WorldWideScience

Sample records for cber current 510k

  1. Premarket Notifications (510(k)s)

    Data.gov (United States)

    U.S. Department of Health & Human Services — Medical device manufacturers are required to submit a premarket notification or 510(k) if they intend to introduce a device into commercial distribution for the...

  2. CBERS-02 Application Assessment

    Institute of Scientific and Technical Information of China (English)

    GUO Jianning; YU Jin; MIN Xiangjun; LI Xingchao; HOU Minghui

    2004-01-01

    As the successor of CBERS-01, CBERS-02 was launched successfully on 21October 2003 and transmitted its first downlink data the next day. According to the OBT (On Board Test) outline, CRESDA cooperated with CAST and many remote sensing organizations in China in implementing the test of the satellite payloads, ground processing system and data application. In this paper, the test is briefly illustrated in three parts: Ⅰ. Satellite Parameters Test (especially the test for payloads), Ⅱ. Payload Image Quality Assessment, and Ⅲ. Data Application Assessment. The results of the test show that the image quality of CBERS-02 is much improved over CBERS-01 and will continue to play a more important role in the society and economic development of China.

  3. 75 FR 4402 - Strengthening the Center for Devices and Radiological Health's 510(k) Review Process; Public...

    Science.gov (United States)

    2010-01-27

    ... requirement), that the device meets the comparative standard of ``substantial equivalence'' to a ``predicate... about devices that have been cleared for marketing through the 510(k) process. Currently, if a device... different ``intended uses'' and explain your reasoning. b. What are the advantages and disadvantages...

  4. Fixing a 510(K) Loophole: In Support of The Sound Devices Act of 2012

    OpenAIRE

    Ho, Shuenn (Patrick)

    2014-01-01

    The current medical device regulatory system contains a dangerous loophole. While the voluntary recall of a harmful medical device removes it from the market, new devices that claim they are substantially equivalent to the recalled device can still reach the market through the 510(k) premarket notification process. Devices that have gained regulatory clearance in this fashion have caused considerable harm and are much more likely to be recalled for safety reasons as well. The recently propo...

  5. The Prototype Development for The Second Generation CBERS Initiates

    Institute of Scientific and Technical Information of China (English)

    SunQing

    2005-01-01

    It's reported that the concept for the second generation CBERS-CBERS-03 & 04 to be jointly developed by China Academy of Space Technology (CAST) and INPE went through the assessment by China Aerospace Science and Technology Corporation (CASC) at the beginning of the year. It means that the prototype development of CBERS-03 & 04 has been initiated.

  6. US definitions, current use, and FDA stance on use of platelet-rich plasma in sports medicine.

    Science.gov (United States)

    Beitzel, Knut; Allen, Donald; Apostolakos, John; Russell, Ryan P; McCarthy, Mary Beth; Gallo, Gregory J; Cote, Mark P; Mazzocca, Augustus D

    2015-02-01

    With increased utilization of platelet-rich plasma (PRP), it is important for clinicians to understand the United States, the Food and Drug Administration (FDA) regulatory role and stance on PRP. Blood products such as PRP fall under the prevue of FDA's Center for Biologics Evaluation and Research (CBER). CBER is responsible for regulating human cells, tissues, and cellular and tissue-based products. The regulatory process for these products is described in the FDA's 21 CFR 1271 of the Code of Regulations. Under these regulations, certain products including blood products such as PRP are exempt and therefore do not follow the FDA's traditional regulatory pathway that includes animal studies and clinical trials. The 510(k) application is the pathway used to bring PRP preparation systems to the market. The 510(k) application allows devices that are "substantially equivalent" to a currently marketed device to come to the market. There are numerous PRP preparation systems on the market today with FDA clearance; however, nearly all of these systems have 510(k) clearance for producing platelet-rich preparations intended to be used to mix with bone graft materials to enhance bone graft handling properties in orthopedic practices. The use of PRP outside this setting, for example, an office injection, would be considered "off label." Clinicians are free to use a product off-label as long as certain responsibilities are met. Per CBER, when the intent is the practice of medicine, clinicians "have the responsibility to be well informed about the product, to base its use on firm scientific rationale and on sound medical evidence, and to maintain records of the product's use and effects." Finally, despite PRP being exempted, the language in 21 CFR 1271 has caused some recent concern over activated PRP; however to date, the FDA has not attempted to regulate activated PRP. Clinicians using activated PRP should be mindful of these concerns and continued to stay informed. PMID

  7. 78 FR 26786 - 510(k) Device Modifications: Deciding When To Submit a 510(k) for a Change to an Existing Device...

    Science.gov (United States)

    2013-05-08

    ... management in the decision process on whether a medical device modification requires a new 510(k) submission... management into this decision process in a way that ensures appropriate and consistent modification decisions... and resolve the following concerns. 1. Risk Management is a Process--Published risk...

  8. Applications Of CBERS Data In Oceanic Research

    Institute of Scientific and Technical Information of China (English)

    Li Xiaomin; Zhang Jie; Ma Yi; Song Pingjian

    2009-01-01

    @@ The CBERS series satellite data has been widely used by the First Institute of Oceanography, State Oceanic Administration (SOA) for the studies related to the monitoring of coral islands, land use changes of islands and coastal zone, green tide,implementation of ocean functional zoning, suspended particulate matter,sea ice, rafts cultivation and so on.The data covers the range of islands,coastal zone and inshore sea areas.

  9. The Application Achievements And Perspective Of CBERS Series Satellite Imagery

    Institute of Scientific and Technical Information of China (English)

    Li Xingchao; Qi Xueyong; Lu Yilin

    2009-01-01

    @@ Since the first China-Brazil Earth Resources Satellite (CBERS-1),launched in 1999,the CBERS data has been applied in many fields extensively.Remarkable social and economic benefits have been achieved.This article presents the application achievements during the past nine years,and gives a perspective for the future.All these applications demonstrate that the CBERS data has been an important data source for resources investigation and monitoring.

  10. Specific heat of rhenium disulfide in 360-510 K temperature range

    International Nuclear Information System (INIS)

    Isobaric specific heat of rhenium disulfide was measured by the method of differential scanning calorimetry in the range of 360-510 K. Thermodynamic functions of rhenium disulfide were calculated using literature data on standard entropy of the compound for the range of 296.15-600 K. 3 refs., 1 fig., 2 tabs

  11. 75 FR 47307 - Center for Devices and Radiological Health 510(k) Working Group Preliminary Report and...

    Science.gov (United States)

    2010-08-05

    ... HUMAN SERVICES Food and Drug Administration Center for Devices and Radiological Health 510(k) Working... ``Center for Devices and Radiological Health Preliminary Internal Evaluations,'' which is comprised of the... public input on the recommendations discussed in these reports, including the feasibility...

  12. Atmospheric correction of CBERS CCD images with MODIS data

    Institute of Scientific and Technical Information of China (English)

    LI Junsheng; ZHANG Bing; CHEN Zhengchao; SHEN Qian

    2006-01-01

    China Brazil Earth Resource Satellite (CBERS) CCD images have much potential for inland water environmental monitoring. However, their atmospheric accuracy correction can affect their quantitative applications. This paper contains an atmospheric correction algorithm for CBERS CCD images with MODIS data from the same day, the use of which improves the atmospheric correction algorithm of ocean color remote sensing developed by Gordon (1993, 1994) and makes it applicable to inland waters. The improved algorithm retrieves atmospheric parameters from MODIS data and uses them to perform the atmospheric correction of CBERS CCD images. Experimental results show that the atmospheric correction algorithm of CBERS CCD images assisted by MODIS data is reliable. Furthermore, MODIS data can be freely obtained on a daily basis, making the algorithm developed in this paper useful for environmental monitoring of inland waters.

  13. 76 FR 81510 - Draft Guidance for Industry and Food and Drug Administration Staff; the 510(k) Program...

    Science.gov (United States)

    2011-12-28

    ... Communication, Outreach and Development (HFM-40), Center for Biologics Evaluation and Research (CBER), Food and...) Paradigm Guidance. FDA recognizes and supports efforts for global convergence of regulatory systems, and...

  14. A tasseled cap transformation for CBERS-02B CCD data

    Institute of Scientific and Technical Information of China (English)

    Li SHENG; Jing-feng HUANG; Xiao-lu TANG

    2011-01-01

    The tasseled cap transformation of remote sensing data has been widely used in agriculture,forest,ecology,and landscape.In this paper,tasseled cap transformation coefficients appropriate for data from a new sensor (China & Brazil Earth Resource Satellite (CBERS-02B)) are presented.The first three components after transformation captured 98% of the four-band variance,and represent the physical characteristics of brightness (coefficients:0.509,0.431,0.330,and 0.668),greenness (coefficients:-0.494,-0.318,-0.324,and 0.741),and blueness (coefficients:0.581,-0.070,-0.811,and 0.003),respectively.We hope these results will enhance the application of CBERS-02B charge-coupled device (CCD) data in the areas of agriculture,forest,ecology,and landscape.

  15. 78 FR 100 - Guidance for Industry and Food and Drug Administration Staff; Refuse To Accept Policy for 510(k)s...

    Science.gov (United States)

    2013-01-02

    ... HUMAN SERVICES Food and Drug Administration Guidance for Industry and Food and Drug Administration Staff; Refuse To Accept Policy for 510(k)s; Availability AGENCY: Food and Drug Administration, HHS. ACTION: Notice. SUMMARY: The Food and Drug Administration (FDA) is announcing the availability of the...

  16. 21 CFR 880.9 - Limitations of exemptions from section 510(k) of the Federal Food, Drug, and Cosmetic Act (the act).

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Limitations of exemptions from section 510(k) of the Federal Food, Drug, and Cosmetic Act (the act). 880.9 Section 880.9 Food and Drugs FOOD AND DRUG... Food, Drug, and Cosmetic Act (the act). The exemption from the requirement of premarket...

  17. 21 CFR 884.9 - Limitations of exemptions from section 510(k) of the Federal Food, Drug, and Cosmetic Act (the act).

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Limitations of exemptions from section 510(k) of the Federal Food, Drug, and Cosmetic Act (the act). 884.9 Section 884.9 Food and Drugs FOOD AND DRUG..., and Cosmetic Act (the act). The exemption from the requirement of premarket notification (section...

