WorldWideScience

Sample records for current observational study

  1. Water Current Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Tidal, river and ocean current observations collected by the U.S. Coast and Geodetic Survey. Period of record is late 1800s to mid-1980s.

  2. An observational study of a shallow gravity current triggered by katabatic flow

    Directory of Open Access Journals (Sweden)

    A. Adachi

    2004-11-01

    Full Text Available Observations from a wind profiler and a meteorological tower are utilized to study the evolution of a gravity current that passed over the Meteorological Research Institute's (MRI field site in Tsukuba, Japan. The gravity current was created by katabatic flow originating on the mountainous slopes west of the field site. The passage of the shallow current was marked by a pronounced pressure disturbance and was accompanied by vertical circulations seen in the tower and profiler data. Direct vertical-beam measurements are difficult, especially at low heights during high-gradient events like density currents. In this study vertical velocities from the profiler are derived from the four oblique beams by use of the Minimizing the Variance of the Differences (MVD method. The vertical velocities derived from the MVD method agree well with in situ vertical velocities measured by a sonic anemometer on the tower.

    The gravity current is analyzed with surface observations, the wind profiler/RASS and tower-mounted instruments. Observations from the profiler/RASS and the tower-mounted instruments illustrate the structure of the gravity current in both wind and temperature fields. The profiler data reveal that there were three regions of waves in the vertical velocity field: lee-type waves, a solitary wave and Kelvin-Helmholtz waves. The lee-type waves in the head region of the gravity current seem to have been generated by the gravity current acting as an obstacle to prefrontal flow. The solitary wave was formed from the elevated head of the gravity current that separated from the feeder flow. Profiler vertical-motion observations resolve this wave and enable us to classify it as a Benjamin-Davis-Ono (BDO type solitary wave. The ducting mechanism that enabled the solitary wave to propagate is also revealed from the wind profiler/RASS measurements. The combination of high-resolution instruments at the MRI site allow us to

  3. Current sedation and monitoring practice for colonoscopy: an International Observational Study (EPAGE)

    DEFF Research Database (Denmark)

    Froehlich, F; Harris, JK; Wietlisbach, V;

    2006-01-01

    in endoscopy centers internationally. PATIENTS AND METHODS: This observational study included consecutive patients referred for colonoscopy at 21 centers in 11 countries. Endoscopists reported sedation and monitoring practice, using a standard questionnaire for each patient. RESULTS: 6004 patients were......BACKGROUND AND STUDY AIMS: Sedation and monitoring practice during colonoscopy varies between centers and over time. Knowledge of current practice is needed to ensure quality of care and help focus future research. The objective of this study was to examine sedation and monitoring practice...... included in this study, of whom 53 % received conscious/moderate sedation during colonoscopy, 30 % received deep sedation, and 17 % received no sedation. Sedation agents most commonly used were midazolam (47 %) and opioids (33 %). Pulse oximetry was done during colonoscopy in 77 % of patients, blood...

  4. Observational Study on Current Sheet of Magnetic Reconnection in Two Solar Eruptions

    Science.gov (United States)

    Qiang-wei, Cai; Ning, Wu; Jun, Lin

    2016-07-01

    The coronal magnetic configuration behind coronal mass ejections (CMEs) can commonly be stretched severely, thus to push the magnetic fields with opposite polarities to approach each other, and to form a current sheet of magnetic reconnection. The current sheet in solar eruptions is not only an important region to convert the magnetic free energy into thermal energy, plasma kinetic energy, and energetic particle beams, but also plays a role to connect CMEs and flares. In the CME events of 2003 January 3 and 2003 November 4, the development of current sheet has been observed in both cases. We have investigated the dynamic features and physical properties of current sheet in the two events, based on the data of LASCO (Large Angle and Spectrometric Coronagraph) and UVCS (Ultraviolet Coronagraph Spectrometer) on board of SOHO (Solar and Heliospheric Observatory), and the Hα data from BBSO (Big Bear Solar Observatory) and YNAO (Yunnan Astronomical Observatory). The existence of ions with a high degree of ionization, such as Fe+17 and Si+11, indicates a high temperature up to 3×106 ∼5×106 K in the region of current sheet. A direct measurement shows that the thickness of current sheet varies between 1.3×104 and 1.1×105 km, which increases first and then decreases with time. Using the CHIANTI code (v.7.1), we have further calculated the average values of electron temperature and corresponding emission measure (EM) respectively to be 3.86×106 K and 6.1×1024 cm-5 in the current sheet of the 2003 January 3 event. We also find that the current sheet twisted forth and back quasi-periodically during the eruption event on 2003 November 4 by analyzing the observational data from SOHO/UVCS.

  5. Observable currents in lattice field theories

    CERN Document Server

    Zapata, José A

    2016-01-01

    Observable currents are spacetime local objects that induce physical observables when integrated on an auxiliary codimension one surface. Since the resulting observables are independent of local deformations of the integration surface, the currents themselves carry most of the information about the induced physical observables. I study observable currents in a multisymplectic framework for Lagrangian field theory over discrete spacetime. A weak version of observable currents preserves many of their properties, while inducing a family of observables capable of separating points in the space of physically distinct solutions. A Poisson bracket gives the space of observable currents the structure of a Lie algebra. Peierls bracket for bulk observables gives an algebra homomorphism mapping equivalence classes of bulk observables to weak observable currents. The study covers scalar fields, nonlinear sigma models and gauge theories (including gauge theory formulations of general relativity) on the lattice. Even when ...

  6. A Comparative Study of Dark Energy Constraints from Current Observational Data

    CERN Document Server

    Wang, Yun; Mukherjee, Pia

    2012-01-01

    We examine how dark energy constraints from current observational data depend on the analysis methods used: the analysis of Type Ia supernovae (SNe Ia), and that of galaxy clustering data. We generalize the flux-averaging analysis method of SNe Ia to allow correlated errors of SNe Ia, in order to reduce the systematic bias due to weak lensing of SNe Ia. We find that flux-averaging leads to larger errors on dark energy and cosmological parameters if only SN Ia data are used. When SN Ia data (the latest compilation by the SNLS team) are combined with WMAP 7 year results (in terms of our Gaussian fits to the probability distributions of the CMB shift parameters), the latest Hubble constant (H_0) measurement using the Hubble Space Telescope (HST), and gamma ray burst (GRB) data, flux-averaging of SNe Ia increases the concordance with other data, and leads to significantly tighter constraints on the dark energy density at z=1, and the cosmic curvature \\Omega_k. The galaxy clustering measurements of H(z=0.35)r_s(z_...

  7. Lagrangian Observations of Rip Currents

    Science.gov (United States)

    2007-09-01

    me with her faith that I could do it and her positive attitude despite the challenges she has faced as a new sixth-grade teacher. xiv THIS PAGE...turned off for the day. Throughout the deployment period drifters were deployed in similar-sized groups composed of new drifters and/or those that... Techonology , 20, 1069-1075, 2003. Schmidt, W.E., R.T. Guza, and D.N. Slinn, Surf zone currents over irregular bathymetry: Drifter observations and numerical

  8. [The management of atrial fibrillation and characteristics of its current care in outpatients. AFABE observational study].

    Science.gov (United States)

    Giménez-García, Emmanuel; Clua-Espuny, Josep Lluís; Bosch-Príncep, Ramón; López-Pablo, Carlos; Lechuga-Durán, Iñigo; Gallofré-López, Miquel; Panisello-Tafalla, Anna; Lucas-Noll, Jorgina; Queralt-Tomas, Maria Lluisa

    2014-02-01

    To provide insights into the characteristics and management of outpatients when their atrial fibrillation (AF) was first detected: diagnosis, treatment and follow-up in the context of the public health system. AFABE is an observational, multicentre descriptive study with retrospective data collection relating to the practice patterns, management and initial strategies of treatment of patients with diagnosed AF in the context of primary care, emergency and cardiologists of the public health system. Primary and Specialist care. Baix Ebre region. Tarragona. Spain. A representative sample of 182 subjects > 60-year-old with AF who have been randomized, recruited among the registered patients with AF in 22 primary care centres in the area of the study. Demographic data, comorbidities (AF), CHA2DS2-VASc and HAS_BLED scores, and practice patterns results between Primary Care and referral services. A total of 182 patients were included (mean age 78.5 SD:7.3 years; 50% women). Most patients (68.3% 95%CI; 60.3-76.3) had the first contact in Primary Care, of which 56.3% (95%CI; 45.2-66.0) were sent to Hospital Emergency Department where 72.7% (95%CI: 63.5-79.0) of the oral anticoagulation and 58.4% (95%CI: 49.4-66.9) of antiarrhytmic treatments were started. More than half (55.9%:95%CI; 47.2-64.7, of patients with permanent AF were followed-up by the Cardiology department. Most patients with newly diagnosed AF made a first contact with Primary Care, but around half were sent to Hospital Emergency departments, where they were treated with an antiarrhythmic and/or oral anticoagulation. Copyright © 2013 Elsevier España, S.L. All rights reserved.

  9. An observational study of the western boundary currents in the Indian and South Atlantic Oceans

    NARCIS (Netherlands)

    Ponsoni, L.

    2016-01-01

    In this thesis we have investigated different aspects of the WBCs in the Indian and South Atlantic Oceans, based on observational data sampled both in situ and from satellites. In October 2010 an array of five moorings were deployed off eastern Madagascar, nominally at 23S, as part of the “INdian-AT

  10. Current Safety of Renal Allograft Biopsy With Indication in Adult Recipients: An Observational Study.

    Science.gov (United States)

    Tsai, Shang-Feng; Chen, Cheng-Hsu; Shu, Kuo-Hsiung; Cheng, Chi-Hung; Yu, Tung-Min; Chuang, Ya-Wen; Huang, Shih-Ting; Tsai, Jun-Li; Wu, Ming-Ju

    2016-02-01

    Renal biopsy remains the golden standard diagnosis of renal function deterioration. The safety in native kidney biopsy is well defined. However, it is a different story in allograft kidney biopsy. We conduct this retrospective study to clarify the safety of allograft kidney biopsy with indication.All variables were grouped by the year of biopsy and they were compared by Mann-Whitney U test (for continuous variables) or Chi-square test (for categorical variables). We collected possible factors associated with complications, including age, gender, body weight, renal function, cause of uremia, status of coagulation, hepatitis, size of needle, and immunosuppressants.We recruited all renal transplant recipients undergoing allograft biopsy between January of 2009 and December of 2014. This is the largest database for allograft kidney biopsy with indication. Of all the 269 biopsies, there was no difference in occurrence among the total 14 complications (5.2%) over these 6 years. There were only 3 cases of hematomas (1.11%), 6 gross hematuria (2.23%), 1 hydronephrosis (0.37%), and 2 hemoglobin decline (0.74%). The outcome of this cohort is the best compared to all other studies, and it is even better than the allograft protocol kidney biopsy. Among all possible factors, patients with pathological report containing "medullary tissue only" were susceptible to complications (P biopsy with indication. Identifying the renal capsule before biopsy to avoid puncture into medulla is the most important element to prevent complications.

  11. Observer Manual and Current Data Collection Forms

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Observer Program web page that lists the observer field manual and all current data collection forms that observers are required to take out to sea.

  12. Observer Manual and Current Data Collection Forms

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Observer Program web page that lists the observer field manual and all current data collection forms that observers are required to take out to sea.

  13. Study of the origin and structure of a nocturnal atmospheric density current from observations and numerical simulations

    Science.gov (United States)

    Ander Arrillaga, Jon; Yagüe, Carlos; Román-Cascón, Carlos; Sastre, Mariano

    2016-04-01

    Density currents are flows generated when a dense fluid passes through a less dense surrounding, under the influence of gravity. They usually appear as a consequence of sea-breeze circulations, thunderstorm outflows or katabatic flows. Density currents acquire a particular relevance during nocturnal stable situations, as their onset causes a significant turbulence increase (both from buoyancy and shear) and they occasionally produce turbulence intermittency through the formation of gravity waves. In this work, the arrival of a density current on 23 September 2015 is analysed in the CIBA site (Spain), which is located in the Spanish Northern Plateau, approximately 200 km away from the sea and 100 km away from the closest mountain ranges. Previous studies at this location associated similar nocturnal events with daytime sea breeze in the eastern Cantabrian coast [1]. Micrometeorological measurements from sonic anemometers and different sensors at multiple levels up to 100 m agl provide a solid database. In this specific case, the outbreak of the density current occurs 2 hours after sunset, causing an abrupt increase of the wind speed and a significant weakening of the surface-based thermal inversion. Besides, turbulent parameters and fluxes such as the friction velocity, the sensible heat flux and the Turbulent Kinetic Energy (TKE) are sharply altered with its arrival. The latter, indeed, increases by two orders of magnitude and the Multi Resolution Flux Decomposition (MRFD) of this and other turbulent variables gives the approximate size of the contributing eddies. Furthermore, simulations with the WRF model, which is tested for different Planetary Boundary Layer (PBL) schemes and the topo_wind option for complex topography [2], give meaningful information about the vertical structure and origin of this density current. [1] Udina, M., Soler, M.R., Viana, S. & Yagüe, C. (2013). Model simulation of gravity waves triggered by a density current. Q J R Meteorol Soc, 139

  14. Observational Study Of The Pacific Western Boundary Currents And The Indonesian Throughflow by the CAS Strategic Priority Project

    Science.gov (United States)

    Yuan, D.; Wang, J.

    2014-12-01

    The warm pool in the western Pacific Ocean has significant impact on the evolution of ENSO and the East Asian monsoon. Ocean circulation in the western Pacific Ocean and in Indonesian seas plays an important role in the interannual climate variations and predictability of the tropical Indo-Pacific Ocean. A major observational program of the Chinese Academy of Sciences is recently launched to study the western Pacific Ocean circulation and the warm pool to test these scientific hypotheses. The physical oceanography project called the "Western Pacific Ocean Circulation and the Warm Pool Variability" is by far the largest and the most intensive observational program in history in the western Pacific ocean study. In this talk, the background and scientific hypotheses of the project, the observational design in the western Pacific Ocean, Indonesian seas, and the eastern Indian Ocean region, and some preliminary results of the program will be presented. The talk serves to encourage more scientists to collaborate in the studies of the ocean circulation and climate in the western Pacific and eastern Indian Oceans.

  15. The current status of observational cosmology

    Indian Academy of Sciences (India)

    Jeremiah P Ostriker; Tarun Souradeep

    2004-10-01

    Observational cosmology has indeed made very rapid progress in recent years. The ability to quantify the universe has largely improved due to observational constraints coming from structure formation. The transition to precision cosmology has been spearheaded by measurements of the anisotropy in the cosmic microwave background (CMB) over the past decade. Observations of the large scale structure in the distribution of galaxies, high red-shift supernova, have provided the required complementary information. We review the current status of cosmological parameter estimates from joint analysis of CMB anisotropy and large scale structure (LSS) data. We also sound a note of caution on overstating the successes achieved thus far.

  16. Associating ground magnetometer observations with current or voltage generators

    DEFF Research Database (Denmark)

    Hartinger, M. D.; Xu, Z.; Clauer, C. R.

    2017-01-01

    A circuit analogy for magnetosphere-ionosphere current systems has two extremes for driversof ionospheric currents: ionospheric elec tric fields/voltages constant while current/conductivity vary—the“voltage generator”—and current constant while electric field/conductivity vary—the “current generator.......”Statistical studies of ground magnetometer observations associated with dayside Transient High LatitudeCurrent Systems (THLCS) driven by similar mechanisms find contradictory results using this paradigm:some studies associate THLCS with voltage generators, others with current generators. We argue that mostof...... these two assumptions substantially alter expectations for magnetic perturbations associatedwith either a current or a voltage generator. Our results demonstrate that before interpreting groundmagnetometer observations of THLCS in the context of current/voltage generators, the location...

  17. Observed eddy dissipation in the Agulhas Current

    Science.gov (United States)

    Braby, Laura; Backeberg, Björn C.; Ansorge, Isabelle; Roberts, Michael J.; Krug, Marjolaine; Reason, Chris J. C.

    2016-08-01

    Analyzing eddy characteristics from a global data set of automatically tracked eddies for the Agulhas Current in combination with surface drifters as well as geostrophic currents from satellite altimeters, it is shown that eddies from the Mozambique Channel and south of Madagascar dissipate as they approach the Agulhas Current. By tracking the offshore position of the current core and its velocity at 30°S in relation to eddies, it is demonstrated that eddy dissipation occurs through a transfer of momentum, where anticyclones consistently induce positive velocity anomalies, and cyclones reduce the velocities and cause offshore meanders. Composite analyses of the anticyclonic (cyclonic) eddy-current interaction events demonstrate that the positive (negative) velocity anomalies propagate downstream in the Agulhas Current at 44 km/d (23 km/d). Many models are unable to represent these eddy dissipation processes, affecting our understanding of the Agulhas Current.

  18. Current Automotive Holometry Studies

    Science.gov (United States)

    Marchi, Mitchell M.; Snyder, D. S.

    1990-04-01

    Holometry studies of automotive body and powertrain components have become a very useful high resolution test methodology to knowledgeable Ford engineering personnel. Current examples of studies that represent the static or dynamic operational conditions of the automotive test component are presented. Continuous wave laser holometry, computer aided holometry (CAH) and pulsed laser holometry were the holometric techniques used to study the following subjects: (1) body in prime (BIP) vibration modes, (2) transmission flexplate stud-torque converter deformation due to engine torque pulses, (3) engine cylinder head and camshaft support structure deformation due to cylinder pressure and (4) engine connecting rod/cap lift-off. Static and dynamic component loading and laboratory techniques required to produce usable and valid test results are discussed along with possible conclusions for the engineering concerns.

  19. Current Observational Constraints on Cosmic Doomsday

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yun

    2004-09-14

    In a broad class of dark energy models, the universe may collapse within a finite time t{sub c}. Here we study a representative model of dark energy with a linear potential, V({phi})=V{sub 0}(1 + {alpha}{phi}). This model is the simplest doomsday model, in which the universe collapses rather quickly after it stops expanding. Observational data from type Ia supernovae (SNe Ia), cosmic microwave background anisotropy (CMB), and large scale structure (LSS) are complementary in constraining dark energy models. Using the new SN Ia data (Riess sample), the CMB data from WMAP, and the LSS data from 2dF, we find that the collapse time of the universe is t{sub c} {approx}> 42 (24) gigayears from today at 68% (95%) confidence.

  20. Some observational results of sea storm current

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@ INTRODUCTION Dr. Hollister, a marine geologist of the Woods Hole Oceanographic Institution, first pointed out that there was ocean storm current in the ocean. He found out the wavy texture in the seabed core samples, and suggested that this wavy texture was caused by the high speed sea current in remote antiquity. He then suggested a bold hypothesis that there existed a benthic storm current near the ocean bottom, and presented this hypothesis at the IUGG conference held at San Francisco in 1963. Unfortunately, the attention was not drawn to the hypothesis at the conference, and the hypothesis was criticized as a sheer nonsense.

  1. After Action Reviews: Current Observations and Recommendations

    Science.gov (United States)

    2007-01-01

    without a verbatim quotation from the first paragraph of the 1993 Training Circular (TC 25-20), A Leader’s Guide to After-Action Reviews. It states...Viet Nam Wars. Marshall spoke with Soldiers in theatre , immediately after combat actions, and although sometimes disparaged because of limited numbers...1). The current EXROE has expanded from 15 to 22 chapters to reflect changes in training offered, but the AAR bottom line is repeated 8 verbatim in

  2. Forest biomass observation: current state and prospective

    Directory of Open Access Journals (Sweden)

    D. G. Schepaschenko

    2017-08-01

    Full Text Available With this article, we provide an overview of the methods, instruments and initiatives for forest biomass observation at global scale. We focus on the freely available information, provided by both remote and in-situ observations. The advantages and limitation of various space borne methods, including optical, radar (C, L and P band and LiDAR, as well as respective instruments available on the orbit (MODIS, Proba-V, Landsat, Sentinel-1, Sentinel-2 , ALOS PALSAR, Envisat ASAR or expecting (BIOMASS, GEDI, NISAR, SAOCOM-CS are discussed. We emphasize the role of in-situ methods in the development of a biomass models, providing calibration and validation of remote sensing data. We focus on freely available forest biomass maps, databases and empirical models. We describe the functionality of Biomass.Geo-Wiki.org portal, which provides access to a collection of global and regional biomass maps in full resolution with unified legend and units overplayed with high-resolution imagery. The Forest-Observation-System.net is announced as an international cooperation to establish a global in-situ forest biomass database to support earth observation and to encourage investment in relevant field-based observations and science. Prospects of unmanned aerial vehicles in the forest inventory are briefly discussed. The work was partly supported by ESA IFBN project (contract 4000114425/15/NL/FF/gp.

  3. Observed eddy dissipation in the Agulhas Current

    CSIR Research Space (South Africa)

    Braby, L

    2016-08-01

    Full Text Available Ruijter et al., 1999; Schouten et al., 2002; Tsugawa andHasumi, 2010]. These pulses have been shown to propagate poleward along the offshore edge of the Agulhas Current [van Leeuwen et al., 2000; Backeberg et al., 2008], occasionally affecting the...), Mesoscale activity in the Comoros Basin from satellite altimetry and a high resolution ocean circulation model, J. Geophys. Res. Oceans, 119, 4570–4760, doi:10.1002/2014JC010008. de Ruijter, W. P. M., P. J. van Leeuwen, and J. R. E. Lutjeharms (1999...

  4. Chrono-nutrition: a review of current evidence from observational studies on global trends in time-of-day of energy intake and its association with obesity.

    Science.gov (United States)

    Almoosawi, S; Vingeliene, S; Karagounis, L G; Pot, G K

    2016-11-01

    The importance of the circadian rhythm in regulating human food intake behaviour and metabolism has long been recognised. However, little is known as to how energy intake is distributed over the day in existing populations, and its potential association with obesity. The present review describes global trends in time-of-day of energy intake in the general population based on data from cross-sectional surveys and longitudinal cohorts. Evidence of the association between time-of-day of energy intake and obesity is also summarised. Overall, there were a limited number of cross-sectional surveys and longitudinal cohorts that provided data on time-of-day of energy intake. In the identified studies, a wide variation in time-of-day of energy intake was observed, with patterns of energy distribution varying greatly by country and geographical area. In relation to obesity, eight cross-sectional surveys and two longitudinal cohorts were identified. The association between time-of-day of energy intake and obesity varied widely, with several studies reporting a positive link between evening energy intake and obesity. In conclusion, the current review summarises global trends in time-of-day of energy intake. The large variations across countries and global regions could have important implications to health, emphasising the need to understand the socio-environmental factors guiding such differences in eating patterns. Evidence of the association between time-of-day of energy intake and BMI also varied. Further larger scale collaborations between various countries and regions are needed to sum data from existing surveys and cohorts, and guide our understanding of the role of chrono-nutrition in health.

  5. Comments on Current Space Systems Observing the Climate

    Science.gov (United States)

    Fisk, L. A.

    2016-07-01

    The Global Climate Observing System (GCOS), which was established in 1992, has been effective in specifying the observations needed for climate studies, and advocating that these observations be made. As a result, there are essential climate variables being observed, particularly from space, and these have formed the basis for our ever-improving models of how the Earth system functions and the human impact on it. We cannot conclude, however, that the current observing system in space is adequate. Climate change is accelerating, and we need to ensure that our observations capture, with completeness and with proper resolution and cadence, the most important changes. Perhaps of most significance, we need to use observations from space to guide the mitigation and adaptation strategies on which at last our civilization seems prepared to embark. And we need to use our observations to educate particularly policy makers on the reality of climate change, so that none deny the need to act. COSPAR is determined to play its part in highlighting the need to strengthen the climate observing system and notably its research component. This is being accomplished through events like the present roundtable, through the work of its Scientific Commission A, its Task Group on GEO (where COSPAR is serving as a member of its Program Board), and by promoting among space agencies and policy-makers the recently released scientific roadmap on Integrated Earth System Science for the period 2016-2025.

  6. Observation of burst frequency in extracted ECR ion current

    NARCIS (Netherlands)

    Taki, G. S.; Sarma, P. R.; Drentje, A. G.; Nakagawa, T.; Ray, P. K.; Bhandari, R. K.

    2007-01-01

    Earlier we reported an ion current jump which was observed at a fixed negative biased disc potential in the 6.4GHz ECR ion source at VECC, Kolkata. In a recent experiment with neon ions, we measured the time spectra of the ion current and observed the presence of a burst frequency in the kilohertz r

  7. An observational European study on clinical outcomes associated with current management strategies for non-variceal upper gastrointestinal bleeding (ENERGIB-Turkey).

    Science.gov (United States)

    Mungan, Zeynel

    2012-01-01

    This observational, retrospective cohort study assessed outcomes of the current management strategies for nonvariceal upper gastrointestinal bleeding in several European countries (Belgium, Greece, Italy, Norway, Portugal, Spain, and Turkey) (NCT00797641; ENERGIB). Turkey contributed 23 sites to this study. Adult patients (≥18 years old) consecutively admitted to hospital and who underwent endoscopy for overt non-variceal upper gastrointestinal bleeding (hematemesis, melena or hematochezia, with other clinical/laboratory evidence of acute upper GI blood loss) were included in the study. Data were collected from patient medical records regarding bleeding continuation, re-bleeding, pharmacological treatment, surgery, and mortality during a 30-day follow-up period. A total of 423 patients (67.4% men; mean age: 57.8 ± 18.9 years) were enrolled in the Turkish study centers, of whom 96.2% were admitted to hospital with acute non-variceal upper gastrointestinal bleeding. At admission, the most common symptom was melena (76.1%); 28.6% of patients were taking aspirin, 19.9% were on non-steroidal anti-inflammatory drugs, and 7.3% were on proton pump inhibitors. The most common diagnoses were duodenal (45.2%) and gastric (27.7%) ulcers and gastritis/gastric erosions (26.2%). Patients were most often managed in general medical wards (45.4%). A gastrointestinal team was in charge of treatment in 64.8% of cases. Therapeutic procedures were performed in 32.4% of patients during endoscopy. After the endoscopy, most patients (94.6%) received proton pump inhibitors. Mean (SD) hospital stay was 5.36 ± 4.91 days. The cumulative proportions of continued bleeding/re-bleeding, complications and mortality within 30 days of the non-variceal upper gastrointestinal bleeding episode were 9.0%, 5.7% and 2.8%, respectively. In the Turkish sub-group of patients, the significant risk factors for bleeding continuation or re-bleeding were age >65 years, presentation with hematemesis or shock

  8. An optimal current observer for predictive current controlled buck DC-DC converters.

    Science.gov (United States)

    Min, Run; Chen, Chen; Zhang, Xiaodong; Zou, Xuecheng; Tong, Qiaoling; Zhang, Qiao

    2014-05-19

    In digital current mode controlled DC-DC converters, conventional current sensors might not provide isolation at a minimized price, power loss and size. Therefore, a current observer which can be realized based on the digital circuit itself, is a possible substitute. However, the observed current may diverge due to the parasitic resistors and the forward conduction voltage of the diode. Moreover, the divergence of the observed current will cause steady state errors in the output voltage. In this paper, an optimal current observer is proposed. It achieves the highest observation accuracy by compensating for all the known parasitic parameters. By employing the optimal current observer-based predictive current controller, a buck converter is implemented. The converter has a convergently and accurately observed inductor current, and shows preferable transient response than the conventional voltage mode controlled converter. Besides, costs, power loss and size are minimized since the strategy requires no additional hardware for current sensing. The effectiveness of the proposed optimal current observer is demonstrated experimentally.

  9. Dynamics of the earth's ring current - Theory and observation

    Science.gov (United States)

    Williams, D. J.

    1985-01-01

    The development of currents within an arbitrary distribution of particles trapped in the geomagnetic field is described. These currents combine to form the earth's ring current and thus are responsible for the worldwide depressions of surface magnetic field strength during periods of magnetic activity known as magnetic storms. Following a brief review of trapped particle motion in magnetic fields, ring current development is described and presented in terms of basic field and particle distribution parameters. Experimental observations then are presented and discussed within the theoretical framework developed earlier. New results are presented which, in the area of composition and charge state observations, hold high promise in solving many long standing ring current problems. Finally, available experimental results will be used to assess the present understanding as to ring current sources, generation, and dissipation.

  10. West Coast Observing System (WCOS) ADCP Currents Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The West Coast Observing System (WCOS) project provides access to temperature and currents data collected at four of the five National Marine Sanctuary sites,...

  11. Satellite observations of the northeast monsoon coastal current

    Digital Repository Service at National Institute of Oceanography (India)

    Shenoi, S.S.C.; Gouveia, A.D.; Shetye, S.R.; Rao, L.V.G.

    Satellite Infrared observations, from Advanced Very High Resolution Radiometer (AVHRR), during November 1987-February 1988 and hydrographic data from the eastern Arabian Sea are used to describe the poleward flowing coastal current in the eastern...

  12. Integrating Observations of the Boundary Current Flow around Sri Lanka

    Science.gov (United States)

    2015-09-30

    GOALS The long-term goal is to investigate the boundary-current and inter -basin ocean circulation which governs the conditions and variability in Bay...observations, and NASCar in general has a focus on the inter -basin exchange to which our observations are expected to provide important insight

  13. Tide and tidal current observation in the Karimata Strait

    Science.gov (United States)

    Wei, Zexun; Fang, Guohong; Sulistiyo, Budi; Dwi Susanto, R.; Setiawan, Agus; Rameyo Adi, Tukul; Qiao, Fangli; Fan, Bin; Li, Shujiang

    2013-04-01

    It is believed that the water exchanges between the South China Sea and the Indonesian Seas are significant, and play an important role in the water mass formation and air-sea interactions of both the South China Sea and Indonesian Seas. It has also been found that the current in Sunda Strait has been obvious seasonal variation, which indicates the water exchange between West Indonesian Seas and India Ocean. In order to make quantitative evaluation of the magnitudes of the exchange, the First Institute of Oceanography (FIO), China, the Agency for Marine and Fisheries Research, Indonesia, and the Lamont-Doheries Earth Observatory, USA established a collaborative program, "The South-China Sea-Indonesian Seas Transport/Exchange (SITE) and Impacts on Seasonal Fish Migration" in 2006. And, they extend and expand the cooperation to Sunda Strait in 2008, the title of the collaborative program was changed to "The South China Sea - Indonesian Seas Transport/Exchange (SITE) and Dynamics of Sunda and Lombok Straits, and Their Impacts on Seasonal Fish Migration". Till now, 12 joint cruises have been conducted since December, 2007. Ten Trawl-Resistant Bottom Mounts (TRBM) have been deployed in the Karimata and Sunda Straits. The TRBMs are equipped with ADCPs and tide gauges for measuring current profiles and sea levels, respectively. The temperature-salinity profiles were measured with ship-board CTD during the cruises. Data obtained in Karimata Strait revealed that a significant water mass transport. This indicates that the Karimata Strait throughflow can greatly impacts the circulation of both the South China Sea and the Indonesian Seas. The data obtained at the 5 stations alone the two sections in the Karimata Strait were used to study the tide and tidal currents in the Karimata Strait. 2 TRBMs were deployed at Section A, as well as 3 at Section B, which lies at the southeast of Section A. Station B1 is in the Gaspar Strait between Bangka Island and Belitung Island, Stations

  14. Morphology of the ring current derived from magnetic field observations

    Directory of Open Access Journals (Sweden)

    G. Le

    2004-04-01

    Full Text Available Our examination of the 20 years of magnetospheric magnetic field data from ISEE, AMPTE/CCE and Polar missions has allowed us to quantify how the ring current flows and closes in the magnetosphere at a variety of disturbance levels. Using intercalibrated magnetic field data from the three spacecraft, we are able to construct the statistical magnetic field maps and derive 3-dimensional current density by the simple device of taking the curl of the statistically determined magnetic field. The results show that there are two ring currents, an inner one that flows eastward at ~3 RE and a main westward ring current at ~4–7 RE for all levels of geomagnetic disturbances. In general, the in-situ observations show that the ring current varies as the Dst index decreases, as we would expect it to change. An unexpected result is how asymmetric it is in local time. Some current clearly circles the magnetosphere but much of the energetic plasma stays in the night hemisphere. These energetic particles appear not to be able to readily convect into the dayside magnetosphere. During quiet times, the symmetric and partial ring currents are similar in strength (~0.5MA and the peak of the westward ring current is close to local midnight. It is the partial ring current that exhibits most drastic intensification as the level of disturbances increases. Under the condition of moderate magnetic storms, the total partial ring current reaches ~3MA, whereas the total symmetric ring current is ~1MA. Thus, the partial ring current contributes dominantly to the decrease in the Dst index. As the ring current strengthens the peak of the partial ring current shifts duskward to the pre-midnight sector. The partial ring current is closed by a meridional current system through the ionosphere, mainly the field-aligned current, which maximizes at local times near the dawn and dusk. The closure currents flow in

  15. Disturbance observer based current controller for vector controlled IM drives

    DEFF Research Database (Denmark)

    Teodorescu, Remus; Dal, Mehmet

    2008-01-01

    In order to increase the accuracy of the current control loop, usually, well known parameter compensation and/or cross decoupling techniques are employed for advanced ac drives. In this paper, instead of using these techniques an observer-based current controller is proposed for vector controlled...... coupling effects and increase robustness against parameters change without requiring any other compensation strategies. The experimental implementation results are provided to demonstrate validity and performance of the proposed control scheme.......In order to increase the accuracy of the current control loop, usually, well known parameter compensation and/or cross decoupling techniques are employed for advanced ac drives. In this paper, instead of using these techniques an observer-based current controller is proposed for vector controlled...

  16. Observability of surface currents in p-wave superconductors

    Science.gov (United States)

    Bakurskiy, S. V.; Klenov, N. V.; Soloviev, I. I.; Kupriyanov, M. Yu; Golubov, A. A.

    2017-04-01

    A general approach is formulated to describe spontaneous surface current distribution in a chiral p-wave superconductor. We use the quasiclassical Eilenberger formalism in the Ricatti parametrization to describe various types of the superconductor surface, including arbitrary roughness and metallic behavior of the surface layer. We calculate angle resolved distributions of the spontaneous surface currents and formulate the conditions of their observability. We argue that local measurements of these currents by muon spin rotation technique may provide an information on the underlying pairing symmetry in the bulk superconductor.

  17. Current studies on megapode phylogeny

    NARCIS (Netherlands)

    Brom, T.G.; Dekker, R.W.R.J.

    1992-01-01

    Hypotheses regarding the phylogenetic relationships between megapodes and other birds are reviewed, and it is concluded that the available evidence supports a sistergroup relationship between megapodes and all other galliforms. Current studies in this direction are discussed. The resolvement of intr

  18. Current systematic carbon cycle observations and needs for implementing a policy-relevant carbon observing system

    Directory of Open Access Journals (Sweden)

    P. Ciais

    2013-07-01

    Full Text Available A globally integrated carbon observation and analysis system is needed to improve the fundamental understanding of the global carbon cycle, to improve our ability to project future changes, and to verify the effectiveness of policies aiming to reduce greenhouse gas emissions and increase carbon sequestration. Building an integrated carbon observation system requires transformational advances from the existing sparse, exploratory framework towards a dense, robust, and sustained system in all components: anthropogenic emissions, the atmosphere, the ocean, and the terrestrial biosphere. The goal of this study is to identify the current state of carbon observations and needs for a global integrated carbon observation system that can be built in the next decade. A key conclusion is the substantial expansion (by several orders of magnitude of the ground-based observation networks required to reach the high spatial resolution for CO2 and CH4 fluxes, and for carbon stocks for addressing policy relevant objectives, and attributing flux changes to underlying processes in each region. In order to establish flux and stock diagnostics over remote areas such as the southern oceans, tropical forests and the Arctic, in situ observations will have to be complemented with remote-sensing measurements. Remote sensing offers the advantage of dense spatial coverage and frequent revisit. A key challenge is to bring remote sensing measurements to a level of long-term consistency and accuracy so that they can be efficiently combined in models to reduce uncertainties, in synergy with ground-based data. Bringing tight observational constraints on fossil fuel and land use change emissions will be the biggest challenge for deployment of a policy-relevant integrated carbon observation system. This will require in-situ and remotely sensed data at much higher resolution and density than currently achieved for natural fluxes, although over a small land area (cities, industrial

  19. Current State of the Teaching of Process Writing in EFL Classes: An Observational Study in the Last Two Years of Secondary School

    Directory of Open Access Journals (Sweden)

    Edgar Mendoza López

    2005-10-01

    Full Text Available This study reports on the process writing activities carried out in EFL classes in the last two years of secondary school. Grades 10 and 11 in six Colombian high schools - three public and three private - were observed in order to determine the way process writing is taught, focusing especially on the planning, composing, and revising activities, and based on the understanding of writing as an activity with a process-oriented approach. The findings indicate that writing and also reading are product-oriented, and that class activities tend to place or emphasize listening and speaking over writing and reading. Most of the time was spent on oral exercises, drills, role-plays and pronunciation, being group work and role-play activities what students enjoyed most.Este estudio presenta las actividades de escritura realizadas en las clases de inglés como lengua extranjera en los dos últimos grados de secundaria (10 y 11 de 6 colegios - tres públicos y tres privados. La observación se enfocó en la forma en que se enseña la escritura, especialmente en lo relacionado con las actividades de planeación, formulación y revisión con base en la concepción de la escritura como un proceso. Los resultados indican que la lectura y la escritura están orientadas hacia el producto, y que las clases privilegian la escucha y el habla sobre la lectura y la escritura. La mayor parte del tiempo se dedicó a ejercicios orales y escritos, juegos de roles y pronunciación, y los estudiantes disfrutaron más los trabajos en grupo y los juegos de roles.

  20. Currents in the Dead Sea: Lagrangian and Eulerian observations

    Science.gov (United States)

    Ozer, Tal; Gertman, Isaac; Katsenelson, Boris; Bodzin, Raanan; Lensly, Nadav

    2015-04-01

    The Dead Sea is a terminal hypersaline lake located in the lowest surface on Earth (currently -429 m bsl). The physical properties of the brine are significantly different than in common marine systems: the DS brine density is ~1.24 gr/cc and its viscosity ~3 times higher than marine systems. We present observational data on wind and currents in the Dead Sea. The observation setup includes a few fixed (Eulerian) stations which are equipped with wind meter and current meter profiler that covers the entire water column (ADCP). Thermal stratification is continuously measured in some of the stations using a thermistor chain. Lagrangian drifters that record the shallow water currents were released in liner array of single drifters between the fixed stations, and also in triplets (15 m triangle). The results include the measured time series data of wind (atmospheric forcing) and the measured current profiles from the fixed stations. Data of the Lagrangian drifters is presented as trajectories along with vector time series. Quality control check included comparison of drifter data and ADCP data whenever the drifters passed by the fixed stations; a very good agreement was found between the different measuring approaches. We discuss the following issues : (i) the relation between the wind and current data, (ii) the Lagrangian trajectories and transport aspects.

  1. Observed currents at Bombay High during a winter

    Digital Repository Service at National Institute of Oceanography (India)

    Fernandes, A.A.; Chandramohan, P.; Nayak, B.U.

    and diurnal tides were oriented roughly perpendicular to the shelf-break while the mean currents were northwestwards along the shelf-break. During the observation period, the mixed layer (-50 m) remained isothermal while a steady rise in temperature (~2˚C...

  2. Study of longshore current equations for currents in Visakhapatnam beach

    Digital Repository Service at National Institute of Oceanography (India)

    Chandramohan, P.; Rao, T.V.N.

    Longshore currents were measured along the Visakhapatnam Beach, Andhra Pradesh, India at weekly intervals from March 1978 to March 1979. Visual observations on breaker characteristics were also made during this period. Using modified Longuet...

  3. [Current studies in myotonic dystrophy].

    Science.gov (United States)

    Zhao, Yimeng; Ishiura, Shoichi

    2014-03-01

    Myotonic dystrophy (DM) is a genetic, progressive, multisystemic disease with muscular disorder as its primary symptom. There are two types of DM (DM1 and DM2) caused by mutations in different genes, and in Japan, DM occurs with an incidence of approximately 1 in 20,000. The pathogenic mechanism underlying the disease is RNA toxicity caused by transcripts of aberrantly elongated CTG or CCTG repeats located in the 3' untranslated region or in the intron. The current treatments for DM is limited to symptomatic care. In this review, we will discuss several new therapeutic strategies based on recent studies of RNA toxicity.

  4. Studies of Current Dependent Effects at ANKA

    CERN Document Server

    Müller, A S; Huttel, E; Pérez, F; Pont, M; Zimmermann, Frank

    2004-01-01

    The ANKA electron storage ring is operated at energies between 0.5 and 2.5 GeV. A major requirement for a synchrotron light source, such as ANKA, is to achieve a high beam current. A multitude of mostly impedance related effects depend on either bunch or total beam current. This paper gives an overview over the various beam studies performed at ANKA in this context, specifically the observation of current dependent detuning, the determination of the bunch length change with current from a measurement of the ratio between coherent and incoherent synchrotron tune and an assessment of the effective longitudinal loss factor from the current dependent horizontal closed orbit distortion.

  5. Female soccer knee injury: observed knowledge gaps in injury prevention among players/parents/coaches and current evidence (the KNOW study).

    Science.gov (United States)

    Orr, B; Brown, C; Hemsing, J; McCormick, T; Pound, S; Otto, D; Emery, C A; Beaupre, L A

    2013-06-01

    This study sought to determine if knowledge regarding the risk for knee injuries and the potential for their prevention is being translated to female adolescent soccer players (13-18 years), their parents, and coaches. Eligible participants in the 2007 indoor soccer season were surveyed to determine their knowledge of the risk for and the potential to prevent knee injuries, and their knowledge of effective prevention strategies, if they felt that injury prevention was possible. Team selection was stratified to be representative of both competitive and recreational level play and age group distributions within the selected soccer association. Of the study subjects, 773/1396 (55.4%) responded to the survey: 408 (53%) players, 292 (38%) parents, and 73 (9%) coaches. Most respondents (538 [71%]) were aware of the risk for knee injury. Coaches and parents were more likely than players to view knee injuries as preventable; however, appropriate prevention strategies were often not identified. Four hundred eighty-four (63.8%) respondents reported that they had never received information on knee injuries. Substantial knowledge gaps regarding knee injury prevention and effective preventative strategies were identified. Given the predominance of knee injuries in female adolescent soccer players, there is an urgent need for knowledge translation of prevention strategies to decrease both incidence and long-term consequences of knee injuries. © 2011 John Wiley & Sons A/S.

  6. Observed residual currents off the Changjiang (Yangtze) River mouth in summertime of 1959 and 1982

    Institute of Scientific and Technical Information of China (English)

    朱建荣; 戚定满; 肖成猷

    2004-01-01

    Data taken in two large scale ocean observations in China in summer 1959 and 1982 were used to analyze the residual current off the Changjiang (Yangtze) River mouth. The currents at surface off the mouth in July 1959 and 1982 flow northeastward and eastward due to the river discharge, the current speed was larger in1982 than in 1959. All the bottom currents flow landward due to baroclinic effect. The surface current was controlled by the river runoff and the Taiwan Warm Current (TWC). A return current at surface off the mouth was observed in September 1959. In general, the bottom currents were controlled by the TWC in most study area in addition to the runoff near the mouth. Although driven by 3-D model with the monthly averaged forces (river discharge, wind stress, baroclinic effect, open boundary water volume flux and tidal mixing) in August, the simulated circulations were basically consistent with the observed ones with episodic time manner.

  7. [Current status of autism studies].

    Science.gov (United States)

    Kurita, H

    2001-01-01

    The current status of autism studies was reviewed based on English articles published during the 1990s. Although the concepts of autism and pervasive developmental disorders (PDD) are established, diagnostic criteria of PDDNOS or atypical autism, which is frequently difficult to differentiate from autism, need to be established. The prevalence of autism has been estimated as about 0.05% in the U.S and many European countries, while it was reported to be 0.1% or higher in Japan and some European countries, though the reasons for this difference are unclear. High-functioning (IQ > or = 70) autism may not be as rare a condition as previously thought and both its difference from and similarity to Asperger's syndrome, the highest functioning PDD subtype, need clarification. About 20 to 40% of children with autism lose meaningful words by the age of 2 years and display autistic symptoms thereafter. Such autism, called the setback type in Japan, has been demonstrated to have a poorer adolescent/adult outcome compared to autism without setback and its relationship with childhood disintegrative disorder, which displays a clearer regression after normal development for at least the first 2 years of life, needs to be addressed. The etiology of autism is now considered mostly genetic for reasons, such as the significantly higher concordance rate of autism in identical twin pairs (60-80%) than in fraternal twin pairs (0-10%) and an 3-5% incidence of autism among sibs of an autism proband, 30 to 100 times higher than that in the general population. The involvement of several genes is implicated to create susceptibility for autism, yet the responsible genes have not been identified. Although there is no medication to cure autism, some psychotropic drugs, such as antipsychotics and SSRIs, seem effective for behavior problems in autism patients. Psychosocial treatments are the main therapeutic approach to autism, though they are yet to be well systematized. It is important to

  8. [Current registry studies of acute ischemic stroke].

    Science.gov (United States)

    Veltkamp, R; Jüttler, E; Pfefferkorn, T; Purrucker, J; Ringleb, P

    2012-10-01

    Study registries offer the opportunity to evaluate the effects of new therapies or to observe the consequences of new treatments in clinical practice. The SITS-MOST registry confirmed the validity of findings from randomized trials on intravenous thrombolysis concerning safety and efficacy in the clinical routine. Current study registries concerning new interventional thrombectomy techniques suggest a high recanalization rate; however, the clinical benefit can only be evaluated in randomized, controlled trials. Similarly, the experiences of the BASICS registry on basilar artery occlusion have led to the initiation of a controlled trial. The benefit of hemicraniectomy in malignant middle cerebral artery infarction has been demonstrated by the pooled analysis of three randomized trials. Numerous relevant aspects are currently documented in the DESTINY-R registry. Finally, the recently started RASUNOA registry examines diagnostic and therapeutic aspects of ischemic and hemorrhagic stroke occurring during therapy with new oral anticoagulants.

  9. Local structure of the magnetotail current sheet: 2001 Cluster observations

    Directory of Open Access Journals (Sweden)

    A. Runov

    2006-03-01

    Full Text Available Thirty rapid crossings of the magnetotail current sheet by the Cluster spacecraft during July-October 2001 at a geocentric distance of 19 RE are examined in detail to address the structure of the current sheet. We use four-point magnetic field measurements to estimate electric current density; the current sheet spatial scale is estimated by integration of the translation velocity calculated from the magnetic field temporal and spatial derivatives. The local normal-related coordinate system for each case is defined by the combining Minimum Variance Analysis (MVA and the curlometer technique. Numerical parameters characterizing the plasma sheet conditions for these crossings are provided to facilitate future comparisons with theoretical models. Three types of current sheet distributions are distinguished: center-peaked (type I, bifurcated (type II and asymmetric (type III sheets. Comparison to plasma parameter distributions show that practically all cases display non-Harris-type behavior, i.e. interior current peaks are embedded into a thicker plasma sheet. The asymmetric sheets with an off-equatorial current density peak most likely have a transient nature. The ion contribution to the electric current rarely agrees with the current computed using the curlometer technique, indicating that either the electron contribution to the current is strong and variable, or the current density is spatially or temporally structured.

  10. Field aligned current observations in the polar cusp ionosphere

    Science.gov (United States)

    Ledley, B. G.; Farthing, W. H.

    1973-01-01

    Vector magnetic field measurements made during a sounding rocket flight in the polar cusp ionosphere show field fluctuations in the lower F-region which are interpreted as being caused by the payload's passage through a structured field aligned current system. The field aligned currents have a characteristic horizontal scale size of one kilometer. Analysis of one large field fluctuation gives a current density of 0.0001 amp/m sq.

  11. Field-aligned current observations in the polar cusp ionosphere

    Science.gov (United States)

    Ledley, B. G.; Farthing, W. H.

    1974-01-01

    Vector magnetic field measurements made during a sounding rocket flight in the polar cusp ionosphere show field fluctuations in the lower F region that are interpreted as being caused by the passage of the payload through a structured field-aligned current system. The field-aligned currents have a characteristic horizontal scale size of about 1 km. Analysis of one large field fluctuation gives a current density of .001 A/sq m.

  12. Experimental observation of direct current voltage-induced phase synchronization

    Indian Academy of Sciences (India)

    Haihong Li; Weiqing Liu; Qiongling Dai; Jinghua Xiao

    2006-09-01

    The dynamics of two uncoupled distinct Chua circuits driven by a common direct current voltage is explored experimentally. It was found that, with increasing current intensity, the dominant frequencies of these two Chua circuits will first vary at different speeds, approach an identical value for a certain current intensity and then separate. Techniques such as synchronization index and phase difference distribution were employed to analyze the phase coherence between these two Chua circuits.

  13. Catapult current sheet relaxation model confirmed by THEMIS observations

    Science.gov (United States)

    Machida, S.; Miyashita, Y.; Ieda, A.; Nose, M.; Angelopoulos, V.; McFadden, J. P.

    2014-12-01

    In this study, we show the result of superposed epoch analysis on the THEMIS probe data during the period from November, 2007 to April, 2009 by setting the origin of time axis to the substorm onset determined by Nishimura with THEMIS all sky imager (THEMS/ASI) data (http://www.atmos.ucla.edu/~toshi/files/paper/Toshi_THEMIS_GBO_list_distribution.xls). We confirmed the presence of earthward flows which can be associated with north-south auroral streamers during the substorm growth phase. At around X = -12 Earth radii (Re), the northward magnetic field and its elevation angle decreased markedly approximately 4 min before substorm onset. A northward magnetic-field increase associated with pre-onset earthward flows was found at around X = -17Re. This variation indicates the occurrence of the local depolarization. Interestingly, in the region earthwards of X = -18Re, earthward flows in the central plasma sheet (CPS) reduced significantly about 3min before substorm onset. However, the earthward flows enhanced again at t = -60 sec in the region around X = -14 Re, and they moved toward the Earth. At t = 0, the dipolarization of the magnetic field started at X ~ -10 Re, and simultaneously the magnetic reconnection started at X ~ -20 Re. Synthesizing these results, we can confirm the validity of our catapult current sheet relaxation model.

  14. In Situ Observations of Ion Scale Current Sheets and Associated Electron Heating in Turbulent Space Plasmas

    Science.gov (United States)

    Chasapis, A.; Retino, A.; Sahraoui, F.; Greco, A.; Vaivads, A.; Khotyaintsev, Y. V.; Sundkvist, D. J.; Canu, P.

    2014-12-01

    We present a statistical study of ion-scale current sheets in turbulent space plasma. The study was performed using in situ measurements from the Earth's magnetosheath downstream of the quasi-parallel shock. Intermittent structures were identified using the Partial Variance of Increments method. We studied the distribution of the identified structures as a function of their magnetic shear angle, the PVI index and the electron heating. The properties of the observed current sheets were different for high (>3) and low (3) structures that accounted for ~20% of the total. Those current sheets have high magnetic shear (>90 degrees) and were observed mostly in close proximity to the bow shock with their numbers reducing towards the magnetopause. Enhancement of the estimated electron temperature within these current sheets suggest that they are important for local electron heating and energy dissipation.

  15. Climate-induced boreal forest change: Predictions versus current observations

    Science.gov (United States)

    Soja, Amber J.; Tchebakova, Nadezda M.; French, Nancy H. F.; Flannigan, Michael D.; Shugart, Herman H.; Stocks, Brian J.; Sukhinin, Anatoly I.; Parfenova, E. I.; Chapin, F. Stuart; Stackhouse, Paul W.

    2007-04-01

    For about three decades, there have been many predictions of the potential ecological response in boreal regions to the currently warmer conditions. In essence, a widespread, naturally occurring experiment has been conducted over time. In this paper, we describe previously modeled predictions of ecological change in boreal Alaska, Canada and Russia, and then we investigate potential evidence of current climate-induced change. For instance, ecological models have suggested that warming will induce the northern and upslope migration of the treeline and an alteration in the current mosaic structure of boreal forests. We present evidence of the migration of keystone ecosystems in the upland and lowland treeline of mountainous regions across southern Siberia. Ecological models have also predicted a moisture-stress-related dieback in white spruce trees in Alaska, and current investigations show that as temperatures increase, white spruce tree growth is declining. Additionally, it was suggested that increases in infestation and wildfire disturbance would be catalysts that precipitate the alteration of the current mosaic forest composition. In Siberia, 7 of the last 9 yr have resulted in extreme fire seasons, and extreme fire years have also been more frequent in both Alaska and Canada. In addition, Alaska has experienced extreme and geographically expansive multi-year outbreaks of the spruce beetle, which had been previously limited by the cold, moist environment. We suggest that there is substantial evidence throughout the circumboreal region to conclude that the biosphere within the boreal terrestrial environment has already responded to the transient effects of climate change. Additionally, temperature increases and warming-induced change are progressing faster than had been predicted in some regions, suggesting a potential non-linear rapid response to changes in climate, as opposed to the predicted slow linear response to climate change.

  16. Climate-Induced Boreal Forest Change: Predictions versus Current Observations

    Science.gov (United States)

    Soja, Amber J.; Tchebakova, Nadezda M.; French, Nancy H. F.; Flannigan, Michael D.; Shugart, Herman H.; Stocks, Brian J.; Sukhinin, Anatoly I.; Parfenova, E. I.; Chapin, F. Stuart, III; Stackhouse, Paul W., Jr.

    2007-01-01

    For about three decades, there have been many predictions of the potential ecological response in boreal regions to the currently warmer conditions. In essence, a widespread, naturally occurring experiment has been conducted over time. In this paper, we describe previously modeled predictions of ecological change in boreal Alaska, Canada and Russia, and then we investigate potential evidence of current climate-induced change. For instance, ecological models have suggested that warming will induce the northern and upslope migration of the treeline and an alteration in the current mosaic structure of boreal forests. We present evidence of the migration of keystone ecosystems in the upland and lowland treeline of mountainous regions across southern Siberia. Ecological models have also predicted a moisture-stress-related dieback in white spruce trees in Alaska, and current investigations show that as temperatures increase, white spruce tree growth is declining. Additionally, it was suggested that increases in infestation and wildfire disturbance would be catalysts that precipitate the alteration of the current mosaic forest composition. In Siberia, five of the last seven years have resulted in extreme fire seasons, and extreme fire years have also been more frequent in both Alaska and Canada. In addition, Alaska has experienced extreme and geographically expansive multi-year outbreaks of the spruce beetle, which had been previously limited by the cold, moist environment. We suggest that there is substantial evidence throughout the circumboreal region to conclude that the biosphere within the boreal terrestrial environment has already responded to the transient effects of climate change. Additionally, temperature increases and warming-induced change are progressing faster than had been predicted in some regions, suggesting a potential non-linear rapid response to changes in climate, as opposed to the predicted slow linear response to climate change.

  17. Countesthorpe College: an observant study

    Science.gov (United States)

    Riley, Ann; Stamatabis, Kathy

    1974-01-01

    Discussed the objectives and the conditions which made possible a new school embodying radical innovations. The results of a observational study at an early stage of the school's development, undertaken by a group of students, are summarised here by two of them, both now teaching in Leicestershire Upper Schools. (Editor/RK)

  18. Satellite observations of an annual cycle in the Agulhas Current

    CSIR Research Space (South Africa)

    Krug, Marjolaine, J

    2012-08-01

    Full Text Available years of along-track altimetry and merged altimetry and close to 7 years of high frequency Sea Surface Temperature (SST) observations. While the position and width of the Agulhas Current’s dynamical core do not display an annual cycle, the geostrophic...

  19. A study of model bivalve siphonal currents

    Science.gov (United States)

    Monismith, Stephen G.; Koseff, Jeffrey R.; Thompson, Janet K.; O'Riordan, Catherine A.; Nepf, Heidi M.

    1990-01-01

    We carried out experiments studying the hydrodynamics of bivalve siphonal currents in a laboratory flume. Rather than use living animals, we devised a simple, model siphon pair connected to a pump. Fluorescence-based flow visualization was used to characterize siphon-jet flows for several geometric configurations and flow speeds. These measurements show that the boundary-layer velocity profile, siphon height, siphon pair orientation, and size of siphon structure all affect the vertical distribution of the excurrent flow downstream of the siphon pair and the fraction of excurrent that is refiltered. The observed flows may effect both the clearance rate of an entire population of siphonate bivalves as well as the efficiency of feeding of any individual. Our results imply that field conditions are properly represented in laboratory flume studies of phytoplankton biomass losses to benthic bivalves when the shear velocity and bottom roughness are matched to values found in the field. Numerical models of feeding by a bivalve population should include an effective sink distribution which is created by the combined incurrent-excurrent flow field. Near-bed flows need to be accounted for to properly represent these benthic-pelagic exchanges. We also present velocity measurements made with a laser-Doppler anemometer (LDA) for a single configuration (siphons flush with bed, inlet downstream) that show that the siphonal currents have a significant local effect on the properties of a turbulent boundary layer.

  20. The CAWSES Global Observing Campaign on Tides: Current Status

    Science.gov (United States)

    Ward, W. E.; Gerding, M.; Goncharenko, L.; Keckhut, P.; Marsh, D.; Oberheide, J.; Rao, D. N.; Scheer, .; Singer, W.

    2007-05-01

    The CAWSES Global Tidal Campaign was initiated to encourage collaboration between satellite and ground based observations and to identify features in various observation types consistent with specific components. This project is one of several sponsored under Theme 3, Atmospheric Coupling Processes, of the international Climate and Weather of the Sun Earth System program (CAWSES, a SCOSTEP sponsored program). The overall goal of the campaign is to provide global data sets for several concentrated time periods over the next few years which includes coordinated ground-based and satellite measurements and modeling efforts. To unambiguously resolve the tidal components present in the Earth's atmosphere requires spatial and temporal sampling sufficient to resolve wavenumbers up to at least 5 and periods down to 4.8 hours every two to three days. Neither satellite or ground based observations on their own are capable of achieving these goals. Interpretation of tidal signatures in different observables (for example wind and temperature) is complicated by the fact the the associated latitudinal structures are typically different. A global network is required to allow these structures to be examined. Three campaign periods have been sceduled to date. The first tidal campaign took place from September 1 to October 31, 2005 and this year two campaigns, March 1 to April 31, and June 1 to August 15 are planned. The first of these latter campaigns will concentrate on the global tidal structures during equinox and their evolution and variability during this time period. The second of these campaigns will address the tidal structures during solstice conditions. Strong hemispheric asymmetries are know to develop in the structure of the migrating diurnal tide and it is of interest to determine the form of other components. These campaigns will allow the characterization of the heating sources, tidal components (migrating and nonmigrating), and tidal effects from the surface of the

  1. Complex state variable- and disturbance observer-based current controllers for AC drives

    DEFF Research Database (Denmark)

    Dal, Mehmet; Teodorescu, Remus; Blaabjerg, Frede

    2013-01-01

    , extracted by a disturbance observer and then injected into the current controller. In this study, a revised version of a disturbance observer-based controller and a well known complex variable model-based design with a single set of complex pole are compared in terms of design aspects and performance...... of the parameter and the cross-coupling effect. Moreover, it provides a better performance, smooth and low noisy operation with respect to the complex variable controller....... of the stator current. In order to improve the current control performance an alternative current control strategy was proposed previously aiming to avoid the undesired cross-coupling and non-linearities between the state variables. These effects are assumed as disturbances arisen in the closed-loop path...

  2. A western boundary current eddy characterisation study

    Science.gov (United States)

    Ribbe, Joachim; Brieva, Daniel

    2016-12-01

    The analysis of an eddy census for the East Australian Current (EAC) region yielded a total of 497 individual short-lived (7-28 days) cyclonic and anticyclonic eddies for the period 1993 to 2015. This was an average of about 23 eddies per year. 41% of the tracked individual cyclonic and anticyclonic eddies were detected off southeast Queensland between about 25 °S and 29 °S. This is the region where the flow of the EAC intensifies forming a swift western boundary current that impinges near Fraser Island on the continental shelf. This zone was also identified as having a maximum in detected short-lived cyclonic eddies. A total of 94 (43%) individual cyclonic eddies or about 4-5 per year were tracked in this region. The census found that these potentially displaced entrained water by about 115 km with an average displacement speed of about 4 km per day. Cyclonic eddies were likely to contribute to establishing an on-shelf longshore northerly flow forming the western branch of the Fraser Island Gyre and possibly presented an important cross-shelf transport process in the life cycle of temperate fish species of the EAC domain. In-situ observations near western boundary currents previously documented the entrainment, off-shelf transport and export of near shore water, nutrients, sediments, fish larvae and the renewal of inner shelf water due to short-lived eddies. This study found that these cyclonic eddies potentially play an important off-shelf transport process off the central east Australian coast.

  3. The Australian Geodetic Observing Program. Current Status and Future Plans

    Science.gov (United States)

    Johnston, G.; Dawson, J. H.

    2015-12-01

    Over the last decade, the Australian government has through programs like AuScope, the Asia Pacific Reference Frame (APREF), and the Pacific Sea Level Monitoring (PSLM) Project made a significant contribution to the Global Geodetic Observing Program. In addition to supporting the national research priorities, this contribution is justified by Australia's growing economic dependence on precise positioning to underpin efficient transportation, geospatial data management, and industrial automation (e.g., robotic mining and precision agriculture) and the consequent need for the government to guarantee provision of precise positioning products to the Australian community. It is also well recognised within Australia that there is an opportunity to exploit our near unique position as being one of the few regions in the world to see all new and emerging satellite navigation systems including Galileo (Europe), GPS III (USA), GLONASS (Russia), Beidou (China), QZSS (Japan) and IRNSS (India). It is in this context that the Australian geodetic program will build on earlier efforts and further develop its key geodetic capabilities. This will include the creation of an independent GNSS analysis capability that will enable Australia to contribute to the International GNSS Service (IGS) and an upgrade of key geodetic infrastructure including the national VLBI and GNSS arrays. This presentation will overview the significant geodetic activities undertaken by the Australian government and highlight its future plans.

  4. Space Technology 5 Multipoint Observations of Temporal and Spatial Variability of Field-Aligned Currents

    Science.gov (United States)

    Le, G.; Wang, Y.; Slavin, J. A.; Strangeway, R. L.

    2009-01-01

    Space Technology 5 (ST5) is a constellation mission consisting of three microsatellites. It provides the first multipoint magnetic field measurements in low Earth orbit, which enables us to separate spatial and temporal variations. In this paper, we present a study of the temporal variability of field-aligned currents using the ST5 data. We examine the field-aligned current observations during and after a geomagnetic storm and compare the magnetic field profiles at the three spacecraft. The multipoint data demonstrate that mesoscale current structures, commonly embedded within large-scale current sheets, are very dynamic with highly variable current density and/or polarity in approx.10 min time scales. On the other hand, the data also show that the time scales for the currents to be relatively stable are approx.1 min for mesoscale currents and approx.10 min for large-scale currents. These temporal features are very likely associated with dynamic variations of their charge carriers (mainly electrons) as they respond to the variations of the parallel electric field in auroral acceleration region. The characteristic time scales for the temporal variability of mesoscale field-aligned currents are found to be consistent with those of auroral parallel electric field.

  5. Observations on the Current Bacteriological Profile of Chronic ...

    African Journals Online (AJOL)

    Keywords: Bilateral, Chronic, Culture and sensitivity, Otitis Media, Pseudomonas ... The Statistical Package for Social Sciences (SPSS Inc.,. Chicago, IL, USA) version 16 was used for analysis. Chi‑square test was used to test the statistical significance of .... study is limited by using retrospective design especially in.

  6. Ozone Lidar Observations for Air Quality Studies

    Science.gov (United States)

    Wang, Lihua; Newchurch, Mike; Kuang, Shi; Burris, John F.; Huang, Guanyu; Pour-Biazar, Arastoo; Koshak, William; Follette-Cook, Melanie B.; Pickering, Kenneth E.; McGee, Thomas J.; Sullivan, John T.; Langford, Andrew O.; Senff, Christoph J.; Alvarez, Raul; Eloranta, Edwin

    2015-01-01

    Tropospheric ozone lidars are well suited to measuring the high spatio-temporal variability of this important trace gas. Furthermore, lidar measurements in conjunction with balloon soundings, aircraft, and satellite observations provide substantial information about a variety of atmospheric chemical and physical processes. Examples of processes elucidated by ozone-lidar measurements are presented, and modeling studies using WRF-Chem, RAQMS, and DALES/LES models illustrate our current understanding and shortcomings of these processes.

  7. In situ observations of ion scale current sheet and associated electron heating in Earth's magnetosheath turbulence

    Science.gov (United States)

    Chasapis, Alexandros; Retinò, Alessandro; Sahraoui, Fouad; Greco, Antonella; Vaivads, Andris; Sundkvist, David; Canu, Patrick

    2014-05-01

    Magnetic reconnection occurs in thin current sheets that form in turbulent plasmas. Numerical simulations indicate that turbulent reconnection contributes to the dissipation of magnetic field energy and results in particle heating and non-thermal acceleration. Yet in situ measurements are required to determine its importance as a dissipation mechanism at those scales. The Earth's magnetosheath downstream of the quasi-parallel shock is a turbulent near-Earth environment that offers a privileged environment for such a study. Here we present a study of the properties of thin current sheets by using Cluster data. We studied the distribution of the current sheets as a function of their magnetic shear angle, the PVI index and the electron heating. The properties of the observed current sheets were different for high shear (θ > 90 degrees) and low shear current sheets (θ < 90 degrees). These high-shear current sheets account for about ˜ 20% of the total and have an average thickness comparable to the ion inertial length. Enhancement of electron temperature within these current sheets suggest that they are important for local electron heating and energy dissipation.

  8. Wave glider observations of surface winds and currents in the core of Typhoon Danas

    Science.gov (United States)

    Mitarai, S.; McWilliams, J. C.

    2016-11-01

    Simultaneous monitoring of surface winds and currents is essential to understand oceanic responses to tropical cyclones. We used a new platform, a Wave Glider (Liquid Robotics) to observe air-sea processes during a typhoon, equivalent to a category 4-hurricane, at peak strength, near Okinawa, Japan. Surface winds showed strong asymmetry in both speed and direction, faster fore than aft. Rotations of surface winds and currents were not coupled; currents rotated clockwise in the wake of the typhoon eye after passage of rapid wind rotations. Wind work was mostly done ahead of the eye, amplifying prior inertial motions with a phase shift. Wind-induced energy was nearly balanced with an increase in estimated kinetic energy of the upper ocean current, relative to prior inertial oscillations. This study provides a newer, more complete view of actual atmosphere-ocean interactions in a typhoon.

  9. Assessing GOCE Gravity Models using Altimetry and In-situ Ocean Current Observation

    DEFF Research Database (Denmark)

    Knudsen, Per; Andersen, Ole Baltazar; Honecker, Johanna

    The Gravity and steady state Ocean Circulation Explorer (GOCE) satellite mission measures Earth's gravity field with an unprecedented accuracy at short spatial scales. Previous results have demonstrated a significant advance in our ability to determine the ocean's general circulation. The improved...... gravity models provided by the GOCE mission have enhanced the resolution and sharpened the boundaries of those features and the associated geostrophic surface currents reveal improvements for all of the ocean's current systems. In this study, a series of 23 newer gravity models including observations from...

  10. Observational Study of Travelers' Diarrhea.

    Science.gov (United States)

    Meuris

    1995-03-01

    Background: European air travelers returning from Algeria, Egypt, Mexico, Morocco, and Tunisia were interviewed about their experience of travelers' diseases upon arrival in Brussels. Diarrhea was mentioned by 37% of the adults and 27% of the children. These subjects were questioned about the types of measures taken, type and duration of drug treatment (if any), and about duration of diarrhea and side effects experienced. Methods: Final analysis was performed based on 2160 interviews. The largest proportion of diarrhea was reported in the age group 15-24 years (46%). Results: The majority of the 2160 subjects had opted for drug treatment (81%): 927 subjects for loperamide alone, 235 for loperamide in combination with nifuroxazide, and 178 for nifuroxazide alone. Other drugs had been used less frequently. The median time to recovery was 2.4 days with loperamide compared to 3.2 days with nifuroxazide and to 3.4 days for the no-treatment group. Conclusions: A stratification of the results by severity of the diarrhea suggests a rank of antidiarrheal potency as follows: loperamide > nifuroxazide > no-drug treatment. The side effect with the highest incidence was constipation (2.4% with loperamide). (J Travel Med 2:11-15, 1995) Travelers' diarrhea is usually defined as the passage of at least three unformed stools per day or any number of such stools when accompanied by fever, abdominal cramping, or vomiting. The definition may be broadened to include more trivial bowel disturbance.1,2 The duration of this self-limited disease generally is 3 to 5 days. Medical intervention aims at shortening the duration of disease, thus allowing the sufferer to resume his or her usual activities at an early stage. A shortened period of recovery to physical well-being has obvious favorable economic implications if the traveler is on business and may help the maintenance of a desired level of quality of life while a traveler is on holiday. An observational study of various medical

  11. Science Studies from Archived Observations

    Science.gov (United States)

    Armstrong, T. P.; Manweiler, J. W.; Patterson, J. D.

    2008-12-01

    Goals for spaceflight investigations include the discovery and characterization of physical features of the in- situ and remote environment. Abundant successes of flight investigations are easily documented. Prudent scientific practice dictates that to the maximum extent possible, observations should be well-characterized, reliably catalogued, and knowledgeably interpreted. This is especially true of data sets used in the publication of results in the reviewed literature. Typical scientific standards include making primary data numbers available to other investigators for replicated study. While NASA's contracts with investigators have required that data be submitted to agency official archives, the details, completeness (especially of ancillary and metadata) and forms differ from investigation to investigation and project to project. After several generations of improvements and refinements, modern computing and communications technology makes it possible to link multiple data sets at multiple locations through a unified data model. Virtual Observatories provide the overall organizational structures and SPASE-compliant XML defines the data granules that can be located. Proofs of the feasibility and value of this latest approach remain to be seen, but its ultimate goal of improving archival research using flight-derived data sets appears to depend on user acceptance and efficient use of the VxO resources. Criteria based on the authors experience in science derived from archival sources follow: 1. Interfaces and tools must be easy to learn, easy to use, and reliable. 2. Data numbers must be promptly downloadable in plain text. 3. Data must be available in or readily converted to physical units using calibrations and algorithms easily traceable as part of the search. Knowledge about (or heritage of) specific data items present in the science literature must be associated with the search for that item. 4. Data items must be trustworthy, having quoted uncertainties and

  12. Multiscale Study of Currents Affected by Topography

    Science.gov (United States)

    2015-09-30

    boundary layers to influence the ambient larger-scale flow. We have studied these issues through ocean model simulations, adjoint sensitivity...circulation be monitored from pressure gauges, temperature sensors, current meters, or other measurements near the feature? • The influence of the

  13. The ENIQ pilot study: current status

    Energy Technology Data Exchange (ETDEWEB)

    Lemaitre, P.; Eriksen, B.; Crutzen, S. [European Commission, DG Joint Research Centre, Petten (Netherlands); Hansch, M. [Preussische Elektrizitaets-AG (Preussenelektra), Hannover (Germany); Whittle, J. [AEA Technology, Warrington (United Kingdom)

    1998-11-01

    A pilot study is currently being carried out by ENIQ (European Network for Inspection Qualification) in order to explore the issues involved in inspection qualification applied along the general principles of the European methodology. The components selected for the pilot study are austenitic pipe to pipe and pipe to elbows welds typical of those in BWR recirculation loops. A range of defect parameters has been defined. A suitable inspection procedure designed to find the designated defects will be applied to geometrically representative test pieces. The procedure/equipment will be qualified through open trials and technical justification. The personnel qualification will be done in a blind way. Once all features of the inspection system will have been qualified an in-service inspection will be simulated in order to test the feasibility of the qualification approach followed. In this paper the current status of this pilot study is discussed. (orig.)

  14. Observational evidence for remote forcing of the west India coastal current

    Digital Repository Service at National Institute of Oceanography (India)

    Shetye, S.R.; Suresh, I.; Shankar, D.; Sundar, D.; Jayakumar, S.; Mehra, P.; Desai, R.G.P.; Pednekar, P.S.

    remote and local forcing in observations. Using field measurements (current, sea level, and wind) for a month during March-April 2003 off Goa in the near-coast regime of the West India Coastal Current (WICC), we show that the current was driven by local...

