Optical frequency comb Faraday rotation spectroscopy

NASA Astrophysics Data System (ADS)

Johansson, Alexandra C.; Westberg, Jonas; Wysocki, Gerard; Foltynowicz, Aleksandra

2018-05-01

We demonstrate optical frequency comb Faraday rotation spectroscopy (OFC-FRS) for broadband interference-free detection of paramagnetic species. The system is based on a femtosecond doubly resonant optical parametric oscillator and a fast-scanning Fourier transform spectrometer (FTS). The sample is placed in a DC magnetic field parallel to the light propagation. Efficient background suppression is implemented via switching the direction of the field on consecutive FTS scans and subtracting the consecutive spectra, which enables long-term averaging. In this first demonstration, we measure the entire Q- and R-branches of the fundamental band of nitric oxide in the 5.2-5.4 µm range and achieve good agreement with a theoretical model.

Scientific Verification of Faraday Rotation Modulators: Detection of Diffuse Polarized Galactic Emission

NASA Technical Reports Server (NTRS)

Moyerman, S.; Bierman, E.; Ade, P. A. R.; Aiken, R.; Barkats, D.; Bischoff, C.; Bock, J. J.; Chiang, H. C.; Dowell, C. D.; Duband, L.;

Wave-particle interaction in the Faraday waves.

PubMed

Francois, N; Xia, H; Punzmann, H; Shats, M

2015-10-01

Wave motion in disordered Faraday waves is analysed in terms of oscillons or quasi-particles. The motion of these oscillons is measured using particle tracking tools and it is compared with the motion of fluid particles on the water surface. Both the real floating particles and the oscillons, representing the collective fluid motion, show Brownian-type dispersion exhibiting ballistic and diffusive mean squared displacement at short and long times, respectively. While the floating particles motion has been previously explained in the context of two-dimensional turbulence driven by Faraday waves, no theoretical description exists for the random walk type motion of oscillons. It is found that the r.m.s velocity ⟨μ̃(osc)⟩(rms) of oscillons is directly related to the turbulent r.m.s. velocity ⟨μ̃⟩(rms) of the fluid particles in a broad range of vertical accelerations. The measured ⟨μ̃(osc)⟩(rms) accurately explains the broadening of the frequency spectra of the surface elevation observed in disordered Faraday waves. These results suggest that 2D turbulence is the driving force behind both the randomization of the oscillons motion and the resulting broadening of the wave frequency spectra. The coupling between wave motion and hydrodynamic turbulence demonstrated here offers new perspectives for predicting complex fluid transport from the knowledge of wave field spectra and vice versa.

Radio Remote Sensing of Coronal Mass Ejections: Implications for Parker Solar Probe and Solar Orbiter

NASA Astrophysics Data System (ADS)

Kooi, J. E.; Thomas, N. C.; Guy, M. B., III; Spangler, S. R.

2017-12-01

Coronal mass ejections (CMEs) are fast-moving magnetic field structures of enhanced plasma density that play an important role in space weather. The Solar Orbiter and Parker Solar Probe will usher in a new era of in situ measurements, probing CMEs within distances of 60 and 10 solar radii, respectively. At the present, only remote-sensing techniques such as Faraday rotation can probe the plasma structure of CMEs at these distances. Faraday rotation is the change in polarization position angle of linearly polarized radiation as it propagates through a magnetized plasma (e.g. a CME) and is proportional to the path integral of the electron density and line-of-sight magnetic field. In conjunction with white-light coronagraph measurements, Faraday rotation observations have been used in recent years to determine the magnetic field strength of CMEs. We report recent results from simultaneous white-light and radio observations made of a CME in July 2015. We made radio observations using the Karl G. Jansky Very Large Array (VLA) at 1 - 2 GHz frequencies of a set of radio sources through the solar corona at heliocentric distances that ranged between 8 - 23 solar radii. These Faraday rotation observations provide a priori estimates for comparison with future in situ measurements made by the Solar Orbiter and Parker Solar Probe. Similar Faraday rotation observations made simultaneously with observations by the Solar Orbiter and Parker Solar Probe in the future could provide information about the global structure of CMEs sampled by these probes and, therefore, aid in understanding the in situ measurements.

Patients' perspectives of fast-track surgery and the role of the fast-track clinical nurse consultant in gynecological oncology.

PubMed

Philp, Shannon; Carter, J; Barnett, C; DʼAbrew, N; Pather, S; White, K

2015-01-01

This study examines the role of the fast-track nurse in gynecology from a patient perspective. The fast-track nurse is a specialist nursing role, which coordinates patient care, in addition to providing specialized clinical care. Semistructured interviews were conducted with women who had fast-track surgery for gynecological cancer.

2D image of local density and magnetic fluctuations from line-integrated interferometry-polarimetry measurements.

PubMed

Lin, L; Ding, W X; Brower, D L

2014-11-01

Combined polarimetry-interferometry capability permits simultaneous measurement of line-integrated density and Faraday effect with fast time response (∼1 μs) and high sensitivity. Faraday effect fluctuations with phase shift of order 0.05° associated with global tearing modes are resolved with an uncertainty ∼0.01°. For physics investigations, local density fluctuations are obtained by inverting the line-integrated interferometry data. The local magnetic and current density fluctuations are then reconstructed using a parameterized fit of the polarimetry data. Reconstructed 2D images of density and magnetic field fluctuations in a poloidal cross section exhibit significantly different spatial structure. Combined with their relative phase, the magnetic-fluctuation-induced particle transport flux and its spatial distribution are resolved.

2D image of local density and magnetic fluctuations from line-integrated interferometry-polarimetry measurements

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

Lin, L., E-mail: lianglin@ucla.edu; Ding, W. X.; Brower, D. L.

2014-11-15

Combined polarimetry-interferometry capability permits simultaneous measurement of line-integrated density and Faraday effect with fast time response (∼1 μs) and high sensitivity. Faraday effect fluctuations with phase shift of order 0.05° associated with global tearing modes are resolved with an uncertainty ∼0.01°. For physics investigations, local density fluctuations are obtained by inverting the line-integrated interferometry data. The local magnetic and current density fluctuations are then reconstructed using a parameterized fit of the polarimetry data. Reconstructed 2D images of density and magnetic field fluctuations in a poloidal cross section exhibit significantly different spatial structure. Combined with their relative phase, the magnetic-fluctuation-induced particlemore » transport flux and its spatial distribution are resolved.« less

18 CFR 385.206 - Complaints (Rule 206).

Code of Federal Regulations, 2012 CFR

2012-04-01

... electronic media as specified by the Secretary. (11) Explain with respect to requests for Fast Track... before an ALJ; (h) Fast Track processing. (1) The Commission may resolve complaints using Fast Track procedures if the complaint requires expeditious resolution. Fast Track procedures may include expedited...

18 CFR 385.206 - Complaints (Rule 206).

Code of Federal Regulations, 2011 CFR

2011-04-01

... electronic media as specified by the Secretary. (11) Explain with respect to requests for Fast Track... before an ALJ; (h) Fast Track processing. (1) The Commission may resolve complaints using Fast Track procedures if the complaint requires expeditious resolution. Fast Track procedures may include expedited...

18 CFR 385.206 - Complaints (Rule 206).

Code of Federal Regulations, 2010 CFR

2010-04-01

... electronic media as specified by the Secretary. (11) Explain with respect to requests for Fast Track... before an ALJ; (h) Fast Track processing. (1) The Commission may resolve complaints using Fast Track procedures if the complaint requires expeditious resolution. Fast Track procedures may include expedited...

40 CFR 72.82 - Fast-track modifications.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 17 2014-07-01 2014-07-01 false Fast-track modifications. 72.82... (CONTINUED) PERMITS REGULATION Permit Revisions § 72.82 Fast-track modifications. The following procedures shall apply to all fast-track modifications. (a) If the Administrator is the permitting authority, the...

40 CFR 72.82 - Fast-track modifications.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 17 2013-07-01 2013-07-01 false Fast-track modifications. 72.82... (CONTINUED) PERMITS REGULATION Permit Revisions § 72.82 Fast-track modifications. The following procedures shall apply to all fast-track modifications. (a) If the Administrator is the permitting authority, the...

40 CFR 72.82 - Fast-track modifications.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 16 2010-07-01 2010-07-01 false Fast-track modifications. 72.82... (CONTINUED) PERMITS REGULATION Permit Revisions § 72.82 Fast-track modifications. The following procedures shall apply to all fast-track modifications. (a) If the Administrator is the permitting authority, the...

40 CFR 72.82 - Fast-track modifications.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 17 2012-07-01 2012-07-01 false Fast-track modifications. 72.82... (CONTINUED) PERMITS REGULATION Permit Revisions § 72.82 Fast-track modifications. The following procedures shall apply to all fast-track modifications. (a) If the Administrator is the permitting authority, the...

40 CFR 72.82 - Fast-track modifications.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 16 2011-07-01 2011-07-01 false Fast-track modifications. 72.82... (CONTINUED) PERMITS REGULATION Permit Revisions § 72.82 Fast-track modifications. The following procedures shall apply to all fast-track modifications. (a) If the Administrator is the permitting authority, the...

76 FR 20679 - Agency Information Collection Activities; Proposed Collection; Comment Request; Guidance for...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-13

...: Fast Track Drug Development Programs: Designation, Development, and Application Review AGENCY: Food and... licenses for fast track designation as provided in the guidance for industry on fast track drug development... appropriate, and other forms of information technology. Guidance for Industry: Fast Track Drug Development...

Comparison of Hall Thruster Plume Expansion Model with Experimental Data

DTIC Science & Technology

2006-05-23

focus of this study, is a hybrid particle- in-cell ( PIC ) model that tracks particles along an unstructured tetrahedral mesh. * Research Engineer...measurements of the ion current density profile, ion energy distributions, and ion species fraction distributions using a nude Faraday probe, retarding...Vol.37 No.1. 6 Oh, D. and Hastings, D., “Three Dimensional PIC -DSMC Simulations of Hall Thruster Plumes and Analysis for Realistic Spacecraft

42 CFR 422.626 - Fast-track appeals of service terminations to independent review entities (IREs).

Code of Federal Regulations, 2013 CFR

2013-10-01

... 42 Public Health 3 2013-10-01 2013-10-01 false Fast-track appeals of service terminations to... ADVANTAGE PROGRAM Grievances, Organization Determinations and Appeals § 422.626 Fast-track appeals of service terminations to independent review entities (IREs). (a) Enrollee's right to a fast-track appeal of...

42 CFR 422.626 - Fast-track appeals of service terminations to independent review entities (IREs).

Code of Federal Regulations, 2012 CFR

2012-10-01

... 42 Public Health 3 2012-10-01 2012-10-01 false Fast-track appeals of service terminations to... ADVANTAGE PROGRAM Grievances, Organization Determinations and Appeals § 422.626 Fast-track appeals of service terminations to independent review entities (IREs). (a) Enrollee's right to a fast-track appeal of...

42 CFR 422.626 - Fast-track appeals of service terminations to independent review entities (IREs).

Code of Federal Regulations, 2014 CFR

2014-10-01

... 42 Public Health 3 2014-10-01 2014-10-01 false Fast-track appeals of service terminations to... ADVANTAGE PROGRAM Grievances, Organization Determinations and Appeals § 422.626 Fast-track appeals of service terminations to independent review entities (IREs). (a) Enrollee's right to a fast-track appeal of...

42 CFR 422.626 - Fast-track appeals of service terminations to independent review entities (IREs).

Code of Federal Regulations, 2010 CFR

2010-10-01

... Grievances, Organization Determinations and Appeals § 422.626 Fast-track appeals of service terminations to independent review entities (IREs). (a) Enrollee's right to a fast-track appeal of an MA organization's termination decision. An enrollee of an MA organization has a right to a fast-track appeal of an MA...

42 CFR 422.626 - Fast-track appeals of service terminations to independent review entities (IREs).

Code of Federal Regulations, 2011 CFR

2011-10-01

... 42 Public Health 3 2011-10-01 2011-10-01 false Fast-track appeals of service terminations to... Grievances, Organization Determinations and Appeals § 422.626 Fast-track appeals of service terminations to independent review entities (IREs). (a) Enrollee's right to a fast-track appeal of an MA organization's...

Fast track in hip arthroplasty

PubMed Central

Hansen, Torben Bæk

2017-01-01

‘Fast-track’ surgery was introduced more than 20 years ago and may be defined as a co-ordinated peri-operative approach aimed at reducing surgical stress and facilitating post-operative recovery.The fast-track programmes have now been introduced into total hip arthroplasty (THA) surgery with reduction in post-operative length of stay, shorter convalescence and rapid functional recovery without increased morbidity and mortality. This has been achieved by focusing on a multidisciplinary collaboration and establishing ‘fast-track’ units, with a well-defined organisational set-up tailored to deliver an accelerated peri-operative course of fast-track surgical THA procedures.Fast-track THA surgery now works extremely well in the standard THA patient. However, all patients are different and fine-tuning of the multiple areas in fast-track pathways to get patients with special needs or high co-morbidity burden through a safe and effective fast-track THA pathway is important.In this narrative review, the principles of fast-track THA surgery are presented together with the present status of implementation and perspectives for further improvements. Cite this article: EFORT Open Rev 2017;2. DOI: 10.1302/2058-5241.2.160060. Originally published online at www.efortopenreviews.org PMID:28630756

Comparison of Hall Thruster Plume Expansion Model with Experimental Data (Preprint)

DTIC Science & Technology

2006-07-01

Cartesian mesh. AQUILA, the focus of this study, is a hybrid PIC model that tracks particles along an unstructured tetrahedral mesh. COLISEUM is capable...measurements of the ion current density profile, ion energy distributions, and ion species fraction distributions using a nude Faraday probe...Spacecraft and Rockets, Vol.37 No.1. 6 Oh, D. and Hastings, D., “Three Dimensional PIC -DSMC Simulations of Hall Thruster Plumes and Analysis for

Dense magnetized plasma associated with a fast radio burst.

PubMed

Masui, Kiyoshi; Lin, Hsiu-Hsien; Sievers, Jonathan; Anderson, Christopher J; Chang, Tzu-Ching; Chen, Xuelei; Ganguly, Apratim; Jarvis, Miranda; Kuo, Cheng-Yu; Li, Yi-Chao; Liao, Yu-Wei; McLaughlin, Maura; Pen, Ue-Li; Peterson, Jeffrey B; Roman, Alexander; Timbie, Peter T; Voytek, Tabitha; Yadav, Jaswant K

2015-12-24

Fast radio bursts are bright, unresolved, non-repeating, broadband, millisecond flashes, found primarily at high Galactic latitudes, with dispersion measures much larger than expected for a Galactic source. The inferred all-sky burst rate is comparable to the core-collapse supernova rate out to redshift 0.5. If the observed dispersion measures are assumed to be dominated by the intergalactic medium, the sources are at cosmological distances with redshifts of 0.2 to 1 (refs 10 and 11). These parameters are consistent with a wide range of source models. One fast burst revealed circular polarization of the radio emission, but no linear polarization was detected, and hence no Faraday rotation measure could be determined. Here we report the examination of archival data revealing Faraday rotation in the fast radio burst FRB 110523. Its radio flux and dispersion measure are consistent with values from previously reported bursts and, accounting for a Galactic contribution to the dispersion and using a model of intergalactic electron density, we place the source at a maximum redshift of 0.5. The burst has a much higher rotation measure than expected for this line of sight through the Milky Way and the intergalactic medium, indicating magnetization in the vicinity of the source itself or within a host galaxy. The pulse was scattered by two distinct plasma screens during propagation, which requires either a dense nebula associated with the source or a location within the central region of its host galaxy. The detection in this instance of magnetization and scattering that are both local to the source favours models involving young stellar populations such as magnetars over models involving the mergers of older neutron stars, which are more likely to be located in low-density regions of the host galaxy.

Variation in 'fast-track' referrals for suspected cancer by patient characteristic and cancer diagnosis: evidence from 670 000 patients with cancers of 35 different sites.

PubMed

Zhou, Y; Mendonca, S C; Abel, G A; Hamilton, W; Walter, F M; Johnson, S; Shelton, J; Elliss-Brookes, L; McPhail, S; Lyratzopoulos, G

2018-01-01

In England, 'fast-track' (also known as 'two-week wait') general practitioner referrals for suspected cancer in symptomatic patients are used to shorten diagnostic intervals and are supported by clinical guidelines. However, the use of the fast-track pathway may vary for different patient groups. We examined data from 669 220 patients with 35 cancers diagnosed in 2006-2010 following either fast-track or 'routine' primary-to-secondary care referrals using 'Routes to Diagnosis' data. We estimated the proportion of fast-track referrals by sociodemographic characteristic and cancer site and used logistic regression to estimate respective crude and adjusted odds ratios. We additionally explored whether sociodemographic associations varied by cancer. There were large variations in the odds of fast-track referral by cancer (P<0.001). Patients with testicular and breast cancer were most likely to have been diagnosed after a fast-track referral (adjusted odds ratios 2.73 and 2.35, respectively, using rectal cancer as reference); whereas patients with brain cancer and leukaemias least likely (adjusted odds ratios 0.05 and 0.09, respectively, for brain cancer and acute myeloid leukaemia). There were sex, age and deprivation differences in the odds of fast-track referral (P<0.013) that varied in their size and direction for patients with different cancers (P<0.001). For example, fast-track referrals were least likely in younger women with endometrial cancer and in older men with testicular cancer. Fast-track referrals are less likely for cancers characterised by nonspecific presenting symptoms and patients belonging to low cancer incidence demographic groups. Interventions beyond clinical guidelines for 'alarm' symptoms are needed to improve diagnostic timeliness.

Cardiac surgery fast-track treatment in a postanesthetic care unit: six-month results of the Leipzig fast-track concept.

PubMed

Ender, Joerg; Borger, Michael Andrew; Scholz, Markus; Funkat, Anne-Kathrin; Anwar, Nadeem; Sommer, Marcus; Mohr, Friedrich Wilhelm; Fassl, Jens

2008-07-01

The authors compared the safety and efficacy of a newly developed fast-track concept at their center, including implementation of a direct admission postanesthetic care unit, to standard perioperative management. All fast-track patients treated within the first 6 months of implementation of our direct admission postanesthetic care unit were matched via propensity scores and compared with a historical control group of patients who underwent cardiac surgery prior to fast-track implementation. A total of 421 fast-track patients were matched successfully to 421 control patients. The two groups of patients had a similar age (64 +/- 13 vs. 64 +/- 12 yr for fast-track vs. control, P = 0.45) and European System for Cardiac Operative Risk Evaluation-predicted risk of mortality (4.8 +/- 6.1% vs. 4.6 +/- 5.1%, P = 0.97). Fast-track patients had significantly shorter times to extubation (75 min [45-110] vs. 900 min [600-1140]), as well as shorter lengths of stay in the postanesthetic or intensive care unit (4 h [3.0-5] vs. 20 h [16-25]), intermediate care unit (21 h [17-39] vs. 26 h [19-49]), and hospital (10 days [8-12] vs. 11 days [9-14]) (expressed as median and interquartile range, all P < 0.01). Fast-track patients also had a lower risk of postoperative low cardiac output syndrome (0.5% vs. 2.9%, P < 0.05) and mortality (0.5% vs. 3.3%, P < 0.01). The Leipzig fast-track protocol is a safe and effective method to manage cardiac surgery patients after a variety of operations.

Alterable Magnetic Gratings for Fiber Optic Switching.

DTIC Science & Technology

1982-12-01

monotonically decreasing function as X moves into the infrared from the visible. The Faraday rotation of bismuth garnet samples including the new large... photodector giving as fast a response as possible while still providing usable signal levels, measure the detector response * using the electro-optic...icity. Normally a stripe domain array is configured as a linear grating. In-plane magnetic fields can rotate the grating as well as alter the periodicity

Multiple feature fusion via covariance matrix for visual tracking

NASA Astrophysics Data System (ADS)

Jin, Zefenfen; Hou, Zhiqiang; Yu, Wangsheng; Wang, Xin; Sun, Hui

2018-04-01

Aiming at the problem of complicated dynamic scenes in visual target tracking, a multi-feature fusion tracking algorithm based on covariance matrix is proposed to improve the robustness of the tracking algorithm. In the frame-work of quantum genetic algorithm, this paper uses the region covariance descriptor to fuse the color, edge and texture features. It also uses a fast covariance intersection algorithm to update the model. The low dimension of region covariance descriptor, the fast convergence speed and strong global optimization ability of quantum genetic algorithm, and the fast computation of fast covariance intersection algorithm are used to improve the computational efficiency of fusion, matching, and updating process, so that the algorithm achieves a fast and effective multi-feature fusion tracking. The experiments prove that the proposed algorithm can not only achieve fast and robust tracking but also effectively handle interference of occlusion, rotation, deformation, motion blur and so on.

Hybrid Ni/SiO2/Au dimer arrays for high-resolution refractive index sensing

NASA Astrophysics Data System (ADS)

Pourjamal, Sara; Kataja, Mikko; Maccaferri, Nicolò; Vavassori, Paolo; van Dijken, Sebastiaan

2018-05-01

We introduce a novel magnetoplasmonic sensor concept for sensitive detection of refractive index changes. The sensor consists of a periodic array of Ni/SiO2/Au dimer nanodisks. Combined effects of near-field interactions between the Ni and Au disks within the individual dimers and far-field diffractive coupling between the dimers of the array produce narrow linewidth features in the magneto-optical Faraday spectrum. We associate these features with the excitation of surface lattice resonances and show that they exhibit a spectral shift when the refractive index of the surrounding environment is varied. Because the resonances are sharp, refractive index changes are accurately detected by tracking the wavelength where the Faraday signal crosses 0. Compared to random distributions of pure Ni nanodisks or Ni/SiO2/Au dimers or periodic arrays of Ni nanodisks, the sensing figure of merit of the hybrid magnetoplasmonic array is more than one order of magnitude larger.

Fast track multi-discipline treatment (FTMDT trial) versus conventional treatment in colorectal cancer--the design of a prospective randomized controlled study

PubMed Central

2011-01-01

Background Laparoscopy-assisted surgery, fast-track perioperative treatment are both increasingly used in colorectal cancer treatment, for their short-time benefits of enhanced recovery and short hospital stays. However, the benefits of the integration of the Laparoscopy-assisted surgery, fast-track perioperative treatment, and even with the Xelox chemotherapy, are still unknown. In this study, the three treatments integration is defined as "Fast Track Multi-Discipline Treatment Model" for colorectal cancer and this model extends the benefits to the whole treatment process of colorectal cancer. The main purpose of the study is to explore the feasibility of "Fast Track Multi-Discipline Treatment" model in treatment of colorectal cancer. Methods The trial is a prospective randomized controlled study with 2 × 2 balanced factorial design. Patients eligible for the study will be randomized to 4 groups: (I) Laparoscopic surgery with fast track perioperative treatment and Xelox chemotherapy; (II) Open surgery with fast track perioperative treatment and Xelox chemotherapy; (III) Laparoscopic surgery with conventional perioperative treatment and mFolfox6 chemotherapy; (IV) Open surgery with conventional perioperative treatment and mFolfox6 chemotherapy. The primary endpoint of this study is the hospital stays. The secondary endpoints are the quality of life, chemotherapy related adverse events, surgical complications and hospitalization costs. Totally, 340 patients will be enrolled with 85 patients in each group. Conclusions The study initiates a new treatment model "Fast Track Multi-Discipline Treatment" for colorectal cancer, and will provide feasibility evidence on the new model "Fast Track Multi-Discipline Treatment" for patients with colorectal cancer. Trial registration ClinicalTrials.gov: NCT01080547 PMID:22111914

Free-space laser communication technologies IV; Proceedings of the 4th Conference, Los Angeles, CA, Jan. 23, 24, 1992

NASA Technical Reports Server (NTRS)

Begley, David L. (Editor); Seery, Bernard D. (Editor)

1992-01-01

Papers included in this volume are grouped under topics of receivers; laser transmitters; components; system analysis, performance, and applications; and beam control (pointing, acquisition, and tracking). Papers are presented on an experimental determination of power penalty contributions in an optical Costas-type phase-locked loop receiver, a resonant laser receiver for free-space laser communications, a simple low-loss technique for frequency-locking lasers, direct phase modulation of laser diodes, and a silex beacon. Particular attention is given to experimental results on an optical array antenna for nonmechanical beam steering, a potassium Faraday anomalous dispersion optical filter, a 100-Mbps resonant cavity phase modulator for coherent optical communications, a numerical simulation of a 325-Mbit/s QPPM optical communication system, design options for an optical multiple-access data relay terminal, CCD-based optical tracking loop design trades, and an analysis of a spatial-tracking subsystem for optical communications.

Diagnostics of ion beam generated from a Mather type plasma focus device

NASA Astrophysics Data System (ADS)

Lim, L. K.; Ngoi, S. K.; Wong, C. S.; Yap, S. L.

2014-03-01

Diagnostics of ion beam emission from a 3 kJ Mather-type plasma focus device have been performed for deuterium discharge at low pressure regime. Deuterium plasma focus was found to be optimum at pressure of 0.2 mbar. The energy spectrum and total number of ions per shot from the pulsed ion beam are determined by using biased ion collectors, Faraday cup, and solid state nuclear track detector CR-39. Average energy of the ion beam obtained is about 60 keV. Total number of the ions has been determined to be in the order of 1011 per shot. Solid state nuclear track detectors (SSNTD) CR39 are employed to measure the particles at all angular direction from end on (0°) to side on (90°). Particle tracks are registered by SSNTD at 30° to 90°, except the one at the end-on 0°.

Variation in ‘fast-track’ referrals for suspected cancer by patient characteristic and cancer diagnosis: evidence from 670 000 patients with cancers of 35 different sites

PubMed Central

Zhou, Y; Mendonca, S C; Abel, G A; Hamilton, W; Walter, F M; Johnson, S; Shelton, J; Elliss-Brookes, L; McPhail, S; Lyratzopoulos, G

2018-01-01

Background: In England, ‘fast-track’ (also known as ‘two-week wait’) general practitioner referrals for suspected cancer in symptomatic patients are used to shorten diagnostic intervals and are supported by clinical guidelines. However, the use of the fast-track pathway may vary for different patient groups. Methods: We examined data from 669 220 patients with 35 cancers diagnosed in 2006–2010 following either fast-track or ‘routine’ primary-to-secondary care referrals using ‘Routes to Diagnosis’ data. We estimated the proportion of fast-track referrals by sociodemographic characteristic and cancer site and used logistic regression to estimate respective crude and adjusted odds ratios. We additionally explored whether sociodemographic associations varied by cancer. Results: There were large variations in the odds of fast-track referral by cancer (P<0.001). Patients with testicular and breast cancer were most likely to have been diagnosed after a fast-track referral (adjusted odds ratios 2.73 and 2.35, respectively, using rectal cancer as reference); whereas patients with brain cancer and leukaemias least likely (adjusted odds ratios 0.05 and 0.09, respectively, for brain cancer and acute myeloid leukaemia). There were sex, age and deprivation differences in the odds of fast-track referral (P<0.013) that varied in their size and direction for patients with different cancers (P<0.001). For example, fast-track referrals were least likely in younger women with endometrial cancer and in older men with testicular cancer. Conclusions: Fast-track referrals are less likely for cancers characterised by nonspecific presenting symptoms and patients belonging to low cancer incidence demographic groups. Interventions beyond clinical guidelines for ‘alarm’ symptoms are needed to improve diagnostic timeliness. PMID:29182609

76 FR 6369 - Changes To Implement the Prioritized Examination Track (Track I) of the Enhanced Examination...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-04

... (Track I), providing fast examination for applicants desiring it, upon payment of the applicable fee and... examiners or supervisory patent examiners, specialized examiner training for fast track processing...

"Fast Track" and "Traditional Path" Coaches: Affordances, Agency and Social Capital

ERIC Educational Resources Information Center

Rynne, Steven

2014-01-01

A recent development in large-scale coach accreditation (certification) structures has been the "fast tracking" of former elite athletes. Former elite athletes are often exempted from entry-level qualifications and are generally granted access to fast track courses that are shortened versions of the accreditation courses undertaken by…

18 CFR 385.206 - Complaints (Rule 206).

Code of Federal Regulations, 2014 CFR

2014-04-01

... electronic media as specified by the Secretary. (11) Explain with respect to requests for Fast Track... merits based upon the pleadings; (3) The Commission may establish a hearing before an ALJ; (h) Fast Track processing. (1) The Commission may resolve complaints using Fast Track procedures if the complaint requires...

18 CFR 385.206 - Complaints (Rule 206).

Code of Federal Regulations, 2013 CFR

2013-04-01

... electronic media as specified by the Secretary. (11) Explain with respect to requests for Fast Track... merits based upon the pleadings; (3) The Commission may establish a hearing before an ALJ; (h) Fast Track processing. (1) The Commission may resolve complaints using Fast Track procedures if the complaint requires...

[Fast-track treatment--second revolution of colorectal surgery].

PubMed

Kellokumpu, Ilmo

2012-01-01

The fast-track treatment model can be regarded as the second revolution of colorectal surgery after the introduction of laparoscopic surgery. In the gastro-surgical unit of the Central Hospital of Central Finland, results equivalent to international studies in colorectal surgery have been achieved by using fast-track model. In a study setting, this treatment model has resulted in significant decrease of total treatment costs and speeded up discharge of the patients from the hospital. The fast-track treatment model requires both a motivated, trained medical team and a motivated patient.

Measurement of the secondary electron emission from CVD diamond films using phosphor screen detectors

NASA Astrophysics Data System (ADS)

Vaz, R.; May, P. W.; Fox, N. A.; Harwood, C. J.; Chatterjee, V.; Smith, J. A.; Horsfield, C. J.; Lapington, J. S.; Osbourne, S.

2015-03-01

Diamond-based photomultipliers have the potential to provide a significant improvement over existing devices due to diamond's high secondary electron yield and narrow energy distribution of secondary electrons which improves energy resolution creating extremely fast response times. In this paper we describe an experimental apparatus designed to study secondary electron emission from diamond membranes only 400 nm thick, observed in reflection and transmission configurations. The setup consists of a system of calibrated P22 green phosphor screens acting as radiation converters which are used in combination with photomultiplier tubes to acquire secondary emission yield data from the diamond samples. The superior signal voltage sampling of the phosphor screen setup compared with traditional Faraday Cup detection allows the variation in the secondary electron yield across the sample to be visualised, allowing spatial distributions to be obtained. Preliminary reflection and transmission yield data are presented as a function of primary electron energy for selected CVD diamond films and membranes. Reflection data were also obtained from the same sample set using a Faraday Cup detector setup. In general, the curves for secondary electron yield versus primary energy for both measurement setups were comparable. On average a 15-20% lower signal was recorded on our setup compared to the Faraday Cup, which was attributed to the lower photoluminescent efficiency of the P22 phosphor screens when operated at sub-kilovolt bias voltages.

Fast Track Teaching: Beginning the Experiment in Accelerated Leadership Development

ERIC Educational Resources Information Center

Churches, Richard; Hutchinson, Geraldine; Jones, Jeff

2009-01-01

This article provides an overview of the development of the Fast Track teaching programme and personalised nature of the training and support that has been delivered. Fast Track teacher promotion rates are compared to national statistics demonstrating significant progression for certain groups, particularly women. (Contains 3 tables and 3 figures.)

Fast Track: A Language Arts Program for Middle School Gifted

ERIC Educational Resources Information Center

Schneider, Jean

2008-01-01

"Fast Track" is a pseudonym for an accelerated, advanced language arts program for verbally gifted and high potential students in grades 6-8. The critical thinking model used for "Fast Track" was gleaned from Coalition of Essential Schools founder Ted Sizer's Habits of Mind: significance, evidence, connections, perspective, and supposition, as…

76 FR 45261 - Agency Information Collection Activities; Submission for Office of Management and Budget Review...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-28

... Request; Guidance for Industry: Fast Track Drug Development Programs: Designation, Development, and... information to OMB for review and clearance. Guidance for Industry: Fast Track Drug Development Programs... to industry on fast track policies and procedures outlined in section 506 of the FD&C Act. The...

A new approach for the screening of carotid lesions: a 'fast-track' method with the use of new generation hand-held ultrasound devices.

PubMed

Aboyans, V; Lacroix, P; Jeannicot, A; Guilloux, J; Bertin, F; Laskar, M

2004-09-01

We assessed the usefulness of fast-track neck sonography with a new-generation hand-held ultrasound scanner in the detection of > or =60% carotid stenosis. Patients with a past history of atherosclerotic disease or presence of risk factors were enrolled. All had fast-track carotid screening with a hand-held ultrasound scanner. Initial assessment was performed with our quick imaging protocol. A second examiner performed a conventional complete carotid duplex as gold-standard. We enrolled 197 consecutive patients with a mean age of 67 years (range 35-94). A carotid stenosis >60% was detected in 13 cases (6%). The sensitivity, specificity, positive and negative predictive value of fast-track sonography was 100%, 64%, 17% and 100%, respectively. Concomitant power Doppler imaging during the fast-track method did not improve accuracy. The use of a fast-track method with a hand-held ultrasound device can reduce the number of unnecessary carotid Duplex and enhance the screening efficiency without missing significant carotid stenoses.

Effect of an emergency department fast track on Press-Ganey patient satisfaction scores.

PubMed

Hwang, Calvin E; Lipman, Grant S; Kane, Marlena

2015-01-01

Mandated patient surveys have become an integral part of Medicare remuneration, putting hundreds of millions of dollars in funding at risk. The Centers for Medicare & Medicaid Services (CMS) recently announced a patient experience survey for the emergency department (ED). Development of an ED Fast Track, where lower acuity patients are rapidly seen, has been shown to improve many of the metrics that CMS examines. This is the first study examining if ED Fast Track implementation affects Press-Ganey scores of patient satisfaction. We analyzed returned Press-Ganey questionnaires from all ESI 4 and 5 patients seen 11AM - 1PM, August-December 2011 (pre-fast track), and during the identical hours of fast track, August-December 2012. Raw ordinal scores were converted to continuous scores for paired student t-test analysis. We calculated an odds ratio with 100% satisfaction considered a positive response. An academic ED with 52,000 annual visits had 140 pre-fast track and 85 fast track respondents. Implementation of a fast track significantly increased patient satisfaction with the following: wait times (68% satisfaction to 88%, OR 4.13, 95% CI [2.32-7.33]), doctor courtesy (90% to 95%, OR 1.97, 95% CI [1.04-3.73]), nurse courtesy (87% to 95%, OR 2.75, 95% CI [1.46-5.15]), pain control (79% to 87%, OR 2.13, 95% CI [1.16-3.92]), likelihood to recommend (81% to 90%, OR 2.62, 95% CI [1.42-4.83]), staff caring (82% to 91%, OR 2.82, 95% CI [1.54-5.19]), and staying informed about delays (66% to 83%, OR 3.00, 95% CI [1.65-5.44]). Implementation of an ED Fast Track more than doubled the odds of significant improvements in Press-Ganey patient satisfaction metrics and may play an important role in improving ED performance on CMS benchmarks.

Nonreciprocal plasmonics enables giant enhancement of thin-film Faraday rotation.

PubMed

Chin, Jessie Yao; Steinle, Tobias; Wehlus, Thomas; Dregely, Daniel; Weiss, Thomas; Belotelov, Vladimir I; Stritzker, Bernd; Giessen, Harald

2013-01-01

Light propagation is usually reciprocal. However, a static magnetic field along the propagation direction can break the time-reversal symmetry in the presence of magneto-optical materials. The Faraday effect in magneto-optical materials rotates the polarization plane of light, and when light travels backward the polarization is further rotated. This is applied in optical isolators, which are of crucial importance in optical systems. Faraday isolators are typically bulky due to the weak Faraday effect of available magneto-optical materials. The growing research endeavour in integrated optics demands thin-film Faraday rotators and enhancement of the Faraday effect. Here, we report significant enhancement of Faraday rotation by hybridizing plasmonics with magneto-optics. By fabricating plasmonic nanostructures on laser-deposited magneto-optical thin films, Faraday rotation is enhanced by one order of magnitude in our experiment, while high transparency is maintained. We elucidate the enhanced Faraday effect by the interplay between plasmons and different photonic waveguide modes in our system.

Bounded tracking for nonminimum phase nonlinear systems with fast zero dynamics

DOT National Transportation Integrated Search

1996-12-01

A PostScript file. In this paper, tracking control laws for nonminimum phase nonlinear systems with both fast and slow, possibly unstable, zero dynamics are derived. The fast zero dynamics arise from a perturbation of a nominal system. These fast zer...

Design and modeling of Faraday cages for substrate noise isolation

NASA Astrophysics Data System (ADS)

Wu, Joyce H.; del Alamo, Jesús A.

2013-07-01

A Faraday cage structure using through-substrate vias is an effective strategy to suppress substrate crosstalk, particularly at high frequencies. Faraday cages can reduce substrate noise by 32 dB at 10 GHz, and 26 dB at 50 GHz. We have developed lumped-element, equivalent circuit models of the Faraday cages and test structures to better understand the performance of the Faraday cages. These models compare well to measured results and show that the vias of the Faraday cage act as an RLC shunt to ground that draws substrate current. Designing a Faraday cage to achieve optimum isolation requires low via impedance and mitigation of via sidewall capacitance. The Faraday cage inductance is correlated to the number of vias and via spacing of the cage and can be optimized for the frequency of operation.

An MR-compatible stereoscopic in-room 3D display for MR-guided interventions.

PubMed

Brunner, Alexander; Groebner, Jens; Umathum, Reiner; Maier, Florian; Semmler, Wolfhard; Bock, Michael

2014-08-01

A commercial three-dimensional (3D) monitor was modified for use inside the scanner room to provide stereoscopic real-time visualization during magnetic resonance (MR)-guided interventions, and tested in a catheter-tracking phantom experiment at 1.5 T. Brightness, uniformity, radio frequency (RF) emissions and MR image interferences were measured. Due to modifications, the center luminance of the 3D monitor was reduced by 14%, and the addition of a Faraday shield further reduced the remaining luminance by 31%. RF emissions could be effectively shielded; only a minor signal-to-noise ratio (SNR) decrease of 4.6% was observed during imaging. During the tracking experiment, the 3D orientation of the catheter and vessel structures in the phantom could be visualized stereoscopically.

Study of the Vertical Magnetic Field in Face-on Galaxies Using Faraday Tomography

NASA Astrophysics Data System (ADS)

Ideguchi, Shinsuke; Tashiro, Yuichi; Akahori, Takuya; Takahashi, Keitaro; Ryu, Dongsu

2017-07-01

Faraday tomography allows astronomers to probe the distribution of the magnetic field along the line of sight (LOS), but that can be achieved only after the Faraday spectrum is interpreted. However, the interpretation is not straightforward, mainly because the Faraday spectrum is complicated due to a turbulent magnetic field; it ruins the one-to-one relation between the Faraday depth and the physical depth, and appears as many small-scale features in the Faraday spectrum. In this paper, by employing “simple toy models” for the magnetic field, we describe numerically as well as analytically the characteristic properties of the Faraday spectrum. We show that the Faraday spectrum along “multiple LOSs” can be used to extract the global properties of the magnetic field. Specifically, considering face-on spiral galaxies and modeling turbulent magnetic field as a random field with a single coherence length, we numerically calculate the Faraday spectrum along a number of LOSs and its shape-characterizing parameters, that is, the moments. When multiple LOSs cover a region of ≳(10 coherence length)2, the shape of the Faraday spectrum becomes smooth and the shape-characterizing parameters are well specified. With the Faraday spectrum constructed as a sum of Gaussian functions with different means and variances, we analytically show that the parameters are expressed in terms of the regular and turbulent components of the LOS magnetic field and the coherence length. We also consider the turbulent magnetic field modeled with a power-law spectrum, and study how the magnetic field is revealed in the Faraday spectrum. Our work suggests a way to obtain information on the magnetic field from a Faraday tomography study.

Study of the Vertical Magnetic Field in Face-on Galaxies Using Faraday Tomography

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

Ideguchi, Shinsuke; Ryu, Dongsu; Tashiro, Yuichi

Faraday tomography allows astronomers to probe the distribution of the magnetic field along the line of sight (LOS), but that can be achieved only after the Faraday spectrum is interpreted. However, the interpretation is not straightforward, mainly because the Faraday spectrum is complicated due to a turbulent magnetic field; it ruins the one-to-one relation between the Faraday depth and the physical depth, and appears as many small-scale features in the Faraday spectrum. In this paper, by employing “simple toy models” for the magnetic field, we describe numerically as well as analytically the characteristic properties of the Faraday spectrum. We showmore » that the Faraday spectrum along “multiple LOSs” can be used to extract the global properties of the magnetic field. Specifically, considering face-on spiral galaxies and modeling turbulent magnetic field as a random field with a single coherence length, we numerically calculate the Faraday spectrum along a number of LOSs and its shape-characterizing parameters, that is, the moments. When multiple LOSs cover a region of ≳(10 coherence length){sup 2}, the shape of the Faraday spectrum becomes smooth and the shape-characterizing parameters are well specified. With the Faraday spectrum constructed as a sum of Gaussian functions with different means and variances, we analytically show that the parameters are expressed in terms of the regular and turbulent components of the LOS magnetic field and the coherence length. We also consider the turbulent magnetic field modeled with a power-law spectrum, and study how the magnetic field is revealed in the Faraday spectrum. Our work suggests a way to obtain information on the magnetic field from a Faraday tomography study.« less

Restoring integrity--A grounded theory of coping with a fast track surgery programme.

PubMed

Jørgensen, Lene Bastrup; Fridlund, Bengt

2016-01-01

The aim of this study was to generate a theory conceptualizing and explaining behavioural processes involved in coping in order to identify the predominant coping types and coping type-specific features. Patients undergoing fast track procedures do not experience a higher risk of complications, readmission, or mortality. However, such programmes presuppose an increasing degree of patient involvement, placing high educational, physical, and mental demands on the patients. There is a lack of knowledge about how patients understand and cope with fast track programmes. The study design used classical grounded theory. The study used a multimodal approach with qualitative and quantitative data sets from 14 patients. Four predominant types of coping, with distinct physiological, cognitive, affective, and psychosocial features, existed among patients going through a fast track total hip replacement programme. These patients' main concern was to restore their physical and psychosocial integrity, which had been compromised by reduced function and mobility in daily life. To restore integrity they economized their mental resources, while striving to fulfil the expectations of the fast track programme. This goal was achieved by being mentally proactive and physically active. Three out of the four predominant types of coping matched the expectations expressed in the fast track programme. The non-matching behaviour was seen among the most nervous patients, who claimed the right to diverge from the programme. In theory, four predominant types of coping with distinct physiological, cognitive, affective, and psychosocial features occur among patients going through a fast track total hip arthroplasty programme.

Earth-based observations of Faraday rotation in radio bursts from Jupiter

NASA Technical Reports Server (NTRS)

Phillips, J. A.; Ferree, Thomas C.; Wang, Joe

1989-01-01

New observations have been made of Faraday rotation in decameter-wavelength radio bursts from the planet Jupiter. Data obtained during six Io-B storms clearly indicate that an appreciable fraction of the observed Faraday rotation occurs in the Jovian magnetosphere. All of the Faraday rotation observed during a single Io-A storm can be accounted for by earth's ionosphere. Measurements of the Faraday effect in Io-B emissions indicate that the source is in Jupiter's northern magnetic hemisphere. Observations of the Faraday effect in Io-C emissions are proposed to determine its location as well.

Michael Faraday vs. the Spiritualists

NASA Astrophysics Data System (ADS)

Hirshfeld, Alan

2006-12-01

In the 1850s, renowned physicist Michael Faraday launched a public campaign against pseudoscience and spiritualism, which were rampant in England at the time. Faraday objected especially to claims that electrical or magnetic forces were responsible for paranormal phenomena, such as table-spinning and communication with the dead. Using scientific methods, Faraday unmasked the deceptions of spiritualists, clairvoyants and mediums and also laid bare the credulity of a public ill-educated in science. Despite his efforts, Victorian society's fascination with the paranormal swelled. Faraday's debacle anticipates current controversies about public science education and the interface between science and religion. This episode is one of many described in the new biography, The Electric Life of Michael Faraday (Walker & Co.), which chronicles Faraday's discoveries and his unlikely rise from poverty to the pinnacle of the English science establishment.

Evaluation of Plume Divergence and Facility Effects on Far-Field Faraday Probe Current Density Profiles

DTIC Science & Technology

2009-09-01

elevated background pressure, compared nude Faraday probe designs, and evaluated design modifications to minimize uncertainty due to charge exchange...evaluated Faraday probe design and facility background pressure on collected ion current. A comparison of two nude Faraday probe designs concluded...140.5 Plasma potential in the region surrounding a nude Faraday probe has been measured to study the possibility of probe bias voltage acting as a

[Shortened hospital stay for elective cesarean section after initiation of a fast-track program and midwifery home-care].

PubMed

Gunnarsdottir, Johanna; Bjornsdottir, Thorbjörg Edda; Halldorsson, Thorhallur Ingi; Halldorsdottir, Gudrun; Geirsson, Reynir Tomas

2011-07-01

To audit whether hospital stay shortened without increasing readmissions after implementation of fast-track methodology for elective cesarean section and characterize what influences length of stay. A fast-track program was initiated in November 2008, with a one year clinical audit and satisfaction survey. Discharge criteria were predefined and midwife home visits included if discharge was within 48 hours. Hospital stay by parity for women with elective section for singleton pregnancy between 1.11. 2008 - 31.10. 2009 (n=213, fast-track 182) was compared to 2003 (n=199) and 2007 (n=183). Readmissions and outpatient visits 2007 and 2008-9 were counted. Reasons for longer stay were recorded in fast-track, and body mass index. Median hospital stay decreased significantly from 81 to 52 hours between 2007 and 2008-9. Readmissions were four in each period and outpatient visit rates similar. In 2008-9, 66% of all women were discharged within 48 hours. Women in the fast-track program were satisfied with early discharge. Hospital stay for parous women was shorter in 2007 compared to 2003, but unchanged for nulliparas. Parity had a minimal influence on length of stay in 2008-9, although nulliparous women ≤ 25 years were more likely to stay >48 hours. Body mass index did not correlate with length of stay. Pain was rarely the reason for a longer stay in the fast-track program and 90% were satisfied with pain-medication after discharge. Most healthy women can be discharged early after singleton birth by elective cesarean, without increasing readmissions.

Indirect Effects of the Fast Track Intervention on Conduct Disorder Symptoms and Callous-Unemotional Traits: Distinct Pathways Involving Discipline and Warmth

PubMed Central

Pasalich, Dave S.; Witkiewitz, Katie; McMahon, Robert J.; Pinderhughes, Ellen E.

2016-01-01

Little is known about intervening processes that explain how prevention programs improve particular youth antisocial outcomes. We examined whether parental harsh discipline and warmth in childhood differentially account for Fast Track intervention effects on conduct disorder (CD) symptoms and callous-unemotional (CU) traits in early adolescence. Participants included 891 high-risk kindergarteners (69% male; 51% African American) from urban and rural United States communities who were randomized into either the Fast Track intervention (n = 445) or non-intervention control (n = 446) groups. The 10-year intervention included parent management training and other services (e.g., social skills training, universal classroom curriculum) targeting various risk factors for the development of conduct problems. Harsh discipline (Grades 1 through 3) and warmth (Grades 1 and 2) were measured using parent responses to vignettes and direct observations of parent-child interaction, respectively. Parents reported on children’s CD symptoms in Grade 6 and CU traits in Grade 7. Results demonstrated indirect effects of the Fast Track intervention on reducing risk for youth antisocial outcomes. That is, Fast Track was associated with lower scores on harsh discipline, which in turn predicted decreased levels of CD symptoms. In addition, Fast Track was associated with higher scores on warmth, which in turn predicted reduced levels of CU traits. Our findings inform developmental and intervention models of youth antisocial behavior by providing evidence for the differential role of harsh discipline and warmth in accounting for indirect effects of Fast Track on CD symptoms versus CU traits, respectively. PMID:26242993

Restoring integrity—A grounded theory of coping with a fast track surgery programme

PubMed Central

Jørgensen, Lene Bastrup; Fridlund, Bengt

2016-01-01

Aims and objectives The aim of this study was to generate a theory conceptualizing and explaining behavioural processes involved in coping in order to identify the predominant coping types and coping type-specific features. Background Patients undergoing fast track procedures do not experience a higher risk of complications, readmission, or mortality. However, such programmes presuppose an increasing degree of patient involvement, placing high educational, physical, and mental demands on the patients. There is a lack of knowledge about how patients understand and cope with fast track programmes. Design The study design used classical grounded theory. Methods The study used a multimodal approach with qualitative and quantitative data sets from 14 patients. Results Four predominant types of coping, with distinct physiological, cognitive, affective, and psychosocial features, existed among patients going through a fast track total hip replacement programme. These patients’ main concern was to restore their physical and psychosocial integrity, which had been compromised by reduced function and mobility in daily life. To restore integrity they economized their mental resources, while striving to fulfil the expectations of the fast track programme. This goal was achieved by being mentally proactive and physically active. Three out of the four predominant types of coping matched the expectations expressed in the fast track programme. The non-matching behaviour was seen among the most nervous patients, who claimed the right to diverge from the programme. Conclusion In theory, four predominant types of coping with distinct physiological, cognitive, affective, and psychosocial features occur among patients going through a fast track total hip arthroplasty programme. PMID:26751199

Indirect Effects of the Fast Track Intervention on Conduct Disorder Symptoms and Callous-Unemotional Traits: Distinct Pathways Involving Discipline and Warmth.

PubMed

Pasalich, Dave S; Witkiewitz, Katie; McMahon, Robert J; Pinderhughes, Ellen E

2016-04-01

Little is known about intervening processes that explain how prevention programs improve particular youth antisocial outcomes. We examined whether parental harsh discipline and warmth in childhood differentially account for Fast Track intervention effects on conduct disorder (CD) symptoms and callous-unemotional (CU) traits in early adolescence. Participants included 891 high-risk kindergarteners (69% male; 51% African American) from urban and rural United States communities who were randomized into either the Fast Track intervention (n = 445) or non-intervention control (n = 446) groups. The 10-year intervention included parent management training and other services (e.g., social skills training, universal classroom curriculum) targeting various risk factors for the development of conduct problems. Harsh discipline (Grades 1 to 3) and warmth (Grades 1 and 2) were measured using parent responses to vignettes and direct observations of parent-child interaction, respectively. Parents reported on children's CD symptoms in Grade 6 and CU traits in Grade 7. Results demonstrated indirect effects of the Fast Track intervention on reducing risk for youth antisocial outcomes. That is, Fast Track was associated with lower scores on harsh discipline, which in turn predicted decreased levels of CD symptoms. In addition, Fast Track was associated with higher scores on warmth, which in turn predicted reduced levels of CU traits. Our findings inform developmental and intervention models of youth antisocial behavior by providing evidence for the differential role of harsh discipline and warmth in accounting for indirect effects of Fast Track on CD symptoms versus CU traits, respectively.

Comparison of algorithms for determination of rotation measure and Faraday structure. I. 1100–1400 MHz

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

Sun, X. H.; Akahori, Takuya; Anderson, C. S.

2015-02-01

Faraday rotation measures (RMs) and more general Faraday structures are key parameters for studying cosmic magnetism and are also sensitive probes of faint ionized thermal gas. A definition of which derived quantities are required for various scientific studies is needed, as well as addressing the challenges in determining Faraday structures. A wide variety of algorithms has been proposed to reconstruct these structures. In preparation for the Polarization Sky Survey of the Universe's Magnetism (POSSUM) to be conducted with the Australian Square Kilometre Array Pathfinder and the ongoing Galactic Arecibo L-band Feeds Array Continuum Transit Survey (GALFACTS), we run a Faradaymore » structure determination data challenge to benchmark the currently available algorithms, including Faraday synthesis (previously called RM synthesis in the literature), wavelet, compressive sampling, and QU-fitting. The input models include sources with one Faraday thin component, two Faraday thin components, and one Faraday thick component. The frequency set is similar to POSSUM/GALFACTS with a 300 MHz bandwidth from 1.1 to 1.4 GHz. We define three figures of merit motivated by the underlying science: (1) an average RM weighted by polarized intensity, RM{sub wtd}, (2) the separation Δϕ of two Faraday components, and (3) the reduced chi-squared χ{sub r}{sup 2}. Based on the current test data with a signal-to-noise ratio of about 32, we find the following. (1) When only one Faraday thin component is present, most methods perform as expected, with occasional failures where two components are incorrectly found. (2) For two Faraday thin components, QU-fitting routines perform the best, with errors close to the theoretical ones for RM{sub wtd} but with significantly higher errors for Δϕ. All other methods, including standard Faraday synthesis, frequently identify only one component when Δϕ is below or near the width of the Faraday point-spread function. (3) No methods as currently implemented work well for Faraday thick components due to the narrow bandwidth. (4) There exist combinations of two Faraday components that produce a large range of acceptable fits and hence large uncertainties in the derived single RMs; in these cases, different RMs lead to the same Q, U behavior, so no method can recover a unique input model. Further exploration of all these issues is required before upcoming surveys will be able to provide reliable results on Faraday structures.« less

Perioperative strategy in colonic surgery; LAparoscopy and/or FAst track multimodal management versus standard care (LAFA trial)

PubMed Central

Wind, Jan; Hofland, Jan; Preckel, Benedikt; Hollmann, Markus W; Bossuyt, Patrick MM; Gouma, Dirk J; van Berge Henegouwen, Mark I; Fuhring, Jan Willem; Dejong, Cornelis HC; van Dam, Ronald M; Cuesta, Miguel A; Noordhuis, Astrid; de Jong, Dick; van Zalingen, Edith; Engel, Alexander F; Goei, T Hauwy; de Stoppelaar, I Erica; van Tets, Willem F; van Wagensveld, Bart A; Swart, Annemiek; van den Elsen, Maarten JLJ; Gerhards, Michael F; de Wit, Laurens Th; Siepel, Muriel AM; van Geloven, Anna AW; Juttmann, Jan-Willem; Clevers, Wilfred; Bemelman, Willem A

2006-01-01

Background Recent developments in large bowel surgery are the introduction of laparoscopic surgery and the implementation of multimodal fast track recovery programs. Both focus on a faster recovery and shorter hospital stay. The randomized controlled multicenter LAFA-trial (LAparoscopy and/or FAst track multimodal management versus standard care) was conceived to determine whether laparoscopic surgery, fast track perioperative care or a combination of both is to be preferred over open surgery with standard care in patients having segmental colectomy for malignant disease. Methods/design The LAFA-trial is a double blinded, multicenter trial with a 2 × 2 balanced factorial design. Patients eligible for segmental colectomy for malignant colorectal disease i.e. right and left colectomy and anterior resection will be randomized to either open or laparoscopic colectomy, and to either standard care or the fast track program. This factorial design produces four treatment groups; open colectomy with standard care (a), open colectomy with fast track program (b), laparoscopic colectomy with standard care (c), and laparoscopic surgery with fast track program (d). Primary outcome parameter is postoperative hospital length of stay including readmission within 30 days. Secondary outcome parameters are quality of life two and four weeks after surgery, overall hospital costs, morbidity, patient satisfaction and readmission rate. Based on a mean postoperative hospital stay of 9 +/- 2.5 days a group size of 400 patients (100 each arm) can reliably detect a minimum difference of 1 day between the four arms (alfa = 0.95, beta = 0.8). With 100 patients in each arm a difference of 10% in subscales of the Short Form 36 (SF-36) questionnaire and social functioning can be detected. Discussion The LAFA-trial is a randomized controlled multicenter trial that will provide evidence on the merits of fast track perioperative care and laparoscopic colorectal surgery in patients having segmental colectomy for malignant disease. PMID:17134506

Fast-Track Management of Patients Undergoing Proximal Pancreatic Resection

PubMed Central

French, JJ; Mansfield, SD; Jaques, K; Jaques, BC; Manas, DM; Charnley, RM

2009-01-01

INTRODUCTION To avoid the risk of complications of biliary drainage, a feasibility study was carried out to determine whether it might be possible to fast-track surgical treatment, with resection before biliary drainage, in jaundiced patients with proximal pancreatic/peri-ampullary malignancy. PATIENTS AND METHODS Over an 18-month period, based on their presenting bilirubin levels and other logistical factors, all jaundiced patients who might be suitable for fast-track management were identified. Data on complications and hospital stay were compared with those patients in whom a conventional pathway (with biliary drainage) was used during the same time period. Data were also compared with a group of patients from the preceding 6 months. RESULTS Nine patients were fast-tracked and 49 patients treated in the conventional pathway. Fast-track patients mean (SD) serum bilirubin level was 265 μmol/l (81.6) at the time of the operation compared to 43 μmol/l (51.3; P ≥ 0.0001) in conventional patients. Mean (SD) of time from referral to operation, 14 days (9) versus 59 days (36.9), was significantly shorter in fast-track patients than conventional patients (P ≤ 0.0001). Length of hospital stay mean (SD) at 17 (6) days versus 22 days (19.6; P = 0.2114), surgical complications and mortality in fast-track patients were similar to conventional patients. Prior to surgery, the 49 conventional patients underwent a total of 73 biliary drainage procedures resulting in seven major complications. Comparison with the group of patients from the previous 6 months indicated that the conventional group were not disadvantaged. CONCLUSIONS Fast-track management by resection without biliary drainage of selected patients with distal biliary strictures is safe and has the potential to reduce the waiting time to surgery, overall numbers of biliary drainage procedures and the complications thereof. PMID:19220943

Faraday rotation dispersion microscopy imaging of diamagnetic and chiral liquids with pulsed magnetic field.

