used as diagnostic elements. Different cool-down procedures and tests in different residual magnetic fields were investigated during the study. Here, three flux-gate magnetometers attached to one of the cavities installed in the refurbished cryomodule C50-12 confirmed the hypothesis of high residual magnetic field as a major cause for the increased RF losses.« less

First operational experience with the HIE-Isolde helium cryogenic system including several RF cryo-modules

NASA Astrophysics Data System (ADS)

Guillotin, N.; Dupont, T.; Gayet, Ph; Pirotte, O.

2017-12-01

The High Intensity and Energy ISOLDE (HIE-ISOLDE) upgrade project at CERN includes the deployment of new superconducting accelerating structures operated at 4.5 K (ultimately of six cryo-modules) installed in series, and the refurbishing of the helium cryo-plant previously used to cool the ALEPH magnet during the operation of the LEP accelerator from 1989 to 2000. The helium refrigerator is connected to a new cryogenic distribution line, supplying a 2000-liter storage dewar and six interconnecting valve boxes (i.e jumper boxes), one for each cryo-module. After a first operation period with one cryo-module during six months in 2015, a second cryo-module has been installed and operated during 2016. The operation of the cryo-plant with these two cryo-modules has required significant technical enhancements and tunings for the compressor station, the cold-box and the cryogenic distribution system in order to reach nominal and stable operational conditions. The present paper describes the commissioning results and the lessons learnt during the operation campaign of 2016 together with the preliminary experience acquired during the 2017 operation phase with a third cryo-module.

Design approach for the development of a cryomodule for compact crab cavities for Hi-Lumi LHC

NASA Astrophysics Data System (ADS)

Pattalwar, Shrikant; Jones, Thomas; Templeton, Niklas; Goudket, Philippe; McIntosh, Peter; Wheelhouse, Alan; Burt, Graeme; Hall, Ben; Wright, Loren; Peterson, Tom

2014-01-01

A prototype Superconducting RF (SRF) cryomodule, comprising multiple compact crab cavities is foreseen to realise a local crab crossing scheme for the "Hi-Lumi LHC", a project launched by CERN to increase the luminosity performance of LHC. A cryomodule with two cavities will be initially installed and tested on the SPS drive accelerator at CERN to evaluate performance with high-intensity proton beams. A series of boundary conditions influence the design of the cryomodule prototype, arising from; the complexity of the cavity design, the requirement for multiple RF couplers, the close proximity to the second LHC beam pipe and the tight space constraints in the SPS and LHC tunnels. As a result, the design of the helium vessel and the cryomodule has become extremely challenging. This paper assesses some of the critical cryogenic and engineering design requirements and describes an optimised cryomodule solution for the evaluation tests on SPS.

Upper-Division Students' Difficulties with Ampere's Law

ERIC Educational Resources Information Center

Wallace, Colin S.; Chasteen, Stephanie V.

2010-01-01

This study presents and interprets some conceptual difficulties junior-level physics students experience with Ampere's law. We present both quantitative data, based on students' written responses to conceptual questions, and qualitative data, based on interviews of students solving Ampere's law problems. We find that some students struggle to…

RESULTS OF THE 2015 HELIUM PROCESSING OF CEBAF CRYOMODULES

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

Drury, Michael A.; Humphry, Jr., Frank J.; King, Larry

2016-10-01

Many conference series have adopted the same The CEBAF accelerator at Jefferson Lab consists of an injec-tor and two linacs connected by arcs. Each linac contains 25 cryomodules that are designed to deliver an integrated energy of 2.2 GeV per pass to an electron beam in order to meet 12 GeV energy requirements. Helium processing is a processing technique that is used to reduce field emis-sion (FE) in SRF cavities. Helium processing of the 50 installed linac cryomodules was seen as necessary to support 12 GeV energy requirements. This paper will describe the processing procedure and summarize the results ofmore » this effort.« less

Electroproduction of K+ Λ at JLab Hall-C

NASA Astrophysics Data System (ADS)

Gogami, T.; Achenbach, P.; Ahmidouch, A.; Albayrak, I.; Androic, D.; Asaturyan, A.; Asaturyan, R.; Ates, O.; Baturin, P.; Badui, R.; Boeglin, W.; Bono, J.; Brash, E.; Carter, P.; Chen, C.; Chiba, A.; Christy, E.; Dalton, M.; Danagoulian, S.; De Leo, R.; Doi, D.; Elaasar, M.; Ent, R.; Fujii, Y.; Furic, M.; Gabrielyan, M.; Gan, L.; Garibaldi, F.; Gaskell, D.; Gasparian, A.; Hashimoto, O.; Horn, T.; Hu, B.; Hungerford, Ed. V.; Jones, M.; Kanda, H.; Kaneta, M.; Kato, S.; Kawai, M.; Kawama, D.; Khanal, H.; Kohl, M.; Liyanage, A.; Luo, W.; Maeda, K.; Margaryan, A.; Markowitz, P.; Maruta, T.; Matsumura, A.; Maxwell, V.; Mkrtchyan, A.; Mkrtchyan, H.; Nagao, S.; Nakamura, S. N.; Narayan, A.; Neville, C.; Niculescu, G.; Niculescu, M. I.; Nunez, A.; Nuruzzaman; Okayasu, Y.; Petkovic, T.; Pochodzalla, J.; Qiu, X.; Reinhold, J.; Rodriguez, V. M.; Samanta, C.; Sawatzky, B.; Seva, T.; Shichijo, A.; Tadevosyan, V.; Tang, L.; Taniya, N.; Tsukada, K.; Veilleux, M.; Vulcan, W.; Wesselmann, F. R.; Wood, S. A.; Yamamoto, T.; Ya, L.; Ye, Z.; Yokota, K.; Yuan, L.; Zhamkochyan, S.; Zhu, L.

2013-08-01

A Λ hypernuclear spectroscopic experiment, JLab E05-115 was performed at JLab Hall-C in 2009 by the (e, e'K+) reaction. Data of Λ hypernuclei with mass numbers from A = 7 to A = 52 were successfully taken, and the analyses are in progress. A polyethylene (CH2) target was used as a proton target to calibrate energy scales, and to study elementary process of the p(e, e'K+) Λ, Σ0 reaction. A preliminary differential cross section of K+ Λ electro-production at low Q2 [~0.01 (GeV/c)2] and at small kaon angles is reported in the present article.

BNL 56 MHz HOM damper prototype fabrication at JLAB

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

Huque, N.; McIntyre, G.; Daly, E. F.

A prototype Higher-Order Mode (HOM) Damper was fabricated at JLab for the Relativistic Heavy-Ion Collider’s (RHIC) 56 MHz cavity at Brookhaven National Laboratory (BNL). Primarily constructed from high RRR Niobium and Sapphire, the coaxial damper presented significant challenges in electron-beam welding (EBW), brazing and machining via acid etching. The results of the prototype operation brought about changes in the damper design, due to overheating braze alloys and possible multi-pacting. Five production HOM dampers are currently being fabricated at JLab. This paper outlines the challenges faced in the fabrication process, and the solutions put in place.

BNL 56 MHz HOM Damper Prototype Fabrication at JLab

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

Huque, Naeem A.; Daly, Edward F.; Clemens, William A.

A prototype Higher-Order Mode (HOM) Damper was fabricated at JLab for the Relativistic Heavy-Ion Collider's (RHIC) 56 MHz cavity at Brookhaven National Laboratory (BNL). Primarily constructed from high RRR Niobium and Sapphire, the coaxial damper presented significant challenges in electron-beam welding (EBW), brazing and machining via acid etching. The results of the prototype operation brought about changes in the damper design, due to overheating braze alloys and possible multi-pacting. Five production HOM dampers are currently being fabricated at JLab. This paper outlines the challenges faced in the fabrication process, and the solutions put in place.

First attempt of at-cavity cryogenic X-ray detection in a CEBAF cryomodule for field emission monitoring

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

Geng, Rongli; Daly, Edward; Drury, Michael

2015-09-01

We report on the first result of at-cavity X-ray detection in a CEBAF cryomodule for field emission monitoring. In the 8-cavity cryomodule F100, two silicon diodes were installed near the end flange of each cavity. Each cavity was individually tested during the cryomodule test in JLab’s cryomodule test facility. The behaviors of these at-cavity cryogenic X-ray detectors were compared with those of the standard ‘in air’ Geiger-Muller (G-M) tubes. Our initial experiments establish correlation between X-ray response of near diodes and the field emission source cavity in the 8-cavity string. For two out of these eight cavities, we also carriedmore » out at-cavity X-ray detection experiment during their vertical testing. The aim is to track field emission behavior uniquely from vertical cavity testing to horizontal cavity testing in the cryomodule. These preliminary results confirmed our expectation and warrant further effort toward the establishment of permanent at-cavity cryogenic X-ray detection for SRF development and operation.« less

CEBAF Upgrade Cryomodule Component Testing in the Horizontal Test Bed (HTB)

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

I.E. Campisi; B. Carpenter; G.K. Davis

2001-06-01

The planned upgrade of the CEBAF electron accelerator includes the development of an improved cryomodule. Several components differ substantially from the original CEBAF cryomodule; these include: the new 7-cell, 1.5 GHz cavities with integral helium vessel, a new, backlash-free cavity tuner, the waveguide coupler with its room-temperature ceramic window, and the HOM damping filters. In order to test the design features and performance of the new components, a horizontal cryostat (Horizontal Test Bed) has been constructed which allows testing with a turn around time of less than three weeks. This cryostat provides the environment for testing one or two cavities,more » with associated auxiliary components, in a condition similar to that of a real cryomodule. A series of tests has been performed on a prototype 7-cell cavity and the above-mentioned systems. In this paper the results of the tests on the cryostat, on the cavity performance, on its coupler, on the tuner characteristics, and on the microphonics behavior will be reported.« less

Assembly and commissioning of a new SRF cryomodule for the ATLAS intensity upgrade

NASA Astrophysics Data System (ADS)

Conway, Z. A.; Barcikowski, A.; Cherry, G. L.; Fischer, R. L.; Fuerst, J. D.; Jansma, W. G.; Gerbick, S. M.; Kedzie, M. J.; Kelly, M. P.; Kim, S. H.; MacDonald, S. W. T.; Murphy, R. C.; Ostroumov, P. N.; Reid, T. C.; Shepard, K. W.

2014-01-01

The Argonne National Laboratory Physics Division is in the final stages of a major upgrade to the Argonne Tandem Linear Accelerator System national user facility, referred to as the intensity upgrade. The intensity upgrade project will substantially increase beam currents for experimenters working with the existing ATLAS stable and in-flight rare isotope beams and for the neutron-rich beams from the Californium Rare Isotope Breeder Upgrade. This project includes the replacement of three existing cryomodules, containing 18 superconducting accelerator cavities and 9 superconducting solenoids, with a single cryomodule with seven SC 72.75 MHz accelerator cavities optimized for ion velocities of 7.7% the speed of light and 4 SC solenoids all operating at 4.5 K. This presentation will report: how we minimized the heat load into the 4 K and 80 K coolant streams feeding the cryomodule, a comparison of the calculated and measured static heat loads at 80 K and the mechanical design of the vacuum vessel.

Performance of Superconducting Magnet Prototypes for LCLS-II Linear Accelerator

DOE PAGES

Kashikhin, Vladimir; Andreev, Nikolai; DiMarco, Joseph; ...

2017-01-05

The new LCLS-II Linear Superconducting Accelerator at SLAC needs superconducting magnet packages installed inside SCRF Cryomodules to focus and steer an electron beam. Two magnet prototypes were built and successfully tested at Fermilab. Magnets have an iron dominated configuration, quadrupole and dipole NbTi superconducting coils, and splittable in the vertical plane configuration. Magnets inside the Cryomodule are conductively cooled through pure Al heat sinks. Both magnets performance was verified by magnetic measurements at room temperature, and during cold tests in liquid helium. Test results including magnetic measurements are discussed. Special attention was given to the magnet performance at low currentsmore » where the iron yoke and the superconductor hysteresis effects have large influence. Both magnet prototypes were accepted for the installation in FNAL and JLAB prototype Cryomodules.« less

Results of Accelerated Life Testing of LCLS-II Cavity Tuner Motor

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

Huque, Naeem; Daly, Edward; Pischalnikov, Yuriy

An Accelerated Life Test (ALT) of the Phytron stepper motor used in the LCLS-II cavity tuner has been conducted at JLab. Since the motor will reside inside the cryomodule, any failure would lead to a very costly and arduous repair. As such, the motor was tested for the equivalent of 30 lifetimes before being approved for use in the production cryomodules. The 9-cell LCLS-II cavity is simulated by disc springs with an equivalent spring constant. Plots of the motor position vs. tuner position ' measured via an installed linear variable differential transformer (LVDT) ' are used to measure motor motion.more » The titanium spindle was inspected for loss of lubrication. The motor passed the ALT, and is set to be installed in the LCLS-II cryomodules.« less

RESULTS OF ACCELERATED LIFE TESTING OF LCLS-II CAVITY TUNER MOTOR

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

Huque, Naeem; Daly, Edward F.; Pischalnikov, Yuriy

An Accelerated Life Test (ALT) of the Phytron stepper motor used in the LCLS-II cavity tuner has been conducted at JLab. Since the motor will reside inside the cryomodule, any failure would lead to a very costly and arduous repair. As such, the motor was tested for the equivalent of 30 lifetimes before being approved for use in the production cryomodules. The 9-cell LCLS-II cavity is simulated by disc springs with an equivalent spring constant. Plots of the motor position vs. tuner position ' measured via an installed linear variable differential transformer (LVDT) ' are used to measure motor motion.more » The titanium spindle was inspected for loss of lubrication. The motor passed the ALT, and is set to be installed in the LCLS-II cryomodules.« less

Superconducting focusing lenses for the SSR-1 cryomodule of PXIE test stand at Fermilab

DOE PAGES

DiMarco, J.; Tartaglia, M.; Terechkine, I.

2016-12-05

Five solenoid-based focusing lenses designed for use inside the SSR1 cryomodule of the PXIE test stand at Fermilab have been fabricated and tested. In addition to a focusing solenoid, each lens is equipped with a set of windings that generate magnetic field in the transverse plane and can be used in the steering dipole mode or as a skew quadrupole corrector. The lenses will be installed between superconducting cavities in the cryomodule, so getting sufficiently low fringe magnetic field was one of the main design requirements. Beam dynamics simulations indicated a need for high accuracy positioning of the lenses inmore » the cryomodule, which triggered a study towards understanding uncertainties of the magnetic axis position relative to the geometric features of the lens. Furthermore, this report summarizes the efforts towards certification of the lenses, including results of performance tests, fringe field data, and uncertainty of the magnetic axis position.« less

Superconducting focusing lenses for the SSR-1 cryomodule of PXIE test stand at Fermilab

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

DiMarco, J.; Tartaglia, M.; Terechkine, I.

Five solenoid-based focusing lenses designed for use inside the SSR1 cryomodule of the PXIE test stand at Fermilab have been fabricated and tested. In addition to a focusing solenoid, each lens is equipped with a set of windings that generate magnetic field in the transverse plane and can be used in the steering dipole mode or as a skew quadrupole corrector. The lenses will be installed between superconducting cavities in the cryomodule, so getting sufficiently low fringe magnetic field was one of the main design requirements. Beam dynamics simulations indicated a need for high accuracy positioning of the lenses inmore » the cryomodule, which triggered a study towards understanding uncertainties of the magnetic axis position relative to the geometric features of the lens. Furthermore, this report summarizes the efforts towards certification of the lenses, including results of performance tests, fringe field data, and uncertainty of the magnetic axis position.« less

The high Beta cryo-modules and the associated cryogenic system for the HIE-ISOLDE upgrade at CERN

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

Delruelle, N.; Leclercq, Y.; Pirotte, O.

2014-01-29

The major upgrade of the energy and intensity of the existing ISOLDE and REX-ISOLDE radioactive ion beam facilities at CERN requires the replacement of most of the existing ISOLDE post-acceleration equipment by a superconducting linac based on quarter-wave resonators housed together with superconducting solenoids in a series of four high-β and two low-β cryo-modules. As well as providing optimum conditions for physics, the cryo-modules need to function under stringent vacuum and cryogenic conditions. We present the detail design and expected cryogenic performance of the high- β cryo-module together with the cryogenic supply and distribution system destined to service the completemore » superconducting linac.« less

The 100 ampere-hour nickel cadmium battery development program, volume 1

NASA Technical Reports Server (NTRS)

Gaston, S.

1974-01-01

A program to develop a long-life, reliable and safe 100 ampere-hour sealed nickel-cadmium cell and battery module with ancillary charge control and automated test equipment to fulfill the requirements of a large Manned Orbital Space Station which uses Solar Arrays as its prime source for 25 kW of electrical power was conducted. A sealed 100 ampere-hour cell with long life potential and a replaceable, space maintainable battery module has been developed for Manned Space Station applications. The 100 ampere-hour cell has been characterized for initial (early life) anticipated conditions.

Cryogenic performance of a conduction-cooling splittable quadrupole magnet for ILC cryomodules

NASA Astrophysics Data System (ADS)

Kimura, N.; Andreev, N.; Kashikhin, V. S.; Kerby, J.; Takahashi, M.; Tartaglia, M. A.; Tosaka, T.; Yamamoto, A.

2014-01-01

A conduction-cooled splittable superconducting quadrupole magnet was designed and fabricated at Fermilab for use in cryomodules of the International Linear Collider (ILC) type, in which the magnet was to be assembled around the beam tube to avoid contaminating the ultraclean superconducting radio frequency cavity volume. This quadrupole was first tested in a liquid helium bath environment at Fermilab, where its quench and magnetic properties were characterized. Because the device is to be cooled by conduction when installed in cryomodules, a separate test with a conduction-cooled configuration was planned at KEK and Fermilab. The magnet was converted to a conduction-cooled configuration by adding conduction-cooling passages made of high-purity aluminum. Efforts to convert and refabricate the magnet into a cryostat equipped with a double-stage pulse-tube-type cryocooler began in 2011, and a thermal performance test, including a magnet excitation test of up to 30 A, was conducted at KEK. In this test, the magnet with the conduction-cooled configuration was successfully cooled to 4 K within 190 h, with an acceptable heat load of less than 1 W at 4 K. It was also confirmed that the conduction-cooled splittable superconducting quadrupole magnet was practical for use in ILC-type cryomodules.

Single Meson Photoproduction at JLab Energies

NASA Astrophysics Data System (ADS)

Mathieu, Vincent; Joint Physics Analysis Center Team

2016-09-01

In this talk, I present the results from the Joint Physics Analysis Center about the photoproduction of a single meson (pseudoscalar or vector meson). We have developed the theoretical formalism to analysis forthcoming data at the, recently upgraded, JLab facility. We also present prediction for observables in the energy range of Eg = 5-11 GeV. Material (codes, notes, sim- ulations, etc) can be found online at the JPAC interactive website: http://www.indiana.edu/ jpac/index.html

First Test Results of the bERLinPro 2-cell Booster Cavities

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

Burrill, Andrew; Anders, W.; Frahm, A.

2015-09-01

The bERLinPro Energy Recovery Linac (ERL) is currently being built at Helmholtz-Zentrum Berlin in order to study the physics of operating a high-current, a 100 mA, 50 MeV ERL utilizing all SRF cavity technology. This machine will utilize three unique SRF cryomodules for the photoinjector, booster and linac cryomodules respectively. The focus of this paper will be on the cavities contained within the booster cryomodule. Here there will be three 2-cell SRF cavities, based on the original design by Cornell University, but optimized to meet the needs of the project. All of the cavity fabrication, processing and testing was carriedmore » out at Jefferson Laboratory, where 4 cavities were produced, and the 3 cavities with the best RF performance were fitted with helium vessels for installation in the cryomodule. This paper will report on the test results of the cavities as measured in the vertical testing dewar at JLab after fabrication and again after outfitting with the helium vessels.« less

Helium refrigeration considerations for cryomodule design

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

Ganni, V.; Knudsen, P.

Many of the present day accelerators are based on superconducting radio frequency (SRF) cavities, packaged in cryo-modules (CM), which depend on helium refrigeration at sub-atmospheric pressures, nominally 2 K. These specialized helium refrigeration systems are quite cost intensive to produce and operate. Particularly as there is typically no work extraction below the 4.5-K supply, it is important that the exergy loss between this temperature level and the CM load temperature(s) be minimized by the process configuration choices. This paper will present, compare and discuss several possible helium distribution process arrangements to support the CM loads.

Hypernuclear Spectroscopy at JLab Hall C

NASA Astrophysics Data System (ADS)

Hashimoto, O.; Chiba, A.; Doi, D.; Fujii, Y.; Gogami, T.; Kanda, H.; Kaneta, M.; Kawama, D.; Maeda, K.; Maruta, T.; Matsumura, A.; Nagao, S.; Nakamura, S. N.; Shichijo, A.; Tamura, H.; Taniya, N.; Yamamoto, T.; Yokota, K.; Kato, S.; Sato, Y.; Takahashi, T.; Noumi, H.; Motoba, T.; Hiyama, E.; Albayrak, I.; Ates, O.; Chen, C.; Christy, M.; Keppel, C.; Kohl, M.; Li, Y.; Liyanage, A.; Tang, L.; Walton, T.; Ye, Z.; Yuan, L.; Zhu, L.; Baturin, P.; Boeglin, W.; Dhamija, S.; Markowitz, P.; Raue, B.; Reinhold, J.; Hungerford, Ed. V.; Ent, R.; Fenker, H.; Gaskell, D.; Horn, T.; Jones, M.; Smith, G.; Vulcan, W.; Wood, S. A.; Johnston, C.; Simicevic, N.; Wells, S.; Samanta, C.; Hu, B.; Shen, J.; Wang, W.; Zhang, X.; Zhang, Y.; Feng, J.; Fu, Y.; Zhou, J.; Zhou, S.; Jiang, Y.; Lu, H.; Yan, X.; Ye, Y.; Gan, L.; Ahmidouch, A.; Danagoulian, S.; Gasparian, A.; Elaasar, M.; Wesselmann, F. R.; Asaturyan, A.; Margaryan, A.; Mkrtchyan, A.; Mkrtchyan, H.; Tadevosyan, V.; Androic, D.; Furic, M.; Petkovic, T.; Seva, T.; Niculescu, G.; Niculescu, I.; Rodriguez, V. M.; Cisbani, E.; Cusanno, F.; Garibaldi, F.; Uuciuoli, G. M.; De Leo, R.; Maronne, S.; Achenback, P.; Pochodzala, J.

2010-04-01

Since the 1st generation experiment, E89-009, which was successfully carried out as a pilot experiment of (e,e'K+) hypernuclear spectroscopy at JLab Hall C in 2000, precision hypernuclear spectroscopy by the (e,e'K+) reactions made considerable progress. It has evolved to the 2nd generation experiment, E01-011, in which a newly constructed high resolution kaon spectrometer (HKS) was installed and the "Tilt method" was adopted in order to suppress large electromagnetic background and to run with high luminosity. Preliminary high-resolution spectra of 7ΛHe and 28ΛAl together with that of 12ΛB that achieved resolution better than 500 keV(FWHM) were obtained. The third generation experiment, E05-115, has completed data taking with an experimental setup combining a new splitter magnet, high resolution electron spectrometer (HES) and the HKS used in the 2nd generation experiment. The data were accumulated with targets of 7Li, 9Be, 10B, 12C and 52Cr as well as with those of CH 2 and H 2O for calibration. The analysis is under way with particular emphasis of determining precision absolute hypernuclear masses. In this article, hypernuclear spectroscopy program in the wide mass range at JLab Hall C that has undergone three generation is described.

Results from sudden loss of vacuum on scaled superconducting radio frequency cryomodule experiment

NASA Astrophysics Data System (ADS)

Dalesandro, Andrew A.; Dhuley, Ram C.; Theilacker, Jay C.; Van Sciver, Steven W.

2014-01-01

Superconducting radio frequency (SRF) cavities for particle accelerators are at risk of failure due to sudden loss of vacuum (SLV) adjacent to liquid helium (LHe) spaces. To better understand this failure mode and its associated risks an experiment is designed to test the longitudinal effects of SLV within the beam tube of a scaled SRF cryomodule that has considerable length relative to beam tube cross section. The scaled cryomodule consists of six individual SRF cavities each roughly 350 mm long, initially cooled to 2 K by a superfluid helium bath and a beam tube pumped to vacuum. A fast-acting solenoid valve is used to simulate SLV on the beam tube, from which point it takes over 3 s for the beam tube pressure to equalize with atmosphere, and 30 s for the helium space to reach the relief pressure of 4 bara. A SLV longitudinal effect in the beam tube is evident in both pressure and temperature data, but interestingly the temperatures responds more quickly to SLV than do the pressures. It takes 500 ms (roughly 100 ms per cavity) for the far end of the 2 m long beam tube to respond to a pressure increase compared to 300 ms for temperature (approximately 50 ms per cavity). The paper expands upon these and other results to better understand the longitudinal effect for SRF cryomodules due to SLV.

On the Monge-Ampere equivalent of the sine-Gordon equation

NASA Astrophysics Data System (ADS)

Ferapontov, E. V.; Nutku, Y.

1994-12-01

Surfaces of constant negative curvature in Euclidean space can be described by either the sine-Gordon equation for the angle between asymptotic directions, or a Monge-Ampere equation for the graph of the surface. We present the explicit form of the correspondence between these two integrable non-linear partial differential equations using their well-known properties in differential geometry. We find that the cotangent of the angle between asymptotic directions is directly related to the mean curvature of the surface. This is a Backlund-type transformation between the sine-Gordon and Monge-Ampere equations.

Assessment of thermal loads in the CERN SPS crab cavities cryomodule1

NASA Astrophysics Data System (ADS)

Carra, F.; Apeland, J.; Calaga, R.; Capatina, O.; Capelli, T.; Verdú-Andrés, S.; Zanoni, C.

2017-07-01

As a part of the HL-LHC upgrade, a cryomodule is designed to host two crab cavities for a first test with protons in the SPS machine. The evaluation of the cryomodule heat loads is essential to dimension the cryogenic infrastructure of the system. The current design features two cryogenic circuits. The first circuit adopts superfluid helium at 2 K to maintain the cavities in the superconducting state. The second circuit, based on helium gas at a temperature between 50 K and 70 K, is connected to the thermal screen, also serving as heat intercept for all the interfaces between the cold mass and the external environment. An overview of the heat loads to both circuits, and the combined numerical and analytical estimations, is presented. The heat load of each element is detailed for the static and dynamic scenarios, with considerations on the design choices for the thermal optimization of the most critical components.

Assessment of thermal loads in the CERN SPS crab cavities cryomodule 1

DOE PAGES

Carra, F.; Apeland, J.; Calaga, R.; ...

2017-07-20

As a part of the HL-LHC upgrade, we designed a cryomodule to host two crab cavities for a first test with protons in the SPS machine. The evaluation of the cryomodule heat loads is essential to dimension the cryogenic infrastructure of the system. The current design features two cryogenic circuits. The first circuit adopts superfluid helium at 2 K to maintain the cavities in the superconducting state. The second circuit, based on helium gas at a temperature between 50 K and 70 K, is connected to the thermal screen, also serving as heat intercept for all the interfaces between themore » cold mass and the external environment. We present an overview of the heat loads to both circuits, and the combined numerical and analytical estimations. The heat load of each element is detailed for the static and dynamic scenarios, with considerations on the design choices for the thermal optimization of the most critical components.« less

Development of BPM Electronics at the JLAB FEL

NASA Astrophysics Data System (ADS)

Sexton, D.; Evtushenko, P.; Jordan, K.; Yan, J.; Dutton, S.; Moore, W.; Evans, R.; Coleman, J.

2006-11-01

A new version of BPM electronics based on the AD8362 RMS detector, which is a direct RF to DC converter, is under development at the JLAB FEL. Each of these new BPM electronics utilizes an embedded ColdFire Microprocessor for data processing and communication with the EPICS control system via TCP/IP. The ColdFire runs RTEMS, which is an open source real-time operating system. The JLAB FEL is a SRF Energy Recovery LINAC capable of running up to 10 mA CW beam with a 74.85 MHz micropulse frequency. For diagnostic reasons and for machine tune up, the micropulse frequency can be reduced to 1.17 MHz, which corresponds to about 160 μA of beam current. It is required that the BPM system would be functional for all micropulse frequencies. By taking into account the headroom for the beam steering and current variations the dynamic range of the RF front end is required to be about 60 dB. A BPM resolution of at least 100 μm is required, whereas better resolution is very desirable to make it possible for more accurate measurements of the electron beam optics. Some results of the RF front end development are presented as well as the first measurements made with an electron beam.

Development of BPM Electronics at the JLAB FEL

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

Sexton, D.; Evtushenko, P.; Jordan, K.

2006-11-20

A new version of BPM electronics based on the AD8362 RMS detector, which is a direct RF to DC converter, is under development at the JLAB FEL. Each of these new BPM electronics utilizes an embedded ColdFire Microprocessor for data processing and communication with the EPICS control system via TCP/IP. The ColdFire runs RTEMS, which is an open source real-time operating system. The JLAB FEL is a SRF Energy Recovery LINAC capable of running up to 10 mA CW beam with a 74.85 MHz micropulse frequency. For diagnostic reasons and for machine tune up, the micropulse frequency can be reducedmore » to 1.17 MHz, which corresponds to about 160 {mu}A of beam current. It is required that the BPM system would be functional for all micropulse frequencies. By taking into account the headroom for the beam steering and current variations the dynamic range of the RF front end is required to be about 60 dB. A BPM resolution of at least 100 {mu}m is required, whereas better resolution is very desirable to make it possible for more accurate measurements of the electron beam optics. Some results of the RF front end development are presented as well as the first measurements made with an electron beam.« less

Development of BPM Electronics at the JLAB FEL

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

Daniel Sexton; Pavel Evtushenko; Kevin Jordan

2006-05-01

A new version of BPM electronics based on the AD8362 RMS detector, which is a direct RF to DC converter, is under development at the JLAB FEL. Each of these new BPM electronics utilizes an embedded ColdFire Microprocessor for data processing and communication with the EPICS control system via TCP/IP. The ColdFire runs RTEMS, which is an open source real-time operating system. The JLAB FEL is a SRF Energy Recovery LINAC capable of running up to 10 mA CW beam with the micropulse up to 74.85 MHz. For diagnostic reasons and for the machine tune up, the micropulse frequency canmore » be reduced to 1.17 MHz, which corresponds to about 160 ?A of beam current. It is required that the BPM system would be functional for all micropulse frequencies. By taking into account the headroom for the beam steering and current variations the dynamic range of the RF front end is required to be about 60 dB. A BPM resolution of at least 100 ?m is required, whereas better resolution is very desirable to make it possible for more accurate measurements of the electron beam optics. Some results of the RF front end development are presented as well as the first measurements made with an electron beam.« less

Theoretical analysis and experimental investigation on performance of the thermal shield of accelerator cryomodules by thermo-siphon cooling of liquid nitrogen

NASA Astrophysics Data System (ADS)

Datta, T. S.; Kar, S.; Kumar, M.; Choudhury, A.; Chacko, J.; Antony, J.; Babu, S.; Sahu, S. K.

2015-12-01

Five beam line cryomodules with total 27 superconducting Radio Frequency (RF) cavities are installed and commissioned at IUAC to enhance the energy of heavy ion from 15 UD Pelletron. To reduce the heat load at 4.2 K, liquid nitrogen (LN2) cooled intermediate thermal shield is used for all these cryomodules. For three linac cryomodules, concept of forced flow LN2 cooling is used and for superbuncher and rebuncher, thermo-siphon cooling is incorporated. It is noticed that the shield temperature of superbuncher varies from 90 K to 110 K with respect to liquid nitrogen level. The temperature difference can't be explained by using the basic concept of thermo-siphon with the heat load on up flow line. A simple thermo-siphon experimental set up is developed to simulate the thermal shield temperature profile. Mass flow rate of liquid nitrogen is measured with different heat load on up flow line for different liquid levels. It is noticed that small amount of heat load on down flow line have a significant effect on mass flow rate. The present paper will be investigating the data generated from the thermosiphon experimental set up and a theoretical analysis will be presented here to validate the measured temperature profile of the cryomodule shield.

Practical Quantum Realization of the Ampere from the Elementary Charge

NASA Astrophysics Data System (ADS)

Brun-Picard, J.; Djordjevic, S.; Leprat, D.; Schopfer, F.; Poirier, W.

2016-10-01

One major change of the future revision of the International System of Units is a new definition of the ampere based on the elementary charge e . Replacing the former definition based on Ampère's force law will allow one to fully benefit from quantum physics to realize the ampere. However, a quantum realization of the ampere from e , accurate to within 10-8 in relative value and fulfilling traceability needs, is still missing despite the many efforts made for the development of single-electron tunneling devices. Starting again with Ohm's law, applied here in a quantum circuit combining the quantum Hall resistance and Josephson voltage standards with a superconducting cryogenic amplifier, we report on a practical and universal programmable quantum current generator. We demonstrate that currents generated in the milliampere range are accurately quantized in terms of e fJ (fJ is the Josephson frequency) with measurement uncertainty of 10-8. This new quantum current source, which is able to deliver such accurate currents down to the microampere range, can greatly improve the current measurement traceability, as demonstrated with the calibrations of digital ammeters. In addition, it opens the way to further developments in metrology and in fundamental physics, such as a quantum multimeter or new accurate comparisons to single-electron pumps.

RF System Requirements for a Medium-Energy Electron-Ion Collider (MEIC) at JLab

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

Rimmer, Robert A; Hannon, Fay E; Guo, Jiquan

2015-09-01

JLab is studying options for a medium energy electron-ion collider that could fit on the JLab site and use CEBAF as a full-energy electron injector. A new ion source, linac and booster would be required, together with collider storage rings for the ions and electrons. In order to achieve the maximum luminosity these will be high-current storage rings with many bunches. We present the high-level RF system requirements for the storage rings, ion booster ring and high-energy ion beam cooling system, and describe the technology options under consideration to meet them. We also present options for staging that might reducemore » the initial capital cost while providing a smooth upgrade path to a higher final energy. The technologies under consideration may also be useful for other proposed storage ring colliders or ultimate light sources.« less

Commissioning and Testing the 1970's Era LASS Solenoid Magnet in JLab's Hall D

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

Ballard, Joshua T.; Biallas, George H.; Brown, G.

2015-06-01

JLab refurbished and reconfigured the LASS1, 1.85m bore Solenoid and installed it as the principal analysis magnet for nuclear physics in the newly constructed, Hall D at Jefferson Lab. The magnet contains four superconducting coils within an iron yoke. The magnet was built in the early1970's at Stanford Linear Accelerator Center and used a second time at Los Alamos National Laboratory. The coils were extensively refurbished and individually tested by JLab. A new Cryogenic Distribution Box provides cryogens and their control valving, current distribution bus, and instrumentation pass-through. A repurposed CTI 2800 refrigerator system and new transfer line complete themore » system. We describe the re-configuration, the process and problems of re-commissioning the magnet and the results of testing the completed magnet.« less

The NASA Standard 20 Ampere Hour Nickel-Cadmium Battery Manual

NASA Technical Reports Server (NTRS)

Webb, D. A.

1979-01-01

The NASA standard 20 ampere hour spacecraft nickel-cadmium battery in described. Mechanical electrical and thermal data are supplied. Both qualification and acceptance tests are described. Information on handling and storage is given.

General Electric 20-ampere hour nickel-cadmium battery

NASA Technical Reports Server (NTRS)

Kirsch, W. W.

1974-01-01

The interaction, effect, and controllability of the performance parameters of the General Electric 20-ampere-hour, 24-cell nickel cadmium battery are investigated. The battery was cycled under simulated orbit conditions. The acquired data was analyzed and evaluated in terms of battery parameters and performance characteristics. Conclusions and tests results are presented along with recommendations for further study.

Commissioning Cornell OSTs for SRF cavity testing at Jlab

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

Eremeev, Grigory

2011-07-01

Understanding the current quench limitations in SRF cavities is a topic essential for any SRF accelerator that requires high fields. This understanding crucially depends on correct and precise quench identification. Second sound quench detection in superfluid liquid helium with oscillating superleak transducers is a technique recently applied at Cornell University as a fast and versatile method for quench identification in SRF cavities. Having adopted Cornell design, we report in this contribution on our experience with OST for quench identification in different cavities at JLab.

Applicability of ASST-A helium refrigeration system for JLab End Station Refrigerator

NASA Astrophysics Data System (ADS)

Hasan, N.; Knudsen, P.; Ganni, V.

2017-12-01

The MØLLER experiment at Jefferson Lab (JLab) is a high power (5 kW) liquid hydrogen target scheduled to be operational in the 12 GeV-era. At present, cryogenic loads and targets at three of JLab’s four experimental halls are supported by the End Station Refrigerator (ESR) - a CTI/Helix 1.5 kW 4.5 K refrigerator. It is not capable of supporting the high power target load and a capacity upgrade of the ESR cryogenic system is essential. The ASST-A helium refrigeration system is a 4 kW 4.5 K refrigerator. It was designed and used for the Superconducting Super Collider Lab (SSCL) magnet string test and later obtained by JLab after the cancellation of that project. The modified ASST-A refrigeration system, which will be called ESR-II along with a support flow from JLab’s Central Helium Liquefier (CHL) is considered as an option for the End Station Refrigerator capacity upgrade. The applicability of this system for ESR-II under varying load conditions is investigated. The present paper outlines the findings of this process study.

Crab Cavity and Cryomodule Prototype Development for the Advanced Photon Source

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

Wang, H; Ciovati, G; Clemens, W A

2011-03-01

We review the single-cell, superconducting crab cavity designs for the short-pulse x-ray (SPX) project at the Advanced Photon Source (APS). The 'on-cell' waveguide scheme is expected to have a more margin for the impedance budget of the APS storage ring, as well as offering a more compact design compared with the original design consisting of a low order mode damping waveguide on the beam pipe. We will report recent fabrication progress, cavity test performance on original and alternate prototypes, and concept designs and analysis for various cryomodule components.

EXPERIMENTAL MEASUREMENT AND INTERPRETATION OF VOLT-AMPERE CURVES

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

Gingrich, J.E.; Warner, C.; Weeks, C.C.

1962-07-01

Cylindrical and parallel-plane cesium vapor thermionic converters were used for obtaining volt-ampere curves for systematic variations of emitter, collector, and cesium reservoir temperatures, with electrode spacings ranging from a few to many mean free paths, and with space charge conditions varying from electron-rich to ion-rich. The resulting curves exhibit much variety. The saturation currents agree well with the data of Houston and Aamodt for the space charge neutralized, few-mean-free-path cases. Apparent'' saturation currents for space charge limited cases were observed and were always less than the currents predicted by Houston and Aamodt. Several discontinuities in slope were observed in themore » reverse current portion of the curves and these have tentatively been identified with volume ionization of atoms in both the ground and excited states. Similar processes may be important for obtaining the ignited mode. The methods used to measure static and dynamic volt-ampere curves are described. The use of a controlled-current load has yielded a negative resistance'' region in the curves which show the ignited mode. The curves obtained with poor current control do not show this phenomenon. Extinction is considered from the standpoint of Kaufmann' s criterion for stability. (auth)« less

Injector Cavities Fabrication, Vertical Test Performance and Primary Cryomodule Design

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

Wang, Haipeng; Cheng, Guangfeng; Clemens, William

2015-09-01

After the electromagnetic design and the mechanical design of a β=0.6, 2-cell elliptical SRF cavity, the cavity has been fabricated. Then both 2-cell and 7-cell cavities have been bench tuned to the target values of frequency, coupling external Q and field flatness. After buffer chemistry polishing (BCP) and high pressure rinses (HPR), Vertical 2K cavity test results have been satisfied the specifications and ready for the string assembly. We will report the cavity performance including Lorenz Force Detuning (LFD) and Higher Order Modes (HOM) damping data. Its integration with cavity tuners to the cryomodule design will be reported.

FERMILAB CRYOMODULE TEST STAND RF INTERLOCK SYSTEM

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

Petersen, Troy; Diamond, J. S.; McDowell, D.

2016-10-12

An interlock system has been designed for the Fermilab Cryo-module Test Stand (CMTS), a test bed for the cryo- modules to be used in the upcoming Linac Coherent Light Source 2 (LCLS-II) project at SLAC. The interlock system features 8 independent subsystems, one per superconducting RF cavity and solid state amplifier (SSA) pair. Each system monitors several devices to detect fault conditions such as arcing in the waveguides or quenching of the SRF system. Additionally each system can detect fault conditions by monitoring the RF power seen at the cavity coupler through a directional coupler. In the event of amore » fault condition, each system is capable of removing RF signal to the amplifier (via a fast RF switch) as well as turning off the SSA. Additionally, each input signal is available for re- mote viewing and recording via a Fermilab designed digitizer board and MVME 5500 processor.« less

Design, Project Execution, and Commissioning of the 1.8 K Superfluid Helium Refrigeration System for SRF Cryomodule Testing

DOE PAGES

Treite, P.; Nuesslein, U.; Jia, Yi; ...

2015-07-15

The Fermilab Cryomodule Test Facility (CMTF) provides a test bed to measure the performance of superconducting radiofrequency (SRF) cryomodules (CM). These SRF components form the basic building blocks of future high intensity accelerators such as the International Linear Collider (ILC) and a Muon Collider. Linde Kryotechnik AG and Linde Cryogenics have designed, constructed and commissioned the superfluid helium refrigerator needed to support SRF component testing at the CMTF Facility. The hybrid refrigerator is designed to operate in a variety of modes and under a wide range of boundary conditions down to 1.8 Kelvin set by CM design. Special features ofmore » the refrigerator include the use of warm and cold compression and high efficiency turbo expanders.This paper gives an overview on the wide range of the challenging cooling requirements, the design, fabrication and the commissioning of the installed cryogenic system.« less

Installation and Commissioning of the Super Conducting RF Linac Cryomodules for the Erlp

NASA Astrophysics Data System (ADS)

Goulden, A. R.; Bate, R.; Buckley, R. K.; Pattalwar, S. M.

2008-03-01

An Energy Recovery Linac Prototype (ERLP) is currently being constructed at Daresbury Laboratory, (UK) to promote the necessary skills in science & technology, particularly in photocathode electron gun and Superconducting RF (SRF), to enable the construction of a fourth generation light source, based on energy recovery linacs-4GLS [1]. The ERLP uses two identical cryomodules, one as a booster Linac used to accelerate the beam to 8.5 MeV, the other as an Energy Recovery Linac (ERL) module with an energy gain of 26.5 MeV. Each module consists of two 9- cell cavities operating at a frequency of 1.3 GHz and a temperature of 2 K. As there is no energy recovery in the booster it requires a peak power of 53 kW; whereas the linac module only requires 8 kW. The RF power is supplied by Inductive Output Tube (IOT) amplifiers. The maximum heat load (or the cooling power) required in the SRF system is 180 W at 2 K and is achieved in two stages: a LN2 pre-cooled Linde TCF50 liquefier produces liquid helium at 4.5 K, followed by a 2 K cold box consisting of a JT valve, recuperator and an external room temperature vacuum pumping system. This presentation reports the experience gained during, installation, commissioning and the initial operation of the cryomodules.

Superconducting Prototype Cavities for the Spallation Neutron Source (SNS) Project

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

G. Ciovati; P. Kneisel; K. Davis

2002-06-01

The Spallation Neutron Source project includes a superconducting linac section in the energy range from 186 MeV to 1000 MeV operating at a frequency of 805 MHz at 2.1 K. For this energy range two types of cavities are needed with geometrical Beta-values of Beta=0.61 and Beta=0.81. An aggressive cavity prototyping program is being pursued at JLab, which calls for fabricating and testing of four Beta=0.61 cavities and two Beta=0.81 cavities. Both types consist of six cells made from high purity niobium and feature one HOM coupler of the TESLA type on each beam pipe and a port for amore » high power coaxial input coupler. Three of the four Beta=0.61 cavities will be used for a cryomodule test in early 2002. At this time, four medium beta cavities and one high beta cavity have been completed and tested at JLab. In addition, the three medium beta cavities for the prototype cryomodule have been equipped with the integrated Ti-Helium vessel, successfully retested and will be assembled into a cavity string. Results from the cryo-module test should be available by the time of the conference. The tests on the Beta=0.61 cavity and the Beta=0.81 cavity exceeded the design values for gradient and Q - value: E{sub acc} =10.1 MV/m and Q = 5 x 10{sup 9} at 2.1K for Beta=0.61 and E{sub acc} = 12.3 MV/m and Q=5 x 10{sup 9} at 2.1K for Beta = 0.81. The medium beta cavities reached gradients between E{sub acc} = 15 MV/m and 21 MV/m. This paper will describe the test results obtained with the various cavities, some aspects of the HOM damping at cryogenic temperatures, results from microphonics and Lorentz force detuning tests and the cavity string assembly at the time of this workshop.« less

Modifications to JLab 12 GeV Refrigerator and Wide Range Mix Mode Performance Testing Results

NASA Astrophysics Data System (ADS)

Knudsen, P.; Ganni, V.; Hasan, N.; Dixon, K.; Norton, R.; Creel, J.

2017-02-01

Analysis of data obtained during the spring 2013 commissioning of the new 4.5 K refrigeration system at Jefferson Lab (JLab) for the 12 GeV upgrade indicated a wide capacity range with good efficiency and minimal operator interaction. Testing also showed that the refrigerator required higher liquid nitrogen (LN) consumption for its pre-cooler than anticipated by the design. This does not affect the capacity of the refrigerator, but it does result in an increased LN utility cost. During the summer of 2015 the modifications were implemented by the cold box manufacturer, according to a design similar to the JLab 12 GeV cold box specification. Subsequently, JLab recommissioned the cold box and performed extensive performance testing, ranging from 20% to 100% of the design maximum capacity, and in various modes of operation, ranging from pure refrigeration, pure liquefaction, half-and-half mix mode and at selected design modes using the Floating Pressure - Ganni Cycle. The testing demonstrated that the refrigerator system has a good and fairly constant performance over a wide capacity range and different modes of operation. It also demonstrated the modifications resulted in a LN consumption that met the design for the pure refrigeration mode (which is the most demanding) and was lower than the design for the nominal and maximum capacity modes. In addition, a pulsed-load test, similar to what is expected for cryogenic systems supporting fusion experiments, was conducted to observe the response using the Floating Pressure - Ganni Cycle, which was stable and robust. This paper will discuss the results and analysis of this testing pertaining to the LN consumption, the system efficiency over a wide range of capacity and different modes and the behaviour of the system to a pulsed load.

Evaluation of the quality of semi-insulating CdTe for radiation detectors by measurement of lux-ampere characteristics

NASA Astrophysics Data System (ADS)

Franc, J.; Kubát, J.; Grill, R.; Dědič, V.; Hlídek, P.; Moravec, P.; Belas, E.