  15. Observation of self-magnetic field relaxations in Bi2223 and Y123 HTS tapes after over-current pulse and DC current operation

    Science.gov (United States)

    Tallouli, M.; Sun, J.; Chikumoto, N.; Otabe, E. S.; Shyshkin, O.; Charfi-Kaddour, S.; Yamaguchi, S.

    2016-07-01

    The development of power transmission lines based on long-length HTS tapes requires the production of high quality tapes. Due to fault conditions, technical mistakes and human errors during the operation of a DC power transmission line, an over-current pulse, several times larger than the rated current, could occur. To study the effect of such over-current pulses on the transport current density distribution in the HTS tapes, we simulated two start-up scenarios for one BSCCO and two YBCO tapes. The first start-up scenario is an initial over-current pulse during which the transport current was turned on rapidly, rising to 900 A during the first milliseconds, then reduced to a 100 A DC current. The second start-up scenario is normal operation, and involved increasing the transport current slowly from 0 A to 100 A at a rate of 1 A/s. For both scenarios, we then measured the vertical component of the self-magnetic field by means of a Hall probe above the tape, and afterward, by solving a linear equation of the inverse problem we obtain the current density profiles. We observe a change of the self-magnetic field above the edge of the BSCCO and YBCO tapes during 30 min after the 5 ms of over-current pulse and during the normal operation. The current density profiles are peaked in the centre for over-current pulse, and more peaked around the edge of the HTS tape for normal operation, which means that the limited time over-current pulse changes the current density profiles of the HTS tapes. We observe also a loop of current for YBCO tapes and we show the role of the HTS tape stabilizer.

  16. ST5 Observations of the Imbalance of Region 1 and 2 Field-Aligned Currents and Its Implication to the Cross-Polar Cap Pedersen Currents

    Science.gov (United States)

    Le, Guan; Slavin, J. A.; Strangeway, Robert

    2011-01-01

    In this study, we use the in-situ magnetic field observations from Space Technology 5 mission to quantify the imbalance of Region 1 (R1) and Region 2 (R2) currents. During the three-month duration of the ST5 mission, geomagnetic conditions range from quiet to moderately active. We find that the R1 current intensity is consistently stronger than the R2 current intensity both for the dawnside and the duskside large-scale field-aligned current system. The net currents flowing into (out of) the ionosphere in the dawnside (duskside) are in the order of 5% of the total R1 currents. We also find that the net currents flowing into or out of the ionosphere are controlled by the solar wind-magnetosphere interaction in the same way as the field-aligned currents themselves are. Since the net currents due to the imbalance of the R1 and R2 currents require that their closure currents flow across the polar cap from dawn to dusk as Pedersen currents, our results indicate that the total amount of the cross-polar cap Pedersen currents is in the order of 0.1 MA. This study, although with a very limited dataset, is one of the first attempts to quantify the cross-polar cap Pedersen currents. Given the importance of the Joule heating due to Pedersen currents to the high-latitude ionospheric electrodynamics, quantifying the cross-polar cap Pedersen currents and associated Joule heating is needed for developing models of the magnetosphere-ionosphere coupling.

  17. Investigation of sounding rocket observations of field-aligned currents and electron temperature

    Science.gov (United States)

    Cohen, I. J.; Lessard, M.; Zettergren, M. D.; Moen, J.; Lynch, K. A.; Heavisides, J. M.

    2014-12-01

    Strangeway et al. [2005] and other authors have concluded that the establishment of the ambipolar field by the deposition of energy from soft electron precipitation is a significant driver of type-2 ion upflows. Likewise, Clemmons et al. [2008] and Zhang et al. [2012] proposed processes by which soft electron precipitation may play a role in heating neutrals and contribute to neutral upwelling. In both situations the thermal ionospheric electron population plays a crucial role in both generation of the ambipolar field and in collisional energy exchange with the atmosphere through a variety of processes. In this study we examine the dynamics of the electron population, specifically the temperature, in a slightly different context - focusing on the auroral downward current region (DCR). In many cases auroral DCRs may be depleted of plasma, which sets up interesting conditions involving thermoelectric heat fluxes (which flow upward - in the opposite direction from the current), adiabatic expansion due to the high (upward) speed of the electrons carrying the downward current, heat exchange from ions which have elevated temperatures due to frictional heating, and direct frictional heating of the electrons. A detailed understanding of the electron temperature in auroral DCRs is necessary to make quantitative statements about recombination, upflow, cavitation and a host of other processes relevant to ion outflow. In this study, we compare in situ rocket observations of electron temperature, density, and current densities with predictions from the Zettergren and Semeter [2012] model in an attempt to better understand the dynamics and relationships between these parameters in DCRs.

  18. UFOs: Observations, Studies and Extrapolations

    CERN Document Server

    Baer, T; Barnes, M J; Bartmann, W; Bracco, C; Carlier, E; Cerutti, F; Dehning, B; Ducimetière, L; Ferrari, A; Ferro-Luzzi, M; Garrel, N; Gerardin, A; Goddard, B; Holzer, E B; Jackson, S; Jimenez, J M; Kain, V; Zimmermann, F; Lechner, A; Mertens, V; Misiowiec, M; Nebot Del Busto, E; Morón Ballester, R; Norderhaug Drosdal, L; Nordt, A; Papotti, G; Redaelli, S; Uythoven, J; Velghe, B; Vlachoudis, V; Wenninger, J; Zamantzas, C; Zerlauth, M; Fuster Martinez, N

    2012-01-01

    UFOs (“ Unidentified Falling Objects”) could be one of the major performance limitations for nominal LHC operation. Therefore, in 2011, the diagnostics for UFO events were significantly improved, dedicated experiments and measurements in the LHC and in the laboratory were made and complemented by FLUKA simulations and theoretical studies. The state of knowledge is summarized and extrapolations for LHC operation in 2012 and beyond are presented. Mitigation strategies are proposed and related tests and measures for 2012 are specified.

  19. Experimental study of the dynamics of a thin current sheet

    Science.gov (United States)

    Gekelman, W.; DeHaas, T.; Van Compernolle, B.; Daughton, W.; Pribyl, P.; Vincena, S.; Hong, D.

    2016-05-01

    Many plasmas in natural settings or in laboratory experiments carry currents. In magnetized plasmas the currents can be narrow field-aligned filaments as small as the electron inertial length ≤ft(\\tfrac{c}{{ω }pe}\\right) in the transverse dimension or fill the entire plasma column. Currents can take the form of sheets, again with the transverse dimension the narrow one. Are laminar sheets of electric current in a magnetized plasma stable? This became an important issue in the 1960s when current-carrying plasmas became key in the quest for thermonuclear fusion. The subject is still under study today. The conditions necessary for the onset for tearing are known, the key issue is that of the final state. Is there a final state? One possibility is a collection of stable tubes of current. On the other hand, is the interaction between the current filaments which are the byproduct endless, or does it go on to become chaotic? The subject of three-dimensional current systems is intriguing, rich in a variety of phenomena on multiple scale sizes and frequencies, and relevant to fusion studies, solar physics, space plasmas and astrophysical phenomena. In this study a long (δz = 11 m) and narrow (δx = 1 cm, δy = 20 cm) current sheet is generated in a background magnetoplasma capable of supporting Alfvén waves. The current is observed to rapidly tear into a series of magnetic islands when viewed in a cross-sectional plane, but they are in essence three-dimensional flux ropes. At the onset of the current, magnetic field line reconnection is observed between the flux ropes. The sheet on the whole is kink-unstable, and after kinking exhibits large-scale, low-frequency (f ≪ f ci ) rotation about the background field with an amplitude that grows with distance from the source of the current. Three-dimensional data of the magnetic and electric fields is acquired throughout the duration of the experiment and the parallel resistivity is derived from it. The parallel

  20. Current models of the observable consequences of cosmic reionization and their detectability

    CERN Document Server

    Iliev, Ilian T; Pen, Ue-Li; Bond, J Richard; Shapiro, Paul R

    2007-01-01

    A number of large current experiments aim to detect the signatures of the Cosmic Reionization at redshifts z>6. Their success depends crucially on understanding the character of the reionization process and its observable consequences and designing the best strategies to use. We use large-scale simulations of cosmic reionization to evaluate the reionization signatures at redshifted 21-cm and small-scale CMB anisotropies in the best current model for the background universe, with fundamental cosmological parameters given by WMAP 3-year results (WMAP3). We find that the optimal frequency range for observing the ``global step'' of the 21-cm emission is 120-150 MHz, while statistical studies should aim at 140-160 MHz, observable by GMRT. Some strongly-nongaussian brightness features should be detectable at frequencies up to ~190 MHz. In terms of sensitivity-signal trade-off relatively low resolutions, corresponding to beams of at least a few arcminutes, are preferable. The CMB anisotropy signal from the kinetic S...

  1. LASCO White-Light Observations of Eruptive Current Sheets Trailing CMEs

    Science.gov (United States)

    Webb, David F.; Vourlidas, Angelos

    2016-12-01

    Many models of eruptive flares or coronal mass ejections (CMEs) involve formation of a current sheet connecting the ejecting CME flux rope with a magnetic loop arcade. However, there is very limited observational information on the properties and evolution of these structures, hindering progress in understanding eruptive activity from the Sun. In white-light images, narrow coaxial rays trailing the outward-moving CME have been interpreted as current sheets. Here, we undertake the most comprehensive statistical study of CME-rays to date. We use SOHO/LASCO data, which have a higher cadence, larger field of view, and better sensitivity than any previous coronagraph. We compare our results to a previous study of Solar Maximum Mission (SMM) CMEs, in 1984 - 1989, having candidate magnetic disconnection features at the CME base, about half of which were followed by coaxial bright rays. We examine all LASCO CMEs during two periods of minimum and maximum activity in Solar Cycle 23, resulting in many more events, ˜130 CME-rays, than during SMM. Important results include: The occurrence rate of the rays is ˜11 % of all CMEs during solar minimum, but decreases to ˜7 % at solar maximum; this is most likely related to the more complex coronal background. The rays appear on average 3 - 4 hours after the CME core, and are typically visible for three-fourths of a day. The mean observed current sheet length over the ray lifetime is ˜12 R_{⊙}, with the longest current sheet of 18.5 R_{⊙}. The mean CS growth rates are 188 km s^{-1} at minimum and 324 km s^{-1} at maximum. Outward-moving blobs within several rays, which are indicative of reconnection outflows, have average velocities of ˜350 km s^{-1} with small positive accelerations. A pre-existing streamer is blown out in most of the CME-ray events, but half of these are observed to reform within ˜1 day. The long lifetime and long lengths of the CME-rays challenge our current understanding of the evolution of the magnetic

  2. An Improved Ocean Observing System for Coastal Louisiana: WAVCIS (WAVE-CURRENT-SURGE Information System )

    Science.gov (United States)

    Zhang, X.; Stone, G. W.; Gibson, W. J.; Braud, D.

    2005-05-01

    WAVCIS is a regional ocean observing and forecasting system. It was designed to measure, process, forecast, and distribute oceanographic and meteorological information. WAVCIS was developed and is maintained by the Coastal Studies Institute at Louisiana State University. The in-situ observing stations are distributed along the central Louisiana and Mississippi coast. The forecast region covers the entire Gulf of Mexico with emphasis on offshore Louisiana. By using state-of-the-art instrumentation, WAVCIS measures directional waves, currents, temperature, water level, conductivity, turbidity, salinity, dissolved oxygen, chlorophyll, Meteorological parameters include wind speed and direction, air pressure and temperature visibility and humidity. Through satellite communication links, the measured data are transmitted to the WAVCIS laboratory. After processing, they are available to the public via the internet on a near real-time basis. WAVCIS also includes a forecasting capability. Waves, tides, currents, and winds are forecast daily for up to 80 hours in advance. There are a number of numerical wave and surge models that can be used for forecasts. WAM and SWAN are used for operational purposes to forecast sea state. Tides at each station are predicted based on the harmonic constants calculated from past in-situ observations at respective sites. Interpolated winds from the ETA model are used as input forcing for waves. Both in-situ and forecast information are available online to the users through WWW. Interactive GIS web mapping is implemented on the WAVCIS webpage to visualize the model output and in-situ observational data. WAVCIS data can be queried, retrieved, downloaded, and analyzed through the web page. Near real-time numerical model skill assessment can also be performed by using the data from in-situ observing stations.

  3. Current problems of dynamics of moons of planets and binary asteroids based on observations

    Science.gov (United States)

    Emel'yanov, N. V.

    2017-01-01

    The general approach to studying the dynamics of moons of planets and asteroids consists in developing more and more accurate models of motion based on observational data. Not only the necessary ephemerides, but also some physical parameters of planets and moons are obtained this way. It is demonstrated in the present study that progress in this field is driven not only by the increase in accuracy of observations. The accuracy of ephemerides may be increased by expanding the observation time interval. Several problems arise on the way toward this goal. Some of them become apparent only when the procedure of observational data processing and use is examined in detail. The method used to derive astrometric data by processing the results of photometric observations of mutual occultations and eclipses of planetary moons is explained below. The primary contribution to the error of astrometric results is produced by the unaccounted noise level in photometric readings and the inaccuracy of received values of the albedo of moons. It is demonstrated that the current methods do not allow one to eliminate the noise completely. Extensive additional photometric measurements should be performed at different angles of rotation of moons and in different spectral bands of the visible wavelength range in order to obtain correct values of the albedo of moons. Many new distant moons of the major planets have been discovered in the early 21st century. However, the observations of these moons are scarce and were performed over short time intervals; as a result, some of the moons were lost. The necessity of further observations of these Solar System bodies is pointed out in the present study. Insufficient knowledge of asteroid masses is an obstacle to improving the accuracy of the ephemerides of Mars. The basic method for determining the masses of large asteroids consists in analyzing their influence on the motion of Mars, the Earth, and spacecraft. The masses of more than 100 large

  4. Variability of the currents in the Luzon Strait during spring of 2002 obtained from observations and satellite geostrophic currents and spectral analyses

    Institute of Scientific and Technical Information of China (English)

    YUAN YaoChu; LIAO GuangHong; WANG HuiQun; LOU RuYun; CHEN Hong

    2009-01-01

    The structure and variability of the currents in the Luzon Strait during spring of 2002 are studied, based on the current measurements at the average position of the mooring station (20°49'57"N, 120°48'12"E) from 03 17 to 04 15, 2002, satellite geostrophic currents in the Luzon Strait, and the spectral analyses, using the maximum entropy method. The subtidal currents at the mooring station show de-creased amplitudes downward with an anti-cyclonic rotation, suggesting that the currents enter and exit the South China Sea in the upper and intermediate layers, respectively. The vertical structure of the currents in the Luzon Strait suggests strongly the sandwiched structure of the LST, even though the bottom part of the profile is not resolved by the observational grid. The spectral analyses show the following periods of significant spectral peaks: (1) the tidal currents variability in the vertical direction; (2) the period about 4-6 d for the two cases of frequency f>0 and f0 and f<0 at the 200, 500 and 800 m levels, namely the Luzon Strait currents exhibit significant synoptical variability throughout the water column up to 800 m deep. Both direct current measurements and in situ hydrographic and satellite survey suggest no Kuroshio loop current in the Luzon Strait during the spring of 2002.

  5. The Angola Current and its seasonal variability as observed at 11°S

    Science.gov (United States)

    Kopte, Robert; Brandt, Peter; Dengler, Marcus; Claus, Martin; Greatbatch, Richard J.

    2016-04-01

    The eastern boundary circulation off the coast of Angola has been described only sparsely to date. The region off Angola, which connects the equatorial Atlantic and the Angola-Benguela upwelling regime, is of particular interest to understand the relative importance of transient equatorial versus local forcing of the observed variability in the coastal upwelling region. For the first time multi-year velocity observations of the Angola Current at 11°S are available. From July 2013 to November 2015 a bottom shield equipped with an ADCP had been deployed at 500m water depth, accompanied by a mooring sitting on the 1200m-isobath with an ADCP being installed at 500m depth. Both upward-looking instruments measured the current speed up to about 50m below the sea surface. During the deployment period the Angola Current was characterized by a weak southward mean flow of 5-8 cm/s at 50m depth (slightly stronger at the in-shore mooring position), with the southward current penetrating down to about 200m depth. The alongshore velocity component reveals a pronounced seasonal variability. It is dominated by 120-day, semi-annual, and annual oscillations with distinct baroclinic structures. Here we apply a reduced gravity model of the tropical Atlantic for the first five baroclinic modes forced with interannually varying wind stress to investigate the seasonal variability along the equatorial and coastal waveguides. In the equatorial Atlantic the 120-day, semi-annual, and annual oscillations are associated with resonant basin modes of the 1st, 2nd, and 4th baroclinic mode, respectively. These basin modes are composed of equatorial Kelvin and Rossby waves as well as coastally trapped waves. The reduced gravity model is further used to study the respective role of the remote equatorial forcing, more specifically the influence of equatorial basin modes via coastally trapped waves, and the local forcing for the observed seasonal variability and associated baroclinic structure of the

  6. Assessing observational studies of medical treatments

    Directory of Open Access Journals (Sweden)

    Butani Yogita

    2005-09-01

    Full Text Available Abstract Background Previous studies have assessed the validity of the observational study design by comparing results of studies using this design to results from randomized controlled trials. The present study examined design features of observational studies that could have influenced these comparisons. Methods To find at least 4 observational studies that evaluated the same treatment, we reviewed meta-analyses comparing observational studies and randomized controlled trials for the assessment of medical treatments. Details critical for interpretation of these studies were abstracted and analyzed qualitatively. Results Individual articles reviewed included 61 observational studies that assessed 10 treatment comparisons evaluated in two studies comparing randomized controlled trials and observational studies. The majority of studies did not report the following information: details of primary and ancillary treatments, outcome definitions, length of follow-up, inclusion/exclusion criteria, patient characteristics relevant to prognosis or treatment response, or assessment of possible confounding. When information was reported, variations in treatment specifics, outcome definition or confounding were identified as possible causes of differences between observational studies and randomized controlled trials, and of heterogeneity in observational studies. Conclusion Reporting of observational studies of medical treatments was often inadequate to compare study designs or allow other meaningful interpretation of results. All observational studies should report details of treatment, outcome assessment, patient characteristics, and confounding assessment.

  7. Acoustic Doppler Current Profiler observations in the southern Caspian Sea: shelf currents and flow field off Freidoonkenar Bay, Iran

    Directory of Open Access Journals (Sweden)

    P. Ghaffari

    2009-12-01

    Full Text Available The results of offshore bottom-mounted ADCP measurements and wind records carried out from August to September 2003 in the coastal waters off Freidoonkenar Bay (FB in the south Caspian Sea (CS are examined in order to characterize the shelf motion, the steady current field and to determine the main driving forces of currents on the study area. Owing to closed basin and absence of the astronomical tide, the atmospheric forcing plays an important role in the flow field of the CS. The lasting regular sea breeze system is present almost throughout the year that performs motive force in diurnal and semi-diurnal bands similar to tides in other regions. In general, current field in the continental shelf could be separated into two distinguishable schemes, which in cross-shelf direction is dominated by high frequencies (1 cpd and higher frequencies, and in along-shelf orientation mostly proportional to lower frequencies in synoptic weather bands. Long-period wave currents, whose velocities are much greater than those of direct wind-induced currents, are dominating the current field in the continental shelf off FB. The propagation of the latter could be described in terms of shore-controlled waves that are remotely generated and travel across the shelf in the southern CS. It has also been shown that long term displacements in this area follow the classic cyclonic, circulation pattern in the southern CS.

  8. Acoustic Doppler Current Profiler observations in the southern Caspian Sea: shelf currents and flow field off Feridoonkenar Bay, Iran

    Directory of Open Access Journals (Sweden)

    P. Ghaffari

    2010-07-01

    Full Text Available The results of offshore bottom-mounted ADCP measurements and wind records carried out from August to September 2003 in the coastal waters off Feridoon-kenar Bay (FB in the south Caspian Sea (CS are examined in order to characterize the shelf motion, the steady current field and to determine the main driving forces of currents on the study area. Owing to closed basin and absence of the astronomical tide, the atmospheric forcing plays an important role in the flow field of the CS. The lasting regular sea breeze system is present almost throughout the year. This system performs the forcing in diurnal and semi-diurnal bands similar to tides in other regions. In general, current field in the continental shelf could be separated into two distinguishable schemes, which in cross-shelf direction is dominated by high frequencies (1 cpd and higher frequencies, and in along-shelf orientation mostly proportional to lower frequencies in synoptic weather bands. Long-period wave currents, whose velocities are much greater than those of direct wind-induced currents, dominates the current field in the continental shelf off FB. The propagation of the latter could be described in terms of shore-controlled waves that are remotely generated and travel across the shelf in the southern CS. It has also been shown that long term displacements in this area follow the classic cyclonic, circulation pattern in the southern CS.

  9. Observational Study of Solar Magnetic Active Phenomena

    Indian Academy of Sciences (India)

    Hongqi Zhang

    2006-06-01

    The electric current separated into two parts reflected the quantative properties of heterogeneity and chirality of magnetic field, and defined them as the shear and twist components of current. We analyze the basic configuration and evolution of superactive region NOAA 6580-6619-6659. It is found that the contribution of the twist component of current cannot be reflected in the normal analysis of the magnetic shear and gradient of the active regions. The observational evidence of kink magnetic ropes generated from the subatmosphere cannot be found completely in some super delta active regions.

  10. Low frequency eigenmodes of thin anisotropic current sheets and Cluster observations

    Directory of Open Access Journals (Sweden)

    L. M. Zelenyi

    2009-02-01

    Full Text Available The eigenmodes of low frequency perturbations of thin anisotropic current sheets with a finite value of the normal magnetic field, are investigated in this paper. It is shown that two possible polarizations of symmetric and asymmetric modes (sausage and kink exist where the growth rate of instabilities is positive. In addition, we demonstrate that a tearing instability might have a positive growth rate in thin anisotropic current sheets. The class of relatively fast wavy flapping oscillations observed by Cluster is described. The main direction of wave motion coincides with the direction of the current and the typical velocity of this motion is comparable with the plasma drift velocity in the current sheet. The comparison of these characteristics with theoretical predictions of the model of anisotropic thin current sheets, demonstrates that, in principle, the theory adequately describes the observations.

  11. Study of the weak charged hadronic current in b decays

    Science.gov (United States)

    Acciarri, M.; Adriani, O.; Aguilar-Benitez, M.; Ahlen, S.; Alpat, B.; Alcaraz, J.; Alemanni, G.; Allaby, J.; Aloisio, A.; Alverson, G.; Alviggi, M. G.; Ambrosi, G.; Anderhub, H.; Andreev, V. P.; Angelescu, T.; Anselmo, F.; Antreasyan, D.; Arefiev, A.; Azemoon, T.; Aziz, T.; Bagnaia, P.; Baksay, L.; Ball, R. C.; Banerjee, S.; Banicz, K.; Barillère, R.; Barone, L.; Bartalini, P.; Baschirotto, A.; Basile, M.; Battiston, R.; Bay, A.; Becattini, F.; Becker, U.; Behner, F.; Berdugo, J.; Berges, P.; Bertucci, B.; Betev, B. L.; Bhattacharya, S.; Biasini, M.; Biland, A.; Bilei, G. M.; Blaising, J. J.; Blyth, S. C.; Bobbink, G. J.; Bock, R.; Böhm, A.; Borgia, B.; Boucham, A.; Bourilkov, D.; Bourquin, M.; Boutigny, D.; Branson, J. G.; Brigljevic, V.; Brock, I. C.; Buffini, A.; Buijs, A.; Burger, J. D.; Burger, W. J.; Busenitz, J.; Buytenhuijs, A.; Cai, X. D.; Campanelli, M.; Capell, M.; Romeo, G. Cara; Caria, M.; Carlino, G.; Cartacci, A. M.; Casaus, J.; Castellini, G.; Cavallari, F.; Cavallo, N.; Cecchi, C.; Cerrada, M.; Cesaroni, F.; Chamizo, M.; Chan, A.; Chang, Y. H.; Chaturvedi, U. K.; Chemarin, M.; Chen, A.; Chen, G.; Chen, G. M.; Chen, H. F.; Chen, H. S.; Chen, M.; Chiefari, G.; Chien, C. Y.; Choi, M. T.; Cifarelli, L.; Cindolo, F.; Civinini, C.; Clare, I.; Clare, R.; Cohn, H. O.; Coignet, G.; Colijn, A. P.; Colino, N.; Commichau, V.; Costantini, S.; Cotorobai, F.; de La Cruz, B.; Csilling, A.; Dai, T. S.; D'Alessandro, R.; de Asmundis, R.; de Boeck, H.; Degré, A.; Deiters, K.; Denes, P.; Denotaristefani, F.; Dibitonto, D.; Diemoz, M.; van Dierendonck, D.; di Lodovico, F.; Dionisi, C.; Dittmar, M.; Dominguez, A.; Doria, A.; Dorne, I.; Dova, M. T.; Drago, E.; Duchesneau, D.; Duinker, P.; Duran, I.; Dutta, S.; Easo, S.; Efremenko, Yu.; El Mamouni, H.; Engler, A.; Eppling, F. J.; Erné, F. C.; Ernenwein, J. P.; Extermann, P.; Fabre, M.; Faccini, R.; Falciano, S.; Favara, A.; Fay, J.; Fedin, O.; Felcini, M.; Fenyi, B.; Ferguson, T.; Fernandez, D.; Ferroni, F.; Fesefeldt, H.; Fiandrini, E.; Field, J. H.; Filthaut, F.; Fisher, P. H.; Forconi, G.; Fredj, L.; Freudenreich, K.; Furetta, C.; Galaktionov, Yu.; Ganguli, S. N.; Garcia-Abia, P.; Gau, S. S.; Gentile, S.; Gerald, J.; Gheordanescu, N.; Giagu, S.; Goldfarb, S.; Goldstein, J.; Gong, Z. F.; Gougas, A.; Gratta, G.; Gruenewald, M. W.; Gupta, V. K.; Gurtu, A.; Gutay, L. J.; Hartmann, B.; Hasan, A.; Hatzifotiadou, D.; Hebbeker, T.; Hervé, A.; van Hoek, W. C.; Hofer, H.; Hoorani, H.; Hou, S. R.; Hu, G.; Innocente, V.; Janssen, H.; Jenkes, K.; Jin, B. N.; Jones, L. W.; de Jong, P.; Josa-Mutuberria, I.; Kasser, A.; Khan, R. A.; Kamrad, D.; Kamyshkov, Yu.; Kapustinsky, J. S.; Karyotakis, Y.; Kaur, M.; Kienzle-Focacci, M. N.; Kim, D.; Kim, J. K.; Kim, S. C.; Kim, Y. G.; Kinnison, W. W.; Kirkby, A.; Kirkby, D.; Kirkby, J.; Kiss, D.; Kittel, W.; Klimentov, A.; König, A. C.; Korolko, I.; Koutsenko, V.; Kraemer, R. W.; Krenz, W.; Kuijten, H.; Kunin, A.; de Guevara, P. Ladron; Landi, G.; Lapoint, C.; Lassila-Perini, K.; Laurikainen, P.; Lebeau, M.; Lebedev, A.; Lebrun, P.; Lecomte, P.; Lecoq, P.; Le Coultre, P.; Lee, J. S.; Lee, K. Y.; Leggett, C.; Le Goff, J. M.; Leiste, R.; Leonardi, E.; Levtchenko, P.; Li, C.; Lieb, E.; Lin, W. T.; Linde, F. L.; Lista, L.; Liu, Z. A.; Lohmann, W.; Longo, E.; Lu, W.; Lu, Y. S.; Lübelsmeyer, K.; Luci, C.; Luckey, D.; Luminari, L.; Lustermann, W.; Ma, W. G.; Maity, M.; Majumder, G.; Malgeri, L.; Malinin, A.; Maña, C.; Mangla, S.; Marchesini, P.; Marin, A.; Martin, J. P.; Marzano, F.; Massaro, G. G. G.; McNally, D.; Mele, S.; Merola, L.; Meschini, M.; Metzger, W. J.; von der Mey, M.; Mi, Y.; Mihul, A.; van Mil, A. J. W.; Mirabelli, G.; Mnich, J.; Molnar, P.; Monteleoni, B.; Moore, R.; Morganti, S.; Moulik, T.; Mount, R.; Müller, S.; Muheim, F.; Nagy, E.; Nahn, S.; Napolitano, M.; Nessi-Tedaldi, F.; Newman, H.; Niessen, T.; Nippe, A.; Nisati, A.; Nowak, H.; Opitz, H.; Organtini, G.; Ostonen, R.; Pandoulas, D.; Paoletti, S.; Paolucci, P.; Park, H. K.; Pascale, G.; Passaleva, G.; Patricelli, S.; Paul, T.; Pauluzzi, M.; Paus, C.; Pauss, F.; Peach, D.; Pei, Y. J.; Pensotti, S.; Perret-Gallix, D.; Petrak, S.; Pevsner, A.; Piccolo, D.; Pieri, M.; Pinto, J. C.; Piroué, P. A.; Pistolesi, E.; Plyaskin, V.; Pohl, M.; Pojidaev, V.; Postema, H.; Produit, N.; Prokofiev, D.; Rahal-Callot, G.; Rancoita, P. G.; Rattaggi, M.; Raven, G.; Razis, P.; Read, K.; Ren, D.; Rescigno, M.; Reucroft, S.; van Rhee, T.; Riemann, S.; Riemers, B. C.; Riles, K.; Rind, O.; Ro, S.; Robohm, A.; Rodin, J.; Rodriguez, F. J.; Roe, B. P.; Romero, L.; Rosier-Lees, S.; Rosselet, Ph.; van Rossum, W.; Roth, S.; Rubio, J. A.; Rykaczewski, H.; Salicio, J.; Sanchez, E.; Santocchia, A.; Sarakinos, M. E.; Sarkar, S.; Sassowsky, M.; Sauvage, G.; Schäfer, C.; Schegelsky, V.; Schmidt-Kaerst, S.; Schmitz, D.; Schmitz, P.; Schneegans, M.; Scholz, N.; Schopper, H.; Schotanus, D. J.; Schwenke, J.; Schwering, G.; Sciacca, C.; Sciarrino, D.; Sens, J. C.; Servoli, L.; Shevchenko, S.; Shivarov, N.; Shoutko, V.; Shukla, J.; Shumilov, E.; Shvorob, A.; Siedenburg, T.; Son, D.; Sopczak, A.; Soulimov, V.; Smith, B.; Spillantini, P.; Steuer, M.; Stickland, D. P.; Stone, H.; Stoyanov, B.; Straessner, A.; Strauch, K.; Sudhakar, K.; Sultanov, G.; Sun, L. Z.; Susinno, G. F.; Suter, H.; Swain, J. D.; Tang, X. W.; Tauscher, L.; Taylor, L.; Ting, Samuel C. C.; Ting, S. M.; Tonutti, M.; Tonwar, S. C.; Tóth, J.; Tully, C.; Tuchscherer, H.; Tung, K. L.; Uchida, Y.; Ulbricht, J.; Uwer, U.; Valente, E.; van de Walle, R. T.; Vesztergombi, G.; Vetlitsky, I.; Viertel, G.; Vivargent, M.; Völkert, R.; Vogel, H.; Vogt, H.; Vorobiev, I.; Vorobyov, A. A.; Vorvolakos, A.; Wadhwa, M.; Wallraff, W.; Wang, J. C.; Wang, X. L.; Wang, Z. M.; Weber, A.; Wittgenstein, F.; Wu, S. X.; Wynhoff, S.; Xu, J.; Xu, Z. Z.; Yang, B. Z.; Yang, C. G.; Yao, X. Y.; Ye, J. B.; Yeh, S. C.; You, J. M.; Zalite, An.; Zalite, Yu.; Zemp, P.; Zeng, Y.; Zhang, Z.; Zhang, Z. P.; Zhou, B.; Zhou, Y.; Zhu, G. Y.; Zhu, R. Y.; Zichichi, A.; Ziegler, F.

    1997-02-01

    Charged and neutral particle multiplicities of jets associated with identified semileptonic and hadronic b decays are studied. The observed differences between these jets are used to determine the inclusive properties of the weak charged hadronic current. The average charged particle multiplicity of the weak charged hadronic current in b decays is measured for the first time to be 2.69+/-0.07 (stat.)+/-0.14(syst.). This result is in good agreement with the JETSET hadronization model of the weak charged hadronic current if 40+/-17% of the produced mesons are light-flavored tensor (L=1) mesons. This level of tensor meson production is consistent with the measurement of the π0 multiplicity in the weak charged hadronic current in b decays.

  12. Study of the Weak Charged Hadronic Current in b Decays

    CERN Document Server

    Acciarri, M; Aguilar-Benítez, M; Ahlen, S P; Alpat, B; Alcaraz, J; Alemanni, G; Allaby, James V; Aloisio, A; Alverson, G; Alviggi, M G; Ambrosi, G; Anderhub, H; Andreev, V P; Angelescu, T; Anselmo, F; Antreasyan, D; Arefev, A; Azemoon, T; Aziz, T; Bagnaia, P; Baksay, L; Ball, R C; Banerjee, S; Banicz, K; Barillère, R; Barone, L; Bartalini, P; Baschirotto, A; Basile, M; Battiston, R; Bay, A; Becattini, F; Becker, U; Behner, F; Berdugo, J; Berges, P; Bertucci, B; Betev, B L; Bhattacharya, S; Biasini, M; Biland, A; Bilei, G M; Blaising, J J; Blyth, S C; Bobbink, Gerjan J; Böck, R K; Böhm, A; Borgia, B; Boucham, A; Bourilkov, D; Bourquin, Maurice; Boutigny, D; Branson, J G; Brigljevic, V; Brock, I C; Buffini, A; Buijs, A; Burger, J D; Burger, W J; Busenitz, J K; Buytenhuijs, A O; Cai, X D; Campanelli, M; Capell, M; Cara Romeo, G; Caria, M; Carlino, G; Cartacci, A M; Casaus, J; Castellini, G; Cavallari, F; Cavallo, N; Cecchi, C; Cerrada-Canales, M; Cesaroni, F; Chamizo-Llatas, M; Chan, A; Chang, Y H; Chaturvedi, U K; Chemarin, M; Chen, A; Chen, G; Chen, G M; Chen, H F; Chen, H S; Chen, M; Chiefari, G; Chien, C Y; Choi, M T; Cifarelli, Luisa; Cindolo, F; Civinini, C; Clare, I; Clare, R; Cohn, H O; Coignet, G; Colijn, A P; Colino, N; Commichau, V; Costantini, S; Cotorobai, F; de la Cruz, B; Csilling, Akos; Dai, T S; D'Alessandro, R; De Asmundis, R; De Boeck, H; Degré, A; Deiters, K; Denes, P; De Notaristefani, F; DiBitonto, Daryl; Diemoz, M; Van Dierendonck, D N; Di Lodovico, F; Dionisi, C; Dittmar, Michael; Dominguez, A; Doria, A; Dorne, I; Dova, M T; Drago, E; Duchesneau, D; Duinker, P; Durán, I; Dutta, S; Easo, S; Efremenko, Yu V; El-Mamouni, H; Engler, A; Eppling, F J; Erné, F C; Ernenwein, J P; Extermann, Pierre; Fabre, M; Faccini, R; Falciano, S; Favara, A; Fay, J; Fedin, O; Felcini, Marta; Fenyi, B; Ferguson, T; Fernández, D; Ferroni, F; Fesefeldt, H S; Fiandrini, E; Field, J H; Filthaut, Frank; Fisher, P H; Forconi, G; Fredj, L; Freudenreich, Klaus; Furetta, C; Galaktionov, Yu; Ganguli, S N; García-Abia, P; Gau, S S; Gentile, S; Gerald, J; Gheordanescu, N; Giagu, S; Goldfarb, S; Goldstein, J; Gong, Z F; Gougas, Andreas; Gratta, Giorgio; Grünewald, M W; Gupta, V K; Gurtu, A; Gutay, L J; Hartmann, B; Hasan, A; Hatzifotiadou, D; Hebbeker, T; Hervé, A; Van Hoek, W C; Hofer, H; Hoorani, H; Hou, S R; Hu, G; Innocente, Vincenzo; Janssen, H; Jenkes, K; Jin, B N; Jones, L W; de Jong, P; Josa-Mutuberria, I; Kasser, A; Khan, R A; Kamrad, D; Kamyshkov, Yu A; Kapustinsky, J S; Karyotakis, Yu; Kaur, M; Kienzle-Focacci, M N; Kim, D; Kim, J K; Kim, S C; Kim, Y G; Kinnison, W W; Kirkby, A; Kirkby, D; Kirkby, Jasper; Kiss, D; Kittel, E W; Klimentov, A; König, A C; Korolko, I; Koutsenko, V F; Krämer, R W; Krenz, W; Kuijten, H; Kunin, A; Ladrón de Guevara, P; Landi, G; Lapoint, C; Lassila-Perini, K M; Laurikainen, P; Lebeau, M; Lebedev, A; Lebrun, P; Lecomte, P; Lecoq, P; Le Coultre, P; Lee Jae Sik; Lee, K Y; Leggett, C; Le Goff, J M; Leiste, R; Leonardi, E; Levchenko, P M; Li Chuan; Lieb, E H; Lin, W T; Linde, Frank L; Lista, L; Liu, Z A; Lohmann, W; Longo, E; Lu, W; Lü, Y S; Lübelsmeyer, K; Luci, C; Luckey, D; Luminari, L; Lustermann, W; Ma Wen Gan; Maity, M; Majumder, G; Malgeri, L; Malinin, A; Maña, C; Mangla, S; Marchesini, P A; Marin, A; Martin, J P; Marzano, F; Massaro, G G G; McNally, D; Mele, S; Merola, L; Meschini, M; Metzger, W J; Von der Mey, M; Mi, Y; Mihul, A; Van Mil, A J W; Mirabelli, G; Mnich, J; Molnár, P; Monteleoni, B; Moore, R; Morganti, S; Moulik, T; Mount, R; Müller, S; Muheim, F; Nagy, E; Nahn, S; Napolitano, M; Nessi-Tedaldi, F; Newman, H; Nippe, A; Nisati, A; Nowak, H; Opitz, H; Organtini, G; Ostonen, R; Pandoulas, D; Paoletti, S; Paolucci, P; Park, H K; Pascale, G; Passaleva, G; Patricelli, S; Paul, T; Pauluzzi, M; Paus, C; Pauss, Felicitas; Peach, D; Pei, Y J; Pensotti, S; Perret-Gallix, D; Petrak, S; Pevsner, A; Piccolo, D; Pieri, M; Pinto, J C; Piroué, P A; Pistolesi, E; Plyaskin, V; Pohl, M; Pozhidaev, V; Postema, H; Produit, N; Prokofev, D; Prokofiev, D O; Rahal-Callot, G; Rancoita, P G; Rattaggi, M; Raven, G; Razis, P A; Read, K; Ren, D; Rescigno, M; Reucroft, S; Van Rhee, T; Riemann, S; Riemers, B C; Riles, K; Rind, O; Ro, S; Robohm, A; Rodin, J; Rodríguez-Calonge, F J; Roe, B P; Romero, L; Rosier-Lees, S; Rosselet, P; Van Rossum, W; Roth, S; Rubio, Juan Antonio; Rykaczewski, H; Salicio, J; Sánchez, E; Santocchia, A; Sarakinos, M E; Sarkar, S; Sassowsky, M; Sauvage, G; Schäfer, C; Shchegelskii, V; Schmidt-Kärst, S; Schmitz, D; Schmitz, P; Schneegans, M; Scholz, N; Schopper, Herwig Franz; Schotanus, D J; Schwenke, J; Schwering, G; Sciacca, C; Sciarrino, D; Sens, Johannes C; Servoli, L; Shevchenko, S; Shivarov, N; Shoutko, V; Shukla, J; Shumilov, E; Shvorob, A V; Siedenburg, T; Son, D; Sopczak, André; Soulimov, V; Smith, B; Spillantini, P; Steuer, M; Stickland, D P; Stone, H; Stoyanov, B; Strässner, A; Strauch, K; Sudhakar, K; Sultanov, G G; Sun, L Z; Susinno, G F; Suter, H; Swain, J D; Tang, X W; Tauscher, Ludwig; Taylor, L; Ting, Samuel C C; Ting, S M; Tonutti, M; Tonwar, S C; Tóth, J; Tully, C; Tuchscherer, H; Tung, K L; Uchida, Y; Ulbricht, J; Uwer, U; Valente, E; Van de Walle, R T; Vesztergombi, G; Vetlitskii, I; Viertel, Gert M; Vivargent, M; Völkert, R; Vogel, H; Vogt, H; Vorobev, I; Vorobyov, A A; Vorvolakos, A; Wadhwa, M; Wallraff, W; Wang, J C; Wang, X L; Wang, Z M; Weber, A; Wittgenstein, F; Wu, S X; Wynhoff, S; Xu, J; Xu, Z Z; Yang, B Z; Yang, C G; Yao, X Y; Ye, J B; Yeh, S C; You, J M; Zalite, A; Zalite, Yu; Zemp, P; Zeng, Y; Zhang, Z; Zhang, Z P; Zhou, B; Zhou, Y; Zhu, G Y; Zhu, R Y; Zichichi, Antonino; Ziegler, F

    1997-01-01

    Charged and neutral particle multiplicities of jets associated with identified semileptonic and hadronic b decays are studied. The observed differences between these jets are used to determine the inclusive properties of the weak charged hadronic current. The average charged particle multiplicity of the weak charged hadronic current in b decays is measured for the first time to be 2.69$\\pm$0.07(stat.)$\\pm$0.14(syst.). This result is in good agreement with the JETSET hadronization model of the weak charged hadronic current if 40$\\pm$17\\% of the produced mesons are light--flavored tensor (L=1) mesons. This level of tensor meson production is consistent with the measurement of the $\\pi^0$ multiplicity in the weak charged hadronic current in b decays. \\end{abstract}

  13. Comparisons of Simulated and Observed Stormtime Magnetic Intensities and Ion Plasma Parameters in the Ring Current

    Science.gov (United States)

    Chen, M. W.; Guild, T. B.; Lemon, C.; Roeder, J. L.; Le, G.; Schulz, M.

    2009-12-01

    Recent progress in ring current and plasma sheet modeling has shown the importance of a self-consistent treatment of particle transport and magnetic and electric fields in the inner magnetosphere. Models with and without self-consistency can lead to significantly different magnitudes and spatial distributions of plasma pressure and magnetic intensity during disturbed times. In this study we compare simulated and observed stormtime magnetic intensities (GOES and Polar/MFE) and ion densities (LANL/MPA and Polar/CAMMICE) to test how well self-consistent simulations can simultaneously reproduce these quantities. We simulate the ring current and plasma sheet for conditions corresponding to the 11 August 2000 storm using the self-consistent Rice Convection Model-Equilibrium (RCM-E) [Lemon et al., JGR, 2004] with a constant magnetopause location. Using the empirical IMF-dependent model of Tsyganenko and Mukai [JGR, 2003], we specify the plasma sheet pressure and density at 10 RE as the plasma boundary location in the RCM-E. The simulated ion densities at different magnetic local times agree fairly well with those from the re-analysis model of LANL/MPA densities of O’Brien and Lemon [Space Weather, 2007]. We compare the simulated magnetic intensity with the magnetic intensity measured by magnetometers on the GOES satellites at geosynchronous altitude (6.6 RE) and on the Polar satellite. Agreement between the simulated and observed magnetic intensities tends to agree better on the nightside than on the dayside in the inner magnetosphere. In particular, the model cannot account for observed drops in the dayside magnetic intensity during decreases in the solar wind pressure. We will modify the RCM-E to include a time-varying magnetopause location to simulate compressions and expansions associated with variations in the solar wind pressure. We investigate whether this will lead to improved agreement between the simulated and model magnetic intensities.

  14. Observation of ocean current response to 1998 Hurricane Georges in the Gulf of Mexico

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The ocean current response to a hurricane on the shelf-break is examined. The study area is the DeSoto Canyon in the northeast Gulf of Mexico, and the event is the passage of 1998 Hurricane Georges with a maximum wind speed of 49 m/s. The data sets used for analysis consist of the mooring data taken by the Field Program of the DeSoto Canyon Eddy Intrusion Study, and simultaneous winds observed by NOAA (National Oceanic and Atmospheric Administration) Moored Buoy 42040. Time-depth ocean current energy density images derived from the observed data show that the ocean currents respond almost immediately to the hurricane with important differences on and offthe shelf. On the shelf, in the shallow water of 100 m, the disturbance penetrates rapidly downward to the bottom and forms two energy peaks, the major peak is located in the mixed layer and the secondary one in the lower layer. The response dissipates quickly after external forcing disappears. Off the shelf, in the deep water, the major disturbance energy seems to be trapped in the mixed layer with a trailing oscillation; although the disturbance signals may still be observed at the depths of 500 and 1 290 m. Vertical dispersion analysis reveals that the near-initial wave packet generated off the shelf consists of two modes. One is a barotropic wave mode characterized by a fast decay rate of velocity amplitude of 0.020 s-1, and the other is baroclinic wave mode characterized by a slow decay rate of 0.006 9 s-1. The band-pass-filtering and empirical function techniques are employed to the frequency analysis. The results indicate that all frequencies shift above the local inertial frequency. On the shelf, the average frequency is 1.04fin the mixed layer, close to the diagnosed frequency of the first baroclinic mode, and the average frequency increases to 1.07fin the thermocline.Off the shelf, all frequencies are a little smaller than the diagnosed frequency of the first mode. The average frequency decreases from 1

  15. Space Technology 5 (ST-5) Observations of the Imbalance of Region 1 and 2 Field-Aligned Currents

    Science.gov (United States)

    Le, Guan

    2010-01-01

    Space Technology 5 (ST-5) is a three micro-satellite constellation deployed into a 300 x 4500 km, dawn-dusk, sun-synchronous polar orbit from March 22 to June 21, 2006, for technology validations. In this study, we use the in-situ magnetic field observations from Space Technology 5 mission to quantify the imbalance of Region 1 (R1) and Region 2 (R2) currents. During the three-month duration of the ST5 mission, geomagnetic conditions range from quiet to moderately active. We find that the R1 current intensity is consistently stronger than the R2 current intensity both for the dawnside and the duskside large-scale field-aligned current system. The net currents flowing into (out of) the ionosphere in the dawnside (duskside) are in the order of 5% of the total RI currents. We also find that the net currents flowing into or out of the ionosphere are controlled by the solar wind-magnetosphere interaction in the same way as the field-aligned currents themselves are. Since the net currents due to the imbalance of the R1 and R2 currents require that their closure currents flow across the polar cap from dawn to dusk as Pedersen currents, our results indicate that the total amount of the cross-polar cap Pedersen currents is in the order of approx. 0.1 MA. This study, although with a very limited dataset, is one of the first attempts to quantify the cross-polar cap Pedersen currents. Given the importance of the Joule heating due to Pedersen currents to the high-latitude ionospheric electrodynamics, quantifying the cross-polar cap Pedersen currents and associated Joule heating is needed for developing models of the magnetosphere-ionosphere coupling.

  16. Direct observation of chiral currents and magnetic reflection in atomic flux lattices

    CERN Document Server

    An, Fangzhao Alex; Gadway, Bryce

    2016-01-01

    The prospect of studying topologically nontrivial phases with the precision and control of atomic physics has driven the development of many techniques for engineering artificial magnetic fields and spin-orbit interactions in atomic gases. Recently, the idea of engineering nontrivial topology through the use of discrete internal (or external) atomic states as effective "artificial dimensions" has garnered attraction for its versatility and promise of immunity from sources of heating. Here, we directly engineer tunable artificial gauge fields through the local control of tunneling phases in an effectively two-dimensional manifold of discrete atomic momentum states. We demonstrate the ability to engineer homogeneous artificial gauge fields of arbitrary value, directly imaging the site-resolved dynamics of induced chiral currents. We furthermore engineer the first inhomogeneous artificial gauge fields for cold atoms, enabling the observation of magnetic reflection of atoms incident upon a step-like variation of ...

  17. Recent Advances in Studies of Current Noise

    Science.gov (United States)

    Blanter, Yaroslav M.

    This is a brief review of recent activities in the field of current noise intended for newcomers. We first briefly discuss main properties of shot noise in nanostructures, and then turn to recent developments, concentrating on issues related to experimental progress: non-symmetrized cumulants and quantum noise; counting statistics; super-Poissonian noise; current noise and interferometry

  18. Confounding in publications of observational intervention studies

    NARCIS (Netherlands)

    Groenwold, Rolf H. H.; Hoes, Arno W.; Hak, Eelko

    2007-01-01

    We conducted a systematic literature search in Medline to assess the proportion of observational intervention studies appreciating confounding bias in peer-reviewed medical literature from 1985 through 2005. This study shows only 9% of all papers on observational intervention studies published in pe

  19. Current systematic carbon-cycle observations and the need for implementing a policy-relevant carbon observing system

    Science.gov (United States)

    Ciais, P.; Dolman, A. J.; Bombelli, A.; Duren, R.; Peregon, A.; Rayner, P. J.; Miller, C.; Gobron, N.; Kinderman, G.; Marland, G.; Gruber, N.; Chevallier, F.; Andres, R. J.; Balsamo, G.; Bopp, L.; Bréon, F.-M.; Broquet, G.; Dargaville, R.; Battin, T. J.; Borges, A.; Bovensmann, H.; Buchwitz, M.; Butler, J.; Canadell, J. G.; Cook, R. B.; DeFries, R.; Engelen, R.; Gurney, K. R.; Heinze, C.; Heimann, M.; Held, A.; Henry, M.; Law, B.; Luyssaert, S.; Miller, J.; Moriyama, T.; Moulin, C.; Myneni, R. B.; Nussli, C.; Obersteiner, M.; Ojima, D.; Pan, Y.; Paris, J.-D.; Piao, S. L.; Poulter, B.; Plummer, S.; Quegan, S.; Raymond, P.; Reichstein, M.; Rivier, L.; Sabine, C.; Schimel, D.; Tarasova, O.; Valentini, R.; Wang, R.; van der Werf, G.; Wickland, D.; Williams, M.; Zehner, C.

    2014-07-01

    A globally integrated carbon observation and analysis system is needed to improve the fundamental understanding of the global carbon cycle, to improve our ability to project future changes, and to verify the effectiveness of policies aiming to reduce greenhouse gas emissions and increase carbon sequestration. Building an integrated carbon observation system requires transformational advances from the existing sparse, exploratory framework towards a dense, robust, and sustained system in all components: anthropogenic emissions, the atmosphere, the ocean, and the terrestrial biosphere. The paper is addressed to scientists, policymakers, and funding agencies who need to have a global picture of the current state of the (diverse) carbon observations. We identify the current state of carbon observations, and the needs and notional requirements for a global integrated carbon observation system that can be built in the next decade. A key conclusion is the substantial expansion of the ground-based observation networks required to reach the high spatial resolution for CO2 and CH4 fluxes, and for carbon stocks for addressing policy-relevant objectives, and attributing flux changes to underlying processes in each region. In order to establish flux and stock diagnostics over areas such as the southern oceans, tropical forests, and the Arctic, in situ observations will have to be complemented with remote-sensing measurements. Remote sensing offers the advantage of dense spatial coverage and frequent revisit. A key challenge is to bring remote-sensing measurements to a level of long-term consistency and accuracy so that they can be efficiently combined in models to reduce uncertainties, in synergy with ground-based data. Bringing tight observational constraints on fossil fuel and land use change emissions will be the biggest challenge for deployment of a policy-relevant integrated carbon observation system. This will require in situ and remotely sensed data at much higher

  20. A foundational observation method for studying design situations

    DEFF Research Database (Denmark)

    Cash, Philip; Hicks, Ben; Culley, Steve

    2015-01-01

    Observational studies of designers play an important role in engineering design research, yet there is currently no accepted standard approach for comparing, combining, or contrasting studies. Consequentially, reuse, reanalysis, replication, and aggregation of data are limited and the potential...... impact of individual studies is severely constrained. This paper begins to address this issue by introducing and developing a foundational method for observational design research to improve replicability, reuse, and overall comparability of empirical studies. A three-step foundational method is proposed...

  1. Observed intraseasonal and seasonal variability of the West India Coastal Current on the continental slope

    Indian Academy of Sciences (India)

    P Amol; D Shankar; V Fernando; A Mukherjee; S G Aparna; R Fernandes; G S Michael; S T Khalap; N P Satelkar; Y Agarvadekar; M G Gaonkar; A P Tari; A Kankonkar; S P Vernekar

    2014-07-01

    We present current data from acoustic Doppler current profilers (ADCPs) moored on the continental slope off the west coast of India. The data were collected at four locations (roughly at Kanyakumari, Kollam, Goa, and Mumbai) extending from ∼7° to ∼20° N during 2008–2012. The observations show that a seasonal cycle, including an annual cycle, is present in the West India Coastal Current (WICC); this seasonal cycle, which strengthens northward, shows considerable interannual variability and is not as strongly correlated along the coast as in climatologies based on ship drifts or the altimeter. The alongshore decorrelation of theWICC is much stronger at intraseasonal periods, which are evident during the winter monsoon all along the coast. This intraseasonal variability is stronger in the south. A striking feature of the WICC is upward phase propagation, which implies an undercurrent whose depth becomes shallower as the season progresses. There are also instances when the phase propagates downward. At the two southern mooring locations off Kollam and Kanyakumari, the cross-shore current, which is usually associated with eddy-like circulations, is comparable to the alongshore current on occasions. A comparison with data from the OSCAR (Ocean Surface Currents Analyses Real-time) data product shows not only similarities, but also significant differences, particularly in the phase. One possible reason for this phase mismatch between the ADCP current at 48 m and the OSCAR current, which represents the current in the 0–30 m depth range, is the vertical phase propagation. Current products based on Ocean General Circulation Models like ECCO2 (Estimating the Circulation and Climate of the Ocean, Phase II) and GODAS (Global Ocean Data Assimilation System) show a weaker correlation with the ADCP current, and ECCO2 does capture some of the observed variability.

  2. Observed intraseasonal and seasonal variability of the West India Coastal Current on the continental slope

    Science.gov (United States)

    Amol, P.; Shankar, D.; Fernando, V.; Mukherjee, A.; Aparna, S. G.; Fernandes, R.; Michael, G. S.; Khalap, S. T.; Satelkar, N. P.; Agarvadekar, Y.; Gaonkar, M. G.; Tari, A. P.; Kankonkar, A.; Vernekar, S. P.

    2014-06-01

    We present current data from acoustic Doppler current profilers (ADCPs) moored on the continental slope off the west coast of India. The data were collected at four locations (roughly at Kanyakumari, Kollam, Goa, and Mumbai) extending from ˜ 7° to ˜ 20°N during 2008-2012. The observations show that a seasonal cycle, including an annual cycle, is present in the West India Coastal Current (WICC); this seasonal cycle, which strengthens northward, shows considerable interannual variability and is not as strongly correlated along the coast as in climatologies based on ship drifts or the altimeter. The alongshore decorrelation of the WICC is much stronger at intraseasonal periods, which are evident during the winter monsoon all along the coast. This intraseasonal variability is stronger in the south. A striking feature of the WICC is upward phase propagation, which implies an undercurrent whose depth becomes shallower as the season progresses. There are also instances when the phase propagates downward. At the two southern mooring locations off Kollam and Kanyakumari, the cross-shore current, which is usually associated with eddy-like circulations, is comparable to the alongshore current on occasions. A comparison with data from the OSCAR (Ocean Surface Currents Analyses Real-time) data product shows not only similarities, but also significant differences, particularly in the phase. One possible reason for this phase mismatch between the ADCP current at 48 m and the OSCAR current, which represents the current in the 0-30 m depth range, is the vertical phase propagation. Current products based on Ocean General Circulation Models like ECCO2 (Estimating the Circulation and Climate of the Ocean, Phase II) and GODAS (Global Ocean Data Assimilation System) show a weaker correlation with the ADCP current, and ECCO2 does capture some of the observed variability.

  3. Rip current evidence by hydrodynamic simulations, bathymetric surveys and UAV observation

    Science.gov (United States)

    Benassai, Guido; Aucelli, Pietro; Budillon, Giorgio; De Stefano, Massimo; Di Luccio, Diana; Di Paola, Gianluigi; Montella, Raffaele; Mucerino, Luigi; Sica, Mario; Pennetta, Micla

    2017-09-01

    The prediction of the formation, spacing and location of rip currents is a scientific challenge that can be achieved by means of different complementary methods. In this paper the analysis of numerical and experimental data, including RPAS (remotely piloted aircraft systems) observations, allowed us to detect the presence of rip currents and rip channels at the mouth of Sele River, in the Gulf of Salerno, southern Italy. The dataset used to analyze these phenomena consisted of two different bathymetric surveys, a detailed sediment analysis and a set of high-resolution wave numerical simulations, completed with Google EarthTM images and RPAS observations. The grain size trend analysis and the numerical simulations allowed us to identify the rip current occurrence, forced by topographically constrained channels incised on the seabed, which were compared with observations.

  4. In situ Observation of Dark Current Emission in a High Gradient RF Photocathode Gun

    CERN Document Server

    Shao, Jiahang; Baryshev, Sergey V; Chen, Huaibi; Conde, Manoel; Gai, Wei; Ha, Gwanghui; Jing, Chunguang; Shi, Jiaru; Wang, Faya; Wisniewski, Eric

    2016-01-01

    Undesirable electron field emission (a.k.a. dark current) in high gradient RF photocathode guns deteriorates the quality of photoemission current and limits the operational gradient. To improve the understanding of dark current emission, a high-resolution (~100 um) dark current imaging experiment has been performed in an L-band photocathode gun operating at ~100 MV/m of surface gradient. Dark current from the cathode has been observed to be dominated by several separated strong emitters. The field enhancement factor, beta, of selected regions on the cathode has been measured. The post scanning electron microscopy (SEM) and white light interferometer (WLI) surface examinations reveal the origins of ~75% strong emitters overlap with the spots where rf breakdown have occurred.

  5. In Situ Observation of Dark Current Emission in a High Gradient rf Photocathode Gun

    Science.gov (United States)

    Shao, Jiahang; Shi, Jiaru; Antipov, Sergey P.; Baryshev, Sergey V.; Chen, Huaibi; Conde, Manoel; Gai, Wei; Ha, Gwanghui; Jing, Chunguang; Wang, Faya; Wisniewski, Eric

    2016-08-01

    Undesirable electron field emission (also known as dark current) in high gradient rf photocathode guns deteriorates the quality of the photoemission current and limits the operational gradient. To improve the understanding of dark current emission, a high-resolution (˜100 μ m ) dark current imaging experiment has been performed in an L -band photocathode gun operating at ˜100 MV /m of surface gradient. Scattered strong emission areas with high current have been observed on the cathode. The field enhancement factor β of selected regions on the cathode has been measured. The postexaminations with scanning electron microscopy and white light interferometry reveal the origins of ˜75 % strong emission areas overlap with the spots where rf breakdown has occurred.

  6. Current desires of conspecific observers affect cache-protection strategies in California scrub-jays and Eurasian jays.

    Science.gov (United States)

    Ostojić, Ljerka; Legg, Edward W; Brecht, Katharina F; Lange, Florian; Deininger, Chantal; Mendl, Michael; Clayton, Nicola S

    2017-01-23

    Many corvid species accurately remember the locations where they have seen others cache food, allowing them to pilfer these caches efficiently once the cachers have left the scene [1]. To protect their caches, corvids employ a suite of different cache-protection strategies that limit the observers' visual or acoustic access to the cache site [2,3]. In cases where an observer's sensory access cannot be reduced it has been suggested that cachers might be able to minimise the risk of pilfering if they avoid caching food the observer is most motivated to pilfer [4]. In the wild, corvids have been reported to pilfer others' caches as soon as possible after the caching event [5], such that the cacher might benefit from adjusting its caching behaviour according to the observer's current desire. In the current study, observers pilfered according to their current desire: they preferentially pilfered food that they were not sated on. Cachers adjusted their caching behaviour accordingly: they protected their caches by selectively caching food that observers were not motivated to pilfer. The same cache-protection behaviour was found when cachers could not see on which food the observers were sated. Thus, the cachers' ability to respond to the observer's desire might have been driven by the observer's behaviour at the time of caching.

  7. Entanglement between Two Distant Observables of Quantum Current as the Mechanism of Radiation

    CERN Document Server

    Park, Jeong-Wan

    2016-01-01

    In this paper, it will be demonstrated that entanglement between two distant observables of quantum electron current enables electromagnetic radiation of free-electron lasers even though the amplified quadrature and the radiated quadrature are out of phase. This is supported by the previously observed sub-Poisson photon intensity fluctuations in the coherent spontaneous harmonic radiation generated by an infrared free-electron laser.

  8. Optical timing studies of isolated neutron stars: Current Status

    CERN Document Server

    Mignani, R P

    2010-01-01

    Being fast rotating objects, Isolated Neutron Stars (INSs) are natural targets for high-time resolution observations across the whole electromagnetic spectrum. With the number of objects detected at optical (plus ultraviolet and infrared) wavelengths now increased to 24, high-time resolution observations of INSs at these wavelengths are becoming more and more important. While classical rotation-powered radio pulsars, like the Crab and Vela pulsars, have been the first INSs studied at high-time resolution in the optical domain, observations performed in the last two decades have unveiled potential targets in other types of INSs which are not rotation powered, although their periodic variability is still related to the neutron star rotation. In this paper I review the current status of high-time resolution observations of INSs in the optical domain for different classes of objects: rotation-powered pulsars, magnetars, thermally emitting neutron stars, and rapid radio transients, I describe their timing properti...

  9. Variability of the currents in the Luzon Strait during spring of 2002 obtained from observations and satellite geostrophic currents and spectral analyses

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The structure and variability of the currents in the Luzon Strait during spring of 2002 are studied, based on the current measurements at the average position of the mooring station (20°49′57"N, 120°48′12"E) from March 17 to April 15, 2002, satellite geostrophic currents in the Luzon Strait, and the spectral analyses, using the maximum entropy method. The subtidal currents at the mooring station show de-creased amplitudes downward with an anti-cyclonic rotation, suggesting that the currents enter and exit the South China Sea in the upper and intermediate layers, respectively. The vertical structure of the currents in the Luzon Strait suggests strongly the sandwiched structure of the LST, even though the bottom part of the profile is not resolved by the observational grid. The spectral analyses show the following periods of significant spectral peaks: (1) the tidal currents variability in the vertical direction; (2) the period about 4-6 d for the two cases of frequency f >0 and f<0 at the 200 and 500 m levels, but at the 800 m level only for the case of f >0; (3) The fluctuation in the period range is about 2-3 days for the two cases of f >0 and f<0 at the 200, 500 and 800 m levels, namely the Luzon Strait currents exhibit significant synoptical variability throughout the water column up to 800 m deep. Both direct current measurements and in situ hydrographic and satellite survey suggest no Kuroshio loop current in the Luzon Strait during the spring of 2002.

  10. The Current Canon in British Romantics Studies.

    Science.gov (United States)

    Linkin, Harriet Kramer

    1991-01-01

    Describes and reports on a survey of 164 U.S. universities to ascertain what is taught as the current canon of British Romantic literature. Asserts that the canon may now include Mary Shelley with the former standard six major male Romantic poets, indicating a significant emergence of a feminist perspective on British Romanticism in the classroom.…

  11. Satellite Observations of the Brazil and Falkland Currents - 1975 to 1976 and 1978

    Science.gov (United States)

    1982-01-01

    suggesting a wave phase speed of 25 km day"’ with the waves travelling in the same direction as the Brazil Current. To a stationary observer, the...cruise 16 XBT and CTD data were obtained by D. GEORGI and S. JACOBS. REFERENCES BALECH E. (1949) Estudio critico de las corrientes marines del Litoral

  12. Seasonal and interannual variability in the Mozambique Channel from moored current observations

    NARCIS (Netherlands)

    Ridderinkhof, H.|info:eu-repo/dai/nl/075005700; van der Werf, P.M.|info:eu-repo/dai/nl/30483193X; Ullgren, J.E.; van Aken, H.M.; van Leeuwen, P.J.|info:eu-repo/dai/nl/102655758; de Ruijter, W.P.M.|info:eu-repo/dai/nl/068476760

    2010-01-01

    Direct observations from an array of current meter moorings across the Mozambique Channel in the south-west Indian Ocean are presented covering a period of more than 4 years. This allows an analysis of the volume transport through the channel, including the variability on interannual and seasonal

  13. Model and performance of current sensor observers for a doubly fed induction generator

    DEFF Research Database (Denmark)

    Li, Hui; Yang, Chao; Hu, Yaogang

    2014-01-01

    a MATLAB/Simulink software platform under the conditions of active power change of doubly fed induction generators and grid voltage dip fault. Furthermore, the robustness of the proposed current observer is investigated when the doubly fed induction generator rotor resistance is changed. Results show...

  14. Statistical research on the motion properties of the magnetotail current sheet:Cluster observations

    Institute of Scientific and Technical Information of China (English)

    H.REME; E.LUCEK

    2010-01-01

    The origin of the flapping motion of the earth’s magnetotail current sheet is one of the most important problems in the magnetotail dynamics.Using Cluster data,we make a statistical research on the motion properties of the magnetotail current sheet of 2001 and 2003.We calculate the velocities of the magnetotail current sheet using new methods and obtain the distribution of the magnetotail current sheet velocities in the X-Y plane in GSE coordinate system.Our results show that although most of the current sheets were propagating toward the tail flanks and those of the exceptions lay in dusk side,which is consistent with previous studies,the proportions of the current sheet which were propagating toward midnight (where |YGSE|=0) were higher than those in previous studies.Motions of the current sheet in the middle area (|YGSE|<8 Re) of the magnetotail are investigated.Relatively high value of the Z component of the velocity further confirms that the middle area of the magnetotail might be a source region for the motion of the current sheets which were propagating towards the tail flanks.According to our case studies,the way the current sheets propagated toward midnight area differs significantly from that toward dusk and dawn side,from which we infer that there might be two different kinds of current sheet motions originated from different sources.The statistical results of this paper may give some clues for further studies on the origin of the flapping motion of the magnetotail current sheet.

  15. Structure and evolution of the current sheet by multi-spacecraft observations

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, X.Y. [Chinese Academy of Sciences, Beijing (China). Inst. of Geophysics; Russell, C.T. [Univ. of California, Los Angeles, CA (United States). Inst. of Geophysics and Planetary Physics; Gosling, J. [Los Alamos National Lab., NM (United States)

    1997-12-31

    On April 22, 1979, from 0840 to 1018 UT, ISEE 1, ISEE 2 and IMP 8 were all in or near the magnetotail current sheet at 17 Re, 16 Re and 35 Re respectively while ISEE 3 monitored the solar wind 206 Re upstream of the Earth. A global perspective of the four spacecraft observations and of the ground magnetic records is presented in this paper. The hyperbolic tangent current sheet model of Harris has been used to calculate the current sheet thickness and to analyze the plasma distribution in the vertical direction. It is found that during this event the current sheet thickness varied from 2.5 Re to 1.5 Re for northward IMF but thinned abruptly to 0.5 Re when the IMF turned southward.

  16. Surface current dynamics under sea breeze conditions observed by simultaneous HF radar, ADCP and drifter measurements

    Science.gov (United States)

    Sentchev, Alexei; Forget, Philippe; Fraunié, Philippe

    2017-02-01

    Ocean surface boundary layer dynamics off the southern coast of France in the NW Mediterranean is investigated by using velocity observations by high-frequency (HF) radars, surface drifting buoys and a downward-looking drifting acoustic Doppler current profiler (ADCP). The analysis confirms that velocities measured by HF radars correspond to those observed by an ADCP at the effective depth z f = k -1, where k is wavenumber of the radio wave emitted by the radar. The radials provided by the radars were in a very good agreement with in situ measurements, with the relative errors of 1 and 9 % and root mean square (RMS) differences of 0.02 and 0.04 m/s for monostatic and bistatic radar, respectively. The total radar-based velocities appeared to be slightly underestimated in magnitude and somewhat biased in direction. At the end of the survey period, the difference in the surface current direction, based on HF radar and ADCP data, attained 10°. It was demonstrated that the surface boundary layer dynamics cannot be reconstructed successfully without taking into the account velocity variation with depth. A significant misalignment of ˜30° caused by the sea breeze was documented between the HF radar (HFR-derived) surface current and the background current. It was also found that the ocean response to a moderate wind forcing was confined to the 4-m-thick upper layer. The respective Ekman current attained the maximum value of 0.15 m/s, and the current rotation was found to be lagging the wind by approximately 40 min, with the current vector direction being 15-20° to the left of the wind. The range of velocity variability due to wind forcing was found comparable with the magnitude of the background current variability.

  17. AN EMPIRICAL STUDY OF CURRENT RATIO

    Directory of Open Access Journals (Sweden)

    Atanas Delev

    2014-10-01

    Full Text Available This work aims to address problems of liquidity and in particular the values and factors that influenced the values of the coefficient of total liquidity sixty Bulgarian public companies for the period 2013 - 2007 year. In the analysis it was found that some businesses fail to achieve favorable values of the ratio between current assets and current liabilities. It was found that plants have a low level of total liquidity, which can create problems in repayment of short-term liabilities. It can be seen that there are companies with very high liquidity, which is not so good phenomenon, ie the retention of a high level of resources required. Businesses should conduct a thorough analysis and implement appropriate measures to correct adverse changes. The financial management of the companies surveyed had worked towards improving the state of the enterprise, thereby seeking to reduce liquidity risk.

  18. Space Technology 5 (ST-5) Observations of Field-Aligned Currents: Temporal Variability

    Science.gov (United States)

    Le, Guan

    2010-01-01

    Space Technology 5 (ST-5) is a three micro-satellite constellation deployed into a 300 x 4500 km, dawn-dusk, sun-synchronous polar orbit from March 22 to June 21, 2006, for technology validations. In this paper, we present a study of the temporal variability of field-aligned currents using multi-point magnetic field measurements from STS. The data demonstrate that masoscale current structures are commonly embedded within large-scale field-aligned current sheets. The meso-scale current structures are very dynamic with highly variable current density and/or polarity in time scales of about 10 min. They exhibit large temporal variations during both quiet and disturbed times in such time scales. On the other hand, the data also shown that the time scales for the currents to be relatively stable are about I min for meso-scale currents and about 10 min for large scale current sheets. These temporal features are obviously associated with dynamic variations of their particle carriers (mainly electrons) as they respond to the variations of the parallel electric field in auroral acceleration region. The characteristic time scales for the temporal variability of meso-scale field-aligned currents are found to be consistent with those of auroral parallel electric field.

  19. Space Technology 5 Multi-Point Observations of Temporal Variability of Field-Aligned Currents

    Science.gov (United States)

    Le, Guan; Wang, Yongli; Slavin, James A.; Strangeway, Robert J.

    2008-01-01

    Space Technology 5 (ST5) is a three micro-satellite constellation deployed into a 300 x 4500 km, dawn-dusk, sun-synchronous polar orbit from March 22 to June 21, 2006, for technology validations. In this paper, we present a study of the temporal variability of field-aligned currents using multi-point magnetic field measurements from ST5. The data demonstrate that meso-scale current structures are commonly embedded within large-scale field-aligned current sheets. The meso-scale current structures are very dynamic with highly variable current density and/or polarity in time scales of approximately 10 min. They exhibit large temporal variations during both quiet and disturbed times in such time scales. On the other hand, the data also shown that the time scales for the currents to be relatively stable are approximately 1 min for meso-scale currents and approximately 10 min for large scale current sheets. These temporal features are obviously associated with dynamic variations of their particle carriers (mainly electrons) as they respond to the variations of the parallel electric field in auroral acceleration region. The characteristic time scales for the temporal variability of meso-scale field-aligned currents are found to be consistent with those of auroral parallel electric field.

  20. STRengthening analytical thinking for observational studies

    DEFF Research Database (Denmark)

    Altman, Douglas G.; le Cessie, Saskia; Abrahamowicz, Michal

    2014-01-01

    The validity and practical utility of observational medical research depends critically on good study design, excellent data quality, appropriate statistical methods and accurate interpretation of results. Statistical methodology has seen substantial development in recent times. Unfortunately, ma...