PubMed

Suwa, Masayori; Nakano, Yusuke; Tsukahara, Satoshi; Watarai, Hitoshi

2013-05-21

We have constructed an experimental setup for Faraday rotation dispersion imaging and demonstrated the performance of a novel imaging principle. By using a pulsed magnetic field and a polarized light synchronized to the magnetic field, quantitative Faraday rotation images of diamagnetic organic liquids in glass capillaries were observed. Nonaromatic hydrocarbons, benzene derivatives, and naphthalene derivatives were clearly distinguished by the Faraday rotation images due to the difference in Verdet constants. From the wavelength dispersion of the Faraday rotation images in the visible region, it was found that the resonance wavelength in the UV region, which was estimated based on the Faraday B-term, could be used as characteristic parameters for the imaging of the liquids. Furthermore, simultaneous acquisition of Faraday rotation image and natural optical rotation image was demonstrated for chiral organic liquids.

SQUIDs vs. Faraday coils for ultlra-low field nuclear magnetic resonance: experimental and simulation comparison

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

Matlashov, Andrei N; Espy, Michelle A; Kraus, Robert H

2010-01-01

Nuclear magnetic resonance (NMR) methods are widely used in medicine, chemistry and industry. One application area is magnetic resonance imaging or MRI. Recently it has become possible to perform NMR and MRI in ultra-low field (ULF) regime that requires measurement field strengths only of the order of 1 Gauss. These techniques exploit the advantages offered by superconducting quantum interference devices or SQUIDs. Our group at LANL has built SQUID based MRI systems for brain imaging and for liquid explosives detection at airports security checkpoints. The requirement for liquid helium cooling limits potential applications of ULF MRI for liquid identification andmore » security purposes. Our experimental comparative investigation shows that room temperature inductive magnetometers provide enough sensitivity in the 3-10 kHz range and can be used for fast liquid explosives detection based on ULF NMR/MRI technique. We describe an experimental and computer simulation comparison of the world's first multichannel SQUID based and Faraday coils based instruments that are capable of performing ULF MRI for liquids identification.« less

Faraday rotation enhancement of gold coated Fe2O3 nanoparticles: comparison of experiment and theory.

PubMed

Dani, Raj Kumar; Wang, Hongwang; Bossmann, Stefan H; Wysin, Gary; Chikan, Viktor

2011-12-14

Understanding plasmonic enhancement of nanoscale magnetic materials is important to evaluate their potential for application. In this study, the Faraday rotation (FR) enhancement of gold coated Fe(2)O(3) nanoparticles (NP) is investigated experimentally and theoretically. The experiment shows that the Faraday rotation of a Fe(2)O(3) NP solution changes from approximately 3 rad/Tm to 10 rad/Tm as 5 nm gold shell is coated on a 9.7 nm Fe(2)O(3) core at 632 nm. The results also show how the volume fraction normalized Faraday rotation varies with the gold shell thickness. From the comparison of experiment and calculated Faraday rotation based on the Maxwell-Garnett theory, it is concluded that the enhancement and shell dependence of Faraday rotation of Fe(2)O(3) NPs is a result of the shifting plasmon resonance of the composite NP. In addition, the clustering of the NPs induces a different phase lag on the Faraday signal, which suggests that the collective response of the magnetic NP aggregates needs to be considered even in solution. From the Faraday phase lag, the estimated time of the full alignment of the magnetic spins of bare (cluster size 160 nm) and gold coated NPs (cluster size 90 nm) are found to be 0.65 and 0.17 μs. The calculation includes a simple theoretical approach based on the Bruggeman theory to account for the aggregation and its effect on the Faraday rotation. The Bruggeman model provides a qualitatively better agreement with the experimentally observed Faraday rotation and points out the importance of making a connection between component properties and the average "effective" optical behavior of the Faraday medium containing magnetic nanoparticles. © 2011 American Institute of Physics

Registered Nurse to Bachelor of Science in Nursing: nesting a fast-track to traditional generic program, teachings from nursing education in Burkina Faso.

PubMed

Beogo, Idrissa; Liu, Chieh-Yu; Dlamini, Colile P; Gagnon, Marie-Pierre

2015-01-01

Nursing education has evolved over time to fit societies' increasing care needs. Innovations in nursing education draw thorny debates on potential jeopardy in the quality, safety, and efficacy of nurse graduates. Accelerated nursing education programs have been among landmark strategic changes to address the persistent bedside nurse shortage. Despite the dearth of empirical studies in sub-Saharan Africa (SSA), the National School of Public Health of Burkina Faso has developed a State Diploma Nursing (SDN) fast-track program. With innovative features, the program is nested into the traditional SDN program. This study investigates preliminary outcomes of the implemented policy using the initial cohort that went through the program. Comparison of the traditional generic program and the fast-track one is drawn to inform nursing education policy. The study was conducted in the three campuses delivering the SDN program. Data collected from a representative sample included 255 students from the 2006-2009 cohort, after concluding the program. Surveyed students were assessed according to the program entry status. Outcomes were measured using students' academic performance. Besides descriptive analysis, bivariate t-test, F-test, and multivariate ordinary least square regression (OLSR) were employed to determine the comparative pattern between the traditional generic and the newly nested fast-track program. Students' varied statuses (private pre-registration, state pre-registration, private post-registration, and state post-registration) were kept to better outline the findings trend. A fifth (19.6 %) of surveyed students were enrolled in the fast-track stream from which, one third (33.7 %) consisted of post-registered students. Fast-track students comparatively achieved the best academic performance (mean: 73.68/100, SD: 5.52). Multivariate OLSR confirmed that fast-track students performed better (β: 5.559, p < 0.001), and further informed differences between campuses. Students entry status also displayed significant differences, yet the academic performance of post-registered students from traditional generic versus fast-track was similar (p = 0.409). Findings suggest that fast-track program students performed better than the ones from the traditional generic program. The uniqueness and success of this mixed nursing program experience sheds light for nursing educators engaged in policy making. The study results can serve as a crucial foundation for policymakers to alleviate the nurse shortage in SSA.

42 CFR 417.840 - Administrative review procedures.

Code of Federal Regulations, 2010 CFR

2010-10-01

... fast-track appeals that affect its Medicare enrollees; and (b) Reconsiderations, hearings, Medicare Appeals Council review, and judicial review of the organization determinations and fast-track appeals...

42 CFR 417.840 - Administrative review procedures.

Code of Federal Regulations, 2011 CFR

2011-10-01

... fast-track appeals that affect its Medicare enrollees; and (b) Reconsiderations, hearings, Medicare Appeals Council review, and judicial review of the organization determinations and fast-track appeals...

12 CFR 261.13 - Processing requests.

Code of Federal Regulations, 2014 CFR

2014-01-01

... Information Office and that have already been cleared for public release may qualify for fast-track processing... will make the determination whether a request qualifies for fast-track processing. A requester may contact the Freedom of Information Office to learn whether a particular request has been assigned to fast...

12 CFR 261.13 - Processing requests.

Code of Federal Regulations, 2012 CFR

2012-01-01

... Information Office and that have already been cleared for public release may qualify for fast-track processing... will make the determination whether a request qualifies for fast-track processing. A requester may contact the Freedom of Information Office to learn whether a particular request has been assigned to fast...

12 CFR 261.13 - Processing requests.

Code of Federal Regulations, 2013 CFR

2013-01-01

... Information Office and that have already been cleared for public release may qualify for fast-track processing... will make the determination whether a request qualifies for fast-track processing. A requester may contact the Freedom of Information Office to learn whether a particular request has been assigned to fast...

12 CFR 261.13 - Processing requests.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Information Office and that have already been cleared for public release may qualify for fast-track processing... will make the determination whether a request qualifies for fast-track processing. A requester may contact the Freedom of Information Office to learn whether a particular request has been assigned to fast...

12 CFR 261.13 - Processing requests.

Code of Federal Regulations, 2011 CFR

2011-01-01

... Information Office and that have already been cleared for public release may qualify for fast-track processing... will make the determination whether a request qualifies for fast-track processing. A requester may contact the Freedom of Information Office to learn whether a particular request has been assigned to fast...

Laparoscopic surgery contributes more to nutritional and immunologic recovery than fast-track care in colorectal cancer.

PubMed

Xu, Dong; Li, Jun; Song, Yongmao; Zhou, Jiaojiao; Sun, Fangfang; Wang, Jianwei; Duan, Yin; Hu, Yeting; Liu, Yue; Wang, Xiaochen; Sun, Lifeng; Wu, Linshan; Ding, Kefeng

2015-02-04

Many clinical trials had repeatedly shown that fast-track perioperative care and laparoscopic surgery are both preferred in the treatment of colorectal cancer. But few studies were designed to explore the diverse biochemical impacts of the two counterparts on human immunologic and nutritional status. Ninety-two cases of colorectal cancer patients meeting the inclusion criteria were randomized to four groups: laparoscopy with fast-track treatment (LAFT); open surgery with fast-track treatment (OSFT); laparoscopy with conventional treatment (LAC); open surgery with conventional treatment (OSC). Peripheral blood tests including nutritional factors (albumin, prealbumin, and transferrin), humoral immunologic factors (IgG, IgM, and IgA), and cellular immunologic factors (T and NK cells) were evaluated. Blood samples were collected preoperatively (baseline) and 12 and 96 h after surgery (indicated as POH12 and POH96, respectively). Albumin, transferrin, prealbumin, and IgG levels were the highest in the LAFT group for both POH12 and POH96 time intervals. Repeated measures (two-way ANOVA) indicated that the difference of albumin, transferrin, and IgG level were attributed to surgery type (P < 0.05) and not perioperative treatment (P > 0.05). Only in the laparoscopy-included groups, the relative albumin and IgG levels of POH96 were obviously higher than that of POH12. Laparoscopic surgery accelerated postoperative nutrition and immune levels rising again while fast-track treatment retarded the drop of postoperative nutrition and immune levels. Laparoscopic surgery might play a more important role than fast-track treatment in the earlier postoperative recovery of nutritional and immunologic status. Combined laparoscopic surgery with fast-track treatment provided best postoperative recovery of nutrition and immune status. These results should be further compared with the clinical outcomes of our FTMDT trial (clinicaltrials.gov: NCT01080547).

Patient experience in fast-track hip and knee arthroplasty--a qualitative study.

PubMed

Specht, Kirsten; Kjaersgaard-Andersen, Per; Pedersen, Birthe D

2016-03-01

To explore the lived experience of patients in fast-track primary unilateral total hip and knee arthroplasty from the first visit at the outpatient clinic until discharge. Fast-track has resulted in increased effectiveness, including faster recovery and shorter length of stay to about two days after hip and knee arthroplasty. However, the patient perspective in fast-track with a median length of stay of less than three days has been less investigated. A qualitative design. A phenomenological-hermeneutic approach was used, inspired by Paul Ricoeur's theory of narrative and interpretation. Eight patients were included. Semi-structured interviews and participant observation were performed. Three themes emerged: dealing with pain; feelings of confidence or uncertainty - the meaning of information; and readiness for discharge. Generally, the patients were resistant to taking analgesics and found it difficult to find out when to take supplementary analgesics; therefore, nursing staff needed enough expertise to take responsibility. Factors that increased patients' confidence: information about fast-track, meeting staff before admission and involving relatives. In contrast, incorrect or conflicting information and a lack of respect for privacy led to uncertainty. In preparing for early discharge, sufficient pain management, feeling well-rested and optimal use of time during hospitalisation were important. The study shows the importance of dealing with pain and getting the right information and support to have confidence in the fast-track programme, to be ready for discharge and to manage postoperatively at home. In fast-track focusing on early discharge, there is an increased need for evidence-based nursing practice, including a qualified judgement of what is best for the patient in certain situations. The knowledge should be gleaned from: research; the patients' expertise, understanding and situation; and nurses' knowledge, skills and experience. © 2015 John Wiley & Sons Ltd.

The Fast Track: Facility for Accelerated Service Testing - Transportation Test Center, Pueblo, Colorado, 2nd edition

DOT National Transportation Integrated Search

1978-07-01

This brochure describes the 22 test sections of the Federal Railroad Administration's FAST Track and the various track and mechanical measurements being made as of September 1977 - the end of the first year of operation at the facility. Because of th...

42 CFR 417.840 - Administrative review procedures.

Code of Federal Regulations, 2012 CFR

2012-10-01

... determinations and fast-track appeals that affect its Medicare enrollees; and (b) Reconsiderations, hearings, Medicare Appeals Council review, and judicial review of the organization determinations and fast-track...

42 CFR 417.840 - Administrative review procedures.

Code of Federal Regulations, 2013 CFR

2013-10-01

... determinations and fast-track appeals that affect its Medicare enrollees; and (b) Reconsiderations, hearings, Medicare Appeals Council review, and judicial review of the organization determinations and fast-track...

42 CFR 417.840 - Administrative review procedures.

Code of Federal Regulations, 2014 CFR

2014-10-01

... determinations and fast-track appeals that affect its Medicare enrollees; and (b) Reconsiderations, hearings, Medicare Appeals Council review, and judicial review of the organization determinations and fast-track...

Ultrafast magnetic vortex core switching driven by the topological inverse Faraday effect.

PubMed

Taguchi, Katsuhisa; Ohe, Jun-ichiro; Tatara, Gen

2012-09-21

We present a theoretical discovery of an unconventional mechanism of inverse Faraday effect which acts selectively on topological magnetic structures. The effect, topological inverse Faraday effect, is induced by the spin Berry's phase of the magnetic structure when a circularly polarized light is applied. Thus a spin-orbit interaction is not necessary unlike that in the conventional inverse Faraday effect. We demonstrate by numerical simulation that topological inverse Faraday effect realizes ultrafast switching of a magnetic vortex within a switching time of 150 ps without magnetic field.

Patients' satisfaction with fast-track surgery in gynaecological oncology.

PubMed

Philp, S; Carter, J; Pather, S; Barnett, C; D'Abrew, N; White, K

2015-07-01

This study investigates the experience and satisfaction with care of fast-tracked gynaecological patients. The Sydney Gynaecological Oncology Group, New South Wales, Australia, has previously shown the benefits of a fast-track surgery programme for gynaecology patients with both complex benign gynaecological pathology and gynaecological malignancy. The question of whether these benefits translate into a positive experience for fast-tracked patients, in the context of their hospital stay and healthcare team care, has not been previously explored in detail. A self-administered satisfaction questionnaire incorporating the European Organisation for Research and Treatment of Cancer (EORTC) cancer in-patient satisfaction with care measure (INPATSAT-32) questionnaire with additional questions was administered to 106 gynaecology participants at Royal Prince Alfred Hospital. Participants reported high levels of satisfaction with patient care and support received from doctors, ward nurses and the hospital as a service and care organisation, within the context of a fast-track surgical programme. Early hospital discharge after gynaecological surgery results in both enhanced recovery after surgery (ERAS) and high levels of patient satisfaction. © 2014 John Wiley & Sons Ltd.

Mode locking of electron spin coherences in singly charged quantum dots.

PubMed

Greilich, A; Yakovlev, D R; Shabaev, A; Efros, Al L; Yugova, I A; Oulton, R; Stavarache, V; Reuter, D; Wieck, A; Bayer, M

2006-07-21

The fast dephasing of electron spins in an ensemble of quantum dots is detrimental for applications in quantum information processing. We show here that dephasing can be overcome by using a periodic train of light pulses to synchronize the phases of the precessing spins, and we demonstrate this effect in an ensemble of singly charged (In,Ga)As/GaAs quantum dots. This mode locking leads to constructive interference of contributions to Faraday rotation and presents potential applications based on robust quantum coherence within an ensemble of dots.

Three-dimensional magnetic bubble memory system

NASA Technical Reports Server (NTRS)

Stadler, Henry L. (Inventor); Katti, Romney R. (Inventor); Wu, Jiin-Chuan (Inventor)

1994-01-01

A compact memory uses magnetic bubble technology for providing data storage. A three-dimensional arrangement, in the form of stacks of magnetic bubble layers, is used to achieve high volumetric storage density. Output tracks are used within each layer to allow data to be accessed uniquely and unambiguously. Storage can be achieved using either current access or field access magnetic bubble technology. Optical sensing via the Faraday effect is used to detect data. Optical sensing facilitates the accessing of data from within the three-dimensional package and lends itself to parallel operation for supporting high data rates and vector and parallel processing.

A Fast MEANSHIFT Algorithm-Based Target Tracking System

PubMed Central

Sun, Jian

2012-01-01

Tracking moving targets in complex scenes using an active video camera is a challenging task. Tracking accuracy and efficiency are two key yet generally incompatible aspects of a Target Tracking System (TTS). A compromise scheme will be studied in this paper. A fast mean-shift-based Target Tracking scheme is designed and realized, which is robust to partial occlusion and changes in object appearance. The physical simulation shows that the image signal processing speed is >50 frame/s. PMID:22969397

Evaluation of a Magnetically-Filtered Faraday Probe for Measuring the ion Current Density Profile of a Hall Thruster

DTIC Science & Technology

2004-07-01

The ability of a magnetically-filtered Faraday probe (MFFP) to obtain the ion current density profile of a Hall thruster is investigated. The MFFP is...MFFP, boxed Faraday probe (BFP), and nude Faraday probe are used to measure the ion current density profile of a 5 kW Hall thruster operated over the

[Principles of fast track surgery. Multimodal perioperative therapy programme].

PubMed

Kehlet, H

2009-08-01

Recent evidence has documented that a combination of single-modality evidence-based care principles into a multimodal effort to enhance postoperative recovery (the fast track methodology) has led to enhanced recovery with reduced medical morbidity, need for hospitalisation and convalescence. Nevertheless, general implementation of fast track surgery has been relatively slow despite concomitant economic benefits. Further improvement in postoperative outcome may be obtained by developments within each care principle with a specific focus on minimally invasive surgery, effective multimodal, non-opioid analgesia and pharmacological stress reduction.

Compact All-Fiber Optical Faraday Components Using 65-wt%-Terbium-Doped Fiber with a Record Verdet Constant of -32 rad/(Tm)

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

Sun, L.; Jiang, S.; Maricante, J.R.

2010-06-04

A compact all-fiber Faraday isolator and a Faraday mirror are demonstrated. At the core of each of these components is an all-fiber Faraday rotator made of a 4-cm-long, 65-wt%-terbium–doped silicate fiber. The effective Verdet constant of the terbium-doped fiber is measured to be –32 rad/(Tm), which is 27 × larger than that of silica fiber. This effective Verdet constant is the largest value measured to date in any fiber and is 83% of the Verdet constant of commercially available crystal used in bulk optics–based isolators. Combining the all-fiber Faraday rotator with fiber polarizers results in a fully fusion spliced all-fibermore » isolator whose isolation is measured to be 19 dB. Combining the all-fiber Faraday rotator with a fiber Bragg grating results in an all-fiber Faraday mirror that rotates the polarization state of the reflected light by 88 ± 4°.« less

Compact all-fiber optical Faraday components using 65-wt%-terbium-doped fiber with a record Verdet constant of -32 rad/(Tm).

PubMed

Sun, L; Jiang, S; Marciante, J R

2010-06-07

A compact all-fiber Faraday isolator and a Faraday mirror are demonstrated. At the core of each of these components is an all-fiber Faraday rotator made of a 4-cm-long, 65-wt%-terbium-doped silicate fiber. The effective Verdet constant of the terbium-doped fiber is measured to be -32 rad/(Tm), which is 27 x larger than that of silica fiber. This effective Verdet constant is the largest value measured to date in any fiber and is 83% of the Verdet constant of commercially available crystal used in bulk optics-based isolators. Combining the all-fiber Faraday rotator with fiber polarizers results in a fully fusion spliced all-fiber isolator whose isolation is measured to be 19 dB. Combining the all-fiber Faraday rotator with a fiber Bragg grating results in an all-fiber Faraday mirror that rotates the polarization state of the reflected light by 88 +/- 4 degrees .

From nanoparticles to large aerosols: Ultrafast measurement methods for size and concentration

NASA Astrophysics Data System (ADS)

Keck, Lothar; Spielvogel, Jürgen; Grimm, Hans

2009-05-01

A major challenge in aerosol technology is the fast measurement of number size distributions with good accuracy and size resolution. The dedicated instruments are frequently based on particle charging and electric detection. Established fast systems, however, still feature a number of shortcomings. We have developed a new instrument that constitutes of a high flow Differential Mobility Analyser (high flow DMA) and a high sensitivity Faraday Cup Electrometer (FCE). The system enables variable flow rates of up to 150 lpm, and the scan time for size distribution can be shortened considerably due to the short residence time of the particles in the DMA. Three different electrodes can be employed in order to cover a large size range. First test results demonstrate that the scan time can be reduced to less than 1 s for small particles, and that the results from the fast scans feature no significant difference to the results from established slow method. The fields of application for the new instrument comprise the precise monitoring of fast processes with nanoparticles, including monitoring of engine exhaust in automotive research.

78 FR 33836 - CPSC Safety Academy

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-05

... compliance issues, and the fast track recall program. The Safety Academy is structured such that the morning... continued, including Fast Track and Section 15; and (Panel 3) Flammable Fabrics, Drawstrings, and Sleepwear...

A novel Cs-(129)Xe atomic spin gyroscope with closed-loop Faraday modulation.

PubMed

Fang, Jiancheng; Wan, Shuangai; Qin, Jie; Zhang, Chen; Quan, Wei; Yuan, Heng; Dong, Haifeng

2013-08-01

We report a novel Cs-(129)Xe atomic spin gyroscope (ASG) with closed-loop Faraday modulation method. This ASG requires approximately 30 min to start-up and 110 °C to operate. A closed-loop Faraday modulation method for measurement of the optical rotation was used in this ASG. This method uses an additional Faraday modulator to suppress the laser intensity fluctuation and Faraday modulator thermal induced fluctuation. We theoretically and experimentally validate this method in the Cs-(129)Xe ASG and achieved a bias stability of approximately 3.25 °∕h.

12 CFR 792.10 - What will NCUA do with my request?

Code of Federal Regulations, 2012 CFR

2012-01-01

... identifiable by the Information Center and have already been cleared for public release may qualify for fast... received. (c) The Information Center will make the determination whether a request qualifies for fast track... request has been assigned. If your request has not qualified for fast track processing, you will have an...

12 CFR 792.10 - What will NCUA do with my request?

Code of Federal Regulations, 2010 CFR

2010-01-01

... identifiable by the Information Center and have already been cleared for public release may qualify for fast... received. (c) The Information Center will make the determination whether a request qualifies for fast track... request has been assigned. If your request has not qualified for fast track processing, you will have an...

12 CFR 792.10 - What will NCUA do with my request?

Code of Federal Regulations, 2013 CFR

2013-01-01

... identifiable by the Information Center and have already been cleared for public release may qualify for fast... received. (c) The Information Center will make the determination whether a request qualifies for fast track... request has been assigned. If your request has not qualified for fast track processing, you will have an...

12 CFR 792.10 - What will NCUA do with my request?

Code of Federal Regulations, 2014 CFR

2014-01-01

... identifiable by the Information Center and have already been cleared for public release may qualify for fast... received. (c) The Information Center will make the determination whether a request qualifies for fast track... request has been assigned. If your request has not qualified for fast track processing, you will have an...

12 CFR 792.10 - What will NCUA do with my request?

Code of Federal Regulations, 2011 CFR

2011-01-01

... identifiable by the Information Center and have already been cleared for public release may qualify for fast... received. (c) The Information Center will make the determination whether a request qualifies for fast track... request has been assigned. If your request has not qualified for fast track processing, you will have an...

77 FR 48506 - CPSC Safety Academy

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-14

... issues and the Fast-Track process. These discussions will be held in a panel format, with a brief... Nuances of 6b''; or ``Fast-Track Process--Compliance.'' An official of the General Administration of...

Exploring Novel Spintronic Responses from Advanced Functional Organic Materials

DTIC Science & Technology

2015-08-13

optical properties of different organic molecules, mesogenics and conjugated polymers, mainly poly(3-alkylthiophene)s, have been investigated by Faraday ...of organic media we focused in our part of the project on studies of the Faraday rotation of an array of organic molecules and conjugated polymers...difficult to measure. However, χeem is easy accessible from Faraday rotation measurements. Faraday rotation, the rotation of the plane of polarization

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

Hu Jing; Rovey, Joshua L.

A movable Faraday cup design with simple structure and adjustable impedance is described in this work. This Faraday cup has external adjustable shunt resistance for self-biased measurement setup and 50 {Omega} characteristic impedance to match with 50 {Omega} standard BNC coaxial cable and vacuum feedthroughs for nanosecond-level pulse signal measurements. Adjustable shunt resistance allows self-biased measurements to be quickly acquired to determine the electron energy distribution function. The performance of the Faraday cup is validated by tests of response time and amplitude of output signal. When compared with a reference source, the percent difference of the Faraday cup signal fallmore » time is less than 10% for fall times greater than 10 ns. The percent difference of the Faraday cup signal pulse width is below 6.7% for pulse widths greater than 10 ns. A pseudospark-generated electron beam is used to compare the amplitude of the Faraday cup signal with a calibrated F-70 commercial current transformer. The error of the Faraday cup output amplitude is below 10% for the 4-14 kV tested pseudospark voltages. The main benefit of this Faraday cup is demonstrated by adjusting the external shunt resistance and performing the self-biased method for obtaining the electron energy distribution function. Results from a 4 kV pseudospark discharge indicate a ''double-humped'' energy distribution.« less

Supplemental Interscalene Blockade to General Anesthesia for Shoulder Arthroscopy: Effects on Fast Track Capability, Analgesic Quality, and Lung Function.

PubMed

Zoremba, Martin; Kratz, Thomas; Dette, Frank; Wulf, Hinnerk; Steinfeldt, Thorsten; Wiesmann, Thomas

2015-01-01

After shoulder surgery performed in patients with interscalene nerve block (without general anesthesia), fast track capability and postoperative pain management in the PACU are improved compared with general anesthesia alone. However, it is not known if these evidence-based benefits still exist when the interscalene block is combined with general anesthesia. We retrospectively analyzed a prospective cohort data set of 159 patients undergoing shoulder arthroscopy with general anesthesia alone (n = 60) or combined with an interscalene nerve block catheter (n = 99) for fast track capability time. Moreover, comparisons were made for VAS scores, analgesic consumption in the PACU, pain management, and lung function measurements. The groups did not differ in mean time to fast track capability (22 versus 22 min). Opioid consumption in PACU was significantly less in the interscalene group, who had significantly better VAS scores during PACU stay. Patients receiving interscalene blockade had a significantly impaired lung function postoperatively, although this did not affect postoperative recovery and had no impact on PACU times. The addition of interscalene block to general anesthesia for shoulder arthroscopy did not enhance fast track capability. Pain management and VAS scores were improved in the interscalene nerve block group.

Competing Turing and Faraday Instabilities in Longitudinally Modulated Passive Resonators.

PubMed

Copie, François; Conforti, Matteo; Kudlinski, Alexandre; Mussot, Arnaud; Trillo, Stefano

2016-04-08

We experimentally investigate the interplay of Turing (modulational) and Faraday (parametric) instabilities in a bistable passive nonlinear resonator. The Faraday branch is induced via parametric resonance owing to a periodic modulation of the resonator dispersion. We show that the bistable switching dynamics is dramatically affected by the competition between the two instability mechanisms, which dictates two completely novel scenarios. At low detunings from resonance, switching occurs between the stable stationary lower branch and the Faraday-unstable upper branch, whereas at high detunings we observe the crossover between the Turing and Faraday periodic structures. The results are well explained in terms of the universal Lugiato-Lefever model.

Theoretical and numerical evaluation of polarimeter using counter-circularly-polarized-probing-laser under the coupling between Faraday and Cotton-Mouton effect.

PubMed

Imazawa, Ryota; Kawano, Yasunori; Itami, Kiyoshi

2016-04-01

This study evaluated an effect of an coupling between the Faraday and Cotton-Mouton effect to a measurement signal of the Dodel-Kunz method which uses counter-circular-polarized probing-laser for measuring the Faraday effect. When the coupling is small (the Faraday effect is dominant and the characteristic eigenmodes are approximately circularly polarized), the measurement signal can be algebraically expressed and it is shown that the finite effect of the coupling is still significant. When the Faraday effect is not dominant, a numerical calculation is necessary. The numerical calculation under an ITER-like condition (Bt = 5.3 T, Ip = 15 MA, a = 2 m, ne = 10(20) m(-3) and λ = 119 μm) showed that difference between the pure Faraday rotation and the measurement signal of the Dodel-Kunz method was an order of one degree, which exceeds allowable error of ITER poloidal polarimeter. In conclusion, similar to other polarimeter techniques, the Dodel-Kunz method is not free from the coupling between the Faraday and Cotton-Mouton effect.

Design of a Holonic Control Architecture for Distributed Sensor Management

DTIC Science & Technology

2009-09-01

Tracking tasks require only intermit - tent access to the sensors to maintain a given track quality. The higher the specified quality, the more often...resolution of the sensor (i.e., sensor mode), which can be adjusted to compensate for fast moving targets tracked over long ranges, or slower moving...but provides higher data update rates that are beneficial when tracking fast agile targets (i.e., a fighter). Table A.2 illustrates the dependence of

[Laparoscopic "fast-track" sigmoidectomy for diverticulitis disease in Germany. Results of a prospective quality assurance program].

PubMed

Tsilimparis, N; Haase, O; Wendling, P; Kipfmüller, K; Schmid, M; Engemann, R; Schwenk, W

2010-09-01

The natural course of sigmoid colon diverticulitis during conservative therapy and the assessment of the perioperative morbidity after sigmoid colon resection are differently evaluated by surgeons and gastroenterologists. The "fast-track" rehabilitation accelerates the reconvalescence and reduces the rate of postoperative general complications after colorectal surgery. The results of the laparoscopic "Fast-track" sigmoidectomy should be examined within a quality assurance program to better evaluate the perioperative risks following surgical management of diverticulitis. A prospective data collection within the voluntary quality assurance program "fast-track" Kolon II was performed. All participating clinics agreed on a multimodal, evidence-based standard perioperative treatment in terms of a "fast-track" rehabilitation for elective operations for sigmoid diverticulitis. Data from 846 patients undergoing laparoscopic "fast-track" sigmoid colon resection in 23 surgical departments in Germany were collected and evaluated. The mean age of the patients was 63 years (range 23 - 91). 203 patients (24 %) had severe co-morbidities (ASA classification III - IV). A conversion to conventional open surgery was necessary in 51 cases (6 %). Complications occurred in 93 patients (11 %). 76 patients suffered a surgical complication (8.9 %) and 32 patients (3.8 %) a general complication. Two patients died postoperatively due to multi-organ failure following anastomotic leaks. The patients took solid food in median on day 1 after surgery (range, 0 - 5) and passed stool on day 2 (range, 0 - 22). Predefined discharge criteria (free of pain on oral medication, normal oral feeding, stool) were met on day 4 (range, 1 - 58) and the patients were discharged on day 7 (range, 3 - 72). The 30-day re-admission rate was 3.9 %. Patients undergoing laparoscopic "fast-track" sigmoidectomy had a low rate of general complications and had a rapid reconvalescence with a short postoperative in-patient treatment as documented in a german quality assurance program. Copyright Georg Thieme Verlag KG Stuttgart . New York.

BROADBAND RADIO POLARIMETRY AND FARADAY ROTATION OF 563 EXTRAGALACTIC RADIO SOURCES

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

Anderson, C. S.; Gaensler, B. M.; Feain, I. J.

2015-12-10

We present a broadband spectropolarimetric survey of 563 discrete, mostly unresolved radio sources between 1.3 and 2.0 GHz using data taken with the Australia Telescope Compact Array. We have used rotation-measure synthesis to identify Faraday-complex polarized sources, those objects whose frequency-dependent polarization behavior indicates the presence of material possessing complicated magnetoionic structure along the line of sight (LOS). For sources classified as Faraday-complex, we have analyzed a number of their radio and multiwavelength properties to determine whether they differ from Faraday-simple polarized sources (sources for which LOS magnetoionic structures are comparatively simple) in these properties. We use this information tomore » constrain the physical nature of the magnetoionic structures responsible for generating the observed complexity. We detect Faraday complexity in 12% of polarized sources at ∼1′ resolution, but we demonstrate that underlying signal-to-noise limitations mean the true percentage is likely to be significantly higher in the polarized radio source population. We find that the properties of Faraday-complex objects are diverse, but that complexity is most often associated with depolarization of extended radio sources possessing a relatively steep total intensity spectrum. We find an association between Faraday complexity and LOS structure in the Galactic interstellar medium (ISM) and claim that a significant proportion of the Faraday complexity we observe may be generated at interfaces of the ISM associated with ionization fronts near neutral hydrogen structures. Galaxy cluster environments and internally generated Faraday complexity provide possible alternative explanations in some cases.« less

Johney Green Joins Inaugural Board of Trustees for the UK's Faraday

Science.gov Websites

experience and leadership to the UKs Faraday Institution. Photo by Dennis Schroeder Johney Green speaks leadership to the UKs Faraday Institution. Photo by Dennis Schroeder Imagine driving an electric car from

A Left-Hand Rule for Faraday's Law

ERIC Educational Resources Information Center

Salu, Yehuda

2014-01-01

A left-hand rule for Faraday's law is presented here. This rule provides a simple and quick way of finding directional relationships between variables of Faraday's law without using Lenz's rule.

Fast-track surgery: Toward comprehensive peri-operative care

PubMed Central

Nanavati, Aditya J.; Prabhakar, S.

2014-01-01

Fast-track surgery is a multimodal approach to patient care using a combination of several evidence-based peri-operative interventions to expedite recovery after surgery. It is an extension of the critical pathway that integrates modalities in surgery, anesthesia, and nutrition, enforces early mobilization and feeding, and emphasizes reduction of the surgical stress response. It entails a great partnership between a surgeon and an anesthesiologist with several other specialists to form a multi-disciplinary team, which may then engage in patient care. The practice of fast-track surgery has yielded excellent results and there has been a significant reduction in hospital stay without a rise in complications or re-admissions. The effective implementation begins with the formulation of a protocol, carrying out each intervention and gathering outcome data. The care of a patient is divided into three phases: Before, during, and after surgery. Each stage needs active participation of few or all the members of the multi-disciplinary team. Other than surgical technique, anesthetic drugs, and techniques form the cornerstone in the ability of the surgeon to carry out a fast-track surgery safely. It is also the role of this team to keep abreast with the latest development in fast-track methodology and make appropriate changes to policy. In the Indian healthcare system, there is a huge benefit that may be achieved by the successful implementation of a fast-track surgery program at an institutional level. The lack of awareness regarding this concept, fear and apprehension regarding its implementation are the main barriers that need to be overcome. PMID:25886214

The yield of colorectal cancer among fast track patients with normocytic and microcytic anaemia.

PubMed

Panagiotopoulou, I G; Fitzrol, D; Parker, R A; Kuzhively, J; Luscombe, N; Wells, A D; Menon, M; Bajwa, F M; Watson, M A

2014-05-01

We receive fast track referrals on the basis of iron deficiency anaemia (IDA) for patients with normocytic anaemia or for patients with no iron studies. This study examined the yield of colorectal cancer (CRC) among fast track patients to ascertain whether awaiting confirmation of IDA is necessary prior to performing bowel investigations. A review was undertaken of 321 and 930 consecutive fast track referrals from Centre A and Centre B respectively. Contingency tables were analysed using Fisher's exact test. Logistic regression analyses were performed to investigate significant predictors of CRC. Overall, 229 patients were included from Centre A and 689 from Centre B. The odds ratio for microcytic anaemia versus normocytic anaemia in the outcome of CRC was 1.3 (95% confidence interval [CI]: 0.5-3.9) for Centre A and 1.6 (95% CI: 0.8-3.3) for Centre B. In a logistic regression analysis (Centre B only), no significant difference in CRC rates was seen between microcytic and normocytic anaemia (adjusted odds ratio: 1.9, 95% CI: 0.9-3.9). There was no statistically significant difference in the yield of CRC between microcytic and normocytic anaemia (p=0.515, Fisher's exact test) in patients with anaemia only and no colorectal symptoms. Finally, CRC cases were seen in both microcytic and normocytic groups with or without low ferritin. There is no significant difference in the yield of CRC between fast track patients with microcytic and normocytic anaemia. This study provides insufficient evidence to support awaiting confirmation of IDA in fast track patients with normocytic anaemia prior to requesting bowel investigations.

Fast-track surgery: Toward comprehensive peri-operative care.

PubMed

Nanavati, Aditya J; Prabhakar, S

2014-01-01

Fast-track surgery is a multimodal approach to patient care using a combination of several evidence-based peri-operative interventions to expedite recovery after surgery. It is an extension of the critical pathway that integrates modalities in surgery, anesthesia, and nutrition, enforces early mobilization and feeding, and emphasizes reduction of the surgical stress response. It entails a great partnership between a surgeon and an anesthesiologist with several other specialists to form a multi-disciplinary team, which may then engage in patient care. The practice of fast-track surgery has yielded excellent results and there has been a significant reduction in hospital stay without a rise in complications or re-admissions. The effective implementation begins with the formulation of a protocol, carrying out each intervention and gathering outcome data. The care of a patient is divided into three phases: Before, during, and after surgery. Each stage needs active participation of few or all the members of the multi-disciplinary team. Other than surgical technique, anesthetic drugs, and techniques form the cornerstone in the ability of the surgeon to carry out a fast-track surgery safely. It is also the role of this team to keep abreast with the latest development in fast-track methodology and make appropriate changes to policy. In the Indian healthcare system, there is a huge benefit that may be achieved by the successful implementation of a fast-track surgery program at an institutional level. The lack of awareness regarding this concept, fear and apprehension regarding its implementation are the main barriers that need to be overcome.

Faraday Rotation Measurement with the SMAP Radiometer

NASA Technical Reports Server (NTRS)

Le Vine, D. M.; Abraham, S.

2016-01-01

Faraday rotation is an issue that needs to be taken into account in remote sensing of parameters such as soil moisture and ocean salinity at L-band. This is especially important for SMAP because Faraday rotation varies with azimuth around the conical scan. SMAP retrieves Faraday rotation in situ using the ratio of the third and second Stokes parameters, a procedure that was demonstrated successfully by Aquarius. This manuscript reports the performance of this algorithm on SMAP. Over ocean the process works reasonably well and results compare favorably with expected values. But over land, the inhomogeneous nature of the scene results in much noisier, and in some cases unreliable estimates of Faraday rotation.

Rapid determination of Faraday rotation in optical glasses by means of secondary Faraday modulator.

PubMed

Sofronie, M; Elisa, M; Sava, B A; Boroica, L; Valeanu, M; Kuncser, V

2015-05-01

A rapid high sensitive method for determining the Faraday rotation of optical glasses is proposed. Starting from an experimental setup based on a Faraday rod coupled to a lock-in amplifier in the detection chain, two methodologies were developed for providing reliable results on samples presenting low and large Faraday rotations. The proposed methodologies were critically discussed and compared, via results obtained in transmission geometry, on a new series of aluminophosphate glasses with or without rare-earth doping ions. An example on how the method can be used for a rapid examination of the optical homogeneity of the sample with respect to magneto-optical effects is also provided.

Giant Faraday Rotation in Metal-Fluoride Nanogranular Films.

PubMed

Kobayashi, N; Ikeda, K; Gu, Bo; Takahashi, S; Masumoto, H; Maekawa, S

2018-03-21

Magneto-optical Faraday effect is widely applied in optical devices and is indispensable for optical communications and advanced information technology. However, the bismuth garnet Bi-YIG is only the Faraday material since 1972. Here we introduce (Fe, FeCo)-(Al-,Y-fluoride) nanogranular films exhibiting giant Faraday effect, 40 times larger than Bi-YIG. These films have a nanocomposite structure, in which nanometer-sized Fe, FeCo ferromagnetic granules are dispersed in a Al,Y-fluoride matrix.

78 FR 52166 - Quantitative Messaging Research

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-22

... COMMODITY FUTURES TRADING COMMISSION Quantitative Messaging Research AGENCY: Commodity Futures... survey will follow qualitative message testing research (for which CFTC received fast-track OMB approval... message testing research (for which CFTC received fast-track OMB approval) and is necessary to identify...

Faraday rotation due to excitation of magnetoplasmons in graphene microribbons.

PubMed

Tymchenko, Mykhailo; Nikitin, Alexey Yu; Martín-Moreno, Luis

2013-11-26

A single graphene sheet, when subjected to a perpendicular static magnetic field, provides a Faraday rotation that, per atomic layer, greatly surpasses that of any other known material. In continuous graphene, Faraday rotation originates from the cyclotron resonance of massless carriers, which allows dynamical tuning through either external electrostatic or magneto-static setting. Furthermore, the rotation direction can be controlled by changing the sign of the carriers in graphene, which can be done by means of an external electric field. However, despite these tuning possibilities, the requirement of large magnetic fields hinders the application of the Faraday effect in real devices, especially for frequencies higher than a few terahertz. In this work we demonstrate that large Faraday rotation can be achieved in arrays of graphene microribbons, through the excitation of the magnetoplasmons of individual ribbons, at larger frequencies than those dictated by the cyclotron resonance. In this way, for a given magnetic field and chemical potential, structuring graphene periodically can produce large Faraday rotation at larger frequencies than what would occur in a continuous graphene sheet. Alternatively, at a given frequency, graphene ribbons produce large Faraday rotation at much smaller magnetic fields than in continuous graphene.

42 CFR 422.624 - Notifying enrollees of termination of provider services.

Code of Federal Regulations, 2012 CFR

2012-10-01

... begins. (iii) A description of the enrollee's right to a fast-track appeal under § 422.626, including... procedures if the enrollee fails to meet the deadline for a fast-track IRE appeal. (iv) The enrollee's right...

75 FR 13774 - Agency Information Collection Activities: Submission for OMB Review; Comment Request, OMB No...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-23

.... 1660-NEW; FEMA Form 089-4, TSGP Investment Justification; FEMA Form 089-27, Fast Track Cost Training...-27, Fast Track Cost Training Matrix. Abstract: The TSGP is an important component of the Department...

42 CFR 422.624 - Notifying enrollees of termination of provider services.

Code of Federal Regulations, 2013 CFR

2013-10-01

... begins. (iii) A description of the enrollee's right to a fast-track appeal under § 422.626, including... procedures if the enrollee fails to meet the deadline for a fast-track IRE appeal. (iv) The enrollee's right...

42 CFR 422.624 - Notifying enrollees of termination of provider services.

Code of Federal Regulations, 2011 CFR

2011-10-01

... begins. (iii) A description of the enrollee's right to a fast-track appeal under § 422.626, including... procedures if the enrollee fails to meet the deadline for a fast-track IRE appeal. (iv) The enrollee's right...

42 CFR 422.624 - Notifying enrollees of termination of provider services.

Code of Federal Regulations, 2010 CFR

2010-10-01

... begins. (iii) A description of the enrollee's right to a fast-track appeal under § 422.626, including... procedures if the enrollee fails to meet the deadline for a fast-track IRE appeal. (iv) The enrollee's right...

42 CFR 422.624 - Notifying enrollees of termination of provider services.

Code of Federal Regulations, 2014 CFR

2014-10-01

... begins. (iii) A description of the enrollee's right to a fast-track appeal under § 422.626, including... procedures if the enrollee fails to meet the deadline for a fast-track IRE appeal. (iv) The enrollee's right...

A Study of the 3-D Reconstruction of Heliospheric Vector Magnetic Fields From Faraday-Rotation Inversion

DTIC Science & Technology

2009-12-30

FA9550-06-1-0107 for “A Study of the 3-D Reconstruction of Heliospheric Vector Magnetic Fields from Faraday-Rotation Inversion” for work performed...from 2005 – 2009 by the University of California at San Diego. There are three aspects to this research: 1) The inversion of simple synthetic Faraday...rotation measurements that can be used to demonstrate the feasibility of performing this inversion when and if Faraday-rotation observations become

Observation of two-dimensional Faraday waves in extremely shallow depth.

PubMed

Li, Xiaochen; Yu, Zhengyue; Liao, Shijun

2015-09-01

A family of two-dimensional Faraday waves in extremely shallow depth (1 mm to 2 mm) of absolute ethanol are observed experimentally using a Hele-Shaw cell that vibrates vertically. The same phenomena are not observed by means of water, ethanol solution, and silicone oil. These Faraday waves are quite different from the traditional ones. These phenomena are helpful to deepen and enrich our understandings about Faraday waves, and besides provide a challenging problem for computational fluid dynamics.

A two-in-one Faraday rotator mirror exempt of active optical alignment.

PubMed

Wan, Qiong; Wan, Zhujun; Liu, Hai; Liu, Deming

2014-02-10

A two-in-one Faraday rotator mirror was presented, which functions as two independent Faraday rotation mirrors with a single device. With the introduction of a reflection lens as substitution of the mirror in traditional structure, this device is characterized by exemption of active optical alignment for the designers and manufacturers of Faraday rotator mirrors. A sample was fabricated by passive mechanical assembly. The insertion loss was measured as 0.46 dB/0.50 dB for the two independent ports, respectively.

Faraday imaging at high temperatures

DOEpatents

Hackel, L.A.; Reichert, P.

1997-03-18

A Faraday filter rejects background light from self-luminous thermal objects, but transmits laser light at the passband wavelength, thus providing an ultra-narrow optical bandpass filter. The filter preserves images so a camera looking through a Faraday filter at a hot target illuminated by a laser will not see the thermal radiation but will see the laser radiation. Faraday filters are useful for monitoring or inspecting the uranium separator chamber in an atomic vapor laser isotope separation process. Other uses include viewing welds, furnaces, plasma jets, combustion chambers, and other high temperature objects. These filters are can be produced at many discrete wavelengths. A Faraday filter consists of a pair of crossed polarizers on either side of a heated vapor cell mounted inside a solenoid. 3 figs.

Faraday imaging at high temperatures

DOEpatents

Hackel, Lloyd A.; Reichert, Patrick

1997-01-01

A Faraday filter rejects background light from self-luminous thermal objects, but transmits laser light at the passband wavelength, thus providing an ultra-narrow optical bandpass filter. The filter preserves images so a camera looking through a Faraday filter at a hot target illuminated by a laser will not see the thermal radiation but will see the laser radiation. Faraday filters are useful for monitoring or inspecting the uranium separator chamber in an atomic vapor laser isotope separation process. Other uses include viewing welds, furnaces, plasma jets, combustion chambers, and other high temperature objects. These filters are can be produced at many discrete wavelengths. A Faraday filter consists of a pair of crossed polarizers on either side of a heated vapor cell mounted inside a solenoid.

Faraday effect in hybrid magneto-plasmonic photonic crystals.

PubMed

Caballero, B; García-Martín, A; Cuevas, J C

2015-08-24

We present a theoretical study of the Faraday effect in hybrid magneto-plasmonic crystals that consist of Au-Co-Au perforated membranes with a periodic array of sub-wavelength holes. We show that in these hybrid systems the interplay between the extraordinary optical transmission and the magneto-optical activity leads to a resonant enhancement of the Faraday rotation, as compared to purely ferromagnetic membranes. In particular, we determine the geometrical parameters for which this enhancement is optimized and show that the inclusion of a noble metal like Au dramatically increases the Faraday rotation over a broad bandwidth. Moreover, we show that the analysis of the Faraday rotation in these periodically perforated membranes provides a further insight into the origin of the extraordinary optical transmission.

Enhancement of magneto-optical Faraday effects and extraordinary optical transmission in a tri-layer structure with rectangular annular arrays.

PubMed

Lei, Chengxin; Chen, Leyi; Tang, Zhixiong; Li, Daoyong; Cheng, Zhenzhi; Tang, Shaolong; Du, Youwei

2016-02-15

The properties of optics and magneto-optical Faraday effects in a metal-dielectric tri-layer structure with subwavelength rectangular annular arrays are investigated. It is noteworthy that we obtained the strongly enhanced Faraday rotation of the desired sign along with high transmittance by optimizing the parameters of the nanostructure in the visible spectral ranges. In this system, we obtained two extraordinary optical transmission (EOT) resonant peaks with enhanced Faraday rotations, whose signs are opposite, which may provide the possibility of designing multi-channel magneto-optical devices. Study results show that the maximum of the figure of merit (FOM) of the structure can be obtained between two EOT resonant peaks accompanied by an enhanced Faraday rotation. The positions of the maximum value of the FOM and resonant peaks of transmission along with a large Faraday rotation can be tailored by simply adjusting the geometric parameters of our models. These research findings are of great importance for future applications of magneto-optical devices.

Competition of Faraday rotation and birefringence in femtosecond laser direct written waveguides in magneto-optical glass.

PubMed

Liu, Qiang; Gross, S; Dekker, P; Withford, M J; Steel, M J

2014-11-17

We consider the process of Faraday rotation in femtosecond laser direct-write waveguides. The birefringence commonly associated with such waveguides may be expected to impact the observable Faraday rotation. Here, we theoretically calculate and experimentally verify the competition between Faraday rotation and birefringence in two waveguides created by laser writing in a commercial magneto-optic glass. The magnetic field applied to induce Faraday rotation is nonuniform, and as a result, we find that the two effects can be clearly separated and used to accurately determine even weak birefringence. The birefringence in the waveguides was determined to be on the scale of Δn = 10(-6) to 10(-5). The reduction in Faraday rotation caused by birefringence of order Δn = 10(-6) was moderate and we obtained approximately 9° rotation in an 11 mm waveguide. In contrast, for birefringence of order 10(-5), a significant reduction in the polarization azimuth change was found and only 6° rotation was observed.

Active Faraday optical frequency standard.

PubMed

Zhuang, Wei; Chen, Jingbiao

2014-11-01

We propose the mechanism of an active Faraday optical clock, and experimentally demonstrate an active Faraday optical frequency standard based on narrow bandwidth Faraday atomic filter by the method of velocity-selective optical pumping of cesium vapor. The center frequency of the active Faraday optical frequency standard is determined by the cesium 6 (2)S(1/2) F=4 to 6 (2)P(3/2) F'=4 and 5 crossover transition line. The optical heterodyne beat between two similar independent setups shows that the frequency linewidth reaches 281(23) Hz, which is 1.9×10(4) times smaller than the natural linewidth of the cesium 852-nm transition line. The maximum emitted light power reaches 75 μW. The active Faraday optical frequency standard reported here has advantages of narrow linewidth and reduced cavity pulling, which can readily be extended to other atomic transition lines of alkali and alkaline-earth metal atoms trapped in optical lattices at magic wavelengths, making it useful for new generation of optical atomic clocks.

Fast-Track Teacher Recruitment.

ERIC Educational Resources Information Center

Grant, Franklin Dean

2001-01-01

Schools need a Renaissance human-resources director to implement strategic staffing and fast-track teacher-recruitment plans. The HR director must attend to customer satisfaction, candidate supply, web-based recruitment possibilities, stabilization of newly hired staff, retention of veteran staff, utilization of retired employees, and latest…

Fast-Track Cleanup at Closing DoD Installations

EPA Pesticide Factsheets

The Fast-Track Cleanup program strives to make parcels available for reuse as quickly as possible by the transfer of uncontaminated or remediated parcels, the lease of contaminated parcels where cleanup is underway, or the 'early transfer' of contaminated property undergoing cleanup.

Clinical evidence of traditional vs fast track recovery methodologies after total arthroplasty for osteoarthritic knee treatment. A retrospective observational study

PubMed Central

Castorina, Sergio; Guglielmino, Claudia; Castrogiovanni, Paola; Szychlinska, Marta Anna; Ioppolo, Francesco; Massimino, Paolo; Leonardi, Pietro; Maci, Christian; Iannuzzi, Maurizio; Di Giunta, Angelo; Musumeci, Giuseppe

2017-01-01

Summary Background During the last years, programs to enhance postoperative recovery and decrease morbidity after total knee arthroplasty, have been developed across a variety of surgical procedures and referred to as “Fast-Track Surgery”. In this study we aimed to find some answers in the management of osteoarthritic patients subjected to total knee arthroplasty, by using the Fast-Track methodology. To this purpose we evaluated parameters such as early mobilization of patients, better pain management, bleeding, possible complications, reduced hospitalization time, an overall improved recovery and patient satisfaction. Methods 132 patients were selected, of which, 95 treated with “Fast Track” method and 37 treated with traditional method (control group). All the patients were hospitalized and underwent the same rehabilitation program for the first three days after surgery. Results In both groups, the parameters of pain and deformity demonstrated the most rapid improvement, while those of function and movement were normalized as gradual and progressive improvement over the next 2 months. The different functional test used (Barthel, MRC, VAS) showed that the mean values were significantly greater in Fast Track group when compared to the control. Conclusion The results of the study confirm that the application of the Fast Track protocol in orthopaedics after total knee replacement results in rapid post-surgery recovery. Level of evidence IV. Case series, low-quality cohort or case-control studies. PMID:29387645

Implementing large scale fast track diagnostics in a comprehensive cancer center, pre- and post-measurement data.

PubMed

van Harten, W H; Goedbloed, N; Boekhout, A H; Heintzbergen, S

2018-02-07

In general, patients with a cancer suspicion visit the hospital multiple times before diagnosis is completed. Using various "operations management" techniques a few fast track diagnostic services were implemented in the Netherlands Cancer Institute (NKI) in 2006. Growing patient numbers and increasing process complexity, led to diminished service levels. To decrease the amount of patient visits and to extend these services beyond the (obvious) breast cancer services, fast track diagnostics is now implemented for all 18 cancer types that present with a frequency of minimally one per week. The throughput time (first visit to diagnosis conversation) was measured before, and after implementation of fast track diagnostics. The process was redesigned closely involving the multidisciplinary teams. In an eclectic approach elements from lean management, theory of constraints and mathematical analysis were used to organize slots per tumor type for MRI, CT, PET and echography. A post measurement was performed after 3 and 6 months. In pre measurement access time was calculated to be 10 to 15 workdays, mean throughput time was 6.0 workdays. It proved possible to design the process of 18 tumors as a fast track, of which 7 as "one stop shop" (diagnosis completed in one visit). Involvement of clinical- and board leadership, massive communication efforts and commitment of physicians to reschedule their work proved decisive. After 3 and 6 months of implementation, the mean access time was 8.2 and 8.7 workdays respectively and mean throughput time was 3.4 and 3.3 workdays respectively. Throughput- and access time were considerably shortened after implementation of fast track diagnostics for 18 cancer types. The involvement of physicians in reorganizing their work and rapid responding to their needs during the implementation phase were a crucial success factor.

Fast Track Extubation In Adult Patients On Pump Open Heart Surgery At A Tertiary Care Hospital.

PubMed

Akhtar, Mohammad Irfan; Sharif, Hasanat; Hamid, Mohammad; Samad, Khalid; Khan, Fazal Hameed

2016-01-01

Fast-track cardiac surgery programs have been established as the standard of cardiac surgical care. Studies have shown that early extubation in elective cardiac surgery patients, including coronary and non-coronary open-heart surgery patients does not increase perioperative morbidity and mortality. The objective of this observational study was to determine the success and failure profile of fast track extubation (FTE) practice in adult open-heart surgical patients. The study was conducted at cardiac operating room and Cardiac Intensive Care Unit (CICU) of a tertiary care hospital for a period of nine months, i.e., from Oct 2014 to June-2015. All on pump elective adult cardiac surgery patients including isolated CABG, isolated Valve replacements, combined procedures and aortic root replacements were enrolled in the study. Standardized anesthetic technique was adopted. Surgical and bypass techniques were tailored according to the procedure. Success of Fast track extubation was defined as extubation within 6 hours of arrival in CICU. A total of 290 patients were recruited. The average age of the patients was 56.3±10.5 years. There were 77.6% male and 22.4% female patients. Overall success rate was 51.9% and failure rate was 48.1%. The peri-operative renal insufficiency, cross clamp time and CICU stay (hours) were significantly lower in success group. Re-intubation rate was 0.74%. The perioperative parameters were significantly better in success group and the safety was also demonstrated in the patients who were fast tracked successfully. To implement the practice in its full capacity and benefit, a fast track protocol needs to be devised to standardize the current practices and to disseminate the strategy among junior anaesthesiologists, perfusionists and nursing staff.

Rethinking Faraday's Law for Teaching Motional Electromotive Force

ERIC Educational Resources Information Center

Zuza, Kristina; Guisasola, Jenaro; Michelini, Marisa; Santi, Lorenzo

2012-01-01

This study shows physicists' discussions on the meaning of Faraday's law where situations involving extended conductors or moving contact points are particularly troublesome. We raise questions to test students' difficulties in applying Faraday's law in motional electromotive force phenomena. We suggest the benefit of analysing these phenomena…

Representing the Electromagnetic Field: How Maxwell's Mathematics Empowered Faraday's Field Theory

ERIC Educational Resources Information Center

Tweney, Ryan D.