  18. CRESDA APPLICATION SYSTEM OF CBERS-1, RESULTS AND TYPICAL EXAMPLES OF APPLICATIONS

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    CRESDA Application System of CBERS-1 was established in 1999. During the operation of the system for more than two years, about 240 000 scenes of CBERS-1 Level 0 data have been archived and more than 13 000 scenes of Level 2 products have been ordered by end users from different application fields.In this paper, the typical examples of applications in crop yield estimation,calamity alleviation, resources survey and protection, environment monitoring and continuable development, and urban planning are mainly described.

  19. Discriminação de variedades de citros em imagens CCD/CBERS-2 Discrimination of citrus varieties using CCD/CBERS-2 satellite imagery

    Directory of Open Access Journals (Sweden)

    Ieda Del'Arco Sanches

    2008-02-01

    Full Text Available O presente trabalho teve o objetivo de avaliar as imagens CCD/CBERS-2 quanto à possibilidade de discriminarem variedades de citros. A área de estudo localiza-se em Itirapina (SP e, para este estudo, foram utilizadas imagens CCD de três datas (30/05/2004, 16/08/2004 e 11/09/2004. Um modelo que integra os elementos componentes da cena citrícola sensoriada é proposto com o objetivo de explicar a variabilidade das respostas das parcelas de citros em imagens orbitais do tipo CCD/CBERS-2. Foram feitas classificações pelos algoritmos Isoseg e Maxver e, de acordo com o índice kappa, concluiu-se que é possível obterem-se exatidões qualificadas como muito boas, sendo que as melhores classificações foram conseguidas com imagens da estação seca.This paper was aimed at evaluating the possibility of discriminating citrus varieties in CCD imageries from CBERS-2 satellite ("China-Brazil Earth Resouces Satellite". The study area is located in Itirapina, São Paulo State. For this study, three CCD images from 2004 were acquired (May 30, August 16, and September 11. In order to acquire a better understanding and for explaining the variability of the spectral behavior of the citrus areas in orbital images (like as the CCD/CBERS-2 images a model that integrates the elements of the citrus scene is proposed and discussed. The images were classified by Isoseg and MaxVer classifiers. According to kappa index, it was possible to obtain classifications qualified as 'very good'. The best results were obtained with the images from the dry season.

  20. Pre-Launch Absolute Calibration of CCD/CBERS-2B Sensor

    Science.gov (United States)

    Ponzoni, Flávio Jorge; Albuquerque, Bráulio Fonseca Carneiro

    2008-01-01

    Pre-launch absolute calibration coefficients for the CCD/CBERS-2B sensor have been calculated from radiometric measurements performed in a satellite integration and test hall in the Chinese Academy of Space Technology (CAST) headquarters, located in Beijing, China. An illuminated integrating sphere was positioned in the test hall facilities to allow the CCD/CBERS-2B imagery of the entire sphere aperture. Calibration images were recorded and a relative calibration procedure adopted exclusively in Brazil was applied to equalize the detectors responses. Averages of digital numbers (DN) from these images were determined and correlated to their respective radiance levels in order to calculate the absolute calibration coefficients. It has been the first time these pre-launch absolute calibration coefficients have been calculated considering the Brazilian image processing criteria. Now it will be possible to compare them to those that will be calculated from vicarious calibration campaigns. This comparison will permit the CCD/CBERS-2B monitoring and the frequently data updating to the user community.

  1. CBERS-02B星CCD与HR数据融合方法探讨%Discussion on the Fusion Methods of CBERS-02B CCD and HR Data

    Institute of Scientific and Technical Information of China (English)

    李石华; 金宝轩

    2013-01-01

    随着CBERS-02B星(以下简称02B星)多光谱CCD数据与全色HR数据在各个领域的广泛应用,两者相差较大的空间分辨率给图像融合带来难题.在对改进型的IHS变换、主成分变换、Brovey变换、GS变换等融合算法分析的基础上,利用02B星数据进行融合试验,并对试验结果进行定性与定量评价,结果表明:①Brovey变换融合效果较差;②在影像的阴影区域,改进型的IHS变换融合结果存在光谱失真;③PCA变换光谱保真较好;④GS变换无论是统计结果还是图像的色彩和清晰度都明显优于上述三种方法.%With the wide application of CBERS-02B Satellite (named as 02B Satellite as follows) multi-spectral CCD data and HR panchromatic data in various fields,it brings the difficulty in image fusion due to the large difference of spatial resolution.Based on the analysis fusion algorithms such as improved-IHS transformation,principal component transformation (PCA),Brovey transformation,GS transformation,etc,02B satellite data is used to for fusion test and the test result is evaluated by the qualitative and quantitative indexes.The results show that Brovey fusion is a less effective transformation method,improved-IHS transformation has the spectrum distortion in the shade area of image and the relationship between the different spectral changes significantly,PCA transformation spectral fidelity is better,and GS transformation is significantly better than the above three methods in terms of the statistics or the color and clarity of the image,but the image brightness need to be improved.

  2. Assessing the Relative Ecological Importance and Deforestation Risks of Unprotected Areas in Western Brazil Using Landsat, CBERS and Quantum GIS

    Science.gov (United States)

    Smith, A.; Sevilla, C.; Lanclos, A.; Carson, C.; Larson, J.; Sankaran, M.; Saad, M.

    2012-12-01

    In addition to understanding Brazilian policies and currently utilized methodologies, the measurement of the impacts of deforestation is essential for enhancing techniques to reduce deforestation in the future. Adverse impacts of deforestation include biodiversity loss, increased carbon dioxide emissions, and a reduced rate of evapotranspiration, all of which contribute directly or indirectly to global warming. With the continual growth in population in developing countries such as Brazil, increased demands are placed on infrastructural development and food production. As a result, forested areas are cleared for agricultural production. Recently, exploration for hydrocarbons in Western Brazil has also intensified as a means to stimulate the economy, as abundant oil and gas is believed to be found in these regions. Unfortunately, hydrocarbon-rich regions of Western Brazil are also home to thousands of species. Many of these regions are as of yet untapped but are at risk of ecological disruption as a result of impending human activity. This project utilized Landsat 5 TM to monitor deforestation in a subsection of the Brazilian states of Rondônia and Amazonas. A risk map identifying areas susceptible to future deforestation, based on factors such as proximity to roads, bodies of water, cities, and proposed hydrocarbon activities such as pipeline construction, was created. Areas at higher risk of clearance were recommended to be a target for enhanced monitoring and law enforcement. In addition, an importance map was created based on biodiversity and location of endangered species. This map was used to identify potential areas for future protection. A Chinese-Brazilian satellite, CBERS 2B CCD was also utilized for comparison. The NDVI model was additionally replicated in Quantum GIS, an open source software, so that local communities and policymakers could benefit without having to pay for expensive ArcGIS software. The capabilities of VIIRS were also investigated to

  3. Bundle Block Adjustment with Self-Calibration of Long Orbit CBERS-02B Imagery

    Science.gov (United States)

    Zhang, Y.; Zheng, M.

    2012-07-01

    CBERS-02B was the first high resolution earth observation satellite in China, which adopted linear array push-broom sensor. The nadir ground resolution of the on board HR camera was 2.36 m. However, the accuracies of the on-board GPS receiver and star tracker were very limited due to the technical restrictions. The accuracy of direct geo-referencing by the on-board measurements of position and attitude parameters was about 1 kilometre, which restrained the wide applications of the CBERS-02B imagery in the surveying and mapping field. It is necessary to perform the bundle block adjustment to improve the accuracy of geo-referencing. A proper sensor model has to be adopted during the bundle block adjustment using strict physical sensor model with long orbit data, in order to solve the problem of too many unknown exterior orientation parameters (EOPs). Several sensor models have been discussed, such as quadratic polynomial model, systematic error compensation model, orientation image model, and piecewise polynomial model. The combination of the systematic error compensation model and the orientation image model will be used to deal with the CBERS-02B imagery in this paper. Furthermore, three TDI-CCD linear arrays were fixed on the focal plane of the HR camera. The middle CCD array was shifted against the left and the right one. The level 1A image used in this paper was mosaicked by the three sub-images collected by the left, the middle and the right CCD, respectively. But there were some displacements among the three sub-images in the mosaicked image and the three CCD arrays may not be rigorously parallel. The angular parameter α and the translation parameters χ, γ of each CCD refer to the theoretical position on the focal plane is used to model the interior distortions, so there are totally 9 interior distortion parameters, although some of them are not significant. The laboratory calibrated parameters of the image sensor are usually different from the true values

  4. Energetic particle radiations measured by particle detector on board CBERS-1 satellite

    Institute of Scientific and Technical Information of China (English)

    HAO YongQiang; XIAO Zuo; ZOU Hong; ZHANG DongHe

    2007-01-01

    Using the data measured by energetic particle detector on board CBERS-01 and -02 for the past five years, statistics was made to show the general features of MeV electrons and protons along a solar synchronous orbit at an altitude of 780 km. This height is in the bottom region of the Earth's radiation belts. Detectors are inside the satellite cabinet and such continuous monitoring of particle radiation environment inside a satellite has seldom conducted so far. After a proper and careful treatment, it is indicated that the data inside satellite are well correlated with the radiation environment outside. Besides the agreement of the general distribution characteristics of energetic electrons and protons with similar observations from other satellites, attention is particularly paid to the disturbed conditions. Variations of particle fluxes are closely related with solar proton events, in general, electron fluxes of outer belt are well correlated with Dst index after three days' delay while the electron injection occurred almost at the same day during great magnetic storms. It is confirmed that both energetic electrons and protons appear in the Polar Cap region only after the solar proton events.

  5. Land use mapping from CBERS-2 images with open source tools by applying different classification algorithms

    Science.gov (United States)

    Sanhouse-García, Antonio J.; Rangel-Peraza, Jesús Gabriel; Bustos-Terrones, Yaneth; García-Ferrer, Alfonso; Mesas-Carrascosa, Francisco J.