  1. Observing Protein & Energy Nutrition (OPEN) Study

    Science.gov (United States)

    The Observing Protein and Energy Nutrition (OPEN) Study was designed to assess dietary measurement error by comparing results from self-reported dietary intake data with four dietary biomarkers: doubly labeled water and urinary nitrogen, sodium, and potassium.

  2. Community Engagement in Observational Human Exposure Studies

    Science.gov (United States)

    Although observational human exposure studies do not deliberately expose participants to chemicals or environmental conditions, merely involving people as research participants and conducting research inside homes raises ethical issues. Community engagement offers a promising st...

  3. Observations of pockmark flow structure in Belfast Bay, Maine, Part 1: current-induced mixing

    Science.gov (United States)

    Fandel, Christina L.; Lippmann, Thomas C.; Irish, James D.; Brothers, Laura L.

    2016-10-01

    Field observations of current profiles and temperature, salinity, and density structure were used to examine vertical mixing within two pockmarks in Belfast Bay, Maine. The first is located in 21 m water depth (sea level to rim), nearly circular in shape with a 45 m rim diameter and 12 m rim-to-bottom relief. The second is located in 25 m water depth, more elongated in shape with an approximately 80 m (36 m) major (minor) axis length at the rim, and 17 m relief. Hourly averaged current profiles were acquired from bottom-mounted acoustic Doppler current profilers deployed on the rim and center of each pockmark over successive 42 h periods in July 2011. Conductivity-temperature-depth casts at the rim and center of each pockmark show warmer, fresher water in the upper water column, evidence of both active and fossil thermocline structure 5-8 m above the rim, and well-mixed water below the rim to the bottom. Vertical velocities show up- and down-welling events that extend into the depths of each pockmark. An observed temperature change at both the rim and center occurs coincident with an overturning event below the rim, and suggests active mixing of the water column into the depths of each pockmark. Vertical profiles of horizontal velocities show depth variation at both the center and rim consistent with turbulent logarithmic current boundary layers, and suggest that form drag may possibly be influencing the local flow regime. While resource limitations prevented observation of the current structure and water properties at a control site, the acquired data suggest that active mixing and overturning within the sampled pockmarks occur under typical benign conditions, and that current flows are influenced by upstream bathymetric irregularities induced by distant pockmarks.

  4. Observations of pockmark flow structure in Belfast Bay, Maine, Part 1: current-induced mixing

    Science.gov (United States)

    Fandel, Christina L.; Lippmann, Thomas C.; Irish, James D.; Brothers, Laura L.

    2017-02-01

    Field observations of current profiles and temperature, salinity, and density structure were used to examine vertical mixing within two pockmarks in Belfast Bay, Maine. The first is located in 21 m water depth (sea level to rim), nearly circular in shape with a 45 m rim diameter and 12 m rim-to-bottom relief. The second is located in 25 m water depth, more elongated in shape with an approximately 80 m (36 m) major (minor) axis length at the rim, and 17 m relief. Hourly averaged current profiles were acquired from bottom-mounted acoustic Doppler current profilers deployed on the rim and center of each pockmark over successive 42 h periods in July 2011. Conductivity-temperature-depth casts at the rim and center of each pockmark show warmer, fresher water in the upper water column, evidence of both active and fossil thermocline structure 5-8 m above the rim, and well-mixed water below the rim to the bottom. Vertical velocities show up- and down-welling events that extend into the depths of each pockmark. An observed temperature change at both the rim and center occurs coincident with an overturning event below the rim, and suggests active mixing of the water column into the depths of each pockmark. Vertical profiles of horizontal velocities show depth variation at both the center and rim consistent with turbulent logarithmic current boundary layers, and suggest that form drag may possibly be influencing the local flow regime. While resource limitations prevented observation of the current structure and water properties at a control site, the acquired data suggest that active mixing and overturning within the sampled pockmarks occur under typical benign conditions, and that current flows are influenced by upstream bathymetric irregularities induced by distant pockmarks.

  5. Observations of pockmark flow structure in Belfast Bay, Maine, Part 1: current-induced mixing

    Science.gov (United States)

    Fandel, Christina L.; Lippmann, Thomas C.; Irish, James D.; Brothers, Laura L.

    2017-01-01

    Field observations of current profiles and temperature, salinity, and density structure were used to examine vertical mixing within two pockmarks in Belfast Bay, Maine. The first is located in 21 m water depth (sea level to rim), nearly circular in shape with a 45 m rim diameter and 12 m rim-to-bottom relief. The second is located in 25 m water depth, more elongated in shape with an approximately 80 m (36 m) major (minor) axis length at the rim, and 17 m relief. Hourly averaged current profiles were acquired from bottom-mounted acoustic Doppler current profilers deployed on the rim and center of each pockmark over successive 42 h periods in July 2011. Conductivity–temperature–depth casts at the rim and center of each pockmark show warmer, fresher water in the upper water column, evidence of both active and fossil thermocline structure 5–8 m above the rim, and well-mixed water below the rim to the bottom. Vertical velocities show up- and down-welling events that extend into the depths of each pockmark. An observed temperature change at both the rim and center occurs coincident with an overturning event below the rim, and suggests active mixing of the water column into the depths of each pockmark. Vertical profiles of horizontal velocities show depth variation at both the center and rim consistent with turbulent logarithmic current boundary layers, and suggest that form drag may possibly be influencing the local flow regime. While resource limitations prevented observation of the current structure and water properties at a control site, the acquired data suggest that active mixing and overturning within the sampled pockmarks occur under typical benign conditions, and that current flows are influenced by upstream bathymetric irregularities induced by distant pockmarks.

  6. IMF By-Related Cusp Currents Observed from the Ørsted Satellite and from Ground

    DEFF Research Database (Denmark)

    Stauning, P.; Primdahl, Fritz; Watermann, J.

    2001-01-01

    from ground-based magnetic observations to define the structure and location of cusp currents and their dependencies on interplanetary magnetic field (IMF) conditions. Example cases illustrate the close relation between IMF B-gamma-related FAC and horizontal ionospheric currents in the cusp region. Our...... statistical analysis defines for the noon region the variations in FAC latitude with IMF B-Z. Comparisons with the statistical cusp location indicate that the more equatorward region of IMF B-gamma-while the more B related FAC is located on field lines closing at the dayside poleward FAC are on "open" field...

  7. Modeling Earth Albedo Currents on Sun Sensors for Improved Vector Observations

    DEFF Research Database (Denmark)

    Bhanderi, Dan

    2006-01-01

    Earth albedo influences vector measurements of the solar line of sight vector, due to the induced current on in the photo voltaics of Sun sensors. Although advanced digital Sun sensors exist, these are typically expensive and may not be suited for satellites in the nano or pico-class. Previously...... data, showing significant improvement in the Earth albedo induced current estimates. Additionally an algorithm for utilizing the Earth albedo model in obtaining a vector observation pair which is superior to the solar line of sight vector pair. It is concluded that the Earth albedo model is valid...

  8. Current Sensor Fault Diagnosis Based on a Sliding Mode Observer for PMSM Driven Systems.

    Science.gov (United States)

    Huang, Gang; Luo, Yi-Ping; Zhang, Chang-Fan; Huang, Yi-Shan; Zhao, Kai-Hui

    2015-05-11

    This paper proposes a current sensor fault detection method based on a sliding mode observer for the torque closed-loop control system of interior permanent magnet synchronous motors. First, a sliding mode observer based on the extended flux linkage is built to simplify the motor model, which effectively eliminates the phenomenon of salient poles and the dependence on the direct axis inductance parameter, and can also be used for real-time calculation of feedback torque. Then a sliding mode current observer is constructed in αβ coordinates to generate the fault residuals of the phase current sensors. The method can accurately identify abrupt gain faults and slow-variation offset faults in real time in faulty sensors, and the generated residuals of the designed fault detection system are not affected by the unknown input, the structure of the observer, and the theoretical derivation and the stability proof process are concise and simple. The RT-LAB real-time simulation is used to build a simulation model of the hardware in the loop. The simulation and experimental results demonstrate the feasibility and effectiveness of the proposed method.

  9. Current Sensor Fault Diagnosis Based on a Sliding Mode Observer for PMSM Driven Systems

    Directory of Open Access Journals (Sweden)

    Gang Huang

    2015-05-01

    Full Text Available This paper proposes a current sensor fault detection method based on a sliding mode observer for the torque closed-loop control system of interior permanent magnet synchronous motors. First, a sliding mode observer based on the extended flux linkage is built to simplify the motor model, which effectively eliminates the phenomenon of salient poles and the dependence on the direct axis inductance parameter, and can also be used for real-time calculation of feedback torque. Then a sliding mode current observer is constructed in αβ coordinates to generate the fault residuals of the phase current sensors. The method can accurately identify abrupt gain faults and slow-variation offset faults in real time in faulty sensors, and the generated residuals of the designed fault detection system are not affected by the unknown input, the structure of the observer, and the theoretical derivation and the stability proof process are concise and simple. The RT-LAB real-time simulation is used to build a simulation model of the hardware in the loop. The simulation and experimental results demonstrate the feasibility and effectiveness of the proposed method.

  10. Electric current in flares ribbons: from the standard model in 3D to observations

    CERN Document Server

    Janvier, Miho; Bommier, V; Schmieder, B; Démoulin, P; Pariat, E

    2014-01-01

    The paper presents for the first time a quantification of the photospheric electric current ribbon evolutions during an eruptive flare, accurately predicted by the standard 3D flare model. The standard flare model in 3D has been developed with the MHD code OHM, which models the evolution of an unstable flux rope. Through a series of paper, the model has been successful in explaining observational characteristics of eruptive flares, as well as the intrinsic 3D reconnection mechanism. Such a model also explains the increase of the photospheric currents as a consequence of the evolution of the coronal current layer where reconnection takes place. The photospheric footprints of the 3D current layer reveal a ribbon shape structure. In the present paper, the evolution of the current density is analyzed for the X-class flare that occurred on 15/02/2011 in AR 11158. We first describe the structural evolution of the high vertical current density regions derived with the UNNOFIT inversion code from magnetograms (HMI, e...

  11. Exploring tidewater glacier retreat using past and current observations at Columbia Glacier, Alaska. (Invited)

    Science.gov (United States)

    O'Neel, S.; Pfeffer, W. T.; Howat, I. M.; Conway, H.; Columbia Glacier Consortium

    2010-12-01

    Since fulfilling Austin Post’s prediction of impending retreat in the late 1970s, Columbia Glacier has repeatedly surprised both casual and careful observers with its ability for rapid change. Over the last three decades, Columbia Glacier has lost approximately 18 km of its original 66 km length, while thinning by approximately 50% at the present terminus. The total ice volume lost to the Gulf of Alaska Estimates upwards of 120 km3 constrain the total ice volume lost to the Gulf of Alaska. Recently, the terminus supported a ~1.5 km long floating tongue for over than a year, contradicting the common assumption that the mechanical properties of temperate ice prohibit flotation over sustained time intervals. The rich history of study offers an opportunity to better understand tidewater glacier retreat, and a valuable analog to the dynamic instability underway at several ice sheet outlet glaciers. Current research aims to improve processing resolution of existing aerial photographic data, while complimenting the 30-year photogrammetric record with a suite of field observations. Recent instrumentation includes: oblique time lapse and still imagery, semi-permanent GPS, airborne radar, mass balance, passive seismology and LiDAR. This presentation will focus on innovative methods developed in recent field seasons, sharing insight each has provided into the retreat process . 1The Columbia Glacier Consortium consists of: Fabian Walter (SIO), Kenichi Matsuoka (NPI), Ben Smith (UW), Ethan Welty (CU-Boulder), Chris Larsen (UAF), Dave Finnegan (CRREL), Dan McNamara (USGS), Yushin Ahn (OSU), Julie Markus (OSU), Adam LeWinter (EIS).

  12. Drifter Observations Of Wave-Current Evolution Through The San Francisco Bight

    Science.gov (United States)

    Pearman, D. W.; Herbers, T. H.; Janssen, T. T.; McIntyre, S.; Jessen, P.

    2012-12-01

    Ocean waves approaching the Golden Gate, the narrow strait connecting the San Francisco Bay to the Pacific Ocean, are affected by refraction over the San Francisco Bar and the strong tidal currents in the area. During ebb tides, when currents through the Golden Gate can exceed 2.5 m/s, the approach to San Francisco Bay is characterized by focusing and steepening of the incident wave field on the opposing current jet. These dynamics are not uncommon in coastal inlets and are known to present hazardous navigation conditions. The strong inhomogeneity and enhanced nonlinearity of the waves can result in deviations from non-Gaussian statistics and changes in the likelihood of extreme waves. However, since observations of wave-current dynamics are so difficult to make with conventional instruments, these dynamics remain still poorly understood. In this work we present the development and testing of a compact, low-cost, Wave-Resolving Drifter (WRD), designed to resolve the wave orbital surface motions and surface drifts in high-energy areas. The WRDs consist of a 30cm buoy equipped with an off-the-shelf GPS receiver and a three-axis accelerometer. The combined GPS-accelerometer package is functionally equivalent to a conventional pitch-roll (or PUV) wave height and direction instrument, but at a fraction of the price. In our presentation we will discuss results from several WRD array deployments in the San Francisco Bight during high-energy conditions with strong ebb currents. The buoys are shown to resolve the surface waves and surface drift with remarkable accuracy and allow the analysis of the evolution of the wave group structure over the opposing current. To obtain statistical results for currents and waves, WRDs were released in clusters (ensemble) from which shoaling effects over the bar and wave-current interaction can be identified.

  13. Observations of the Formation, Development, and Structure of a Current Sheet in an Eruptive Solar Flare

    CERN Document Server

    Seaton, Daniel B; Darnel, Jonathan M

    2016-01-01

    We present AIA observations of a structure we interpret as a current sheet associated with an X4.9 flare and coronal mass ejection that occurred on 2014~February~25 in NOAA Active Region 11990. We characterize the properties of the current sheet, finding that the sheet remains on the order of a few thousand km thick for much of the duration of the event and that its temperature generally ranged between $8-10\\,\\mathrm{MK}$. We also note the presence of other phenomena believed to be associated with magnetic reconnection in current sheets, including supra-arcade downflows and shrinking loops. We estimate that the rate of reconnection during the event was $M_{A} \\approx 0.004-0.007$, a value consistent with model predictions. We conclude with a discussion of the implications of this event for reconnection-based eruption models.

  14. DMSP F7 observations of a substorm field-aligned current

    Science.gov (United States)

    Lopez, R. E.; Spence, H. E.; Meng, C.-I.

    1991-01-01

    Observations are described of a substorm field-aligned current (FAC) system traversed by the DMSP F7 spacecraft just after 0300 UT on April 25, 1985. It is shown that the substorm FAC portion of the current system was located equatorward of the boundary between open and closed field lines. The equatorward boundary of the substorm FAC into the magnetotail was mapped using the Tsyganenko (1987) model, showing that the boundary corresponds to 6.9 earth radii. The result is consistent with the suggestion of Akasofu (1972) and Lopez and Lui (1990) that the region of substorm initiation lies relatively close to the earth and the concept that an essential feature of substorms is the disruption and diversion of the near-earth current sheet.

  15. Observations of the Formation, Development, and Structure of a Current Sheet in an Eruptive Solar Flare

    Science.gov (United States)

    Seaton, Daniel B.; Bartz, Allison E.; Darnel, Jonathan M.

    2017-02-01

    We present Atmospheric Imaging Assembly observations of a structure we interpret as a current sheet associated with an X4.9 flare and coronal mass ejection that occurred on 2014 February 25 in NOAA Active Region 11990. We characterize the properties of the current sheet, finding that the sheet remains on the order of a few thousand kilometers thick for much of the duration of the event and that its temperature generally ranged between 8 and 10 MK. We also note the presence of other phenomena believed to be associated with magnetic reconnection in current sheets, including supra-arcade downflows and shrinking loops. We estimate that the rate of reconnection during the event was MA ≈ 0.004–0.007, a value consistent with model predictions. We conclude with a discussion of the implications of this event for reconnection-based eruption models.

  16. Ukrainian Virtual Observatory: Current Status and Perspectives of Development of Joint Archives of Observations

    Science.gov (United States)

    Vavilova, I. B.; Pakuliak, L. K.; Protsyuk, Yu. I.; Virun, N. V.; Kashuba, S. G.; Pikhun, A. I.; Andrievsky, S. M.; Mazhaev, A. E.; Kazantseva, L. V.; Shlyapnikov, A. A.; Shulga, A. V.; Zolotukhina, A. V.; Sergeeva, T. P.; Miroshnichenko, A. P.; Andronov, I. L.; Breus, V. V; Virnina, N. A.

    2011-07-01

    The current state of the observational data archives of seven observatories of Ukraine which were created from 1898 to 2010 is considered in respect to their suitability for including into the Ukrainian Virtual Observatory (UkrVO) database. In accordance with a current UkrVO conception approved by the Ukrainian Astronomical Association, the database of astro negatives is the main scientific component of the UkrVO. The database will include all the photo plates accumulated in Ukraine and combine them into the Joint Digitized Archive (JDA). This will provide for a user an easy access to textual data and images using web interface and a corresponding search engine. The data archives obtained from CCD and radio observations in Ukraine are also discussed as scientific components of the UkrVO. Some prospects of the JDA development are formulated.

  17. Field-aligned current observed on ISEE-2 in the innermagnetosphere

    Institute of Scientific and Technical Information of China (English)

    徐荣栏; 王左丁; 谢榴香; 杨龙

    1995-01-01

    Field-aligned currents in the inner magnetosphere arc studied by using ISEE-2 magnetometer da-la, A method is proposed to calculate ×B with single-satellite data. From the morphology of ×B in time (or L). a lot of large fluctuations are found in ×B near L = 5.5RE corresponding to the field-aligned currents. Statistical study shows that the field-aligned current in the inner magnetosphere is a function of B, L, MLT and AL. The region of the projections of ×B along the magnetic field line onto the ionosphere is not symmetrical for the geomagnetic pole. The inner boundary is independent of the geomagnetic disturbance, but during substorms the outer boundary shifts equatorward. The spatial distribution of the in- and out-flowing currents is complicated. The region-1-and-2 system is hardly distinguishable.

  18. [The Strengthening the Reporting of Observational Studies in Epidemiology [STROBE] statement: guidelines for reporting observational studies

    DEFF Research Database (Denmark)

    Elm, E. von; Altman, D.G.; Egger, M.

    2008-01-01

    Much biomedical research is observational. The reporting of such research is often inadequate, which hampers the assessment of its strengths and weaknesses and of a study's generalisability. The Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) initiative developed rec...

  19. Study of toroidal current penetration during current ramp in JIPP T-IIU with fast response Zeeman polarimeter

    Energy Technology Data Exchange (ETDEWEB)

    Kuramoto, H.; Hiraki, N. [Kyushu Inst. of Tech., Kitakyushu, Fukuoka (Japan); Toi, K. [and others

    1997-01-01

    The toroidal current penetration is studied in current ramp experiments of the JIPP T-IIU tokamak. The poloidal magnetic field profile in the peripheral region of a plasma (0.5 {<=} {rho} {<=} 1.0) has been measured directly with a newly developed fast response Zeeman polarimeter. The experimental results indicate that an obvious skin effect of toroidal current density is clearly observed during both the current ramp-up and ramp-down experiments. The experimentally obtained toroidal current density profiles are well described by the profiles calculated on the assumption of the neoclassical electrical conductivity. Quasi-linear {Delta}`-analysis of tearing modes for the measured current density profile is consistent with time behaviour of coherent MHD modes such as m=4/n=1 or m=3/n=1 (m: poloidal mode number, n: toroidal mode number) often observed during the current ramp-up phase. The effect of these MHD modes on current penetration during the current ramp-up discharges is studied. (author)

  20. The primacy of residential quality in urban creation. A current observation of a recurring notion

    OpenAIRE

    2013-01-01

    As a current observation this contribution intends to situate origins of the notion of the primacy of residential quality in urban creation in a historical context before May ’68 and to show the relevance and actuality of this concept in emerging contemporary projective urban architectural practices. This is done through a retrospective re–reading of a major research contribution of architectural residential sociology elaborated by Henri Raymond and his team of ISU directed by Henri Lefebvre....

  1. Observed wintertime tidal and subtidal currents over the continental shelf in the northern South China Sea

    Science.gov (United States)

    Li, Ruixiang; Chen, Changsheng; Xia, Huayong; Beardsley, Robert C.; Shi, Maochong; Lai, Zhigang; Lin, Huichan; Feng, Yanqing; Liu, Changjian; Xu, Qichun; Ding, Yang; Zhang, Yu

    2014-08-01

    Synthesis analyses were performed to examine characteristics of tidal and subtidal currents at eight mooring sites deployed over the northern South China Sea (NSCS) continental shelf in the 2006-2007 and 2009-2010 winters. Rotary spectra and harmonic analysis results showed that observed tidal currents in the NSCS were dominated by baroclinic diurnal tides with phases varying both vertically and horizontally. This feature was supported by the CC-FVCOM results, which demonstrated that the diurnal tidal flow over this shelf was characterized by baroclinic Kelvin waves with vertical phase differences varying in different flow zones. The northeasterly wind-induced southwestward flow prevailed over the NSCS shelf during winter, with episodic appearances of mesoscale eddies and a bottom-intensified buoyancy-driven slope water intrusion. The moored current records captured a warm-core anticyclonic eddy, which originated from the southwestern coast of Taiwan and propagated southwestward along the slope consistent with a combination of β-plane and topographic Rossby waves. The eddy was surface-intensified with a swirl speed of >50 cm/s and a vertical scale of ˜400 m. In absence of eddies and onshore deep slope water intrusion, the observed southwestward flow was highly coherent with the northeasterly wind stress. Observations did not support the existence of the permanent wintertime South China Sea Warm Current (SCSWC). The definition of SCSWC, which was based mainly on thermal wind calculations with assumed level of no motion at the bottom, needs to be interpreted with caution since the observed circulation over the NSCS shelf in winter included both barotropic and baroclinic components.

  2. Analysis of Equatorial Currents Observed by Eastern Indian Ocean Cruises in 2010 and 2011

    Institute of Scientific and Technical Information of China (English)

    ZENG Xue-Zhi; LI Yi-Neng; PENG Shi-Qiu

    2012-01-01

    Hydrographic and direct current measurements were made in the Eastern Equatorial Indian Ocean in May 2010 and April 2011 as part of the Eastern Indian Ocean Cruises (EIOC) organized by the South China Sea Institute of Oceanology (SCSIO). Analyses of the shipdrift Acoustic Doppler Current Profiler (ADCP) data in- dicate that the equatorial currents observed in May 2010 are characterized by a strongly eastward surface current (Wyrtki Jets, WJs) with a maximum velocity of 0.9 m s-1, while that observed in April 2011 is weak and without a consistent direction. The strongly eastward WJ transports the surface water eastward, resulting in a deeper upper mixed layer, as shown in the temperature and salinity pro- files. However, it was found that the Equatorial Undercurrent (EUC) in the Eastern Indian Ocean is strong in April 2011 and weak in May 2010. The EUC was located approximately at the position of the thermocline, and it had higher salinity (up to approximately 35.5 psu) than the upper and lower waters.

  3. Sharp burnout failure observed in high current-carrying double-walled carbon nanotube fibers

    Science.gov (United States)

    Song, Li; Toth, Geza; Wei, Jinquan; Liu, Zheng; Gao, Wei; Ci, Lijie; Vajtai, Robert; Endo, Morinobu; Ajayan, Pulickel M.

    2012-01-01

    We report on the current-carrying capability and the high-current-induced thermal burnout failure modes of 5-20 µm diameter double-walled carbon nanotube (DWNT) fibers made by an improved dry-spinning method. It is found that the electrical conductivity and maximum current-carrying capability for these DWNT fibers can reach up to 5.9 × 105 S m - 1 and over 1 × 105 A cm - 2 in air. In comparison, we observed that standard carbon fiber tended to be oxidized and burnt out into cheese-like morphology when the maximum current was reached, while DWNT fiber showed a much slower breakdown behavior due to the gradual burnout in individual nanotubes. The electron microscopy observations further confirmed that the failure process of DWNT fibers occurs at localized positions, and while the individual nanotubes burn they also get aligned due to local high temperature and electrostatic field. In addition a finite element model was constructed to gain better understanding of the failure behavior of DWNT fibers.

  4. [Critical reading of analytical observational studies].

    Science.gov (United States)

    García Villar, C; Marín León, I

    2015-11-01

    Analytical observational studies provide very important information about real-life clinical practice and the natural history of diseases and can suggest causality. Furthermore, they are very common in scientific journals. The aim of this article is to review the main concepts necessary for the critical reading of articles about radiological studies with observational designs. It reviews the characteristics that case-control and cohort studies must have to ensure high quality. It explains a method of critical reading that involves checking the attributes that should be evaluated in each type of article using a structured list of specific questions. It underlines the main characteristics that confer credibility and confidence on the article evaluated. Readers are provided with tools for the critical analysis of the observational studies published in scientific journals. Copyright © 2014 SERAM. Published by Elsevier España, S.L.U. All rights reserved.

  5. Statistical challenges in observational cohort studies

    NARCIS (Netherlands)

    Hof, M.H.P.

    2015-01-01

    For over a century observational cohort studies have been used to study determinants of health and disease. Within a sample from the population, we can determine the relation between health outcomes (e.g. death) and a broad range of factors as genetic markers, environmental exposures, and lifestyle

  6. Statistical challenges in observational cohort studies

    NARCIS (Netherlands)

    Hof, M.H.P.

    2015-01-01

    For over a century observational cohort studies have been used to study determinants of health and disease. Within a sample from the population, we can determine the relation between health outcomes (e.g. death) and a broad range of factors as genetic markers, environmental exposures, and lifestyle

  7. Case Study Observational Research: A Framework for Conducting Case Study Research Where Observation Data Are the Focus.

    Science.gov (United States)

    Morgan, Sonya J; Pullon, Susan R H; Macdonald, Lindsay M; McKinlay, Eileen M; Gray, Ben V

    2017-06-01

    Case study research is a comprehensive method that incorporates multiple sources of data to provide detailed accounts of complex research phenomena in real-life contexts. However, current models of case study research do not particularly distinguish the unique contribution observation data can make. Observation methods have the potential to reach beyond other methods that rely largely or solely on self-report. This article describes the distinctive characteristics of case study observational research, a modified form of Yin's 2014 model of case study research the authors used in a study exploring interprofessional collaboration in primary care. In this approach, observation data are positioned as the central component of the research design. Case study observational research offers a promising approach for researchers in a wide range of health care settings seeking more complete understandings of complex topics, where contextual influences are of primary concern. Future research is needed to refine and evaluate the approach.

  8. Three-dimensional model-observation comparison in the Loop Current region

    Science.gov (United States)

    Rosburg, K. C.; Donohue, K. A.; Chassignet, E. P.

    2016-12-01

    Accurate high-resolution ocean models are required for hurricane and oil spill pathway predictions, and to enhance the dynamical understanding of circulation dynamics. Output from the 1/25° data-assimilating Gulf of Mexico HYbrid Coordinate Ocean Model (HYCOM31.0) is compared to daily full water column observations from a moored array, with a focus on Loop Current path variability and upper-deep layer coupling during eddy separation. Array-mean correlation was 0.93 for sea surface height, and 0.93, 0.63, and 0.75 in the thermocline for temperature, zonal, and meridional velocity, respectively. Peaks in modeled eddy kinetic energy were consistent with observations during Loop Current eddy separation, but with modeled deep eddy kinetic energy at half the observed amplitude. Modeled and observed LC meander phase speeds agreed within 8% and 2% of each other within the 100 - 40 and 40 - 20 day bands, respectively. The model reproduced observed patterns indicative of baroclinic instability, that is, a vertical offset with deep stream function leading upper stream function in the along-stream direction. While modeled deep eddies differed slightly spatially and temporally, the joint development of an upper-ocean meander along the eastern side of the LC and the successive propagation of upper-deep cyclone/anticylone pairs that preceded separation were contained within the model solution. Overall, model-observation comparison indicated that HYCOM31.0 could provide insight into processes within the 100 - 20 day band, offering a larger spatial and temporal window than observational arrays.

  9. Arctic Observing Network Data Management: Current Capabilities and Their Promise for the Future

    Science.gov (United States)

    Collins, J.; Fetterer, F.; Moore, J. A.

    2008-12-01

    CADIS (the Cooperative Arctic Data and Information Service) serves as the data management, discovery and delivery component of the Arctic Observing Network (AON). As an International Polar Year (IPY) initiative, AON comprises 34 land, atmosphere and ocean observation sites, and will acquire much of the data coming from the interagency Study of Environmental Arctic Change (SEARCH). CADIS is tasked with ensuring that these observational data are managed for long term use by members of the entire Earth System Science community. Portions of CADIS are either in use by the community or available for testing. We now have an opportunity to evaluate the feedback received from our users, to identify any design shortcomings, and to identify those elements which serve their purpose well and will support future development. This presentation will focus on the nuts-and-bolts of the CADIS development to date, with an eye towards presenting lessons learned and best practices based on our experiences so far. The topics include: - How did we assess our users' needs, and how are those contributions reflected in the end product and its capabilities? - Why did we develop a CADIS metadata profile, and how does it allow CADIS to support preservation and scientific interoperability? - How can we shield the user from metadata complexities (especially those associated with various standards) while still obtaining the metadata needed to support an effective data management system? - How can we bridge the gap between the data storage formats considered convenient by researchers in the field, and those which are necessary to provide data interoperability? - What challenges have been encountered in our efforts to provide access to federated data (data stored outside of the CADIS system)? - What are the data browsing and visualization needs of the AON community, and which tools and technologies are most promising in terms of supporting those needs? A live demonstration of the current

  10. Laboratory observations of saline and turbidity currents flowing in U-shaped flume

    Science.gov (United States)

    Stagnaro, M.; Bolla Pittaluga, M.

    2013-12-01

    Saline and turbidity currents belong to the large family of gravity currents. Due to the difficulties to predict and observe these kinds of phenomena, especially turbidity currents, we developed an experimental apparatus able to reproduce these currents in our Marchi Environmental Laboratory (Genova, Italy). The experiments were performed in a large U-shaped flume, 30 m long, characterized by a constant curvature bend (radius of 2.5 m) joining two straight reaches approximately 12 m long. The flume has a rectangular cross section 0.6 m wide and 0.5 m deep. Inside the flume we made a uniform concrete bottom slope (0.005), which proceeds from the inlet section along the first straight track and finishes 3 m after the bend exit. For each experiment we have been able to measure density distribution and velocity profiles along the vertical in different cross section. Density measurements were obtained using two ranks of siphons that sample the currents at different heights. Velocity was acquired with the DOP2000 ultrasound velocimeter; we measured longitudinal component in the straight reach of the flume, and both longitudinal and transversal velocity in the curved reach. We performed 30 experiments by changing the inlet conditions: primary defining the nature of the currents, saline or sediment laden, then varying two of the main parameters governing the currents: the density of the mixture and the flow discharge. The former covered a range between 1003 and 1023 kg/m^3 and the flow discharge ranged between 0.5 to 4.0 l/s. Both of these parameters influence the densimetric Froude Number, and allowed us to reproduce both subcritical and supercritical flow. In each experiment water entrainment from above was negligible hence the current was able to attain a quasi-uniform configuration in the first straight reach, whereby the longitudinal velocity and the thickness of the current were approximately constant. By varying the inlet conditions, it was possible to observe the

  11. Global Simulations of the March 17, 2013 Storm: Importance of Boundary Conditions in Reproducing Ring Current Observations

    Science.gov (United States)

    Yu, Y.; Jordanova, V.; Larsen, B.; Claudepierre, S. G.; Welling, D. T.; Skoug, R. M.; Kletzing, C.

    2013-12-01

    As modeling capabilities become increasingly available for the study of inner magnetospheric dynamics, the models' boundary conditions remain a crucial controlling factor in reproducing observations. In this study, we use the kinetic Ring current-Atmosphere Interaction Model (RAM) two-way coupled with the global MHD model BATS-R-US to study the evolution of the ring current and its feedback to the ionospheric electrodynamics during the March 17, 2013 storm. The MHD code solves fluid quantities and provides the inner magnetosphere code with plasma sheet plasma, which is the primary source for the development of the ring current. In this study, we examine the effect of different boundary conditions in specifying the plasma sheet plasma source on reproducing observations of the inner magnetospheric/subauroral region, such as in-situ observations (e.g., flux, magnetic fields, and electric fields) from Van Allen Probes (RBSP), field-aligned currents from AMPERE, and global convection maps from SuperDARN. These different boundary settings include a Maxwellian distribution assumption with MHD single-fluid temperature and density, a Kappa distribution assumption with MHD single-fluid temperature and density, and a bi-Maxwellian distribution with anisotropic pressures passed from the MHD code. Results indicate that a Kappa distribution at the boundary of RAM leads to a better ring current flux prediction than that with a Maxwellian distribution assumption, as well as a more realistic spatial distribution of ion anisotropy, which is important in driving electromagnetic ion cyclotron waves. The anisotropic pressure coupling between the kinetic code and the MHD code with a bi-Maxwellian function significantly improves the agreement with observations, especially the Dst index prediction.

  12. Current Research on Chinese Students Studying Abroad

    Science.gov (United States)

    Henze, Jurgen; Zhu, Jiani

    2012-01-01

    As a result of China's growing participation and importance in the process of internationalization and globalization a continuously rising number of Chinese students has gone abroad for further study. By the end of the last decade the number of Chinese students abroad made up the largest group of international students in the USA (surpassing those…

  13. Current Research on Chinese Students Studying Abroad

    Science.gov (United States)

    Henze, Jurgen; Zhu, Jiani

    2012-01-01

    As a result of China's growing participation and importance in the process of internationalization and globalization a continuously rising number of Chinese students has gone abroad for further study. By the end of the last decade the number of Chinese students abroad made up the largest group of international students in the USA (surpassing those…

  14. Bottom currents observed in and around a submarine valley on the continental slope of the northern South China Sea

    Science.gov (United States)

    Wu, Lunyu; Xiong, Xuejun; Li, Xiaolong; Shi, Maochong; Guo, Yongqing; Chen, Liang

    2016-12-01

    Bottom currents at about 1000 m depth in and around a submarine valley on the continental slope of the northern South China Sea were studied by a 14-month long experiment from July 2013 to September 2014. The observations reveal that bottom currents are strongly influenced by the topography, being along valley axis or isobaths. Power density spectrum analysis shows that all the currents have significant peaks at diurnal and semi-diurnal frequencies. Diurnal energy is dominant at the open slope site, which is consistent with many previous studies. However, at the site inside the valley the semi-diurnal energy dominates, although the distance between the two sites of observation is quite small (11 km) compared to a typical horizontal first-mode internal tide wavelength (200 km). We found this phenomenon is caused by the focusing of internal waves of certain frequencies in the valley. The inertial peak is found only at the open slope site in the first deployment but missing at the inside valley site and the rest of the deployments. Monthly averaged residual currents reveal that the near-bottom currents on the slope flow southwestward throughout the year except in August and September, 2013, from which we speculate that this is a result of the interaction between a mesoscale eddy and the canyon/sag topography. Currents inside the valley within about 10 mab basically flow along slope and in the layers above the 10 mab the currents are northwestward, that is, from the deep ocean to the shelf. The monthly mean current vectors manifest an Ekman layer-like vertical structure at both sites, which rotate counter-clockwise looking from above.

  15. Bottom Currents Observed in and Around a Submarine Valley on the Continental Slope of the Northern South China Sea

    Institute of Scientific and Technical Information of China (English)

    WU Lunyu; XIONG Xuejun; LI Xiaolong; SHI Maochong; GUO Yongqing; CHEN Liang

    2016-01-01

    Bottom currents at about 1000m depth in and around a submarine valley on the continental slope of the northern South China Sea were studied by a 14-month long experiment from July 2013 to September 2014. The observations reveal that bottom currents are strongly influenced by the topography, being along valley axis or isobaths. Power density spectrum analysis shows that all the currents have significant peaks at diurnal and semi-diurnal frequencies. Diurnal energy is dominant at the open slope site, which is consistent with many previous studies. However, at the site inside the valley the semi-diurnal energy dominates, although the distance between the two sites of observation is quite small (11km) compared to a typical horizontal first-mode internal tide wavelength (200km). We found this phenomenon is caused by the focusing of internal waves of certain frequencies in the valley. The inertial peak is found only at the open slope site in the first deployment but missing at the inside valley site and the rest of the de-ployments. Monthly averaged residual currents reveal that the near-bottom currents on the slope flow southwestward throughout the year except in August and September, 2013, from which we speculate that this is a result of the interaction between a mesoscale eddy and the canyon/sag topography. Currents inside the valley within about 10mab basically flow along slope and in the layers above the 10mab the currents are northwestward, that is, from the deep ocean to the shelf. The monthly mean current vectors manifest an Ek-man layer-like vertical structure at both sites, which rotate counter-clockwise looking from above.

  16. Observed seasonal and intraseasonal variability of the East India Coastal Current on the continental slope

    Indian Academy of Sciences (India)

    A Mukherjee; D Shankar; V Fernando; P Amol; S G Aparna; R Fernandes; G S Michael; S T Khalap; N P Satelkar; Y Agarvadekar; M G Gaonkar; A P Tari; A Kankonkar; S Vernekar

    2014-08-01

    We present data from three acoustic Doppler current profilers (ADCPs) moored off Cuddalore (12°N), Kakinada (16.5°N), and Gopalpur (19°N) on the continental slope of the western Bay of Bengal and one mooring on the slope of the northern bay (89°E, 19°N; referred to as being located at Paradip). The data were collected during May 2009 to March 2013 and the observations show that the seasonal cycle, which includes the annual cycle, the semi-annual cycle, and a peak around 120 days, dominates the observed variability of the East India Coastal Current (EICC). Spectral analysis suggests that the 120-day peak dominates the seasonal variability at Paradip and is strong at Gopalpur and Kakinada. The annual cycle is coherent along the western boundary of the bay, i.e., the east coast of India, but with significant phase differences between moorings. At the semi-annual and 120-day periods, the alongshore coherence is weaker. Intraseasonal variability is weaker than the seasonal cycle, particularly at Cuddalore and Paradip, and it exhibits seasonality: the strongest intraseasonal variation is during spring (February–April). Peaks around 12 and 20–22 days are also seen at Gopalpur, Kakinada, and Cuddalore. A striking feature of the currents is the upward phase propagation, but there are also instances when phase propagates downward. The much lower vertical phase speed in the top ∼100 m at Cuddalore leads to a distinct undercurrent at this location; at other locations, the undercurrent, though it exists often, is not as striking. During spring, however, the EICC tends to flow poleward (eastward) at Cuddalore, Kakinada, and Gopalpur (Paradip) over the top ∼300 m, which is the maximum depth to which observations were made. The cross-shore component of the EICC is much weaker than the alongshore component at Cuddalore and, except for a few bursts during spring, at Kakinada and Gopalpur. It is only at Paradip, on the slope of the northern boundary, that significant

  17. Observed seasonal and intraseasonal variability of the East India Coastal Current on the continental slope

    Science.gov (United States)

    Mukherjee, A.; Shankar, D.; Fernando, V.; Amol, P.; Aparna, S. G.; Fernandes, R.; Michael, G. S.; Khalap, S. T.; Satelkar, N. P.; Agarvadekar, Y.; Gaonkar, M. G.; Tari, A. P.; Kankonkar, A.; Vernekar, S.

    2014-08-01

    We present data from three acoustic Doppler current profilers (ADCPs) moored off Cuddalore (12∘N), Kakinada (16.5∘N), and Gopalpur (19∘N) on the continental slope of the western Bay of Bengal and one mooring on the slope of the northern bay (89∘E, 19∘N; referred to as being located at Paradip). The data were collected during May 2009 to March 2013 and the observations show that the seasonal cycle, which includes the annual cycle, the semi-annual cycle, and a peak around 120 days, dominates the observed variability of the East India Coastal Current (EICC). Spectral analysis suggests that the 120-day peak dominates the seasonal variability at Paradip and is strong at Gopalpur and Kakinada. The annual cycle is coherent along the western boundary of the bay, i.e., the east coast of India, but with significant phase differences between moorings. At the semi-annual and 120-day periods, the alongshore coherence is weaker. Intraseasonal variability is weaker than the seasonal cycle, particularly at Cuddalore and Paradip, and it exhibits seasonality: the strongest intraseasonal variation is during spring (February-April). Peaks around 12 and 20-22 days are also seen at Gopalpur, Kakinada, and Cuddalore. A striking feature of the currents is the upward phase propagation, but there are also instances when phase propagates downward. The much lower vertical phase speed in the top ˜100 m at Cuddalore leads to a distinct undercurrent at this location; at other locations, the undercurrent, though it exists often, is not as striking. During spring, however, the EICC tends to flow poleward (eastward) at Cuddalore, Kakinada, and Gopalpur (Paradip) over the top ˜300 m, which is the maximum depth to which observations were made. The cross-shore component of the EICC is much weaker than the alongshore component at Cuddalore and, except for a few bursts during spring, at Kakinada and Gopalpur. It is only at Paradip, on the slope of the northern boundary, that significant

  18. Current studies on myofascial pain syndrome.

    Science.gov (United States)

    Kuan, Ta-Shen

    2009-10-01

    Recent studies have clarified the nature of myofascial trigger points (MTrPs). In an MTrP region, multiple hyperirritable loci can be found. The sensory components of the MTrP locus are sensitized nociceptors that are responsible for pain, referred pain, and local twitch responses. The motor components are dysfunctional endplates that are responsible for taut band formation as a result of excessive acetylcholine (ACh) leakage. The concentrations of pain- and inflammation-related substances are increased in the MTrP region. It has been hypothesized that excessive ACh release, sarcomere shortening, and release of sensitizing substances are three essential features that relate to one another in a positive feedback cycle. This MTrP circuit is the connection among spinal sensory (dorsal horn) neurons responsible for the MTrP phenomena. Recent studies suggest that measurement of biochemicals associated with pain and inflammation in the MTrP region, the sonographic study of MTrPs, and the magnetic resonance elastography for taut band image are potential tools for the diagnosis of MTrPs. Many methods have been used to treat myofascial pain, including laser therapy, shockwave therapy, and botulinum toxin type A injection.

  19. Data assimilation in the low noise, accurate observation regime with application to the Kuroshio current

    CERN Document Server

    Vanden-Eijnden, Eric

    2012-01-01

    On-line data assimilation techniques such as ensemble Kalman filters and particle filters tend to loose accuracy dramatically when presented with an unlikely observation. Such an observation may be caused by an unusually large measurement error or reflect a rare fluctuation in the dynamics of the system. Over a long enough span of time it becomes likely that one or several of these events will occur. In some cases they are signatures of the most interesting features of the underlying system and their prediction becomes the primary focus of the data assimilation procedure. The Kuroshio current that runs along the eastern coast of Japan is an example of just such a system. It undergoes infrequent but dramatic changes of state between a small meander during which the current remains close to the coast of Japan, and a large meander during which the current bulges away from the coast. Because of the important role that the Kuroshio plays in distributing heat and salinity in the surrounding region, prediction of th...

  20. Observations of Thin Current Sheets in the Solar Wind and Their Role in Magnetic Energy Dissipation

    Science.gov (United States)

    Perri, S.; Goldstein, M. L.; Dorelli, J.; Sahraoui, F.; Gurgiolo, C. A.; Karimabadi, H.; Mozer, F.; Wendel, D. E.; TenBarge, J.; Roytershteyn, V.

    2013-12-01

    A recent analysis of 450 vec/s resolution data from the STAFF search-coil magnetometer on board Cluster has revealed, for the first time, the presence of thin current sheets and discontinuities from the proton Larmor scale down to the electron Larmor scale in the solar wind. This is in the range of scales where a cascade of energy consistent with highly oblique kinetic Alfvénic fluctuations (KAW), eventually dissipated by electron Landau damping, has been detected. The current sheets have been found to have a size between 20-200 km, indicating that they are very localized. We will compare the observations with results coming from 2D Hall MHD, Gyrokinetic, and full Particle-in-Cell turbulence simulations. Preliminary work has highlighted promising qualitative agreement between the properties of the structures observed in the Cluster data and the current sheets generated in the simulations. With the aim of investigating the role played by those structures in dissipating the magnetic energy in the solar wind, E●J has been computed within each magnetic discontinuity. This has been made possible via a combined analysis of both STAFF-SC magnetic field data and the electric field data from the Electric Fields and Wave instrument (EFW). We describe procedures used to reduce the noise in the EFW data. The results obtained represent an effort to clarify the processes involved in the dissipation of magnetic energy in the solar wind.

  1. Tobin Tax: Arguments and Current Derivative Studies

    Directory of Open Access Journals (Sweden)

    Ozekicioglu Seda

    2015-04-01

    Full Text Available Tobin Tax and its derivative applications have started to be discussed again in many platforms as the issue regarding taxation of short-term capital movements has become an agenda among international communities such as European Union (EU and G20 since the beginning of 2000s. In this study, Tobin Tax, which is the first significant step towards taxation of foreign currency transactions, has been discussed theoretically and considering its possible effects on application. Also, in this context, the initiatives of countries such as USA, Belgium, France and Austria regarding international implementation of Tobin Tax and its derivatives are being evaluated. The intended use of the taxes, determination of transactions exempt from tax and international cooperation in the implementation of taxation are possible problems that can be faced regarding Tobin Tax. In this study the conclusion, which the effects of Tobin Tax in developing and developed countries will be different but imposing such tax regarding cyclic balance of the world economy will be a positive improvement, has been reached.

  2. Ocular biomechanics study: current state and perspectives

    Directory of Open Access Journals (Sweden)

    S. Yu. Petrov

    2015-03-01

    Full Text Available Despite the fact that the eye represents a challenge for biomechanical research due to its size, over the last two decades, much data on ocular biomechanics were accumulated. Scleral and lamina cribrosa biomechanics contribute to our understanding of myopia and open-angle glaucoma; iris and trabecular meshwork biomechanics to that of angle-closure glaucoma; vitreous biomechanics to that of retinal detachment and ocular drug delivery; corneal biomechanics to that of keratoconus; and lens capsule biomechanics to that of cataract. This paper offers a general overview of recent advances in corneal, scleral, crystalline lens, and lamina cribrosa biomechanics and summarizes the results of experimental and clinical studies. Ocular biomechanics abnormalities affect etiology of many eye diseases. Ocular biomechanics plays an important role in the development of novel diagnostic methods, therapeutic and surgical procedures. Corneal biomechanics impacts etiology and pathogenesis of keratoconus as well as tonometry accuracy and explains corneal refractive surgery effect. Scleral biomechanics is associated with IOP and progressive myopia. Accommodative apparatus (ciliary body and crystalline lens is an important anatomic physiological structure. Recent studies uncovered the causes of agerelated loss of accommodation as a result of lens involution. Optic nerve head abnormalities due to IOP fluctuations are the key factor of glaucomatous neuropathy. They are directly associated with ocular biomechanics as well.

  3. Ocular biomechanics study: current state and perspectives

    Directory of Open Access Journals (Sweden)

    S. Yu. Petrov

    2015-01-01

    Full Text Available Despite the fact that the eye represents a challenge for biomechanical research due to its size, over the last two decades, much data on ocular biomechanics were accumulated. Scleral and lamina cribrosa biomechanics contribute to our understanding of myopia and open-angle glaucoma; iris and trabecular meshwork biomechanics to that of angle-closure glaucoma; vitreous biomechanics to that of retinal detachment and ocular drug delivery; corneal biomechanics to that of keratoconus; and lens capsule biomechanics to that of cataract. This paper offers a general overview of recent advances in corneal, scleral, crystalline lens, and lamina cribrosa biomechanics and summarizes the results of experimental and clinical studies. Ocular biomechanics abnormalities affect etiology of many eye diseases. Ocular biomechanics plays an important role in the development of novel diagnostic methods, therapeutic and surgical procedures. Corneal biomechanics impacts etiology and pathogenesis of keratoconus as well as tonometry accuracy and explains corneal refractive surgery effect. Scleral biomechanics is associated with IOP and progressive myopia. Accommodative apparatus (ciliary body and crystalline lens is an important anatomic physiological structure. Recent studies uncovered the causes of agerelated loss of accommodation as a result of lens involution. Optic nerve head abnormalities due to IOP fluctuations are the key factor of glaucomatous neuropathy. They are directly associated with ocular biomechanics as well.

  4. Study of high current commutation by explosive switch

    Science.gov (United States)

    Usuba, S.; Kakudate, Y.; Yoshida, M.; Fujiwara, S.; Miyamoto, M.; Morita, T.; Kubota, A.; den, M.

    1993-01-01

    The study presents the basic experimental data obtained with a large current opening switch for current commutation using explosives. It is shown that currents up to a maximum of 40 kA can be completely interrupted within 30 microsec. The mechanism of current interruption using a thin conductor plate and methods of measuring interrupting current with a pickup coil and taking photographs with a high-speed camera (one frame per microsec) are discussed.

  5. Experimental observations of stray current effects on steel fibres embedded in mortar

    DEFF Research Database (Denmark)

    Solgaard, A.O.S.; Carsana, M.; Geiker, M.R.;

    2013-01-01

    It is known that stray direct current can cause corrosive damage over time to bar reinforced concrete, but knowledge on the consequences to steel fibre reinforced concrete is limited. This paper presents analyses and corresponding results from an experimental program (parametric study) investigat...

  6. Observation of Thermoelectric Currents in High-Field Superconductor-Ferromagnet Tunnel Junctions.

    Science.gov (United States)

    Kolenda, S; Wolf, M J; Beckmann, D

    2016-03-01

    We report on the experimental observation of spin-dependent thermoelectric currents in superconductor-ferromagnet tunnel junctions in high magnetic fields. The thermoelectric signals are due to a spin-dependent lifting of the particle-hole symmetry, and are found to be in excellent agreement with recent theoretical predictions. The maximum Seebeck coefficient inferred from the data is about -100  μV/K, much larger than commonly found in metallic structures. Our results directly prove the coupling of spin and heat transport in high-field superconductors.

  7. Observed intraseasonal and seasonal variability of the West India coastal current on the continental slope.

    Digital Repository Service at National Institute of Oceanography (India)

    Amol, P.; Shankar, D.; Fernando, V.; Mukherjee, A.; Aparna, S.G.; Fernandes, R.; Michael, G.S.; Khalap, S.T.; Satelkar, N.P.; Agarvadekar, Y.; Gaonkar, M.G.; Tari, A.P.; Kankonkar, A.; Vernekar, S.

    between the Arabian Sea, a concentration basin, and the Bay of Bengal, a dilution basin (Jensen 2001; Han et al. 2001) and plays a major role in the region’s climate (see, for example, the reviews by Schott and McCreary 2001; Schott et al. 2009). The WICC... to the regional climate and marine living resources imply that it is important to be able to describe its variability and understand what causes the observed variability. In the rest of this introduction, we review our current state of knowledge of the WICC. We...

  8. Numerical simulation of the observed near-surface East India Coastal Current on the continental slope

    Science.gov (United States)

    Mukherjee, A.; Shankar, D.; Chatterjee, Abhisek; Vinayachandran, P. N.

    2017-08-01

    We simulate the East India Coastal Current (EICC) using two numerical models (resolution 0.1° × 0.1°), an oceanic general circulation model (OGCM) called Modular Ocean Model and a simpler, linear, continuously stratified (LCS) model, and compare the simulated current with observations from moorings equipped with acoustic Doppler current profilers deployed on the continental slope in the western Bay of Bengal (BoB). We also carry out numerical experiments to analyse the processes. Both models simulate well the annual cycle of the EICC, but the performance degrades for the intra-annual and intraseasonal components. In a model-resolution experiment, both models (run at a coarser resolution of 0.25° × 0.25° ) simulate well the currents in the equatorial Indian Ocean (EIO), but the performance of the high-resolution LCS model as well as the coarse-resolution OGCM, which is good in the EICC regime, degrades in the eastern and northern BoB. An experiment on forcing mechanisms shows that the annual EICC is largely forced by the local alongshore winds in the western BoB and remote forcing due to Ekman pumping over the BoB, but forcing from the EIO has a strong impact on the intra-annual EICC. At intraseasonal periods, local (equatorial) forcing dominates in the south (north) because the Kelvin wave propagates equatorward in the western BoB. A stratification experiment with the LCS model shows that changing the background stratification from EIO to BoB leads to a stronger surface EICC owing to strong coupling of higher order vertical modes with wind forcing for the BoB profiles. These high-order modes, which lead to energy propagating down into the ocean in the form of beams, are important only for the current and do not contribute significantly to the sea level.

  9. Experimental Study on Current-Driven Domain Wall Motion

    Science.gov (United States)

    Ono, T.; Yamaguchi, A.; Tanigawa, H.; Yano, K.; Kasai, S.

    2006-06-01

    Current-driven domain wall (DW) motion for a well-defined single DW in a micro-fabricated magnetic wire with submicron width was investigated by real-space observation with magnetic force microscopy. Magnetic force microscopy visualizes that a single DW introduced in a wire is displaced back and forth by positive and negative pulsed-current, respectively. Effect of the Joule heating, reduction of the threshold current density by shape control, and magnetic ratchet effect are also presented.

  10. Evidence for a current sheet forming in the wake of a Coronal Mass Ejection from multi-viewpoint coronagraph observations

    OpenAIRE

    Patsourakos, S.; Vourlidas, A.

    2010-01-01

    Ray-like features observed by coronagraphs in the wake of Coronal Mass Ejections (CMEs) are sometimes interpreted as the white light counterparts of current sheets (CSs) produced by the eruption. The 3D geometry of these ray-like features is largely unknown and its knowledge should clarify their association to the CS and place constraints on CME physics and coronal conditions. With this study we test these important implications for the first time. An example of such a post-CME ray was observ...

  11. Spectroscopic observations of evolving flare ribbon substructure suggesting origin in current sheet waves

    Science.gov (United States)

    Brannon, Sean R.; Longcope, Dana; Qiu, Jiong

    2015-04-01

    A flare ribbon is the chromospheric image of reconnection at a coronal current sheet. The dynamics and structure of the ribbon can thus reveal properties of the current sheet, including motion of the reconnecting flare loops. We present imaging and spectroscopic observations from the Interface Region Imaging Spectrograph (IRIS) of the evolution of a flare ribbon at high spatial resolution and time cadence. These reveal small-scale substructure in the ribbon, which manifest as oscillations in both position and Doppler velocities. We consider various alternative explanations for these oscillations, including modulation of chromospheric evaporation flows. Among these we find the best support for some form of elliptical wave localized to the coronal current sheet, such as a tearing mode or Kelvin-Helmholtz instability.IRIS is a NASA Small Explorer mission developed and operated by Lockheed Martin Solar and Astrophysics Laboratory. This work is supported by contract 8100002702 from Lockheed Martin to Montana State University, a Montana Space Grant Consortium fellowship, and by NASA through HSR.

  12. Current Efforts in European Projects to Facilitate the Sharing of Scientific Observation Data

    Science.gov (United States)

    Bredel, Henning; Rieke, Matthes; Maso, Joan; Jirka, Simon; Stasch, Christoph

    2017-04-01

    This presentation is intended to provide an overview of currently ongoing efforts in European projects to facilitate and promote the interoperable sharing of scientific observation data. This will be illustrated through two examples: a prototypical portal developed in the ConnectinGEO project for matching available (in-situ) data sources to the needs of users and a joint activity of several research projects to harmonise the usage of the OGC Sensor Web Enablement standards for providing access to marine observation data. ENEON is an activity initiated by the European ConnectinGEO project to coordinate in-situ Earth observation networks with the aim to harmonise the access to observations, improve discoverability, and identify/close gaps in European earth observation data resources. In this context, ENEON commons has been developed as a supporting Web portal for facilitating discovery, access, re-use and creation of knowledge about observations, networks, and related activities (e.g. projects). The portal is based on developments resulting from the European WaterInnEU project and has been extended to cover the requirements for handling knowledge about in-situ earth observation networks. A first prototype of the portal was completed in January 2017 which offers functionality for interactive discussion, information exchange and querying information about data delivered by different observation networks. Within this presentation, we will introduce the presented prototype and initiate a discussion about potential future work directions. The second example concerns the harmonisation of data exchange in the marine domain. There are many organisation who operate ocean observatories or data archives. In recent years, the application of the OGC Sensor Web Enablement (SWE) technology has become more and more popular to increase the interoperability between marine observation networks. However, as the SWE standards were intentionally designed in a domain independent manner

  13. SABRE observations of Pi2 pulsations: case studies

    Science.gov (United States)

    Bradshaw, E. G.; Lester, M.

    1997-01-01

    The characteristics of substorm-associated Pi2 pulsations observed by the SABRE coherent radar system during three separate case studies are presented. The SABRE field of view is well positioned to observe the differences between the auroral zone pulsation signature and that observed at mid-latitudes. During the first case study the SABRE field of view is initially in the eastward electrojet, equatorward and to the west of the substorm-enhanced electrojet current. As the interval progresses, the western, upward field-aligned current of the substorm current wedge moves westward across the longitudes of the radar field of view. The westward motion of the wedge is apparent in the spatial and temporal signatures of the associated Pi2 pulsation spectra and polarisation sense. During the second case study, the complex field-aligned and ionospheric currents associated with the pulsation generation region move equatorward into the SABRE field of view and then poleward out of it again after the third pulsation in the series. The spectral content of the four pulsations during the interval indicate different auroral zone and mid-latitude signatures. The final case study is from a period of low magnetic activity when SABRE observes a Pi2 pulsation signature from regions equatorward of the enhanced substorm currents. There is an apparent mode change between the signature observed by SABRE in the ionosphere and that on the ground by magnetometers at latitudes slightly equatorward of the radar field of view. The observations are discussed in terms of published theories of the generation mechanisms for this type of pulsation. Different signatures are observed by SABRE depending on the level of magnetic activity and the position of the SABRE field of view relative to the pulsation generation region. A twin source model for Pi2 pulsation generation provides the clearest explanation of the signatures observed Acknowledgements. The authors are grateful to Prof. D. J. Southwood

  14. Airglow Observation with IMAP/ VISI on the International Space Station: Current status and simulation

    Science.gov (United States)

    Perwitasari, S.; Sakanoi, T.; Yamazaki, A.; Otsuka, Y.; Akiya, Y.; Saito, A.

    2012-12-01

    The Visible and near-Infrared Spectral Imager (VISI) of the IMAP mission was launched successfully by H-IIB/HTV3 on July 21 2012. At this moment HTV3 is docked onto the International Space Station (ISS), and VISI is scheduled to be installed on the exposed facility within a week. VISI will be operated in the nightside hemisphere in the range of +/- 51 deg. GLAT, and measure the airglow emissions of OI at 630 nm, the OH Meinel band at 730 nm and the O2 atmospheric band (0-0) at 762 nm at an altitude of ~400 km with typical spatial resolution of 16 - 50 km. Since the influence of cloud reflections of moonlight is overlapped with the airglow pattern in the visible wavelength range, the precise subtraction of the cloud influence is a key issue of this mission. Therefore, a simulation work to study on how much the surface albedo on the cloud top will affect the data is critically important. The height profiles of volume emission rates were estimated for O2 and OH airglows with the MSIS models, and then the airglow intensities were integrated along the line-of-sight direction. The cloud pattern was estimated based on the realistic data measured with a geostationary climate satellite. The simulation result shows that for OH Meinel at 730 nm, the moonlight reflection during the first/last quarter will increase the brightness of the airglow by factor of 1.5-2 and ~5 for full moon phase. Meanwhile, for O2 atmospheric band (0-0) at 762 nm, the simulation result shows that there's no significant (structured) background, even during the full moon phase. We will report the quantitative effect of cloud albedo on the airglow pattern, and discuss the physical parameters those expected to be derived from the VISI data. Concerning on the operation of VISI, we will carry out the initial function check by the middle of August, and start nominal observation within a few months. Thus, we will also report the current status and initial result of VISI.

  15. The NOAA Satellite Observing System Architecture Study

    Science.gov (United States)

    Volz, Stephen; Maier, Mark; Di Pietro, David

    2016-01-01

    NOAA is beginning a study, the NOAA Satellite Observing System Architecture (NSOSA) study, to plan for the future operational environmental satellite system that will follow GOES and JPSS, beginning about 2030. This is an opportunity to design a modern architecture with no pre-conceived notions regarding instruments, platforms, orbits, etc. The NSOSA study will develop and evaluate architecture alternatives to include partner and commercial alternatives that are likely to become available. The objectives will include both functional needs and strategic characteristics (e.g., flexibility, responsiveness, sustainability). Part of this study is the Space Platform Requirements Working Group (SPRWG), which is being commissioned by NESDIS. The SPRWG is charged to assess new or existing user needs and to provide relative priorities for observational needs in the context of the future architecture. SPRWG results will serve as input to the process for new foundational (Level 0 and Level 1) requirements for the next generation of NOAA satellites that follow the GOES-R, JPSS, DSCOVR, Jason-3, and COSMIC-2 missions.

  16. Globally Gridded Satellite observations for climate studies

    Science.gov (United States)

    Knapp, K.R.; Ansari, S.; Bain, C.L.; Bourassa, M.A.; Dickinson, M.J.; Funk, C.; Helms, C.N.; Hennon, C.C.; Holmes, C.D.; Huffman, G.J.; Kossin, J.P.; Lee, H.-T.; Loew, A.; Magnusdottir, G.

    2011-01-01

    Geostationary satellites have provided routine, high temporal resolution Earth observations since the 1970s. Despite the long period of record, use of these data in climate studies has been limited for numerous reasons, among them that no central archive of geostationary data for all international satellites exists, full temporal and spatial resolution data are voluminous, and diverse calibration and navigation formats encumber the uniform processing needed for multisatellite climate studies. The International Satellite Cloud Climatology Project (ISCCP) set the stage for overcoming these issues by archiving a subset of the full-resolution geostationary data at ~10-km resolution at 3-hourly intervals since 1983. Recent efforts at NOAA's National Climatic Data Center to provide convenient access to these data include remapping the data to a standard map projection, recalibrating the data to optimize temporal homogeneity, extending the record of observations back to 1980, and reformatting the data for broad public distribution. The Gridded Satellite (GridSat) dataset includes observations from the visible, infrared window, and infrared water vapor channels. Data are stored in Network Common Data Format (netCDF) using standards that permit a wide variety of tools and libraries to process the data quickly and easily. A novel data layering approach, together with appropriate satellite and file metadata, allows users to access GridSat data at varying levels of complexity based on their needs. The result is a climate data record already in use by the meteorological community. Examples include reanalysis of tropical cyclones, studies of global precipitation, and detection and tracking of the intertropical convergence zone.

  17. Modeling Earth Albedo Currents on Sun Sensors for Improved Vector Observations

    DEFF Research Database (Denmark)

    Bhanderi, Dan

    2006-01-01

    Earth albedo influences vector measurements of the solar line of sight vector, due to the induced current on in the photo voltaics of Sun sensors. Although advanced digital Sun sensors exist, these are typically expensive and may not be suited for satellites in the nano or pico-class. Previously...... for modeling Sun sensor output by incorporating the Earth albedo model is presented. This model utilizes the directional information of in the Earth albedo model, which is achieved by Earth surface partitioning. This allows accurate simulation of the Sun sensor output and the results are consistent with Ørsted...... and useful for space environment simulations, and may be utilized to improve attitude estimation algorithms applying Sun sensor vector observations....

  18. Current Sheet Structures Observed by the TESIS EUV Telescope during a Flux Rope Eruption on the Sun

    Science.gov (United States)

    Reva, A. A.; Ulyanov, A. S.; Kuzin, S. V.

    2016-11-01

    We use the TESIS EUV telescope to study the current sheet signatures observed during flux rope eruption. The special feature of the TESIS telescope was its ability to image the solar corona up to a distance of 2 {R}⊙ from the Sun’s center in the Fe 171 Å line. The Fe 171 Å line emission illuminates the magnetic field lines, and the TESIS images reveal the coronal magnetic structure at high altitudes. The analyzed coronal mass ejection (CME) had a core with a spiral—flux rope—structure. The spiral shape indicates that the flux rope radius varied along its length. The flux rope had a complex temperature structure: cold legs (70,000 K, observed in He 304 Å line) and a hotter core (0.7 MK, observed in Fe 171 Å line). Such a structure contradicts the common assumption that the CME core is a cold prominence. When the CME impulsively accelerated, a dark double Y-structure appeared below the flux rope. The Y-structure timing, location, and morphology agree with the previously performed MHD simulations of the current sheet. We interpreted the Y-structure as a hot envelope of the current sheet and hot reconnection outflows. The Y-structure had a thickness of 6.0 Mm. Its length increased over time from 79 Mm to more than 411 Mm.

  19. Observation of the Field, Current and Force Distributions in an Optimized Superconducting Levitation with Translational Symmetry

    Science.gov (United States)

    Ye, Chang-Qing; Ma, Guang-Tong; Liu, Kun; Wang, Jia-Su

    2016-08-01

    The superconducting levitation realized by immersing the high-temperature superconductors (HTSs) into nonuniform magnetic field is deemed promising in a wide range of industrial applications such as maglev transportation and kinetic energy storage. Using a well-established electromagnetic model to mathematically describe the HTS, we have developed an efficient scheme that is capable of intelligently and globally optimizing the permanent magnet guideway (PMG) with single or multiple HTSs levitated above for the maglev transportation applications. With maximizing the levitation force as the principal objective, we optimized the dimensions of a Halbach-derived PMG to observe how the field, current and force distribute inside the HTSs when the optimized situation is achieved. Using a pristine PMG as a reference, we have analyzed the critical issues for enhancing the levitation force through comparing the field, current and force distributions between the optimized and pristine PMGs. It was also found that the optimized dimensions of the PMG are highly dependent upon the levitated HTS. Moreover, the guidance force is not always contradictory to the levitation force and may also be enhanced when the levitation force is prescribed to be the principle objective, depending on the configuration of levitation system and lateral displacement.

  20. Observation of the Field, Current and Force Distributions in an Optimized Superconducting Levitation with Translational Symmetry

    Science.gov (United States)

    Ye, Chang-Qing; Ma, Guang-Tong; Liu, Kun; Wang, Jia-Su

    2017-01-01

    The superconducting levitation realized by immersing the high-temperature superconductors (HTSs) into nonuniform magnetic field is deemed promising in a wide range of industrial applications such as maglev transportation and kinetic energy storage. Using a well-established electromagnetic model to mathematically describe the HTS, we have developed an efficient scheme that is capable of intelligently and globally optimizing the permanent magnet guideway (PMG) with single or multiple HTSs levitated above for the maglev transportation applications. With maximizing the levitation force as the principal objective, we optimized the dimensions of a Halbach-derived PMG to observe how the field, current and force distribute inside the HTSs when the optimized situation is achieved. Using a pristine PMG as a reference, we have analyzed the critical issues for enhancing the levitation force through comparing the field, current and force distributions between the optimized and pristine PMGs. It was also found that the optimized dimensions of the PMG are highly dependent upon the levitated HTS. Moreover, the guidance force is not always contradictory to the levitation force and may also be enhanced when the levitation force is prescribed to be the principle objective, depending on the configuration of levitation system and lateral displacement.

  1. Nonlinear Gulf Stream Interaction with the Deep Western Boundary Current System: Observations and a Numerical Simulation

    Science.gov (United States)

    Dietrich, David E.; Mehra, Avichal; Haney, Robert L.; Bowman, Malcolm J.; Tseng, Yu-Heng

    2003-01-01

    Gulf Stream (GS) separation near its observed Cape Hatteras (CH) separation location, and its ensuing path and dynamics, is a challenging ocean modeling problem. If a model GS separates much farther north than CH, then northward GS meanders, which pinch off warm core eddies (rings), are not possible or are strongly constrained by the Grand Banks shelfbreak. Cold core rings pinch off the southward GS meanders. The rings are often re-absorbed by the GS. The important warm core rings enhance heat exchange and, especially, affect the northern GS branch after GS bifurcation near the New England Seamount Chain. This northern branch gains heat by contact with the southern branch water upstream of bifurcation, and warms the Arctic Ocean and northern seas, thus playing a major role in ice dynamics, thermohaline circulation and possible global climate warming. These rings transport heat northward between the separated GS and shelf slope/Deep Western Boundary Current system (DWBC). This region has nearly level time mean isopycnals. The eddy heat transport convergence/divergence enhances the shelfbreak and GS front intensities and thus also increases watermass transformation. The fronts are maintained by warm advection by the Florida Current and cool advection by the DWBC. Thus, the GS interaction with the DWBC through the intermediate eddy field is climatologically important.

  2. The inconsistency between proton charge exchange and the observed ring current decay

    Science.gov (United States)

    Lyons, L. R.; Evans, D. S.

    1976-01-01

    The equatorial pitch-angle distributions of ring-current ions observed during a storm recovery phase at L values between 3 and 4 are compared with the pitch-angle distributions predicted by proton charge exchange with neutral hydrogen. Large disagreements are found, and three alternative explanations are explored. (1) A strong proton source acts to mask the effects of charge exchange. It is believed that the required strong continual source with a unique pitch-angle and energy dependence is unrealistic at these low L values. (2) Presently accepted neutral hydrogen density models have densities well over an order of magnitude too large for a storm recovery phase. No evidence is known to support the required large errors in the densities. (3) The ring current at particle energies not exceeding 50 keV was dominated by some ion species other than protons during the storm recovery phase. Such ions must have much longer lifetimes for charge exchange with hydrogen than do protons. This alternative is strongly favored, with He(+) being an attractive candidate.

  3. Improved upper bounds on Kaluza-Klein gravity with current Solar System experiments and observations

    CERN Document Server

    Deng, Xue-Mei

    2015-01-01

    As an extension of previous works on classical tests of Kaluza-Klein (KK) gravity and as an attempt to find more stringent constraints on this theory, its effects on physical experiments and astronomical observations conducted in the Solar System are studied. We investigate the gravitational time delay at inferior conjunction caused by KK gravity, and use new Solar System ephemerides and the observation of \\textit{Cassini} to strengthen constraints on KK gravity by up to two orders of magnitude. These improved upper bounds mean that the fifth-dimensional space in the soliton case is a very flat extra dimension in the Solar System, even in the vicinity of the Sun.

  4. Improved upper bounds on Kaluza-Klein gravity with current Solar System experiments and observations

    Energy Technology Data Exchange (ETDEWEB)

    Deng, Xue-Mei [Chinese Academy of Sciences, Purple Mountain Observatory, Nanjing (China); Xie, Yi [Nanjing University, School of Astronomy and Space Science, Nanjing (China); Shanghai Key Laboratory of Space Navigation and Position Techniques, Shanghai (China); Nanjing University, Ministry of Education, Key Laboratory of Modern Astronomy and Astrophysics, Nanjing (China)

    2015-11-15

    As an extension of previous works on classical tests of Kaluza-Klein (KK) gravity and as an attempt to find more stringent constraints on this theory, its effects on physical experiments and astronomical observations conducted in the Solar System are studied. We investigate the gravitational time delay at inferior conjunction caused by KK gravity, and use new Solar System ephemerides and the observation of Cassini to strengthen constraints on KK gravity by up to two orders of magnitude. These improved upper bounds mean that the fifth-dimensional space in the soliton case is a very flat extra dimension in the Solar System, even in the vicinity of the Sun. (orig.)