2011-05-01

Accumulation of space charge on deep levels represents one of the major problems in fabrication of semi-insulating CdTe and CdZnTe X-ray and gamma-ray detectors, because it influences the applied electric field and can even result in a complete breakdown of the field in part of the sample (polarization and dead layer formation). The goal of the study was to evaluate possibilities of localization of areas of potential space charge accumulation in as grown crystals by steady state measurement of lux-ampere characteristics. All measurements were done at room temperature using He-Ne laser. Voltage was applied parallel to the direction of light propagation in the range 10-100 V. It was observed that all lux-ampere characteristics are sub-linear. Screening effects caused by space charge accumulated on deep levels explain these results. Crystals prepared by Vertical gradient freeze method in our laboratory are compared to a commercially available detector-grade sample prepared by Travelling heater method. Comparison of crystals grown from precursors of different starting purity shows an increase of the slope of lux-ampere characteristics with a decrease of impurity content. A correlation between the slope of lux-ampere characteristics and the mobility-lifetime product of electrons was observed, too.

Calculation of the Displacement Current Using the Integral Form of Ampere's Law.

ERIC Educational Resources Information Center

Dahm, A. J.

1978-01-01

Derives the magnetic field as a function of position between two capacitor plates during discharge with the use of the integral form of Ampere's law and real currents only. The displacement current must be included to obtain the same result for arbitrary choices of contours. (Author/GA)

Timelike Compton Scattering off the nucleon: observables and experimental perspectives for JLab at 12 GeV

NASA Astrophysics Data System (ADS)

Boër, Marie

2016-03-01

Hard exclusive processes such as photoproduction or electroproduction of photon or meson off the nucleon provide access to the Generalized Parton Distributions (GPDs), in the regime where the scattering amplitude is factorized into a hard and a soft part. GPDs contain the correlation between the longitudinal momentum fraction and the transverse spatial densities of quarks and gluons in the nucleon. Timelike Compton Scattering (TCS) correspond to the reaction γN → γ*N → e+e-N, where the photon is scattered off a quark. It is measured through its interference with the associated Bethe-Heitler process, which has the same final state. TCS allows to access the GPDs and test their universality by comparison to the results obtained with the DVCS process (eN → eγN). Also, results obtained with TCS provide additional independent constrains to the GPDs parameterization. We will present the physical motivations for TCS, with our theoretical predictions for TCS observables and their dependencies. We calculated for JLab 12 GeV energies all the single and double beam and/or target polarization observables off the proton and off the neutron. We will also present the experimental perspectives for the next years at JLab. Two proposals were already accepted at JLab: in Hall B, with the CLAS12 spectrometer, in order to measure the unpolarized cross section and in Hall A, with the SoLID spectrometer, in order to measure the unpolarized cross section and the beam spin asymmetry at high intensity. A Letter Of Intent was also submitted in order to measure the transverse target spin asymmetries in Hall C. We will discuss the merits of this different experiments and present some of the expected results.

Bunch Length Measurements at JLab FEL

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

P. Evtushenko; J. L. Coleman; K. Jordan

2006-09-01

The JLab FEL is routinely operated with sub-picosecond bunches. The short bunch length is important for high gain of the FEL. Coherent transition radiation has been used for the bunch length measurements for many years. This diagnostic can be used only in the pulsed beam mode. It is our goal to run FEL with CW beam and 74.85 MHz micropulse repetition rate. Hence it is very desirable to have the possibility of doing the bunch length measurements when running CW beam with any micropulse frequency. We use a Fourier transform infrared interferometer, which is essentially a Michelson interferometer, to measuremore » the spectrum of the coherent synchrotron radiation generated in the last dipole of the magnetic bunch compressor upstream of the FEL wiggler. This noninvasive diagnostic provides the bunch length measurements for CW beam operation at any micropulse frequency. We also compare the measurements made with the help of the FTIR interferometer with the data obtained by the Martin-Puplett interferometer. Results of the two diagnostics are usually agree within 15%. Here we present a description of the experimental setup, data evaluation procedure and results of the beam measurements.« less

The Hall D solenoid helium refrigeration system at JLab

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

Laverdure, Nathaniel A.; Creel, Jonathan D.; Dixon, Kelly d.

Hall D, the new Jefferson Lab experimental facility built for the 12GeV upgrade, features a LASS 1.85 m bore solenoid magnet supported by a 4.5 K helium refrigerator system. This system consists of a CTI 2800 4.5 K refrigerator cold box, three 150 hp screw compressors, helium gas management and storage, and liquid helium and nitrogen storage for stand-alone operation. The magnet interfaces with the cryo refrigeration system through an LN2-shielded distribution box and transfer line system, both designed and fabricated by JLab. The distribution box uses a thermo siphon design to respectively cool four magnet coils and shields withmore » liquid helium and nitrogen. We describe the salient design features of the cryo system and discuss our recent commissioning experience.« less

FRIB Cryogenic Distribution System and Status

NASA Astrophysics Data System (ADS)

Ganni, V.; Dixon, K.; Laverdure, N.; Yang, S.; Nellis, T.; Jones, S.; Casagrande, F.

2015-12-01

The MSU-FRIB cryogenic distribution system supports the 2 K primary, 4 K primary, and 35 - 55 K shield operation of more than 70 loads in the accelerator and the experimental areas. It is based on JLab and SNS experience with bayonet-type disconnects between the loads and the distribution system for phased commissioning and maintenance. The linac transfer line, which features three separate transfer line segments for additional independence during phased commissioning at 4 K and 2 K, connects the folded arrangement of 49 cryomodules and 4 superconducting dipole magnets and a fourth transfer line supports the separator area cryo loads. The pressure reliefs for the transfer line process lines, located in the refrigeration room outside the tunnel/accelerator area, are piped to be vented outdoors. The transfer line designs integrate supply and return flow paths into a combined vacuum space. The main linac distribution segments are produced in a small number of standard configurations; a prototype of one such configuration has been fabricated at Jefferson Lab and has been installed at MSU to support testing of a prototype FRIB cryomodule.

Parallel 50 ampere hour nickel cadmium battery performance in the Modular Power Subsystems (MPS)

NASA Technical Reports Server (NTRS)

Webb, D. A.

1980-01-01

The thermal performance of 50-ampere-hour, nickel cadmium batteries for use in a modular spacecraft is examined in near-Earth orbit simulation. Battery voltage and temperature profiles for temperature extreme cycles are given and discussed.

Latest Results of ILC High-Gradient R&D 9-cell Cavities at JLAB

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

Geng, Rongli

2008-02-11

It has been over a year since JLAB started processing and testing ILC 9-cell cavities in the frame work of ILC high-gradient cavity R&D, aiming at the goal of a 35 MV/m gradient at a Q of 1E10 with a yield of 90%. The necessary cavity processing steps include field flatness tuning, electropolishing (EP), hydrogen out-gassing under vacuum, high-pressure water rinsing, clean room assembly, and low temperature bake. These are followed by RF test at 2 Kelvin. Ultrasonic cleaning with Micro-90, an effective post-EP rinsing recipe discovered at JLAB, is routinely used. Seven industry manufactured 9-cell TESLAshape cavities are processedmore » and tested repeatedly. So far, 33 EP cycles are accumulated, corresponding to more than 65 hours of active EP time. An emphasis put on RF testing is to discern cavity quench characteristics, including its nature and its location. Often times, the cavity performance is limited by thermal-magnetic quench instead of field emission. The quench field in some cavities is lower than 20 MV/m and remains unchanged despite repeated EP, implying material and/or fabrication defects. The quench field in some other cavities is high but changes unpredictably after repeated EP, suggesting processing induced defects. Based on our experience and results, several areas are identified where improvement is needed to improve cavity performance as well as yield.« less

Aerospace technology development of three types of solid state remote power controllers for 120VDC with current ratings of five, and thirty amperes, one type having current limiting

NASA Technical Reports Server (NTRS)

Baker, D. E.

1975-01-01

The first generation of remote power controllers (RPC) developed included: a 5-ampere design (Type 1), capable of limiting maximum overload current to 15 amperes for .1 sec; and 5-ampere noncurrent (Type 2) and 30-ampere noncurrent (Type 3) limiting designs, both with selectable instant trip levels for high-current overload. Each design provides overcurrent protection through an inverse I squared T trip-out function with an automatic reset option and demonstrates step-applied fault capability with a 4000-ampere surge, fast-risetime (low-inductance) power source. They also meet MIL - STD - 461A specification for electromagnetic interference. The second generation RPCs traded off specification compliance for reduction in cost and complexity for the Type 1 and 2 designs and give comparable or improved performance in most areas. The noncurrent limiting RPC proved to be a more economical and feasible method of overload protection for certain load types.

One hundred ampere-hour nickel-cadmium battery cells of improved design

NASA Technical Reports Server (NTRS)

Kantner, E.

1972-01-01

Nickel cadmium battery cells with 100 ampere hour capacity were developed. The design features, notably extension of the current collector tab to the full width of the battery plate, and the location of the cell terminals on the opposite ends, resulted in a reduction of internal impedance, and improved electrical performance with expected improvement in thermal performance. Tables of data and performance curves are included to support the theoretical considerations.

Workshop on Physics with Neutral Kaon Beam at JLab (KL2016) Mini-Proceedings

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

Strakovsky, Igor I.; Amaryan, Moskov; Chudakov, Eugene A.

2016-05-01

The KL2016 Workshop is following the Letter of Intent LoI12-15-001 "Physics Opportunities with Secondary KL beam at JLab" submitted to PAC43 with the main focus on the physics of excited hyperons produced by the Kaon beam on unpolarized and polarized targets with GlueX setup in Hall D. Such studies will broaden a physics program of hadron spectroscopy extending it to the strange sector. The Workshop was organized to get a feedback from the community to strengthen physics motivation of the LoI and prepare a full proposal.

The Gauss and Ampere Laws: Different Laws but Similar Difficulties for Student Learning

ERIC Educational Resources Information Center

Guisasola, Jenaro; Almudi, Jose M.; Salinas, Julia; Zuza, Kristina; Ceberio, Mikel

2008-01-01

This study aims to analyse university students' reasoning regarding two laws of electromagnetism: Gauss's law and Ampere's law. It has been supposed that the problems seen in understanding and applying both laws do not spring from students' misconceptions. Students habitually use reasoning known in the literature as 'common sense' methodology that…

Exotic Effects at the Charm Threshold and Other Novel Physics Topics at JLab-12 GeV

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

Brodsky, Stanley J.; /SLAC

I briefly survey a number of novel hadron physics topics which can be investigated with the 12 GeV upgrade at J-Lab. The topics include new the formation of exotic heavy quark resonances accessible above the charm threshold, intrinsic charm and strangeness phenomena, the exclusive Sivers effect, hidden-color Fock states of nuclei, local two-photon interactions in deeply virtual Compton scattering, and non-universal antishadowing.

Magnetic field sensor based on the Ampere's force using dual-polarization DBR fiber laser

NASA Astrophysics Data System (ADS)

Yao, Shuang; Zhang, Yang; Guan, Baiou

2015-08-01

A novel magnetic field sensor using distributed Bragg reflector (DBR) fiber laser by Ampere's force effect is proposed and experimentally demonstrated. The key sensing element, that is the dual-polarization DBR fiber laser, is fixed on the middle part of two copper plates which carry the current. Ampere's force is applied onto the coppers due to an external magnetic field generated by a DC solenoid. Thus, the lateral force from the coppers is converted to a corresponding beat frequency signal shift produced by the DBR laser. The electric current sensing is also realized by the same configuration and same principle simultaneously in an intuitive manner. Good agreement between the theory calculation and the experimental results is obtained, which shows a good linearity. This sensor's sensitivity to the magnetic field and to the electric current finally reaches ~258.92 kHz/mT and ~1.08727 MHz/A, respectively.

Evaluation program for secondary spacecraft cells: Acceptance test of McDonnell-Douglas, Astropower division, 40.0 ampere hour silver-zinc cells

NASA Technical Reports Server (NTRS)

Harkness, J. D.

1971-01-01

The development of an inorganic separator material for use in construction of 40 ampere-hour silver zinc cells is discussed. Acceptance tests were conducted to determine real quality, physical defects and ampere-hour capacity. All acceptance tests were performed at an ambient temperature of 23 to 27 C at existing relative humidity and atmospheric pressure. Of the 63 cells tested, only one failed to meet the equipment specifications.

Online helium inventory monitoring of JLab cryogenic systems

NASA Astrophysics Data System (ADS)

Hasan, N.; Knudsen, P.; Wright, M.

2017-12-01

There are five cryogenic plants at Jefferson Lab which support the LINAC, experiment hall end-stations and test facility. The majority of JLab’s helium inventory, which is around 15 tons, is allocated in the LINAC cryo-modules, with the majority of the balance of helium distributed at the cryogenic-plant level mainly as stored gas and liquid for stable operation. Due to the organic evolution of the five plants and independent actions within the experiment halls, the traditional inventory management strategy suffers from rapid identification of potential leaks. This can easily result in losses many times higher than the normally accepted (average) loss rate. A real-time program to quickly identify potential excessive leakage was developed and tested. This program was written in MATLAB© for portability, easy diagnostics and modification. It interfaces directly with EPICS to access the cryogenic system state, and with and NIST REFPROP© for real fluid properties. This program was validated against the actual helium offloaded into the system. The present paper outlines the details of the inventory monitoring program, its validation and a sample of the achieved results.

Photoproduction of scalar mesons using CLAS at JLab

NASA Astrophysics Data System (ADS)

Chandavar, Shloka; Hicks, Kenneth; Keller, Dustin

2013-04-01

The standard quark model makes no allowance for the existence of gluons outside hadrons. However lattice QCD predicts bound states of pure gluons, called glueballs. According to lattice calculations, the lightest of these experimentally unverified particles is expected to have J^PC=0^++. There are three known mesons candidates with this spin and parity that can mix with the glueball: the f0(1370), the f0(1500) and the f0(1710). All of these particles have been reported in various experiments with the exception of photoproduction. The ZEUS collaboration observed a resonance at 1.7 GeV in ep collisions (with an exchanged virtual photon). To search for the presence of this resonance in photoproduction, the reaction γp->fJp->Ks^0 KS^0 p->2(^amp;+^amp;-)p was analyzed using data from two experiments conducted using the CLAS detector at JLab. The KsKschannel was chosen because this fixes the parity of the parent fJ particle to be positive. Preliminary results from analysis of these data will be presented

Toroidal Ampere-Faraday Equations Solved Consistently with the CQL3D Fokker-Planck Time-Evolution

NASA Astrophysics Data System (ADS)

Harvey, R. W.; Petrov, Yu. V.

2013-10-01

A self-consistent, time-dependent toroidal electric field calculation is a key feature of a complete 3D Fokker-Planck kinetic distribution radial transport code for f(v,theta,rho,t). In the present CQL3D finite-difference model, the electric field E(rho,t) is either prescribed, or iteratively adjusted to obtain prescribed toroidal or parallel currents. We discuss first results of an implementation of the Ampere-Faraday equation for the self-consistent toroidal electric field, as applied to the runaway electron production in tokamaks due to rapid reduction of the plasma temperature as occurs in a plasma disruption. Our previous results assuming a constant current density (Lenz' Law) model showed that prompt ``hot-tail runaways'' dominated ``knock-on'' and Dreicer ``drizzle'' runaways; we will examine modifications due to the more complete Ampere-Faraday solution. Work supported by US DOE under DE-FG02-ER54744.

Toroidal Ampere-Faraday Equations Solved Simultaneously with CQL3D Fokker-Planck Time-Evolution

NASA Astrophysics Data System (ADS)

Harvey, R. W. (Bob); Petrov, Yu. V. (Yuri); Forest, C. B.; La Haye, R. J.

2017-10-01

A self-consistent, time-dependent toroidal electric field calculation is a key feature of a complete 3D Fokker-Planck kinetic distribution radial transport code for f(v,theta,rho,t). We discuss benchmarking and first applications of an implementation of the Ampere-Faraday equation for the self-consistent toroidal electric field, as applied to (1) resistive turn on of applied electron cyclotron current in the DIII-D tokamak giving initial back current adjacent to the direct CD region and having possible NTM stabilization implications, and (2) runaway electron production in tokamaks due to rapid reduction of the plasma temperature as occurs in pellet injection, massive gas injection, or a plasma disruption. Our previous results assuming a constant current density (Lenz' Law) model showed that prompt ``hot-tail runaways'' dominated ``knock-on'' and Dreicer ``drizzle'' runaways; we perform full-radius modeling and examine modifications due to the more complete Ampere-Faraday solution. Presently, the implementation relies on a fixed shape eqdsk, and this limitation will be addressed in future work. Research supported by USDOE FES award ER54744.

The Role of Historical-Philosophical Controversies in Teaching Sciences: The Debate between Biot and Ampere

ERIC Educational Resources Information Center

Braga, Marco; Guerra, Andreia; Reis, Jose Claudio

2012-01-01

This paper evaluates the viability of using controversies in teaching. An educational project has been elaborated in which some historical-philosophical clashes were introduced into the classical syllabus of physics. The historical-philosophical controversy dealt with here, took place between the French physicists Biot and Ampere in the 19th…

Electron Beam Diagnostics Of The JLAB UV FEL

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

Evtushenko, Pavel; Benson, Stephen; Biallas, George

2011-03-01

In this contribution we describe various systems and aspects of the electron beam diagnostics of the JLab UV FEL. The FEL is installed on a new bypass beam line at the existing 10 kW IR Upgrade FEL. Here, we describe a set of the following systems. A combination of OTR and phosphor viewers is used for measurements of the transverse beam profile, transverse emittance, and Twiss parameters. This system is also used for alignment of the optical cavity of the UV oscillator and to ensure the overlap between the electron beam and optical mode in the FEL wiggler. A systemmore » of beam position monitors equipped with log-amp based BPM electronics. Bunch length on the order of 120 fs RMS is measured with the help of a modified Martin-Puplett interferometer. The longitudinal transfer function measurement system is used to set up bunch compression in an optimal way, such that the LINAC RF curvature is compensated using only higher order magnetic elements of the beam transport. This set of diagnostic systems made a significant contribution in achieving first lasing of the FEL after only about 60 hours of beam operation.« less

Electroweak radiative corrections for polarized Moller scattering at the future 11 GeV JLab experiment

DOE PAGES

Aleksejevs, Aleksandrs; Barkanova, Svetlana; Ilyichev, Alexander; ...

2010-11-19

We perform updated and detailed calculations of the complete NLO set of electroweak radiative corrections to parity violating e – e – → e – e – (γ) scattering asymmetries at energies relevant for the ultra-precise Moller experiment coming soon at JLab. Our numerical results are presented for a range of experimental cuts and relative importance of various contributions is analyzed. In addition, we also provide very compact expressions analytically free from non-physical parameters and show them to be valid for fast yet accurate estimations.

Investigations on Absorber Materials at Cryogenic Temperatures

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

Marhauser, Frank; Elliott, Thomas; Rimmer, Robert

2009-05-01

In the framework of the 12 GeV upgrade project for the Continuous Electron Beam Accelerator Facility (CEBAF) improvements are being made to refurbish cryomodules housing Thomas Jefferson National Accelerator Facility's (JLab) original 5-cell cavities. Recently we have started to look into a possible simplification of the existing Higher Order Mode (HOM) absorber design combined with the aim to find alternative material candidates. The absorbers are implemented in two HOM-waveguides immersed in the helium bath and operate at 2 K temperature. We have built a cryogenic setup to perform measurements on sample load materials to investigate their lossy characteristics and variationsmore » from room temperature down to 2 K. Initial results are presented in this paper.« less

Application of JLab 12GeV helium refrigeration system for the FRIB accelerator at MSU

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

Ganni, Venkatarao; Knudsen, Peter N.; Arenius, Dana M.

The planned approach to have a turnkey helium refrigeration system for the MSU-FRIB accelerator system, encompassing the design, fabrication, installation and commissioning of the 4.5-K refrigerator cold box(es), cold compression system, warm compression system, gas management, oil removal and utility/ancillary systems, was found to be cost prohibitive. Following JLab’s suggestion, MSU-FRIB accelerator management made a formal request to evaluate the applicability of the recently designed 12GeV JLab cryogenic system for this application. The following paper will outline the findings and the planned approach for the FRIB helium refrigeration system.

Incorporation of a PbSe Array Based Spectrograph into EPICS using LabView at the JLab FEL Facility

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

D. Hardy; S.V. Benson; Michelle D. Shinn

2005-08-21

A real-time spectrograph with a 1Hz update rate was designed and installed at the JLab FEL facility using a Cal Sensors PbSe array and a Roper Scientific SpectraPro 300 monochrometer. This paper describes the implementation of EPICS channel access on a remote PC running LabView with modification of vendor supplied LabView VI's to allow display of FEL light spectra in real-time on a remote workstation. This allows PC based diagnostics to be used in EPICS.

Parity Violation in Deep Inelastic Scattering in Hall C at JLab

NASA Astrophysics Data System (ADS)

Dalton, Mark Macrae; Keppel, Cynthia; Paschke, Kent

2017-09-01

The measurement of parity-violation in inclusive electron deep inelastic scattering (DIS) from a proton or deuteron target can be used to study the flavor structure of the nucleon. While valence quark parton distribution functions (PDF) can be probed in high- x measurements such as with the proposed SoLID spectrometer, complementary measurements are possible at moderate x 0.1 where the sea quarks may still play a significant role. In particular, such measurements would provide a cleanly interpretable measurement of the strange quark PDF. These measurements are possible with the upgraded CEBAF accelerator at JLab and do not require significant new experimental hardware. The prospects and potential impacts of such a measurement will be presented. This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics under Contract DE-AC05-06OR23177 and DE-FG02-07ER41522.

Tunable mega-ampere electron current propagation in solids by dynamic control of lattice melt

DOE PAGES

MacLellan, D.  A.; Carroll, D.  C.; Gray, R.  J.; ...

2014-10-31

The influence of lattice-melt-induced resistivity gradients on the transport of mega-ampere currents of fast electrons in solids is investigated numerically and experimentally using laser-accelerated protons to induce isochoric heating. Tailoring the heating profile enables the resistive magnetic fields which strongly influence the current propagation to be manipulated. This tunable laser-driven process enables important fast electron beam properties, including the beam divergence, profile, and symmetry to be actively tailored, and without recourse to complex target manufacture.

Science Innovation Through Industry Partnership: Lessons from AMPERE in Bridging the Federal Sponsor/Private Corporation Divide

NASA Astrophysics Data System (ADS)

Anderson, B. J.; Korth, H.; Erlandson, R. E.

2017-12-01

The Active Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE) was made possible by harnessing an fortuitous capability of the Iridium Communications constellation of 70 polar orbiting satellites. In 1996 it was realized that the attitude magnetometers on-board the Iridium satellites, then in fabrication, could potentially be used to obtain the first ever global and continuous measurements of the Birkeland currents with a sufficiently short re-sampling cadence (10 minutes) to track the dynamic evolution of the large-scale currents. The experience of taking this idea from 1996 through various research grant supported efforts, mission of opportunity proposal attempts, and finally through funding and implementation as a National Science Foundation geospace facility, revealed a number of challenges both in proposing innovative solutions to existing sponsor programs and also in working between the federal sponsor community and the private commercial space environment. Implementing AMPERE required a code change to on-board software on the Iridium satellites and it proved necessary to engage NASA to adjust the solicitation language to allow AMPERE. For NASA proposals we also encountered a conflict with respect to federal sponsorship such that the original business configuration of Iridium could not accept the accounting regime implied by a sub-contract derived from a federal contract acquisition. Subsequent mission of opportunity efforts encountered various other challenges including the cancellation of an explorer to fund the exploration initiative in 2001. The facilities proposal to NSF was almost not submitted owing a funding vehicle disparity between the preferred proposer structure (contract) vs NSF's requirement to fund only grants and a final hurdle concerned the structure of the contract with Iridium which was initially a sub-contract but was changed to a fixed-price data purchase due to NSF's limitations on funding fee-bearing engineering

Evaluation program for secondary spacecraft cells. Initial evaluation tests of General Electric Company standard and teflonated negative electrode 20.0 ampere-hour, nickel-cadmium spacecraft cells with auxiliary electrodes

NASA Technical Reports Server (NTRS)

1974-01-01

The standard plate cells exhibited higher average end-of-charge (EOC) voltages than the cells with teflonated negative plates; they also delivered a higher capacity output in ampere hours following these charges. All the cells reached a pressure of 20 psia before reaching the voltage limit of 1.550 volts during the pressure versus capacity test. The average ampere hours in and voltages at this pressure were 33.6 and 1.505 volts respectively for the teflonated negative plate cells and 35.5 and 1.523 volts for the standard plate cells. All cells exhibited pressure decay in the range of 1 to 7 psia during the last 30 minutes of the 1-hour open circuit stand. Average capacity out for the teflonated and standard negative plate cells was 29.4 and 29.9 ampere hours respectively.

New Analytical Solution of the Equilibrium Ampere's Law Using the Walker's Method: a Didactic Example

NASA Astrophysics Data System (ADS)

Sousa, A. N. Laurindo; Ojeda-González, A.; Prestes, A.; Klausner, V.; Caritá, L. A.

2018-02-01

This work aims to demonstrate the analytical solution of the Grad-Shafranov (GS) equation or generalized Ampere's law, which is important in the studies of self-consistent 2.5-D solution for current sheet structures. A detailed mathematical development is presented to obtain the generating function as shown by Walker (RSPSA 91, 410, 1915). Therefore, we study the general solution of the GS equation in terms of the Walker's generating function in details without omitting any step. The Walker's generating function g( ζ) is written in a new way as the tangent of an unspecified function K( ζ). In this trend, the general solution of the GS equation is expressed as exp(- 2Ψ) = 4| K '( ζ)|2/cos2[ K( ζ) - K( ζ ∗)]. In order to investigate whether our proposal would simplify the mathematical effort to find new generating functions, we use Harris's solution as a test, in this case K( ζ) = arctan(exp( i ζ)). In summary, one of the article purposes is to present a review of the Harris's solution. In an attempt to find a simplified solution, we propose a new way to write the GS solution using g( ζ) = tan( K( ζ)). We also present a new analytical solution to the equilibrium Ampere's law using g( ζ) = cosh( b ζ), which includes a generalization of the Harris model and presents isolated magnetic islands.

New Analytical Solution of the Equilibrium Ampere's Law Using the Walker's Method: a Didactic Example

NASA Astrophysics Data System (ADS)

Sousa, A. N. Laurindo; Ojeda-González, A.; Prestes, A.; Klausner, V.; Caritá, L. A.

2017-12-01

This work aims to demonstrate the analytical solution of the Grad-Shafranov (GS) equation or generalized Ampere's law, which is important in the studies of self-consistent 2.5-D solution for current sheet structures. A detailed mathematical development is presented to obtain the generating function as shown by Walker (RSPSA 91, 410, 1915). Therefore, we study the general solution of the GS equation in terms of the Walker's generating function in details without omitting any step. The Walker's generating function g(ζ) is written in a new way as the tangent of an unspecified function K(ζ). In this trend, the general solution of the GS equation is expressed as exp(- 2Ψ) = 4|K '(ζ)|2/cos2[K(ζ) - K(ζ ∗)]. In order to investigate whether our proposal would simplify the mathematical effort to find new generating functions, we use Harris's solution as a test, in this case K(ζ) = arctan(exp(i ζ)). In summary, one of the article purposes is to present a review of the Harris's solution. In an attempt to find a simplified solution, we propose a new way to write the GS solution using g(ζ) = tan(K(ζ)). We also present a new analytical solution to the equilibrium Ampere's law using g(ζ) = cosh(b ζ), which includes a generalization of the Harris model and presents isolated magnetic islands.

Characterization testing of a 40 ampere hour bipolar nickel-hydrogen battery

NASA Technical Reports Server (NTRS)

Brewer, Jeffrey C.; Manzo, Michelle A.; Gemeiner, Russel P.

1990-01-01

Extensive characterization testing has been done on a second 40-ampere hour (A h), 10-cell, bipolar nickel-hydrogen (Ni-H2) battery, to study the effects of operating parameters such as charge and discharge rates, temperature, and pressure on capacity, A h and watt hour (W h) efficiencies, and end-of-charge and midpoint discharge voltages. Testing to date has produced many interesting results, with the battery performing well throughout the test matrix except during the high-rate (5 C and 10 C) discharges, where poorer than expected results were observed. The exact cause of this poor performance is, as yet, unknown. Small scale 2 in. x 2 in. battery tests are to be used in studying this problem. Low earth orbit cycle life testing at a 40-percent depth of discharge and 10 C is scheduled to follow the characterization testing.

Relation of field-aligned currents measured by AMPERE project to solar wind and substorms

NASA Astrophysics Data System (ADS)

McPherron, R. L.; Anderson, B. J.; Chu, X.

2016-12-01

Magnetic perturbations measured in the Active Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE) by the Iridium constellation of spacecraft have been processed to obtain the time history of field-aligned currents (FAC) connecting the magnetosphere to the ionosphere. We find that the strength of these currents is closely related to the strength of the solar wind driver defined as a running average of the previous three hours of the optimum AL (auroral lower) coupling function. The relation is well represented by a saturation model I = A*S*Ss/(S+Ss) with I the current strength in mega Amps, S the driver strength in mV/m, Ss the saturation value of 7.78 mV/m, and A = 2.55 scales the relation to units of current. We also find that in general the upward current on the nightside increases with each substorm expansion onset defined by a combination of the SuperMag SML (SuperMag AL) and midlatitude positive bay (MPB) onset lists. A superposed epoch analysis using 700 onsets in 2010 shows the following: solar wind coupling peaks at expansion onset; dayside outward current starts to increase one hour before onset while nightside outward current starts suddenly at onset; nightside outward current reaches a peak at 28 minutes as do SML and MPB indices; FAC, SML, and MPB respectively take 1, 2, and 3 hours to decay to background. The data indicate that the substorm current wedge is superposed on a pre-existing field-aligned current system and that the location and properties of the current wedge can be studied with the AMPERE data.

The DarkLight Experiment at the JLab FEL

NASA Astrophysics Data System (ADS)

Fisher, Peter

2013-10-01

DarkLight will study the production of gauge bosons associated with Dark Forces theories in the scattering of 100 MeV electrons on proton a target. DarkLight is a spectrometer to measure all the final state particles in e- + p -->e- + p +e- +e+ . QED allows this process and the invariant mass distribution of the e+e- pair is a continuum from nearly zero to nearly the electron beam energy. Dark Forces theories, which allow the dark matter mass scale to be over 1 TeV, predict a gauge boson A' in the mass range of 10-1,000 MeV and decays to an electron-positron pair with an invariant mass of mA'. We aim to search for this process using the 100 MeV, 10 mA electron beam at the JLab Free Electron Laser impinging on a hydrogen target with a 1019 cm-2 density. The resulting luminosity of 6 ×1035/cm2-s gives the experiment enough sensitivity to probe A' couplings of 10-9 α . DarkLight is unique in its design to detect all four particles in the final state. The leptons will be measured in a large high-rate TPC and a silicon sensor will measure the protons. A 0.5 T solenoidal magnetic field provides the momentum resolution and focuses the copious Møller scattering background down the beam line, away from the detectors. A first beam test has shown the FEL beam is compatible with the target design and that the hall backgrounds are manageable. The experiment has been approved by Jefferson Lab for first running in 2017.

Evaluation program for secondary spacecraft cells: Initial evaluation tests of General Electric Company 6.0 ampere hour nickel-cadmium spacecraft cells with auxiliary electrodes for the atmospheric Explorer satellite C and D. [quality control testing

NASA Technical Reports Server (NTRS)

Harkness, J. D.

1974-01-01

The capacity of the cells ranged from 6.6 to 7.6 ampere hours during the three capacity tests. No voltage requirements or limits were exceeded during any portion of the test. All cells recovered to a voltage in excess of 1.193 volts during the 24-hour open-circuit portion of the internal short test. All the cells reached a pressure of 20 psia before reaching the voltage limit of 1.550 volts during the pressure versus capacity test. The average ampere/hours in and voltages at this pressure were 9.1 and 1.513, respectively. All cells exhibited pressure decay in the range of 1 to 5 psia during the last 30 minutes of the 1-hour open circuit stand. Average capacity out was 7.2 ampere/hours.

A time-implicit numerical method and benchmarks for the relativistic Vlasov–Ampere equations

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

Carrie, Michael; Shadwick, B. A.

2016-01-04

Here, we present a time-implicit numerical method to solve the relativistic Vlasov–Ampere system of equations on a two dimensional phase space grid. The time-splitting algorithm we use allows the generalization of the work presented here to higher dimensions keeping the linear aspect of the resulting discrete set of equations. The implicit method is benchmarked against linear theory results for the relativistic Landau damping for which analytical expressions using the Maxwell-Juttner distribution function are derived. We note that, independently from the shape of the distribution function, the relativistic treatment features collective behaviors that do not exist in the non relativistic case.more » The numerical study of the relativistic two-stream instability completes the set of benchmarking tests.« less

A time-implicit numerical method and benchmarks for the relativistic Vlasov–Ampere equations

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

Carrié, Michael, E-mail: mcarrie2@unl.edu; Shadwick, B. A., E-mail: shadwick@mailaps.org

2016-01-15

We present a time-implicit numerical method to solve the relativistic Vlasov–Ampere system of equations on a two dimensional phase space grid. The time-splitting algorithm we use allows the generalization of the work presented here to higher dimensions keeping the linear aspect of the resulting discrete set of equations. The implicit method is benchmarked against linear theory results for the relativistic Landau damping for which analytical expressions using the Maxwell-Jüttner distribution function are derived. We note that, independently from the shape of the distribution function, the relativistic treatment features collective behaviours that do not exist in the nonrelativistic case. The numericalmore » study of the relativistic two-stream instability completes the set of benchmarking tests.« less

Large size GEM for Super Bigbite Spectrometer (SBS) polarimeter for Hall A 12GeV program at JLab

DOE PAGES

Gnanvo, Kondo; Liyanage, Nilanga; Nelyubin, Vladimir; ...

2015-05-01

We report on the R&D effort in the design and construction of a large size GEM chamber for the Proton Polarimeter of the Super Bigbite Spectrometer (SBS) in Hall A at Thomas Jefferson National Laboratory (JLab). The SBS Polarimeter trackers consist of two sets of four large chambers of size 200 cm x 60 cm 2. Each chamber is a vertical stack of four GEM modules with an active area of 60 cm x 50 cm. We have built and tested several GEM modules and we describe in this paper the design and construction of the final GEM as wellmore » as the preliminary results on performances from tests carried out in our detector lab and with test beams at (Fermilab).« less

MO-E-18C-05: Global Health Catalyst: A Novel Platform for Enhancing Access to Medical Physics Education and Research Excellence (AMPERE)

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

Ngwa, W; University of Massachusetts, Lowell, Massachusetts; Moreau, M

Purpose: To develop a platform for catalyzing collaborative global Cancer Care Education and Research (CaRE), with a prime focus on enhancing Access to Medical Physics Education and Research Excellence (AMPERE) Methods: An analysis of over 50 global health collaborations between partners in the U.S. and low and middle income countries (LMIC) in Africa was carried out to assess the models of collaborations in Education and Research and relative success. A survey was carried out with questions including: the nature of the collaboration, how it was initiated, impact of culture and other factors, and recommendations for catalyzing/enhancing such collaborations. An onlinemore » platform called Global Health Catalyst was developed for enhancing AMPERE. Results: The analysis yielded three main models for global health collaborations with survey providing key recommendations on how to enhance such collaborations. Based on this, the platform was developed, and customized to allow Medical Physicists and other Radiation oncology (RadOnc) professionals interested in participating in Global health to readily do so e.g. teach an online course module, participate in training Medical Physicists or other RadOnc health professionals in LMIC, co-mentor students, residents or postdocs, etc. The growing list of features on the platform also include: a feature to enable people to easily find each other, form teams, operate more effectively as partners from different disciplines, institutions, nations and cultural backgrounds, share tools and technologies, obtain seed funding to develop curricula and/or embark upon new areas of investigation, and participate in humanitarian outreach: remote treatment planning assistance, and participation in virtual Chart Rounds, etc. Conclusion: The developed Global Health Catalyst platform could enable any Medical Physicist or RadoOnc professional interested in global health to readily participate in the Education/training of next generation Rad

Commissioning of helium refrigeration system at JLab for 12 GeV upgrade

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

Ganni, Venkatarao; Dixon, Kelly D.; Knudsen, Peter N.

The new 4.5 K refrigerator system added to the Jefferson Lab (JLab) Central Helium Liquefier (CHL) for the 12 GeV upgrade will double its previous capacity. It includes a 4.5 K cold box system and compressor system with associated oil removal and gas management systems. At its maximum capacity condition, this new system supports an additional 238 g/s 30 K 1.16 bar cold compressor return flow, a 15 g/s 4.5 K liquefaction load and a 12.6 kW 35–55 K shield load. Five more design conditions, ranging from liquefaction to refrigeration and a stand-by/reduced load state, were specified for the sizingmore » and selection of its components. The cold box system is comprised of a 300–60 K vertical cold box that incorporates a liquid nitrogen pre-cooler and a 60–4.5 K horizontal cold box housing seven turbines that are configured in four expansion stages including one Joule-Thompson expander. The helium compression system has five compressors to support three pressure levels in the cold box. This paper will briefly review the salient 4.5 K system design features and discuss the recent commissioning results.« less

Commissioning results of Nb 3Sn cavity vapor diffusion deposition system at JLab

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

Eremeev, Grigory; Clemens, William A.; Macha, Kurt M.

2015-09-01

Nb 3Sn as a BCS superconductor with a superconducting critical temperature higher than that of niobium offers potential benefit for SRF cavities via a lower-than-niobium surface resistance at the same temperature and frequency. A Nb 3Sn vapor diffusion deposition system designed for coating of 1.5 and 1.3 GHz single-cell cavities was built and commissioned at JLab. As the part of the commissioning, RF performance at 2.0 K of a single-cell 1.5 GHz CEBAF-shaped cavity was measured before and after coating in the system. Before Nb 3Sn coating the cavity had a Q 0 of about 10 10 and was limitedmore » by the high field Q-slope at E acc ≅ 27 MV/m. Coated cavity exhibited the superconducting transition at about 17.9 K. The low-field quality factor was about 5∙10 9 at 4.3 K and 7∙10 9 at 2.0 K decreasing with field to about 1∙10 9 at E acc ≅ 8 MV/m at both temperatures. The highest field was limited by the available RF power.« less

Failure analysis of a 3.5 inch, 50 ampere-hour nickel-hydrogen cell

NASA Technical Reports Server (NTRS)

Fuhr, Kenneth H.

1987-01-01

The 3.5 inch, 50 ampere-hour nickel-hydrogen cell was on a Low Earth Orbit (LEO) test regime and was being cycled at 10 C and 60 percent depth of discharge. At cycle number 511 the Automatic Control and Data Acquisition System (ACDAS) terminated the test when the end of discharge voltage dropped below the 1.00 volt cutoff. Upon removal of the stack assembly from the pressure vessel, portions of the zircar separator were found to be completely missing. Upon further examination portions of both the positive and negative plates were found to be missing from its substrate and several gas screens were damaged due to excessive heat which caused fusing. The postulated cause of failure is free electrolyte in the cell which caused oxygen channelization resulting in localized recombination which degraded the stack components.

The JLab high power ERL light source

NASA Astrophysics Data System (ADS)

Neil, G. R.; Behre, C.; Benson, S. V.; Bevins, M.; Biallas, G.; Boyce, J.; Coleman, J.; Dillon-Townes, L. A.; Douglas, D.; Dylla, H. F.; Evans, R.; Grippo, A.; Gruber, D.; Gubeli, J.; Hardy, D.; Hernandez-Garcia, C.; Jordan, K.; Kelley, M. J.; Merminga, L.; Mammosser, J.; Moore, W.; Nishimori, N.; Pozdeyev, E.; Preble, J.; Rimmer, R.; Shinn, M.; Siggins, T.; Tennant, C.; Walker, R.; Williams, G. P.; Zhang, S.

2006-02-01

A new THz/IR/UV photon source at Jefferson Lab is the first of a new generation of light sources based on an Energy-Recovered, (superconducting) Linac (ERL). The machine has a 160 MeV electron beam and an average current of 10 mA in 75 MHz repetition rate hundred femtosecond bunches. These electron bunches pass through a magnetic chicane and therefore emit synchrotron radiation. For wavelengths longer than the electron bunch the electrons radiate coherently a broadband THz ˜ half cycle pulse whose average brightness is >5 orders of magnitude higher than synchrotron IR sources. Previous measurements showed 20 W of average power extracted [Carr, et al., Nature 420 (2002) 153]. The new facility offers simultaneous synchrotron light from the visible through the FIR along with broadband THz production of 100 fs pulses with >200 W of average power. The FELs also provide record-breaking laser power [Neil, et al., Phys. Rev. Lett. 84 (2000) 662]: up to 10 kW of average power in the IR from 1 to 14 μm in 400 fs pulses at up to 74.85 MHz repetition rates and soon will produce similar pulses of 300-1000 nm light at up to 3 kW of average power from the UV FEL. These ultrashort pulses are ideal for maximizing the interaction with material surfaces. The optical beams are Gaussian with nearly perfect beam quality. See www.jlab.org/FEL for details of the operating characteristics; a wide variety of pulse train configurations are feasible from 10 ms long at high repetition rates to continuous operation. The THz and IR system has been commissioned. The UV system is to follow in 2005. The light is transported to user laboratories for basic and applied research. Additional lasers synchronized to the FEL are also available. Past activities have included production of carbon nanotubes, studies of vibrational relaxation of interstitial hydrogen in silicon, pulsed laser deposition and ablation, nitriding of metals, and energy flow in proteins. This paper will present the status of the

Cryogenic test of the 4 K / 2 K insert for the ARIEL e-Linac cryomodule

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

Laxdal, R. E.; Ma, Y.; Harmer, P.

2014-01-29

The ARIEL project at TRIUMF requires a 50 MeV superconducting electron linac consisting of five nine cell 1.3 GHz cavities divided into three cryomodules with one, two and two cavities in each module respectively. LHe is distributed in parallel to each module at 4 K and at ∼1.2 bar. Each module has a cryogenic insert on board that receives the 4 K liquid and produces 2 K into a cavity phase separator. The module combines a 4 K phase separator, a plate and fin heat exchanger from DATE and a J-T valve expanding into the 2 K phase separator. Themore » unit also supplies 4 K liquid to thermal intercepts in the module in siphon loops that return the vaporized liquid to the 4 K reservoir. For testing purposes the unit is outfitted with a dummy 2 K phase separator and thermal intercepts with variable heaters that mimic the final heat loads in order to test the cryogenic performance. The design of the 4 K / 2 K insert, the results of the cold tests and a summary of the test infrastructure including cryogenics services will be presented.« less

Lattice Design for a High-Power Infrared FEL

NASA Astrophysics Data System (ADS)

Douglas, D. R.

1997-05-01

A 1 kW infrared FEL, funded by the U.S. Navy, is under construction at jlab.org/>Jefferson Lab. This device will be driven by a compact, 42 MeV, 5 mA, energy-recovering, CW SRF-based linear accelerator to produce light in the 3-6.6 μm range. The jlab.org/ douglas/irfelconcept.gif>machine concept comprises a 10 MeV injector, a linac based on a single high-gradient Jefferson Lab accelerator cryomodule, a wiggler and optical cavity, and an energy-recovery recirculation arc. Energy recovery limits cost and technical risk by reducing the RF power requirements in the driver accelerator. Following deceleration to 10 MeV, the beam is dumped. Stringent phase space requirements at the wiggler, low beam energy, and high beam current subject the accelerator lattice to numerous constraints. Principal considerations include: transport and delivery to the FEL of a high-quality, high-current beam; the impact of coherent synchrotron radiation (CSR) during beam recirculation transport; beam optics aberration control, to provide low-loss energy-recovery transport of a 5% relative momentum spread, high-current beam; attention to possible beam breakup (BBU) instabilities in the recirculating accelerator; and longitudinal phase space management during beam transport, to optimize RF drive system control during energy recovery and FEL operation. The presentation will address the design process and design solution for an accelerator transport lattice that meets the requirements imposed by these physical phenomena and operational necessities.

Bunch Length Measurements at the JLab FEL Using Coherent Transition and Synchrotron Radiation

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

Pavel Evtushenko; James Coleman; Kevin Jordan

2006-05-01

The JLab FEL is routinely operated with sub-picosecond bunches. The short bunch length is important for high gain of the FEL. Coherent transition radiation has been used for the bunch length measurements for many years [1]. This diagnostic can be used only in the pulsed beam mode. It is our goal to run the FEL with CW beam and a 74.85 MHz micropulse repetition rate, which, with the 135 pC nominal bunch charge corresponds to the beam average current of 10 mA. Hence it is very desirable to have the possibility of making bunch length measurements when running CW beammore » with any micropulse frequency. We use a Fourier transform infrared (FTIR) interferometer, which is essentially a Michelson interferometer, to measure the spectrum of the coherent synchrotron radiation generated in the last dipole of the magnetic bunch compressor upstream of the FEL wiggler. This noninvasive diagnostic provides bunch length measurements for CW beam operation at any micropulse frequency. We also compare the measurements made with the help of the FTIR interferometer with data obtained using the Martin-Puplett interferometer [1]. Results of the two diagnostics agree within 15 %. Here we present a description of the experimental setup, data evaluation procedure and results of the beam measurements.« less

Bunch Length Measurements at the JLab FEL Using Coherent Transition and Synchrotron Radiation

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

Evtushenko, P.; Coleman, J.; Jordan, K.

2006-11-20

The JLab FEL is routinely operated with sub-picosecond bunches. The short bunch length is important for high gain of the FEL. Coherent transition radiation has been used for the bunch length measurements for many years. This diagnostic can be used only in the pulsed beam mode. It is our goal to run the FEL with CW beam and a 74.85 MHz micropulse repetition rate, which, with the 135 pC nominal bunch charge corresponds to the beam average current of 10 mA, Hence it is very desirable to have the possibility of making bunch length measurements when running CW beam withmore » any micropulse frequency. We use a Fourier transform infrared (FTIR) interferometer, which is essentially a Michelson interferometer, to measure the spectrum of the coherent synchrotron radiation generated in the last dipole of the magnetic bunch compressor upstream of the FEL wiggler. This noninvasive diagnostic provides bunch length measurements for CW beam operation at any micropulse frequency. We also compare the measurements made with the help of the FTIR interferometer with data obtained using the Martin-Puplett interferometer. Results of the two diagnostics agree within 15 %. Here we present a description of the experimental setup, data evaluation procedure and results of the beam measurements.« less

High Latitude Precipitating Energy Flux and Joule Heating During Geomagnetic Storms Determined from AMPERE Field-aligned Currents

NASA Astrophysics Data System (ADS)

Robinson, R. M.; Zanetti, L. J.; Anderson, B. J.; Korth, H.; Samara, M.; Michell, R.; Grubbs, G. A., II; Hampton, D. L.; Dropulic, A.