    2016-02-01

    Land cover classification is often based on different characteristics between their classes, but with great homogeneity within each one of them. This cover is obtained through field work or by mean of processing satellite images. Field work involves high costs; therefore, digital image processing techniques have become an important alternative to perform this task. However, in some developing countries and particularly in Casacoima municipality in Venezuela, there is a lack of geographic information systems due to the lack of updated information and high costs in software license acquisition. This research proposes a low cost methodology to develop thematic mapping of local land use and types of coverage in areas with scarce resources. Thematic mapping was developed from CBERS-2 images and spatial information available on the network using open source tools. The supervised classification method per pixel and per region was applied using different classification algorithms and comparing them among themselves. Classification method per pixel was based on Maxver algorithms (maximum likelihood) and Euclidean distance (minimum distance), while per region classification was based on the Bhattacharya algorithm. Satisfactory results were obtained from per region classification, where overall reliability of 83.93% and kappa index of 0.81% were observed. Maxver algorithm showed a reliability value of 73.36% and kappa index 0.69%, while Euclidean distance obtained values of 67.17% and 0.61% for reliability and kappa index, respectively. It was demonstrated that the proposed methodology was very useful in cartographic processing and updating, which in turn serve as a support to develop management plans and land management. Hence, open source tools showed to be an economically viable alternative not only for forestry organizations, but for the general public, allowing them to develop projects in economically depressed and/or environmentally threatened areas.

  6. Identifying Spatial Units of Human Occupation in the Brazilian Amazon Using Landsat and CBERS Multi-Resolution Imagery

    Directory of Open Access Journals (Sweden)

    Maria Isabel Sobral Escada

    2012-01-01

    Full Text Available Every spatial unit of human occupation is part of a network structuring an extensive process of urbanization in the Amazon territory. Multi-resolution remote sensing data were used to identify and map human presence and activities in the Sustainable Forest District of Cuiabá-Santarém highway (BR-163, west of Pará, Brazil. The limits of spatial units of human occupation were mapped based on digital classification of Landsat-TM5 (Thematic Mapper 5 image (30m spatial resolution. High-spatial-resolution CBERS-HRC (China-Brazil Earth Resources Satellite-High-Resolution Camera images (5 m merged with CBERS-CCD (Charge Coupled Device images (20 m were used to map spatial arrangements inside each populated unit, describing intra-urban characteristics. Fieldwork data validated and refined the classification maps that supported the categorization of the units. A total of 133 spatial units were individualized, comprising population centers as municipal seats, villages and communities, and units of human activities, such as sawmills, farmhouses, landing strips, etc. From the high-resolution analysis, 32 population centers were grouped in four categories, described according to their level of urbanization and spatial organization as: structured, recent, established and dependent on connectivity. This multi-resolution approach provided spatial information about the urbanization process and organization of the territory. It may be extended into other areas or be further used to devise a monitoring system, contributing to the discussion of public policy priorities for sustainable development in the Amazon.

  7. Identificação de fragmentos de floresta nativa, por diferentes intérpretes, com a utilização de imagens landsat e cbers em lavras, MG Identification of small areas of semideciduous forest, by different analysts, in Lavras region, MG, using Landsat and Cbers sattelites images

    Directory of Open Access Journals (Sweden)

    Elizabeth Ferreira

    2005-06-01

    Full Text Available Neste trabalho, as imagens dos satélites Landsat 7 e Cbers 2 foram analisadas com o objetivo de identificar áreas com fragmentos de floresta semidecídua e de avaliar a exatidão da classificação feita por diferentes intérpretes e técnicas de interpretação. O estudo foi realizado em Lavras, MG, utilizando o SIG-SPRING, que possui recursos para realização da classificação digital e visual. Na comparação das diferentes classificações e avaliação da exatidão, foram empregadas as exatidões global, do consumidor, do produtor e o coeficiente Kappa. Pelos resultados, verificou-se que a exatidão global foi maior que 90% e o coeficiente Kappa variou de 50% a 77% nas comparações feitas por diferentes intérpretes, em imagens Landsat e Cbers. Os mapas de fragmentos de vegetação produzidos com base na classificação digital das imagens Cbers e Landsat apresentaram alta porcentagem de áreas comuns e os intérpretes produziram diferentes mapas, porém, aqueles gerados pela imagem Cbers apresentaram a melhor concordância entre as classificações.In this work two images from Landsat 7 and Cbers 2 were analyzed in order to identify small areas of semideciduous forest and to evaluate the classification accuracy made by three different analysts. The study was carried out in Lavras region, MG, using the SPRING GIS with the appropriate functions to jufil the digital classification and visual inspection. The comparisons between the classifications and accuracy assessment procedures employed the overall accuracy, the user's accuracy, the producer's accuracy and the Kappa coefficient. The results showed that the overall accuracy were higher than 90% and the Kappa coefficient ranged from 50% to 77% when the Landsat and Cbers images were compared by different analysts. The fragments vegetation maps made from digital classification of Cbers and Landsat satellites images presented high percentage of common areas and analysts made different maps

  8. Remote Sensing of the EnviSat and Cbers-2B satellites rotation around the centre of mass by photometry

    Science.gov (United States)

    Koshkin, N.; Korobeynikova, E.; Shakun, L.; Strakhova, S.; Tang, Z. H.

    2016-08-01

    During 2013-2015 the photometric observations of the EnviSat satellite, which became space debris after the failure in April 2012 in low Earth orbit, were performed. The rotation pole position and slow change in sidereal rotation period were updated on the basis of analysis of specular glints observed in 222 light curves using reduction of synodic periods. Apparently, there are minor oscillations of the rotation pole near the normal to the orbital plane. The sense of the EnviSat's spinning is opposite to the sense of its orbital rotation. The sidereal period is best approximated by the second-order polynomial: Psid (sec) = 0.000021534 ·T2 + 0.04936003 · T + 121.18195 where T is measured in days from the beginning of 2013. This method being applied to another representative of space debris, namely the Cbers-2B satellite, has shown a similar result: there is not precise solution for the rotation pole either as it undergoes oscillations with various time scale from several hours to several months. In 2014, the spin axis made the 10 ° angle with the normal to the orbital plane while the sense of spinning is direct in this case, i.e. coincides with the sense of orbital rotation. The sidereal period is best approximated by the following expression: Psid (sec) = 0.000029543 ·T2 + 0.08094931 · T + 81.31775 where T is measured in days starting from March 10, 2014. This method allows of controlling slow changes in the spatial orientation of the rotation axis of the satellites in which specular reflection of light from flat faces of the surface is inherent.

  9. Análise de mapas de represas publicados na web usando imagens orbitais CCD/CBERS no estado de Minas Gerais Analysis of dams maps published on the web by using orbital CCD/CBERS images in Minas Gerais State, Brazil

    Directory of Open Access Journals (Sweden)

    Elizabeth Ferreira

    2010-02-01

    Full Text Available Neste trabalho, bancos de dados públicos e gratuitos disponíveis na World Wide Web (WEB foram utilizados para avaliar as áreas das superfícies dos espelhos d'água das represas de Furnas e do Funil, no Estado de Minas Gerais. O objetivo foi comparar as informações obtidas nos bancos da WEB com os valores das áreas calculadas a partir de imagens do sensor CCD a bordo dos satélites CBERS2 e CBERS2B. A área da represa de Furnas obtida a partir das imagens CCD/CBERS2B, ano 2008, foi de 1.138 km², mas nos bancos de dados consultados esta área estava entre 1.182 e 1.503 km². A represa do Funil, construída em 2003, com superfície de espelho d'água de 29,37 km² e uma ilha com área de 1,93 km² não aparecem nos bancos Atlas, Geominas, IGAM e IBGE. Os resultados mostraram algumas discrepâncias nos bancos de dados publicados na WEB, tais como diferenças em áreas e supressão ou extrapolação de limites do espelho d'água. Concluiu-se que, até o momento, os responsáveis por algumas publicações de bancos de dados no Estado de Minas Gerais não tiveram rigor suficiente com as atualizações. As imagens CCD/CBERS, que também são dados públicos disponíveis na WEB, mostraram ser produtos adequados para verificar, atualizar e melhorar as informações publicadas.In this work some public databases from the World Wide Web (WEB were used to find the area of the Furnas and Funil Dams in Minas Gerais State. The purpose of this work was to compare the WEB public databases values and the real values obtained from the CCD camera images on board CBERS2 and CBERS2B satellites. The Furnas Dam area obtained from CCD/ CBERS2B images, in 2008, was 1.138 km², but in the consulted databases this area ranged from 1.182 to 1.503 km². The dam of the Funil, built in 2003, with a water surface of 29.37 km² and an island with 1.93 km² area, did not appear in Atlas, Geominas, IGAM and IBGE databases. The results revealed some problems in the WEB public

  10. Concentration of chlorhophyll-a and the limit of the photic zone in the Third River reservoir (Córdoba-Argentina, using images from CBERS-2B satellite

    Directory of Open Access Journals (Sweden)

    Claudia Maria Rodriguez

    2012-12-01

    Full Text Available The satellite images provided by remote sensors represent an important tool for monitoring, controlling and administering water resources. The aim of this work was to model the spatial distribution of the concentration of chlorhophyll-a and the limit of the photic zone in the Rio Tercero reservoir (Córdoba-Argentina, using images from CBERS-2B satellite and a geographical information system (SIG. We selected 15 samples places wherefrom we measured physical, chemical and biological parameters during the fall of 2008. By using a georeferenced image from sensor CBERS-2B and performing an analysis of the principal components (ACP, we were able to identify associations between variables and reflectance values of the satellite bands. Based on these associations and with simple regression models, we were able to know the spatial distribution of the variables: concentration of chlorophyll-a (R2 = 0, 73 and the limit of the photic zone (R2 = 0, 78 in the reservoir as a whole. We may conclude thata there exists a negative correlation between the concentration of chlorophyll-a and the water transparency in reservoir Rio Tercero, as well as that the sensor used allows us to evaluate the quality of the water in a relative short time.