  5. Observed and Expected Mortality in Cohort Studies.

    Science.gov (United States)

    Richardson, David B; Keil, Alexander P; Cole, Stephen R; MacLehose, Richard F

    2017-03-15

    Epidemiologists often compare the observed number of deaths in a cohort with the expected number of deaths, obtained by multiplying person-time accrued in the cohort by mortality rates for a reference population (ideally, a reference that represents the mortality rate in the cohort in the absence of exposure). However, if exposure is hazardous (or salutary), this calculation will not consistently estimate the number of deaths expected in the absence of exposure because exposure will have affected the distribution of person-time observed in the study cohort. While problems with interpretation of this standard calculation of expected counts were discussed more than 2 decades ago, these discussions had little impact on epidemiologic practice. The logic of counterfactuals may help clarify this topic as we revisit these issues. In this paper, we describe a simple way to consistently estimate the expected number of deaths in such settings, and we illustrate the approach using data from a cohort study of mortality among underground miners. © The Author 2017. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  6. Solar cycle in current reanalyses: (nonlinear attribution study

    Directory of Open Access Journals (Sweden)

    A. Kuchar

    2014-12-01

    Full Text Available This study focusses on the variability of temperature, ozone and circulation characteristics in the stratosphere and lower mesosphere with regard to the influence of the 11 year solar cycle. It is based on attribution analysis using multiple nonlinear techniques (Support Vector Regression, Neural Networks besides the traditional linear approach. The analysis was applied to several current reanalysis datasets for the 1979–2013 period, including MERRA, ERA-Interim and JRA-55, with the aim to compare how this type of data resolves especially the double-peaked solar response in temperature and ozone variables and the consequent changes induced by these anomalies. Equatorial temperature signals in the lower and upper stratosphere were found to be sufficiently robust and in qualitative agreement with previous observational studies. The analysis also pointed to the solar signal in the ozone datasets (i.e. MERRA and ERA-Interim not being consistent with the observed double-peaked ozone anomaly extracted from satellite measurements. Consequently the results obtained by linear regression were confirmed by the nonlinear approach through all datasets, suggesting that linear regression is a relevant tool to sufficiently resolve the solar signal in the middle atmosphere. Furthermore, the seasonal dependence of the solar response was also discussed, mainly as a source of dynamical causalities in the wave propagation characteristics in the zonal wind and the induced meridional circulation in the winter hemispheres. The hypothetical mechanism of a weaker Brewer Dobson circulation was reviewed together with discussion of polar vortex stability.

  7. Solar cycle in current reanalyses: (non)linear attribution study

    Science.gov (United States)

    Kuchar, A.; Sacha, P.; Miksovsky, J.; Pisoft, P.

    2014-12-01

    This study focusses on the variability of temperature, ozone and circulation characteristics in the stratosphere and lower mesosphere with regard to the influence of the 11 year solar cycle. It is based on attribution analysis using multiple nonlinear techniques (Support Vector Regression, Neural Networks) besides the traditional linear approach. The analysis was applied to several current reanalysis datasets for the 1979-2013 period, including MERRA, ERA-Interim and JRA-55, with the aim to compare how this type of data resolves especially the double-peaked solar response in temperature and ozone variables and the consequent changes induced by these anomalies. Equatorial temperature signals in the lower and upper stratosphere were found to be sufficiently robust and in qualitative agreement with previous observational studies. The analysis also pointed to the solar signal in the ozone datasets (i.e. MERRA and ERA-Interim) not being consistent with the observed double-peaked ozone anomaly extracted from satellite measurements. Consequently the results obtained by linear regression were confirmed by the nonlinear approach through all datasets, suggesting that linear regression is a relevant tool to sufficiently resolve the solar signal in the middle atmosphere. Furthermore, the seasonal dependence of the solar response was also discussed, mainly as a source of dynamical causalities in the wave propagation characteristics in the zonal wind and the induced meridional circulation in the winter hemispheres. The hypothetical mechanism of a weaker Brewer Dobson circulation was reviewed together with discussion of polar vortex stability.

  8. Theoretical studies of non inductive current drive in compact toroids

    NARCIS (Netherlands)

    Farengo, R; Lifschitz, AF; Caputi, KI; Arista, NR; Clemente, RA

    2002-01-01

    Three non inductive current drive methods that can be applied to compact toroids axe studied. The use of neutral beams to drive current in field reversed configurations and spheromaks is studied using a Monte Carlo code that includes a complete ionization package and follows the exact particle orbit

  9. Observation of Transient Overcritical Currents in YBCO Thin Films using High-Speed Magneto-Optical Imaging and Dynamic Current Mapping

    Science.gov (United States)

    Wells, Frederick S.; Pan, Alexey V.; Golovchanskiy, Igor A.; Fedoseev, Sergey A.; Rozenfeld, Anatoly

    2017-01-01

    The dynamics of transient current distributions in superconducting YBa2Cu3O7−δ thin films were investigated during and immediately following an external field ramp, using high-speed (real-time) Magneto-Optical Imaging and calculation of dynamic current profiles. A number of qualitatively unique and previously unobserved features are seen in this novel analysis of the evolution of supercurrent during penetration. As magnetic field ramps up from zero, the dynamic current profile is characterized by strong peaks, the magnitude of which exceed the conventional critical current density (as determined from static current profiles). These peaks develop close to the sample edges, initially resembling screening currents but quickly growing in intensity as the external field increases. A discontinuity in field and current behaviour is newly observed, indicating a novel transition from increasing peak current toward relaxation behaviour. After this transition, the current peaks move toward the centre of the sample while reducing in intensity as magnetic vortices penetrate inward. This motion slows exponentially with time, with the current distribution in the long-time limit reducing to the expected Kim-model profile. PMID:28067331

  10. Observation of Transient Overcritical Currents in YBCO Thin Films using High-Speed Magneto-Optical Imaging and Dynamic Current Mapping.

    Science.gov (United States)

    Wells, Frederick S; Pan, Alexey V; Golovchanskiy, Igor A; Fedoseev, Sergey A; Rozenfeld, Anatoly

    2017-01-09

    The dynamics of transient current distributions in superconducting YBa2Cu3O7-δ thin films were investigated during and immediately following an external field ramp, using high-speed (real-time) Magneto-Optical Imaging and calculation of dynamic current profiles. A number of qualitatively unique and previously unobserved features are seen in this novel analysis of the evolution of supercurrent during penetration. As magnetic field ramps up from zero, the dynamic current profile is characterized by strong peaks, the magnitude of which exceed the conventional critical current density (as determined from static current profiles). These peaks develop close to the sample edges, initially resembling screening currents but quickly growing in intensity as the external field increases. A discontinuity in field and current behaviour is newly observed, indicating a novel transition from increasing peak current toward relaxation behaviour. After this transition, the current peaks move toward the centre of the sample while reducing in intensity as magnetic vortices penetrate inward. This motion slows exponentially with time, with the current distribution in the long-time limit reducing to the expected Kim-model profile.

  11. Observation of Transient Overcritical Currents in YBCO Thin Films using High-Speed Magneto-Optical Imaging and Dynamic Current Mapping

    Science.gov (United States)

    Wells, Frederick S.; Pan, Alexey V.; Golovchanskiy, Igor A.; Fedoseev, Sergey A.; Rozenfeld, Anatoly

    2017-01-01

    The dynamics of transient current distributions in superconducting YBa2Cu3O7‑δ thin films were investigated during and immediately following an external field ramp, using high-speed (real-time) Magneto-Optical Imaging and calculation of dynamic current profiles. A number of qualitatively unique and previously unobserved features are seen in this novel analysis of the evolution of supercurrent during penetration. As magnetic field ramps up from zero, the dynamic current profile is characterized by strong peaks, the magnitude of which exceed the conventional critical current density (as determined from static current profiles). These peaks develop close to the sample edges, initially resembling screening currents but quickly growing in intensity as the external field increases. A discontinuity in field and current behaviour is newly observed, indicating a novel transition from increasing peak current toward relaxation behaviour. After this transition, the current peaks move toward the centre of the sample while reducing in intensity as magnetic vortices penetrate inward. This motion slows exponentially with time, with the current distribution in the long-time limit reducing to the expected Kim-model profile.

  12. GEOPHYSICS, ASTRONOMY, AND ASTROPHYSICS: Cluster Observation of Electrostatic Solitary Waves around Magnetic Null Point in Thin Current Sheet

    Science.gov (United States)

    Li, Shi-You; Deng, Xiao-Hua; Zhou, Meng; Yuan, Zhi-Gang; Wang, Jing-Fang; Lin, Xi; Lin, Min-Hui; Fu, Song

    2010-01-01

    Electrostatic solitary waves (ESWs) are observed in the vicinity of the magnetic null of the widely studied magnetic reconnection taking place at the near-earth tail when current sheet becomes dramatic thinning during substorm time on 1 October 2001. We use the Imada method for the 2-D reconnection model and study the characteristics of ESWs near the X-line region and the magnetic null points. The result shows that the amplitude of the observed ESWs in the vicinity of X-line region ranges from 0.1 mV/m to 5 mV/m, and the amplitude is larger near the magnetic null points. The generation mechanism and the role of ESWs associated with magnetic reconnection are also discussed.

  13. The Canadian Enhanced Polar Outflow Probe (e-POP Mission: Current Status and Planned Observations and Data Distribution

    Directory of Open Access Journals (Sweden)

    A W Yau

    2009-04-01

    Full Text Available The CASSIOPE Enhanced Polar Outflow Probe (e-POP is a Canadian small-satellite mission dedicated to the study of polar ion outflows and related magnetosphere-ionosphere coupling processes in the topside ionosphere. Scheduled for launch in 2009, it will carry eight scientific instruments, including imaging plasma and neutral particle sensors, magnetometers, dual-frequency GPS receivers, CCD cameras, a radio wave receiver and a beacon transmitter, for in-situ particle, field, and current measurements and auroral imaging and radio measurements. We present an overview of the e-POP mission, its current status and plan of observations and data distribution during the operation phase of the mission.

  14. Forum for Arctic Modeling and Observational Synthesis (FAMOS): Past, current, and future activities

    Science.gov (United States)

    Proshutinsky, A.; Steele, M.; Timmermans, M.-L.

    2016-06-01

    The overall goal of the Forum for Arctic Modeling and Observational Synthesis (FAMOS) community activities reported in this special issue is to enhance understanding of processes and mechanisms driving Arctic Ocean marine and sea ice changes, and the consequences of those changes especially in biogeochemical and ecosystem studies. Major 2013-2015 FAMOS accomplishments to date are: identification of consistent errors across Arctic regional models; approaches to reduce these errors, and recommendations for the most effective coupled sea ice-ocean models for use in fully coupled regional and global climate models. 2013-2015 FAMOS coordinated analyses include many process studies, using models together with observations to investigate: dynamics and mechanisms responsible for drift, deformation and thermodynamics of sea ice; pathways and mechanisms driving variability of the Atlantic, Pacific and river waters in the Arctic Ocean; processes of freshwater accumulation and release in the Beaufort Gyre; the fate of melt water from Greenland; characteristics of ocean eddies; biogeochemistry and ecosystem processes and change, climate variability, and predictability. Future FAMOS collaborations will focus on employing models and conducting observations at high and very high spatial and temporal resolution to investigate the role of subgrid-scale processes in regional Arctic Ocean and coupled ice-ocean and atmosphere-ice-ocean models.

  15. Current Sheet Structures Observed by the TESIS EUV Telescope During A Flux Rope Eruption on the Sun

    CERN Document Server

    Reva, Anton; Kuzin, Ssergey

    2016-01-01

    We use the TESIS EUV telescope to study the current sheet signatures observed during flux rope eruption. The special feature of the TESIS telescope was its ability to image the solar corona up to a distance of 2 $R_\\odot$ from the Sun's center in the Fe 171 \\AA\\ line. The Fe 171 \\AA\\ line emission illuminates the magnetic field lines, and the TESIS images reveal the coronal magnetic structure at high altitudes. The analyzed CME had a core with a spiral-flux rope-structure. The spiral shape indicates that the flux rope radius varied along its length. The flux rope had a complex temperature structure: cold legs (70 000 K, observed in He 304 \\AA\\ line) and a hotter core (0.7 MK, observed in Fe 171 \\AA\\ line). Such structure contradicts the common assumption that the CME core is a cold prominence. When the CME impulsively accelerated, a dark double Y-structure appeared below the flux rope. The Y-structure timing, location, and morphology agree with the previously performed MHD simulations of the current sheet. We...

  16. Using the Nordic Geodetic Observing System for land uplift studies

    Science.gov (United States)

    Nordman, M.; Poutanen, M.; Kairus, A.; Virtanen, J.

    2014-07-01

    Geodetic observing systems have been planned and developed during the last decade. An ideal observing system consists of a network of geodetic observing stations with several techniques at the same site, publicly accessible databases, and as a product delivers data time series, combination of techniques or some other results obtained from the data sets. Globally, there is the International Association of Geodesy (IAG) Global Geodetic Observing System (GGOS), and there are ongoing attempts to create also regional observing systems. In this paper we introduce one regional system, the Nordic Geodetic Observing System (NGOS) hosted by the Nordic Geodetic Commission (NKG). Data availability and accessibility are one of the major issues today. We discuss in general data-related topics, and introduce a pilot database project of NGOS. As a demonstration of the use of such a database, we apply it for postglacial rebound studies in the Fennoscandian area. We compare land uplift values from three techniques, GNSS, tide gauges and absolute gravity, with the Nordic Geodetic Commission NKG2005LU land uplift model for Fennoscandia. The purpose is to evaluate the data obtained from different techniques and different sources and get the most reliable values for the uplift using publicly available data. The primary aim of observing systems will be to produce data and other products needed by multidisciplinary projects, such as Upper Mantle Dynamics and Quaternary Climate in Cratonic Areas (DynaQlim) or the European Plate Observing System (EPOS), but their needs may currently exceed the scope of an existing observing system. We discuss what requirements the projects pose to observing systems and their development. To make comparisons between different studies possible and reliable, the researcher should document what they have in detail, either in appendixes, supplementary material or some other available format.

  17. The Strengthening the Reporting of Observational Studies in Epidemiology (STROBE statement: guidelines for reporting observational studies.

    Directory of Open Access Journals (Sweden)

    Erik von Elm

    2007-10-01

    Full Text Available Much biomedical research is observational. The reporting of such research is often inadequate, which hampers the assessment of its strengths and weaknesses and of a study's generalisability. The Strengthening the Reporting of Observational Studies in Epidemiology (STROBE Initiative developed recommendations on what should be included in an accurate and complete report of an observational study. We defined the scope of the recommendations to cover three main study designs: cohort, case-control, and cross-sectional studies. We convened a 2-day workshop in September 2004, with methodologists, researchers, and journal editors to draft a checklist of items. This list was subsequently revised during several meetings of the coordinating group and in e-mail discussions with the larger group of STROBE contributors, taking into account empirical evidence and methodological considerations. The workshop and the subsequent iterative process of consultation and revision resulted in a checklist of 22 items (the STROBE Statement that relate to the title, abstract, introduction, methods, results, and discussion sections of articles. 18 items are common to all three study designs and four are specific for cohort, case-control, or cross-sectional studies. A detailed Explanation and Elaboration document is published separately and is freely available on the Web sites of PLoS Medicine, Annals of Internal Medicine, and Epidemiology. We hope that the STROBE Statement will contribute to improving the quality of reporting of observational studies.

  18. Je pense donc je fais: transcranial direct current stimulation modulates brain oscillations associated with motor imagery and movement observation

    Directory of Open Access Journals (Sweden)

    Olivia Morgan Lapenta

    2013-06-01

    Full Text Available Motor system neural networks are activated during movement imagery, observation and execution, with a neural signature characterized by suppression of the Mu rhythm. In order to investigate the origin of this neurophysiological marker, we tested whether transcranial direct current stimulation (tDCS modifies Mu rhythm oscillations during tasks involving observation and imagery of biological and non-biological movements. We applied tDCS (anodal, cathodal and sham in 21 male participants (mean age 23.8+3.06, over the left M1 with a current of 2mA for 20 minutes. Following this, we recorded the EEG at C3, C4 and Cz and surrounding C3 and C4 electrodes. Analyses of C3 and C4 showed significant effects for biological vs. non-biological movement (p=0.005, and differential hemisphere effects according to the type of stimulation (p=0.04 and type of movement (p=0.02. Analyses of surrounding electrodes revealed significant interaction effects considering type of stimulation and imagery or observation of biological or non-biological movement (p=0.03. The main findings of this study were (i Mu desynchronization during biological movement of the hand region in the contralateral hemisphere after sham tDCS; (ii polarity-dependent modulation effects of tDCS on the Mu rhythm, i.e. anodal tDCS led to Mu synchronization while cathodal tDCS led to Mu desynchronization during movement observation and imagery (iii specific focal and opposite inter-hemispheric effects, i.e. contrary effects for the surrounding electrodes during imagery condition and also for inter-hemispheric electrodes (C3 vs. C4. These findings provide insights into the cortical oscillations during movement observation and imagery. Furthermore it shows that tDCS can be highly focal when guided by a behavioral task.

  19. Study of a fibre optics current sensor for the measurement of plasma current in ITER

    Science.gov (United States)

    Wuilpart, Marc; Vanus, Benoit; Andrasan, Alina; Gusarov, Andrei; Moreau, Philippe; Mégret, Patrice

    2016-05-01

    In this article, we study the feasibility of using a fibre-optics current sensor (FOCS) for the measurement of plasma current in the future fusion reactor ITER. The sensor is based on a classical FOCS interrogator involving the measurement of the state of polarization rotation undergone by the light in presence of a magnetic field (Faraday effect) in an optical fibre surrounding the current and terminated by a Faraday mirror. We considered a uniformly spun optical fibre as the sensing element and we used the Stokes formalism to simulate the sensor. The objective of the simulations is to quantify the ratio LB/SP (beat length over the spun period of the spun fibre) enabling a measurement error in agreement with the ITER specifications. The simulator takes into account the temperature variations undergone by the measurement system under ITER operation. The simulation work showed that a LB/SP ratio of 19.2 is adequate.

  20. Evolution of the current system during solar wind pressure pulses based on aurora and magnetometer observations

    Science.gov (United States)

    Nishimura, Yukitoshi; Kikuchi, Takashi; Ebihara, Yusuke; Yoshikawa, Akimasa; Imajo, Shun; Li, Wen; Utada, Hisashi

    2016-08-01

    We investigated evolution of ionospheric currents during sudden commencements using a ground magnetometer network in conjunction with an all-sky imager, which has the advantage of locating field-aligned currents much more accurately than ground magnetometers. Preliminary (PI) and main (MI) impulse currents showed two-cell patterns propagating antisunward, particularly during a southward interplanetary magnetic field (IMF). Although this overall pattern is consistent with the Araki (solar wind sources of magnetospheric ultra-low-frequency waves. Geophysical monograph series, vol 81. AGU, Washington, DC, pp 183-200, 1994. doi: 10.1029/GM081p0183) model, we found several interesting features. The PI and MI currents in some events were highly asymmetric with respect to the noon-midnight meridian; the post-noon sector did not show any notable PI signal, but only had an MI starting earlier than the pre-noon MI. Not only equivalent currents but also aurora and equatorial magnetometer data supported the much weaker PI response. We suggest that interplanetary shocks impacting away from the subsolar point caused the asymmetric current pattern. Additionally, even when PI currents form in both pre- and post-noon sectors, they can initiate and disappear at different timings. The PI currents did not immediately disappear but coexisted with the MI currents for the first few minutes of the MI. During a southward IMF, the MI currents formed equatorward of a preexisting DP-2, indicating that the MI currents are a separate structure from a preexisting DP-2. In contrast, the MI currents under a northward IMF were essentially an intensification of a preexisting DP-2. The magnetometer and imager combination has been shown to be a powerful means for tracing evolution of ionospheric currents, and we showed various types of ionospheric responses under different upstream conditions.

  1. Multicenter observational prehospital resuscitation on helicopter study.

    Science.gov (United States)

    Holcomb, John B; Swartz, Michael D; DeSantis, Stacia M; Greene, Thomas J; Fox, Erin E; Stein, Deborah M; Bulger, Eileen M; Kerby, Jeffrey D; Goodman, Michael; Schreiber, Martin A; Zielinski, Martin D; O'Keeffe, Terence; Inaba, Kenji; Tomasek, Jeffrey S; Podbielski, Jeanette M; Appana, Savitri N; Yi, Misung; Wade, Charles E

    2017-07-01

    Earlier use of in-hospital plasma, platelets, and red blood cells (RBCs) has improved survival in trauma patients with severe hemorrhage. Retrospective studies have associated improved early survival with prehospital blood product transfusion (PHT). We hypothesized that PHT of plasma and/or RBCs would result in improved survival after injury in patients transported by helicopter. Adult trauma patients transported by helicopter from the scene to nine Level 1 trauma centers were prospectively observed from January to November 2015. Five helicopter systems had plasma and/or RBCs, whereas the other four helicopter systems used only crystalloid resuscitation. All patients meeting predetermined high-risk criteria were analyzed. Patients receiving PHT were compared with patients not receiving PHT. Our primary analysis compared mortality at 3 hours, 24 hours, and 30 days, using logistic regression to adjust for confounders and site heterogeneity to model patients who were matched on propensity scores. Twenty-five thousand one hundred eighteen trauma patients were admitted, 2,341 (9%) were transported by helicopter, of which 1,058 (45%) met the highest-risk criteria. Five hundred eighty-five of 1,058 patients were flown on helicopters carrying blood products. In the systems with blood available, prehospital median systolic blood pressure (125 vs 128) and Glasgow Coma Scale (7 vs 14) was significantly lower, whereas median Injury Severity Score was significantly higher (21 vs 14). Unadjusted mortality was significantly higher in the systems with blood products available, at 3 hours (8.4% vs 3.6%), 24 hours (12.6% vs 8.9%), and 30 days (19.3% vs 13.3%). Twenty-four percent of eligible patients received a PHT. A median of 1 unit of RBCs and plasma were transfused prehospital. Of patients receiving PHT, 24% received only plasma, 7% received only RBCs, and 69% received both. In the propensity score matching analysis (n = 109), PHT was not significantly associated with mortality

  2. Observational evidence of seasonality in the timing of loop current eddy separation

    Science.gov (United States)

    Hall, Cody A.; Leben, Robert R.

    2016-12-01

    Observational datasets, reports and analyses over the time period from 1978 through 1992 are reviewed to derive pre-altimetry Loop Current (LC) eddy separation dates. The reanalysis identified 20 separation events in the 15-year record. Separation dates are estimated to be accurate to approximately ± 1.5 months and sufficient to detect statistically significant LC eddy separation seasonality, which was not the case for previously published records because of the misidentification of separation events and their timing. The reanalysis indicates that previously reported LC eddy separation dates, determined for the time period before the advent of continuous altimetric monitoring in the early 1990s, are inaccurate because of extensive reliance on satellite sea surface temperature (SST) imagery. Automated LC tracking techniques are used to derive LC eddy separation dates in three different altimetry-based sea surface height (SSH) datasets over the time period from 1993 through 2012. A total of 28-30 LC eddy separation events were identified in the 20-year record. Variations in the number and dates of eddy separation events are attributed to the different mean sea surfaces and objective-analysis smoothing procedures used to produce the SSH datasets. Significance tests on various altimetry and pre-altimetry/altimetry combined date lists consistently show that the seasonal distribution of separation events is not uniform at the 95% confidence level. Randomization tests further show that the seasonal peak in LC eddy separation events in August and September is highly unlikely to have occurred by chance. The other seasonal peak in February and March is less significant, but possibly indicates two seasons of enhanced probability of eddy separation centered near the spring and fall equinoxes. This is further quantified by objectively dividing the seasonal distribution into two seasons using circular statistical techniques and a k-means clustering algorithm. The estimated

  3. Observed features of temperature, salinity and current in central Chukchi Sea during the summer of 2012

    Institute of Scientific and Technical Information of China (English)

    HE Yan; LIU Na; CHEN Hongxia; TENG Fei; LIN Lina; WANG Huiwu

    2015-01-01

    During the summer of 2012, the fifth CHINARE Arctic Expedition was carried out, and a submersible mooring system was deployed in M5 station located at (69°30.155'N,169°00.654'W) and recovered 50d later. A set of temperature, salinity and current profile records was acquired. The characteristics of these observations are analyzed in this paper. Some main results are achieved as below. (1) Temperature generally decreases while salinity generally increases with increasing depth. The average values of all records are 2.98℃ and 32.21 psu. (2) Salinity and temperature are well negatively correlated, and the correlation coefficient between them is –0.84. However, they did not always vary synchronously. Their co-variation featured different characters during different significant periods. (3) The average velocity for the whole water column is 141 mm/s with directional angle of 347.1°. The statistical distribution curve of velocity record number gets narrower with increasing depth. More than 85% of the recorded velocities are northward, and the mean magnitudes of dominated northward velocities are 100–150 mm/s. (4) Rotary spectrum analysis shows that motions with low frequency take a majority of energy in all layers. The most significant energy peaks for all layers are around 0.012 cph (about 3.5 d period), while the tidal motion in mooring area is nonsignificant. (5) Velocities in all layers feature similar and synchronous temporal variations, except for the slight decrease in magnitude and leftward twist from top to bottom. The directions of velocity correspond well to those of surface wind. The average northward volume transport per square meter is 0.1–0.2 m3/s under southerly wind, but about –0.2 m3/s during northerly wind burst.

  4. Highly intense lightning over the oceans: Estimated peak currents from global GLD360 observations

    OpenAIRE

    İnan, Umran Savaş; Said, R. K.; Cohen, M. B

    2013-01-01

    We present the ?rst global distribution of the average estimated peak currents in negative lightning ?ashes using 1 year of continuous data from the Vaisala global lightning data set GLD360. The data set, composed of 353 million ?ashes, was compared with the National Lightning Detection NetworkTM for peak current accuracy, location accuracy, and detection ef?ciency. The validation results demonstrated a mean (geometric mean) peak current magnitude error of 21% (6%), a median lo...

  5. THEMIS multispacecraft observations of a reconnecting magnetosheath current sheet with symmetric boundary conditions and a large guide field

    Science.gov (United States)

    Øieroset, M.; Phan, T. D.; Shay, M. A.; Haggerty, C. C.; Fujimoto, M.; Angelopoulos, V.; Eastwood, J. P.; Mozer, F. S.

    2017-08-01

    We report three spacecraft observations of a reconnecting magnetosheath current sheet with a guide field of unity, with THEMIS D (THD) and THEMIS E (THE)/THEMIS A (THA) observing oppositely directed reconnection exhausts, indicating the presence of an X line between the spacecraft. The near-constant convective speed of the magnetosheath current sheet allowed the direct translation of the observed time series into spatial profiles. THD observed asymmetries in the plasma density and temperature profiles across the exhaust, characteristics of symmetric reconnection with a guide field. The exhausts at THE and THA, on the other hand, were not the expected mirror image of the THD exhaust in terms of the plasma and field profiles. They consisted of a main outflow at the center of the current sheet, flanked by oppositely directed flows at the two edges of the current sheet, suggesting the presence of a second X line, whose outflow wraps around the outflow from the first X line.

  6. National study of emergency department observation services.

    Science.gov (United States)

    Wiler, Jennifer L; Ross, Michael A; Ginde, Adit A

    2011-09-01

    The objective was to describe patient and facility characteristics of emergency department (ED) observation services in the United States. The authors analyzed the 2007 National Hospital Ambulatory Medical Care Survey (NHAMCS). Characteristics of EDs with observation units (OUs) were compared to those without, and patients with a disposition of ED observation were compared to those with a "short-stay" (observational analysis. An estimated 1,746 U.S. EDs (36%) reported having OUs, of which 56% are administratively managed by ED staff. Fifty-two percent of hospitals with ED-managed OUs are in an urban location, and 89% report ED boarding, compared to 29 and 65% of those that do not have an OU. The admission rate is 38% at those with ED-managed OUs and 15% at those without OUs. Of the 15.1% of all ED patients who are kept in the hospital following an ED visit, one-quarter are kept for either a short-stay admission (1.8%) or an ED observation admission (2.1%). Most (82%) ED observation patients were discharged from the ED. ED observation patients were similar to short-stay admission patients in terms of age (median = 52 years for both, interquartile range = 36 to 70 years), self-pay (12% vs. 10%), ambulance arrival (37% vs. 36%), urgent/emergent triage acuity (77% vs. 74%), use of ≥1 ED medication (64% vs.76%), and the most common primary chief complaints and primary diagnoses. Over one-third of U.S. EDs have an OU. Short-stay admission patients have similar characteristics as ED observation patients and may represent an opportunity for the growth of OUs. © 2011 by the Society for Academic Emergency Medicine.

  7. Century Scale Evaporation Trend: An Observational Study

    Science.gov (United States)

    Bounoui, Lahouari

    2012-01-01

    Several climate models with different complexity indicate that under increased CO2 forcing, runoff would increase faster than precipitation overland. However, observations over large U.S watersheds indicate otherwise. This inconsistency between models and observations suggests that there may be important feedbacks between climate and land surface unaccounted for in the present generation of models. We have analyzed century-scale observed annual runoff and precipitation time-series over several United States Geological Survey hydrological units covering large forested regions of the Eastern United States not affected by irrigation. Both time-series exhibit a positive long-term trend; however, in contrast to model results, these historic data records show that the rate of precipitation increases at roughly double the rate of runoff increase. We considered several hydrological processes to close the water budget and found that none of these processes acting alone could account for the total water excess generated by the observed difference between precipitation and runoff. We conclude that evaporation has increased over the period of observations and show that the increasing trend in precipitation minus runoff is correlated to observed increase in vegetation density based on the longest available global satellite record. The increase in vegetation density has important implications for climate; it slows but does not alleviate the projected warming associated with greenhouse gases emission.

  8. Satellite-tracked drifting buoy observations in the south equatorial current in the Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Shetye, S.R.; Michael, G.S.

    Three satellite-tracked drifting buoys released in the south equatorial current in the Indian Ocean followed the path of the current moving westward approximately zonally in the vicinity of 10 degrees S latitude. On nearing the east coast of Africa...

  9. Thermally stimulated depolarization current studies of sulfonated polystyrene ionomers

    Science.gov (United States)

    Carvalho, Antonio José Felix; Viana, Vicente Galber Freitas; Faria, Roberto Mendonça

    2009-12-01

    A detailed study of thermally stimulated depolarization current (TSDC) was carried out to investigate dipolar relaxation and the charge storage phenomenon in films of sulfonated polystyrene (SPS) ionomers having lithium or potassium as counterions. Differential scanning calorimetry measurements were also applied as a complementary technique, mainly to follow the change of the glass transition temperature with the amount of sulfonated groups. It was observed that, since the glass transition does not change significantly with the amount of sulfonated groups, a cluster of multiplets is expected not to be formed in the range used in this work. TSDC of SPS samples polarized at temperatures higher than the glass transition temperature showed three peaks: one at lower temperature (peak β), an intermediate peak (peak α), and a third that appeared at a temperature coincident with the polarization temperature (peak ρ). Quantitative information about trapping-detrapping and dipolar relaxation and their corresponding activation energies was determined by fittings of the deconvoluted peaks with kinetic relaxation processes.

  10. Thermally stimulated depolarization current studies of sulfonated polystyrene ionomers

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, Antonio Jose Felix [Universidade Federal de Sao Carlos, Laboratory of Polymers and Renewable Materials, Sorocaba, SP (Brazil); Viana, Vicente Galber Freitas [Universidade Federal do Piaui, Centro de Ciencias da Natureza, Teresina, PI (Brazil); Faria, Roberto Mendonca [USP, Instituto de Fisica de Sao Carlos, SP (Brazil)

    2009-12-15

    A detailed study of thermally stimulated depolarization current (TSDC) was carried out to investigate dipolar relaxation and the charge storage phenomenon in films of sulfonated polystyrene (SPS) ionomers having lithium or potassium as counterions. Differential scanning calorimetry measurements were also applied as a complementary technique, mainly to follow the change of the glass transition temperature with the amount of sulfonated groups. It was observed that, since the glass transition does not change significantly with the amount of sulfonated groups, a cluster of multiplets is expected not to be formed in the range used in this work. TSDC of SPS samples polarized at temperatures higher than the glass transition temperature showed three peaks: one at lower temperature (peak {beta}), an intermediate peak (peak {alpha}), and a third that appeared at a temperature coincident with the polarization temperature (peak {rho}). Quantitative information about trapping-detrapping and dipolar relaxation and their corresponding activation energies was determined by fittings of the deconvoluted peaks with kinetic relaxation processes. (orig.)

  11. Key science issues after MESSENGER and current observation plans of BepiColombo MMO

    Science.gov (United States)

    Murakami, Go; Hayakawa, Hajime; Fujimoto, Masaki

    2017-04-01

    Little had been known about the Hermean magnetosphere until MESSENGER explored the region. The region is formed as the weak planetary magnetic field stands against the intense solar wind in the close proximity of the Sun. Various prediction had been given by noting the difference in the parameters from the well-studied terrestiral magnetosphere of a similar setting and scaling the well-knowns to the Hermean environment. MESSENGER results, however, show a wide varieity of phenomena that are out of the scope of what one could have reasonably argued. The micro-magnetosphere of Mercury is much more dynamic than one had predicted. BepiColombo MMO, the JAXA spacecraft of the BepiColombo Mercury exploration mission which will be launched in 2018 and will arrive at Mercury in 2025, is equipped to study the space environment of the planet Mercury. BepiColombo MMO is mainly designed for plasma observations and is expected to extract essential elements of space plasma physics that become visible in the Hermean environment. MMO has large constraints on science operations, such as thermal issue and limited telemetry rate. Due to the thermal issue each science instrument cannot always be turned on. In addition, due to the low telemetry rate in average, only a part ( 20-30%) of science mission data with high resolution can be downlinked. Therefore, in order to maximize the scientific results and outcomes to be achieved by MMO, we are now working to optimize the science observation and downlink plans in detail. Here we review MESSENGER results and how MMO will contribute to deepen our understanding of space plasmas by addressing the puzzles raised by MESSEGNER.

  12. Small spatial scale field aligned currents in middle and low latitudes as observed by the CHAMP satellite and verification of their current circuit model

    Science.gov (United States)

    Nakanishi, K.; Iyemori, T.; Luhr, H.

    2013-12-01

    The magnetic field observation by the CHAMP satellite shows the global and frequent appearance of small scale (1-5 nT) magnetic fluctuations with period around a few tens seconds along the satellites. They have the following characteristics. 1. The signal is perpendicular to the geomagnetic main field, and the amplitude of the zonal component is larger than that of the meridional component. 2. Around the dip equator, as the latitude becomes lower, the period and amplitudes of the two components perpendicular to the main field respectively tend to become longer and smaller (to nearly zero on the dip equator). 3. The amplitude of the magnetic fluctuations on the dayside is larger than that on the night side by around one order in magnitude, which highly correlates to the electric conductivity of the ionospheric dynamo layer. 4. The amplitude shows symmetry about the magnetic dip equator which indicates a magnetic conjugacy to a certain extent. 5. The amplitude shows almost no dependence on the solar wind parameters such as the IMF cone angle nor the solar wind speed, which strongly suggests no association with the Pc3 micro pulsation. 6. The amplitude also shows almost no dependence on the geomagnetic activity. 7. The amplitude has a clear seasonal dependence with topographical characteristics. They can be interpreted as the spatial structure of small scale field-aligned currents generated by the ionospheric dynamo driven by atmospheric gravity waves propagating from the lower atmosphere. The mechanism is the following; first, the gravity waves generated by the lower atmospheric disturbance propagate to the ionosphere; the neutral winds oscillate, cause ionospheric dynamo and Pedersen and Hall currents flow; because the dynamo region is finite, the currents cause polarized electric fields; and the polarized electric fields propagate along the geomagnetic filed as Alfven waves accompanied by field-aligned currents, at the same time, the ionospheric currents divert to

  13. Wind-driven changes of surface current, temperature, and chlorophyll observed by satellites north of New Guinea

    Science.gov (United States)

    Radenac, Marie-Hélène; Léger, Fabien; Messié, Monique; Dutrieux, Pierre; Menkes, Christophe; Eldin, Gérard

    2016-04-01

    Satellite observations of wind, sea level and derived currents, sea surface temperature (SST), and chlorophyll are used to expand our understanding of the physical and biological variability of the ocean surface north of New Guinea. Based on scarce cruise and mooring data, previous studies differentiated a trade wind situation (austral winter) when the New Guinea Coastal Current (NGCC) flows northwestward and a northwest monsoon situation (austral summer) when a coastal upwelling develops and the NGCC reverses. This circulation pattern is confirmed by satellite observations, except in Vitiaz Strait where the surface northwestward flow persists. We find that intraseasonal and seasonal time scale variations explain most of the variance north of New Guinea. SST and chlorophyll variabilities are mainly driven by two processes: penetration of Solomon Sea waters and coastal upwelling. In the trade wind situation, the NGCC transports cold Solomon Sea waters through Vitiaz Strait in a narrow vein hugging the coast. Coastal upwelling is generated in westerly wind situations (westerly wind event, northwest monsoon). Highly productive coastal waters are advected toward the equator and, during some westerly wind events, toward the eastern part of the warm pool. During El Niño, coastal upwelling events and northward penetration of Solomon Sea waters combine to influence SST and chlorophyll anomalies.

  14. Study on Fault Current of DFIG during Slight Fault Condition

    OpenAIRE

    Xiangping Kong; Zhe Zhang; Xianggen Yin; Zhenxing Li

    2013-01-01

    In order to ensure the safety of DFIG when severe fault happens, crowbar protection is adopted. But during slight fault condition, the crowbar protection will not trip, and the DFIG is still excited by AC-DC-AC converter. In this condition, operation characteristics of the converter have large influence on the fault current characteristics of DFIG. By theoretical analysis and digital simulation, the fault current characteristics of DFIG during slight voltage dips are studied. And the influenc...

  15. Evaluating Current and Future Rangeland Health in the Great Basin Ecoregion Using NASA Earth Observing Systems

    Science.gov (United States)

    Essoudry, E.; Wilson, K.; Ely, J.; Patadia, N.; Zajic, B.; Torres-Perez, J. L.; Schmidt, C.

    2014-12-01

    The Great Basin ecoregion in the western United States represents one of the last large expanses of wild lands in the nation and is currently facing significant challenges due to human impacts, drought, invasive species encroachment such as cheatgrass, and climate change. Rangelands in the Great Basin are of important ecological and economic significance for the United States; however, 40% of public rangelands fail to meet required health standards set by the Bureau of Land Management (BLM). This project provided a set of assessment tools for researchers and land managers that integrate remotely-sensed and in situ datasets to quantify and mitigate threats to public lands in the Great Basin ecoregion. The study area, which accounts for 20% of the total Great Basin ecoregion, was analyzed using 30 m resolution data from Landsat 8. Present conditions were evaluated from vegetation indices, landscape features, hydrological processes, and atmospheric conditions derived from the remotely-sensed data and validated with available in situ ground survey data, provided by the BLM. Rangeland health metrics were developed and landscape change drivers were identified. Subsequently, projected climate conditions derived from the Coupled Model Intercomparison Project (CMIP5) were used to forecast the impact of changing climatic conditions within the study area according to the RCP4.5 and RCP8.5 projections. These forecasted conditions were used in the Maximum Entropy Model (MaxEnt) to predict areas at risk for rangeland degradation on 30 year intervals for 2040, 2070, and 2100. Finally, vegetation health risk maps were provided to the project partners to aid in future land management decisions in the Great Basin ecoregion. These tools provide a low cost solution to assess landscape conditions, provide partners with a metric to identify potential problematic areas, and mitigate serious threats to the ecosystems.

  16. Polar mesosphere summer echoes (PMSE: Review of observations and current understanding

    Directory of Open Access Journals (Sweden)

    M. Rapp

    2004-01-01

    Full Text Available Polar mesosphere summer echoes (PMSE are very strong radar echoes primarily studied in the VHF wavelength range from altitudes close to the polar summer mesopause. Radar waves are scattered at irregularities in the radar refractive index which at mesopause altitudes is effectively determined by the electron number density. For efficient scatter, the electron number density must reveal structures at the radar half wavelength (Bragg condition for monostatic radars; ~3 m for typical VHF radars. The question how such small scale electron number density structures are created in the mesopause region has been a longstanding open scientific question for almost 30 years. This paper reviews experimental and theoretical milestones on the way to an advanced understanding of PMSE. Based on new experimental results from in situ observations with sounding rockets, ground based observations with radars and lidars, numerical simulations with microphysical models of the life cycle of mesospheric aerosol particles, and theoretical considerations regarding the diffusivity of electrons in the ice loaded complex plasma of the mesopause region, a consistent explanation for the generation of these radar echoes has been developed. The main idea is that mesospheric neutral air turbulence in combination with a significantly reduced electron diffusivity due to the presence of heavy charged ice aerosol particles (radii ~5–50 nm leads to the creation of structures at spatial scales significantly smaller than the inner scale of the neutral gas turbulent velocity field itself. Importantly, owing to their very low diffusivity, the plasma structures acquire a very long lifetime, i.e., 10 min to hours in the presence of particles with radii between 10 and 50 nm. This leads to a temporal decoupling of active neutral air turbulence and the existence of small scale plasma structures and PMSE and thus readily explains observations proving the absence of neutral air turbulence at

  17. Observation of Current Structures at Type-III ELM Onset on EAST

    DEFF Research Database (Denmark)

    Yan, Ning; Naulin, Volker; Xu, G.

    In far scrape-o layer (SOL), alternating negative and positive burst structures in ion saturation current were detected at the onset of each type-III edge localized mode (ELM) on EAST. Different from the fast streaming phenomenon reported previously, one subsequent positive burst structure appears...... led generated by scrape-off layer current can ultimately trigger the ELM through the coupling with MHD modes inside the separatrix....

  18. Long-term observations of Alaska Coastal Current in the northern Gulf of Alaska

    Science.gov (United States)

    Stabeno, Phyllis J.; Bell, Shaun; Cheng, Wei; Danielson, Seth; Kachel, Nancy B.; Mordy, Calvin W.

    2016-10-01

    The Alaska Coastal Current is a continuous, well-defined system extending for ~1700 km along the coast of Alaska from Seward, Alaska to Samalga Pass in the Aleutian Islands. The currents in this region are examined using data collected at >20 mooring sites and from >400 satellite-tracked drifters. While not continuous, the mooring data span a 30 year period (1984-2014). Using current meter data collected at a dozen mooring sites spread over four lines (Seward, Gore Point, Kennedy and Stevenson Entrances, and the exit to Shelikof Strait) total transport was calculated. Transport was significantly correlated with alongshore winds, although the correlation at the Seward Line was weak. The largest mean transport in the Alaska Coastal Current occurred at Gore Point (1.4×106 m3 s-1 in winter and 0.6×106 m3 s-1 in summer), with the transport at the exit to Shelikof Strait (1.3×106 m3 s-1 in winter and 0.6×106 m3 s-1 in summer) only slightly less. The transport was modified at the Seward Line in late summer and fall by frontal undulations associated with strong river discharge that enters onto the shelf at that time of year. The interaction of the Alaska Coastal Current and tidal currents with shallow banks in the vicinity of Kodiak Archipeligo and in Kennedy-Stevenson Entrance results in mixing and prolonged primary production throughout the summer.

  19. Seasonal Suspended Particles Distribution Patterns in Western South Yellow Sea Based on Acoustic Doppler Current Profiler Observation

    Institute of Scientific and Technical Information of China (English)

    LI Jianchao; LI Guangxue; XU Jishang; QIAO Lulu; DONG Ping; DING Dong; LIU Shidong

    2015-01-01

    An Acoustic Doppler Current Profiler (ADCP) observation site was set up in the Western South Yellow Sea from 2012 to 2013 to study the local suspended particle matters (SPM) distribution pattern. The SPM concentration could be semi-quantitatively represented by backscatter intensity (Sv), converted by the echo intensity (EI) of ADCP. Results show two types of SPM in the water column: the quasi-biological SPM and quasi-mineral SPM. The quasi-biological SPM mainly exists in summer half year and is con-centrated above the thermocline. It has periodically diurnal variations with high concentration at night and low concentration in the daytime. The quasi-mineral SPM is located in lower part of the water column, with similar relation to monthly tidal current variation all year round. However, the daily quasi-mineral SPM distribution patterns vary between summer and winter half year. The sunlight is thought to be the origin factor leading to the diurnally vertical motion of the biological features, which might cause the diurnalSv variation. Unlike in winter half year when tidal current is relatively single driving force of the monthly SPM pattern, the high speed current near the thermocline is also responsible for the concentration of quasi-mineral SPM in summer half year. The sediment input difference between summer and winter half year contribute to the varied daily variation of quasi-mineral SPM with re-suspended SPM in winter and sediments from Yellow Sea Mud Area (YSMA) in summer. The seasonal variations in hydrodynamics, water structure and heavy-wind incidents are the primary factors influencing the differential seasonal SPM distribution patterns.

  20. Critical current studies of a HTS rectangular coil

    Energy Technology Data Exchange (ETDEWEB)

    Zhong, Z. [Department of Engineering, University of Cambridge (United Kingdom); Chudy, M., E-mail: Michal.chudy@stuba.sk [Graduate School of Technology Management, University of Pretoria (South Africa); Institute of Power and Applied Electrical Engineering, Slovak University of Technology in Bratislava (Slovakia); Ruiz, H.S. [Department of Engineering, University of Leicester, Leicester LE1 7RH (United Kingdom); Zhang, X.; Coombs, T. [Department of Engineering, University of Cambridge (United Kingdom)

    2017-05-15

    Highlights: • Unique square pancake coil was manufactured. • Measurements in relatively high magnetic field were performed. • Different sections of the coil were characterized. • Parts of the coil which are limiting critical current were identified. - Abstract: Nowadays, superconducting high field magnets are used in numerous applications due to their superior properties. High temperature superconductors (HTS) are usually used for production of circular pancake or racetrack coils. However different geometries of HTS coils might be required for some specific applications. In this study, the HTS coil wound on a rectangular frame was fully characterized in homogeneous DC background field. The study contains measurements of critical current angular dependencies. The critical current of the entire coil and two selected strands under different magnitudes and orientations of external magnetic fields are measured. The critical regions of the coil in different angular regimes are determined. This study brings better understanding of the in- field performance of HTS coils wound on frames with right-angles.

  1. Potential New Lidar Observations for Cloud Studies

    Science.gov (United States)

    Winker, Dave; Hu, Yong; Narir, Amin; Cai, Xia

    2015-01-01

    The response of clouds to global warming represents a major uncertainty in estimating climate sensitivity. These uncertainties have been tracked to shallow marine clouds in the tropics and subtropics. CALIOP observations have already been used extensively to evaluate model predictions of shallow cloud fraction and top height (Leahy et al. 2013; Nam et al 2012). Tools are needed to probe the lowest levels of the troposphere. The large footprint of satellite lidars gives large multiple scattering from clouds which presents new possibilities for cloud retrievals to constrain model predictions.

  2. Summertime coastal current reversal opposing offshore forcing and local wind near the middle east coast of Korea: Observation and dynamics

    Science.gov (United States)

    Park, Jae-Hyoung; Chang, Kyung-Il; Nam, SungHyun

    2016-07-01

    A 6 year long current measurement at a buoy station off the middle east coast of Korea reveals an equatorward reversal of coastal current in summer opposing poleward local wind stress and offshore boundary current. The current reversal extends about 40 km offshore from the coast and is concurrent with warming and freshening of water column. Estimates of the depth-averaged alongshore momentum balance suggest a major balance between the alongshore pressure gradient and the lateral friction. Sources of the pressure gradient for the summertime current reversal are identified as the alongshore buoyancy gradient driven by the wind curl gradient and the prevalence of warmer and lower salinity water in the north. Alongshore pressure gradient and velocity induced by the wind curl gradient are quantified, which yields the observed seasonal current reversal.

  3. An Isopycnic Coordinate Numerical Model of the Agulhas Current with Comparison to Observations

    Science.gov (United States)

    1990-12-01

    text 71 Numerical modeling of the Agulhas Current in a limited domain begun by Boudra and Chassignet (1988) is extended. First, five experiments...satellite SST images are of limited use after the rings have propagated into the Atlantic. Recently, however, satellite measurements of sea surface height...eddy activity occurs just southeast of the African tip. 49 -- 1. 13.3 CMISEC MOODL -mcW¢c 1 13.3 CMISEC CURRENT METER -- is CM’IC A REGIONAL MOO)FI. OF

  4. Direct observation of current-induced conductive path in colossal-electroresistance manganite thin films

    Science.gov (United States)

    Wei, Wengang; Zhu, Yinyan; Bai, Yu; Liu, Hao; Du, Kai; Zhang, Kai; Kou, Yunfang; Shao, Jian; Wang, Wenbin; Hou, Denglu; Dong, Shuai; Yin, Lifeng; Shen, Jian

    2016-01-01

    Manganites are known to often show colossal electroresistance (CER) in addition to colossal magnetoresistance. The (La1-yP ry) 1 -xC axMn O3 (LPCMO) system has a peculiar CER behavior in that little change of magnetization occurs. We use a magnetic force microscope to uncover the CER mechanism in the LPCMO system. In contrast to the previous belief that current reshapes the ferromagnetic metallic (FMM) domains, we show that the shape of the FMM domains remain virtually unchanged after passing electric current. Instead, it is the appearance of a tiny fraction of FMM "bridges" that is responsible for the CER behavior.

  5. Geomagnetic Observations for Main Field Studies

    DEFF Research Database (Denmark)

    Matzka, Jürgen; Chulliat, A.; Mandea, M.

    2010-01-01

    Direct measurements of the geomagnetic field have been made for more than 400 years, beginning with individual determinations of the angle between geographic and magnetic North. This was followed by the start of continuous time series of full vector measurements at geomagnetic observatories and t...... for magnetic field measurements on ground and in space and covers geomagnetic observatories, repeat stations, automatic observatories, satellites and historic observations. Special emphasis is laid on the global network of geomagnetic observatories....... and the beginning of geomagnetic repeat stations surveys in the 19th century. In the second half of the 20th century, true global coverage with geomagnetic field measurements was accomplished by magnetometer payloads on low-Earth-orbiting satellites. This article describes the procedures and instruments...

  6. Current Awareness Services--Observations of the Past and Present, and Implications for the Future

    Science.gov (United States)

    Brandli, Michael J.

    1976-01-01

    A brief history of the College of Medicine and Dentistry of New Jersey Library's current awareness service shows the progression from manual participation, to an on-line system, and finally to access of the State University of New York's Automatic MEDLARS service. (Author)

  7. Observed low-frequency currents in the deep mid-Arabian sea

    Digital Repository Service at National Institute of Oceanography (India)

    Shetye, S.R.; Shenoi, S.S.C.; Sundar, D.

    . MEaxz (1984) A 40- to 60-day oscillation in the source region of the Somali current during 1976. Journal of Geophysical Research, 89, 711-715. NAIR R. R., V. ITrEKKOT, S. J. MANGININI, V. RAMASWAMY, B. HAAKE, E. T. DEGENS, B. N. DESAI and S. Homo...

  8. Cost-of-illness studies : a review of current methods.

    Science.gov (United States)

    Akobundu, Ebere; Ju, Jing; Blatt, Lisa; Mullins, C Daniel

    2006-01-01

    The number of cost-of-illness (COI) studies has expanded considerably over time. One outcome of this growth is that the reported COI estimates are inconsistent across studies, thereby raising concerns over the validity of the estimates and methods. Several factors have been identified in the literature as reasons for the observed variation in COI estimates. To date, the variation in the methods used to calculate costs has not been examined in great detail even though the variations in methods are a major driver of variation in COI estimates. The objective of this review was to document the variation in the methodologies employed in COI studies and to highlight the benefits and limitations of these methods. The review of COI studies was implemented following a four-step procedure: (i) a structured literature search of MEDLINE, JSTOR and EconLit; (ii) a review of abstracts using pre-defined inclusion and exclusion criteria; (iii) a full-text review using pre-defined inclusion and exclusion criteria; and (iv) classification of articles according to the methods used to calculate costs. This review identified four COI estimation methods (Sum_All Medical, Sum_Diagnosis Specific, Matched Control and Regression) that were used in categorising articles. Also, six components of direct medical costs and five components of indirect/non-medical costs were identified and used in categorising articles.365 full-length articles were reflected in the current review following the structured literature search. The top five cost components were emergency room/inpatient hospital costs, outpatient physician costs, drug costs, productivity losses and laboratory costs. The dominant method, Sum_Diagnosis Specific, was a total costing approach that restricted the summation of medical expenditures to those related to a diagnosis of the disease of interest. There was considerable variation in the methods used within disease subcategories. In several disease subcategories (e.g. asthma, dementia

  9. Cutaneous hypopigmentary disorders – An observational study

    Directory of Open Access Journals (Sweden)

    Kalegowda Deepadarshan

    2016-04-01

    Full Text Available Background: Hypopigmented skin lesions is very common among people of all age groups. There are limited studies in India about evaluation of hypopigmented skin conditions. The aim of my study is to evaluate the different etiologies of cutaneous hypopigmentation. Aim: The present study was undertaken to find the relative incidence of the various disorders causing a hypopigmented lesion in a random sample of 200 cases and to study site, distribution and characteristics of the lesions. Methods: A random sample of 200 patients presenting with one or more hypopigmented lesions to the outpatient department of Dermatology, Venereology and Leprosy in KVG Medical College and Hospital, Sullia from December 2011 to January 2013 was studied. Detailed history including address and occupation with special reference to onset and duration, preceding skin conditions, exposure to chemicals, topical application and family history was taken. Various characteristics of the lesion like site, size, number, distribution, surface and sensation were studied. After this samples were taken for relevant investigations like complete hemogram, biopsy, slit skin smear, KOH mount and assessed for the causes of hypopigmented lesions. Results: In our study, most common cause with cutaneous hypopigmentation was pityriasis versicolor, seen in 52%, followed by post inflammatory hypopigmentation in 32%, pre vitiligo in 6.5%, Hansen’s disease, idiopathic guttate hypomelanosis, nevus anemicus each in 2%, Woronoff’s ring in 1.5% and miscellaneous conditions in 2% of the cases. Commonest age group affected was 21-30 years. Males (49% and females (51% were almost equally affected. Conclusion: The study concludes that various conditions comes under hypopigmentary disorders. More common in young adults. Most common scaly condition was pityriasis versicolor and non scaly condition was pre vitiligo. Proper counseling and ruling out Hansen’s disease is required to alleviate the patient

  10. Observing the Agulhas Current with sea surface temperature and altimetry data: challenges and perspectives

    CSIR Research Space (South Africa)

    Krug, Marjolaine, J

    2014-06-01

    Full Text Available -Red Sea Surface Temperature datasets still suffer from inadequate cloud masking algorithms, particularly in regions of strong temperature gradient. Despite both Sea Surface Height and Sea Surface Temperature observations being severely compromised...

  11. Adaptive current compensation with nonlinear disturbance observer for single-sided linear induction motor considering dynamic eddy-effect

    Institute of Scientific and Technical Information of China (English)

    DENG Jiang-ming; CHEN Te-fang; CHEN Chun-yang

    2015-01-01

    An adaptive current compensation control for a single-sided linear induction motor (SLIM) with nonlinear disturbance observer was developed. First, to maintaint-axis secondary component flux constant with consideration of the specially dynamic eddy-effect (DEE) of the SLIM, a instantaneously tracing compensation ofm-axis current component was analyzed. Second, adaptive current compensation based on Taylor-discretization algorithm was proposed. Third, an effective kind of nonlinear disturbance observer (NDOB) was employed to estimate and compensate the undesired load vibrations, then the robustness of the control system could be guaranteed. Experimental verification of the feasibility of the proposed method for an SLIM control system was performed, and it showed that the proposed adaptive compensation scheme with NDOB could significantly promote speed dynamical response and minimize speed ripple under the conditions of external load coupled vibrations and unavoidable feedback control variables measured errors, i.e., current and speed.

  12. Current research projects on traffic conflicts technique studies.

    NARCIS (Netherlands)

    Hondel, M. van den & and Kraay, J.H.

    1979-01-01

    A review of current research concerning the development, evaluation and use of the traffic conflicts technique is presented. The 32 studies, selected from the IRRD data base, are listed alphabetically by names of countries and under countries by names of research organizations. The IRRD descriptions

  13. Subminiature eddy current transducers for studying boride coatings

    Science.gov (United States)

    Dmitriev, S. F.; Ishkov, A. V.; Malikov, V. N.; Sagalakov, A. M.

    2016-07-01

    Strengthening of parts and units of machines, increased reliability and longer service life is an important task of modern mechanical engineering. The main objects of study in the work were selected steel 65G and 50HGA, wear-resistant boride coatings ternary system Fe-B-Fe n B which were investigated by scanning electron microscopy and eddy-current nondestructive methods.

  14. A study of eddy current measurement (1986-1987)

    Energy Technology Data Exchange (ETDEWEB)

    Ramachandran, R.S.; Armstrong, K.P.

    1989-06-22

    A study was conducted in 1986 to evaluate a modified eddy current system for measuring copper thickness on Kapton. Results showed a measurement error of 0.42 {mu}in. for a thickness range of 165 to 170 {mu}in. and a measurement variability of 3.2 {mu}in.

  15. Cartography and Population Geography as Current Events: A Case Study

    Science.gov (United States)

    Comenetz, Joshua

    2003-01-01

    The Sanders housing lawsuit in Pennsylvania provides a case study of how to incorporate current events into the teaching of cartography or population geography at the high school or college level. Settlement of the Sanders case resulted in the release of information about the segregation of public housing by race in the Pittsburgh area. The issues…

  16. High latitude currents in the 0600 to 0900 MLT sector - Observations from Viking and DMSP-F7

    Science.gov (United States)

    Bythrow, P. F.; Potemra, T. A.; Zanetti, L. J.; Erlandson, R. A.; Hardy, D. A.; Rich, F. J.; Acuna, M. H.

    1987-01-01

    High-resolution magnetic field and charged-particle data acquired on March 25, 1986 by the Viking and DMSP-F7 satellites, as they traversed the dawn sector auroral zone on nearly antiparallel trajectories within 40 min of each oher, are analyzed. Magnetic field measurements by Viking at 0850 MLT and by DMSP at 0630 MLT indicate the presence of a large-scale earthward-directed region 1 Birkeland current and an upward-flowing region 2 current. Both satellites also observed a third Birkeland current adjacent to and poleward of the region 1 system with opposite flow. This poleward system is about 0.5 deg invariant latitude wide and has a current density comparable to the region 1 and 2 systems. The highest-latitude current is identified as region 0. Its charged-particle signatures were used to infer field line mapping to the equatorial plane.

  17. Refractory status epilepticus: a prospective observational study.

    Science.gov (United States)

    Novy, Jan; Logroscino, Giancarlo; Rossetti, Andrea O

    2010-02-01

    Status epilepticus (SE) that is resistant to two antiepileptic compounds is defined as refractory status epilepticus (RSE). In the few available retrospective studies, estimated RSE frequency is between 31% and 43% of patients presenting an SE episode; almost all seem to require a coma induction for treatment. We prospectively assessed RSE frequency, clinical predictors, and outcome in a tertiary clinical setting. Over 2 years we collected 128 consecutive SE episodes (118 patients) in adults. Clinical data and their relationship to outcome (mortality and return to baseline clinical conditions) were analyzed. Twenty-nine of 128 SE episodes (22.6%) were refractory to first- and second-line antiepileptic treatments. Severity of consciousness impairment and de novo episodes were independent predictors of RSE. RSE showed a worse outcome than non-RSE (39% vs. 11% for mortality; 21% vs. 63% for return to baseline clinical conditions). Only 12 patients with RSE (41%) required coma induction for treatment. This prospective study identifies clinical factors predicting the onset of SE refractoriness. RSE appears to be less frequent than previously reported in retrospective studies; furthermore, most RSE episodes were treated outside the intensive care unit (ICU). Nonetheless, we confirm that RSE is characterized by high mortality and morbidity.

  18. Differential Thermostimulated Discharge Current Method for Studying Electrets

    Science.gov (United States)

    Mekishev, G. A.; Yovcheva, T. A.; Viraneva, A. P.; Gencheva, E. A.

    2010-01-01

    The thermostimulated discharge current method (TSDC) is widely used for the study of charge storage mechanisms in electrets. A new discharged technique, called differential, which consists in discharging a charged sample through an otherwise identical but uncharged one, has been proposed by J.-P. Reboul and A. Toureille. In the present paper a new version of the differential thermostimulated discharge current method is advanced. In contrast to the differential technique described earlier, the measuring cell allows to realize typical differential technique. In this case the measuring system records the difference of the thermostimulated currents of two samples which have been preliminary charged (or thermally treated) under the same or different conditions. Samples of 0.85 mm thick polymethylmethacrylate are used to demonstrate an operation of the developed differential TSDC method.

  19. Study on Fault Current of DFIG during Slight Fault Condition

    Directory of Open Access Journals (Sweden)

    Xiangping Kong

    2013-04-01

    Full Text Available In order to ensure the safety of DFIG when severe fault happens, crowbar protection is adopted. But during slight fault condition, the crowbar protection will not trip, and the DFIG is still excited by AC-DC-AC converter. In this condition, operation characteristics of the converter have large influence on the fault current characteristics of DFIG. By theoretical analysis and digital simulation, the fault current characteristics of DFIG during slight voltage dips are studied. And the influence of controller parameters of converter on the fault current characteristics is analyzed emphatically. It builds a basis for the construction of relay protection which is suitable for the power gird with accession of DFIG.

  20. Pandemrix™ and narcolepsy: A critical appraisal of the observational studies.

    Science.gov (United States)

    Verstraeten, Thomas; Cohet, Catherine; Dos Santos, Gaël; Ferreira, Germano Lc; Bollaerts, Kaatje; Bauchau, Vincent; Shinde, Vivek

    2016-01-01

    A link between Pandemrix™ (AS03-adjuvanted H1N1 pandemic influenza vaccine, GSK Vaccines, Belgium) and narcolepsy was first suspected in 2010 in Sweden and Finland following a number of reports in children and adolescents. Initial scepticism about the reported association faded as additional countries reported similar findings, leading several regulatory authorities to restrict the use of Pandemrix™. The authors acknowledge that currently available data suggest an increased risk of narcolepsy following vaccination with Pandemrix™; however, from an epidemiologist's perspective, significant methodological limitations of the studies have not been fully addressed and raise questions about the reported risk estimates. We review the most important biases and confounders that potentially occurred in 12 European studies of the observed association between Pandemrix™ and narcolepsy, and call for further analyses and debate.

  1. Observed tidal currents on the continental shelf off the west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Subeesh, M.P.; Unnikrishnan, A.S.; Fernando, V.; Agarwadekar, Y.; Khalap, S.T.; Satelkar, N.P.; Shenoi, S.S.C.

    . The observations extended over a 6-month period (March–August), which includes two seasons, pre-monsoon (March–April) and southwest (SW) monsoon (May–August) during 2008, 2009 and 2011. Tidal ellipses, constructed for M2 and K1 constituents...

  2. Management of rheumatic chorea: an observational study

    Directory of Open Access Journals (Sweden)

    Araújo Alexandra Prufer de Queiroz Campos

    2002-01-01

    Full Text Available BACKGROUND: Rheumatic chorea (RC has recently been linked to an antibody-mediated immune mechanism. OBJECTIVE/METHOD: To verify if this knowledge reflected in management changes we conceived a descriptive study. RESULTS: The medical charts of 20 children (13 females aged 6 to 12 years (mean 8 years, diagnosed as RC from June 1996 to June 1999, were reviewed. All patients received some medical treatment. Haloperidol was the most prescribed medication (15 patients - 75 %. Sulpiride, diazepam and valproate were also used as symptomatic treatment. Imune-modulating therapy with prednisone was prescribed for seven children. The shortest course of chorea (16 days occurred in a patient treated with prednisone. CONCLUSION: Prednisone has been prescribed for rheumatic chorea besides the traditional symptomatic approach. A great variety of antichoreic drugs are being employed.

  3. Eddies on the boundary between the Kuroshio current and coastal waters observed by HF ocean surface radar

    Science.gov (United States)

    Nadai, A.

    2016-02-01

    The HF ocean surface radar (HFOSR) is one of the powerful tools to measure the ocean current parameters like surface currents. Three observations of the Kuroshio current in the Tokara straight using HFOSR had done by the National Institute of Information and Comunications Technology (NICT: the former name is the Communications Research Laboratory). The first-order echoes on Doppler spectra of HFOSR shows broaden and splitting shape in the region of the border between the Kuroshio currents and coastal waters. The surface velocity maps show the existence of eddy on the border. The investigation of the mechanism of broadening first order-echoes by Nadai (2006) revealed that the modulation of wave fields from surface currents like eddy is the cause of broadening and the measured current fields also influenced the modulated wave fields. Moreover, Nadai (2006) also suggested that the influence is able to reduce using the average of two radial velocities extracted by the first-order echoes. In this paper, the results of current field observation around the border between the Kuroshio current and coastal waters are presented. Many small scale eddies are observed at the border of the Kuroshio current and coastal waters. The typical radius of the eddies is about 10km. Usury the observation of such a small scale eddy is difficult, but the eddies with same scale are observed by airborne synthetic aperture radar in the same area at different time. The eddies shows strong rotation as the typical tangential speed is about 1m/s. While the typical speed of the Kuroshio current is about 1.5m/s, the typical speed of the eddy movements is about 0.7m/s. No eddies generated in the radar coverage, but one or two eddies entered in the radar coverage a day. Therefore the origin of these eddies will exist in the upstream area of the radar coverage. Using the compensation method for the influence of the modulated wave field suggested by Nadai (2006), the eddies shows weak divergence. It is

  4. Infectious bronchitis in Brazilian chickens: current data and observations of field service personnel

    Directory of Open Access Journals (Sweden)

    EN Silva

    2010-09-01

    Full Text Available The infectious bronchitis virus (IBV was detected for the first time in Brazil by Hipólito in 1957 in chickens sold life in the municipal market of Belo Horizonte, MG, when commercial poultry production was just starting in that country. The Massachusetts (Mass serotype was identified. However, the clinical disease was only observed in 1975, when poultry production was intensely growing. The extensive outbreak produced the classical condition in layers and breeders, affecting egg production and quality, whereas broilers presented respiratory and "nephritis-nephrosis" signs. The disease rapidly spread to all poultry-producing regions in the country, and in 1979, both the imports and the manufacturing of live vaccines against IB strains Mass, H120 and H52, were licensed. In 1980, inactivated vaccines were introduced. Molecular techniques, particularly PCR, started to bed in the identification of IBV. A retrospective analysis showed that, up to 1989, the main IBV strain circulating in Brazil was Mass. However, other studies shows the presence of a wide diversity of IBV strains in Brazil since the first strains were isolated, even before vaccination was introduced. Most researchers agree that the incidence of IBV different from Mass has increased, including of exclusively Brazilian genotypes, different from those described in other countries. Indeed, during the last few years, the number of genotypical variants has been much higher than that of the classical Mass serotype. Clinically, in addition of the classic presentations, atypical forms such as testicular atrophy and stones in the epidydimis associated to low fertility have been described. Serological techniques started to be used in vaccination monitoring and as a diagnostic tool. Serological response standards were developed, and have shown to be very useful to determine the expected profile in vaccination programs and when clinical disease is suspected. However, the immuno-enzymatic test

  5. Experimental Study on Current Decay Characteristics of Persistent Current HTS Magnet by Alternating Magnetic Field

    Science.gov (United States)

    Park, Young Gun; Lee, Chang Young; Hwang, Young Jin; Lee, Woo Seung; Lee, Jiho; Jo, Hyun Chul; Chung, Yoon Do; Ko, Tae Kuk

    This paper deals with a current decay characteristics of a high temperature superconducting (HTS) magnet operated in persistent current mode (PCM). In superconducting synchronous machine applications such as linear synchronous motor (LSM), the superconducting coil is designed to operate in the PCM to obtain steady magnetic field with DC transport current. This superconducting magnet operates on a direct current, but it can be exposed to alternating magnetic field due to the armature winding. When the magnet is subjected to an external time-varying magnetic field, it is possible to result in a decay of the current in PCM system due to AC loss. In this research, a PCM system with armature coil which generates time-varying magnetic field was fabricated to verify current decay characteristics by external alternating magnetic field. The current decay rate was measured by using a hall sensor as functions of amplitude and frequency of armature coil.

  6. Improving Aerosol and Visibility Forecasting Capabilities Using Current and Future Generations of Satellite Observations

    Science.gov (United States)

    2015-08-27

    indicate that the assimilation of satellite observations significantly improves NAAPS aerosol forecasting capability and reliability. To fully utilize...method derives a semi-quantitative indicator of nighttime x using artificial light sources. Nighttime x retrievals from the newly-developed method are...Kemper, T. Craig, I. Ginis , Evaluation of Maine aerosol production simulated using the WaveWatchlll prognostic Wave Model coupled to the Community

  7. Quintessence versus phantom dark energy: the arbitrating power of current and future observations

    CERN Document Server

    Novosyadlyj, B; Durrer, R; Pelykh, V

    2013-01-01

    We analyze the possibility to distinguish between quintessence and phantom scalar field models of dark energy using observations of luminosity distance moduli of SNe Ia, CMB anisotropies and polarization, matter density perturbations and baryon acoustic oscillations. None of the present observations can decide between quintessence or phantom scalar field models at a statistically significant level: for each model a set of best-fit parameters exists, which matches all data with similar goodness of fit. We compare the relative differences of best-fit model predictions with observational uncertainties for each type of data and we show that the accuracy of SNe Ia luminosity distance data is far from the one necessary to distinguish these types of dark energy models, while the CMB data (WMAP, SPT and Planck) are close to being able to distinguish them. Also a significant improvement of the large-scale structure data (e.g. Euclid or BigBOSS) will enable us to decide between quintessence and phantom dark energy.

  8. An auroral westward flow channel (AWFC and its relationship to field-aligned current, ring current, and plasmapause location determined using multiple spacecraft observations

    Directory of Open Access Journals (Sweden)

    M. L. Parkinson

    2007-02-01

    Full Text Available An auroral westward flow channel (AWFC is a latitudinally narrow channel of unstable F-region plasma with intense westward drift in the dusk-to-midnight sector ionosphere. AWFCs tend to overlap the equatorward edge of the auroral oval, and their life cycle is often synchronised to that of substorms: they commence close to substorm expansion phase onset, intensify during the expansion phase, and then decay during the recovery phase. Here we define for the first time the relationship between an AWFC, large-scale field-aligned current (FAC, the ring current, and plasmapause location. The Tasman International Geospace Environment Radar (TIGER, a Southern Hemisphere HF SuperDARN radar, observed a jet-like AWFC during ~08:35 to 13:28 UT on 7 April 2001. The initiation of the AWFC was preceded by a band of equatorward expanding ionospheric scatter (BEES which conveyed an intense poleward electric field through the inner plasma sheet. Unlike previous AWFCs, this event was not associated with a distinct substorm surge; rather it occurred during an interval of persistent, moderate magnetic activity characterised by AL~−200 nT. The four Cluster spacecraft had perigees within the dusk sector plasmasphere, and their trajectories were magnetically conjugate to the radar observations. The Waves of High frequency and Sounder for Probing Electron density by Relaxation (WHISPER instruments on board Cluster were used to identify the plasmapause location. The Imager for Magnetopause-to-Aurora Global Exploration (IMAGE EUV experiment also provided global-scale observations of the plasmapause. The Cluster fluxgate magnetometers (FGM provided successive measurements specifying the relative location of the ring current and filamentary plasma sheet current. An analysis of Iridium spacecraft magnetometer measurements provided estimates of large-scale ionospheric FAC in relation to the AWFC evolution. Peak flows in the AWFC were located close to the peak of a Region 2

  9. Thermally stimulated current observation of trapping centers in undoped GaSe layered single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Gasanly, N.M.; Salihoglu, Oe. [Middle East Technical Univ., Ankara (Turkey). Dept. of Physics; Aydinli, A. [Middle East Technical Univ., Ankara (Turkey). Dept. of Physics; Bilkent Univ., Ankara (Turkey). Dept. of Physics

    2001-07-01

    Undoped p-GaSe layered single crystals were grown using Bridgman technique. Thermally stimulated current measurements in the temperature range of 10-300 K were performed at a heating rate of 0.18 K/s. The analysis of the data revealed three trap levels at 0.02, 0.10 and 0.26 eV. The calculation for these traps yielded 8.8 x 10{sup -27}, 1.9 x 10{sup -25}, and 3.2 x 10{sup -21} cm{sup 2} for capture cross sections and 3.2 x 10{sup 14}, 1.1 x 10{sup 16}, and 1.2 x 10{sup 16} cm{sup -3} for the concentrations, respectively. (orig.)

  10. Electric double layer effect on observable characteristics of the tunnel current through a bridged electrochemical contact

    DEFF Research Database (Denmark)

    Kuznetsov, A.M.; Medvedev, I.G.; Ulstrup, Jens

    2007-01-01

    Scanning tunneling microscopy and electrical conductivity of redox molecules in conducting media (aqueous or other media) acquire increasing importance both as novel single-molecule science and with a view on molecular scale functional elements. Such configurations require full and independent....../overpotential relation shows a maximum at a position which depends on the ionic strength. It is shown, in particular, that the dependence of the maximum position on the bias voltage may be nonmonotonous. Approximate expressions for the limiting value of the slope of the current/overpotential dependence and the width...... of the maximum on the bias voltage are also given and found to depend strongly on both the Debye screening and the position of the redox group in the tunnel gap, with diagnostic value in experimental data analysis....