2016-12-01

A high latitude conductivity model based on field-aligned currents measured by the Active Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE) provides the means for complete specification of electric fields and currents at high latitudes. Based on coordinated measurements made by AMPERE and the Poker Flat Incoherent Scatter Radar, the model determines the most likely value of the ionospheric conductance from the direction, magnitude, and magnetic local time of the field-aligned current. A conductance model driven by field-aligned currents ensures spatial and temporal consistency between the calculated electrodynamic parameters. To validate the results, the Pedersen and Hall conductances were used to calculate the energy flux associated with the energetic particle precipitation. When integrated over the entire hemisphere, the total energy flux compares well with the Hemispheric Power Index derived from the OVATION-PRIME model. The conductances were also combined with the field-aligned currents to calculate the self-consistent electric field, which was then used to compute horizontal currents and Joule heating. The magnetic perturbations derived from the currents replicate most of the variations observed in ground-based magnetograms. The model was used to study high latitude particle precipitation, currents, and Joule heating for 24 magnetic storms. In most cases, the total energy input from precipitating particles and Joule heating exhibits a sharply-peaked maximum at the times of local minima in Dst, suggesting a close coupling between the ring current and the high latitude currents driven by the Region 2 field-aligned currents. The rapid increase and decrease of the high latitude energy deposition suggests an explosive transfer of energy from the magnetosphere to the ionosphere just prior to storm recovery.

Evaluation program for secondary spacecraft cells: Acceptance tests of Eagle-Picher 20.0 ampere-hour nickel-cadmium cells with auxiliary electrodes

NASA Technical Reports Server (NTRS)

Christy, D. E.

1972-01-01

A group of 29 cells with capacities ranging from 21.7 to 28.8 ampere-hours were tested. A summary of the results indicates: (1) All cells exceeded the rated capacity on all three capacity checks. (2) Five cells failed to recover to 1.150 volts. (3) During the overcharge tests, 15 of the 29 cells had to be removed from charge before completion of the respective tests due to high pressure.

Derivation of the Biot-Savart Law from Ampere's Law Using the Displacement Current

NASA Astrophysics Data System (ADS)

Buschauer, Robert

2013-12-01

The equation describing the magnetic field due to a single, nonrelativistic charged particle moving at constant velocity is often referred to as the "Biot-Savart law for a point charge." Introductory calculus-based physics books usually state this law without proof.2 Advanced texts often present it either without proof or as a special case of a complicated mathematical formalism.3 Either way, little or no physical insight is provided to the student regarding the underlying physics. This paper presents a novel, basic, and transparent derivation of the Biot-Savart law for a point charge based only on Maxwell's displacement current term in Ampere's law. This derivation can serve many pedagogical purposes. For example, it can be used as lecture material at any academic level to obtain the Biot-Savart law for a point charge from simple principles. It can also serve as a practical example of the important fact that a changing electric flux produces a magnetic field.

Evaluation program for secondary spacecraft cells: Initial evaluation tests of Eagle-Picher Industries, Incorporated 6.0 ampere-hour, nickel-cadmium spacecraft cells for separator material evaluation

NASA Technical Reports Server (NTRS)

Harkness, J. D.

1975-01-01

Several groups of nickel cadmium cells were tested for the durability of their separator materials. The cells were rated at 6.0 ampere-hours, and contained double ceramic seals. Two cells in each group were fitted with pressure gauge assemblies. Results are presented for various brands of separator materials.

Parity Violation in DIS region with SoLID at the upgraded 12 GeV JLab

NASA Astrophysics Data System (ADS)

Tian, Ye; SoLID Collaboration

2017-09-01

In this talk, an overview of PVDIS future experiment by using a Solenoidal Large Intensity Device (SoLID) at Jefferson Lab (JLab) Hall A with the 12 GeV upgrade, along with a brief description of the proposed SoLID spectrometer is discussed. We will obtain data with high statistic and large kinematic coverage for Bjorken 0.3 < x < 0.7 and in the momentum transfer Q2 range 2 - 10 GeV2 by a polarized electron beam scattering on unpolarized deuteron and proton targets. A measurement of PVDIS in deuteron aims to extract fundamental coupling constants C1 q ,C2 q as well as the weak mixing angle sin2θw with a high precision. This measurement can also access QCD physics of searching for charge asymmetry violation in PDF's and higher-twist effects with quark-quark correlations. In addition, the proton target experiment can be a powerful probe of the d / u ratio at high x without any nuclear correction. The designed SoLID spectrometer with its unique feature of high luminosity and large acceptance provides an opportunity to probe physics beyond the Standard Model.

Evaluation program for secondary spacecraft cells: Initial evaluation tests of General Electric Company 12.0 ampere-hour nickel-cadmium spacecraft cells for the international ultraviolet explorer

NASA Technical Reports Server (NTRS)

Harkness, J. D.

1976-01-01

An evaluation test program was conducted to insure that all cells put into the life cycle program are of high quality by the screening of cells found to have electrolyte leakage, internal shorts, low capacity, or inability of any cell to recover its open-circuit voltage above 1.150 volts during the internal short test. The 20 cells were manufactured for the National Aeronautics and Space Administration, Goddard Space Flight Center (GSFC). The cells are from a lot of 175 cells procured for the International Ultraviolet Explorer project. Due to a change in requirements, the project selected to use 6.0 ampere-hour cells. Therefore, the remaining cells of this lot have been placed in storage at GSFC for use on a future GSFC project. All the cells are rated at 12.0 ampere-hours and contain double ceramic seals. Test limits specify those values in which a cell is to be terminated from a particular charge or discharge. Requirements are referred to as normally expected values based on past performance of aerospace nickel cadmium cells with demonstrated life characteristics.

Toroidal ripple transport of beam ions in the mega-ampere spherical tokamak

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

McClements, K. G.; Hole, M. J.

The transport of injected beam ions due to toroidal magnetic field ripple in the mega-ampere spherical tokamak (MAST) is quantified using a full orbit particle tracking code, with collisional slowing-down and pitch-angle scattering by electrons and bulk ions taken into account. It is shown that the level of ripple losses is generally rather low, although it depends sensitively on the major radius of the outer midplane plasma edge; for typical values of this parameter in MAST plasmas, the reduction in beam heating power due specifically to ripple transport is less than 1%, and the ripple contribution to beam ion diffusivitymore » is of the order of 0.1 m{sup 2} s{sup -1} or less. It is concluded that ripple effects make only a small contribution to anomalous transport rates that have been invoked to account for measured neutron rates and plasma stored energies in some MAST discharges. Delayed (non-prompt) losses are shown to occur close to the outer midplane, suggesting that banana-drift diffusion is the most likely cause of the ripple-induced losses.« less

Cooling for SC devices of test cryomodule for ADS Injector II at IMP

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

Wang, L.; Wang, S. Y.; Sun, S.

2014-01-29

The superconducting half-wave resonance cavities connected in series with superconducting solenoids will be applied to the Injector II of the Accelerator Driven Sub-critical System (ADS) to be built at the Modern Physics Institute, China. A test system has been developed for the purpose of performance test of the HWR cavities as well as validating the relevant technique for cooling the cavity and the solenoids together. It mainly comprises a cryogenic valve box (TVB), a test cryomodule (TCM1) and transfer lines. The TCM1 includes one HWR cavity, two superconducting solenoids, one cold BPM and their cooling system. The design of themore » TCM1 cryostat was carried out by the Shanghai Institute of Applied Physics (SINAP), CAS. Both the cavity and the solenoids will work at 4.4 K by bath cooling. The fast cooling down for the cavity from around 100 K to 120 K is required to avoid degrading of the cavity performance. After cool down and before energization, the solenoids should be warmed up to above 10 K and re-cooled down for the purpose of degaussing. The TCM1 can not only be cooled by using the dewar-filling system, but also operated by the refrigerator system. For the purpose of reducing the heat loads to the cold mass at 4 K from room temperature, thermal radiation shields cooled by liquid nitrogen flowing in tubing were employed. This paper presents the design details of cooling circuits and thermal shields of the TCM1 as well as related calculations and analyses.« less

Cooling for SC devices of test cryomodule for ADS Injector II at IMP

NASA Astrophysics Data System (ADS)

Wang, L.; Wang, S. Y.; Sun, S.; Guo, X. L.; Wang, S. H.; Liu, Y. Y.

2014-01-01

The superconducting half-wave resonance cavities connected in series with superconducting solenoids will be applied to the Injector II of the Accelerator Driven Sub-critical System (ADS) to be built at the Modern Physics Institute, China. A test system has been developed for the purpose of performance test of the HWR cavities as well as validating the relevant technique for cooling the cavity and the solenoids together. It mainly comprises a cryogenic valve box (TVB), a test cryomodule (TCM1) and transfer lines. The TCM1 includes one HWR cavity, two superconducting solenoids, one cold BPM and their cooling system. The design of the TCM1 cryostat was carried out by the Shanghai Institute of Applied Physics (SINAP), CAS. Both the cavity and the solenoids will work at 4.4 K by bath cooling. The fast cooling down for the cavity from around 100 K to 120 K is required to avoid degrading of the cavity performance. After cool down and before energization, the solenoids should be warmed up to above 10 K and re-cooled down for the purpose of degaussing. The TCM1 can not only be cooled by using the dewar-filling system, but also operated by the refrigerator system. For the purpose of reducing the heat loads to the cold mass at 4 K from room temperature, thermal radiation shields cooled by liquid nitrogen flowing in tubing were employed. This paper presents the design details of cooling circuits and thermal shields of the TCM1 as well as related calculations and analyses.

Heat Exchanger Can Assembly for Provision of Helium Coolant Streams for Cryomodule Testing below 2K

NASA Astrophysics Data System (ADS)

Smith, E. N.; Eichhorn, R.; Quigley, P.; Sabol, D.; Shore, C.; Widger, D.

2017-02-01

A series of heat exchanger can (HXC) assemblies have been designed, constructed and built to utilize existing 4.2 K liquefaction and compressor capabilities to provide helium gas coolant streams of 80 K, 4.5 K, and liquid from 1.6 to 2.0 K for operating cryomodules containing from one to six superconducting RF cavities built for an energy recovery linear accelerator. Designs for the largest assemblies required up to 100 W of cooling at 1.8 K with precise temperature control, especially during cool-down, and up to 2000 W at 80 K (with a 40 K temperature rise). A novel feature of these assemblies was the use of relatively inexpensive brazed stainless steel plate heat exchangers intended for room-temperature operation with water or oil, but which in practice worked well at cryogenic temperatures. The choice of operating temperatures/pressures were to provide single-phase helium flow for better control of coolant distribution in the 80 K and 4.5 K streams, to take advantage of locally elevated heat capacity near the critical point for the 4.5 K stream, and in the region below 2 K to get the best possible Q from the niobium cavities under test.

Voltage-ampere characteristics of YBCO coated conductor under inhomogeneous oscillating magnetic field

NASA Astrophysics Data System (ADS)

Geng, J.; Shen, B.; Li, C.; Zhang, H.; Matsuda, K.; Li, J.; Zhang, X.; Coombs, T. A.

2016-06-01

Direct current carrying type II superconductors present a dynamic resistance when subjected to an oscillating magnetic field perpendicular to the current direction. If a superconductor is under a homogeneous field with high magnitude, the dynamic resistance value is nearly independent of transport current. Hoffmann and coworkers [Hoffmann et al., IEEE Trans. Appl. Supercond. 21, 1628 (2011)] discovered, however, flux pumping effect when a superconducting tape is under an inhomogeneous field orthogonal to the tape surface generated by rotating magnets. Following their work, we report the whole Voltage-Ampere (V-I) curves of an YBCO coated conductor under permanent magnets rotating with different frequencies and directions. We discovered that the two curves under opposite rotating directions differ from each other constantly when the transport current is less than the critical current, whereas the difference gradually reduces after the transport current exceeds the critical value. We also find that for different field frequencies, the difference between the two curves decreases faster with lower field frequency. The result indicates that the transport loss is dependent on the relative direction of the transport current and field travelling, which is distinct from traditional dynamic resistance model. The work may be instructive for the design of superconducting motors.

Development of multi-ampered D{sup {minus}} source for fusion applications

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

Jacquot, C.; Belchenko, Y.; Bucalossi, J.

1996-07-01

Large current and high current density deuterium negative ion sources are investigated on the MANTIS test bed with the objective of producing several amperes of D{sup {minus}} beams, at an accelerated current density in the range 10{endash}20 mA/cm{sup 2}, for possible application in future neutral beam injectors, e.g. ITER. As a first step, the DRAGON source, which was built by Culham Laboratory was tested on the MANTIS test bed in order to test this large source using only {open_quote}{open_quote}pure volume{close_quote}{close_quote} production of negative ions. The accelerated negative ion current is found to be a strong function of the source operatingmore » pressure and the arc power, and a significant isotopic effect is observed. The maximum accelerated currents are 1.3 A of H{sup {minus}} (3.3 mA/cm{sup 2}) and 0.5 A (1.3 mA/cm{sup 2}) at 110 kW of arc power. Cesium injection from a non conventional dispenser together with an improved extraction system, have significantly improved the D-current. A maximum of 14 mA/cm{sup 2} of D{sup {minus}1} are accelerated at 30 kV, which corresponds potentially, to more than 5 A for a full aperture extraction with an arc power of 140 kW (2250 A of arc current). {copyright} {ital 1996 American Institute of Physics.}« less

Evaluation program for secondary spacecraft cells: Initial evaluation tests of General Electric Company 40.0 ampere-hour nickel-cadmium spacecraft cells for the tracking data relay satellite system

NASA Technical Reports Server (NTRS)

Harkness, J. D.

1978-01-01

Five cells provided by NASA's Goddard Space Flight Center were evaluated at room temperature and pressure (25 C plus or minus 2 C) with discharges at the 2 hour rate. Measurements of the cell containers following test, indicated an average increase of .006 inches at the plate thickness. Average end of charge voltages and pressures, and capacity output in ampere hours were determined. Three cells exceeded the voltage requirements of 1.52 volts during both c/10 charges at 20 C. All cells exceeded the voltage requirement of 1.52 volts during the 0 C overcharge test, although their end charges were below 1.50 volts. The pressure requirement of 65 psia was exceeded by both pressure transducer cells during c/10 charges at 25 C and 20 C and also during the 0 C overcharge test. The cells with pressure transducers reached a pressure of 20 psia before reaching the voltage limit of 1.550 volts during the pressure versus capacity test, and exhibited a pressure decay of 2 psia during the last 30 minutes of the 1 hour open circuit stand. Average capacity was 51.3 ampere hours.

Measured Radiation and Background Levels During Transmission of Megawatt Electron Beams Through Millimeter Apertures

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

Alarcon, Ricardo; Balascuta, S.; Benson, Stephen V.

2013-11-01

We report measurements of photon and neutron radiation levels observed while transmitting a 0.43 MW electron beam through millimeter-sized apertures and during beam-off, but accelerating gradient RF-on, operation. These measurements were conducted at the Free-Electron Laser (FEL) facility of the Jefferson National Accelerator Laboratory (JLab) using a 100 MeV electron beam from an energy-recovery linear accelerator. The beam was directed successively through 6 mm, 4 mm, and 2 mm diameter apertures of length 127 mm in aluminum at a maximum current of 4.3 mA (430 kW beam power). This study was conducted to characterize radiation levels for experiments that needmore » to operate in this environment, such as the proposed DarkLight Experiment. We find that sustained transmission of a 430 kW continuous-wave (CW) beam through a 2 mm aperture is feasible with manageable beam-related backgrounds. We also find that during beam-off, RF-on operation, multipactoring inside the niobium cavities of the accelerator cryomodules is the primary source of ambient radiation when the machine is tuned for 130 MeV operation.« less

Magnetosphere dynamics during the 14 November 2012 storm inferred from TWINS, AMPERE, Van Allen Probes, and BATS-R-US-CRCM

NASA Astrophysics Data System (ADS)

Buzulukova, Natalia; Goldstein, Jerry; Fok, Mei-Ching; Glocer, Alex; Valek, Phil; McComas, David; Korth, Haje; Anderson, Brian

2018-01-01

During the 14 November 2012 geomagnetic storm, the Van Allen Probes spacecraft observed a number of sharp decreases (dropouts) in particle fluxes for ions and electrons of different energies. In this paper, we investigate the global magnetosphere dynamics and magnetosphere-ionosphere (M-I) coupling during the dropout events using multipoint measurements by Van Allen Probes, TWINS, and AMPERE together with the output of the two-way coupled global BATS-R-US-CRCM model. We find different behavior for two pairs of dropouts. For one pair, the same pattern was repeated: (1) weak nightside Region 1 and 2 Birkeland currents before and during the dropout; (2) intensification of Region 2 currents after the dropout; and (3) a particle injection detected by TWINS after the dropout. The model predicted similar behavior of Birkeland currents. TWINS low-altitude emissions demonstrated high variability during these intervals, indicating high geomagnetic activity in the near-Earth tail region. For the second pair of dropouts, the structure of both Birkeland currents and ENA emissions was relatively stable. The model also showed quasi-stationary behavior of Birkeland currents and simulated ENA emissions with gradual ring current buildup. We confirm that the first pair of dropouts was caused by large-scale motions of the OCB (open-closed boundary) during substorm activity. We show the new result that this OCB motion was associated with global changes in Birkeland (M-I coupling) currents and strong modulation of low-altitude ion precipitation. The second pair of dropouts is the result of smaller OCB disturbances not related to magnetospheric substorms. The local observations of the first pair of dropouts result from a global magnetospheric reconfiguration, which is manifested by ion injections and enhanced ion precipitation detected by TWINS and changes in the structure of Birkeland currents detected by AMPERE. This study demonstrates that multipoint measurements along with the

Magnetosphere dynamics during the 14 November 2012 storm inferred from TWINS, AMPERE, Van Allen Probes, and BATS-R-US–CRCM

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

Buzulukova, Natalia; Goldstein, Jerry; Fok, Mei-Ching

During the 14 November 2012 geomagnetic storm, the Van Allen Probes spacecraft observed a number of sharp decreases ("dropouts") in particle fluxes for ions and electrons of different energies. In this paper, we investigate the global magnetosphere dynamics and magnetosphere–ionosphere (M–I) coupling during the dropout events using multipoint measurements by Van Allen Probes, TWINS, and AMPERE together with the output of the two-way coupled global BATS-R-US–CRCM model. We find different behavior for two pairs of dropouts. For one pair, the same pattern was repeated: (1) weak nightside Region 1 and 2 Birkeland currents before and during the dropout; (2) intensificationmore » of Region 2 currents after the dropout; and (3) a particle injection detected by TWINS after the dropout. The model predicted similar behavior of Birkeland currents. TWINS low-altitude emissions demonstrated high variability during these intervals, indicating high geomagnetic activity in the near-Earth tail region. For the second pair of dropouts, the structure of both Birkeland currents and ENA emissions was relatively stable. The model also showed quasi-stationary behavior of Birkeland currents and simulated ENA emissions with gradual ring current buildup. We confirm that the first pair of dropouts was caused by large-scale motions of the OCB (open–closed boundary) during substorm activity. We show the new result that this OCB motion was associated with global changes in Birkeland (M–I coupling) currents and strong modulation of low-altitude ion precipitation. The second pair of dropouts is the result of smaller OCB disturbances not related to magnetospheric substorms. The local observations of the first pair of dropouts result from a global magnetospheric reconfiguration, which is manifested by ion injections and enhanced ion precipitation detected by TWINS and changes in the structure of Birkeland currents detected by AMPERE. This study demonstrates that multipoint measurements

Magnetosphere Dynamics During the 14 November 2012 Storm Inferred from TWINS, AMPERE, Van Allen Probes, and BATS-R-US-CRCM

NASA Technical Reports Server (NTRS)

Buzulukova, Natalia; Goldstein, Jerry; Fok, Mei-Ching; Glocer, Alex; Valek, Phil; McComas, David; Korth, Haje; Anderson, Brian

2018-01-01

During the 14 November 2012 geomagnetic storm, the Van Allen Probes spacecraft observed a number of sharp decreases ('dropouts') in particle fluxes for ions and electrons of different energies. In this paper, we investigate the global magnetosphere dynamics and magnetosphere- ionosphere (M-I) coupling during the dropout events using multipoint measurements by Van Allen Probes, TWINS, and AMPERE together with the output of the two-way coupled global BATS-R-US-CRCM model. We find different behavior for two pairs of dropouts. For one pair, the same pattern was repeated: (1) weak nightside Region 1 and 2 Birkeland currents before and during the dropout; (2) intensification of Region 2 currents after the dropout; and (3) a particle injection detected by TWINS after the dropout. The model predicted similar behavior of Birkeland currents. TWINS low-altitude emissions demonstrated high variability during these intervals, indicating high geomagnetic activity in the near-Earth tail region. For the second pair of dropouts, the structure of both Birkeland currents and ENA emissions was relatively stable. The model also showed quasi-stationary behavior of Birkeland currents and simulated ENA emissions with gradual ring current buildup. We confirm that the first pair of dropouts was caused by large-scale motions of the OCB (open-closed boundary) during substorm activity. We show the new result that this OCB motion was associated with global changes in Birkeland (M-I coupling) currents and strong modulation of low-altitude ion precipitation. The second pair of dropouts is the result of smaller OCB disturbances not related to magnetospheric substorms. The local observations of the first pair of dropouts result from a global magnetospheric reconfiguration, which is manifested by ion injections and enhanced ion precipitation detected by TWINS and changes in the structure of Birkeland currents detected by AMPERE. This study demonstrates that multipoint measurements along with the

Magnetosphere dynamics during the 14 November 2012 storm inferred from TWINS, AMPERE, Van Allen Probes, and BATS-R-US–CRCM

DOE PAGES

Buzulukova, Natalia; Goldstein, Jerry; Fok, Mei-Ching; ...

2018-01-25

During the 14 November 2012 geomagnetic storm, the Van Allen Probes spacecraft observed a number of sharp decreases ("dropouts") in particle fluxes for ions and electrons of different energies. In this paper, we investigate the global magnetosphere dynamics and magnetosphere–ionosphere (M–I) coupling during the dropout events using multipoint measurements by Van Allen Probes, TWINS, and AMPERE together with the output of the two-way coupled global BATS-R-US–CRCM model. We find different behavior for two pairs of dropouts. For one pair, the same pattern was repeated: (1) weak nightside Region 1 and 2 Birkeland currents before and during the dropout; (2) intensificationmore » of Region 2 currents after the dropout; and (3) a particle injection detected by TWINS after the dropout. The model predicted similar behavior of Birkeland currents. TWINS low-altitude emissions demonstrated high variability during these intervals, indicating high geomagnetic activity in the near-Earth tail region. For the second pair of dropouts, the structure of both Birkeland currents and ENA emissions was relatively stable. The model also showed quasi-stationary behavior of Birkeland currents and simulated ENA emissions with gradual ring current buildup. We confirm that the first pair of dropouts was caused by large-scale motions of the OCB (open–closed boundary) during substorm activity. We show the new result that this OCB motion was associated with global changes in Birkeland (M–I coupling) currents and strong modulation of low-altitude ion precipitation. The second pair of dropouts is the result of smaller OCB disturbances not related to magnetospheric substorms. The local observations of the first pair of dropouts result from a global magnetospheric reconfiguration, which is manifested by ion injections and enhanced ion precipitation detected by TWINS and changes in the structure of Birkeland currents detected by AMPERE. This study demonstrates that multipoint measurements

Evaluation program for secondary spacecraft cells: Acceptance test of Eagle-Picher 100 ampere-hour nickel-cadmium cells with auxiliary electrodes

NASA Technical Reports Server (NTRS)

Christy, D. E.

1972-01-01

Tests were conducted on a group of 29 cells for the purpose of removing from the life cycle program all cells found to have electrolyte leakage, internal shorts, low capacity, or inability to recover open circuit voltage above 1.150 volts after the cell short test. The test findings include the following: (1) All the cells exceeded the rated capacity of 103.5 to 119.0 ampere-hours on all three capacity checks. (2) All cells recovered above the 1.150 volt requirement after the cell short test. (3) The cells cannot be overcharged at the c/10 rate without exceeding 1.500 volts after approximately 12 to 13 hours of charge. (4) The resistance value necessary to provide maximum signal power across the auxiliary electrode was found to be 10 ohms. (5) One cell revealed a definite leak at the negative terminal.

The fault monitoring and diagnosis knowledge-based system for space power systems: AMPERES, phase 1

NASA Technical Reports Server (NTRS)

Lee, S. C.

1989-01-01

The objective is to develop a real time fault monitoring and diagnosis knowledge-based system (KBS) for space power systems which can save costly operational manpower and can achieve more reliable space power system operation. The proposed KBS was developed using the Autonomously Managed Power System (AMPS) test facility currently installed at NASA Marshall Space Flight Center (MSFC), but the basic approach taken for this project could be applicable for other space power systems. The proposed KBS is entitled Autonomously Managed Power-System Extendible Real-time Expert System (AMPERES). In Phase 1 the emphasis was put on the design of the overall KBS, the identification of the basic research required, the initial performance of the research, and the development of a prototype KBS. In Phase 2, emphasis is put on the completion of the research initiated in Phase 1, and the enhancement of the prototype KBS developed in Phase 1. This enhancement is intended to achieve a working real time KBS incorporated with the NASA space power system test facilities. Three major research areas were identified and progress was made in each area. These areas are real time data acquisition and its supporting data structure; sensor value validations; development of inference scheme for effective fault monitoring and diagnosis, and its supporting knowledge representation scheme.

Evaluation program for secondary spacecraft cells: Initial evaluation tests of General Electric Company 40.0 ampere hour nickel cadmium spacecraft cells for the tracking data relay satellite system

NASA Technical Reports Server (NTRS)

Hall, S. W.

1980-01-01

Average end of charge voltages and pressures, and capacity output in ampere hours are presented. Test limits specify those values at which a cell is to be terminated from charge or discharge. Requirements are based on past cell performance data. The requirement does not constitute a limit for discontinuance from testing. The nickel cadmium batteries were screened for internal shorts, low capacity, electrolyte leakage, or inability of any cell to recover its open circuit voltage above 1.150 volts during the internal short test.

805 MHz Beta = 0.47 Elliptical Accelerating Structure R & D

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

S. Bricker; C. Compton; W. Hartung

2008-09-22

A 6-cell 805 MHz superconducting cavity for acceleration in the velocity range of about 0.4 to 0.53 times the speed of light was designed. After single-cell prototyping, three 6-cell niobium cavities were fabricated. In vertical RF tests of the 6-cell cavities, the measured quality factors (Q{sub 0}) were between 7 {center_dot} 10{sup 9} and 1.4 {center_dot} 10{sup 10} at the design field (accelerating gradient of 8 to 10 MV/m). A rectangular cryomodule was designed to house 4 cavities per cryomodule. The 4-cavity cryomodule could be used for acceleration of ions in a linear accelerator, with focusing elements between the cryomodules.more » A prototype cryomodule was fabricated to test 2 cavities under realistic operating conditions. Two of the 6-cell cavities were equipped with helium tanks, tuners, and input coupler and installed into the cryomodule. The prototype cryomodule was used to verify alignment, electromagnetic performance, frequency tuning, cryogenic performance, low-level RF control, and control of microphonics.« less

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

Peterson, T. J.; Weisend, II, J. G.

The TESLA collaboration developed a unique variant of SRF cryomodule designs, the chief feature being use of the large, low pressure helium vapor return pipe as the structural support backbone of the cryomodule. Additional innovative features include all cryogenic piping within the cryomodule (no parallel external cryogenic transfer line), long strings of RF cavities within a single cryomodule, and cryomodules connected in series. Several projects, including FLASH and XFEL at DESY, LCLS-II at SLAC, and the ILC technical design have adopted this general design concept. Advantages include saving space by eliminating the external transfer line, relatively tight packing of RFmore » cavities along the beamline due to fewer warm-cold transitions, and potentially lower costs. However, a primary disadvantage is the relative lack of independence for warm-up, replacement, and cool-down of individual cryomodules.« less

Commissioning and operational results of helium refrigeration system at JLab for the 12GeV upgrade

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

Knudsen, Peter N.; Ganni, Venkatarao; Dixon, Kelly D.

The new 4.5 K refrigerator system at the Jefferson Lab (JLab) Central Helium Liquefier (CHL-2) for the 12 GeV upgrade was commissioned in late spring of 2013, following the commissioning of the new compressor system, and has been supporting 12 GeV LINAC commissioning since that time. Six design modes were tested during commissioning, consisting of a maximum capacity, nominal capacity, maximum liquefaction, maximum refrigeration, maximum fill and a stand-by/reduced load condition. The maximum capacity was designed to support a 238 g/s, 30 K and 1.16 bar cold compressor return flow, a 15 g/s, 4.5 K liquefaction load and a 12.6more » kW, 35-55 K shield load. The other modes were selected to ensure proper component sizing and selection to allow the cold box to operate over a wide range of conditions and capacities. The cold box system is comprised of two physically independent cold boxes with interconnecting transfer-lines. The outside (upper) 300-60 K vertical cold box has no turbines and incorporates a liquid nitrogen pre-cooler and 80-K beds. The inside (lower) 60-4.5 K horizontal cold box houses seven turbines that are configured in four expansion stages including one Joule-Thompson expander and a 20-K bed. The helium compression system has five compressors to support three pressure levels in the cold box. This paper will summarize the analysis of the test data obtained over the wide range of operating conditions and capacities which were tested.« less

Superconducting Prototype Cavities for the Spallation Neutron Source (SNS) Project

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

Peter Kneisel; John Brawley; Richard Bundy

2001-06-01

The Spallation Neutron Source project includes a superconducting linac section in the energy range from 192 MeV to 1000 MeV. For this energy range two types of cavities are needed with geometrical beta - values of beta = 0.61 and beta = 0.81. An aggressive cavity prototyping program is being pursued at Jlab, which calls for fabricating and testing of four beta = 0.61 cavities and two beta = 0.81 cavities. Both types consist of six cells made from high purity niobium and feature one HOM coupler of the TESLA type on each beam pipe and a port for amore » high power coaxial input coupler. Three of the four beta = 0.61 cavities will be used for a cryomodule test at the end of the year 2001. At this time two cavities of each type have been fabricated and the first tests on the beta = 0.61 cavity exceeded the design values for gradient and Q - value: Eacc = 10.3 MV/m and Q = 6.5 x 10{sup 9} at 2.1K. This paper will describe the cavity design with respect to electrical and mechanical features, the fabrication efforts and the results obtained with the different cavities existing at the time of the conference.« less

Magnetic Materials Characterization and Modeling for the Enhanced Design of Magnetic Shielding of Cryomodules in Particle Accelerators

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

Sah, Sanjay

Particle accelerators produce beams of high-energy particles, which are used for both fundamental and applied scientific research and are critical to the development of accelerator driven sub-critical reactor systems. An effective magnetic shield is very important to achieve higher quality factor (Qo) of the cryomodule of a particle accelerator. The allowed value of field inside the cavity due to all external fields (particularly the Earth’s magnetic field) is ~15 mG or less. The goal of this PhD dissertation is to comprehensively study the magnetic properties of commonly used magnetic shielding materials at both cryogenic and room temperatures. This knowledge canmore » be used for the enhanced design of magnetic shields of cryomodes (CM) in particle accelerators. To this end, we first studied the temperature dependent magnetization behavior (M-H curves) of Amumetal and A4K under different annealing and deformation conditions. This characterized the effect of stress or deformation induced during the manufacturing processes and subsequent restoration of high permeability with appropriate heat treatment. Next, an energy based stochastic model for temperature dependent anhysteretic magnetization behavior of ferromagnetic materials was proposed and benchmarked against experimental data. We show that this model is able to simulate and explain the magnetic behavior of as rolled, deformed and annealed amumetal and A4K over a large range of temperatures. The experimental results for permeability are then used in a finite element model (FEM) in COMSOL to evaluate the shielding effectiveness of multiple shield designs at room temperature as well as cryogenic temperature. This work could serve as a guideline for future design, development and fabrication of magnetic shields of CMs.« less

Superconducting Prototype Cavities for the Spallation Neutron Source (SNS) Project

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

G. Ciovati, P. Kneisel , J. Brawley, R. Bundy, I. Campisi, K. Davis; K. Macha; D. Machie

2001-09-01

The Spallation Neutron Source project includes a superconducting linac section in the energy range from 192 MeV to 1000 MeV, operating at a frequency of 805 MHz at 2.1 K. For this energy range two types of cavities are needed with geometrical beta - values of beta= 0.61 and beta= 0.81. An aggressive cavity prototyping program is being pursued at Jlab, which calls for fabricating and testing of four beta= 0.61 cavities and two beta= 0.81 cavities. Both types consist of six cells made from high purity niobium and feature one HOM coupler on each beam pipe and a portmore » for a high power coaxial input coupler. Three of the four beta= 0.61 cavities will be used for a cryomodule test in early 2002. At this time four medium beta cavities and one high beta cavity have been completed at JLab. The first tests on the beta=0.61 cavity and the beta= 0.81 exceeded the design values for gradient and Q - value: E{sub acc} = 1 0.3 MV/m and Q = 5 x 10{sup 9} at 2.1K for beta= 0.61 and E{sub acc} = 12.3 MV/m and Q = 5 x 10{sup 9} at 2.1K for beta= 0.81. One of the medium beta cavities has been equipped with an integrated helium vessel and measurements of the static and dynamic Lorentz force detuning will be done and compared to the ''bare'' cavities. In addition two single cell cavities have been fabricated, equipped with welded-on HOM couplers. They are being used to evaluate the HOM couplers with respect to multipacting, fundamental mode rejection and HOM damping as far as possible in a single cell. This paper will describe the cavity design with respect to electrical and mechanical features, the fabrication efforts and the results obtained with the different cavities existing at the time of this workshop.« less

Measurements of turbulence and fossil turbulence near ampere seamount

NASA Astrophysics Data System (ADS)

Gibson, Carl H.; Nabatov, Valeriy; Ozmidov, Rostislav

1993-10-01

Measurements of temperature and velocity microstructure near and downstream of a shallow seamount are used to compare fossil turbulence versus non-fossil turbulence models for the evolution of turbulence microstructure patches in the stratified ocean. According to non-fossil oceanic turbulence models, all overturn length scales LT of the microstructure grow and collapse in constant proportion to each other and to the turbulence energy (Oboukov) scale LO and the inertial buoyancy (Ozmidov) scale L R≡(ɛ/N 3) 1/2 of the patches; that is, with LTrms ≈1.2 LR and viscous dissipation rate ɛ ≈ ɛ 0∗. According to the Gibson fossil turbulence model, all microstructure originates from completely active turbulence with ɛ ⩾ ɛ 0 ≈ 3L T2N 3(≈ 28ɛ 0∗) and L T/√6 ≈ L Trms, but this rapidly decays into a more persistent active-fossil state with ɛ0⩾ ɛ⩾ ɛF ≈ 30 vN2, where N is the buoyancy frequency and v is the kinematic viscosity and, without further energy supply, finally reaches a completely fossil turbulence hydrodynamic state of internal wave motions, with ɛ ⩽ ɛF. The last turbulence eddies, with ɛ ≈ ɛF, vanish at a buoyant-inertial-viscous (fossil Kolmogorov) scale LKF that is much smaller than the remnant overturn scales LT for large ɛ0/ ɛF ratios. These density, temperature, and salinity overturns with LT ≈ 0.6 LR0 ≫ 0.6 LR persist as turbulence fossils (by retaining the memory of ɛo) and collapse very slowly. In the near wake below the summit depth of Ampere seamount, a much larger proportion of completely active turbulence patches was found than is usually found in the ocean interior away from sources. Dissipation rates ɛ and turbulence activity coefficients A T ≡ (ɛ/ɛ 0) 1/2 of microstructure patches were found to decrease downstream, suggesting that the active turbulence indicated by the patches with AT ⩾ 1 was caused by the presence of the seamount as a turbulence source. Therefore, the turbulence and mixing

Linear beam dynamics and ampere class superconducting RF cavities at RHIC

NASA Astrophysics Data System (ADS)

Calaga, Rama R.

The Relativistic Heavy Ion Collider (RHIC) is a hadron collider designed to collide a range of ions from protons to gold. RHIC operations began in 2000 and has successfully completed five physics runs with several species including gold, deuteron, copper, and polarized protons. Linear optics and coupling are fundamental issues affecting the collider performance. Measurement and correction of optics and coupling are important to maximize the luminosity and sustain stable operation. A numerical approach, first developed at SLAC, was implemented to measure linear optics from coherent betatron oscillations generated by ac dipoles and recorded at multiple beam position monitors (BPMs) distributed around the collider. The approach is extended to a fully coupled 2D case and equivalence relationships between Hamiltonian and matrix formalisms are derived. Detailed measurements of the transverse coupling terms are carried out at RHIC and correction strategies are applied to compensate coupling both locally and globally. A statistical approach to determine BPM reliability and performance over the past three runs and future improvements also discussed. Aiming at a ten-fold increase in the average heavy-ion luminosity, electron cooling is the enabling technology for the next luminosity upgrade (RHIC II). Cooling gold ion beams at 100 GeV/nucleon requires an electron beam of approximately 54 MeV and a high average current in the range of 50-200 mA. All existing e-Coolers are based on low energy DC accelerators. The only viable option to generate high current, high energy, low emittance CW electron beam is through a superconducting energy-recovery linac (SC-ERL). In this option, an electron beam from a superconducting injector gun is accelerated using a high gradient (˜ 20 MV/m) superconducting RF (SRF) cavity. The electrons are returned back to the cavity with a 180° phase shift to recover the energy back into the cavity before being dumped. A design and development of a half-cell electron gun and a five-cell SRF linac cavity are presented. Several RF and beam dynamics issues ultimately resulting in an optimum cavity design are discussed in detail.

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

Kashikhin, V.; Cheban, S.; DiMarco, J.

New LCLS-II Linear Superconducting Accelerator Cry-omodules are under construction at Fermilab. Installed in-side each SCRF Cryomodule is a superconducting magnet package to focus and steer an electron beam. The magnet package is an iron dominated configuration with conduc-tively cooled racetrack-type quadrupole and dipole coils. For easier installation the magnet can be split in the vertical plane. Initially the magnet was tested in a liquid helium bath, and high precision magnetic field measurements were performed. The first (prototype) Cryomodule with the magnet inside was built and successfully tested at Fermilab test facility. In this paper the magnet package is discussed, themore » Cryomodule magnet test results and current leads con-duction cooling performance are presented. So far magnets in nine Cryomodules were successfully tested at Fermilab.« less

Evaluation program for secondary spacecraft cells: Acceptance tests of Eagle-Picher 12.0 ampere-hour nickel-cadmium cells with auxiliary electrodes

NASA Technical Reports Server (NTRS)

Christy, D. E.

1971-01-01

An acceptance test program was conducted on 24 cells to insure that all cells put into the life cycle program were of high quality by the removal of cells found to have electrolyte leakage, internal shorts, low capacity, or inability of any cell to recover its open circuit voltage above 1.150 volts after the cell short test. The cells were rated at 12.0 ampere-hours and equipped with auxiliary electrodes. Test results were: (1) The capacity of the 24 cells ranged from 14.6 to 16.8 ah. All the cells exceeded the rated capacity on all three capacity checks. (2) One cell failed to recover to 1.150 volts after the cell short test. (3) During the overcharge tests, all cells but one failed the test at the c/10 rate after the first minute. (4) A special resistance test was conducted on the auxiliary electrodes of these cells to establish the resistance value necessary which would provide maximum signal power across the auxiliary electrode. The resistance value established was 10 ohms. (5) No electrolyte leakage was observed.

Progress update on cryogenic system for ARIEL E-linac at TRIUMF

NASA Astrophysics Data System (ADS)

Koveshnikov, A.; Bylinskii, I.; Hodgson, G.; Yosifov, D.

2014-01-01

TRIUMF is involved in a major upgrade. The Advanced Rare IsotopeE Laboratory (ARIEL) has become a fully funded project in July 2010. A 10 mA 50 MeV SRF electron linac (e-linac) operating CW at 1.3 GHz is the key component of this initiative. This machine will serve as a second independent photo-fission driver for Rare Isotope Beams (RIB) production at TRIUMF's Isotope Separator and Accelerator (ISAC) facility. The cryogens delivery system requirements are driven by the electron accelerator cryomodule design [1, 2]. Since commencement of the project in 2010 the cryogenic system of e-linac has moved from the conceptual design phase into engineering design and procurement stage. The present document summarizes the progress in cryogenic system development and construction. Current status of e-linac cryogenic system including details of LN2 storage and delivery systems, and helium subatmospheric (SA) system is presented. The first phase of e-linac consisting of two cryomodules, cryogens storage, delivery, and distribution systems, and a 600 W class liquid helium cryoplant is scheduled for installation and commissioning by year 2014.

PIP-II Cryogenic System and the Evolution of Superfluid Helium Cryogenic Plant Specifications

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

Chakravarty, Anindya; Rane, Tejas; Klebaner, Arkadiy

2017-01-01

PIP-II cryogenic system: Superfluid Helium Cryogenic Plant (SHCP) and Cryogenic Distribution System (CDS) connecting the SHCP and the SC Linac (25 cryomodules) PIP-II Cryogenic System Static and dynamic heat loads for the SC Linac and static load of CDS listed out Simulation study carried out to compute SHe flow requirements for each cryomodule Comparison between the flow requirements of the cryomodules for the CW and pulsed modes of operation presented From computed heat load and pressure drop values, SHCP basic specifications evolved.

[Simultaneous analysis of trehalose, glucose and maltose in biotransformation samples by high performance anion exchange chromatography with pulsed ampere detection].

PubMed

Xu, Ying; Zang, Ying; Jiang, Ting; Zheng, Zhaojuan; Quyang, Jia

2014-12-01

An analytical method for the determination of trehalose, maltose, and glucose in biotransformation samples was developed by using high performance anion exchange chromatography coupled with pulsed ampere detection (HPAEC-PAD). The analysis was performed on a CarboPac™ 10 column (250 mm x 2 mm) with the gradient elution of NaOH-NaAc as the mobile phase. The column temperature was set at 30 °C, the flow rate was 0. 30 mL/min. The results showed that trehalose, maltose, and glucose in biotransformation system were completely separated and determined in 15 min. The linear ranges and the working curves were determined by using standard samples. The correlation coefficients of three kinds of carbohydrates were over 0. 9998 . The detection limits (LODs) were 0. 010 - 0. 100 mg/L. Under the optimized separation conditions, the recoveries of saccharides in the transformation system at three different spiked levels ranged from 89. 4% to 103. 2%. In biotransformation system, 50 IU trehalose synthase were added into 200 g/L maltose for reaction of 8 h at 37 °C, pH 8. 0. Under the above conditions, the concentration of trehalose in biotransformation sample was 101. 084 g/L, and the conversion rate of trehalose reached 50. 5%. The method can be applied to determine the composition in the transformation system with the advantages of simplicity and convenience.

Cryomdoule Test Stand Reduced-Magnetic Support Design at Fermilab

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

McGee, Mike; Chandrasekaran, Saravan Kumar; Crawford, Anthony

2016-06-01

In a partnership with SLAC National Accelerator Laboratory (SLAC) and Jefferson Lab, Fermilab will assemble and test 17 of the 35 total 1.3 GHz cryomodules for the Linac Coherent Light Source II (LCLS-II) Project. These devices will be tested at Fermilab's Cryomodule Test Facility (CMTF) within the Cryomodule Test Stand (CMTS-1) cave. The problem of magnetic pollution became one of major issues during design stage of the LCLS-II cryomodule as the average quality factor of the accelerating cavities is specified to be 2.7 x 10¹⁰. One of the possible ways to mitigate the effect of stray magnetic fields and tomore » keep it below the goal of 5 mGauss involves the application of low permeable materials. Initial permeability and magnetic measurement studies regarding the use of 316L stainless steel material indicated that cold work (machining) and heat affected zones from welding would be acceptable.« less

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

McKisson, John

The source code for the Java Data Acquisition suite provides interfaces to the JLab built USB FPGA ADC across a LAN network. Each jDaq node provides ListMode data from JLab built detector systems and readouts.

Plasma Radiation Source on the Basis of the Gas Puff with Outer Plasma Shell in the Circuit of a Mega-Ampere Load Current Doubler

NASA Astrophysics Data System (ADS)

Kokshenev, V. A.; Labetsky, A. Yu.; Shishlov, A. V.; Kurmaev, N. E.; Fursov, F. I.; Cherdizov, R. K.

2017-12-01

Characteristics of Z-pinch plasma radiation in the form of a double shell neon gas puff with outer plasma shell are investigated in the microsecond implosion mode. Experiments are performed using a GIT-12 mega-joule generator with load current doubler having a ferromagnetic core at implosion currents up to 5 MA. Conditions for matching of the nonlinear load with the mega-ampere current multiplier circuit are determined. The load parameters (plasma shell characteristics and mass and geometry of gas puff shells) are optimized on the energy supplied to the gas puff and n energy characteristics of radiation. It is established that the best modes of K-shell radiation in neon are realized for such radial distribution of the gas-puff material at which the compression velocity of the shell is close to a constant and amounts to 27-30 cm/μs. In these modes, up to 40% of energy supplied to the gas puff is converted into K-shell radiation. The reasons limiting the efficiency of the radiation source with increasing implosion current are analyzed. A modernized version of the energy supply from the current doubler to the Z-pinch is proposed.

SNS proton power upgrade

NASA Astrophysics Data System (ADS)

Howell, M.; DeGraff, B.; Galambos, J.; Kim, S.-H.

2017-12-01

The Spallation Neutron Source (SNS) at Oak Ridge National Laboratory (ORNL) is preparing for the Proton Power Upgrade (PPU) project to increase the output energy of the accelerator from 1.0 GeV to 1.3 GeV. As part of this project with the combination of increasing the output energy and beam current, the beam power capability will be doubled from 1.4MW to 2.8MW. In this project, seven new high beta cryomodules housing 28 superconducting niobium cavities will be added to the LINAC tunnel. Lessons learned from over ten years of operation will be incorporated into the new cryomodule and cavity design. The design and the fabrication of these cryomodules and how these will be integrated into the existing accelerator will be detailed in this paper.

Press Release | News

Science.gov Websites

Chicagoland area. Fermilab delivers first cryomodule for ultrapowerful X-ray laser at SLAC January 19, 2018 The first cryomodule for SLAC's LCLS-II X-ray laser departed Fermilab on Jan. 16. Photo: Reidar Hahn A , which will be the nation's only X-ray free-electron laser facility. 1 2 3 ... 40 » Go Fermilab news

ARIEL E-linac Cryogenic System: Commissioning and First Operational Experience

NASA Astrophysics Data System (ADS)

Koveshnikov, A.; Bylinskii, I.; Hodgson, G.; Kishi, D.; Laxdal, R.; Ma, Y.; Nagimov, R.; Yosifov, D.

2015-12-01

The Advanced Rare IsotopE Laboratory (ARIEL) is a major expansion of the Isotope Separator and Accelerator (ISAC) facility at TRIUMF. A key part of the ARIEL project is a 10 mA 50 MeV continuous-wave superconducting radiofrequency (SRF) electron linear accelerator (e-linac). The 1.3 GHz SRF cavities are operated at 2 K. HELIAL LL helium liquefier by Air Liquide Advanced Technologies (ALAT) with a tuneable liquid helium (LHe) production was installed and commissioned in Q4’2013 [1]. It provides 4 K liquid helium to one injector and one accelerator cryomodules that were installed and tested in 2014. The 4 K to 2 K liquid helium transition is achieved on-board of each cryomodule. The cryoplant, LHe and LN2 distributions, sub-atmospheric (S/A) system and cryomodules were successfully commissioned and integrated into the e-linac cryogenic system. Required pressure regulation for both 4 K cryoplant in the Dewar and 2 K with the S/A system was achieved under simulated load. Final integration tests confirmed overall stable performance of the cryogenic system with two cryomodules installed. The paper presents details of the cryogenic system commissioning tests as well as highlights of the initial operational experience.