2011-01-01

James Clerk Maxwell "translated" Michael Faraday's experimentally-based field theory into the mathematical representation now known as "Maxwell's Equations." Working with a variety of mathematical representations and physical models Maxwell extended the reach of Faraday's theory and brought it into consistency with other…

Diagnostic Suite for HyperV Coaxial Plasma Gun Development for the PLX- α Project

NASA Astrophysics Data System (ADS)

Case, Andrew; Brockington, Sam; Witherspoon, F. Douglas

2015-11-01

We present the diagnostic suite to be used during development of the coaxial guns HyperV will deliver to LANL in support of the ARPA-E Accelerating Low-Cost Plasma Heating And Assembly (ALPHA) program. For plasma jet diagnostics this includes fast photodiodes for velocimetry, a ballistic pendulum for measuring total plasmoid momentum, interferometry for line integrated plasma density, deflectometry for line integrated perpendicular density gradient measurements, and spectroscopy, both time resolved high resolution spectroscopy using a novel detector developed by HyperV and time integrated survey spectroscopy, for measurements of velocity and temperature as well as impurities. In addition, we plan to use fast pressure probes for stagnation pressure, a Faraday cup for density, fast imaging for plume geometry and time integrated imaging for overall light emission. A novel low resolution long record length camera developed by HyperV will also be used for plume diagnostics. For diagnostics of gun operation, we will use Rogowski coils to measure current, voltage dividers for voltages, B-dot probes for magnetic field, and time resolved fast photodiodes to measure plasmoid velocity inside the accelerator. This work supported by the ARPA-E ALPHA program.

Diagnostics and results from coaxial plasma gun development for the PLX- α project

NASA Astrophysics Data System (ADS)

Case, A.; Brockington, S.; Cruz, E.; Witherspoon, F. D.

2016-10-01

We present results from the diagnostics used during development of the contoured gap coaxial plasma guns for the PLX- α project at LANL. Plasma-jet diagnostics include fast photodiodes for velocimetry, a ballistic pendulum for total plasmoid momentum, and interferometry for line integrated density. Deflectometry will be used for line integrated perpendicular density gradients. Time-resolved high-resolution spectroscopy using a novel detector and time-integrated survey spectroscopy are used for measurements of velocity and temperature, as well as impurities. We will also use a Faraday cup for density, fast imaging for plume geometry, and time-integrated imaging for overall light emission. Experimental results are compared to the desired target parameters for the plasma jets (up to n 2 ×1016cm-3 , v 50km / s , mass 5gm , radius = 4cm , and length 10cm). This work supported by the ARPA-E ALPHA Program.

Affordable Electro-Magnetic Interference (EMI) Testing on Large Space Vehicles

NASA Technical Reports Server (NTRS)

Aldridge, Edward; Curry, Bruce; Scully, Robert

2015-01-01

Objective: Perform System-Level EMI testing of the Orion Exploration Flight Test-1 (EFT-1) spacecraft in situ in the Kennedy Space Center's Neil Armstrong Operations & Checkout (O&C) Facility in 6 days. The only way to execute the system-level EMI testing and meet this schedule challenge was to perform the EMI testing in situ in the Final Assembly & System Test (FAST) Cell in a reverberant mode, not the direct illumination mode originally planned. This required the unplanned construction of a Faraday Cage around the vehicle and FAST Cell structure. The presence of massive steel platforms created many challenges to developing an efficient screen room to contain the RF energy and yield an effective reverberant chamber. An initial effectiveness test showed marginal performance, but improvements implemented afterward resulted in the final test performing surprisingly well! The paper will explain the design, the challenges, and the changes that made the difference in performance!

The magnetic field and turbulence of the cosmic web measured using a brilliant fast radio burst.

PubMed

Ravi, V; Shannon, R M; Bailes, M; Bannister, K; Bhandari, S; Bhat, N D R; Burke-Spolaor, S; Caleb, M; Flynn, C; Jameson, A; Johnston, S; Keane, E F; Kerr, M; Tiburzi, C; Tuntsov, A V; Vedantham, H K

2016-12-09

Fast radio bursts (FRBs) are millisecond-duration events thought to originate beyond the Milky Way galaxy. Uncertainty surrounding the burst sources, and their propagation through intervening plasma, has limited their use as cosmological probes. We report on a mildly dispersed (dispersion measure 266.5 ± 0.1 parsecs per cubic centimeter), exceptionally intense (120 ± 30 janskys), linearly polarized, scintillating burst (FRB 150807) that we directly localize to 9 square arc minutes. On the basis of a low Faraday rotation (12.0 ± 0.7 radians per square meter), we infer negligible magnetization in the circum-burst plasma and constrain the net magnetization of the cosmic web along this sightline to <21 nanogauss, parallel to the line-of-sight. The burst scintillation suggests weak turbulence in the ionized intergalactic medium. Copyright © 2016, American Association for the Advancement of Science.

Michael Faraday's Bicentenary.

ERIC Educational Resources Information Center

Williams, L. Pearce; And Others

1991-01-01

Six articles discuss the work of Michael Faraday, a chemist whose work revolutionized physics and led directly to both classical field and relativity theory. The scientist as a young man, the electromagnetic experiments of Faraday, his search for the gravelectric effect, his work on optical glass, his laboratory notebooks, and his creative use of…

Spin and Valley Noise in Two-Dimensional Dirac Materials

NASA Astrophysics Data System (ADS)

Tse, Wang-Kong; Saxena, A.; Smith, D. L.; Sinitsyn, N. A.

2014-07-01

We develop a theory for optical Faraday rotation noise in two-dimensional Dirac materials. In contrast to spin noise in conventional semiconductors, we find that the Faraday rotation fluctuations are influenced not only by spins but also the valley degrees of freedom attributed to intervalley scattering processes. We illustrate our theory with two-dimensional transition-metal dichalcogenides and discuss signatures of spin and valley noise in the Faraday noise power spectrum. We propose optical Faraday noise spectroscopy as a technique for probing both spin and valley relaxation dynamics in two-dimensional Dirac materials.

Optical properties and Faraday effect of ceramic terbium gallium garnet for a room temperature Faraday rotator.

PubMed

Yoshida, Hidetsugu; Tsubakimoto, Koji; Fujimoto, Yasushi; Mikami, Katsuhiro; Fujita, Hisanori; Miyanaga, Noriaki; Nozawa, Hoshiteru; Yagi, Hideki; Yanagitani, Takagimi; Nagata, Yutaka; Kinoshita, Hiroo

2011-08-01

The optical properties, Faraday effect and Verdet constant of ceramic terbium gallium garnet (TGG) have been measured at 1064 nm, and were found to be similar to those of single crystal TGG at room temperature. Observed optical characteristics, laser induced bulk-damage threshold and optical scattering properties of ceramic TGG were compared with those of single crystal TGG. Ceramic TGG is a promising Faraday material for high-average-power YAG lasers, Yb fiber lasers and high-peak power glass lasers for inertial fusion energy drivers.

Real time Faraday spectrometer

DOEpatents

Smith, Jr., Tommy E.; Struve, Kenneth W.; Colella, Nicholas J.

1991-01-01

This invention uses a dipole magnet to bend the path of a charged particle beam. As the deflected particles exit the magnet, they are spatially dispersed in the bend-plane of the magnet according to their respective momenta and pass to a plurality of chambers having Faraday probes positioned therein. Both the current and energy distribution of the particles is then determined by the non-intersecting Faraday probes located along the chambers. The Faraday probes are magnetically isolated from each other by thin metal walls of the chambers, effectively providing real time current-versus-energy particle measurements.

The RSC Faraday prize lecture of 1989 on platinum.

PubMed

Thomas, John Meurig

2017-08-25

In 1861, Michael Faraday gave one of his last Friday Evening Discourses at the Royal Institution of Great Britain, London, on platinum, which he described as "this beautiful, magnificent and valuable metal". More than a hundred and twenty years later (in 1989), the author re-enacted, at the Royal Institution, many of the demonstrations that Faraday carried out in his memorable Discourse. This article outlines many of Faraday's views on, and experiments with, platinum. It also describes the continuing importance and utilization of platinum, both as perceived in 1989 and from present perspectives.

Secure FAST: Security Enhancement in the NATO Time Sensitive Targeting Tool

DTIC Science & Technology

2010-11-01

designed to aid in the tracking and prosecuting of Time Sensitive Targets. The FAST tool provides user level authentication and authorisation in terms...level authentication and authorisation in terms of security. It uses operating system level security but does not provide application level security for...and collaboration tool, designed to aid in the tracking and prosecuting of Time Sensitive Targets. The FAST tool provides user level authentication and

The Influence of Domain Structure on the Faraday Effect in Terbium Garnet Ferrite in the Vicinity of the Magnetic-Compensation Temperature

NASA Astrophysics Data System (ADS)

Sokolov, B. Yu.; Sharipov, M. Z.

2013-12-01

The temperature dependence of the Faraday effect in terbium garnet ferrite, Tb3Fe5O12, is investigated near its magnetic-compensation temperature, Т с = 249 K. A non-monotonous variation in the value of the Faraday rotation angle Ф is observed in a weak magnetic field as the temperature approaches Т с : the temperature plot of the Faraday rotation angle has two local maxima observed left and right of the magnetic compensation point. A theoretical model is proposed, which follows from the phenomenological theory of domain-boundary displacement under the action of a magnetic field, offering an unambiguous description of the principles of domain-structure influence on the Faraday effect in Tb3Fe5O12 near Т с .

Faraday anomalous dispersion optical tuners

NASA Technical Reports Server (NTRS)

Wanninger, P.; Valdez, E. C.; Shay, T. M.

1992-01-01

Common methods for frequency stabilizing diode lasers systems employ gratings, etalons, optical electric double feedback, atomic resonance, and a Faraday cell with low magnetic field. Our method, the Faraday Anomalous Dispersion Optical Transmitter (FADOT) laser locking, is much simpler than other schemes. The FADOT uses commercial laser diodes with no antireflection coatings, an atomic Faraday cell with a single polarizer, and an output coupler to form a compound cavity. This method is vibration insensitive, thermal expansion effects are minimal, and the system has a frequency pull in range of 443.2 GHz (9A). Our technique is based on the Faraday anomalous dispersion optical filter. This method has potential applications in optical communication, remote sensing, and pumping laser excited optical filters. We present the first theoretical model for the FADOT and compare the calculations to our experimental results.

Fast-track program vs traditional care in surgery for gastric cancer.

PubMed

Chen, Zhi-Xing; Liu, Ae-Huey Jennifer; Cen, Ying

2014-01-14

To systematically review the evidence for the effectiveness of fast-track program vs traditional care in laparoscopic or open surgery for gastric cancer. PubMed, Embase and the Cochrane library databases were electronically searched for published studies between January 1995 and April 2013, and only randomized trials were included. The references of relevant studies were manually searched for further studies that may have been missed. Search terms included "gastric cancer", "fast track" and "enhanced recovery". Five outcome variables were considered most suitable for analysis: postoperative hospital stay, medical cost, duration to first flatus, C-reactive protein (CRP) level and complications. Postoperative hospital stay was calculated from the date of operation to the date of discharge. Fixed effects model was used for meta-analysis. Compared with traditional care, fast-track program could significantly decrease the postoperative hospital stay [weighted mean difference (WMD) = -1.19, 95%CI: -1.79--0.60, P = 0.0001, fixed model], duration to first flatus (WMD = -6.82, 95%CI: -11.51--2.13, P = 0.004), medical costs (WMD = -2590, 95%CI: -4054--1126, P = 0.001), and the level of CRP (WMD = -17.78, 95%CI: -32.22--3.35, P = 0.0001) in laparoscopic surgery for gastric cancer. In open surgery for gastric cancer, fast-track program could also significantly decrease the postoperative hospital stay (WMD = -1.99, 95%CI: -2.09--1.89, P = 0.0001), duration to first flatus (WMD = -12.0, 95%CI: -18.89--5.11, P = 0.001), medical cost (WMD = -3674, 95%CI: -5025--2323, P = 0.0001), and the level of CRP (WMD = -27.34, 95%CI: -35.42--19.26, P = 0.0001). Furthermore, fast-track program did not significantly increase the incidence of complication (RR = 1.39, 95%CI: 0.77-2.51, P = 0.27, for laparoscopic surgery; and RR = 1.52, 95%CI: 0.90-2.56, P = 0.12, for open surgery). Our overall results suggested that compared with traditional care, fast-track program could result in shorter postoperative hospital stay, less medical costs, and lower level of CRP, with no more complications occurring in both laparoscopic and open surgery for gastric cancer.

The role of general practice in routes to diagnosis of lung cancer in Denmark: a population-based study of general practice involvement, diagnostic activity and diagnostic intervals.

PubMed

Guldbrandt, Louise Mahncke; Fenger-Grøn, Morten; Rasmussen, Torben Riis; Jensen, Henry; Vedsted, Peter

2015-01-22

Lung cancer stage at diagnosis predicts possible curative treatment. In Denmark and the UK, lung cancer patients have lower survival rates than citizens in most other European countries, which may partly be explained by a comparatively longer diagnostic interval in these two countries. In Denmark, a pathway was introduced in 2008 allowing general practitioners (GPs) to refer patients suspected of having lung cancer directly to fast-track diagnostics. However, symptom presentation of lung cancer in general practice is known to be diverse and complex, and systematic knowledge of the routes to diagnosis is needed to enable earlier lung cancer diagnosis in Denmark. This study aims to describe the routes to diagnosis, the diagnostic activity preceding diagnosis and the diagnostic intervals for lung cancer in the Danish setting. We conducted a national registry-based cohort study on 971 consecutive incident lung cancer patients in 2010 using data from national registries and GP questionnaires. GPs were involved in 68.3% of cancer patients' diagnostic pathways, and 27.4% of lung cancer patients were referred from the GP to fast-track diagnostic work-up. A minimum of one X-ray was performed in 85.6% of all cases before diagnosis. Patients referred through a fast-track route more often had diagnostic X-rays (66.0%) than patients who did not go through fast-track (49.4%). Overall, 33.6% of all patients had two or more X-rays performed during the 90 days before diagnosis. Patients whose symptoms were interpreted as non-alarm symptoms or who were not referred to fast-track were more likely to experience a long diagnostic interval than patients whose symptoms were interpreted as alarm symptoms or who were referred to fast-track. Lung cancer patients followed several diagnostic pathways. The existing fast-track pathway must be supplemented to ensure earlier detection of lung cancer. The high incidence of multiple X-rays warrants a continued effort to develop more accurate lung cancer tests for use in primary care.

Characterization of beam-driven instabilities and current redistribution in MST plasmas

NASA Astrophysics Data System (ADS)

Parke, E.

2015-11-01

A unique, high-rep-rate (>10 kHz) Thomson scattering diagnostic and a high-bandwidth FIR interferometer-polarimeter on MST have enabled characterization of beam-driven instabilities and magnetic equilibrium changes observed during high power (1 MW) neutral beam injection (NBI). While NBI leads to negligible net current drive, an increase in on-axis current density observed through Faraday rotation is offset by a reduction in mid-radius current. Identification of the phase flip in temperature fluctuations associated with tearing modes provides a sensitive measure of rational surface locations. This technique strongly constrains the safety factor for equilibrium reconstruction and provides a powerful new tool for measuring the equilibrium magnetic field. For example, the n = 6 temperature structure is observed to shift inward 1.1 +/- 0.6 cm, with an estimated reduction of q0 by 5%. This is consistent with a mid-radius reduction in current, and together the Faraday rotation and Thomson scattering measurements corroborate an inductive redistribution of current that compares well with TRANSP/MSTFit predictions. Interpreting tearing mode temperature structures in the RFP remains challenging; the effects of multiple, closely-spaced tearing modes on the mode phase measurement require further verification. In addition to equilibrium changes, previous work has shown that the large fast ion population drives instabilities at higher frequencies near the Alfvén continuum. Recent observations reveal a new instability at much lower frequency (~7 kHz) with strongly chirping behavior. It participates in extensive avalanches of the higher frequency energetic particle and Alfvénic modes to drive enhanced fast ion transport. Internal structures measured from Te and ne fluctuations, their dependence on the safety factor, as well as frequency scaling motivate speculation about mode identity. Work supported by U.S. DOE.

Accelerated Leadership Development: Fast Tracking School Leaders

ERIC Educational Resources Information Center

Earley, Peter; Jones, Jeff

2010-01-01

"Accelerated Leadership Development" captures and communicates the lessons learned from successful fast-track leadership programmes in the private and public sector, and provides a model which schools can follow and customize as they plan their own leadership development strategies. As large numbers of headteachers and other senior staff…

Fast Track Option: An Accelerated Associate's Degree Program.

ERIC Educational Resources Information Center

Price, J. Randall

1998-01-01

Alternative instructional delivery options such as self-paced and flexible enrollment courses are designed to increase enrollment, promote retention, and encourage student success without lowering academic standards. The Fast Track Associate's Degree Program, developed by a team of faculty, staff, and administrators at Richland Community College,…

Fast track surgery: a clinical audit.

PubMed

Carter, Jonathan; Szabo, Rebecca; Sim, Wee Wee; Pather, Selvan; Philp, Shannon; Nattress, Kath; Cotterell, Stephen; Patel, Pinki; Dalrymple, Chris

2010-04-01

Fast track surgery is a concept that utilises a variety of techniques to reduce the surgical stress response, allowing a shortened length of stay, improved outcomes and decreased time to full recovery. To evaluate a peri-operative Fast Track Surgical Protocol (FTSP) in patients referred for abdominal surgery. All patients undergoing a laparotomy over a 12-month period were entered prospectively on a clinical database. Data were retrospectively analysed. Over the study period, 72 patients underwent a laparotomy. Average patient age was 54 years and average weight and BMI were 67.2 kg and 26 respectively. Sixty three (88%) patients had a vertical midline incision (VMI). There were no intraoperative blood transfusions. The median length of stay (LOS) was 3.0 days. Thirty eight patients (53%) were discharged on or before post op day 3, seven (10%) of whom were discharged on postoperative day 2. On stepwise regression analysis, the following were found to be independently associated with reduced LOS: able to tolerate early enteral nutrition, good performance status, use of COX inhibitor and transverse incision. In comparison with colleagues at the SGOG not undertaking FTS for their patients, the authors' LOS was lower and the RANZCOG modified Quality Indicators (QI's) did not demonstrate excess morbidity. Patients undergoing fast track surgery can be discharged from hospital with a reduced LOS, without an increased readmission rate and with comparative outcomes to non-fast tracked patients.

Lines of Force: Faraday's and Students' Views.

ERIC Educational Resources Information Center

Pocovi, M. Cecilia; Finley, Fred

2002-01-01

Analyzes how electric and magnetic lines of force were conceived by Faraday and how they are understood by a group of Argentine university students after receiving instruction. Results show that many students possess ideas similar to those of Faraday in that lines of force are conceived as real physical entities responsible for the transmission of…

The gravitational analog of Faraday's induction law

NASA Astrophysics Data System (ADS)

Zile, Daniel; Overduin, James

2015-04-01

Michael Faraday, the discoverer of electromagnetic induction, was convinced that there must also be a gravitational analog of this law, and he carried out drop-tower experiments in 1849 to look for the electric current induced in a coil by changes in gravitational flux through the coil. This work, now little remembered, was in some ways the first investigation of what we would now call a unified-field theory. We revisit Faraday's experiments in the light of current knowledge and ask what might be learned if they were to be performed today. We then review the gravitational analog for Faraday's law that arises within the vector (or gravito-electromagnetic) approximation to Einstein's theory of general relativity in the weak-field, low-velocity limit. This law relates spinning masses and induced ``mass currents'' rather than spinning charges and electric currents, but is otherwise remarkably similar to its electromagnetic counterpart. The predicted effects are completely unobservable in everyday settings like those envisioned by Faraday, but are thought to be relevant in astrophysical contexts like the accretion disks around collapsed stars, thus bearing out Faraday's remarkable intuition. Undergraduate student.

Fast Track to Success: Top Young Trainers 2012

ERIC Educational Resources Information Center

Freifeld, Lorri

2012-01-01

Supercharged. High-performers. Leaders of the pack. This article presents "Training" magazine's 2012 Top Young Trainers--those high-potential training professionals who are on the fast track to success. For the fifth year, "Training" magazine is pleased to recognize the outstanding talents, accomplishments, and leadership exhibited by 40 learning…

MOJAVE: Monitoring of Jets in Active Galactic Nuclei with VLBA Experiments. VIII. Faraday Rotation in Parsec-scale AGN Jets

NASA Astrophysics Data System (ADS)

Hovatta, Talvikki; Lister, Matthew L.; Aller, Margo F.; Aller, Hugh D.; Homan, Daniel C.; Kovalev, Yuri Y.; Pushkarev, Alexander B.; Savolainen, Tuomas

2012-10-01

We report observations of Faraday rotation measures for a sample of 191 extragalactic radio jets observed within the MOJAVE program. Multifrequency Very Long Baseline Array observations were carried out over 12 epochs in 2006 at four frequencies between 8 and 15 GHz. We detect parsec-scale Faraday rotation measures in 149 sources and find the quasars to have larger rotation measures on average than BL Lac objects. The median core rotation measures are significantly higher than in the jet components. This is especially true for quasars where we detect a significant negative correlation between the magnitude of the rotation measure and the de-projected distance from the core. We perform detailed simulations of the observational errors of total intensity, polarization, and Faraday rotation, and concentrate on the errors of transverse Faraday rotation measure gradients in unresolved jets. Our simulations show that the finite image restoring beam size has a significant effect on the observed rotation measure gradients, and spurious gradients can occur due to noise in the data if the jet is less than two beams wide in polarization. We detect significant transverse rotation measure gradients in four sources (0923+392, 1226+023, 2230+114, and 2251+158). In 1226+023 the rotation measure is for the first time seen to change sign from positive to negative over the transverse cuts, which supports the presence of a helical magnetic field in the jet. In this source we also detect variations in the jet rotation measure over a timescale of three months, which are difficult to explain with external Faraday screens and suggest internal Faraday rotation. By comparing fractional polarization changes in jet components between the four frequency bands to depolarization models, we find that an external purely random Faraday screen viewed through only a few lines of sight can explain most of our polarization observations, but in some sources, such as 1226+023 and 2251+158, internal Faraday rotation is needed.

Diagnostics of ion beam generated from a Mather type plasma focus device

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

Lim, L. K., E-mail: yapsl@um.edu.my; Ngoi, S. K., E-mail: yapsl@um.edu.my; Wong, C. S., E-mail: yapsl@um.edu.my

Diagnostics of ion beam emission from a 3 kJ Mather-type plasma focus device have been performed for deuterium discharge at low pressure regime. Deuterium plasma focus was found to be optimum at pressure of 0.2 mbar. The energy spectrum and total number of ions per shot from the pulsed ion beam are determined by using biased ion collectors, Faraday cup, and solid state nuclear track detector CR-39. Average energy of the ion beam obtained is about 60 keV. Total number of the ions has been determined to be in the order of 10{sup 11} per shot. Solid state nuclear trackmore » detectors (SSNTD) CR39 are employed to measure the particles at all angular direction from end on (0°) to side on (90°). Particle tracks are registered by SSNTD at 30° to 90°, except the one at the end-on 0°.« less

Faraday effect in Sn2P2S6 crystals.

PubMed

Krupych, Oleh; Adamenko, Dmytro; Mys, Oksana; Grabar, Aleksandr; Vlokh, Rostyslav

2008-11-10

We have revealed a large Faraday rotation in tin thiohypodiphosphate (Sn(2)P(2)S(6)) crystals, which makes this material promising for magneto-optics. The effective Faraday tensor component and the Verdet constant for the direction of the optic axis have been determined by measuring the pure Faraday rotation in Sn(2)P(2)S(6) crystals with both the single-ray and small-angular polarimetric methods at the normal conditions and a wavelength of 632.8 nm. The effective Verdet constant is found to be equal to 115 rad/T x m.

If Maxwell had worked between Ampère and Faraday: An historical fable with a pedagogical moral

NASA Astrophysics Data System (ADS)

Jammer, Max; Stachel, John

1980-01-01

If one drops the Faraday induction term from Maxwell's equations, they become exactly Galilei invariant. This suggests that if Maxwell had worked between Ampère and Faraday, he could have developed this Galilei-invariant electromagnetic theory so that Faraday's discovery would have confronted physicists with the dilemma: give up the Galileian relativity principle for electromagnetism (ether hypothesis), or modify it (special relativity). This suggests a new pedagogical approach to electromagnetic theory, in which the displacement current and the Galileian relativity principle are introduced before the induction term is discussed.

Faraday diamagnetism under slowly oscillating magnetic fields

NASA Astrophysics Data System (ADS)

Kimura, Tsunehisa; Kimura, Fumiko; Kimura, Yosuke

2018-04-01

Diamagnetism is a universal phenomenon of materials arising from the orbital motion of electrons bound to atoms, which is commonly known as Langevin diamagnetism. The orbital motion also occurs according to the Faraday's law of induction when the applied magnetic field is oscillating. However, the influence of this dynamic effect on the magnetism of materials has seldom been studied. Here, we propose a new type diamagnetism coined Faraday diamagnetism. The magnitude of this diamagnetism evaluated by an atomic electric circuit model was as large as that of Langevin diamagnetism. The predicted scale of Faraday diamagnetism was supported by experiments.

Faraday wave lattice as an elastic metamaterial.

PubMed

Domino, L; Tarpin, M; Patinet, S; Eddi, A

2016-05-01

Metamaterials enable the emergence of novel physical properties due to the existence of an underlying subwavelength structure. Here, we use the Faraday instability to shape the fluid-air interface with a regular pattern. This pattern undergoes an oscillating secondary instability and exhibits spontaneous vibrations that are analogous to transverse elastic waves. By locally forcing these waves, we fully characterize their dispersion relation and show that a Faraday pattern presents an effective shear elasticity. We propose a physical mechanism combining surface tension with the Faraday structured interface that quantitatively predicts the elastic wave phase speed, revealing that the liquid interface behaves as an elastic metamaterial.

Enhanced Faraday rotation in one dimensional magneto-plasmonic structure due to Fano resonance

NASA Astrophysics Data System (ADS)

Sadeghi, S.; Hamidi, S. M.

2018-04-01

Enhanced Faraday rotation in a new type of magneto-plasmonic structure with the capability of Fano resonance, has been reported theoretically. A magneto-plasmonic structure composed of a gold corrugated layer deposited on a magneto-optically active layer was studied by means of Lumerical software based on finite-difference time-domain. In our proposed structure, plasmonic Fano resonance and localized surface plasmon have induced enhancement in magneto-optical Faraday rotation. It is shown that the influence of geometrical parameters in gold layer offers a desirable platform for engineering spectral position of Fano resonance and enhancement of Faraday rotation.

Enhanced modified faraday cup for determination of power density distribution of electron beams

DOEpatents

Elmer, John W.; Teruya, Alan T.

2001-01-01

An improved tomographic technique for determining the power distribution of an electron or ion beam using electron beam profile data acquired by an enhanced modified Faraday cup to create an image of the current density in high and low power ion or electron beams. A refractory metal disk with a number of radially extending slits, one slit being about twice the width of the other slits, is placed above a Faraday cup. The electron or ion beam is swept in a circular pattern so that its path crosses each slit in a perpendicular manner, thus acquiring all the data needed for a reconstruction in one circular sweep. The enlarged slit enables orientation of the beam profile with respect to the coordinates of the welding chamber. A second disk having slits therein is positioned below the first slit disk and inside of the Faraday cup and provides a shield to eliminate the majority of secondary electrons and ions from leaving the Faraday cup. Also, a ring is located below the second slit disk to help minimize the amount of secondary electrons and ions from being produced. In addition, a beam trap is located in the Faraday cup to provide even more containment of the electron or ion beam when full beam current is being examined through the center hole of the modified Faraday cup.

Active imaging system with Faraday filter

DOEpatents

Snyder, James J.

1993-01-01

An active imaging system has a low to medium powered laser transmitter and receiver wherein the receiver includes a Faraday filter with an ultranarrow optical bandpass and a bare (nonintensified) CCD camera. The laser is locked in the vicinity of the passband of the Faraday filter. The system has high sensitivity to the laser illumination while eliminating solar background.

Active imaging system with Faraday filter

DOEpatents

Snyder, J.J.

1993-04-13

An active imaging system has a low to medium powered laser transmitter and receiver wherein the receiver includes a Faraday filter with an ultranarrow optical bandpass and a bare (nonintensified) CCD camera. The laser is locked in the vicinity of the passband of the Faraday filter. The system has high sensitivity to the laser illumination while eliminating solar background.

Merging universal and indicated prevention programs: the Fast Track model. Conduct Problems Prevention Research Group.

PubMed

2000-01-01

Fast Track is a multisite, multicomponent preventive intervention for young children at high risk for long-term antisocial behavior. Based on a comprehensive developmental model, this intervention includes a universal-level classroom program plus social-skill training, academic tutoring, parent training, and home visiting to improve competencies and reduce problems in a high-risk group of children selected in kindergarten. The theoretical principles and clinical strategies utilized in the Fast Track Project are described to illustrate the interplay between basic developmental research, the understanding of risk and protective factors, and a research-based model of preventive intervention that integrates universal and indicated models of prevention.

The Faraday effect of natural and artificial ferritins.

PubMed

Koralewski, M; Kłos, J W; Baranowski, M; Mitróová, Z; Kopčanský, P; Melníková, L; Okuda, M; Schwarzacher, W

2012-09-07

Measurements of the Faraday rotation at room temperature over the light wavelength range of 300-680 nm for horse spleen ferritin (HSF), magnetoferritin with different loading factors (LFs) and nanoscale magnetite and Fe(2)O(3) suspensions are reported. The Faraday rotation and the magnetization of the materials studied present similar magnetic field dependences and are characteristic of a superparamagnetic system. The dependence of the Faraday rotation on the magnetic field is described, excluding HSF and Fe(2)O(3), by a Langevin function with a log-normal distribution of the particle size allowing the core diameters of the substances studied to be calculated. It was found that the specific Verdet constant depends linearly on the LF. Differences in the Faraday rotation spectra and their magnetic field dependences allow discrimination between magnetoferritin with maghemite and magnetite cores which can be very useful in biomedicine.

Transparent Flexible Active Faraday Cage Enables In Vivo Capacitance Measurement in Assembled Microsensor.

PubMed

Ahmadi, Mahdi; Rajamani, Rajesh; Sezen, Serdar

2017-10-01

Capacitive micro-sensors such as accelerometers, gyroscopes and pressure sensors are increasingly used in the modern electronic world. However, the in vivo use of capacitive sensing for measurement of pressure or other variables inside a human body suffers from significant errors due to stray capacitance. This paper proposes a solution consisting of a transparent thin flexible Faraday cage that surrounds the sensor. By supplying the active sensing voltage simultaneously to the deformable electrode of the capacitive sensor and to the Faraday cage, the stray capacitance during in vivo measurements can be largely eliminated. Due to the transparency of the Faraday cage, the top and bottom portions of a capacitive sensor can be accurately aligned and assembled together. Experimental results presented in the paper show that stray capacitance is reduced by a factor of 10 by the Faraday cage, when the sensor is subjected to a full immersion in water.

Giant Faraday rotation in Bi(x)Ce(3-x)Fe5O12 epitaxial garnet films.

PubMed

Chandra Sekhar, M; Singh, Mahi R; Basu, Shantanu; Pinnepalli, Sai

2012-04-23

Thin films of Bi(x)Ce(3-x)Fe(5)O(12) with x = 0.7 and 0.8 compositions were prepared by using pulsed laser deposition. We investigated the effects of processing parameters used to fabricate these films by measuring various physical properties such as X-ray diffraction, transmittance, magnetization and Faraday rotation. In this study, we propose a phase diagram which provides a suitable window for the deposition of Bi(x)Ce(3-x)Fe(5)O(12) epitaxial films. We have also observed a giant Faraday rotation of 1-1.10 degree/µm in our optimized films. The measured Faraday rotation value is 1.6 and 50 times larger than that of CeYIG and YIG respectively. A theoretical model has been proposed for Faraday rotation based on density matrix method and an excellent agreement between experiment and theory is found. © 2012 Optical Society of America

"Joined up" Thinking? Unsupported "Fast-Track" Transitions in the Context of Parental Substance Use

ERIC Educational Resources Information Center

Wilson, Sarah; Cunningham-Burley, Sarah; Bancroft, Angus; Backett-Milburn, Kathryn

2008-01-01

Recent policy responses to the risks entailed in "fast-track" school-work transitions have targeted careleavers and young people identified as "not in education, employment or training" (NEET). However, this approach has been criticised as diverting attention away from the fragile circumstances of others who may receive little…

Preventing Serious Conduct Problems in School-Age Youth: The Fast Track Program

ERIC Educational Resources Information Center

Slough, Nancy M.; McMahon, Robert J.; Bierman, Karen L.; Coie, John D.; Dodge, Kenneth A.; Foster, E. Michael; Greenberg, Mark T.; Lochman, John E.; McMahon, Robert J.; Pinderhughes, Ellen E.

2008-01-01

Children with early-starting conduct problems have a very poor prognosis and exact a high cost to society. The Fast Track project is a multisite, collaborative research project investigating the efficacy of a comprehensive, long-term, multicomponent intervention designed to "prevent" the development of serious conduct problems in high-risk…

The Effects of a Multiyear Universal Social-Emotional Learning Program: The Role of Student and School Characteristics

ERIC Educational Resources Information Center

Bierman, Karen L.; Coie, John D.; Dodge, Kenneth A.; Greenberg, Mark T.; Lochman, John E.; McMahon, Robert J.; Pinderhughes, Ellen

2010-01-01

Objective: This article examines the impact of a universal social-emotional learning program, the Fast Track PATHS (Promoting Alternative Thinking Strategies) curriculum and teacher consultation, embedded within the Fast Track selective prevention model. Method: The longitudinal analysis involved 2,937 children of multiple ethnicities who remained…

Fast track pathway for perforated appendicitis.

PubMed

Frazee, Richard; Abernathy, Stephen; Davis, Matthew; Isbell, Travis; Regner, Justin; Smith, Randall

2017-04-01

Perforated appendicitis is associated with an increased morbidity and length of stay. "Fast track" protocols have demonstrated success in shortening hospitalization without increasing morbidity for a variety of surgical processes. This study evaluates a fast track pathway for perforated appendicitis. In 2013, a treatment pathway for perforated appendicitis was adopted by the Acute Care Surgery Service for patients having surgical management of perforated appendicitis. Interval appendectomy was excluded. Patients were treated initially with intravenous antibiotics and transitioned to oral antibiotics and dismissed when medically stable and tolerating oral intake. A retrospective review of patients managed on the fast track pathway was undertaken to analyze length of stay, morbidity, and readmissions. Thirty-four males and twenty-one females with an average age of 46.8 years underwent laparoscopic appendectomy for perforated appendicitis between January 2013 and December 2014. Pre-existing comorbidities included hypertension 42%, diabetes mellitus 11%, COPD 5% and heart disease 2%. No patient had conversion to open appendectomy. Average length of stay was 2.67 days and ranged from 1 to 12 days (median 2 days). Postoperative morbidity was 20% and included abscess (6 patients), prolonged ileus (3 patients), pneumonia (1 patient), and congestive heart failure (1 patient). Five patients were readmitted for abscess (3 patients), congestive heart failure (1 patient), and pneumonia (1 patient). A fast track pathway for perforated appendicitis produced shorter length of stay and acceptable postoperative morbidity and readmission. This offers the potential for significant cost savings over current national practice patterns. Copyright © 2016 Elsevier Inc. All rights reserved.

Electrically-Generated Spin Polarization in Non-Magnetic Semiconductors

DTIC Science & Technology

2016-03-31

resolved Faraday rotation data due to electron spin polarization from previous pump pulses was characterized, and an analytic solution for this phase...electron spin polarization was shown to produce nuclear hyperpolarization through dynamic nuclear polarization. Time-resolved Faraday rotation...Distribution approved for public release. 3    Figure 3. Total magnetic field measured using time-resolved Faraday rotation with the electrically

Experimental study of the mutual influence of fibre Faraday elements in a spun-fibre interferometer

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

Gubin, V P; Morshnev, S K; Przhiyalkovsky, Ya V

2015-08-31

An all-spun-fibre linear reflective interferometer with two linked Faraday fibre coils is studied. It is found experimentally that there is mutual influence of Faraday fibre coils in this interferometer. It manifests itself as an additional phase shift of the interferometer response, which depends on the circular birefringence induced by the Faraday effect in both coils. In addition, the interferometer contrast and magneto-optical sensitivity of one of the coils change. A probable physical mechanism of the discovered effect is the distributed coupling of orthogonal polarised waves in the fibre medium, which is caused by fibre bend in the coil. (interferometry)

Miniature modified Faraday cup for micro electron beams

DOEpatents

Teruya, Alan T.; Elmer, John W.; Palmer, Todd A.; Walton, Chris C.

2008-05-27

A micro beam Faraday cup assembly includes a refractory metal layer with an odd number of thin, radially positioned traces in this refractory metal layer. Some of the radially positioned traces are located at the edge of the micro modified Faraday cup body and some of the radially positioned traces are located in the central portion of the micro modified Faraday cup body. Each set of traces is connected to a separate data acquisition channel to form multiple independent diagnostic networks. The data obtained from the two diagnostic networks are combined and inputted into a computed tomography algorithm to reconstruct the beam shape, size, and power density distribution.

Electrical control of Faraday rotation at a liquid-liquid interface.

PubMed

Marinescu, Monica; Kornyshev, Alexei A; Flatté, Michael E

2015-01-01

A theory is developed for the Faraday rotation of light from a monolayer of charged magnetic nanoparticles at an electrified liquid-liquid interface. The polarization fields of neighboring nanoparticles enhance the Faraday rotation. At such interfaces, and for realistic sizes and charges of nanoparticles, their adsorption-desorption can be controlled with a voltage variation<1 V, providing electrovariable Faraday rotation. A calculation based on the Maxwell-Garnett theory predicts that the corresponding redistribution of 40 nm nanoparticles of yttrium iron garnet can switch a cavity with a quality factor larger than 10(4) for light of wavelength 500 nm at normal incidence.

Faraday polarization fluctuations of satellite beacon signals

NASA Technical Reports Server (NTRS)

Lee, M. C.; Klobuchar, J. A.

1988-01-01

The anisotropic effects of random density irregularities in causing Faraday polarization fluctuations of VHF radio signals are examined, taking both rod-like and sheet-like irregularities into consideration. It is found that the variance of Faraday polarization fluctuations depends on the ratio of perpendicular to parallel correlation lengths. The anisotropic effect of rod-like ionospheric irregularities are shown to be most appreciable for longitudinal propagation. The anisotropic effect of sheet-like ionospheric irregularities, however, is not strongly dependent on the radio propagation angle. During transionospheric propagation at large angles with respect to the geomagnetic field, sheet-like irregularities may cause greater Faraday polarization fluctuations than rod-like irregularities.

Fabry-Perot enhanced Faraday rotation in graphene.

PubMed

Ubrig, Nicolas; Crassee, Iris; Levallois, Julien; Nedoliuk, Ievgeniia O; Fromm, Felix; Kaiser, Michl; Seyller, Thomas; Kuzmenko, Alexey B

2013-10-21

We demonstrate that giant Faraday rotation in graphene in the terahertz range due to the cyclotron resonance is further increased by constructive Fabry-Perot interference in the supporting substrate. Simultaneously, an enhanced total transmission is achieved, making this effect doubly advantageous for graphene-based magneto-optical applications. As an example, we present far-infrared spectra of epitaxial multilayer graphene grown on the C-face of 6H-SiC, where the interference fringes are spectrally resolved and a Faraday rotation up to 0.15 radians (9°) is attained. Further, we discuss and compare other ways to increase the Faraday rotation using the principle of an optical cavity.

Position control of desiccation cracks by memory effect and Faraday waves.

PubMed

Nakayama, Hiroshi; Matsuo, Yousuke; Takeshi, Ooshida; Nakahara, Akio

2013-01-01

Pattern formation of desiccation cracks on a layer of a calcium carbonate paste is studied experimentally. This paste is known to exhibit a memory effect, which means that a short-time application of horizontal vibration to the fresh paste predetermines the direction of the cracks that are formed after the paste is dried. While the position of the cracks (as opposed to their direction) is still stochastic in the case of horizontal vibration, the present work reports that their positioning is also controllable, at least to some extent, by applying vertical vibration to the paste and imprinting the pattern of Faraday waves, thus breaking the translational symmetry of the system. The experiments show that the cracks tend to appear in the node zones of the Faraday waves: in the case of stripe-patterned Faraday waves, the cracks are formed twice more frequently in the node zones than in the anti-node zones, presumably due to the localized horizontal motion. As a result of this preference of the cracks to the node zones, the memory of the square lattice pattern of Faraday waves makes the cracks run in the oblique direction differing by 45 degrees from the intuitive lattice direction of the Faraday waves.

Faraday instability in a near-critical fluid under weightlessness.

PubMed

Gandikota, G; Chatain, D; Amiroudine, S; Lyubimova, T; Beysens, D

2014-01-01

Experiments on near-critical hydrogen have been conducted under magnetic compensation of gravity to investigate the Faraday instability that arises at the liquid-vapor interface under zero-gravity conditions. We investigated such instability in the absence of stabilizing gravity. Under such conditions, vibration orients the interface and can destabilize it. The experiments confirm the existence of Faraday waves and demonstrate a transition from a square to a line pattern close to the critical point. They also show a transition very close to the critical point from Faraday to periodic layering of the vapor-liquid interface perpendicular to vibration. It was seen that the Faraday wave instability is favored when the liquid-vapor density difference is large enough (fluid far from the critical point), whereas periodic layering predominates for small difference in the liquid and vapor densities (close to the critical point). It was observed for the Faraday wave instability that the wavelength of the instability decreases as one approaches the critical point. The experimental results demonstrate good agreement to the dispersion relation for zero gravity except for temperatures very close to the critical point where a transition from a square pattern to a line pattern is detected, similarly to what is observed under 1g conditions.

Finite-time control for nonlinear spacecraft attitude based on terminal sliding mode technique.

PubMed

Song, Zhankui; Li, Hongxing; Sun, Kaibiao

2014-01-01

In this paper, a fast terminal sliding mode control (FTSMC) scheme with double closed loops is proposed for the spacecraft attitude control. The FTSMC laws are included both in an inner control loop and an outer control loop. Firstly, a fast terminal sliding surface (FTSS) is constructed, which can drive the inner loop tracking-error and the outer loop tracking-error on the FTSS to converge to zero in finite time. Secondly, FTSMC strategy is designed by using Lyaponov's method for ensuring the occurrence of the sliding motion in finite time, which can hold the character of fast transient response and improve the tracking accuracy. It is proved that FTSMC can guarantee the convergence of tracking-error in both approaching and sliding mode surface. Finally, simulation results demonstrate the effectiveness of the proposed control scheme. © 2013 ISA. Published by Elsevier Ltd. All rights reserved.

Fast emulation of track reconstruction in the CMS simulation

NASA Astrophysics Data System (ADS)

Komm, Matthias; CMS Collaboration

2017-10-01

Simulated samples of various physics processes are a key ingredient within analyses to unlock the physics behind LHC collision data. Samples with more and more statistics are required to keep up with the increasing amounts of recorded data. During sample generation, significant computing time is spent on the reconstruction of charged particle tracks from energy deposits which additionally scales with the pileup conditions. In CMS, the FastSimulation package is developed for providing a fast alternative to the standard simulation and reconstruction workflow. It employs various techniques to emulate track reconstruction effects in particle collision events. Several analysis groups in CMS are utilizing the package, in particular those requiring many samples to scan the parameter space of physics models (e.g. SUSY) or for the purpose of estimating systematic uncertainties. The strategies for and recent developments in this emulation are presented, including a novel, flexible implementation of tracking emulation while retaining a sufficient, tuneable accuracy.

Rapid, High-Throughput Tracking of Bacterial Motility in 3D via Phase-Contrast Holographic Video Microscopy

PubMed Central

Cheong, Fook Chiong; Wong, Chui Ching; Gao, YunFeng; Nai, Mui Hoon; Cui, Yidan; Park, Sungsu; Kenney, Linda J.; Lim, Chwee Teck

2015-01-01

Tracking fast-swimming bacteria in three dimensions can be extremely challenging with current optical techniques and a microscopic approach that can rapidly acquire volumetric information is required. Here, we introduce phase-contrast holographic video microscopy as a solution for the simultaneous tracking of multiple fast moving cells in three dimensions. This technique uses interference patterns formed between the scattered and the incident field to infer the three-dimensional (3D) position and size of bacteria. Using this optical approach, motility dynamics of multiple bacteria in three dimensions, such as speed and turn angles, can be obtained within minutes. We demonstrated the feasibility of this method by effectively tracking multiple bacteria species, including Escherichia coli, Agrobacterium tumefaciens, and Pseudomonas aeruginosa. In addition, we combined our fast 3D imaging technique with a microfluidic device to present an example of a drug/chemical assay to study effects on bacterial motility. PMID:25762336

Simulations of extragalactic magnetic fields and of their observables

NASA Astrophysics Data System (ADS)

Vazza, F.; Brüggen, M.; Gheller, C.; Hackstein, S.; Wittor, D.; Hinz, P. M.

2017-12-01

The origin of extragalactic magnetic fields is still poorly understood. Based on a dedicated suite of cosmological magneto-hydrodynamical simulations with the ENZO code we have performed a survey of different models that may have caused present-day magnetic fields in galaxies and galaxy clusters. The outcomes of these models differ in cluster outskirts, filaments, sheets and voids and we use these simulations to find observational signatures of magnetogenesis. With these simulations, we predict the signal of extragalactic magnetic fields in radio observations of synchrotron emission from the cosmic web, in Faraday rotation, in the propagation of ultra high energy cosmic rays, in the polarized signal from fast radio bursts at cosmological distance and in spectra of distant blazars. In general, primordial scenarios in which present-day magnetic fields originate from the amplification of weak (⩽nG ) uniform seed fields result in more homogeneous and relatively easier to observe magnetic fields than astrophysical scenarios, in which present-day fields are the product of feedback processes triggered by stars and active galaxies. In the near future the best evidence for the origin of cosmic magnetic fields will most likely come from a combination of synchrotron emission and Faraday rotation observed at the periphery of large-scale structures.

Developmental Mediation of Genetic Variation in Response to the Fast Track Prevention Program

PubMed Central

Albert, Dustin; Belsky, Daniel W.; Crowley, D. Max; Bates, John E.; Pettit, Gregory S.; Lansford, Jennifer E.; Dick, Danielle; Dodge, Kenneth A.

2015-01-01

We conducted a developmental analysis of genetic moderation of the effect of the Fast Track intervention on adult externalizing psychopathology. The Fast Track intervention enrolled 891 children at high risk to develop externalizing behavior problems when they were in kindergarten. Half of the enrolled children were randomly assigned to receive 10 years of treatment with a range of services and resources provided to the children and their families and the other half to usual care (controls). We previously showed that the effect of the Fast Track intervention on participants’ risk of externalizing psychopathology at age 25 years was moderated by a variant in the Glucocorticoid Receptor Gene (NR3C1). Children who carried copies of the A-allele of the single-nucleotide polymorphism rs10482672 had the highest risk of externalizing psychopathology if they were in the control arm of the trial and the lowest risk of externalizing psychopathology if they were in the treatment arm. In this study, we test a developmental hypothesis about the origins of this for-better-and-for-worse gene-by-intervention interaction (GxI): That the observed GxI effect on adult psychopathology is mediated by the proximal impact of intervention on childhood externalizing problems and adolescent substance use and delinquency. We analyzed longitudinal data tracking the 270 European-American children in the Fast Track RCT with available genetic information (129 intervention children and 141 control-group peers, 69% male) from kindergarten through age 25 years. Results show that the same pattern of “for-better-and-for-worse” susceptibility to intervention observed at the age-25 follow-up was evident already during childhood. At the elementary school follow-ups and at the middle/high-school follow-ups, rs10482672 predicted better adjustment among children receiving the Fast Track intervention, and worse adjustment among children in the control condition. In turn, these proximal GxI effects early in development mediated the ultimate GxI effect on externalizing psychopathology at age 25 years. We discuss the contribution of these findings to the growing literature on genetic susceptibility to environmental intervention. PMID:25640832

Linear theory on temporal instability of megahertz faraday waves for monodisperse microdroplet ejection.

PubMed

Tsai, Shirley C; Tsai, Chen S

2013-08-01

A linear theory on temporal instability of megahertz Faraday waves for monodisperse microdroplet ejection based on mass conservation and linearized Navier-Stokes equations is presented using the most recently observed micrometer- sized droplet ejection from a millimeter-sized spherical water ball as a specific example. The theory is verified in the experiments utilizing silicon-based multiple-Fourier horn ultrasonic nozzles at megahertz frequency to facilitate temporal instability of the Faraday waves. Specifically, the linear theory not only correctly predicted the Faraday wave frequency and onset threshold of Faraday instability, the effect of viscosity, the dynamics of droplet ejection, but also established the first theoretical formula for the size of the ejected droplets, namely, the droplet diameter equals four-tenths of the Faraday wavelength involved. The high rate of increase in Faraday wave amplitude at megahertz drive frequency subsequent to onset threshold, together with enhanced excitation displacement on the nozzle end face, facilitated by the megahertz multiple Fourier horns in resonance, led to high-rate ejection of micrometer- sized monodisperse droplets (>10(7) droplets/s) at low electrical drive power (<;1 W) with short initiation time (<;0.05 s). This is in stark contrast to the Rayleigh-Plateau instability of a liquid jet, which ejects one droplet at a time. The measured diameters of the droplets ranging from 2.2 to 4.6 μm at 2 to 1 MHz drive frequency fall within the optimum particle size range for pulmonary drug delivery.

[Effects of a nutritional intervention in a fast-track program for a colorectal cancer surgery: systematic review].

PubMed

Wanden-Berghe, Carmina; Sanz-Valero, Javier; Arroyo-Sebastián, Antonio; Cheikh-Moussa, Kamila; Moya-Forcen, Pedro

2016-07-19

Introducción: Preoperative nutritional status (NS) has consequences on postoperative (POSTOP) recovery. Our aim was to systematically review the nutritional interventions (NI) in Fast-Track protocols for colorectal cancer surgery and assess morbidity-mortality and patient´s recovery. Systematic review of scientific literature after consulting bibliographic databases: Medline, The Cochrane Library, Scopus, Embase, Web of Science, Institute for Scientific Information, Latin American and Caribbean Health Sciences Literature, The Cumulative Index to Nursing and Allied Health Literature. MeSH Descriptors: "Colorectal Surgery", "Fast-Track", "Perioperative Care", "Nutrition Therapy" and "Enhanced recovery programme". Filters: "Humans", Adult (19+ years) and "Clinical Trial". Variables POSTOP outcomes: bowel recovery (BR), hospital stay (HS), complications and death. Selected studies, 27, had good or excellent methodological quality. From 25 to 597 patients were included. Aged between 16-94 years, men were predominant in 66.6%. NS was evaluated in 13 studies; 7 by Body Mass Index while one by Subjective Global Assessment. One presented POSTOP data. Fast-Track groups had solids, liquids or supplements (SS) in prior 2-8 hours. SS were high in carbohydrates, immune-nutrients and non-residue. Free liquids, solids and SS intake was allowed in POSTOP. Half traditional groups fasted between 3-12 hours and resumed POSTOP food intake progressively. Fast-Track groups had early BR (p < 0.01). Traditional groups had more infections episodes, deaths and a longer HS. Great variability between NI but had a common item; early intake. Although was seen patient's recovery. Future studies with detailed NI characteristics are need. Nutritional status must be assessed for a higher acknowledgement of NI impact.

Michael Faraday, media man.

PubMed

Fara, Patricia

2006-03-01

Michael Faraday was an enthusiastic portrait collector, and he welcomed the invention of photography not only as a possible means of recording observations accurately, but also as a method for advertising science and its practitioners. This article (which is part of the Science in the Industrial Revolution series) shows that like many eminent scientists, Faraday took advantage of the burgeoning Victorian media industry by posing in various roles.

Optical Magnetometry for Detecting Underwater Objects

DTIC Science & Technology

2015-09-21

underwater object. The two mechanisms responsible for the polarization rotation are the Surface Magneto-Optical Kerr Effect (SMOKE) and the Faraday effect...the underwater object itself ( Faraday effect). An analytical expression is obtained for the polarization-rotated field when the incident plane wave...Washington, DC 20375-5320 October 2014 – August 2015 NRL *University of Maryland, College Park, MD 20742-4111 Faraday SMOKE 67-4374-C4 1 Optical

MOJAVE: MONITORING OF JETS IN ACTIVE GALACTIC NUCLEI WITH VLBA EXPERIMENTS. VIII. FARADAY ROTATION IN PARSEC-SCALE AGN JETS

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

Hovatta, Talvikki; Lister, Matthew L.; Aller, Margo F.

2012-10-01

We report observations of Faraday rotation measures for a sample of 191 extragalactic radio jets observed within the MOJAVE program. Multifrequency Very Long Baseline Array observations were carried out over 12 epochs in 2006 at four frequencies between 8 and 15 GHz. We detect parsec-scale Faraday rotation measures in 149 sources and find the quasars to have larger rotation measures on average than BL Lac objects. The median core rotation measures are significantly higher than in the jet components. This is especially true for quasars where we detect a significant negative correlation between the magnitude of the rotation measure andmore » the de-projected distance from the core. We perform detailed simulations of the observational errors of total intensity, polarization, and Faraday rotation, and concentrate on the errors of transverse Faraday rotation measure gradients in unresolved jets. Our simulations show that the finite image restoring beam size has a significant effect on the observed rotation measure gradients, and spurious gradients can occur due to noise in the data if the jet is less than two beams wide in polarization. We detect significant transverse rotation measure gradients in four sources (0923+392, 1226+023, 2230+114, and 2251+158). In 1226+023 the rotation measure is for the first time seen to change sign from positive to negative over the transverse cuts, which supports the presence of a helical magnetic field in the jet. In this source we also detect variations in the jet rotation measure over a timescale of three months, which are difficult to explain with external Faraday screens and suggest internal Faraday rotation. By comparing fractional polarization changes in jet components between the four frequency bands to depolarization models, we find that an external purely random Faraday screen viewed through only a few lines of sight can explain most of our polarization observations, but in some sources, such as 1226+023 and 2251+158, internal Faraday rotation is needed.« less

Fast Track Randomized Controlled Trial to Prevent Externalizing Psychiatric Disorders: Findings from Grades 3 to 9

ERIC Educational Resources Information Center

Journal of the American Academy of Child & Adolescent Psychiatry, 2007

2007-01-01

Objective: This study tests the efficacy of the Fast Track Program in preventing antisocial behavior and psychiatric disorders among groups varying in initial risk. Method: Schools within four sites (Durham, NC; Nashville, TN; Seattle, WA; and rural central Pennsylvania) were selected as high-risk institutions based on neighborhood crime and…

Fast Tracking School Site Acquisition: A Perspective of an Eminent Domain Attorney.

ERIC Educational Resources Information Center

Behrens, Jerry

This paper discusses key issues in fast-tracking the acquisition of school sites in California. Discussion addresses: (1) assembling an experienced team; (2) whether the property owner is a willing or unwilling seller; (3) level of community support or opposition to the site; (4) timing and commencement of California Environmental Quality Act…

Fast Track Initiative: Building a Global Compact for Education. Education Notes

ERIC Educational Resources Information Center

Human Development Network Education, 2005

2005-01-01

This note series is intended to summarize lessons learned and key policy findings on the World Bank's work in education. "Fast Track Initiative" ("FTI") was launched in 2002 as a partnership between donor and developing countries to accelerate progress towards the Millennium Development Goal (MDG) of universal primary education. "FTI" is built on…

Electrically tunable lens speeds up 3D orbital tracking

PubMed Central

Annibale, Paolo; Dvornikov, Alexander; Gratton, Enrico

2015-01-01

3D orbital particle tracking is a versatile and effective microscopy technique that allows following fast moving fluorescent objects within living cells and reconstructing complex 3D shapes using laser scanning microscopes. We demonstrated notable improvements in the range, speed and accuracy of 3D orbital particle tracking by replacing commonly used piezoelectric stages with Electrically Tunable Lens (ETL) that eliminates mechanical movement of objective lenses. This allowed tracking and reconstructing shape of structures extending 500 microns in the axial direction. Using the ETL, we tracked at high speed fluorescently labeled genomic loci within the nucleus of living cells with unprecedented temporal resolution of 8ms using a 1.42NA oil-immersion objective. The presented technology is cost effective and allows easy upgrade of scanning microscopes for fast 3D orbital tracking. PMID:26114037

Automatic detection of recoil-proton tracks and background rejection criteria in liquid scintillator-micro-capillary-array fast neutron spectrometer

NASA Astrophysics Data System (ADS)

Mor, Ilan; Vartsky, David; Dangendorf, Volker; Tittelmeier, Kai.; Weierganz, Mathias; Goldberg, Mark Benjamin; Bar, Doron; Brandis, Michal

2018-06-01

We describe an analysis procedure for automatic unambiguous detection of fast-neutron-induced recoil proton tracks in a micro-capillary array filled with organic liquid scintillator. The detector is viewed by an intensified CCD camera. This imaging neutron detector possesses the capability to perform high position-resolution (few tens of μm), energy-dispersive transmission-imaging using ns-pulsed beams. However, when operated with CW or DC beams, it also features medium-quality spectroscopic capabilities for incident neutrons in the energy range 2-20 MeV. In addition to the recoil proton events which display a continuous extended track structure, the raw images exhibit complex ion-tracks from nuclear interactions of fast-neutrons in the scintillator, capillaries quartz-matrix and CCD. Moreover, as expected, one also observes a multitude of isolated scintillation spots of varying intensity (henceforth denoted "blobs") that originate from several different sources, such as: fragmented proton tracks, gamma-rays, heavy-ion reactions as well as events and noise that occur in the image-intensifier and CCD. In order to identify the continuous-track recoil proton events and distinguish them from all these background events, a rapid, computerized and automatic track-recognition-procedure was developed. Based on an appropriately weighted analysis of track parameters such as: length, width, area and overall light intensity, the method is capable of distinguishing a single continuous-track recoil proton from typically surrounding several thousands of background events that are found in each CCD frame.