  11. Observed air-sea interactions in tropical cyclone Isaac over Loop Current mesoscale eddy features

    Science.gov (United States)

    Jaimes, Benjamin; Shay, Lynn K.; Brewster, Jodi K.

    2016-12-01

    Air-sea interactions during the intensification of tropical storm Isaac (2012) into a hurricane, over warm oceanic mesoscale eddy features, are investigated using airborne oceanographic and atmospheric profilers. Understanding these complex interactions is critical to correctly evaluating and predicting storm effects on marine and coastal facilities in the Gulf of Mexico, wind-driven mixing and transport of suspended matter throughout the water column, and oceanic feedbacks on storm intensity. Isaac strengthened as it moved over a Loop Current warm-core eddy (WCE) where sea surface warming (positive feedback mechanism) of ∼0.5 °C was measured over a 12-h interval. Enhanced bulk enthalpy fluxes were estimated during this intensification stage due to an increase in moisture disequilibrium between the ocean and atmosphere. These results support the hypothesis that enhanced buoyant forcing from the ocean is an important intensification mechanism in tropical cyclones over warm oceanic mesoscale eddy features. Larger values in equivalent potential temperature (θE = 365   ∘K) were measured inside the hurricane boundary layer (HBL) over the WCE, where the vertical shear in horizontal currents (δV) remained stable and the ensuing cooling vertical mixing was negligible; smaller values in θE (355   ∘K) were measured over an oceanic frontal cyclone, where vertical mixing and upper-ocean cooling were more intense due to instability development in δV . Thus, correctly representing oceanic mesoscale eddy features in coupled numerical models is important to accurately reproduce oceanic responses to tropical cyclone forcing, as well as the contrasting thermodynamic forcing of the HBL that often causes storm intensity fluctuations over these warm oceanic regimes.

  12. Current methods for studying dynamic processes in the ionosphere

    Science.gov (United States)

    Filipp, Nikolai D.; Blaunshtein, Natan Sh.; Erukhimov, Lev M.; Ivanov, Vladimir A.; Uriadov, Valerii P.

    Current experimental and theoretical data relevant to the study of dynamic processes in the ionospheric plasma using state-of-the-art methods are summarized. The methods used include linear FM sounding, partial radio wave reflection, oblique-incidence radio wave scattering, radio wave heating of the ionosphere, plasma injection, and computer simulation of physical processes. For each specific method, experimental data are compared against theoretical predictions and numerical calculations.

  13. Pancreatic exocrine studies in intact animals: historic and current methods.

    Science.gov (United States)

    Niebergall-Roth, E; Teyssen, S; Singer, M V

    1997-12-01

    This report presents a review of the historic and current methods for performing pancreatic exocrine studies in intact animals. Special emphasis is given to the various surgical procedures--pancreatic fistulas, duodenal pouches, and duodenal fistulas--and practice of collecting pancreatic secretion in dogs. Procedures in other animal species--rat, cat, pig, rabbit, cattle, sheep, and horse--also are specified. The advantages and disadvantages, as well as the indications and limitations of the distinct methods, are discussed.

  14. How safe do teenagers behave on Facebook? An observational study.

    Science.gov (United States)

    Vanderhoven, Ellen; Schellens, Tammy; Valcke, Martin; Raes, Annelies

    2014-01-01

    The substantial use of social network sites by teenagers has raised concerns about privacy and security. Previous research about behavior on social network sites was mostly based on surveys and interviews. Observational research overcomes problems inherent to this research method, for example social desirability. However, existing observational research mostly focuses on public profiles of young adults. Therefore, the current observation-study includes 1050 public and non-public Facebook-profiles of teenagers (13-18) to investigate (1) what kind of information teenagers post on their profile, (2) to what extent they protect this information using privacy-settings and (3) how much risky information they have on their profile. It was found that young people mostly post pictures, interests and some basic personal information on their profile. Some of them manage their privacy-settings as such that this information is reserved for friends' eyes only, but a lot of information is accessible on the friends-of-friends' pages. Although general risk scores are rather low, more detailed analyses show that teenagers nevertheless post a significant amount of risky information. Moreover, older teenagers and girls post more (risky) information while there are no differences in applying privacy settings. We found no differences in the Facebook behavior of teenagers enrolled in different education forms. Implications of these results are discussed.

  15. Current Sounding Capability From Satellite Meteorological Observation With Ultraspectral Infrared Instruments

    Science.gov (United States)

    Zhou, Daniel K.; Liu, Xu; Larar, Allen M.

    2008-01-01

    Ultraspectral resolution infrared spectral radiance obtained from near nadir observations provide atmospheric, surface, and cloud property information. The intent of the measurement of tropospheric thermodynamic state and trace abundances is the initialization of climate models and the monitoring of air quality. The NPOESS Airborne Sounder Testbed-Interferometer (NAST-I), designed to support the development of future satellite temperature and moisture sounders, aboard high altitude aircraft has been collecting data throughout many field campaigns. An advanced retrieval algorithm developed with NAST-I is now applied to satellite data collected with the Atmospheric InfraRed Sounder (AIRS) on the Aqua satellite launched on 4 May 2002 and the Infrared Atmospheric Sounding Interferometer (IASI) on the MetOp satellite launched on October 19, 2006. These instruments possess an ultra-spectral resolution, for example, both IASI and NAST-I have 0.25 cm-1 and a spectral coverage from 645 to 2760 cm-1. The retrieval algorithm with a fast radiative transfer model, including cloud effects, is used for atmospheric profile and cloud parameter retrieval. The physical inversion scheme has been developed, dealing with cloudy as well as cloud-free radiance observed with ultraspectral infrared sounders, to simultaneously retrieve surface, atmospheric thermodynamic, and cloud microphysical parameters. A fast radiative transfer model, which applies to the clouded atmosphere, is used for atmospheric profile and cloud parameter retrieval. A one-dimensional (1-d) variational multi-variable inversion solution is used to improve an iterative background state defined by an eigenvector-regression-retrieval. The solution is iterated in order to account for non-linearity in the 1-d variational solution. It is shown that relatively accurate temperature and moisture retrievals can be achieved below optically thin clouds. For optically thick clouds, accurate temperature and moisture profiles down to

  16. Current and Density Observations of Packets of Nonlinear Internal Waves on the Outer New Jersey Shelf

    Science.gov (United States)

    2011-05-01

    continental shelf 16. SECURITY CLASSIFICATION OF: a. REPORT Unclassified b. ABSTRACT Unclassified c. THIS PAGE Unclassified 17. LIMITATION OF... decimal day. The number of events observed at each location is shown. Case/day Al A2 A3 A4 SI S2 Level tow 1/170.3 2 2 2 II/170.7 3 3 3 3 II1...Klymak and Mourn 2003: Dewey and Crawford 1988). Richardson number Ri calculations based on the den- sity profiles from the siring moorings (SI, S2) and

  17. Electrostatic solitary waves in current layers: from Cluster observations during a super-substorm to beam experiments at the LAPD

    Directory of Open Access Journals (Sweden)

    J. S. Pickett

    2009-06-01

    Full Text Available Electrostatic Solitary Waves (ESWs have been observed by several spacecraft in the current layers of Earth's magnetosphere since 1982. ESWs are manifested as isolated pulses (one wave period in the high time resolution waveform data obtained on these spacecraft. They are thus nonlinear structures generated out of nonlinear instabilities and processes. We report the first observations of ESWs associated with the onset of a super-substorm that occurred on 24 August 2005 while the Cluster spacecraft were located in the magnetotail at around 18–19 RE and moving northward from the plasma sheet to the lobes. These ESWs were detected in the waveform data of the WBD plasma wave receiver on three of the Cluster spacecraft. The majority of the ESWs were detected about 5 min after the super-substorm onset during which time 1 the PEACE electron instrument detected significant field-aligned electron fluxes from a few 100 eV to 3.5 keV, 2 the EDI instrument detected bursts of field-aligned electron currents, 3 the FGM instrument detected substantial magnetic fluctuations and the presence of Alfvén waves, 4 the STAFF experiment detected broadband electric and magnetic waves, ion cyclotron waves and whistler mode waves, and 5 CIS detected nearly comparable densities of H+ and O+ ions and a large tailward H+ velocity. We compare the characteristics of the ESWs observed during this event to those created in the laboratory at the University of California-Los Angeles Plasma Device (LAPD with an electron beam. We find that the time durations of both space and LAPD ESWs are only slightly larger than the respective local electron plasma periods, indicating that electron, and not ion, dynamics are responsible for generation of the ESWs. We have discussed possible mechanisms for generating the ESWs in space, including the beam and kinetic Buneman type instabilities and the acoustic instabilities. Future studies will examine these mechanisms in

  18. HOW TO DESCRIBE THE RESULTS OF OBSERVATIONAL EPIDEMIOLOGICAL STUDIES

    Directory of Open Access Journals (Sweden)

    S. A. Shal'nova

    2016-01-01

    Full Text Available Principles and fundamentals of proper presentation of observational epidemiological study results are focused. Principles of observational study publication developed by expert epidemiologists (STROBE statement are explained in detail.

  19. Current Directions in Adding Value to Earth Observation Products for Decision Support

    Science.gov (United States)

    Ryker, S. J.

    2015-12-01

    Natural resource managers and infrastructure planners face increasingly complex challenges, given competing demands for resources and changing conditions due to climate and land use change. These pressures create demand for high-quality, timely data; for both one-time decision support and long-term monitoring; and for techniques to articulate the value of resources in monetary and nonmonetary terms. To meet the need for data, the U.S. government invests several billion dollars per year in Earth observations collected from satellite, airborne, terrestrial, and ocean-based systems. Earth observation-based decision support is coming of age; user surveys show that these data are used in an increasing variety of analyses. For example, since the U.S. Department of the Interior/U.S. Geological Survey's (USGS) 2008 free and open data policy for the Landsat satellites, downloads from the USGS archive have increased from 20,000 Landsat scenes per year to 10 million per year and climbing, with strong growth in both research and decision support fields. However, Earth observation-based decision support still poses users a number of challenges. Many of those Landsat downloads support a specialized community of remote sensing scientists, though new technologies promise to increase the usability of remotely sensed data for the larger GIS community supporting planning and resource management. Serving this larger community also requires supporting the development of increasingly interpretive products, and of new approaches to host and update products. For example, automating updates will add value to new essential climate variable products such as surface water extent and wildfire burned area extent. Projections of future urbanization in the southeastern U.S. are most useful when long-term land cover trends are integrated with street-level community data and planning tools. The USGS assessment of biological carbon sequestration in vegetation and shallow soils required a significant

  20. Impact of neutrino properties on the estimation of inflationary parameters from current and future observations

    CERN Document Server

    Gerbino, Martina; Vagnozzi, Sunny; Lattanzi, Massimiliano; Mena, Olga; Giusarma, Elena; Ho, Shirley

    2016-01-01

    We study the impact of assumptions about neutrino properties on the estimation of inflationary parameters from cosmological data, with a specific focus on the allowed contours in the $n_s/r$ plane. We study the following neutrino properties: (i) the total neutrino mass $ M_\

  1. Current Status of Integral Medical Study on Endometriosis

    Institute of Scientific and Technical Information of China (English)

    YU Chao-qin (俞超芹); YU Jin (俞瑾)

    2003-01-01

    @@ Endometriosis (EM), an estrogen dependent disease that comes from the planting of endometrial gland and stroma outside the uterine cavity, is characterized by invasiveness, wide planting and liability to relapse. It has been proved by recent studies that the pathogenesis of EM has its genetic background and is closely related with neuro-, endocrino- and immuno-factors. There has been great progress in the treatment of EM, but the clinical effect is not yet satisfactory. Traditional Chinese medicine (TCM) has definitely played its role in EM treatment. In this article, the current status of integral medical study on EM is reviewed.

  2. The impact of the ocean observing system on estimates of the California current circulation spanning three decades

    Science.gov (United States)

    Moore, Andrew M.; Jacox, Michael G.; Crawford, William J.; Laughlin, Bruce; Edwards, Christopher A.; Fiechter, Jérôme

    2017-08-01

    Data assimilation is now used routinely in oceanography on both regional and global scales for computing ocean circulation estimates and for making ocean forecasts. Regional ocean observing systems are also expanding rapidly, and observations from a wide array of different platforms and sensor types are now available. Evaluation of the impact of the observing system on ocean circulation estimates (and forecasts) is therefore of considerable interest to the oceanographic community. In this paper, we quantify the impact of different observing platforms on estimates of the California Current System (CCS) spanning a three decade period (1980-2010). Specifically, we focus attention on several dynamically related aspects of the circulation (coastal upwelling, the transport of the California Current and the California Undercurrent, thermocline depth and eddy kinetic energy) which in many ways describe defining characteristics of the CCS. The circulation estimates were computed using a 4-dimensional variational (4D-Var) data assimilation system, and our analyses also focus on the impact of the different elements of the control vector (i.e. the initial conditions, surface forcing, and open boundary conditions) on the circulation. While the influence of each component of the control vector varies between different metrics of the circulation, the impact of each observing system across metrics is very robust. In addition, the mean amplitude of the circulation increments (i.e. the difference between the analysis and background) remains relatively stable throughout the three decade period despite the addition of new observing platforms whose impact is redistributed according to the relative uncertainty of observations from each platform. We also consider the impact of each observing platform on CCS circulation variability associated with low-frequency climate variability. The low-frequency nature of the dominant climate modes in this region allows us to track through time the

  3. Space Technology 5 (ST-5) Multipoint Observations of Temporal and Spatial Variability of Field-Aligned Currents

    Science.gov (United States)

    Le, Guan

    2010-01-01

    Space Technology 5 (ST-5) is a three micro-satellite constellation deployed into a 300 x 4500 km, dawn-dusk, sun-synchronous polar orbit from March 22 to June 21, 2006, for technology validations. In this paper, we present a study of the temporal variability of field-aligned currents using multi-point magnetic field measurements from ST5. The data demonstrate that mesoscale current structures are commonly embedded within large-scale field-aligned current sheets. The meso-scale current structures are very dynamic with highly variable current density and/or polarity in time scales of about 10 min. They exhibit large temporal variations during both quiet and disturbed times in such time scales. On the other hand, the data also shown that the time scales for the currents to be relatively stable are about 1 min for meso-scale currents and about 10 min for large scale current sheets. These temporal features are obviously associated with dynamic variations of their particle carriers (mainly electrons) as they respond to the variations of the parallel electric field in auroral acceleration region. The characteristic time scales for the temporal variability of meso-scale field-aligned currents are found to be consistent with those of auroral parallel electric field.

  4. Cost-of-Illness Studies: A Review of Current Methods

    OpenAIRE

    Ebere Akobundu; Jing Ju; Lisa Blatt; C Daniel Mullins

    2006-01-01

    The number of cost-of-illness (COI) studies has expanded considerably over time. One outcome of this growth is that the reported COI estimates are inconsistent across studies, thereby raising concerns over the validity of the estimates and methods. Several factors have been identified in the literature as reasons for the observed variation in COI estimates. To date, the variation in the methods used to calculate costs has not been examined in great detail even though the variations in methods...

  5. Measuring parent-child mutuality: a review of current observational coding systems.

    Science.gov (United States)

    Funamoto, Allyson; Rinaldi, Christina M

    2015-01-01

    Mutuality is defined as a smooth, back-and-forth positive interaction consisting of mutual enjoyment, cooperation, and responsiveness. The bidirectional nature of mutuality is an essential component to the parent-child relationship since a high quality parent-child mutual relationship is crucial to encouraging children's positive socialization and development (S. Lollis & L. Kuczynski, 1997; E.E. Maccoby, 2007). Several coding systems have been developed in recent years to assess this distinct and crucial aspect of the parent-child relationship. The present article reviews the following four mutuality coding schemes: the Parent-Child Interaction System (K. Deater-Deckard, M.V. Pylas, & S. Petrill, 1997), the Mutually Responsive Orientation Scale (N. Aksan, G. Kochanska, & M.R. Ortmann, 2006), the Caregiver-Child Affect, Responsiveness, and Engagement Scale (C.S. Tamis-LeMonda, P. Ahuja, B. Hannibal, J.D. Shannon, & M. Spellmann, 2002), and the Synchrony and Control Coding Scheme (J. Mize & G.S. Pettit, 1997). The review will focus on observational coding schemes available to researchers interested a central element of quality parent-child relationships in the early years.

  6. Design of Nonlinear Robust Rotor Current Controller for DFIG Based on Terminal Sliding Mode Control and Extended State Observer

    Directory of Open Access Journals (Sweden)

    Guowei Cai

    2014-01-01

    Full Text Available As to strong nonlinearity of doubly fed induction generators (DFIG and uncertainty of its model, a novel rotor current controller with nonlinearity and robustness is proposed to enhance fault ride-though (FRT capacities of grid-connected DFIG. Firstly, the model error, external disturbances, and the uncertain factors were estimated by constructing extended state observer (ESO so as to achieve linearization model, which is compensated dynamically from nonlinear model. And then rotor current controller of DFIG is designed by using terminal sliding mode variable structure control theory (TSMC. The controller has superior dynamic performance and strong robustness. The simulation results show that the proposed control approach is effective.

  7. Switch failure diagnosis based on inductor current observation for boost converters

    Science.gov (United States)

    Jamshidpour, E.; Poure, P.; Saadate, S.

    2016-09-01

    Face to the growing number of applications using DC-DC power converters, the improvement of their reliability is subject to an increasing number of studies. Especially in safety critical applications, designing fault-tolerant converters is becoming mandatory. In this paper, a switch fault-tolerant DC-DC converter is studied. First, some of the fastest Fault Detection Algorithms (FDAs) are recalled. Then, a fast switch FDA is proposed which can detect both types of failures; open circuit fault as well as short circuit fault can be detected in less than one switching period. Second, a fault-tolerant converter which can be reconfigured under those types of fault is introduced. Hardware-In-the-Loop (HIL) results and experimental validations are given to verify the validity of the proposed switch fault-tolerant approach in the case of a single switch DC-DC boost converter with one redundant switch.

  8. Understanding Thermohaline Mixing in the Agulhas Return Current from Seismic and Finestructure Observations

    Science.gov (United States)

    2014-07-01

    conducive to salt fingering in the study area were produced as a result of warm and salty SISW waters existing above colder and fresher waters below in...mesoscale variability and abundant eddy events (Lutjeharms and Ansorge, 2001). In addition, the close contact between subpolar and sub-tropical water ...Lutjeharms and Ansorge, 2001). In addition, the close contact between sub- polar and sub-tropical water masses in this region produces a strong frontal

  9. Impact of neutrino properties on the estimation of inflationary parameters from current and future observations

    Science.gov (United States)

    Gerbino, Martina; Freese, Katherine; Vagnozzi, Sunny; Lattanzi, Massimiliano; Mena, Olga; Giusarma, Elena; Ho, Shirley

    2017-02-01

    We study the impact of assumptions about neutrino properties on the estimation of inflationary parameters from cosmological data, with a specific focus on the allowed contours in the ns/r plane, where ns is the scalar spectral index and r is the tensor-to-scalar ratio. We study the following neutrino properties: (i) the total neutrino mass Mν=∑i mi (where the index i =1 , 2, 3 runs over the three neutrino mass eigenstates); (ii) the number of relativistic degrees of freedom Neff at the time of recombination; and (iii) the neutrino hierarchy. Whereas previous literature assumed three degenerate neutrino masses or two massless neutrino species (approximations that clearly do not match neutrino oscillation data), we study the cases of normal and inverted hierarchy. Our basic result is that these three neutrino properties induce measurements are included, the standard contours in the ns/r plane are basically reproduced. Larger shifts of the contours in the ns/r plane (up to 0.8 σ ) arise for nonstandard values of Neff. We also provide forecasts for the future CMB experiments Cosmic Origins Explorer (COrE, satellite) and Stage-IV (ground-based) and show that the incomplete knowledge of neutrino properties, taken into account by a marginalization over Mν, could induce a shift of ˜0.4 σ toward lower values in the determination of ns (or a ˜0.8 σ shift if one marginalizes over Neff). Comparison to specific inflationary models is shown. Imperfect knowledge of neutrino properties must be taken into account properly, given the desired precision in determining whether or not inflationary models match the future data.

  10. Paying research participants: a study of current practices in Australia.

    Science.gov (United States)

    Fry, C L; Ritter, A; Baldwin, S; Bowen, K J; Gardiner, P; Holt, T; Jenkinson, R; Johnston, J

    2005-09-01

    To examine current research payment practices and to inform development of clearer guidelines for researchers and ethics committees. Exploratory email based questionnaire study of current research participant reimbursement practices. A diverse sample of organisations and individuals were targeted. Australia. Contacts in 84 key research organisations and select electronic listservers across Australia. A total of 100 completed questionnaires were received with representations from a variety of research areas (for example, market, alcohol and drug, medical, pharmaceutical and social research). Open-ended and fixed alternative questions about type of research agency; type of research; type of population under study; whether payment is standard; amounts and mechanisms of payment; factors taken into account when deciding on payment practices; and whether payment policies exist. Reimbursement practice is highly variable. Where it occurs (most commonly for drug dependent rather than health professional or general population samples) it is largely monetary and is for time and out-of-pocket expenses. Ethics committees were reported to be often involved in decision making around reimbursement. Research subject payment practices vary in Australia. Researchers who do provide payments to research participants generally do so without written policy and procedures. Ethics committees have an important role in developing guidelines in this area. Specific guidelines are needed considering existing local policies and procedures; payment models and their application in diverse settings; case study examples of types and levels of reimbursement; applied definitions of incentive and inducement; and the rationale for diverse payment practices in different settings.

  11. Current Mathematical Methods Used in QSAR/QSPR Studies

    Directory of Open Access Journals (Sweden)

    Peixun Liu

    2009-04-01

    Full Text Available This paper gives an overview of the mathematical methods currently used in quantitative structure-activity/property relationship (QASR/QSPR studies. Recently, the mathematical methods applied to the regression of QASR/QSPR models are developing very fast, and new methods, such as Gene Expression Programming (GEP, Project Pursuit Regression (PPR and Local Lazy Regression (LLR have appeared on the QASR/QSPR stage. At the same time, the earlier methods, including Multiple Linear Regression (MLR, Partial Least Squares (PLS, Neural Networks (NN, Support Vector Machine (SVM and so on, are being upgraded to improve their performance in QASR/QSPR studies. These new and upgraded methods and algorithms are described in detail, and their advantages and disadvantages are evaluated and discussed, to show their application potential in QASR/QSPR studies in the future.

  12. Current management of bronchiectasis: review and 3 case studies.

    Science.gov (United States)

    Silverman, Enid; Ebright, Linda; Kwiatkowski, Marianne; Cullina, Joanne

    2003-01-01

    Bronchiectasis is the abnormal, irreversible dilatation of diseased bronchi. Permanently dilated airways, usually in the medium-sized bronchi, are inflamed and often obstructed with thick, purulent secretions. Known causative factors include postinfection bronchial damage, postinhalation injury, hypersensitivity reactions, and congenital airway obstructive disorders. Typical symptoms include sputum overproduction, fever, pleurisy, dyspnea, and chronic cough. Diagnosis involves radiographic studies and pulmonary function testing. Treatment includes oral, aerosolized, or intravenous antibiotic therapy according to the severity of the exacerbation, and mucus clearance by means of bronchial hygiene assistive devices, chest physiotherapy, postural drainage, and high-frequency chest compression. We present a review of bronchiectasis and offer 3 case studies illustrating current management of different presentations, including use of aerosolized antibiotics for patients infected with Pseudomonas aeruginosa. Although an adjunctive program of pulmonary rehabilitation may be useful for patients with bronchiectasis, no confirming studies have been performed to date, and additional research in this area is warranted.

  13. Experimental study on directional solidification of Al-Si alloys under the influence of electric currents

    Science.gov (United States)

    Räbiger, D.; Zhang, Y.; Galindo, V.; Franke, S.; Willers, B.; Eckert, S.

    2016-07-01

    The application of electric currents during solidification can cause grain refinement in metallic alloys. However, the knowledge about the mechanisms underlying the decrease in grain size remains fragmentary. This study considers the solidification of Al-Si alloys under the influence of electric currents for the configuration of two parallel electrodes at the free surface. Solidification experiments were performed under the influence of both direct currents (DC) and rectangular electric current pulses (ECP). The interaction between the applied current and its own induced magnetic field causes a Lorentz force which produces an electro-vortex flow. Numerical simulations were conducted to calculate the Lorentz force, the Joule heating and the induced melt flow. The numerical predictions were confirmed by isothermal flow measurements in eutectic GaInSn. The results demonstrate that the grain refining effect observed in our experiments can be ascribed solely to the forced melt flow driven by the Lorentz force.

  14. Inorganic pollution around the Qinghai-Tibet Plateau: An overview of the current observations.

    Science.gov (United States)

    Wu, Jun; Duan, Dongping; Lu, Jian; Luo, Yongming; Wen, Xiaohu; Guo, Xiaoying; Boman, Brian J

    2016-04-15

    The Qinghai-Tibet Plateau is the highest geographical unit in the world. Thus, it serves an important role in evaluating long-term ecologic conditions and environmental status and changes over time. This study summarizes major and trace element concentrations in biota and in water and soil. It also pays attention to gaseous pollutant and particle concentrations in air around the Qinghai-Tibet Plateau. The degree of soil heavy metal contamination and the water heavy metal hazard index were respectively evaluated. The contamination degrees of two sampling areas around the Qinghai-Tibet Plateau reached extremely high levels with soil mCd (modified degree of contamination) values exceeding 20. Surprisingly, over 54% of sampling areas showed moderate or more serious soil contamination degree (mCd>1.5). Moreover, the hazard indexes of two important rivers were 1.56 and 7.59, reaching unacceptable level. The potential risk might be beyond our expectation. Therefore, it should be an urgent and top priority to identify and confirm possible pollution sources around the Qinghai-Tibet Plateau. Then, it is imperative to implement feasible and effective environmental quality control strategies.

  15. The Study of the Geomagnetic Variation for Sq current System

    Science.gov (United States)

    Zhao, X.; Du, A.

    2012-04-01

    The solar quiet variation (Sq) with a period of 24 hrs is a typical one of the quiet variations. Sq is generally caused by atmospheric tide-dynamo in ionosphere and it is controlled by the electric field, electric conductivity in ionosphere and neutral wind in middle-high altitude atmosphere. In our work, the geomagnetic field data observed by 90 ground-based observatories is used to analyze the local time variation of Sq. Sq is derived from five quiet-day geomagnetic data in every month by the FFT method. According to the pattern of geomagnetic X component in Sq, there is a prenoon-postnoon (before noon and after noon) asymmetry. This asymmetry is obvious in spring, summer and winter. The X component at 12:00-13:00 LT is about 5 nT larger than it at 11:00-12:00 LT. The ratio between the X component of daily variable amplitude and Y component of daily variable amplitude in middle and low (high) latitude regions in summer is greater (smaller) than that in winter. Used the sphere harmonic analysis method, the Sq equivalent current system is obtained. From the pattern of Sq current system, the prenoon-postnoon asymmetry may be caused by the electric field in the high latitude region. This electric field has two effects: the one is that the electric field from high latitude maps to the low latitude region; the other is this electric field penetrate to the middle latitude region directly. The combined action of these two effects makes the prenoon-postnoon asymmetry of Sq. The asymmetry also has an obvious seasonal effect. It may relate to the polar Sq and DP2 in the high latitude region.

  16. Simulation studies of direct-current microdischarges for electric propulsion

    Science.gov (United States)

    Deconinck, Thomas Dominique

    The structure of direct-current microdischarges is investigated using a detailed two-dimensional multi-species continuum model. Microdischarges are direct-current discharges that operate at a relatively high pressure of about 100 Torr and geometric dimensions in the 10-100 micrometer range. Our motivation for the study of microdischarges comes from a potential application of these devices in microthrusters for small satellite propulsion. The Micro Plasma Thruster (MPT) concept consists of a direct-current microdischarge in a geometry comprising a constant area flow section followed by a diverging exit nozzle. A detailed description of the plasma dynamics inside the MPT including power deposition, ionization, coupling of the plasma phenomena with high-speed flow, and propulsion system performance is reported in this study. A two-dimensional model is developed as part of this study. The model consists of a plasma module coupled to a flow module and is solved on a hybrid unstructured mesh framework. The plasma module provides a self-consistent, multi-species, multi-temperature description of the microdischarge phenomena while the flow module provides a description of the low Reynolds number compressible flow through the system. The plasma module solves conservation equations for plasma species continuity and electron energy, and Poisson's equation for the self-consistent electric field. The flow module solves mass, bulk gas momentum and energy equations. The coupling of energy from the electrostatic field to the plasma species is modeled by the Joule heating term which appears in the electron and heavy species energy equations. Discretization of the Joule heating term on unstructured meshes requires special attention. We propose a new robust method for the numerical discretization of the Joule heating term on such meshes using a cell-centered, finite volume approach. A prototypical microhollow cathode discharge (MHCD) is studied to guide and validate the modeling

  17. Current Conceptual Challenges in the Study of Rhythm Processing Deficits

    Directory of Open Access Journals (Sweden)

    Pauline eTranchant

    2015-06-01

    Full Text Available Interest in the study of rhythm processing deficits (RPD is currently growing in the cognitive neuroscience community, as this type of investigation constitutes a powerful tool for the understanding of normal rhythm processing. Because this field is in its infancy, it still lacks a common conceptual vocabulary to facilitate effective communication between different researchers and research groups. In this commentary, we provide a brief review of recent reports of RPD through the lens of one important empirical issue: the method by which beat perception is measured, and the consequences of method selection for the researcher’s ability to specify which mechanisms are impaired in RPD. This critical reading advocates for the importance of matching measurement tools to the putative neurocognitive mechanisms under study, and reveals the need for effective and specific assessments of the different aspects of rhythm perception and synchronization.

  18. Ozone sonde cell current measurements and implications for observations of near-zero ozone concentrations in the tropical upper troposphere

    Directory of Open Access Journals (Sweden)

    H. Vömel

    2009-12-01

    Full Text Available Laboratory measurements of the Electrochemical Concentration Cell (ECC ozone sonde cell current using ozone free air as well as defined amounts of ozone reveal that background current measurements during sonde preparation are neither constant as a function of time, nor constant as a function of ozone concentration. Using these background currents in the processing of ECC data may lead to operator dependent uncertainties and may frequently lead to artificially low ozone concentrations in the upper tropical troposphere. Based on these laboratory measurements an improved cell current to partial pressure conversion is proposed, which removes operator dependent variability in the background reading, and possible artifacts in this measurement. Data from the Central Equatorial Pacific Experiment (CEPEX have been reprocessed using the improved background treatment based on these laboratory measurements. In the reprocessed data set near-zero ozone events no longer occur. At Samoa, Fiji, Tahiti, and San Cristóbal, nearly all near-zero ozone concentrations occur in soundings with larger background currents. To a large extent, these events are no longer observed in the reprocessed data set using the improved background treatment.

  19. Ozone sonde cell current measurements and implications for observations of near-zero ozone concentrations in the tropical upper troposphere

    Directory of Open Access Journals (Sweden)

    H. Vömel

    2010-04-01

    Full Text Available Laboratory measurements of the Electrochemical Concentration Cell (ECC ozone sonde cell current using ozone free air as well as defined amounts of ozone reveal that background current measurements during sonde preparation are neither constant as a function of time, nor constant as a function of ozone concentration. Using a background current, measured at a defined timed after exposure to high ozone may often overestimate the real background, leading to artificially low ozone concentrations in the upper tropical troposphere, and may frequently lead to operator dependent uncertainties. Based on these laboratory measurements an improved cell current to partial pressure conversion is proposed, which removes operator dependent variability in the background reading and possible artifacts in this measurement. Data from the Central Equatorial Pacific Experiment (CEPEX have been reprocessed using the improved background treatment based on these laboratory measurements. In the reprocessed data set near-zero ozone events no longer occur. At Samoa, Fiji, Tahiti, and San Cristóbal, nearly all near-zero ozone concentrations occur in soundings with larger background currents. To a large extent, these events are no longer observed in the reprocessed data set using the improved background treatment.

  20. CURRENT STUDY ON THE FUNDING SOURCES COVERAGE OF CURRENT ASSETS TO COMPANIES LISTED ON THE BUCHAREST STOCK EXCHANGE

    Directory of Open Access Journals (Sweden)

    Teodor HADA

    2014-06-01

    Full Text Available This paper presents issues about the coverage with financing sources of current assets for 64 companies listed on the Bucharest Stock Exchange. The aim of the study is to see how to calculate indicators specific to current assets and the general framework offered as whole analysis of the financing sources of current assets. The introduction of the paper presents the objective, the research methodology and the novelties brought by this study. Further on, this study shows the various views of the authors about the concept of "current assets", financing sources of current assets, the calculation of net working capital, setting the limits of the normal working capital and determining the speed of rotation. After that was done, based on the theory, a case study was performed, for companies covered in this study. Conclusions focused on determining the final data about what was detailed in the previous paragraphs.

  1. Experimental study of blockage of monochromatic waves by counter currents

    NARCIS (Netherlands)

    Suastika, I.K.

    1999-01-01

    Blockage of waves by a current can occur if waves are propagating on a spatially varying opposing current in which the velocity is increasing in the wave propagation direction. The ongoing waves become shorter and steeper while they are propagating against the current. Blocking occurs at the

  2. Observational studies and the difficult quest for causality

    DEFF Research Database (Denmark)

    Lipsitch, Marc; Jha, Ayan; Simonsen, Lone

    2017-01-01

    be answered once the vaccine is in use, from observational studies. However, such studies are inherently at risk for bias. Using a causal framework and illustrating with examples, we review newer approaches to detecting and avoiding confounding and selection bias in three major classes of observational study...

  3. Numerical Study on the Bifurcation of the North Equatorial Current

    Institute of Scientific and Technical Information of China (English)

    LIU Yulong; WANG Qi; SONG Jun; ZHU Xiande; GONG Xiaoqing; WU Fang

    2011-01-01

    A 1.5-layer reduced-gravity model forced by wind stress is used to study the bifurcations of the North Equatorial Current (NEC).The authors found that after removing the Ekman drift,the modelled circulations can serve well as a proxy of the SODA circulations on the σθ=25.0kgm-3 potential density surface based on available long-term reanalysis wind stress data.The modelled results show that the location of the western boundary bifurcation of the NEC depends on both zonal averaged and local zero wind stress curl latitude.The effects of the anomalous wind stress curl added in different areas are also investigated and it is found that they can change the strength of the Mindanao Eddy (ME),and then influence the interior pathway.

  4. Strengthening the Reporting of Observational Studies in Epidemiology (STROBE)

    DEFF Research Database (Denmark)

    Vandenbroucke, Jan P; von Elm, Erik; Altman, Douglas G

    2014-01-01

    Much medical research is observational. The reporting of observational studies is often of insufficient quality. Poor reporting hampers the assessment of the strengths and weaknesses of a study and the generalisability of its results. Taking into account empirical evidence and theoretical conside......, and the associated Web site (http://www.strobe-statement.org/) should be helpful resources to improve reporting of observational research....... to the title, abstract, introduction, methods, results and discussion sections of articles. Eighteen items are common to cohort studies, case-control studies and cross-sectional studies and four are specific to each of the three study designs. The STROBE Statement provides guidance to authors about how...

  5. DSP-Based Sensorless Speed Control of a Permanent Magnet Synchronous Motor using Sliding Mode Current Observer

    Directory of Open Access Journals (Sweden)

    Rachid Askour

    2014-05-01

    Full Text Available In this paper, experimental results of 3-phase permanent magnet synchronous motor (PMSM sensorless speed control are presented. To estimate the rotor position, a sliding mode current observer (SMCO was implemented. This observer estimates the back emfs of the motor in the stationary reference frame using only the measured voltages and currents of the motor. These emfs were utilized to obtain the rotor position. The speed of the motor was calculated by differentiating the rotor position angle. The stability of the proposed SMCO was verified using Lyapunov method to determine the observer gain. The saturation function was adopted in order to reduce the chattering phenomenon caused by the SMCO. A vector control method was employed to achieve the sensorless drive system. The control application was developed in C/C++ language and implemented using the Texas Instruments TMS320LF2812 digital signal processor (DSP. This new processor enables intelligent control for motors. We used to test the drive the MCK2812 which is a professional development kit available from Technosoft Company. The theoretical finding is validated with experimental results that show the effectiveness of the real-time implementation.

  6. Period-doubling bifurcation cascade observed in a ferromagnetic nanoparticle under the action of a spin-polarized current

    Energy Technology Data Exchange (ETDEWEB)

    Horley, Paul P., E-mail: paul.horley@cimav.edu.mx [Centro de Investigación en Materiales Avanzados, S.C. (CIMAV), Chihuahua/Monterrey, 120 Avenida Miguel de Cervantes, 31109 Chihuahua (Mexico); Kushnir, Mykola Ya. [Yuri Fedkovych Chernivtsi National University, 2 Kotsyubynsky str., 58012 Chernivtsi (Ukraine); Morales-Meza, Mishel [Centro de Investigación en Materiales Avanzados, S.C. (CIMAV), Chihuahua/Monterrey, 120 Avenida Miguel de Cervantes, 31109 Chihuahua (Mexico); Sukhov, Alexander [Institut für Physik, Martin-Luther Universität Halle-Wittenberg, 06120 Halle (Saale) (Germany); Rusyn, Volodymyr [Yuri Fedkovych Chernivtsi National University, 2 Kotsyubynsky str., 58012 Chernivtsi (Ukraine)

    2016-04-01

    We report on complex magnetization dynamics in a forced spin valve oscillator subjected to a varying magnetic field and a constant spin-polarized current. The transition from periodic to chaotic magnetic motion was illustrated with bifurcation diagrams and Hausdorff dimension – the methods developed for dissipative self-organizing systems. It was shown that bifurcation cascades can be obtained either by tuning the injected spin-polarized current or by changing the magnitude of applied magnetic field. The order–chaos transition in magnetization dynamics can be also directly observed from the hysteresis curves. The resulting complex oscillations are useful for development of spin-valve devices operating in harmonic and chaotic modes.

  7. Concatenation of observed grasp phases with observer's distal movements: a behavioural and TMS study.

    Directory of Open Access Journals (Sweden)

    Elisa De Stefani

    Full Text Available The present study aimed at determining how actions executed by two conspecifics can be coordinated with each other, or more specifically, how the observation of different phases of a reaching-grasping action is temporary related to the execution of a movement of the observer. Participants observed postures of initial finger opening, maximal finger aperture, and final finger closing of grasp after observation of an initial hand posture. Then, they opened or closed their right thumb and index finger (experiments 1, 2 and 3. Response times decreased, whereas acceleration and velocity of actual finger movements increased when observing the two late phases of grasp. In addition, the results ruled out the possibility that this effect was due to salience of the visual stimulus when the hand was close to the target and confirmed an effect of even hand postures in addition to hand apparent motion due to the succession of initial hand posture and grasp phase. In experiments 4 and 5, the observation of grasp phases modulated even foot movements and pronunciation of syllables. Finally, in experiment 6, transcranial magnetic stimulation applied to primary motor cortex 300 ms post-stimulus induced an increase in hand motor evoked potentials of opponens pollicis muscle when observing the two late phases of grasp. These data suggest that the observation of grasp phases induced simulation which was stronger during observation of finger closing. This produced shorter response times, greater acceleration and velocity of the successive movement. In general, our data suggest best concatenation between two movements (one observed and the other executed when the observed (and simulated movement was to be accomplished. The mechanism joining the observation of a conspecific's action with our own movement may be precursor of social functions. It may be at the basis for interactions between conspecifics, and related to communication between individuals.

  8. Observation

    Science.gov (United States)

    Patell, Hilla

    2016-01-01

    In order to achieve the goal of observation, preparation of the adult, the observer, is necessary. This preparation, says Hilla Patell, requires us to "have an appreciation of the significance of the child's spontaneous activities and a more thorough understanding of the child's needs." She discusses the growth of both the desire to…

  9. Observation

    Science.gov (United States)

    Kripalani, Lakshmi A.

    2016-01-01

    The adult who is inexperienced in the art of observation may, even with the best intentions, react to a child's behavior in a way that hinders instead of helping the child's development. Kripalani outlines the need for training and practice in observation in order to "understand the needs of the children and...to understand how to remove…

  10. Learning to observe mathematical learning in lesson studies

    DEFF Research Database (Denmark)

    Rasmussen, Klaus; Østergaard, Camilla Hellsten; Foss, Kristian Kildemoes

    2016-01-01

    This poster deals with lesson study (LS) in pre-service teacher education. In particular how to prepare for, carry out, and reflect upon, observations of pupil learning. Observation is of crucial importance to the lesson study process, and here we present a study of observation features which...... enable or hinder fruitful lesson study. While substantial research has been carried out in the general field of bserving pupils’ learning processes and teachers’ pedagogical practice, little is known about this in the particular setting of lesson study....

  11. Current state of the hydrothermal geochemistry studies at Cerro Prieto

    Energy Technology Data Exchange (ETDEWEB)

    Fausto L, J.J.; Jimenez S, M.E.; Esquer P, I.

    1981-01-01

    The current state of hydrothermal geochemistry studies being carried out at the field are reported. These studies are based on the results of chemical analysis of water samples collected during 1979 and 1980 at the geothermal wells of the area known as Cerro Prieto I, as well as from those located in the Cerro Prieto II and Cerro Prieto III areas, some of which have only recently started flowing. Data are presented on the chemical variations of the main chemical constituents dissolved in the waters, as well as on the Na/K and Na-K-Ca chemical relations and the temperatures calculated from them and from SiO/sub 2/. Fluid recharge into the reservoir and its direction of flow are interpreted from isotherm contour maps of the field prepared from Na/K and Na-K-Ca geothermometry and from concentration contour maps of some of the main chemical constituents. Well M-43 is discussed as an example of a well affected by well completion problems in its production casing. Its behavior is explained on the basis of the chemical characteristics of the produced water. The chemical changes that have taken place in some of the wells during production are explained by correlating the chemistry with the production mechanisms of the well (steam-water production rates).

  12. Current Advances in the Metabolomics Study on Lotus Seeds.

    Science.gov (United States)

    Zhu, Mingzhi; Liu, Ting; Guo, Mingquan

    2016-01-01

    Lotus (Nelumbo nucifera), which is distributed widely throughout Asia, Australia and North America, is an aquatic perennial that has been cultivated for over 2,000 years. It is very stimulating that almost all parts of lotus have been consumed as vegetable as well as food, especially the seeds. Except for the nutritive values of lotus, there has been increasing interest in its potential as functional food due to its rich secondary metabolites, such as flavonoids and alkaloids. Not only have these metabolites greatly contributed to the biological process of lotus seeds, but also have been reported to possess multiple health-promoting effects, including antioxidant, anti-amnesic, anti-inflammatory, and anti-tumor activities. Thus, comprehensive metabolomic profiling of these metabolites is of key importance to help understand their biological activities, and other chemical biology features. In this context, this review will provide an update on the current technological platforms, and workflow associated with metabolomic studies on lotus seeds, as well as insights into the application of metabolomics for the improvement of food safety and quality, assisting breeding, and promotion of the study of metabolism and pharmacokinetics of lotus seeds; meanwhile it will also help explore new perspectives and outline future challenges in this fast-growing research subject.

  13. Simultaneous prenoon and postnoon observations of three field-aligned current systems from Viking and DMSP-F7

    Science.gov (United States)

    Ohtani, S.; Potemra, T. A.; Newell, P. T.; Zanetti, L. J.; Iijima, T.; Watanabe, M.; Yamauchi, M.; Elphinstone, R. D.; De La Beauijardie, O.; Blomberg, L. G.

    1995-01-01

    The spatial structure of dayside large-scale field-aligned current (FAC) systems is examined by using Viking and Defense Meteorological Satellite Program-F7 (DMSP-F7) data. We focus on four events in which the satellites simultaneously observed postnoon and prenoon three FAC systems: the region 2, the region 1, and the mantle (referred to as midday region O) systems, from equatorward to poleward. These events provide the most solid evidence to date that the midday region O system is a separate and unique FAC system, and is not an extension of the region 1 system from other local times. The events are examined comprehensively by making use of a mulit-instrumental data set, which includes magnetic field, particle flux, electric field, auroral UV image data from the satellites, and the Sondrestrom convection data. The results are summarized as follows: (1) Region 2 currents flow mostly in the central plasma sheet (CPS) precipitation region, often overlapping with the boundary plasma sheet (BPD) at their poleward edge. (2) The region 1 system is located in the core part of the auroral oval and is confined in a relatively narrow range in latitude which includes the convection reversal. The low-latitude boundary layer, possibly including the outer part of the plasma sheet, and the external cusp are the major source regions of dayside region 1 currents. (2) Midday region O currents flow on open field lines and are collocated with the shear of antisunward convection flows with velocites decreasing poleward. On the basis of these results we support the view that both prenoon and postnoon current systems consist of the three-sheet structure when the disctortion ofthe convection pattern associated with interplanetary magnetic field (IMF) B(sub Y) is small and both morningside and eveningside convection cells are crescent-shaped. We also propose that the midday region O and a part of the region 1 systems are closely coupled to the same source.

  14. Observation of pentaquark states and perspectives of further studies

    CERN Document Server

    Shen, Cheng-Ping

    2015-01-01

    In this invited short "news and views", we review very briefly the history of pentaquark studies and the recent observations of the tetraquark and pentaquark states. We also discuss further experimental studies such as at Belle-II.

  15. Currents in the Luzon Strait during the spring of 2002: observation and computation by modified inverse model

    Institute of Scientific and Technical Information of China (English)

    YUAN Yaochu; LOU Ruyun; LIU Yonggang; SU Jilan; WANG Kangshan; CHEN Hong

    2005-01-01

    On the basis of the current measurements at 200,500 and 800 m from moored current meters with the time series data from March 17 to April 15 at the mooring station (20°49′57″N, 120°48' 12″E ) and the hydrographic data obtained in the Luzon Strait during the spring of 2002 cruise, the circulation in the investigated area is computed by using the modified inverse method. The major observed results are as follows: (1) the average velocity and the flow direction in the observing days are (47.4 cm/s, 346°) at the 200 m level. The aver age velocity in the observing days is (20.3 cm/s, 350°) at the 500 m level. These mean that the Kuroshio intrudes into the South Chin Sea to flow northwestward through the Luzon Strait at 200 and 500 m levels. (2) The average velocity in the observing days is (1.2cm/s, 35°) at the 800 m level, I. E., its direction is northeastward. This means that the flow condition at the 800 m level very differs from that at the 200 and 500 m levels. (3) There is the high density and cold water (HDCW) in the middle of western part of in the investigated region, and its center is located near the hydrological station 3 at Section A. (4) There is the lower density and warm water (LDWW) in the southeastern part of investigated region. (5) The currents in April 2002 are stronger than those in March 2002.The major computed results are as follows: (1) The northwestward and southeastward VTs through Section B are 32.48×106 m3/s (inclusive of VT ofanticyclonic eddy) and 3.34×106m3/s, respectively. The net northwestward VT through Section B in the investigated area is about 29.14×106 m3/s. (2) The eastern and western VTs through Section A are about 16.71× 106 and 8.57×106 m3/s, respectively. Thus,the net eastward VT through Section A is about 8.14×106 m3/s. (3) The net northward VT through Section M is about 24.68×106 m3/s.(4) After about 24.68×106 m3/s flows through Section M, most of it, about 16.54×106 m3/s, flows northward through the

  16. EISCAT radar observations of enhanced incoherent scatter spectra; their relation to red aurora and field-aligned currents

    Energy Technology Data Exchange (ETDEWEB)

    Collis, P.N. (EISCAT, Kiruna (Sweden)); Haeggstroem, I. (IRF, Kiruna (Sweden)); Kaila, K. (Univ. of Oulu (Finland)); Rietveld, M.T. (EISCAT, Ramfjordmoen (Norway))

    1991-06-01

    Enhancements of one, or both, of the ion-acoustic peaks of incoherent scatter spectra in the auroral ionosphere have been observed with the EISCAT UHF and VHF radars. All occurrences for which optical data are available show these events to coincide with active, unusually intense, red auroral forms in the vicinity of the radar beam at high altitudes. Both the optical and the radar signatures are expected to be caused by large fluxes of low energy electrons. Analyses of the measured spectra, in which the electron drift speed is estimated, imply field-aligned current densities up to several mA m{sup {minus}2}. The vertically-directed VHF observations from {approximately}1,000 km altitude reveal that the spectral enhancements, which are transient features in field-aligned measurements, can exist for up to several minutes.

  17. Signal of right-handed currents using $B\\to K^*\\ell^+\\ell^-$ observables at the kinematic endpoint

    CERN Document Server

    Karan, Anirban; Nayak, Abinash Kumar; Sinha, Rahul; Browder, Thomas E

    2016-01-01

    The decay mode $B\\to K^*\\ell^+\\ell^-$ is one of the most promising modes to probe physics beyond the standard model (SM), since the angular distribution of the decay products enable measurement of several constraining observables. LHCb has recently measured these observables using $3\\,fb^{-1}$ of data as a binned function of $q^2$, the dilepton invariant mass squared. We show that LHCb data implies a $5\\sigma$ overall signal for new physics and provides unambiguous evidence for right-handed currents, which are absent in the SM. These conclusions are derived in the maximum $q^2$ limit and are free from hadronic corrections. Our approach differs from other approaches that probe new physics at low $q^2$ as it does not require estimates of hadronic parameters but relies instead on heavy quark symmetries that are reliable at the maximum $q^2$ kinematic endpoint.

  18. Field-aligned currents observed by MMS in the near-Earth plasma sheet during large-scale substorm dipolarizations.

    Science.gov (United States)

    Nakamura, Rumi; Nagai, Tsugunobu; Giles, Barbara; Le Contel, Olivier; Stawarz, Julia; Khotyaintsev, Yuri; Artemyev, Anton

    2017-04-01

    During substorms significant energy conversion has been reported to take place at the sharp dipolarization front in the flow braking region where the probability of observing bursty bulk flows (BBFs) significantly drops. On 10 August 2016, MMS traversed the pre-midnight near-Earth plasma sheet when dipolarization disturbances were detected in an extended nightside local time region by Cluster, Geotail, GOES 13, 14 and 15, and the Van Allen Probes. In an expanding plasma sheet during the dipolarization, MMS detected sub-ion scale field-aligned current layers that are propagating both Earthward (equatorward) as well as tailward (outward). These multi-scale multi-point observations enable a unique investigation of both the meso-scale evolution of the disturbances and the detailed kinetic structures of the fronts and boundaries relevant to the dipolarizations.

  19. ADDING CONTEXT TO JAMES WEBB SPACE TELESCOPE SURVEYS WITH CURRENT AND FUTURE 21 cm RADIO OBSERVATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Beardsley, A. P.; Morales, M. F. [Department of Physics, University of Washington Seattle, WA 98195 (United States); Lidz, A.; Malloy, M. [Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA 19104 (United States); Sutter, P. M., E-mail: beards@phys.washington.edu [INFN - National Institute for Nuclear Physics via Valerio 2, I-34127, Trieste (Italy)

    2015-02-20

    Infrared and radio observations of the Epoch of Reionization promise to revolutionize our understanding of the cosmic dawn, and major efforts with the JWST, MWA, and HERA are underway. While measurements of the ionizing sources with infrared telescopes and the effect of these sources on the intergalactic medium with radio telescopes should be complementary, to date the wildly disparate angular resolutions and survey speeds have made connecting proposed observations difficult. In this paper we develop a method to bridge the gap between radio and infrared studies. While the radio images may not have the sensitivity and resolution to identify individual bubbles with high fidelity, by leveraging knowledge of the measured power spectrum we are able to separate regions that are likely ionized from largely neutral, providing context for the JWST observations of galaxy counts and properties in each. By providing the ionization context for infrared galaxy observations, this method can significantly enhance the science returns of JWST and other infrared observations.

  20. On Alfvenic Waves and Stochastic Ion Heating with 1Re Observations of Strong Field-aligned Currents, Electric Fields, and O+ ions

    Science.gov (United States)

    Coffey, Victoria; Chandler, Michael; Singh, Nagendra

    2008-01-01

    The role that the cleft/cusp has in ionosphere/magnetosphere coupling makes it a very dynamic region having similar fundamental processes to those within the auroral regions. With Polar passing through the cusp at 1 Re in the Spring of 1996, we observe a strong correlation between ion heating and broadband ELF (BBELF) emissions. This commonly observed relationship led to the study of the coupling of large field-aligned currents, burst electric fields, and the thermal O+ ions. We demonstrate the role of these measurements to Alfvenic waves and stochastic ion heating. Finally we will show the properties of the resulting density cavities.

  1. Particle Image Velocimetry Study of Density Current Fronts

    Science.gov (United States)

    Martin, Juan Ezequiel

    2009-01-01

    Gravity currents are flows that occur when a horizontal density difference causes fluid to move under the action of gravity; density currents are a particular case, for which the scalar causing the density difference is conserved. Flows with a strong effect of the horizontal density difference, even if only partially driven by it--such as the…

  2. Field current tracing control of a BSG based on sliding mode current observer%BSG电机励磁电流观测器跟踪控制

    Institute of Scientific and Technical Information of China (English)

    余腾伟; 王旭东

    2011-01-01

    Aiming at the nonlinearities of belt driven starter generator' s (BSG) excitation winding driving circuit and a variety of interference outside the engine compartment, making it difficult for conventional PWM strategy to achieve the optimal output current. According to the sliding mode control theory, a sliding mode observer approach is proposed, and the mathematical module of BSG field windings' driven system is established, utilizing advantages that including good control robustness to conduct online setting. Simulation and experimental results show that the step response time is about 10 ms, and the maximum overshoot is less than 5% . What' s more, the method enhances the systems self adaptive capacity, improves the startup performance of BSG-hybrid cars, and has good current tracking performance, and low costing.%针对弱混合动力汽车中带式驱动启动发电机(BSG)的励磁绕组驱动电路存在的非线性问题,以及发动机舱各种外部干扰导致传统的PWM技术难以使控制电流输出达到最优的问题,依据滑模变结构控制理论,采用电流观测器的方法,建立BSG电机励磁绕组驱动系统的数学模型,给出电流观测器的控制算法,利用滑模变结构控制鲁棒性好的优势对BSG电机励磁电流进行在线整定.仿真和试验结果表明,该方法的阶跃响应时间为10 ms,跟踪电流最大超调小于5%,增强了系统的自适应能力,提高了BSG混合动力轿车启动性能,并且具有较好的电流跟踪效果,降低了成本.

  3. A New Regime for Studying the High Bootstrap Current Fraction Plasma

    Institute of Scientific and Technical Information of China (English)

    A. Isayama; Y. Kamada; K. Ushigusa; T. Fujita; T. Suzuki; X. Gao

    2001-01-01

    A new experimental regime has recently been studied for achieving the high fraction of the bootstrap current in the JT-60U hydrogen discharges. The high poloidal beta(βp ~ 3.61) plasma was obtained by high-power neutral beam injection heating at a very high edge safety factor (Ip = 0.3 MA, Bt = 3.65 T, qeff = 25 - 35) region, and the bootstrap current fraction (fBS) was correspondingly about 40% using the ACCOME code calculation. It was observed that there were no magnetohydrodynamic instabilities to retard the increase of the βp and fBS parameters in the new regime.

  4. A Study of Strange Particles Produced in Neutrino Neutral Current Interactions in the NOMAD Experiment

    CERN Document Server

    Naumov, D V; Naumova, E; Popov, B; Astier, Pierre; Autiero, D; Baldisseri, Alberto; Baldo-Ceolin, Massimilla; Banner, M; Bassompierre, G; Benslama, K; Besson, N; Bird, I; Blumenfeld, B; Bobisut, F; Bouchez, J; Boyd, S; Bueno, A G; Bunyatov, S; Camilleri, L L; Cardini, A; Cattaneo, P W; Cavasinni, V; Cervera-Villanueva, A; Challis, R C; Collazuol, G; Conforto, G; Conta, C; Contalbrigo, M; Cousins, R; Daniels, D; Das, R; Degaudenzi, H M; Del Prete, T; De Santo, A; Dignan, T; Di Lella, L; do Couto e Silva, E; Dumarchez, J; Ellis, M; Feldman, G J; Ferrari, R; Ferrère, D; Flaminio, V; Fraternali, M; Gaillard, J M; Gangler, E; Geiser, A; Geppert, D; Gibin, D; Gninenko, S; Godley, A; Gómez-Cadenas, J J; Gosset, J; Gössling, C; Gouanère, M; Grant, A; Graziani, G; Guglielmi, A M; Hagner, C; Hernando, J; Hong, T M; Hubbard, D B; Hurst, P; Hyett, N; Iacopini, E; Joseph, C L; Juget, F R; Kent, N; Kirsanov, M; Klimov, O; Kokkonen, J; Kovzelev, A; Krasnoperov, A V; Lacaprara, S; Lachaud, C; Lakic, B; Lanza, A; La Rotonda, L; Laveder, M; Letessier-Selvon, A A; Lévy, J M; Linssen, Lucie; Ljubicic, A; Long, J; Lupi, A; Lyubushkin, V V; Marchionni, A; Martelli, F; Méchain, X; Mendiburu, J P; Meyer, J P; Mezzetto, Mauro; Mishra, S R; Moorhead, G F; Nédélec, P; Nefedov, Yu A; Nguyen-Mau, C; Orestano, D; Pastore, F; Peak, L S; Pennacchio, E; Pessard, H; Petti, R; Placci, A; Polesello, G; Pollmann, D; Polyarush, A Yu; Poulsen, C; Rebuffi, L; Rico, J; Roda, C; Rubbia, André; Salvatore, F; Schahmaneche, K; Schmidt, B; Schmidt, T; Sconza, A; Sevior, M E; Shih, D; Sillou, D; Soler, F J P; Sozzi, G; Steele, D; Stiegler, U; Stipcevic, M; Stolarczyk, T; Tareb-Reyes, M; Taylor, G N; Tereshchenko, V V; Toropin, A N; Touchard, A M; Tovey, Stuart N; Tran, M T; Tsesmelis, E; Ulrichs, J; Vacavant, L; Valdata-Nappi, M; Valuev, V Yu; Vannucci, François; Varvell, K E; Veltri, M; Vercesi, V; Vidal-Sitjes, G; Vieira, J M; Vinogradova, T G; Weber, F V; Weisse, T; Wilson, F F; Winton, L J; Yabsley, B D; Zaccone, Henri; Zuber, K; Zuccon, P

    2004-01-01

    Results of a detailed study of strange particle production in neutrino neutral current interactions are presented using the data from the NOMAD experiment. Integral yields of neutral strange particles (K0s, Lambda, Lambda-bar) have been measured. Decays of resonances and heavy hyperons with an identified K0s or Lambda in the final state have been analyzed. Clear signals corresponding to K* and Sigma(1385) have been observed. First results on the measurements of the Lambda polarization in neutral current interactions have been obtained.

  5. A study of strange particles produced in neutrino neutral current interactions in the NOMAD experiment

    Science.gov (United States)

    Naumov, D.; Chukanov, A.; Naumova, E.; Popov, B.; Astier, P.; Autiero, D.; Baldisseri, A.; Baldo-Ceolin, M.; Banner, M.; Bassompierre, G.; Benslama, K.; Besson, N.; Bird, I.; Blumenfeld, B.; Bobisut, F.; Bouchez, J.; Boyd, S.; Bueno, A.; Bunyatov, S.; Camilleri, L.; Cardini, A.; Cattaneo, P. W.; Cavasinni, V.; Cervera-Villanueva, A.; Challis, R.; Collazuol, G.; Conforto, G.; Conta, C.; Contalbrigo, M.; Cousins, R.; Daniels, D.; Das, R.; Degaudenzi, H.; Del Prete, T.; de Santo, A.; Dignan, T.; di Lella, L.; Do Couto E Silva, E.; Dumarchez, J.; Ellis, M.; Feldman, G. J.; Ferrari, R.; Ferrère, D.; Flaminio, V.; Fraternali, M.; Gaillard, J.-M.; Gangler, E.; Geiser, A.; Geppert, D.; Gibin, D.; Gninenko, S.; Godley, A.; Gomez-Cadenas, J.-J.; Gosset, J.; Gößling, C.; Gouanère, M.; Grant, A.; Graziani, G.; Guglielmi, A.; Hagner, C.; Hernando, J.; Hong, T. M.; Hubbard, D.; Hurst, P.; Hyett, N.; Iacopini, E.; Joseph, C.; Juget, F.; Kent, N.; Kirsanov, M.; Klimov, O.; Kokkonen, J.; Kovzelev, A.; Krasnoperov, A.; Lacaprara, S.; Lachaud, C.; Lakić, B.; Lanza, A.; La Rotonda, L.; Laveder, M.; Letessier-Selvon, A.; Levy, J.-M.; Linssen, L.; Ljubičić, A.; Long, J.; Lupi, A.; Lyubushkin, V.; Marchionni, A.; Martelli, F.; Méchain, X.; Mendiburu, J.-P.; Meyer, J.-P.; Mezzetto, M.; Mishra, S. R.; Moorhead, G. F.; Nédélec, P.; Nefedov, Yu.; Nguyen-Mau, C.; Orestano, D.; Pastore, F.; Peak, L. S.; Pennacchio, E.; Pessard, H.; Petti, R.; Placci, A.; Polesello, G.; Pollmann, D.; Polyarush, A.; Poulsen, C.; Rebuffi, L.; Rico, J.; Riemann, P.; Roda, C.; Rubbia, A.; Salvatore, F.; Schahmaneche, K.; Schmidt, B.; Schmidt, T.; Sconza, A.; Sevior, M.; Shih, D.; Sillou, D.; Soler, F. J. P.; Sozzi, G.; Steele, D.; Stiegler, U.; Stipčević, M.; Stolarczyk, Th.; Tareb-Reyes, M.; Taylor, G. N.; Tereshchenko, V.; Toropin, A.; Touchard, A.-M.; Tovey, S. N.; Tran, M.-T.; Tsesmelis, E.; Ulrichs, J.; Vacavant, L.; Valdata-Nappi, M.; Valuev, V.; Vannucci, F.; Varvell, K. E.; Veltri, M.; Vercesi, V.; Vidal-Sitjes, G.; Vieira, J.-M.; Vinogradova, T.; Weber, F. V.; Weisse, T.; Wilson, F. F.; Winton, L. J.; Yabsley, B. D.; Zaccone, H.; Zuber, K.; Zuccon, P.; NOMAD Collaboration

    2004-11-01

    Results of a detailed study of strange particle production in neutrino neutral current interactions are presented using the data from the NOMAD experiment. Integral yields of neutral strange particles ( Ks0, Λ, Λ¯) have been measured. Decays of resonances and heavy hyperons with an identified Ks0 or Λ in the final state have been analyzed. Clear signals corresponding to K and Σ(1385 have been observed. First results on the measurements of the Λ polarization in neutral current interactions have been obtained.

  6. An Optimal PR Control Strategy with Load Current Observer for a Three-Phase Voltage Source Inverter

    Directory of Open Access Journals (Sweden)

    Xiaobo Dou

    2015-07-01

    Full Text Available Inverter voltage control is an important task in the operation of a DC/AC microgrid system. To improve the inverter voltage control dynamics, traditional approaches attempt to measure and feedforward the load current, which, however, needs remote measurement with communications in a microgrid system with distributed loads. In this paper, a load current observer (LCO based control strategy, which does not need remote measurement, is proposed for sinusoidal signals tracking control of a three-phase inverter of the microgrid. With LCO, the load current is estimated precisely, acting as the feedforward of the dual-loop control, which can effectively enlarge the stability margin of the control system and improve the dynamic response to load disturbance. Furthermore, multiple PR regulators are applied in this strategy conducted in a stationary  frame to suppress the transient fluctuations and the total harmonic distortion (THD of the output voltage and achieve faster transient performance compared with traditional dual-loop control in a rotating dq0 frame under instantaneous change of various types of load (i.e., balanced load, unbalanced load, and nonlinear load. The parameters of multiple PR regulators are analyzed and selected through the root locus method and the stability of the whole control system is evaluated and analyzed. Finally, the validity of the proposed approach is verified through simulations and a three-phase prototype test system with a TMS320F28335 DSP.

  7. Measurement of the neutrino-oxygen neutral-current interaction cross section by observing nuclear deexcitation γ rays

    Science.gov (United States)

    Abe, K.; Adam, J.; Aihara, H.; Akiri, T.; Andreopoulos, C.; Aoki, S.; Ariga, A.; Ariga, T.; Assylbekov, S.; Autiero, D.; Barbi, M.; Barker, G. J.; Barr, G.; Bass, M.; Batkiewicz, M.; Bay, F.; Bentham, S. W.; Berardi, V.; Berger, B. E.; Berkman, S.; Bertram, I.; Bhadra, S.; Blaszczyk, F. d. M.; Blondel, A.; Bojechko, C.; Bordoni, S.; Boyd, S. B.; Brailsford, D.; Bravar, A.; Bronner, C.; Buchanan, N.; Calland, R. G.; Caravaca Rodríguez, J.; Cartwright, S. L.; Castillo, R.; Catanesi, M. G.; Cervera, A.; Cherdack, D.; Christodoulou, G.; Clifton, A.; Coleman, J.; Coleman, S. J.; Collazuol, G.; Connolly, K.; Cremonesi, L.; Dabrowska, A.; Danko, I.; Das, R.; Davis, S.; de Perio, P.; De Rosa, G.; Dealtry, T.; Dennis, S. R.; Densham, C.; Dewhurst, D.; Di Lodovico, F.; Di Luise, S.; Drapier, O.; Duboyski, T.; Duffy, K.; Dufour, F.; Dumarchez, J.; Dytman, S.; Dziewiecki, M.; Emery-Schrenk, S.; Ereditato, A.; Escudero, L.; Finch, A. J.; Fiorentini Aguirre, G. A.; Friend, M.; Fujii, Y.; Fukuda, Y.; Furmanski, A. P.; Galymov, V.; Gaudin, A.; Giffin, S.; Giganti, C.; Gilje, K.; Goeldi, D.; Golan, T.; Gomez-Cadenas, J. J.; Gonin, M.; Grant, N.; Gudin, D.; Hadley, D. R.; Haegel, L.; Haesler, A.; Haigh, M. D.; Hamilton, P.; Hansen, D.; Hara, T.; Hartz, M.; Hasegawa, T.; Hastings, N. C.; Hayato, Y.; Hearty, C.; Helmer, R. L.; Hierholzer, M.; Hignight, J.; Hillairet, A.; Himmel, A.; Hiraki, T.; Hirota, S.; Holeczek, J.; Horikawa, S.; Huang, K.; Ichikawa, A. K.; Ieki, K.; Ieva, M.; Ikeda, M.; Imber, J.; Insler, J.; Irvine, T. J.; Ishida, T.; Ishii, T.; Ives, S. J.; Iwai, E.; Iwamoto, K.; Iyogi, K.; Izmaylov, A.; Jacob, A.; Jamieson, B.; Johnson, R. A.; Johnson, S.; Jo, J. H.; Jonsson, P.; Jung, C. K.; Kabirnezhad, M.; Kaboth, A. C.; Kajita, T.; Kakuno, H.; Kameda, J.; Kanazawa, Y.; Karlen, D.; Karpikov, I.; Katori, T.; Kearns, E.; Khabibullin, M.; Khotjantsev, A.; Kielczewska, D.; Kikawa, T.; Kilinski, A.; Kim, J.; King, S.; Kisiel, J.; Kitching, P.; Kobayashi, T.; Koch, L.; Kolaceke, A.; Konaka, A.; Kormos, L. L.; Korzenev, A.; Koseki, K.; Koshio, Y.; Kreslo, I.; Kropp, W.; Kubo, H.; Kudenko, Y.; Kumaratunga, S.; Kurjata, R.; Kutter, T.; Lagoda, J.; Laihem, K.; Lamont, I.; Larkin, E.; Laveder, M.; Lawe, M.; Lazos, M.; Lee, K. P.; Licciardi, C.; Lindner, T.; Lister, C.; Litchfield, R. P.; Longhin, A.; Ludovici, L.; Macaire, M.; Magaletti, L.; Mahn, K.; Malek, M.; Manly, S.; Marino, A. D.; Marteau, J.; Martin, J. F.; Martynenko, S.; Maruyama, T.; Marzec, J.; Mathie, E. L.; Matveev, V.; Mavrokoridis, K.; Mazzucato, E.; McCarthy, M.; McCauley, N.; McFarland, K. S.; McGrew, C.; Mefodiev, A.; Metelko, C.; Mezzetto, M.; Mijakowski, P.; Miller, C. A.; Minamino, A.; Mineev, O.; Mine, S.; Missert, A.; Miura, M.; Monfregola, L.; Moriyama, S.; Mueller, Th. A.; Murakami, A.; Murdoch, M.; Murphy, S.; Myslik, J.; Nagasaki, T.; Nakadaira, T.; Nakahata, M.; Nakai, T.; Nakamura, K.; Nakayama, S.; Nakaya, T.; Nakayoshi, K.; Nantais, C.; Naples, D.; Nielsen, C.; Nirkko, M.; Nishikawa, K.; Nishimura, Y.; Nowak, J.; O'Keeffe, H. M.; Ohta, R.; Okumura, K.; Okusawa, T.; Oryszczak, W.; Oser, S. M.; Ovsyannikova, T.; Owen, R. A.; Oyama, Y.; Palladino, V.; Palomino, J. L.; Paolone, V.; Payne, D.; Pearce, G. F.; Perevozchikov, O.; Perkin, J. D.; Petrov, Y.; Pickard, L.; Pinzon Guerra, E. S.; Pistillo, C.; Plonski, P.; Poplawska, E.; Popov, B.; Posiadala-Zezula, M.; Poutissou, J.-M.; Poutissou, R.; Przewlocki, P.; Quilain, B.; Radicioni, E.; Ratoff, P. N.; Ravonel, M.; Rayner, M. A. M.; Redij, A.; Reeves, M.; Reinherz-Aronis, E.; Riccio, C.; Retiere, F.; Robert, A.; Rodrigues, P. A.; Rojas, P.; Rondio, E.; Roth, S.; Rubbia, A.; Ruterbories, D.; Sacco, R.; Sakashita, K.; Sánchez, F.; Sato, F.; Scantamburlo, E.; Scholberg, K.; Schoppmann, S.; Schwehr, J.; Scott, M.; Seiya, Y.; Sekiguchi, T.; Sekiya, H.; Sgalaberna, D.; Shaker, F.; Shiozawa, M.; Short, S.; Shustrov, Y.; Sinclair, P.; Smith, B.; Smith, R. J.; Smy, M.; Sobczyk, J. T.; Sobel, H.; Sorel, M.; Southwell, L.; Stamoulis, P.; Steinmann, J.; Still, B.; Suda, Y.; Suzuki, A.; Suzuki, K.; Suzuki, S. Y.; Suzuki, Y.; Szeglowski, T.; Tacik, R.; Tada, M.; Takahashi, S.; Takeda, A.; Takeuchi, Y.; Tanaka, H. K.; Tanaka, H. A.; Tanaka, M. M.; Taylor, I. J.; Terhorst, D.; Terri, R.; Thompson, L. F.; Thorley, A.; Tobayama, S.; Toki, W.; Tomura, T.; Totsuka, Y.; Touramanis, C.; Tsukamoto, T.; Tzanov, M.; Uchida, Y.; Ueno, K.; Vacheret, A.; Vagins, M.; Vasseur, G.; Wachala, T.; Waldron, A. V.; Walter, C. W.; Wark, D.; Wascko, M. O.; Weber, A.; Wendell, R.; Wilkes, R. J.; Wilking, M. J.; Wilkinson, C.; Williamson, Z.; Wilson, J. R.; Wilson, R. J.; Wongjirad, T.; Yamada, Y.; Yamamoto, K.; Yanagisawa, C.; Yano, T.; Yen, S.; Yershov, N.; Yokoyama, M.; Yuan, T.; Yu, M.; Zalewska, A.; Zalipska, J.; Zambelli, L.; Zaremba, K.; Ziembicki, M.; Zimmerman, E. D.; Zito, M.; Żmuda, J.; T2K Collaboration

    2014-10-01

    We report the first measurement of the neutrino-oxygen neutral-current quasielastic (NCQE) cross section. It is obtained by observing nuclear deexcitation γ rays which follow neutrino-oxygen interactions at the Super-Kamiokande water Cherenkov detector. We use T2K data corresponding to 3.01 ×1 020 protons on target. By selecting only events during the T2K beam window and with well-reconstructed vertices in the fiducial volume, the large background rate from natural radioactivity is dramatically reduced. We observe 43 events in the 4-30 MeV reconstructed energy window, compared with an expectation of 51.0, which includes an estimated 16.2 background events. The background is primarily nonquasielastic neutral-current interactions and has only 1.2 events from natural radioactivity. The flux-averaged NCQE cross section we measure is 1.55 ×1 0-38 cm2 with a 68% confidence interval of (1.22 ,2.20 )×1 0-38 cm2 at a median neutrino energy of 630 MeV, compared with the theoretical prediction of 2.01 ×1 0-38 cm2 .