  11. Cadastral maps of irrigated areas by center pivots in the State of Minas Gerais, using CBERS-2B/CCD satellite imaging Cadastro das áreas irrigadas por pivôs centrais, em Minas Gerais, utilizando imagens do satélite CBERS-2B/CCD

    Directory of Open Access Journals (Sweden)

    Elizabeth Ferreira

    2011-01-01

    Full Text Available Medium-resolution satellite images have been widely used for the identification and quantification of irrigated areas by center pivot. These areas, which present predominantly circular forms, can be easily identified by visual analyses of these images. In addition to identifying and quantifying areas irrigated by center pivot, other information that is associated to these areas is fundamental for producing cadastral maps. The goal of this work was to generate cadastral mapping of areas irrigated by center pivots in the State of Minas Gerais, Brazil, with the purpose of supplying information on irrigated agriculture. Using the satellite CBERS2B/CCD, images were used to identify and quantify irrigated areas and then associate these areas with a database containing information about: irrigated area, perimeter, municipality, path row, basin in which the pivot is located, and the date of image acquisition.3,781 center pivots systems were identified. The smallest area irrigated was 4.6 hectares and the largest one was 192.6 hectares. The total estimated value of irrigated area was 254,875 hectares. The largest number of center pivots appeared in the municipalities of Unaí and Paracatu, with 495 and 459 systems, respectively. Cadastral mapping is a very useful tool to assist and enhance information on irrigated agriculture in the State of Minas Gerais.As imagens de satélite de média resolução são bastante utilizadas para a identificação e quantificação de áreas irrigadas por pivô central. Essas áreas, por apresentarem formas predominantemente circulares, podem ser facilmente identificadas por meio de análises visuais dessas imagens. Além da identificação e quantificação das áreas irrigadas por pivô, a adição de outras informações complementares a estas áreas é fundamental para gerar mapas cadastrais. O objetivo deste trabalho foi gerar um mapeamento cadastral das áreas irrigadas por pivôs centrais no Estado de Minas Gerais

  12. Caracterização espectral de áreas de gramíneas forrageiras infectadas com a doença "mela-das-sementes da braquiária" por meio de imagens CCD/CBERS-2 Spectral characterization of forage grasses infected with the disease "mela-das-sementes da braquiária" through CCD/CDBERS -2 images

    Directory of Open Access Journals (Sweden)

    José C. Rosatti

    2006-12-01

    Full Text Available Imagens CCD/CBERS-2, nas bandas espectrais CCD2, CCD3 e CCD4, dos anos de 2004 e 2005, de Mirante do Paranapanema - SP, foram transformadas em reflectância de superfície usando o modelo 5S de correção atmosférica e normalizadas radiometricamente. O objetivo principal foi caracterizar espectralmente áreas de pastagens de Brachiaria brizantha em fase de florescimento, isentas e infectadas com a doença "mela-das-sementes da braquiária", possibilitando a sua detecção por meio da comparação entre os valores de reflectância de superfície denominada de Fator de Reflectância Bidirecional de Superfície (FRBS. Teve-se, também, o objetivo de avaliar a eficácia das imagens CCD/CBERS-2 para a obtenção de respostas espectrais de pastagens. Os dosséis sadios e doentes da Brachiaria brizantha foram identificados por meio da análise dos valores de reflectância e dos dados observados no Índice de Estresse Hídrico Acumulativo Relativo da Cultura (ACWSI obtidos na área de estudo. Os resultados indicaram que as principais diferenças foram a diminuição da reflectância na banda CCD3 e o aumento da reflectância na banda CCD4 nas áreas doentes. A metodologia empregada com o uso de dados do sensor CCD/CBERS-2, associados ao ACWSI, mostrou-se eficaz para discriminar dosséis infectados com a "mela-das-sementes da braquiária".CCD/CBERS-2 images in the spectral bands of CCD2, CCD3 and CCD4 of the years 2004 and 2005, from Mirante do Paranapanema - SP (Brazil, were transformed into surface reflectance images using the 5S atmospheric correction model and radiometrically normalized. The main objective was to spectrally characterize pastures of Brachiaria brizantha in the flowering phase, exempt and infected with the disease "mela-das-sementes da braquiária" making it possible its detection through the comparison among the SBRF - Surface Bidirectional Reflectance Factor values. At the same time, it was aimed to evaluate the effectiveness of the

  13. 76 FR 50230 - Center for Devices and Radiological Health 510(k) Clearance Process; Recommendations Proposed in...

    Science.gov (United States)

    2011-08-12

    ... August 5, 2010 (75 FR 47307). After reviewing public comment, CDRH issued a plan of action for... public meeting will be held at the Silver Spring Hilton Hotel, 8727 Colesville Rd., Silver Spring, MD... inhibiting innovation in the medical device industry. 7. FDA should develop procedures that ensure the...

  14. 21 CFR 807.93 - Content and format of a 510(k) statement.

    Science.gov (United States)

    2010-04-01

    ... identifiers, and trade secret and confidential commercial information, as defined in 21 CFR 20.61. (2) The... (CONTINUED) MEDICAL DEVICES ESTABLISHMENT REGISTRATION AND DEVICE LISTING FOR MANUFACTURERS AND INITIAL... patient identifiers, and trade secret and confidential commercial information as defined in § 20.61...

  15. 78 FR 14097 - Pulse Oximeters-Premarket Notification Submissions [510(k)s]; Guidance for Industry and Food and...

    Science.gov (United States)

    2013-03-04

    ... Federal Register of July 19, 2007 (72 FR 39631), FDA announced the availability of the draft guidance... HUMAN SERVICES Food and Drug Administration Pulse Oximeters--Premarket Notification Submissions... availability of the guidance entitled ``Pulse Oximeters--Premarket Notification Submissions .'' This...

  16. Effects of direct current on the wetting behavior and interfacial morphology between molten Sn and Cu substrate

    Energy Technology Data Exchange (ETDEWEB)

    Gu, Yan; Shen, Ping, E-mail: shenping@jlu.edu.cn; Yang, Nan-Nan; Cao, Kang-Zhan

    2014-02-15

    Highlights: • Applying DC has a noticeable effect on the wetting of oxidized Cu by molten Sn. • Current polarity does not have a strong effect on wettability but on microstructure. • The IMC layer greatly thickens with increasing current intensity. • An unusual morphology was formed at the interface under a larger current intensity. -- Abstract: The effect of applying a direct electric current on the wetting behavior of molten Sn on Cu substrates at a nominal temperature of 510 K was investigated using a sessile drop method. The final stable contact angles were 37 ± 5° without employing a direct current (DC) while they decreased from 29 ± 3° to 16 ± 2° when the current increased from 2.5 A to 7.5 A. The current polarity does not have a noticeable effect on the wetting behavior but on interfacial morphology. Cross-sectional microstructure observations revealed that applying a current promoted the dissolution of the Cu substrate in molten Sn and the effect was enhanced with increasing current intensity. An unusual morphology with Cu{sub 3}Sn being the principal phase and Cu{sub 6}Sn{sub 5} being the secondary phase was observed under a relatively large current intensity, particularly for the case of electrons flowing from the Cu substrate to the molten Sn side. Joule heat-induced Marangoni convection in the liquid droplet and electromigration are likely to play significant roles in determining the wettability and interfacial microstructure under the application of a direct electric current.

  17. Spin current

    CERN Document Server

    Valenzuela, Sergio O; Saitoh, Eiji; Kimura, Takashi

    2012-01-01

    In a new branch of physics and technology called spin-electronics or spintronics, the flow of electrical charge (usual current) as well as the flow of electron spin, the so-called 'spin current', are manipulated and controlled together. This book provides an introduction and guide to the new physics and application of spin current.

  18. Current Titles

    Energy Technology Data Exchange (ETDEWEB)

    Various

    2006-06-01

    This booklet is published for those interested in current research being conducted at the National Center for Electron Microscopy. The NCEM is a DOE-designated national user facility and is available at no charge to qualified researchers. Access is controlled by an external steering committee. Interested researchers may contact Jane Cavlina, Administrator, at 510/486-6036.

  19. Current titles

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-07-01

    This booklet is published for those interested in current research being conducted at the National Center for Electron Microscopy. The NCEM is a DOE-designated national user facility and is available at no charge to qualified researchers. Access is controlled by an external steering committee. Interested researchers may contact Gretchen Hermes at (510) 486-5006 or address below for a User`s Guide. Copies of available papers can be ordered from: Theda Crawford National Center for Electron Microscopy, Lawrence Berkeley Laboratory, One Cyclotron Rd., MS72, Berkeley, California, USA 94720.

  20. Current ornithology

    CERN Document Server

    1983-01-01

    The appearance of the first volume of a projected series is the occasion for comment on scope, aims, and genesis of the work. The scope of Current Ornithology is all of the biology of birds. Ornithology, as a whole-organism science, is concerned with birds at every level of bi­ ological organization, from the molecular to the community, at least from the Jurassic to the present time, and over every scholarly discipline in which bird biology is done; to say this is merely to expand a dic­ tionary definition of "ornithology. " The aim of the work, to be realized over several volumes, is to present reviews or position statements con­ cerning the active fields of ornithological research. The reviews will be relatively short, and often will be done from the viewpoint of a readily­ identified group or school. Such a work could have come into being at any time within the past fifty years, but that Current Ornithology appears now is a result of events that are only seven to eight years old. One important event wa...

  1. Neutral currents

    International Nuclear Information System (INIS)

    A short survey of the new experimental data on weak neutral currents is given, followed by a comparison with modern theoretical models. Cross sections of the anti νsub(e)e → anti νsub(e)e, anti νsub(μ)e→ νsub(μ)e, νp → νp and anti νp → anti νp elastic scattering as well as inclusive cross sections of the ν+N → ν+X and anti ν+N → anti ν+X deep inelastic scattering are presented. On the basis of the comparison the Weinberg-Salam model is concluded to be in a good agreement with the shape of the cross sections. Six-quark vector models appear to be ruled out. The five-quark model due to Achiman, Koller and Walsh and two versions of the Gursey-Sikivie model satisfactorily account for the observed data in shape and in magnitude

  2. 21 CFR 866.9 - Limitations of exemptions from section 510(k) of the Federal Food, Drug, and Cosmetic Act (the act).

    Science.gov (United States)

    2010-04-01

    ... marketed device in that generic type of device; e.g., a surgical instrument cuts tissue with a laser beam... (AIDS), chronic or active hepatitis, tuberculosis, or myocardial infarction or to monitor therapy;...

  3. 21 CFR 876.9 - Limitations of exemptions from section 510(k) of the Federal Food, Drug, and Cosmetic Act (the act).

    Science.gov (United States)

    2010-04-01

    ... marketed device in that generic type of device; e.g., a surgical instrument cuts tissue with a laser beam... (AIDS), chronic or active hepatitis, tuberculosis, or myocardial infarction or to monitor therapy;...