Inverse energy cascade and emergence of large coherent vortices in turbulence driven by Faraday waves.

PubMed

Francois, N; Xia, H; Punzmann, H; Shats, M

2013-05-10

We report the generation of large coherent vortices via inverse energy cascade in Faraday wave driven turbulence. The motion of floaters in the Faraday waves is three dimensional, but its horizontal velocity fluctuations show unexpected similarity with two-dimensional turbulence. The inverse cascade is detected by measuring frequency spectra of the Lagrangian velocity, and it is confirmed by computing the third moment of the horizontal velocity fluctuations. This is observed in deep water in a broad range of wavelengths and vertical accelerations. The results broaden the scope of recent findings on Faraday waves in thin layers [A. von Kameke et al., Phys. Rev. Lett. 107, 074502 (2011)].

All-fiber Faraday Devices Based on Terbium-doped Fiber

NASA Astrophysics Data System (ADS)

Sun, Lei

Surface damage is one of the most problematic power limits in high-power fiber laser systems. All-fiber Faraday components are demonstrated as a solution to this problem, since they can be completely fusion-spliced into existing systems, eliminating all glass-air interfaces. Beam filamentation due to self-focusing places another limit on the peak power attainable from fiber laser systems. The limits imposed by this phenomenon are analyzed for the first time. The concept of an effective Verdet constant is proposed and experimentally validated. The effective Verdet constant of light propagation in a fiber includes contributions from the materials in both the core and the cladding. It is measured in a 25-wt% terbium-doped-core phosphate fiber to be --6.2 rad/(Tm) at 1053 nm, which is six times larger than silica fiber. The result agrees well with Faraday rotation theory in optical fiber. A compact all-fiber Faraday isolator and a Faraday mirror are demonstrated. At the core of each of these components is an all-fiber Faraday rotator made of a 4cm-long, 65-wt%-terbium-doped silicate fiber. The effective Verdet constant of the terbium-doped fiber is measured to be -32 rad/(Tm), which is 27x larger than that of silica fiber. This effective Verdet constant is the largest value measured to date in any fiber and is 83% of the Verdet constant of commercially available crystals used in bulk-optics-based isolators. Combining the all-fiber Faraday rotator with fiber polarizers results in a fully fusion-spliced all-fiber isolator whose isolation is measured to be 19 dB. Combining the all-fiber Faraday rotator with a fiber Bragg grating results in an all-fiber Faraday mirror that rotates the polarization state of the reflected light by 88 +/- 4°. An all-fiber optical magnetic field sensor is also demonstrated. It consists of a fiber Faraday rotator and a fiber polarizer. The fiber Faraday rotator uses a 2-cm-long section of 56-wt%-terbium-doped silicate fiber with a Verdet constant of -24.5 rad/(Tm) at 1053 nm. The fiber polarizer is Corning SP1060 single-polarization fiber. The sensor has a sensitivity of 0.49 rad/T and can measure magnetic fields from 0.02 to 3.2 T. An all-fiber wavelength-tunable laser based on Faraday rotation is proposed. It consists of an all-fiber wavelength-tunable filter in a conventional fiber laser cavity. The filter includes a fiber polarizer and a fiber Faraday mirror in which a chirped fiber Bragg grating is directly written onto the 65-wt% terbium fiber. The ytterbium-doped fiber in the laser is gain flattened using a. 1030/1090 rim WDM filter, resulting a net gain ripple that is measured to he less than 0.2 dB from 1047 to 1060 nm. The wavelength tuning range of the resulting fiber laser is therefore expected to be in this 1047 to 1060 nm range. Filamentation is one of the nonlinear peak-power-threshold limits in high-power fiber lasers. Starting from the paraxial wave equation, an analytic expression for the filamentation threshold in fiber lasers is derived using a perturbation method. The occurrence of filamentation is determined by the larger of two thresholds, one of perturbative gain and one of spatial confinement. The threshold value is around a few megawatts, depending on the parameters of the fiber.

Theory of Kerr and Faraday rotations and linear dichroism in Topological Weyl Semimetals.

PubMed

Kargarian, Mehdi; Randeria, Mohit; Trivedi, Nandini

2015-08-03

We consider the electromagnetic response of a topological Weyl semimetal (TWS) with a pair of Weyl nodes in the bulk and corresponding Fermi arcs in the surface Brillouin zone. We compute the frequency-dependent complex conductivities σαβ(ω) and also take into account the modification of Maxwell equations by the topological θ-term to obtain the Kerr and Faraday rotations in a variety of geometries. For TWS films thinner than the wavelength, the Kerr and Faraday rotations, determined by the separation between Weyl nodes, are significantly larger than in topological insulators. In thicker films, the Kerr and Faraday angles can be enhanced by choice of film thickness and substrate refractive index. We show that, for radiation incident on a surface with Fermi arcs, there is no Kerr or Faraday rotation but the electric field develops a longitudinal component inside the TWS, and there is linear dichroism signal. Our results have implications for probing the TWS phase in various experimental systems.

Temperature Dependence of Faraday Effect-Induced Bias Error in a Fiber Optic Gyroscope

PubMed Central

Li, Xuyou; Guang, Xingxing; Xu, Zhenlong; Li, Guangchun

2017-01-01

Improving the performance of interferometric fiber optic gyroscope (IFOG) in harsh environments, such as magnetic field and temperature field variation, is necessary for its practical applications. This paper presents an investigation of Faraday effect-induced bias error of IFOG under varying temperature. Jones matrix method is utilized to formulize the temperature dependence of Faraday effect-induced bias error. Theoretical results show that the Faraday effect-induced bias error changes with the temperature in the non-skeleton polarization maintaining (PM) fiber coil. This phenomenon is caused by the temperature dependence of linear birefringence and Verdet constant of PM fiber. Particularly, Faraday effect-induced bias errors of two polarizations always have opposite signs that can be compensated optically regardless of the changes of the temperature. Two experiments with a 1000 m non-skeleton PM fiber coil are performed, and the experimental results support these theoretical predictions. This study is promising for improving the bias stability of IFOG. PMID:28880203

Temperature Dependence of Faraday Effect-Induced Bias Error in a Fiber Optic Gyroscope.

PubMed

Li, Xuyou; Liu, Pan; Guang, Xingxing; Xu, Zhenlong; Guan, Lianwu; Li, Guangchun

2017-09-07

Improving the performance of interferometric fiber optic gyroscope (IFOG) in harsh environments, such as magnetic field and temperature field variation, is necessary for its practical applications. This paper presents an investigation of Faraday effect-induced bias error of IFOG under varying temperature. Jones matrix method is utilized to formulize the temperature dependence of Faraday effect-induced bias error. Theoretical results show that the Faraday effect-induced bias error changes with the temperature in the non-skeleton polarization maintaining (PM) fiber coil. This phenomenon is caused by the temperature dependence of linear birefringence and Verdet constant of PM fiber. Particularly, Faraday effect-induced bias errors of two polarizations always have opposite signs that can be compensated optically regardless of the changes of the temperature. Two experiments with a 1000 m non-skeleton PM fiber coil are performed, and the experimental results support these theoretical predictions. This study is promising for improving the bias stability of IFOG.

Galactic foreground science: Faraday Tomography at low frequencies

NASA Astrophysics Data System (ADS)

Haverkorn, Marijke

2018-05-01

This contribution describes how low-frequency radio-spectropolarimetric imaging as done for Epoch of Reionization detection is used to investigate the nearby Galactic interstellar medium. The method of Faraday Tomography allows disentangling of every line of sight into various components in Faraday depth, which is a proxy for density-weighted magnetic field. I discuss instrumental biases and side effects of this method, and early results it has yielded.

Faraday rotation measurements at Ootacamund

NASA Technical Reports Server (NTRS)

Sethia, G.; Chandra, H.; Deshpande, M. R.; Rastogi, R. G.

1978-01-01

The results of Faraday rotation measurements made at Ootacamund during ATS-6 phase II are presented. For summer and equinoctial months, even though no clear noon bite-out is observed in the variation of Faraday a decrease is observed in the rate of increase of rotation around 0900-1000 hours LT. This is attributed to the 'fountain effect' which is responsible for the noontime bite-out in F2-region peak electron density.

Evaluation of ion collection area in Faraday probes.

PubMed

Brown, Daniel L; Gallimore, Alec D

2010-06-01

A Faraday probe with three concentric rings was designed and fabricated to assess the effect of gap width and collector diameter in a systematic study of the diagnostic ion collection area. The nested Faraday probe consisted of two concentric collector rings and an outer guard ring, which enabled simultaneous current density measurements on the inner and outer collectors. Two versions of the outer collector were fabricated to create gaps of 0.5 and 1.5 mm between the rings. Distribution of current density in the plume of a low-power Hall thruster ion source was measured in azimuthal sweeps at constant radius from 8 to 20 thruster diameters downstream of the exit plane with variation in facility background pressure. A new analytical technique is proposed to account for ions collected in the gap between the Faraday probe collector and guard ring. This method is shown to exhibit excellent agreement between all nested Faraday probe configurations, and to reduce the magnitude of integrated ion beam current to levels consistent with Hall thruster performance analyses. The technique is further studied by varying the guard ring bias potential with a fixed collector bias potential, thereby controlling ion collection in the gap. Results are in agreement with predictions based on the proposed analytical technique. The method is applied to a past study comparing the measured ion current density profiles of two Faraday probe designs. These findings provide new insight into the nature of ion collection in Faraday probe diagnostics, and lead to improved accuracy with a significant reduction in measurement uncertainty.

Implementation and audit of 'Fast-Track Surgery' in gynaecological oncology surgery.

PubMed

Sidhu, Verinder S; Lancaster, Letitia; Elliott, David; Brand, Alison H

2012-08-01

Fast-track surgery is a multidisciplinary approach to surgery that results in faster recovery from surgery and decreased length of stay (LOS). The aims of this study were as follows: (i) to report on the processes required for the introduction of fast-track surgery to a gynaecological oncology unit and (ii) to report the results of a clinical audit conducted after the protocol's implementation. A fast-track protocol, specific to our unit, was developed after a series of multidisciplinary meetings. The protocol, agreed upon by those involved in the care of women in our unit, was then introduced into clinical practice. An audit was conducted of all women undergoing laparotomy, with known or suspected malignancy. Information on LOS, complication and readmission rates was collected. Descriptive statistics and Poisson regression were used for statistical analysis. The developed protocol involved a multidisciplinary approach to pre-, intra- and postoperative care. The audit included 104 consecutive women over a 6-month period, who were followed for 6 weeks postoperatively. The median LOS was 4 days. The readmission rate was 7% and the complication rate was 19% (1% intraoperative, 4% major and 14% minor). Multivariate analysis revealed that increased duration of surgery and increasing age were predictors of longer LOS. The development of a fast-track protocol is achievable in a gynaecological oncology unit, with input from a multidisciplinary team. Effective implementation of the protocol can result in a short LOS, with acceptable complication and readmission rates when applied non-selectively to gynaecological oncology patients. © 2012 The Authors ANZJOG © 2012 The Royal Australian and New Zealand College of Obstetricians and Gynaecologists.

Maintaining Unity - relatives in older patients' fast-track treatment programmes. A grounded theory study.

PubMed

Berthelsen, Connie Bøttcher; Lindhardt, Tove; Frederiksen, Kirsten

2014-12-01

To generate a substantive grounded theory of relatives' pattern of behaviour in older patients' fast-track treatment programmes during total hip or knee replacement. Fast-track treatment programmes are designed to make total hip and knee replacements more efficient through recovery improvements. The support of relatives during older patients' trajectory is important. However, knowledge is needed on the relatives' pattern of behaviour to strengthen their involvement in fast-track treatment programmes. We used a Glaserian grounded theory approach based on a systematic generation of theory from data to explain the latent pattern of behaviour of relatives. Data were collected from 2010-2011 in orthopaedic wards at two Danish university hospitals and consisted of 14 non-participant observations, 14 postobservational interviews and five interviews. Seven relatives of patients over 70 years of age participated. The constant comparative method was the guiding principle for simultaneous data collection, data analysis and coding, while theoretically sampling and writing memos. Maintaining Unity emerged as the relatives' pattern of behaviour through which they resolved their main concern: preventing the patients from feeling alone. The relatives resolved their main concern through three interchangeable behavioural modes: Protecting Mode, by providing loving and respectful support; Substituting Mode, with practical and cognitive support; and an Adapting Mode, by trying to fit in with the patients' and health professionals' requirements. The substantive theory of Maintaining Unity offers knowledge of relatives' strong desire to provide compassionate and loving support for the older patients during fast-track treatment programmes. © 2014 John Wiley & Sons Ltd.

Fast left ventricle tracking in CMR images using localized anatomical affine optical flow

NASA Astrophysics Data System (ADS)

Queirós, Sandro; Vilaça, João. L.; Morais, Pedro; Fonseca, Jaime C.; D'hooge, Jan; Barbosa, Daniel

2015-03-01

In daily cardiology practice, assessment of left ventricular (LV) global function using non-invasive imaging remains central for the diagnosis and follow-up of patients with cardiovascular diseases. Despite the different methodologies currently accessible for LV segmentation in cardiac magnetic resonance (CMR) images, a fast and complete LV delineation is still limitedly available for routine use. In this study, a localized anatomically constrained affine optical flow method is proposed for fast and automatic LV tracking throughout the full cardiac cycle in short-axis CMR images. Starting from an automatically delineated LV in the end-diastolic frame, the endocardial and epicardial boundaries are propagated by estimating the motion between adjacent cardiac phases using optical flow. In order to reduce the computational burden, the motion is only estimated in an anatomical region of interest around the tracked boundaries and subsequently integrated into a local affine motion model. Such localized estimation enables to capture complex motion patterns, while still being spatially consistent. The method was validated on 45 CMR datasets taken from the 2009 MICCAI LV segmentation challenge. The proposed approach proved to be robust and efficient, with an average distance error of 2.1 mm and a correlation with reference ejection fraction of 0.98 (1.9 +/- 4.5%). Moreover, it showed to be fast, taking 5 seconds for the tracking of a full 4D dataset (30 ms per image). Overall, a novel fast, robust and accurate LV tracking methodology was proposed, enabling accurate assessment of relevant global function cardiac indices, such as volumes and ejection fraction

VLA Measurements of Faraday Rotation through Coronal Mass Ejections

NASA Astrophysics Data System (ADS)

Kooi, Jason E.; Fischer, Patrick D.; Buffo, Jacob J.; Spangler, Steven R.

2017-04-01

Coronal mass ejections (CMEs) are large-scale eruptions of plasma from the Sun, which play an important role in space weather. Faraday rotation is the rotation of the plane of polarization that results when a linearly polarized signal passes through a magnetized plasma such as a CME. Faraday rotation is proportional to the path integral through the plasma of the electron density and the line-of-sight component of the magnetic field. Faraday-rotation observations of a source near the Sun can provide information on the plasma structure of a CME shortly after launch. We report on simultaneous white-light and radio observations made of three CMEs in August 2012. We made sensitive Very Large Array (VLA) full-polarization observations using 1 - 2 GHz frequencies of a constellation of radio sources through the solar corona at heliocentric distances that ranged from 6 - 15 R_{⊙}. Two sources (0842+1835 and 0900+1832) were occulted by a single CME, and one source (0843+1547) was occulted by two CMEs. In addition to our radioastronomical observations, which represent one of the first active hunts for CME Faraday rotation since Bird et al. ( Solar Phys., 98, 341, 1985) and the first active hunt using the VLA, we obtained white-light coronagraph images from the Large Angle and Spectrometric Coronagraph (LASCO) C3 instrument to determine the Thomson-scattering brightness [BT], providing a means to independently estimate the plasma density and determine its contribution to the observed Faraday rotation. A constant-density force-free flux rope embedded in the background corona was used to model the effects of the CMEs on BT and Faraday rotation. The plasma densities (6 - 22×103 cm^{-3}) and axial magnetic-field strengths (2 - 12 mG) inferred from our models are consistent with the modeling work of Liu et al. ( Astrophys. J., 665, 1439, 2007) and Jensen and Russell ( Geophys. Res. Lett., 35, L02103, 2008), as well as previous CME Faraday-rotation observations by Bird et al. (1985).

Electromagnetic Induction Rediscovered Using Original Texts

NASA Astrophysics Data System (ADS)

Barth Tu, Michael

Some of Faraday's diary-entries from 1831 have been used frequently as starting point to introduce the phenomenon of electromagnetic induction. This has been done on various levels of knowledge and to pupils of different ages during the last 5 years. I try to let my pupils witness, how Faraday made his discovery, but to show as well, that we cannot infer from his notes, how he arrived at his ideas proper. Reading the original notes (in English), my pupils were expected to take out of it, what Faraday did at his lab, what apparatus he used and what his observations were. Why he did what he did was point of discussion later on. Just here, I expected, that my pupils learn a lot about the properties of electricity, of taking conclusions from experiment, of scientific methodology etc. In addition, we repeated some of Faradays experiments with modern quipment, realizing always to common surprise that the effects observed are extremely faint ones. Depending on knowledge, age and motivation of the group, Lenz's Law was rediscovered in succession. Here I myself try to find out, why Faradays initial mistake as for the direction of the induced current is likely to be overlooked even by the informed modern reader (myself included!). This may become part of a story, why this mistake of Faraday has found serious attention by historians of science only very recently. My approach was connected with group work with English courses, with the reading of more papers by Faraday and two times even with a visit of the Royal Institution at London. In any case, I always tried to put my pupils into the state of knowledge Faraday had at the time of his discovery before this unit, to make the process of discovery as correct as possible. For this claim is somewhat artificial at first glance, it may be an interesting point of discussion.

Commercial associative memory performance for applications in track-based triggers at the Large Hadron Collider

NASA Astrophysics Data System (ADS)

Webster, Jordan

2017-01-01

Dense track environments in pp collisions at the Large Hadron Collider (LHC) motivate the use of triggers with dedicated hardware for fast track reconstruction. The ATLAS Collaboration is in the process of implementing a Fast Tracker (FTK) trigger upgrade, in which Content Addressable Memories (CAMs) will be used to rapidly match hit patterns with large banks of simulated tracks. The FTK CAMs are produced primarily at the University of Pisa. However, commercial CAM technology is rapidly developing due to applications in computer networking devices. This poster presents new studies comparing FTK CAMs to cutting-edge ternary CAMs developed by Cavium. The comparison is intended to guide the design of future track-based trigger systems for the next Phase at the LHC.

Fast Track Study

NASA Technical Reports Server (NTRS)

1996-01-01

The NASA Fast Track Study supports the efforts of a Special Study Group (SSG) made up of members of the Advanced Project Management Class number 23 (APM-23) that met at the Wallops Island Management Education Center from April 28 - May 8, 1996. Members of the Class expressed interest to Mr. Vem Weyers in having an input to the NASA Policy Document (NPD) 7120.4, that will replace NASA Management Institute (NMI) 7120.4, and the NASA Program/Project Management Guide. The APM-23 SSG was tasked with assisting in development of NASA policy on managing Fast Track Projects, defined as small projects under $150 million and completed within three years. 'Me approach of the APM-23 SSG was to gather data on successful projects working in a 'Better, Faster, Cheaper' environment, within and outside of NASA and develop the Fast Track Project section of the NASA Program/Project Management Guide. Fourteen interviews and four other data gathering efforts were conducted by the SSG, and 16 were conducted by Strategic Resources, Inc. (SRI), including five interviews at the Jet Propulsion Laboratory (JPL) and one at the Applied Physics Laboratory (APL). The interviews were compiled and analyzed for techniques and approaches commonly used to meet severe cost and schedule constraints.

Fast-track cardiac care for adult cardiac surgical patients.

PubMed

Zhu, Fang; Lee, Anna; Chee, Yee Eot

2012-10-17

Fast-track cardiac care is a complex intervention involving several components of care during cardiac anaesthesia and in the postoperative period, all with the ultimate aim of early extubation after surgery, to reduce the length of stay in the intensive care unit and in the hospital. Safe and effective fast-track cardiac care may reduce hospital costs. This is an update of a Cochrane review published in 2003. To update the evidence on the safety and effectiveness of fast-track cardiac care compared to conventional (not fast-track) care in adult patients undergoing cardiac surgery. We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (2012, Issue 3), MEDLINE (January 1966 to April 2012), EMBASE (January 1980 to April 2012), CINAHL (January 1982 to April 2012), and ISI Web of Science (January 2003 to April 2012). We searched reference lists of articles and contacted experts in the field. All randomized controlled trials of adult cardiac surgical patients (coronary artery bypass grafts, aortic valve replacement, mitral valve replacement) that compared fast-track cardiac care and conventional (not fast-track) care groups were included. We focused on the following fast-track interventions that were designed for early extubation after surgery, administration of low-dose opioid based general anaesthesia during cardiac surgery and the use of a time-directed extubation protocol after surgery. The primary outcome was the risk of mortality. Secondary outcomes included postoperative complications, reintubation within 24 hours of surgery, time to extubation, length of stay in the intensive care unit and in the hospital, quality of life after surgery and hospital costs. Two review authors independently assessed trial quality and extracted the data. Study authors were contacted for additional information. We used a random-effects model and reported relative risk (RR), mean difference (MD) and 95% confidence intervals (95% CI). Twenty-five trials involving 4118 patients were included in the review. There were two studies with a low risk of bias and nine studies with a high risk of bias. There were no differences in the risk of mortality within the first year after surgery between low-dose versus high-dose opioid based general anaesthesia groups (RR 0.58, 95% CI 0.28 to 1.18) and between early extubation protocol versus usual care groups (RR 0.84, 95% CI 0.40 to 1.75).There were no significant differences between low-dose versus high-dose opioid based anaesthesia groups for postoperative complications: myocardial infarction (RR 0.98, 95% CI 0.48 to 1.99), reintubation (RR 1.77, 95% CI 0.38 to 8.27), acute renal failure (RR 1.19, 95% CI 0.33 to 4.33), major bleeding (RR 0.48, 95% CI 0.16 to 1.44), and stroke (RR 1.17, 95% CI 0.36 to 3.78). Compared to the usual care, there were no significant differences in the risk of postoperative complications associated with early extubation: myocardial infarction (RR 0.94, 95% CI 0.55 to 1.60), reintubation (RR 1.91, 95% CI 0.90 to 4.07), acute renal failure (RR 0.77, 95% CI 0.19 to 3.10), major bleeding (RR 0.80, 95% CI 0.45 to 1.44), stroke (RR 0.87, 95% CI 0.31 to 2.46), major sepsis (RR 1.25, 95% CI 0.08 to 19.75) and wound infection (RR 0.67, 95% CI 0.25 to 1.83).Although there were high levels of heterogeneity, both low-dose opioid anaesthesia and the use of time-directed extubation protocols were associated with reductions in the time to extubation (3.0 to 10.5 hours) and in the length of stay in the intensive care unit (0.4 to 8.7 hours). However, these fast-track care interventions were not associated with reductions in the total length of stay in hospital. One high quality cost-effectiveness analysis included in a randomized controlled trial showed that early extubation was likely to be cost-effective. The use of low-dose opioid based general anaesthesia and time-directed protocols for fast-track interventions have similar risks of mortality and major postoperative complications to conventional (not fast-track) care, and therefore appear to be safe in patients considered to be at low to moderate risk. These fast-track interventions reduced the time to extubation and shortened the length of stay in the intensive care unit, but did not reduce the length of stay in the hospital.

Fast Markerless Tracking for Augmented Reality in Planar Environment

NASA Astrophysics Data System (ADS)

Basori, Ahmad Hoirul; Afif, Fadhil Noer; Almazyad, Abdulaziz S.; AbuJabal, Hamza Ali S.; Rehman, Amjad; Alkawaz, Mohammed Hazim

2015-12-01

Markerless tracking for augmented reality should not only be accurate but also fast enough to provide a seamless synchronization between real and virtual beings. Current reported methods showed that a vision-based tracking is accurate but requires high computational power. This paper proposes a real-time hybrid-based method for tracking unknown environments in markerless augmented reality. The proposed method provides collaboration of vision-based approach with accelerometers and gyroscopes sensors as camera pose predictor. To align the augmentation relative to camera motion, the tracking method is done by substituting feature-based camera estimation with combination of inertial sensors with complementary filter to provide more dynamic response. The proposed method managed to track unknown environment with faster processing time compared to available feature-based approaches. Moreover, the proposed method can sustain its estimation in a situation where feature-based tracking loses its track. The collaboration of sensor tracking managed to perform the task for about 22.97 FPS, up to five times faster than feature-based tracking method used as comparison. Therefore, the proposed method can be used to track unknown environments without depending on amount of features on scene, while requiring lower computational cost.

Far-Field Plume Measurements of a Nested-Channel Hall-Effect Thruster (PREPRINT)

DTIC Science & Technology

2010-12-13

nude Faraday probe, retarding potential analyzer, and ExB probe. Data from these probes were used to calculate utilization efficiencies from existing...USA Far-field plume measurements were performed on the X2 nested-channel Hall-effect thruster using an ar- ray of diagnostics, including a nude Faraday...mode to nested-channel mode by utilizing a traditional array of far-field diagnostics, which include a nude Faraday probe, retarding potential analyzer

Dilution Refrigerator Technology for Scalable Quantum Computing

DTIC Science & Technology

2014-05-22

Faraday cage but we did not do this for vibration concerns. 3. 90 degree Aeroquip fitting This elbow can be used (or not) depending upon where you...place. 4. Gas ballast tanks We have them mounted inside of the Faraday cage 5. Gas handling system Everything in this picture is...lines will work for your installation. 11. Cryostat test stand and faraday cage We were not planning on sending the test stand because it is

Effects of Faraday Rotation on Microwave Remote Sensing From Space at L-Band

NASA Technical Reports Server (NTRS)

LeVine, D. M.; Kao, M.

1997-01-01

The effect of Faraday rotation on the remote sensing of soil moisture from space is investigated using the International Reference Ionosphere (IRI) to obtain electron density profiles and the International Geomagnetic Reference Field (IGRF) to model the magnetic field. With a judicious choice of satellite orbit (6 am, sunsynchronous) the errors caused by ignoring Faraday rotation are less than 1 K at incidence angles less than 40 degrees.

Irregularities and Forecast Studies of Equatorial Spread

DTIC Science & Technology

2016-07-13

less certain and requires investigation. It should be possible to observe the Faraday rotation of the signals received at Jicamarca. This is another...indication of the line-integrated electron number 9 DISTRIBUTION A: Distribution approved for public release. density. Like the phase delay, the Faraday ...angle is a modulo-two-pi quantity that is best used to constrain the time evolution of the ionosphere. Both the Faraday angle and the phase delay are

Diode-laser frequency stabilization based on the resonant Faraday effect

NASA Technical Reports Server (NTRS)

Wanninger, P.; Valdez, E. C.; Shay, T. M.

1992-01-01

The authors present the results of a method for frequency stabilizing laser diodes based on the resonant Faraday effects. A Faraday cell in conjunction with a polarizer crossed with respect to the polarization of the laser diode comprises the intracavity frequency selective element. In this arrangement, a laser pull-in range of 9 A was measured, and the laser operated at a single frequency with a linewidth less than 6 MHz.

Ultrafast Imaging of Electronic Motion in Atoms and Molecules

DTIC Science & Technology

2016-01-12

pulses were measured with a home-made faraday cup and laser-triggered streak camera, respectively. Both are retractable and can measure the beam in...100 fs. The charge and duration of the electron pulses were measured with a home-made faraday cup and laser-triggered streak camera, respectively... faraday cup and laser-triggered streak camera, respectively. Both are retractable and can measure the beam in-situ. The gun was shown to generate pulses

Aquarius: The Instrument and Initial Results

NASA Technical Reports Server (NTRS)

Vine, David M Le; Lagerloef, G.S.E.; Ruf, C.; Wentz, F.; Yueh, S.; Piepmeier, J.; Lindstrom, E.; Dinnat, E.

2012-01-01

Aquarius was launched on June 10, 2011 aboard the Aquarius/SAC-D observatory and the instrument has been operating continuously since the initial turned-on was completed on August 25. The initial observed antenna temperatures were close to predicted and the first salinity map was released in September. In order to map the ocean salinity field, Aquarius includes several special features such as the inclusion of a scatterometer to provide a roughness correction, measurement of the third Stokes parameter to correct for Faraday rotation, and fast sampling to mitigate the effects of RFI. This paper provides an overview of the instrument and an example of initial results. Details are covered in subsequent papers in the session on Aquarius

An Optimal Control Modification to Model-Reference Adaptive Control for Fast Adaptation

NASA Technical Reports Server (NTRS)

Nguyen, Nhan T.; Krishnakumar, Kalmanje; Boskovic, Jovan

2008-01-01

This paper presents a method that can achieve fast adaptation for a class of model-reference adaptive control. It is well-known that standard model-reference adaptive control exhibits high-gain control behaviors when a large adaptive gain is used to achieve fast adaptation in order to reduce tracking error rapidly. High gain control creates high-frequency oscillations that can excite unmodeled dynamics and can lead to instability. The fast adaptation approach is based on the minimization of the squares of the tracking error, which is formulated as an optimal control problem. The necessary condition of optimality is used to derive an adaptive law using the gradient method. This adaptive law is shown to result in uniform boundedness of the tracking error by means of the Lyapunov s direct method. Furthermore, this adaptive law allows a large adaptive gain to be used without causing undesired high-gain control effects. The method is shown to be more robust than standard model-reference adaptive control. Simulations demonstrate the effectiveness of the proposed method.

Issues in NASA Program and Project Management. Special Report: 1997 Conference. Project Management Now and in the New Millennium

NASA Technical Reports Server (NTRS)

Hoffman, Edward J. (Editor); Lawbaugh, William M. (Editor)

1997-01-01

Topics Considered Include: NASA's Shared Experiences Program; Core Issues for the Future of the Agency; National Space Policy Strategic Management; ISO 9000 and NASA; New Acquisition Initiatives; Full Cost Initiative; PM Career Development; PM Project Database; NASA Fast Track Studies; Fast Track Projects; Earned Value Concept; Value-Added Metrics; Saturn Corporation Lessons Learned; Project Manager Credibility.

The Faraday rotation experiment. [solar corona

NASA Technical Reports Server (NTRS)

Volland, H.; Levy, G. S.; Bird, M. K.; Stelzried, C. T.; Seidel, B. L.

1984-01-01

The magnetized plasma of the solar corona was remotely sounded using the Faraday rotation effect. The solar magnetic field together with the electrons of the coronal plasma cause a measurable Faraday rotation effect, since the radio waves of Helios are linearly polarized. The measurement is performed at the ground stations. Alfven waves traveling from the Sun's surface through the corona into interplanetary space are observed. Helios 2 signals penetrating through a region where coronal mass is ejected show wavelike structures.

Optical Properties of Lithium Terbium Fluoride and Implications for Performance in High Power Lasers (Postprint)

DTIC Science & Technology

2016-02-01

Maximum 200 words) LiTbF4 has the potential to replace traditional magneto-optic (MO) garnet materials as a Faraday rotator in high power laser systems...TERMS LiTbF4; magneto-optic (MO) garnet materials; Faraday rotator; high power laser; Verdet constant; Sellmeier; optical isolator 16. SECURITY... Faraday rotator in high power laser systems due to its high Verdet constant. New measurements are reported of the ordinary and extraor- dinary

Dust Observations by Faraday Cups Onboard Spektr-R

NASA Astrophysics Data System (ADS)

Pavlu, J.; Kociscak, S.; Safrankova, J.; Nemecek, Z.; Prech, L.

2017-12-01

Dust of both interstellar and interplanetary origins was reported in many in-situ experiments devoted to dust detection during past tens of years. Recently, a number of reports employed unintended devices to observe dust (Voyager, Cassini, STEREO …). Most of such observations is based on impact ionization occurring when hypervelocity grains hit a surface being vaporized together with a portion of the surface material. The thermal ionization generates a plasma plume and the dust detection is based on collection of plasma particles by, e.g., antennas. In this contribution, we apply a similar approach to dust impact detection using the multi Faraday cup instrument (BMSW) onboard the Spektr-R spacecraft. It is orbiting the Earth along the highly elliptical trajectory with perigee of 2 and apogee of 50 Re. The BMSW instrument consists of 6 Faraday cups measuring local environmental properties with a rate as high as 30 Hz, i.e., high enough to detect aforementioned plasma plumes. The advantages of the multiple Faraday cup instrument include an easy recognition of dust impacts among plasma disturbances/solitons — dust grain impact can be detected only by one Faraday cup at a given time. We analyze Faraday cup waveforms applying simple criteria on impact spike shape and find a number of dust impact candidates. Based on this experience, we suggest a modification of future devices with a similar detection system.

A Faraday laser lasing on Rb 1529 nm transition.

PubMed

Chang, Pengyuan; Peng, Huanfa; Zhang, Shengnan; Chen, Zhangyuan; Luo, Bin; Chen, Jingbiao; Guo, Hong

2017-08-21

We present the design and performance characterization of a Faraday laser directly lasing on the Rb 1529 nm transition (Rb, 5P 3/2  - 4D 5/2 ) with high stability, narrow spectral linewidth and low cost. This system does not need an additional frequency-stabilized pump laser as a prerequisite to preparing Rb atom from 5S to 5P excited state. Just by using a performance-improved electrodeless discharge lamp-based excited-state Faraday anomalous dispersion optical filter (LESFADOF), we realized a heterogeneously Faraday laser with the frequency corresponding to atomic transition, working stably over a range of laser diode (LD) current from 85 mA to 171 mA and the LD temperature from 11 °C to 32 °C, as well as the 24-hour long-term frequency fluctuation range of no more than 600 MHz. Both the laser linewidth and relative intensity noisy (RIN) are measured. The Faraday laser lasing on Rb 1529 nm transition (telecom C-band) can be applied to further research on metrology, microwave photonics and optical communication systems. Besides, since the transitions correspongding to the populated excited-states of alkali atoms within lamp are extraordinarily rich, this scheme can increase the flexibility for choosing proper wavelengths for Faraday laser and greatly expand the coverage of wavelength corresponding to atomic transmission for laser frequency stabilization.

Shot-noise-limited optical Faraday polarimetry with enhanced laser noise cancelling

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

Li, Jiaming; Department of Physics, Indiana University Purdue University Indianapolis, Indianapolis, Indiana 46202; Luo, Le, E-mail: leluo@iupui.edu

2014-03-14

We present a shot-noise-limited measurement of optical Faraday rotations with sub-ten-nanoradian angular sensitivity. This extremely high sensitivity is achieved by using electronic laser noise cancelling and phase sensitive detection. Specially, an electronic laser noise canceller with a common mode rejection ratio of over 100 dB was designed and built for enhanced laser noise cancelling. By measuring the Faraday rotation of ambient air, we demonstrate an angular sensitivity of up to 9.0×10{sup −9} rad/√(Hz), which is limited only by the shot-noise of the photocurrent of the detector. To date, this is the highest angular sensitivity ever reported for Faraday polarimeters in the absencemore » of cavity enhancement. The measured Verdet constant of ambient air, 1.93(3)×10{sup −9}rad/(G cm) at 633 nm wavelength, agrees extremely well with the earlier experiments using high finesse optical cavities. Further, we demonstrate the applications of this sensitive technique in materials science by measuring the Faraday effect of an ultrathin iron film.« less

Thermooptics of magnetoactive media: Faraday isolators for high average power lasers

NASA Astrophysics Data System (ADS)

Khazanov, E. A.

2016-09-01

The Faraday isolator, one of the key high-power laser elements, provides optical isolation between a master oscillator and a power amplifier or between a laser and its target, for example, a gravitational wave detector interferometer. However, the absorbed radiation inevitably heats the magnetoactive medium and leads to thermally induced polarization and phase distortions in the laser beam. This self-action process limits the use of Faraday isolators in high average power lasers. A unique property of magnetoactive medium thermooptics is that parasitic thermal effects arise on the background of circular birefringence rather than in an isotropic medium. Also, even insignificant polarization distortions of the radiation result in a worse isolation ratio, which is the key characteristic of the Faraday isolator. All possible laser beam distortions are analyzed for their deteriorating effect on the Faraday isolator parameters. The mechanisms responsible for and key physical parameters associated with different kinds of distortions are identified and discussed. Methods for compensating and suppressing parasitic thermal effects are described in detail, the published experimental data are systematized, and avenues for further research are discussed based on the results achieved.

In-vacuum optical isolation changes by heating in a Faraday isolator.

PubMed

Acernese, Fausto; Alshourbagy, Mohamed; Amico, Paolo; Antonucci, Federica; Aoudia, S; Astone, P; Avino, Saverio; Ballardin, G; Baggio, L; Barone, Fabrizio; Barsotti, Lisa; Barsuglia, Matteo; Bauer, Th S; Bigotta, Stefano; Birindelli, Simona; Bizouard, Marie-Anne; Boccara, Albert-Claude; Bondu, François; Bosi, Leone; Braccini, Stefano; Bradaschia, Carlo; Brillet, Alain; Brisson, Violette; Buskulic, Damir; Cagnoli, G; Calloni, Enrico; Campagna, Enrico; Carbognani, Franco; Carbone, L; Cavalier, Fabien; Cavalieri, R; Cella, G; Cesarini, E; Chassande-Mottin, E; Chatterji, S; Cleva, F; Coccia, E; Corda, C; Corsi, A; Cottone, F; Coulon, J-P; Cuoco, E; D'Antonio, S; Dari, A; Dattilo, V; Davier, M; De Rosa, R; Del Prete, M; Di Fiore, L; Di Lieto, A; Di Paolo Emilio, M; Di Virgilio, A; Evans, M; Fafone, V; Ferrante, I; Fidecaro, F; Fiori, I; Flaminio, R; Fournier, J-D; Frasca, S; Frasconi, F; Gammaitoni, L; Garufi, F; Genin, E; Gennai, A; Giazotto, A; Giordano, L; Granata, V; Greverie, C; Grosjean, D; Guidi, G; Hamdani, S; Hebri, S; Heitmann, H; Hello, P; Huet, D; La Penna, P; Laval, M; Leroy, N; Letendre, N; Lopez, B; Lorenzini, M; Loriette, V; Losurdo, G; Mackowski, J-M; Majorana, E; Man, N; Mantovani, M; Marchesoni, F; Marion, F; Marque, J; Martelli, F; Masserot, A; Menzinger, F; Milano, L; Minenkov, Y; Moins, C; Morgado, N; Mosca, S; Mours, B; Neri, I; Nocera, F; Pagliaroli, G; Palomba, C; Paoletti, F; Pardi, S; Pasqualetti, A; Passaquieti, R; Passuello, D; Persichetti, G; Piergiovanni, F; Pinard, L; Poggiani, R; Punturo, M; Puppo, P; Rabaste, O; Rapagnani, P; Regimbau, T; Remillieux, A; Ricci, F; Ricciardi, I; Rocchi, A; Rolland, L; Romano, R; Ruggi, P; Russo, G; Sentenac, D; Solimeno, S; Swinkels, B L; Tarallo, M; Terenzi, R; Toncelli, A; Tonelli, M; Tournefier, E; Travasso, F; Vajente, G; van den Brand, J F J; van der Putten, S; Verkindt, D; Vetrano, F; Viceré, A; Vinet, J-Y; Vocca, H; Yvert, M

2008-11-01

We describe a model evaluating changes in the optical isolation of a Faraday isolator when passing from air to vacuum in terms of different thermal effects in the crystal. The changes are particularly significant in the crystal thermal lensing (refraction index and thermal expansion) and in its Verdet constant and can be ascribed to the less efficient convection cooling of the magneto-optic crystal of the Faraday isolator. An isolation decrease by a factor of 10 is experimentally observed in a Faraday isolator that is used in a gravitational wave experiment (Virgo) with a 10 W input laser when going from air to vacuum. A finite element model simulation reproduces with a great accuracy the experimental data measured on Virgo and on a test bench. A first set of measurements of the thermal lensing has been used to characterize the losses of the crystal, which depend on the sample. The isolation factor measured on Virgo confirms the simulation model and the absorption losses of 0.0016 +/- 0.0002/cm for the TGG magneto-optic crystal used in the Faraday isolator.

Faraday cage-type electrochemiluminescence immunosensor for ultrasensitive detection of Vibrio vulnificus based on multi-functionalized graphene oxide.

PubMed

Guo, Zhiyong; Sha, Yuhong; Hu, Yufang; Yu, Zhongqing; Tao, Yingying; Wu, Yanjie; Zeng, Min; Wang, Sui; Li, Xing; Zhou, Jun; Su, Xiurong

2016-10-01

A novel Faraday cage-type electrochemiluminescence (ECL) immunosensor devoted to the detection of Vibrio vulnificus (VV) was fabricated. The sensing strategy was presented by a unique Faraday cage-type immunocomplex based on immunomagnetic beads (IMBs) and multi-functionalized graphene oxide (GO) labeled with (2,2'-bipyridine)(5-aminophenanthroline)ruthenium (Ru-NH2). The multi-functionalized GO could sit on the electrode surface directly due to the large surface area, abundant functional groups, and good electronic transport property. It ensures that more Ru-NH2 is entirely caged and become "effective," thus improving sensitivity significantly, which resembles extending the outer Helmholtz plane (OHP) of the electrode. Under optimal conditions, the developed immunosensor achieves a limit of detection as low as 1 CFU/mL. Additionally, the proposed immunosensor with high sensitivity and selectivity can be used for the detection of real samples. The novel Faraday cage-type method has shown potential application for the diagnosis of VV and opens up a new avenue in ECL immunoassay. Graphical abstract Faraday cage-type immunoassay mode for ultrasensitive detection by extending OHP.

Giant Faraday Rotation through Ultrasmall Fe0 n Clusters in Superparamagnetic FeO-SiO2 Vitreous Films.

PubMed

Nakatsuka, Yuko; Pollok, Kilian; Wieduwilt, Torsten; Langenhorst, Falko; Schmidt, Markus A; Fujita, Koji; Murai, Shunsuke; Tanaka, Katsuhisa; Wondraczek, Lothar

2017-04-01

Magnetooptical (MO) glasses and, in particular, Faraday rotators are becoming key components in lasers and optical information processing, light switching, coding, filtering, and sensing. The common design of such Faraday rotator materials follows a simple path: high Faraday rotation is achieved by maximizing the concentration of paramagnetic ion species in a given matrix material. However, this approach has reached its limits in terms of MO performance; hence, glass-based materials can presently not be used efficiently in thin film MO applications. Here, a novel strategy which overcomes this limitation is demonstrated. Using vitreous films of x FeO·(100 - x )SiO 2 , unusually large Faraday rotation has been obtained, beating the performance of any other glassy material by up to two orders of magnitude. It is shown that this is due to the incorporation of small, ferromagnetic clusters of atomic iron which are generated in line during laser deposition and rapid condensation of the thin film, generating superparamagnetism. The size of these clusters underbids the present record of metallic Fe incorporation and experimental verification in glass matrices.

Inductional Effects in a Halbach Magnet Motion Above Distributed Inductance

NASA Astrophysics Data System (ADS)

Tchatchoua, Yves; Conrow, Ary; Kim, Dong; Morgan, Daniel; Majewski, Walerian; Zafar, Zaeema

2013-03-01

We experimented with attempts to levitate a linear (bar) Halbach array of five 1'' Nd magnets above a linear inductive track. Next, in order to achieve a control over the relative velocity, we designed a different experiment. In it a large wheel with circumferentially positioned along its rim inducting coils rotates, while the magnet is suspended directly above the rim of the wheel on a force sensor. Faraday's Law with the Lenz's Rule is responsible for the lifting and drag forces on the magnet; the horizontal drag force is measured by another force sensor. Approximating the magnet's linear relative motion over inductors with a motion along a large circle, we may use formulas derived earlier in the literature for linear inductive levitation. We measured lift and drag forces as functions of relative velocity of the Halbach magnet and the inductive ``track,'' in an approximate agreement with the existing theory. We then vary the inductance and shape of the inductive elements to find the most beneficial choice for the lift/drag ratio at the lowest relative speed.

Multi-second magnetic coherence in a single domain spinor Bose–Einstein condensate

NASA Astrophysics Data System (ADS)

Palacios, Silvana; Coop, Simon; Gomez, Pau; Vanderbruggen, Thomas; Natali Martinez de Escobar, Y.; Jasperse, Martijn; Mitchell, Morgan W.

2018-05-01

We describe a compact, robust and versatile system for studying the macroscopic spin dynamics in a spinor Bose–Einstein condensate. Condensates of {}87{Rb} are produced by all-optical evaporation in a 1560 nm optical dipole trap, using a non-standard loading sequence that employs an ancillary 1529 nm beam for partial compensation of the strong differential light-shift induced by the dipole trap itself. We use near-resonant Faraday rotation probing to non-destructively track the condensate magnetization, and demonstrate few-Larmor-cycle tracking with no detectable degradation of the spin polarization. In the ferromagnetic F = 1 ground state, we observe the spin orientation between atoms in the condensate is preserved, such that they precess all together like one large spin in the presence of a magnetic field. We characterize this dynamics in terms of the single-shot magnetic coherence times {{ \\mathcal T }}1 and {{ \\mathcal T }}2* , and observe them to be of several seconds, limited only by the residence time of the atoms in the trap. At the densities used, this residence is restricted only by one-body losses set by the vacuum conditions.

Enhanced recovery after elective coronary revascularization surgery with minimal versus conventional extracorporeal circulation: a prospective randomized study.

PubMed

Anastasiadis, Kyriakos; Asteriou, Christos; Antonitsis, Polychronis; Argiriadou, Helena; Grosomanidis, Vassilios; Kyparissa, Magdalena; Deliopoulos, Apostolos; Konstantinou, Dimitrios; Tossios, Paschalis

2013-10-01

A minimal extracorporeal circulation (MECC) circuit integrates the advances in cardiopulmonary bypass (CPB) technology into a single circuit and is associated with improved short-term outcome. The aim of this study was to prospectively evaluate MECC compared with conventional CPB in facilitating fast-track recovery after elective coronary revascularization procedures. Prospective randomized study. All patients scheduled for elective coronary artery surgery were evaluated, excluding those considered particularly high risk for fast-track failure. The fast-track protocol included careful preoperative patient selection, a fast-track anesthetic technique based on minimal administration of fentanyl, surgery at normothermia, early postoperative extubation in the cardiac recovery unit, and admission to the cardiothoracic ward within the first 24 hours postoperatively. One hundred twenty patients were assigned randomly into 2 groups (60 in each group). Group A included patients who were operated on using the MECC circuit, whereas patients in Group B underwent surgery on conventional CPB. Incidence of fast-track recovery was significantly higher in patients undergoing MECC (25% v 6.7%, p = 0.006). MECC also was recognized as a strong independent predictor of early recovery, with an odds ratio of 3.8 (p = 0.011). Duration of mechanical ventilation and cardiac recovery unit stay were significantly lower in patients undergoing MECC together with the need for blood transfusion, duration of inotropic support, need for an intra-aortic balloon pump, and development of postoperative atrial fibrillation and renal failure. MECC promotes successful early recovery after elective coronary revascularization procedures, even in a nondedicated cardiac intensive care unit setting. Copyright © 2013 Elsevier Inc. All rights reserved.

The risk of manipulation under anesthesia due to unsatisfactory knee flexion after fast-track total knee arthroplasty.

PubMed

Wied, Christian; Thomsen, Morten G; Kallemose, Thomas; Myhrmann, Lis; Jensen, Lotte S; Husted, Henrik; Troelsen, Anders

2015-10-01

Fast-track TKA has significantly shortened the time available for physiotherapists to optimize knee ROM before discharge. Safety aspects concerning knee stiffness and the need for manipulation in a fast-track setting need to be illuminated. The study aims were to analyze if fast-track TKA can be considered safe considering rates of knee manipulation and if there is an association between knee ROM at time of discharge and the need for later manipulation. Primary TKAs operated in 2011 at our institution were eligible for inclusion. The study group consisted of 359 TKAs. Manipulation of the knee was performed in 21 of 359 TKAs (5.8%). Seventy-one percent were discharged with a flexion ≥70° combined with an extension deficit of ≤10°. The occurrence of MUA for these patients was 4.3%. The prevalence of knee manipulation showed a statistically significant association with the achieved knee flexion at discharge (p=0.02). Median length of stay was two days. Compared with literature findings fast-track TKA surgery may be considered safe based on the acceptable rate of knee manipulations after TKA (5.8%). We suggest ROM of ≥70° flexion combined with an extension deficit of ≤10° as an "optimal-zone" for ROM at discharge. The reason for this is the low occurrence of MUA (4.3%) in relation to the large amount of TKAs it represents (71%). The indication for MUA is multifactorial and ROM at discharge serves only as an indicator of later MUA risk. Copyright © 2015 Elsevier B.V. All rights reserved.

FAST: A fully asynchronous and status-tracking pattern for geoprocessing services orchestration

NASA Astrophysics Data System (ADS)

Wu, Huayi; You, Lan; Gui, Zhipeng; Gao, Shuang; Li, Zhenqiang; Yu, Jingmin

2014-09-01

Geoprocessing service orchestration (GSO) provides a unified and flexible way to implement cross-application, long-lived, and multi-step geoprocessing service workflows by coordinating geoprocessing services collaboratively. Usually, geoprocessing services and geoprocessing service workflows are data and/or computing intensive. The intensity feature may make the execution process of a workflow time-consuming. Since it initials an execution request without blocking other interactions on the client side, an asynchronous mechanism is especially appropriate for GSO workflows. Many critical problems remain to be solved in existing asynchronous patterns for GSO including difficulties in improving performance, status tracking, and clarifying the workflow structure. These problems are a challenge when orchestrating performance efficiency, making statuses instantly available, and constructing clearly structured GSO workflows. A Fully Asynchronous and Status-Tracking (FAST) pattern that adopts asynchronous interactions throughout the whole communication tier of a workflow is proposed for GSO. The proposed FAST pattern includes a mechanism that actively pushes the latest status to clients instantly and economically. An independent proxy was designed to isolate the status tracking logic from the geoprocessing business logic, which assists the formation of a clear GSO workflow structure. A workflow was implemented in the FAST pattern to simulate the flooding process in the Poyang Lake region. Experimental results show that the proposed FAST pattern can efficiently tackle data/computing intensive geoprocessing tasks. The performance of all collaborative partners was improved due to the asynchronous mechanism throughout communication tier. A status-tracking mechanism helps users retrieve the latest running status of a GSO workflow in an efficient and instant way. The clear structure of the GSO workflow lowers the barriers for geospatial domain experts and model designers to compose asynchronous GSO workflows. Most importantly, it provides better support for locating and diagnosing potential exceptions.

Telemedicine support shortens length of stay after fast-track hip replacement.

PubMed

Vesterby, Martin Svoldgaard; Pedersen, Preben Ulrich; Laursen, Malene; Mikkelsen, Søren; Larsen, Jens; Søballe, Kjeld; Jørgensen, Lene Bastrup

2017-02-01

Background and purpose - Telemedicine could allow patients to be discharged more quickly after surgery and contribute to improve fast-track procedures without compromising quality, patient safety, functionality, anxiety, or other patient-perceived parameters. We investigated whether using telemedicine support (TMS) would permit hospital discharge after 1 day without loss of self-assessed quality of life, loss of functionality, increased anxiety, increased rates of re-admission, or increased rates of complications after hip replacement. Patients and methods - We performed a randomized controlled trial involving 72 Danish patients in 1 region who were referred for elective fast-track total hip replacement between August 2009 and March 2011 (654 were screened for eligibility). Half of the patients received a telemedicine solution connected to their TV. The patients were followed until 1 year after surgery. Results - Length of stay was reduced from 2.1 days (95% CI: 2.0-2.3) to 1.1 day (CI: 0.9-1.4; p < 0.001) with the TMS intervention. Health-related quality of life increased in both groups, but there were no statistically significant differences between groups. There were also no statistically significant differences between groups regarding timed up-and-go test and Oxford hip score at 3-month follow-up. At 12-month follow-up, the rates of complications and re-admissions were similar between the groups, but the number of postoperative hospital contacts was lower in the TMS group. Interpretation - Length of postoperative stay was shortened in patients with the TMS solution, without compromising patient-perceived or clinical parameters in patients undergoing elective fast-track surgery. These results indicate that telemedicine can be of value in fast-track treatment of patients undergoing total hip replacement.

On Faraday's law in the presence of extended conductors

NASA Astrophysics Data System (ADS)

Bilbao, Luis

2018-06-01

The use of Faraday's Law of induction for calculating the induced currents in an extended conducting body is discussed. In a general case with arbitrary geometry, the solution to the problem of a moving metal object in the presence of a magnetic field is difficult and implies solving Maxwell's equations in a time-dependent situation. In many cases, including cases with good conductors (but not superconductors) Ampère's Law can be neglected and a simpler solution based solely in Faraday's law can be obtained. The integral form of Faraday's Law along any loop in the conducting body is equivalent to a Kirkhhoff's voltage law of a circuit. Therefore, a numerical solution can be obtained by solving a linear system of equations corresponding to a discrete number of loops in the body.

Helicons, magnetoplasma edge, and faraday rotation in solid state plasmas at microwave frequencies.

PubMed

Furdyna, J K

1967-04-01

The effect of magnetic field on propagation of electromagnetic waves through free carrier plasmas in semiconductors is discussed. The Faraday configuration and the parameter ranges omega(c),omega(p) > omega and omega(c) > tau(-1) are specifically considered. Dispersion of helicon waves, propagation near the magnetoplasma edge (omega(p)(2) = omegaomega(c)), and the Faraday rotation are developed in terms of the one-electron Drude theory. Microwave transmission measurements at 35 Gc/s on n-type InSb are presented. Experiments near the magnetoplasma edge yield the value of the static dielectric constant of the InSb lattice K(l) = 19.3 +/- 0.8. Faraday rotation, observed beyond the edge, is found to be extremely large. Some practical possibilities for this effect are considered.

Cavity-enhanced Faraday rotation measurement with auto-balanced photodetection.

PubMed

Chang, Chia-Yu; Shy, Jow-Tsong

2015-10-01

Optical cavity enhancement for a tiny Faraday rotation is demonstrated with auto-balanced photodetection. This configuration is analyzed using the Jones matrix formalism. The resonant rotation signal is amplified, and thus, the angular sensitivity is improved. In the experiment, the air Faraday rotation is measured with an auto-balanced photoreceiver in single-pass and cavity geometries. The result shows that the measured Faraday rotation in the single-pass geometry is enhanced by a factor of 85 in the cavity geometry, and the sensitivity is improved to 7.54×10(-10)  rad Hz(-1/2), which agrees well with the Jones matrix analysis. With this verification, we propose an AC magnetic sensor whose magnetic sensitivity is expected to achieve 10  pT Hz(-1/2).

Magneto-optical Faraday rotation of semiconductor nanoparticles embedded in dielectric matrices.

PubMed

Savchuk, Andriy I; Stolyarchuk, Ihor D; Makoviy, Vitaliy V; Savchuk, Oleksandr A

2014-04-01

Faraday rotation has been studied for CdS, CdTe, and CdS:Mn semiconductor nanoparticles synthesized by colloidal chemistry methods. Additionally these materials were prepared in a form of semiconductor nanoparticles embedded in polyvinyl alcohol films. Transmission electron microscopy and atomic force microscopy analyses served as confirmation of nanocrystallinity and estimation of the average size of the nanoparticles. Spectral dependence of the Faraday rotation for the studied nanocrystals and nanocomposites is correlated with a blueshift of the absorption edge due to the confinement effect in zero-dimensional structures. Faraday rotation spectra and their temperature behavior in Mn-doped nanocrystals demonstrates peculiarities, which are associated with s, p-d exchange interaction between Mn²⁺ ions and band carriers in diluted magnetic semiconductor nanostructures.