  8. Study on electrical current variations in electromembrane extraction process: Relation between extraction recovery and magnitude of electrical current.

    Science.gov (United States)

    Rahmani, Turaj; Rahimi, Atyeh; Nojavan, Saeed

    2016-01-15

    This contribution presents an experimental approach to improve analytical performance of electromembrane extraction (EME) procedure, which is based on the scrutiny of current pattern under different extraction conditions such as using different organic solvents as supported liquid membrane, electrical potentials, pH values of donor and acceptor phases, variable extraction times, temperatures, stirring rates, different hollow fiber lengths and the addition of salts or organic solvents to the sample matrix. In this study, four basic drugs with different polarities were extracted under different conditions with the corresponding electrical current patterns compared against extraction recoveries. The extraction process was demonstrated in terms of EME-HPLC analyses of selected basic drugs. Comparing the obtained extraction recoveries with the electrical current patterns, most cases exhibited minimum recovery and repeatability at the highest investigated magnitude of electrical current. . It was further found that identical current patterns are associated with repeated extraction efficiencies. In other words, the pattern should be repeated for a successful extraction. The results showed completely different electrical currents under different extraction conditions, so that all variable parameters have contributions into the electrical current pattern. Finally, the current patterns of extractions from wastewater, plasma and urine samples were demonstrated. The results indicated an increase in the electrical current when extracting from complex matrices; this was seen to decrease the extraction efficiency.

  9. Auroral current systems in Saturn's magnetosphere: comparison of theoretical models with Cassini and HST observations

    Directory of Open Access Journals (Sweden)

    S. W. H. Cowley

    2008-09-01

    Full Text Available The first simultaneous observations of fields and plasmas in Saturn's high-latitude magnetosphere and UV images of the conjugate auroral oval were obtained by the Cassini spacecraft and the Hubble Space Telescope (HST in January 2007. These data have shown that the southern auroral oval near noon maps to the dayside cusp boundary between open and closed field lines, associated with a major layer of upward-directed field-aligned current (Bunce et al., 2008. The results thus support earlier theoretical discussion and quantitative modelling of magnetosphere-ionosphere coupling at Saturn (Cowley et al., 2004, that suggests the oval is produced by electron acceleration in the field-aligned current layer required by rotational flow shear between strongly sub-corotating flow on open field lines and near-corotating flow on closed field lines. Here we quantitatively compare these modelling results (the "CBO" model with the Cassini-HST data set. The comparison shows good qualitative agreement between model and data, the principal difference being that the model currents are too small by factors of about five, as determined from the magnetic perturbations observed by Cassini. This is suggested to be principally indicative of a more highly conducting summer southern ionosphere than was assumed in the CBO model. A revised model is therefore proposed in which the height-integrated ionospheric Pedersen conductivity is increased by a factor of four from 1 to 4 mho, together with more minor adjustments to the co-latitude of the boundary, the flow shear across it, the width of the current layer, and the properties of the source electrons. It is shown that the revised model agrees well with the combined Cassini-HST data, requiring downward acceleration of outer magnetosphere electrons through a ~10 kV potential in the current layer at the open-closed field line boundary to produce an auroral oval of ~1° width with UV emission intensities of a few tens of kR.

  10. MODEL STUDY OF THE DOUBLE FED MACHINE WITH CURRENT CONTROL

    Directory of Open Access Journals (Sweden)

    A. S. Lyapin

    2016-07-01

    Full Text Available The paper deals with modeling results of the double fed induction machine with current control in the rotor circuit. We show the most promising applications of electric drives on the basis of the double fed induction machine and their advantages. We present and consider functional scheme of the electric drive on the basis of the double fed induction machine with current control. Equations are obtained for creation of such machine mathematical model. Expressions for vector projections of rotor current are given. According to the obtained results, the change of the vector projections of rotor current ensures operation of the double fed induction machine with the specified values of active and reactive stator power throughout the variation range of sliding motion. We consider static characteristics of double fed machine with current control. Energy processes proceeding in the machine are analyzed. We confirm the operationpossibility of double fed induction machine with current controlin the rotor circuit with given values of active and reactive stator power. The presented results can be used for creation of mathematical models and static characteristics of double fed machines with current control of various capacities.

  11. Simulation study on heterogeneous variance adjustment for observations with different measurement error variance

    DEFF Research Database (Denmark)

    Pitkänen, Timo; Mäntysaari, Esa A; Nielsen, Ulrik Sander

    2013-01-01

    of variance correction is developed for the same observations. As automated milking systems are becoming more popular the current evaluation model needs to be enhanced to account for the different measurement error variances of observations from automated milking systems. In this simulation study different...... models and different approaches to account for heterogeneous variance when observations have different measurement error variances were investigated. Based on the results we propose to upgrade the currently applied models and to calibrate the heterogeneous variance adjustment method to yield same genetic...

  12. Study of wavelet transform type high-current transformer

    Institute of Scientific and Technical Information of China (English)

    卢文科; 朱长纯; 刘君华; 张建军

    2002-01-01

    The wavelet transformation is applied to the high-current transformer.The high-current transformer elaborated in the paper is mainly applied to the measurement of AC/DC high-current.The principle of the transformer is the Hall direct-measurement principle.The transformer has the following three characteristics:firstly, the effect of the remnant field of the iron core on the measurement is decreased;secondly,because the temperature compensation is adopted,the transformer has good temperature charactreristic;thirdly,be-cause the wavelet transfomation technology is adopted,the transformer has the capacity of good antijanming.

  13. Meta-analysis of observational epidemiological studies: a review.

    OpenAIRE

    Jones, D R

    1992-01-01

    Meta-analyses (integration of findings by quantitative analyses of results of individual studies) are already widely used in the psychological and educational sciences and in the pooling of clinical trial results. Examples of the application of such techniques to the results of observational epidemiological studies are now proliferating. In this paper meta-analysis of the results of observational epidemiological studies is reviewed. Uncritical adoption of techniques used in pooled analyses of...

  14. Sub-mesoscale Eddies and Their Propagation Paths in Long Bay, SC Observed in HF Radar Surface Currents

    Science.gov (United States)

    Cahl, D.; Voulgaris, G.

    2015-12-01

    Sub-mesoscale eddies on the shoreward front of the Gulf Stream (GS) are thought to play a critical role in controlling cross-shelf transport and momentum flux in the South Atlantic Bight (SAB) but cannot be observed continuously from satellites due to cloud cover. Non-linear eddies have the ability to trap and transport water as they propagate, which make them a potential source of cross-shelf transport. Long Bay, SC, just downstream of the Charleston Bump is the area of highest eddy activity in the SAB. Surface currents in Long Bay have been observed since 2012 using HF radars. The accuracy of three eddy detection methods (Okubo-Weiss, Vector-geometry, Winding-angle) are compared in this area of high shear on the shoreward front of the GS. The Okubo-Weiss parameter does not perform well in this area due to the high shear environment where eddies propagate. The Vector-Geometry method has good successful detection rates but suffers in shape analysis from inaccurate Stream Function contours in this area due to divergent surface currents. The Winding-Angle method performs well and was used to detect eddies and their propagation paths in Long Bay for years 2013 and 2014. Detected eddies propagate predominantly along-shelf, with cyclonic (anticyclonic) eddies propagating downstream (upstream) with respect the GS. Few eddies with the ability to trap and transport water propagating in the across-shelf direction were observed, leading to the conclusion that most of the influence of these eddies is confined to the shoreward front of the GS, near the shelf break.

  15. Overview of the Cassini In-Situ Observations of Auroral Field-Aligned Currents During the 2013 Saturn Aurora Campaign

    Science.gov (United States)

    Bunce, E. J.; Badman, S. V.; Cowley, S. W.; Dougherty, M. K.; Gurnett, D. A.; Jinks, S.; Kurth, W. S.; Mitchell, D. G.; Nichols, J. D.; Provan, G.; Pryor, W. R.

    2013-12-01

    The Saturn Aurora Campaign 2013 is a coordinated effort to provide a clearer understanding of Saturn's auroral emissions at multiple wavelengths in the upper atmosphere, and their associated magnetospheric signatures and dynamics. Structures such as Corotating Interaction Regions (CIRs) are known to play a significant role in the modulation of Saturn's auroral emissions via abrupt changes in the dynamic pressure associated with forward shocks at the start of the CIR compression regions. Recent observations from the Cassini spacecraft at Saturn have also taught us that the 'magnetosphere oscillations' observed in magnetic field perturbations in the northern and southern hemispheres, which are associated with the SKR modulations in each hemisphere, also significantly modulate the magnetosphere and auroral emissions. Here we present an overview of the in situ magnetosphere measurements during the campaign, along with an overview of the solar wind conditions upstream of Saturn inferred from the Saturn Kilometric Radiation (SKR) emissions. We will discuss evidence of the high-latitude field-aligned currents and plasma boundaries (e.g. the open-closed field line (or related) boundary) from the magnetic field data, plasma signatures and/or auroral hiss observations (using the Cassini magnetometer-MAG, the Magnetospheric Imaging Instrument-MIMI, and the Radio Plasma Wave Science-RPWS instruments respectively). We will attempt to characterise the morphology and variability (e.g. co-latitude, intensity) of the current system(s) from both the knowledge of the northern or southern magnetosphere oscillation phase (according to the location of the spacecraft) and the inferred solar wind conditions. We will compare these results with available IR/UV auroral images from the campaign.

  16. Study on UPF Harmonic Current Detection Method Based on DSP

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, H J [Northwestern Polytechnical University, Xi' an 710072 (China); Pang, Y F [Xi' an University of Technology, Xi' an 710048 (China); Qiu, Z M [Xi' an University of Technology, Xi' an 710048 (China); Chen, M [Northwestern Polytechnical University, Xi' an 710072 (China)

    2006-10-15

    Unity power factor (UPF) harmonic current detection method applied to active power filter (APF) is presented in this paper. The intention of this method is to make nonlinear loads and active power filter in parallel to be an equivalent resistance. So after compensation, source current is sinusoidal, and has the same shape of source voltage. Meanwhile, there is no harmonic in source current, and the power factor becomes one. The mathematic model of proposed method and the optimum project for equivalent low pass filter in measurement are presented. Finally, the proposed detection method applied to a shunt active power filter experimental prototype based on DSP TMS320F2812 is developed. Simulation and experiment results indicate the method is simple and easy to implement, and can obtain the real-time calculation of harmonic current exactly.

  17. Durability Study of SOFCs Under Cycling Current Load Conditions

    DEFF Research Database (Denmark)

    Hagen, Anke; Hendriksen, Peter Vang; Frandsen, Henrik Lund;

    2009-01-01

    In fuel cell applications, the cells must be able to withstand varying operating conditions. Anode supported solid oxide fuel cells were tested under cycling current load in order to determine the durability and possibly identify degradation mechanisms. At 750 °C and a cycling between zero and 0.......75 A cm-2, the cell voltage degradation rate was similar to tests with the corresponding high constant current density. However, by analyzing the impedance spectra it was found that anode degradation was becoming more important when going from constant to cycling conditions. Running the cycling load tests...... at 850 °C, the cells degraded similarly as under the corresponding constant current load whereas, in some cases, cells failed mechanically after a few hundred hours. These cells did not experience severe additional degradation due to the cycling of the current density until the point of failure...

  18. Transcranial direct-current stimulation induced in stroke patients with aphasia: a prospective experimental cohort study

    Directory of Open Access Journals (Sweden)

    Michele Devido Santos

    Full Text Available CONTEXT AND OBJECTIVE: Previous animal and human studies have shown that transcranial direct current stimulation can induce significant and lasting neuroplasticity and may improve language recovery in patients with aphasia. The objective of the study was to describe a cohort of patients with aphasia after stroke who were treated with transcranial direct current stimulation. DESIGN AND SETTING: Prospective cohort study developed in a public university hospital. METHODS: Nineteen patients with chronic aphasia received 10 transcranial direct current stimulation sessions lasting 20 minutes each on consecutive days, using a current of 2 mA. The anode was positioned over the supraorbital area and the cathode over the contralateral motor cortex. The following variables were analyzed before and after the 10 neuromodulation sessions: oral language comprehension, copying, dictation, reading, writing, naming and verbal fluency. RESULTS: There were no adverse effects in the study. We found statistically significant differences from before to after stimulation in relation to simple sentence comprehension (P = 0.034, naming (P = 0.041 and verbal fluency for names of animals (P = 0.038. Improved scores for performing these three tasks were seen after stimulation. CONCLUSIONS: We observed that excitability of the primary motor cortex through transcranial direct current stimulation was associated with effects on different aspects of language. This can contribute towards future testing in randomized controlled trials.

  19. The EULAR Study Group for Registers and Observational Drug Studies

    DEFF Research Database (Denmark)

    Kearsley-Fleet, Lianne; Závada, Jakub; Hetland, Merete Lund

    2015-01-01

    OBJECTIVE: Under the auspices of the European League Against Rheumatism (EULAR), a study group of investigators representing European biologic DMARD (bDMARD) registers was convened. The purpose of this initial assessment was to collect and compare a cross section of patient characteristics...

  20. Study of lower hybrid current drive for the demonstration reactor

    Energy Technology Data Exchange (ETDEWEB)

    Molavi-Choobini, Ali Asghar [Dept. of Physics, Faculty of Engineering, Islamic Azad University, Shahr-e-kord Branch, Shahr-e-kord (Iran, Islamic Republic of); Naghidokht, Ahmed [Dept. of Physics, Urmia University, Urmia (Iran, Islamic Republic of); Karami, Zahra [Dept. of Engineering, Islamic Azad University, Zanjan Branch, Zanjan (Iran, Islamic Republic of)

    2016-06-15

    Steady-state operation of a fusion power plant requires external current drive to minimize the power requirements, and a high fraction of bootstrap current is required. One of the external sources for current drive is lower hybrid current drive, which has been widely applied in many tokamaks. Here, using lower hybrid simulation code, we calculate electron distribution function, electron currents and phase velocity changes for two options of demonstration reactor at the launched lower hybrid wave frequency 5 GHz. Two plasma scenarios pertaining to two different demonstration reactor options, known as pulsed (Option 1) and steady-state (Option 2) models, have been analyzed. We perceive that electron currents have major peaks near the edge of plasma for both options but with higher efficiency for Option 1, although we have access to wider, more peripheral regions for Option 2. Regarding the electron distribution function, major perturbations are at positive velocities for both options for flux surface 16 and at negative velocities for both options for flux surface 64.

  1. Quantitative study of electrophoretic and electroosmotic enhancement during alternating current iontophoresis across synthetic membranes.

    Science.gov (United States)

    Yan, Guang; Li, S Kevin; Peck, Kendall D; Zhu, Honggang; Higuchi, William I

    2004-12-01

    One of the primary safety and tolerability limitations of direct current iontophoresis is the potential for electrochemical burns associated with the necessary current densities and/or application times required for effective treatment. Alternating current (AC) transdermal iontophoresis has the potential to eliminate electrochemical burns that are frequently observed during direct current transdermal iontophoresis. Although it has been demonstrated that the intrinsic permeability of skin can be increased by applying low-to-moderate AC voltages, transdermal transport phenomena and enhancement under AC conditions have not been systematically studied and are not well understood. The aim of the present work was to study the fundamental transport mechanisms of square-wave AC iontophoresis using a synthetic membrane system. The model synthetic membrane used was a composite Nuclepore membrane. AC frequencies ranging from 20 to 1000 Hz and AC fields ranging from 0.25 to 0.5 V/membrane were investigated. A charged permeant, tetraethyl ammonium, and a neutral permeant, arabinose, were used. The transport studies showed that flux was enhanced by increasing the AC voltage and decreasing AC frequency. Two theoretical transport models were developed: one is a homogeneous membrane model; the other is a heterogeneous membrane model. Experimental transport data were compared with computer simulations based on these models. Excellent agreement between model predictions and experimental data was observed when the data were compared with the simulations from the heterogeneous membrane model.

  2. MOOSES: Multiple Option Observation System for Experimental Studies.

    Science.gov (United States)

    Tapp, Jon; Wehby, Joseph

    The Multiple Option Observation System for Experimental Studies (MOOSES) is a flexible data collection and analysis package for applied behavioral research that addresses the needs of researchers interested in live coding of observational data. MOOSES allows the researcher to design a coding system for a particular research question. General types…

  3. Handover patterns: an observational study of critical care physicians

    Directory of Open Access Journals (Sweden)

    Ilan Roy

    2012-01-01

    Full Text Available Abstract Background Handover (or 'handoff' is the exchange of information between health professionals that accompanies the transfer of patient care. This process can result in adverse events. Handover 'best practices', with emphasis on standardization, have been widely promoted. However, these recommendations are based mostly on expert opinion and research on medical trainees. By examining handover communication of experienced physicians, we aim to inform future research, education and quality improvement. Thus, our objective is to describe handover communication patterns used by attending critical care physicians in an academic centre and to compare them with currently popular, standardized schemes for handover communication. Methods Prospective, observational study using video recording in an academic intensive care unit in Ontario, Canada. Forty individual patient handovers were randomly selected out of 10 end-of-week handover sessions of attending physicians. Two coders independently reviewed handover transcripts documenting elements of three communication schemes: SBAR (Situation, Background, Assessment, Recommendations; SOAP (Subjective, Objective, Assessment, Plan; and a standard medical admission note. Frequency and extent of questions asked by incoming physicians were measured as well. Analysis consisted of descriptive statistics. Results Mean (± standard deviation duration of patient-specific handovers was 2 min 58 sec (± 57 sec. The majority of handovers' content consisted of recent and current patient status. The remainder included physicians' interpretations and advice. Questions posed by the incoming physicians accounted for 5.8% (± 3.9% of the handovers' content. Elements of all three standardized communication schemes appeared repeatedly throughout the handover dialogs with no consistent pattern. For example, blocks of SOAP's Assessment appeared 5.2 (± 3.0 times in patient handovers; they followed Objective blocks in only 45

  4. Perspective of the study on the ring current - past, present and future

    Science.gov (United States)

    Ebihara, Y.

    2016-12-01

    The study of the ring current has a long history going back to the early 20th century. The ring current was predicted by Carl Stoermer to explain the equatorward movement of the auroral zone during magnetic storms. In 1917, Adolf Schmidt introduced the concept of the ring current to explain the global decrease of the geomagnetic field. Since then, number of studies have been accomplished in the context of the growth and recovery of magnetic storms. Observations have shown that protons and oxygen ions with energies 1 - 100 keV significantly increase during the storm main phase, which are most likely the major contributor to the storm-time ring current. When the loss of the ions dominates the injection of them, the storm recovery phase takes place. Immediate problems are the origin, transport and loss of the ions. All these relevant processes are essential to understand the growth and decay of the ring current. Derived problems, for example, include the entry of solar wind plasma into the magnetosphere, the outflow of ionospheric ions, generation of the convection electric field, influence of substorm-associated electric field, and pitch angle scattering of ions. Recalling that the ring current is the diamagnetic current, we shall consider the force balance and stress carefully. Generation of field-aligned currents is one of the consequences, which might redistribute the state of the inner magnetosphere including the plasmasphere, the ring current and the radiation belts. The ring current may also have a large influence on the geomagnetically induced current (GIC) on the ground at mid- and low-latitudes. The magnetic storms can be easily identified by looking at magnetograms, but the processes behind the magnetic storms cannot be easily understood because the processes depend on each other. From this sense, we shall pay much attention to the detailed function of each process as well as its role on the overall system. Dealing with the ring current as a complex system

  5. Air Quality Study Using Satellites - Current Capability and Future Plans

    Science.gov (United States)

    Bhartia, Pawan K.; Joiner, Joanna; Gleason, James; Liu, Xiong; Torres, Omar; Krotkov, Nickolay; Ziemke, Jerry; Chandra, Sushil

    2008-01-01

    Satellite instruments have had great success in monitoring the stratospheric ozone and in understanding the processes that control its daily to decadal scale variations. This field is now reaching its zenith with a number of satellite instruments from the US, Europe and Canada capping several decades of active research in this field. The primary public policy imperative of this research was to make reliable prediction of increases in biologically active surface UV radiation due to human activity. By contrast retrieval from satellite data of atmospheric constituents and photo-chemically active radiation that affect air quality is a new and growing field that is presenting us with unique challenges in measurement and data interpretation. A key distinction compared to stratospheric sensors is the greatly enhanced role of clouds, aerosols, and surfaces (CAS) in determining the quality and quantity of useful data that is available for air quality research. In our presentation we will use data from several sensors that are currently flying on the A-train satellite constellation, including OMI, MODIS, CLOUDSAT, and CALIPSO, to highlight that CAS can have both positive and negative effects on the information content of satellite measurements. This is in sharp contrast to other fields of remote sensing where CAS are usually considered an interference except in those cases when they are the primary subject of study. Our analysis has revealed that in the reflected wavelengths one often sees much further down into the atmosphere, through most cirrus, than one does in the emitted wavelengths. The lower level clouds provide a nice background against which one can track long-range transport of trace gases and aerosols. In addition, differences in trace gas columns estimated over cloudy and adjacent clear pixels can be used to measure boundary layer trace gases. However, in order to take full advantage of these features it will be necessary to greatly advance our understanding of

  6. High resolution modelling and observation of wind-driven surface currents in a semi-enclosed estuary

    Science.gov (United States)

    Nash, S.; Hartnett, M.; McKinstry, A.; Ragnoli, E.; Nagle, D.

    2012-04-01

    offline coupling with the wind forecast models. Modelled surface currents show good correlation with CODAR observed currents and the resolution of the surface wind data is shown to be important for model accuracy.

  7. Current state of epidemiological studies in Belarus about Chernobyl sufferers

    Energy Technology Data Exchange (ETDEWEB)

    Matsko, V.P. [Institute of Radiobiology, Academy Sciences of Belarus, Minsk (Belarus)

    1998-03-01

    The present paper is an analysis of the results of epidemiological studies in Belarus about the after-effects of the accident at the Chernobyl atomic power station (ChAPS), based on published data at scientific institutes, organs and institutions of Ministry of Health. In the last years the affected population showed thereby more significant - as compared with republican indices - growth of incidence in the majority of diseases (first of all: digestion, urogenital, nervous, endocrine systems, diseases of ear, throat, nose both among adults and among children). Aggravation of health state continues in the participants of liquidation of the ChAPS accident consequences and the evacuees from the alienation zone which have obtained considerable radiation load to organism (rise of incidence of diseases of endocrine, cardiovascular, nervous system etc.). Considerable growth of thyroid cancer incidence is registered in Belarus children and adolescents, especially in the Gomel and Brest regions. This is conditioned by dose commitments on thyroid gland due to iodine radionuclides in first period after the accident, incorrect iodine prophylaxy, and goitre endemic. The rise of hereditary pathology is registered too. An expressed increase of oncological diseases is observed therewith mainly in the Gomel region, especially in the districts with high level of radiocontamination and, consequently, significant radiation load. First of all, this relates to the growth of incidence of cancer of lungs, mammary gland, bladder. The analysis of epidemiological studies performed in Belarus after the ChAPS catastrophe and comparison of them with data obtained in the pre-Chernobyl period testify to the aggravation of health state of Belarus population. The specialists unambiguously recognize the direct influence of radioactive pollution in the environment on rise of thyroid pathologies, hereditary and congenial diseases, and cancers of different localizations. There is no unique opinion

  8. Evidence of the Relationship between the Emerging Magnetic Fields, Electric Currents, and Solar Flares Observed on May 10, 2012

    CERN Document Server

    Livshits, M A; Myshyakov, I I; Rudenko, G V

    2016-01-01

    We have analyzed multi-wavelength observations and magnetic-field data for the solar flare of May 10, 2012 (04:18 UT) and have detected a sign inversion of the signal in the line-of-sight magnetic measurements in the umbra of a small spot. This effect is associated, at least partly, with the emergence of a new magnetic field. Almost at the same time, a burst of hard X-rays was recorded, and a wave in the vacuum ultraviolet (EUV) range (a "sunquake") was generated due to the impact of the disturbance in the energy release range on the photosphere. At the beginning of the event, a sigmoid flare was recorded, but it did not spread, as it usually does, along the polarity inversion (neutral) line. SDO/HMI full-vector measurements were used to extrapolate the AR 11476 magnetic field to the corona, and the distribution of vertical currents $j_z$ in the photosphere was obtained. The distribution of currents in the active region shows that the relationship between them and the occurrence of flares is very intricate. W...

  9. Models of field-aligned currents needful to simulate the substorm variations of the electric field and other parameters observed by EISCAT

    Directory of Open Access Journals (Sweden)

    M. A. Volkov

    Full Text Available We have used the global numerical model of the coupled ionosphere-thermosphere-protonosphere system to simulate the electric-field, ion- and electron-temperature and -concentration variations observed by EISCAT during the substorm event of 25 March 1987. In our previous studies we adopted the model input data for field-aligned currents and precipitating electron fluxes to obtain an agreement between observed and modelled ionospheric variations. Now, we have calculated the field-aligned currents needful to simulate the substrom variations of the electric field and other parameters observed by EISCAT. The calculations of the field-aligned currents have been performed by means of numerical integration of the time-dependent continuity equation for the cold magnetospheric electrons. This equation was added to the system of the modelling equations including the equation for the electric-field potential to be solved jointly. In this case the inputs of the model are the spatial and time variations of the electric-field potential at the polar-cap boundaries and those of the cold magnetospheric electron concentration which have been adopted to obtain the agreement between the observed and modelled ionospheric variations for the substorm event of 25 March 1987. By this means it has been found that during the active phase of the substorm the current wedge is formed. It is connected with the region of the decreased cold magnetospheric electron content travelling westwards with a velocity of about 1 km s–1 at ionospheric levels.

  10. Writing Instruction in First Grade: An Observational Study

    Science.gov (United States)

    Coker, David L., Jr.; Farley-Ripple, Elizabeth; Jackson, Allison F.; Wen, Huijing; MacArthur, Charles A.; Jennings, Austin S.

    2016-01-01

    As schools work to meet the ambitious Common Core State Standards in writing in the US, instructional approaches are likely to be examined (National Governors Association Center for Best Practices, Council of Chief State School Officers, 2010). However, there is little research on the current state of instruction. This study was designed to…

  11. Turbulent Gravity Current of Lock Release Type:A Numerical Study

    Institute of Scientific and Technical Information of China (English)

    G.Q.CHEN; J.H.W.LEE

    1999-01-01

    The time evolution of a turbulent gravity current of lock release type,formed by a finite volume of homogenous fluid released instantaneously into another fluid of slightly lower density,is studied numerically via the renormalization group(RNG)κ-ε model for Reynolds-stress closure to characterize the flow with transitional and highly localized turbulence,Consistent with previous experimental observations,the numerical results show that the gravity current passes through two distinct phases,an initial slumping phase in which the current head advances steadily,and a second self-similar phase in which the front velocity decreases like the negative third power of the time after release.An overall entrainment ratio proportional to the distance from the release point is found and comares well with available experimental data for the slumping phase.

  12. Current, temperature, backscatter, and other data from bottom instrument packages deployed from the RV Oceanus and other platforms in support of sediment transport observation in the Middle Atlantic Bight from 11 December 1975 to 30 October 1980 (NODC Accession 0066005)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A series of studies to assess environmental hazards to petroleum development in the Middle Atlantic Bight. Long-term observations of currents and near-bottom...

  13. First observation of neutral current proton electron scattering at the square root of s = 300 GeV

    Science.gov (United States)

    Hasegawa, Takuya

    1993-02-01

    Neutral current proton electron scattering at center of mass energy 295 GeV was observed for the first time, using the newly built proton electron collider HERA (Hadron Elektron Ring Anlage) and the general purpose detector ZEUS. The distributions of Q(sup 2), Bjorken-x(x), and Bjorken-y(y) were compared with the expectation based on the standard electroweak theory and QCD. Regarding the investigation of high-Q(sup 2) region, an event of Q(sup 2) approximately 1000 GeV(exp 2) was observed for the first time. From the x-distribution of the events, a limit on the mass and the coupling of an exotic s-channel resonance of a quark-lepton system (leptoquark) was obtained. The mass limit is 72 GeV (97 GeV) at 95% confidence level for a scalar type leptoquark with a left-handed (right-handed) electromagnetic coupling to ordinary leptons. The leptoquark is assumed to be weak-isoscalar. To realize this experiment, a uranium scintillator sandwich type calorimeter was developed. Equal response to electrons and hadrons (e/h = 1), which is essential for the good energy resolution for hadrons, has been achieved. One of the main characteristics of this calorimeter is a possibility of calibration utilizing its own uranium radioactivity. The grain variation of each channel can be detected with an accuracy of plus or minus one percent.

  14. Issues of reporting in observational studies in veterinary medicine.

    Science.gov (United States)

    Sargeant, Jan M; O'Connor, Annette M

    2014-02-15

    Observational studies are common in veterinary medicine; the results may be used to inform decision-making, future research, or as inputs to systematic reviews or risk assessment. To be of use, the results must be published, all of the outcomes that were assessed must be included in the publication, and the research (methods and results) must be reported in sufficient detail that the reader can evaluate the internal and external validity. In human healthcare, concerns about the completeness of reporting - and evidence that poor reporting is associated with study results - have led to the creation of reporting guidelines; these include the STROBE statement for observational studies. There is evidence from a limited body of research that there also are reporting inadequacies in veterinary observational studies. There are differences between human and veterinary observational studies that might be relevant to recommendations for reporting. Such differences include: the use of observational studies in animal populations for simultaneously estimating disease frequency and risk-factor identification; the distinction between the animal owners who consent to participate and the animals that are the study subjects; and the complexity of organizational levels inherent in animal research (in particular, for studies in livestock species). In veterinary medicine, it is common to have clustering within outcomes (due to animal grouping) and clustering of predictor variables. We argue that there is a compelling need for the scientific community involved in veterinary observational studies to use the STROBE statement, use an amended version of STROBE, or to develop and use reporting guidelines that are specific to veterinary medicine to improve reporting of these studies.

  15. ECR离子源引出束流周期性波动研究%Observation of Burst Frequency in Extracted ECR Ion Current

    Institute of Scientific and Technical Information of China (English)

    G.S.Taki; P.R.Sarma; A.G.Drentje; T.Nakagawa; P.K.Ray; R.K.Bhandari

    2007-01-01

    Earlier we reported an ion current jump which was observed at a fixed negative biased disc potential in the 6.4GHz ECR ion source at VECC,Kolkata.In a recent experiment with neon ions.we measured the time spectra of the ion current and observed the presence of a burst frequency in the kilohertz range.This frequency shows a correlated jump with the ion current jump described above.Another interesting feature is that the observed burst frequency shows a good linear correlation with the extracted ion current.The higher the ion current,the higher is the burst frequency.This means that current per burst is a constant factor;when there are more number of bursts,the current also increases.

  16. A EUropean study on effectiveness and sustainability of current Cardiac Rehabilitation programmes in the Elderly

    DEFF Research Database (Denmark)

    Prescott, Eva; Meindersma, Esther P; van der Velde, Astrid E

    2016-01-01

    on effectiveness and sustainability of current cardiac rehabilitation programmes in the elderly (EU-CaRE) project consists of an observational study and an open prospective, investigator-initiated multicentre randomised controlled trial (RCT) involving mobile telemonitoring guided CR (mCR). OBJECTIVE: The aim...... of EU-CaRE is to map the efficiency of current CR of the elderly in Europe, and to investigate whether mCR is an effective alternative in terms of efficacy, adherence and sustainability. METHODS AND RESULTS: The EU-CaRE study includes patients aged 65 years or older with ischaemic heart disease or who...... home-based programme while the control group will receive no advice or coaching throughout the study period. Outcomes will be assessed after the end of CR and at 12 months follow-up. The primary outcome is VO2peak and secondary outcomes include variables describing CR uptake, adherence, efficacy...

  17. Deterministic and Stochastic Study of Wind Farm Harmonic Currents

    DEFF Research Database (Denmark)

    Sainz, Luis; Mesas, Juan Jose; Teodorescu, Remus;

    2010-01-01

    Wind farm harmonic emissions are a well-known power quality problem, but little data based on actual wind farm measurements are available in literature. In this paper, harmonic emissions of an 18 MW wind farm are investigated using extensive measurements, and the deterministic and stochastic...... characterization of wind farm harmonic currents is analyzed. Specific issues addressed in the paper include the harmonic variation with the wind farm operating point and the random characteristics of their magnitude and phase angle....

  18. Zinc electrowinning: anode conditioning and current distribution studies

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, J.A. [Cominco Research, Cominco Ltd., Trail, British Columbia (Canada)

    2001-07-01

    In the zinc electrowinning (EW) process, Pb-Ag anodes are widely used. Prior to their use in the EW process, anodes are conditioned to form a stable oxide layer that can evolve O{sub 2} without excessive Pb contamination of the cathode and MnO{sub 2} precipitation. The most widely used conditioning techniques are: passivation in a KF-H{sub 2}SO{sub 4} electrolysis bath, chemical oxidation in a KMnO{sub 4}-H{sub 2}SO{sub 4} solution, and sandblasting. In this paper, a comparison of these treatments using flat and corrugated anodes is presented. Laboratory and industrial-scale tests carried out at Cominco's Trail and Cajamarquilla zinc plants indicated that flat anodes should be sandblasted or electrochemically passivated before their use in the Zn electrowinning process. Further, corrugated anodes should be sandblasted or chemically conditioned in a KMnO{sub 4}-H{sub 2}SO{sub 4} -electrolyte. The beneficial effects of chemical conditioning are lost if the anode is non-corrugated. Flat, chemically conditioned anodes generate up to 10 times more mud than corrugated-chemically conditioned anodes. Because anode mud growth is evenly distributed on sandblasted anodes, short-circuit frequency may decrease and anode life may increase. Sandblasting does not appear to affect anode performance. Parallel to the industrial anode conditioning tests, current distribution measurements were made. Current flow measurements were used to correct troublesome electrodes and/or bad electrical contacts. In Cajamarquilla, this technique was used in four industrial electrowinning cells and energy consumption values lower than 3000 kWh/t Zn were obtained at current efficiencies as high as 95% and at current densities up to 450 A/m{sup 2}. (author)

  19. Hippocampal-dependent neurocognitive impairment following cranial irradiation observed in pre-clinical models: current knowledge and possible future directions.

    Science.gov (United States)

    Tomé, Wolfgang A; Gökhan, Şölen; Gulinello, Maria E; Brodin, N Patrik; Heard, John; Mehler, Mark F; Guha, Chandan

    2016-01-01

    We reviewed the literature for studies pertaining to impaired adult neurogenesis leading to neurocognitive impairment following cranial irradiation in rodent models. This compendium was compared with respect to radiation dose, converted to equivalent dose in 2 Gy fractions (EQD2) to allow for direct comparison between studies. The effects of differences between animal species and the dependence on animal age as well as for time after irradiation were also considered. One of the major sites of de novo adult neurogenesis is the hippocampus, and as such, this review also focuses on assessing evidence related to the expression and potential effects of inflammatory cytokines on neural stem cells in the subgranular zone of the dentate gyrus and whether this correlates with neurocognitive impairment. This review also discusses potential strategies to mitigate the detrimental effects on neurogenesis and neurocognition resulting from cranial irradiation, and how the rationale for these strategies compares with the current outcome of pre-clinical studies.

  20. Passive output feedback and observer based autopilots: A comparative study

    Directory of Open Access Journals (Sweden)

    Marit Paulsen

    1996-04-01

    Full Text Available Two methods for course-keeping of a ship are studied where no measurements of the yaw rate are available. The two methods are a passive output feedback controller and a controller-observer structure. A comparison with special attention to stability and wave filtering properties, is provided. Finally, a case study of a ship autopilot is included.

  1. Observations

    DEFF Research Database (Denmark)

    Rossiter, John R.; Percy, Larry

    2013-01-01

    unrealistic laboratory studies, textbook writers continuing to ignore practitioners' research appearing in trade publications and practitioner-oriented journals, and practitioners peeling off into high-sounding but meaningless jargon. also evident is the tendency to regard the new electronic media...... as a classification of the new advertising formats in terms of traditional analogs with mainstream media advertising....

  2. Computational and experimental studies of laser cutting of the current collectors for lithium-ion batteries

    Science.gov (United States)

    Lee, Dongkyoung; Patwa, Rahul; Herfurth, Hans; Mazumder, Jyotirmoy

    2012-07-01

    Sizing electrodes is an important step during Lithium-ion battery manufacturing processes since poor cut edge affects battery performance significantly and sometime leads to fire hazard. Mechanical cutting could result in a poor cut quality with defects. The cutting quality can be improved by using a laser, due to its high energy concentration, fast processing time, small heat-affected zone, and high precision. The cutting quality is highly influenced by operating parameters such as laser power and scanning speed. Thus, we studied a numerical simulation to provide a guideline for achieving clear edge quality. In order to simulate electrodes laser cutting for Lithium-Ion batteries, understanding the behavior of current collectors is crucial. This study focuses on current collectors, such as pure copper and aluminium. Numerical studies utilized a 3D self-consistent mathematical model for laser-material interaction. Observations of penetration time, depth, and threshold during laser cutting processes of current collectors are described. The model is validated experimentally by cutting current collectors and single side-coated electrodes with a single mode fiber laser. The copper laser cutting is laser intensity and interaction time dependent process. The aluminium laser cutting depends more on laser intensity than the interaction time. Numerical and experimental results show good agreement.

  3. An observational study of sexual behavior in demented male patients.

    Science.gov (United States)

    Zeiss, A M; Davies, H D; Tinklenberg, J R

    1996-11-01

    Concerns have been expressed that patients with dementia will display disinhibited, inappropriate sexual behavior. Retrospective research suggests that this is rare, but no observational research has been reported. The purpose of this study was to conduct such an observational study. Subjects were 40 patients with a dementia diagnosis who were living in institutional settings; subjects ranged in age from 60 to 98. Coders observed subjects on nine separate occasions, three in the morning, three in the afternoon, and three in the evening. Subjects were observed in multiple situations; coding included appropriate, ambiguous, and inappropriate sexual behaviors. Reliability coding was obtained for 42% of the patients on 11% of coded episodes. Behaviors could be coded with high reliability (94% to 100% across categories of behavior). On average, patients displayed 43 appropriate sexual behaviors, 1.48 ambiguous behaviors, and .83 inappropriate behaviors across the nine observation periods. This was not evenly distributed across patients, however; only 18% of patients ever displayed a sexually inappropriate behavior, and these were usually brief and minor. Inappropriate sexual behavior was observed in only 1.6% of the observed one-minute time segments. Observational research documents what had been previously suggested by retrospective reports: inappropriate sexual behavior is uncommon in dementia patients and brief and minor even when it occurs. Ambiguous behaviors, such as appearing in public incompletely dressed, which could suggest exhibitionism but more likely reflects self-care deficits, were more common. Misinterpretation of these events may be the source for some of the persistent lore regarding sexually disinhibited behavior in dementia patients.

  4. Observations

    DEFF Research Database (Denmark)

    Rossiter, John R.; Percy, Larry

    2013-01-01

    as requiring a new model of how advertising communicates and persuades, which, as the authors' textbooks explain, is sheer nonsense and contrary to the goal of integrated marketing. We provide in this article a translation of practitioners' jargon into more scientifically acceptable terminology as well...... product or service or to achieve a higher price that consumers are willing to pay than would obtain in the absence of advertising. What has changed in recent years is the notable worsening of the academic-practitioner divide, which has seen academic advertising researchers pursuing increasingly...... unrealistic laboratory studies, textbook writers continuing to ignore practitioners' research appearing in trade publications and practitioner-oriented journals, and practitioners peeling off into high-sounding but meaningless jargon. also evident is the tendency to regard the new electronic media...

  5. A study of the current collecting sectors of a U-25B diagonal megnetohydrodynamic generator

    Energy Technology Data Exchange (ETDEWEB)

    Kirillov, V.V.; Panovka, M.Ya.; Semenov, V.D.; Sokolov, Yu.N.

    1983-01-01

    The results are cited of an experimental study and a calculated analysis of the operation of current collecting sectors of the U-25B magnetohydrodynamic (MHD) generator. The effect was studied of the parameters of the current, the coefficient of electrical loading, the disposition of the current collecting sectors (T) relative to the diagram of the magnetic field on the distribution of current along the length of the current collecting sectors. It is established that with optimal disposition of the current collecting sectors a uniform distribution of current is achieved. A simplified calculation model of the current collecting sector is developed. It is shown that the experimental and calculated relationships match well. The effect of the ballast resisters installed in the current collecting circuits on the distribution of current is examined. Their positive role in preventing current overloads on the frames and in supporting the uniform distribution of current is noted.

  6. Observer rated sleepiness and real road driving: an explorative study.

    Directory of Open Access Journals (Sweden)

    Anna Anund

    Full Text Available The aim of the present study was to explore if observer rated sleepiness (ORS is a feasible method for quantification of driver sleepiness in field studies. Two measures of ORS were used: (1 one for behavioural signs based on facial expression, body gestures and body movements labelled B-ORS, and (2 one based on driving performance e.g. if swerving and other indicators of impaired driving occurs, labelled D-ORS. A limited number of observers sitting in the back of an experimental vehicle on a motorway about 2 hours repeatedly 3 times per day (before lunch, after lunch, at night observed 24 participant's sleepiness level with help of the two observer scales. At the same time the participant reported subjective sleepiness (KSS, EOG was recorded (for calculation of blink duration and several driving measure were taken and synchronized with the reporting. Based on mixed model Anova and correlation analysis the result showed that observer ratings of sleepiness based on drivers' impaired performance and behavioural signs are sensitive to extend the general pattern of time awake, circadian phase and time of driving. The detailed analysis of the subjective sleepiness and ORS showed weak correspondence on an individual level. Only 16% of the changes in KSS were predicted by the observer. The correlation between the observer ratings based on performance (D-ORS and behavioural signs (B-ORS are high (r = .588, and the B-ORS shows a moderately strong association (r = .360 with blink duration. Both ORS measures show an association (r>0.45 with KSS, whereas the association with driving performance is weak. The results show that the ORS-method detects the expected general variations in sleepy driving in field studies, however, sudden changes in driver sleepiness on a detailed level as 5 minutes is usually not detected; this holds true both when taking into account driving behaviour or driver behavioural signs.

  7. Anomalous diurnal variation of atmospheric potential gradient and air-Earth current density observed at Maitri, Antarctica

    Science.gov (United States)

    Jeeva, K.; Gurubaran, S.; Williams, E. R.; Kamra, A. K.; Sinha, A. K.; Guha, A.; Selvaraj, C.; Nair, K. U.; Dhar, Ajay

    2016-11-01

    The scope of this paper is to explore the mechanisms operating over Maitri (70.76°S, 11.74°E, 117 m above mean sea level), a coastal Antarctic station, that produce an anomalous fair-weather diurnal pattern of the atmospheric electric potential gradient (PG) and air-Earth current density (AEC). The anomaly in the diurnal variations of AEC and the PG is displaying an ostensible minimum at 10 UT and a diminished response to the thunderstorm over the African continent in the 14-16 UT time frame. The data sets (2005-2014, except 2012) of the PG, and to some extent, AEC, from Maitri, are used to explore this anomaly. It follows that the fair-weather electrical phenomena over Maitri can be ascribed to global electrified convection on the one hand and to regional phenomena like convection due to the replacement of warm air by katabatic winds on the other hand. The katabatic winds originate on the polar plateau and blow from 130° at Maitri which are likely to transport various elements from the mountain slopes, and space charge from the polar plateau is expected to produce various disturbances in the PG and AEC monitored over the coastal Antarctica. This mechanism may be responsible for peaks in the early UT hours and also for the anomalous behavior of atmospheric electrical parameters observed at Maitri. Maitri data are compared with that of Carnegie cruise and Vostok to explain the source of anomaly.

  8. Field-aligned current associated with low-latitude plasma blobs as observed by the CHAMP satellite

    Directory of Open Access Journals (Sweden)

    J. Park

    2010-03-01

    Full Text Available Here we give two examples of low-latitude plasma blobs accompanied by linearly polarized perpendicular magnetic deflections which imply that associated field-aligned currents (FACs have a 2-D sheet structure located at the blob walls. The estimated FAC density is of the order of 0.1 μA/m2. The direction of magnetic deflections points westward of the magnetic meridian and there is a linear correlation between perpendicular and parallel variations. All these properties are similar to those of equatorial plasma bubbles (EPBs. According to CHAMP observations from August 2000 to July 2004, blobs show except for these two good examples no clear signatures of 2-D FAC sheets at the walls. Generally, perpendicular magnetic deflections inside blobs are weaker than inside EPBs on average. Our results are consistent with existing theories: if a blob exists, (1 a significant part of EPB FAC will be closed through it, exhibiting similar perpendicular magnetic deflection inside EPBs and blobs, (2 the FAC closure through blobs leads to smaller perpendicular magnetic deflection at its poleward/downward side, and (3 superposition of different FAC elements might result in a complex magnetic signature around blobs.

  9. The current status of orbital experiments for UHECR studies

    Science.gov (United States)

    Panasyuk, M. I.; Casolino, M.; Garipov, G. K.; Ebisuzaki, T.; Gorodetzky, P.; Khrenov, B. A.; Klimov, P. A.; Morozenko, V. S.; Sakaki, N.; Saprykin, O. A.; Sharakin, S. A.; Takizawa, Y.; Tkachev, L. G.; Yashin, I. V.; Zotov, M. Yu

    2015-08-01

    Two types of orbital detectors of extreme energy cosmic rays are being developed nowadays: (i) TUS and KLYPVE with reflecting optical systems (mirrors) and (ii) JEM-EUSO with high- transmittance Fresnel lenses. They will cover much larger areas than existing ground-based arrays and almost uniformly monitor the celestial sphere. The TUS detector is the pioneering mission developed in SINP MSU in cooperation with several Russian and foreign institutions. It has relatively small field of view (±4.5°), which corresponds to a ground area of 6.4 • 103 km2. The telescope consists of a Fresnel-type mirror-concentrator (∼ 2 m2) and a photo receiver (a matrix of 16 x 16 photomultiplier tubes). It is to be deployed on the Lomonosov satellite, and is currently at the final stage of preflight tests. Recently, SINP MSU began the KLYPVE project to be installed on board of the Russian segment of the ISS. The optical system of this detector contains a larger primary mirror (10 m2), which allows decreasing the energy threshold. The total effective field of view will be at least ±14° to exceed the annual exposure of the existing ground-based experiments. Several configurations of the detector are being currently considered. Finally, JEM-EUSO is a wide field of view (±30°) detector. The optics is composed of two curved double-sided Fresnel lenses with 2.65 m external diameter, a precision diffractive middle lens and a pupil. The ultraviolet photons are focused onto the focal surface, which consists of nearly 5000 multi-anode photomultipliers. It is developed by a large international collaboration. All three orbital detectors have multi-purpose character due to continuous monitoring of various atmospheric phenomena. The present status of development of the TUS and KLYPVE missions is reported, and a brief comparison of the projects with JEM-EUSO is given.

  10. Comparative study between an alternating current (AC) and a direct current (DC) electrification of an urban railway

    OpenAIRE

    Garriga Turu, Jordi

    2015-01-01

    This study will evaluate technically, energetic and economically the traction electrification network of the line Barcelona – Vallès operated by Ferrocarrils de la Generalitat de Catalunya (FGC) in the existing voltage system (1500 Vdc) and a new electrification under alternative current (25 kVac) will be proposed to be as well studied. The results obtained will be compared in order to obtain decision factors on which system best fits.

  11. Study of white-light flares observed by Hinode

    Institute of Scientific and Technical Information of China (English)

    Hai-Min Wang

    2009-01-01

    White-light flares are considered to be the most energetic flaring events that are observable in the optical broad-band continuum of the solar spectrum. They have not been commonly observed. Observations of white-light flares with sub-arcsecond resolution have been very rare. The continuous high resolution observations of Hinode provide a unique opportunity to systematically study the white-light flares with a spatial resolution around 0.2 arcsec. We surveyed all the flares above GOES magnitude C5.0 since the launch of Hinode in 2006 October. 13 of these kinds of flares were covered by the Hinode G-band observations. We analyzed the peak contrasts and equivalent areas (calculated via integrated excess emission contrast) of these flares as a function of the GOES X-ray flux, and found that the cut-off visibility is likely around M1 flares under the observing limit of Hinode. Many other observational and physical factors should affect the visibility of white-light flares; as the observing conditions are improved, smaller flares are likely to have detectable white-light emissions. We are cautious that this limiting visibility is an overestimate, because G-band observations contain emissions from the upper atmosphere.Among the 13 events analyzed, only the M8.7 flare of 2007 June 4 had near-simultaneous observations in both the G-band and the blue continuum. The blue continuum had a peak contrast of 94% vs. 175% in G-band for this event. The equivalent area in the blue continuum is an order of magnitude lower than that in the G-band. Very recently, Jess et al.studied a C2.0 flare with a peak contrast of 300% in the blue continuum. Compared to the events presented in this letter, that event is probably an unusual white-light flare: a very small kernel with a large contrast that can be detected in high resolution observations.

  12. Scientific and Ethical Approaches for Observational Exposure Studies

    Science.gov (United States)

    Researchers conduct observational human exposure studies to understand how and the extent to which people come into contact with chemicals and environmental stressors in their everyday lives, through the air they breathe, the food and liquids they consume, and the things they tou...

  13. Serum YKL-40 and gestational diabetes - an observational cohort study

    DEFF Research Database (Denmark)

    Gybel-Brask, Dorte; Johansen, Julia S; Christiansen, Ib J

    2016-01-01

    To examine serum YKL-40 in women developing gestational diabetes mellitus (GDM). In the present large observational cohort study of 1179 pregnant women, we determined serum YKL-40 four times during pregnancy (at gestational age 12, 20, 25, and 32 weeks). Pregnancy outcome was obtained from medical...

  14. Observer study to evaluate the simulation of mammographic calcification clusters

    Science.gov (United States)

    Sousa, Maria A. Z.; Marcomini, Karem D.; Bakic, Predrag R.; Maidment, Andrew D. A.; Schiabel, Homero

    2016-03-01

    Numerous breast phantoms have been developed to be as realistic as possible to ensure the accuracy of image quality analysis, covering a greater range of applications. In this study, we simulated three different densities of the breast parenchyma using paraffin gel, acrylic plates and PVC films. Hydroxyapatite was used to simulate calcification clusters. From the images acquired with a GE Senographe DR 2000D mammography system, we selected 68 regions of interest (ROIs) with and 68 without a simulated calcification cluster. To validate the phantom simulation, we selected 136 ROIs from the University of South Florida's Digital Database for Screening Mammography (DDSM). Seven trained observers performed two observer experiments by using a high-resolution monitor Barco mod. E-3620. In the first experiment, the observers had to distinguish between real or phantom ROIs (with and without calcification). In the second one, the observers had to indicate the ROI with calcifications between a pair of ROIs. Results from our study show that the hydroxyapatite calcifications had poor contrast in the simulated breast parenchyma, thus observers had more difficulty in identifying the presence of calcification clusters in phantom images. Preliminary analysis of the power spectrum was conducted to investigate the radiographic density and the contrast thresholds for calcification detection. The values obtained for the power spectrum exponent (β) were comparable with those found in the literature.

  15. An Observational Study of Entrainment Rate in Deep Convection

    OpenAIRE

    Xiaohao Guo; Chunsong Lu; Tianliang Zhao; Guang J. Zhang; Yangang Liu

    2015-01-01

    This study estimates entrainment rate and investigates its relationships with cloud properties in 156 deep convective clouds based on in-situ aircraft observations during the TOGA-COARE (Tropical Ocean Global Atmosphere Coupled Ocean Atmosphere Response Experiment) field campaign over the western Pacific. To the authors’ knowledge, this is the first study on the probability density function of entrainment rate, the relationships between entrainment rate and cloud microphysics, and the effects...

  16. Observational studies of transiting extrasolar planets (invited review)

    CERN Document Server

    Southworth, John

    2014-01-01

    The study of transiting extrasolar planets is only 15 years old, but has matured into a rich area of research. I review the observational aspects of this work, concentrating on the discovery of transits, the characterisation of planets from photometry and spectroscopy, the Homogeneous Studies project, starspots, orbital obliquities, and the atmospheric properties of the known planets. I begin with historical context and conclude with a glance to a future of TESS, CHEOPS, Gaia and PLATO.

  17. Data assimilation of physical and chlorophyll a observations in the California Current System using two biogeochemical models

    Science.gov (United States)

    Mattern, Jann Paul; Song, Hajoon; Edwards, Christopher A.; Moore, Andrew M.; Fiechter, Jerome

    2017-01-01

    Biogeochemical numerical models coupled to physical ocean circulation models are commonly combined with data assimilation in order to improve the models' state or parameter estimates. Yet much still needs to be learned about important aspects of biogeochemical data assimilation, such as the effect of model complexity and the importance of more realistic model formulations on assimilation results. In this study, 4D-Var-based state estimation is applied to two biogeochemical ocean models: a simple NPZD model with 4 biogeochemical variables (including 1 phytoplankton, 1 zooplankton) and the more complex NEMURO model, containing 11 biogeochemical variables (including 2 phytoplankton, 3 zooplankton). Both models are coupled to a 3-dimensional physical ocean circulation model of the U.S. west coast based on the Regional Ocean Modelling System (ROMS). Chlorophyll satellite observations and physical observations are assimilated into the model, yielding substantial improvements in state estimates for the observed physical and biogeochemical variables in both model formulations. In comparison to the simpler NPZD model, NEMURO shows a better overall fit to the observations. The assimilation also results in small improvements for simulated nitrate concentrations in both models and no apparent degradation of the output for other unobserved variables. The forecasting skill of the biogeochemical models is strongly linked to model performance without data assimilation: for both models, the improved fit obtained through assimilation degrades at similar relative rates, but drops to different absolute levels. Despite the better performance of NEMURO in our experiments, the choice of model and desired level of complexity should depend on the model application and the data available for assimilation.

  18. The current status of orbital experiments for UHECR studies

    CERN Document Server

    Panasyuk, M I; Garipov, G K; Ebisuzaki, T; Gorodetzky, P; Khrenov, B A; Klimov, P A; Morozenko, V S; Sakaki, N; Saprykin, O A; Sharakin, S A; Takizawa, Y; Tkachev, L G; Yashin, I V; Zotov, M Yu

    2015-01-01

    Two types of orbital detectors of extreme energy cosmic rays are being developed nowadays: (i) TUS and KLYPVE with reflecting optical systems (mirrors) and (ii) JEM-EUSO with high-transmittance Fresnel lenses. They will cover much larger areas than existing ground-based arrays and almost uniformly monitor the celestial sphere. The TUS detector is the pioneering mission developed in SINP MSU in cooperation with several Russian and foreign institutions. It has relatively small field of view (+/-4.5 deg), which corresponds to a ground area of 6.4x10^3 sq.km. The telescope consists of a Fresnel-type mirror-concentrator (~2 sq.m) and a photo receiver (a matrix of 16x16 photomultiplier tubes). It is to be deployed on the Lomonosov satellite, and is currently at the final stage of preflight tests. Recently, SINP MSU began the KLYPVE project to be installed on board of the Russian segment of the ISS. The optical system of this detector contains a larger primary mirror (10 sq.m), which allows decreasing the energy thr...

  19. Current studies on human papillomavirus in Saudi Arabia.

    Science.gov (United States)

    Alhamlan, Fatimah Saeed; Al-Qahtani, Ahmed A; Al-Ahdal, Mohammed N

    2015-07-04

    Human papillomavirus (HPV) infection is a significant etiological factor and an important prognosticator in cervical cancer. Indeed, researchers worldwide have confirmed these roles for high-risk HVPs in over 70% of cervical cancer cases. According to the World Health Organization, approximately 561,200 new cancer cases (5.2% of all new cancers) are attributed to HPV infection. Over 120 types of HPV are classified further as either low-risk HPV (LR-HPV) or high-risk HPV (HR-HPV) based on their oncological potential of transforming cells. The LR-HPV types cause benign hyperproliferative lesions (i.e. genital warts) while the HR-HPV types are strongly associated with premalignant and malignant cervical lesions. Data on the prevalence of HPV, survival of infected patients, and mortality rate are scarce in Saudi Arabia. The unsubstantiated assumption of a low prevalence of HPV in Saudi Arabia has contributed to limiting HPV research in this conservative country. Therefore, the goal of this review is to shed light on the current HPV research being conducted and the prevalence of HPV in Saudi Arabia.

  20. Retooling the Social Studies Classroom for the Current Generation

    Science.gov (United States)

    Wilson, Elizabeth K.; Wright, Vivian H.; Inman, Christopher T.; Matherson, Lisa H.

    2011-01-01

    Digital technologies have changed the way students read and communicate. Subsequently, teachers must use technology to engage their students in learning. This article illustrates the value of using Web 2.0 tools (blogs, wikis, and digital media-sharing) in the social studies classroom. Additionally, a social studies teacher shares insights into…

  1. A Review of Current Studies on Human Capital

    Institute of Scientific and Technical Information of China (English)

    黄思雅

    2012-01-01

      This paper introduces some previous studies on human capital, mainly regarding human capital’s properties and its relationship with corporate performance and capital structure. This study shows the importance of human capital and suggests that managers should pay more attention to employees.

  2. Review of current study methods for VRU safety

    DEFF Research Database (Denmark)

    Andersen, Camilla Sloth; Kamaluddin, Noor Azreena; Várhelyi, András

    written questionnaires (either online or paper-based), interviews may be performed (either face-to-face or via telephone) and people may be asked to report their accident via an app on their mobile device. The method for gaining self-reported information thus varies greatly – and so does the information...... that people are asked to give. In most studies, only the number of accidents in which the respondent was involved is relevant for the researcher. In other studies, respondents are asked about possible accident causation factors, and some studies deal with respondents’ recall of the accident details. In other...

  3. Constraining Annual Water Balance Estimates with Basin-Scale Observations from the Airborne Snow Observatory during the Current Californian Drought

    Science.gov (United States)

    Bormann, K.; Painter, T. H.; Marks, D. G.; Hedrick, A. R.; Deems, J. S.; Patterson, V.; McGurk, B. J.

    2015-12-01

    One of the great unknowns in mountain hydrology is how much water is stored within a seasonal snowpack at the basin scale. Quantifying mountain water resources is critical for assisting with water resource management, but has proven elusive due to high spatial and temporal variability of mountain snow cover, complex terrain, accessibility constraints and limited in-situ networks. The Airborne Snow Observatory (ASO, aso.jpl.nasa.gov) uses coupled airborne LiDAR and spectrometer instruments for high resolution snow depth retrievals which are used to derive unprecedented basin-wide estimates of snow water mass (snow water equivalent, SWE). ASO has been operational over key basins in the Sierra Nevada Mountains in California since 2013. Each operational year has been very dry, with precipitation in 2013 at 75% of average, 2014 at 50% of average and 2015 - the lowest snow year on record for the region. With vastly improved estimates of the snowpack water content from ASO, we can now for the first time conduct observation-based mass balance accounting of surface water in snow-dominated basins, and reconcile these estimates with observed reservoir inflows. In this study we use ASO SWE data to constrain mass balance accounting of basin annual water storages to quantify the water contained within the snowpack above the Hetch Hetchy water supply reservoir (Tuolumne River basin, California). The analysis compares and contrasts annual snow water volumes from observed reservoir inflows, snow water volume estimates from ASO, a physically based model that simulates the snowpack from meteorological inputs and a semi-distributed hydrological model. The study provides invaluable insight to the overall volume of water contained within a seasonal snowpack during a severe drought and how these quantities are simulated in our modelling systems. We envisage that this research will be of great interest to snowpack modellers, hydrologists, dam operators and water managers worldwide.

  4. Numerical study on tidal currents and seawater exchange in the Benoa Bay, Bali, Indonesia

    Institute of Scientific and Technical Information of China (English)

    HENDRAWAN I. Gede; ASAI Koji

    2014-01-01

    A three-dimensional (3-D) finite volume coastal ocean model (FVCOM) was used for the study of water cir-culation and seawater exchange in the Benoa Bay, Bali Island. The M2 tidal component was forced in open boundary and discharge from six rivers was included in the numerical calculation. The M2 tidal elevation produced by the FVCOM has a good agreement with the observation data. The M2 tidal current is also suc-cessfully calculated under the ebb tide and flood tide conditions. The non-linear M2 tidal residual current was produced by the coastline geometry, especially surrounding the narrow strait between the Serangan Is-land and the Benoa Peninsula. The tidal residual current also generated two small eddies within the bay and one small eddy in the bay mouth. The salinity distribution influenced by river discharge could be success-fully calculated, where the numerical calculation and the observation results have a good correlation (r2) of 0.75. Finally in order to examine the seawater exchange in the Benoa Bay, the Lagrangian particle tracking method and calculation of residence time are applied. The mechanism of particle transport to the flushing of seawater is depicted clearly by both methods.

  5. Current approaches of genome-wide association studies

    Institute of Scientific and Technical Information of China (English)

    Jianfeng Xu

    2008-01-01

    @@ With rapid advances in high-throughput genotyping technology and the great increase in information available on SNPs throughout the genuine, genuine-wide association(GWA) studies have now become feasible.

  6. Everolimus-eluting stents: update on current clinical studies

    Directory of Open Access Journals (Sweden)

    Allocco DJ

    2011-07-01

    Full Text Available Dominic J Allocco, Anita A Joshi, Keith D DawkinsBoston Scientific Corporation, Natick, MA, USAAbstract: Everolimus-eluting stents (EES have become the most commonly implanted coronary stents worldwide. This review describes and analyzes the clinical data supporting the use of EES, focusing primarily on published, randomized, controlled trials. Everolimuseluting stents have been shown to have less restenosis, stent thrombosis, and periprocedural myocardial infarction compared with earlier generation paclitaxel-eluting stents (PES. Lower rates of adverse events for EES compared with PES were generally seen in all subgroups, with the notable exception of patients with diabetes mellitus. There have been fewer, randomized, clinical trials comparing EES with either sirolimus-eluting stents or zotarolimus-eluting stents, although very good results with EES have been observed in the trials that have been performed. Recent clinical trial data suggest that this excellent safety and efficacy profile is maintained in a next-generation EES designed to have improved mechanical properties and radiopacity.Keywords: drug-eluting stents, everolimus, Xience V, Promus, Promus ElementVideo Abstract:  http://dvpr.es/allocco  

  7. The Course of Schizophrenia: E. Kraepelin's View and Current Studies

    Directory of Open Access Journals (Sweden)

    Norbert Müller

    2014-10-01

    Full Text Available Kraepelin's concept of dementia praecox and Bleuler's concept of the group of schizophrenias differ mainly under the aspect of course of the disorder. Follow-up studies play an important role for research regarding course, outcome and prognosis of psychiatric disorders, especially in terms of validation of psychiatric diagnosis and other psychiatric concepts, such as the concept of schizophrenic negative symptoms. Long-term studies also have their place in the description and evaluation of first treatment procedures. This paper will describe some general aspects of the long-term course and outcome of schizophrenic psychoses. The problem of relapses and relapse prevention will then be discussed. Especially data from recent studies will be considered in this overview.

  8. Ozone sonde cell current measurements and implications for observations of near-zero ozone concentrations in the tropical upper troposphere

    OpenAIRE

    H. Vömel; K. Diaz

    2009-01-01

    Laboratory measurements of the Electrochemical Concentration Cell (ECC) ozone sonde cell current using ozone free air as well as defined amounts of ozone reveal that background current measurements during sonde preparation are neither constant as a function of time, nor constant as a function of ozone concentration. Using a background current, measured at a defined timed after exposure to high ozone may often overestimate the real background, leading to artificially low ozone concentrations i...

  9. Current methodology and methods in psychophysiological studies of creative thinking.

    Science.gov (United States)

    Bechtereva, N P; Danko, S G; Medvedev, S V

    2007-05-01

    Important points on methodology and detailed description of methods used in polymodal psychophysiological studies of human verbal creative thinking are presented. The psychophysiological studies were conducted with healthy volunteers during implementations of specially developed and adapted psychological tests aimed to bring the subjects into states of verbal creative thinking. Four different task sets ("story composition", "associative chains", "original definitions", "proverb sense flipping") were developed and applied. Positron emission tomography of regional cerebral blood flow (rCBF) and state-related quantitative electroencephalography (power and coherence evaluated) were used. The effectiveness of the methods is illustrated with figures.

  10. UK pneumonectomy outcome study (UKPOS: a prospective observational study of pneumonectomy outcome

    Directory of Open Access Journals (Sweden)

    Davies Paul

    2009-07-01

    Full Text Available Abstract Background In order to assess the short term risks of pneumonectomy for lung cancer in contemporary practice a one year prospective observational study of pneumonectomy outcome was made. Current UK practice for pneumonectomy was observed to note patient and treatment factors associated with major complications. Methods A multicentre, prospective, observational cohort study was performed. All 35 UK thoracic surgical centres were invited to submit data to the study. All adult patients undergoing pneumonectomy for lung cancer between 1 January and 31 December 2005 were included. Patients undergoing pleuropneumonectomy, extended pneumonectomy, completion pneumonectomy following previous lobectomy and pneumonectomy for benign disease, were excluded from the study. The main outcome measure was suffering a major complication. Major complications were defined as: death within 30 days of surgery; treated cardiac arrhythmia or hypotension; unplanned intensive care admission; further surgery or inotrope usage. Results 312 pneumonectomies from 28 participating centres were entered. The major complication incidence was: 30-day mortality 5.4%; treated cardiac arrhythmia 19.9%; unplanned intensive care unit admission 9.3%; further surgery 4.8%; inotrope usage 3.5%. Age, American Society of Anesthesiologists physical status ≥ P3, pre-operative diffusing capacity for carbon monoxide (DLCO and epidural analgesia were collectively the strongest risk factors for major complications. Major complications prolonged median hospital stay by 2 days. Conclusion The 30 day mortality rate was less than 8%, in agreement with the British Thoracic Society guidelines. Pneumonectomy was associated with a high rate of major complications. Age, ASA physical status, DLCO and epidural analgesia appeared collectively most associated with major complications.

  11. Organ preconditioning: the past, current status, and related lung studies

    Institute of Scientific and Technical Information of China (English)

    LUH Shi-ping; YANG Pan-chyr

    2006-01-01

    Preconditioning (PC) has emerged as a powerful method for experimentally and clinically attenuating various types of organ injuries. In this paper related clinical and basic research issues on organ preconditioning issues were systemically reviewed.Since lung injuries, including ischemia-reperfusion and others, play important roles in many clinical results, including thromboembolism, trauma, thermal injury, hypovolemic and endotoxin shock, reimplantation response after organ transplantation, and many respiratory diseases in critical care. It is of interest to uncover methods, including the PCs, to protect the lung from the above injuries. However, related studies on pulmonary PC are relatively rare and still being developed, so we will review previous literature on experimental and clinical studies on pulmonary PC in the following paragraphs.

  12. CHATURBEEJA IN PRIMARY DYSMENORRHOEA (KASHTARTAVA: AN OBSERVATIONAL STUDY

    Directory of Open Access Journals (Sweden)

    Dhiman Kamini

    2012-06-01

    Full Text Available In folk medicines, Chaturbeeja(combination of seeds of four plants i.e Trigonella Foenum-graecum, Lepidium sativum , Nigella sativa, Trachyspermum ammi in equal quantity has been traditionally used for variety of applications including treatment of Dysmenorrhoea, the most common gynaecological symptom reported by women. To promote the proper use of such medicines and to determine their potential as sources for new drugs, it is essential to study medicinal plants, which have folklore reputation in a more intensified way. A Single blind, prospective observational clinical study was conducted to evaluate the efficacy of Chaturbeeja powder in Primary Dysmenorrhoea (Kashtartava. 25 patients were administered Chaturbeeja powder in a single dose of 3g with hot water at night, 7 days before starting of menstruation till 3rd day of the menstruation cycle. After assessing the results it was observed that12 patients were markedly improved, 8 moderately improved and 5 were improved.

  13. Animal venom studies: Current benefits and future developments

    Institute of Scientific and Technical Information of China (English)

    Yuri; N; Utkin

    2015-01-01

    Poisonous organisms are represented in many taxa, including kingdom Animalia. During evolution, animals have developed special organs for production and injection of venoms. Animal venoms are complex mixtures, compositions of which depend on species producing venom. The most known and studied poisonous terrestrial animals are snakes, scorpions and spiders. Among marine animals, these are jellyfishes, anemones and cone snails. The toxic substances in the venom ofthese animals are mainly of protein and peptide origin. Recent studies have indicated that the single venom may contain up to several hundred different components producing diverse physiological effects. Bites or stings by certain poisonous species result in severe envenomations leading in some cases to death. This raises the problem of bite treatment. The most effective treatment so far is the application of antivenoms. To enhance the effectiveness of such treatments, the knowledge of venom composition is needed. On the other hand, venoms contain substances with unique biological properties, which can be used both in basic science and in clinical applications. The best example of toxin application in basic science is α-bungarotoxin the discovery of which made a big impact on the studies of nicotinic acetylcholine receptor. Today compositions of venom from many species have already been examined. Based on these data, one can conclude that venoms contain a large number of individual components belonging to a limited number of structural types. Often minor changes in the amino acid sequence give rise to new biological properties. Change in the living conditions of poisonous animals lead to alterations in the composition of venoms resulting in appearance of new toxins. At the same time introduction of new methods of proteomics and genomics lead to discoveries of new compounds, which may serve as research tools or as templates for the development of novel drugs. The application of these sensitive and

  14. Electrophysiological studies of malaria parasite-infected erythrocytes: Current status

    OpenAIRE

    Staines, Henry M.; Alkhalil, Abdulnaser; Allen, Richard J.; De Jonge, Hugo R.; Derbyshire, Elvira; Egée, Stéphane; Ginsburg, Hagai; Hill, David A.; Huber, Stephan M.; Kirk, Kiaran; Lang, Florian; Lisk, Godfrey; Oteng, Eugene; Pillai, Ajay D.; Rayavara, Kempaiah

    2007-01-01

    The altered permeability characteristics of erythrocytes infected with malaria parasites have been a source of interest for over 30 years. Recent electrophysiological studies have provided strong evidence that these changes reflect transmembrane transport through ion channels in the host erythrocyte plasma membrane. However, conflicting results and differing interpretations of the data have led to confusion in this field. In an effort to unravel these issues, the groups involved recently came...

  15. Study of the upper atmosphere observation by artificial ion beam

    OpenAIRE

    Sugimoto, Sachiko; Kuninaka, Hitoshi; TOKI, Kyoichiro; Arakawa, Yoshihiro; 杉本 幸子; 國中 均; 都木 恭一郎; 荒川 義博

    2005-01-01

    The observing method that uses ENA (Energetic Neutral Atoms), produced by ion beam injected from an ion thruster, is studied and researched in order to estimate the density of neutral particles in the upper atmosphere. The ion beam experiences charge exchange collision (CEX) with neighboring neutral particles to transform into ENAs. The ENA preserves the information about the particles concerned with those collisions. A new method of estimating the density and the composition of the neutral p...

  16. Observed Orbit Effects during Long Range Beam-Beam Studies

    CERN Document Server

    Alemany, R; Buffat, X; Calaga, R; Fitterer, M; Giachino, R; Hemelsoet, GH; Herr, W; Papotti, G; Pieloni, T; Poyer, M; Schaumann, M; Trad, G; Wollmann, D

    2012-01-01

    Possible limitations due to long range beam-beam effects at the LHC have been studied and are presented in this note. With a larger number of bunches and collisions in all interaction points, the crossing angles were reduced to enhance long range beam-beam effects. The analysis of the effects on the dynamic aperture and losses are documented in [1]. This note concentrates on the bunch-by-bunch orbit effects observed during the experiment.