  4. 21 CFR 892.9 - Limitations of exemptions from section 510(k) of the Federal Food, Drug, and Cosmetic Act (the act).

    Science.gov (United States)

    2010-04-01

    ... that generic type of device; e.g., a surgical instrument cuts tissue with a laser beam rather than with... hepatitis, tuberculosis, or myocardial infarction or to monitor therapy; (4) For assessing the risk...

  5. 21 CFR 868.9 - Limitations of exemptions from section 510(k) of the Federal Food, Drug, and Cosmetic Act (the act).

    Science.gov (United States)

    2010-04-01

    ... that generic type of device; e.g., a surgical instrument cuts tissue with a laser beam rather than with... hepatitis, tuberculosis, or myocardial infarction or to monitor therapy; (4) For assessing the risk...

  6. 21 CFR 890.9 - Limitations of exemptions from section 510(k) of the Federal Food, Drug, and Cosmetic Act (the act).

    Science.gov (United States)

    2010-04-01

    ... that generic type of device; e.g., a surgical instrument cuts tissue with a laser beam rather than with... hepatitis, tuberculosis, or myocardial infarction or to monitor therapy; (4) For assessing the risk...

  7. 21 CFR 864.9 - Limitations of exemptions from section 510(k) of the Federal Food, Drug, and Cosmetic Act (the act).

    Science.gov (United States)

    2010-04-01

    ... marketed device in that generic type of device; e.g., a surgical instrument cuts tissue with a laser beam... (AIDS), chronic or active hepatitis, tuberculosis, or myocardial infarction or to monitor therapy;...

  8. 21 CFR 886.9 - Limitations of exemptions from section 510(k) of the Federal Food, Drug, and Cosmetic Act (the act).

    Science.gov (United States)

    2010-04-01

    ... that generic type of device; e.g., a surgical instrument cuts tissue with a laser beam rather than with... hepatitis, tuberculosis, or myocardial infarction or to monitor therapy; (4) For assessing the risk...

  9. 21 CFR 872.9 - Limitations of exemptions from section 510(k) of the Federal Food, Drug, and Cosmetic Act (the act).

    Science.gov (United States)

    2010-04-01

    ... that generic type of device; e.g., a surgical instrument cuts tissue with a laser beam rather than with... hepatitis, tuberculosis, or myocardial infarction or to monitor therapy; (4) For assessing the risk...

  10. 21 CFR 870.9 - Limitations of exemptions from section 510(k) of the Federal Food, Drug, and Cosmetic Act (the act).

    Science.gov (United States)

    2010-04-01

    ... that generic type of device; e.g., a surgical instrument cuts tissue with a laser beam rather than with... hepatitis, tuberculosis, or myocardial infarction or to monitor therapy; (4) For assessing the risk...

  11. 21 CFR 862.9 - Limitations of exemptions from section 510(k) of the Federal Food, Drug, and Cosmetic Act (the act).

    Science.gov (United States)

    2010-04-01

    ... laser beam rather than with a sharpened metal blade, or an in vitro diagnostic device detects or... therapy; (4) For assessing the risk of cardiovascular diseases; (5) For use in diabetes management;...

  12. 21 CFR 882.9 - Limitations of exemptions from section 510(k) of the Federal Food, Drug, and Cosmetic Act (the act).

    Science.gov (United States)

    2010-04-01

    ... that generic type of device; e.g., a surgical instrument cuts tissue with a laser beam rather than with... hepatitis, tuberculosis, or myocardial infarction or to monitor therapy; (4) For assessing the risk...

  13. 21 CFR 878.9 - Limitations of exemptions from section 510(k) of the Federal Food, Drug, and Cosmetic Act (the act).

    Science.gov (United States)

    2010-04-01

    ... marketed device in that generic type of device; e.g., a surgical instrument cuts tissue with a laser beam... (AIDS), chronic or active hepatitis, tuberculosis, or myocardial infarction or to monitor therapy;...

  14. 21 CFR 888.9 - Limitations of exemptions from section 510(k) of the Federal Food, Drug, and Cosmetic Act (the act).

    Science.gov (United States)

    2010-04-01

    ... that generic type of device; e.g., a surgical instrument cuts tissue with a laser beam rather than with... hepatitis, tuberculosis, or myocardial infarction or to monitor therapy; (4) For assessing the risk...

  15. 21 CFR 874.9 - Limitations of exemptions from section 510(k) of the Federal Food, Drug, and Cosmetic Act (the act).

    Science.gov (United States)

    2010-04-01

    ... that generic type of device; e.g., a surgical instrument cuts tissue with a laser beam rather than with... hepatitis, tuberculosis, or myocardial infarction or to monitor therapy; (4) For assessing the risk...

  16. 78 FR 63219 - International Conference on Harmonisation; Draft Guidance on Elemental Impurities; Availability

    Science.gov (United States)

    2013-10-23

    ... Health, Labour, and Welfare; the Japanese Pharmaceutical Manufacturers Association; CDER and CBER, FDA... represent the Agency's current thinking on this topic. It does not create or confer any rights for or on...

  17. The current catalog--how current?

    Science.gov (United States)

    Sargent, C W

    1968-07-01

    NLM's Current Catalog has recently come in for some criticism. To be useful as a tool in acquisition and cataloging, currency in receipt of the Current Catalog is necessary. A survey of 263 titles with 1967 imprints, which were received by the Library of the Medical Sciences, University of New Mexico School of Medicine, was made to determine the correlation between the receipt of these books in the library and their appearance in the Current Catalog. PMID:5695111

  18. 78 FR 73553 - Prospective Grant of Exclusive License: Development of Cripto-1 Point of Care (POC) Tests and...

    Science.gov (United States)

    2013-12-06

    ... 510K cleared Point of Care (POC) tests and kits for the purpose of disease state recognition, detection..., pancreas, stomach, gallbladder, breast, lung, endometrium and cervix. Current methodologies of...

  19. Current measurement apparatus

    Science.gov (United States)

    Umans, Stephen D.

    2008-11-11

    Apparatus and methods are provided for a system for measurement of a current in a conductor such that the conductor current may be momentarily directed to a current measurement element in order to maintain proper current without significantly increasing an amount of power dissipation attributable to the current measurement element or adding resistance to assist in current measurement. The apparatus and methods described herein are useful in superconducting circuits where it is necessary to monitor current carried by the superconducting elements while minimizing the effects of power dissipation attributable to the current measurement element.

  20. Cryogenic current leads

    Energy Technology Data Exchange (ETDEWEB)

    Zizek, F.

    1982-01-01

    Theoretical, technical and design questions are examined of cryogenic current leads for SP of magnetic systems. Simplified mathematical models are presented for the current leads. To illustrate modeling, the calculation is made of the real current leads for 500 A and three variants of current leads for 1500 A for the enterprise ''Shkoda.''

  1. Marine Current Energy Conversion

    OpenAIRE

    Lundin, Staffan

    2016-01-01

    Marine currents, i.e. water currents in oceans and rivers, constitute a large renewable energy resource. This thesis presents research done on the subject of marine current energy conversion in a broad sense. A review of the tidal energy resource in Norway is presented, with the conclusion that tidal currents ought to be an interesting option for Norway in terms of renewable energy. The design of marine current energy conversion devices is studied. It is argued that turbine and generator cann...

  2. Current interruption transients calculation

    CERN Document Server

    Peelo, David F

    2014-01-01

    Provides an original, detailed and practical description of current interruption transients, origins, and the circuits involved, and how they can be calculated Current Interruption Transients Calculationis a comprehensive resource for the understanding, calculation and analysis of the transient recovery voltages (TRVs) and related re-ignition or re-striking transients associated with fault current interruption and the switching of inductive and capacitive load currents in circuits. This book provides an original, detailed and practical description of current interruption transients, origins,

  3. Currents for Arbitrary Helicity

    CERN Document Server

    Dragon, Norbert

    2016-01-01

    Using Mackey's classification of unitary representations of the Poincar\\'e group on massles states of arbitrary helicity we disprove the claim that states with helicity |h|>=1 cannot couple to a conserved current by constructing such a current.

  4. Current Research Studies

    Science.gov (United States)

    ... Home > Explore CCFA Research > Current Research Studies Current Research Studies Email Print + Share The Crohn’s & Colitis Foundation ... online. Learn more about CCFA Partners. CCFA Clinical Research Alliance The Clinical Research Alliance is a network ...

  5. Current enhancement update

    International Nuclear Information System (INIS)

    Net current enhancement to levels in excess of the beam current has been observed in gases at pressures excess of 50 torr. We delineate the regimes where enhancement is observed. The experimental results fall into two very distinct classes; current enhancement at injection where the beam is only slightly displaced and current enhancement clearly associated with the high amplitude hose instability. A careful theoretical and experimental study of the diagnostics revealed no fundamental flaws although there are several complex and unlikely scenarios which could introduce fictitious current enhancement. Theoretical efforts indicate several mechanisms for generating enhancement but none of the theories can account for the detailed observations. 4 references, 4 figures

  6. Inrush Current Control Circuit

    Science.gov (United States)

    Cole, Steven W. (Inventor)

    2002-01-01

    An inrush current control circuit having an input terminal connected to a DC power supply and an output terminal connected to a load capacitor limits the inrush current that charges up the load capacitor during power up of a system. When the DC power supply applies a DC voltage to the input terminal, the inrush current control circuit produces a voltage ramp at the load capacitor instead of an abrupt DC voltage. The voltage ramp results in a constant low level current to charge up the load capacitor, greatly reducing the current drain on the DC power supply.

  7. Fast wave current drive

    Energy Technology Data Exchange (ETDEWEB)

    Goree, J.; Ono, M.; Colestock, P.; Horton, R.; McNeill, D.; Park, H.

    1985-07-01

    Fast wave current drive is demonstrated in the Princeton ACT-I toroidal device. The fast Alfven wave, in the range of high ion-cyclotron harmonics, produced 40 A of current from 1 kW of rf power coupled into the plasma by fast wave loop antenna. This wave excites a steady current by damping on the energetic tail of the electron distribution function in the same way as lower-hybrid current drive, except that fast wave current drive is appropriate for higher plasma densities.