A single-mode external cavity diode laser using an intra-cavity atomic Faraday filter with short-term linewidth <400 kHz and long-term stability of <1 MHz.

PubMed

Keaveney, James; Hamlyn, William J; Adams, Charles S; Hughes, Ifan G

2016-09-01

We report on the development of a diode laser system - the "Faraday laser" - using an atomic Faraday filter as the frequency-selective element. In contrast to typical external-cavity diode laser systems which offer tunable output frequency but require additional control systems in order to achieve a stable output frequency, our system only lases at a single frequency, set by the peak transmission frequency of the internal atomic Faraday filter. Our system has both short-term and long-term stability of less than 1 MHz, which is less than the natural linewidth of alkali-atomic D-lines, making similar systems suitable for use as a "turn-key" solution for laser-cooling experiments.

Real-time tracking and fast retrieval of persons in multiple surveillance cameras of a shopping mall

NASA Astrophysics Data System (ADS)

Bouma, Henri; Baan, Jan; Landsmeer, Sander; Kruszynski, Chris; van Antwerpen, Gert; Dijk, Judith

2013-05-01

The capability to track individuals in CCTV cameras is important for e.g. surveillance applications at large areas such as train stations, airports and shopping centers. However, it is laborious to track and trace people over multiple cameras. In this paper, we present a system for real-time tracking and fast interactive retrieval of persons in video streams from multiple static surveillance cameras. This system is demonstrated in a shopping mall, where the cameras are positioned without overlapping fields-of-view and have different lighting conditions. The results show that the system allows an operator to find the origin or destination of a person more efficiently. The misses are reduced with 37%, which is a significant improvement.

Preventing Serious Conduct Problems in School-Age Youths: The Fast Track Program

PubMed Central

Slough, Nancy M.; McMahon, Robert J.; Bierman, Karen L.; Coie, John D.; Dodge, Kenneth A.; Foster, E. Michael; Greenberg, Mark T.; Lochman, John E.; McMahon, Robert J.; Pinderhughes, Ellen E.

2009-01-01

Children with early-starting conduct Problems have a very poor prognosis and exact a high cost to society. The Fast Track project is a multisite, collaborative research project investigating the efficacy of a comprehensive, long-term, multicomponent intervention designed to prevent the development of serious conduct problems in high-risk children. In this article, we (a) provide an overview of the development model that serves as the conceptual foundation for the Fast Track intervention and describe its integration into the intervention model; (b) outline the research design and intervention model, with an emphasis on the elementary school phase of the intervention; and (c) summarize findings to dale concerning intervention outcomes. We then provide a case illustration, and conclude with a discussion of guidelines for practitioners who work with children with conduct problems. PMID:19890487

Research on Precision Tracking on Fast Steering Mirror and Control Strategy

NASA Astrophysics Data System (ADS)

Di, Lin; Yi-ming, Wu; Fan, Zhu

2018-01-01

Fast steering mirror is a device used for controlling the beam direction precisely. Due to the short travel of the push-pull FSM, a compound fast steering mirror system driven by both limited-angle voice coil motor and push-pull FSM together is proposed. In the compound FSM system, limited-angle voice coil motor quickly swings at wide angle, while the push-pull FSM do high frequency movement in a small range, which provides the system with the high bandwidth and long travel. In the control strategy, the method of combining feed-forward control in Kalman filtering with auto-disturbance rejection control is used to improve trajectory tracking accuracy. The simulation result shows that tracking accuracy measured by the compound method can be improved by more than 5 times than that of the conventional PID.

The Flexible Faraday Cage

NASA Astrophysics Data System (ADS)

Gluck, Paul

2004-03-01

The Faraday ice-pail experiment is performed when studying the distribution of charges in conductors: Inside a hollow conductor the net charge is zero, and any excess charge resides on the outside surface.

Graphite-ceramic rf Faraday-thermal shield and plasma limiter

DOEpatents

Hwang, D.L.Q.; Hosea, J.C.

1983-05-05

The present invention is directed to a brazing procedure for joining a ceramic or glass material (e.g., Al/sub 2/O/sub 3/ or Macor) to graphite. In particular, the present invention is directed to a novel brazing procedure for the production of a brazed ceramic graphite product useful as a Faraday shield. The brazed ceramic graphite Faraday shield of the present invention may be used in Magnetic Fusion Devices (e.g., Princeton Large Torus Tokamak) or other high temperature resistant apparatus.

Micro And Nanostructured Materials For Fluid And Ion Transport For Miniaturized Applications

DTIC Science & Technology

2016-06-08

micromachined tip. The setup is shown in Figure 7(a). The RPA instrument consists of a Faraday cup collector and a set of grids placed in between the...collector. Therefore, by varying the retarding potential and measuring the current arriving to the Faraday cup, it is possible to obtain the beam energy...distribution. The instrument consists of seven grids followed by a Faraday cup. The first grid is a 90% transparent tungsten mesh, which is grounded

Why "The Best Way of Learning to Coach the Game Is Playing the Game": Conceptualising "Fast-Tracked" High-Performance Coaching Pathways

ERIC Educational Resources Information Center

Blackett, Alexander David; Evans, Adam; Piggott, David

2017-01-01

At the beginning of the 2013/2014 season in England and Wales, 90 head coaches of the 92 men's national professional football league clubs and 20 of the 22 men's professional rugby union clubs had tenure as a professional elite player in their respective sports. Moreover, Rynne [(2014). "'Fast track' and 'traditional path' coaches:…

Radiolysis of water at elevated temperatures—III. Simulation of radiolytic products at 25 and 250°C under the irradiation with γ-rays and fast neutrons

NASA Astrophysics Data System (ADS)

Sunaryo, Geni R.; Katsumura, Yosuke; Ishigure, Kenkichi

1995-05-01

The G-values of water decomposition products under the irradiations with γ-rays and fast neutrons up to 250°C have been determined in previous studies. In order to clarify the characteristics of the determined G-values, computer simulations under the simplified conditions in nuclear reactors have been carried out. The recent G-values for γ-radiolysis reported by Elliot, Chenier and Quellete [(1990) Can. J. Chem.68, 712; (1993) J. Chem. Soc. Faraday Trans.89, 1193], Kent and Sims [(1992) Water Chemistry of Nuclear Reactor Systems 6, p. 153. BNES, London], and Sunaryo, Katsumura, Shirai, Hiroishi and Ishigure [(1994) Radiat. Phys. Chem.44, 273] and Sunaryo, Katsumura, Hiroishi and Ishigure [(1995) Radiat. Phys. Chem.45, 131] are almost equivalent from the point of simulations. On the contrary, G-values for fast neutron radiolysis give a significant influence to the result, which arises from the higher molecular yields and smaller radical yields of water decomposition in fast neutron radiolysis, and it has been revealed that the dose evaluation in the reactor is inevitably important. In addition, it was pointed out by the simulations that reverse reactions for H 2+ .OH→ .H+H 2O and e aq-+H +→ .H, be neglected at room temperature, become important at higher temperatures.

NMT - A new individual ion counting method: Comparison to a Faraday cup

NASA Astrophysics Data System (ADS)

Burton, Michael; Gorbunov, Boris

2018-03-01

Two sample detectors used to analyze the emission from Gas Chromatography (GC) columns are the Flame Ionization Detector (FID) and the Electron Capture Detector (ECD). Both of these detectors involve ionization of the sample molecules and then measuring electric current in the gas using a Faraday cup. In this paper a newly discovered method of ion counting, Nanotechnology Molecular Tagging (NMT) is tested as a replacement to the Faraday cup in GCs. In this method the effective physical volume of individual molecules is enlarged up to 1 billion times enabling them to be detected by an optical particle counter. It was found that the sensitivity of NMT was considerably greater than the Faraday cup. The background in the NMT was circa 200 ions per cm3, corresponding to an extremely low electric current ∼10-17 A.

Giant Faraday Rotation of High-Order Plasmonic Modes in Graphene-Covered Nanowires.

PubMed

Kuzmin, Dmitry A; Bychkov, Igor V; Shavrov, Vladimir G; Temnov, Vasily V

2016-07-13

Plasmonic Faraday rotation in nanowires manifests itself in the rotation of the spatial intensity distribution of high-order surface plasmon polariton (SPP) modes around the nanowire axis. Here we predict theoretically the giant Faraday rotation for SPPs propagating on graphene-coated magneto-optically active nanowires. Upon the reversal of the external magnetic field pointing along the nanowire axis some high-order plasmonic modes may be rotated by up to ∼100° on the length scale of about 500 nm at mid-infrared frequencies. Tuning the carrier concentration in graphene by chemical doping or gate voltage allows for controlling SPP-properties and notably the rotation angle of high-order azimuthal modes. Our results open the door to novel plasmonic applications ranging from nanowire-based Faraday isolators to the magnetic control in quantum-optical applications.

Observation of two coupled Faraday waves in a vertically vibrating Hele-Shaw cell with one of them oscillating horizontally

NASA Astrophysics Data System (ADS)

Li, Xiaochen; Li, Xiaoming; Liao, Shijun

2018-01-01

A system of two coupled Faraday waves is experimentally observed at the two interfaces of the three layers of fluids (air, pure ethanol, and silicon oil) in a covered Hele-Shaw cell with periodic vertical vibration. Both the upper and lower Faraday waves are subharmonic, but they coexist in different forms: the upper one vibrates vertically, while the crests of the lower one oscillate horizontally with unchanged wave height, and the troughs of the lower one usually remain in the same place (relative to the basin). Besides, they are strongly coupled: the wave height of the lower Faraday waves is either a linear function (when forcing frequency is fixed) or a parabolic function (when acceleration amplitude is fixed) of that of the upper one with a same wavelength.

Basic research for development of the beam profile monitor based on a Faraday cup array system

NASA Astrophysics Data System (ADS)

Park, Mook-Kwang

2015-10-01

The basic design used to develop a beam profile monitor based on a Faraday cup array (FCA), which has the advantages of high robustness, reliability, and long-term stability, along with the ability to measure the ion current over a wide dynamic range, was developed. The total system is divided into three parts: i.e., a faraday cup, measuring electronics, and a display program part. The FCA was considered to consist of a collimator, suppressor, insulator frame, and 64 (8 × 8 array) tiny Faraday cups (FC). An electronic circuit using a multiplexer was applied to effectively address many signal lines and the printed circuit board (PCB) was designed to be divided into three parts, i.e., an electrode PCB (ELEC PCB), capacitance PCB (CAP PCB), and control PCB (CON PCB).

Versatile, high-sensitivity faraday cup array for ion implanters

DOEpatents

Musket, Ronald G.; Patterson, Robert G.

2003-01-01

An improved Faraday cup array for determining the dose of ions delivered to a substrate during ion implantation and for monitoring the uniformity of the dose delivered to the substrate. The improved Faraday cup array incorporates a variable size ion beam aperture by changing only an insertable plate that defines the aperture without changing the position of the Faraday cups which are positioned for the operation of the largest ion beam aperture. The design enables the dose sensitivity range, typically 10.sup.11 -10.sup.18 ions/cm.sup.2 to be extended to below 10.sup.6 ions/cm.sup.2. The insertable plate/aperture arrangement is structurally simple and enables scaling to aperture areas between <1 cm.sup.2 and >750 cm.sup.2, and enables ultra-high vacuum (UHV) applications by incorporation of UHV-compatible materials.

Polycrystalline (TbXY1-X)2O3 Faraday rotator.

PubMed

Ikesue, Akio; Aung, Yan Lin; Makikawa, Shinji; Yahagi, Akira

2017-11-01

We have succeeded for the first time in synthesizing an optical grade (Tb X Y 1-X ) 2 O 3 (X=0.5-1.0) ceramic Faraday rotator, which greatly exceeds the basic characteristics of the commercial terbium gallium garnet (TGG) (Tb 3 Ga 5 O 12 ) crystal. The Faraday rotation angle increased as the Tb concentration increased, and the Verdet constant increased from 2.1 (82  rad T -1  m -1 at X=0.5) to 3.8 times (154  rad T -1  m -1 at X=1.0) than the TGG single crystal, which is regarded as highest class. Therefore, it is possible to minimize the Faraday rotator length and the magnet in building an optical isolator. It was also confirmed that its optical quality was very comparable to the commercial TGG crystal.

Parsec-scale Faraday rotation and polarization of 20 active galactic nuclei jets

NASA Astrophysics Data System (ADS)

Kravchenko, E. V.; Kovalev, Y. Y.; Sokolovsky, K. V.

2017-05-01

We perform polarimetry analysis of 20 active galactic nuclei jets using the very long baseline array at 1.4, 1.6, 2.2, 2.4, 4.6, 5.0, 8.1, 8.4 and 15.4 GHz. The study allowed us to investigate linearly polarized properties of the jets at parsec scales: distribution of the Faraday rotation measure (RM) and fractional polarization along the jets, Faraday effects and structure of Faraday-corrected polarization images. Wavelength dependence of the fractional polarization and polarization angle is consistent with external Faraday rotation, while some sources show internal rotation. The RM changes along the jets, systematically increasing its value towards synchrotron self-absorbed cores at shorter wavelengths. The highest core RM reaches 16 900 rad m-2 in the source rest frame for the quasar 0952+179, suggesting the presence of highly magnetized, dense media in these regions. The typical RM of transparent jet regions has values of an order of a hundred rad m-2. Significant transverse RM gradients are observed in seven sources. The magnetic field in the Faraday screen has no preferred orientation, and is observed to be random or regular from source to source. Half of the sources show evidence for the helical magnetic fields in their rotating magneto-ionic media. At the same time jets themselves contain large-scale, ordered magnetic fields and tend to align its direction with the jet flow. The observed variety of polarized signatures can be explained by a model of spine-sheath jet structure.

Rotation measure synthesis at the 2 m wavelength of the FAN region: unveiling screens and bubbles

NASA Astrophysics Data System (ADS)

Iacobelli, M.; Haverkorn, M.; Katgert, P.

2013-01-01

Context. Rotation measure synthesis of the Westerbork Synthesis Radio Telescope (WSRT) observations at λ ~ 2 m of the FAN region at l = 137°, b = +7° shows the morphology of structures in the ionized interstellar medium. Aims: We interpret the diffuse polarized synchrotron emission in terms of coherent structures in the interstellar medium and the properties of the interstellar magnetic field. Methods: We performed statistical analysis of the polarization data cube obtained through rotation measure synthesis. For the first time, cross-correlation is applied to identify and characterize polarized structures in Faraday depth space. Complementary information about the medium are derived from Hα emission, properties of nearby pulsars, and optical polarized starlight measurements. Results: We find an overall asymmetric Faraday dispersion function in a Faraday depth range of [-13, +5] rad m-2, which is peaked around -1 rad m-2. Three morphological patterns are recognized, showing structures on scales from degrees down to the beam size. The first structure is a nearby synchrotron emission component with low Faraday depth, filling the entire field of view. The second pattern is a circular polarization structure with enhanced (negative) Faraday depth, which has the same morphology as a low-emission region within the third component. This third component is interpreted as the background in which the circular structure is embedded. At low Faraday depth values, a low gradient across the imaged field is detected, almost aligned with the Galactic plane. Power spectra of polarized structures in Faraday depth space provide evidence of turbulence. Conclusions: A sign reversal in Faraday depth from the nearby component to the circular component indicates a reversal of the magnetic field component along the line of sight, from towards the observer and nearby to away from the observer at large distances. The distance to the nearby, extended component is estimated as ≲100 pc, which suggests that this structure corresponds to the Local Bubble wall. For the circular component, various physical interpretations are discussed. The most likely explanation is that the circular component seems to be the presence of a nearby (~200 pc away) relic Strömgren sphere, associated with an old unidentified white dwarf star and expanding in a low-density environment. Faraday rotation datacubes are only available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/549/A56

Object tracking on mobile devices using binary descriptors

NASA Astrophysics Data System (ADS)

Savakis, Andreas; Quraishi, Mohammad Faiz; Minnehan, Breton

2015-03-01

With the growing ubiquity of mobile devices, advanced applications are relying on computer vision techniques to provide novel experiences for users. Currently, few tracking approaches take into consideration the resource constraints on mobile devices. Designing efficient tracking algorithms and optimizing performance for mobile devices can result in better and more efficient tracking for applications, such as augmented reality. In this paper, we use binary descriptors, including Fast Retina Keypoint (FREAK), Oriented FAST and Rotated BRIEF (ORB), Binary Robust Independent Features (BRIEF), and Binary Robust Invariant Scalable Keypoints (BRISK) to obtain real time tracking performance on mobile devices. We consider both Google's Android and Apple's iOS operating systems to implement our tracking approach. The Android implementation is done using Android's Native Development Kit (NDK), which gives the performance benefits of using native code as well as access to legacy libraries. The iOS implementation was created using both the native Objective-C and the C++ programing languages. We also introduce simplified versions of the BRIEF and BRISK descriptors that improve processing speed without compromising tracking accuracy.

Faraday instability on patterned surfaces

NASA Astrophysics Data System (ADS)

Feng, Jie; Rubinstein, Gregory; Jacobi, Ian; Stone, Howard

2013-11-01

We show how micro-scale surface patterning can be used to control the onset of the Faraday instability in thin liquid films. It is well known that when a liquid film on a planar substrate is subject to sufficient vibrational accelerations, the free surface destabilizes, exhibiting a family of non-linear standing waves. This instability remains a canonical problem in the study of spontaneous pattern formation, but also has practical uses. For example, the surface waves induced by the Faraday instability have been studied as a means of enhanced damping for mechanical vibrations (Genevaux et al. 2009). Also the streaming within the unstable layer has been used as a method for distributing heterogeneous cell cultures on growth medium (Takagi et al. 2002). In each of these applications, the roughness of the substrate significantly affects the unstable flow field. We consider the effect of patterned substrates on the onset and behavior of the Faraday instability over a range of pattern geometries and feature heights where the liquid layer is thicker than the pattern height. Also, we describe a physical model for the influence of patterned roughness on the destabilization of a liquid layer in order to improve the design of practical systems which exploit the Faraday instability.

Faraday effect on stimulated Raman scattering in the linear region

NASA Astrophysics Data System (ADS)

Liu, Z. J.; Li, B.; Xiang, J.; Cao, L. H.; Zheng, C. Y.; Hao, L.

2018-04-01

The paper presents the effect of Faraday rotation on stimulated Raman scattering (SRS). When light propagates along the magnetic field upon plasma, Faraday rotation occurs. The rotation angle can be expressed as {{d}}θ /{{d}}{s}=2.93× {10}-4B\\tfrac{{n}e/{n}c}{\\sqrt{1-{n}e/{n}c}} {cm}}-1 approximately, where θ is the rotation angle and s is distance, n e is the electron density, n c is the critical density and B is magnetic field in unit of Gauss. Both the incident light and Raman light have Faraday effects. The angle between the polarization directions of incident light and Raman light changes with position. The driven force of electron plasma wave also reduces, and then SRS scattering level is reduced. Faraday rotation effect can increase the laser intensity threshold of Raman scattering, even if the magnetic field strength is small. The circularly polarized light incident case is also compared with that of the linearly polarized light incident. The Raman scattering level of linearly polarized light is much smaller than that of circularly polarized light in the magnetized plasma. The difference between linearly and circularly polarized lights is also discussed.

Effects of stray lights on Faraday rotation measurement for polarimeter-interferometer system on EAST.

PubMed

Zou, Z Y; Liu, H Q; Ding, W X; Chen, J; Brower, D L; Lian, H; Wang, S X; Li, W M; Yao, Y; Zeng, L; Jie, Y X

2018-01-01

A double-pass radially view 11 chords polarimeter-interferometer system has been operated on the experimental advanced superconducting tokamak and provides important current profile information for plasma control. Stray light originating from spurious reflections along the optical path (unwanted reflections from various optical components/mounts and transmissive optical elements such as windows, waveplates, and lens as well as the detectors) and also direct feedback from the retro-reflector used to realize the double-pass configuration can both contribute to contamination of the Faraday rotation measurement accuracy. Modulation of the Faraday rotation signal due to the interference from multiple reflections is observable when the interferometer phase (plasma density) varies with time. Direct reflection from the detector itself can be suppressed by employing an optical isolator consisting of a λ/4-waveplate and polarizer positioned in front of the mixer. A Faraday angle oscillation during the density ramping up (or down) can be reduced from 5°-10° to 1°-2° by eliminating reflections from the detector. Residual modulation arising from misalignment and stray light from other sources must be minimized to achieve accurate measurements of Faraday rotation.

How Does the Fast Track Intervention Prevent Adverse Outcomes in Young Adulthood?

PubMed

Sorensen, Lucy C; Dodge, Kenneth A

2016-01-01

Numerous studies have shown that childhood interventions can foster improved outcomes in adulthood. Less well understood is precisely how-that is, through which developmental pathways-these interventions work. This study assesses mechanisms by which the Fast Track project (n = 891), a randomized intervention in the early 1990s for high-risk children in four communities (Durham, NC; Nashville, TN; rural PA; and Seattle, WA), reduced delinquency, arrests, and general and mental health service utilization in adolescence through young adulthood (ages 12-20). A decomposition of treatment effects indicates that about a third of Fast Track's impact on later crime outcomes can be accounted for by improvements in social and self-regulation skills during childhood (ages 6-11), such as prosocial behavior, emotion regulation, and problem solving. These skills proved less valuable for the prevention of general and mental health problems. © 2015 The Authors. Child Development © 2015 Society for Research in Child Development, Inc.

The new millennium program: Fast-track procurements

NASA Astrophysics Data System (ADS)

Metzger, Robert M.

1996-11-01

The National Aeronautics and Space Administration's (NASA's) New Millennium Program (NMP) has embarked on a technology flight-validation demonstration program to enable the kinds of missions that NASA envisions for the 21st century. Embedded in this program is the concept of rapid mission development supported by a fast-track procurement process. This process begins with the decision to initiate a procurement very early in the program along with the formation of a technical acquisition team. A close working relationship among the team members is essential to avoiding delays and developing a clear acquisition plan. The request for proposal (RFP) that is subsequently issued seeks a company with proven capabilities, so that the time allotted for responses from proposers and the length of proposals they submit can be shortened. The fast-track procurement process has been demonstrated during selection of NMP's industrial partners and has been proven to work.

LASER APPLICATIONS AND OTHER TOPICS IN QUANTUM ELECTRONICS: Use of Spun optical fibres in current sensors

NASA Astrophysics Data System (ADS)

Gubin, Vladimir P.; Isaev, Victor A.; Morshnev, Sergey K.; Sazonov, Aleksandr I.; Starostin, Nikolay I.; Chamorovsky, Yury K.; Oussov, Aleksey I.

2006-03-01

The polarisation properties of a Spun optical fibre are studied in connection with their applications in fibreoptic current sensors based on the Faraday effect. A model of this fibre is proposed which represents it as an anisotropic medium with the spiral structure of the fast and slow birefringence axes. A sensor is developed based on an all-fibre low-coherence linear interferometer with a threshold sensitivity of 70 mA Hz-1/2, a maximum measured current of 3000 A, and a scale-factor reproducibility of ±0.6%. It is found that for a given diameter of the fibre contour, the normalised sensitivity is independent of the fibre length. The experimental results confirm the theory.

The extraordinary impact of Michael Faraday on chemistry and related subjects.

PubMed

Thomas, John Meurig

2017-08-25

Biographers of Michael Faraday, as well as many dictionaries of science, often describe him as a physicist, which he certainly was. But he was also an astonishingly effective chemist: in fact, he was the Fullerian Professor of Chemistry (at the Royal Institution, RI) from 1834 until the time of his death in August, 1867. To mark the sesquicentenary of his passing, this editorial, by one of his distant successors as Director and Fullerian Professor at the RI, focuses on Faraday's output and influence as a scientist.

The Rb 780-nanometer Faraday anomalous dispersion optical filter: Theory and experiment

NASA Technical Reports Server (NTRS)

Yin, B.; Alvarez, L. S.; Shay, T. M.

1994-01-01

The Faraday anomalous dispersion optical filter may provide ultra-high background noise rejection for free-space laser communications systems. The theoretical model for the filter is reported. The experimental measurements and their comparison with theoretical results are discussed. The results show that the filter can provide a 56-dB solar background noise rejection with about a 2-GHz transmission bandwidth and no image degradation. To further increase the background noise rejection, a composite Zeeman and Faraday anomalous dispersion optical filter is designed and experimentally demonstrated.

A new learning strategy for the two-time-scale neural controller with its application to the tracking control of rigid arms

NASA Technical Reports Server (NTRS)

Cheng, W.; Wen, J. T.

1992-01-01

A novel fast learning rule with fast weight identification is proposed for the two-time-scale neural controller, and a two-stage learning strategy is developed for the proposed neural controller. The results of the stability analysis show that both the tracking error and the fast weight error will be uniformly bounded and converge to a bounded region which depends only on the accuracy of the slow learning if the system is sufficiently excited. The efficiency of the two-stage learning is also demonstrated by a simulation of a two-link arm.

Revealing the Faraday depth structure of radio galaxy NGC 612 with broad-band radio polarimetric observations

NASA Astrophysics Data System (ADS)

Kaczmarek, J. F.; Purcell, C. R.; Gaensler, B. M.; Sun, X.; O'Sullivan, S. P.; McClure-Griffiths, N. M.

2018-05-01

We present full-polarization, broad-band observations of the radio galaxy NGC 612 (PKS B0131-637) from 1.3 to 3.1 GHz using the Australia Telescope Compact Array. The relatively large angular scale of the radio galaxy makes it a good candidate with which to investigate the polarization mechanisms responsible for the observed Faraday depth structure. By fitting complex polarization models to the polarized spectrum of each pixel, we find that a single polarization component can adequately describe the observed signal for the majority of the radio galaxy. While we cannot definitively rule out internal Faraday rotation, we argue that the bulk of the Faraday rotation is taking place in a thin skin that girts the polarized emission. Using minimum energy estimates, we find an implied total magnetic field strength of 4.2 μG.

Michael Faraday on the Learning of Science and Attitudes of Mind

NASA Astrophysics Data System (ADS)

Crawford, Elspeth

The paper makes use of Michael Faraday's ideas about learning, in particular his thoughts about attitudes to the unknowns of science and the development of an attitude which improves scientific decision-making. An invented scenario involving nursery school children demonstrates some attitudes displayed there. Discussion of the scenario and variation in possible outcomes suggests that Faraday's views are relevant to scientific learning in general. The main thesis of the paper is that it is central to learning in science to acknowledge that there is an inner struggle involved in facing unknowns, and that empathy with the fears and expectations of learners is an essential quality if genuinely scientific thought is to develop. It is suggested, following Faraday, that understanding our own feelings while we teach is a pre-requisite to enabling such empathy and that only then will we be in a position to evaluate accurately whether or not our pupils are thinking scientifically.

Faraday-Shielded dc Stark-Shift-Free Optical Lattice Clock

NASA Astrophysics Data System (ADS)

Beloy, K.; Zhang, X.; McGrew, W. F.; Hinkley, N.; Yoon, T. H.; Nicolodi, D.; Fasano, R. J.; Schäffer, S. A.; Brown, R. C.; Ludlow, A. D.

2018-05-01

We demonstrate the absence of a dc Stark shift in an ytterbium optical lattice clock. Stray electric fields are suppressed through the introduction of an in-vacuum Faraday shield. Still, the effectiveness of the shielding must be experimentally assessed. Such diagnostics are accomplished by applying high voltage to six electrodes, which are grounded in normal operation to form part of the Faraday shield. Our measurements place a constraint on the dc Stark shift at the 10-20 level, in units of the clock frequency. Moreover, we discuss a potential source of error in strategies to precisely measure or cancel nonzero dc Stark shifts, attributed to field gradients coupled with the finite spatial extent of the lattice-trapped atoms. With this consideration, we find that Faraday shielding, complemented with experimental validation, provides both a practically appealing and effective solution to the problem of dc Stark shifts in optical lattice clocks.

Faraday-Shielded dc Stark-Shift-Free Optical Lattice Clock.

PubMed

Beloy, K; Zhang, X; McGrew, W F; Hinkley, N; Yoon, T H; Nicolodi, D; Fasano, R J; Schäffer, S A; Brown, R C; Ludlow, A D

2018-05-04

We demonstrate the absence of a dc Stark shift in an ytterbium optical lattice clock. Stray electric fields are suppressed through the introduction of an in-vacuum Faraday shield. Still, the effectiveness of the shielding must be experimentally assessed. Such diagnostics are accomplished by applying high voltage to six electrodes, which are grounded in normal operation to form part of the Faraday shield. Our measurements place a constraint on the dc Stark shift at the 10^{-20} level, in units of the clock frequency. Moreover, we discuss a potential source of error in strategies to precisely measure or cancel nonzero dc Stark shifts, attributed to field gradients coupled with the finite spatial extent of the lattice-trapped atoms. With this consideration, we find that Faraday shielding, complemented with experimental validation, provides both a practically appealing and effective solution to the problem of dc Stark shifts in optical lattice clocks.

Mode-locking via dissipative Faraday instability

PubMed Central

Tarasov, Nikita; Perego, Auro M.; Churkin, Dmitry V.; Staliunas, Kestutis; Turitsyn, Sergei K.

2016-01-01

Emergence of coherent structures and patterns at the nonlinear stage of modulation instability of a uniform state is an inherent feature of many biological, physical and engineering systems. There are several well-studied classical modulation instabilities, such as Benjamin–Feir, Turing and Faraday instability, which play a critical role in the self-organization of energy and matter in non-equilibrium physical, chemical and biological systems. Here we experimentally demonstrate the dissipative Faraday instability induced by spatially periodic zig-zag modulation of a dissipative parameter of the system—spectrally dependent losses—achieving generation of temporal patterns and high-harmonic mode-locking in a fibre laser. We demonstrate features of this instability that distinguish it from both the Benjamin–Feir and the purely dispersive Faraday instability. Our results open the possibilities for new designs of mode-locked lasers and can be extended to other fields of physics and engineering. PMID:27503708

Novel configuration for an enhanced and compact all-fiber Faraday rotator with matched birefringence.

PubMed

Asraf, Sagie; Sintov, Yoav; Zalevsky, Zeev

2017-08-07

We propose a novel configuration for an improved and compact all fiber Faraday rotator based on phase matching between the Faraday rotation and bend-induced birefringence. The device utilizes a coiled fiber within two electro-magnetic toroids, such that the fiber length required for getting the beat length is quite long and several rounds of fiber are needed. Analysis of the capabilities of the proposed device and its sensitivity to different parameters is presented. Faraday rotation of 13° was experimentally measured in six meters of single mode silica fiber, with a magnetic field of about 0.06T at a wavelength of 1064nm. We show that phase matching between the two phenomena significantly improves the polarization rotation by a factor of 4-10. In addition, we demonstrate the ability to achieve higher rotation by using Fabry Perot resonator in low terbium doped glass.

Faraday waves under time-reversed excitation.

PubMed

Pietschmann, Dirk; Stannarius, Ralf; Wagner, Christian; John, Thomas

2013-03-01

Do parametrically driven systems distinguish periodic excitations that are time mirrors of each other? Faraday waves in a Newtonian fluid are studied under excitation with superimposed harmonic wave forms. We demonstrate that the threshold parameters for the stability of the ground state are insensitive to a time inversion of the driving function. This is a peculiarity of some dynamic systems. The Faraday system shares this property with standard electroconvection in nematic liquid crystals [J. Heuer et al., Phys. Rev. E 78, 036218 (2008)]. In general, time inversion of the excitation affects the asymptotic stability of a parametrically driven system, even when it is described by linear ordinary differential equations. Obviously, the observed symmetry has to be attributed to the particular structure of the underlying differential equation system. The pattern selection of the Faraday waves above threshold, on the other hand, discriminates between time-mirrored excitation functions.

Mode-locking via dissipative Faraday instability.

PubMed

Tarasov, Nikita; Perego, Auro M; Churkin, Dmitry V; Staliunas, Kestutis; Turitsyn, Sergei K

2016-08-09

Emergence of coherent structures and patterns at the nonlinear stage of modulation instability of a uniform state is an inherent feature of many biological, physical and engineering systems. There are several well-studied classical modulation instabilities, such as Benjamin-Feir, Turing and Faraday instability, which play a critical role in the self-organization of energy and matter in non-equilibrium physical, chemical and biological systems. Here we experimentally demonstrate the dissipative Faraday instability induced by spatially periodic zig-zag modulation of a dissipative parameter of the system-spectrally dependent losses-achieving generation of temporal patterns and high-harmonic mode-locking in a fibre laser. We demonstrate features of this instability that distinguish it from both the Benjamin-Feir and the purely dispersive Faraday instability. Our results open the possibilities for new designs of mode-locked lasers and can be extended to other fields of physics and engineering.

Using the online and offline change model to improve efficiency for fast-track patients in an emergency department.

PubMed

Docimo, A B; Pronovost, P J; Davis, R O; Concordia, E B; Gabrish, C M; Adessa, M S; Bessman, E

2000-09-01

In 1998 the emergency department (ED) Work Group at Johns Hopkins Bayview Medical Center (Baltimore) worked to reinvigorate the fast-track program within the ED to improve throughput for patients with minor illnesses and injuries who present for care. There had been two prior unsuccessful attempts to overhaul the fast-track process. The work group used a change model intended to improve both processes and relationships for complex organizational problems that span departments and functional units. Before the first work group meeting, the work group evaluated the institutional commitment to address the issue. The next step was to find data to fully understand the issues and establish a baseline for evaluating improvements--for example, patients with minor illnesses and injuries had excessively long total ED (registration to discharge) times: 5 hours 57 minutes on average for nonacute patients. ONLINE AND OFFLINE MEETINGS: The work group identified process problems, but relationship barriers became evident as the new processes were discussed. Yet offline work was needed to minimize the potential for online surprises. The work group leaders met separately in small groups with nursing staff, lab staff, x-ray staff, registrars, and physician's assistants to inform them of data, obtain input about process changes, and address any potential concerns. The group conducted four tests of change (using Plan-Do-Study-Act cycles) to eliminate the root causes of slow turnaround identified previously. Total ED time decreased to an average of 1 hour 47 minutes; the practice of placing nonacute patients in fast track before all higher-acuity patients were seen gained acceptance. The percentage of higher-acuity patients sent to fast track decreased from 17% of all patients seen in fast track in January 1998 to 8.5% by February 1999. Patients with minor illnesses and injuries no longer had to wait behind higher-acuity patients just to be registered. The average wait for registration decreased from 42 minutes in January 1998 to 14 minutes in February 1999. Physician's assistant, nursing, and technician staff all report improved working relationships and feeling a team spirit. The offline component of the integrated model helped to improve organizational relationships and dialogue among team members, thereby facilitating the effectiveness of online efforts to improve processes. This model has also been applied to improve patient registration (revenue recovery) and the emergency transfer and admissions process.

Diagnostics of the solar corona from comparison between Faraday rotation measurements and magnetohydrodynamic simulations

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

Le Chat, G.; Cohen, O.; Kasper, J. C.

Polarized natural radio sources passing behind the Sun experience Faraday rotation as a consequence of the electron density and magnetic field strength in coronal plasma. Since Faraday rotation is proportional to the product of the density and the component of the magnetic field along the line of sight of the observer, a model is required to interpret the observations and infer coronal structures. Faraday rotation observations have been compared with relatively ad hoc models of the corona. Here for the first time we compare these observations with magnetohydrodynamic (MHD) models of the solar corona driven by measurements of the photosphericmore » magnetic field. We use observations made with the NRAO Very Large Array of 34 polarized radio sources occulted by the solar corona between 5 and 14 solar radii. The measurements were made during 1997 May, and 2005 March and April. We compare the observed Faraday rotation values with values extracted from MHD steady-state simulations of the solar corona. We find that (1) using a synoptic map of the solar magnetic field just one Carrington rotation off produces poorer agreements, meaning that the outer corona changes in the course of one month, even in solar minimum; (2) global MHD models of the solar corona driven by photospheric magnetic field measurements are generally able to reproduce Faraday rotation observations; and (3) some sources show significant disagreement between the model and the observations, which appears to be a function of the proximity of the line of sight to the large-scale heliospheric current sheet.« less

Comparison of methods for removing electromagnetic noise from electromyographic signals.

PubMed

Defreitas, Jason M; Beck, Travis W; Stock, Matt S

2012-02-01

The purpose of this investigation was to compare three different methods of removing noise from monopolar electromyographic (EMG) signals: (a) electrical shielding with a Faraday cage, (b) denoising with a digital notch-filter and (c) applying a bipolar differentiation with another monopolar EMG signal. Ten men and ten women (mean age = 24.0 years) performed isometric muscle actions of the leg extensors at 10-100% of their maximal voluntary contraction on two separate occasions. One trial was performed inside a Faraday tent (a flexible Faraday cage made from conductive material), and the other was performed outside the Faraday tent. The EMG signals collected outside the Faraday tent were analyzed three separate ways: as a raw signal, as a bipolar signal, and as a signal digitally notch filtered to remove 60 Hz noise and its harmonics. The signal-to-noise ratios were greatest after notch-filtering (range: 3.0-33.8), and lowest for the bipolar arrangement (1.6-10.2). Linear slope coefficients for the EMG amplitude versus force relationship were also used to compare the methods of noise removal. The results showed that a bipolar arrangement had a significantly lower linear slope coefficient when compared to the three other conditions (raw, notch and tent). These results suggested that an appropriately filtered monopolar EMG signal can be useful in situations that require a large pick-up area. Furthermore, although it is helpful, a Faraday tent (or cage) is not required to achieve an appropriate signal-to-noise ratio, as long as the correct filters are applied.

Promotion Policies and Career Management - An Empirical Analysis of Below-Zone Promotion of U.S. Navy Officers

DTIC Science & Technology

1997-03-01

found in several different terms: Deep selection, early promotion or fast-track promotion. The latter is common lingo of labor economics . Throughout...this thesis the military terms will be used interchangeably, "fast-track promotion" will be used as term in a labor economics context. because they put...found that FITREP 5 Holt: Managerial Principles & Practices, Ehrenberg/Smith: Modern Labor Economics , WEST Series of Organizational Behaviour, as a few

Navigator GPS Receiver for Fast Acquisition and Weak Signal Space Applications

NASA Technical Reports Server (NTRS)

Winternitz, Luke; Moreau, Michael; Boegner, Gregory J.; Sirotzky, Steve

2004-01-01

NASA Goddard Space Flight Center (GSFC) is developing a new space-borne GPS receiver that can operate effectively in the full range of Earth orbiting missions from Low Earth Orbit (LEO) to geostationary and beyond. Navigator is designed to be a fully space flight qualified GPS receiver optimized for fast signal acquisition and weak signal tracking. The fast acquisition capabilities provide exceptional time to first fix performance (TIFF) with no a priori receiver state or GPS almanac information, even in the presence of high Doppler shifts present in LEO (or near perigee in highly eccentric orbits). The fast acquisition capability also makes it feasible to implement extended correlation intervals and therefore significantly reduce Navigator s acquisition threshold. This greatly improves GPS observability when the receiver is above the GPS constellation (and satellites must be tracked from the opposite side of the Earth) by providing at least 10 dB of increased acquisition sensitivity. Fast acquisition and weak signal tracking algorithms have been implemented and validated on a hardware development board. A fully functional version of the receiver, employing most of the flight parts, with integrated navigation software is expected by mid 2005. An ultimate goal of this project is to license the Navigator design to an industry partner who will then market the receiver as a commercial product.

Graphit-ceramic RF Faraday-thermal shield and plasma limiter

DOEpatents

Hwang, David L.; Hosea, Joel C.

1989-01-01

The present invention is directed to a process of brazing a ceramic mater to graphite. In particular, the brazing procedure is directed to the production of a novel brazed ceramic graphite product useful as a Faraday shield.

One-Piece Faraday Generator: A Paradoxical Experiment from 1851

ERIC Educational Resources Information Center

Crooks, M. J.; And Others

1978-01-01

Describes an experiment based on Faraday's one-piece generator, where the rotating disk is replaced by a cylindrical permanent magnet. Explains the apparent paradox that an observer in an inertial frame could measure his absolute velocity. (GA)

Full characterization of laser-accelerated ion beams using Faraday cup, silicon carbide, and single-crystal diamond detectors

NASA Astrophysics Data System (ADS)

Margarone, D.; Krása, J.; Giuffrida, L.; Picciotto, A.; Torrisi, L.; Nowak, T.; Musumeci, P.; Velyhan, A.; Prokůpek, J.; Láska, L.; Mocek, T.; Ullschmied, J.; Rus, B.

2011-05-01

Multi-MeV beams of light ions have been produced using the 300 picosecond, kJ-class iodine laser, operating at the Prague Asterix Laser System facility in Prague. Real-time ion diagnostics have been performed by the use of various time-of-flight (TOF) detectors: ion collectors (ICs) with and without absorber thin films, new prototypes of single-crystal diamond and silicon carbide detectors, and an electrostatic ion mass spectrometer (IEA). In order to suppress the long photopeak induced by soft X-rays and to avoid the overlap with the signal from ultrafast particles, the ICs have been shielded with Al foil filters. The application of large-bandgap semiconductor detectors (>3 eV) ensured cutting of the plasma-emitted visible and soft-UV radiation and enhancing the sensitivity to the very fast proton/ion beams. Employing the IEA spectrometer, various ion species and charge states in the expanding laser-plasma have been determined. Processing of the experimental data based on the TOF technique, including estimation of the plasma fast proton maximum and peak energy, ion beam currents and total charge, total number of fast protons, as well as deconvolution processes, ion stopping power, and ion/photon transmission calculations for the different metallic filters used, are reported.

Fast-track eligibility of geriatric patients undergoing short urologic surgery procedures.

PubMed

Fredman, Brian; Sheffer, Offer; Zohar, Edna; Paruta, Irena; Richter, Santiago; Jedeikin, Robert; White, Paul F

2002-03-01

Our primary objective was to assess the feasibility of geriatric patients (>65 yr) bypassing the postanesthesia care unit (PACU) after ambulatory surgery. A secondary objective was to compare recovery profiles when using three different maintenance anesthetics. Ninety ASA physical status I--III consenting outpatients (>65 yr) undergoing short urologic procedures were randomly assigned to one of three anesthetic treatment groups. After a standardized induction with fentanyl and propofol, anesthesia was maintained with propofol (75-150 microg center dot kg(-1) center dot min(-1) IV), isoflurane (0.7%-1.2% end tidal), or desflurane (3%-6% end tidal), in combination with nitrous oxide 70% in oxygen. In all three groups, the primary anesthetic was titrated to maintain an electroencephalographic-bispectral index value of 60-65. Recovery times, postanesthesia recovery scores, and therapeutic interventions in the PACU were recorded. Although emergence times were similar in the three groups, the time to achieve a fast-track discharge score of 14 was significantly shorter in patients receiving desflurane compared with propofol and isoflurane (22 +/- 23 vs 33 +/- 25 and 44 +/- 36 min, respectively). On arrival in the PACU, a significantly larger percentage of patients receiving desflurane were judged to be fast-track eligible compared with those receiving either isoflurane and propofol (73% vs 43% and 44%, respectively). The number of therapeutic interventions in the PACU was also significantly larger in the Isoflurane group when compared with the Propofol and Desflurane groups (21 vs 11 and 7, respectively). In conclusion, use of desflurane for maintenance of anesthesia should facilitate PACU bypass ("fast-tracking") of geriatric patients undergoing short urologic procedures. Geriatric outpatients undergoing brief urologic procedures more rapidly achieve fast-tracking discharge criteria after desflurane (versus isoflurane and propofol) anesthesia. Use of isoflurane was also associated with an increased need for nursing interventions in the early recovery period compared with desflurane and propofol.

77 FR 3478 - Center for Scientific Review; Notice of Closed Meetings

Federal Register 2010, 2011, 2012, 2013, 2014

2012-01-24

... Marriott Tysons Corner, 1960--A Chain Bridge Road, McLean, VA 22102. Contact Person: Martha M Faraday, Ph.D... Marriott Tysons Corner, 1960-A Chain Bridge Road McLean, VA 22102. Contact Person: Martha M Faraday, Ph.D...

Measurements of high-current electron beams from X pinches and wire array Z pinches.

PubMed

Shelkovenko, T A; Pikuz, S A; Blesener, I C; McBride, R D; Bell, K S; Hammer, D A; Agafonov, A V; Romanova, V M; Mingaleev, A R

2008-10-01

Some issues concerning high-current electron beam transport from the X pinch cross point to the diagnostic system and measurements of the beam current by Faraday cups are discussed. Results of computer simulation of electron beam propagation from the pinch to the Faraday cup give limits for the measured current for beams having different energy spreads. The beam is partially neutralized as it propagates from the X pinch to a diagnostic system, but within a Faraday cup diagnostic, space charge effects can be very important. Experimental results show evidence of such effects.

Magnetically Filtered Faraday Probe for Measuring the Ion Current Density Profile of a Hall Thruster

DTIC Science & Technology

2006-01-01

Hall thruster is investigated. The MFFP is designed to eliminate the collection of low-energy, charge-exchange (CEX) ions by using a variable magnetic field as an ion filter. In this study, a MFFP, Faraday probe with a reduced acceptance angle (BFP), and nude Faraday probe are used to measure the ion current density profile of a 5 kW Hall thruster operating over the range of 300-500 V and 5-10 mg/s. The probes are evaluated on a xenon propellant Hall thruster in the University of Michigan Large Vacuum Test Facility at operating

Electrodeless-discharge-vapor-lamp-based Faraday anomalous-dispersion optical filter.

PubMed

Sun, Qinqing; Zhuang, Wei; Liu, Zhiwen; Chen, Jingbiao

2011-12-01

We report an excited-state Faraday anomalous-dispersion optical filter operating on the rubidium 5P(3/2)-5D(5/2) transition (775.9 nm in vacuum) without the use of a pump laser. An electrodeless discharge vapor lamp is employed to replace the Rb vapor cell in a traditional Faraday anomalous-dispersion optical filter system. Atoms can be excited by power rather than a complex frequency-locked pump laser. A proof-of-concept experimental demonstration with a maximum transmission of 1.9% and a filter bandwidth of 650 MHz is presented. © 2011 Optical Society of America

Concluding remarks: Faraday Discussion on chemistry in the urban atmosphere.

PubMed

Jimenez, Jose L

2016-07-18

This article summarises the Concluding remarks from the Faraday Discussion on Chemistry in the Urban Atmosphere. The following themes are addressed: (a) new results that inform our understanding of the evolving sources and composition of the urban atmosphere ("News"); (b) results that identify gaps in our understanding that necessitate further work ("Gaps"); (c) the emerging instrumentation revolution and some of the challenges that it brings; (d) the structural issues of insufficient support for the analysis of field campaigns; and (e) some important areas that were missing from this Faraday Discussion and that should receive an increasing focus in the future.

Faraday's first dynamo: A retrospective

NASA Astrophysics Data System (ADS)

Smith, Glenn S.

2013-12-01

In the early 1830s, Michael Faraday performed his seminal experimental research on electromagnetic induction, in which he created the first electric dynamo—a machine for continuously converting rotational mechanical energy into electrical energy. His machine was a conducting disc, rotating between the poles of a permanent magnet, with the voltage/current obtained from brushes contacting the disc. In his first dynamo, the magnetic field was asymmetric with respect to the axis of the disc. This is to be contrasted with some of his later symmetric designs, which are the ones almost invariably discussed in textbooks on electromagnetism. In this paper, a theoretical analysis is developed for Faraday's first dynamo. From this analysis, the eddy currents in the disc and the open-circuit voltage for arbitrary positioning of the brushes are determined. The approximate analysis is verified by comparing theoretical results with measurements made on an experimental recreation of the dynamo. Quantitative results from the analysis are used to elucidate Faraday's qualitative observations, from which he learned so much about electromagnetic induction. For the asymmetric design, the eddy currents in the disc dissipate energy that makes the dynamo inefficient, prohibiting its use as a practical generator of electric power. Faraday's experiments with his first dynamo provided valuable insight into electromagnetic induction, and this insight was quickly used by others to design practical generators.

Preliminary investigation of Faraday rotation effects and description of polarization measurements on the AFGL high latitude meteor scatter test bed

NASA Astrophysics Data System (ADS)

Ostergaard, Jens C.

1989-01-01

The background, methodology and preliminary results of an investigation of Faraday rotation effects on the Meteor Scatter High Latitude Test Bed in Greenland are presented. A short review of polarization theory for radio waves, presenting basic properties and changes when reflected from the surface of the earth or propagated through the ionosphere is included. Material published by other workers is presented to give the background for the current interest in Faraday rotation on meteor scatter links. Propagation losses for meteor scatter paths originate from spatial spreading of RF energy, scattering losses at the meteor trail, ionospheric absorption and polarization mismatch at the receiving antenna. That part of the polarization mismatch generated by the ionosphere, the Faraday rotation, is described and evaluated. A method to compute the Faraday rotation is presented and results obtained for the AFGL MSHL Test Bed are given. An experiment, including the measurement of signal strength and polarization throughout the lifetime of the individual meteor scatter return is needed to fully assess the combined affects of absorption and depolarization during both quiet and disturbed ionospheric conditions. The measurement accuracy to be expected from a proposed experiment is evaluated. A few examples of meteor scatter returns obtained with a prototype experiment in Greenland are shown and discussed.

Recent VLA Measurements of CME-Induced Faraday Rotation

NASA Astrophysics Data System (ADS)

Kooi, Jason; Thomas, Najma; Guy, Michael; Spangler, Steven R.

2018-01-01

Observations of Faraday rotation, the change in polarization position angle of linearly polarized radiation as it propagates through a magnetized plasma, have been used for decades to determine the strength and structure of the coronal magnetic field and plasma density. Similarly, observations of Faraday rotation through a coronal mass ejection (CME) have the potential to improve our understanding of the CME’s plasma structure. We report recent results from simultaneous white-light coronagraph and radio observations made of a CME in July 2015. We made radio observations using the Karl G. Jansky Very Large Array (VLA) at 1 - 2 GHz frequencies of a set of cosmic radio sources through the solar corona at heliocentric distances that ranged between 8 - 23 solar radii. A unique aspect of these observations is that the CME occulted several of these radio sources and, therefore, our Faraday rotation measurements provide information on the plasma structure in different regions of the CME. We successfully measured CME-induced Faraday rotation along multiple lines of sight because we made special arrangements with the staff at the National Radio Astronomy Observatory to trigger VLA observations when a candidate CME appeared low in the corona in near real-time images from the Large Angle and Spectrometric Coronagraph (LASCO) C2 instrument.

A New Method for Analyzing Near-Field Faraday Probe Data in Hall Thrusters

NASA Technical Reports Server (NTRS)

Huang, Wensheng; Shastry, Rohit; Herman, Daniel A.; Soulas, George C.; Kamhawi, Hani

2013-01-01

This paper presents a new method for analyzing near-field Faraday probe data obtained from Hall thrusters. Traditional methods spawned from far-field Faraday probe analysis rely on assumptions that are not applicable to near-field Faraday probe data. In particular, arbitrary choices for the point of origin and limits of integration have made interpretation of the results difficult. The new method, called iterative pathfinding, uses the evolution of the near-field plume with distance to provide feedback for determining the location of the point of origin. Although still susceptible to the choice of integration limits, this method presents a systematic approach to determining the origin point for calculating the divergence angle. The iterative pathfinding method is applied to near-field Faraday probe data taken in a previous study from the NASA-300M and NASA-457Mv2 Hall thrusters. Since these two thrusters use centrally mounted cathodes the current density associated with the cathode plume is removed before applying iterative pathfinding. A procedure is presented for removing the cathode plume. The results of the analysis are compared to far-field probe analysis results. This paper ends with checks on the validity of the new method and discussions on the implications of the results.

Far off-resonance laser frequency stabilization using multipass cells in Faraday rotation spectroscopy.

PubMed

Quan, Wei; Li, Yang; Li, Rujie; Shang, Huining; Fang, Zishan; Qin, Jie; Wan, Shuangai

2016-04-01

We propose a far off-resonance laser frequency stabilization method by using multipass cells in Rb Faraday rotation spectroscopy. Based on the detuning equation, if multipass cells with several meters optical path length are used in the conventional Faraday spectroscopy, the detuning of the lock point can be extended much further from the alkali metal resonance. A plate beam splitter was used to generate two different Faraday signals at the same time. The transmitted optical path length was L=50  mm and the reflected optical path length was 2L=100  mm. When the optical path length doubled, the detuning of the lock points moved further away from the atomic resonance. The temperature dependence of the detuning of the lock point was also analyzed. A temperature-insensitive lock point was found near resonance when the cell temperature was between 110°C and 130°C. We achieved an rms fluctuation of 0.9 MHz/23 h at a detuning of 0.5 GHz. A frequency drift of 16 MHz/h at a detuning of -5.6  GHz and 4 MHz/h at a detuning of -5.2  GHz were also obtained for the transmitted and reflected light Faraday signal.

A New Method for Analyzing Near-Field Faraday Probe Data in Hall Thrusters

NASA Technical Reports Server (NTRS)

Huang, Wensheng; Shastry, Rohit; Herman, Daniel A.; Soulas, George C.; Kamhawi, Hani

2013-01-01

This paper presents a new method for analyzing near-field Faraday probe data obtained from Hall thrusters. Traditional methods spawned from far-field Faraday probe analysis rely on assumptions that are not applicable to near-field Faraday probe data. In particular, arbitrary choices for the point of origin and limits of integration have made interpretation of the results difficult. The new method, called iterative pathfinding, uses the evolution of the near-field plume with distance to provide feedback for determining the location of the point of origin. Although still susceptible to the choice of integration limits, this method presents a systematic approach to determining the origin point for calculating the divergence angle. The iterative pathfinding method is applied to near-field Faraday probe data taken in a previous study from the NASA-300M and NASA-457Mv2 Hall thrusters. Since these two thrusters use centrally mounted cathodes, the current density associated with the cathode plume is removed before applying iterative pathfinding. A procedure is presented for removing the cathode plume. The results of the analysis are compared to far-field probe analysis results. This paper ends with checks on the validity of the new method and discussions on the implications of the results.

A novel approach to Hough Transform for implementation in fast triggers

NASA Astrophysics Data System (ADS)

Pozzobon, Nicola; Montecassiano, Fabio; Zotto, Pierluigi

2016-10-01

Telescopes of position sensitive detectors are common layouts in charged particles tracking, and programmable logic devices, such as FPGAs, represent a viable choice for the real-time reconstruction of track segments in such detector arrays. A compact implementation of the Hough Transform for fast triggers in High Energy Physics, exploiting a parameter reduction method, is proposed, targeting the reduction of the needed storage or computing resources in current, or next future, state-of-the-art FPGA devices, while retaining high resolution over a wide range of track parameters. The proposed approach is compared to a Standard Hough Transform with particular emphasis on their application to muon detectors. In both cases, an original readout implementation is modeled.

77 FR 28193 - Excepted Service, Career and Career-Conditional Employment; and Pathways Programs

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-11

... advancement opportunities to Pathways Participants who are ``fast-tracked'' into desirable positions. The union's concern is misplaced. As an initial matter, the Pathways Participants are not being ``fast...-the-job experience that they otherwise would not be able to obtain. Indeed, rather than being ``fast...

MF/HF Multistatic Mid-Ocean Radar Experiments in Support of SWOTHR (surface-Wave Over-the-Horizon Radar)

DTIC Science & Technology

1989-09-16

SWOTHR was conceived to be an organic asset capable of providing early detection and tracking of fast , surface-skimming threats, such as cruise missiles...distributed real-time processing and threat tracking system. Spe- cific project goals were to verify detection performance pree ctions for small, fast targets...means that enlarging the ground plane would have been a fruitless excercise in any event. B-6 5 i I U Table B-1 summarizes the calculated parameters of

Getting on the fast track, or how to get an MLIS through distance education, with a specialization in medical librarianship.

PubMed

Detlefsen, Ellen G

2004-01-01

The article describes an innovation in MLIS education for medical librarianship, with an introduction to the FastTrack, the distance education program at the University of Pittsburgh's library and information science school, together with an overview of a model program linking the biomedical library at Vanderbilt University with the School of Information Sciences in Pittsburgh. Admissions requirements and specific curriculum for the distance education master's degree are detailed in an FAQ format.

Studies on fast triggering and high precision tracking with Resistive Plate Chambers

NASA Astrophysics Data System (ADS)

Aielli, G.; Ball, R.; Bilki, B.; Chapman, J. W.; Cardarelli, R.; Dai, T.; Diehl, E.; Dubbert, J.; Ferretti, C.; Feng, H.; Francis, K.; Guan, L.; Han, L.; Hou, S.; Levin, D.; Li, B.; Liu, L.; Paolozzi, L.; Repond, J.; Roloff, J.; Santonico, R.; Song, H. Y.; Wang, X. L.; Wu, Y.; Xia, L.; Xu, L.; Zhao, T.; Zhao, Z.; Zhou, B.; Zhu, J.