  17. Strategies GeoCape Intelligent Observation Studies @ GSFC

    Science.gov (United States)

    Cappelaere, Pat; Frye, Stu; Moe, Karen; Mandl, Dan; LeMoigne, Jacqueline; Flatley, Tom; Geist, Alessandro

    2015-01-01

    This presentation provides information a summary of the tradeoff studies conducted for GeoCape by the GSFC team in terms of how to optimize GeoCape observation efficiency. Tradeoffs include total ground scheduling with simple priorities, ground scheduling with cloud forecast, ground scheduling with sub-area forecast, onboard scheduling with onboard cloud detection and smart onboard scheduling and onboard image processing. The tradeoffs considered optimzing cost, downlink bandwidth and total number of images acquired.

  18. Observational study of maternal anthropometry and fetal insulin

    OpenAIRE

    Soltani-K, H; Bruce, C; Fraser, R

    1999-01-01

    AIMS—To examine the relation between maternal body fat and fetal metabolism.
METHODS—In this observational study, cord blood samples were collected from 60 infants of healthy women for the measurement of insulin and C peptide concentrations. Maternal weight, height, body mass index (BMI) and body composition (skinfold thickness measurements and bioelectrical impedance) were assessed at 13-15 weeks of gestation. Twenty five of the volunteers agreed to have a 75 g oral gluc...

  19. The value of including observational studies in systematic reviews was unclear: a descriptive study.

    Science.gov (United States)

    Seida, Jennifer; Dryden, Donna M; Hartling, Lisa

    2014-12-01

    To evaluate (1) how often observational studies are included in comparative effectiveness reviews (CERs); (2) the rationale for including observational studies; (3) how data from observational studies are appraised, analyzed, and graded; and (4) the impact of observational studies on strength of evidence (SOE) and conclusions. Descriptive study of 23 CERs published through the Effective Health Care Program of the U.S. Agency for Healthcare Research and Quality. Authors searched for observational studies in 20 CERs, of which 18 included a median of 11 (interquartile range, 2-31) studies. Sixteen CERs incorporated the observational studies in their SOE assessments. Seventy-eight comparisons from 12 CERs included evidence from both trials and observational studies; observational studies had an impact on SOE and conclusions for 19 (24%) comparisons. There was diversity across the CERs regarding decisions to include observational studies; study designs considered; and approaches used to appraise, synthesize, and grade SOE. Reporting and methods guidance are needed to ensure clarity and consistency in how observational studies are incorporated in CERs. It was not always clear that observational studies added value in light of the additional resources needed to search for, select, appraise, and analyze such studies. Copyright © 2014 Elsevier Inc. All rights reserved.

  20. Observations of wind-generated waves on variable current. [laboratory ocean dynamics for water wave generator research

    Science.gov (United States)

    Long, S. R.; Huang, N. E.

    1976-01-01

    Laboratory measurements utilizing a laser probe are made for the slopes of wind waves generated on both positive and negative currents at different values of fetch. The data are then processed electronically to yield an average wave-slope spectrum in frequency space with 128 degrees of freedom. These spectra are used to obtain the growth of the spectral components at various frequency bands for increasing wind and different values of fetch and current. The results indicate that the growth of these components is not monotonic with the frictional wind speed, but rather exhibits an 'overshoot' phenomena at lower values of frictional wind speed, and in addition, displays a significant effect due to current. The peak location and spectral intensity of the spectra also show strong influence by the current condition. This results in the rms surface slope value increasing with negative current and decreasing with positive current. The results agree qualitatively with some theoretical predictions. The potential use of the current-induced effects as a means for remote sensing of ocean current is also briefly discussed.

  1. Electrophysiological studies of malaria parasite-infected erythrocytes: Current status

    Science.gov (United States)

    Staines, Henry M.; Alkhalil, Abdulnaser; Allen, Richard J.; De Jonge, Hugo R.; Derbyshire, Elvira; Egée, Stéphane; Ginsburg, Hagai; Hill, David A.; Huber, Stephan M.; Kirk, Kiaran; Lang, Florian; Lisk, Godfrey; Oteng, Eugene; Pillai, Ajay D.; Rayavara, Kempaiah; Rouhani, Sherin; Saliba, Kevin J.; Shen, Crystal; Solomon, Tsione; Thomas, Serge L. Y.; Verloo, Patrick; Desai, Sanjay A.

    2009-01-01

    The altered permeability characteristics of erythrocytes infected with malaria parasites have been a source of interest for over 30 years. Recent electrophysiological studies have provided strong evidence that these changes reflect transmembrane transport through ion channels in the host erythrocyte plasma membrane. However, conflicting results and differing interpretations of the data have led to confusion in this field. In an effort to unravel these issues, the groups involved recently came together for a week of discussion and experimentation. In this article, the various models for altered transport are reviewed, together with the areas of consensus in the field and those that require a better understanding. PMID:17292372

  2. The end of universality: new collectivities in current literary studies

    Directory of Open Access Journals (Sweden)

    Ronald Greene

    2015-11-01

    Full Text Available The author investigates how the literary studies reacted to the conceptual crises of universalism, especially after WWII. In order to replace a concept that refers to the ability of a literary work to transcend time and space, literary studies should focus on different and specific collectivities that, situated in time and space, read and interpret literary works. The author makes use of the concept of the obverse, in which two poems, from different historical moments and intellectual traditions are compared based on a common social-historical problem they are trying to solve.    O autor investiga sobre como os estudos literários reagiram à crise do conceito de universalismo, sobretudo depois da II Guerra Mundial. Para substituir um conceito que se refere à capacidade de uma obra literária transcender tempo e espaço, os estudos literários deveriam indagar sobre as diferentes coletividades específicas, no tempo e no espaço, que leem e dão significado à obra literária. Para isso, o autor se utiliza do conceito de “obverso”, em que dois poemas, de épocas e tradições intelectuais diferentes, são comparados a partir de um problema sócio-histórico que tentam resolver.      This work is licensed under a Creative Commons Attribution 3.0 License.

  3. Current studies on physiological functions and biological production of lactosucrose.

    Science.gov (United States)

    Mu, Wanmeng; Chen, Qiuming; Wang, Xiao; Zhang, Tao; Jiang, Bo

    2013-08-01

    Lactosucrose (O-β-D-galactopyranosyl-(1,4)-O-α-D-glucopyranosyl-(1,2)-β-D-fructofuranoside) is a trisaccharide formed from lactose and sucrose by enzymatic transglycosylation. This rare trisaccharide is a kind of indigestible carbohydrate, has good prebiotic effect, and promotes intestinal mineral absorption. It has been used as a functional ingredient in a range of food products which are approved as foods for specified health uses in Japan. Using lactose and sucrose as substrates, lactosucrose can be produced through transfructosylation by β-fructofuranosidase from Arthrobacter sp. K-1 or a range of levansucrases, or through transgalactosylation by β-galactosidase from Bacillus circulans. This article presented a review of recent studies on the physiological functions of lactosucrose and the biological production from lactose and sucrose by different enzymes.

  4. Descriptive currents in philosophy of religion for Hebrew Bible studies

    Directory of Open Access Journals (Sweden)

    Jacobus W. Gericke

    2011-03-01

    Full Text Available This article argued that the utilisation of philosophy of religion in the study of the Hebrew Bible is possible if we look beyond the stereotype of erroneously equating the auxiliary field with natural theology, apologetics or atheological criticism. Fruitful possibilities for interdisciplinary research are available in the form of descriptive varieties of philosophy of religion primarily concerned with understanding and the clarification of meaning rather than with the stereotypical tasks of propositional justification or critical evaluation. Three examples are discussed in the article: analytic traditions (Wittgensteinianism and ordinarylanguage philosophy, phenomenological perspectives involving reduction (bracketing and comparative philosophy of religion that works in tandem with the history of religion and comparative religion.

  5. Using data mining techniques to characterize participation in observational studies.

    Science.gov (United States)

    Linden, Ariel; Yarnold, Paul R

    2016-12-01

    Data mining techniques are gaining in popularity among health researchers for an array of purposes, such as improving diagnostic accuracy, identifying high-risk patients and extracting concepts from unstructured data. In this paper, we describe how these techniques can be applied to another area in the health research domain: identifying characteristics of individuals who do and do not choose to participate in observational studies. In contrast to randomized studies where individuals have no control over their treatment assignment, participants in observational studies self-select into the treatment arm and therefore have the potential to differ in their characteristics from those who elect not to participate. These differences may explain part, or all, of the difference in the observed outcome, making it crucial to assess whether there is differential participation based on observed characteristics. As compared to traditional approaches to this assessment, data mining offers a more precise understanding of these differences. To describe and illustrate the application of data mining in this domain, we use data from a primary care-based medical home pilot programme and compare the performance of commonly used classification approaches - logistic regression, support vector machines, random forests and classification tree analysis (CTA) - in correctly classifying participants and non-participants. We find that CTA is substantially more accurate than the other models. Moreover, unlike the other models, CTA offers transparency in its computational approach, ease of interpretation via the decision rules produced and provides statistical results familiar to health researchers. Beyond their application to research, data mining techniques could help administrators to identify new candidates for participation who may most benefit from the intervention. © 2016 John Wiley & Sons, Ltd.

  6. Aspartame: a safety evaluation based on current use levels, regulations, and toxicological and epidemiological studies.

    Science.gov (United States)

    Magnuson, B A; Burdock, G A; Doull, J; Kroes, R M; Marsh, G M; Pariza, M W; Spencer, P S; Waddell, W J; Walker, R; Williams, G M

    2007-01-01

    Aspartame is a methyl ester of a dipeptide used as a synthetic nonnutritive sweetener in over 90 countries worldwide in over 6000 products. The purpose of this investigation was to review the scientific literature on the absorption and metabolism, the current consumption levels worldwide, the toxicology, and recent epidemiological studies on aspartame. Current use levels of aspartame, even by high users in special subgroups, remains well below the U.S. Food and Drug Administration and European Food Safety Authority established acceptable daily intake levels of 50 and 40 mg/kg bw/day, respectively. Consumption of large doses of aspartame in a single bolus dose will have an effect on some biochemical parameters, including plasma amino acid levels and brain neurotransmitter levels. The rise in plasma levels of phenylalanine and aspartic acid following administration of aspartame at doses less than or equal to 50 mg/kg bw do not exceed those observed postprandially. Acute, subacute and chronic toxicity studies with aspartame, and its decomposition products, conducted in mice, rats, hamsters and dogs have consistently found no adverse effect of aspartame with doses up to at least 4000 mg/kg bw/day. Critical review of all carcinogenicity studies conducted on aspartame found no credible evidence that aspartame is carcinogenic. The data from the extensive investigations into the possibility of neurotoxic effects of aspartame, in general, do not support the hypothesis that aspartame in the human diet will affect nervous system function, learning or behavior. Epidemiological studies on aspartame include several case-control studies and one well-conducted prospective epidemiological study with a large cohort, in which the consumption of aspartame was measured. The studies provide no evidence to support an association between aspartame and cancer in any tissue. The weight of existing evidence is that aspartame is safe at current levels of consumption as a nonnutritive

  7. Affective bias and current, past and future adolescent depression: A familial high risk study

    Science.gov (United States)

    Kilford, Emma J.; Foulkes, Lucy; Potter, Robert; Collishaw, Stephan; Thapar, Anita; Rice, Frances

    2015-01-01

    Background Affective bias is a common feature of depressive disorder. However, a lack of longitudinal studies means that the temporal relationship between affective bias and depression is not well understood. One group where studies of affective bias may be particularly warranted is the adolescent offspring of depressed parents, given observations of high rates of depression and a severe and impairing course of disorder in this group. Methods A two wave panel design was used in which adolescent offspring of parents with recurrent depression completed a behavioural task assessing affective bias (The Affective Go/No Go Task) and a psychiatric interview. The affective processing of adolescents with current, prior and future depressive disorder was compared to that of adolescents free from disorder. Results Adolescents with current depression and those who developed depression at follow-up made more commission errors for sad than happy targets compared to adolescents free from disorder. There was no effect of prior depression on later affective processing. Limitations Small cell sizes meant we were unable to separately compare those with new onset and recurrent depressive disorder. Conclusions Valence-specific errors in behavioural inhibition index future vulnerability to depression in adolescents already at increased risk and may represent a measure of affective control. Currently depressed adolescents show a similar pattern of affective bias or deficits in affective control. PMID:25527997

  8. Current practice in continuous renal replacement therapy: An epidemiological multicenter study.

    Science.gov (United States)

    Tomasa Irriguible, T M; Sabater Riera, J; Poch López de Briñas, E; Fort Ros, J; Lloret Cora, M J; Roca Antònio, J; Navas Pérez, A; Ortiz Ballujera, P; Servià Goixart, L; González de Molina Ortiz, F J; Rovira Anglès, C; Rodríguez López, M; Roglan Piqueras, A

    2017-05-01

    The aim of the study is to ascertain the most relevant aspects of the current management of renal replacement therapy (RRT) in critically ill patients, and to analyze renal function recovery and mortality in patients undergoing RRT. A non-interventional three-month observational study was made in 2012, with a follow-up period of 90 days, in 21 centers in Catalonia (Spain). Demographic information, severity scores and clinical data were obtained, as well as RRT parameters. patients aged ≥ 16 years admitted to Intensive Care Units (ICUs) and subjected to RRT. A total of 261 critically ill patients were recruited, of which 35% had renal dysfunction prior to admission. The main reason for starting RRT was oliguria; the most widely used RRT modality was hemodiafiltration; and the median prescribed dose at baseline was 35mL/kg/h. The median time of RRT onset from ICU admission was one day. The mortality rate at 30 and 90 days was 46% and 54%, respectively, and was associated to greater severity scores and a later onset of RRT. At discharge, 85% of the survivors had recovered renal function. Current practice in RRT in Catalonia abides with the current clinical practice guidelines. Mortality related to RRT is associated to later onset of such therapy. The renal function recovery rate at hospital discharge was 85% among the patients subjected to RRT. Copyright © 2016 Elsevier España, S.L.U. y SEMICYUC. All rights reserved.

  9. Studying the start of the Maunder Minimum to understand the current situation

    Science.gov (United States)

    Neuhäuser, Ralph; Neuhäuser, Dagmar L.

    2016-04-01

    To investigate whether we now enter a Maunder-like grand minimum, we have to compare the current situation with the time around the start of the Maunder minimum. Sunspot observations in the 1610s are of particular importance and relevance, because they are shortly before the start of the Maunder Grand Minimum. While the Maunder Minimum it is usually dated from 1645 to 1715, Vaquero & Trigo (2015) argue that what they call the "Extended Maunder Minimum" would have started in 1618 during or around a Schwabe cycle minimum around that time. We have therefore studied the sunspot record of that time in detail. Hoyt & Schatten (1998) compiled for all known telescopic observers a list of their observations; recent solar activity studies for the past four centuries are based on their compilation. In addition to 12 observers listed by Hoyt & Schatten (1998) for the 1610s, we list six more observers with datable spot observations. Furthermore, while Hoyt & Schatten (1998) argue that Simon Marius would have observed from mid 1617 to the end of 1618 almost every day, but would have never seen a spot, we can show with the original reports by Marius that he observed from Aug 1611 to spring 1619 with a lot of sunspot detections. Similar, while Hoyt & Schatten (1998) argue that Giovanni Riccioli would have observed on almost every day in 1618, but would have never seen a spot, he did not report any own observations at all that year, but quoted Argoli for that there were no spots during the periods with comets in 1618. The data base by Hoyt & Schatten (1998) has several more errors in the 1610s, as we show also for the observations by Harriot, Scheiner, Malapert, Saxonius, and Tarde. We also compare drawings from Jungius with the observations by Harriot, Galilei, and Marius. In contrast to what is specified in Hoyt & Schatten (1998), after Harriot, the two Fabricius (father and son), Scheiner and Cysat, Marius and Schmidnerus are among the earliest datable telescopic sunspot

  10. Harvesting Collective Trend Observations from Large Scale Study Trips

    DEFF Research Database (Denmark)

    Eriksen, Kaare; Ovesen, Nis

    2014-01-01

    To enhance industrial design students’ decoding and understanding of the technological possibilities and the diversity of needs and preferences in different cultures it is not unusual to arrange study trips where such students acquire a broader view to strengthen their professional skills...... and approach, hence linking the design education and the design culture of the surrounding world. To improve the professional learning it is useful, though, to facilitate and organize the trips in a way that involves systematic data collection and reporting. This paper presents a method for facilitating study...... trips for engineering students in architecture & design and the results from crowd-collecting a large amount of trend observations as well as the derived experience from using the method on a large scale study trip. The method has been developed and formalized in relation to study trips with large...

  11. Observational study of food safety practices in retail deli departments.

    Science.gov (United States)

    Lubran, M B; Pouillot, R; Bohm, S; Calvey, E M; Meng, J; Dennis, S

    2010-10-01

    In order to improve the safety of refrigerated ready-to-eat food products prepared at retail deli departments, a better understanding of current practices in these establishments is needed. Food employees in deli departments at six chain and three independent retail establishments in Maryland and Virginia were observed, using notational analysis, as they prepared deli products for sale. The frequency of contact with objects and deli products before sale, hand washing and glove changing during preparation, and equipment, utensil, and surface cleaning and sanitizing was determined. Compliance with the U.S. Food and Drug Administration's 2005 model Food Code recommendations, which must be adopted by the individual state and local jurisdictions that are responsible for directly regulating retail establishments, was also assessed. Observations indicated there were a large number of actions for which hand washing was recommended at independent and chain stores (273 recommended of 1,098 total actions and 439 recommended of 3,073 total actions, respectively). Moreover, 67% (295 of 439) of the actions for which hand washing was recommended at the chain stores and 86% (235 of 273) of those at the independent stores resulted from employees touching non-food contact surfaces prior to handling ready-to-eat food. Compliance with hand washing recommendations was generally low and varied depending on store type with independent stores exhibiting lower compliance than chain stores (5 instances of compliance for 273 recommended actions and 73 instances of compliance for 439 recommended actions, respectively). Potential risk mitigation measures that may reduce the frequency of hand washing actions needed during ready-to-eat food preparation in retail deli departments are discussed. More research is needed to determine the impact of such measures on food safety.

  12. Parental behaviour in paediatric chronic pain: a qualitative observational study.

    Science.gov (United States)

    Dunford, Emma; Thompson, Miles; Gauntlett-Gilbert, Jeremy

    2014-10-01

    Parental behaviour appears to influence the adjustment of children with chronic pain. However, research in this area has failed to produce consistent evidence. Studies have tended to rely on self-report measures derived from adult pain populations. This qualitative, observational research provides descriptive data of parental behaviour in a clinical environment. A qualitative observational study was made of parents and adolescents in a physically stressful setting. Modified grounded theory was used to analyse verbal and non-verbal behaviours. Eight parent-adolescent dyads seeking treatment for chronic pain were videoed during physical exercise sessions. Verbal and non-verbal behaviours were recorded and transcribed. Four overarching categories emerged: 'monitoring', 'protecting', 'encouraging' and 'instructing'. These often had both verbal and non-verbal aspects. Within these categories, more precise behavioural groups were also identified. This research identifies categories of parental behaviour that were derived directly from observation, rather than imposed on the basis of results from different populations. Four categories of behaviour were derived, which clarify and extend dimensions used in existing self-report instruments. Careful description of parental behaviours showed features that past research has neglected, and highlighted potential drawbacks of apparently positive parental actions. © The Author(s) 2013.

  13. Observations of radiographer communication: An exploratory study using Transactional Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Booth, Lisa A. [School of Medical Imaging Sciences, St. Martin' s College, Bowerham Road, Lancaster LA1 3JD (United Kingdom)]. E-mail: l.booth@ucsm.ac.uk; Manning, David J. [School of Medical Imaging Sciences, St. Martin' s College, Bowerham Road, Lancaster LA1 3JD (United Kingdom)

    2006-11-15

    Purpose: Communication in medical imaging is a neglected area of research, despite the necessity for good communication if optimum diagnostic images are to be achieved. Methods: The present study has investigated the styles of communication used in medical imaging, using an approach known as Transactional Analysis. This approach has been demonstrated previously as having reliability and validity, using observations and supporting interviews with medical imaging staff, along with inter-rater observations of radiographer-patient interactions. Results: The results indicate that Transactional Analysis can be used effectively for identifying and naming interaction events in diagnostic radiography, with diagnostic radiographers using five styles of communication. Conclusion: Radiographers tend to use Parental styles of communicating; these styles are commonly associated with a practitioner-centred approach to dealing with patients which often result in non-adherence.

  14. Linking Indigenous Knowledge and Observed Climate Change Studies

    Science.gov (United States)

    Alexander, Chief Clarence; Bynum, Nora; Johnson, Liz; King, Ursula; Mustonen, Tero; Neofotis, Peter; Oettle, Noel; Rosenzweig, Cynthia; Sakakibara, Chie; Shadrin, Chief Vyacheslav; Vicarelli, Marta; Waterhouse, Jon; Weeks, Brian

    2010-01-01

    We present indigenous knowledge narratives and explore their connections to documented temperature and other climate changes and observed climate change impact studies. We then propose a framework for enhancing integration of these indigenous narratives of observed climate change with global assessments. Our aim is to contribute to the thoughtful and respectful integration of indigenous knowledge with scientific data and analysis, so that this rich body of knowledge can inform science, and so that indigenous and traditional peoples can use the tools and methods of science for the benefit of their communities if they choose to do so. Enhancing ways of understanding such connections are critical as the Intergovernmental Panel on Climate Change Fifth Assessment process gets underway.

  15. Observing Magnetic and Current Profiles of the Night side and Terminator of Mars through the Mars Global Surveyor Data

    Science.gov (United States)

    Ponce, N.; Fillingim, M. O.; Fogle, A. L.

    2014-12-01

    Mars has no global magnetic field. Changes in the solar wind and interplanetary magnetic field can impact the upper atmosphere and induce currents in the ionosphere of Mars. During aerobraking maneuvers, Mars Global Surveyor (MGS) made over 1000 passes through Mars's ionosphere. During these passes, MGS measured the local magnetic field. From these measurements, we can determine the ionospheric currents. We restrict our analysis to passes where the radial component of the magnetic field is nearly zero. This restriction, along with some assumptions about the gradients in the magnetic field, allows us to estimate the horizontal ionospheric currents. Additionally, we focus on the magnetic field data acquired over regions above negligible crustal magnetic fields in order to simplify the analysis. At a maximum altitude of 250 km, the Mars map was segmented to 30 by 30 degrees east longitude and latitude for analysis. We find that on the night side, where the solar zenith angle (SZA) lies between 130 to 180 degrees, only 4% of the data (out of a total of 52 profiles) is usable for computing currents, that is the radial component of the magnetic field is nearly zero. We also find that near the terminator, where the SZA lies between 50 to 130 degrees, an average of 2% of the magnetic field profiles (out of 1905) are usable to compute currents. This implies that currents are rarely horizontal (as required by our assumptions) in these regions. The currents computed from these profiles can give us insights into how the changing solar wind and interplanetary magnetic field can affect the upper atmosphere of Mars. For example, induced currents can lead to Joule heating of the atmosphere potentially modifying the neutral dynamics.

  16. Direct observation of current-induced motion of a 3D vortex domain wall in cylindrical nanowires

    KAUST Repository

    Ivanov, Yurii P.

    2017-05-08

    The current-induced dynamics of 3D magnetic vortex domain walls in cylindrical Co/Ni nanowires are revealed experimentally using Lorentz microscopy and theoretically using micromagnetic simulations. We demonstrate that a spin-polarized electric current can control the reversible motion of 3D vortex domain walls, which travel with a velocity of a few hundred meters per second. This finding is a key step in establishing fast, high-density memory devices based on vertical arrays of cylindrical magnetic nanowires.

  17. The Current Status of Usability Studies of Information Technologies in China: A Systematic Study

    OpenAIRE

    Lei, Jianbo; Xu, Lufei; Meng, Qun; Zhang, Jiajie; Gong, Yang

    2014-01-01

    Objectives. To systematically review and analyze the current status and characteristics of usability studies in China in the field of information technology in general and in the field of healthcare in particular. Methods. We performed a quantitative literature analysis in three major Chinese academic databases and one English language database using Chinese search terms equivalent to the concept of usability. Results. Six hundred forty-seven publications were selected for analysis. We found ...

  18. Observational studies of regions of massive star formation

    Science.gov (United States)

    Cooper, Heather Danielle Blythe

    2013-03-01

    Massive stars have a profound influence on their surroundings. However, relatively little is known about their formation. The study of massive star formation is hindered by a lack of observational evidence, primarily due to difficulties observing massive stars at early stages in their development. The Red MSX Source survey (RMS survey) is a valuable tool with which to address these issues. Near-infrared H- and K-band spectra were taken for 247 candidate massive young stellar objects (MYSOs), selected from the RMS survey. 195 (∼80%) of the targets are YSOs, of which 131 are massive YSOs (LBOL>5E3L⊙, M>8 M⊙). This is the largest spectroscopic study of massive YSOs to date. This study covers minimally obscured objects right through to very red, dusty sources. Almost all YSOs show some evidence for emission lines, though there is a wide variety of observed properties, with HI, H2 Fe II, and CO among the most commonly observed lines. Evidence for disks and outflows was frequently seen. Comparisons of Brγ and H2 emission with low mass YSOs suggest that the emission mechanism for these lines is the same for low-, intermediate-, and high-mass YSOs, i.e. high-mass YSOs appear to resemble scaled-up versions of low-mass YSOs. It was found that the YSOs form an evolutionary sequence, based on their spectra, consistent with the existing theoretical models. Type I YSOs have strong H2 emission, no ionized lines, and are redder than the other two subtypes. As such, these are considered to be the youngest sources. The Type III sources are bluest, and therefore considered to be the oldest subtype. They have strong H I lines and fluorescent Fe II 1.6878 μm emission. They may also have weak H2 emission. Type III sources may even be beginning to form a mini-H II region. XSHOOTER data from 10 Herbig Be stars were analysed. The evidence suggests that winds and disks are common among Herbig stars, as they are among their main sequence classical Be star counterparts. Line

  19. Lightning Attachment to Wind Turbines in Central Kansas: Video Observations, Correlation with the NLDN and in-situ Peak Current Measurements

    Science.gov (United States)

    Myers, J.; Cummins, K. L.; Hutchinson, M.; Nag, A.

    2012-12-01

    Lightning attachment to tall objects has been studied for decades. The attachment of lightning to electric power transmission towers in elevated terrain has driven much of the quantitative assessment of lightning characteristics in the 1970's and 80's. This has led to the understanding that in flat terrain, the probability of upward-initiated lightning is negligible for tower heights less than 100 m. For tower heights greater than 100, the probability increases roughly linearly with the log of height, reaching 100% at a height of 400 m. Additionally, the probability of upward initiation increases when the object resides on locally-elevated terrain. Over the last decade, there has been renewed interest in the study of lightning attachment to tall objects in general, and wind turbines in particular, following the establishment of large "wind farms" in lightning-prone regions. In this study, we present video observations, radiation magnetic field, and in-situ peak current measurements of lightning from an ongoing field program in a large wind farm in north-central Kansas, located in the U.S. Central Great Plains. The terrain variations within the wind farm are small rolling hills with peak variations on the order of 25 m. All turbines had a turbine hub height of 80 m, and a blade tip maximum height of 125 m. Two digital video camera systems (60 fields-per-second) were configured to self-trigger 2-second video sequences using a sequential-field-subtraction scene analysis (ufo-Capture). The two cameras had a common field of view that included 8 of the wind turbines. Nearby NLDN sensors were configured to record information that allows reconstruction of magnetic field waveforms within the bandwidth of the NLDN sensors. Some of the turbines were equipped with semi-quantitative in-situ peak current measuring devices. To date, more than 100 cloud-to-ground (CG) flashes have terminated within the perimeter of the wind farm. Video observations of flashes that attached to

  20. Modeling studies of the coastal/littoral current system off Southern Australia

    OpenAIRE

    Miller, Henry A.

    2006-01-01

    Both theoretical and numerical modeling studies of the current system off western and southern Australia are conducted to characterize the features of the current system, their temporal variability, and their impact on the sound speed structure. The theoretical study examines why boundary current separation occurs off Cape Leeuwin creating an area of enhanced eddy generation. It is shown that the beta effect, vortex stretching, and streamline curvature all act to decelerate the current a...

  1. [The reporting of observational studies: analysis using the STROBE statement].

    Science.gov (United States)

    Galera Llorca, Jordi; Lahoz Grillo, Raquel; Roig Loscertales, Francesc

    2011-12-01

    Deficiencies detected in biomedical studies publication different Guidelines to improve. The objective of the study is to assess the communication of observational studies of Cardiovascular and Metabolism therapeutic area (CVM) published in 6 Spanish journals in 2009 using the STROBE statement. Cross-sectional analysis of articles related to CVM therapeutic area, published during 2009 in 6 Spanish journals applying the 34 items of the STROBE statement. Descriptive analysis of the results for qualitative variables was performed using a frequency analysis. Quantitative variables were analyzed by sample estimates and dispersion. A comparative analysis of journals was performed using ANOVA with a statistical significance of pGaceta Sanitaria and a minimum of 19 (DE±2.8) in Hipertensión. Evaluated papers comply with slightly more than a half items (58%) of the STROBE recommendations. The Methods and Results sections showed more deficiencies.

  2. Wave propagation against current : a study of the effects of vertical shears of the mean current on the geometrical focusing of water waves

    Science.gov (United States)

    Charland, Jenna; Touboul, Julien; Rey, Vincent

    2013-04-01

    Wave propagation against current : a study of the effects of vertical shears of the mean current on the geometrical focusing of water waves J. Charland * **, J. Touboul **, V. Rey ** jenna.charland@univ-tln.fr * Direction Générale de l'Armement, CNRS Délégation Normandie ** Université de Toulon, 83957 La Garde, France Mediterranean Institute of Oceanography (MIO) Aix Marseille Université, 13288 Marseille, France CNRS/INSU, IRD, MIO, UM 110 In the nearshore area, both wave propagation and currents are influenced by the bathymetry. For a better understanding of wave - current interactions in the presence of a 3D bathymetry, a large scale experiment was carried out in the Ocean Basin FIRST, Toulon, France. The 3D bathymetry consisted of two symmetric underwater mounds on both sides in the mean wave direction. The water depth at the top the mounds was hm=1,5m, the slopes of the mounds were of about 1:3, the water depth was h=3 m elsewhere. For opposite current conditions (U of order 0.30m/s), a huge focusing of the wave up to twice its incident amplitude was observed in the central part of the basin for T=1.4s. Since deep water conditions are verified, the wave amplification is ascribed to the current field. The mean velocity fields at a water depth hC=0.25m was measured by the use of an electromagnetic current meter. The results have been published in Rey et al [4]. The elliptic form of the "mild slope" equation including a uniform current on the water column (Chen et al [1]) was then used for the calculations. The calculated wave amplification of factor 1.2 is significantly smaller than observed experimentally (factor 2). So, the purpose of this study is to understand the physical processes which explain this gap. As demonstrated by Kharif & Pelinovsky [2], geometrical focusing of waves is able to modify significantly the local wave amplitude. We consider this process here. Since vertical velocity profiles measured at some locations have shown significant

  3. Palliative care team visits. Qualitative study through participant observation

    Directory of Open Access Journals (Sweden)

    María del Mar Alfaya Góngora

    2016-04-01

    Full Text Available Objectives:To describe the clinical encounters that occur when a palliative care team provides patient care and the features that influence these encounters and indicate whether they are favorable or unfavorable depending on the expectations and feelings of the various participants.Methods:A qualitative case study conducted via participant observation. A total of 12 observations of the meetings of palliative care teams with patients and families in different settings (home, hospital and consultation room were performed. The visits were follow-up or first visits, either scheduled or on demand. Content analysis of the observation was performed.Results:The analysis showed the normal follow-up activity of the palliative care unit that was focused on controlling symptoms, sharing information and providing advice on therapeutic regimens and care. The environment appeared to condition the patients' expressions and the type of patient relationship. Favorable clinical encounter conditions included kindness and gratitude. Unfavorable conditions were deterioration caused by approaching death, unrealistic family objectives and limited resources.Conclusion:Home visits from basic palliative care teams play an important role in patient and family well-being. The visits seem to focus on controlling symptoms and are conditioned by available resources.

  4. An observational study of emergency department intern activities.

    Science.gov (United States)

    Zhu, Jia Ni; Weiland, Tracey J; Taylor, David M; Dent, Andrew W

    2008-05-05

    To describe how intern time is spent, and the frequency of activities performed by interns during emergency department (ED) rotations. Prospective observational study of 42 ED interns from three Melbourne city teaching hospitals during 5 months in 2006. Direct observations were made by a single researcher for 390.8 hours, sampling all days of the week and all hours of the day. Proportion of time spent on tasks and number of procedures performed or observed by interns. Direct patient-related tasks accounted for 86.6% of total intern time, including 43.9% spent on liaising and documentation, 17.5% obtaining patient histories, 9.3% on physical examinations, 5.6% on procedures, 4.8% ordering or interpreting investigations, 3.0% on handover and 4.9% on other clinical activities. Intern time spent on non-clinical activities included 4.2% on breaks, 3.7% on downtime, 1.7% on education, and 1.3% on teaching others. Adjusted for an 8-week term, the ED intern would take 253 patient histories, consult more senior ED staff on 683 occasions, perform 237 intravenous cannulations/phlebotomies, 39 arterial punctures, 12 wound repairs and apply 16 plasters. They would perform chest compressions under supervision on seven occasions, observe defibrillation twice and intubation once, but may not see a thoracostomy. The ED exposes interns to a broad range of activities. With the anticipated increase in intern numbers, dilution of the emergency medicine experience may occur, and requirements for supervision may increase. Substitution of ED rotations may deprive interns of a valuable learning experience.

  5. An observational study of hand hygiene compliance in paediatric wards.

    Science.gov (United States)

    Randle, Jacqueline; Firth, Joseph; Vaughan, Natalie

    2013-09-01

    To measure healthcare workers', children's and visitors' hand hygiene compliance in a paediatric oncology ward and a paediatric respiratory ward in an English hospital. Children are especially vulnerable to healthcare-associated infections, yet few studies have reported on hand hygiene compliance in paediatric clinical areas. This was an observational study. We measured hand hygiene compliance over an eight-hour period in two hospital wards using the 'five moments of hand hygiene' observation tool. We monitored a total of 407 hand hygiene opportunities. Overall opportunities for compliance were 74% for healthcare workers (n = 315) and children and visitors 23% (n = 92). Compliance was 84% for allied health professionals, 81% for doctors, 75% for nurses and 73% for ancillary and other staff. Hand hygiene compliance varied depending on which of the five moments of hygiene healthcare workers were undertaking (p hygiene compliance, and for visitors to the oncology ward, hand hygiene compliance was higher (p hygiene compliance; however, visitors' compliance was low. Among healthcare workers, levels of compliance were higher compared with previous reported estimates. Visitors had the lowest level of compliance yet owing to the nature of the clinical environments, nearly a quarter of care is delivered by them rather than healthcare workers, and so, this offers opportunities for specific future interventions aimed at families and carers. © 2012 Blackwell Publishing Ltd.

  6. An Observational Study of Entrainment Rate in Deep Convection

    Directory of Open Access Journals (Sweden)

    Xiaohao Guo

    2015-09-01

    Full Text Available This study estimates entrainment rate and investigates its relationships with cloud properties in 156 deep convective clouds based on in-situ aircraft observations during the TOGA-COARE (Tropical Ocean Global Atmosphere Coupled Ocean Atmosphere Response Experiment field campaign over the western Pacific. To the authors’ knowledge, this is the first study on the probability density function of entrainment rate, the relationships between entrainment rate and cloud microphysics, and the effects of dry air sources on the calculated entrainment rate in deep convection from an observational perspective. Results show that the probability density function of entrainment rate can be well fitted by lognormal, gamma or Weibull distribution, with coefficients of determination being 0.82, 0.85 and 0.80, respectively. Entrainment tends to reduce temperature, water vapor content and moist static energy in cloud due to evaporative cooling and dilution. Inspection of the relationships between entrainment rate and microphysical properties reveals a negative correlation between volume-mean radius and entrainment rate, suggesting the potential dominance of homogeneous mechanism in the clouds examined. In addition, entrainment rate and environmental water vapor content show similar tendencies of variation with the distance of the assumed environmental air to the cloud edges. Their variation tendencies are non-monotonic due to the relatively short distance between adjacent clouds.

  7. Memantine (Ebixa) in clinical practice - results of an observational study.

    Science.gov (United States)

    Calabrese, Pasquale; Essner, Ute; Forstl, Hans

    2007-01-01

    In a post-marketing observational study, the efficacy and tolerability of memantine were examined in patients with moderate to severe Alzheimer's disease. The patients were treated with 20 mg/day of memantine for a 6-month period. The efficacy of memantine was evaluated using the Mini-Mental State Examination, the Nurses' Observation Scale for Geriatric Patients (NOSGER) and the Explorationsmodul Demenz (EMD) scale. In addition, a global assessment was made by the physician. After 6 months of open-label treatment with memantine, the patients' cognitive function, ability to perform daily activities and global performance all showed a marked improvement. In the overall evaluation by the physician, improvement or stabilisation had been achieved by 78.8% of patients after 6 months of therapy. Memantine also demonstrated an excellent tolerability profile. The results of this naturalistic study support the significant efficacy and tolerability of memantine that has been previously demonstrated in randomised, controlled clinical Alzheimer's disease trials. (c) 2007 S. Karger AG, Basel.

  8. Complete control, direct observation and study of molecular super rotors

    CERN Document Server

    Korobenko, Aleksey; Milner, Valery

    2013-01-01

    Extremely fast rotating molecules carrying significantly more energy in their rotation than in any other degree of freedom are known as "super rotors". It has been speculated that super rotors may exhibit a number of unique and intriguing properties. Theoretical studies showed that ultrafast molecular rotation may change the character of molecular scattering from solid surfaces, alter molecular trajectories in external fields, make super rotors surprisingly stable against collisions, and lead to the formation of gas vortices. New ways of molecular cooling and selective chemical bond breaking by ultrafast spinning have been proposed. Owing to the fundamental laws of nature, bringing a large number of molecules to fast, directional and synchronous rotation is rather challenging. As a result, only indirect evidence of super rotors has been reported to date. Here we demonstrate the first controlled creation, direct observation and study of molecular super rotors. Using intense laser pulses tailored to produce an ...

  9. Empirical study of sensor observation services server instances

    CERN Document Server

    Tamayo, Alain; Granell, Carlos; Huerta, Joaquín; 10.1007/978-3-642-19789-5_10

    2011-01-01

    The number of Sensor Observation Service (SOS) instances available online has been increasing in the last few years. The SOS specification standardises interfaces and data formats for exchanging sensor-related in-formation between information providers and consumers. SOS in conjunction with other specifications in the Sensor Web Enablement initiative, at-tempts to realise the Sensor Web vision, a worldwide system where sensor networks of any kind are interconnected. In this paper we present an empirical study of actual instances of servers implementing SOS. The study focuses mostly in which parts of the specification are more frequently included in real implementations, and how exchanged messages follows the structure defined by XML Schema files. Our findings can be of practical use when implementing servers and clients based on the SOS specification, as they can be optimized for common scenarios.

  10. [Registration of observational studies: it is time to comply with the Declaration of Helsinki requirement].

    Science.gov (United States)

    Dal-Ré, Rafael; Delgado, Miguel; Bolumar, Francisco

    2015-01-01

    Publication bias is a serious deficiency in the current system of disseminating the results of human research studies. Clinical investigators know that, from an ethical standpoint, they should prospectively register clinical trials in a public registry before starting them. In addition, it is believed that this approach will help to reduce publication bias. However, most studies conducted in humans are observational rather than experimental. It is estimated that less than 2% out of 2 million concluded or ongoing observational studies have been registered. The 2013 revision of the Declaration of Helsinki requires registration of any type of research study involving humans or identifiable samples or data. It is proposed that funding agencies, such as the Fondo de Investigaciones Sanitarias, as well as private companies, require preregistration of observational studies before providing funding. It is also proposed that Research Ethics Committees which, following Spanish regulation, have been using the Declaration as the framework for assessing the ethics of clinical trials with medicines since 1990, should follow the same provisions for the assessment of health-related observational studies: therefore, they should require prospective registration of studies before granting their final approval. This would allow observational study investigators to be educated in complying with an ethical requirement recently introduced in the most important ethical code for research involving humans. Copyright © 2014 SESPAS. Published by Elsevier Espana. All rights reserved.

  11. Direct observation of current in type-I edge-localized-mode filaments on the ASDEX upgrade tokamak

    DEFF Research Database (Denmark)

    Vianello, N.; Zuin, M.; Cavazzana, R.;

    2011-01-01

    Magnetically confined plasmas in the high confinement regime are regularly subjected to relaxation oscillations, termed edge localized modes (ELMs), leading to large transport events. Present ELM theories rely on a combined effect of edge current and the edge pressure gradients which result in in...

  12. Equity perceptions and marital satisfaction in former and current marriage : A study among the remarried

    NARCIS (Netherlands)

    Buunk, BP; Mutsaers, W

    1999-01-01

    A study among 290 remarried individuals examined equity perceptions in the former and the current marriage. The results showed that equity in the former and the current marriage were not related to each other. In general, respondents perceived much more inequity in the former than in the current mar

  13. Simulation Study Of Early Afterglows Observed With Swift

    Science.gov (United States)

    Nishikawa, Ken-Ichi; Hededal, C.; Hardee, P.; Mizuno, Y.; Fishman, G. J.

    2006-09-01

    A 3-D relativistic particle-in-cell code has been used to simulate the dynamics of forward and reverse shocks with thin and thick shells within the parameter constraints provided by present Swift observations and the present models of GRB emission. Our 3-D RPIC simulations have provided the dynamics of collisionless shocks in electron-ion and electron-positron plasmas with and without initial ambient magnetic fields and revealed the importance of ``jitter radiation'' with prompt and afterglow spectra due to the inhomogeneous magnetic fields generated by the Weibel instability. It is different from synchrotron radiation, which is usually assumed to be the dominant radiation process. We have investigated gamma-ray burst emissions from prompt, early, and late afterglows considering microscopic processes. Based on our previous investigation of the Weibel instability for each stage of evolution of ejecta propagating in the ISM, we have incorporated the plasma conditions (relativistic jets) with the density and composition of the plasmas, the magnetic field strength ($\\sigma$-values (the ratio of the electromagnetic energy flux to the particle energy flux)) and its direction, and the Lorentz factor for the different stages in prompt and afterglows. Systematic simulation studies of the relativistic collisionless shocks, associated particle acceleration, magnetic field generation and self-consistent radiation provide insight into undetermined issues in prompt and afterglows observed by Swift. Self-consistently calculated lightcurves, spectra, spectral evolutions, and polarization as function of viewing angle will be done to light a shed on recent new observations by Swift, in particular, X-ray flares, early steep decay, and shallow decay.

  14. Warfarin and fibrinolysis - a challenging combination: an observational cohort study

    Directory of Open Access Journals (Sweden)

    Luurila Harri

    2011-04-01

    Full Text Available Abstract Background Patients presenting with ST-segment elevation myocardial infarction (STEMI frequently use warfarin. Fibrinolytic agents and warfarin both increase bleeding risk, but only a few studies have been published concerning the bleeding risk of warfarin-prescribed patients receiving fibrinolysis. The objective of this study was to define the prevalence for intracranial haemorrhage (ICH or major bleeding in patients on warfarin treatment receiving pre-hospital fibrinolysis. Methods This was an observational cohort study. Data for this retrospective case series were collected in Helsinki Emergency Medical Service catchment area from 1.1.1997 to 30.6.2010. All warfarin patients with suspected ST-segment elevation myocardial infarction (STEMI, who received pre-hospital fibrinolysis, were included. Bleeding complications were detected from Medical Records and classified as ICH, major or minor bleeding. Results Thirty-six warfarin patients received fibrinolysis during the study period. Fourteen patients had bleeding complications. One (3%, 95% CI 0-15% patient had ICH, six (17%, 95% CI 7-32% had major and seven (19%, 95% CI 9-35% had minor bleeding. The only fatal bleeding occurred in a patient with ICH. Patients' age, fibrinolytic agent used or aspirin use did not predispose to bleeding complications. High International Normalized Ratio (INR seemed to predispose to bleedings with values over 3, but no statistically significant difference was found. Conclusions Bleedings occur frequently in warfarin patients treated with fibrinolysis in the real world setting, but they are rarely fatal.

  15. Mucocutaneous manifestations of acquired hypoparathyroidism: An observational study

    Directory of Open Access Journals (Sweden)

    Somenath Sarkar

    2012-01-01

    Full Text Available Hypoparathyroidism is a disorder of calcium and phosphorus metabolism due to decreased secretion of parathyroid hormone. Hypoparathyroidism can be hereditary and acquired. Acquired hypoparathyroidism usually occurs following neck surgery (thyroid surgery or parathyroid surgery. Along with systemic manifestations, hypoparathyroidism produces some skin manifestations. Lack of study regarding mucocutaneous manifestations of acquired hypoparathyroidism prompted us to undertake this study. To evaluate the mucocutaneous manifestations of acquired hypoparathyroidism. An observational study done in a tertiary care hospital of Kolkata by comprehensive history taking, through clinical examination and relevant laboratory investigations. Twenty-one patients were included in the study. The commonest form of acquired hypoparathyroidism was neck surgery (thyroidectomy and parathyroidectomy operation. Mucocutaneous manifestations were present in 76.19% of patients. The most frequent mucocutaneous manifestation was found in the hairs like the loss of axillary hair (61.9%, loss of pubic hair (52.38%, coarsening of body hair (47.62%, and alopecia areata (9.52%. The nail changes noted were brittle and ridged nail, followed by onycholysis, onychosezia, and onychomedesis. The most common skin features were xerotic skin in 11 patients (52.38%, followed by pellagra-like skin pigmentation, pustular psoriasis and acne form eruption, bullous impetigo, etc. Mucosa was normal in all the cases excepting the one which showed oral candidiasis.

  16. Adverse effect profile of trichlormethiazide: a retrospective observational study

    Directory of Open Access Journals (Sweden)

    Nishida Yayoi

    2011-05-01

    Full Text Available Abstract Background Trichlormethiazide, a thiazide diuretic, was introduced in 1960 and remains one of the most frequently used diuretics for treating hypertension in Japan. While numerous clinical trials have indicated important side effects of thiazides, e.g., adverse effects on electrolytes and uric acid, very few data exist on serum electrolyte levels in patients with trichlormethiazide treatment. We performed a retrospective cohort study to assess the adverse effects of trichlormethiazide, focusing on serum electrolyte and uric acid levels. Methods We used data from the Clinical Data Warehouse of Nihon University School of Medicine obtained between Nov 1, 2004 and July 31, 2010, to identify cohorts of new trichlormethiazide users (n = 99 for 1 mg, n = 61 for 2 mg daily dosage and an equal number of non-users (control. We used propensity-score matching to adjust for differences between users and control for each dosage, and compared serum chemical data including serum sodium, potassium, uric acid, creatinine and urea nitrogen. The mean exposure of trichlormethiazide of 1 mg and 2 mg users was 58 days and 64 days, respectively. Results The mean age was 66 years, and 55% of trichlormethiazide users of the 1 mg dose were female. In trichlormethiazide users of the 2 mg dose, the mean age was 68 years, and 43% of users were female. There were no statistically significant differences in all covariates (age, sex, comorbid diseases, past drugs, and current antihypertensive drugs between trichlormethiazide users and controls for both doses. In trichlormethiazide users of the 2 mg dose, the reduction of serum potassium level and the elevation of serum uric acid level were significant compared with control, whereas changes of mean serum sodium, creatinine and urea nitrogen levels were not significant. In trichlormethiazide users of the 1 mg dose, all tests showed no statistically significant change from baseline to during the exposure period in

  17. Providers' response to child eating behaviors: A direct observation study.

    Science.gov (United States)

    Tovar, Alison; Vaughn, Amber E; Fallon, Megan; Hennessy, Erin; Burney, Regan; Østbye, Truls; Ward, Dianne S

    2016-10-01

    Child care providers play an important role in feeding young children, yet little is known about children's influence on providers' feeding practices. This qualitative study examines provider and child (18 months -4 years) feeding interactions. Trained data collectors observed 200 eating occasions in 48 family child care homes and recorded providers' responses to children's meal and snack time behaviors. Child behaviors initiating provider feeding practices were identified and practices were coded according to higher order constructs identified in a recent feeding practices content map. Analysis examined the most common feeding practices providers used to respond to each child behavior. Providers were predominately female (100%), African-American (75%), and obese (77%) and a third of children were overweight/obese (33%). Commonly observed child behaviors were: verbal and non-verbal refusals, verbal and non-verbal acceptance, being "all done", attempts for praise/attention, and asking for seconds. Children's acceptance of food elicited more autonomy supportive practices vs. coercive controlling. Requests for seconds was the most common behavior, resulting in coercive controlling practices (e.g., insisting child eat certain food or clean plate). Future interventions should train providers on responding to children's behaviors and helping children become more aware of internal satiety and hunger cues.

  18. Critical Observation on Methodologies of Select Doctoral Research Studies

    Directory of Open Access Journals (Sweden)

    Dr Indrajit Goswami

    2014-12-01

    Full Text Available The present article aims to critically observe and interpret the methodological deficiencies as found in randomly selected 14 doctoral theses submitted to two different universities in India. Despite their serious deviation from the expected methodological standards, all those theses were accepted and approved by the universities and scholars concerned conferred with PhD degrees. Undoubtedly, those theses kept in the reference sections at the respective university libraries would potentially misguide and mislead the future researchers. Some of the common technical deficiencies, as have been noticed, include (1 absence of careful thoughts in framing research titles, (ii biased method of data collection, (ii absence of logical explanation in favour of sample size and sample selection process, (iii designing and execution of instrument for data collection, (iv theory formulation in terms of framing of objectives, hypotheses and operational definitions etc. The article attempts to present the critical observations on case-to-case basis so that their conceptual, instrumental and procedural deficiencies and deviations are easily understood by the academicians, researchers and students. The content of this article is divided in to three broad sections. The first section deals with an introduction to quantitative and qualitative research methods and their advantages and limitations. The next section deals with the review of the selected theses followed by conclusion and suggested remedial measures. The objective of this article is purely academic and its scope is limited to enhancement of quality of future research studies in the domains and related fields.

  19. Nursing diagnoses in patients with chronic venous ulcer: observational study

    Directory of Open Access Journals (Sweden)

    Glycia de Almeida Nogueira

    2015-06-01

    Full Text Available This study aimed to analyze nursing diagnoses in people with chronic venous ulcer. An observational, descriptive, quantitative research conducted in an ambulatory specialized in wound treatment, with a non-probabilistic sample of 20 patients.  Data collection was performed in an institutional form denominated Assessment Protocol for Clients with Tissue Lesions. Diagnoses were established by consensus among four researchers with experience in nursing diagnoses and wound treatments. From data analysis, 16 diagnoses were identified, with 100% of participants presenting: Impaired tissue integrity, Ineffective peripheral tissue perfusion, Risk of infection, Impaired physical mobility and Ineffective health self-control. These diagnoses are found in Safety/Protection, Activity/Rest and Health promotion domains, which from the clinical practice stand point should be priority focuses in nursing intervention and assessment.

  20. Solar Radio Observation using Callisto Spectrometer at Sumedang West Java Indonesia: Current Status and Future Development Plan in Indonesia

    Science.gov (United States)

    Manik, T.; Sitompul, P.; Batubara, M.; Harjana, T.; Yatini, C. Y.; Monstein, C.

    2016-04-01

    Sumedang Observatory (6.91°S, 107,84°E) was established in 1975 and is one of the solar observation facilities of the Space Science Center of Indonesian National Institute of Aeronautics and Space (LAPAN), located around 40 km, east part of Bandung City, West Java, Indonesia. Several instrumentations for solar and space observation such as optical telescopes, radio solar spectrograph, flux gate magnetometer, etc. are operated there, together with an ionosphere sounding system (ionosonde) that was set up later. In July 2014, a standard Callisto (Compound Astronomical Low-cost Low-frequency Instrument for Spectroscopy and Transportable Observatory) spectrometer was installed at Sumedang Observatory for solar radio activity monitoring. Callisto has been developed in the framework of IHY2007 and ISWI, supported by UN and NASA. Callisto spectrometer has observation capability in the frequency range of 45-870 MHz. The Callisto spectrometer receives signal by using a set of 21 elements log-periodic antenna, model CLP5130-1N, pointed to the Sun and equipped with a low noise pre-amplifier. With respect to the Radio Frequency Interferences (RFI) measurements, the Callisto spectrometer is operated individually in frequency ranges of 45-80 MHz and 180-450 MHz. Observation status and data flow are monitored in on-line from center office located in Bandung. The data was transferred to central database at FHNW (Fachhochschule Nordwestschweiz) server every 15 minutes to appear on e-Callisto network subsequently. A real time data transfer and data processing based on Python software also has been developed successfully to be used as an input for Space Weather Information and Forecasting Services (SWIFtS) provided by LAPAN. On 5th November 2014, Callisto spectrometer at Sumedang observed the first clear solar radio event, a solar radio burst type II corresponding to a coronal mass ejection (CME), indicated by a strong X-ray event of M7.9 that was informed on by Space Weather

  1. Obesity in adolescents with chronic fatigue syndrome: an observational study.

    Science.gov (United States)

    Norris, T; Hawton, K; Hamilton-Shield, J; Crawley, E

    2017-01-01

    Identify the prevalence of obesity in patients with chronic fatigue syndrome (CFS) compared with healthy adolescents, and those identified with CFS in a population cohort. Cross-sectional analysis of multiple imputed data. Data from UK paediatric CFS/myalgic encephalomyelitis (CFS/ME) services compared with data collected at two time points in the Avon Longitudinal Study of Parents and Children (ALSPAC). 1685 adolescents who attended a CFS/ME specialist service between 2004 and 2014 and 13 978 adolescents aged approximately 13 years and 16 years participating in the ALSPAC study. Body mass index (BMI) (kg/m(2)), sex-specific and age-specific BMI Z-scores (relative to the International Obesity Task Force cut-offs) and prevalence of obesity (%). Adolescents who had attended specialist CFS/ME services had a higher prevalence of obesity (age 13 years: 9.28%; age 16 years: 16.43%) compared with both adolescents classified as CFS/ME in ALSPAC (age 13 years: 3.72%; age 16 years: 5.46%) and those non-CFS in ALSPAC (age 13 years: 4.18%; age 16 years: 4.46%). The increased odds of obesity in those who attended specialist services (relative to non-CFS in ALSPAC) was apparent at both 13 years (OR: 2.31 (1.54 to 3.48)) and 16 years, with a greater likelihood observed at 16 years (OR: 4.07 (2.04 to 8.11)). We observed an increased prevalence of obesity in adolescents who were affected severely enough to be referred to a specialist CFS/ME service. Further longitudinal research is required in order to identify the temporal relationship between the two conditions. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  2. Constraints on the Formation of Double Neutron Stars from the Observed Eccentricities and Current Limits on Merger Rates

    Science.gov (United States)

    Chruslinska, M.; Belczynski, K.; Bulik, T.; Gladysz, W.

    2017-03-01

    We employ population synthesis method to model the double neutron star (DNS) population and test various possibilities on natal kick velocities gained by neutron stars after their formation. We first choose natal kicks after standard core collapse supernovae (CCSN) from a Maxwellian distribution with velocity dispersion of σ = 265 km/s as proposed by Hobbs and then modify this distribution by changing σ toward smaller and larger kick values. We also take into account the possibility of NS formation through electron capture supernova. In this case we test two scenarios: zero natal kick or small natal kick, drawn from Maxwellian distribution with σ = 26.5 km/s. We calculate the present-day orbital parameters of binaries and compare the resulting eccentricities with those known for observed DNSs. As an additional test we calculate Galactic merger rates for our model populations and confront them with observational limits. We do not find any model unequivocally consistent with both observational constraints simultaneously. The models with low kicks after CCSN for binaries with the second NS forming through core collapse SN are marginally consistent with the observations. This means that either 14 observed DNSs are not representative of the intrinsic Galactic population, or that our modeling of DNS formation needs revision.

  3. Molecular Carbon in the Galaxy: Laboratory and Observational Studies

    Science.gov (United States)

    Saykally, Richard James

    2003-01-01

    In a collaboration with the Mats Larsson group from Stockholm, we carried out a new measurement of the rate of dissociative recombination of H(sup *, sub j), using a new pulsed supersonic beam source of rotationally cold H(sup *, sub j). This source was first designed and characterized in our lab by IR cavity ringdown spectroscopy, determining a rotationaYtranslationa1 temperature of 20-60K, depending on conditions. This new source was then taken to Stockholm for the recombination rate studies at the CRYRING storage ring. The recombination rate constant measured against temperature yields values consistent with the most recent calculations, whereas previous experimental measurements varied over a range of 10(exp 4) and were poor agreement with theory. This is a crucial achievement for understanding the ion chemistry of diffuse clouds. Moreover, this result in combination with recent observations implies a greatly enhanced (factor of 40) cosmic ray ionization rate in a diffuse cloud (zeta Persei) relative to previous studies. The implications of this are discussed in our recent Nature paper. An enhanced cosmic-ray flux towards zeta Persei inferred from a laboratory study of the H(sup *, sub j)-e(sup -) recombination rate.

  4. From geospatial observations of ocean currents to causal predictors of spatio-economic activity using computer vision and machine learning

    Science.gov (United States)

    Popescu, Florin; Ayache, Stephane; Escalera, Sergio; Baró Solé, Xavier; Capponi, Cecile; Panciatici, Patrick; Guyon, Isabelle

    2016-04-01

    The big data transformation currently revolutionizing science and industry forges novel possibilities in multi-modal analysis scarcely imaginable only a decade ago. One of the important economic and industrial problems that stand to benefit from the recent expansion of data availability and computational prowess is the prediction of electricity demand and renewable energy generation. Both are correlates of human activity: spatiotemporal energy consumption patterns in society are a factor of both demand (weather dependent) and supply, which determine cost - a relation expected to strengthen along with increasing renewable energy dependence. One of the main drivers of European weather patterns is the activity of the Atlantic Ocean and in particular its dominant Northern Hemisphere current: the Gulf Stream. We choose this particular current as a test case in part due to larger amount of relevant data and scientific literature available for refinement of analysis techniques. This data richness is due not only to its economic importance but also to its size being clearly visible in radar and infrared satellite imagery, which makes it easier to detect using Computer Vision (CV). The power of CV techniques makes basic analysis thus developed scalable to other smaller and less known, but still influential, currents, which are not just curves on a map, but complex, evolving, moving branching trees in 3D projected onto a 2D image. We investigate means of extracting, from several image modalities (including recently available Copernicus radar and earlier Infrared satellites), a parameterized representation of the state of the Gulf Stream and its environment that is useful as feature space representation in a machine learning context, in this case with the EC's H2020-sponsored 'See.4C' project, in the context of which data scientists may find novel predictors of spatiotemporal energy flow. Although automated extractors of Gulf Stream position exist, they differ in methodology

  5. An observational asteroseismic study of the pulsating B-stars in the open cluster NGC 884

    CERN Document Server

    Saesen, S; Aerts, C; Miglio, A; Carrier, F

    2013-01-01

    Recent progress in the seismic interpretation of field {\\beta} Cep stars has resulted in improvements of the physical description in the stellar structure and evolution model computations of massive stars. Further asteroseismic constraints can be obtained from studying ensembles of stars in a young open cluster, which all have similar age, distance and chemical composition. We present an observational asteroseismic study based on the discovery of numerous multi-periodic and mono-periodic B-stars in the open cluster NGC 884. Our study illustrates the current status of ensemble asteroseismology of a young open cluster.

  6. NASA Satellite Observations: A Unique Asset for the Study of the Environment and Implications for Public Health

    Science.gov (United States)

    Estes Sue M.

    2010-01-01

    This slide presentation highlights how satellite observation systems are assets for studying the environment in relation to public health. It includes information on current and future satellite observation systems, NASA's public health and safety research, surveillance projects, and NASA's public health partners.

  7. A characterization of the current communication patterns in Danish community pharmacies - an observational study

    DEFF Research Database (Denmark)

    Kaae, Susanne; Mygind, Anna; Saleem, Sahdia

    2013-01-01

    Community pharmacies have been trying to expand their core function by counseling customers at the counter. This has been challenging given that customers' interest in receiving counseling may be limited.......Community pharmacies have been trying to expand their core function by counseling customers at the counter. This has been challenging given that customers' interest in receiving counseling may be limited....

  8. Constraints from atmospheric CO2 and satellite-based vegetation activity observations on current land carbon cycle trends

    Directory of Open Access Journals (Sweden)

    S. Zaehle

    2012-11-01

    Full Text Available Terrestrial ecosystem models used for Earth system modelling show a significant divergence in future patterns of ecosystem processes, in particular carbon exchanges, despite a seemingly common behaviour for the contemporary period. An in-depth evaluation of these models is hence of high importance to achieve a better understanding of the reasons for this disagreement. Here, we develop an extension for existing benchmarking systems by making use of the complementary information contained in the observational records of atmospheric CO2 and remotely-sensed vegetation activity to provide a firm set of diagnostics of ecosystem responses to climate variability in the last 30 yr at different temporal and spatial scales. The selection of observational characteristics (traits specifically considers the robustness of information given the uncertainties in both data and evaluation analysis. In addition, we provide a baseline benchmark, a minimum test that the model under consideration has to pass, to provide a more objective, quantitative evaluation framework. The benchmarking strategy can be used for any land surface model, either driven by observed meteorology or coupled to a climate model. We apply this framework to evaluate the offline version of the MPI-Earth system model's land surface scheme JSBACH. We demonstrate that the complementary use of atmospheric CO2 and satellite based vegetation activity data allows to pinpoint specific model failures that would not be possible by the sole use of atmospheric CO2 observations.

  9. Evidence of clinical competence by simulation, a hermeneutical observational study.

    Science.gov (United States)

    Lejonqvist, Gun-Britt; Eriksson, Katie; Meretoja, Riitta

    2016-03-01

    Making the transition from theory to practise easier in nursing education through simulation is widely implemented all over the world, and there is research evidence of the positive effects of simulation. The pre-understanding for this study is based on a definition of clinical competence as encountering, knowing, performing, maturing and developing, and the hypothesis is that these categories should appear in simulated situations. The aim of the study was to explore the forms and expressions of clinical competence in simulated situations and furthermore to explore if and how clinical competence could be developed by simulation. An observational hermeneutic study with a hypothetic-deductive approach was used in 18 simulated situations with 39 bachelor degree nursing students. In the situations, the scenarios, the actors and the plots were described. The story told was "the way from suffering to health" in which three main plots emerged. The first was, doing as performing and knowing, which took the shape of knowing what to do, acting responsibly, using evidence and equipment, appearing confident and feeling comfortable, and sharing work and information with others. The second was, being as encountering the patient, which took the shape of being there for him/her and confirming by listening and answering. The third plot was becoming as maturing and developing which took the shape of learning in co-operation with other students. All the deductive categories, shapes and expressions appeared as dialectic patterns having their negative counterparts. The study showed that clinical competence can be made evident and developed by simulation and that the challenge is in encountering the patient and his/her suffering.

  10. Oral implications of the vegan diet: observational study.

    Science.gov (United States)

    Laffranchi, L; Zotti, F; Bonetti, S; Dalessandri, D; Fontana, P

    2010-01-01

    The aim of this study was to investigate oral changes in subjects who have assumed a vegan diet for a long time (at least 18 months), that is to say, a diet completely lacking in meat and animal derivatives. A sample of 15 subjects was analyzed, all from northern Italy and aged 24 to 60 year, composed of 11 men and 4 women who had been following a vegan diet for a minimum of 18 months to a maximum of 20 years. In parallel with the study sample, a control group (15 subjects) with the same criteria of age, sex, and place of origin all following an omnivorous diet was chosen. The sample answered a questionnaire that investigated their eating habits, the frequency with which they eat meals, the main foodstuffs assumed, oral hygiene habits, and any painful symptomatology of the teeth or more general problems in the oral cavity. The sample was then subject to objective examination in which the saliva pH was measured and the teeth were checked for demineralization of the enamel, white spots, and caries (using KaVo DIAGNOdent) with particular attention being paid to the localization of these lesions, and lastly, sounding was carried out to detect any osseous defects and periodontal pockets. The study revealed greater incidence of demineralization and white spots in the vegan subjects compared to the omnivorous ones localized at the neck of the teeth and on the vestibular surfaces of dental elements (with the exception of the lower anterior group). The saliva pH, more acid in the omnivorous patients, ranged between four and six. Changes in oral conditions in both groups of subjects were observed. In order to research into the cause-effect relationship of the vegan diet on the oral cavity effectively, the sample needs to be studied for a longer period of time and the results re-evaluated.

  11. Evaluation of Xerostomia in Different Psychological Disorders: An Observational Study

    Science.gov (United States)

    Chandrappa, Pramod Redder; Patil, Snehal; Roodmal, Seema Yadav; Kumarswamy, Akshay; Chappi, Mounesh Kumar

    2016-01-01

    Introduction Psychiatric diseases like anxiety, depression, schizophrenia and bipolar disorders are increasing at an alarming rate. These diseases can affect the quantity and quality of saliva leading to multiple oral diseases. Although many researchers have evaluated xerostomia in general population, its prevalence is not been assessed in patients suffering from different psychological disorders. Aim To investigate the prevalence of xerostomia and to assess the correlation between xerostomia and dryness of lip and mucosa in different psychological disorders. Materials and Methods A cross-sectional observational study was conducted over a period of six months in Department of Psychiatry and Department of Oral Medicine. Patients with anxiety, depression, schizophrenia and bipolar disorder, as diagnosed by an experienced psychiatrist, were given a questionnaire to evaluate the xerostomia. Patients with symptoms of xerostomia were subjected to oral examination by a skilled oral diagnostician to check for dryness of lips and mucosa. One hundred patients from each group of psychiatric diseases were included in the study using a consecutive sampling technique. An equal number of healthy individuals reporting to oral medicine department for routine oral screening were included as control group after initial psychiatric evaluation. Results In this study statistically significant increase in the xerostomia in psychiatric patients was recorded when compared to the control group (p<0.01). Xerostomia was significantly higher in anxiety patients (51%) followed by depression (47%), bipolar disorder (41%), schizophrenia (39%) and control group (27%). The majority of the psychiatric patients had ‘moderate’ to ‘severe’ xerostomia whereas the control group had ‘mild’ xerostomia. Xerostomia was significantly higher in younger age group (18–49 years) than in older age group and females patients had higher xerostomia than male patients. Psychiatric patients had

  12. 2D vs. 3D mammography observer study

    Science.gov (United States)

    Fernandez, James Reza F.; Hovanessian-Larsen, Linda; Liu, Brent

    2011-03-01

    Breast cancer is the most common type of non-skin cancer in women. 2D mammography is a screening tool to aid in the early detection of breast cancer, but has diagnostic limitations of overlapping tissues, especially in dense breasts. 3D mammography has the potential to improve detection outcomes by increasing specificity, and a new 3D screening tool with a 3D display for mammography aims to improve performance and efficiency as compared to 2D mammography. An observer study using a mammography phantom was performed to compare traditional 2D mammography with this ne 3D mammography technique. In comparing 3D and 2D mammography there was no difference in calcification detection, and mass detection was better in 2D as compared to 3D. There was a significant decrease in reading time for masses, calcifications, and normals in 3D compared to 2D, however, as well as more favorable confidence levels in reading normal cases. Given the limitations of the mammography phantom used, however, a clearer picture in comparing 3D and 2D mammography may be better acquired with the incorporation of human studies in the future.

  13. Study of the NWC electrons belt observed on DEMETER Satellite

    CERN Document Server

    Li, Xinqiao; Wang, Ping; Wang, Huanyu; Lu, Hong; Zhang, Xuemin; Huang, Jianping; Shi, Feng; Yu, Xiaoxia; Xu, Yanbing; Meng, Xiangcheng; Wang, Hui; Zhao, Xiaoyun; Parrot, M

    2010-01-01

    We analyzed the data from 2007 to 2008, which is observed by IDP onboard DEMETER satellite, during ten months of NWC working and seven months of NWC shutdown. The characteristic of the space instantaneous electron belts, which come from the influence of the VLF transmitted by NWC, is studied comprehensively. The main distribution region of the NWC electron belts and the flux change are given. We also studied the distribution characteristic of the average energy spectrum in different magnetic shell at the height of DEMETER orbit and the difference of the average energy spectrum of the electrons in the drift loss-cone between day and night. As a result, the powerful power of NWC transmitter and the 19.8 kHz narrow bandwidth VLF emission not only created a momentary electrons enhancement region, which strides 180 degree in them longitude direction and from 1.6 to 1.9 in L value, with the rise of the electrons flux reaching to 3 orders of magnitude mostly, but also induced the enhancement or loss of electrons in ...

  14. Treatment of Crohn's disease with cannabis: an observational study.

    Science.gov (United States)

    Naftali, Timna; Lev, Lihi Bar; Yablecovitch, Doron; Yablekovitz, Doron; Half, Elisabeth; Konikoff, Fred M

    2011-08-01

    The marijuana plant cannabis is known to have therapeutic effects, including improvement of inflammatory processes. However, no report of patients using cannabis for Crohn's disease (CD) was ever published. To describe the effects of cannabis use in patients suffering from CD. In this retrospective observational study we examined disease activity, use of medication, need for surgery, and hospitalization before and after cannabis use in 30 patients (26 males) with CD. Disease activity was assessed by the Harvey Bradshaw index for Crohn's disease. Of the 30 patients 21 improved significantly after treatment with cannabis. The average Harvey Bradshaw index improved from 14 +/- 6.7 to 7 +/- 4.7 (P < 0.001). The need for other medication was significantly reduced. Fifteen of the patients had 19 surgeries during an average period of 9 years before cannabis use, but only 2 required surgery during an average period of 3 years of cannabis use. This is the first report of cannabis use in Crohn's disease in humans. The results indicate that cannabis may have a positive effect on disease activity, as reflected by reduction in disease activity index and in the need for other drugs and surgery. Prospective placebo-controlled studies are warranted to fully evaluate the efficacy and side effects of cannabis in CD.

  15. Recognising advancing nursing practice: evidence from two observational studies.

    Science.gov (United States)

    Wilson-Barnett, J; Barriball, K L; Reynolds, H; Jowett, S; Ryrie, I

    2000-10-01

    Debates over title, grades and relationships across the profession has tended to dominate the literature in advancing nursing practice. Fewer research projects have attempted to study the activities of nurses who are designated as undertaking advancing nursing roles. One study evaluating Masters courses for Clinical Nursing Practice and a second addressing the impact of the 'Scope of Professional Practice' (United Kingdom Central Council for Nursing, Midwifery & Health Visiting, 1992) document by this team of authors afforded these research opportunities. In this paper empirical data from 'reflective' observation with 19 nurses (including midwives and health visitors) are presented to illustrate the range and type of functions undertaken by a small group of practitioners developing their practice. A number of characteristic features emerged. Assessment of individual and group needs, positive motivation to constantly improve practice, inter-disciplinary and cross agency working for planned change and an ability to identify and prioritize service requirements were recognised in these nurses' roles. Certain personal attributes were seen to be essential for successful role development such as confidence, commitment and problem solving powers combined with a positive working environment and supportive managers.

  16. Observational Study of Spinal Muscular Atrophy Type 2 and 3

    Science.gov (United States)

    Kaufmann, Petra; McDermott, Michael P.; Darras, Basil T.; Finkel, Richard; Kang, Peter; Oskoui, Maryam; Constantinescu, Andrei; Sproule, Douglas Michael; Foley, A. Reghan; Yang, Michele; Tawil, Rabi; Chung, Wendy; Martens, Bill; Montes, Jacqueline; O'Hagen, Jessica; Dunaway, Sally; Flickinger, Jean M.; Quigley, Janet; Riley, Susan; Glanzman, Allan M.; Benton, Maryjane; Ryan, Patricia A.; Irvine, Carrie; Annis, Christine L.; Butler, Hailly; Caracciolo, Jayson; Montgomery, Megan; Marra, Jonathan; Koo, Benjamin; De Vivo, Darryl C.