Upgrade of the cryogenic CERN RF test facility

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

Pirotte, O.; Benda, V.; Brunner, O.

2014-01-29

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 RFmore » 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.« less

PIP-II Cryogenic System and the evolution of Superfluid Helium Cryogenic Plant Specifications

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

Chakravarty, Anindya; Rane, Tejas; Klebaner, Arkadiy

2017-07-06

The PIP-II cryogenic system consists of a Superfluid Helium Cryogenic Plant (SHCP) and a Cryogenic Distribution System (CDS) connecting the SHCP to the Superconducting (SC) Linac consisting of 25 cryomodules. The dynamic heat load of the SC cavities for continuous wave (CW) as well as pulsed mode of operation has been listed out. The static heat loads of the cavities along with the CDS have also been discussed. Simulation study has been carried out to compute the supercritical helium (SHe) flow requirements for each cryomodule. Comparison between the flow requirements of the cryomodules for the CW and pulsed modes ofmore » operation have also been made. From the total computed heat load and pressure drop values in the CDS, the basic specifications for the SHCP, required for cooling the SC Linac, have evolved.« less

Social Class Dialogues and the Fostering of Class Consciousness

ERIC Educational Resources Information Center

Madden, Meredith

2015-01-01

How do critical pedagogies promote undergraduate students' awareness of social class, social class identity, and social class inequalities in education? How do undergraduate students experience class consciousness-raising in the intergroup dialogue classroom? This qualitative study explores undergraduate students' class consciousness-raising in an…

High Resolution Λ Hypernuclear Spectroscopy with Electron Beams

NASA Astrophysics Data System (ADS)

Gogami, T.; Achenbach, P.; Ahmidouch, A.; Albayrak, I.; Androic, D.; Asaturyan, A.; Asaturyan, R.; Ates, O.; Baturin, P.; Badui, R.; Boeglin, W.; Bono, J.; Brash, E.; Carter, P.; Chen, C.; Chiba, A.; Christy, E.; Danagoulian, S.; De Leo, R.; Doi, D.; Elaasar, M.; Ent, R.; Fujii, Y.; Fujita, M.; Furic, M.; Gabrielyan, M.; Gan, L.; Garibaldi, F.; Gaskell, D.; Gasparian, A.; Hashimoto, O.; Horn, T.; Hu, B.; Hungerford, Ed. V.; Jones, M.; Kanda, H.; Kaneta, M.; Kato, S.; Kawai, M.; Kawama, D.; Khanal, H.; Kohl, M.; Liyanage, A.; Luo, W.; Maeda, K.; Margaryan, A.; Markowitz, P.; Maruta, T.; Matsumura, A.; Maxwell, V.; Mkrtchyan, A.; Mkrtchyan, H.; Nagao, S.; Nakamura, S. N.; Narayan, A.; Neville, C.; Niculescu, G.; Niculescu, M. I.; Nunez, A.; Nuruzzaman; Okayasu, Y.; Petkovic, T.; Pochodzalla, J.; Qiu, X.; Reinhold, J.; Rodriguez, V. M.; Samanta, C.; Sawatzky, B.; Seva, T.; Shichijo, A.; Tadevosyan, V.; Tang, L.; Taniya, N.; Tsukada, K.; Veilleux, M.; Vulcan, W.; Wesselmann, F. R.; Wood, S. A.; Yamamoto, T.; Ya, L.; Ye, Z.; Yokota, K.; Yuan, L.; Zhamkochyan, S.; Zhu, L.

JLab E05-115 which is an experiment for Λ hypernuclear spectroscopy with electron beams was carried out at Jefferson Lab (JLab) in 2009. In the experiment, Λ 7He, Λ 9Li, Λ 10Be, Λ 12B and Λ 52V were measured by new magnetic spectrometer systems (SPL+HES+HKS) which were necessary for spectroscopy with high energy resolution of sub-MeV (FWHM). This is the first attempt to measure a Λ hypernucleus with up to medium-heavy mass region by the (e,e' K + ) reaction, overcoming high rate and high multiplicity conditions due to electromagnetic background particles. An overview of the hypernuclear experiments at JLab Hall-C and preliminary binding energy spectrum of Λ 10Be are shown.

Describing three-class task performance: three-class linear discriminant analysis and three-class ROC analysis

NASA Astrophysics Data System (ADS)

He, Xin; Frey, Eric C.

2007-03-01

Binary ROC analysis has solid decision-theoretic foundations and a close relationship to linear discriminant analysis (LDA). In particular, for the case of Gaussian equal covariance input data, the area under the ROC curve (AUC) value has a direct relationship to the Hotelling trace. Many attempts have been made to extend binary classification methods to multi-class. For example, Fukunaga extended binary LDA to obtain multi-class LDA, which uses the multi-class Hotelling trace as a figure-of-merit, and we have previously developed a three-class ROC analysis method. This work explores the relationship between conventional multi-class LDA and three-class ROC analysis. First, we developed a linear observer, the three-class Hotelling observer (3-HO). For Gaussian equal covariance data, the 3- HO provides equivalent performance to the three-class ideal observer and, under less strict conditions, maximizes the signal to noise ratio for classification of all pairs of the three classes simultaneously. The 3-HO templates are not the eigenvectors obtained from multi-class LDA. Second, we show that the three-class Hotelling trace, which is the figureof- merit in the conventional three-class extension of LDA, has significant limitations. Third, we demonstrate that, under certain conditions, there is a linear relationship between the eigenvectors obtained from multi-class LDA and 3-HO templates. We conclude that the 3-HO based on decision theory has advantages both in its decision theoretic background and in the usefulness of its figure-of-merit. Additionally, there exists the possibility of interpreting the two linear features extracted by the conventional extension of LDA from a decision theoretic point of view.

Social affiliation in same-class and cross-class interactions.

PubMed

Côté, Stéphane; Kraus, Michael W; Carpenter, Nichelle C; Piff, Paul K; Beermann, Ursula; Keltner, Dacher

2017-02-01

Historically high levels of economic inequality likely have important consequences for relationships between people of the same and different social class backgrounds. Here, we test the prediction that social affiliation among same-class partners is stronger at the extremes of the class spectrum, given that these groups are highly distinctive and most separated from others by institutional and economic forces. An internal meta-analysis of 4 studies (N = 723) provided support for this hypothesis. Participant and partner social class were interactively, rather than additively, associated with social affiliation, indexed by affiliative behaviors and emotions during structured laboratory interactions and in daily life. Further, response surface analyses revealed that paired upper or lower class partners generally affiliated more than average-class pairs. Analyses with separate class indices suggested that these patterns are driven more by parental income and subjective social class than by parental education. The findings illuminate the dynamics of same- and cross-class interactions, revealing that not all same-class interactions feature the same degree of affiliation. They also reveal the importance of studying social class from an intergroup perspective. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

A Novel Class of Helical Nanostructures: Paradigms for their Design and Synthesis Using Imprint Lithography and Carbon Nanotubes

NASA Astrophysics Data System (ADS)

Smalling, David

2006-03-01

This research focuses on the use of solenoid-like configurations which are both microscopic and macroscopic, to make energy conversions between electrical energy and other forms. Numerous conceptual models are to be evaluated for the construction of an environment in which a charged particle could be allowed travel along a helical path of extremely small pitch and comparatively large large radius. The two main types of solenoid designs discussed, are lithographically synthesized solenoids and coiled carbon nano tube solenoids. For future identification the family of structures described will be referred to as Zeta (ζ) Structures. In the case of a ζ solenoid, the objective would be to create a solenoid whose general structure is macroscopic but comprises a conductive trace which is on the nano-scale, In the case of such a solenoid the current flowing I and the magnetic flux B would be related approximately by B 1.256x10^3I. Such a situation gives rise to a very fascinating relationship between B and I. This means that if a current of say 1 ampere was made to flow through the solenoid, a magnetic flux of 1250 Tesla would be generated. The defining characteristic of ζ structures is their overall macroscopic dimensions which comprise high level nano-scale repetition. This research discusses theoretical propositions for the development of a class sub micron structures defined by a unique helical foundation, to be used for the generation of magnetic fields.

Exploring social class: voices of inter-class couples.

PubMed

McDowell, Teresa; Melendez-Rhodes, Tatiana; Althusius, Erin; Hergic, Sara; Sleeman, Gillian; Ton, Nicky Kieu My; Zimpfer-Bak, A J

2013-01-01

Social class is not often discussed or examined in-depth in couple and family therapy research and literature even though social class shapes familial relationships and is considered an important variable in marital satisfaction. In this qualitative study, we explored the perceptions of eight couples who made lasting commitments across class lines by asking them about the impact of their social class backgrounds on their relationships. Three categories of themes emerged including: (a) differences and similarities in values and attitudes toward education, work, money, and class awareness/classism, (b) relationship issues involving families of origin, friends, and class-based couple conflict, and (c) differences in economic resources, social capital and privileges/opportunities. Implications for assessment and treatment of couples are included. © 2012 American Association for Marriage and Family Therapy.

MFV-class: a multi-faceted visualization tool of object classes.

PubMed

Zhang, Zhi-meng; Pan, Yun-he; Zhuang, Yue-ting

2004-11-01

Classes are key software components in an object-oriented software system. In many industrial OO software systems, there are some classes that have complicated structure and relationships. So in the processes of software maintenance, testing, software reengineering, software reuse and software restructure, it is a challenge for software engineers to understand these classes thoroughly. This paper proposes a class comprehension model based on constructivist learning theory, and implements a software visualization tool (MFV-Class) to help in the comprehension of a class. The tool provides multiple views of class to uncover manifold facets of class contents. It enables visualizing three object-oriented metrics of classes to help users focus on the understanding process. A case study was conducted to evaluate our approach and the toolkit.

Analytical design equations for self-tuned Class-E power amplifier.

PubMed

Hu, Zhe; Troyk, Philip

2011-01-01

For many emerging neural prosthesis designs that are powered by inductive coupling, their small physical size requires large current in the extracorporeal transmitter coil, and the Class-E power amplifier topology is often used for the transmitter design. Tuning of Class-E circuits for efficient operation is difficult and a self-tuned circuit can facilitate the tuning. The coil current is sensed and used to tune the switching of the transistor switch in the Class-E circuit in order to maintain its high-efficiency operation. Although mathematically complex, the analysis and design procedure for the self-tuned Class-E circuit can be simplified due to the current feedback control, which makes the phase angle between the switching pulse and the coil current predetermined. In this paper explicit analytical design equations are derived and a detailed design procedure is presented and compared with the conventional Class-E design approaches.

A dual-mode highly efficient class-E stimulator controlled by a low-Q class-E power amplifier through duty cycle.

PubMed

Chiu, Hung-Wei; Lu, Chien-Chi; Chuang, Jia-min; Lin, Wei-Tso; Lin, Chii-Wann; Kao, Ming-Chien; Lin, Mu-Lien

2013-06-01

This paper presents the design flow of two high-efficiency class-E amplifiers for the implantable electrical stimulation system. The implantable stimulator is a high-Q class-E driver that delivers a sine-wave pulsed radiofrequency (PRF) stimulation, which was verified to have a superior efficacy in pain relief to a square wave. The proposed duty-cycle-controlled class-E PRF driver designed with a high-Q factor has two operational modes that are able to achieve 100% DC-AC conversion, and involves only one switched series inductor and an unchanged parallel capacitor. The measured output amplitude under low-voltage (LV) mode using a 22% duty cycle was 0.98 V with 91% efficiency, and under high-voltage (HV) mode using a 47% duty cycle was 2.95 V with 92% efficiency. These modes were inductively controlled by a duty-cycle detector, which can detect the duty-cycle modulated signal generated from the external complementary low-Q class-E power amplifier (PA). The design methodology of the low-Q inductive interface for a non-50% duty cycle is presented. The experimental results exhibits that the 1.5-V PA that consumes DC power of 14.21 mW was able to deliver a 2.9-V sine wave to a 500 Ω load. The optimal 60% drain efficiency of the system from the PA to the load was obtained at a 10-mm coupling distance.

47 CFR 73.25 - Clear channels; Class A, Class B and Class D stations.

Code of Federal Regulations, 2012 CFR

2012-10-01

..., 770, 780, 820, 830, 840, 870, 880, 890, 1020, 1030, 1040, 1100, 1120, 1160, 1180, 1200, and 1210 kHz..., 1530, 1540, 1550, and 1560 kHz. Note: Until superseded by a new agreement, protection of the Bahama Islands shall be in accordance with NARBA. Accordingly, a Class A, Class B or Class D station on 1540 kHz...

47 CFR 73.25 - Clear channels; Class A, Class B and Class D stations.

Code of Federal Regulations, 2010 CFR

2010-10-01

..., 770, 780, 820, 830, 840, 870, 880, 890, 1020, 1030, 1040, 1100, 1120, 1160, 1180, 1200, and 1210 kHz..., 1530, 1540, 1550, and 1560 kHz. Note: Until superseded by a new agreement, protection of the Bahama Islands shall be in accordance with NARBA. Accordingly, a Class A, Class B or Class D station on 1540 kHz...

47 CFR 73.25 - Clear channels; Class A, Class B and Class D stations.

Code of Federal Regulations, 2014 CFR

2014-10-01

..., 770, 780, 820, 830, 840, 870, 880, 890, 1020, 1030, 1040, 1100, 1120, 1160, 1180, 1200, and 1210 kHz..., 1530, 1540, 1550, and 1560 kHz. Note: Until superseded by a new agreement, protection of the Bahama Islands shall be in accordance with NARBA. Accordingly, a Class A, Class B or Class D station on 1540 kHz...

47 CFR 73.25 - Clear channels; Class A, Class B and Class D stations.

Code of Federal Regulations, 2011 CFR

2011-10-01

..., 770, 780, 820, 830, 840, 870, 880, 890, 1020, 1030, 1040, 1100, 1120, 1160, 1180, 1200, and 1210 kHz..., 1530, 1540, 1550, and 1560 kHz. Note: Until superseded by a new agreement, protection of the Bahama Islands shall be in accordance with NARBA. Accordingly, a Class A, Class B or Class D station on 1540 kHz...

47 CFR 73.25 - Clear channels; Class A, Class B and Class D stations.

Code of Federal Regulations, 2013 CFR

2013-10-01

..., 770, 780, 820, 830, 840, 870, 880, 890, 1020, 1030, 1040, 1100, 1120, 1160, 1180, 1200, and 1210 kHz..., 1530, 1540, 1550, and 1560 kHz. Note: Until superseded by a new agreement, protection of the Bahama Islands shall be in accordance with NARBA. Accordingly, a Class A, Class B or Class D station on 1540 kHz...

30 CFR 19.7 - Protection against explosion hazard.

Code of Federal Regulations, 2010 CFR

2010-07-01

..., EVALUATION, AND APPROVAL OF MINING PRODUCTS ELECTRIC CAP LAMPS § 19.7 Protection against explosion hazard. Unless properly designed, electric cap lamps may present two sources of probable explosion hazards... of cap lamp batteries: 100 amperes for a 4-volt battery; 75 amperes for a 6-volt battery; 50 amperes...

24 CFR 3280.804 - Disconnecting means and branch-circuit protective equipment.

Code of Federal Regulations, 2011 CFR

2011-04-01

... etched, metal-stamped or embossed brass, stainless steel, anodized or alclad aluminum not less than 0.020.../240 Volt, 3-Pole, 4-Wire, 60 Hertz, ____ Ampere Supply. The correct ampere rating shall be marked on....804(j) shall read: “This connection for 120/240 volt, 3 pole, 3 wire, 60 Hertz, ____ Ampere Supply...

Teachers in Class

ERIC Educational Resources Information Center

Van Galen, Jane

2008-01-01

In this article, I argue for a closer read of the daily "class work" of teachers, as posited by Reay, 1998. In developing exploratory class portraits of four teachers who occupy distinctive social positions (two from working-class homes now teaching upper-middle-class children and two from upper-middle-class homes now teaching poor children), I…

Class Construction: White Working-Class Student Identity in the New Millennium

ERIC Educational Resources Information Center

Freie, Carrie

2007-01-01

"Class Construction" explores class, racial, and gender identity construction among white, working-class students. Delving into River City High School, Freie asks what happens to the adolescent children of working-class families when economic changes such as globalization and technological advancements have altered the face of working-class jobs.…

47 CFR 73.6017 - Digital Class A TV station protection of Class A TV and digital Class A TV stations.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 47 Telecommunication 4 2011-10-01 2011-10-01 false Digital Class A TV station protection of Class A TV and digital Class A TV stations. 73.6017 Section 73.6017 Telecommunication FEDERAL... Broadcast Stations § 73.6017 Digital Class A TV station protection of Class A TV and digital Class A TV...

47 CFR 73.6017 - Digital Class A TV station protection of Class A TV and digital Class A TV stations.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 4 2010-10-01 2010-10-01 false Digital Class A TV station protection of Class A TV and digital Class A TV stations. 73.6017 Section 73.6017 Telecommunication FEDERAL... Broadcast Stations § 73.6017 Digital Class A TV station protection of Class A TV and digital Class A TV...

Class and ideological orientations revisited: an exploration of class-based mechanisms.

PubMed

Bengtsson, Mattias; Berglund, Tomas; Oskarson, Maria

2013-12-01

Studies of the relationship between class position and political outlooks still only have a limited understanding of the class-related mechanisms that matter for ideological orientations. This article presents a comprehensive analysis of the mechanisms that link class position and left/right and authoritarian/libertarian orientations. Besides main factors such as income, career prospects, job security, education, class origin and class identification, the significance of work-related factors such as work autonomy, working in a team, a physically demanding job and a mentally demanding job is studied. The findings are based on a survey specifically designed for this purpose and collected in Sweden in 2008/2009. A great deal of the association between class position and left/right orientations is explained by socio-economic conditions; different classes sympathize with policies that will benefit them economically. Another important factor is class identification. Work-related factors also have relevance, but the effect of class position on left/right orientations works mainly through the remuneration system. Class position is also related to authoritarian/libertarian orientations. However, this relationship is less explained by socio-economic position per se, but is rather an effect of the educational system and its allocation of the workforce into different class positions. It also turns out that work-related factors do not explain the class effects; however, a physically demanding job shows a unique effect. Overall, our findings suggest that besides factors such as class position, income, education and class identification, we need to consider work-related aspects to derive a more complete understanding of the distribution of ideological orientations in Western societies. © London School of Economics and Political Science 2013.

Class Matters

ERIC Educational Resources Information Center

Valdata, Patricia

2005-01-01

Ever since George Washington opted for the title of president rather than king, Americans have been uncomfortable with the idea of class distinctions. This article presents an interview with Dr. Janet Galligani Casey regarding the idea of class distinctions. Galligani Casey, who grew up in a working-class neighborhood in Somerville, Massachusetts,…

Simplified Design Equations for Class-E Neural Prosthesis Transmitters

PubMed Central

Troyk, Philip; Hu, Zhe

2013-01-01

Extreme miniaturization of implantable electronic devices is recognized as essential for the next generation of neural prostheses, owing to the need for minimizing the damage and disruption of the surrounding neural tissue. Transcutaneous power and data transmission via a magnetic link remains the most effective means of powering and controlling implanted neural prostheses. Reduction in the size of the coil, within the neural prosthesis, demands the generation of a high-intensity radio frequency magnetic field from the extracoporeal transmitter. The Class-E power amplifier circuit topology has been recognized as a highly effective means of producing large radio frequency currents within the transmitter coil. Unfortunately, design of a Class-E circuit is most often fraught by the need to solve a complex set of equations so as to implement both the zero-voltage-switching and zero-voltage-derivative-switching conditions that are required for efficient operation. This paper presents simple explicit design equations for designing the Class-E circuit topology. Numerical design examples are presented to illustrate the design procedure. PMID:23292784

Factors Related to In-Class Spiritual Experience: Relationship between Pre-Class Scripture Reading, In-Class Note-Taking, and Perceived In-Class Spiritual Experiences

ERIC Educational Resources Information Center

Hilton, John, III; Sweat, Anthony R.; Plummer, Kenneth

2015-01-01

The purpose of this study is to examine the relationship between student in-class note-taking and pre-class reading with perceived in-class spiritual and religious outcomes. This study surveyed 620 students enrolled in six different sections of an introductory religion course at a private religious university. Full-time religious faculty members…

Science Requirements and Conceptual Design for a Polarized Medium Energy Electron-Ion Collider at Jlab

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

Abeyratne, S; Ahmed, S; Barber, D

2012-08-01

very beginning, the design studies at Jefferson Lab have focused on achieving high collider performance, particularly ultrahigh luminosities up to 10{sup 34} cm{sup -2}s{sup -1} per detector with large acceptance, while maintaining high polarization for both the electron and light-ion beams. These are the two key performance requirements of a future electron-ion collider facility as articulated by the NSAC Long Range Plan. In MEIC, a new ion complex is designed specifically to deliver ion beams that match the high bunch repetition and highly polarized electron beam from CEBAF. During the last two years, both development of the science case and optimization of the machine design point toward a medium-energy electron-ion collider as the topmost goal for Jefferson Lab. The MEIC, with relatively compact collider rings, can deliver a luminosity above 10{sup 34} cm{sup -2}s{sup -1} at a center-of-mass energy up to 65 GeV. It offers an electron energy up to 11 GeV, a proton energy up to 100 GeV, and corresponding energies per nucleon for heavy ions with the same magnetic rigidity. This design choice balances the scope of the science program, collider capabilities, accelerator technology innovation, and total project cost. An energy upgrade could be implemented in the future by adding two large collider rings housed in another large tunnel to push the center-of-mass energy up to or exceeding 140 GeV. After careful consideration of an alternative electron energy recovery linac on ion storage ring approach, a ring-ring collider scenario at high bunch repetition frequency was found to offer fully competitive performance while eliminating the uncertainties of challenging R&D on ampere-class polarized electron sources and many-pass energy-recovery linacs (ERLs). The essential new elements of an MEIC facility at Jefferson Lab are an electron storage ring and an entirely new, modern ion acceleration and storage complex. For the high-current electron collider ring, the upgraded 12 Ge

77 FR 40488 - Amendment of Class D and Class E Airspace; Lakehurst, NJ

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-10

...-0456; Airspace Docket No. 12-AEA-9] Amendment of Class D and Class E Airspace; Lakehurst, NJ AGENCY... changes the name of the airport associated with the Class D and Class E airspace at Lakehurst, NJ. The... associated with the Class D airspace and Class E airspace designated as an extension to a Class D airspace...

A proposed U.S./China theoretical/experimental collaborative effort on baryon resonance extraction

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

P.L. Cole

2009-12-01

In this paper we discuss the reasons for our work towards establishing a new collaboration between Jefferson Lab (JLab) and the Institute of High Energy Physics (IHEP) in Beijing. We seek to combine experimentalists and theorists into a dedicated group focused on better understanding the current and future data from JLab and from the Beijing Electron Positron Collider (BEPC). Recent JLab results on the extraction of single- and double-polarization observables in both the 1{pi}- and 2{pi}-channel show their high sensitivity to small production amplitudes and therefore their importance for the extraction of resonance parameters. The Beijing Electron Spectrometer (BES) atmore » the BEPC has collected high statistics data on J/{Psi} production. Its decay into baryon-antibaryon channels offers a unique and complementary way of probing nucleon resonances. The CEBAF Large Acceptance Spectrometer, CLAS, has access to N* form factors at high Q{sup 2}, which is advantageous for the study of dynamical properties of nucleon resonances, while the low-background BES results will be able to provide guidance for the search for less-dominant excited states at JLab. Moreover, with the recently approved experimental proposal Nucleon Resonance Studies with CLAS12 and the high-quality data streaming from BES-III and CLAS, the time has come for forging a new Trans-Pacific collaboration of theorists and experimentalists on NSTAR physics.« less

BERLinPro Booster Cavity Design, Fabrication and Test Plans

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

Burrill, Andrew; Anders, W; Frahm, A.

2014-12-01

The bERLinPro project, a 100 mA, 50 MeV superconducting RF (SRF) Energy Recovery Linac (ERL) is under construction at Helmholtz-Zentrum Berlin for the purpose of studying the technical challenges and physics of operating a high current, c.w., 1.3 GHz ERL. This machine will utilize three unique SRF cryomodules for the injector, booster and linac module respectively. The booster cryomodule will contain three 2-cell SRF cavities, based on the original design by Cornell University, and will be equipped with twin 115 kW RF power couplers in order to provide the appropriate acceleration to the high current electron beam. This paper willmore » review the status of the fabrication of the 4 booster cavities that have been built for this project by Jefferson Laboratory and look at the challenges presented by the incorporation of fundamental power couplers capable of delivering 115 kW. The test plan for the cavities and couplers will be given along with a brief overview of the cryomodule design.« less

Analysis and design of continuous class-E power amplifier at sub-nominal condition

NASA Astrophysics Data System (ADS)

Chen, Peng; Yang, Kai; Zhang, Tianliang

2017-12-01

The continuous class-E power amplifier at sub-nominal condition is proposed in this paper. The class-E power amplifier at continuous mode means it can be high efficient on a series matching networks while at sub-nominal condition means it only requires the zero-voltage-switching condition. Comparing with the classical class-E power amplifier, the proposed design method releases two additional design freedoms, which increase the class-E power amplifier's design flexibility. Also, the proposed continuous class-E power amplifier at sub-nominal condition can perform high efficiency over a broad bandwidth. The performance study of the continuous class-E power amplifier at sub-nominal condition is derived and the design procedure is summarised. The normalised switch voltage and current waveforms are investigated. Furthermore, the influences of different sub-nominal conditions on the power losses of the switch-on resistor and the output power capability are also discussed. A broadband continuous class-E power amplifier based on a Gallium Nitride (GaN) transistor is designed and testified to verify the proposed design methodology. The measurement results show, it can deliver 10-15 W output power with 64-73% power-added efficiency over 1.4-2.8 GHz.

Class categories and the subjective dimension of class: the case of Denmark.

PubMed

Harrits, Gitte Sommer; Pedersen, Helene Helboe

2018-03-01

Class relations have been proven to affect various aspects of social life, even in modern individualized societies. However, following claims on individualization and the so-called 'death of class' thesis, studying the subjective dimension of class - that is, the way individuals perceive of class relations and their own position within them - has gone out of style. We argue that even in equalized societies, subjective class perceptions may still influence attitudes and behaviour as they evolve to fit modern class relations. To explore the existence as well as structure and content of perceived social classes, this article investigates how people describe society and social groups in focus group discussions. We find that groups in different positions in terms of education and economy all tend to apply hierarchical class categories to describe Danish society, which is normally seen as one of the most equal societies and political systems in the world. In addition, we find that economic resources serve as a baseline for the hierarchical ordering, often supplemented with notions of education, lifestyle and/or occupational profile. Even though people are somewhat uncomfortable with the notion of class, their descriptions of Danish society and classes are surprisingly similar within and across groups. We conclude that not only do class relations matter; people are also highly aware of the existing classes and able to position themselves and others according to their notion of classes. © London School of Economics and Political Science 2017.

Teaching the Class with "The Class": Debunking the Need for Heroes

ERIC Educational Resources Information Center

Miretzky, Debra

2017-01-01

The French film "Entre Les Murs" ("The Class") is a somewhat unusual film in its portrayal of a Parisian working class school and its protagonist, Mr. Marin, who attempts to teach an unruly class of young and very diverse teenagers. This article explores the ways the author used the film "The Class" as a culminating…

40 CFR 144.19 - Transitioning from Class II to Class VI.

Code of Federal Regulations, 2011 CFR

2011-07-01

... primary purpose of long-term storage into an oil and gas reservoir must apply for and obtain a Class VI geologic sequestration permit when there is an increased risk to USDWs compared to Class II operations. In... Class II operations and a Class VI permit is required. In order to make this determination the Director...

77 FR 34208 - Amendment of Class D and Class E Airspace; Leesburg, FL

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-11

... amends Class D and Class E airspace at Leesburg, FL, changing the airport's name to Leesburg... and public procedures under 5 U.S.C. 553(b) are unnecessary. The Class D airspace, Class E surface...-0445; Airspace Docket No. 12-ASO-27] Amendment of Class D and Class E Airspace; Leesburg, FL AGENCY...

77 FR 7525 - Revision of Class D and Class E Airspace; Hawthorne, CA

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-13

...-0610; Airspace Docket No. 11-AWP-10] Revision of Class D and Class E Airspace; Hawthorne, CA AGENCY... Part 71.1. The Class D airspace and Class E airspace designations listed in this document will be... CFR) Part 71 by revising Class D airspace and Class E surface airspace designated as an extension to...

Engineering the Big Chill: The story of JLab’s Central Helium Liquefier

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

Westfall, Catherine

This article tells the story of the Central Helium Liquefier (CHL) at the Thomas Jefferson National Accelerator Facility (JLab), one of the US National Laboratories. JLab’s successful superconducting radio frequency accelerator was only possible because a group of JLab engineers successfully tackled a complex of difficulties to build a cryogenic system that included the CHL, a task that required advancing the frontier of cryogenic technology. Ultimately, these cryogenic advances were applied far beyond JLab to the benefit of cutting-edge programs at other US national laboratories (Oak Ridge, Brookhaven, and the Facility for Rare Isotope Beams at MSU) as well asmore » NASA. In addition, this innovation story dramatizes the sort of engineer-driven technological problem solving that allows the successful launch and operation of experimental projects. Along the way, the CHL story also provides an important addition to our understanding of the role played by engineers and industry in creating knowledge at physics laboratories.« less

Engineering the Big Chill: The story of JLab’s Central Helium Liquefier

DOE PAGES

Westfall, Catherine

2014-03-29

This article tells the story of the Central Helium Liquefier (CHL) at the Thomas Jefferson National Accelerator Facility (JLab), one of the US National Laboratories. JLab’s successful superconducting radio frequency accelerator was only possible because a group of JLab engineers successfully tackled a complex of difficulties to build a cryogenic system that included the CHL, a task that required advancing the frontier of cryogenic technology. Ultimately, these cryogenic advances were applied far beyond JLab to the benefit of cutting-edge programs at other US national laboratories (Oak Ridge, Brookhaven, and the Facility for Rare Isotope Beams at MSU) as well asmore » NASA. In addition, this innovation story dramatizes the sort of engineer-driven technological problem solving that allows the successful launch and operation of experimental projects. Along the way, the CHL story also provides an important addition to our understanding of the role played by engineers and industry in creating knowledge at physics laboratories.« less

Prevalence of class-I, class-II and class-III obesity in Australian adults between 1995 and 2011-12.

PubMed

Keating, Catherine; Backholer, Kathryn; Gearon, Emma; Stevenson, Christopher; Swinburn, Boyd; Moodie, Marj; Carter, Rob; Peeters, Anna

2015-01-01

To compare the prevalence of class-I, II and III obesity in Australian adults between 1995, 2007-08 and 2011-12. Prevalence data for adults (aged 18+ years) were sourced from customised data from the nationally representative National Nutrition Survey (1995), the National Health Survey (2007-08), and the Australian Health Survey (2011-12) conducted by the Australian Bureau of Statistics. Obesity classifications were based on measured height and weight (class-I body mass index: 30.0-34.9 kg/m(2), class-II: 35.0-39.9 kg/m(2) and class-III: ≥ 40.0 kg/m(2)). Severe obesity was defined as class-II or class-III obesity. Between 1995 and 2011-12, the prevalence of obesity (all classes combined) increased from 19.1% to 27.2%. During this 17 year period, relative increases in class I, II and III obesity were 1.3, 1.7 and 2.2-fold respectively. In 2011-12, the prevalence of class I, II and III obesity was 19.4, 5.9 and 2.0 per cent respectively in men, and 16.1, 6.9 and 4.2 per cent respectively in women. One in every ten people was severely obese, increasing from one in twenty in 1995, and women were disproportionally represented in this population. Obesity prevalence increased with increasing levels of area-level socioeconomic disadvantage, particularly for the more severely obese classes. Severe obesity affected 6.2% and 13.4% in the least and most disadvantaged quintiles respectively. Over the last two decades, there have been substantial increases in the prevalence of obesity, particularly the more severe levels of obesity. This study highlights high risk groups who warrant targeted weight gain prevention interventions. Copyright © 2015 Asia Oceania Association for the Study of Obesity. Published by Elsevier Ltd. All rights reserved.

Cutting Classes

ERIC Educational Resources Information Center

Hacker, Andrew

1976-01-01

Provides critical reviews of three books, "The Political Economy of Social Class", "Ethnicity: Theory and Experience," and "Ethnicity in the United States," focusing on the political economy of social class and ethnicity. (Author/AM)

Operationalizing Max Weber's probability concept of class situation: the concept of social class.

PubMed

Smith, Ken

2007-03-01

In this essay I take seriously Max Weber's astonishingly neglected claim that class situation may be defined, not in categorial terms, but probabilistically. I then apply this idea to another equally neglected claim made by Weber that the boundaries of social classes may be determined by the degree of social mobility within such classes. Taking these two ideas together I develop the idea of a non-categorial boundary 'surface' between classes and of a social class 'corridor' made up of all those people who are still to be found within the boundaries of the social class into which they were born. I call social mobility within a social class 'intra-class social mobility' and social mobility between classes 'inter-class social mobility'. I also claim that this distinction resolves the dispute between those sociologists who claim that late industrial societies are still highly class bound and those who think that this is no longer the case. Both schools are right I think, but one is referring to a high degree of intra-class social mobility and the other to an equally high degree of inter-class mobility. Finally I claim that this essay provides sociology with only one example among many other possible applications of how probability theory might usefully be used to overcome boundary problems generally in sociology.

77 FR 64889 - Amendment of Class D and Class E Airspace; Hawthorne, CA

Federal Register 2010, 2011, 2012, 2013, 2014

2012-10-24

...-2012-1092; Airspace Docket No. 12-AWP-6] Amendment of Class D and Class E Airspace; Hawthorne, CA...: This action amends the airspace description for Class D and Class E airspace at Jack Northrop Field... the legal description of the existing Class D and E airspace at Jack Northrop Field/Hawthorne...

Class network routing

DOEpatents

Bhanot, Gyan [Princeton, NJ; Blumrich, Matthias A [Ridgefield, CT; Chen, Dong [Croton On Hudson, NY; Coteus, Paul W [Yorktown Heights, NY; Gara, Alan G [Mount Kisco, NY; Giampapa, Mark E [Irvington, NY; Heidelberger, Philip [Cortlandt Manor, NY; Steinmacher-Burow, Burkhard D [Mount Kisco, NY; Takken, Todd E [Mount Kisco, NY; Vranas, Pavlos M [Bedford Hills, NY

2009-09-08

Class network routing is implemented in a network such as a computer network comprising a plurality of parallel compute processors at nodes thereof. Class network routing allows a compute processor to broadcast a message to a range (one or more) of other compute processors in the computer network, such as processors in a column or a row. Normally this type of operation requires a separate message to be sent to each processor. With class network routing pursuant to the invention, a single message is sufficient, which generally reduces the total number of messages in the network as well as the latency to do a broadcast. Class network routing is also applied to dense matrix inversion algorithms on distributed memory parallel supercomputers with hardware class function (multicast) capability. This is achieved by exploiting the fact that the communication patterns of dense matrix inversion can be served by hardware class functions, which results in faster execution times.

75 FR 51171 - Amendment of Class D and Class E Airspace; Kaneohe, HI

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-19

...; Airspace Docket No. 10-AWP-10] Amendment of Class D and Class E Airspace; Kaneohe, HI AGENCY: Federal... Class D and Class E airspace at Kaneohe Bay Marine Corps Air Station (MCAS), Kaneohe, HI. The FAA is... airspace and Class E airspace upward from 700 feet above the surface at Kaneohe Bay MCAS, Kaneohe Bay, HI...

75 FR 63709 - Revocation of Class C Airspace, Establishment of Class D Airspace, and Modification of Class E...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-18

... foot Class E airspace at Columbus, GA. The FAA is taking this action because Columbus Metropolitan... area and the 700 foot Class E airspace area at Columbus, GA (75 FR 27670). Interested parties were... from 700 feet above the surface at Columbus, Ga. The radius of the Class E surface area at the airport...

76 FR 67103 - Proposed Revision of Class D and Class E Airspace; Hawthorne, CA

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-31

...-0610; Airspace Docket No. 11-AWP-10] Proposed Revision of Class D and Class E Airspace; Hawthorne, CA...: This action proposes to revise Class D and E airspace at Jack Northrop Field/Hawthorne Municipal... (14 CFR) Part 71 by revising Class D airspace and Class E airspace designated as an extension to Class...

75 FR 61341 - Airworthiness Directives; Agusta S.p.A. (Agusta) Model A109E Helicopters

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-05

... electrical failure, an investigation revealed inadequate functioning of the 35 amperes (Amps) battery bus... investigation revealed inadequate functioning of the 35 amperes (Amps) battery bus (BATT BUS) circuit breaker...

FY98 Class Convening Schedule for Coast Guard Class

DOT National Transportation Integrated Search

1998-08-12

This Notice publishes the FY98 class convening schedule of Coast Guard Class "A" : and "C" resident and exportable training courses defined by program/force : managers as essential or directly related to mission accomplishment for : achievement of pr...

Inhibition of the archaeal beta-class (Cab) and gamma-class (Cam) carbonic anhydrases.

PubMed

Zimmerman, Sabrina A; Ferry, James G; Supuran, Claudiu T

2007-01-01

Five independently evolved classes (alpha-, beta-, gamma-, delta-, zeta-) of carbonic anhydrases facilitate the reversible hydration of carbon dioxide to bicarbonate of which the alpha-class is the most extensively studied. Detailed inhibition studies of the alpha-class with the two main classes of inhibitors, sulfonamides and metal-complexing anions, revealed many inhibitors that are used as therapeutic agents to prevent and treat many diseases. Recent inhibitor studies of the archaeal beta-class (Cab) and the gamma-class (Cam) carbonic anhydrases show differences in inhibition response to sulfonamides and metal-complexing anions, when compared to the alpha-class carbonic anhydrases. In addition, inhibition between Cab and Cam differ. These inhibition patterns are consistent with the idea that although, alpha-, beta-, and gamma-class carbonic anhydrases participate in the same two-step isomechanism, diverse active site architecture among these classes predicts variations on the catalytic mechanism. These inhibitor studies of the archaeal beta- and gamma-class carbonic anhydrases give insight to new applications of current day carbonic anhydrase inhibitors, as well as direct research to develop new compounds that may be specific inhibitors of prokaryotic carbonic anhydrases.

Commissioning of the helium cryogenic system for the HIE- ISOLDE accelerator upgrade at CERN

NASA Astrophysics Data System (ADS)

Delruelle, N.; Inglese, V.; Leclercq, Y.; Pirotte, O.; Williams, L.

2015-12-01

The High Intensity and Energy ISOLDE (HIE-ISOLDE) project is a major upgrade of the existing ISOLDE and REX-ISOLDE facilities at CERN. The most significant improvement will come from replacing the existing REX accelerating structure by a superconducting linear accelerator (SC linac) composed ultimately of six cryo-modules installed in series, each containing superconducting RF cavities and solenoids operated at 4.5 K. In order to provide the cooling capacity at all temperature levels between 300 K and 4.5 K for the six cryo-modules, an existing helium refrigerator, manufactured in 1986 and previously used to cool the ALEPH magnet during LEP operation from 1989 to 2000, has been refurbished, reinstalled and recommissioned in a dedicated building located next to the HIE-ISOLDE experimental hall. This helium refrigerator has been connected to a new cryogenic distribution line, consisting of a 30-meter long vacuum-insulated transfer line, a 2000-liter storage dewar and six interconnecting valve boxes, one for each cryo-module. This paper describes the whole cryogenic system and presents the commissioning results including the preliminary operation at 4.5 K of the first cryo- module in the experimental hall.

Pentaquark Searches at Jlab

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

Rossi, Patrizia

2007-01-01

Since LEPS collaboration reported the first evidence for a S=+1 baryon resonance in early 2003 with a mass of 1.54 GeV, dubbed Θ+, more than ten experiments have confirmed this exotic state, among these two carried out at Jefferson Laboratory. At the same time, there are a number of experiments, mostly at high energies, that report null results. To try to clarify this situation, during the past year, The CLAS Collaboration at Jefferson Laboratory has undertaken a second generation high-statistics experimental program to search for exotics baryons. Here the preliminary results from these experiments are reported.

77 FR 27144 - Airworthiness Directives; Agusta S.p.A. Helicopters

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-09

... that resulted from ``inadequate functioning of the 35 amperes (amps) BATT BUS circuit breaker.'' The.... (b) Unsafe Condition This AD defines the unsafe condition as failure of the 35 ampere (amp) ``BATT...

First-Class Inquiry

ERIC Educational Resources Information Center

Hesser, Kathi; Buck, Gayle; Dopp, Sandra

2005-01-01

In the activity described in this article, students will explore how variables in a first-class lever, specifically arm length, position of the fulcrum, and placement of the load, affect the effort needed to lift the load. To begin the lesson, demonstrate to the class how a first-class lever works and review what is meant by the terms fulcrum,…

Class Size.

ERIC Educational Resources Information Center

Ellis, Thomas I.

1985-01-01

After a brief introduction identifying current issues and trends in research on class size, this brochure reviews five recent studies bearing on the relationship of class size to educational effectiveness. Part 1 is a review of two interrelated and highly controversial "meta-analyses" or statistical integrations of research findings on…

Measurements of Polarization Transfers in Real Compton Scattering by a proton target at JLAB. A new source of information on the 3D shape of the nucleon

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

Fanelli, Cristiano V.

2015-03-01

In this thesis work, results of the analysis of the polarization transfers measured in real Compton scattering (RCS) by the Collaboration E07-002 at the Je fferson Lab Hall-C are presented. The data were collected at large scattering angle (theta_cm = 70deg) and with a polarized incident photon beam at an average energy of 3.8 GeV. Such a kind of experiments allows one to understand more deeply the reaction mechanism, that involves a real photon, by extracting both Compton form factors and Generalized Parton Distributions (GPDs) (also relevant for possibly shedding light on the total angular momentum of the nucleon). Themore » obtained results for the longitudinal and transverse polarization transfers K_LL and K_LT, are of crucial importance, since they confirm unambiguously the disagreement between experimental data and pQCD prediction, as it was found in E99-114 experiment, and favor the Handbag mechanism. The E99-114 and E07-002 results can contribute to attract new interest on the great yield of the Compton scattering by a nucleon target, as demonstrated by the recent approval of an experimental proposal submitted to the Jefferson Lab PAC 42 for a Wide-angle Compton Scattering experiment, at 8 and 10 GeV Photon Energies. The new experiments approved to run with the updated 12 GeV electron beam at JLab, are characterized by much higher luminosities, and a new GEM tracker is under development to tackle the challenging backgrounds. Within this context, we present a new multistep tracking algorithm, based on (i) a Neural Network (NN) designed for a fast and efficient association of the hits measured by the GEM detector which allows the track identification, and (ii) the application of both a Kalman filter and Rauch-Tung-Striebel smoother to further improve the track reconstruction. The full procedure, i.e. NN and filtering, appears very promising, with high performances in terms of both association effciency and reconstruction accuracy, and these preliminary

Culture and social class.

PubMed

Miyamoto, Yuri

2017-12-01

A large body of research in Western cultures has demonstrated the psychological and health effects of social class. This review outlines a cultural psychological approach to social stratification by comparing psychological and health manifestations of social class across Western and East Asian cultures. These comparisons suggest that cultural meaning systems shape how people make meaning and respond to material/structural conditions associated with social class, thereby leading to culturally divergent manifestations of social class. Specifically, unlike their counterparts in Western cultures, individuals of high social class in East Asian cultures tend to show high conformity and other-orientated psychological attributes. In addition, cultures differ in how social class impacts health (i.e. on which bases, through which pathways, and to what extent). Copyright © 2017 Elsevier Ltd. All rights reserved.

Cosmology with CLASS

NASA Astrophysics Data System (ADS)

Watts, Duncan; CLASS Collaboration

2018-01-01

The Cosmology Large Angular Scale Surveyor (CLASS) will use large-scale measurements of the polarized cosmic microwave background (CMB) to constrain the physics of inflation, reionization, and massive neutrinos. The experiment is designed to characterize the largest scales, which are inaccessible to most ground-based experiments, and remove Galactic foregrounds from the CMB maps. In this dissertation talk, I present simulations of CLASS data and demonstrate their ability to constrain the simplest single-field models of inflation and to reduce the uncertainty of the optical depth to reionization, τ, to near the cosmic variance limit, significantly improving on current constraints. These constraints will bring a qualitative shift in our understanding of standard ΛCDM cosmology. In particular, CLASS's measurement of τ breaks cosmological parameter degeneracies. Probes of large scale structure (LSS) test the effect of neutrino free-streaming at small scales, which depends on the mass of the neutrinos. CLASS's τ measurement, when combined with next-generation LSS and BAO measurements, will enable a 4σ detection of neutrino mass, compared with 2σ without CLASS data.. I will also briefly discuss the CLASS experiment's measurements of circular polarization of the CMB and the implications of the first-such near-all-sky map.

Imagining class: A study into material social class position, subjective identification, and voting behavior across Europe.

PubMed

D'Hooge, Lorenzo; Achterberg, Peter; Reeskens, Tim

2018-02-01

The traditional approach to class voting has largely ignored the question whether material class positions coincide with subjective class identification. Following Sosnaud et al. (2013), this study evaluates party preferences when Europeans' material and subjective social class do not coincide. Seminal studies on voting behavior have suggested that members of lower classes are more likely to vote for the economic left and cultural right and that higher classes demonstrate the opposite pattern. Yet, these studies have on the one hand overlooked the possibility that there is a mismatch between the material class people can be classified in and the class they think they are part of, and on the other hand the consequences of this discordant class identification on voting behavior. Analyzing the 2009 wave of the European Elections Study, we find that the majority of the Europeans discordantly identify with the middle class, whereas only a minority of the lower and higher classes concordantly identify with their material social class. Further, material class only seems to predict economic voting behavior when it coincides with subjective class; for instance, individuals who have an inflated class identification are more likely to vote for the economic left, even when they materially can be classified as middle or high class. We conclude this paper with a discussion on scholarly debates concerning class and politics. Copyright © 2017 Elsevier Inc. All rights reserved.

ClassPrep: A Peer Review System for Class Preparation

ERIC Educational Resources Information Center

Park, Jooyong

2017-01-01

Class preparation is recommended by instructors in most college courses, but checking whether a student does so is not easy. A new blended learning system, named ClassPrep, has been proposed and implemented. The usability of the system was examined for two undergraduate psychology courses: one advanced course (n = 11) and one introductory course…

Finishing occlusion in Class II or Class III molar relation: therapeutic Class II and III.

PubMed

Nangia, A; Darendeliler, M A

2001-11-01

The most frequent extraction regime consists of the removal of upper and lower premolars. Depending on anchorage requirements, camouflage treatment options, surgical intervention, or the absence of teeth in only one arch, it may become necessary to finalize the occlusion with a one-dental-unit discrepancy between the upper and lower dental arches. Guidelines are presented for finishing occlusions in Class II or Class III molar relation.