2013-06-01

We report on studies of fast triggering and high precision tracking using Resistive Plate Chambers (RPCs). Two beam tests were carried out with the 180 GeV/c muon beam at CERN using glass RPCs with gas gaps of 1.15 mm and equipped with readout strips with 1.27 mm pitch. This is the first beam test of RPCs with fine-pitch readout strips that explores precision tracking and triggering capabilities. RPC signals were acquired with precision timing and charge integrating readout electronics at both ends of the strips. The time resolution was measured to be better than 600 ps and the average spatial resolution was found to be 220 μm using charge information and 287 μm only using signal arrival time information. The dual-ended readout allows the determination of the average and the difference of the signal arrival times. The average time was found to be independent of the incident particle position along the strip and is useful for triggering purposes. The time difference yielded a determination of the hit position with a precision of 7.5 mm along the strip. These results demonstrate the feasibility using RPCs for fast and high-resolution triggering and tracking.

Measuring Sound Speed in Gas Mixtures Using a Photoacoustic Generator

NASA Astrophysics Data System (ADS)

Suchenek, Mariusz; Borowski, Tomasz

2018-01-01

We present a new method which allows us to percentage distinction of gas composition with a fast response time. This system uses the speed of sound in a resonant cell along with temperature to determine the gas mixture composition. The gas mixtures contain two gases with an unknown combination. In our experiment, the acoustic waves were excited inside the acoustic longitudinal resonator with the use of a positive feedback. This feedback provides fast tracking of a resonance frequency of the cell and causes fast tracking changes in the speed of sound. The presented method corresponds to the theoretical description of this topic. Two gas mixtures—carbon dioxide and argon mixed with nitrogen—were tested.

A-Track: Detecting Moving Objects in FITS images

NASA Astrophysics Data System (ADS)

Atay, T.; Kaplan, M.; Kilic, Y.; Karapinar, N.

2017-04-01

A-Track is a fast, open-source, cross-platform pipeline for detecting moving objects (asteroids and comets) in sequential telescope images in FITS format. The moving objects are detected using a modified line detection algorithm.

Comment on: The Pioneer 6 Faraday Rotation Transients -- On the Interpretation of Coronal Faraday Rotation Data, by Patzold and Bird

NASA Technical Reports Server (NTRS)

Woo, R.

1998-01-01

The detection of coronal streamers in Doppler scintillation measurements revealed for the first time that variations in radio occultation measurements near the Sun could be caused by quasi-stationary raylike structures.

Time-Resolved Tandem Faraday Cup Development for High Energy TNSA Particles

NASA Astrophysics Data System (ADS)

Padalino, S.; Simone, A.; Turner, E.; Ginnane, M. K.; Glisic, M.; Kousar, B.; Smith, A.; Sangster, C.; Regan, S.

2015-11-01

MTW and OMEGA EP Lasers at LLE utilize ultra-intense laser light to produce high-energy ion pulses through Target Normal Sheath Acceleration (TNSA). A Time Resolved Tandem Faraday Cup (TRTF) was designed and built to collect and differentiate protons from heavy ions (HI) produced during TNSA. The TRTF includes a replaceable thickness absorber capable of stopping a range of user-selectable HI emitted from TNSA plasma. HI stop within the primary cup, while less massive particles continue through and deposit their remaining charge in the secondary cup, releasing secondary electrons in the process. The time-resolved beam current generated in each cup will be measured on a fast storage scope in multiple channels. A charge-exchange foil at the TRTF entrance modifies the charge state distribution of HI to a known distribution. Using this distribution and the time of flight of the HI, the total HI current can be determined. Initial tests of the TRTF have been made using a proton beam produced by SUNY Geneseo's 1.7 MV Pelletron accelerator. A substantial reduction in secondary electron production, from 70% of the proton beam current at 2MeV down to 0.7%, was achieved by installing a pair of dipole magnet deflectors which successfully returned the electrons to the cups in the TRTF. Ultimately the TRTF will be used to normalize a variety of nuclear physics cross sections and stopping power measurements. Based in part upon work supported by a DOE NNSA Award#DE-NA0001944.

Testosterone reactivity to provocation mediates the effect of early intervention on aggressive behavior.

PubMed

Carré, Justin M; Iselin, Anne-Marie R; Welker, Keith M; Hariri, Ahmad R; Dodge, Kenneth A

2014-05-01

We tested the hypotheses that the Fast Track intervention program for high-risk children would reduce adult aggressive behavior and that this effect would be mediated by decreased testosterone responses to social provocation. Participants were a subsample of males from the full trial sample, who during kindergarten had been randomly assigned to the 10-year Fast Track intervention or to a control group. The Fast Track program attempted to develop children's social competencies through child social-cognitive and emotional-coping skills training, peer-relations coaching, academic tutoring, and classroom management, as well as training for parents to manage their child's behavior. At a mean age of 26 years, participants responded to laboratory provocations. Results indicated that, relative to control participants, men assigned to the intervention demonstrated reduced aggression and testosterone reactivity to social provocations. Moreover, reduced testosterone reactivity mediated the effect of intervention on aggressive behavior, which provides evidence for an enduring biological mechanism underlying the effect of early psychosocial intervention on aggressive behavior in adulthood.

Chlamydia trachomatis infection: the efficacy and safety of a fast-track referral and treatment system.

PubMed

Sethupathi, M; Blackwell, A

2009-03-01

We introduced a Nurse/Health Advisor-led fast-track service for treating patients diagnosed with chlamydia outside a genitourinary medicine setting and contacts of chlamydia/non-specific urethritis/cervicitis wherever diagnosed. Asymptomatic patients were treated without initial testing and asked to return for full screening at four to six weeks. We assessed the efficacy and safety of the system and need for follow-up after treatment. Case-notes of 226 patients (121 men and 105 women) were analysed, of whom 140 attended follow-up. With the exception of one case of gonorrhoea, no other serious sexually transmitted infection was detected. Twenty-seven (19.2%) patients were re-treated for either chlamydia (six patients, 4.4%) or non-specific genital infection or because of having unprotected intercourse with untreated or partially treated partners. We conclude that in our relatively low-risk population, our fast-track service is safe and effective. Test of cure for chlamydia seems essential because of the high percentage of patients requiring re-treatment.

Real-Time Robust Tracking for Motion Blur and Fast Motion via Correlation Filters.

PubMed

Xu, Lingyun; Luo, Haibo; Hui, Bin; Chang, Zheng

2016-09-07

Visual tracking has extensive applications in intelligent monitoring and guidance systems. Among state-of-the-art tracking algorithms, Correlation Filter methods perform favorably in robustness, accuracy and speed. However, it also has shortcomings when dealing with pervasive target scale variation, motion blur and fast motion. In this paper we proposed a new real-time robust scheme based on Kernelized Correlation Filter (KCF) to significantly improve performance on motion blur and fast motion. By fusing KCF and STC trackers, our algorithm also solve the estimation of scale variation in many scenarios. We theoretically analyze the problem for CFs towards motions and utilize the point sharpness function of the target patch to evaluate the motion state of target. Then we set up an efficient scheme to handle the motion and scale variation without much time consuming. Our algorithm preserves the properties of KCF besides the ability to handle special scenarios. In the end extensive experimental results on benchmark of VOT datasets show our algorithm performs advantageously competed with the top-rank trackers.

Flying Qualities Design Requirements for Sidestick Controllers

DTIC Science & Technology

1979-10-01

Harper vs wc - Fine Tracking 111 56. Cooper-Harper vs wc - Fine Tracking 111 57. Cooper-Harper ve wc - Landing 112 58. Cooper-Harper vs wc - Lending 112...c - Fine Tracking 119 62. Preference Rating vs wc - Fine Tracking 119 64. Preference Rating vs wc - Landing 120 65. Preference Rating vs w(c...a "fast airplane" to make up for the filtering effect of his arm and the stick. In fine tracking with a center stick the pilot will rest his arm

More on Faraday's and Lenz's laws - Qualitative demonstrations

NASA Astrophysics Data System (ADS)

Hessel, Roberto

2011-03-01

A large variety of simple setups for demonstrating Faraday's and Lenz's laws have been described in the literature.1-4 For a few semesters, we tested some of these setups, especially those suggested in Ref. 1, but recently we decided to develop our own version.

Michael Faraday on the Learning of Science and Attitudes of Mind.

ERIC Educational Resources Information Center

Crawford, Elspeth

1998-01-01

Makes use of Michael Faraday's ideas on learning, focusing on his attitudes toward the unknowns of science and the development of an attitude that improves scientific decision making. This approach acknowledges that there is an inner struggle involved in facing unknowns. (DDR)

Thin-film magnetless Faraday rotators for compact heterogeneous integrated optical isolators

NASA Astrophysics Data System (ADS)

Karki, Dolendra; Stenger, Vincent; Pollick, Andrea; Levy, Miguel

2017-06-01

This report describes the fabrication, characterization, and transfer of ultra-compact thin-film magnetless Faraday rotators to silicon photonic substrates. Thin films of magnetization latching bismuth-substituted rare-earth iron garnets were produced from commercially available materials by mechanical lapping, dice polishing, and crystal-ion-slicing. Eleven- μ m -thick films were shown to retain the 45 ° Faraday rotation of the bulk material to within 2 ° at 1.55 μ m wavelength without re-poling. Anti-reflection coated films evince 0.09 dB insertion loses and better than -20 dB extinction ratios. Lower extinction ratios than the bulk are ascribed to multimode propagation. Significantly larger extinction ratios are predicted for single-mode waveguides. Faraday rotation, extinction ratios, and insertion loss tests on He-ion implanted slab waveguides of the same material yielded similar results. The work culminated with bond alignment and transfer of 7 μ m -thick crystal-ion-sliced 50 × 480 μ m 2 films onto silicon photonic substrates.

A sun-tracking environmental chamber for the outdoor quantification of CPV modules

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

Faiman, David, E-mail: faiman@bgu.ac.il; Melnichak, Vladimir, E-mail: faiman@bgu.ac.il; Bokobza, Dov, E-mail: faiman@bgu.ac.il

2014-09-26

The paper describes a sun-tracking environmental chamber and its associated fast electronics, devised for the accurate outdoor characterization of CPV cells, receivers, mono-modules, and modules. Some typical measurement results are presented.

A Faraday rotation search for magnetic fields in quasar damped Ly alpha absorption systems

NASA Technical Reports Server (NTRS)

Oren, Abraham L.; Wolfe, Arthur M.

1995-01-01

We present the results of a Faraday rotation survey of 61 radio-bright QSOs conducted at the National Radio Astronomy Observatory (NRAO) Very Large Array (VLA). The Galactic contribution to the Faraday rotation is estimated and subtracted to determine the extragalactic rotation measure (RRM) for each source. Eleven of these QSOs are known to exhibit damped Ly alpha absorption. The rate of incidence of significant Faraday rotation of these 11 sources is compared to the remaining 50 and is found to be higher at the 99.8% confidence level. However, as this is based upon only two detections of Faraday rotation in the damped Ly alpha sample, the result is only tentative. If the two detections in the damped Ly alpha sample are dug to the absorbing systems, then the inferred rotation measure induced by these systems is roughly 250 rad/sq m. The two detections were for the two lowest redshift absorbers in the sample. We find that a rotation measure of 250 rad/sq m would have gone undetected for any other absorber in the damped Ly alpha sample due to the 1/(1 + 2) squared dilution of the observed RRM with redshift. Thus the data are consistent with, but do not prove, the hypothesis that Faraday rotation is a generic property of damped Ly alpha absorbers. We do not confirm the suggestion that the amplitude of RRMs increases with redshift. Rather, the data are consistent with no redshift evolution. We find that the uncertainty in the estimation of the Galactic rotation measure (GRM) is a more serious problem than previously realized for extra-galactic Faraday rotation studies of QSO absorbers. A careful analysis of current methods for estimating GRM indicate that it can be determined to an accuracy of about 15 - 20 rad/sq m. Previous studies underestimated this uncertainty by more than a factor of 2. Due to this uncertainty, rotation measures such as we suspect are associated with damped Ly alpha absorption systems can only be detected at redshifts less than z approximately equal 1.

Implementing a Cancer Fast-track Programme between primary and specialised care in Catalonia (Spain): a mixed methods study

PubMed Central

Prades, J; Espinàs, J A; Font, R; Argimon, J M; Borràs, J M

2011-01-01

Background: The Cancer Fast-track Programme's aim was to reduce the time that elapsed between well-founded suspicion of breast, colorectal and lung cancer and the start of initial treatment in Catalonia (Spain). We sought to analyse its implementation and overall effectiveness. Methods: A quantitative analysis of the programme was performed using data generated by the hospitals on the basis of seven fast-track monitoring indicators for the period 2006–2009. In addition, we conducted a qualitative study, based on 83 semistructured interviews with primary and specialised health professionals and health administrators, to obtain their perception of the programme's implementation. Results: About half of all new patients with breast, lung or colorectal cancer were diagnosed via the fast track, though the cancer detection rate declined across the period. Mean time from detection of suspected cancer in primary care to start of initial treatment was 32 days for breast, 30 for colorectal and 37 for lung cancer (2009). Professionals associated with the implementation of the programme showed that general practitioners faced with suspicion of cancer had changed their conduct with the aim of preventing lags. Furthermore, hospitals were found to have pursued three specific implementation strategies (top-down, consensus-based and participatory), which made for the cohesion and sustainability of the circuits. Conclusion: The programme has contributed to speeding up diagnostic assessment and treatment of patients with suspicion of cancer, and to clarifying the patient pathway between primary and specialised care. PMID:21829194

Impact of fast-track concept elements in the classical pancreatic head resection (Kausch-Whipple procedure).

PubMed

Gastinger, Ingo; Meyer, Frank; Lembcke, Thomas; Schmidt, Uwe; Ptok, Henry; Lippert, Hans

2012-08-01

The aim of the study was to determine statistically significant factors with an impact on the early postoperative surgical outcome. The influence of applied fast-track components on surgical results and early postoperative outcome in 143 consecutive Kausch-Whipple procedure patients was evaluated in a single-center retrospective analysis of a prospective collection of patient-associated pre-, peri- and postoperative data from 1997-2006. The in-hospital mortality rate was 2.8% (n=4). Fast-track measures were shown to have no effect on the morbidity rate in the multi-variate analysis. Over the study period, a decrease of intraoperative infusion volume from 14.2 mL/kg body weight/h in the first year to 10.7 mL/kg body weight/h in the last year was accompanied by an increase in patients requiring intraoperative catecholamines, up from 17% to 95%. The administration of ropivacain/sufentanil via thoracic peri-dural catheter injection initiated in 2000 and now considered the leading analgesic method, was used in 95% of the cases in 2006. Early extubation rate rose from 16.6% to 57.9%. Fast-track aspects in the perioperative management have become more important in several surgical procedure even in those with a greater invasiveness such as Kausch-Whipple. However, such techniques used in peri-operative management of Kausch-Whipple pancreatic-head resections had no impact on the morbidity rate. In addition, the low in-hospital mortality rate was particularly attributed to surgical competence.

A modulation technique for the measurement of the DC longitudinal Faraday effect

NASA Astrophysics Data System (ADS)

Hunte, Carlos

2018-03-01

A modulation of light technique, using a lock-in amplifier, is described and tested to investigate the longitudinal Faraday effect in isotropic media. The Faraday rotation is measured directly from the lock-in amplifier. The Verdet constant and dispersion of lead-silica SF-59 Schott glass, at room temperature of 25 °C, were determined for varying wavelengths and expressions for their wavelength dependence were determined. The Verdet constant of water is also investigated. The results compare extremely well with other studies. The technique is suited to measure very small Verdet constants and can be easily conducted in an upper-level undergraduate laboratory.

Todd, Faraday and the electrical basis of brain activity.

PubMed

Reynolds, Edward

2007-10-01

The origins of our understanding of brain electricity and electrical discharges in epilepsy can be traced to Robert Bentley Todd (1809-60). Todd was influenced by his contemporary in London, Michael Faraday (1791-1867), who in the 1830 s and 1840 s was laying the foundations of our modern understanding of electromagnetism. Todd's concept of nervous polarity, generated in nerve vesicles and transmitted in nerve fibres (neurons in later terminology), was confirmed a century later by the Nobel Prize-winning work of Hodgkin and Huxley, who demonstrated the ionic basis of neuro-transmission, involving the same ions which had had been discovered by Faraday's mentor, Sir Humphry Davy (1778-1829).

VizieR Online Data Catalog: Faraday tomography of foreground towards IC342 (Van Eck+, 2017)

NASA Astrophysics Data System (ADS)

van Eck, C. L.; Haverkorn, M.; Alves, M. I. R.; Beck, R.; de Bruyn, A. G.; Ensslin, T.; Farnes, J. S.; Ferriere, K.; Heald, G.; Horellou, C.; Horneffer, A.; Iacobelli, M.; Jelic, V.; Marti-Vidal, I.; Mulcahy, D. D.; Reich, W.; Rottgering, H. J. A.; Scaife, A. M. M.; Schnitzeler, D. H. F. M.; Sobey, C.; Sridhar, S. S.

2016-11-01

The Faraday depth cube of the IC342 field in polarized intensity, produced from LOFAR HBA observations as part of LOFAR proposal LC0_043. The cube is approximately 5x5 degrees in size, with 4-arcmin resolution, and covers Faraday depths from -25 to +25rad/m2. The detailed specifications are given in the table and in the FITS header. Selected frames from this cubes are shown in the paper in Figures 2 through 5. An extended description of the data processing leading to this cube is included in the paper. (2 data files).

LASER APPLICATIONS AND OTHER TOPICS IN QUANTUM ELECTRONICS: Considerable reduction of thermooptical distortions in Faraday isolators cooled to 77 K

NASA Astrophysics Data System (ADS)

Zheleznov, D. S.; Voitovich, A. V.; Mukhin, I. B.; Palashov, O. V.; Khazanov, E. A.

2006-04-01

It is shown experimentally that cooling of a Faraday isolator to liquid nitrogen temperature considerably suppresses the thermally induced depolarisation and reduces the thermal lens. This leads to an increase in the maximum average laser radiation power passing through the isolator by a factor of more than thirty for the same degree of isolation. It is shown that for the same level of cooling, conventional Faraday isolators can operate for powers up to 10 kW, while isolators with compensation of depolarisation and thermal lens can operate up to 100 kW.

Theoretical model for frequency locking a diode laser with a Faraday cell

NASA Technical Reports Server (NTRS)

Wanninger, P.; Shay, T. M.

1992-01-01

A new method was developed for frequency locking a diode lasers, called 'the Faraday anomalous dispersion optical transmitter (FADOT) laser locking', which is much simpler than other known locking schemes. The FADOT laser locking method uses commercial laser diodes with no antireflection coatings, an atomic Faraday cell with a single polarizer, and an output coupler to form a compound cavity. The FADOT method is vibration insensitive and exhibits minimal thermal expansion effects. The system has a frequency pull in the range of 443.2 GHz (9 A). The method has potential applications in optical communication, remote sensing, and pumping laser excited optical filters.

Note: Comparison experimental results of the laser heterodyne interferometer for angle measurement based on the Faraday effect.

PubMed

Zhang, Enzheng; Chen, Benyong; Zheng, Hao; Teng, Xueying; Yan, Liping

2018-04-01

A laser heterodyne interferometer for angle measurement based on the Faraday effect is proposed. A novel optical configuration, designed by using the orthogonal return method for a linearly polarized beam based on the Faraday effect, guarantees that the measurement beam can return effectively even though an angular reflector has a large lateral displacement movement. The optical configuration and measurement principle are presented in detail. Two verification experiments were performed; the experimental results show that the proposed interferometer can achieve a large lateral displacement tolerance of 7.4 mm and also can realize high precision angle measurement with a large measurement range.

Strong interband Faraday rotation in 3D topological insulator Bi2Se3.

PubMed

Ohnoutek, L; Hakl, M; Veis, M; Piot, B A; Faugeras, C; Martinez, G; Yakushev, M V; Martin, R W; Drašar, Č; Materna, A; Strzelecka, G; Hruban, A; Potemski, M; Orlita, M

2016-01-11

The Faraday effect is a representative magneto-optical phenomenon, resulting from the transfer of angular momentum between interacting light and matter in which time-reversal symmetry has been broken by an externally applied magnetic field. Here we report on the Faraday rotation induced in the prominent 3D topological insulator Bi2Se3 due to bulk interband excitations. The origin of this non-resonant effect, extraordinarily strong among other non-magnetic materials, is traced back to the specific Dirac-type Hamiltonian for Bi2Se3, which implies that electrons and holes in this material closely resemble relativistic particles with a non-zero rest mass.

Note: Comparison experimental results of the laser heterodyne interferometer for angle measurement based on the Faraday effect

NASA Astrophysics Data System (ADS)

Zhang, Enzheng; Chen, Benyong; Zheng, Hao; Teng, Xueying; Yan, Liping

2018-04-01

A laser heterodyne interferometer for angle measurement based on the Faraday effect is proposed. A novel optical configuration, designed by using the orthogonal return method for a linearly polarized beam based on the Faraday effect, guarantees that the measurement beam can return effectively even though an angular reflector has a large lateral displacement movement. The optical configuration and measurement principle are presented in detail. Two verification experiments were performed; the experimental results show that the proposed interferometer can achieve a large lateral displacement tolerance of 7.4 mm and also can realize high precision angle measurement with a large measurement range.

A potassium Faraday anomalous dispersion optical filter

NASA Technical Reports Server (NTRS)

Yin, B.; Shay, T. M.

1992-01-01

The characteristics of a potassium Faraday anomalous dispersion optical filter operating on the blue and near infrared transitions are calculated. The results show that the filter can be designed to provide high transmission, very narrow pass bandwidth, and low equivalent noise bandwidth. The Faraday anomalous dispersion optical filter (FADOF) provides a narrow pass bandwidth (about GHz) optical filter for laser communications, remote sensing, and lidar. The general theoretical model for the FADOF has been established in our previous paper. In this paper, we have identified the optimum operational conditions for a potassium FADOF operating on the blue and infrared transitions. The signal transmission, bandwidth, and equivalent noise bandwidth (ENBW) are also calculated.

Faraday Cage Protects Against Lightning

NASA Technical Reports Server (NTRS)

Jafferis, W.; Hasbrouck, R. T.; Johnson, J. P.

1992-01-01

Faraday cage protects electronic and electronically actuated equipment from lightning. Follows standard lightning-protection principles. Whether lightning strikes cage or cables running to equipment, current canceled or minimized in equipment and discharged into ground. Applicable to protection of scientific instruments, computers, radio transmitters and receivers, and power-switching equipment.

Three-dimensional particle tracking velocimetry using dynamic vision sensors

NASA Astrophysics Data System (ADS)

Borer, D.; Delbruck, T.; Rösgen, T.

2017-12-01

A fast-flow visualization method is presented based on tracking neutrally buoyant soap bubbles with a set of neuromorphic cameras. The "dynamic vision sensors" register only the changes in brightness with very low latency, capturing fast processes at a low data rate. The data consist of a stream of asynchronous events, each encoding the corresponding pixel position, the time instant of the event and the sign of the change in logarithmic intensity. The work uses three such synchronized cameras to perform 3D particle tracking in a medium sized wind tunnel. The data analysis relies on Kalman filters to associate the asynchronous events with individual tracers and to reconstruct the three-dimensional path and velocity based on calibrated sensor information.

[Morbidity and hospital cost reduction in cardiac surgery using a presurgery ambulatory strategy].

PubMed

Ávila-Vanzzini, Nydia; Kuri-Alfaro, Jorge; Rodríguez-Chávez, Laura Leticia; Meléndez-Ramírez, Gabriela; Trevethan-Cravioto, Sergio; Quiroz-Martínez, Alejandro; Herrera-Bello, Héctor; Herrera-Alarcón, Valentín; Martínez-Hernández, Humberto; Martínez-Ríos, Marco Antonio

2010-01-01

In our hospital, the patients that need an elective cardiac surgery are admitted through the admission department on the basis of a waiting list. Since 1999, a fast track to hospitalization program has existed in the National Institute of Cardiology Ignacio Chavez for patients with low surgical risk. Later, in 2004, this program was extended to patients to moderate risk, based on rules accepted worldwide, and our own experience. 1) To compare two ways of admission that are used currently: fast track to hospitalization, against admission department waiting list. We compared major events: death or events that increased the hospital stay by more than 14 days (infections, alterations of rhythm and conduction, reoperations and others), 2) To compare the days of hospitalization and money spent by the hospital. We conformed 2 groups of 347 patients. The admission department waiting list group was admitted before doing their preoperative studies, which is the customary form for hospitalization by our admissions department, while the group of fast track to hospitalization was obligated to have their laboratory exams complete and any other diseases resolved or controlled previously. The monetary cost per patient for the hospital was calculated based on the patient's socioeconomic classification. Student t test was conduncted on independent samples and numerical variables, and Chi square for categorical variables. We considered a p <0.05 to be statistically significant. In average in both groups, 75% underwent valve operation and 25% underwent congenital heart disease repair, 49% were women, age 47 15 years. The comparison between the groups fast track to hospitalization and admission department waiting list group were: Mortality: 4.3% vs. 5.8% (p=0.38). Major events that needed a hospital stay of more than 14 days: 73 vs. 97 cases respectively (p = 0.032). Infections: 22 vs. 29 (p = 0.14). Mediastinitis: 2 vs. 9 respectively (p = 0.033). In-hospital stay: were 11 days vs. 20 days (p = 0.0001), the biggest difference was found in the pre-surgical time: 2 vs. 9 days respectively (p = 0.0001). The postoperative morbidity in general was lower in fast track to hospitalization group, and the mediastinitis showed a decrease with statistical significance. The time interval between hospital admission an operation in fast track to hospitalization group was significantly shorter. We believe that the decrease in the exposure time to nosocomial pathogens present in the hospital environment was directly related to the low number of mediastinitis. Finally, the decrease in time of hospital stay represented a 32% monetary savings for the hospital.

On the Boundary Conditions at an Oscillating Contact Line: A Physical/Numerical Experimental Program

NASA Technical Reports Server (NTRS)

Perlin, Marc; Schultz, William W.

1996-01-01

We will pursue an improved physical understanding and mathematical model for the boundary condition at an oscillating contact line at high Reynolds number. We expect that the body force is locally unimportant for earth-based systems, and that the local behavior may dominate the mechanics of partially-filled reservoirs in the microgravity environment. One important space-based application for this contact-line study is for Faraday-waves. Oscillations in the direction of gravity (or acceleration) can dominate the fluid motion during take-off and reentry with large steady-state accelerations and in orbit, where fluctuations on the order of 10(exp -4)g occur about a zero mean. Our experience with Faraday waves has shown them to be 'cleaner' than those produced by vertical or horizontal oscillation of walls. They are easier to model analytically or computationally, and they do not have strong vortex formation at the bottom of the plate. Hence many, if not most, of the experiments will be performed in this manner. The importance of contact lines in the microgravity environment is well established. We will compare high resolution measurements of the velocity field (lO micro-m resolution) using particle-tracking and particle-image velocimetry as the fluid/fluid interface is approached from the lower fluid. The spatial gradients in the deviation provide additional means to determine an improved boundary condition and a measure of the slip region. Dissipation, the size of the eddy near the contact line, and hysteresis will be measured and compare to linear and nonlinear models of viscous and irrotational but dissipative models.

Maxwell's inductions from Faraday's induction law

NASA Astrophysics Data System (ADS)

Redžić, D. V.

2018-03-01

In article 598 of his Treatise on Electricity and Magnetism (Maxwell 1891 A Treatise on Electricity and Magnetism (Oxford: Clarendon)), Maxwell gives a seminal analysis of Faraday's law of electromagnetic induction. We present a detailed account of the analysis, attempting to reconstruct the missing steps, and discuss some related matters.

Building a better Faraday cage

NASA Astrophysics Data System (ADS)

MartinAlfven; Wright, David; skocpol; Rounce, Graham; Richfield, Jon; W, Nick; wheelsonfire

2015-11-01

In reply to the physicsworld.com news article “Are Faraday cages less effective than previously thought?” (15 September, http://ow.ly/SfklO), about a study that indicated, based on mathematical modelling, that conducting wire-mesh cages may not be as good at excluding electromagnetic radiation as is commonly assumed.

SMAP Faraday Rotation

NASA Technical Reports Server (NTRS)

Le Vine, David

2016-01-01

Faraday rotation is a change in the polarization as signal propagates through the ionosphere. At L-band it is necessary to correct for this change and measurements are made on the spacecraft of the rotation angle. These figures show that there is good agreement between the SMAP measurements (blue) and predictions based on models (red).

Theoretical model for a Faraday anomalous dispersion optical filter

NASA Technical Reports Server (NTRS)

Yin, B.; Shay, T. M.

1991-01-01

A model for the Faraday anomalous dispersion optical filter is presented. The model predicts a bandwidth of 0.6 GHz and a transmission peak of 0.98 for a filter operating on the Cs (D2) line. The model includes hyperfine effects and is valid for arbitrary magnetic fields.

Exact Solution of a Faraday's Law Problem that Includes a Nonlinear Term and Its Implication for Perturbation Theory.

ERIC Educational Resources Information Center

Fulcher, Lewis P.

1979-01-01

Presents an exact solution to the nonlinear Faraday's law problem of a rod sliding on frictionless rails with resistance. Compares the results with perturbation calculations based on the methods of Poisson and Pincare and of Kryloff and Bogoliuboff. (Author/GA)

Faraday's Law and Seawater Motion

ERIC Educational Resources Information Center

De Luca, R.

2010-01-01

Using Faraday's law, one can illustrate how an electromotive force generator, directly utilizing seawater motion, works. The conceptual device proposed is rather simple in its components and can be built in any high school or college laboratory. The description of the way in which the device generates an electromotive force can be instructive not…

Research on anisotropy of fusion-produced protons and neutrons emission from high-current plasma-focus discharges.

PubMed

Malinowski, K; Skladnik-Sadowska, E; Sadowski, M J; Szydlowski, A; Czaus, K; Kwiatkowski, R; Zaloga, D; Paduch, M; Zielinska, E

2015-01-01

The paper concerns fast protons and neutrons from D-D fusion reactions in a Plasma-Focus-1000U facility. Measurements were performed with nuclear-track detectors arranged in "sandwiches" of an Al-foil and two PM-355 detectors separated by a polyethylene-plate. The Al-foil eliminated all primary deuterons, but was penetrable for fast fusion protons. The foil and first PM-355 detector were penetrable for fast neutrons, which were converted into recoil-protons in the polyethylene and recorded in the second PM-355 detector. The "sandwiches" were irradiated by discharges of comparable neutron-yields. Analyses of etched tracks and computer simulations of the fusion-products behavior in the detectors were performed.

Research on anisotropy of fusion-produced protons and neutrons emission from high-current plasma-focus discharges

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

Malinowski, K., E-mail: karol.malinowski@ncbj.gov.pl; Sadowski, M. J.; Szydlowski, A.

2015-01-15

The paper concerns fast protons and neutrons from D-D fusion reactions in a Plasma-Focus-1000U facility. Measurements were performed with nuclear-track detectors arranged in “sandwiches” of an Al-foil and two PM-355 detectors separated by a polyethylene-plate. The Al-foil eliminated all primary deuterons, but was penetrable for fast fusion protons. The foil and first PM-355 detector were penetrable for fast neutrons, which were converted into recoil-protons in the polyethylene and recorded in the second PM-355 detector. The “sandwiches” were irradiated by discharges of comparable neutron-yields. Analyses of etched tracks and computer simulations of the fusion-products behavior in the detectors were performed.

The Flex Track: Flexible Partitioning between Low- and High-Acuity Areas of an Emergency Department

PubMed Central

Laker, Lauren F.; Froehle, Craig M.; Lindsell, Christopher J.; Ward, Michael J.

2014-01-01

Study Objective EDs with both low- and high-acuity treatment areas often have fixed allocation of resources, regardless of demand. We demonstrate the utility of discrete-event simulation to evaluate flexible partitioning between low- and high-acuity ED areas to identify the best operational strategy for subsequent implementation. Methods A discrete-event simulation was used to model patient flow through a 50-bed, urban, teaching ED that handles 85,000 patient visits annually. The ED has historically allocated ten beds to a Fast Track for low-acuity patients. We estimated the effect of a Flex Track policy, which involved switching up to five of these Fast Track beds to serving both low- and high-acuity patients, on patient waiting times. When the high-acuity beds were not at capacity, low-acuity patients were given priority access to flexible beds. Otherwise, high-acuity patients were given priority access to flexible beds. Wait times were estimated for patients by disposition and emergency severity index (ESI) score. Results A Flex Track policy using three flexible beds produced the lowest mean patient waiting of 30.9 (95% CI 30.6–31.2) minutes. The typical Fast Track approach of rigidly separating high- and low–acuity beds produced a mean patient wait time of 40.6 (95% CI 40.2–50.0) minutes, 31% higher than the three-bed Flex Track. A completely flexible ED, where all beds can accommodate any patient, produced mean wait times of 35.1 (95% CI 34.8–35.4) minutes. The results from the three-bed Flex Track scenario were robust, performing well across a range of scenarios involving higher and lower patient volumes and care durations. Conclusion Using discrete-event simulation, we have shown that adding some flexibility into bed allocation between low- and high-acuity can provide substantial reductions in overall patient waiting and a more efficient ED. PMID:24954578

Nonequilibrium Nonideal Nanoplasma Generated by a Fast Single Ion in Condensed Matter

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

Faenov, A. Ya.; Kansai Photon Science Institut, Japan Atomic Energy Agency; Lankin, A. V.

A plasma model of relaxation of a medium in heavy ion tracks in condensed matter is proposed. The model is based on three assumptions: the Maxwell distribution of plasma electrons, localization of plasma inside the track nanochannel and constant values of the plasma electron density and temperature during the X-ray irradiation. It is demonstrated that the plasma relaxation model adequately describes the X-ray spectra observed upon interaction of a fast ion with condensed target. Preassumptions of plasma relaxation model are validated by the molecular dynamics modeling and simulation.

The Interactions between Global Education Initiatives and National Education Policy and Planning Processes: A Comparative Case Study of the Education For All Fast Track Initiative in Rwanda and Ethiopia. CREATE Pathways to Access. Research Monograph No. 67

ERIC Educational Resources Information Center

Bermingham, Desmond

2011-01-01

The Education for All Fast Track Initiative (FTI) was launched by the World Bank in 2002 as a global initiative to help low income countries accelerate progress towards the MDG target of universal primary education by 2015. Over the past decade, the FTI has expanded to become one of the most important initiatives to emerge out of the Dakar World…

Fast track lunar NTR systems assessment for the First Lunar Outpost and its evolvability to Mars

NASA Technical Reports Server (NTRS)

Borowski, Stanley K.; Alexander, Stephen W.

1992-01-01

The objectives of the 'fast track' lunar Nuclear Thermal Rocket (NTR) analysis are to quantify necessary engine/stage characteristics to perform NASA's 'First Lunar Outpost' scenario and to assess the potential for evolution to Mars mission applications. By developing NTR/stage technologies for use in NASA's 'First Lunar Outpost' scenario, NASA will make a major down payment on the key components needed for the follow-on Mars Space Transportation System. A faster, cheaper approach to overall lunar/Mars exploration is expected.

Aerospace plane guidance using geometric control theory

NASA Technical Reports Server (NTRS)

Van Buren, Mark A.; Mease, Kenneth D.

1990-01-01

A reduced-order method employing decomposition, based on time-scale separation, of the 4-D state space in a 2-D slow manifold and a family of 2-D fast manifolds is shown to provide an excellent approximation to the full-order minimum-fuel ascent trajectory. Near-optimal guidance is obtained by tracking the reduced-order trajectory. The tracking problem is solved as regulation problems on the family of fast manifolds, using the exact linearization methodology from nonlinear geometric control theory. The validity of the overall guidance approach is indicated by simulation.

Exhausting Attentional Tracking Resources with a Single Fast-Moving Object

ERIC Educational Resources Information Center

Holcombe, Alex O.; Chen, Wei-Ying

2012-01-01

Driving on a busy road, eluding a group of predators, or playing a team sport involves keeping track of multiple moving objects. In typical laboratory tasks, the number of visual targets that humans can track is about four. Three types of theories have been advanced to explain this limit. The fixed-limit theory posits a set number of attentional…

U.S. masters track participation reveals a stable sex difference in competitiveness.

PubMed

Deaner, Robert O; Addona, Vittorio; Mead, Michael P

2014-10-06

It is well established that men are more likely than women to engage in direct competition, but it is unclear if this reflects social structural conditions or evolved predispositions. These hypotheses can be addressed by quantifying competitiveness in sports and testing if the sex difference is decreasing over time in the U.S., a society where social roles have converged. Study 1 assessed participation and the occurrence of relatively fast performances by masters runners (40-74 years old) at recent road races and track meets. Fast performances occurred over 20 times more often at track meets than at road races. Women comprised 55% of finishers at roads races but only 15-28% of finishers at track meets. Thus, the sex difference in masters track participation can serve as a measure of the sex difference in competitiveness. Study 2 used data from national championship meets and yearly rankings lists to test whether the sex difference in masters track participation decreased from 1988-2012. The sex difference decreased overall, but there was no evidence of change since the late 1990s. Therefore, the sex difference in the willingness to engage in direct sports competition appears to reflect both social structural conditions and evolved predispositions.

A high-speed tracking algorithm for dense granular media

NASA Astrophysics Data System (ADS)

Cerda, Mauricio; Navarro, Cristóbal A.; Silva, Juan; Waitukaitis, Scott R.; Mujica, Nicolás; Hitschfeld, Nancy

2018-06-01

Many fields of study, including medical imaging, granular physics, colloidal physics, and active matter, require the precise identification and tracking of particle-like objects in images. While many algorithms exist to track particles in diffuse conditions, these often perform poorly when particles are densely packed together-as in, for example, solid-like systems of granular materials. Incorrect particle identification can have significant effects on the calculation of physical quantities, which makes the development of more precise and faster tracking algorithms a worthwhile endeavor. In this work, we present a new tracking algorithm to identify particles in dense systems that is both highly accurate and fast. We demonstrate the efficacy of our approach by analyzing images of dense, solid-state granular media, where we achieve an identification error of 5% in the worst evaluated cases. Going further, we propose a parallelization strategy for our algorithm using a GPU, which results in a speedup of up to 10 × when compared to a sequential CPU implementation in C and up to 40 × when compared to the reference MATLAB library widely used for particle tracking. Our results extend the capabilities of state-of-the-art particle tracking methods by allowing fast, high-fidelity detection in dense media at high resolutions.

ACC Effectiveness Review, 1999-2002.

ERIC Educational Resources Information Center

Wallace, Roslyn, Ed.

2002-01-01

These newsletters on Institutional Effectiveness (IE) at Austin Community College (ACC) in Texas include the following articles: (1) "The 'Fast Track'...Students Say It Works!" (2) "Are Students Successfully Completing Distance Learning Courses at ACC?" (3) "Tracking Transfers"; (4) "Math Pilot: Study Skills…

Faraday Rotation for SMOS Retrievals of Ocean Salinity and Soil Moisture

NASA Technical Reports Server (NTRS)

El-Nimri, Salem; Le Vine, David M.

2016-01-01

Faraday rotation is a change in polarization as radiation propagates from the surface through the ionosphere to the sensor. At L-band (1.4 GHz) this change can be significant and can be important for the remote sensing of soil moisture and ocean salinity from space. Consequently, modern L-band radiometers (SMOS, Aquarius and SMOS) are polarimetric to measure Faraday rotation in situ so that a correction can be made. This is done using the ratio of the third and second Stokes parameters. In the case of SMOS this procedure has produced very noisy estimates. An alternate procedure is reported here in which the total electron content is estimated and averaged to reduce noise.

Enhancement of the nonreciprocal magneto-optic effect of TM modes using iron garnet double layers with opposite Faraday rotation

NASA Astrophysics Data System (ADS)

Wallenhorst, M.; Niemöller, M.; Dötsch, H.; Hertel, P.; Gerhardt, R.; Gather, B.

1995-04-01

Garnet films of composition Lu3-xBixFe5-yGayO12 are grown by liquid-phase epitaxy on [111]-oriented substrates of gadolinium gallium garnet. Faraday rotation and saturation magnetization are measured as a function of substitution levels, which range up to x=1.4 and y=1.8, respectively. Nonreciprocal propagation of the TM0 is studied at a wavelength of 1.3 μm. It is shown that the difference between forward and backward propagation constants can be optimized using double layers with opposite sign of the Faraday rotation. Agreement between experiments and calculations is excellent.

Faraday-effect polarimeter-interferometer system for current density measurement on EAST

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

Liu, H. Q.; Jie, Y. X., E-mail: yx-jie@ipp.ac.cn; Zou, Z. Y.

2014-11-15

A multichannel far-infrared laser-based POlarimeter-INTerferometer (POINT) system utilizing the three-wave technique is under development for current density and electron density profile measurements in the EAST tokamak. Novel molybdenum retro-reflectors are mounted in the inside wall for the double-pass optical arrangement. A Digital Phase Detector with 250 kHz bandwidth, which will provide real-time Faraday rotation angle and density phase shift output, have been developed for use on the POINT system. Initial calibration indicates the electron line-integrated density resolution is less than 5 × 10{sup 16} m{sup −2} (∼2°), and the Faraday rotation angle rms phase noise is <0.1°.

Search for the Acoustic Faraday Effect in Superfluid ^3He-B

NASA Astrophysics Data System (ADS)

Lee, Y.; Haard, T. M.; Kycia, J. B.; Halperin, W. P.

1997-03-01

Transverse zero sound is another propagating mode predicted to exist in Fermi liquids by Landau. However, it has been difficult to achieve clear experimental evidence for propagating transverse zero sound in ^3He. A recent theoretical calculation(G.F. Moores and J.A. Sauls, JLTP 91), 13 (1993). showed that this mode may be rather easily detected at very low temperatures in the B-phase of superfluid ^3He. Futhermore, in the presence of a magnetic field the polarization of the sound wave rotates as it propagates, which is analogous to the Faraday effect in optics. We report our preliminary experimental results on the acoustic Faraday effect in ^3He-B.

Faraday waves in a Hele-Shaw cell

NASA Astrophysics Data System (ADS)

Li, Jing; Li, Xiaochen; Chen, Kaijie; Xie, Bin; Liao, Shijun

2018-04-01

We investigate Faraday waves in a Hele-Shaw cell via experimental, numerical, and theoretical studies. Inspired by the Kelvin-Helmholtz-Darcy theory, we develop the gap-averaged Navier-Stokes equations and end up with the stable standing waves with half frequency of the external forced vibration. To overcome the dependency of a numerical model on the experimental parameter of wave length, we take two-phase flow into consideration and a novel dispersion relation is derived. The numerical results compare well with our experimental data, which effectively validates our proposed mathematical model. Therefore, this model can produce robust solutions of Faraday wave patterns and resolve related physical phenomena, which demonstrates the practical importance of the present study.

Use of a genetic algorithm for the analysis of eye movements from the linear vestibulo-ocular reflex

NASA Technical Reports Server (NTRS)

Shelhamer, M.

2001-01-01

It is common in vestibular and oculomotor testing to use a single-frequency (sine) or combination of frequencies [sum-of-sines (SOS)] stimulus for head or target motion. The resulting eye movements typically contain a smooth tracking component, which follows the stimulus, in which are interspersed rapid eye movements (saccades or fast phases). The parameters of the smooth tracking--the amplitude and phase of each component frequency--are of interest; many methods have been devised that attempt to identify and remove the fast eye movements from the smooth. We describe a new approach to this problem, tailored to both single-frequency and sum-of-sines stimulation of the human linear vestibulo-ocular reflex. An approximate derivative is used to identify fast movements, which are then omitted from further analysis. The remaining points form a series of smooth tracking segments. A genetic algorithm is used to fit these segments together to form a smooth (but disconnected) wave form, by iteratively removing biases due to the missing fast phases. A genetic algorithm is an iterative optimization procedure; it provides a basis for extending this approach to more complex stimulus-response situations. In the SOS case, the genetic algorithm estimates the amplitude and phase values of the component frequencies as well as removing biases.

What Is Required to End the AIDS Epidemic as a Public Health Threat by 2030? The Cost and Impact of the Fast-Track Approach.

PubMed

Stover, John; Bollinger, Lori; Izazola, Jose Antonio; Loures, Luiz; DeLay, Paul; Ghys, Peter D

2016-01-01

In 2011 a new Investment Framework was proposed that described how the scale-up of key HIV interventions could dramatically reduce new HIV infections and AIDS-related deaths in low and middle income countries by 2015. This framework included ambitious coverage goals for prevention and treatment services for 2015, resulting in a reduction of new HIV infections by more than half, in line with the goals of the declaration of the UN High Level Meeting in June 2011. However, the approach suggested a leveling in the number of new infections at about 1 million annually-far from the UNAIDS goal of ending AIDS by 2030. In response, UNAIDS has developed the Fast-Track approach that is intended to provide a roadmap to the actions required to achieve this goal. The Fast-Track approach is predicated on a rapid scale-up of focused, effective prevention and treatment services over the next 5 years and then maintaining a high level of programme implementation until 2030. Fast-Track aims to reduce new infections and AIDS-related deaths by 90% from 2010 to 2030 and proposes a set of biomedical, behavioral and enabling intervention targets for 2020 and 2030 to achieve that goal, including the rapid scale-up initiative for antiretroviral treatment known as 90-90-90. Compared to a counterfactual scenario of constant coverage for all services at early-2015 levels, the Fast-Track approach would avert 18 million HIV infections and 11 million deaths from 2016 to 2030 globally. This paper describes the analysis that produced these targets and the estimated resources needed to achieve them in low- and middle-income countries. It indicates that it is possible to achieve these goals with a significant push to achieve rapid scale-up of key interventions between now and 2020. The annual resources required from all sources would rise to US$7.4Bn in low-income countries, US$8.2Bn in lower middle-income countries and US$10.5Bn in upper-middle-income-countries by 2020 before declining approximately 9% by 2030.

Faraday, Dickens and Science Education in Victorian Britain

ERIC Educational Resources Information Center

Melville, Wayne; Allingham, Philip V.

2011-01-01

The achievements of Michael Faraday in the fields of electricity and electrochemistry have led some to describe him as the greatest experimental scientist in history. Charles Dickens was the creative genius behind some of the most memorable characters in literature. In this article, we share an historical account of how the collaboration of these…

The Minus Sign in Faraday's Law Revisited

ERIC Educational Resources Information Center

O'Sullivan, Colm; Hurley, Donal

2013-01-01

By introducing the mathematical concept of orientation, the significance of the minus sign in Faraday's law may be made clear to students with some knowledge of vector calculus. For many students, however, the traditional approach of treating the law as a relationship between positive scalars and of relying on Lenz's law to provide the information…

Web life: Faraday's Cage Is Where You Put Schrödinger's Cat

NASA Astrophysics Data System (ADS)

2012-01-01

Faraday's Cage Is Where You Put Schrödinger's Cat (FCIWYPSC) is a blog written by Cherish Bauer-Reich, who is pursuing a PhD in geophysics at the University of Minnesota while also working part-time as a research engineer at North Dakota State University (NDSU), some 250 miles away.

Faraday's Investigation of Electromagnetic Induction. Experiment No. 21.

ERIC Educational Resources Information Center

Devons, Samuel

This paper focuses on Michael Faraday's experimental research in electricity in the 1830's. Historical notes related to his work are included as well as experiments, his objectives, and illustrations of equipment for the experiments. Examples from his diary are given so that students can attempt to emulate his honest and systematic manner of…

If Maxwell Had Worked between Ampere and Faraday: An Historical Fable with a Pedagogical Moral.

ERIC Educational Resources Information Center

Jammer, Max; Stachel, John

1980-01-01

Describes a new pedagogical approach to electromagnetic theory, in which the displacement current and the Galilean relativity principle are introduced before discussion of the Faraday induction term. Rationale for the alternate order of introducing these concepts and laws is explained, relative to their historical development. (CS)

Various Paths to Faraday's Law

ERIC Educational Resources Information Center

Redzic, Dragan V.

2008-01-01

In a recent note, the author presented a derivation of Faraday's law of electromagnetic induction for a closed filamentary circuit C(t) which is moving at relativistic velocities and also changing its shape as it moves via the magnetic vector potential. Recently, Kholmetskii et al, while correcting an error in an equation, showed that it can be…

Faraday rotation data analysis with least-squares elliptical fitting

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

White, Adam D.; McHale, G. Brent; Goerz, David A.

2010-10-15

A method of analyzing Faraday rotation data from pulsed magnetic field measurements is described. The method uses direct least-squares elliptical fitting to measured data. The least-squares fit conic parameters are used to rotate, translate, and rescale the measured data. Interpretation of the transformed data provides improved accuracy and time-resolution characteristics compared with many existing methods of analyzing Faraday rotation data. The method is especially useful when linear birefringence is present at the input or output of the sensing medium, or when the relative angle of the polarizers used in analysis is not aligned with precision; under these circumstances the methodmore » is shown to return the analytically correct input signal. The method may be pertinent to other applications where analysis of Lissajous figures is required, such as the velocity interferometer system for any reflector (VISAR) diagnostics. The entire algorithm is fully automated and requires no user interaction. An example of algorithm execution is shown, using data from a fiber-based Faraday rotation sensor on a capacitive discharge experiment.« less

Development and first experimental tests of Faraday cup array.

PubMed

Prokůpek, J; Kaufman, J; Margarone, D; Krůs, M; Velyhan, A; Krása, J; Burris-Mog, T; Busold, S; Deppert, O; Cowan, T E; Korn, G

2014-01-01

A new type of Faraday cup, capable of detecting high energy charged particles produced in a high intensity laser-matter interaction environment, has recently been developed and demonstrated as a real-time detector based on the time-of-flight technique. An array of these Faraday cups was designed and constructed to cover different observation angles with respect to the target normal direction. Thus, it allows reconstruction of the spatial distribution of ion current density in the subcritical plasma region and the ability to visualise its time evolution through time-of-flight measurements, which cannot be achieved with standard laser optical interferometry. This is a unique method for two-dimensional visualisation of ion currents from laser-generated plasmas. A technical description of the new type of Faraday cup is introduced along with an ad hoc data analysis procedure. Experimental results obtained during campaigns at the Petawatt High-Energy Laser for Heavy Ion Experiments (GSI, Darmstadt) and at the Prague Asterix Laser System (AS CR) are presented. Advantages and limitations of the used diagnostic system are discussed.

Demonstration of a mid-infrared NO molecular Faraday optical filter.

PubMed

Wu, Kuijun; Feng, Yutao; Li, Juan; Yu, Guangbao; Liu, Linmei; Xiong, Yuanhui; Li, Faquan

2017-12-11

A molecular Faraday optical filter (MFOF) working in the mid-infrared region is realized for the first time. NO molecule was used as the working material of the MFOF for potential applications in atmospheric remote sensing and combustion diagnosis. We develop a complete theory to describe the performance of MFOF by taking both Zeeman absorption and Faraday rotation into account. We also record the Faraday rotation transmission (FRT) signal using a quantum cascade laser over the range of 1,820 cm -1 to 1,922 cm -1 and calibrate it by using a 101.6 mm long solid germanium etalon with a free spectral range of 0.012 cm -1 . Good agreement between the simulation results and experimental data is achieved. The NO-MFOF's transmission characteristics as a function of magnetic field and pressure are studied in detail. Both Comb-like FRT spectrum and single branch transmission spectrum are obtained by changing the magnetic field. The diversity of FRT spectrum expands the range of potential applications in infrared optical remote sensing. This filtering method can also be extended to the lines of other paramagnetic molecules.

Spectral-domain low-coherence interferometry for phase-sensitive measurement of Faraday rotation at multiple depths.

PubMed

Yeh, Yi-Jou; Black, Adam J; Akkin, Taner

2013-10-10

We describe a method for differential phase measurement of Faraday rotation from multiple depth locations simultaneously. A polarization-maintaining fiber-based spectral-domain interferometer that utilizes a low-coherent light source and a single camera is developed. Light decorrelated by the orthogonal channels of the fiber is launched on a sample as two oppositely polarized circular states. These states reflect from sample surfaces and interfere with the corresponding states of the reference arm. A custom spectrometer, which is designed to simplify camera alignment, separates the orthogonal channels and records the interference-related oscillations on both spectra. Inverse Fourier transform of the spectral oscillations in k-space yields complex depth profiles, whose amplitudes and phase difference are related to reflectivity and Faraday rotation within the sample, respectively. Information along a full depth profile is produced at the camera speed without performing an axial scan for a multisurface sample. System sensitivity for the Faraday rotation measurement is 0.86 min of arc. Verdet constants of clear liquids and turbid media are measured at 687 nm.

Polarization Rotation and the Third Stokes Parameter: The Effects of Spacecraft Attitude and Faraday Rotation

NASA Technical Reports Server (NTRS)

Meissner, Thomas; Wentz, Frank J.

2006-01-01

The third Stokes parameter of ocean surface brightness temperatures measured by the WindSat instrument is sensitive to the rotation angle between the polarization vectors at the ocean surface and the instrument. This rotation angle depends on the spacecraft attitude (roll, pitch, yaw) as well as the Faraday rotation of the electromagnetic radiation passing through the Earth's ionosphere. Analyzing the WindSat antenna temperatures, we find biases in the third Stokes parameter as function of the along-scan position of up to 1.5 K in all feedhorns. This points to a misspecification of the reported spacecraft attitude. A single attitude correction of -0.16deg roll and 0.18deg pitch for the whole instrument eliminates all the biases. We also study the effect of Faraday rotation at 10.7 GHz on the accuracy of the third Stokes parameter and the sea surface wind direction retrieval and demonstrate how this error can be corrected using values from the International Reference Ionosphere for the total electron content when computing Faraday rotation.

Comparison of the calibration of ionospheric delay in VLBI data by the methods of dual frequency and Faraday rotation

NASA Technical Reports Server (NTRS)

Scheid, J. A.

1985-01-01

When both S-band and X-band data are recorded for a signal which has passed through the ionosphere, it is possible to calculate the ionospheric contribution to signal delay. In Very Long Baseline Interferometry (VLBI) this method is used to calibrate the ionosphere. In the absence of dual frequency data, the ionospheric content measured by Faraday rotation, using a signal from a geostationary satellite, is mapped to the VLBI observing direction. The purpose here is to compare the ionospheric delay obtained by these two methods. The principal conclusions are: (1) the correlation between delays obtained by these two methods is weak; (2) in mapping Faraday rotation measurements to the VLBI observing direction, a simple mapping algorithm which accounts only for changes in hour angle and elevation angle is better than a more elaborate algorithm which includes solar and geomagnetic effects; (3) fluctuations in the difference in total electron content as seen by two antennas defining a baseline limit the application of Faraday rotation data to VLBI.

Effects of interband transitions on Faraday rotation in metallic nanoparticles.

PubMed

Wysin, G M; Chikan, Viktor; Young, Nathan; Dani, Raj Kumar

2013-08-14

The Faraday rotation in metallic nanoparticles is considered based on a quantum model for the dielectric function ϵ(ω) in the presence of a DC magnetic field B. We focus on effects in ϵ(ω) due to interband transitions (IBTs), which are important in the blue and ultraviolet for noble metals used in plasmonics. The dielectric function is found using the perturbation of the electron density matrix due to the optical field of the incident electromagnetic radiation. The calculation is applied to transitions between two bands (d and p, for example) separated by a gap, as one finds in gold at the L-point of the Fermi surface. The result of the DC magnetic field is a shift in the effective optical frequency causing IBTs by ±μBB/ħ, where opposite signs are associated with left/right circular polarizations. The Faraday rotation for a dilute solution of 17 nm diameter gold nanoparticles is measured and compared with both the IBT theory and a simpler Drude model for the bound electron response. Effects of the plasmon resonance mode on Faraday rotation in nanoparticles are also discussed.

Effects of Faraday Rotation Observed in Filter Magnetograph Data

NASA Technical Reports Server (NTRS)

Hagyard, Mona J.; Adams, Mitzi L.; Smith, J. E.; West, Edward A.

1999-01-01

In this paper we analyze the effects of Faraday rotation on the azimuth of the transverse magnetic field from observations taken with the Marshall Space Flight Center's vector magnetograph for a simple sunspot observed on June 9, 1985. Vector magnetograms were obtained over the wavelength interval of 170 mA redward of line center of the Fe I 5250.22 A spectral line to 170 mA to the blue, in steps of 10 mA. These data were analyzed to produce the variation of the azimuth as a function of wavelength at each pixel over the field of vi ew of the sunspot. At selected locations in the sunspot, curves of the observed variation of azimuth with wavelength were compared with model calculations for the amount of Faraday rotation of the azimuth. From these comparisons we derived the amount of rotation as functions of bo th the magnitude and inclination of the sunspot's field and deduced the ranges of these field values for which Faraday rotation presents a significant problem in observations taken near the center of a spectral line.

The Interaction of Intense Laser Pulses with Preformed Plasmas for Fast Ignitor Studies

NASA Astrophysics Data System (ADS)

MacKinnon, A. J.