    2013-01-01

    Objective To characterize the short-term course of spinal muscular atrophy (SMA) in a genetically and clinically well-defined cohort of patients with SMA. Design A comprehensive multicenter, longitudinal, observational study. Setting The Pediatric Neuromuscular Clinical Research Network for SMA, a consortium of clinical investigators at 3 clinical sites. Participants Sixty-five participants with SMA types 2 and 3, aged 20 months to 45 years, were prospectively evaluated. Intervention We collected demographic and medical history information and determined the SMN2 copy number. Main Outcome Measures Clinical outcomes included measures of motor function (Gross Motor Function Measure and expanded Hammersmith Functional Motor Scale), pulmonary function (forced vital capacity), and muscle strength (myometry). Participants were evaluated every 2 months for the initial 6 months and every 3 months for the subsequent 6 months. We evaluated change over 12 months for all clinical outcomes and examined potential correlates of change over time including age, sex, SMA type, ambulatory status, SMN2 copy number, medication use, and baseline function. Results There were no significant changes over 12 months in motor function, pulmonary function, and muscle strength measures. There was evidence of motor function gain in ambulatory patients, especially in those children younger than 5 years. Scoliosis surgery during the observation period led to a subsequent decline in motor function. Conclusions Our results confirm previous clinical reports suggesting that SMA types 2 and 3 represent chronic phenotypes that have relatively stable clinical courses. We did not detect any measurable clinical disease progression in SMA types 2 and 3 over 12 months, suggesting that clinical trials will have to be designed to measure improvement rather than stabilization of disease progression. PMID:21320981

  17. [Pregnancy-Associated Breast Cancer: An analytical observational study].

    Science.gov (United States)

    Baulies, Sonia; Cusidó, Maite; Tresserra, Francisco; Rodríguez, Ignacio; Ubeda, Belén; Ara, Carmen; Fábregas, Rafael

    2014-03-04

    Pregnancy-associated breast cancer is defined as breast cancer diagnosed during pregnancy and up to one year postpartum. A retrospective, analytical, observational study comparing 56 cases of breast cancer and pregnancy (PABC) diagnosed 1976-2008 with 73 patients with breast cancer not associated with pregnancy (non-PABC) was performed. Demographic data, prognostic factors, treatment and survival were reviewed and compared. The prevalence of PABC in our center is 8.3/10,000. The highest frequency (62%) appeared during the postpartum period. The stages are higher in PABC, being 31.3% advanced (EIII and EIV) in PABC versus 13.3% in non-PABC (P < .05). Regarding prognostic factors, 27.3% in PABC had a tumoral grade 3 versus 15.8% of non-PABC. Among women with PABC, 33.3% had negative estrogen receptors, 48.7% negative progesterone receptors and 34.5% positive Her2Neu compared with 22.2, 24.1 and 31%, respectively of non-PABC patients. Finally, positive lymph nodes were found in 52.8% of PABC, versus 33.8% non-PABC (P < .05). Overall and disease-free survival rate at 5 years for PABC was 63.7 and 74.2%, respectively. The poorer survival observed is possibly due to the presence of adverse prognostic features such as lymph node metastases, negative hormone receptors, tumoral grade iii, as well as a delay in diagnosis with a higher rate of advanced stages. Copyright © 2012 Elsevier España, S.L. All rights reserved.

  18. Using hypertext and the Internet for structure and management of observational studies.

    Science.gov (United States)

    Carey, V J

    1997-08-15

    The evolution of computer and communications systems in the past decade brings new opportunities for increased efficiency and accuracy of observational studies. In ongoing, large scale research studies, the problem of bridging organizational and analytical methods of the past to modern methods of data structure and control can consume considerable effort. A model for information flow in an observational study is sketched, and the flow is found inherently complex. This complexity and corresponding managerial demands are compounded by database file proliferation and by evolution of system hardware and software. Interactive, network-based database mapping and documentation tools are described as currently implemented in an SAS-based system for the management and analysis of several large epidemiologic studies.

  19. Observing power blackouts from space - A disaster related study

    Science.gov (United States)

    Aubrecht, C.; Elvidge, C. D.; Ziskin, D.; Baugh, K. E.; Tuttle, B.; Erwin, E.; Kerle, N.

    2009-04-01

    world. Elvidge et al. (1998) first demonstrated that under certain conditions a detection of power outages is possible using OLS data. A standard procedure for visual detection of power outages has been developed. The procedure is based on identifying locations where consistently observed lighting is missing or reduced following a disaster event. Visible and thermal spectral bands of the event-related OLS data are compared to a recent cloud-free composite of nighttime lights by producing a color (RGB) composite image. For the cloud-free nighttime lights composite serving as reference information both monthly and annual composites can be used, depending on the respective availability and suitability of OLS data. The RGB color composite uses the reference lights as red (R), the current visible band as green (G) and the current thermal band as blue (B). The thermal band is typically inverted to make clouds appear bright. As clouds are typically colder than the surface of the Earth, in the thermal band higher values are observed on cloud-free areas, which thus appear brighter in standard visualization modes. The resulting color composite is visually interpreted to identify power outages, which show up as red lights on a dark (cloud-free) background. Red color stands for high values in the reference data (red band of the RGB composite) compared to low values in the event data (green and blue bands of the RGB composite), thus showing the disaster-related absence or reduction of lighting. Heavy cloud cover also obscures lights, resulting in red lights on a blue background. Yellow color in the RGB composite indicates areas where the lights are on, i.e. both red and green band (reference composite and visible band of the event image) feature high values with no cloud cover present (low values in the blue band). Under ideal conditions the presented procedure detects individual cities and towns where power has been lost or has been reduced. Conditions reducing or eliminating the

  20. Nursing practice in the prevention of pressure ulcers: an observational study of German Hospitals.

    Science.gov (United States)

    Hoviattalab, Khadijeh; Hashemizadeh, Haydeh; D'Cruz, Gibson; Halfens, Ruud J G; Dassen, Theo

    2015-06-01

    The study aimed to establish the range and extent of preventive interventions undertaken by nurses for patients who are at high risk of developing or currently have a pressure ulcer. Since 2000, the German National Expert Standard for the prevention of pressure ulcers has provided evidence-based recommendations, but limited studies have been published on its adherence in hospitals. There are also limited observational studies that investigated whether patients who are at risk of or have pressure ulcers are provided with appropriate preventative measures. A nonparticipant observational descriptive design was used. A sample of 32 adult patients who were at high risk of developing or currently had a pressure ulcer were observed during all shifts in medical and surgical wards in two general hospitals in Germany. A range of preventive interventions that were in line with the German National Expert Standard was observed. The most frequent preventive measures were 'cleaning the patients' skin' and 'minimizing exposure to moisture' that were undertaken in more than 90% of all patients. The least frequent measures were 'patient and relative education', 'assessment and recording of nutritional status'. This study demonstrates that the pressure ulcers preventive interventions as set out in the German National Expert Standard were not fully implemented. The study highlights the need for further studies on the barriers that impede the undertaking of the interventions that may prevent the development or deterioration of pressure ulcers and the delivery of evidence-based preventative care. This study provides an insight into the extent of pressure ulcers preventive practices used by nurses. The results may serve as a basis for developing an effective strategy to improve nursing practice in this area and the promotion of evidence-based practice. However, our results refer to two general hospitals and for a broader population, further studies with larger data samples are needed.

  1. Primary care capitation payments in the UK. An observational study

    Directory of Open Access Journals (Sweden)

    Beerstecher Hendrik J

    2010-06-01

    Full Text Available Abstract Background In 2004 an allocation formula for primary care services was introduced in England and Wales so practices would receive equitable pay. Modifications were made to this formula to enable local health authorities to pay practices. Similar pay formulae were introduced in Scotland and Northern Ireland, but these are unique to the country and therefore could not be included in this study. Objective To examine the extent to which the Global Sum, and modifications to the original formula, determine practice funding. Methods The allocation formula determines basic practice income, the Global Sum. We compared practice Global Sum entitlements using the original and the modified allocation formula calculations. Practices receive an income supplement if Global Sum payments were below historic income in 2004. We examined current overall funding levels to estimate what the effect will be when the income supplements are removed. Results Virtually every Welsh and English practice (97% received income supplements in 2004. Without the modifications to the formula only 72% of Welsh practices would have needed supplements. No appreciable change would have occurred in England. The formula modifications increased the Global Sum for 99.5% of English practices, while it reduced entitlement for every Welsh practice. In 2008 Welsh practices received approximately £6.15 (9% less funding per patient per year than an identical English practice. This deficit will increase to 11.2% when the Minimum Practice Income Guarantee is abolished. Conclusions Identical practices in different UK countries do not receive equitable pay. The pay method disadvantages Wales where the population is older and has higher health needs.

  2. Eddy currents in the anisotropy of out-of-phase magnetic susceptibility measurement - A model study

    Science.gov (United States)

    Jezek, Josef; Hrouda, Frantisek

    2016-04-01

    Analytical solutions of Maxwell equations for eddy currents caused by AC field in a conductive sphere, known from 1950s, provide a general formula for magnetic susceptibility. It contains the parameters describing the sphere (its size, conductivity and permeability), surrounding medium (permeability) and the applied field (frequency). The formula is complex and without numerical evaluation it is difficult to distinguish the real (in-phase) and imaginary (out-of-phase) part of susceptibility. Representing all the parameters by only two, relative permeability (sphere vs. medium) and skin ratio (summarizing the effect of sphere size, conductivity and permeability, and frequency of the field), we derive approximate formulas for both phases and the phase angle. These are valid for a reasonable range of parameters (from rock magnetism point of view) and enable us to study their influence. The in-phase susceptibility depends very weakly on the fourth power of the skin ratio while the out-of-phase susceptibility depends more strongly on its second power. The coefficients of the dependence are expressed by means of relative permeability. The approximations of in-phase and out-of-phase susceptibilities provide a possibility to assess possible effects of eddy currents in rocks in case of low content of conductive minerals and solve problems of the type by which size one piece of a mineral in the measured sample can produce a phase shift that is observed by measurement. Examples of magnetite and pyrrhotite are given.

  3. A comparative study: the impact of different lipid extraction methods on current microalgal lipid research.

    Science.gov (United States)

    Li, Yan; Ghasemi Naghdi, Forough; Garg, Sourabh; Adarme-Vega, Tania Catalina; Thurecht, Kristofer J; Ghafor, Wael Abdul; Tannock, Simon; Schenk, Peer M

    2014-01-24

    Microalgae cells have the potential to rapidly accumulate lipids, such as triacylglycerides that contain fatty acids important for high value fatty acids (e.g., EPA and DHA) and/or biodiesel production. However, lipid extraction methods for microalgae cells are not well established, and there is currently no standard extraction method for the determination of the fatty acid content of microalgae. This has caused a few problems in microlagal biofuel research due to the bias derived from different extraction methods. Therefore, this study used several extraction methods for fatty acid analysis on marine microalga Tetraselmis sp. M8, aiming to assess the potential impact of different extractions on current microalgal lipid research. These methods included classical Bligh & Dyer lipid extraction, two other chemical extractions using different solvents and sonication, direct saponification and supercritical CO₂ extraction. Soxhlet-based extraction was used to weigh out the importance of solvent polarity in the algal oil extraction. Coupled with GC/MS, a Thermogravimetric Analyser was used to improve the quantification of microalgal lipid extractions. Among these extractions, significant differences were observed in both, extract yield and fatty acid composition. The supercritical extraction technique stood out most for effective extraction of microalgal lipids, especially for long chain unsaturated fatty acids. The results highlight the necessity for comparative analyses of microalgae fatty acids and careful choice and validation of analytical methodology in microalgal lipid research.

  4. Dental injury after conventional direct laryngoscopy: a prospective observational study.

    Science.gov (United States)

    Mourão, J; Neto, J; Luís, C; Moreno, C; Barbosa, J; Carvalho, J; Tavares, J

    2013-10-01

    This observational study assessed the frequency and risk factors of dental damage after classic direct laryngoscopy for tracheal intubation in 536 adult patients. The patients' sex, age, height, weight, dental condition, dental mobility, Mallampati class, interincisor gap, thyromental distance, neck circumference, and head and neck extension were recorded. From anaesthesia records, the difficulty of intubation, the number of attempts, type of neuromuscular blocking agent used and duration of anaesthesia were recorded. After anaesthesia, examination revealed that 134 patients (25.0%) had dental damage affecting 162 teeth (147 maxillary; 15 mandibular). Enamel fracture was the commonest injury. In tooth number 21, the interincisor gap (OR 2.5 (95% CI 1.0-5.9)) and in tooth number 22, the number of intubation attempts (OR 5.3 (95% CI 1.3-22.0)) were considered a risk factor for dental injury. Conventional direct laryngoscopy is associated with a strikingly high incidence of dental damage, although specific risk factors remain unclear. © 2013 The Association of Anaesthetists of Great Britain and Ireland.

  5. Current status of the Essential Variables as an instrument to assess the Earth Observation Networks in Europe

    Science.gov (United States)

    Blonda, Palma; Maso, Joan; Bombelli, Antonio; Plag, Hans Peter; McCallum, Ian; Serral, Ivette; Nativi, Stefano Stefano

    2016-04-01

    ConnectinGEO (Coordinating an Observation Network of Networks EnCompassing saTellite and IN-situ to fill the Gaps in European Observations" is an H2020 Coordination and Support Action with the primary goal of linking existing Earth Observation networks with science and technology (S&T) communities, the industry sector, the Group on Earth Observations (GEO), and Copernicus. The project will end in February 2017. Essential Variables (EVs) are defined by ConnectinGEO as "a minimal set of variables that determine the system's state and developments, are crucial for predicting system developments, and allow us to define metrics that measure the trajectory of the system". . Specific application-dependent characteristics, such as spatial and temporal resolution of observations and data quality thresholds, are not generally included in the EV definition. This definition and the present status of EV developments in different societal benefit areas was elaborated at the ConnectinGEO workshop "Towards a sustainability process for GEOSS Essential Variables (EVs)," which was held in Bari on June 11-12, 2015 (http://www.gstss.org/2015_Bari/). Presentations and reports contributed by a wide range of communities provided important inputs from different sectors for assessing the status of the EV development. In most thematic areas, the development of sets of EVs is a community process leading to an agreement on what is essential for the goals of the community. While there are many differences across the communities in the details of the criteria, methodologies and processes used to develop sets of EVs, there is also a considerable common core across the communities, particularly those with a more advanced discussion. In particular, there is some level of overlap in different topics (e.g., Climate and Water), and there is a potential to develop an integrated set of EVs common to several thematic areas as well as specific ones that satisfy only one community. The thematic areas with

  6. A method for f0F2 monitoring over Spain using the El Arenosillo digisonde current observations

    Directory of Open Access Journals (Sweden)

    G. Miro

    1999-06-01

    Full Text Available Ionosphere monitoring implies: observations, prediction and mapping of ionospheric parameters. A case with one available (El Arenosillo ionosonde is considered. Some statistical methods for f0F2 short-term (1-24 h in advance prediction are compared. The analysis of multi-dimensional regression for Df0F2 (relative deviation from running median with Ap, F10.7 and previous Df0F2 observations has shown that inclusion of additional terms with Ap and F10.7 improves the prediction accuracy for lead time more than 15 h. For lead time 1-6 h a linear regression with earlier observed Df0F2 provides the f0F2 forecast with Relative Mean Deviation (RMD 6-11%. This is acceptable from a practical point of view. A 24-h forecast can be done with RMD 10-11%. Multi-regressional methods provide better prediction accuracy than the usual 10-day running median or quasi-inertial method based on such median. Hourly f0F2 values may be used to calculate the effective index R12eff used as input to the ITU-R monthly median model. This allows the ITU-R model to "breathe" following hour-to-hour f0F2 variations. Then standard surfering methods may be applied for f0F2 mapping over the whole area. The f0F2 mapping accuracy based on the hourly R12eff index is shown to be 9-11% depending on solar activity level.

  7. Giant cell arteritis: a multicenter observational study in Brazil

    Directory of Open Access Journals (Sweden)

    Alexandre Wagner Silva de Souza

    2013-01-01

    Full Text Available OBJECTIVE: To describe demographic features, disease manifestations and therapy in patients with giant cell arteritis from referral centers in Brazil. METHODS: A retrospective cohort study was performed on 45 giant cell arteritis patients from three university hospitals in Brazil. Diagnoses were based on the American College of Rheumatology classification criteria for giant cell arteritis or temporal artery biopsy findings. RESULTS: Most patients were Caucasian, and females were slightly more predominant. The frequencies of disease manifestations were as follows: temporal headache in 82.2%, neuro-ophthalmologic manifestations in 68.9%, jaw claudication in 48.9%, systemic symptoms in 44.4%, polymyalgia rheumatica in 35.6% and extra-cranial vessel involvement in 17.8% of cases. Aortic aneurysms were observed in 6.6% of patients. A comparison between patients with biopsy-proven giant cell arteritis and those without temporal artery biopsies did not yield significant differences in disease manifestations. All patients were treated with oral prednisone, and intravenous methylprednisolone was administered to nearly half of the patients. Methotrexate was the most commonly used immunosuppressive agent, and low-dose aspirin was prescribed to the majority of patients. Relapses occurred in 28.9% of patients, and aspirin had a protective effect against relapses. Females had higher prevalences of polymyalgia rheumatica, systemic manifestations and jaw claudication, while permanent visual loss was more prevalent in men. CONCLUSIONS: Most of the clinical features of Brazilian giant cell arteritis patients were similar to those found in other studies, except for the high prevalence of neuro-ophthalmic manifestations and permanent blindness in the Brazilian patients. Aspirin had a protective effect on relapses.

  8. External Validation of the HERNIAscore: An Observational Study.

    Science.gov (United States)

    Cherla, Deepa V; Moses, Maya L; Mueck, Krislynn M; Hannon, Craig; Ko, Tien C; Kao, Lillian S; Liang, Mike K

    2017-09-01

    The HERNIAscore is a ventral incisional hernia (VIH) risk assessment tool that uses only preoperative variables and predictable intraoperative variables. The aim of this study was to validate and modify, if needed, the HERNIAscore in an external dataset. This was a retrospective observational study of all patients undergoing resection for gastrointestinal malignancy from 2011 through 2015 at a safety-net hospital. The primary end point was clinical postoperative VIH. Patients were stratified into low-risk, medium-risk, and high-risk groups based on HERNIAscore. A revised HERNIAscore was calculated with the addition of earlier abdominal operation as a categorical variable. Cox regression of incisional hernia with stratification by risk class was performed. Incidence rates of clinical VIH formation within each risk class were also calculated. Two hundred and forty-seven patents were enrolled. On Cox regression, in addition to the 3 variables of the HERNIAscore (BMI, COPD, and incision length), earlier abdominal operation was also predictive of VIH. The revised HERNIAscore demonstrated improved predictive accuracy for clinical VIH. Although the original HERNIAscore effectively stratified the risk of an incisional radiographic VIH developing, the revised HERNIAscore provided a statistically significant stratification for both clinical and radiographic VIHs in this patient cohort. We have externally validated and improved the HERNIAscore. The revised HERNIAscore uses BMI, incision length, COPD, and earlier abdominal operation to predict risk of postoperative incisional hernia. Future research should assess methods to prevent incisional hernias in moderate-to-high risk patients. Copyright © 2017 American College of Surgeons. Published by Elsevier Inc. All rights reserved.

  9. Ventilation strategies in burn intensive care: A retrospective observational study

    Directory of Open Access Journals (Sweden)

    Stefano Palazzo

    2014-01-01

    Full Text Available Consensus regarding optimal burns intensive care (BICU patient management is lacking. This study aimed to assess whether ventilation strategies, cardiovascular support and sedation in BICU patients have changed over time, and whether this affects outcome. A retrospective observational study comparing two 12-patient BICU cohorts (2005/06 and 2010/11 was undertaken. Demographic and admission characteristics, ventilation parameters, sedation, fluid resuscitation, cardiovascular support and outcome (length of stay, mortality data were collected from patient notes. Data was analysed using T-tests, Fisher's exact and Mann-Whitney U tests. In our study cohort groups were equivalent in demographic and admission parameters. There were equal ventilator-free days in the two cohorts 10 ± 12.7 vs. 13.3 ± 12.2 ventilator free days; P = 0.447. The 2005/06 cohort were mechanically ventilated more often than in 2010/11 cohort (568 ventilator days/1000 patient BICU days vs. 206 ventilator days/1000 patient BICU days; P = 0.001. The 2005/06 cohort were ventilated less commonly in tracheostomy group/endotracheal tube spontaneous (17.8% vs. 26%; P = 0.001 and volume-controlled modes (34.4% vs. 40.8%; P = 0.001. Patients in 2010/11 cohort were more heavily sedated (P = 0.001 with more long-acting sedative drug use (P = 0.001 than the 2005/06 cohort, fluid administration was equivalent. Patient outcome did not vary. Inhalational injury patients were ventilated in volume-controlled (44.5% vs. 28.1%; P = 0.001 and pressure-controlled modes (18.2% vs. 9.5%; P = 0.001 more frequently than those without. Outcome did not vary. This study showed there has been shift away from mechanical ventilation, with increased use of tracheostomy/tracheal tube airway spontaneous ventilation. Inhalation injury patients require more ventilatory support though patient outcomes do not differ. Prospective trials are required to establish which strategies confer benefit.

  10. Fatal poisonings in Oslo: a one-year observational study

    Directory of Open Access Journals (Sweden)

    Heyerdahl Fridtjof

    2010-06-01

    Full Text Available Abstract Background Acute poisonings are common and are treated at different levels of the health care system. Since most fatal poisonings occur outside hospital, these must be included when studying characteristics of such deaths. The pattern of toxic agents differs between fatal and non-fatal poisonings. By including all poisoning episodes, cause-fatality rates can be calculated. Methods Fatal and non-fatal acute poisonings in subjects aged ≥16 years in Oslo (428 198 inhabitants were included consecutively in an observational multi-centre study including the ambulance services, the Oslo Emergency Ward (outpatient clinic, and hospitals, as well as medico-legal autopsies from 1st April 2003 to 31st March 2004. Characteristics of fatal poisonings were examined, and a comparison of toxic agents was made between fatal and non-fatal acute poisoning. Results In Oslo, during the one-year period studied, 103 subjects aged ≥16 years died of acute poisoning. The annual mortality rate was 24 per 100 000. The male-female ratio was 2:1, and the mean age was 44 years (range 19-86 years. In 92 cases (89%, death occurred outside hospital. The main toxic agents were opiates or opioids (65% of cases, followed by ethanol (9%, tricyclic anti-depressants (TCAs (4%, benzodiazepines (4%, and zopiclone (4%. Seventy-one (69% were evaluated as accidental deaths and 32 (31% as suicides. In 70% of all cases, and in 34% of suicides, the deceased was classified as drug or alcohol dependent. When compared with the 2981 non-fatal acute poisonings registered during the study period, the case fatality rate was 3% (95% C.I., 0.03-0.04. Methanol, TCAs, and antihistamines had the highest case fatality rates; 33% (95% C.I., 0.008-0.91, 14% (95% C.I., 0.04-0.33, and 10% (95% C.I., 0.02-0.27, respectively. Conclusions Three per cent of all acute poisonings were fatal, and nine out of ten deaths by acute poisonings occurred outside hospital. Two-thirds were evaluated as accidental

  11. The East Greenland Current and its impacts on the Nordic Seas: observed trends in the past decade

    OpenAIRE

    Rudels, B.; M. Korhonen; Budeus, G.; Beszczynska-Moller, A.; Schauer, U.; Nummelin, A.; Quadfasel, D.; Valdimarsson, H.

    2012-01-01

    For the past 30 years, it has been known that dense waters are created in the Arctic Ocean. However, before the late 1980s, observations indicated that Arctic Ocean deep waters only modified the deep water in the Greenland Sea, which was still thought of as the major source of dense water. In the mid-1990s, this picture began to fade. The deep convection in the Greenland Sea weakened and only Arctic Intermediate Water was formed. A deep salinity maximum was reinforced and a temperature max...

  12. Flapping current sheet motions in magnetotail excited by non-adiabatic ions: case study

    Science.gov (United States)

    Wei, X., Jr.

    2015-12-01

    The current sheet is a crucial region of the magnetotail, where energy reserve and release take place. The origin of the up-down motions of the current sheet, referred to as flapping motions, is among the most fundamental issues of magnetotail dynamics. Observational evidences suggest that the flapping motion is a kind of internal excited kink-like waves, but its particular propagating features such as the low phase speeds and the propagating direction from the tail center toward flanks do not match any local generation mechanisms previously established so far. Here we report observations of the current sheet flapping motions induced by non-adiabatic ions in the magnetic field configurations with a finite guiding component, whose population present periodic hemispherical asymmetries. Three type of current sheet flapping event in this paper will be discussed. This current sheet flapping phenomenon implies that the excitation mechanism of the current sheet flapping motions is a self-circulation process between the non-adiabatic ion population and the current sheet equilibrium itself.

  13. Maintaining turbidity and current flow in laboratory aquarium studies, a case study using Sabellaria spinulosa

    DEFF Research Database (Denmark)

    Davies, Andrew J.; S. Last, Kim; Attard, Karl

    2009-01-01

    Many aquatic organisms rely on the suspension of particulate matter for food or for building materials, yet these conditions are difficult to replicate in laboratory mesocosms. Consequently, husbandry and experimental conditions may often be sub-optimal. The Vortex Resuspension Tank (Vo......RT) is a simple and reliable system for the resuspension of food or sediments using an enclosed airlift. The particle rain from the lift is mixed in the tank by two water inputs that provide directional current flow across the study organism(s). The vortex mixing creates a turbulent lateral water flow that allows...... whereas under intermediate and high sediment rates there was consistent cumulative growth throughout a 15 d experiment. This highlights the importance of suspended sediment for S. spinulosa and also the suitability of the VoRT system for maintaining organisms with suspended matter requirements....

  14. Constraints on the formation of double neutron stars from the observed eccentricities and current limits on merger rates

    CERN Document Server

    Chruslinska, Martyna; Bulik, Tomasz; Gladysz, Wojciech

    2016-01-01

    We employ population synthesis method to model the double neutron star (DNS) population and test various possibilities on natal kick velocities gained by neutron stars after their formation. We first choose natal kicks after standard core collapse SN from a Maxwellian distribution with velocity dispersion of sigma=265 km/s as proposed by Hobbs et al. (2005) and then modify this distribution by changing the velocity dispersion towards smaller and larger kick values. We also take into account the possibility of NS formation through electron capture supernova. In this case we test two scenarios: zero natal kick or small natal kick, drawn from Maxwellian distribution with sigma = 26.5 km/s. We calculate the present-day orbital parameters of binaries and compare the resulting eccentricities with those known for observed DNSs. As an additional test we calculate Galactic merger rates for our model populations and confront them with observational limits. We do not find any model unequivocally consistent with both obs...

  15. Nitration of Norcorrolatonickel(II): First Observation of a Diatropic Current in a System Comprising a Norcorrole Ring.

    Science.gov (United States)

    Deng, Zhihong; Li, Xiaofang; Stępień, Marcin; Chmielewski, Piotr J

    2016-03-14

    A one-pot reaction of 5,14-bis(mesityl)-norcorrolatonickel(II) with isoamyl nitrite under mild reaction conditions resulted in the consecutive formation of 3-nitro-, 3,12-dinitro- and 3,16-dinitro-, 3,7,12-trinitro-, and 3,7,12,16-tetranitro-norcorrolatonickel(II) in 50-80% yield. The substituted macrocycles retained their antiaromatic character. The observed regioselectivity of the substitution was analyzed by comparing the relative energies of the DFT energy-optimized models of the radical or arenium cationic intermediates that can be formed upon reaction with NO2. The nitrated systems were characterized by high-resolution mass spectrometry, NMR and UV/Vis spectroscopy, X-ray diffraction analysis, cyclic voltammetry, and DFT calculations. A significant and systematic cathodic shift of the redox couples was observed to correlate with an increasing number of the NO2 group. A decrease of the LUMO energies in the tri- and tetra-nitrated products stabilizes mono- and bis-reduced complexes of these ligands. The reduction takes place on the macrocycle rather than on the metal ion leading to the consecutive formation of stable paramagnetic monoanion radicals and water-soluble diamagnetic dianions with an aromatic character, which were revealed by ESR and (1)H NMR measurements, respectively. The electronic structures of the reduced forms were analyzed by extensive TD-DFT calculations. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Smoking habits and benign prostatic hyperplasia: A systematic review and meta-analysis of observational studies.

    Science.gov (United States)

    Xu, Huan; Fu, Shi; Chen, Yanbo; Chen, Qi; Gu, Meng; Wang, Zhong

    2016-08-01

    Previous studies have warned against the promoting effects of cigarette smoking on benign prostatic hyperplasia (BPH). In contrast, some have argued that smoking confers a protective effect regarding BPH, while others have observed an aggravated effect. Thus, we performed this meta-analysis to determine whether cigarette use is associated with BPH risk.To identify articles from observational studies of relevance, a search was performed concurrent to March 21, 2016, on PubMed, Web of Science, Cochrane, EBSCO, and EMBASE databases. Random-effect model, according to the heterogeneity, was calculated to reveal the relative risks (RRs) and corresponding 95% confidence intervals (CIs).Eight articles were included in this meta-analysis, representing data for 44,100 subjects, of which 5221 (11.8%) had BPH as defined according to the criteria. Seven reports are concerned with analysis between nonsmokers and ex-smokers, in which no significant difference was observed (RR = 0.99, 95% CI 0.94-1.05). Another meta-analysis of 7 studies indicated an observable trend, but without significant difference between groups of nonsmokers and current smokers (RR = 1.17, 95% CI 0.98-1.41). Between groups of heavy (6 articles; RR = 1.02, 95% CI 0.84-1.24) and light smokers (5 articles; RR = 0.90, 95% CI 0.71-1.15), again no significant difference appears. Finally, we combined individuals as never-smokers and ever-smokers and still found no significant difference between the 2 groups of patients (RR = 1.03, 95% CI 0.92-1.15). Sensitivity analysis was displayed and confirmed the stability of the present results.Combined evidence from observational studies shows no significant association between cigarette smoking and BPH risk, either for ex-smokers or for current smokers. The trend of elevated BPH risk from smoking was observed only in current smokers compared with nonsmokers, while marginal significance was observed in comparing ever-smokers with never-smokers in

  17. Gap Filling of the CALYPSO HF Radar Sea Surface Current Data through Past Measurements and Satellite Wind Observations

    Directory of Open Access Journals (Sweden)

    Adam Gauci

    2016-01-01

    Full Text Available High frequency (HF radar installations are becoming essential components of operational real-time marine monitoring systems. The underlying technology is being further enhanced to fully exploit the potential of mapping sea surface currents and wave fields over wide areas with high spatial and temporal resolution, even in adverse meteo-marine conditions. Data applications are opening to many different sectors, reaching out beyond research and monitoring, targeting downstream services in support to key national and regional stakeholders. In the CALYPSO project, the HF radar system composed of CODAR SeaSonde stations installed in the Malta Channel is specifically serving to assist in the response against marine oil spills and to support search and rescue at sea. One key drawback concerns the sporadic inconsistency in the spatial coverage of radar data which is dictated by the sea state as well as by interference from unknown sources that may be competing with transmissions in the same frequency band. This work investigates the use of Machine Learning techniques to fill in missing data in a high resolution grid. Past radar data and wind vectors obtained from satellites are used to predict missing information and provide a more consistent dataset.

  18. Contribution of amateur observations to Saturn storm studies

    CERN Document Server

    Delcroix, Marc

    2010-01-01

    Since 2004, Saturn Electrostatic Discharges (SEDs), which are the radio signatures of lightning in Saturn's atmosphere, have been observed by the Cassini Radio and Plasma Wave Science instrument (RPWS). Despite their important time coverage, these observations lack the resolution and positioning given by imaging around visible wavelengths. Amateur observations from Earth have been increasing in quality and coverage since a few years, bringing information on positions, drift rates and shape evolutions of large visible white spots in Saturn's atmosphere. Combining these two complementary sources has brought better analysis of Saturn's storms evolutions.

  19. Pulp polyp - A periapical lesion: Radiographic observational study

    Directory of Open Access Journals (Sweden)

    Kandagal V Suresh

    2015-01-01

    Full Text Available Introduction: Pulp polyp (PP is a chronic hyperplastic condition resulting in formation of granulation tissue and proliferative mass. The radiographic appearance of PP has innumerable presentations. Diagnosing and treatment planning of periapical lesions, heavily relies on the radiographic changes surrounding the root structures. Objective: To evaluate different radiographic periapical changes in clinically detected PP patients. Materials and Methods: Patients reporting to Department of Oral Medicine and Radiology and who were clinically diagnosed with PP by an oral diagnostician were subjected to radiographic examination. Digital intraoral periapical radiographs of 50 patients with PP were taken. Various periapical changes in the digital radiographs were recorded by a skilled oral radiologist. The data obtained was subjected to statistical analysis using SPSS ver 17.0 and P-value was set at <0.05 as significant. Result: Periapical changes like periodontal space widening (PDLW, loss of lamina dura, periapical abscess, periapical granuloma, hypercementosis, condensing osteitis and root resorption were noted. Periodontal space widening was seen in all patients (100%, loss of lamina dura was noted in 72%, periapical rarefying osteitis in 56%, condensing osteitis in 8%, hypercementosis, periapical granuloma, and root resorption were seen in 4% of PP patients. Majority of PP were asymptomatic (66%. Pulp polyp was commonly seen in mandibular first molar followed by mandibular second molar and maxillary first molar. Statistically significant difference was noticed between periapical changes in PP patients (P value <0.0001. All PP patients showed definite periapical changes suggesting it to be a periapical lesion. Conclusion: Pulp polyp is confined to the pulpal portion of the tooth which, may or may not cause changes in periapical region. The results of the present study showed that majority of the PP patients were associated with definite periapical

  20. An observational study of glycemic control in canagliflozin treated patients.

    Science.gov (United States)

    Meckley, L M; Miyasato, G; Kokkotos, F; Bumbaugh, J; Bailey, R A

    2015-08-01

    To evaluate changes in glycemic control following the initial canagliflozin pharmacy claim in a real-world population. A retrospective cohort analysis of adult patients with type 2 diabetes mellitus (T2DM) was conducted using 2013 medical, pharmacy and laboratory claims from the Inovalon MORE 2 Registry. Patients with T2DM aged ≥18 years with ≥60 days of canagliflozin supply and HbA1c test results within 120 days before and ≥60 days after initial canagliflozin claim (defined as index date) were included. The differences between HbA1c levels pre- and post-index were assessed. Changes pre- and post-index in Healthcare Effectiveness Data and Information Set (HEDIS) glycemic control criteria of HbA1c 9% were evaluated. Subgroup analyses of patients with HbA1c >7% at baseline and patients aged ≥65 were also conducted. Among the 268 patients meeting the study criteria, mean HbA1c pre-index was 8.3% and post-index was 7.6%; the mean reduction in HbA1c pre-post index was 0.7% (95% CI: 0.6%, 0.9%). The proportions of patients meeting the HEDIS glycemic control measures (HbA1c 9%) improved and was significantly different pre- and post-index (all p 7% prior to index (81% of the cohort; mean pre-index HbA1c = 8.8%), HbA1c was reduced by 0.9% (95% CI: 0.8%, 1.1%). The aged ≥65 subgroup consisted of 15% of the cohort, with a pre-index HbA1c of 8.3%. The mean reduction in HbA1c test results pre- and post-canagliflozin index was 0.6% (95% CI: 0.4%, 0.9%). This analysis did not adjust for changes in antihyperglycemic agents during the study period. Patients with T2DM were observed to have improved glycemic control following initial canagliflozin pharmacy claim as measured by HbA1c change and attainment of specific glycemic control criteria.

  1. Management of Symptomatic Tarlov Cysts: A Retrospective Observational Study.

    Science.gov (United States)

    Jiang, Wei; Hu, Zhenming; Hao, Jie

    2017-07-01

    Symptomatic Tarlov cysts are a common cause of chronic pain. Many methods have been reported to treat this disease, with variable results. Most previous reports concerning the treatment methods of symptomatic Tarlov cysts were either sporadic case reports or series of limited cases. This study aimed to further optimize the management for patients with symptomatic Tarlov cysts (TCs) by analyzing the results of 82 patients who were treated with different strategies. Three different strategies were applied to 82 patients with symptomatic TCs and their clinical effects were evaluated in 13 months to 12 years follow-up. A pain management practice, a medical center, major metropolitan city, China. From June 2003 to August 2015, a total number of 82 patients with symptomatic TCs were treated with 3 different methods (microsurgical cyst fenestration and imbrication, C-arm fluoroscopy guided percutaneous fibrin gel injection, and conservative management) in the first affiliated hospital of Chongqing Medical University. The pain severity was assessed according to visual analog scale (VAS), and imaging changes were evaluated by magnetic resonance imaging (MRI). Patient improvements in pain and neurologic function were evaluated during a follow-up the period of 13 months to 12 years. All the patients who underwent microsurgical cyst fenestration and imbrication had either complete (7 patients, 50%) or substantial (7 patients, 50%) resolution of their preoperative symptoms and neurological deficits. However, 3 patients (21%) had cerebrospinal fluid (CSF) leakage and 3 patients (21%) suffered from recurrent symptoms. In C-arm fluoroscopy guided percutaneous fibrin gel injection group, 34 patients (61%) had complete resolution and 22 patients had (39%) substantial resolution, and no CSF leakage or recurrence occurred. Only 3 patients (25%) got substantial resolution in the conservative management group, but 9 patients (75%) had aggravation. An observational study with a

  2. Initial results on the correlation between the magnetic and electric fields observed from the DE-2 satellite in the field-aligned current regions

    Science.gov (United States)

    Sugiura, M.; Maynard, N. C.; Farthing, W. H.; Heppner, J. P.; Ledley, B. G.; Cahill, L. J., Jr.

    1982-01-01

    Initial results of the electric and magnetic field observations from the DE-2 satellite show a remarkably good correlation between the north-south component of the electric field and the east-west component of the magnetic field in many passes of the field-aligned current regions. For a dayside cusp pass on August 15, 1981 the coefficient of correlation between these components was 0.996. A preliminary inspection of the available data from the first 6 months of the DE operation indicates that the similarity between the electric and magnetic field signatures of the field-aligned currents is a commonly observed feature at all local times. This high correlation is interpreted to be an indication that the closure of the field-aligned current is essentially meridional. When the correlation between these components is not good, the closure current is likely to be flowing along the auroral belt. When the correlation between the electric and magnetic fields is high, it is possible to estimate the height-integrated Pedersen conductivity from the observed field components.

  3. Comparing modeled and observed changes in mineral dust transport and deposition to Antarctica between the Last Glacial Maximum and current climates

    Energy Technology Data Exchange (ETDEWEB)

    Albani, Samuel [University of Siena, Graduate School in Polar Sciences, Siena (Italy); University of Milano-Bicocca, Department of Environmental Sciences, Milano (Italy); Cornell University, Department of Earth and Atmospheric Sciences, Ithaca, NY (United States); Mahowald, Natalie M. [Cornell University, Department of Earth and Atmospheric Sciences, Ithaca, NY (United States); Delmonte, Barbara; Maggi, Valter [University of Milano-Bicocca, Department of Environmental Sciences, Milano (Italy); Winckler, Gisela [Columbia University, Lamont-Doherty Earth Observatory, Palisades, NY (United States); Columbia University, Department of Earth and Environmental Sciences, New York, NY (United States)

    2012-05-15

    Mineral dust aerosols represent an active component of the Earth's climate system, by interacting with radiation directly, and by modifying clouds and biogeochemistry. Mineral dust from polar ice cores over the last million years can be used as paleoclimate proxy, and provide unique information about climate variability, as changes in dust deposition at the core sites can be due to changes in sources, transport and/or deposition locally. Here we present results from a study based on climate model simulations using the Community Climate System Model. The focus of this work is to analyze simulated differences in the dust concentration, size distribution and sources in current climate conditions and during the Last Glacial Maximum at specific ice core locations in Antarctica, and compare with available paleodata. Model results suggest that South America is the most important source for dust deposited in Antarctica in current climate, but Australia is also a major contributor and there is spatial variability in the relative importance of the major dust sources. During the Last Glacial Maximum the dominant source in the model was South America, because of the increased activity of glaciogenic dust sources in Southern Patagonia-Tierra del Fuego and the Southernmost Pampas regions, as well as an increase in transport efficiency southward. Dust emitted from the Southern Hemisphere dust source areas usually follow zonal patterns, but southward flow towards Antarctica is located in specific areas characterized by southward displacement of air masses. Observations and model results consistently suggest a spatially variable shift in dust particle sizes. This is due to a combination of relatively reduced en route wet removal favouring a generalized shift towards smaller particles, and on the other hand to an enhanced relative contribution of dry coarse particle deposition in the Last Glacial Maximum. (orig.)

  4. Assessing the completeness of reporting of observational studies in Colombian Journal of Anesthesiology. Cross sectional study

    NARCIS (Netherlands)

    Bravo-Peña, M. (Mary); Barona-Fong, L. (Luis); Campo-López, J. (Julio); Arroyave, Y. (Yeni); J.A. Calvache (Jose Andres)

    2017-01-01

    textabstractIntroduction The STROBE statement (Strengthening the Reporting of Observational Studies in Epidemiology), consisting of 22 points, was published in 2007 with the aim of improving the reporting of observational research. Objective To determine the completeness of reporting of observationa

  5. Assessing the completeness of reporting of observational studies in Colombian Journal of Anesthesiology. Cross sectional study

    NARCIS (Netherlands)

    Bravo-Peña, M. (Mary); Barona-Fong, L. (Luis); Campo-López, J. (Julio); Arroyave, Y. (Yeni); J.A. Calvache (Jose Andres)

    2017-01-01

    textabstractIntroduction The STROBE statement (Strengthening the Reporting of Observational Studies in Epidemiology), consisting of 22 points, was published in 2007 with the aim of improving the reporting of observational research. Objective To determine the completeness of reporting of observationa

  6. Adjoint sensitivity studies of loop current and eddy shedding in the Gulf of Mexico

    KAUST Repository

    Gopalakrishnan, Ganesh

    2013-07-01

    Adjoint model sensitivity analyses were applied for the loop current (LC) and its eddy shedding in the Gulf of Mexico (GoM) using the MIT general circulation model (MITgcm). The circulation in the GoM is mainly driven by the energetic LC and subsequent LC eddy separation. In order to understand which ocean regions and features control the evolution of the LC, including anticyclonic warm-core eddy shedding in the GoM, forward and adjoint sensitivities with respect to previous model state and atmospheric forcing were computed using the MITgcm and its adjoint. Since the validity of the adjoint model sensitivities depends on the capability of the forward model to simulate the real LC system and the eddy shedding processes, a 5 year (2004–2008) forward model simulation was performed for the GoM using realistic atmospheric forcing, initial, and boundary conditions. This forward model simulation was compared to satellite measurements of sea-surface height (SSH) and sea-surface temperature (SST), and observed transport variability. Despite realistic mean state, standard deviations, and LC eddy shedding period, the simulated LC extension shows less variability and more regularity than the observations. However, the model is suitable for studying the LC system and can be utilized for examining the ocean influences leading to a simple, and hopefully generic LC eddy separation in the GoM. The adjoint sensitivities of the LC show influences from the Yucatan Channel (YC) flow and Loop Current Frontal Eddy (LCFE) on both LC extension and eddy separation, as suggested by earlier work. Some of the processes that control LC extension after eddy separation differ from those controlling eddy shedding, but include YC through-flow. The sensitivity remains stable for more than 30 days and moves generally upstream, entering the Caribbean Sea. The sensitivities of the LC for SST generally remain closer to the surface and move at speeds consistent with advection by the high-speed core of

  7. The current status of usability studies of information technologies in China: a systematic study.

    Science.gov (United States)

    Lei, Jianbo; Xu, Lufei; Meng, Qun; Zhang, Jiajie; Gong, Yang

    2014-01-01

    To systematically review and analyze the current status and characteristics of usability studies in China in the field of information technology in general and in the field of healthcare in particular. We performed a quantitative literature analysis in three major Chinese academic databases and one English language database using Chinese search terms equivalent to the concept of usability. Six hundred forty-seven publications were selected for analysis. We found that in China the literature on usability in the field of information technology began in 1994 and increased thereafter. The usability definitions from ISO 9241-11:1998 and Nielsen (1993) have been widely recognized and cited. Authors who have published several publications are rare. Fourteen journals have a publishing rate over 1%. Only nine publications about HIT were identified. China's usability research started relatively late. There is a lack of organized research teams and dedicated usability journals. High-impact theoretical studies are scarce. On the application side, no original and systematic research frameworks have been developed. The understanding and definition of usability is not well synchronized with international norms. Besides, usability research in HIT is rare. More human and material resources need to be invested in China's usability research, particularly in HIT.

  8. The Current Status of Usability Studies of Information Technologies in China: A Systematic Study

    Directory of Open Access Journals (Sweden)

    Jianbo Lei

    2014-01-01

    Full Text Available Objectives. To systematically review and analyze the current status and characteristics of usability studies in China in the field of information technology in general and in the field of healthcare in particular. Methods. We performed a quantitative literature analysis in three major Chinese academic databases and one English language database using Chinese search terms equivalent to the concept of usability. Results. Six hundred forty-seven publications were selected for analysis. We found that in China the literature on usability in the field of information technology began in 1994 and increased thereafter. The usability definitions from ISO 9241-11:1998 and Nielsen (1993 have been widely recognized and cited. Authors who have published several publications are rare. Fourteen journals have a publishing rate over 1%. Only nine publications about HIT were identified. Discussions. China’s usability research started relatively late. There is a lack of organized research teams and dedicated usability journals. High-impact theoretical studies are scarce. On the application side, no original and systematic research frameworks have been developed. The understanding and definition of usability is not well synchronized with international norms. Besides, usability research in HIT is rare. Conclusions. More human and material resources need to be invested in China’s usability research, particularly in HIT.

  9. Study of eddy current power loss in an RCS vacuum chamber

    Institute of Scientific and Technical Information of China (English)

    XU Shou-Yan; WANG Sheng

    2012-01-01

    In a Rapid Cycling Synchrotron (RCS),power loss due to an eddy current on the metal vacuum chamber would cause heating of the vacuum chamber.It is important to study the effect for estimating eddy current induced power loss and temperature growth.Analytical formulas for eddy current power loss for various types of vacuum chambers are derived for dipole and quadrupole repectively.By using the prototype of dipole of CSNS/RCS,an experiment was done to test the analytical formula.The derived formulas were applied to calculating the eddy current power loss on some special structures of an RCS vacuum chamber.

  10. Bedside practice of blood transfusion in a large teaching hospital in Uganda: An observational study

    Directory of Open Access Journals (Sweden)

    de Graaf J

    2009-01-01

    Full Text Available Background: Adverse transfusion reactions can cause morbidity and death to patients who receive a blood transfusion. Blood transfusion practice in Mulago Hospital, Kampala, Uganda is analyzed to see if and when these practices play a role in the morbidity and mortality of patients. Materials and Methods: An observational study on three wards of Mulago Hospital. Physicians, paramedics, nurses, medical students and nurse students were observed using two questionnaires. For comparison, a limited observational study was performed in the University Medical Centre Groningen (UMCG in Groningen, The Netherlands. Results: In Mulago Hospital guidelines for blood transfusion practice were not easily available. Medical staff members work on individual professional levels. Students perform poorly due to inconsistency in their supervision. Documentation of blood transfusion in patient files is scarce. There is no immediate bedside observation, so transfusion reactions and obstructions in the blood transfusion flow are not observed. Conclusion: The poor blood transfusion practice is likely to play a role in the morbidity and mortality of patients who receive a blood transfusion. There is a need for a blood transfusion policy and current practical guidelines.

  11. Charge transfer on porous silicon membranes studied by current-sensing atomic force microscopy

    Institute of Scientific and Technical Information of China (English)

    Bing Xia; Qiang Miao; Jie Chao; Shou Jun Xiao; Hai Tao Wang; Zhong Dang Xiao

    2008-01-01

    A visible rectification effect on the current-voltage curves of metal/porous silicon/p-silicon has been observed by currentsensing atomic force microscopy.The current-voltage curves of porous silicon membranes with different porosities,prepared through variation of etching current density for a constant time,indicate that a higher porosity results in a higher resistance and thus a lower rectification,until the current reaches a threshold at a porosity>55%.We propose that the conductance mode in the porous silicon membrane with porosities>55% is mainly a hopping mechanism between nano-crystallites and an inverse static electric field between the porous silicon and p-Si interface blocks the electron injection from porous silicon to p-Si,but with porosities <55%,electron flows through a direct continuous channel between nano-crystallites.

  12. Experimental study of yttrium barium copper oxide superconducting tape’s critical current under twisting moment

    Indian Academy of Sciences (India)

    Ziauddin Khan; Ananya Kundu; Subrata Pradhan

    2013-10-01

    Critical current (c) characteristics of 2G YBCO superconducting tape under the influence of twisting moment was experimentally investigated at varying current ramp rates in the self-field. Under a uniform twist, the degradation in the current-carrying capacity of YBCO tape up to 30% was observed at 77 K. The degradation is largely attributed to the shear stress and torsional shear strain resulting from the twisting. The superconductor to resistive transition index, , is also found to behave in an identical manner with increase in the twisting. Finite element analysis (FEA) of the tape in the experimental configuration with twisting moment being applied on to it has been carried out in COMSOL. The torsional strain calculated analytically as per the experimental configuration matches closely with that of FEA results, which shows that the critical current degradation is a function of strain.

  13. Synergy of multifrequency studies from observations of NGC6334I

    CERN Document Server

    Seifahrt, Andreas; Beuther, Henrik; Leurini, Silvia; Brogan, Crystal L; Hunter, Todd R; Menten, Karl M; Stecklum, Bringfried; 10.1088/1742-6596/131/1/012030

    2008-01-01

    We combine multifrequency observations from the millimeter to near infrared wavelengths that demonstrate the spatial distributions of H2, CO, and NH3 emission, which are all manifestations of various shocks driven by outflows of deeply embedded sources in NGC6334I. In addition to the well-known northeast-southwest outflow we detect at least one more outflow in the region by combining observations from APEX, ATCA, SMA, Spitzer and VLT/ISAAC. Potential driving sources will be discussed. NGC6334I exhibits several signs of active star formation and will be a major target for future observatories such as Herschel and ALMA.

  14. Large-scale atmospheric circulation and local particulate matter concentrations in Bavaria - from current observations to future projections

    Science.gov (United States)

    Beck, Christoph; Weitnauer, Claudia; Brosy, Caroline; Hald, Cornelius; Lochbihler, Kai; Siegmund, Stefan; Jacobeit, Jucundus

    2016-04-01

    Particulate matter with an aerodynamic diameter of 10 μm or less (PM10) may have distinct adverse effects on human health. Spatial and temporal variations in PM10 concentrations reflect local emission rates, but are as well influenced by the local and synoptic-scale atmospheric conditions. Against this background, it can be furthermore argued that potential future climate change and associated variations in large-scale atmospheric circulation and local meteorological parameters will probably provoke corresponding changes in future PM10 concentration levels. The DFG-funded research project „Particulate matter and climate change in Bavaria" aimed at establishing quantitative relationships between daily and monthly PM10 indices at different Bavarian urban stations and the corresponding large-scale atmospheric circulation as well as local meteorological conditions. To this end, several statistical downscaling approaches have been developed for the period 1980 to 2011. PM10 data from 19 stations from the air quality monitoring network (LÜB) of the Bavarian Environmental Agency (LfU) have been utilized as predictands. Large-scale atmospheric gridded data from the NCEP/NCAR reanalysis data base and local meteorological observational data provided by the German Meteorological Service (DWD) served as predictors. The downscaling approaches encompass the synoptic downscaling of daily PM10 concentrations and several multivariate statistical models for the estimation of daily and monthly PM10, i.e.monthly mean and number of days exceeding a certain PM10 concentration threshold. Both techniques utilize objective circulation type classifications, which have been optimized with respect to their synoptic skill for the target variable PM10. All downscaling approaches have been evaluated via cross validation using varying subintervals of the 1980-2011 period as calibration and validation periods respectively. The most suitable - in terms of model skill determined from cross

  15. The New Worlds Observer: The Astrophysics Strategic Mission Concept Study

    Science.gov (United States)

    2009-08-01

    the target star to its antipodal stars and compute where the telescope should appear among the antipodal stars. The addi- tion of corner-cube...starshade observes an optical beacon on the telescope to find the telescope’s location against antipodal stars for medium alignment. Proc. of SPIE Vol

  16. A study on diffuse source detection by HXMT scanning observation

    CERN Document Server

    Guan, Ju; Wu, Mei; Song, Li-Ming; Huo, Zhuo-Xi

    2015-01-01

    The Hard X-ray Modulation Telescope (HXMT) is a collimated scan X-ray satellite mainly devoted to a sensitive all-sky survey and pointed observations in 1-250 keV. We expect various diffuse sources to be detected in its scanning observations due to the large rigidity factor of the telescope. Diffuse source detection performance of HXMT scanning observation depends not only on the instrument but also on its data analysis method since images have to be reconstructed from HXMT observed data. In this paper, we introduce a multiscale maximum entropy (MSME) algorithm for HXMT image restoration and propose an improved method, ensemble multiscale maximum entropy (EMSME) method, to alleviate the problem of mode mixing exiting in MSME. Simulation have been performed on the detection of the diffuse source Cen A by HXMT in the all-sky survey mode. The results show that the MSME method is adapted to the deconvolution task of HXMT for diffuse source detection and the improved method could suppress noise and improve the cor...

  17. Mechanistic studies of flux variability of neutral and ionic permeants during constant current dc iontophoresis with human epidermal membrane.

    Science.gov (United States)

    Li, S Kevin; Higuchi, William I; Kochambilli, Rajan P; Zhu, Honggang

    2004-04-01

    Although constant current iontophoresis is supposed to provide constant transdermal transport, significant flux variability and/or time-dependent flux drifts are observed during iontophoresis with human skin in vitro and human studies in vivo. The objectives of the present study were to determine (a) the causes of flux variability in constant current dc transdermal iontophoresis and (b) the relationships of flux variabilities among permeants of different physicochemical properties. Changes in the human epidermal membrane (HEM) effective pore size and/or electroosmosis during constant current dc iontophoresis were examined. Tetraethylammonium ion (TEA), urea, and mannitol were the model permeants. For the neutral permeants, the results in the present study showed a significant increase of fluxes with time in a given experiment and large HEM sample-to-sample variability. Although both effective pore size and pore charge density variations contributed to the time-dependent flux drifts observed in electroosmotic transport, the significant flux drifts observed were found to be primarily a result of the time-dependent increase in effective pore charge density. For the ionic permeant, the observed flux variability was smaller than that of the neutral permeants and was believed to be primarily due to effective pore size alteration in HEM during iontophoresis as suggested in a previous study. The different extents of flux variability observed between neutral and ionic permeants are consistent with the different iontophoretically enhanced transport mechanisms for the neutral and ionic permeants (i.e. electroosmosis and electrophoresis, respectively). The results of the present study also demonstrate that flux variability of two neutral permeants are inter-related, so the flux of one neutral permeant can be predicted if the permeability coefficient of the other neutral permeant is known.

  18. Analytical Model and Characteristics of Current-Observer-Based Induction Motor Speed-Sensorless Vector Control System Taking into Account Iron Loss

    Science.gov (United States)

    Tsuji, Mineo; Xu, Fujin; Tsuruda, Yasutaka; Hamasaki, Shin-Ichi

    We have proposed a current-observer-based speed-sensorless vector control system that is in a rotating reference frame and takes into account iron loss. By deriving a linear model and by computing the trajectories of poles and zeros, the system stability on various parameters such as operating points, observer gain, controller gain and stator resistance has been investigated. Furthermore, an exact analytical model including PWM control, dead time and non-ideal features of power devices is developed. The characteristic improvement and stability limit of the proposed system are discussed by simulation and experiment.

  19. Demagnetization treatment of remanent composite microspheres studied by alternating current susceptibility measurements

    NARCIS (Netherlands)

    van Berkum, S.; Erné, B.H.

    2013-01-01

    The magnetic remanence of silica microspheres with a low concentration of embedded cobalt ferrite nanoparticles is studied after demagnetization and remagnetization treatments. When the microspheres are dispersed in a liquid, alternating current (AC) magnetic susceptibility spectra reveal a constant

  20. NUMERICAL STUDY ON THE FORMATION OF THE SOUTH CHINA SEA WARM CURRENT I. BAROTROPIC CASE

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    In this work, Princeton Ocean Model (POM) was used to study the formation of the South China Sea Warm Current (SCSWC) in the barotropic case. Monthly averaged wind stress and the inflow/outflow transports in January were used in the numerical simulation which reproduced the SCSWC. The effects of wind stress and inflow/outflow were studied separately. Numerical experiments showed that the Kuroshio intrusion through the Luzon Strait and the slope shelf in the northern SCS are necessary conditions for the formation of the SCSWC. In a flat bottom topography experiment, the wind stress driven northeast current in the northern SCS is a compensatory current.

  1. A status analysis of current digital marketing: a case study of Kauneusstudio FAB

    OpenAIRE

    Tran, Trong

    2015-01-01

    The subject of this thesis is a small company's current digital marketing status. This study was con-ducted in order for the owners of the beauty and hair salon Kauneusstudio FAB to improve their understanding of their customers’ behavior online and the significance of each digital channel they are using in the present marketing strategy. The goal of this study is to provide information for the company to recognize the strengths and the development points of the current digital marketing stra...

  2. Numerical study on short-circuit current of single layer organic solar cells with Schottkey contacts

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The influence of the cathode work function,carriers mobilities and temperature on the short-circuit current of single layer organic solar cells with Schottkey contacts was numerically studied,and the quantitative dependences of the short-circuit current on these quantities were obtained.The results provide the theoretical foundation for experimental study of single layer organic solar cells with Schottkey contacts.

  3. Synchronous Study of Ferroresonance and Inrush Current Phenomena and their Related Reasons in Ground Power Networks

    Science.gov (United States)

    Akrami, Amin; Ghaderi, Mohammad; Ghadi, Saeed

    2010-01-01

    Energizing the power transformers usually results in flowing very high inrush currents. This harmful current can be minimized using controlled switching and considering the value of residual flux. But nowadays, developing the ground power networks results in high increment of ferroresonance phenomenon occurrence due to the line' capacitance reactance and nonlinear inductive reactance of power transformer's core. In this study, these transient phenomena and their cause have studied synchronously.

  4. Study of Leakage Current Behaviour on Artificially Polluted Surface of Ceramic Insulator

    Institute of Scientific and Technical Information of China (English)

    B. Subba Reddy; G. R. Nagabhushana

    2003-01-01

    This paper presents the results of the study concerning to the leakage current be-haviour on artificially polluted ceramic insulator surface. From the present study it was observedthat there is a reasonably well-defined inception of current i.e. scintillations at a finite voltage.The corresponding voltages for extinction of the current are in the range of 0.8 kV to 2.1 kV.Obviously, the dry band formed in the immediate vicinity of the pin prevents smooth current flowas the voltage rises from zero. Only when the voltage is adequate it causes a flashover of the dryband and current starts flowing. As is common in similar current extinction phenomena, herealso, the extinction voltages are significantly lower than the inception voltages.Further, the voltage-current curves invariably show hysteresis - the leakage currents are lowerin the reducing portion of the voltage. This is obviously due to drying of the wet pollutantlayer thereby increasing its resistance. It is believed that this is the first time that such a directquantitative evidence of drying in individual half cycles is experimentally visualized.

  5. Observational study of compliance with Queensland bicycle helmet laws.

    Science.gov (United States)

    Debnath, Ashim Kumar; Haworth, Narelle; Schramm, Amy; Williamson, Amy

    2016-12-01

    Mandatory bicycle helmet laws have been found to increase helmet wearing rates in Australia and internationally. However, much of the research on factors influencing compliance with the Australian helmet laws is dated or focuses on commuters and city areas only. To address this gap, video recordings of bicycle riders were undertaken at 17 sites across Queensland, Australia, representing a mixture of on- and off-road locations, speed limits and regions. Helmet status was able to be determined for 98% of riders observed. The level of compliance with the laws was very high, with 98.3% of the more than 27,000 riders observed wearing helmets. Riders riding on roads were less compliant than those riding on bicycle paths, but no significant differences were observed between the school-holiday and school-term periods. Among the on-road riders, boys were less compliant than girls and overall children were less compliant than adults. Higher compliance levels were found for group riders, road bike riders, lycra-clad riders, during morning hours, and on 50km/h or lower speed limit roads. While the overall level of compliance was very high, certain subgroups were identified as a possible focus for interventions to further improve the compliance level, for example children (particularly boys) riding mountain bikes away from groups during the afternoon hours on 60km/h roads.

  6. ShopTrip Pilot Study : The Preference-Conscious Choice Modelled and Observed

    DEFF Research Database (Denmark)

    Barratt, Daniel; Selsøe-Sørensen, Henrik; Qvistgaard, Francoise

    The goal of the current pilot study was to construct and test a new kind of setup for observing the consumer’s purchasing behaviour, with a particular focus on fairness and misleadingness issues as opposed to marketing and sales. The setup described represents a compromise between ecological...... validity and experimental control in at least two ways: the way the consumer’s behaviour is monitored and the way the consumer’s behaviour is brought about. The first part of the pilot study involved a simulation of an ‘e-shopping environment’ which had the advantage of creating a relatively realistic...... of the pilot study, the participants were presented with actual products and instructed to assume the role of ‘health detectives’ in order to enhance the degree of preference consciousness even further. In the third and final part of the pilot study, the participants were asked to fill out a questionnaire...

  7. Observing participating observation

    DEFF Research Database (Denmark)

    Keiding, Tina Bering

    2011-01-01

    Current methodology concerning participating observation in general leaves the act of observation unobserved. Approaching participating observation from systems theory offers fundamental new insights into the topic. Observation is always participation. There is no way to escape becoming...... as the idea of the naïve observer becomes a void. Not recognizing and observing oneself as observer and co-producer of empirical data simply leaves the process of observation as the major unobserved absorber of contingency in data production based on participating observation....

  8. Observing participating observation

    DEFF Research Database (Denmark)

    Keiding, Tina Bering

    2010-01-01

    Current methodology concerning participating observation in general leaves the act of observation unobserved. Approaching participating observation from systems theory offers fundamental new insights into the topic. Observation is always participation. There is no way to escape becoming...... as the idea of the naïve observer becomes a void. Not recognizing and observing oneself as observer and co-producer of empirical data simply leaves the process of observation as the major unobserved absorber of contingency in data production based on participating observation....

  9. A Case Study of Hogtown Creek: Justification for Field Observations.

    Science.gov (United States)

    West, Felicia E.

    A case-study model of a field trip to a small creek was made to facilitate the use of field studies as a technique for involving students and teachers in studying the earth as it undergoes change. Methods and techniques of planning are presented which include familiarization with the area by the teacher, the development of goals and objectives,…

  10. Copepod flow modes and modulation: a modelling study of the water currents produced by an unsteadily swimming copepod

    OpenAIRE

    2007-01-01

    Video observation has shown that feeding-current-producing calanoid copepods modulate their feeding currents by displaying a sequence of different swimming behaviours during a time period of up to tens of seconds. In order to understand the feeding-current modulation process, we numerically modelled the steady feeding currents for different modes of observed copepod motion behaviours (i.e. free sinking, partial sinking, hovering, vertical swimming upward and horizontal swimming backward or fo...

  11. AHEAD Study: an observational study of the management of anticoagulated patients who suffer head injury

    Science.gov (United States)

    Mason, Suzanne; Kuczawski, Maxine; Teare, M Dawn; Stevenson, Matt; Goodacre, Steve; Ramlakhan, Shammi; Morris, Francis; Rothwell, Joanne

    2017-01-01

    Objectives Management of anticoagulated patients after head injury is unclear due to lack of robust evidence. This study aimed to determine the adverse outcome rate in these patients and identify risk factors associated with poor outcome. Design Multicentre, observational study using routine patient records. Setting 33 emergency departments in England and Scotland. Participants 3566 adults (aged ≥16 years) who had suffered blunt head injury and were currently taking warfarin. Main outcome measures Primary outcome measure was rate of adverse outcome defined as death or neurosurgery following initial injury, clinically significant CT scan finding or reattendance with related complication within 10 weeks of initial hospital attendance. Secondary objectives included identifying risk factors for adverse outcome using univariable and multivariable analyses. Results Clinical data available for 3534/3566 patients (99.1%), median age 79 years; mean initial international normalised ratio (INR) 2.67 (SD 1.34); 81.2% Glasgow Coma Scale (GCS) 15: 59.8% received a CT scan with significant head injury-related finding in 5.4% (n=208); 0.5% underwent neurosurgery; 1.2% patients suffered a head injury-related death. Overall adverse outcome rate was 5.9% (95% CI 5.2% to 6.7%). Patients with GCS=15 and no associated symptoms had lowest risk of adverse outcome (risk 2.7%; 95% CI 2.1 to 3.6). Patients with GCS=15 multivariable analysis (using imputation) found risk of adverse outcome to increase when reporting at least one associated symptom: vomiting (relative risk (RR) 1.8; 95% CI 1.0 to 3.4), amnesia (RR 3.5; 95% CI 2.1 to 5.7), headache (RR 1.3; 95% CI 0.8 to 2.2), loss of consciousness (RR 1.75; 95% CI 1.0 to 3.0). INR measurement did not predict adverse outcome in patients with GCS=15 (RR 1.1; 95% CI 1.0 to 1.2). Conclusions In alert warfarinised patients following head injury, the presence of symptoms is associated with greater risk of adverse outcome. Those with GCS=15

  12. Astronomical Observations Astronomy and the Study of Deep Space

    CERN Document Server

    2010-01-01

    Our Search for knowledge about the universe has been remarkable, heartbreaking, fantastical, and inspiring, and this search is just beginning. Astronomical Observations is part of a 7 book series that takes readers through a virtual time warp of our discovery. From the nascent space programs of the 1960's to today's space tourism and the promise of distant planet colonization, readers will be transfixed. Throughout this journey of the mind, Earth-bound explorers gain keen insight into the celestial phenomena that have fascinated humans for centuries. Thrilling narratives about indefatigable sc

  13. Temporal sequence in observational studies to establish causality

    Directory of Open Access Journals (Sweden)

    Luis Carlos Silva Ayçaguer, PhD

    2014-05-01

    Full Text Available The article includes a brief summary on the scope of the notions of causality and risk and considers some operational difficulties that arise when dealing with problems associated with them. It underscores the vital importance of timing and its link with the most commonly used observational research designs that address causal relationships. The article describes in detail the need to record the order in which the relevant events occur and how to consider this in the analysis. A detailed example of errors that are usually incurred in and their effect is provided.

  14. A Training Study of the Hercules Observer Trainer

    Science.gov (United States)

    2009-04-01

    des tâches et des exigences en matière de formation, et a déterminé une solution technique qui a été mise en œuvre dans toute une gamme de contrats ...CAE Professional Services Inc. Call-up 7949-08 under Standing Offer W7711-057949. April 2007 – March 2008. [7] Hercules Observer Trainer System...Development. CAE Professional Services Inc. Call-up 7949-06 under Standing Offer W7711-057949. December 2006 – March 2007. [8] High Performance Visual

  15. A study of pickup and signal processing for HLS-Ⅱ bunch current measurement system

    Institute of Scientific and Technical Information of China (English)

    YANG Yong-Liang; MA Tian-Ji; SUN Bao-Gen; WANG Ji-Gang; ZOU Jun-Ying; CHENG Chao-Cai; LU Ping

    2013-01-01

    For the HLS-Ⅱ bunch current measurement system,in order to obtain the absolute value of bunch current,the calibration factor should be determined by using DCCT.At the HLS storage ring,the stretch effect of bunch length is observed and the change rate is about 19% when the bunch current decays over time and this will affect the performance of bunch current detection.To overcome the bunch stretch influence in the HLS-Ⅱ bunch current measurement,an evaluation about pickup type and signal processing is carried out.Strip-line pickup and button pickup are selectable,and the theoretical analysis and demonstration experiment are performed to find out an acceptable solution for the bunch current measurement system at HLS-Ⅱ.The experimental data analysis shows that the normalized calibration factor will change by about 27% when the bunch length changes by about 19% if using the button pickup and processing by peak value of bunch signal; the influence will be reduced to 2% less if adopting the strip-line pickup and integral.

  16. Potential and limitations of multidecadal satellite soil moisture observations for selected climate model evaluation studies

    Directory of Open Access Journals (Sweden)

    A. Loew

    2013-09-01

    Full Text Available Soil moisture is an essential climate variable (ECV of major importance for land–atmosphere interactions and global hydrology. An appropriate representation of soil moisture dynamics in global climate models is therefore important. Recently, a first multidecadal, observation-based soil moisture dataset has become available that provides information on soil moisture dynamics from satellite observations (ECVSM, essential climate variable soil moisture. The present study investigates the potential and limitations of this new dataset for several applications in climate model evaluation. We compare soil moisture data from satellite observations, reanalysis and simulations from a state-of-the-art land surface model and analyze relationships between soil moisture and precipitation anomalies in the different dataset. Other potential applications like model parameter optimization or model initialization are not investigated in the present study. In a detailed regional study, we show that ECVSM is capable to capture well the interannual and intraannual soil moisture and precipitation dynamics in the Sahelian region. Current deficits of the new dataset are critically discussed and summarized at the end of the paper to provide guidance for an appropriate usage of the ECVSM dataset for climate studies.

  17. Activity in the action observation network enhances emotion regulation during observation of risk-taking: an fMRI study.

    Science.gov (United States)

    Tamura, Miyuki; Moriguchi, Yoshiya; Higuchi, Shigekazu; Hida, Akiko; Enomoto, Minori; Umezawa, Jun; Mishima, Kazuo

    2013-01-01

    The results of neuroimaging studies have indicated that viewing emotional stimuli can lead to activity increases in brain regions associated with processing actions. We hypothesized that observation of actions involving the potential for harm (i.e., risk-taking actions) would activate emotion- and pain-related processing. We used functional magnetic resonance imaging to examine the changes in neural activity during the observation of safe and risk-taking actions in 34 healthy participants (14 females, 20 males; mean age: 23·4±3·7 years). Observation of risk-taking actions elicited significantly stronger neural activation in the inferior frontal gyrus, ventromedial prefrontal cortex, superior frontal gyrus/frontal pole, inferior parietal lobule, middle temporal gyrus, middle occipital gyrus, lingual gyrus, cuneus (including the calcarine sulcus), insula, and amygdala, than observation of safe actions. Interestingly, we observed significant activation of affect-related brain areas (ventromedial prefrontal cortex, amygdala, and insula), thought to be implicated in various aspects of emotion regulation during the observation of risk-taking actions. No brain regions exhibited greater activation during observation of safe actions than during observation of risk-taking actions associated with risk. Our results reveal that the risk-related content of the observed actions in the video clips elicited activation of a network of visual input and processing regions, including the action observation network, that appears to encode the meanings of observed actions as well as the reflective or retrospective monitoring of their outcomes. These findings suggest that risk-taking situations may increase cognitive load on the entire action perception system, and may command more attention.

  18. Photometric Observation and Modeling Study of the Asteroid (26) Proserpina

    Science.gov (United States)

    Bin, Li; Hai-bin, Zhao; Xin, Wang

    2016-07-01

    We present the new CCD observations on the asteroid (26) Proserpina performed between 2011 December and 2012 February. Based upon the new observations, a synodic rotation period of (13.107 ± 0.002) h is obtained. Using all the light curves available sofar, the rotation vector, rotation period, and the shape model of the asteroid are determined with the convex-hull inversion method. Further more, a bootstrap method is applied to estimating the uncertainties of the rotation parameters. We derive a pair of possible rotation poles for (26) Proserpina, and believe that it has a retrograde rotation. The rotation poles are determined to be λ1 = 90.8° ± 1.4°, β1 = -53.1° ± 3.2°, and λ2 = 259.3° ± 2.2°, β2 = -62.0° ± 2.0°. The sidereal rotation periods corresponding to the two poles are almost the same as (13.1