Class Counts: Education, Inequality, and the Shrinking Middle Class

ERIC Educational Resources Information Center

Ornstein, Allan

2007-01-01

Class differences and class warfare have existed since the beginning of western civilization, but the gap in income and wealth between the rich (top 10 percent) and the rest has increased steadily in the last twenty-five years. The U.S. is heading for a financial oligarchy much worse than the aristocratic old world that our Founding Fathers feared…

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

Okihira, K.; Hara, H.; Ikeda, N.

MHI have supplied several 9-cell cavities for STF (R&D of ILC project at KEK) and have been considering production method for stable quality and cost reduction, seamless dumb-bell cavity was one of them. We had fabricated a 2 cell seamless dumb-bell cavity for cost reduction and measured RF performance in collaboration with JLab, KEK and MHI. Surface treatment recipe for ILC was applied for MHI 2-cell cavity and vertical test was performed at JLab. The cavity reached Eacc=32.4MV/m after BCP and EP. Details of the result are reported.

78 FR 74004 - Amendment of Class D and Class E Airspace; Lake Charles, LA

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-10

...-0948; Airspace Docket No. 13-ASW-25] Amendment of Class D and Class E Airspace; Lake Charles, LA AGENCY... amends Class D and Class E airspace within the Lake Charles, LA, area by updating the geographic coordinates for Lake Charles Regional Airport, and the airport name and geographic coordinates for Chennault...

Evolution of major histocompatibility complex class I and class II genes in the brown bear

PubMed Central

2012-01-01

Background Major histocompatibility complex (MHC) proteins constitute an essential component of the vertebrate immune response, and are coded by the most polymorphic of the vertebrate genes. Here, we investigated sequence variation and evolution of MHC class I and class II DRB, DQA and DQB genes in the brown bear Ursus arctos to characterise the level of polymorphism, estimate the strength of positive selection acting on them, and assess the extent of gene orthology and trans-species polymorphism in Ursidae. Results We found 37 MHC class I, 16 MHC class II DRB, four DQB and two DQA alleles. We confirmed the expression of several loci: three MHC class I, two DRB, two DQB and one DQA. MHC class I also contained two clusters of non-expressed sequences. MHC class I and DRB allele frequencies differed between northern and southern populations of the Scandinavian brown bear. The rate of nonsynonymous substitutions (dN) exceeded the rate of synonymous substitutions (dS) at putative antigen binding sites of DRB and DQB loci and, marginally significantly, at MHC class I loci. Models of codon evolution supported positive selection at DRB and MHC class I loci. Both MHC class I and MHC class II sequences showed orthology to gene clusters found in the giant panda Ailuropoda melanoleuca. Conclusions Historical positive selection has acted on MHC class I, class II DRB and DQB, but not on the DQA locus. The signal of historical positive selection on the DRB locus was particularly strong, which may be a general feature of caniforms. The presence of MHC class I pseudogenes may indicate faster gene turnover in this class through the birth-and-death process. South–north population structure at MHC loci probably reflects origin of the populations from separate glacial refugia. PMID:23031405

Evolution of major histocompatibility complex class I and class II genes in the brown bear.

PubMed

Kuduk, Katarzyna; Babik, Wiesław; Bojarska, Katarzyna; Sliwińska, Ewa B; Kindberg, Jonas; Taberlet, Pierre; Swenson, Jon E; Radwan, Jacek

2012-10-02

Major histocompatibility complex (MHC) proteins constitute an essential component of the vertebrate immune response, and are coded by the most polymorphic of the vertebrate genes. Here, we investigated sequence variation and evolution of MHC class I and class II DRB, DQA and DQB genes in the brown bear Ursus arctos to characterise the level of polymorphism, estimate the strength of positive selection acting on them, and assess the extent of gene orthology and trans-species polymorphism in Ursidae. We found 37 MHC class I, 16 MHC class II DRB, four DQB and two DQA alleles. We confirmed the expression of several loci: three MHC class I, two DRB, two DQB and one DQA. MHC class I also contained two clusters of non-expressed sequences. MHC class I and DRB allele frequencies differed between northern and southern populations of the Scandinavian brown bear. The rate of nonsynonymous substitutions (dN) exceeded the rate of synonymous substitutions (dS) at putative antigen binding sites of DRB and DQB loci and, marginally significantly, at MHC class I loci. Models of codon evolution supported positive selection at DRB and MHC class I loci. Both MHC class I and MHC class II sequences showed orthology to gene clusters found in the giant panda Ailuropoda melanoleuca. Historical positive selection has acted on MHC class I, class II DRB and DQB, but not on the DQA locus. The signal of historical positive selection on the DRB locus was particularly strong, which may be a general feature of caniforms. The presence of MHC class I pseudogenes may indicate faster gene turnover in this class through the birth-and-death process. South-north population structure at MHC loci probably reflects origin of the populations from separate glacial refugia.

78 FR 51138 - Designation of Muncie (IN) To Provide Class X or Class Y Weighing Services

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-20

... Muncie (IN) To Provide Class X or Class Y Weighing Services AGENCY: Grain Inspection, Packers and... Grain Inspection, Inc. (East Indiana) to provide Class X or Class Y weighing services under the United... amended to include Class X or Class Y weighing within their assigned geographic area, effective July 29...

Peer Victimisation and Its Relation to Class Relational Climate and Class Moral Disengagement among School Children

ERIC Educational Resources Information Center

Thornberg, Robert; Wänström, Linda; Pozzoli, Tiziana

2017-01-01

The aim of the present study was to examine whether class climate and class moral disengagement each contribute to explain different levels of victimisation among classes. Eight-hundred-and-ninety-nine children from 43 Swedish elementary school classes participated in the current study. Class moral disengagement, class relational climate and peer…

76 FR 54153 - Proposed Amendment of Class D and Class E Airspace; Baltimore, MD

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-31

...: This action proposes to amend Class D and Class E Airspace at Baltimore, MD, as the Martin Non... developed at Martin State Airport. This action would also update the geographic coordinates of the Baltimore... Federal Regulations (14 CFR) part 71 to amend Class D airspace and Class E surface airspace at Martin...

ARIEL e-LINAC: Commissioning and Development

NASA Astrophysics Data System (ADS)

Laxdal, R. E.; Zvyagintsev, V.

2016-09-01

A superconducting electron Linac (e-Linac) will be a part of the ARIEL facility for the production of radioactive ion beams (RIB) at TRIUMF. The e-Linac will consist of five 1.3GHz 9-cell cavities in three cryomodules delivering a 50MeV 10mA beam. The baseline operation will be single pass but a re-circulating ring is planned to allow either energy boost or energy recovery operation. The first stage of the accelerator which consists of two cryomodules has been successfully commissioned in 2014. The paper will discuss the superconducting radio-frequency (SRF) challenges of the accelerator. Cavities, crymodules and RF system design, preparation, and performance will be presented.

Limits to Open Class Performance?

NASA Technical Reports Server (NTRS)

Bowers, Albion H.

2007-01-01

This viewgraph presentation describes the limits to open class performance. The contents include: 1) Standard Class; 2) 15m/Racing Class; 3) Open Class; and 4) Design Solutions associated with assumptions, limiting parameters, airfoil performance, current trends, and analysis.

77 FR 52217 - Amendment of Class D and Class E Airspace; Bozeman, MT

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-29

... Bozeman Yellowstone International Airport. This improves the safety and management of Instrument Flight... Class E airspace at Bozeman Yellowstone International Airport, Bozeman, MT. This action aligns two Class... airspace designated as an extension to Class D, at Bozeman Yellowstone International Airport, Bozeman, MT...

Social class, power, and selfishness: when and why upper and lower class individuals behave unethically.

PubMed

Dubois, David; Rucker, Derek D; Galinsky, Adam D

2015-03-01

Are the rich more unethical than the poor? To answer this question, the current research introduces a key conceptual distinction between selfish and unethical behavior. Based on this distinction, the current article offers 2 novel findings that illuminate the relationship between social class and unethical behavior. First, the effects of social class on unethical behavior are not invariant; rather, the effects of social class are moderated by whether unethical behavior benefits the self or others. Replicating past work, social class positively predicted unethical behavior; however, this relationship was only observed when that behavior was self-beneficial. When unethical behavior was performed to benefit others, social class negatively predicted unethical behavior; lower class individuals were more likely than upper class individuals to engage in unethical behavior. Overall, social class predicts people's tendency to behave selfishly, rather than predicting unethical behavior per se. Second, individuals' sense of power drove the effects of social class on unethical behavior. Evidence for this relationship was provided in three forms. First, income, but not education level, predicted unethical behavior. Second, feelings of power mediated the effect of social class on unethical behavior, but feelings of status did not. Third, two distinct manipulations of power produced the same moderation by self-versus-other beneficiary as was found with social class. The current theoretical framework and data both synthesize and help to explain a range of findings in the social class and power literatures. PsycINFO Database Record (c) 2015 APA, all rights reserved.

DIRECT COUPLED AMPLIFIER

DOEpatents

Dandl, R.A.

1961-09-19

A transistor amplifier is designed for vyery small currents below 10/sup -8/ amperes. The filrst and second amplifier stages use unusual selected transistors in which the current amplification increases markedly for values of base current below 10/sup -6/ amperes.

Petabyte Class Storage at Jefferson Lab (CEBAF)

NASA Technical Reports Server (NTRS)

Chambers, Rita; Davis, Mark

1996-01-01

By 1997, the Thomas Jefferson National Accelerator Facility will collect over one Terabyte of raw information per day of Accelerator operation from three concurrently operating Experimental Halls. When post-processing is included, roughly 250 TB of raw and formatted experimental data will be generated each year. By the year 2000, a total of one Petabyte will be stored on-line. Critical to the experimental program at Jefferson Lab (JLab) is the networking and computational capability to collect, store, retrieve, and reconstruct data on this scale. The design criteria include support of a raw data stream of 10-12 MB/second from Experimental Hall B, which will operate the CEBAF (Continuous Electron Beam Accelerator Facility) Large Acceptance Spectrometer (CLAS). Keeping up with this data stream implies design strategies that provide storage guarantees during accelerator operation, minimize the number of times data is buffered allow seamless access to specific data sets for the researcher, synchronize data retrievals with the scheduling of postprocessing calculations on the data reconstruction CPU farms, as well as support the site capability to perform data reconstruction and reduction at the same overall rate at which new data is being collected. The current implementation employs state-of-the-art StorageTek Redwood tape drives and robotics library integrated with the Open Storage Manager (OSM) Hierarchical Storage Management software (Computer Associates, International), the use of Fibre Channel RAID disks dual-ported between Sun Microsystems SMP servers, and a network-based interface to a 10,000 SPECint92 data processing CPU farm. Issues of efficiency, scalability, and manageability will become critical to meet the year 2000 requirements for a Petabyte of near-line storage interfaced to over 30,000 SPECint92 of data processing power.

Resonance Properties of Class I and Class II Neurons Differentially Modulated by Channel Noise

NASA Astrophysics Data System (ADS)

Wang, Lei

2018-01-01

Resonance properties of two different neuron types (Class I and Class II) induced by channel noise are investigated in this study. It is found that for Class I neuron, spiking activity is enhanced when certain noise intensity is presented, especially under weak current stimuli -- a typical phenomenon of stochastic resonance (SR); while for Class II neuron, in addition to perform the SR, certain noise intensity would inhibit neuronal activity under some current stimuli -- a typical phenomenon of inverse stochastic resonance (ISR). Moreover, we show that only sodium channel noise or potassium channel noise variation can achieve the similar phenomena. Consequently, the model results suggest that channel noise may exert differential roles in modulating the resonance properties of Class I and Class II neurons.

“Markings” of a Class

PubMed Central

Mather, James M.; Anderson, Donald O.; Cox, Albert R.; Williams, Donald H.

1965-01-01

In 1954 the first class in medicine graduated from the University of British Columbia. This class of 57 men and three women left a statistical trail behind them which began before they entered medical school, and which now has extended 10 years into their professional postgraduate careers. This first class was made up largely of British Columbians of older age than subsequent classes. The overall achievement and aptitude of the class was high, as measured by premedical grades, intelligence tests and Medical College Admission Test scores. Interest tests at the time of admission indicated that the members of the class had major interest levels in the fields of science and social service or humanitarianism. The subsequent medical school performance of the class was exceptional. Of the class, 63.4% interned in teaching hospitals. By 1964 only 53.4% of the graduates were engaged in general practice. Most of the graduates are now practising in British Columbia. PMID:14278023

32 CFR 1636.5 - Exclusion from Class 1-A-0 and Class 1-0.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 32 National Defense 6 2010-07-01 2010-07-01 false Exclusion from Class 1-A-0 and Class 1-0. 1636.5... be excluded from Class 1-A-0 or Class 1-0: (a) Who asserts beliefs which are of a religious, moral or... theocratic, spiritual war between the forces of good and evil, he may not by reason of that belief alone be...

32 CFR 1636.5 - Exclusion from Class 1-A-0 and Class 1-0.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 32 National Defense 6 2013-07-01 2013-07-01 false Exclusion from Class 1-A-0 and Class 1-0. 1636.5... be excluded from Class 1-A-0 or Class 1-0: (a) Who asserts beliefs which are of a religious, moral or... theocratic, spiritual war between the forces of good and evil, he may not by reason of that belief alone be...

32 CFR 1636.5 - Exclusion from Class 1-A-0 and Class 1-0.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 32 National Defense 6 2014-07-01 2014-07-01 false Exclusion from Class 1-A-0 and Class 1-0. 1636.5... be excluded from Class 1-A-0 or Class 1-0: (a) Who asserts beliefs which are of a religious, moral or... theocratic, spiritual war between the forces of good and evil, he may not by reason of that belief alone be...

32 CFR 1636.5 - Exclusion from Class 1-A-0 and Class 1-0.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 32 National Defense 6 2011-07-01 2011-07-01 false Exclusion from Class 1-A-0 and Class 1-0. 1636.5... be excluded from Class 1-A-0 or Class 1-0: (a) Who asserts beliefs which are of a religious, moral or... theocratic, spiritual war between the forces of good and evil, he may not by reason of that belief alone be...

32 CFR 1636.5 - Exclusion from Class 1-A-0 and Class 1-0.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 32 National Defense 6 2012-07-01 2012-07-01 false Exclusion from Class 1-A-0 and Class 1-0. 1636.5... be excluded from Class 1-A-0 or Class 1-0: (a) Who asserts beliefs which are of a religious, moral or... theocratic, spiritual war between the forces of good and evil, he may not by reason of that belief alone be...

Class Notes for "Class-Y-News."

ERIC Educational Resources Information Center

Stuart, Judy L.

1991-01-01

A self-contained class of students with mild to moderate disabilities published a monthly newsletter which was distributed to students' families. Students became involved in writing, typing, drawing, folding, basic editing, and disseminating. (JDD)

A Tale of Two Classes: The Black Poor and the Black Middle Class.

ERIC Educational Resources Information Center

Lewin, Arthur

1991-01-01

To understand the African-American family, the African-American poor and middle class must be investigated. Extra costs mean that it is much harder for African Americans to reach the middle class. Ways to improve the economic status of African-American families and to increase the middle class are discussed. (SLD)

78 FR 13014 - Designation of West Lafayette (IN) To Provide Class X or Class Y Weighing Services

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-26

... West Lafayette (IN) To Provide Class X or Class Y Weighing Services AGENCY: Grain Inspection, Packers... Titus Grain Inspection, Inc. (Titus) to provide Class X or Class Y weighing services under the United... currently assigned geographic area. Titus's present designation is amended to include Class X or Class Y...

77 FR 17362 - Proposed Modification of Class D and Class E Airspace and Revocation of Class E Airspace...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-26

... (IFR) at Bellingham International Airport. This action also would remove Class E airspace designated as an extension to a Class D or E surface area at Bellingham International Airport. This action, initiated by the biennial review of the Bellingham airspace area, would enhance the safety and management of...

Conscription and Class.

ERIC Educational Resources Information Center

Useem, Michael

1981-01-01

Discusses how social class origins of age-eligible men have affected their likelihood of being drafted into military service since the Civil War. Holds that class bias in any future system must be considered a major social cost accompanying the revival of conscription. (Author/GC)

Classification of stellar spectra with SVM based on within-class scatter and between-class scatter

NASA Astrophysics Data System (ADS)

Liu, Zhong-bao; Zhou, Fang-xiao; Qin, Zhen-tao; Luo, Xue-gang; Zhang, Jing

2018-07-01

Support Vector Machine (SVM) is a popular data mining technique, and it has been widely applied in astronomical tasks, especially in stellar spectra classification. Since SVM doesn't take the data distribution into consideration, and therefore, its classification efficiencies can't be greatly improved. Meanwhile, SVM ignores the internal information of the training dataset, such as the within-class structure and between-class structure. In view of this, we propose a new classification algorithm-SVM based on Within-Class Scatter and Between-Class Scatter (WBS-SVM) in this paper. WBS-SVM tries to find an optimal hyperplane to separate two classes. The difference is that it incorporates minimum within-class scatter and maximum between-class scatter in Linear Discriminant Analysis (LDA) into SVM. These two scatters represent the distributions of the training dataset, and the optimization of WBS-SVM ensures the samples in the same class are as close as possible and the samples in different classes are as far as possible. Experiments on the K-, F-, G-type stellar spectra from Sloan Digital Sky Survey (SDSS), Data Release 8 show that our proposed WBS-SVM can greatly improve the classification accuracies.

Automatic discovery of optimal classes

NASA Technical Reports Server (NTRS)

Cheeseman, Peter; Stutz, John; Freeman, Don; Self, Matthew

1986-01-01

A criterion, based on Bayes' theorem, is described that defines the optimal set of classes (a classification) for a given set of examples. This criterion is transformed into an equivalent minimum message length criterion with an intuitive information interpretation. This criterion does not require that the number of classes be specified in advance, this is determined by the data. The minimum message length criterion includes the message length required to describe the classes, so there is a built in bias against adding new classes unless they lead to a reduction in the message length required to describe the data. Unfortunately, the search space of possible classifications is too large to search exhaustively, so heuristic search methods, such as simulated annealing, are applied. Tutored learning and probabilistic prediction in particular cases are an important indirect result of optimal class discovery. Extensions to the basic class induction program include the ability to combine category and real value data, hierarchical classes, independent classifications and deciding for each class which attributes are relevant.

75 FR 49866 - Proposed Amendment of Class D and Class E Airspace; Klamath Falls, OR

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-16

...-0651; Airspace Docket No. 10-ANM-7] Proposed Amendment of Class D and Class E Airspace; Klamath Falls...). SUMMARY: This action proposes to amend Class D and Class E airspace at Klamath Falls, OR. Decommissioning of the Merrill Non-Directional Radio Beacon (NDB) at Klamath Falls Airport has made this action...

The relationship between Class I and Class II methanol masers at high angular resolution

NASA Astrophysics Data System (ADS)

McCarthy, T. P.; Ellingsen, S. P.; Voronkov, M. A.; Cimò, G.

2018-06-01

We have used the Australia Telescope Compact Array (ATCA) to make the first high-resolution observations of a large sample of class I methanol masers in the 95-GHz (80-71A+) transition. The target sources consist of a statistically complete sample of 6.7-GHz class II methanol masers with an associated 95-GHz class I methanol maser, enabling a detailed study of the relationship between the two methanol maser classes at arcsecond angular resolution. These sources have been previously observed at high resolution in the 36- and 44-GHz transitions, allowing comparison between all three class I maser transitions. In total, 172 95-GHz maser components were detected across the 32 target sources. We find that at high resolution, when considering matched maser components, a 3:1 flux density ratio is observed between the 95- and 44-GHz components, consistent with a number of previous lower angular resolution studies. The 95-GHz maser components appear to be preferentially located closer to the driving sources and this may indicate that this transition is more strongly inverted nearby to background continuum sources. We do not observe an elevated association rate between 95-GHz maser emission and more evolved sources, as indicated by the presence of 12.2-GHz class II masers. We find that in the majority of cases where both class I and class II methanol emission is observed, some component of the class I emission is associated with a likely outflow candidate.

Thin-plate spline analysis of craniofacial growth in Class I and Class II subjects.

PubMed

Franchi, Lorenzo; Baccetti, Tiziano; Stahl, Franka; McNamara, James A

2007-07-01

To compare the craniofacial growth characteristics of untreated subjects with Class II division 1 malocclusion with those of subjects with normal (Class I) occlusion from the prepubertal through the postpubertal stages of development. The Class II division 1 sample consisted of 17 subjects (11 boys and six girls). The Class I sample also consisted of 17 subjects (13 boys and four girls). Three craniofacial regions (cranial base, maxilla, and mandible) were analyzed on the lateral cephalograms of the subjects in both groups by means of thin-plate spline analysis at T1 (prepubertal) and T2 (postpubertal). Both cross-sectional and longitudinal comparisons were performed on both size and shape differences between the two groups. The results showed an increased cranial base angulation as a morphological feature of Class II malocclusion at the prepubertal developmental phase. Maxillary changes in either shape or size were not significant. Subjects with Class II malocclusion exhibited a significant deficiency in the size of the mandible at the completion of active craniofacial growth as compared with Class I subjects. A significant deficiency in the size of the mandible became apparent in Class II subjects during the circumpubertal period and it was still present at the completion of active craniofacial growth.

Techniques Class: September 12, 2001.

ERIC Educational Resources Information Center

More, William; Corsetti, Patricia L.; Endleman, Orna; Julian, Sarah; Lindemann, Evie; Spinelli, Laura

2002-01-01

On September 12, 2001, the Techniques in Art Therapy class in the art therapy program at Albertus Magnus College met at its normal Wednesday evening time. This article describes the class session through the words and images of several class members who found the class useful in their own process of beginning to deal with the attacks and their…

Automatic Identification Systems the Effects of Class B on the Use of Class A Systems

NASA Astrophysics Data System (ADS)

Norris, Andy

2006-05-01

The standards for CSTDMA Class B AIS will shortly be published by the International Electrotechnical Commission and equipment will become available during 2006. The perceived benefits that Class B brings to leisure craft users and its relatively low cost will make it attractive in the market place. A rapid take-up of Class B use can therefore be expected. This paper considers the impact that increased use of Class B will have on users of Class A AIS that are compulsorily fitted to larger vessels to meet the requirements of the International Maritime Organization Safety of Life at Sea convention. The CSTDMA Class B system has been designed to prevent overloading of the AIS VHF data link. This is briefly reviewed but there are a number of other aspects that need to be considered. These include: the increased garbling of Class B messages compared to those of Class A; the problems accruing from the low update rate of Class B information; the increase in display information that will need to be managed; and the possible increase in inappropriate manoeuvres of leisure craft caused by misplaced reliance on AIS. As a result of the investigation the paper highlights the fact that Class B users must not assume that their own presence, in the form of Class B transmissions, will be particularly visible on the bridge of many SOLAS vessels. This will continue to be the case for many years into the future, until such vessels are mandated to carry radar with AIS target overlay capability.

Anteroposterior condylar position: a comparative study between subjects with normal occlusion and patients with Class I, Class II Division 1, and Class III malocclusions.

PubMed

Fraga, Marcelo Reis; Rodrigues, Andréia Fialho; Ribeiro, Luiz Claudio; Campos, Marcio José da Silva; Vitral, Robert Willer Farinazzo

2013-10-29

The present study aimed to determine and compare the anteroposterior position of the condyle in the mandibular fossa between groups of asymptomatic subjects with normal occlusion and asymptomatic subjects with Class I, Class II Division 1, and Class III malocclusions. Thirty persons with normal occlusion, 30 with Class I malocclusion, 30 with Class II Division 1, and 30 with Class III had computed tomography scans of their temporomandibular joints. The anterior joint space/posterior joint space (AJS/PJS) ratio was determined for the right and left joints. The paired t test was used to analyze the AJS/PJS ratio between both sides for each group. The ANOVA test was applied to verify the differences between the groups for the measurements of the right and left sides. In case the ANOVA test confirmed significance, the Dunnett's t test was performed to compare the groups of malocclusion with that of normal occlusion. The paired t test between the AJS/PJS relationships in the right and left sides showed the following p values: Class I (0.168), Class II Division 1 (0.662), Class III (0.991), and normal occlusion (0.390). The ANOVA test showed a p value of 0.445 for the comparisons of the right side and 0.040 for the left side. The Dunnett's t test demonstrated a statistically significant difference between the Class II group and the normal occlusion group (p value of 0.026) in the joints of the left side. Bilateral symmetry and lack of condyle centralization were common characteristics among all groups. The greatest condylar decentralization was observed in the Class II group, whereas the least condylar decentralization was found in the normal occlusion group.

Pocket nickel cadmium cell and battery evaluation

NASA Technical Reports Server (NTRS)

Lear, J. W.

1980-01-01

The Nickel Cadmium 129-ampere hour cell was tested in order to characterize the cell under controlled conditions. Results of charge characterization and discharge characterization are reported. Ampere hour efficiency, open circuit stand, and cycle life operation results are included. The battery is briefly described.

Gender, social class, and women's employment.

PubMed

McGinn, Kathleen L; Oh, Eunsil

2017-12-01

People in low-power positions, whether due to gender or class, tend to exhibit other-oriented rather than self-oriented behavior. Women's experiences at work and at home are shaped by social class, heightening identification with gender for relatively upper class women and identification with class for relatively lower class women, potentially mitigating, or even reversing, class-based differences documented in past research. Gender-class differences are reflected in women's employment beliefs and behaviors. Research integrating social class with gendered experiences in homes and workplaces deepens our understanding of the complex interplay between sources of power and status in society. Copyright © 2017 Elsevier Ltd. All rights reserved.

76 FR 9266 - Proposed Amendment of Class D and Class E Airspace; Idaho Falls, ID

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-17

...-0023; Airspace Docket No. 11-ANM-2] Proposed Amendment of Class D and Class E Airspace; Idaho Falls, ID...: This action proposes to amend the Class D and Class E airspace areas at Idaho Falls, ID, by changing the name of the airport to Idaho Falls Regional Airport, and adjusting the geographic coordinates of...

76 FR 30045 - Amendment of Class D and Class E Airspace; Columbus Lawson AAF, GA

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-24

... Columbus Lawson AAF, GA [AMENDED] Columbus Lawson AAF, GA (Lat. 32[deg]19'55'' N., long. 84[deg]59'14'' W...-0012; Airspace Docket No. 10-ASO-44] Amendment of Class D and Class E Airspace; Columbus Lawson AAF, GA...: This action would modify Class D and Class E airspace at Lawson Army Airfield (AAF), Columbus, GA, by...

Social Class Experiences of Working-Class Students: Transitioning out of College

ERIC Educational Resources Information Center

Treager Huber, Carey

2010-01-01

Issues surrounding social class are often overlooked and rarely discussed in higher education; however, they affect students and institutions in critical ways. Although research has demonstrated that social class is a predictor of access to college, retention, academic performance, overall undergraduate and graduate experience, and college…

78 FR 4306 - Amendment of Class D and Class E Airspace; Twentynine Palms, CA

Federal Register 2010, 2011, 2012, 2013, 2014

2013-01-22

... the safety and management of aircraft operations at Twentynine Palms SELF Airport, Twentynine Palms.... SUMMARY: This action amends Class D and Class E airspace at Twentynine Palms SELF Airport, Twentynine... name and geographic coordinates of Twentynine Palms SELF Airport, Twentynine Palms, CA. The Class D...

Changes in Cranial Base Morphology in Class I and Class II Division 1 Malocclusions

PubMed Central

Agarwal, Anirudh; Pandey, Harsh; Bajaj, Kamal; Pandey, Lavesh

2013-01-01

Introduction: The cranial base plays a key role in craniofacial growth; it helps to integrate spatially and functionally different patterns of growth in various adjoining regions of the skull such as components of the brain, the nasal and oral cavity and the pharynx. The aim of this study was to evaluate the difference in cranial base flexure between skeletal and dental Class I and Class II division 1. Materials & Methods: Lateral cephalometric radiograph, of Class I and Class II with an average growth pattern were analyzed and compared. A total of 103 patients having class I (n=52) and class II (n=51) malocclusion, were taken from Department of Orthodontics, Rajasthan Dental College & Hospital, Jaipur. Cranial base angle (N-S-Ar) and ANB were measured on pre treatment lateral cephalograms. Results: In this study cranial base angle did not show statistically significant difference between the two groups studied. Conclusion: In the assessment of orthodontic problems involving anteroposterior malrelationships of the jaws, the problem is usually the result of size, form and position of the jaw. The present study failed to find any differences in cranial base angle between sagittal malocclusions. How to cite this article: Agarwal A, Pandey H, Bajaj K, Pandey L. Changes in Cranial Base Morphology in Class I and Class II Division 1 Malocclusion. J Int Oral Health 2013; 5(1):39-42. PMID:24155576

Teaching Social Class

ERIC Educational Resources Information Center

Tablante, Courtney B.; Fiske, Susan T.

2015-01-01

Discussing socioeconomic status in college classes can be challenging. Both teachers and students feel uncomfortable, yet social class matters more than ever. This is especially true, given increased income inequality in the United States and indications that higher education does not reduce this inequality as much as many people hope. Resources…

Digital High-Current Monitor

NASA Technical Reports Server (NTRS)

Cash, B.

1985-01-01

Simple technique developed for monitoring direct currents up to several hundred amperes and digitally displaying values directly in current units. Used to monitor current magnitudes beyond range of standard laboratory ammeters, which typically measure 10 to 20 amperes maximum. Technique applicable to any current-monitoring situation.

Class E/F switching power amplifiers

NASA Technical Reports Server (NTRS)

Hajimiri, Seyed-Ali (Inventor); Aoki, Ichiro (Inventor); Rutledge, David B. (Inventor); Kee, Scott David (Inventor)

2004-01-01

The present invention discloses a new family of switching amplifier classes called class E/F amplifiers. These amplifiers are generally characterized by their use of the zero-voltage-switching (ZVS) phase correction technique to eliminate of the loss normally associated with the inherent capacitance of the switching device as utilized in class-E amplifiers, together with a load network for improved voltage and current wave-shaping by presenting class-F.sup.-1 impedances at selected overtones and class-E impedances at the remaining overtones. The present invention discloses a several topologies and specific circuit implementations for achieving such performance.

School Class Size: Research and Policy

ERIC Educational Resources Information Center

Glass, Gene V.; And Others

This book synthesizes research evidence to demonstrate that 1) class size is strongly related to pupil achievement; 2) smaller classes are more conducive to improved pupil performance than larger classes; 3) smaller classes provide more opportunities to adapt learning programs to individual needs; 4) pupils in smaller classes have more interest in…

The character strengths of class clowns.

PubMed

Ruch, Willibald; Platt, Tracey; Hofmann, Jennifer

2014-01-01

Class clowns traditionally were studied as a type concept and identified via sociometric procedures. In the present study a variable-centered approach was favored and class clown behaviors were studied in the context of character strengths, orientations to happiness and satisfaction with life. A sample of 672 Swiss children and adolescents filled in an 18 item self-report instrument depicting class clown behaviors. A hierarchical model of class clown behaviors was developed distinguishing a general factor and the four positively correlated dimensions of "identified as a class clown," "comic talent," "disruptive rule-breaker," and "subversive joker." Analysis of the general factor showed that class clowns were primarily male, and tended to be seen as class clowns by the teacher. Analyses of the 24 character strengths of the VIA-Youth (Park and Peterson, 2006) showed that class clowns were high in humor and leadership, and low in strengths like prudence, self-regulation, modesty, honesty, fairness, perseverance, and love of learning. An inspection of signature strengths revealed that 75% of class clowns had humor as a signature strength. Furthermore, class clown behaviors were generally shown by students indulging in a life of pleasure, but low life of engagement. The four dimensions yielded different character strengths profiles. While all dimensions of class clowns behaviors were low in temperance strengths, the factors "identified as the class clown" and "comic talent" were correlated with leadership strengths and the two negative factors ("disruptive rule-breaker," "subversive joker") were low in other directed strengths. The disruptive rule breaking class clown was additionally low in intellectual strengths. While humor predicted life satisfaction, class clowning tended to go along with diminished satisfaction with life. It is concluded that different types of class clowns need to be kept apart and need different attention by teachers.

The character strengths of class clowns

PubMed Central

Ruch, Willibald; Platt, Tracey; Hofmann, Jennifer

2014-01-01

Class clowns traditionally were studied as a type concept and identified via sociometric procedures. In the present study a variable-centered approach was favored and class clown behaviors were studied in the context of character strengths, orientations to happiness and satisfaction with life. A sample of 672 Swiss children and adolescents filled in an 18 item self-report instrument depicting class clown behaviors. A hierarchical model of class clown behaviors was developed distinguishing a general factor and the four positively correlated dimensions of “identified as a class clown,” “comic talent,” “disruptive rule-breaker,” and “subversive joker.” Analysis of the general factor showed that class clowns were primarily male, and tended to be seen as class clowns by the teacher. Analyses of the 24 character strengths of the VIA-Youth (Park and Peterson, 2006) showed that class clowns were high in humor and leadership, and low in strengths like prudence, self-regulation, modesty, honesty, fairness, perseverance, and love of learning. An inspection of signature strengths revealed that 75% of class clowns had humor as a signature strength. Furthermore, class clown behaviors were generally shown by students indulging in a life of pleasure, but low life of engagement. The four dimensions yielded different character strengths profiles. While all dimensions of class clowns behaviors were low in temperance strengths, the factors “identified as the class clown” and “comic talent” were correlated with leadership strengths and the two negative factors (“disruptive rule-breaker,” “subversive joker”) were low in other directed strengths. The disruptive rule breaking class clown was additionally low in intellectual strengths. While humor predicted life satisfaction, class clowning tended to go along with diminished satisfaction with life. It is concluded that different types of class clowns need to be kept apart and need different attention by

Making Class: Children's Perceptions of Social Class through Illustrations

ERIC Educational Resources Information Center

Howard, Adam; Swalwell, Katy; Adler, Karlyn

2018-01-01

Background/Context: Though there has been attention to how class differences impact children's experiences in schools and how young people perceive racial and gender differences, very little research to date has examined how young people make sense of social class differences. Purpose: In this article, the authors examine young children's…

Linking Classes: Learning Communities, "High" Culture, and the Working Class Student

ERIC Educational Resources Information Center

Rodriguez, Ginger G.; Buczinsky, Christopher

2013-01-01

How do you teach the humanities to working class students living in the shadow of a BP oil refinery? Calumet College uses freshman learning communities that link humanities, social justice, and English composition classes to provide a foundation for college success to predominantly first-generation students who are often underprepared for…

The Conversation Class

ERIC Educational Resources Information Center

Jackson, Acy L.

2012-01-01

The conversation class occupies a unique place in the process of learning English as a second or foreign language. From the author's own experience in conducting special conversation classes with Persian-speaking adults, he has drawn up a number of simple but important guidelines, some of which he hopes may provide helpful suggestions for the…

Characteristic classes of gauge systems

NASA Astrophysics Data System (ADS)

Lyakhovich, S. L.; Sharapov, A. A.

2004-12-01

We define and study invariants which can be uniformly constructed for any gauge system. By a gauge system we understand an (anti-)Poisson supermanifold provided with an odd Hamiltonian self-commuting vector field called a homological vector field. This definition encompasses all the cases usually included into the notion of a gauge theory in physics as well as some other similar (but different) structures like Lie or Courant algebroids. For Lagrangian gauge theories or Hamiltonian first class constrained systems, the homological vector field is identified with the classical BRST transformation operator. We define characteristic classes of a gauge system as universal cohomology classes of the homological vector field, which are uniformly constructed in terms of this vector field itself. Not striving to exhaustively classify all the characteristic classes in this work, we compute those invariants which are built up in terms of the first derivatives of the homological vector field. We also consider the cohomological operations in the space of all the characteristic classes. In particular, we show that the (anti-)Poisson bracket becomes trivial when applied to the space of all the characteristic classes, instead the latter space can be endowed with another Lie bracket operation. Making use of this Lie bracket one can generate new characteristic classes involving higher derivatives of the homological vector field. The simplest characteristic classes are illustrated by the examples relating them to anomalies in the traditional BV or BFV-BRST theory and to characteristic classes of (singular) foliations.

25 CFR 522.10 - Individually owned class II and class III gaming operations other than those operating on...

Code of Federal Regulations, 2010 CFR

2010-04-01

... 25 Indians 2 2010-04-01 2010-04-01 false Individually owned class II and class III gaming... GAMING COMMISSION, DEPARTMENT OF THE INTERIOR APPROVAL OF CLASS II AND CLASS III ORDINANCES AND RESOLUTIONS SUBMISSION OF GAMING ORDINANCE OR RESOLUTION § 522.10 Individually owned class II and class III...

A Model for Teaching Large Classes: Facilitating a "Small Class Feel"

ERIC Educational Resources Information Center

Lynch, Rosealie P.; Pappas, Eric

2017-01-01

This paper presents a model for teaching large classes that facilitates a "small class feel" to counteract the distance, anonymity, and formality that often characterize large lecture-style courses in higher education. One author (E. P.) has been teaching a 300-student general education critical thinking course for ten years, and the…

76 FR 28306 - Amendment of Class D and Class E Airspace; Idaho Falls, ID

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-17

...-0023; Airspace Docket No. 11-ANM-2] Amendment of Class D and Class E Airspace; Idaho Falls, ID AGENCY... D and Class E airspace at Idaho Falls, ID, by changing the name of the airport to Idaho Falls... Performance (RNP) standard instrument approach procedures at Idaho Falls Regional Airport. This improves the...

Lay theories about social class buffer lower-class individuals against poor self-rated health and negative affect.

PubMed

Tan, Jacinth J X; Kraus, Michael W

2015-03-01

The economic conditions of one's life can profoundly and systematically influence health outcomes over the life course. Our present research demonstrates that rejecting the notion that social class categories are biologically determined-a nonessentialist belief-buffers lower-class individuals from poor self-rated health and negative affect, whereas conceiving of social class categories as rooted in biology-an essentialist belief-does not. In Study 1, lower-class individuals self-reported poorer health than upper-class individuals when they endorsed essentialist beliefs but showed no such difference when they rejected such beliefs. Exposure to essentialist theories of social class also led lower-class individuals to report greater feelings of negative self-conscious emotions (Studies 2 and 3), and perceive poorer health (Study 3) than upper-class individuals, whereas exposure to nonessentialist theories did not lead to such differences. Discussion considers how lay theories of social class potentially shape long-term trajectories of health and affect of lower-class individuals. © 2015 by the Society for Personality and Social Psychology, Inc.

46 CFR 63.25-3 - Electric hot water supply boilers.

Code of Federal Regulations, 2013 CFR

2013-10-01

... boilers that meet the requirements of UL 174 may have temperature-pressure relief valves that meet the... having a current rating of more than 48 amperes and employing resistance type heating elements must have... supply boiler employing a resistance type immersion electric heating element, must not exceed 48 amperes...

46 CFR 63.25-3 - Electric hot water supply boilers.

Code of Federal Regulations, 2012 CFR

2012-10-01

... boilers that meet the requirements of UL 174 may have temperature-pressure relief valves that meet the... having a current rating of more than 48 amperes and employing resistance type heating elements must have... supply boiler employing a resistance type immersion electric heating element, must not exceed 48 amperes...

46 CFR 63.25-3 - Electric hot water supply boilers.

Code of Federal Regulations, 2014 CFR

2014-10-01

... boilers that meet the requirements of UL 174 may have temperature-pressure relief valves that meet the... having a current rating of more than 48 amperes and employing resistance type heating elements must have... supply boiler employing a resistance type immersion electric heating element, must not exceed 48 amperes...

Self-Education, Class and Gender in Edwardian Britain: Women in Lower Middle Class Families

ERIC Educational Resources Information Center

Sutherland, Gillian

2015-01-01

Once societies embarked on programmes of mass education home schooling became essentially a middle-class project and remains so. This paper looks at the educational experiences of some lower middle class women at the turn of the nineteenth and twentieth centuries for whom the resources of the middle-class home were simply not available. It…

Reading in Class & out of Class: An Experience Sampling Method Study

ERIC Educational Resources Information Center

Shumow, Lee; Schmidt, Jennifer A.; Kackar, Hayal

2008-01-01

This study described and compared the reading of sixth and eighth grade students both in and out of school using a unique data set collected with the Experience Sampling Method (ESM). On average, students read forty minutes a day out of class and seventeen minutes a day in class indicating that reading is a common leisure practice for…

Process simulations for the LCLS-II cryogenic systems

NASA Astrophysics Data System (ADS)

Ravindranath, V.; Bai, H.; Heloin, V.; Fauve, E.; Pflueckhahn, D.; Peterson, T.; Arenius, D.; Bevins, M.; Scanlon, C.; Than, R.; Hays, G.; Ross, M.

2017-12-01

Linac Coherent Light Source II (LCLS-II), a 4 GeV continuous-wave (CW) superconducting electron linear accelerator, is to be constructed in the existing two mile Linac facility at the SLAC National Accelerator Laboratory. The first light from the new facility is scheduled to be in 2020. The LCLS-II Linac consists of thirty-five 1.3 GHz and two 3.9 GHz superconducting cryomodules. The Linac cryomodules require cryogenic cooling for the super-conducting niobium cavities at 2.0 K, low temperature thermal intercept at 5.5-7.5 K, and a thermal shield at 35-55 K. The equivalent 4.5 K refrigeration capacity needed for the Linac operations range from a minimum of 11 kW to a maximum of 24 kW. Two cryogenic plants with 18 kW of equivalent 4.5 K refrigeration capacity will be used for supporting the Linac cryogenic cooling requirements. The cryogenic plants are based on the Jefferson Lab’s CHL-II cryogenic plant design which uses the “Floating Pressure” design to support a wide variation in the cooling load. In this paper, the cryogenic process for the integrated LCLS-II cryogenic system and the process simulation for a 4.5 K cryoplant in combination with a 2 K cold compressor box, and the Linac cryomodules are described.

24 CFR 3280.806 - Receptacle outlets.

Code of Federal Regulations, 2014 CFR

2014-04-01

..., 125-volt, either single or duplex. (b) All 120 volt single phase, 15 and 20 ampere receptacle outlets... Receptacle outlets. (b) All 125-volt, single-phase, 15- and 20-ampere receptacle outlets installed outdoors... 24 Housing and Urban Development 5 2014-04-01 2014-04-01 false Receptacle outlets. 3280.806...

How 'core' are motor timing difficulties in ADHD? A latent class comparison of pure and comorbid ADHD classes.

PubMed

van der Meer, Jolanda M J; Hartman, Catharina A; Thissen, Andrieke J A M; Oerlemans, Anoek M; Luman, Marjolein; Buitelaar, Jan K; Rommelse, Nanda N J

2016-04-01

Children with attention-deficit/hyperactivity disorder (ADHD) have motor timing difficulties. This study examined whether affected motor timing accuracy and variability are specific for ADHD, or that comorbidity with autism spectrum disorders (ASD) contributes to these motor timing difficulties. An 80-trial motor timing task measuring accuracy (μ), variability (σ) and infrequent long response times (τ) in estimating a 1-s interval was administered to 283 children and adolescents (8-17 years) from both a clinic and population based sample. They were divided into four latent classes based on the SCQ and L data. These classes were: without behavioral problems 'Normal-class' (n = 154), with only ADHD symptoms 'ADHD-class' (n = 49), and two classes with both ASD and ADHD symptoms; ADHD(+ASD)-class (n = 39) and ASD(+ADHD)-class (n = 41). The pure ADHD-class did not deviate from the Normal class on any of the motor timing measures (mean RTs 916 and 925 ms, respectively). The comorbid ADHD(+ASD) and ASD(+ADHD) classes were significantly less accurate (more time underestimations) compared to the Normal class (mean RTs 847 and 870 ms, respectively). Variability in motor timing was reduced in the younger children in the ADHD(+ASD) class, which may reflect a tendency to rush the tedious task. Only patients with more severe behavioral symptoms show motor timing deficiencies. This cannot merely be explained by high ADHD severity with ASD playing no role, as ADHD symptom severity in the pure ADHD-class and the ASD(+ADHD) class was highly similar, with the former class showing no motor timing deficits.

Making the Introductory Journalism Class Tick.

ERIC Educational Resources Information Center

Dorway, Tim

2003-01-01

Proposes that beginning journalism classes teach multiple skills, including law, decision-making, interpersonal communication, interviewing, and critical thinking. Outlines how to convince administrators of the need for beginning journalism classes, and how to develop an effective class. Lists philosophy and course goals for one such class. (PM)

Education, Social Class and Social Exclusion.

ERIC Educational Resources Information Center

Whitty, Geoff

2001-01-01

Concerned about working-class failure, argues that recent (British) government policies have insufficiently considered sociological studies on how social class affects educational success or failure. Social-inclusion policies must address forms of middle-class self-exclusion from mainstream public education as well as working-class social…

Contrasting evolutionary histories of MHC class I and class II loci in grouse—effects of selection and gene conversion

PubMed Central

Minias, P; Bateson, Z W; Whittingham, L A; Johnson, J A; Oyler-McCance, S; Dunn, P O

2016-01-01

Genes of the major histocompatibility complex (MHC) encode receptor molecules that are responsible for recognition of intracellular and extracellular pathogens (class I and class II genes, respectively) in vertebrates. Given the different roles of class I and II MHC genes, one might expect the strength of selection to differ between these two classes. Different selective pressures may also promote different rates of gene conversion at each class. Despite these predictions, surprisingly few studies have looked at differences between class I and II genes in terms of both selection and gene conversion. Here, we investigated the molecular evolution of MHC class I and II genes in five closely related species of prairie grouse (Centrocercus and Tympanuchus) that possess one class I and two class II loci. We found striking differences in the strength of balancing selection acting on MHC class I versus class II genes. More than half of the putative antigen-binding sites (ABS) of class II were under positive or episodic diversifying selection, compared with only 10% at class I. We also found that gene conversion had a stronger role in shaping the evolution of MHC class II than class I. Overall, the combination of strong positive (balancing) selection and frequent gene conversion has maintained higher diversity of MHC class II than class I in prairie grouse. This is one of the first studies clearly demonstrating that macroevolutionary mechanisms can act differently on genes involved in the immune response against intracellular and extracellular pathogens. PMID:26860199

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

Eddy, N.; Fellenz, B.; Prieto, P.

The first cryomodule for the beam test facility at the Fermilab New-Muon-Lab building is currently under RF commissioning. Among other diagnostics systems, the transverse position of the helium gas return pipe with the connected 1.3 GHz SRF accelerating cavities is measured along the {approx}15 m long module using a stretched-wire position monitoring system. An overview of the wire position monitor system technology is given, along with preliminary results taken at the initial module cooldown, and during further testing. As the measurement system offers a high resolution, we also discuss options for use as a vibration detector. An electron beam testmore » facility, based on superconducting RF (SRF) TESLA-style cryomodules is currently under construction at the Fermilab New-Muon-Lab (NML) building. The first, so-called type III+, cryomodule (CM-1), equipped with eight 1.3 GHz nine-cell accelerating cavities was recently cooled down to 2 K, and is currently under RF conditioning. The transverse alignment of the cavity string within the cryomodule is crucial for minimizing transverse kick and beam break-up effects, generated by the high-order dipole modes of misaligned accelerating structures. An optimum alignment can only be guaranteed during the assembly of the cavity string, i.e. at room temperatures. The final position of the cavities after cooldown is uncontrollable, and therefore unknown. A wire position monitoring system (WPM) can help to understand the transverse motion of the cavities during cooldown, their final location and the long term position stability after cryo-temperatures are settled, as well as the position reproducibility for several cold-warm cycles. It also may serve as vibration sensor, as the wire acts as a high-Q resonant detector for mechanical vibrations in the low-audio frequency range. The WPM system consists out of a stretched-wire position detection system, provided with help of INFN-Milano and DESY Hamburg, and RF generation and read

Early talk about the past revisited: affect in working-class and middle-class children's co-narrations.