  8. Shaft Current Protection

    OpenAIRE

    Rabuzin, Tin

    2015-01-01

    Shaft current protection in hydro and turbo generators is an important generatorprotection issue. Currents owing in the generator shaft might damagegenerator bearings which, in turn, could reduce operating time and cause largenancial losses. Therefore, it is important to prevent operation of the generatorunder conditions of high shaft currents.In this project, task was to develop measurement and protection system thatis able to operate under certain conditions. Measurement device has to be ab...

  9. Quantization of interface currents

    Energy Technology Data Exchange (ETDEWEB)

    Kotani, Motoko [AIMR, Tohoku University, Sendai (Japan); Schulz-Baldes, Hermann [Department Mathematik, Universität Erlangen-Nürnberg, Erlangen (Germany); Villegas-Blas, Carlos [Instituto de Matematicas, Cuernavaca, UNAM, Cuernavaca (Mexico)

    2014-12-15

    At the interface of two two-dimensional quantum systems, there may exist interface currents similar to edge currents in quantum Hall systems. It is proved that these interface currents are macroscopically quantized by an integer that is given by the difference of the Chern numbers of the two systems. It is also argued that at the interface between two time-reversal invariant systems with half-integer spin, one of which is trivial and the other non-trivial, there are dissipationless spin-polarized interface currents.

  10. Low current beam techniques

    Energy Technology Data Exchange (ETDEWEB)

    Saint, A.; Laird, J.S.; Bardos, R.A.; Legge, G.J.F. [Melbourne Univ., Parkville, VIC (Australia). School of Physics; Nishijima, T.; Sekiguchi, H. [Electrotechnical Laboratory, Tsukuba (Japan).

    1993-12-31

    Since the development of Scanning Transmission Microscopy (STIM) imaging in 1983 many low current beam techniques have been developed for the scanning (ion) microprobe. These include STIM tomography, Ion Beam Induced Current, Ion Beam Micromachining and Microlithography and Ionoluminense. Most of these techniques utilise beam currents of 10{sup -15} A down to single ions controlled by beam switching techniques This paper will discuss some of the low beam current techniques mentioned above, and indicate, some of their recent applications at MARC. A new STIM technique will be introduced that can be used to obtain Z-contrast with STIM resolution. 4 refs., 3 figs.

  11. Current and Current Fluctuations in Quantum Shuttles

    DEFF Research Database (Denmark)

    Jauho, Antti-Pekka; Flindt, Christian; Novotny, Tomas;

    2005-01-01

    We review the properties of electron shuttles, i.e., nanoelectromechanical devices that transport electrons one by one by utilizing a combination of electronic and mechanical degrees of freedom. We focus on the extreme quantum limit, where the mechanical motion is quantized. We introduce the main...... theoretical tools needed for the analysis, e.g., generalized master equations and Wigner functions, and we outline the methods how the resulting large numerical problems can be handled. Illustrative results are given for current, noise, and full counting statistics for a number of model systems. Throughout...

  12. Direct current transformer

    Science.gov (United States)

    Khanna, S. M.; Urban, E. W. (Inventor)

    1979-01-01

    A direct current transformer in which the primary consists of an elongated strip of superconductive material, across the ends of which is direct current potential is described. Parallel and closely spaced to the primary is positioned a transformer secondary consisting of a thin strip of magnetoresistive material.

  13. Electric Current Solves Mazes

    Science.gov (United States)

    Ayrinhac, Simon

    2014-01-01

    We present in this work a demonstration of the maze-solving problem with electricity. Electric current flowing in a maze as a printed circuit produces Joule heating and the right way is instantaneously revealed with infrared thermal imaging. The basic properties of electric current can be discussed in this context, with this challenging question:…

  14. On current trace problem

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The pricing of electricity trasmission requires determining how much use each generator is making of a transmission line and what is each generator's contribution to the system losses. Such problems cannot be solved by only using Kirchoff's laws. This paper proposes two current decomposition axioms based on which the theories and models are established for the current trace problem. To create an efficient algorithm the graph theory is employed. It is proved that there is no directed circuit in a directed current distribution graph. According to this theorem a very simple and efficient algorithm based on recursive elimination process is suggested. A simple example is used to explain the algorithm.

  15. NOAA NDBC SOS - currents

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA NDBC SOS server is part of the IOOS DIF SOS Project. The stations in this dataset have currents data. Because of the nature of SOS requests, requests for...

  16. Geothermal Energy: Current abstracts

    Energy Technology Data Exchange (ETDEWEB)

    Ringe, A.C. (ed.)

    1988-02-01

    This bulletin announces the current worldwide information available on the technologies required for economic recovery of geothermal energy and its use as direct heat or for electric power production. (ACR)

  17. Medicare Current Beneficiary Survey

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Characteristics and Perceptions of the Medicare Population Data from the 2010 Medicare Current Beneficiary Survey is a series of source books based on the...

  18. Current Resource Imagery Projects

    Data.gov (United States)

    Farm Service Agency, Department of Agriculture — Map showing coverage of current Resource imagery projects. High resolution/large scale Resource imagery is typically acquired for the U.S. Forest Service and other...

  19. Eddy current testing

    Energy Technology Data Exchange (ETDEWEB)

    Song, Sung Jin; Lee, Hyang Beom; Kim, Young Hwan [Soongsil Univ., Seoul (Korea, Republic of); Shin, Young Kil [Kunsan Univ., Gunsan (Korea, Republic of)

    2004-02-15

    Eddy current testing has been widely used for non destructive testing of steam generator tubes. In order to retain reliability in ECT, the following subjects were carried out in this study: numerical modeling and analysis of defects by using BC and RPC probes in SG tube, preparation of absolute coil impedance plane diagram by FEM. Signal interpretation of the eddy current signals obtained from nuclear power plants.

  20. Current power plant

    Energy Technology Data Exchange (ETDEWEB)

    Nickell, J.H.

    1979-03-06

    A current power plant is described that includes a shaft mounted turbine wheel for employment in water current, a housing adjacent the impeller and to which the shaft extends, a ramp positioned on the upstream side of the impellar, and a frame on which the turbine wheel is mounted. The frame is mounted by rollers on a tract such that the impeller and frame may be rolled on the tracks inside the housing, whereafter doors are closed, and water around the turbine wheel may be pumped out to facilitate turbine repair.

  1. [Acromegaly: current view].

    Science.gov (United States)

    Kršek, Michal

    2015-10-01

    Acromegaly is a rare disorder caused by autonomous oversecretion of growth hormone mostly by pituitary adenoma. Untreated acromegaly leads to significantly increased morbidity and mortality and impaired quality of life. Early diagnosis and treatment is therefore essential for improvement of patients prognosis and management of acromegaly should be concentrated in specialized centres. Present article summarizes current view on diagnosis and treatment of acromegaly.

  2. Issues in neutral currents

    International Nuclear Information System (INIS)

    The experimental results on low energy confirming the structure of the effective Lagrangian of the weak neutral current processes as predicted by the Salam-Weinberg model are reviewed. Some possible modifications of the effective Lagrangian and the feasibility of their experimental verification are also considered. (P.L.)

  3. Current topics in photovoltaics

    International Nuclear Information System (INIS)

    This book contains papers on current research in photovoltaics. Areas include: outdoor spectral odor radiation variations and their relationship to photovoltaic device performance, numerical modeling for analysis and design of solar cells, radiation damage mechanisms in GaAs and Si solar cells, and health and safety issues in the manufacturing of photovoltaic cells

  4. 基于CBERS-02B高分辨率遥感影像分割的最优尺度选取%Optimal scale selection base on CBERS-02B high-resolution remote sensing images

    Institute of Scientific and Technical Information of China (English)

    况润元; 袁秀华; 罗卫; 张萌; 王聪颖

    2013-01-01

    高分辨遥感影像的信息提取对矿山的监测有着重要意义,影像分割是高分辨率遥感影像信息提取关键的一步.文中以赣州稀土矿山的高分辨率遥感影像为源数据,采用分形网络演化多尺度分割算法对高分辨率遥感影像进行分割,通过Robert算子的边缘提取结果计算分割参数获取分割尺度,并在此基础上设置不同分割尺度对影像进行分割,对比分析分割结果表明,沉淀池的最优分割尺度为35.最后利用分割质量值对分割结果进行评价分析,验证了试验结果的正确性.%It has important significance for high resolution remote sensing image information extraction to monitor rare earth mine. Image segmentation is a key step in the high resolution remote sensing image information extraction. In order to obtain the optimal segmentation results, this paper chooses high-resolution remote sensing image of Ganzhou rare earth mines, uses Fractal Net Evolution Approach algorithm to segment high resolution remote sensing image, and computes segmentation parameter to obtain segmentation scale by edge extraction results of Robert operator, and sets different segmentation scale to segment image base on it, after comparing and analyzing segmentation results, it shows that optimal segmentation scale of sedimentation tank was 35. At last Segmentation results were evaluated by segmentation quality value, it verifies the accuracy of experimental result.

  5. Marijuana: Current concepts

    Directory of Open Access Journals (Sweden)

    Donald eGreydanus

    2013-10-01

    Full Text Available Marijuana (cannabis remains a controversial drug in the 21st century. This paper considers current research on use of Cannabis sativa and its constituents such as the cannabinoids. Topics reviewed include prevalence of cannabis use, other drugs consumed with pot, the endocannabinoid system, use of medicinal marijuana, medical adverse effects of cannabis, and psychiatric adverse effects of cannabis use. Treatment of cannabis withdrawal and dependence is difficult and remains mainly based on psychological therapy; current research on pharmacologic management of problems related to cannabis consumption is also considered. The potential role of specific cannabinoids for medical benefit will be revealed as the 21st century matures. However, potential dangerous adverse effects from smoking marijuana are well known and should be clearly taught to a public often confused by a media-driven, though false message and promise of benign pot consumption.