1998-11-01

The understanding of the interaction of intense picosecond laser pulses with preformed plasmas is essential for the fast ignitor concept. One of the major issues for this scheme concerns the propagation of ultra intense laser pulses through near critical density plasmas. Measurements of self-channelling of picosecond pulses due to relativistic and ponderomotive expulsion effects have recently been obtained in preformed plasmas at laser irradiances between 5-9x10^18 Wcm-2 footnote M. Borghesi et al, Phys. Rev Lett 78, 879 (1997).. The channel expansion after the laser pulse has been measured and an expansion velocity up to 1x10^9cms-1. was observed, implying ion energies around 1MeV. In addition, it was observed via Faraday rotation of an optical probe that the self focused channel is surrounded by a multi-megagauss magnetic field as predicted by 3D PIC simulations footnote A. Pukhov and J. Meyer-ter-Vehn, Phys. Rev Lett 76, 3975 (1996); M. Borghesi et al, Phys. Rev. Lett. 80, 5137 (1998).. The existence of this magnetic field is important for magnetic self-channelling of the relativistic electrons to high plasma densities. Good agreement was observed between the measurements and the 3D PIC simulations. The experimental results and PIC simulations will be presented and their relevance to the fast ignitor concept will be discussed.

Excitation of slow waves in front of an ICRF antenna in a basic plasma experiment

NASA Astrophysics Data System (ADS)

Soni, Kunal; van Compernolle, Bart; Crombe, Kristel; van Eester, Dirk

2017-10-01

Recent results of ICRF experiments at the Large Plasma Device (LAPD) indicate parasitic coupling to the slow wave by the fast wave antenna. Plasma parameters in LAPD are similar to the scrape-off layer of current fusion devices. The machine has a 17 m long, 60 cm diameter magnetized plasma column with typical plasma parameters ne 1012 -1013 cm-3, Te 1 - 10 eV and B0 1000 G. It was found that coupling to the slow mode occurs when the plasma density in front of the antenna is low enough such that the lower hybrid resonance is present in the plasma. The radial density profile is tailored to allow for fast mode propagation in the high density core and slow mode propagation in the low density edge region. Measurements of the wave fields clearly show two distinct modes, one long wavelength m=1 fast wave mode in the core and a short wavelength backward propagating mode in the edge. Perpendicular wave numbers compare favorably to the predicted values. The experiment was done for varying frequencies, ω /Ωi = 25 , 6 and 1.5. Future experiments will investigate the dependence on antenna tilt angle with respect to the magnetic field, with and without Faraday screen. This work is performed at the Basic Plasma Science Facility, sponsored jointly by DOE and NSF.

Scintillator based detector for fast-ion losses induced by magnetohydrodynamic instabilities in the ASDEX upgrade tokamak.

PubMed

García-Muñoz, M; Fahrbach, H-U; Zohm, H

2009-05-01

A scintillator based detector for fast-ion losses has been designed and installed on the ASDEX upgrade (AUG) tokamak [A. Herrmann and O. Gruber, Fusion Sci. Technol. 44, 569 (2003)]. The detector resolves in time the energy and pitch angle of fast-ion losses induced by magnetohydrodynamics (MHD) fluctuations. The use of a novel scintillator material with a very short decay time and high quantum efficiency allows to identify the MHD fluctuations responsible for the ion losses through Fourier analysis. A Faraday cup (secondary scintillator plate) has been embedded behind the scintillator plate for an absolute calibration of the detector. The detector is mounted on a manipulator to vary its radial position with respect to the plasma. A thermocouple on the inner side of the graphite protection enables the safety search for the most adequate radial position. To align the scintillator light pattern with the light detectors a system composed by a lens and a vacuum-compatible halogen lamp has been allocated within the detector head. In this paper, the design of the scintillator probe, as well as the new technique used to analyze the data through spectrograms will be described. A last section is devoted to discuss the diagnosis prospects of this method for ITER [M. Shimada et al., Nucl. Fusion 47, S1 (2007)].

Velocity-free attitude coordinated tracking control for spacecraft formation flying.

PubMed

Hu, Qinglei; Zhang, Jian; Zhang, Youmin

2018-02-01

This article investigates the velocity-free attitude coordinated tracking control scheme for a group of spacecraft with the assumption that the angular velocities of the formation members are not available in control feedback. Initially, an angular velocity observer is constructed based on each individual's attitude quarternion. Then, the distributed attitude coordinated control law is designed by using the observed states, in which adaptive control method is adopted to handle the external disturbances. Stability of the overall closed-loop system is analyzed theoretically, which shows the system trajectory converges to a small set around origin with fast convergence rate. Numerical simulations are performed to demonstrate fast convergence and improved tracking performance of the proposed control strategy. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

Faraday signature of magnetic helicity from reduced depolarization

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

Brandenburg, Axel; Stepanov, Rodion

2014-05-10

Using one-dimensional models, we show that a helical magnetic field with an appropriate sign of helicity can compensate the Faraday depolarization resulting from the superposition of Faraday-rotated polarization planes from a spatially extended source. For radio emission from a helical magnetic field, the polarization as a function of the square of the wavelength becomes asymmetric with respect to zero. Mathematically speaking, the resulting emission occurs then either at observable or at unobservable (imaginary) wavelengths. We demonstrate that rotation measure (RM) synthesis allows for the reconstruction of the underlying Faraday dispersion function in the former case, but not in the latter.more » The presence of positive magnetic helicity can thus be detected by observing positive RM in highly polarized regions in the sky and negative RM in weakly polarized regions. Conversely, negative magnetic helicity can be detected by observing negative RM in highly polarized regions and positive RM in weakly polarized regions. The simultaneous presence of two magnetic constituents with opposite signs of helicity is shown to possess signatures that can be quantified through polarization peaks at specific wavelengths and the gradient of the phase of the Faraday dispersion function. Similar polarization peaks can tentatively also be identified for the bi-helical magnetic fields that are generated self-consistently by a dynamo from helically forced turbulence, even though the magnetic energy spectrum is then continuous. Finally, we discuss the possibility of detecting magnetic fields with helical and non-helical properties in external galaxies using the Square Kilometre Array.« less

Structure, spectra and thermal, mechanical, Faraday rotation properties of novel diamagnetic SeO2-PbO-Bi2O3-B2O3 glasses

NASA Astrophysics Data System (ADS)

Chen, Qiuling; Su, Kai; Li, Yantao; Zhao, Zhiwei

2018-06-01

Faraday rotation diamagnetic glass has attracted research attentions in photonics, sensing and magneto optical devices due to their high refractive index, wide transmittance in UV and Fourier transform infrared (FT-IR) range and temperature independent Faraday rotation. Selenite modified heavy metal oxides glasses with composition of xSeO2-(10-x) B2O3-45PbO-45Bi2O3 (x = 0, 1, 5 and 10mol%) and 15%SeO2-40%PbO-45%Bi2O3 have been fabricated by melt-quenching method in present study. The influence of SeO2 on glass forming ability, thermal, mechanical properties and Faraday rotation were evaluated through X-ray Diffraction (XRD), Fourier transforms infrared spectra (FT-IR), Raman, X-ray photoelectron spectroscopy (XPS), differential scanning calorimetry (DSC), Vicker's hardness and Verdet constant measurements. XRD spectra reveal that the good vitrification was achieved for glass with SeO2 amounts ≤10% even without B2O3. FT-IR, Raman and XPS spectra ascertain the existence of characteristic vibration of SeO4, SeO3, PbO4, BiO3 and BO3 units. The incorporation of SeO2 increases the connectivity of glassy network by increasing the Tg, thermal stability and mechanical hardness. The small band gap, high polarizable Se4+ ions and isolated SeO3 units contribute to Faraday rotation improvement.

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

Shao, Michael; Nemati, Bijan; Zhai, Chengxing

We present an approach that significantly increases the sensitivity for finding and tracking small and fast near-Earth asteroids (NEAs). This approach relies on a combined use of a new generation of high-speed cameras which allow short, high frame-rate exposures of moving objects, effectively 'freezing' their motion, and a computationally enhanced implementation of the 'shift-and-add' data processing technique that helps to improve the signal-to-noise ratio (SNR) for detection of NEAs. The SNR of a single short exposure of a dim NEA is insufficient to detect it in one frame, but by computationally searching for an appropriate velocity vector, shifting successive framesmore » relative to each other and then co-adding the shifted frames in post-processing, we synthetically create a long-exposure image as if the telescope were tracking the object. This approach, which we call 'synthetic tracking,' enhances the familiar shift-and-add technique with the ability to do a wide blind search, detect, and track dim and fast-moving NEAs in near real time. We discuss also how synthetic tracking improves the astrometry of fast-moving NEAs. We apply this technique to observations of two known asteroids conducted on the Palomar 200 inch telescope and demonstrate improved SNR and 10 fold improvement of astrometric precision over the traditional long-exposure approach. In the past 5 yr, about 150 NEAs with absolute magnitudes H = 28 (∼10 m in size) or fainter have been discovered. With an upgraded version of our camera and a field of view of (28 arcmin){sup 2} on the Palomar 200 inch telescope, synthetic tracking could allow detecting up to 180 such objects per night, including very small NEAs with sizes down to 7 m.« less

First results of the silicon telescope using an 'artificial retina' for fast track finding

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

Neri, N.; Abba, A.; Caponio, F.

We present the first results of the prototype of a silicon tracker with trigger capabilities based on a novel approach for fast track finding. The working principle of the 'artificial retina' is inspired by the processing of visual images by the brain and it is based on extensive parallelization of data distribution and pattern recognition. The algorithm has been implemented in commercial FPGAs in three main logic modules: a switch for the routing of the detector hits, a pool of engines for the digital processing of the hits, and a block for the calculation of the track parameters. The architecturemore » is fully pipelined and allows the reconstruction of real-time tracks with a latency less then 100 clock cycles, corresponding to 0.25 microsecond at 400 MHz clock. The silicon telescope consists of 8 layers of single-sided silicon strip detectors with 512 strips each. The detector size is about 10 cm x 10 cm and the strip pitch is 183 μm. The detectors are read out by the Beetle chip, a custom ASICs developed for LHCb, which provides the measurement of the hit position and pulse height of 128 channels. The 'artificial retina' algorithm has been implemented on custom data acquisition boards based on FPGAs Xilinx Kintex 7 lx160. The parameters of the tracks detected are finally transferred to host PC via USB 3.0. The boards manage the read-out ASICs and the sampling of the analog channels. The read-out is performed at 40 MHz on 4 channels for each ASIC that corresponds to a decoding of the telescope information at 1.1 MHz. We report on the first results of the fast tracking device and compare with simulations. (authors)« less

Real-Time Robust Tracking for Motion Blur and Fast Motion via Correlation Filters

PubMed Central

Xu, Lingyun; Luo, Haibo; Hui, Bin; Chang, Zheng

2016-01-01

Visual tracking has extensive applications in intelligent monitoring and guidance systems. Among state-of-the-art tracking algorithms, Correlation Filter methods perform favorably in robustness, accuracy and speed. However, it also has shortcomings when dealing with pervasive target scale variation, motion blur and fast motion. In this paper we proposed a new real-time robust scheme based on Kernelized Correlation Filter (KCF) to significantly improve performance on motion blur and fast motion. By fusing KCF and STC trackers, our algorithm also solve the estimation of scale variation in many scenarios. We theoretically analyze the problem for CFs towards motions and utilize the point sharpness function of the target patch to evaluate the motion state of target. Then we set up an efficient scheme to handle the motion and scale variation without much time consuming. Our algorithm preserves the properties of KCF besides the ability to handle special scenarios. In the end extensive experimental results on benchmark of VOT datasets show our algorithm performs advantageously competed with the top-rank trackers. PMID:27618046

The Difficulty of Maintaining Positive Intervention Effects: A Look at Disruptive Behavior, Deviant Peer Relations, and Social Skills During the Middle School Years

PubMed Central

2013-01-01

This paper examines the effects of the Fast Track preventive intervention on youths’ functioning in three domains: disruptive behavior problems, involvement with deviant peers, and social skills during the middle school years. Eight hundred ninety-one children had been randomly assigned by sets of schools within four sites to intervention (n = 445) or to control (n = 446) conditions. In contrast to prior findings of the effectiveness of the Fast Track intervention during the elementary school years, the current findings indicate that Fast Track had little overall impact on children’s functioning in these domains during this age period. There were positive intervention effects on only 2 of 17 outcomes examined. Although the intervention had positive impact on children’s hyperactive and self-reported delinquent behaviors in seventh grade, there were no intervention effects on other externalizing behavior problems or on social skills, and there was a negative intervention effect on children’s involvement with deviant peers during this age period. PMID:24319308

F-16 MMC Strafe in Mountainous Terrain

DTIC Science & Technology

2016-04-01

19 Figure 10. Steep fast (480 KIAS ) high-angle strafe...a fast (480 KIAS in this example) approach varies from the recovery radius (4000 feet in this case) and down track range prior to recovery initiation...Steep fast (480 KIAS ) high-angle strafe Alternate Analysis The F-16 community, to some extent, has adopted high-angle strafe as the de facto strafe

Faraday Rotation Studies of Indium Antimonide and CADMIUM(1-X) Manganese(x) Telluride

NASA Astrophysics Data System (ADS)

Jimenez Gonzalez, Hector J.

Faraday rotation has been studied in two material systems: narrow-gap InSb and wide-gap Cd_ {1-x}Mn_{x}Te. The measurements were done in the infrared region using high magnetic fields up to 150 kG. The Faraday rotation of n-type InSb has been measured for wavelengths between 8.0 and 13.0 μm at 9 K, using magnetic fields up to 150 kG. Measurements were made on samples with nominal carrier concentrations of 1 times 10^{14 }, 6 times 10 ^{14}, 1 times 10^{15}, and 5 times 10^{15} cm^{-3}. The experimental results have been successfully analyzed in terms of intraband and interband transitions at the Gamma point in the Brillouin zone, using a quantum-mechanical treatment. In this approach, there are three contributions to the Faraday rotation: (a) interband, (b) plasma, and (c) spin contributions. The interband contribution is dominant in the low concentration samples where the plasma and spin contributions, which are due to the free carriers, are small. At high carrier concentrations the spin and plasma contributions are dominant. In the low-magnetic -field regime the interband and plasma contributions are linearly proportional to the magnetic field and become small. This makes the spin contribution the leading contribution to the Faraday rotation at low magnetic fields. The 4 -band k cdot p Pidgeon and Brown model was used to calculate the energy levels and the matrix elements for these transitions. Quantum oscillatory effects were observed at low magnetic field. Cyclotron resonance absorption was observed in all samples for wavelengths _sp{~}{>}16.0 mum. The Faraday rotation of Cd_{1 -x}Mn_{x}Te has been measured for x = 0 to 0.27 at 300 and 77 K for photon energies between 0.1 and 1.5 eV, corresponding to wavelengths of 12.0 and 0.8 mum, respectively. We have developed a multioscillator model for the Faraday rotation using an analytical expression for the refractive index that includes contributions from interband transitions at the Gamma, L, and X points of the Brillouin zone as well as the lattice contribution from optical phonons. The multioscillator model explains the measured behavior of the Verdet constant as a function of photon energy for all the above values of x at both temperatures. This model has also been applied successfully to Faraday rotation data for Cd_ {1-x}Mn_{x}Te and Zn_{1-x}Mn _{x}Te from previous studies. (Copies available exclusively from MIT Libraries, Rm. 14-0551, Cambridge, MA 02139-4307. Ph. 617-253-5668; Fax 617-253 -1690.).

FastSim: A Fast Simulation for the SuperB Detector

NASA Astrophysics Data System (ADS)

Andreassen, R.; Arnaud, N.; Brown, D. N.; Burmistrov, L.; Carlson, J.; Cheng, C.-h.; Di Simone, A.; Gaponenko, I.; Manoni, E.; Perez, A.; Rama, M.; Roberts, D.; Rotondo, M.; Simi, G.; Sokoloff, M.; Suzuki, A.; Walsh, J.

2011-12-01

We have developed a parameterized (fast) simulation for detector optimization and physics reach studies of the proposed SuperB Flavor Factory in Italy. Detector components are modeled as thin sections of planes, cylinders, disks or cones. Particle-material interactions are modeled using simplified cross-sections and formulas. Active detectors are modeled using parameterized response functions. Geometry and response parameters are configured using xml files with a custom-designed schema. Reconstruction algorithms adapted from BaBar are used to build tracks and clusters. Multiple sources of background signals can be merged with primary signals. Pattern recognition errors are modeled statistically by randomly misassigning nearby tracking hits. Standard BaBar analysis tuples are used as an event output. Hadronic B meson pair events can be simulated at roughly 10Hz.

International collaborative project to compare and track the nutritional composition of fast foods.

PubMed

2012-07-27

Chronic diseases are the leading cause of premature death and disability in the world with over-nutrition a primary cause of diet-related ill health. Excess quantities of energy, saturated fat, sugar and salt derived from fast foods contribute importantly to this disease burden. Our objective is to collate and compare nutrient composition data for fast foods as a means of supporting improvements in product formulation. Surveys of fast foods will be done in each participating country each year. Information on the nutrient composition for each product will be sought either through direct chemical analysis, from fast food companies, in-store materials or from company websites. Foods will be categorized into major groups for the primary analyses which will compare mean levels of saturated fat, sugar, sodium, energy and serving size at baseline and over time. Countries currently involved include Australia, New Zealand, France, UK, USA, India, Spain, China and Canada, with more anticipated to follow. This collaborative approach to the collation and sharing of data will enable low-cost tracking of fast food composition around the world. This project represents a significant step forward in the objective and transparent monitoring of industry and government commitments to improve the quality of fast foods.

UKIRT fast guide system improvements

NASA Astrophysics Data System (ADS)

Balius, Al; Rees, Nicholas P.

1997-09-01

The United Kingdom Infra-Red Telescope (UKIRT) has recently undergone the first major upgrade program since its construction. One part of the upgrade program was an adaptive tip-tilt secondary mirror closed with a CCD system collectively called the fast guide system. The installation of the new secondary and associated systems was carried out in the first half of 1996. Initial testing of the fast guide system has shown great improvement in guide accuracy. The initial installation included a fixed integration time CCD. In the first part of 1997 an integration time controller based on computed guide star luminosity was implemented in the fast guide system. Also, a Kalman type estimator was installed in the image tracking loop based on a dynamic model and knowledge of the statistical properties of the guide star position error measurement as a function of computed guide star magnitude and CCD integration time. The new configuration was tested in terms of improved guide performance nd graceful degradation when tracking faint guide stars. This paper describes the modified fast guide system configuration and reports the results of performance tests.

Recent Progress of the HL-2A Multi-Channel HCOOH Laser Interferometer/Polarimeter

NASA Astrophysics Data System (ADS)

Li, Yonggao; Zhou, Yan; Deng, Zhongchao; Li, Yuan; Yi, Jiang; Wang, Haoxi

2015-05-01

A multichannel methanoic acid (HCOOH, λ = 432.5 μm) laser interferometer/polarimeter is being developed from the previous eight-channel hydrogen cyanide (HCN, λ = 337 μm) laser interferometer in the HL-2A tokamak. A conventional Michelson-type interometer is used for the electron density measurement, and a Dodel-Kunz-type polarimeter is used for the Faraday rotation effect measurement, respectively. Each HCOOH laser can produce a linearly polarized radiation at a power lever of ˜30 mW, and a power stability <10% in 50 min. A beam waist (diameter d0 ≈12.0 mm, about 200 mm away from the outlet) is finally determined through a chopping modulation technique. The latest optical layout of the interferometer/polarimeter has been finished, and the hardware data processing system based on the fast Fourier transform phase-comparator technique is being explored. In order to demonstrate the feasibility of the diagnostic scheme, two associated bench simulation experiments were carried out in the laboratory, in which the plasma was simulated by a piece of polytetrafluoroethene plate, and the Faraday rotation effect was simulated by a rotating half-wave plate. Simulation results agreed well with the initial experimental conditions. At present, the HCOOH laser interferometer/polarimeter system is being assembled on HL-2A, and is planned to be applied in the 2014-2015 experimental campaign. supported by the National Magnetic Confinement Fusion Science Programs of China (Nos. 2010GB101002 and 2014GB109001), and National Natural Science Foundation of China (Nos. 11075048 and 11275059)

Reflections of a Faraday Challenge Day Leader

ERIC Educational Resources Information Center

Sewell, Keira

2014-01-01

Keira Sewell has just finished her second year as a Challenge Leader for the Faraday Challenge, a STEM-based scheme run by the Institution of Engineering and Technology. Aimed at 12-13 year-old students, its purpose is to engage students in future careers in engineering. Each year, a new challenge is held in over sixty schools and universities…

Highlights from Faraday Discussion 182: Solid Oxide Electrolysis: Fuels and Feedstocks from Water and Air, York, UK, July 2015.

PubMed

Stefan, Elena; Norby, Truls

2016-01-31

The rising importance of converting high peak electricity from renewables to fuels has urged field specialists to organize this Faraday Discussion on Solid Oxide Electrolysis. The topic is of essential interest in order to achieve a greater utilization of renewable energy and storage at higher densities.

A Mobile Phone Faraday Cage

ERIC Educational Resources Information Center

French, M. M. J.

2011-01-01

A Faraday cage is an interesting physical phenomenon where an electromagnetic wave can be excluded from a volume of space by enclosure with an electrically conducting material. The practical application of this in the classroom is to block the signal to a mobile phone by enclosing it in a metal can. The background of the physics behind this is…

Conditions for the Validity of Faraday's Law of Induction and Their Experimental Confirmation

ERIC Educational Resources Information Center

Lopez-Ramos, A.; Menendez, J. R.; Pique, C.

2008-01-01

This paper, as its main didactic objective, shows the conditions needed for the validity of Faraday's law of induction. Inadequate comprehension of these conditions has given rise to several paradoxes about the issue; some are analysed and solved in this paper in the light of the theoretical deduction of the induction law. Furthermore, an…

Following Michael Faraday's Footprints

ERIC Educational Resources Information Center

Galeano, Javier

2011-01-01

Last fall I had the good fortune of receiving financial support to shoot a documentary about Michael Faraday. I took the opportunity to learn more about this great experimentalist and to visit the highlights of places in his life. In this paper, I would like to share a list and description of some of the most remarkable places in London suitable…

Exploring Faraday's Law of Electrolysis Using Zinc-Air Batteries with Current Regulative Diodes

ERIC Educational Resources Information Center

Kamata, Masahiro; Paku, Miei

2007-01-01

Current regulative diodes (CRDs) are applied to develop new educational experiments on Faraday's law by using a zinc-air battery (PR2330) and a resistor to discharge it. The results concluded that the combination of zinc-air batteries and the CRD array is simpler, less expensive, and quantitative and gives accurate data.

Highlights from the Faraday Discussion on Ionic Liquids: From Fundamental Properties to Practical Applications, Cambridge, UK, September 2017.

PubMed

Aldous, Leigh; Bendova, Magdalena; Gonzalez-Miquel, Maria; Swadźba-Kwaśny, Małgorzata

2018-05-22

For the third time, a Faraday Discussion addressed ionic liquids. Encompassing the wealth of research in this field, the contributions ranged from fundamental insights to the diverse applications of ionic liquids. Lively discussions initiated in the lecture hall and during poster sessions then seamlessly continued during the social program.

A Bright Spark: Open Teaching of Science Using Faraday's Lectures on Candles

ERIC Educational Resources Information Center

Walker, Mark; Groger, Martin; Schutler, Kirsten; Mosler, Bernd

2008-01-01

As well as being a founding father of modern chemistry and physics Michael Faraday was also a skilled lecturer, able to explain scientific principles and ideas simply and concisely to nonscientific audiences. However science didactics today emphasizes the use of open and student-centered methods of teaching in which students find and develop…

Elliptical polarization of near-resonant linearly polarized probe light in optically pumped alkali metal vapor

PubMed Central

Li, Yingying; Wang, Zhiguo; Jin, Shilong; Yuan, Jie; Luo, Hui

2017-01-01

Optically pumped alkali metal atoms currently provide a sensitive solution for magnetic microscopic measurements. As the most practicable plan, Faraday rotation of linearly polarized light is extensively used in spin polarization measurements of alkali metal atoms. In some cases, near-resonant Faraday rotation is applied to improve the sensitivity. However, the near-resonant linearly polarized probe light is elliptically polarized after passing through optically pumped alkali metal vapor. The ellipticity of transmitted near-resonant probe light is numerically calculated and experimentally measured. In addition, we also analyze the negative impact of elliptical polarization on Faraday rotation measurements. From our theoretical estimate and experimental results, the elliptical polarization forms an inevitable error in spin polarization measurements. PMID:28216649

Faraday-Michelson system for quantum cryptography.

PubMed

Mo, Xiao-Fan; Zhu, Bing; Han, Zheng-Fu; Gui, You-Zhen; Guo, Guang-Can

2005-10-01

Quantum key distribution provides unconditional security for communication. Unfortunately, current experimental schemes are not suitable for long-distance fiber transmission because of phase drift or Rayleigh backscattering. In this Letter we present a unidirectional intrinsically stable scheme that is based on Michelson-Faraday interferometers, in which ordinary mirrors are replaced with 90 degree Faraday mirrors. With the scheme, a demonstration setup was built and excellent stability of interference fringe visibility was achieved over a fiber length of 175 km. Through a 125 km long commercial communication fiber cable between Beijing and Tianjin, the key exchange was performed with a quantum bit-error rate of less than 6%, which is to our knowledge the longest reported quantum key distribution experiment under field conditions.

More vertical etch profile using a Faraday cage in plasma etching

NASA Astrophysics Data System (ADS)

Cho, Byeong-Ok; Hwang, Sung-Wook; Ryu, Jung-Hyun; Moon, Sang Heup

1999-05-01

Scanning electron microscope images of sidewalls obtained by plasma etching of an SiO2 film with and without a Faraday cage have been compared. When the substrate film is etched in the Faraday cage, faceting is effectively suppressed and the etch profile becomes more vertical regardless of the process conditions. This is because the electric potential in the cage is nearly uniform and therefore distortion of the electric field at the convex corner of a microfeature is prevented. The most vertical etch profile is obtained when the cage is used in fluorocarbon plasmas, where faceting is further suppressed due to the decrease in the chemical sputtering yield and the increase in the radical/ion flux on the substrate.

Linearity of the Faraday-rotation-type ac magnetic-field sensor with a ferrimagnetic or ferromagnetic rotator film

NASA Astrophysics Data System (ADS)

Mori, Hiroshi; Asahara, Yousuke

1996-03-01

We analyze the linearity and modulation depth of ac magnetic-field sensors or current sensors, using a ferrimagnetic or ferromagnetic film as the Faraday rotator and employing the detection of only the zeroth-order optical diffraction component from the rotator. It is theoretically shown that for this class of sensor the condition of a constant modulation depth and that of a constant ratio error give an identical series of curves for the relationship between Faraday rotation angle greater than or equals V and polarizer/analyzer relative angle Phi . We give some numerical examples to demonstrate the usefulness of the result with reference to a rare-earth iron garnet film as the rotator.

Terahertz spectroscopy on Faraday and Kerr rotations in a quantum anomalous Hall state.

PubMed

Okada, Ken N; Takahashi, Youtarou; Mogi, Masataka; Yoshimi, Ryutaro; Tsukazaki, Atsushi; Takahashi, Kei S; Ogawa, Naoki; Kawasaki, Masashi; Tokura, Yoshinori

2016-07-20

Electrodynamic responses from three-dimensional topological insulators are characterized by the universal magnetoelectric term constituent of the Lagrangian formalism. The quantized magnetoelectric coupling, which is generally referred to as topological magnetoelectric effect, has been predicted to induce exotic phenomena including the universal low-energy magneto-optical effects. Here we report the experimental indication of the topological magnetoelectric effect, which is exemplified by magneto-optical Faraday and Kerr rotations in the quantum anomalous Hall states of magnetic topological insulator surfaces by terahertz magneto-optics. The universal relation composed of the observed Faraday and Kerr rotation angles but not of any material parameters (for example, dielectric constant and magnetic susceptibility) well exhibits the trajectory towards the fine structure constant in the quantized limit.

Transfer matrix approach for the Kerr and Faraday rotation in layered nanostructures.

PubMed

Széchenyi, Gábor; Vigh, Máté; Kormányos, Andor; Cserti, József

2016-09-21

To study the optical rotation of the polarization of light incident on multilayer systems consisting of atomically thin conductors and dielectric multilayers we present a general method based on transfer matrices. The transfer matrix of the atomically thin conducting layer is obtained using the Maxwell equations. We derive expressions for the Kerr (Faraday) rotation angle and for the ellipticity of the reflected (transmitted) light as a function of the incident angle and polarization of the light. The method is demonstrated by calculating the Kerr (Faraday) angle for bilayer graphene in the quantum anomalous Hall state placed on the top of dielectric multilayers. The optical conductivity of the bilayer graphene is calculated in the framework of a four-band model.

Faraday-Active Fabry-Perot Resonator: Transmission, Reflection, and Emissivity

NASA Technical Reports Server (NTRS)

Liptuga, Anatoliy; Morozhenko, Vasyl; Pipa, Viktor; Venger, Evgen; Kostiuk, Theodor

2011-01-01

The propagation of light within a semiconductor Faraday-active Fabry-Perot resonator (FAFR) is investigated theoretically and experimentally. It is shown that an external magnetic field radically changes the angular and spectral characteristics of transmission, reflection and emissivity of the resonator not only for polarized, but also for unpolarized light. Suppression of interference patterns and phase inversion of the interference extrema were observed in both monochromatic and polychromatic light. The investigations were carried out for the plane-parallel plates of n-InAs in the spectral range of free charge carrier absorption. The results can be used to create new controllable optical and spectroscopic devices for investigation of Faraday-active material properties and for control of parameters of plane-parallel layers and structures.

Kinetics of ion and prompt electron emission from laser-produced plasma

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

Farid, N.; Key Laboratory of Materials Modification by Laser, Ion and Electron Beams, School of Physics and Optical Engineering, Dalian University of Technology, Dalian; Harilal, S. S.

2013-07-15

We investigated ion emission dynamics of laser-produced plasma from several elements, comprised of metals and non-metals (C, Al, Si, Cu, Mo, Ta, W), under vacuum conditions using a Faraday cup. The estimated ion flux for various targets studied showed a decreasing tendency with increasing atomic mass. For metals, the ion flux is found to be a function of sublimation energy. A comparison of temporal ion profiles of various materials showed only high-Z elements exhibited multiple structures in the ion time of flight profile indicated by the observation of higher peak kinetic energies, which were absent for low-Z element targets. Themore » slower ions were seen regardless of the atomic number of target material propagated with a kinetic energy of 1–5 keV, while the fast ions observed in high-Z materials possessed significantly higher energies. A systematic study of plasma properties employing fast photography, time, and space resolved optical emission spectroscopy, and electron analysis showed that there existed different mechanisms for generating ions in laser ablation plumes. The origin of high kinetic energy ions is related to prompt electron emission from high-Z targets.« less

On-Demand Calibration and Evaluation for Electromagnetically Tracked Laparoscope in Augmented Reality Visualization

PubMed Central

Liu, Xinyang; Plishker, William; Zaki, George; Kang, Sukryool; Kane, Timothy D.; Shekhar, Raj

2017-01-01

Purpose Common camera calibration methods employed in current laparoscopic augmented reality systems require the acquisition of multiple images of an entire checkerboard pattern from various poses. This lengthy procedure prevents performing laparoscope calibration in the operating room (OR). The purpose of this work was to develop a fast calibration method for electromagnetically (EM) tracked laparoscopes, such that calibration can be performed in the OR on demand. Methods We designed a mechanical tracking mount to uniquely and snugly position an EM sensor to an appropriate location on a conventional laparoscope. A tool named fCalib was developed to calibrate intrinsic camera parameters, distortion coefficients, and extrinsic parameters (transformation between the scope lens coordinate system and the EM sensor coordinate system) using a single image that shows an arbitrary portion of a special target pattern. For quick evaluation of calibration result in the OR, we integrated a tube phantom with fCalib and overlaid a virtual representation of the tube on the live video scene. Results We compared spatial target registration error between the common OpenCV method and the fCalib method in a laboratory setting. In addition, we compared the calibration re-projection error between the EM tracking-based fCalib and the optical tracking-based fCalib in a clinical setting. Our results suggested that the proposed method is comparable to the OpenCV method. However, changing the environment, e.g., inserting or removing surgical tools, would affect re-projection accuracy for the EM tracking-based approach. Computational time of the fCalib method averaged 14.0 s (range 3.5 s – 22.7 s). Conclusions We developed and validated a prototype for fast calibration and evaluation of EM tracked conventional (forward viewing) laparoscopes. The calibration method achieved acceptable accuracy and was relatively fast and easy to be performed in the OR on demand. PMID:27250853

On-demand calibration and evaluation for electromagnetically tracked laparoscope in augmented reality visualization.

PubMed

Liu, Xinyang; Plishker, William; Zaki, George; Kang, Sukryool; Kane, Timothy D; Shekhar, Raj

2016-06-01

Common camera calibration methods employed in current laparoscopic augmented reality systems require the acquisition of multiple images of an entire checkerboard pattern from various poses. This lengthy procedure prevents performing laparoscope calibration in the operating room (OR). The purpose of this work was to develop a fast calibration method for electromagnetically (EM) tracked laparoscopes, such that the calibration can be performed in the OR on demand. We designed a mechanical tracking mount to uniquely and snugly position an EM sensor to an appropriate location on a conventional laparoscope. A tool named fCalib was developed to calibrate intrinsic camera parameters, distortion coefficients, and extrinsic parameters (transformation between the scope lens coordinate system and the EM sensor coordinate system) using a single image that shows an arbitrary portion of a special target pattern. For quick evaluation of calibration results in the OR, we integrated a tube phantom with fCalib prototype and overlaid a virtual representation of the tube on the live video scene. We compared spatial target registration error between the common OpenCV method and the fCalib method in a laboratory setting. In addition, we compared the calibration re-projection error between the EM tracking-based fCalib and the optical tracking-based fCalib in a clinical setting. Our results suggest that the proposed method is comparable to the OpenCV method. However, changing the environment, e.g., inserting or removing surgical tools, might affect re-projection accuracy for the EM tracking-based approach. Computational time of the fCalib method averaged 14.0 s (range 3.5 s-22.7 s). We developed and validated a prototype for fast calibration and evaluation of EM tracked conventional (forward viewing) laparoscopes. The calibration method achieved acceptable accuracy and was relatively fast and easy to be performed in the OR on demand.

The use of ultrasonic properties of CR-39 track detectors in neutron dosimetry

NASA Astrophysics Data System (ADS)

Afifi, H.; El-Sersy, A.; Khaled, N.

2004-01-01

The longitudinal and shear wave ultrasonic velocities have been measured before and after exposing 5-mm thick CR-39 solid state nuclear track detectors to both a mixed field of gamma-rays and fast neutrons from an Am-Be source in the ranges from 0 to 10 4 mSv. The change in the intermolecular structure as caused by the fast neutron exposure was studied by the ultrasonic pulse echo method at a frequency of 2 MHz and at room temperature. The elastic coefficients, Poisson's ratio, microhardness, ultrasonic absorption coefficient and internal friction have been determined. The study shows that the gamma-ray irradiation had no effect on the ultrasonic properties of CR-39 at least at the used doses. However, all the ultrasonic properties are influenced by the fast neutrons at doses up to 10 4 mSv. Our experimental results confirmed that the ultrasonic technique is useful for fast neutron detection, by exploiting the differences in mechanical properties of CR-39.

Global fast dynamic terminal sliding mode control for a quadrotor UAV.

PubMed

Xiong, Jing-Jing; Zhang, Guo-Bao

2017-01-01

A control method based on global fast dynamic terminal sliding mode control (TSMC) technique is proposed to design the flight controller for performing the finite-time position and attitude tracking control of a small quadrotor UAV. Firstly, the dynamic model of the quadrotor is divided into two subsystems, i.e., a fully actuated subsystem and an underactuated subsystem. Secondly, the dynamic flight controllers of the quadrotor are formulated based on global fast dynamic TSMC, which is able to guarantee that the position and velocity tracking errors of all system state variables converge to zero in finite-time. Moreover, the global fast dynamic TSMC is also able to eliminate the chattering phenomenon caused by the switching control action and realize the high precision performance. In addition, the stabilities of two subsystems are demonstrated by Lyapunov theory, respectively. Lastly, the simulation results are given to illustrate the effectiveness and robustness of the proposed control method in the presence of external disturbances. Copyright © 2016 ISA. Published by Elsevier Ltd. All rights reserved.

Motion-Blur-Free High-Speed Video Shooting Using a Resonant Mirror

PubMed Central

Inoue, Michiaki; Gu, Qingyi; Takaki, Takeshi; Ishii, Idaku; Tajima, Kenji

2017-01-01

This study proposes a novel concept of actuator-driven frame-by-frame intermittent tracking for motion-blur-free video shooting of fast-moving objects. The camera frame and shutter timings are controlled for motion blur reduction in synchronization with a free-vibration-type actuator vibrating with a large amplitude at hundreds of hertz so that motion blur can be significantly reduced in free-viewpoint high-frame-rate video shooting for fast-moving objects by deriving the maximum performance of the actuator. We develop a prototype of a motion-blur-free video shooting system by implementing our frame-by-frame intermittent tracking algorithm on a high-speed video camera system with a resonant mirror vibrating at 750 Hz. It can capture 1024 × 1024 images of fast-moving objects at 750 fps with an exposure time of 0.33 ms without motion blur. Several experimental results for fast-moving objects verify that our proposed method can reduce image degradation from motion blur without decreasing the camera exposure time. PMID:29109385

Three-dimensional reconstruction of the fast-start swimming kinematics of densely schooling fish

PubMed Central

Paley, Derek A.

2012-01-01

Information transmission via non-verbal cues such as a fright response can be quantified in a fish school by reconstructing individual fish motion in three dimensions. In this paper, we describe an automated tracking framework to reconstruct the full-body trajectories of densely schooling fish using two-dimensional silhouettes in multiple cameras. We model the shape of each fish as a series of elliptical cross sections along a flexible midline. We estimate the size of each ellipse using an iterated extended Kalman filter. The shape model is used in a model-based tracking framework in which simulated annealing is applied at each step to estimate the midline. Results are presented for eight fish with occlusions. The tracking system is currently being used to investigate fast-start behaviour of schooling fish in response to looming stimuli. PMID:21642367

A STUDY OF BROADBAND FARADAY ROTATION AND POLARIZATION BEHAVIOR OVER 1.3–10 GHz IN 36 DISCRETE RADIO SOURCES

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

Anderson, C. S.; Gaensler, B. M.; Feain, I. J., E-mail: craiga@physics.usyd.edu.au

We present a broadband polarization analysis of 36 discrete polarized radio sources over a very broad, densely sampled frequency band. Our sample was selected on the basis of polarization behavior apparent in narrowband archival data at 1.4 GHz: half the sample shows complicated frequency-dependent polarization behavior (i.e., Faraday complexity) at these frequencies, while half shows comparatively simple behavior (i.e., they appear Faraday simple ). We re-observed the sample using the Australia Telescope Compact Array in full polarization, with 6 GHz of densely sampled frequency coverage spanning 1.3–10 GHz. We have devised a general polarization modeling technique that allows us tomore » identify multiple polarized emission components in a source, and to characterize their properties. We detect Faraday complex behavior in almost every source in our sample. Several sources exhibit particularly remarkable polarization behavior. By comparing our new and archival data, we have identified temporal variability in the broadband integrated polarization spectra of some sources. In a number of cases, the characteristics of the polarized emission components, including the range of Faraday depths over which they emit, their temporal variability, spectral index, and the linear extent of the source, allow us to argue that the spectropolarimetric data encode information about the magneto-ionic environment of active galactic nuclei themselves. Furthermore, the data place direct constraints on the geometry and magneto-ionic structure of this material. We discuss the consequences of restricted frequency bands on the detection and interpretation of polarization structures, and the implications for upcoming spectropolarimetric surveys.« less

HF coherent backscatter in the ionosphere: In situ measurements of SuperDARN backscatter with e-POP RRI

NASA Astrophysics Data System (ADS)

Perry, G. W.; James, H. G.; Hussey, G. C.; Howarth, A. D.; Yau, A. W.

2017-12-01

We report in situ polarimetry measurements of HF scattering obtained by the Enhanced Polar Outflow Probe (e-POP) Radio Receiver Instrument (RRI) during a coherent backscatter scattering event detected by the Saskatoon Super Dual Auroral Radar Network (SuperDARN). On April 1, 2015, e-POP conducted a 4 minute coordinated experiment with SuperDARN Saskatoon, starting at 3:38:44 UT (21:38:44 LT). Throughout the experiment, SuperDARN was transmitting at 17.5 MHz and e-POP's ground track moved in a northeastward direction, along SuperDARN's field-of-view, increasing in altitude from 331 to 352 km. RRI was tuned to 17.505 MHz, and recorded nearly 12,000 SuperDARN radar pulses during the experiment. In the first half of the experiment, radar pulses recorded by RRI were "well behaved": they retained their transmitted amplitude envelope, and their pulse-to-pulse polarization characteristics were coherent - Faraday rotation was easily measured. During the second half of the experiment the pulses showed clear signs of scattering: their amplitude envelopes became degraded and dispersed, and their pulse-to-pulse polarization characteristics became incoherent - Faraday rotation was difficult to quantify. While these pulses were being received by RRI, SuperDARN Saskatoon detected a latitudinal band of coherent backscatter at e-POP's location, indicating that the scattered pulses measured by RRI may be a signature of HF backscatter. In this presentation, we will outline the polarimetric details of the scattered pulses, and provide an analytic interpretation of RRI's measurements to give new insight into the nature of HF coherent backscatter mechanism taking place in the terrestrial ionosphere.

Interferometer using a 3 × 3 coupler and Faraday mirrors

NASA Astrophysics Data System (ADS)

Breguet, J.; Gisin, N.

1995-06-01

A new interferometric setup using a 3 \\times 3 coupler and two Faraday mirrors is presented. It has the advantages of being built only with passive components, of freedom from the polarization fading problem, and of operation with a LED. It is well suited for sensing time-dependent signals and does not depend on reciprocal or nonreciprocal constant perturbations.

New Insights in Catalytic Sites: Characterization of Spectroscopy and Reactivity of Metal Oxide Clusters with Anion Slow Electron Velocity-Map Imaging

DTIC Science & Technology

2016-06-08

Yacovitch, E. Garand, J. B. Kim, C. Hock, T. Theis, and D. M. Neumark, Faraday Disc. 157, 399 (2012). [10] I. Yourshaw, T. Lenzer, G. Reiser, and D...University of Nottingham, Faraday Lecture Invited Lecture June 3-5, 2013 Quebec City, Quebec, Canada “Herbert P. Broida Prize Lecture: Probing

Faraday anomalous dispersion optical filters

NASA Technical Reports Server (NTRS)

Shay, T. M.; Yin, B.; Alvarez, L. S.

1993-01-01

The effect of Faraday anomalous dispersion optical filters on infrared and blue transitions of some alkali atoms is calculated. A composite system is designed to further increase the background noise rejection. The measured results of the solar background rejection and image quality through the filter are presented. The results show that the filter may provide high transmission and high background noise rejection with excellent image quality.

Analysis of three advanced practice roles in emergency nursing.

PubMed

Considine, Julie; Lucas, Elspeth; Payne, Roslyn; Kropman, Matthew; Stergiou, Helen E; Chiu, Herman

2012-11-01

There are many Emergency Department (ED) demand management systems that include advanced practice emergency nursing roles. The aim of this study is to examine and compare three advanced emergency nursing practice roles: ED Fast Track, Clinical Initiatives Nurse (CIN) and Rapid Intervention and Treatment Zone (RITZ). A descriptive exploratory approach was used to conduct this study at an urban district hospital in Melbourne, Australia. The study participants were patients managed in each of the three systems with advanced practice emergency nursing roles: Fast Track, CIN and RITZ. There were a total of 551 patients: 195 Fast Track patients, 163 CIN managed patients and 193 RITZ patients. CIN managed patients were older (p<0.001), with higher levels of clinical urgency (p<0.001), and higher hospital admission rates (p<0.001). CIN managed patients had shorter waiting time for nursing care (p=0.001) and lower incidence of medical assessment within the time associated with their triage category (p<0.0001). ED LOS for discharged patients was significantly longer for CIN managed patients (p<0.001). CIN managed patients had a significantly higher incidence of electrocardiography (p<0.001), blood glucose measurement (p<0.001), intravenous cannulation (p<0.001), pathology testing (p<0.001), and analgesia administration (p<0.001) when compared to Fast Track and RITZ patients. Advanced practice roles in emergency nursing can have different applications in the ED context. Clarity about role intent and scope of practice is important and should inform educational preparation and teams within which these roles operate. Copyright © 2012 College of Emergency Nursing Australasia Ltd. Published by Elsevier Ltd. All rights reserved.

Direct hospital costs of total laparoscopic hysterectomy compared with fast-track open hysterectomy at a tertiary hospital: a retrospective case-controlled study.

PubMed

Rhou, Yoon J J; Pather, Selvan; Loadsman, John A; Campbell, Neil; Philp, Shannon; Carter, Jonathan

2015-12-01

To assess the direct intraoperative and postoperative costs in women undergoing total laparoscopic hysterectomy and fast-track open hysterectomy. A retrospective review of the direct hospital-related costs in a matched cohort of women undergoing total laparoscopic hysterectomy (TLH) and fast-track open hysterectomy (FTOH) at a tertiary hospital. All costs were calculated, including the cost of advanced high-energy laparoscopic devices. The effect of the learning curve on cost in laparoscopic hysterectomy was also assessed, as was the hospital case-weighted cost, which was compared with the actual cost. Fifty women were included in each arm of the study. TLH had a higher intraoperative cost, but a lower postoperative cost than FTOH (AUD$3877 vs AUD$2776 P < 0.001, AUD$3965 vs AUD$6233 P < 0.001). The total cost of TLH was not different from FTOH (AUD$7842 vs AUD$9009 P = 0.068) and after a learning curve; TLH cost less than FTOH (AUD$6797 vs AUD$8647, P < 0.001). The use of high-energy devices did not impact on the cost benefit of TLH, and hospital case-weight-based funding correlated poorly with actual cost. Despite the use of fast-track recovery protocols, the cost of TLH is no different to FTOH and after a learning curve is cheaper than open hysterectomy. Judicious use of advanced energy devices does not impact on the cost, and hospital case-weight-based funding model in our hospital is inaccurate when compared to directly calculated hospital costs. © 2013 The Authors ANZJOG © 2013 The Royal Australian and New Zealand College of Obstetricians and Gynaecologists.

Giant enhancement of Faraday rotation due to electromagnetically induced transparency in all-dielectric magneto-optical metasurfaces.

PubMed

Christofi, Aristi; Kawaguchi, Yuma; Alù, Andrea; Khanikaev, Alexander B

2018-04-15

In this Letter we introduce a new class of Fano-resonant all-dielectric metasurfaces for enhanced, high figure of merit magneto-optical response. The metasurfaces are formed by an array of magneto-optical bismuth-substituted yttrium iron garnet nano-disks embedded into a low-index matrix. The strong field enhancement in the magneto-optical disks, which results in over an order of magnitude enhancement of Faraday rotation, is achieved by engineering two (electric and magnetic) resonances. It is shown that while enhancement of rotation also takes place for spectrally detuned resonances, the resonant excitation inevitably results in stronger reflection and low figure of merit of the device. We demonstrate that this can be circumvented by overlapping electric and magnetic resonances of the nanodisks, yielding a sharp electromagnetically induced transparency peak in the transmission spectrum, which is accompanied by gigantic Faraday rotation. Our results show that one can simultaneously obtain a large Faraday rotation enhancement along with almost 100% transmittance in an all-dielectric metasurface as thin as 300 nm. A simple analytical model based on coupled-mode theory is introduced to explain the effects observed in first-principle finite element method simulations.

Energy Dynamics: A Fast Track Inquiry

ERIC Educational Resources Information Center

Schmidt, Stan M.; Hrynyshyn, Alec

2004-01-01

Students investigate energy conversions by collaborating to develop a free standing track of plastic tubing through which a ball bearing moves at the fastest possible speed. Friendly competition leads to discussion of what worked and did not work and to the identification and investigation of underlying principles. (Contains 4 charts.)

The performance of the γ-ray tracking array GRETINA for γ-ray spectroscopy with fast beams of rare isotopes

DOE PAGES

Weisshaar, D.; Bazin, D.; Bender, P. C.; ...

2016-12-03

The gamma-ray tracking array GRETINA was coupled to the S800 magnetic spectrometer for spectroscopy with fast beams of rare isotopes at the National Superconducting Cyclotron Laboratory on the campus of Michigan State University. We describe the technical details of this powerful setup and report on GRETINA's performance achieved with source and in-beam measurements. The gamma-ray multiplicity encountered in experiments with fast beams is usually low, allowing for a simplified and efficient treatment of the data in the gamma-ray analysis in terms of Doppler reconstruction and spectral quality. Finally, the results reported in this work were obtained from GRETINA consisting ofmore » 8 detector modules hosting four high-purity germanium crystals each. Currently, GRETINA consists of 10 detector modules.« less

An object detection and tracking system for unmanned surface vehicles

NASA Astrophysics Data System (ADS)

Yang, Jian; Xiao, Yang; Fang, Zhiwen; Zhang, Naiwen; Wang, Li; Li, Tao

2017-10-01

Object detection and tracking are critical parts of unmanned surface vehicles(USV) to achieve automatic obstacle avoidance. Off-the-shelf object detection methods have achieved impressive accuracy in public datasets, though they still meet bottlenecks in practice, such as high time consumption and low detection quality. In this paper, we propose a novel system for USV, which is able to locate the object more accurately while being fast and stable simultaneously. Firstly, we employ Faster R-CNN to acquire several initial raw bounding boxes. Secondly, the image is segmented to a few superpixels. For each initial box, the superpixels inside will be grouped into a whole according to a combination strategy, and a new box is thereafter generated as the circumscribed bounding box of the final superpixel. Thirdly, we utilize KCF to track these objects after several frames, Faster-RCNN is again used to re-detect objects inside tracked boxes to prevent tracking failure as well as remove empty boxes. Finally, we utilize Faster R-CNN to detect objects in the next image, and refine object boxes by repeating the second module of our system. The experimental results demonstrate that our system is fast, robust and accurate, which can be applied to USV in practice.

Fast track in colo-rectal surgery. Preliminary experience in a rural hospital

PubMed Central

FRONTERA, D.; ARENA, L.; CORSALE, I.; FRANCIOLI, N.; MAMMOLITI, F.; BUCCIANELLI, E.

2014-01-01

Background “Fast Track surgery” is a therapeutic program of large application, despite some doubts about its applicability and real validity. Literature review shows that this approach to colo-rectal surgery, particularly video-assisted, can allow a rapid recovery, better performance and a faster postoperative functional autonomy of the work, which can be discharged without cause additional welfare costs; in addition it can be reproducible in different health reality. Purpose To analyze the possibility to apply the Fast Truck protocol in patients undergoing colorectal surgery in a rural hospital and non specialistic Unit of Surgery. Patients and methods We have conducted a prospective, randomized study on 80 patients subjected to colorectal surgery in the last year. Results The protocol was observed in 95% of cases, compliance with the Fast Track was high and general morbidity was limited (7.8%). Conclusion This “aggressive” approach, which has fundamentally altered the usual surgical behavior, seems to allow a mean length of stay significantly lower than in controls (p < 0.05) with positive implications for patients and containment of health care costs, even after discharge (no need for home care in 92% of cases, no early re-admittance to the hospital). Homogeneous protocols are desirable, as well as an increased enrollment, to consolidate these rehabilitation programs in order to provide a reference for all hospitals. PMID:25644732

The flex track: flexible partitioning between low- and high-acuity areas of an emergency department.

PubMed

Laker, Lauren F; Froehle, Craig M; Lindsell, Christopher J; Ward, Michael J

2014-12-01

Emergency departments (EDs) with both low- and high-acuity treatment areas often have fixed allocation of resources, regardless of demand. We demonstrate the utility of discrete-event simulation to evaluate flexible partitioning between low- and high-acuity ED areas to identify the best operational strategy for subsequent implementation. A discrete-event simulation was used to model patient flow through a 50-bed, urban, teaching ED that handles 85,000 patient visits annually. The ED has historically allocated 10 beds to a fast track for low-acuity patients. We estimated the effect of a flex track policy, which involved switching up to 5 of these fast track beds to serving both low- and high-acuity patients, on patient waiting times. When the high-acuity beds were not at capacity, low-acuity patients were given priority access to flexible beds. Otherwise, high-acuity patients were given priority access to flexible beds. Wait times were estimated for patients by disposition and Emergency Severity Index score. A flex track policy using 3 flexible beds produced the lowest mean patient waiting time of 30.9 minutes (95% confidence interval [CI] 30.6 to 31.2 minutes). The typical fast track approach of rigidly separating high- and low-acuity beds produced a mean patient wait time of 40.6 minutes (95% CI 40.2 to 50.0 minutes), 31% higher than that of the 3-bed flex track. A completely flexible ED, in which all beds can accommodate any patient, produced mean wait times of 35.1 minutes (95% CI 34.8 to 35.4 minutes). The results from the 3-bed flex track scenario were robust, performing well across a range of scenarios involving higher and lower patient volumes and care durations. Using discrete-event simulation, we have shown that adding some flexibility into bed allocation between low and high acuity can provide substantial reductions in overall patient waiting and a more efficient ED. Copyright © 2014 American College of Emergency Physicians. Published by Elsevier Inc. All rights reserved.

Dual linear structured support vector machine tracking method via scale correlation filter

NASA Astrophysics Data System (ADS)

Li, Weisheng; Chen, Yanquan; Xiao, Bin; Feng, Chen

2018-01-01

Adaptive tracking-by-detection methods based on structured support vector machine (SVM) performed well on recent visual tracking benchmarks. However, these methods did not adopt an effective strategy of object scale estimation, which limits the overall tracking performance. We present a tracking method based on a dual linear structured support vector machine (DLSSVM) with a discriminative scale correlation filter. The collaborative tracker comprised of a DLSSVM model and a scale correlation filter obtains good results in tracking target position and scale estimation. The fast Fourier transform is applied for detection. Extensive experiments show that our tracking approach outperforms many popular top-ranking trackers. On a benchmark including 100 challenging video sequences, the average precision of the proposed method is 82.8%.

Mathematical representations in science: a cognitive-historical case history.

PubMed

Tweney, Ryan D

2009-10-01

The important role of mathematical representations in scientific thinking has received little attention from cognitive scientists. This study argues that neglect of this issue is unwarranted, given existing cognitive theories and laws, together with promising results from the cognitive historical analysis of several important scientists. In particular, while the mathematical wizardry of James Clerk Maxwell differed dramatically from the experimental approaches favored by Michael Faraday, Maxwell himself recognized Faraday as "in reality a mathematician of a very high order," and his own work as in some respects a re-representation of Faraday's field theory in analytic terms. The implications of the similarities and differences between the two figures open new perspectives on the cognitive role of mathematics as a learned mode of representation in science. Copyright © 2009 Cognitive Science Society, Inc.

Nonresonant Faraday rotation in glassy semiconductors

NASA Astrophysics Data System (ADS)

van den Keybus, P.; Grevendonk, W.

1986-06-01

Nonresonant interband Faraday rotation in amorphous semiconductors, as a function of photon energy, may be described by an equation derived for direct transitions in crystalline semiconductors. In this paper it is shown how this equation may be obtained for the former case also, assuming a parabolic density of states function N(E) and a correlation between valence- and conduction-band states. The analysis of experiments on chalcogenide glasses reveals a Faraday-rotation energy gap EFRg that is significantly larger than the optical gap Eoptg. The effect is attributed to transitions between extended states, so that it is meaningful to compare EFRg with the mobility gap Eμg. For oxide glasses both gaps are comparable but for chalcogenide glasses EFRg is too large by a few tenths of 1 eV.

Probing the gravitational Faraday rotation using quasar X-ray microlensing.

PubMed

Chen, Bin

2015-11-17

The effect of gravitational Faraday rotation was predicted in the 1950s, but there is currently no practical method for measuring this effect. Measuring this effect is important because it will provide new evidence for correctness of general relativity, in particular, in the strong field limit. We predict that the observed degree and angle of the X-ray polarization of a cosmologically distant quasar microlensed by the random star field in a foreground galaxy or cluster lens vary rapidly and concurrently with flux during caustic-crossing events using the first simulation of quasar X-ray microlensing polarization light curves. Therefore, it is possible to detect gravitational Faraday rotation by monitoring the X-ray polarization of gravitationally microlensed quasars. Detecting this effect will also confirm the strong gravity nature of quasar X-ray emission.