PubMed

Burger, L K; Miller, P J

1999-02-01

This study contributes to our understanding of sociocultural variation in children's early storytelling by comparing co-narrations produced by children and their families from two European-American communities, one working-class and one middle-class. Six children from each community were observed in their homes at 2;6 and 3;0 years of age, yielding a corpus of nearly 400 naturally-occurring co-narrations of past experience. Analyses of generic properties, content, and emotion talk revealed a complex configuration of similarities and differences. Working-class and middle-class families produced co-narrations that were similar in referential/evaluative functions and temporal structure, with a preponderance of positive content. Working-class families produced twice as many co-narrations as their middle-class counterparts, produced more negative emotion talk, and used more dramatic language for conveying negative emotional experience. These findings suggest that (1) differentiation between working-class and middle-class communities in the content of early narratives may occur primarily with respect to negative experience and (2) researchers need to go beyond emotion state terms in order to accurately represent sociocultural variation in personal storytelling.

Class-Size Effects in Secondary School

ERIC Educational Resources Information Center

Krassel, Karl Fritjof; Heinesen, Eskil

2014-01-01

We analyze class-size effects on academic achievement in secondary school in Denmark exploiting an institutional setting where pupils cannot predict class size prior to enrollment, and where post-enrollment responses aimed at affecting realized class size are unlikely. We identify class-size effects combining a regression discontinuity design with…

7 CFR 28.4 - Classing offices.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false Classing offices. 28.4 Section 28.4 Agriculture... § 28.4 Classing offices. Classing Offices shall be maintained at points designated by the Administrator. Requests for the review of the classification and/or comparison of cotton performed by Classing Offices may...

16 CFR 1025.18 - Class actions.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 16 Commercial Practices 2 2011-01-01 2011-01-01 false Class actions. 1025.18 Section 1025.18... PROCEEDINGS Pleadings, Form, Execution, Service of Documents § 1025.18 Class actions. (a) Prerequisites to a class action. One or more members of a class of respondents may be proceeded against as representative...

Contrasting evolutionary histories of MHC class I and class II loci in grouse—Effects of selection and gene conversion

USGS Publications Warehouse

Minias, Piotr; Bateson, Zachary W.; Whittingham, Linda A.; Johnson, Jeff A.; Oyler-McCance, Sara J.; Dunn, Peter O.

2016-01-01

Genes of the major histocompatibility complex (MHC) encode receptor molecules that are responsible for recognition of intracellular and extracellular pathogens (class I and class II genes, respectively) in vertebrates. Given the different roles of class I and II MHC genes, one might expect the strength of selection to differ between these two classes. Different selective pressures may also promote different rates of gene conversion at each class. Despite these predictions, surprisingly few studies have looked at differences between class I and II genes in terms of both selection and gene conversion. Here, we investigated the molecular evolution of MHC class I and II genes in five closely related species of prairie grouse (Centrocercus and Tympanuchus) that possess one class I and two class II loci. We found striking differences in the strength of balancing selection acting on MHC class I versus class II genes. More than half of the putative antigen-binding sites (ABS) of class II were under positive or episodic diversifying selection, compared with only 10% at class I. We also found that gene conversion had a stronger role in shaping the evolution of MHC class II than class I. Overall, the combination of strong positive (balancing) selection and frequent gene conversion has maintained higher diversity of MHC class II than class I in prairie grouse. This is one of the first studies clearly demonstrating that macroevolutionary mechanisms can act differently on genes involved in the immune response against intracellular and extracellular pathogens.

Oil and gas: Oilfield class actions

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

McArthur, J.B.

1997-06-01

The use of class actions is getting alot of attention in the oilfield. Plaintiffs have filed class actions challenging two of the most rooted industry practices, oil posted prices and deregulated natural gas affiliate deduction and charges. The classes will include tens or hundreds of thousands of plaintiffs and may transform two of the industry`s most settled practices. The emotions surrounding the class action risk obscuring the fact that it is an old and oft-used tool in oilfield litigation. The class action {open_quotes}provides a means by which, where a large group of persons are interested in a matter, one ormore » more may sue or be sued as representatives of the class without needing to join every member of the class.{close_quotes} The procedure avoids waste by combining scattered disputes, even if some injured might sue individually, and it enables plaintiffs who could not afford to sue to be represented anyway. The lawyers draw their fees from any recovery. Almost all oilpatch class actions are brought to resolve a {open_quotes}common question{close_quotes} under Federal Rules of Civil Procedure 23(b)(3) or state counterparts. The rule`s {open_quotes}opt-out{close_quotes} provisions give class actions a tremendous boost because members stay in unless they take steps to get out. This article discusses present and future class actions.« less

Class Action Suits against Public Schools.

ERIC Educational Resources Information Center

Mesibov, Laurie

1984-01-01

If a suit is brought as a class action, either plaintiff or defendant may move to uphold or challenge class certification. If neither does so, the court decides whether the action may be maintained as a class suit. Prerequisites for class certification from Rule 23 (Federal Rules of Civil Procedure) are explained. (TE)

Making the Invisible More Visible: Home Literacy Practices of Middle-Class and Working-Class Families.

ERIC Educational Resources Information Center

McCarthey, Sarah J.

1997-01-01

Interviews with eight families showed that literacy materials and goals for using literacy differed between middle and working class families, with middle class families drawing on more resources to learn about the child's classroom. However, all families expressed value for literacy activities, challenging the myth that working-class families do…

Imbalanced class learning in epigenetics.

PubMed

Haque, M Muksitul; Skinner, Michael K; Holder, Lawrence B

2014-07-01

In machine learning, one of the important criteria for higher classification accuracy is a balanced dataset. Datasets with a large ratio between minority and majority classes face hindrance in learning using any classifier. Datasets having a magnitude difference in number of instances between the target concept result in an imbalanced class distribution. Such datasets can range from biological data, sensor data, medical diagnostics, or any other domain where labeling any instances of the minority class can be time-consuming or costly or the data may not be easily available. The current study investigates a number of imbalanced class algorithms for solving the imbalanced class distribution present in epigenetic datasets. Epigenetic (DNA methylation) datasets inherently come with few differentially DNA methylated regions (DMR) and with a higher number of non-DMR sites. For this class imbalance problem, a number of algorithms are compared, including the TAN+AdaBoost algorithm. Experiments performed on four epigenetic datasets and several known datasets show that an imbalanced dataset can have similar accuracy as a regular learner on a balanced dataset.

Stainless Steel to Titanium Bimetallic Transitions

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

Kaluzny, J. A.; Grimm, C.; Passarelli, D.

In order to use stainless steel piping in an LCLS-II (Linac Coherent Light Source Upgrade) cryomodule, stainless steel to titanium bimetallic transitions are needed to connect the stainless steel piping to the titanium cavity helium vessel. Explosion bonded stainless steel to titanium transition pieces and bimetallic transition material samples have been tested. A sample transition tube was subjected to tests and x-ray examinations between tests. Samples of the bonded joint material were impact and tensile tested at room temperature as well as liquid helium temperature. The joint has been used successfully in horizontal tests of LCLS-II cavity helium vessels andmore » is planned to be used in LCLS-II cryomodules. Results of material sample and transition tube tests will be presented.« less

Magnetic Flux Expulsion Studies in Niobium SRF Cavities

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

Posen, Sam; Checchin, Mattia; Crawford, Anthony

2016-06-01

With the recent discovery of nitrogen doping treatment for SRF cavities, ultra-high quality factors at medium accelerating fields are regularly achieved in vertical RF tests. To preserve these quality factors into the cryomodule, it is important to consider background magnetic fields, which can become trapped in the surface of the cavity during cooldown and cause Q₀ degradation. Building on the recent discovery that spatial thermal gradients during cooldown can significantly improve expulsion of magnetic flux, a detailed study was performed of flux expulsion on two cavities with different furnace treatments that are cooled in magnetic fields amplitudes representative of whatmore » is expected in a realistic cryomodule. In this contribution, we summarize these cavity results, in order to improve understanding of the impact of flux expulsion on cavity performance.« less

A Touch of...Class!

ERIC Educational Resources Information Center

Netten, Joan W., Ed.

1984-01-01

A collection of ideas for class activities in elementary and secondary language classes includes a vocabulary review exercise and games of memory, counting, vocabulary, flashcard tic-tac-toe, dice, trashcans, questioning, and spelling. Some are designed specifically for French. (MSE)

When Mode Does Not Matter: Evaluation in Class versus Out of Class

ERIC Educational Resources Information Center

Kordts-Freudinger, Robert; Geithner, Eva

2013-01-01

This article investigates if online evaluation leads to different results than paper-and-pencil evaluation. Given that most previous studies confound the evaluation mode (online versus paper) with the evaluation situation (in class versus after class), we expected that evaluation results would be influenced only by the evaluation situation,…

Electron-ion collider: The next QCD frontier: Understanding the glue that binds us all

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

Accardi, A.; Albacete, J. L.; Anselmino, M.

This White Paper presents the science case of an Electron-Ion Collider (EIC), focused on the structure and interactions of gluon-dominated matter, with the intent to articulate it to the broader nuclear science community. It was commissioned by the managements of Brookhaven National Laboratory (BNL) and Thomas Jefferson National Accelerator Facility (JLab) with the objective of presenting a summary of scientific opportunities and goals of the EIC as a follow-up to the 2007 NSAC Long Range plan. This document is a culmination of a community-wide effort in nuclear science following a series of workshops on EIC physics over the past decadesmore » and, in particular, the focused ten-week program on “Gluons and quark sea at high energies” at the Institute for Nuclear Theory in Fall 2010. It contains a brief description of a few golden physics measurements along with accelerator and detector concepts required to achieve them. It has been benefited profoundly from inputs by the users’ communities of BNL and JLab. Furthermore, this White Paper offers the promise to propel the QCD science program in the US, established with the CEBAF accelerator at JLab and the RHIC collider at BNL, to the next QCD frontier.« less

Electron-ion collider: The next QCD frontier: Understanding the glue that binds us all

DOE PAGES

Accardi, A.; Albacete, J. L.; Anselmino, M.; ...

2016-09-08

This White Paper presents the science case of an Electron-Ion Collider (EIC), focused on the structure and interactions of gluon-dominated matter, with the intent to articulate it to the broader nuclear science community. It was commissioned by the managements of Brookhaven National Laboratory (BNL) and Thomas Jefferson National Accelerator Facility (JLab) with the objective of presenting a summary of scientific opportunities and goals of the EIC as a follow-up to the 2007 NSAC Long Range plan. This document is a culmination of a community-wide effort in nuclear science following a series of workshops on EIC physics over the past decadesmore » and, in particular, the focused ten-week program on “Gluons and quark sea at high energies” at the Institute for Nuclear Theory in Fall 2010. It contains a brief description of a few golden physics measurements along with accelerator and detector concepts required to achieve them. It has been benefited profoundly from inputs by the users’ communities of BNL and JLab. Furthermore, this White Paper offers the promise to propel the QCD science program in the US, established with the CEBAF accelerator at JLab and the RHIC collider at BNL, to the next QCD frontier.« less

Cosmic Ray Tests of Gas Electron Multipliers

NASA Astrophysics Data System (ADS)

Harris, Letrell; Kohl, Michael; Super Bigbite Spectrometer Collaboration; MUSE Collaboration; Hampton University Collaboration; DarkLight Collaboration

2017-09-01

The Super Bigbite Spectrometer (SBS) collaboration at Jefferson Laboratory (Jlab) is conducting an experimental program to measure the elastic form factors of nucleons. In association with Jlab, SBS Gas Electron Multipliers (GEMs) have been constructed by the University of Virginia (back trackers) and INFN in Italy (front trackers). The SBS GEMs measuring 40 × 150 cm2 (front trackers) and 60 × 200 cm2 (back trackers) in surface area are in the process of being conditioned and analyzed for tracking efficiency using cosmic rays in a clean room test lab before further assembly in the fall. These GEMs will be used to track the path of particles scattered off nuclear targets. Scintillators are placed both above and below GEM stacks to trigger a readout. In addition, Hampton University has also constructed a set of 10 × 10 cm2 GEMs originally for the OLYMPUS experiment at DESY in Germany, which are now being used for both the MUSE experiment at Paul Scherrer Institute (PSI) in Switzerland and the DarkLight experiment at Jlab's Low Energy Recirculatory Facility (LERF), where they are in the process of being characterized with cosmic rays. Jefferson Laboratory. This work has been supported by Jefferson Laboratory.

75 FR 65250 - Proposed Amendment of Class E Airspace and Revocation of Class E Airspace; Easton, MD

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-22

... rulemaking (NPRM). SUMMARY: This action proposes to modify Class E surface airspace and airspace 700 feet... modify Class E surface airspace and Class E airspace extending upward from 700 feet above the surface to... Class E airspace extending upward from 700 feet above the surface are published in Paragraph 6002, 6004...

78 FR 72006 - Establishment of Class D Airspace and Class E Airspace; Laguna AAF, AZ

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-02

... establishes Class D airspace and Class E airspace at Laguna Army Air Field (AAF), (Yuma Proving Ground), Yuma...) within a 3.5- mile radius of Laguna AAF (Yuma Proving Ground), Yuma, AZ; and Class E airspace extending... scope of that authority as it establishes controlled airspace at Laguna AAF, (Yuma Proving Ground), Yuma...

Active site nanospace of aminoacyl tRNA synthetase: difference between the class I and class II synthetases.

PubMed

Dutta, Saheb; Choudhury, Kaberi; Banik, Sindrila Dutta; Nandi, Nilashis

2014-03-01

The present work is aimed at understanding the origin of the difference in the molecular organization of the active site nanospaces of the class I and class II aminoacyl tRNA synthetases (aaRSs) which are tunnel-like structures. The active site encloses the cognate amino acid (AA) and the adenosine triphosphate (ATP) to carry out aminoacylation reaction. Comparison of the structures of the active site of the class I and class II (aaRSs) shows that the nanodimensional tunnels are curved in opposite directions in the two classes. We investigated the origin of this difference using quantum mechanical computation of electrostatic potential (ESP) of substrates, surrounding residues and ions, using Atoms in Molecule (AIM) Theory and charge population analysis. We show that the difference is principally due to the variation in the spatial charge distribution of ATP in the two classes which correspond to extended and bent conformations of ATP. The present computation shows that the most feasible pathway for nucleophilic attack to alphaP is oppositely directed for class I and class II aaRSs. The available crystal structures show that the cognate AA is indeed located along the channel favorable for nucleophilic attack as predicted by the ESP analysis. It is also shown that the direction of the channel changes its orientation when the orientation of ATP is changed from extended to a bent like structure. We further used the AIM theory to confirm the direction of the approach of AA in each case and the results corroborate the results from the ESP analysis. The opposite curvatures of the active site nanospaces in class I and class II aaRSs are related with the influence of the charge distributions of the extended and bent conformations of ATP, respectively. The results of the computation of electrostatic potential by successive addition of active site residues show that their roles on the reaction are similar in both classes despite the difference in the organization of the

Gender and the Construction of Class.

ERIC Educational Resources Information Center

Acker, Joan

Only by recognizing that class is not gender neutral can the processes of class formation and reproduction be understood. Class is defined as a process in which human beings take an active part, rather than a structure of categories into which individuals may be inserted. Gender organizes or structures class in many different ways. For example,…

Characteristics of the Class of 1974.

ERIC Educational Resources Information Center

Houston, John W.; Cooke, James L.

The biographical characteristics and achievements of the 1373 cadets who entered the Class of 1974 are presented. A separate report compares selected characteristics of this class with previous classes. In order to obtain data on the American College Testing Program, the ACT was administered to 1336 members of the Class of 1974 in July 1970.…

Revisiting Parametric Types and Virtual Classes

NASA Astrophysics Data System (ADS)

Madsen, Anders Bach; Ernst, Erik

This paper presents a conceptually oriented updated view on the relationship between parametric types and virtual classes. The traditional view is that parametric types excel at structurally oriented composition and decomposition, and virtual classes excel at specifying mutually recursive families of classes whose relationships are preserved in derived families. Conversely, while class families can be specified using a large number of F-bounded type parameters, this approach is complex and fragile; and it is difficult to use traditional virtual classes to specify object composition in a structural manner, because virtual classes are closely tied to nominal typing. This paper adds new insight about the dichotomy between these two approaches; it illustrates how virtual constraints and type refinements, as recently introduced in gbeta and Scala, enable structural treatment of virtual types; finally, it shows how a novel kind of dynamic type check can detect compatibility among entire families of classes.

Social class, contextualism, and empathic accuracy.

PubMed

Kraus, Michael W; Côté, Stéphane; Keltner, Dacher

2010-11-01

Recent research suggests that lower-class individuals favor explanations of personal and political outcomes that are oriented to features of the external environment. We extended this work by testing the hypothesis that, as a result, individuals of a lower social class are more empathically accurate in judging the emotions of other people. In three studies, lower-class individuals (compared with upper-class individuals) received higher scores on a test of empathic accuracy (Study 1), judged the emotions of an interaction partner more accurately (Study 2), and made more accurate inferences about emotion from static images of muscle movements in the eyes (Study 3). Moreover, the association between social class and empathic accuracy was explained by the tendency for lower-class individuals to explain social events in terms of features of the external environment. The implications of class-based patterns in empathic accuracy for well-being and relationship outcomes are discussed.

Working-Class Women's Ways of Knowing: Effects of Gender, Race and Class.

ERIC Educational Resources Information Center

Luttrell, Wendy

1989-01-01

Analyzes the way black and white working-class women define and claim knowledge, challenging feminist analyses that have identified a single or universal mode of knowing for women. Contends that women speak to complex gender, racial, and class relations of power that shape how they think about learning and knowing. (Author/SLM)

The Ampere and Electrical Standards

PubMed Central

Elmquist, Randolph E.; Cage, Marvin E.; Tang, Yi-hua; Jeffery, Anne-Marie; Kinard, Joseph R.; Dziuba, Ronald F.; Oldham, Nile M.; Williams, Edwin R.

2001-01-01

This paper describes some of the major contributions to metrology and physics made by the NIST Electricity Division, which has existed since 1901. It was one of the six original divisions of the National Bureau of Standards. The Electricity Division provides dc and low-frequency calibrations for industrial, scientific, and research organizations, and conducts research on topics related to electrical metrology and fundamental constants. The early work of the Electricity Division staff included the development of precision standards, such as Rosa and Thomas standard resistors and the ac-dc thermal converter. Research contributions helped define the early international system of measurement units and bring about the transition to absolute units based on fundamental principles and physical and dimensional measurements. NIST research has helped to develop and refine electrical standards using the quantum Hall effect and the Josephson effect, which are both based on quantum physics. Four projects covering a number of voltage and impedance measurements are described in detail. Several other areas of current research at NIST are described, including the use of the Internet for international compatibility in metrology, determination of the fine-structure and Planck constants, and construction of the electronic kilogram. PMID:27500018

Reanalyzing the Ampere-Maxwell Law

ERIC Educational Resources Information Center

Hill, S. Eric

2011-01-01

In a recent "TPT" article, I addressed a common miscommunication about Faraday's law, namely, that introductory texts often say the law expresses a causal relationship between the magnetic fields time variation and the electric fields circulation. In that article, I demonstrated that these field behaviors share a common cause in a time-varying…

Working-Class Boys, Educational Success and the Misrecognition of Working-Class Culture

ERIC Educational Resources Information Center

Ingram, Nicola

2009-01-01

This article contributes to the theory of institutional habitus by exploring the differing ways in which the institutional habitus of two schools in Belfast, Northern Ireland mediates the local habitus of working-class boys. All of the boys in this qualitative case study live in the same disadvantaged working-class community but attend two…

Class Discussions: Locating Social Class in Novels for Children and Young Adults

ERIC Educational Resources Information Center

McLeod, Cynthia Anne

2008-01-01

Few studies on representations of social class in children's literature have been published in the United States. As a language arts teacher and media specialist in a high poverty school, the author describes children's novels that directly address social class and the subtopic of the labor movement and consider the continued relevance of social…

Making the middle classes on shifting ground? Residential status, performativity and middle-class subjectivities in contemporary London.

PubMed

Benson, Michaela; Jackson, Emma

2017-06-01

This paper argues that shifts in access to housing - both in relation to rental and ownership - disrupt middle-class reproduction in ways that fundamentally influence class formation. While property ownership has had a long association with middle-class identities, status and distinction, an increasingly competitive rental market alongside inflated property prices has impacted on expectations and anxieties over housing futures. In this paper, we consider two key questions: (1) What happens to middle-class identities under the conditions of this wider structural change? (2) How do the middle classes variously manoeuvre within this? Drawing on empirical research conducted in London, we demonstrate that becoming an owner-occupier may be fractured along lines of class but also along the axes of age, wealth and timing, particularly as this relates to the housing market. It builds on understandings of residential status and place as central to the formation of class, orienting this around the recognition of both people and place as mutable, emphasizing that changing economic and social processes generate new class positionalities and strategies for class reproduction. We argue that these processes are writ large in practices of belonging and claims to place, with wider repercussions within the urban landscape. © London School of Economics and Political Science 2017.

Longitudinal analysis of latent classes of psychopathology and patterns of class migration in survivors of severe injury.

PubMed

Forbes, David; Nickerson, Angela; Alkemade, Nathan; Bryant, Richard A; Creamer, Mark; Silove, Derrick; McFarlane, Alexander C; Van Hooff, Miranda; Fletcher, Susan L; O'Donnell, Meaghan

2015-09-01

Little research to date has explored the typologies of psychopathology following trauma, beyond development of particular diagnoses such as posttraumatic stress disorder (PTSD). The objective of this study was to determine the longitudinal patterns of these typologies, especially the movement of persons across clusters of psychopathology. In this 6-year longitudinal study, 1,167 hospitalized severe injury patients who were recruited between April 2004-February 2006 were analyzed, with repeated measures at baseline, 3 months, 12 months, and 72 months after injury. All patients met the DSM-IV criterion A1 for PTSD. Structured clinical interviews were used to assess psychiatric disorders at each follow-up point. Latent class analysis and latent transition analysis were applied to assess clusters of individuals determined by psychopathology. The Mini International Neuropsychiatric Interview (MINI) and Clinician-Administered PTSD Scale (CAPS) were employed to complete diagnoses. Four latent classes were identified at each time point: (1) Alcohol/Depression class (3 months, 2.1%; 12 months, 1.3%; and 72 months, 1.1%), (2) Alcohol class (3 months, 3.3%; 12 months, 3.7%; and 72 months, 5.4%), (3) PTSD/Depression class (3 months, 10.3%; 12 months, 11.5%; and 72 months, 6.4%), and (4) No Disorder class (3 months, 84.2%; 12 months, 83.5%; and 72 months, 87.1%). Latent transition analyses conducted across the 2 transition points (12 months and 72 months) found consistently high levels of stability in the No Disorder class (90.9%, 93.0%, respectively) but lower and reducing levels of consistency in the PTSD/Depression class (81.3%, 46.6%), the Alcohol/Depression class (59.7%, 21.5%), and the Alcohol class (61.0%, 36.5%), demonstrating high levels of between-class migration. Despite the array of psychiatric disorders that may develop following severe injury, a 4-class model best described the data with excellent classification certainty. The high levels of migration across

Maintaining a Class M 5.5 environment in a Class M 6.5 cleanroom

NASA Astrophysics Data System (ADS)

Hughes, David W.; Hedgeland, Randy J.; Geer, Wayne C.; Greenberg, Barry N.

1994-10-01

During Kennedy Space Center processing of the Hubble Space Telescope First Servicing Mission, critical optical components were integrated in a Class 100,000 (M 6.5 at 0.5 micrometers and 5.0 micrometers , per Fed-Std 209E) cleanroom. A Class 10,000 (M 5.5) environment was mandated by the 400B (per Mil-Std 1246B) surface cleanliness requirement of the Scientific Instruments. To maintain a Class M 5.5 environment, a contamination control plan was implemented which addressed personnel constraints, operations, and site management. This plan limited personnel access, imposed strict gowning requirements, and increased cleanroom janitorial operations, prohibited operations known to generate contamination while sensitive hardware was exposed to the environment, and controlled roadwork, insecticide spraying, and similar activities. Facility preparations included a ceiling to floor cleaning, sealing of vents and doors, and revising the garment change room entry patterns. The cleanroom was successfully run below Class 5000 while the instruments were present; certain operations, however, were observed to cause local contamination levels to increase above Class M 5.5.

Collector/collector guard ring balancing circuit eliminates edge effects

NASA Technical Reports Server (NTRS)

Lieb, D. P.

1966-01-01

Circuit in which an emitter is maintained opposite a concentric collector and guard structure is achieved by matching the temperature and potential of the guard with that of the collector over the operating range. This control system is capable of handling up to 100 amperes in the guard circuit and 200 amperes in the collectors circuit.

Social class rank, essentialism, and punitive judgment.

PubMed

Kraus, Michael W; Keltner, Dacher

2013-08-01

Recent evidence suggests that perceptions of social class rank influence a variety of social cognitive tendencies, from patterns of causal attribution to moral judgment. In the present studies we tested the hypotheses that upper-class rank individuals would be more likely to endorse essentialist lay theories of social class categories (i.e., that social class is founded in genetically based, biological differences) than would lower-class rank individuals and that these beliefs would decrease support for restorative justice--which seeks to rehabilitate offenders, rather than punish unlawful action. Across studies, higher social class rank was associated with increased essentialism of social class categories (Studies 1, 2, and 4) and decreased support for restorative justice (Study 4). Moreover, manipulated essentialist beliefs decreased preferences for restorative justice (Study 3), and the association between social class rank and class-based essentialist theories was explained by the tendency to endorse beliefs in a just world (Study 2). Implications for how class-based essentialist beliefs potentially constrain social opportunity and mobility are discussed.

Identifying classes of persons with mild intellectual disability or borderline intellectual functioning: a latent class analysis.

PubMed

Nouwens, Peter J G; Lucas, Rosanne; Smulders, Nienke B M; Embregts, Petri J C M; van Nieuwenhuizen, Chijs

2017-07-17

Persons with mild intellectual disability or borderline intellectual functioning are often studied as a single group with similar characteristics. However, there are indications that differences exist within this population. Therefore, the aim of this study was to identify classes of persons with mild intellectual disability or borderline intellectual functioning and to examine whether these classes are related to individual and/or environmental characteristics. Latent class analysis was performed using file data of 250 eligible participants with a mean age of 26.1 (SD 13.8, range 3-70) years. Five distinct classes of persons with mild intellectual disability or borderline intellectual functioning were found. These classes significantly differed in individual and environmental characteristics. For example, persons with a mild intellectual disability experienced fewer problems than those with borderline intellectual disability. The identification of five classes implies that a differentiated approach is required towards persons with mild intellectual disability or borderline intellectual functioning.

14 CFR 71.51 - Class C airspace.

Code of Federal Regulations, 2013 CFR

2013-01-01

... DESIGNATION OF CLASS A, B, C, D, AND E AIRSPACE AREAS; AIR TRAFFIC SERVICE ROUTES; AND REPORTING POINTS Class C Airspace § 71.51 Class C airspace. The Class C airspace areas listed in subpart C of FAA Order... 14 Aeronautics and Space 2 2013-01-01 2013-01-01 false Class C airspace. 71.51 Section 71.51...

14 CFR 71.51 - Class C airspace.

Code of Federal Regulations, 2010 CFR

2010-01-01

... DESIGNATION OF CLASS A, B, C, D, AND E AIRSPACE AREAS; AIR TRAFFIC SERVICE ROUTES; AND REPORTING POINTS Class C Airspace § 71.51 Class C airspace. The Class C airspace areas listed in subpart C of FAA Order... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Class C airspace. 71.51 Section 71.51...

CLASS Shifts in Modeling Instruction

NASA Astrophysics Data System (ADS)

Brewe, Eric; Kramer, Laird; O'Brien, George

2008-10-01

Among the most surprising findings in Physics Education Research is the lack of positive results on attitudinal measures, such as Colorado Learning Attitudes about Science Survey (CLASS) and Maryland Physics Expectations Survey (MPEX). The uniformity with which physics teaching manages to negatively shift attitudes toward physics learning is striking. Strategies which have been shown to improve learning, such as interactive engagement and studio format classes, provide more authentic science experiences for students, yet do not produce positive attitudinal results. Florida International University's Physics Education Research Group has implemented Modeling Instruction in University Physics classes. Using the CLASS as a pre/post measure has shown attitudinal improvements through both semesters of the introductory physics sequence. In this paper, we report positive shifts on the CLASS in two sections of Modeling Physics, one in Mechanics (N=30) and one in Electricity and Magnetism, (N=31) and examine how these results reflect on Modeling Instruction.

78 FR 72056 - Proposed Amendment of Class D and Class E Airspace; Christiansted, St. Croix, VI

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-02

... Class D and Class E Airspace; Christiansted, St. Croix, VI AGENCY: Federal Aviation Administration (FAA... Class E Airspace at Christiansted, St. Croix, VI, to adjust the geographic coordinates of Henry E..., Christiansted, St. Croix, VI, to bring it in concert with the FAAs aeronautical database. The coordinates would...

A Novel Way to Relate Ontology Classes

PubMed Central

Choksi, Ami T.; Jinwala, Devesh C.

2015-01-01

The existing ontologies in the semantic web typically have anonymous union and intersection classes. The anonymous classes are limited in scope and may not be part of the whole inference process. The tools, namely, the pellet, the jena, and the protégé, interpret collection classes as (a) equivalent/subclasses of union class and (b) superclasses of intersection class. As a result, there is a possibility that the tools will produce error prone inference results for relations, namely, sub-, union, intersection, equivalent relations, and those dependent on these relations, namely, complement. To verify whether a class is complement of other involves utilization of sub- and equivalent relations. Motivated by the same, we (i) refine the test data set of the conference ontology by adding named, union, and intersection classes and (ii) propose a match algorithm to (a) calculate corrected subclasses list, (b) correctly relate intersection and union classes with their collection classes, and (c) match union, intersection, sub-, complement, and equivalent classes in a proper sequence, to avoid error prone match results. We compare the results of our algorithms with those of a candidate reasoner, namely, the pellet reasoner. To the best of our knowledge, ours is a unique attempt in establishing a novel way to relate ontology classes. PMID:25984560

Cutting Class Harms Grades

ERIC Educational Resources Information Center

Taylor, Lewis A., III

2012-01-01

An accessible business school population of undergraduate students was investigated in three independent, but related studies to determine effects on grades due to cutting class and failing to take advantage of optional reviews and study quizzes. It was hypothesized that cutting classes harms exam scores, attending preexam reviews helps exam…

Stiefel-Whitney classes of curve covers

NASA Astrophysics Data System (ADS)

Selander, Björn

2016-10-01

Let D be a Dedekind scheme with the characteristic of all residue fields not equal to 2. To every tame cover Cto D with only odd ramification we associate a second Stiefel-Whitney class in the second cohomology with mod 2 coefficients of a certain tame orbicurve [D] associated to D. This class is then related to the pull-back of the second Stiefel-Whitney class of the push-forward of the line bundle of half of the ramification divisor. This shows (indirectly) that our Stiefel-Whitney class is the pull-back of a sum of cohomology classes considered by Esnault, Kahn and Viehweg in `Coverings with odd ramification and Stiefel-Whitney classes'. Perhaps more importantly, in the case of a proper and smooth curve over an algebraically closed field, our Stiefel-Whitney class is shown to be the pull-back of an invariant considered by Serre in `Revêtements à ramification impaire et thêta-caractéristiques', and in this case our arguments give a new proof of the main result of that article.

How social-class stereotypes maintain inequality.

PubMed

Durante, Federica; Fiske, Susan T

2017-12-01

Social class stereotypes support inequality through various routes: ambivalent content, early appearance in children, achievement consequences, institutionalization in education, appearance in cross-class social encounters, and prevalence in the most unequal societies. Class-stereotype content is ambivalent, describing lower-SES people both negatively (less competent, less human, more objectified), and sometimes positively, perhaps warmer than upper-SES people. Children acquire the wealth aspects of class stereotypes early, which become more nuanced with development. In school, class stereotypes advantage higher-SES students, and educational contexts institutionalize social-class distinctions. Beyond school, well-intentioned face-to-face encounters ironically draw on stereotypes to reinforce the alleged competence of higher-status people and sometimes the alleged warmth of lower-status people. Countries with more inequality show more of these ambivalent stereotypes of both lower-SES and higher-SES people. At a variety of levels and life stages, social-class stereotypes reinforce inequality, but constructive contact can undermine them; future efforts need to address high-status privilege and to query more heterogeneous samples. Copyright © 2017 Elsevier Ltd. All rights reserved.

47 CFR 73.210 - Station classes.

Code of Federal Regulations, 2012 CFR

2012-10-01

... this distance is greater than 39 km and less than or equal to 52 km, the station is Class B. (3) For a... than or equal to 78 km, the station is Class B. [52 FR 37788, Oct. 9, 1987; 52 FR 39920, Oct. 26, 1987.... Class A, B1 and B stations may be authorized in Zones I and I-A. Class A, C3, C2, C1, C0 and C stations...

47 CFR 73.210 - Station classes.

Code of Federal Regulations, 2013 CFR

2013-10-01

... this distance is greater than 39 km and less than or equal to 52 km, the station is Class B. (3) For a... than or equal to 78 km, the station is Class B. [52 FR 37788, Oct. 9, 1987; 52 FR 39920, Oct. 26, 1987.... Class A, B1 and B stations may be authorized in Zones I and I-A. Class A, C3, C2, C1, C0 and C stations...

47 CFR 73.210 - Station classes.

Code of Federal Regulations, 2014 CFR

2014-10-01

... this distance is greater than 39 km and less than or equal to 52 km, the station is Class B. (3) For a... than or equal to 78 km, the station is Class B. [52 FR 37788, Oct. 9, 1987; 52 FR 39920, Oct. 26, 1987.... Class A, B1 and B stations may be authorized in Zones I and I-A. Class A, C3, C2, C1, C0 and C stations...

47 CFR 73.210 - Station classes.

Code of Federal Regulations, 2010 CFR

2010-10-01

... this distance is greater than 39 km and less than or equal to 52 km, the station is Class B. (3) For a... than or equal to 78 km, the station is Class B. [52 FR 37788, Oct. 9, 1987; 52 FR 39920, Oct. 26, 1987.... Class A, B1 and B stations may be authorized in Zones I and I-A. Class A, C3, C2, C1, C0 and C stations...

47 CFR 73.210 - Station classes.

Code of Federal Regulations, 2011 CFR

2011-10-01

... this distance is greater than 39 km and less than or equal to 52 km, the station is Class B. (3) For a... than or equal to 78 km, the station is Class B. [52 FR 37788, Oct. 9, 1987; 52 FR 39920, Oct. 26, 1987.... Class A, B1 and B stations may be authorized in Zones I and I-A. Class A, C3, C2, C1, C0 and C stations...

Early Talk About the Past Revisited: Affect in Working-Class and Middle-Class Children's Co-Narrations.

ERIC Educational Resources Information Center

Burger, Lisa K.; Miller, Peggy J.

1999-01-01

Investigated personal storytelling among young working-class and middle-class children, observing them at home at age 2; age 6 and 3; and under-one year. Analysis of generic properties, narrative content, and emotion talk revealed a complex configuration of similarities and differences. Differentiation between working-class and middle-class…

White Middle-Class Privilege: Social Class Bias and Implications for Training and Practice

ERIC Educational Resources Information Center

Liu, William Ming; Pickett, Theodore, Jr.; Ivey, Allen E.

2007-01-01

Social class, classism, and privilege and their relationship to counseling have been given insufficient attention. This article defines and explores White middle-class privilege; it proffers support for its integration in a multicultural competency, as well as its intersection with race and other dimensions of multiculturalism and privilege.…

76 FR 72837 - Amendment of Class D and Class E Airspace; Baltimore, MD

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-28

... Class E airspace at Baltimore, MD, as the Martin Non-Directional Beacon (NDB) has been decommissioned and new Standard Instrument Approach Procedures have been developed at Martin State Airport. This... Register a notice of proposed rulemaking (NPRM) to amend Class D and E airspace at Martin State Airport...

78 FR 33015 - Proposed Amendment of Class D Airspace; Waco, TX, and Establishment of Class D Airspace; Waco...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-03

...-0136; Airspace Docket No. 13-ASW-4] Proposed Amendment of Class D Airspace; Waco, TX, and Establishment of Class D Airspace; Waco, TSTC-Waco Airport, TX AGENCY: Federal Aviation Administration (FAA), DOT... Waco, TX, by separating the Class D airspace at Waco Regional Airport from the Class D airspace at TSTC...

The Class Size Debate.

ERIC Educational Resources Information Center

Mishel, Lawrence, Ed.; Rothstein, Richard, Ed.

This collection of papers debates the merits of smaller class sizes and research methods used to evaluate the efficacy of this education reform measure. Four chapters focus on (1) "Understanding the Magnitude and Effect of Class Size on Student Achievement" (Alan B. Krueger), which discusses expenditures per student and economic criterion; (2)…

49 CFR 177.838 - Class 4 (flammable solid) materials, Class 5 (oxidizing) materials, and Division 4.2 (pyroforic...

Code of Federal Regulations, 2014 CFR

2014-10-01

... (flammable solid) or Class 5 (oxidizing) materials shall be contained entirely within the body of the motor.... Special care shall also be taken in the loading of any motor vehicle with Class 4 (flammable solid) or... 49 Transportation 2 2014-10-01 2014-10-01 false Class 4 (flammable solid) materials, Class 5...

49 CFR 177.838 - Class 4 (flammable solid) materials, Class 5 (oxidizing) materials, and Division 4.2 (pyroforic...

Code of Federal Regulations, 2013 CFR

2013-10-01

... (flammable solid) or Class 5 (oxidizing) materials shall be contained entirely within the body of the motor.... Special care shall also be taken in the loading of any motor vehicle with Class 4 (flammable solid) or... 49 Transportation 2 2013-10-01 2013-10-01 false Class 4 (flammable solid) materials, Class 5...

49 CFR 177.838 - Class 4 (flammable solid) materials, Class 5 (oxidizing) materials, and Division 4.2 (pyroforic...

Code of Federal Regulations, 2012 CFR

2012-10-01

... (flammable solid) or Class 5 (oxidizing) materials shall be contained entirely within the body of the motor.... Special care shall also be taken in the loading of any motor vehicle with Class 4 (flammable solid) or... 49 Transportation 2 2012-10-01 2012-10-01 false Class 4 (flammable solid) materials, Class 5...

MHC class II expression in lung cancer.

PubMed

He, Yayi; Rozeboom, Leslie; Rivard, Christopher J; Ellison, Kim; Dziadziuszko, Rafal; Yu, Hui; Zhou, Caicun; Hirsch, Fred R

2017-10-01

Immunotherapy is an exciting development in lung cancer research. In this study we described major histocompatibility complex (MHC) Class II protein expression in lung cancer cell lines and patient tissues. We studied MHC Class II (DP, DQ, DR) (CR3/43, Abcam) protein expression in 55 non-small cell lung cancer (NSCLC) cell lines, 42 small cell lung cancer (SCLC) cell lines and 278 lung cancer patient tissues by immunohistochemistry (IHC). Seven (12.7%) NSCLC cell lines were positive for MHC Class II. No SCLC cell lines were found to be MHC Class II positive. We assessed 139 lung cancer samples available in the Hirsch Lab for MHC Class II. There was no positive MHC Class II staining on SCLC tumor cells. MHC Class II expression on TILs in SCLC was significantly lower than that on TILs in NSCLC (P＜0.001). MHC Class II was also assessed in an additional 139 NSCLC tumor tissues from Medical University of Gdansk, Poland. Patients with positive staining of MHC Class II on TILs had longer regression-free survival (RFS) and overall survival (OS) than those whose TILs were MHC Class II negative (2.980 years, 95% CI 1.628-4.332 vs. 1.050 years, 95% CI 0.556-1.554, P=0.028) (3.230 years, 95% CI 2.617-3.843 vs. 1.390 years, 95% CI 0.629-2.151, P=0.014). MHC Class II was expressed both in NSCLC cell lines and tissues. However, MHC Class II was not detected in SCLC cell lines or tissue tumor cells. MHC Class II expression was lower on SCLC TILs than on NSCLC TILs. Loss of expression of MHC Class II on SCLC tumor cells and reduced expression on SCLC TILs may be a means of escaping anti-cancer immunity. Higher MHC Class II expression on TILs was correlated with better prognosis in patients with NSCLC. Copyright © 2017. Published by Elsevier B.V.

Work-life balance/imbalance: the dominance of the middle class and the neglect of the working class.

PubMed

Warren, Tracey

2015-12-01

The paper was stimulated by the relative absence of the working class from work-life debates. The common conclusion from work-life studies is that work-life imbalance is largely a middle-class problem. It is argued here that this classed assertion is a direct outcome of a particular and narrow interpretation of work-life imbalance in which time is seen to be the major cause of difficulty. Labour market time, and too much of it, dominates the conceptualization of work-life and its measurement too. This heavy focus on too much labour market time has rendered largely invisible from dominant work-life discourses the types of imbalance that are more likely to impact the working class. The paper's analysis of large UK data-sets demonstrates a reduction in hours worked by working-class men, more part-time employment in working-class occupations, and a substantial growth in levels of reported financial insecurity amongst the working classes after the 2008-9 recession. It shows too that economic-based work-life imbalance is associated with lower levels of life satisfaction than is temporal imbalance. The paper concludes that the dominant conceptualization of work-life disregards the major work-life challenge experienced by the working class: economic precarity. The work-life balance debate needs to more fully incorporate economic-based work-life imbalance if it is to better represent class inequalities. © London School of Economics and Political Science 2015.

Class I Underground Injection Control Program: Study of the Risks Associated with Class I Underground Injection Wells

EPA Pesticide Factsheets

The document provides describes the current Class I UIC program, the history of Class I injection, and studies of human health risks associated with Class I injection wells, which were conducted for past regulatory efforts and policy documentation.

Comparing a Yoga Class with a Resistance Exercise Class: Effects on Body Satisfaction and Social Physique Anxiety in University Women.

PubMed

Gammage, Kimberley L; Drouin, Breanne; Lamarche, Larkin

2016-11-01

The current study compared a single yoga group exercise class and a resistance group exercise class for their effects on state body satisfaction and social physique anxiety in women. A pretest-posttest design was used. Participants (N = 46) completed both a resistance exercise class and yoga class in a counterbalanced order. Measures of body satisfaction and social physique anxiety were completed immediately before and after each class. A 2 (time) × 2 (class type) repeatedmeasures multiple analysis of variance showed a significant overall Time × Class Type interaction (F 2,44 = 5.69, P < .01, η p 2 = .21). There was a significant increase in body satisfaction after the yoga class. After both classes, there was a significant decrease in social physique anxiety, but the magnitude of the change was larger after the yoga class than after the resistance class. Both types of exercise class were associated with improvements in body image, but there were greater improvements after the yoga class. This study provided evidence of the positive effects of yoga for reducing state social physique anxiety and increasing state body satisfaction, adding to correlational evidence suggesting that yoga is particularly beneficial for improving body image-related outcomes in women.

Comparison of second molar eruption patterns in patients with skeletal Class II and skeletal Class I malocclusions.

PubMed

Brin, Ilana; Camasuvi, Semin; Dali, Nasser; Aizenbud, Dror

2006-12-01

The eruptive positions of the second molars in Class I and Class II malocclusions were studied. Pretreatment records of 221 patients with a mean age of 11.3 years were evaluated. About 19% of them had skeletal Class I, 31% had skeletal maxillary Class II, and 50% had skeletal mandibular Class II malocclusions. The mean values of the dental and chronologic ages of the subjects were similar. The eruptive positions in relation to a reference line, the developmental stages of the patients' second molars and dental ages were recorded from the panoramic roentgenograms. The distribution of the various developmental stages in each malocclusion group was similar, and no association between skeletal malocclusion and dental developmental stage of the second molars was encountered. The eruptive position of the maxillary second molars was more occlusal only in the oldest maxillary Class II group, above 12 years of age (P = .02). These results support, in part, previous reports suggesting that the maxillary second molars may erupt earlier in patients with skeletal maxillary Class II malocclusions.

Recent Results of TMD Measurements from Jefferson Lab Hall A

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

Jiang, Xiaodong

2013-10-01

This slide-show presents results on transverse momentum distributions. The presentation covers: target single-spin asymmetry (SSA) (in parity conserving interactions); • Results of JLab Hall A polarized {sup 3}He target TMD measurement; • Semi-­inclusive deep-inelastic scattering channels (E06-010); • Target single-spin asymmetry A{sub UT}, Collins and Sivers SSA on neutron; • Double-spin asymmetry A{sub LT}, extract TMD g{sub 1T} on neutron; • Inclusive channels SSA (E06-010, E05-015, E07-013) • Target SSA: inclusive {sup 3}He(e,e’) quasi-elastic scattering; • Target SSA: inclusive {sup 3}He(e,e’) deep inelastic-elastic scattering; • New SIDIS experiments planned in Hall-A for JLab-12 GeV.

Superconducting 112 MHz QWR electron gun

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

Belomestnykh, S.; Ben-Zvi, I.; Boulware, C.H.

Brookhaven National Laboratory and Niowave, Inc. have designed and fabricated a superconducting 112 MHz quarter-wave resonator (QWR) electron gun. The first cold test of the QWR cryomodule has been completed at Niowave. The paper describes the cryomodule design, presents the cold test results, and outline plans to upgrade the cryomodule. Future experiments include studies of different photocathodes and use for the coherent electron cooling proof-of-principle experiment. Two cathode stalk options, one for multi-alkali photocathodes and the other one for a diamond-amplified photocathode, are discussed. A quarter-wave resonator concept of superconducting RF (SRF) electron gun was proposed at BNL for electronmore » cooling hadron beams in RHIC. QWRs can be made sufficiently compact even at low RF frequencies (long wavelengths). The long wavelength allows to produce long electron bunches, thus minimizing space charge effects and enabling high bunch charge. Also, such guns should be suitable for experiments requiring high average current electron beams. A 112 MHz QWR gun was designed, fabricated, and cold-tested in collaboration between BNL and Niowave. This is the lowest frequency SRF gun ever tested successfully. In this paper we describe the gun design and fabrication, present the cold test results, and outline our plans. This gun will also serve as a prototype for a future SRF gun to be used for coherent electron cooling of hadrons in eRHIC.« less

Instructor Facilitation of Whole-Class Discussion in Two Mathematics Classes for Preservice Teachers

ERIC Educational Resources Information Center

Young, Sarah Helen

2014-01-01

This study investigated how instructors engage preservice teachers (PSTs) in whole-class discussion in mathematics classes for PSTs. Participating in discussions of mathematical ideas by explaining mathematical ideas to others and responding to others' ideas and arguments might be beneficial for PSTs both to help them develop deeper knowledge of…

The Intersection between Out-of-Class Language Learning Strategies and In-Class Activities

ERIC Educational Resources Information Center

Saad, Noor Saazai Mat; Yunus, Melor Md; Embi, Mohamed Amin

2013-01-01

Studies on out-of-class language learning strategies (OCLLSs) are usually divorced from the activities in class. Thus, this study addresses the connection of the two entities. The participants in this study were nine international postgraduate students who were undergoing their English language proficiency course in an institution in Malaysia.…

Social class rank, threat vigilance, and hostile reactivity.