  6. The NLM current catalog.

    Science.gov (United States)

    Wiggins, E V

    1969-01-01

    When the National Library of Medicine acquired a computer to augment its publication program, the intent was to present in one medium an index to journal articles and a catalog of books and new serial titles. The computer programs designed for indexing were unsatisfactory for cataloging, however; so two publications were issued, the Index Medicus and the NLM Current Catalog. The Current Catalog features separate name and subject sections, added volumes, and technical reports. The Express Cataloging Service was one of the first attempts to increase the speed and coverage of the Catalog. Shared cataloging with the Library of Congress, the Countway Library at Harvard, and the Upstate Medical Library in Syracuse, New York, have also contributed to the efforts toward improving this library service. An additional shared cataloging program, this time with the National Medical Audiovisual Center, is expected to be implemented shortly. PMID:5782262

  7. Current management of presbyopia

    Directory of Open Access Journals (Sweden)

    Pandelis A Papadopoulos

    2014-01-01

    Full Text Available Presbyopia is a physiologic inevitability that causes gradual loss of accommodation during the fifth decade of life. The correction of presbyopia and the restoration of accommodation are considered the final frontier of refractive surgery. Different approaches on the cornea, the crystalline lens and the sclera are being pursued to achieve surgical correction of this disability. There are however, a number of limitations and considerations that have prevented widespread acceptance of surgical correction for presbyopia. The quality of vision, optical and visual distortions, regression of effect, complications such as corneal ectasia and haze, anisometropia after monovision correction, impaired distance vision and the invasive nature of the currently techniques have limited the utilization of presbyopia surgery. The purpose of this paper is to provide an update of current procedures available for presbyopia correction and their limitations.

  8. Light Cone Current Algebra

    OpenAIRE

    Fritzsch, H.; Gell-Mann, M.

    2003-01-01

    This talk follows by a few months a talk by the same authors on nearly the same subject at the Coral Gables Conference. The ideas presented here are basically the same, but with some amplification, some change of viewpoint, and a number of new questions for the future. For our own convenience, we have transcribed the Coral Gables paper, but with an added ninth section, entitled "Problems of light cone current algebra", dealing with our present views and emphasizing research topics that requir...

  9. Lupus nephritis: current update

    OpenAIRE

    Saxena, Ramesh; Mahajan, Tina; Mohan, Chandra

    2011-01-01

    Lupus nephritis is a major cause of morbidity and mortality in patients with systemic lupus erythematosus. The general consensus is that 60% of lupus patients will develop clinically relevant nephritis at some time in the course of their illness. Prompt recognition and treatment of renal disease is important, as early response to therapy is correlated with better outcome. The present review summarizes our current understanding of the pathogenic mechanisms underlying lupus nephritis and how th...

  10. [Acromegaly: current view].

    Science.gov (United States)

    Kršek, Michal

    2015-10-01

    Acromegaly is a rare disorder caused by autonomous oversecretion of growth hormone mostly by pituitary adenoma. Untreated acromegaly leads to significantly increased morbidity and mortality and impaired quality of life. Early diagnosis and treatment is therefore essential for improvement of patients prognosis and management of acromegaly should be concentrated in specialized centres. Present article summarizes current view on diagnosis and treatment of acromegaly. PMID:26486485

  11. Current ADC Linker Chemistry

    OpenAIRE

    Jain, Nareshkumar; Smith, Sean W.; Ghone, Sanjeevani; Tomczuk, Bruce

    2015-01-01

    The list of ADCs in the clinic continues to grow, bolstered by the success of first two marketed ADCs: ADCETRIS® and Kadcyla®. Currently, there are 40 ADCs in various phases of clinical development. However, only 34 of these have published their structures. Of the 34 disclosed structures, 24 of them use a linkage to the thiol of cysteines on the monoclonal antibody. The remaining 10 candidates utilize chemistry to surface lysines of the antibody. Due to the inherent heterogeneity of conjugati...

  12. Sustainable winegrowing: current perspectives

    OpenAIRE

    Mariani A; Vastola A

    2015-01-01

    Angela Mariani,1 Antonella Vastola2 1Department of Economic and Legal Studies, University Parthenope, Naples, 2School of Agricultural, Forestry, Food and Environmental Sciences, University of Basilicata, Potenza, Italy Abstract: The winegrowing sector worldwide is strongly committed to improving environmental and social sustainability. The aim of this work, based on a literature review, is to highlight current sustainability perspectives and the related main issues. There is a broad consensu...

  13. Fast wave current drive

    International Nuclear Information System (INIS)

    Experiments on the fast wave in the range of high ion cyclotron harmonics in the ACT-1 device show that current drive is possible with the fast wave just as it is for the lower hybrid wave, except that it is suitable for higher plasma densities. A 1400 loop antenna launched the high ion cyclotron harmonic fast wave [ω/Ω = O(10)] into a He+ plasma with n/sub e/approx. =4 x 1012 cm-3 and B = 4.5 kG. Probe and magnetic loop diagnostics and FIR laser scattering confirmed the presence of the fast wave, and the Rogowski loop indicated that the circulating plasma current increased by up to 40A with 1 kW of coupled power, which is comparable to lower hybrid current drive in the same device with the same unidirectional fast electron beam used as the target for the RF. A phased antenna array would be used for FWCD in a tokamak without the E-beam

  14. Clopidogrel Resistance: Current Issues

    Directory of Open Access Journals (Sweden)

    NS Neki

    2016-05-01

    Full Text Available Antiplatelet agents are mainly used in the prevention and management of atherothrombotic complications. Dual antiplatelet therapy, combining aspirin and clopidogrel, is the standard care for patients having acute coronary syndromes or undergoing percutaneous coronary intervention according to the current ACC/AHA and ESC guidelines. But in spite of administration of dual antiplatelet therapy, some patients develop recurrent cardiovascular ischemic events especially stent thrombosis which is a serious clinical problem. Antiplatelet response to clopidogrel varies widely among patients based on ex vivo platelet function measurements. Clopidogrel is an effective inhibitor of platelet activation and aggregation due to its selective and irreversible blockade of the P2Y12 receptor. Patients who display little attenuation of platelet reactivity with clopidogrel therapy are labeled as low or nonresponders or clopidogrel resistant. The mechanism of clopidogrel resistance remains incompletely defined but there are certain clinical, cellular and genetic factors including polymorphisms responsible for therapeutic failure. Currently there is no standardized or widely accepted definition of clopidogrel resistance. The future may soon be realised in the routine measurement of platelet activity in the same way that blood pressure, cholesterol and blood sugar are followed to help guide the therapy, thus improving the care for millions of people. This review focuses on the methods used to identify patients with clopidogrel resistance, the underlying mechanisms, metabolism, clinical significance and current therapeutic strategies to overcome clopidogrel resistance. J Enam Med Col 2016; 6(1: 38-46

  15. Turbidity Current Head Mixing

    Science.gov (United States)

    Hernandez, David; Sanchez, Miguel Angel; Medina, Pablo

    2010-05-01

    A laboratory experimental set - up for studying the behaviour of sediment in presence of a turbulent field with zero mean flow is compared with the behaviour of turbidity currents [1] . Particular interest is shown on the initiation of sediment motion and in the sediment lift - off. The behaviour of the turbidity current in a flat ground is compared with the zero mean flow oscilating grid generated turbulence as when wave flow lifts off suspended sediments [2,3]. Some examples of the results obtained with this set-up relating the height of the head of the turbidity current to the equilibrium level of stirred lutoclines are shown. A turbulent velocity u' lower than that estimated by the Shield diagram is required to start sediment motion. The minimum u' required to start sediment lift - off, is a function of sediment size, cohesivity and resting time. The lutocline height depends on u', and the vorticity at the lutocline seems constant for a fixed sediment size [1,3]. Combining grid stirring and turbidty current head shapes analyzed by means of advanced image analysis, sediment vertical fluxes and settling speeds can be measured [4,5]. [1] D. Hernandez Turbulent structure of turbidity currents and sediment transport Ms Thesis ETSECCPB, UPC. Barcelona 2009. [2] A. Sánchez-Arcilla; A. Rodríguez; J.C. Santás; J.M. Redondo; V. Gracia; R. K'Osyan; S. Kuznetsov; C. Mösso. Delta'96 Surf-zone and nearshore measurements at the Ebro Delta. A: International Conference on Coastal Research through large Scale Experiments (Coastal Dynamics '97). University of Plymouth, 1997, p. 186-187. [3] P. Medina, M. A. Sánchez and J. M. Redondo. Grid stirred turbulence: applications to the initiation of sediment motion and lift-off studies Physics and Chemistry of the Earth, Part B: Hydrology, Oceans and Atmosphere. 26, Issue 4, 2001, Pages 299-304 [4] M.O. Bezerra, M. Diez, C. Medeiros, A. Rodriguez, E. Bahia., A. Sanchez-Arcilla and J.M. Redondo. Study on the influence of waves on

  16. Identifying Spatial Units of Human Occupation in the Brazilian Amazon Using Landsat and CBERS Multi-Resolution Imagery

    OpenAIRE

    Maria Isabel Sobral Escada; Antonio Miguel Vieira Monteiro; Silvana Amaral; Newton Brigatti; Ana Paula Dal’Asta

    2012-01-01

    Every spatial unit of human occupation is part of a network structuring an extensive process of urbanization in the Amazon territory. Multi-resolution remote sensing data were used to identify and map human presence and activities in the Sustainable Forest District of Cuiabá-Santarém highway (BR-163), west of Pará, Brazil. The limits of spatial units of human occupation were mapped based on digital classification of Landsat-TM5 (Thematic Mapper 5) image (30m spatial resolution). High-spatial-...

  17. Analysis of the observation of particle detector inside ‘CBERS-1’ satellite under solar quiet conditions

    Institute of Scientific and Technical Information of China (English)

    ZOU; Hong; XIAO; Zuo; HAO; Yongqiang; ZOU; Jiqing; ZHU; Wenming; WU; Zhongxiang

    2006-01-01

    Based on the knowledge and related theory of earth's radiation belt, the data chronous orbit were analyzed. It is proved that the observational results are in agreement with the theoretical description of the radiation belt structures. Analysis of more than 3years' data showed clearly that under quiet solar conditions, at a height of about 800 km the energetic particles were mainly located in three regions: northern auroral belt (40°-80°), southern auroral belt (-40°- -80°) and South Atlantic Geomagnetic Anomaly Region (SAA). Actually, this is for the global distribution, at each longitude the latitudinal coverage is much narrower and particles are along the geomagnetic latitude of about ±60°.The species of particles in different regions and their counting rates are different. In SAA,usually both electrons and protons are observed, which should come from inner radiation belt; in polar regions only energetic electrons are observed under the quiet condition,which belongs to the outer radiation belt. The distribution of outer radiation electrons is asymmetrical for longitudes as well as northern and southern polar regions. These asymmetries can be explained with the reflecting altitudes of the mirror points of charged particles at the same L shell.