Terahertz spectroscopy on Faraday and Kerr rotations in a quantum anomalous Hall state

PubMed Central

Okada, Ken N.; Takahashi, Youtarou; Mogi, Masataka; Yoshimi, Ryutaro; Tsukazaki, Atsushi; Takahashi, Kei S.; Ogawa, Naoki; Kawasaki, Masashi; Tokura, Yoshinori

2016-01-01

Electrodynamic responses from three-dimensional topological insulators are characterized by the universal magnetoelectric term constituent of the Lagrangian formalism. The quantized magnetoelectric coupling, which is generally referred to as topological magnetoelectric effect, has been predicted to induce exotic phenomena including the universal low-energy magneto-optical effects. Here we report the experimental indication of the topological magnetoelectric effect, which is exemplified by magneto-optical Faraday and Kerr rotations in the quantum anomalous Hall states of magnetic topological insulator surfaces by terahertz magneto-optics. The universal relation composed of the observed Faraday and Kerr rotation angles but not of any material parameters (for example, dielectric constant and magnetic susceptibility) well exhibits the trajectory towards the fine structure constant in the quantized limit. PMID:27436710

ipole: Semianalytic scheme for relativistic polarized radiative transport

NASA Astrophysics Data System (ADS)

Moscibrodzka, Monika; Gammie, Charles F.

2018-04-01

ipole is a ray-tracing code for covariant, polarized radiative transport particularly useful for modeling Event Horizon Telescope sources, though may also be used for other relativistic transport problems. The code extends the ibothros scheme for covariant, unpolarized transport using two representations of the polarized radiation field: in the coordinate frame, it parallel transports the coherency tensor, and in the frame of the plasma, it evolves the Stokes parameters under emission, absorption, and Faraday conversion. The transport step is as spacetime- and coordinate- independent as possible; the emission, absorption, and Faraday conversion step is implemented using an analytic solution to the polarized transport equation with constant coefficients. As a result, ipole is stable, efficient, and produces a physically reasonable solution even for a step with high optical depth and Faraday depth.

Modified Faraday cup

DOEpatents

Elmer, John W.; Teruya, Alan T.; O'Brien, Dennis W.

1996-01-01

A tomographic technique for measuring the current density distribution in electron beams using electron beam profile data acquired from a modified Faraday cup to create an image of the current density in high and low power beams. The modified Faraday cup includes a narrow slit and is rotated by a stepper motor and can be moved in the x, y and z directions. The beam is swept across the slit perpendicular thereto and controlled by deflection coils, and the slit rotated such that waveforms are taken every few degrees form 0.degree. to 360.degree. and the waveforms are recorded by a digitizing storage oscilloscope. Two-din-tensional and three-dimensional images of the current density distribution in the beam can be reconstructed by computer tomography from this information, providing quantitative information about the beam focus and alignment.

CRADA Final Report, 2011S003, Faraday Technologies

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

Faraday Technologies

2012-12-12

This Phase I SBIR program addressed the need for an improved manufacturing process for electropolishing niobium RF superconducting cavities for the International Linear Collider (ILC). The ILC is a proposed particle accelerator that will be used to gain a deeper understanding of the forces of energy and matter by colliding beams of electrons and positrons at nearly the speed of light. The energy required for this to happen will be achieved through the use of advanced superconducting technology, specifically ~16,000 RF superconducting cavities operating at near absolute zero. The RF superconductor cavities will be fabricated from highly pure Nb, whichmore » has an extremely low surface resistance at 2 Kelvin when compared to other materials. To take full advantage of the superconducting properties of the Nb cavities, the inner surface must be a) polished to a microscale roughness < 0.1 µm with removal of at least 100 µm of material, and b) cleaned to be free of impurities that would degrade performance of the ILC. State-of-the-art polishing uses either chemical polishing or electropolishing, both of which require hydrofluoric acid to achieve breakdown of the strong passive film on the surface. In this Phase I program, Faraday worked with its collaborators at the Thomas Jefferson National Accelerator Facility (JLab) to demonstrate the feasibility of an electropolishing process for pure niobium, utilizing an environmentally benign alternative to chemical or electrochemical polishing electrolytes containing hydrofluoric acid. Faraday utilized a 31 wt% aqueous sulfuric acid solution (devoid of hydrofluoric acid) in conjunction with the FARADAYICSM Process, which uses pulse/pulse reverse fields for electropolishing, to demonstrate the ability to electropolish niobium to the desired surface finish. The anticipated benefits of the FARADAYICSM Electropolishing process will be a simpler, safer, and less expensive method capable of surface finishing high purity niobium cavities. Another potential benefit would be for the medical industry that uses hydrofluoric acid to electropolish niobium-alloy materials. The FARADAYICSM Electropolishing process will eliminate the environmental hazards posed by the use of hydrofluoric acid employed by chemical polishing and conventional electropolishing. Further, improved performance benefits may be possible. The overall objective of the Phase I program was to demonstrate that FARADAYIC Electropolishing of niobium cavities in electrolytes free of hydrofluoric acid can meet the RF superconducting performance criteria of those cavities. The FARADAYIC Electropolishing Process developed in the Phase I program was used to polish 50 mm Nb disks to a surface roughness (RA) of < 1 nm over a small area through process and post-processing optimization. An excellent level of surface cleanliness was achieved. While the desired 2K RF performance has not yet been achieved, Faraday believes that surface oxide state can be controlled through manipulation of the process parameters, to meet the 2K RF standard. Faraday is establishing apparatus and facilities infrastructure for single-cell SRF cavity electropolishing, through a synergistic effort with the Fermi National Accelerator Facility (Fermilab) to scale-up electropolishing of superconducting RF cavities. Faraday proposes to commercialize the subject technology via an IP based strategic relationship with a partner with established market channels within two primary commercialization avenues: 1) the superconducting particle accelerator community, 2) the medical device and implant market. Faraday will initially maintain Low Rate Initial Production capabilities for an application, but latterly seek a strategic partner who is solely dedicated to high rate production.« less

A maximum power point tracking algorithm for buoy-rope-drum wave energy converters

NASA Astrophysics Data System (ADS)

Wang, J. Q.; Zhang, X. C.; Zhou, Y.; Cui, Z. C.; Zhu, L. S.

2016-08-01

The maximum power point tracking control is the key link to improve the energy conversion efficiency of wave energy converters (WEC). This paper presents a novel variable step size Perturb and Observe maximum power point tracking algorithm with a power classification standard for control of a buoy-rope-drum WEC. The algorithm and simulation model of the buoy-rope-drum WEC are presented in details, as well as simulation experiment results. The results show that the algorithm tracks the maximum power point of the WEC fast and accurately.

Fast and Accurate Cell Tracking by a Novel Optical-Digital Hybrid Method

NASA Astrophysics Data System (ADS)

Torres-Cisneros, M.; Aviña-Cervantes, J. G.; Pérez-Careta, E.; Ambriz-Colín, F.; Tinoco, Verónica; Ibarra-Manzano, O. G.; Plascencia-Mora, H.; Aguilera-Gómez, E.; Ibarra-Manzano, M. A.; Guzman-Cabrera, R.; Debeir, Olivier; Sánchez-Mondragón, J. J.

2013-09-01

An innovative methodology to detect and track cells using microscope images enhanced by optical cross-correlation techniques is proposed in this paper. In order to increase the tracking sensibility, image pre-processing has been implemented as a morphological operator on the microscope image. Results show that the pre-processing process allows for additional frames of cell tracking, therefore increasing its robustness. The proposed methodology can be used in analyzing different problems such as mitosis, cell collisions, and cell overlapping, ultimately designed to identify and treat illnesses and malignancies.

Trajectory tracking and backfitting techniques against theater ballistic missiles

NASA Astrophysics Data System (ADS)

Hutchins, Robert G.; Britt, Patrick T.

1999-10-01

Since the SCUD launches in the Gulf War, theater ballistic missile (TBM) systems have become a growing concern for the US military. Detection, fast track initiation, backfitting for launch point determination, and tracking and engagement during boost phase or shortly after booster cutoff are goals that grow in importance with the proliferation of weapons of mass destruction. This paper focuses on track initiation and backfitting techniques, as well as extending some earlier results on tracking a TBM during boost phase cutoff. Results indicate that Kalman techniques are superior to third order polynomial extrapolations in estimating the launch point, and that some knowledge of missile parameters, especially thrust, is extremely helpful in track initiation.

Fast Deep Tracking via Semi-Online Domain Adaptation

NASA Astrophysics Data System (ADS)

Li, Xiaoping; Luo, Wenbing; Zhu, Yi; Li, Hanxi; Wang, Mingwen

2018-04-01

Deep tracking has been illustrating overwhelming superiorities over the shallow methods. Unfortunately, it also suffers from low FPS rates. To alleviate the problem, a number of real-time deep trackers have been proposed via removing the online updating procedure on the CNN model. However, the absent of the online update leads to a significant drop on tracking accuracy. In this work, we propose to perform the domain adaptation for visual tracking in two stages for transferring the information from the visual tracking domain and the instance domain respectively. In this way, the proposed visual tracker achieves comparable tracking accuracy to the state-of-the-art trackers and runs at real-time speed on an average consuming GPU.

Tracking multiple objects is limited only by object spacing, not by speed, time, or capacity.

PubMed

Franconeri, S L; Jonathan, S V; Scimeca, J M

2010-07-01

In dealing with a dynamic world, people have the ability to maintain selective attention on a subset of moving objects in the environment. Performance in such multiple-object tracking is limited by three primary factors-the number of objects that one can track, the speed at which one can track them, and how close together they can be. We argue that this last limit, of object spacing, is the root cause of all performance constraints in multiple-object tracking. In two experiments, we found that as long as the distribution of object spacing is held constant, tracking performance is unaffected by large changes in object speed and tracking time. These results suggest that barring object-spacing constraints, people could reliably track an unlimited number of objects as fast as they could track a single object.

Fast Track to the Cloud: Design Patterns for 12-Factor Earth Sciences Applications

NASA Technical Reports Server (NTRS)

Pawloski, Andrew; McLaughlin, Brett; Lynnes, Christopher

2016-01-01

As expanding service offerings and decreasing prices make the cloud increasingly attractive to Earth Science applications, there are nontrivial practical considerations which can hinder its meaningful use. In this talk, we will discuss architectural recommendations and lessons learned while working on EOSDIS' cloud efforts, particularly the NASA-compliant General Application Platform (NGAP) and its associated applications. Prominent in our findings is the importance of 12-factor design patterns and the powerful "wins" they enable in the cloud. We will share our strategies for "fast-tracking" applications to the cloud --whether they be legacy, planned for the future, or somewhere in between.

Returning nurses to the workforce: developing a fast track back program.

PubMed

Burns, Helen K; Sakraida, Teresa J; Englert, Nadine C; Hoffmann, Rosemary L; Tuite, Patricia; Foley, Susan M

2006-01-01

Fast Track Back: Re-entry into Nursing Practice program. Describes the development, implementation, and evaluation of a state-of-the-art re-entry program facilitating the return of licensed nonpracticing RNs to the workforce through a quality education program that retools them for the workforce in the areas of pharmacology, skill development using the latest technology, practice standards, and nursing issues. The program consists of didactic content taught via classroom, Internet, skills laboratory, and high fidelity human simulated technology and a clinical component. The program is a mechanism that enables re-entry nurses to improve skills and competencies necessary to practice in today's healthcare environment.

'Fast-track' colonic surgery in Austria and Germany--results from the survey on patterns in current perioperative practice.

PubMed

Hasenberg, T; Keese, M; Längle, F; Reibenwein, B; Schindler, K; Herold, A; Beck, G; Post, S; Jauch, K W; Spies, C; Schwenk, W; Shang, E

2009-02-01

'Fast-track' rehabilitation has been shown to accelerate recovery, reduce general morbidity and decrease hospital stay after elective colonic surgery. Despite this evidence, there is no information on the acceptance and utilization of these concepts among the entirety of Austrian and German surgeons. In 2006, a questionnaire concerning perioperative routines in elective, open colonic resection was sent to the chief surgeons of 1270 German and 120 Austrian surgical centres. The response rate was 63% in Austria (76 centres) and 30% in Germany (385 centres). Mechanical bowel preparation is used by the majority (Austria, 91%; Germany, 94%); the vertical incision is the standard method of approach to the abdomen in Austria (79%) and Germany (83%), nasogastric decompression tubes are rarely used, one-third of the questioned surgeons in both countries use intra-abdominal drains. Half of the surgical centres allow the intake of clear fluids on the day of surgery and one-fifth offer solid food on that day. Epidural analgesia is used in three-fourths of the institutions. Although there is an evident benefit of fast-track management, the survey shows that they are not yet widely used as a routine in Austria and Germany.

A Fast Track approach to deal with the temporal dimension of crop water footprint

NASA Astrophysics Data System (ADS)

Tuninetti, Marta; Tamea, Stefania; Laio, Francesco; Ridolfi, Luca

2017-07-01

Population growth, socio-economic development and climate changes are placing increasing pressure on water resources. Crop water footprint is a key indicator in the quantification of such pressure. It is determined by crop evapotranspiration and crop yield, which can be highly variable in space and time. While the spatial variability of crop water footprint has been the objective of several investigations, the temporal variability remains poorly studied. In particular, some studies approached this issue by associating the time variability of crop water footprint only to yield changes, while considering evapotranspiration patterns as marginal. Validation of this Fast Track approach has yet to be provided. In this Letter we demonstrate its feasibility through a comprehensive validation, an assessment of its uncertainty, and an example of application. Our results show that the water footprint changes are mainly driven by yield trends, while evapotranspiration plays a minor role. The error due to considering constant evapotranspiration is three times smaller than the uncertainty of the model used to compute the crop water footprint. These results confirm the suitability of the Fast Track approach and enable a simple, yet appropriate, evaluation of time-varying crop water footprint.

Can Genetics Predict Response to Complex Behavioral Interventions? Evidence from a Genetic Analysis of the Fast Track Randomized Control Trial

PubMed Central

Albert, Dustin; Belsky, Daniel W.; Crowley, D. Max; Latendresse, Shawn J.; Aliev, Fazil; Riley, Brien; Sun, Cuie; Dick, Danielle M.; Dodge, Kenneth R.

2014-01-01

Early interventions are a preferred method for addressing behavioral problems in high-risk children, but often have only modest effects. Identifying sources of variation in intervention effects can suggest means to improve efficiency. One potential source of such variation is the genome. We conducted a genetic analysis of the Fast Track Randomized Control Trial, a 10-year-long intervention to prevent high-risk kindergarteners from developing adult externalizing problems including substance abuse and antisocial behavior. We tested whether variants of the glucocorticoid receptor gene NR3C1 were associated with differences in response to the Fast Track intervention. We found that in European-American children, a variant of NR3C1 identified by the single-nucleotide polymorphism rs10482672 was associated with increased risk for externalizing psychopathology in control group children and decreased risk for externalizing psychopathology in intervention group children. Variation in NR3C1 measured in this study was not associated with differential intervention response in African-American children. We discuss implications for efforts to prevent externalizing problems in high-risk children and for public policy in the genomic era. PMID:26106668

The use of a break-even analysis: financial analysis of a fast-track program.

PubMed

Saywell, R M; Cordell, W H; Nyhuis, A W; Giles, B K; Culler, S D; Woods, J R; Chu, D K; McKinzie, J P; Rodman, G H

1995-08-01

To calculate the financial break-even point and illustrate how changes in third-party reimbursement and eligibility could affect a program's fiscal standing. Demographic, clinical, and financial data were collected retrospectively for 446 patients treated in a fast-track program during June 1993. The fast-track program is located within the confines of the emergency medicine and trauma center at a 1,050-bed tertiary care Midwestern teaching hospital and provides urgent treatment to minimally ill patients. A financial break-even analysis was performed to determine the point where the program generated enough revenue to cover its total variable and fixed costs, both direct and indirect. Given the relatively low average collection rate (62%) and high percentage of uninsured patients (31%), the analysis showed that the program's revenues covered its direct costs but not all of the indirect costs. Examining collection rates or payer class mix without examining both costs and revenues may lead to an erroneous conclusion about a program's fiscal viability. Sensitivity analysis also shows that relatively small changes in third-party coverage or eligibility (income) requirements can have a large impact on the program's financial solvency and break-even volumes.

A hardware fast tracker for the ATLAS trigger

NASA Astrophysics Data System (ADS)

Asbah, Nedaa

2016-09-01

The trigger system of the ATLAS experiment is designed to reduce the event rate from the LHC nominal bunch crossing at 40 MHz to about 1 kHz, at the design luminosity of 1034 cm-2 s-1. After a successful period of data taking from 2010 to early 2013, the LHC already started with much higher instantaneous luminosity. This will increase the load on High Level Trigger system, the second stage of the selection based on software algorithms. More sophisticated algorithms will be needed to achieve higher background rejection while maintaining good efficiency for interesting physics signals. The Fast TracKer (FTK) is part of the ATLAS trigger upgrade project. It is a hardware processor that will provide, at every Level-1 accepted event (100 kHz) and within 100 microseconds, full tracking information for tracks with momentum as low as 1 GeV. Providing fast, extensive access to tracking information, with resolution comparable to the offline reconstruction, FTK will help in precise detection of the primary and secondary vertices to ensure robust selections and improve the trigger performance. FTK exploits hardware technologies with massive parallelism, combining Associative Memory ASICs, FPGAs and high-speed communication links.

A fast method for optical simulation of flood maps of light-sharing detector modules.

PubMed

Shi, Han; Du, Dong; Xu, JianFeng; Moses, William W; Peng, Qiyu

2015-12-01

Optical simulation of the detector module level is highly desired for Position Emission Tomography (PET) system design. Commonly used simulation toolkits such as GATE are not efficient in the optical simulation of detector modules with complicated light-sharing configurations, where a vast amount of photons need to be tracked. We present a fast approach based on a simplified specular reflectance model and a structured light-tracking algorithm to speed up the photon tracking in detector modules constructed with polished finish and specular reflector materials. We simulated conventional block detector designs with different slotted light guide patterns using the new approach and compared the outcomes with those from GATE simulations. While the two approaches generated comparable flood maps, the new approach was more than 200-600 times faster. The new approach has also been validated by constructing a prototype detector and comparing the simulated flood map with the experimental flood map. The experimental flood map has nearly uniformly distributed spots similar to those in the simulated flood map. In conclusion, the new approach provides a fast and reliable simulation tool for assisting in the development of light-sharing-based detector modules with a polished surface finish and using specular reflector materials.

Sublingual sufentanil tablet system Zalviso® for postoperative analgesia after knee replacement in fast track surgery: a pilot observational study.

PubMed

Scardino, Marco; D'Amato, Tiziana; Martorelli, Federica; Fenocchio, Giorgia; Simili, Vincenzo; Di Matteo, Berardo; Bugada, Dario; Kon, Elizaveta

2018-03-20

Currently many TKA protocols rely on multimodal analgesic protocols with patient-controlled analgesia systems that administer opioids through a patient controlled IV infusion pump, in addition to concomitant peripheral nerve blocks and local anesthetics. Although effective, PCA IV opioids do not provide optimal results with fast track rehabilitation protocols. The present is a retrospective study comparing the novel sublingual sufentanil PCA system (SSTS) to our standard of care foreseeing continuous femoral nerve block (cFNB) within a multimodal analgesic in a TKA fast-track protocol. The study evaluated 95 patients on SSTS (SSTS group) and 87 on cFNB (cFNB/control group) and collected data on numeric rating scores for pain from day 1-3 after surgery (T1, T2, T3), both at rest (NRS) and during movement (mNRS), patient's ability to walk, need for supplementary analgesia (rescue dose), occurrence of adverse effects, length of hospital stay, and usability rating for SSTS by both patients and hospital staff. NRS at rest was lower in the cFNB than in the SSTS group for all 3 days after surgery, whereas mNRS scores were lower in the SSTS group at all time points measured. Adverse effects were significantly fewer among patients of the SSTS group (6% patients) than those of the cFNB (74% patients) (p <  0.001). Rescue doses were needed by 5% of SSTS patients vs 60% of cFNB. The fewer adverse events and lower pain scores for the SSTS group were associated to a notably better ability to ambulate, with all patients (100%) of the SSTS group being able to stand and walk for 10 m from T1 on; patients in the cFNB group showed a slower recovery with only 40% being able to stand and walk on T1, 70% on T2 and 85% on T3. All patients of the SSTS group had a length of stay of 4 days (day of surgery plus 3 after) as foreseen by the fast track protocol, in comparison only 36% of cFNB. Lastly, patient and nursing staff judged SSTS easy to use. Our experience suggests that SSTS is a valuable strategy for routine postoperative analgesia following TKA in the context of a multimodal analgesic approach within the fast-track setting.

Evaluation of a Chlamydia trachomatis-specific, commercial, real-time PCR for use with ocular swabs.

PubMed

Pickering, Harry; Holland, Martin J; Last, Anna R; Burton, Matthew J; Burr, Sarah E

2018-02-20

Trachoma, the leading infectious cause of blindness worldwide, is caused by conjunctival Chlamydia trachomatis infection. Trachoma is diagnosed clinically by observation of conjunctival inflammation and/or scarring; however, there is evidence that monitoring C. trachomatis infection may be required for elimination programmes. There are many commercial and 'in-house' nucleic acid amplification tests for the detection of C. trachomatis DNA, but the majority have not been validated for use with ocular swabs. This study evaluated a commercial assay, the Fast-Track Vaginal swab kit, using conjunctival samples from trachoma-endemic areas. An objective, biostatistical-based method for binary classification of continuous PCR data was developed, to limit potential user-bias in diagnostic settings. The Fast-Track Vaginal swab assay was run on 210 ocular swab samples from Guinea-Bissau and Tanzania. Fit of individual amplification curves to exponential or sigmoid models, derivative and second derivative of the curves and final fluorescence value were examined for utility in thresholding for determining positivity. The results from the Fast-Track Vaginal swab assay were evaluated against a commercial test (Amplicor CT/NG) and a non-commercial test (in-house droplet digital PCR), both of whose performance has previously been evaluated. Significant evidence of exponential amplification (R 2  > 0.99) and final fluorescence > 0.15 were combined for thresholding. This objective approach identified a population of positive samples, however there were a subset of samples that amplified towards the end of the cycling protocol (at or later than 35 cycles), which were less clearly defined. The Fast-Track Vaginal swab assay showed good sensitivity against the commercial (95.71) and non-commercial (97.18) tests. Specificity was lower against both (90.00 and 96.55, respectively). This study defined a simple, automated protocol for binary classification of continuous, real-time qPCR data, for use in an end-point diagnostic test. This method identified a population of positive samples, however, as with manual thresholding, a subset of samples that amplified towards the end of the cycling program were less easily classified. When used with ocular swabs, the Fast-Track Vaginal swab assay had good sensitivity for C. trachomatis detection, but lower specificity than the commercial and non-commercial assays it was evaluated against, possibly leading to false positives.

SMMR data set development for GARP. [impact of cross polarization and Faraday rotation on SMMR derived brightness temperatures

NASA Technical Reports Server (NTRS)

Kogut, J.

1981-01-01

The NIMBUS 7 Scanning Multichannel Microwave Radiometer (SMMR) data are analyzed. The impact of cross polarization and Faraday rotation on SMMR derived brightness temperatures is evaluated. The algorithms used to retrieve the geophysical parameters are tested, refined, and compared with values derived by other techniques. The technical approach taken is described and the results presented.

Design and construction of a Faraday cup for measurement of small electronic currents

NASA Technical Reports Server (NTRS)

Veyssiere, A.

1985-01-01

The design of a device to measure and integrate very small currents generated by the impact of a charged particle beam upon a Faraday cut is described. The main component is a graphite block capable of stopping practically all the incident changes. The associated electronic apparatus required to measure better than 10/13 ampere with a precision of 10/0 is described.

A novel method to recover DD fusion proton CR-39 data corrupted by fast ablator ions at OMEGA and the National Ignition Facility

NASA Astrophysics Data System (ADS)

Sutcliffe, G. D.; Milanese, L. M.; Orozco, D.; Lahmann, B.; Gatu Johnson, M.; Séguin, F. H.; Sio, H.; Frenje, J. A.; Li, C. K.; Petrasso, R. D.; Park, H.-S.; Rygg, J. R.; Casey, D. T.; Bionta, R.; Turnbull, D. P.; Huntington, C. M.; Ross, J. S.; Zylstra, A. B.; Rosenberg, M. J.; Glebov, V. Yu.

2016-11-01

CR-39 detectors are used routinely in inertial confinement fusion (ICF) experiments as a part of nuclear diagnostics. CR-39 is filtered to stop fast ablator ions which have been accelerated from an ICF implosion due to electric fields caused by laser-plasma interactions. In some experiments, the filtering is insufficient to block these ions and the fusion-product signal tracks are lost in the large background of accelerated ion tracks. A technique for recovering signal in these scenarios has been developed, tested, and implemented successfully. The technique involves removing material from the surface of the CR-39 to a depth beyond the endpoint of the ablator ion tracks. The technique preserves signal magnitude (yield) as well as structure in radiograph images. The technique is effective when signal particle range is at least 10 μm deeper than the necessary bulk material removal.

A novel method to recover DD fusion proton CR-39 data corrupted by fast ablator ions at OMEGA and the National Ignition Facility.

PubMed

Sutcliffe, G D; Milanese, L M; Orozco, D; Lahmann, B; Gatu Johnson, M; Séguin, F H; Sio, H; Frenje, J A; Li, C K; Petrasso, R D; Park, H-S; Rygg, J R; Casey, D T; Bionta, R; Turnbull, D P; Huntington, C M; Ross, J S; Zylstra, A B; Rosenberg, M J; Glebov, V Yu

2016-11-01

CR-39 detectors are used routinely in inertial confinement fusion (ICF) experiments as a part of nuclear diagnostics. CR-39 is filtered to stop fast ablator ions which have been accelerated from an ICF implosion due to electric fields caused by laser-plasma interactions. In some experiments, the filtering is insufficient to block these ions and the fusion-product signal tracks are lost in the large background of accelerated ion tracks. A technique for recovering signal in these scenarios has been developed, tested, and implemented successfully. The technique involves removing material from the surface of the CR-39 to a depth beyond the endpoint of the ablator ion tracks. The technique preserves signal magnitude (yield) as well as structure in radiograph images. The technique is effective when signal particle range is at least 10 μm deeper than the necessary bulk material removal.

Surveillance of Space - Optimal Use of Complementary Sensors for Maximum Efficiency

DTIC Science & Technology

2006-04-01

as track - before - detect [4] have been shown to allow improved sensitivity. This technique employs fast running algorithms and computing power to pre...Multifunction Radar” IEEE Signal Processing Magazine, January 2006. [4] Wallace W R “The Use of Track - Before - Detect in Pulse-Doppler Radar” IEE 490, Radar

Leadership in Australian Rural Schools: Bush Track, Fast Track

ERIC Educational Resources Information Center

Graham, Lorraine; Paterson, David; Miller, Judith

2008-01-01

Due to the difficulties inherent in staffing rural schools it is increasingly common for beginning teachers to fill school leadership roles early in their careers. The accelerated progression of some teachers impacts on the overall nature of leadership in rural schools and creates unique pathways, generally different from those available to…

Why Graduate Students Reject the Fast Track

ERIC Educational Resources Information Center

Mason, Mary Ann; Goulden, Marc; Frasch, Karie

2009-01-01

The authors recently completed an unparalleled survey, with more than eight thousand doctoral student respondents across the University of California system, and what they heard is worrisome: major research universities may be losing some of the most talented tenure-track academics before they even arrive. In the eyes of many doctoral students,…

Fast regional readout CMOS Image Sensor for dynamic MLC tracking

NASA Astrophysics Data System (ADS)

Zin, H.; Harris, E.; Osmond, J.; Evans, P.

2014-03-01

Advanced radiotherapy techniques such as volumetric modulated arc therapy (VMAT) require verification of the complex beam delivery including tracking of multileaf collimators (MLC) and monitoring the dose rate. This work explores the feasibility of a prototype Complementary metal-oxide semiconductor Image Sensor (CIS) for tracking these complex treatments by utilising fast, region of interest (ROI) read out functionality. An automatic edge tracking algorithm was used to locate the MLC leaves edges moving at various speeds (from a moving triangle field shape) and imaged with various sensor frame rates. The CIS demonstrates successful edge detection of the dynamic MLC motion within accuracy of 1.0 mm. This demonstrates the feasibility of the sensor to verify treatment delivery involving dynamic MLC up to ~400 frames per second (equivalent to the linac pulse rate), which is superior to any current techniques such as using electronic portal imaging devices (EPID). CIS provides the basis to an essential real-time verification tool, useful in accessing accurate delivery of complex high energy radiation to the tumour and ultimately to achieve better cure rates for cancer patients.

Wide field polarimetry around the Perseus cluster at 350 MHz

NASA Astrophysics Data System (ADS)

Brentjens, M. A.

2011-02-01

Aims: This paper investigates the fascinating diffuse polarization structures at 350 MHz that have previously been tentatively attributed to the Perseus cluster and, more specifically, tries to find out whether the structures are located at (or near) the Perseus cluster, or in the Milky Way. Methods: A wide field, eight point Westerbork Synthesis Radio Telescope mosaic of the area around the Perseus cluster was observed in full polarization. The frequency range was 324 to 378 MHz and the resolution of the polarization maps was 2' × 3'. The maps were processed using Faraday rotation measure synthesis to counter bandwidth depolarization. The RM-cube covers Faraday depths of -384 to +381 rad m-2 in steps of 3 rad m-2. Results: There is emission all over the field at Faraday depths between -50 and +100 rad m-2. All previously observed structures were detected. However, no compelling evidence was found supporting association of those structures with either the Perseus cluster or large scale structure formation gas flows in the Perseus-Pisces super cluster. On the contrary, one of the structures is clearly associated with a Galactic depolarization canal at 1.41 GHz. Another large structure in polarized intensity, as well as Faraday depth at a Faraday depth of +30 rad m-2, coincides with a dark object in WHAM Hα maps at a kinematic distance of 0.5 ± 0.5 kpc. All diffuse polarized emission at 350 MHz towards the Perseus cluster is most likely located within 1 kpc from the Sun. The layers that emit the polarized radiation are less than 40 pc/|B_∥| thick. Appendix is only available in electronic form at http://www.aanda.org

An extreme magneto-ionic environment associated with the fast radio burst source FRB 121102

NASA Astrophysics Data System (ADS)

Michilli, D.; Seymour, A.; Hessels, J. W. T.; Spitler, L. G.; Gajjar, V.; Archibald, A. M.; Bower, G. C.; Chatterjee, S.; Cordes, J. M.; Gourdji, K.; Heald, G. H.; Kaspi, V. M.; Law, C. J.; Sobey, C.; Adams, E. A. K.; Bassa, C. G.; Bogdanov, S.; Brinkman, C.; Demorest, P.; Fernandez, F.; Hellbourg, G.; Lazio, T. J. W.; Lynch, R. S.; Maddox, N.; Marcote, B.; McLaughlin, M. A.; Paragi, Z.; Ransom, S. M.; Scholz, P.; Siemion, A. P. V.; Tendulkar, S. P.; van Rooy, P.; Wharton, R. S.; Whitlow, D.

2018-01-01

Fast radio bursts are millisecond-duration, extragalactic radio flashes of unknown physical origin. The only known repeating fast radio burst source—FRB 121102—has been localized to a star-forming region in a dwarf galaxy at redshift 0.193 and is spatially coincident with a compact, persistent radio source. The origin of the bursts, the nature of the persistent source and the properties of the local environment are still unclear. Here we report observations of FRB 121102 that show almost 100 per cent linearly polarized emission at a very high and variable Faraday rotation measure in the source frame (varying from +1.46 × 105 radians per square metre to +1.33 × 105 radians per square metre at epochs separated by seven months) and narrow (below 30 microseconds) temporal structure. The large and variable rotation measure demonstrates that FRB 121102 is in an extreme and dynamic magneto-ionic environment, and the short durations of the bursts suggest a neutron star origin. Such large rotation measures have hitherto been observed only in the vicinities of massive black holes (larger than about 10,000 solar masses). Indeed, the properties of the persistent radio source are compatible with those of a low-luminosity, accreting massive black hole. The bursts may therefore come from a neutron star in such an environment or could be explained by other models, such as a highly magnetized wind nebula or supernova remnant surrounding a young neutron star.

An extreme magneto-ionic environment associated with the fast radio burst source FRB 121102.

PubMed

Michilli, D; Seymour, A; Hessels, J W T; Spitler, L G; Gajjar, V; Archibald, A M; Bower, G C; Chatterjee, S; Cordes, J M; Gourdji, K; Heald, G H; Kaspi, V M; Law, C J; Sobey, C; Adams, E A K; Bassa, C G; Bogdanov, S; Brinkman, C; Demorest, P; Fernandez, F; Hellbourg, G; Lazio, T J W; Lynch, R S; Maddox, N; Marcote, B; McLaughlin, M A; Paragi, Z; Ransom, S M; Scholz, P; Siemion, A P V; Tendulkar, S P; Van Rooy, P; Wharton, R S; Whitlow, D

2018-01-10

Fast radio bursts are millisecond-duration, extragalactic radio flashes of unknown physical origin. The only known repeating fast radio burst source-FRB 121102-has been localized to a star-forming region in a dwarf galaxy at redshift 0.193 and is spatially coincident with a compact, persistent radio source. The origin of the bursts, the nature of the persistent source and the properties of the local environment are still unclear. Here we report observations of FRB 121102 that show almost 100 per cent linearly polarized emission at a very high and variable Faraday rotation measure in the source frame (varying from +1.46 × 10 5 radians per square metre to +1.33 × 10 5 radians per square metre at epochs separated by seven months) and narrow (below 30 microseconds) temporal structure. The large and variable rotation measure demonstrates that FRB 121102 is in an extreme and dynamic magneto-ionic environment, and the short durations of the bursts suggest a neutron star origin. Such large rotation measures have hitherto been observed only in the vicinities of massive black holes (larger than about 10,000 solar masses). Indeed, the properties of the persistent radio source are compatible with those of a low-luminosity, accreting massive black hole. The bursts may therefore come from a neutron star in such an environment or could be explained by other models, such as a highly magnetized wind nebula or supernova remnant surrounding a young neutron star.

Detection of Ballast Damage by In-Situ Vibration Measurement of Sleepers

NASA Astrophysics Data System (ADS)

Lam, H. F.; Wong, M. T.; Keefe, R. M.

2010-05-01

Ballasted track is one of the most important elements of railway transportation systems worldwide. Owing to its importance in railway safety, many monitoring and evaluation methods have been developed. Current railway track monitoring systems are comprehensive, fast and efficient in testing railway track level and alignment, rail gauge, rail corrugation, etc. However, the monitoring of ballast condition still relies very much on visual inspection and core tests. Although extensive research has been carried out in the development of non-destructive methods for ballast condition evaluation, a commonly accepted and cost-effective method is still in demand. In Hong Kong practice, if abnormal train vibration is reported by the train operator or passengers, permanent way inspectors will locate the problem area by track geometry measurement. It must be pointed out that visual inspection can only identify ballast damage on the track surface, the track geometry deficiencies and rail twists can be detected using a track gauge. Ballast damage under the sleeper loading area and the ballast shoulder, which are the main factors affecting track stability and ride quality, are extremely difficult if not impossible to be detected by visual inspection. Core test is a destructive test, which is expensive, time consuming and may be disruptive to traffic. A fast real-time ballast damage detection method that can be implemented by permanent way inspectors with simple equipment can certainly provide valuable information for engineers in assessing the safety and riding quality of ballasted track systems. The main objective of this paper is to study the feasibility in using the vibration characteristics of sleepers in quantifying the ballast condition under the sleepers, and so as to explore the possibility in developing a handy method for the detection of ballast damage based on the measured vibration of sleepers.

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

Kung, C C; Brunkhorst, C; Greenough, N

Experimental results have shown that the high harmonic fast wave (HHFW) at 30 MHz can provide substantial plasma heating and current drive for the NSTX spherical tokamak operation. However, the present antenna strap design rarely achieves the design goal of delivering the full transmitter capability of 6 MW to the plasma. In order to deliver more power to the plasma, a new antenna strap design and the associated coaxial line feeds are being constructed. This new antenna strap design features two feedthroughs to replace the old single feed-through design. In the design process, CST Microwave Studio has been used tomore » simulate the entire new antenna strap structure including the enclosure and the Faraday shield. In this paper, the antenna strap model and the simulation results will be discussed in detail. The test results from the new antenna straps with their associated resonant loops will be presented as well.« less

Effect of plasma grid bias on extracted currents in the RF driven surface-plasma negative ion source

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

Belchenko, Yu., E-mail: belchenko@inp.nsk.su; Ivanov, A.; Sanin, A.

2016-02-15

Extraction of negative ions from the large inductively driven surface-plasma negative ion source was studied. The dependencies of the extracted currents vs plasma grid (PG) bias potential were measured for two modifications of radio-frequency driver with and without Faraday screen, for different hydrogen feeds and for different levels of cesium conditioning. The maximal PG current was independent of driver modification and it was lower in the case of inhibited cesium. The maximal extracted negative ion current depends on the potential difference between the near-PG plasma and the PG bias potentials, while the absolute value of plasma potential in the drivermore » and in the PG area is less important for the negative ion production. The last conclusion confirms the main mechanism of negative ion production through the surface conversion of fast atoms.« less

Development of bunch shape monitor for high-intensity beam on the China ADS proton LINAC Injector II

NASA Astrophysics Data System (ADS)

Zhu, Guangyu; Wu, Junxia; Du, Ze; Zhang, Yong; Xue, Zongheng; Xie, Hongming; Wei, Yuan; Jing, Long; Jia, Huan

2018-05-01

The development, performance, and testing of the longitudinal bunch shape monitor, namely, the Fast Faraday Cup (FFC), are presented in this paper. The FFC is an invasive instrument controlled by a stepper motor, and its principle of operation is based on a strip line structure. The longitudinal bunch shape was determined by sampling a small part of the beam hitting the strip line through a 1-mm hole. The rise time of the detector reached 24 ps. To accommodate experiments that utilize high-intensity beams, the materials of the bunch shape monitor were chosen to sustain high temperatures. Water cooling was also integrated in the detector system to enhance heat transfer and prevent thermal damage. We also present an analysis of the heating caused by the beam. The bunch shape monitor has been installed and commissioned at the China ADS proton LINAC Injector II.

How Does the Fast Track Intervention Prevent Adverse Outcomes in Young Adulthood?

PubMed Central

Sorensen, Lucy C.; Dodge, Kenneth A.

2015-01-01

Numerous studies have shown that childhood interventions can foster improved outcomes in adulthood. Less well understood is precisely how – that is, through which developmental pathways – these interventions work. This study assesses mechanisms by which the Fast Track project (n=891), a randomized intervention in the early 1990s for high-risk children in four communities (Durham, NC; Nashville, TN; rural PA; and Seattle, WA), reduced delinquency, arrests, and health and mental health service utilization in adolescence through young adulthood (ages 12–20). A decomposition of treatment effects indicates that about a third of Fast Track’s impact on later crime outcomes can be accounted for by improvements in social and self-regulation skills during childhood (ages 6–11), such as prosocial behavior, emotion regulation and problem solving. These skills proved less valuable for the prevention of mental and physical health problems. PMID:26670938

Obscura telescope with a MEMS micromirror array for space observation of transient luminous phenomena or fast-moving objects.

PubMed

Park, J H; Garipov, G K; Jeon, J A; Khrenov, B A; Kim, J E; Kim, M; Kim, Y K; Lee, C-H; Lee, J; Na, G W; Nam, S; Park, I H; Park, Y-S

2008-12-08

We introduce a novel telescope consisting of a pinhole-like camera with rotatable MEMS micromirrors substituting for pinholes. The design is ideal for observations of transient luminous phenomena or fast-moving objects, such as upper atmospheric lightning and bright gamma ray bursts. The advantage of the MEMS "obscura telescope" over conventional cameras is that it is capable both of searching for events over a wide field of view, and fast zooming to allow detailed investigation of the structure of events. It is also able to track the triggering object to investigate its space-time development, and to center the interesting portion of the image on the photodetector array. We present the proposed system and the test results for the MEMS obscura telescope which has a field of view of 11.3 degrees, sixteen times zoom-in and tracking within 1 ms. (c) 2008 Optical Society of America

The research on the mean shift algorithm for target tracking

NASA Astrophysics Data System (ADS)

CAO, Honghong

2017-06-01

The traditional mean shift algorithm for target tracking is effective and high real-time, but there still are some shortcomings. The traditional mean shift algorithm is easy to fall into local optimum in the tracking process, the effectiveness of the method is weak when the object is moving fast. And the size of the tracking window never changes, the method will fail when the size of the moving object changes, as a result, we come up with a new method. We use particle swarm optimization algorithm to optimize the mean shift algorithm for target tracking, Meanwhile, SIFT (scale-invariant feature transform) and affine transformation make the size of tracking window adaptive. At last, we evaluate the method by comparing experiments. Experimental result indicates that the proposed method can effectively track the object and the size of the tracking window changes.

Intracavity Faraday modulation spectroscopy (INFAMOS): A tool for radical detection

NASA Astrophysics Data System (ADS)

Gianella, Michele; Pinto, Tomas H. P.; Wu, Xia; Ritchie, Grant A. D.

2017-08-01

We present the intra-cavity Faraday modulation spectroscopy technique, whereby optical feedback cavity-enhanced spectroscopy is coupled with Faraday modulation spectroscopy to greatly enhance the interaction path length of a laser beam with a paramagnetic sample in a magnetic field. We describe a first prototype based upon a cw quantum cascade laser targeting a selection of fundamental rovibrational R-branch transitions of nitric oxide (1890 cm-1), consisting of a linear cavity (finesse F =6300 ) and a water-cooled solenoid. We demonstrate a minimum detectable Verdet constant of Vmin=4.7 ×10-14 rad cm-1 G-1 H z-1/2 (at SNR = 1), corresponding to a single-pass rotation angle of 1.6 ×10-10 rad Hz-1/2 and a limit of detection of 0.21 ppbv Hz-1/2 NO.

The Effect of Faraday Waves on Gas Transport

NASA Astrophysics Data System (ADS)

Saylor, J. R.; Handler, R. A.

1996-11-01

The increase in the rate of gas transport at the onset of capillary wave formation is a frequently observed phenomenon. However, a causal relationship between the presence of capillary waves and enhanced gas transport has not been experimentally demonstrated. Here we present experimental results of CO2 transport rates across Faraday waves. The piston velocity versus wave slope data explicitly demonstrates an enhancement in gas transport due to these waves. The functional relationship between gas flux and wave slope is also obtained. The Faraday wave system permits investigation of capillary waves in the absence of the obfuscating effects of air turbulence, water turbulence, droplets and bubbles, all of which are present in wind/wave tank studies. Hence, our results are solely due to the effects of capillary wave action. Data for wave frequencies varying from 20Hz to 200Hz are presented.

Faraday rotation of Automatic Dependent Surveillance Broadcast (ADS-B) signals as a method of ionospheric characterization

NASA Astrophysics Data System (ADS)

Cushley, A. C.; Kabin, K.; Noel, J. M. A.

2017-12-01

Radio waves propagating through plasma in the Earth's ambient magnetic field experience Faraday rotation; the plane of the electric field of a linearly polarized wave changes as a function of the distance travelled through a plasma. Linearly polarized radio waves at 1090 MHz frequency are emitted by Automatic Dependent Surveillance Broadcast (ADS-B) devices which are installed on most commercial aircraft. These radio waves can be detected by satellites in low earth orbits, and the change of the polarization angle caused by propagation through the terrestrial ionosphere can be measured. In this work we discuss how these measurements can be used to characterize the ionospheric conditions. In the present study, we compute the amount of Faraday rotation from a prescribed total electron content value and two of the profile parameters of the NeQuick model.

Probing the gravitational Faraday rotation using quasar X-ray microlensing

PubMed Central

Chen, Bin

2015-01-01

The effect of gravitational Faraday rotation was predicted in the 1950s, but there is currently no practical method for measuring this effect. Measuring this effect is important because it will provide new evidence for correctness of general relativity, in particular, in the strong field limit. We predict that the observed degree and angle of the X-ray polarization of a cosmologically distant quasar microlensed by the random star field in a foreground galaxy or cluster lens vary rapidly and concurrently with flux during caustic-crossing events using the first simulation of quasar X-ray microlensing polarization light curves. Therefore, it is possible to detect gravitational Faraday rotation by monitoring the X-ray polarization of gravitationally microlensed quasars. Detecting this effect will also confirm the strong gravity nature of quasar X-ray emission. PMID:26574051

Faraday rotation in the M87 radio/X-ray halo

NASA Technical Reports Server (NTRS)

Dennison, B.

1980-01-01

Comparison of polarization maps at various wavelengths demonstrates the existence of a large Faraday rotation uniform over the radio core of M87. Much of this rotation must be external to the core, lest it appear completely depolarized when the rotation is about 90 degrees. The Faraday rotation is shown to occur primarily in the surrounding radio/X-ray halo. Using the electron density inferred from X-ray observations, the magnetic field in the halo is found to be 2.5 microgauss. The deduced magnetic field strength permits an evaluation of the importance of Compton scattering of 3 K background photons by relativistic electrons in the radio halo. The emergent Compton-scattered spectrum is calculated, and its contribution to the observed X-ray flux is small, probably about a percent or so, while the rest is due to thermal bremsstrahlung.

Diode laser operating on an atomic transition limited by an isotope ⁸⁷Rb Faraday filter at 780 nm.

PubMed

Tao, Zhiming; Hong, Yelong; Luo, Bin; Chen, Jingbiao; Guo, Hong

2015-09-15

We demonstrate an extended cavity Faraday laser system using an antireflection-coated laser diode as the gain medium and the isotope (87)Rb Faraday anomalous dispersion optical filter (FADOF) as the frequency selective device. Using this method, the laser wavelength works stably at the highest transmission peak of the isotope (87)Rb FADOF over the laser diode current from 55 to 140 mA and the temperature from 15°C to 35°C. Neither the current nor the temperature of the laser diode has significant influence on the output frequency. Compared with previous extended cavity laser systems operating at frequencies irrelevant to spectacular atomic transition lines, the laser system realized here provides a stable laser source with the frequency operating on atomic transitions for many practical applications.

Modified Faraday cup

DOEpatents

Elmer, J.W.; Teruya, A.T.; O`Brien, D.W.

1996-09-10

A tomographic technique for measuring the current density distribution in electron beams using electron beam profile data acquired from a modified Faraday cup to create an image of the current density in high and low power beams is disclosed. The modified Faraday cup includes a narrow slit and is rotated by a stepper motor and can be moved in the x, y and z directions. The beam is swept across the slit perpendicular thereto and controlled by deflection coils, and the slit rotated such that waveforms are taken every few degrees from 0{degree} to 360{degree} and the waveforms are recorded by a digitizing storage oscilloscope. Two-dimensional and three-dimensional images of the current density distribution in the beam can be reconstructed by computer tomography from this information, providing quantitative information about the beam focus and alignment. 12 figs.

Universal Faraday Rotation in HgTe Wells with Critical Thickness.

PubMed

Shuvaev, A; Dziom, V; Kvon, Z D; Mikhailov, N N; Pimenov, A

2016-09-09

The universal value of the Faraday rotation angle close to the fine structure constant (α≈1/137) is experimentally observed in thin HgTe quantum wells with a thickness on the border between trivial insulating and the topologically nontrivial Dirac phases. The quantized value of the Faraday angle remains robust in the broad range of magnetic fields and gate voltages. Dynamic Hall conductivity of the holelike carriers extracted from the analysis of the transmission data shows a theoretically predicted universal value of σ_{xy}=e^{2}/h, which is consistent with the doubly degenerate Dirac state. On shifting the Fermi level by the gate voltage, the effective sign of the charge carriers changes from positive (holes) to negative (electrons). The electronlike part of the dynamic response does not show quantum plateaus and is well described within the classical Drude model.

On intracluster Faraday rotation. II - Statistical analysis

NASA Technical Reports Server (NTRS)

Lawler, J. M.; Dennison, B.

1982-01-01

The comparison of a reliable sample of radio source Faraday rotation measurements seen through rich clusters of galaxies, with sources seen through the outer parts of clusters and therefore having little intracluster Faraday rotation, indicates that the distribution of rotation in the former population is broadened, but only at the 80% level of statistical confidence. Employing a physical model for the intracluster medium in which the square root of magnetic field strength/turbulent cell per gas core radius number ratio equals approximately 0.07 microgauss, a Monte Carlo simulation is able to reproduce the observed broadening. An upper-limit analysis figure of less than 0.20 microgauss for the field strength/turbulent cell ratio, combined with lower limits on field strength imposed by limitations on the Compton-scattered flux, shows that intracluster magnetic fields must be tangled on scales greater than about 20 kpc.

Fast calibration of electromagnetically tracked oblique-viewing rigid endoscopes.

PubMed

Liu, Xinyang; Rice, Christina E; Shekhar, Raj

2017-10-01

The oblique-viewing (i.e., angled) rigid endoscope is a commonly used tool in conventional endoscopic surgeries. The relative rotation between its two moveable parts, the telescope and the camera head, creates a rotation offset between the actual and the projection of an object in the camera image. A calibration method tailored to compensate such offset is needed. We developed a fast calibration method for oblique-viewing rigid endoscopes suitable for clinical use. In contrast to prior approaches based on optical tracking, we used electromagnetic (EM) tracking as the external tracking hardware to improve compactness and practicality. Two EM sensors were mounted on the telescope and the camera head, respectively, with considerations to minimize EM tracking errors. Single-image calibration was incorporated into the method, and a sterilizable plate, laser-marked with the calibration pattern, was also developed. Furthermore, we proposed a general algorithm to estimate the rotation center in the camera image. Formulas for updating the camera matrix in terms of clockwise and counterclockwise rotations were also developed. The proposed calibration method was validated using a conventional [Formula: see text], 5-mm laparoscope. Freehand calibrations were performed using the proposed method, and the calibration time averaged 2 min and 8 s. The calibration accuracy was evaluated in a simulated clinical setting with several surgical tools present in the magnetic field of EM tracking. The root-mean-square re-projection error averaged 4.9 pixel (range 2.4-8.5 pixel, with image resolution of [Formula: see text] for rotation angles ranged from [Formula: see text] to [Formula: see text]. We developed a method for fast and accurate calibration of oblique-viewing rigid endoscopes. The method was also designed to be performed in the operating room and will therefore support clinical translation of many emerging endoscopic computer-assisted surgical systems.

SU-F-T-370: A Fast Monte Carlo Dose Engine for Gamma Knife

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

Song, T; Zhou, L; Li, Y

2016-06-15

Purpose: To develop a fast Monte Carlo dose calculation algorithm for Gamma Knife. Methods: To make the simulation more efficient, we implemented the track repeating technique on GPU. We first use EGSnrc to pre-calculate the photon and secondary electron tracks in water from two mono-energy photons of 60Co. The total photon mean free paths for different materials and energies are obtained from NIST. During simulation, each entire photon track was first loaded to shared memory for each block, the incident original photon was then splitted to Nthread sub-photons, each thread transport one sub-photon, the Russian roulette technique was applied formore » scattered and bremsstrahlung photons. The resultant electrons from photon interactions are simulated by repeating the recorded electron tracks. The electron step length is stretched/shrunk proportionally based on the local density and stopping power ratios of the local material. Energy deposition in a voxel is proportional to the fraction of the equivalent step length in that voxel. To evaluate its accuracy, dose deposition in a 300mm*300mm*300mm water phantom is calculated, and compared to EGSnrc results. Results: Both PDD and OAR showed great agreements (within 0.5%) between our dose engine result and the EGSnrc result. It only takes less than 1 min for every simulation, being reduced up to ∼40 times compared to EGSnrc simulations. Conclusion: We have successfully developed a fast Monte Carlo dose engine for Gamma Knife.« less

Scalable Track Detection in SAR CCD Images

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

Chow, James G; Quach, Tu-Thach

Existing methods to detect vehicle tracks in coherent change detection images, a product of combining two synthetic aperture radar images ta ken at different times of the same scene, rely on simple, fast models to label track pixels. These models, however, are often too simple to capture natural track features such as continuity and parallelism. We present a simple convolutional network architecture consisting of a series of 3-by-3 convolutions to detect tracks. The network is trained end-to-end to learn natural track features entirely from data. The network is computationally efficient and improves the F-score on a standard dataset to 0.988,more » up fr om 0.907 obtained by the current state-of-the-art method.« less

New Combustion Regimes and Kinetic Studies of Plasma Assisted Combustion

DTIC Science & Technology

2012-11-01

IR Faraday Rotational Spectroscopy Method to quantify HO2 29 30 Brian Brumfield, Wenting Sun, Gerard Wysock, and Yinguang Ju, submitted...to JACS, 2012 7.1 μm Mid infra-red Faraday Rotation Spectroscopy (FRS), 1396 cm-1 Quantitative HO2 Measurement (very challenging!): 2L + 1...paramagnetic species Polarization rotation detection Linearly-polarized laser light 610 Hz oscillating magnetic field 125 Gauss rms Sub-ppm level

In-electrode vs. on-electrode: ultrasensitive Faraday cage-type electrochemiluminescence immunoassay.

PubMed

Guo, Zhiyong; Sha, Yuhong; Hu, Yufang; Wang, Sui

2016-03-28

A new-concept of an "in-electrode" Faraday cage-type electrochemiluminescence immunoassay (ECLIA) method for the ultrasensitive detection of neurotensin (NT) was reported with capture antibody (Ab1)-nanoFe3O4@graphene (GO) and detector antibody (Ab2)&N-(4-aminobutyl)-N-ethylisoluminol (ABEI)@GO, which led to about 1000-fold improvement in sensitivity by extending the Helmholtz plane (OHP) of the proposed electrode assembly effectively.

High-frequency Faraday rotation observations of the solar corona

NASA Astrophysics Data System (ADS)

Jensen, Elizabeth A.; Russell, Christopher T.

2008-10-01

This thesis, presented on January 31, 2007 under the supervision of Professor Christopher T. Russell, discusses the solar coronal magnetic field observations that can be obtained using the phenomenon of Faraday rotation. It was defended in the Department of Earth and Space Sciences at the University of California, Los Angeles (595 Charles E. Young, Dr. East, Los Angeles, CA 90095). A resume can be found at http://acs-consulting.com/.

Time-division multiplexing of polarization-insensitive fiber-optic Michelson interferometric sensors

NASA Astrophysics Data System (ADS)

Huang, S. C.; Lin, W. W.; Chen, M. H.

1995-06-01

A system of time-division multiplexing of polarization-insensitive fiber-optic Michelson interferometric sensors that uses Faraday rotator mirror elements is demonstrated. This system is constructed with conventional low-birefringence single-mode fiber and is able to solve the polarization-fading problem by a combination of Faraday rotator mirrors with unbalanced Michelson interferometers. The system is lead-fiber insensitive and has potentials for practical field applications.

[Occupational exposure of physical therapists to electric and magnetic fields and the efficacy of Faraday cages].

PubMed

Messias, Iracimara de Anchieta; Okuno, Emico; Colacioppo, Sérgio

2011-10-01

Measure physical therapists' exposure to the electric and magnetic fields produced by 17 shortwave diathermy devices in physical therapy clinics in the city of Presidente Prudente, São Paulo State, Brazil. Compare the observed values with the exposure levels recommended by the International Commission on Non-ionizing Radiation Protection (ICNIRP). Observe the efficacy of Faraday cages as a means of protecting physical therapists from exposure to oscillating electric and magnetic fields. Electric and magnetic field measurements were taken at four points during actual physical therapy sessions: in proximity to the operator's pelvis and head, the devices' electrical cables, and the electrodes. The measuring equipment was a Wandel & Goltermann EMR-200. The values obtained in proximity to the electrodes and cables were 10 to 30 times higher than ICNIRP's recommended occupational reference levels. In the shortwave diathermy treatment rooms with Faraday cages, the fields were even higher than in treatment rooms not so equipped-principally the magnetic field, where the values were more than 100 times higher than the ICNIRP exposure limit. The electric and magnetic field intensities obtained in this study are generally above the exposure levels recommend in ICNIRP standards. It was also observed that the Faraday cage offers physical therapists no protection, and instead, increases their level of exposure.

Faraday dispersion functions of galaxies

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

Ideguchi, Shinsuke; Tashiro, Yuichi; Takahashi, Keitaro

2014-09-01

The Faraday dispersion function (FDF), which can be derived from an observed polarization spectrum by Faraday rotation measure synthesis, is a profile of polarized emissions as a function of Faraday depth. We study intrinsic FDFs along sight lines through face-on Milky Way like galaxies by means of a sophisticated galactic model incorporating three-dimensional MHD turbulence, and investigate how much information the FDF intrinsically contains. Since the FDF reflects distributions of thermal and cosmic-ray electrons as well as magnetic fields, it has been expected that the FDF could be a new probe to examine internal structures of galaxies. We, however, findmore » that an intrinsic FDF along a sight line through a galaxy is very complicated, depending significantly on actual configurations of turbulence. We perform 800 realizations of turbulence and find no universal shape of the FDF even if we fix the global parameters of the model. We calculate the probability distribution functions of the standard deviation, skewness, and kurtosis of FDFs and compare them for models with different global parameters. Our models predict that the presence of vertical magnetic fields and the large-scale height of cosmic-ray electrons tend to make the standard deviation relatively large. In contrast, the differences in skewness and kurtosis are relatively less significant.« less