PubMed

Kraus, Michael W; Horberg, E J; Goetz, Jennifer L; Keltner, Dacher

2011-10-01

Lower-class individuals, because of their lower rank in society, are theorized to be more vigilant to social threats relative to their high-ranking upper-class counterparts. This class-related vigilance to threat, the authors predicted, would shape the emotional content of social interactions in systematic ways. In Study 1, participants engaged in a teasing interaction with a close friend. Lower-class participants--measured in terms of social class rank in society and within the friendship--more accurately tracked the hostile emotions of their friend. As a result, lower-class individuals experienced more hostile emotion contagion relative to upper-class participants. In Study 2, lower-class participants manipulated to experience lower subjective socioeconomic rank showed more hostile reactivity to ambiguous social scenarios relative to upper-class participants and to lower-class participants experiencing elevated socioeconomic rank. The results suggest that class affects expectations, perception, and experience of hostile emotion, particularly in situations in which lower-class individuals perceive their subordinate rank.

Constructing Class: Exploring the Lived Experience of White Female Student Affairs Professionals from Working Class Families

ERIC Educational Resources Information Center

Svoboda, Victoria

2012-01-01

Researchers have explored the issue of social class in higher education through the experiences of students and faculty, but have not yet analyzed the experiences of student affairs staff. Past researchers have conflated or ignored issues of race in studies on class, and rarely acknowledge gender as a variable in the classed experience. Student…

Social class and body weight among Chinese urban adults: the role of the middle classes in the nutrition transition.

PubMed

Bonnefond, Céline; Clément, Matthieu

2014-07-01

While a plethoric empirical literature addresses the relationship between socio-economic status and body weight, little is known about the influence of social class on nutritional outcomes, particularly in developing countries. The purpose of this article is to contribute to the analysis of the social determinants of adult body weight in urban China by taking into account the influence of social class. More specifically, we propose to analyse the position of the Chinese urban middle class in terms of being overweight or obese. The empirical investigations conducted as part of this research are based on a sample of 1320 households and 2841 adults from the China Health and Nutrition Survey for 2009. For the first step, we combine an economic approach and a sociological approach to identify social classes at household level. First, households with an annual per capita income between 10,000 Yuan and the 95th income percentile are considered as members of the middle class. Second, we strengthen the characterization of the middle class using information on education and employment. By applying clustering methods, we identify four groups: the elderly and inactive middle class, the old middle class, the lower middle class and the new middle class. For the second step, we implement an econometric analysis to assess the influence of social class on adult body mass index and on the probability of being overweight or obese. We use multinomial treatment regressions to deal with the endogeneity of the social class variable. Our results show that among the four subgroups of the urban middle class, the new middle class is the only one to be relatively well-protected against obesity. We suggest that this group plays a special role in adopting healthier food consumption habits and seems to be at a more advanced stage of the nutrition transition. Copyright © 2014 Elsevier Ltd. All rights reserved.

Clinical classes of injured workers with chronic low back pain: a latent class analysis with relationship to working status.

PubMed

Carlesso, Lisa C; Raja Rampersaud, Y; Davis, Aileen M

2018-01-01

To determine (a) clinical classes of injured workers with chronic low back pain (CLBP), (b) predictors of class membership and (c) associations of classes with baseline work status. Patients with CLBP from a tertiary care outpatient clinic in Toronto, Canada were sampled. Latent class analysis was applied to determine class structure using physical, psychological and coping indicators. Classes were interpreted by class-specific means and analyzed for predictors of membership. Lastly, association of the classes with being off work was modeled. A 3-class model was chosen based on fit criteria, theoretical and clinical knowledge of this population. The resultant 3 classes represented low, moderate and high levels of clinical severity. Predictors of being in the high severity group compared to the low severity group were < high school education [odds ratio (OR) 3.06, 95% CI (1.47, 6.37)] and comorbidity total [OR 1.28, 95% CI (1.03, 1.59)]. High severity class membership was associated with four times increased risk of being off work at baseline compared to those in the low severity group [OR 3.98, 95% CI (1.61, 6.34)]. In a cohort of injured workers with CLBP, 3 clinical classes were identified with distinct psychological and physical profiles. These profiles are useful in aiding clinicians to identify patients of high clinical severity who may be potentially at risk for problematic return to work.

The three latent classes of adolescent delinquency and the risk factors for membership in each class.

PubMed

Hasking, Penelope Anne; Scheier, Lawrence M; Abdallah, Arbi Ben

2011-01-01

This study used latent class analysis to examine subpopulation membership based on self-reports of delinquent behaviors obtained from Australian youth. Three discrete identifiable classes were derived based on 51 indicators of physical violence, property damage, minor infractions, drug use, and social delinquency. One class of youth engaged in primarily rule breaking and norm violations including underage alcohol use, typical of this age period. A second class was more actively delinquent emphasizing drug use, trespassing, and various forms of disobedience. A third class of highly delinquent youth differed from their counterparts by endorsing drug use, thievery that involved stealing money, goods, and cars, property damage, gambling, precocious sexual experiences, involvement with pornographic materials, and fighting. Multinomial logistic regression predicting class membership indicated highly delinquent youth were more likely to be older males, use venting coping strategies, and be fun or novelty seeking compared with rule breakers. Findings are discussed in terms of refining current taxonomic arguments regarding the structure of delinquency and implications for prevention of early-stage antisocial behavior. © 2010 Wiley-Liss, Inc.

48 CFR 3401.404 - Class deviations.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 7 2010-10-01 2010-10-01 false Class deviations. 3401.404 Section 3401.404 Federal Acquisition Regulations System DEPARTMENT OF EDUCATION ACQUISITION REGULATION GENERAL ED ACQUISITION REGULATION SYSTEM Deviations 3401.404 Class deviations. A class deviation from the...

Higher social class predicts increased unethical behavior

PubMed Central

Piff, Paul K.; Stancato, Daniel M.; Côté, Stéphane; Mendoza-Denton, Rodolfo; Keltner, Dacher

2012-01-01

Seven studies using experimental and naturalistic methods reveal that upper-class individuals behave more unethically than lower-class individuals. In studies 1 and 2, upper-class individuals were more likely to break the law while driving, relative to lower-class individuals. In follow-up laboratory studies, upper-class individuals were more likely to exhibit unethical decision-making tendencies (study 3), take valued goods from others (study 4), lie in a negotiation (study 5), cheat to increase their chances of winning a prize (study 6), and endorse unethical behavior at work (study 7) than were lower-class individuals. Mediator and moderator data demonstrated that upper-class individuals’ unethical tendencies are accounted for, in part, by their more favorable attitudes toward greed. PMID:22371585

Higher social class predicts increased unethical behavior.

PubMed

Piff, Paul K; Stancato, Daniel M; Côté, Stéphane; Mendoza-Denton, Rodolfo; Keltner, Dacher

2012-03-13

Seven studies using experimental and naturalistic methods reveal that upper-class individuals behave more unethically than lower-class individuals. In studies 1 and 2, upper-class individuals were more likely to break the law while driving, relative to lower-class individuals. In follow-up laboratory studies, upper-class individuals were more likely to exhibit unethical decision-making tendencies (study 3), take valued goods from others (study 4), lie in a negotiation (study 5), cheat to increase their chances of winning a prize (study 6), and endorse unethical behavior at work (study 7) than were lower-class individuals. Mediator and moderator data demonstrated that upper-class individuals' unethical tendencies are accounted for, in part, by their more favorable attitudes toward greed.

78 FR 21044 - Amendment of Class D and Class E Airspace; Reading, PA

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-09

...This action amends Class D and Class E Airspace at Reading, PA, as the SHAPP OM navigation aid has been decommissioned, requiring the modification of Standard Instrument Approach Procedures (SIAPs) at Reading Regional/Carl A. Spaatz Field. This action enhances the safety and management of Instrument Flight Rules (IFR) operations at the airport.

Advanced low-beta cavity development for proton and ion accelerators

NASA Astrophysics Data System (ADS)

Conway, Z. A.; Kelly, M. P.; Ostroumov, P. N.

2015-05-01

Recent developments in designing and processing low-beta superconducting cavities at Argonne National Laboratory are very encouraging for future applications requiring compact proton and ion accelerators. One of the major benefits of these accelerating structures is achieving real-estate accelerating gradients greater than 3 MV/m very efficiently either continuously or for long-duty cycle operation (>1%). The technology has been implemented in low-beta accelerator cryomodules for the Argonne ATLAS heavy-ion linac where the cryomodules are required to have real-estate gradients of more than 3 MV/m. In offline testing low-beta cavities with even higher gradients have already been achieved. This paper will review this work where we have achieved surface fields greater than 166 mT magnetic and 117 MV/m electric in a 72 MHz quarter-wave resonator optimized for β = 0.077 ions.

Jefferson Lab 12 GEV Cebaf Upgrade

NASA Astrophysics Data System (ADS)

Rode, C. H.

2010-04-01

The existing continuous electron beam accelerator facility (CEBAF) at Thomas Jefferson National Accelerator Facility (TJNAF) is a 5-pass, recirculating cw electron Linac operating at ˜6 GeV and is devoted to basic research in nuclear physics. The 12 GeV CEBAF Upgrade is a 310 M project, sponsored by the Department of Energy (DOE) Office of Nuclear Physics, that will expand its research capabilities substantially by doubling the maximum energy and adding major new experimental apparatus. The project received construction approval in September 2008 and has started the major procurement process. The cryogenic aspects of the 12 GeV CEBAF Upgrade includes: doubling the accelerating voltages of the Linacs by adding ten new high-performance, superconducting radiofrequency (SRF) cryomodules (CMs) to the existing 42 1/4 cryomodules; doubling of the 2 K cryogenics plant; and the addition of eight superconducting magnets.

Bayesian Hierarchical Classes Analysis

ERIC Educational Resources Information Center

Leenen, Iwin; Van Mechelen, Iven; Gelman, Andrew; De Knop, Stijn

2008-01-01

Hierarchical classes models are models for "N"-way "N"-mode data that represent the association among the "N" modes and simultaneously yield, for each mode, a hierarchical classification of its elements. In this paper we present a stochastic extension of the hierarchical classes model for two-way two-mode binary data. In line with the original…

Learning the Class Test

ERIC Educational Resources Information Center

Kasanen, Kati; Raty, Hannu; Snellman, Leila

2003-01-01

The class test is one of the important school practices which construct and convey to the pupils the predominant conception of ability and the related psychometric notion of individuality represented by the school. The aim of this study was to examine how the class test is actually "taught" to children--what sorts of elements the teacher…

Teaching Large Evening Classes

ERIC Educational Resources Information Center

Wambuguh, Oscar

2008-01-01

High enrollments, conflicting student work schedules, and the sheer convenience of once-a-week classes are pushing many colleges to schedule evening courses. Held from 6 to 9 pm or 7 to 10 pm, these classes are typically packed, sometimes with more than 150 students in a large lecture theater. How can faculty effectively teach, control, or even…

29 CFR 1614.204 - Class complaints.

Code of Federal Regulations, 2011 CFR

2011-07-01

... media employed to give notice of the existence of the class complaint. The notice, where appropriate... 29 Labor 4 2011-07-01 2011-07-01 false Class complaints. 1614.204 Section 1614.204 Labor... EMPLOYMENT OPPORTUNITY Provisions Applicable to Particular Complaints § 1614.204 Class complaints. (a...

Conceptualizing "Homework" in Flipped Mathematics Classes

ERIC Educational Resources Information Center

de Araujo, Zandra; Otten, Samuel; Birisci, Salih

2017-01-01

Flipped instruction is becoming more common in the United States, particularly in mathematics classes. One of the defining characteristics of this increasingly popular instructional format is the homework teachers assign. In contrast to traditional mathematics classes in which homework consists of problem sets, homework in flipped classes often…

7 CFR 30.5 - Class.

Code of Federal Regulations, 2012 CFR

2012-01-01

... AND STANDARDS Classification of Leaf Tobacco Covering Classes, Types and Groups of Grades § 30.5 Class. One of the major divisions of leaf tobacco based on the distinct characteristics of the tobacco caused...

7 CFR 30.5 - Class.

Code of Federal Regulations, 2013 CFR

2013-01-01

... AND STANDARDS Classification of Leaf Tobacco Covering Classes, Types and Groups of Grades § 30.5 Class. One of the major divisions of leaf tobacco based on the distinct characteristics of the tobacco caused...

7 CFR 30.5 - Class.

Code of Federal Regulations, 2010 CFR

2010-01-01

... AND STANDARDS Classification of Leaf Tobacco Covering Classes, Types and Groups of Grades § 30.5 Class. One of the major divisions of leaf tobacco based on the distinct characteristics of the tobacco caused...

7 CFR 30.5 - Class.

Code of Federal Regulations, 2011 CFR

2011-01-01

... AND STANDARDS Classification of Leaf Tobacco Covering Classes, Types and Groups of Grades § 30.5 Class. One of the major divisions of leaf tobacco based on the distinct characteristics of the tobacco caused...

7 CFR 30.5 - Class.

Code of Federal Regulations, 2014 CFR

2014-01-01

... AND STANDARDS Classification of Leaf Tobacco Covering Classes, Types and Groups of Grades § 30.5 Class. One of the major divisions of leaf tobacco based on the distinct characteristics of the tobacco caused...

49 CFR 176.400 - Stowage of Division 1.5, Class 4 (flammable solids) and Class 5 (oxidizers and organic peroxides...

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 2 2011-10-01 2011-10-01 false Stowage of Division 1.5, Class 4 (flammable solids... Solids), Class 5 (Oxidizers and Organic Peroxides), and Division 1.5 Materials § 176.400 Stowage of Division 1.5, Class 4 (flammable solids) and Class 5 (oxidizers and organic peroxides) materials. (a) Class...

Aeroflex Technology as Class-Y Demonstrator

NASA Technical Reports Server (NTRS)

Suh, Jong-ook; Agarwal, Shri; Popelar, Scott

2014-01-01

Modern space field programmable gate array (FPGA) devices with increased functional density and operational frequency, such as Xilinx Virtex 4 (V4) and S (V5), are packaged in non-hermetic ceramic flip chip forms. These next generation space parts were not qualified to the MIL-PRF-38535 Qualified Manufacturer Listing (QML) class-V when they were released because class-V was only intended for hermetic parts. In order to bring Xilinx V5 type packages into the QML system, it was suggested that class-Y be set up as a new category. From 2010 through 2014, a JEDEC G12 task group developed screening and qualification requirements for Class-Y products. The Document Standardization Division of the Defense Logistics Agency (DLA) has completed an engineering practice study. In parallel with the class-Y efforts, the NASA Electronic Parts and Packaging (NEPP) program has funded JPL to study potential reliability issues of the class-Y products. The major hurdle of this task was the absence of adequate research samples. Figure 1-1 shows schematic diagrams of typical structures of class-Y type products. Typically, class-Y products are either in ceramic flip chip column grid array (CGA) or land grid array (LGA) form. In class-Y packages, underfill and heat spread adhesive materials are directly exposed to the spacecraft environment due to their non-hermeticity. One of the concerns originally raised was that the underfill material could degrade due to the spacecraft environment and negatively impact the reliability of the package. In order to study such issues, it was necessary to use ceramic daisy chain flip chip package samples so that continuity of flip chip solder bumps could be monitored during the reliability tests. However, none of the commercially available class-Y daisy chain parts had electrical connections through flip chip solder bumps; only solder columns were daisy chained, which made it impossible to test continuity of flip chip solder bumps without using extremely

Student versus Faculty Perceptions of Missing Class.

ERIC Educational Resources Information Center

Sleigh, Merry J.; Ritzer, Darren R.; Casey, Michael B.

2002-01-01

Examines and compares student and faculty attitudes towards students missing classes and class attendance. Surveys undergraduate students (n=231) in lower and upper level psychology courses and psychology faculty. Reports that students found more reasons acceptable for missing classes and that the amount of in-class material on the examinations…

Focus on California's Class-Size Reduction: Smaller Classes Aim To Launch Early Literacy.

ERIC Educational Resources Information Center

McRobbie, Joan

Smaller class sizes in California were viewed as a way to improve K-3 education, especially in the area of literacy. The urgency to act prompted state leaders to adopt class-size reduction (CSR) without knowing for sure that it would work and without establishing a formal procedure for evaluating the program. This report looks at past research on…

Mixture class recovery in GMM under varying degrees of class separation: frequentist versus Bayesian estimation.

PubMed

Depaoli, Sarah

2013-06-01

Growth mixture modeling (GMM) represents a technique that is designed to capture change over time for unobserved subgroups (or latent classes) that exhibit qualitatively different patterns of growth. The aim of the current article was to explore the impact of latent class separation (i.e., how similar growth trajectories are across latent classes) on GMM performance. Several estimation conditions were compared: maximum likelihood via the expectation maximization (EM) algorithm and the Bayesian framework implementing diffuse priors, "accurate" informative priors, weakly informative priors, data-driven informative priors, priors reflecting partial-knowledge of parameters, and "inaccurate" (but informative) priors. The main goal was to provide insight about the optimal estimation condition under different degrees of latent class separation for GMM. Results indicated that optimal parameter recovery was obtained though the Bayesian approach using "accurate" informative priors, and partial-knowledge priors showed promise for the recovery of the growth trajectory parameters. Maximum likelihood and the remaining Bayesian estimation conditions yielded poor parameter recovery for the latent class proportions and the growth trajectories. (PsycINFO Database Record (c) 2013 APA, all rights reserved).

Reflections on Teaching a Large Class.

ERIC Educational Resources Information Center

Miner, Rick

1992-01-01

Uses an analysis of small- and large-class differences as a framework for planning for and teaching a large class. Analyzes the process of developing and offering an organizational behavior class to 141 college students. Suggests ways to improve teaching effectiveness by minimizing psychological and physical distances, redistributing resources,…

12 CFR 268.204 - Class complaints.

Code of Federal Regulations, 2011 CFR

2011-01-01

... shall notify class members of the final decision and relief awarded, if any, through the same media... 12 Banks and Banking 3 2011-01-01 2011-01-01 false Class complaints. 268.204 Section 268.204 Banks... REGARDING EQUAL OPPORTUNITY Provisions Applicable to Particular Complaints § 268.204 Class complaints. (a...

Flipping Quantitative Classes: A Triple Win

ERIC Educational Resources Information Center

Swart, William; Wuensch, Karl L.

2016-01-01

In the "flipped" class, students use online materials to learn what is traditionally learned by attending lectures, and class time is used for interactive group learning. A required quantitative business class was taught as a flipped classroom in an attempt to improve student satisfaction in the course and reduce the "transactional…

77 FR 38227 - Proposed Amendment of Class D and Class E Airspace; Bozeman, MT

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-27

...: This action proposes to modify Class D and Class E airspace at Bozeman Yellowstone International.... This action would also update the airport name to Bozeman Yellowstone International Airport. This action would enhance the safety and management of aircraft operations at the airport. DATES: Comments...

Backbone Brackets and Arginine Tweezers delineate Class I and Class II aminoacyl tRNA synthetases

PubMed Central

Haupt, V. Joachim; Schroeder, Michael; Labudde, Dirk

2018-01-01

The origin of the machinery that realizes protein biosynthesis in all organisms is still unclear. One key component of this machinery are aminoacyl tRNA synthetases (aaRS), which ligate tRNAs to amino acids while consuming ATP. Sequence analyses revealed that these enzymes can be divided into two complementary classes. Both classes differ significantly on a sequence and structural level, feature different reaction mechanisms, and occur in diverse oligomerization states. The one unifying aspect of both classes is their function of binding ATP. We identified Backbone Brackets and Arginine Tweezers as most compact ATP binding motifs characteristic for each Class. Geometric analysis shows a structural rearrangement of the Backbone Brackets upon ATP binding, indicating a general mechanism of all Class I structures. Regarding the origin of aaRS, the Rodin-Ohno hypothesis states that the peculiar nature of the two aaRS classes is the result of their primordial forms, called Protozymes, being encoded on opposite strands of the same gene. Backbone Brackets and Arginine Tweezers were traced back to the proposed Protozymes and their more efficient successors, the Urzymes. Both structural motifs can be observed as pairs of residues in contemporary structures and it seems that the time of their addition, indicated by their placement in the ancient aaRS, coincides with the evolutionary trace of Proto- and Urzymes. PMID:29659563

Performance Testing of Jefferson Lab 12 GeV Helium Screw Compressors

DOE PAGES

Knudsen, P.; Ganni, V.; Dixon, K.; ...

2015-08-10

Oil injected screw compressors have essentially superseded all other types of compressors in modern helium refrigeration systems due to their large displacement capacity, reliability, minimal vibration, and capability of handling helium's high heat of compression. At the present state of compressor system designs for helium refrigeration systems, typically two-thirds of the lost input power is due to the compression system. It is important to understand the isothermal and volumetric efficiencies of these machines to help properly design the compression system to match the refrigeration process. It is also important to identify those primary compressor skid exergetic loss mechanisms which maymore » be reduced, thereby offering the possibility of significantly reducing the input power to helium refrigeration processes which are extremely energy intensive. This paper summarizes the results collected during the commissioning of the new compressor system for Jefferson Lab's (JLab's) 12 GeV upgrade. The compressor skid packages were designed by JLab and built to print by industry. They incorporate a number of modifications not typical of helium screw compressor packages and most importantly allow a very wide range of operation so that JLab's patented Floating Pressure Process can be fully utilized. This paper also summarizes key features of the skid design that allow this process and facilitate the maintenance and reliability of these helium compressor systems.« less

Performance Testing of Jefferson Lab 12 GeV Helium Screw Compressors

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

Knudsen, P.; Ganni, V.; Dixon, K.

Oil injected screw compressors have essentially superseded all other types of compressors in modern helium refrigeration systems due to their large displacement capacity, reliability, minimal vibration, and capability of handling helium's high heat of compression. At the present state of compressor system designs for helium refrigeration systems, typically two-thirds of the lost input power is due to the compression system. It is important to understand the isothermal and volumetric efficiencies of these machines to help properly design the compression system to match the refrigeration process. It is also important to identify those primary compressor skid exergetic loss mechanisms which maymore » be reduced, thereby offering the possibility of significantly reducing the input power to helium refrigeration processes which are extremely energy intensive. This paper summarizes the results collected during the commissioning of the new compressor system for Jefferson Lab's (JLab's) 12 GeV upgrade. The compressor skid packages were designed by JLab and built to print by industry. They incorporate a number of modifications not typical of helium screw compressor packages and most importantly allow a very wide range of operation so that JLab's patented Floating Pressure Process can be fully utilized. This paper also summarizes key features of the skid design that allow this process and facilitate the maintenance and reliability of these helium compressor systems.« less

34 CFR 300.143 - Separate classes prohibited.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Private Schools § 300.143 Separate classes prohibited. An LEA may not use funds available under section 611 or 619 of the Act for classes that are organized separately on the basis of school enrollment or religion of the children if—' (a) The classes are at the same site; and (b) The classes include children...

34 CFR 300.143 - Separate classes prohibited.

Code of Federal Regulations, 2014 CFR

2014-07-01

... Private Schools § 300.143 Separate classes prohibited. An LEA may not use funds available under section 611 or 619 of the Act for classes that are organized separately on the basis of school enrollment or religion of the children if—' (a) The classes are at the same site; and (b) The classes include children...

34 CFR 300.143 - Separate classes prohibited.

Code of Federal Regulations, 2013 CFR

2013-07-01

... Private Schools § 300.143 Separate classes prohibited. An LEA may not use funds available under section 611 or 619 of the Act for classes that are organized separately on the basis of school enrollment or religion of the children if—' (a) The classes are at the same site; and (b) The classes include children...

34 CFR 300.143 - Separate classes prohibited.

Code of Federal Regulations, 2012 CFR

2012-07-01

... Private Schools § 300.143 Separate classes prohibited. An LEA may not use funds available under section 611 or 619 of the Act for classes that are organized separately on the basis of school enrollment or religion of the children if—' (a) The classes are at the same site; and (b) The classes include children...

Developing an Internet-Based Chemistry Class

NASA Astrophysics Data System (ADS)

Patterson, Mary Jane

2000-05-01

With the increasing popularity of Internet-based classes, more faculty are being asked to develop them (1). In Texas, the Virtual College of Texas (http://www.vct.org) even provides a forum that allows community colleges to advertise their distance-learning classes, and it paves the way for a college to offer a distance-learning class from any other college in the state. The two colleges simply work out a Memorandum of Understanding, mutually deciding how to administer the class, divide fees, set enrollment limits, among other details. While some classes are easily adapted to an Internet format, lab sciences raise a number of issues that must be tackled before a quality course can be developed in this new medium. I will raise some of those issues and offer a few possibilities.

49 CFR 1150.35 - Procedures and relevant dates-transactions that involve creation of Class I or Class II carriers.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 8 2014-10-01 2014-10-01 false Procedures and relevant dates-transactions that involve creation of Class I or Class II carriers. 1150.35 Section 1150.35 Transportation Other Regulations.... 10901 § 1150.35 Procedures and relevant dates—transactions that involve creation of Class I or Class II...

49 CFR 1150.35 - Procedures and relevant dates-transactions that involve creation of Class I or Class II carriers.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 8 2013-10-01 2013-10-01 false Procedures and relevant dates-transactions that involve creation of Class I or Class II carriers. 1150.35 Section 1150.35 Transportation Other Regulations.... 10901 § 1150.35 Procedures and relevant dates—transactions that involve creation of Class I or Class II...

49 CFR 1150.35 - Procedures and relevant dates-transactions that involve creation of Class I or Class II carriers.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 8 2012-10-01 2012-10-01 false Procedures and relevant dates-transactions that involve creation of Class I or Class II carriers. 1150.35 Section 1150.35 Transportation Other Regulations.... 10901 § 1150.35 Procedures and relevant dates—transactions that involve creation of Class I or Class II...

49 CFR 1150.35 - Procedures and relevant dates-transactions that involve creation of Class I or Class II carriers.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 8 2011-10-01 2011-10-01 false Procedures and relevant dates-transactions that involve creation of Class I or Class II carriers. 1150.35 Section 1150.35 Transportation Other Regulations.... 10901 § 1150.35 Procedures and relevant dates—transactions that involve creation of Class I or Class II...

49 CFR 1150.35 - Procedures and relevant dates-transactions that involve creation of Class I or Class II carriers.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 8 2010-10-01 2010-10-01 false Procedures and relevant dates-transactions that involve creation of Class I or Class II carriers. 1150.35 Section 1150.35 Transportation Other Regulations.... 10901 § 1150.35 Procedures and relevant dates—transactions that involve creation of Class I or Class II...

78 FR 48290 - Amendment of Class D Airspace; Waco, TX, and Establishment of Class D Airspace; Waco, TSTC-Waco...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-08

...-0136; Airspace Docket No. 13-ASW-4] Amendment of Class D Airspace; Waco, TX, and Establishment of Class D Airspace; Waco, TSTC-Waco Airport, TX AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final rule. SUMMARY: This action amends Class D airspace at Waco, TX, by separating the Class D airspace...

Class Size, Academic Achievement and Public Policy.

ERIC Educational Resources Information Center

Ziegler, Suzanne

1997-01-01

This report addresses some of the concerns surrounding smaller classes and looks at whether reduced class sizes result in higher achievement levels, and concludes that it in fact does increase student achievement, so long as classes do not exceed 17 students. But many critics question whether the high cost of reducing classes to 17 or fewer…

A Discussion Strategy for an Online Class

ERIC Educational Resources Information Center

Reese-Durham, Nancy Faith

2014-01-01

As a former teacher of face-to-face classes now assigned to teach only online classes, Nancy Reese Durham found herself challenged to change to accommodate online learners. She was determined to provide an environment in the online class where the high level of discussion she had provided in face-to-face classes could flourish as well. Here she…

49 CFR 172.446 - CLASS 9 label.

Code of Federal Regulations, 2010 CFR

2010-10-01

... the six white spaces between them. The lower half of the label must be white with the class number “9... 49 Transportation 2 2010-10-01 2010-10-01 false CLASS 9 label. 172.446 Section 172.446... SECURITY PLANS Labeling § 172.446 CLASS 9 label. (a) Except for size and color, the “CLASS 9...

Analysis of class II (hydrolytic) and class I (beta-lyase) apurinic/apyrimidinic endonucleases with a synthetic DNA substrate.

PubMed Central

Levin, J D; Demple, B

1990-01-01

We have developed simple and sensitive assays that distinguish the main classes of apurinic/apyrimidinic (AP) endonucleases: Class I enzymes that cleave on the 3' side of AP sites by beta-elimination, and Class II enzymes that cleave by hydrolysis on the 5' side. The distinction of the two types depends on the use of a synthetic DNA polymer that contains AP sites with 5'-[32P]phosphate residues. Using this approach, we now show directly that Escherichia coli endonuclease IV and human AP endonuclease are Class II enzymes, as inferred previously on the basis of indirect assays. The assay method does not exhibit significant interference by nonspecific nucleases or primary amines, which allows the ready determination of different AP endonuclease activities in crude cell extracts. In this way, we show that virtually all of the Class II AP endonuclease activity in E. coli can be accounted for by two enzymes: exonuclease III and endonuclease IV. In the yeast Saccharomyces cerevisiae, the Class II AP endonuclease activity is totally dependent on a single enzyme, the Apn1 protein, but there are probably multiple Class I enzymes. The versatility and ease of our approach should be useful for characterizing this important class of DNA repair enzymes in diverse systems. PMID:1698278

Class Size Reduction: Implementation and Solutions.

ERIC Educational Resources Information Center

Krieger, Jean

This is a report of a study designed to discover the nature of interactions between teachers and students in regular-size classes (25 or more students) and small-size classes (fewer than 18 students). It also describes the efforts of one public school to maintain smaller classes. A review of the literature and observations of 11 primary classrooms…

Application of TBT in Reading Class

ERIC Educational Resources Information Center

Yu, Hong-qin

2007-01-01

"TBT" means "task-based teaching". In a TBT class, students play the central role. In the class where students are provided with plenty of chances to be engaged in activities, the teacher is more like a patient listener rather than a talkative speaker. This paper mainly explores how task-based teaching is used in English reading class.

Haemophilus ducreyi Cutaneous Ulcer Strains Diverged from Both Class I and Class II Genital Ulcer Strains: Implications for Epidemiological Studies

PubMed Central

Gangaiah, Dharanesh

2016-01-01

Background Haemophilus ducreyi has emerged as a major cause of cutaneous ulcers (CU) in yaws-endemic regions of the tropics in the South Pacific, South East Asia and Africa. H. ducreyi was once thought only to cause the genital ulcer (GU) disease chancroid; GU strains belong to 2 distinct classes, class I and class II. Using whole-genome sequencing of 4 CU strains from Samoa, 1 from Vanuatu and 1 from Papua New Guinea, we showed that CU strains diverged from the class I strain 35000HP and that one CU strain expressed β-lactamase. Recently, the Center for Disease Control and Prevention released the genomes of 11 additional CU strains from Vanuatu and Ghana; however, the evolutionary relationship of these CU strains to previously-characterized CU and GU strains is unknown. Methodology/Principal Findings We performed phylogenetic analysis of 17 CU and 10 GU strains. Class I and class II GU strains formed two distinct clades. The class I strains formed two subclades, one containing 35000HP and HD183 and the other containing the remainder of the class I strains. Twelve of the CU strains formed a subclone under the class I 35000HP subclade, while 2 CU strains formed a subclone under the other class I subclade. Unexpectedly, 3 of the CU strains formed a subclone under the class II clade. Phylogenetic analysis of dsrA-hgbA-ncaA sequences yielded a tree similar to that of whole-genome phylogenetic tree. Conclusions/Significance CU strains diverged from multiple lineages within both class I and class II GU strains. Multilocus sequence typing of dsrA-hgbA-ncaA could be reliably used for epidemiological investigation of CU and GU strains. As class II strains grow relatively poorly and are relatively more susceptible to vancomycin than class I strains, these findings have implications for methods to recover CU strains. Comparison of contemporary CU and GU isolates would help clarify the relationship between these entities. PMID:28027326

Haemophilus ducreyi Cutaneous Ulcer Strains Diverged from Both Class I and Class II Genital Ulcer Strains: Implications for Epidemiological Studies.

PubMed

Gangaiah, Dharanesh; Spinola, Stanley M

2016-12-01

Haemophilus ducreyi has emerged as a major cause of cutaneous ulcers (CU) in yaws-endemic regions of the tropics in the South Pacific, South East Asia and Africa. H. ducreyi was once thought only to cause the genital ulcer (GU) disease chancroid; GU strains belong to 2 distinct classes, class I and class II. Using whole-genome sequencing of 4 CU strains from Samoa, 1 from Vanuatu and 1 from Papua New Guinea, we showed that CU strains diverged from the class I strain 35000HP and that one CU strain expressed β-lactamase. Recently, the Center for Disease Control and Prevention released the genomes of 11 additional CU strains from Vanuatu and Ghana; however, the evolutionary relationship of these CU strains to previously-characterized CU and GU strains is unknown. We performed phylogenetic analysis of 17 CU and 10 GU strains. Class I and class II GU strains formed two distinct clades. The class I strains formed two subclades, one containing 35000HP and HD183 and the other containing the remainder of the class I strains. Twelve of the CU strains formed a subclone under the class I 35000HP subclade, while 2 CU strains formed a subclone under the other class I subclade. Unexpectedly, 3 of the CU strains formed a subclone under the class II clade. Phylogenetic analysis of dsrA-hgbA-ncaA sequences yielded a tree similar to that of whole-genome phylogenetic tree. CU strains diverged from multiple lineages within both class I and class II GU strains. Multilocus sequence typing of dsrA-hgbA-ncaA could be reliably used for epidemiological investigation of CU and GU strains. As class II strains grow relatively poorly and are relatively more susceptible to vancomycin than class I strains, these findings have implications for methods to recover CU strains. Comparison of contemporary CU and GU isolates would help clarify the relationship between these entities.

Materials Development in Three Italian CALL Projects: Seeking an Optimal Mix between In-Class and Out-of-Class Learning

ERIC Educational Resources Information Center

Levy, Mike; Kennedy, Claire

2010-01-01

This paper considers the design and development of CALL materials with the aim of achieving an optimal mix between in-class and out-of-class learning in the context of teaching Italian at an Australian university. The authors discuss three projects in relation to the following themes: (a) conceptions of the in-class/out-of-class relationship, (b)…

Social Class and Social Action: The Middle-Class Bias of Democratic Theory in Education

ERIC Educational Resources Information Center

Schutz, Aaron

2008-01-01

Background: This article examines the emergence of the middle and working classes in America and describes key characteristics of these cultures as they manifest themselves today. It then explores the effects of social class on our conceptions of democracy. Purpose: To help educators understand the relationship between social action strategies and…

Comparison of Group Cohesion, Class Participation, and Exam Performance in Live and Online Classes

ERIC Educational Resources Information Center

Galyon, Charles E.; Heaton, Eleanore C. T.; Best, Tiffany L.; Williams, Robert L.

2016-01-01

Though class participation and group cohesion have shown some potential to promote student performance in conventional classrooms, their efficacy has not yet been demonstrated in an online-class setting. Group cohesion, defined as member attraction to and self-identification with a group, is thought to promote positive interdependence and the…

FDM Video Classe: Modes d'emploi pour la classe (FDM Video Class: Classroom Uses).

ERIC Educational Resources Information Center

Beacco, Marcella Di Giura

1996-01-01

Content and design of the videotape series FDM Video Classe, produced by the journal "Le francais dans le monde," are described and classroom uses suggested. The materials are from authentic television programs, selected to illustrate aspects of French culture. It is suggested that the teacher also provide students with supporting…

Online, Bigger Classes May Be Better Classes

ERIC Educational Resources Information Center

Parry, Marc

2010-01-01

In his work as a professor, Stephen Downes used to feel that he was helping those who least needed it. His students at places like the University of Alberta already had a leg up in life and could afford the tuition. When a colleague suggested they co-teach an online class in learning theory at the University of Manitoba, in 2008, Downes welcomed…

49 CFR 192.5 - Class locations.

Code of Federal Regulations, 2011 CFR

2011-10-01

... assembly) that is occupied by 20 or more persons on at least 5 days a week for 10 weeks in any 12-month period. (The days and weeks need not be consecutive.) (4) A Class 4 location is any class location unit... 2, 3, and 4 may be adjusted as follows: (1) A Class 4 location ends 220 yards (200 meters) from the...

Major Histocompatibility Complex (MHC) Class I and MHC Class II Proteins: Conformational Plasticity in Antigen Presentation

PubMed Central

Wieczorek, Marek; Abualrous, Esam T.; Sticht, Jana; Álvaro-Benito, Miguel; Stolzenberg, Sebastian; Noé, Frank; Freund, Christian

2017-01-01

Antigen presentation by major histocompatibility complex (MHC) proteins is essential for adaptive immunity. Prior to presentation, peptides need to be generated from proteins that are either produced by the cell’s own translational machinery or that are funneled into the endo-lysosomal vesicular system. The prolonged interaction between a T cell receptor and specific pMHC complexes, after an extensive search process in secondary lymphatic organs, eventually triggers T cells to proliferate and to mount a specific cellular immune response. Once processed, the peptide repertoire presented by MHC proteins largely depends on structural features of the binding groove of each particular MHC allelic variant. Additionally, two peptide editors—tapasin for class I and HLA-DM for class II—contribute to the shaping of the presented peptidome by favoring the binding of high-affinity antigens. Although there is a vast amount of biochemical and structural information, the mechanism of the catalyzed peptide exchange for MHC class I and class II proteins still remains controversial, and it is not well understood why certain MHC allelic variants are more susceptible to peptide editing than others. Recent studies predict a high impact of protein intermediate states on MHC allele-specific peptide presentation, which implies a profound influence of MHC dynamics on the phenomenon of immunodominance and the development of autoimmune diseases. Here, we review the recent literature that describe MHC class I and II dynamics from a theoretical and experimental point of view and we highlight the similarities between MHC class I and class II dynamics despite the distinct functions they fulfill in adaptive immunity. PMID:28367149

49 CFR 173.120 - Class 3-Definitions.

Code of Federal Regulations, 2014 CFR

2014-10-01

... Materials Other Than Class 1 and Class 7 § 173.120 Class 3—Definitions. (a) Flammable liquid. For the purpose of this subchapter, a flammable liquid (Class 3) means a liquid having a flash point of not more...) and below 93 °C (200 °F). (2) A flammable liquid with a flash point at or above 38 °C (100 °F) that...

49 CFR 173.120 - Class 3-Definitions.

Code of Federal Regulations, 2012 CFR

2012-10-01

... Materials Other Than Class 1 and Class 7 § 173.120 Class 3—Definitions. (a) Flammable liquid. For the purpose of this subchapter, a flammable liquid (Class 3) means a liquid having a flash point of not more...) and below 93 °C (200 °F). (2) A flammable liquid with a flash point at or above 38 °C (100 °F) that...

49 CFR 173.120 - Class 3-Definitions.

Code of Federal Regulations, 2013 CFR

2013-10-01

... Materials Other Than Class 1 and Class 7 § 173.120 Class 3—Definitions. (a) Flammable liquid. For the purpose of this subchapter, a flammable liquid (Class 3) means a liquid having a flash point of not more...) and below 93 °C (200 °F). (2) A flammable liquid with a flash point at or above 38 °C (100 °F) that...

49 CFR 173.120 - Class 3-Definitions.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Materials Other Than Class 1 and Class 7 § 173.120 Class 3—Definitions. (a) Flammable liquid. For the purpose of this subchapter, a flammable liquid (Class 3) means a liquid having a flash point of not more...) and below 93 °C (200 °F). (2) A flammable liquid with a flash point at or above 38 °C (100 °F) that...

The College Literature Class: Observation and Description of Class Sessions on "The Scarlet Letter."

ERIC Educational Resources Information Center

Kitkpatrick, Carolyn Grinnell

How seven college teachers and their students discussed Hawthorne's "The Scarlet Letter" is described in order to discover basic information about how different teachers approach the teaching of the same work. All of the classes were surveys of American literature taught by experienced teachers. The 24 class hours were tape-recorded and…

The YouTube Makeup Class

NASA Astrophysics Data System (ADS)

Haase, David G.

2009-05-01

When a college instructor goes out of town and must miss a lecture, the standard options are to cancel the class meeting or to enlist a colleague to fill in. In the former case a teaching opportunity is lost; in the latter the substitute may not lead the class in the same way as the instructor. Some students routinely skip lectures by a guest instructor, in the belief that the material in the substitute lecture will not be covered on the exam. There are other makeup options such as a directed study assignment. For instance, a missed class is sometimes a good opportunity to require students to investigate web-based simulations such as Physlets® that illustrate the class topics. These are most effective if the students are given a clear structure and if there are questions that the students must answer from their investigations with the Physlets. But many students are more comfortable with the audio and visual communication that occurs in the classroom. Web 2.0 technology, e.g., YouTube (http://www.youtube.com), makes it convenient for faculty to upload videos of lectures and demonstrations that can be used for makeup classes. College students already use YouTube for entertainment, and the YouTube format is simple to view on any web-connected computer. Although some universities have highly developed media delivery systems, YouTube is extremely convenient and accessible by anyone. This paper discusses how a YouTube makeup class can be efficiently produced and structured to be an effective learning experience.

HD gas purification for polarized HDice targets production at Jefferson Lab

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

Whisnant, Charles; D'Angelo, Annalisa; Colaneri, Luca

2014-06-01

Solid, frozen-spin targets of molecular HD were rst developed for nuclear physics by a collaboration between Syracuse University and Brookhaven National Lab. They have been successfully used in measurements with photon beams, rst at the Laser-Electron-Gamma-Source [1] and most recently at Je erson Lab during the running of the E06-101 (g14) experiment [2]. Preparations are underway to utilize the targets in future electron experiments after the completion of the 12 GeV JLab upgrade [3]. HD is an attractive target since all of the material is polarizable, of low Z, and requires only modest holding elds. At the same time, themore » small contributions from the target cell can be subtracted from direct measurements. Reaching the frozen-spin state with both high polarization and a signi cant spin relaxation time requires careful control of H2 and D2 impurities. Commercially available HD contains 0.5 - 2% concentrations of H2 and D2. Low-temperature distillation is required to reduce these concentrations to the 104 level to enable useful target production. This distillation is done using a column lled with heli-pack C [4] to give good separation e ciency. Approximately 12 moles of commercial HD is condensed into the mechanically refrigerated system at the base temperature of 11K. The system is then isolated and the temperature stabilized at 18K producing liquid HD, which is boiled by a resistive heater. The circulation established by the boil-o condensing throughout the column then ltering back down produces a steady-state isotopic separation permitting the extraction of HD gas with very low H2 and D2 content. A residual gas analyzer initially monitors distillation. Once the H2 concentration falls below its useful operating range, samples are periodically collected for analysis using gas chromatography [5] and Raman scattering. Where the measurement techniques overlap, good agreement is obtained. The operation of the distillery and results of gas analysis will be

How do older adult drivers self-regulate? Characteristics of self-regulation classes defined by latent class analysis.

PubMed

Bergen, Gwen; West, Bethany A; Luo, Feijun; Bird, Donna C; Freund, Katherine; Fortinsky, Richard H; Staplin, Loren

2017-06-01

Motor-vehicle crashes were the second leading cause of injury death for adults aged 65-84years in 2014. Some older drivers choose to self-regulate their driving to maintain mobility while reducing driving risk, yet the process remains poorly understood. Data from 729 older adults (aged ≥60years) who joined an older adult ride service program between April 1, 2010 and November 8, 2013 were analyzed to define and describe classes of driving self-regulation. Latent class analysis was employed to characterize older adult driving self-regulation classes using driving frequency and avoidance of seven driving situations. Logistic regression was used to explore associations between characteristics affecting mobility and self-regulation class. Three classes were identified (low, medium, and high self-regulation). High self-regulating participants reported the highest proportion of always avoiding seven risky driving situations and the lowest driving frequency followed by medium and low self-regulators. Those who were female, aged 80years or older, visually impaired, assistive device users, and those with special health needs were more likely to be high self-regulating compared with low self-regulating. Avoidance of certain driving situations and weekly driving frequency are valid indicators for describing driving self-regulation classes in older adults. Understanding the unique characteristics and mobility limitations of each class can guide optimal transportation strategies for older adults. Published by Elsevier Ltd.

Class 1 railroad statistics, 2010

DOT National Transportation Integrated Search

2010-05-24

U.S. Class I Railroads are line haul freight railroads with 2008 operating revenue in excess of $401.4 million. Two Canadian railroads, CN and Canadian Pacific, have enough revenue that they would be U.S. Class I railroads if they were U.S. companies...

75 FR 57848 - Revocation of Class E Airspace, Brunswick, ME; and Establishment of Class E Airspace, Wiscasset, ME

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-23

...-0248; Airspace Docket No. 10-ANE-10] Revocation of Class E Airspace, Brunswick, ME; and Establishment of Class E Airspace, Wiscasset, ME AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final rule. SUMMARY: This action removes Class E Airspace at Brunswick NAS, Brunswick, ME, as the airport has...

Advanced low-beta cavity development for proton and ion accelerators

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

Conway, Z. A.; Kelly, M. P.; Ostroumov, P. N.

2015-05-01

Recent developments in designing and processing low-beta superconducting cavities at Argonne National Laboratory are very encouraging for future applications requiring compact proton and ion accelerators. One of the major benefits of these accelerating structures is achieving real-estate accelerating gradients greater than 3 MV/m very efficiently either continuously or for long-duty cycle operation (>1%). The technology has been implemented in low-beta accelerator cryomodules for the Argonne ATLAS heavy-ion linac where the cryomodules are required to have real-estate gradients of more than 3 MV/m. In offline testing low-beta cavities with even higher gradients have already been achieved. This paper will review thismore » work where we have achieved surface fields greater than 166 mT magnetic and 117 MV/m electric in a 72 MHz quarter-wave resonator optimized for beta = 0.077 ions.« less

Creating world-class supply chains.

PubMed

Katzorke, M; Lee, W B

2000-08-01

This article will share knowledge in two areas: The elements of world-class supply chains and the linking processes from customers' customers to suppliers' suppliers and the management approaches needed to engage the people and the organization in an effective implementation process to achieve world-class status.

Student Engagement and Marketing Classes

ERIC Educational Resources Information Center

Taylor, Steven A.; Hunter, Gary L.; Melton, Horace; Goodwin, Stephen A.

2011-01-01

A study is reported that investigates the goals underlying undergraduate students' engagement in their major classes, nonmajor classes, and in extracurricular activities. The qualitative study employs both focus groups and goal-mapping exercises. The results suggest that students tend to focus on utilitarian, attribute-level considerations mainly…

Social Class and the Extracurriculum

ERIC Educational Resources Information Center

Barratt, Will

2012-01-01

Social class is a powerful and often unrecognized influence on student participation in the extracurriculum. Spontaneous student-created extracurricular experiences depend on students affiliating and interacting with each other; student social class is a powerful influence on student affiliations. Students tend to exercise consciousness of kind-…

Efficacy of Sibling Preparation Classes.

PubMed

Beyers-Carlson, Emma E A; Volling, Brenda L

To examine the effectiveness of sibling preparation classes to facilitate the adjustment of a firstborn child to the birth of a sibling. Longitudinal study with five measurement occasions: third trimester of the mother's pregnancy and 1, 4, 8, and 12 months after the sibling's birth. Communities in southeastern Michigan. A total of 241 families, including mothers, fathers, and firstborn children. Mothers and fathers completed questionnaires to assess changes in children's adjustment. Parents were also asked about their children's attendance at a sibling preparation class focused specifically on preparation for the newborn. Effects of attendance were tested using linear mixed models. Other than avoidance of the infant, children who attended sibling preparation classes did not differ from children who did not attend. Sibling preparation classes for adjustment after the birth of an infant sibling had few effects on participants. Copyright © 2017 AWHONN, the Association of Women's Health, Obstetric and Neonatal Nurses. Published by Elsevier Inc. All rights reserved.

Maxillary molar distalization with first class appliance

PubMed Central

Ramesh, Namitha; Palukunnu, Biswas; Ravindran, Nidhi; Nair, Preeti P

2014-01-01

Non-extraction treatment has gained popularity for corrections of mild-to-moderate class II malocclusion over the past few decades. The distalization of maxillary molars is of significant value for treatment of cases with minimal arch discrepancy and mild class II molar relation associated with a normal mandibular arch and acceptable profile. This paper describes our experience with a 16-year-old female patient who reported with irregularly placed upper front teeth and unpleasant smile. The patient was diagnosed to have angles class II malocclusion with moderate maxillary anterior crowding, deep bite of 4 mm on a skeletal class II base with an orthognathic maxilla and retrognathic mandible and normal growth pattern. She presented an ideal profile and so molar distalization was planned with the first-class appliance. Molars were distalised by 8 mm on the right and left quadrants and class I molar relation achieved within 4 months. The space gained was utilised effectively to align the arch and establish a class I molar and canine relation. PMID:24577171

Do Convolutional Neural Networks Learn Class Hierarchy?

PubMed

Bilal, Alsallakh; Jourabloo, Amin; Ye, Mao; Liu, Xiaoming; Ren, Liu

2018-01-01

Convolutional Neural Networks (CNNs) currently achieve state-of-the-art accuracy in image classification. With a growing number of classes, the accuracy usually drops as the possibilities of confusion increase. Interestingly, the class confusion patterns follow a hierarchical structure over the classes. We present visual-analytics methods to reveal and analyze this hierarchy of similar classes in relation with CNN-internal data. We found that this hierarchy not only dictates the confusion patterns between the classes, it furthermore dictates the learning behavior of CNNs. In particular, the early layers in these networks develop feature detectors that can separate high-level groups of classes quite well, even after a few training epochs. In contrast, the latter layers require substantially more epochs to develop specialized feature detectors that can separate individual classes. We demonstrate how these insights are key to significant improvement in accuracy by designing hierarchy-aware CNNs that accelerate model convergence and alleviate overfitting. We further demonstrate how our methods help in identifying various quality issues in the training data.

47 CFR 74.708 - Class A TV and digital Class A TV station protection.

Code of Federal Regulations, 2012 CFR

2012-10-01

... SERVICES Low Power TV, TV Translator, and TV Booster Stations § 74.708 Class A TV and digital Class A TV... booster station or change the facilities of an existing station will not be accepted if it fails to... prior to the date the low power TV, TV translator, or TV booster application is filed. (c) Applications...

47 CFR 74.708 - Class A TV and digital Class A TV station protection.

Code of Federal Regulations, 2011 CFR

2011-10-01

... SERVICES Low Power TV, TV Translator, and TV Booster Stations § 74.708 Class A TV and digital Class A TV... booster station or change the facilities of an existing station will not be accepted if it fails to... prior to the date the low power TV, TV translator, or TV booster application is filed. (c) Applications...

47 CFR 74.708 - Class A TV and digital Class A TV station protection.

Code of Federal Regulations, 2013 CFR

2013-10-01

... SERVICES Low Power TV, TV Translator, and TV Booster Stations § 74.708 Class A TV and digital Class A TV... booster station or change the facilities of an existing station will not be accepted if it fails to... prior to the date the low power TV, TV translator, or TV booster application is filed. (c) Applications...

47 CFR 74.708 - Class A TV and digital Class A TV station protection.

Code of Federal Regulations, 2014 CFR

2014-10-01

... SERVICES Low Power TV, TV Translator, and TV Booster Stations § 74.708 Class A TV and digital Class A TV... booster station or change the facilities of an existing station will not be accepted if it fails to... prior to the date the low power TV, TV translator, or TV booster application is filed. (c) Applications...

47 CFR 74.708 - Class A TV and digital Class A TV station protection.

Code of Federal Regulations, 2010 CFR

2010-10-01

... SERVICES Low Power TV, TV Translator, and TV Booster Stations § 74.708 Class A TV and digital Class A TV... § 73.6010 of this chapter. (b) An application to construct a new low power TV, TV translator, or TV... prior to the date the low power TV, TV translator, or TV booster application is filed. (c) Applications...

Second Class Resolver: a retrospective analysis.

PubMed

D'Attilio, M; Rodolfino, D; Filippakos, A; Saccucci, M; Festa, F; Tripodi, D

2014-03-01

To evaluate the use of Second Class Resolver (SCR), a new fixed orthopaedic appliance, for the treatment of skeletal Class II malocclusion in growing subjects. Design Retrospective analysis. Forty subjects were treated with Second Class Resolver (SCR). The mean age was 8 years at the beginning of treatment and 10 years at the end of treatment. Digital cephalometric superimpositions on lateral radiographs taken at start and end of treatment were assessed. The cephalometric values were statistically analysed. Cephalometric analysis of changes during treatment shows reduction of ANB angle (mean 2°); reduction of Witts Index (mean 3 mm); reduction of Maxillo-Mandibular angle (MM) (mean 1°); reduction of SNA (angle mean 3°); reduction of gonial angle (mean 1.8°); increase of the mandibular branch length (mean 5 mm); increase of mandibular body (mean 2.9°). The Second Class Resolver can be beneficially used for the treatment of Class II malocclusion.

Class-specific effector functions of therapeutic antibodies.

PubMed

Pascal, Virginie; Laffleur, Brice; Cogné, Michel

2012-01-01

Physiology usually combines polyclonal antibodies of multiple classes in a single humoral response. Beyond their common ability to bind antigens, these various classes of human immunoglobulins carry specific functions which can each serve specific goals. In many cases, the function of a monoclonal therapeutic antibody may thus be modulated according to the class of its constant domains. Depending on the immunoglobulin class, different functional assays will be used in order to evaluate the functional activity of a monoclonal antibody.

Vitality and Interest-Enjoyment as a Function of Class-to-Class Variation in Need-Supportive Teaching and Pupils' Autonomous Motivation

ERIC Educational Resources Information Center

Mouratidis, Athanasios A.; Vansteenkiste, Maarten; Sideridis, Georgios; Lens, Willy

2011-01-01

In 2 quasi-experimental field studies in a real-life physical education (PE) setting, the authors investigated whether the interest-enjoyment and vitality of Greek pupils (age range, 10-12 years) varied from class to class as a function of the class-to-class variation in the manipulated motivational environment (Studies 1 and 2) and pupils'…

A Large-Scale Blended and Flipped Class: Class Design and Investigation of Factors Influencing Students' Intention to Learn

ERIC Educational Resources Information Center

Zhang, Yulei; Dang, Yan; Amer, Beverly

2016-01-01

This paper reports a study of a large-scale blended and flipped class and has two major parts. First, it presents the design of the class, i.e., a coordinated and multisection undergraduate introduction-to-computer-information-systems course. The detailed design of various teaching methods used in the class is presented, including a digital…

A low power on-chip class-E power amplifier for remotely powered implantable sensor systems

NASA Astrophysics Data System (ADS)

Ture, Kerim; Kilinc, Enver G.; Dehollain, Catherine

2015-06-01

This paper presents a low power fully integrated class-E power amplifier and its integration with remotely powered sensor system. The class-E power amplifier is suitable solution for low-power applications due to its high power efficiency. However, the required high inductance values which make the on-chip integration of the power amplifier difficult. The designed power amplifier is fully integrated in the remotely powered sensor system and fabricated in 0.18 μm CMOS process. The power is transferred to the implantable sensor system at 13.56 MHz by using an inductively coupled remote powering link. The induced AC voltage on the implant coil is converted into a DC voltage by a passive full-wave rectifier. A voltage regulator is used to suppress the ripples and create a clean and stable 1.8 V supply voltage for the sensor and communication blocks. The data collected from the sensors is transmitted by on-off keying modulated low-power transmitter at 1.2 GHz frequency. The transmitter is composed of a LC tank oscillator and a fully on-chip class-E power amplifier. An additional output network is used for the power amplifier which makes the integration of the power amplifier fully on-chip. The integrated power amplifier with 0.2 V supply voltage has a drain efficiency of 31.5% at -10 dBm output power for 50 Ω load. The measurement results verify the functionality of the power amplifier and the remotely powered implantable sensor system. The data communication is also verified by using a commercial 50 Ω chip antenna and has 600 kbps data rate at 1 m communication distance.

Pipeline of Known Chemical Classes of Antibiotics

PubMed Central

d’Urso de Souza Mendes, Cristina; de Souza Antunes, Adelaide Maria

2013-01-01

Many approaches are used to discover new antibiotic compounds, one of the most widespread being the chemical modification of known antibiotics. This type of discovery has been so important in the development of new antibiotics that most antibiotics used today belong to the same chemical classes as antibiotics discovered in the 1950s and 1960s. Even though the discovery of new classes of antibiotics is urgently needed, the chemical modification of antibiotics in known classes is still widely used to discover new antibiotics, resulting in a great number of compounds in the discovery and clinical pipeline that belong to existing classes. In this scenario, the present article presents an overview of the R&D pipeline of new antibiotics in known classes of antibiotics, from discovery to clinical trial, in order to map out the technological trends in this type of antibiotic R&D, aiming to identify the chemical classes attracting most interest, their spectrum of activity, and the new subclasses under development. The result of the study shows that the new antibiotics in the pipeline belong to the following chemical classes: quinolones, aminoglycosides, macrolides, oxazolidinones, tetracyclines, pleuromutilins, beta-lactams, lipoglycopeptides, polymyxins and cyclic lipopeptides. PMID:27029317

Social closure, micro-class immobility and the intergenerational reproduction of the upper class: a comparative study.

PubMed

Ruggera, Lucia; Barone, Carlo

2017-06-01

This article assesses how processes of social closure enhance intergenerational immobility in the regulated professions and thus promote persistence at the top of the occupational hierarchy. We compare four European countries (GB, Germany, Denmark and Sweden) that differ considerably in their degree of professional regulation and in their broader institutional arrangements. We run log-linear and logistic regression models on a cumulative dataset based on three large-scale surveys with detailed and highly comparable information at the level of unit occupations. Our analyses indicate that children of licensed professionals are far more likely to inherit the occupation of their parents and that this stronger micro-class immobility translates into higher chances of persistence in the upper class. These results support social closure theory and confirm the relevance of a micro-class approach for the explanation of social fluidity and of its cross-national variations. Moreover, we find that, when children of professionals do not reproduce the micro-class of their parents, they still display disproportionate chances of persistence in professional employment. Hence, on the one hand, processes of social closure erect barriers between professions and fuel micro-class immobility at the top. On the other hand, the cultural proximity of different professional groups drives intense intergenerational exchanges between them. Our analyses indicate that these micro- and meso-class rigidities work as complementary routes to immobility at the top. © London School of Economics and Political Science 2017.

Modelling Symmetry Classes 233 and 432.

ERIC Educational Resources Information Center

Dutch, Steven I.

1986-01-01

Offers instructions and geometrical data for constructing solids of the enantiomorphous symmetry classes 233 and 432. Provides background information for each class and highlights symmetrical relationships and construction patterns. (ML)

Alveolar bone thickness and lower incisor position in skeletal Class I and Class II malocclusions assessed with cone-beam computed tomography

PubMed Central

Ucar, Faruk Izzet; Buyuk, Suleyman Kutalmis; Ozer, Torun; Uysal, Tancan

2013-01-01

Objective To evaluate lower incisor position and bony support between patients with Class II average- and high-angle malocclusions and compare with the patients presenting Class I malocclusions. Methods CBCT records of 79 patients were divided into 2 groups according to sagittal jaw relationships: Class I and II. Each group was further divided into average- and high-angle subgroups. Six angular and 6 linear measurements were performed. Independent samples t-test, Kruskal-Wallis, and Dunn post-hoc tests were performed for statistical comparisons. Results Labial alveolar bone thickness was significantly higher in Class I group compared to Class II group (p = 0.003). Lingual alveolar bone angle (p = 0.004), lower incisor protrusion (p = 0.007) and proclination (p = 0.046) were greatest in Class II average-angle patients. Spongious bone was thinner (p = 0.016) and root apex was closer to the labial cortex in high-angle subgroups when compared to the Class II average-angle subgroup (p = 0.004). Conclusions Mandibular anterior bony support and lower incisor position were different between average- and high-angle Class II patients. Clinicians should be aware that the range of lower incisor movement in high-angle Class II patients is limited compared to average- angle Class II patients. PMID:23814708

Alveolar bone thickness and lower incisor position in skeletal Class I and Class II malocclusions assessed with cone-beam computed tomography.

PubMed

Baysal, Asli; Ucar, Faruk Izzet; Buyuk, Suleyman Kutalmis; Ozer, Torun; Uysal, Tancan

2013-06-01

To evaluate lower incisor position and bony support between patients with Class II average- and high-angle malocclusions and compare with the patients presenting Class I malocclusions. CBCT records of 79 patients were divided into 2 groups according to sagittal jaw relationships: Class I and II. Each group was further divided into average- and high-angle subgroups. Six angular and 6 linear measurements were performed. Independent samples t-test, Kruskal-Wallis, and Dunn post-hoc tests were performed for statistical comparisons. Labial alveolar bone thickness was significantly higher in Class I group compared to Class II group (p = 0.003). Lingual alveolar bone angle (p = 0.004), lower incisor protrusion (p = 0.007) and proclination (p = 0.046) were greatest in Class II average-angle patients. Spongious bone was thinner (p = 0.016) and root apex was closer to the labial cortex in high-angle subgroups when compared to the Class II average-angle subgroup (p = 0.004). Mandibular anterior bony support and lower incisor position were different between average- and high-angle Class II patients. Clinicians should be aware that the range of lower incisor movement in high-angle Class II patients is limited compared to average- angle Class II patients.

The undervalued self: social class and self-evaluation

PubMed Central

Kraus, Michael W.; Park, Jun W.

2014-01-01

Social class ranks people on the social ladder of society, and in this research we examine how perceptions of economic standing shape the way that individuals evaluate the self. Given that reminders of one’s own subordinate status in society are an indicator of how society values the self in comparison to others, we predicted that chronic lower perceptions of economic standing vis-à-vis others would explain associations between objective social class and negative self-evaluation, whereas situation-specific reminders of low economic standing would elicit negative self-evaluations, particularly in those from lower-class backgrounds. In Study 1, perceptions of social class rank accounted for the positive relationship between objective material resource measures of social class and self-esteem. In Study 2, lower-class individuals who received a low (versus equal) share of economic resources in an economic game scenario reported more negative self-conscious emotions—a correlate of negative self-evaluation—relative to upper-class individuals. Discussion focused on the implications of this research for understanding class-based cultural models of the self, and for how social class shapes self-evaluations chronically. PMID:25538654

The undervalued self: social class and self-evaluation.

PubMed

Kraus, Michael W; Park, Jun W

2014-01-01

Social class ranks people on the social ladder of society, and in this research we examine how perceptions of economic standing shape the way that individuals evaluate the self. Given that reminders of one's own subordinate status in society are an indicator of how society values the self in comparison to others, we predicted that chronic lower perceptions of economic standing vis-à-vis others would explain associations between objective social class and negative self-evaluation, whereas situation-specific reminders of low economic standing would elicit negative self-evaluations, particularly in those from lower-class backgrounds. In Study 1, perceptions of social class rank accounted for the positive relationship between objective material resource measures of social class and self-esteem. In Study 2, lower-class individuals who received a low (versus equal) share of economic resources in an economic game scenario reported more negative self-conscious emotions-a correlate of negative self-evaluation-relative to upper-class individuals. Discussion focused on the implications of this research for understanding class-based cultural models of the self, and for how social class shapes self-evaluations chronically.

Longitudinal magnet forces?

NASA Astrophysics Data System (ADS)

Graneau, P.

1984-03-01

The Ampere electrodynamics of metallic conductors and experiments supporting it predict that the interaction of a current-carrying wire with its own magnetic field should produce longitudinal mechanical forces in the conductor, existing in addition to the transverse Lorentz forces. The longitudinal forces should stretch the conductor and have been referred to as Ampere tension. In 1964 it was discovered that a current pulse would break a straight copper wire into many fragments without visible melting. A metallurgical examination of the pieces confirmed that the metal parted in the solid state. The same observation has now been made with aluminum wires. In the latest experiments the wire was bent into a semicircle and arc-connected to a capacitor discharge circuit. The arc connections ruled out rupture by Lorentz hoop tension and indicated the longitudinal forces may also arise in circular magnet windings. Explanations of wire fragmentation by thermal shock, longitudinal stress waves, Lorentz pinch-off, bending stresses, and material defects have been considered and found unconvincing. Computed Ampere tensions would be sufficient to fracture hot wires. The Ampere tension would double the hoop tension normally expected in dipole magnets. This should be borne in mind in the design of large dipole magnets contemplated for MHD power generators and railgun accelerators.

Race and Class on Campus

ERIC Educational Resources Information Center

Perez, Angel B.

2016-01-01

Colleges and universities have a significant role to play in shaping the future of race and class relations in America. As exhibited in this year's presidential election, race and class continue to divide. Black Lives Matter movements, campus protests, and police shootings are just a few examples of the proliferation of intolerance, and higher…

Mapping NEHRP VS30 site classes

USGS Publications Warehouse

Holzer, T.L.; Padovani, A.C.; Bennett, M.J.; Noce, T.E.; Tinsley, J. C.

2005-01-01

Site-amplification potential in a 140-km2 area on the eastern shore of San Francisco Bay, California, was mapped with data from 210 seismic cone penetration test (SCPT) soundings. NEHRP VS30 values were computed on a 50-m grid by both taking into account the thickness and using mean values of locally measured shear-wave velocities of shallow geologic units. The resulting map of NEHRP VS30 site classes differs from other published maps that (1) do not include unit thickness and (2) are based on regional compilations of velocity. Although much of the area in the new map is now classified as NEHRP Site Class D, the velocities of the geologic deposits within this area are either near the upper or lower VS30 boundary of Class D. If maps of NEHRP site classes are to be based on geologic maps, velocity distributions of geologic units may need to be considered in the definition of VS30 boundaries of NEHRP site classes. ?? 2005, Earthquake Engineering Research Institute.

Object-oriented sequence analysis: SCL--a C++ class library.

PubMed

Vahrson, W; Hermann, K; Kleffe, J; Wittig, B

1996-04-01

SCL (Sequence Class Library) is a class library written in the C++ programming language. Designed using object-oriented programming principles, SCL consists of classes of objects performing tasks typically needed for analyzing DNA or protein sequences. Among them are very flexible sequence classes, classes accessing databases in various formats, classes managing collections of sequences, as well as classes performing higher-level tasks like calculating a pairwise sequence alignment. SCL also includes classes that provide general programming support, like a dynamically growing array, sets, matrices, strings, classes performing file input/output, and utilities for error handling. By providing these components, SCL fosters an explorative programming style: experimenting with algorithms and alternative implementations is encouraged rather than punished. A description of SCL's overall structure as well as an overview of its classes is given. Important aspects of the work with SCL are discussed in the context of a sample program.

Comparison of temporomandibular joint and ramus morphology between class II and class III cases before and after bi-maxillary osteotomy.

PubMed

Iguchi, Ran; Yoshizawa, Kunio; Moroi, Akinori; Tsutsui, Takamitsu; Hotta, Asami; Hiraide, Ryota; Takayama, Akihiro; Tsunoda, Tatsuya; Saito, Yuki; Sato, Momoko; Baba, Nana; Ueki, Koichiro

2017-12-01

The purpose of this study was to compare changes in temporomandibular joint (TMJ) and ramus morphology between class II and III cases before and after sagittal split ramus osteotomy (SSRO) and Le Fort I osteotomy. The subjects were 39 patients (78 sides) who underwent bi-maxillary surgery. They consisted of 2 groups (18 class II cases and 21 class III cases), and were selected randomly from among patients who underwent surgery between 2012 and 2016. The TMJ disc tissue and joint effusion were assessed by magnetic resonance imaging (MRI) and the TMJ space, condylar height, ramus height, ramus inclination and condylar square were assessed by computed tomography (CT), pre- and post-operatively. The number of joints with anterior disc displacement in class II was significantly higher than that in class III (p < 0.0001). However, there were no significant differences between the two classes regarding ratio of joint symptoms and ratio of joint effusion pre- and post-operatively. Class II was significantly better than class III regarding reduction ratio of condylar height (p < 0.0001) and square (p = 0.0005). The study findings suggest that condylar morphology could change in both class II and III after bi-maxillary surgery. The findings of the numerical analysis also demonstrated that reduction of condylar volume occurred frequently in class II, although TMJ disc position classification did not change significantly, as previously reported. Copyright © 2017 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

Predictors of Latent Trajectory Classes of Dating Violence Victimization

PubMed Central

Brooks-Russell, Ashley; Foshee, Vangie; Ennett, Susan

2014-01-01

This study identified classes of developmental trajectories of physical dating violence victimization from grades 8 to 12 and examined theoretically-based risk factors that distinguished among trajectory classes. Data were from a multi-wave longitudinal study spanning 8th through 12th grade (n = 2,566; 51.9% female). Growth mixture models were used to identify trajectory classes of physical dating violence victimization separately for girls and boys. Logistic and multinomial logistic regressions were used to identify situational and target vulnerability factors associated with the trajectory classes. For girls, three trajectory classes were identified: a low/non-involved class; a moderate class where victimization increased slightly until the 10th grade and then decreased through the 12th grade; and a high class where victimization started at a higher level in the 8th grade, increased substantially until the 10th grade, and then decreased until the 12th grade. For males, two classes were identified: a low/non-involved class, and a victimized class where victimization increased slightly until the 9th grade, decreased until the 11th grade, and then increased again through the 12th grade. In bivariate analyses, almost all of the situational and target vulnerability risk factors distinguished the victimization classes from the non-involved classes. However, when all risk factors and control variables were in the model, alcohol use (a situational vulnerability) was the only factor that distinguished membership in the moderate trajectory class from the non-involved class for girls; anxiety and being victimized by peers (target vulnerability factors) were the factors that distinguished the high from the non-involved classes for the girls; and victimization by peers was the only factor distinguishing the victimized from the non-involved class for boys. These findings contribute to our understanding of the heterogeneity in physical dating violence victimization during

Occupational class inequalities in disability retirement after hospitalisation.

PubMed

Pietiläinen, Olli; Laaksonen, Mikko; Lahelma, Eero; Salonsalmi, Aino; Rahkonen, Ossi

2018-05-01

This study aimed to investigate whether hospitalisation is associated with increased risk of disability retirement differently across four occupational classes. 170,510 employees of the City of Helsinki, Finland were followed from 1990 to 2013 using national registers for hospitalisations and disability retirement. Increases in the risk of disability retirement after hospitalisation for any cause, cardiovascular diseases, musculoskeletal disorders, mental disorders, malignant neoplasms, respiratory diseases and injuries were assessed across four occupational classes: professional, semi-professional, routine non-manual and manual, using competing risks models. In general, hospitalisation showed a slightly more increased risk of disability retirement in the lower ranking occupational classes. Hospitalisation among women for mental disorders showed a more increased risk in the professional class (hazard ratio 14.73, 95% confidence interval 12.67 to 17.12) compared to the routine manual class (hazard ratio 7.27, 95% confidence interval 6.60 to 8.02). Occupational class differences were similar for men and women. The risk of disability retirement among women increased most in the routine non-manual class after hospitalisation for musculoskeletal disorders and injuries, and most in the professional class after hospitalisation for cardiovascular diseases. The corresponding risks among men increased most in the two lowest ranking classes after hospitalisation for injuries. Ill-health as measured by hospitalisation affected disability retirement in four occupational classes differently, and the effects also varied by the diagnostic group of hospitalisation. Interventions that tackle work disability should consider the impact of ill-health on functioning while taking into account working conditions in each occupational class.

Class, Identity, and Teacher Education

ERIC Educational Resources Information Center

Van Galen, Jane A.

2010-01-01

This paper explores the possibilities of working with White, working-class teacher education students to explore the "complex social trajectory" (Reay in Women's Stud Int Forum 20(2):225-233, 1997a, p. 19) of class border crossing as they progress through college. Through analysis of a course that I have developed, "Education and the American…

Eustace Tilley Comes to Class

ERIC Educational Resources Information Center

Arin, Jennifer

2009-01-01

Of all the reasons to use "The New Yorker" in a college writing class, the most compelling may be that its articles go beyond--well beyond--the five-paragraph model. Why, oh why, did that paradigm become such a fixture in composition courses? Students in the author's writing classes invariably suppose they can compose a quick introduction, add…

Class Size: Teachers' Perspectives

ERIC Educational Resources Information Center

Watson, Kevin; Handal, Boris; Maher, Marguerite

2016-01-01

A consistent body of research shows that large classes have been perceived by teachers as an obstacle to deliver quality teaching. This large-scale study sought to investigate further those differential effects by asking 1,119 teachers from 321 K-12 schools in New South Wales (Australia) their perceptions of ideal class size for a variety of…

Class and SLA: Making Connections

ERIC Educational Resources Information Center

Block, David

2012-01-01

This article explores how class might be brought to the fore as an identity inscription in studies of second language learning, alongside other identity inscriptions such as gender, ethnicity and national identity, which have been the focus of rather more research. It begins by clarifying what is meant by class through a brief discussion of the…

Translanguaging in a Reading Class

ERIC Educational Resources Information Center

Vaish, Viniti; Subhan, Aidil

2015-01-01

Using translanguaging as a theoretical foundation, this paper analyses findings from a Grade 2 reading class for low achieving students, where Malay was used as a scaffold to teach English. Data come from one class in one school in Singapore and its Learning Support Programme (LSP), which is part of a larger research project on biliteracy. The LSP…

Multi-Positioning Mathematics Class Size: Teachers' Views

ERIC Educational Resources Information Center

Handal, Boris; Watson, Kevin; Maher, Marguerite

2015-01-01

This paper explores mathematics teachers' perceptions about class size and the impact class size has on teaching and learning in secondary mathematics classrooms. It seeks to understand teachers' views about optimal class sizes and their thoughts about the education variables that influence these views. The paper draws on questionnaire responses…

Class Inclusion and Role-Taking: Structural Mediation.

ERIC Educational Resources Information Center

Gash, Hugh

The mediational linkage between class inclusion and role-taking skills was investigated by studying the effects of a successive perspective-taking training technique on the consolidation of class inclusion structures. Sixty preoperational Irish boys were given two pretest measures of class inclusion and two of role-taking. They were then grouped…

Speech Music Discrimination Using Class-Specific Features

DTIC Science & Technology

2004-08-01

Speech Music Discrimination Using Class-Specific Features Thomas Beierholm...between speech and music . Feature extraction is class-specific and can therefore be tailored to each class meaning that segment size, model orders...interest. Some of the applications of audio signal classification are speech/ music classification [1], acoustical environmental classification [2][3

Students' different understandings of class diagrams

NASA Astrophysics Data System (ADS)

Boustedt, Jonas

2012-03-01

The software industry needs well-trained software designers and one important aspect of software design is the ability to model software designs visually and understand what visual models represent. However, previous research indicates that software design is a difficult task to many students. This article reports empirical findings from a phenomenographic investigation on how students understand class diagrams, Unified Modeling Language (UML) symbols, and relations to object-oriented (OO) concepts. The informants were 20 Computer Science students from four different universities in Sweden. The results show qualitatively different ways to understand and describe UML class diagrams and the "diamond symbols" representing aggregation and composition. The purpose of class diagrams was understood in a varied way, from describing it as a documentation to a more advanced view related to communication. The descriptions of class diagrams varied from seeing them as a specification of classes to a more advanced view, where they were described to show hierarchic structures of classes and relations. The diamond symbols were seen as "relations" and a more advanced way was seeing the white and the black diamonds as different symbols for aggregation and composition. As a consequence of the results, it is recommended that UML should be adopted in courses. It is briefly indicated how the phenomenographic results in combination with variation theory can be used by teachers to enhance students' possibilities to reach advanced understanding of phenomena related to UML class diagrams. Moreover, it is recommended that teachers should put more effort in assessing skills in proper usage of the basic symbols and models and students should be provided with opportunities to practise collaborative design, e.g. using whiteboards.

Coping with Multi-Level Classes Effectively and Creatively.

ERIC Educational Resources Information Center

Strasheim, Lorraine A.

This paper includes a discussion of the problem of multilevel Latin classes, a description of various techniques and perspectives the teacher might use in dealing with these classes, and copies of materials and exercises that have proved useful in multilevel classes. Because the reasons for the existence of such classes are varied, it is suggested…

Class and compassion: socioeconomic factors predict responses to suffering.

PubMed

Stellar, Jennifer E; Manzo, Vida M; Kraus, Michael W; Keltner, Dacher

2012-06-01

Previous research indicates that lower-class individuals experience elevated negative emotions as compared with their upper-class counterparts. We examine how the environments of lower-class individuals can also promote greater compassionate responding-that is, concern for the suffering or well-being of others. In the present research, we investigate class-based differences in dispositional compassion and its activation in situations wherein others are suffering. Across studies, relative to their upper-class counterparts, lower-class individuals reported elevated dispositional compassion (Study 1), as well as greater self-reported compassion during a compassion-inducing video (Study 2) and for another person during a social interaction (Study 3). Lower-class individuals also exhibited heart rate deceleration-a physiological response associated with orienting to the social environment and engaging with others-during the compassion-inducing video (Study 2). We discuss a potential mechanism of class-based influences on compassion, whereby lower-class individuals' are more attuned to others' distress, relative to their upper-class counterparts.

Tooth size discrepancies in Class II division 1 and Class III malocclusion requiring surgical-orthodontic or orthodontic treatment.

PubMed

McSwiney, Timothy P; Millett, Declan T; McIntyre, Grant T; Barry, Mark K; Cronin, Michael S

2014-06-01

To compare mean anterior (AR) and mean overall (OR) tooth size ratios, prevalence of clinically significant tooth size discrepancies (TSDs) and correlation between AR and OR in subjects with Class II division 1 and Class III malocclusion treated by surgical-orthodontic or orthodontic means. Retrospective, cross-sectional. State-funded and private clinics. From pre-treatment cohorts of 770 surgical and 610 non-surgical subjects, Class II division 1 and Class III malocclusion groups were identified with 60 surgical and 60 non-surgical subjects, comprising 30 males and 30 females, in each. AR and OR were calculated by landmarking digital models. Differences in AR and OR and their relationship were analysed using two-way analysis of variance (ANOVA) and a correlation coefficient, respectively. The proportions of the surgical and non-surgical groups with a TSD were assessed using logistic regression. Intra-examiner reproducibility involved re-landmarking 30 randomly selected image sets and differences in ARs and ORs were compared using a paired t-test. Random error was assessed using the intraclass correlation coefficient (ICC). Analyses were performed using SAS (SAS Institute Inc., Cary, NC, USA) at the 5% level of significance. There were no statistically significant differences associated with the measurement of either the mean AR (P = 0·913) or the mean OR (P = 0·874). ICC values were very high (AR = 0·95; OR = 0·90). Differences existed between both Class II and Class III surgical (AR: P<0·001; OR: P<0·001) and non-surgical groups (AR: P = 0·012; OR: P = 0·003). The AR and OR relationship was strong (correlation coefficient = 0·72). The highest percentage of clinically significant TSDs was seen in the AR of both Class II and Class III surgical groups (23·3%). In the cohort examined: AR and OR differed significantly for malocclusion groups. The prevalence of clinically significant TSDs did not differ significantly between

25 CFR 502.2 - Class I gaming.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 25 Indians 2 2011-04-01 2011-04-01 false Class I gaming. 502.2 Section 502.2 Indians NATIONAL INDIAN GAMING COMMISSION, DEPARTMENT OF THE INTERIOR GENERAL PROVISIONS DEFINITIONS OF THIS CHAPTER § 502.2 Class I gaming. Class I gaming means: (a) Social games played solely for prizes of minimal value...

25 CFR 502.2 - Class I gaming.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 25 Indians 2 2010-04-01 2010-04-01 false Class I gaming. 502.2 Section 502.2 Indians NATIONAL INDIAN GAMING COMMISSION, DEPARTMENT OF THE INTERIOR GENERAL PROVISIONS DEFINITIONS OF THIS CHAPTER § 502.2 Class I gaming. Class I gaming means: (a) Social games played solely for prizes of minimal value...

25 CFR 502.2 - Class I gaming.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 25 Indians 2 2012-04-01 2012-04-01 false Class I gaming. 502.2 Section 502.2 Indians NATIONAL INDIAN GAMING COMMISSION, DEPARTMENT OF THE INTERIOR GENERAL PROVISIONS DEFINITIONS OF THIS CHAPTER § 502.2 Class I gaming. Class I gaming means: (a) Social games played solely for prizes of minimal value...

25 CFR 502.2 - Class I gaming.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 25 Indians 2 2013-04-01 2013-04-01 false Class I gaming. 502.2 Section 502.2 Indians NATIONAL INDIAN GAMING COMMISSION, DEPARTMENT OF THE INTERIOR GENERAL PROVISIONS DEFINITIONS OF THIS CHAPTER § 502.2 Class I gaming. Class I gaming means: (a) Social games played solely for prizes of minimal value...

25 CFR 502.2 - Class I gaming.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 25 Indians 2 2014-04-01 2014-04-01 false Class I gaming. 502.2 Section 502.2 Indians NATIONAL INDIAN GAMING COMMISSION, DEPARTMENT OF THE INTERIOR GENERAL PROVISIONS DEFINITIONS OF THIS CHAPTER § 502.2 Class I gaming. Class I gaming means: (a) Social games played solely for prizes of minimal value...

Do Class Size Effects Differ across Grades?

ERIC Educational Resources Information Center

Nandrup, Anne Brink

2016-01-01

This paper contributes to the class size literature by analysing whether short-run class size effects are constant across grade levels in compulsory school. Results are based on administrative data on all pupils enrolled in Danish public schools. Identification is based on a government-imposed class size cap that creates exogenous variation in…

In-Class Purposes of Flipped Mathematics Educators

ERIC Educational Resources Information Center

Eisenhut, Lindsay A.; Taylor, Cynthia E.

2015-01-01

This paper provides empirical findings from a study that examined how three grade 7-12 flipped mathematics educators utilized class time when implementing a flipped learning model. Additionally, the researchers investigated the educators' purposes for various in-class tasks as well as their general use of class time. The data revealed flipped…

Laser ion source for heavy ion inertial fusion

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

Okamura, Masahiro

The proposed heavy ion inertial fusion (HIF) scenarios require ampere class low charge state ion beams of heavy species. A laser ion source (LIS) is recognized as one of the promising candidates of ion beam providers, since it can deliver high brightness heavy ion beams to accelerators. A design of LIS for the HIF depends on the accelerator structure and accelerator complex following the source. In this article, we discuss the specifications and design of an appropriate LIS assuming two major types of the accelerators: radio frequency (RF) high quality factor cavity type and non-resonant induction core type. We believemore » that a properly designed LIS satisfies the requirements of both types, however some issues need to be verified experimentally.« less

Laser ion source for heavy ion inertial fusion

DOE PAGES

Okamura, Masahiro

2018-01-10

The proposed heavy ion inertial fusion (HIF) scenarios require ampere class low charge state ion beams of heavy species. A laser ion source (LIS) is recognized as one of the promising candidates of ion beam providers, since it can deliver high brightness heavy ion beams to accelerators. A design of LIS for the HIF depends on the accelerator structure and accelerator complex following the source. In this article, we discuss the specifications and design of an appropriate LIS assuming two major types of the accelerators: radio frequency (RF) high quality factor cavity type and non-resonant induction core type. We believemore » that a properly designed LIS satisfies the requirements of both types, however some issues need to be verified experimentally.« less

49 CFR 238.315 - Class IA brake test.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 4 2011-10-01 2011-10-01 false Class IA brake test. 238.315 Section 238.315... Requirements for Tier I Passenger Equipment § 238.315 Class IA brake test. (a) Except as provided in paragraph (b) of this section, either a Class I or a Class IA brake test shall be performed: (1) Prior to the...

Is Your Accounting Class a Flip or Flop?

ERIC Educational Resources Information Center

Weisenfeld, Leslie

2017-01-01

The flipped class allows the instructor to put materials online that would normally be provided in the traditional lecture format and frees up class time for hands-on learning activities. This paper provides a broad overview of what is required outside of the class via an electronic platform such as Blackboard (Bb) and what is done during class.…

Does Class Size Make a Difference?

ERIC Educational Resources Information Center

Glass, Gene V.; Down, A. Graham

1979-01-01

Argues that study findings indicate that lowered class size increases student achievement and improves school attitudes. Counter argument indicates there is little educational payoff and great monetary expense in small reductions in class size. (RH)

Comparison of psychosocial status in treatment-seeking women with class III vs. class I-II obesity.

PubMed

Wadden, Thomas A; Butryn, Meghan L; Sarwer, David B; Fabricatore, Anthony N; Crerand, Canice E; Lipschutz, Patti E; Faulconbridge, Lucy; Raper, Steven; Williams, Noel N

2006-01-01

This study compared the psychosocial status and weight loss expectations of women with extreme (class III) obesity who sought bariatric surgery with those of women with class I-II obesity who enrolled in a research study on behavioral weight control. Before treatment, all participants completed the Beck Depression Inventory-II and the Weight and Lifestyle Inventory. This latter questionnaire assesses several domains including symptoms of depression and low self-esteem, history of psychiatric complications, current stressors, and weight loss expectations. Women with class III obesity, as compared with class I-II, reported significantly more symptoms of depression. Fully 25% of women in the former group appeared to have a significant mood disorder that would benefit from treatment. As compared with women with class I-II obesity, significantly more women with class III obesity also reported a history of psychiatric complications, which included physical and sexual abuse and greater stress related to their physical health and financial/legal matters. Both groups of women had unrealistic weight loss expectations. Those who sought surgery expected to lose 47.6 +/- 9.3% of initial weight, compared with 24.8 +/- 8.7% for those who enrolled in behavioral weight control. These findings suggest that women with extreme obesity who seek bariatric surgery should be screened for psychosocial complications. Those determined to have significant psychiatric distress should be referred for behavioral or pharmacological treatment to alleviate their suffering. Long-term studies are needed to provide definitive guidance concerning the relationship between preoperative psychopathology and the outcome of bariatric surgery.

McIntosh active-region class similarities and suggestions for mergers

NASA Technical Reports Server (NTRS)

Bornmann, P. L.; Kalmbach, D.; Kulhanek, D.

1994-01-01

McIntosh active-region classifications reported during a five-year period were examined to determine similarities among the classes. Two methods were used extensively to determine these similarities. The number of transitions among classes were used to determine the most frequent transitions out of each class, and the alternative classes reported for the same region by different sites were used to establish which classes were neighboring classes. These transition frequencies and neighboring classes were used to identify classes that could be eliminated or merged with other classes. Class similarities were used to investigate the relative importance of several pairs of decisions that occur within a single McIntosh parameter. In particular, the redundancy of parameters in some classes was examined, and the class similarities were used to identify which of these parameters could be eliminated. Infrequently reported classes were also considered, and suggestions for mergers were made when similarities between classes could be identified.

Class Cuisine: Food in the Foreign Language Class.

ERIC Educational Resources Information Center

Rauschenberg, Gretchen S.

1984-01-01

Food can both interest students in a foreign culture and motivate them to broaden their interests. Cooking with students can take many forms. The students can cook in class if adequate preparations are made and permission is granted. Students can contribute toward the purchase of food for snacks and meals, and the cost can be kept to the price of…

Class Extraction and Classification Accuracy in Latent Class Models

ERIC Educational Resources Information Center

Wu, Qiong

2009-01-01

Despite the increasing popularity of latent class models (LCM) in educational research, methodological studies have not yet accumulated much information on the appropriate application of this modeling technique, especially with regard to requirement on sample size and number of indicators. This dissertation study represented an initial attempt to…

Th-1 polarization is regulated by dendritic-cell comparison of MHC class I and class II antigens

PubMed Central

Xing, Dongxia; Li, Sufang; Robinson, Simon N.; Yang, Hong; Steiner, David; Komanduri, Krishna V.; Shpall, Elizabeth J.

2009-01-01

In the control of T-helper type I (Th-1) polarization, dendritic cells (DCs) must interpret a complex array of stimuli, many of which are poorly understood. Here we demonstrate that Th-1 polarization is heavily influenced by DC-autonomous phenomena triggered by the loading of DCs with antigenically matched major histocompatibility complex (MHC) class I and class II determinants, that is, class I and II peptide epitopes exhibiting significant amino acid sequence overlap (such as would be physiologically present during infectious processes requiring Th-1 immunity for clearance). Data were derived from 13 independent antigenic models including whole-cell systems, single-protein systems, and 3 different pairs of overlapping class I and II binding epitopes. Once loaded with matched class I and II antigens, these “Th-1 DCs” exhibited differential cytokine secretion and surface marker expression, a distinct transcriptional signature, and acquired the ability to enhance generation of CD8+ T lymphocytes. Mechanistically, tRNA-synthetases were implicated as components of a putative sensor complex involved in the comparison of class I and II epitopes. These data provide rigorous conceptual explanations for the process of Th-1 polarization and the antigenic specificity of cognate T-cell help, enhance the understanding of Th-1 responses, and should contribute to the formulation of more effective vaccination strategies. PMID:19171878

14 CFR 101.25 - Operating limitations for Class 2-High Power Rockets and Class 3-Advanced High Power Rockets.

Code of Federal Regulations, 2013 CFR

2013-01-01

... Power Rockets and Class 3-Advanced High Power Rockets. 101.25 Section 101.25 Aeronautics and Space... OPERATING RULES MOORED BALLOONS, KITES, AMATEUR ROCKETS AND UNMANNED FREE BALLOONS Amateur Rockets § 101.25 Operating limitations for Class 2-High Power Rockets and Class 3-Advanced High Power Rockets. When operating...

14 CFR 101.25 - Operating limitations for Class 2-High Power Rockets and Class 3-Advanced High Power Rockets.

Code of Federal Regulations, 2012 CFR

2012-01-01

... Power Rockets and Class 3-Advanced High Power Rockets. 101.25 Section 101.25 Aeronautics and Space... OPERATING RULES MOORED BALLOONS, KITES, AMATEUR ROCKETS AND UNMANNED FREE BALLOONS Amateur Rockets § 101.25 Operating limitations for Class 2-High Power Rockets and Class 3-Advanced High Power Rockets. When operating...

14 CFR 101.25 - Operating limitations for Class 2-High Power Rockets and Class 3-Advanced High Power Rockets.

Code of Federal Regulations, 2014 CFR

2014-01-01

... Power Rockets and Class 3-Advanced High Power Rockets. 101.25 Section 101.25 Aeronautics and Space... OPERATING RULES MOORED BALLOONS, KITES, AMATEUR ROCKETS AND UNMANNED FREE BALLOONS Amateur Rockets § 101.25 Operating limitations for Class 2-High Power Rockets and Class 3-Advanced High Power Rockets. When operating...

14 CFR 101.25 - Operating limitations for Class 2-High Power Rockets and Class 3-Advanced High Power Rockets.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Power Rockets and Class 3-Advanced High Power Rockets. 101.25 Section 101.25 Aeronautics and Space... OPERATING RULES MOORED BALLOONS, KITES, AMATEUR ROCKETS AND UNMANNED FREE BALLOONS Amateur Rockets § 101.25 Operating limitations for Class 2-High Power Rockets and Class 3-Advanced High Power Rockets. When operating...

14 CFR 101.25 - Operating limitations for Class 2-High Power Rockets and Class 3-Advanced High Power Rockets.

Code of Federal Regulations, 2011 CFR

2011-01-01

... Power Rockets and Class 3-Advanced High Power Rockets. 101.25 Section 101.25 Aeronautics and Space... OPERATING RULES MOORED BALLOONS, KITES, AMATEUR ROCKETS AND UNMANNED FREE BALLOONS Amateur Rockets § 101.25 Operating limitations for Class 2-High Power Rockets and Class 3-Advanced High Power Rockets. When operating...

7 CFR 800.153 - Maintenance and retention of records on official inspection, Class X or Class Y weighing, and...

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 7 2011-01-01 2011-01-01 false Maintenance and retention of records on official inspection, Class X or Class Y weighing, and equipment testing service. 800.153 Section 800.153 Agriculture... and Forms (general) § 800.153 Maintenance and retention of records on official inspection, Class X or...

7 CFR 800.153 - Maintenance and retention of records on official inspection, Class X or Class Y weighing, and...

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 7 2013-01-01 2013-01-01 false Maintenance and retention of records on official inspection, Class X or Class Y weighing, and equipment testing service. 800.153 Section 800.153 Agriculture... and Forms (general) § 800.153 Maintenance and retention of records on official inspection, Class X or...

7 CFR 800.153 - Maintenance and retention of records on official inspection, Class X or Class Y weighing, and...

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 7 2014-01-01 2014-01-01 false Maintenance and retention of records on official inspection, Class X or Class Y weighing, and equipment testing service. 800.153 Section 800.153 Agriculture... and Forms (general) § 800.153 Maintenance and retention of records on official inspection, Class X or...

7 CFR 800.153 - Maintenance and retention of records on official inspection, Class X or Class Y weighing, and...

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 7 2010-01-01 2010-01-01 false Maintenance and retention of records on official inspection, Class X or Class Y weighing, and equipment testing service. 800.153 Section 800.153 Agriculture... and Forms (general) § 800.153 Maintenance and retention of records on official inspection, Class X or...

7 CFR 800.153 - Maintenance and retention of records on official inspection, Class X or Class Y weighing, and...

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 7 2012-01-01 2012-01-01 false Maintenance and retention of records on official inspection, Class X or Class Y weighing, and equipment testing service. 800.153 Section 800.153 Agriculture... and Forms (general) § 800.153 Maintenance and retention of records on official inspection, Class X or...

Social class at birth and risk of psychosis.