  18. Generalized Quantum Current Algebras

    Institute of Scientific and Technical Information of China (English)

    ZHAO Liu

    2001-01-01

    Two general families of new quantum-deformed current algebras are proposed and identified both as infinite Hopf family of algebras, a structure which enables one to define "tensor products" of these algebras. The standard quantum affine algebras turn out to be a very special case of the two algebra families, in which case the infinite Hopf family structure degenerates into a standard Hopf algebra. The relationship between the two algebraic families as well as thefr various special examples are discussed, and the free boson representation is also considered.

  19. Light Cone Current Algebra

    CERN Document Server

    Fritzsch, Harald

    2003-01-01

    This talk follows by a few months a talk by the same authors on nearly the same subject at the Coral Gables Conference. The ideas presented here are basically the same, but with some amplification, some change of viewpoint, and a number of new questions for the future. For our own convenience, we have transcribed the Coral Gables paper, but with an added ninth section, entitled "Problems of light cone current algebra", dealing with our present views and emphasizing research topics that require study.

  20. Andropause: Current concepts

    Directory of Open Access Journals (Sweden)

    Parminder Singh

    2013-01-01

    Full Text Available Andropause or late-onset hypogonadism is a common disorder which increases in prevalence with advancing age. Diagnosis of late-onset of hypogonadism is based on presence of symptoms suggestive of testosterone deficiency - prominent among them are sexual symptoms like loss of libido, morning penile erection and erectile dysfunction; and demonstration of low testosterone levels. Adequate therapeutic modalities are currently available, but disparate results of clinical trial suggest further evaluation of complex interaction between androgen deficiency and ageing. Before initiating therapy benefits and risk should be discussed with patients and in case of poor response , alternative cause should be investigated.

  1. Saturn's Other Ring Current

    Science.gov (United States)

    Crary, F. J.

    2014-04-01

    Saturn's main rings orbit the planet within an atmosphere and ionosphere of water, oxygen and hydrogen, produced by meteoritic impacts on and ultraviolet photodesorbtion of the ring particles [Johnson et al., 2006; Luhmann et al., 2006; Tseng et al., 2010]. The neutral atmosphere itself has only been tentatively detected through ultraviolet fluorescents of OH [Hall et al., 1996] while the ionosphere was observed in situ by the Cassini spacecraft shortly after orbital insertion [Coates et al.,2005; Tokar et al. 2005, Waite et al. 2005]. Although the plasma flow velocity of this ionosphere is not well-constrained, but the close association with the rings suggests that its speed would be couppled to the keplarian velocity of the rings themselves. As a result, the motion of the plasma through Saturn's magnetic field would produce an induced voltage, oriented away from the planet outside synchronous orbit and towards the planet inside synchronous orbit. Such a potential could result in currents flowing across the ring plane and closeing along magnetic field lines and through Saturn's ionosphere at latitudes between 36o and 48o. Cassini observations of whistler-mode plasma wave emissions [Xin et al.,2006] centered on synchronous orbit (1.76 Rs, mapping to 41o latitude) have been interpreted as a product of field-aligned electron beams associated with such a current. This presentation will investigate the magnitude of these currents and the resulting Joule heating of the ionosphere. An important constraint is that no auroral ultraviolet emissions have been observed at the relevant latitudes. In contrast, Joule heating could affect infrared emissions from H3+. Variations in H3+ emission associated with Saturn's rings have been reported by O'Donoghue et al., 2013, and interpreted as a result of ring "rain", i.e. precipitating water group species from the rings which alter ionosphereic chemistry and H3+ densities. As noted by O'Donoghue et al., this interpretation may be

  2. BLOCKING ALGORITHM FOR CURRENT PROTECTION DURING INRUSH MAGNETIZATION CURRENT

    Directory of Open Access Journals (Sweden)

    F. A. Romaniuk

    2014-01-01

    Full Text Available The paper presents blocking algorithm for current protection during inrush process. The algorithm is based on the evaluation of the ratio of the positive sequence second harmonic current to the negative sequence first harmonic current.

  3. 如何进入美国医疗器械市场--医疗器械企业注册、产品列名与510(K)申请%How to Enter American Medical Device Market

    Institute of Scientific and Technical Information of China (English)

    甄辉

    2003-01-01

    @@ 随着中国加入WTO,中国医疗器械工业与国际间的贸易交往将越来越多.目前国内医疗器械市场上技术含量高的医疗器械以进口居多,但技术含量较低或劳动密集型的设备及易耗品则还是以国内产品为主,而且这类产品在国际医疗器械市场上也有一定竞争力,即使在美国也占有一席之地,但目前这些产品出口美国绝大部分以OEM或转口贸易方式进行,很少打自己的品牌直接进入美国,这对于树立自己的品牌,进一步拓宽市场和获得更大企业利益是不利的,而要以自己的品牌进入美国市场就必须获得美国食品药品管理局(FDA-Food and Drug Administration)的批准认可.本文将简要介绍医疗器械进入美国市场的程序以及如何准备申报资料以获得FDA批准认可等问题.

  4. Influence of Current Transformer Saturation on Operation of Current Protection

    OpenAIRE

    F. A. Romaniouk; A. A. Tishechkin; V. I. Roumiantsev; I. V. Novash; N. N. Bobko; E. V. Glinsky

    2010-01-01

    An analysis of the influence of instrument current transformer errors on operation of current protection of power supply diagram elements has been carried out in the paper. The paper shows the influence of an aperiodic component of transient current and secondary load on current  transformer errors.Peculiar operational features of measuring elements of electromechanical and microprocessor current protection with their joint operation with electromagnetic current transformers have been analyze...

  5. Influence of Current Transformer Saturation on Operation of Current Protection

    Directory of Open Access Journals (Sweden)

    F. A. Romaniouk

    2010-01-01

    Full Text Available An analysis of the influence of instrument current transformer errors on operation of current protection of power supply diagram elements has been carried out in the paper. The paper shows the influence of an aperiodic component of transient current and secondary load on current  transformer errors.Peculiar operational features of measuring elements of electromechanical and microprocessor current protection with their joint operation with electromagnetic current transformers have been analyzed in the paper.

  6. Current Controlled Current Differencing Buffered Amplifier: Implementation and Applications

    Directory of Open Access Journals (Sweden)

    Sudhanshu Maheshwari

    2004-01-01

    Full Text Available A new four terminal current-controlled active element is introduced, where parasitic resistances at two current input ports are controlled leading to the definition of current-controlled current differencing buffered amplifier. Bipolar implementation and as application current-mode band-pass filter circuits are proposed. Simulation results using real device parameters are included, which show device bandwidth of 35 MHz, low total harmonic distortions, and tuning over a wide current range.

  7. Dispersion and current measurements

    International Nuclear Information System (INIS)

    A model for the simulation of particle movements in water should incorporate the mutual distance dependent correlation. As long as reliable data are given accessible a model can be created of the dispersion in a given area from a statistical description of turbulence. Current measurements have been performed in an area north of the Swedish nuclear power plant Barsebaeck, and statistical time series analysis have made it possible to estimate multivariate autoregressive moving-average (ARMA) models for these data using the Box-Jenkins method. The correlation structure for the area has been investigated in detail. Transport and dispersion models for the marine environment are used in estimating doses to the population from the aquatic food chain. Some of these models are described with special emphasis on the time and length scales they cover. Furthermore, to illustrate the background of the simulation model, short introductuions are given to health physics, time series analysis, and turbulence theory. Analysis of the simulation model shows the relative importance of the different parameters. The model can be expanded to conditional simulation, where the current measurements are used directly to simulate the movement of one of the particles. Results from the model are also compared to results from a sampling of bioindicators (Fucus vesiculosus) along the Danish coast. The reliability of bioindicators in this kind of experiment is discussed. (author)

  8. Current Climate Variability & Change

    Science.gov (United States)

    Diem, J.; Criswell, B.; Elliott, W. C.

    2013-12-01

    Current Climate Variability & Change is the ninth among a suite of ten interconnected, sequential labs that address all 39 climate-literacy concepts in the U.S. Global Change Research Program's Climate Literacy: The Essential Principles of Climate Sciences. The labs are as follows: Solar Radiation & Seasons, Stratospheric Ozone, The Troposphere, The Carbon Cycle, Global Surface Temperature, Glacial-Interglacial Cycles, Temperature Changes over the Past Millennium, Climates & Ecosystems, Current Climate Variability & Change, and Future Climate Change. All are inquiry-based, on-line products designed in a way that enables students to construct their own knowledge of a topic. Questions representative of various levels of Webb's depth of knowledge are embedded in each lab. In addition to the embedded questions, each lab has three or four essential questions related to the driving questions for the lab suite. These essential questions are presented as statements at the beginning of the material to represent the lab objectives, and then are asked at the end as questions to function as a summative assessment. For example, the Current Climate Variability & Change is built around these essential questions: (1) What has happened to the global temperature at the Earth's surface, in the middle troposphere, and in the lower stratosphere over the past several decades?; (2) What is the most likely cause of the changes in global temperature over the past several decades and what evidence is there that this is the cause?; and (3) What have been some of the clearly defined effects of the change in global temperature on the atmosphere and other spheres of the Earth system? An introductory Prezi allows the instructor to assess students' prior knowledge in relation to these questions, while also providing 'hooks' to pique their interest related to the topic. The lab begins by presenting examples of and key differences between climate variability (e.g., Mt. Pinatubo eruption) and

  9. Brain abscess: Current management.

    Science.gov (United States)

    Alvis Miranda, Hernando; Castellar-Leones, Sandra Milena; Elzain, Mohammed Awad; Moscote-Salazar, Luis Rafael

    2013-08-01

    Brain abscess (BA) is defined as a focal infection within the brain parenchyma, which starts as a localized area of cerebritis, which is subsequently converted into a collection of pus within a well-vascularized capsule. BA must be differentiated from parameningeal infections, including epidural abscess and subdural empyema. The BA is a challenge for the neurosurgeon because it is needed good clinical, pharmacological, and surgical skills for providing good clinical outcomes and prognosis to BA patients. Considered an infrequent brain infection, BA could be a devastator entity that easily left the patient into dead. The aim of this work is to review the current concepts regarding epidemiology, pathophysiology, etiology, clinical presentation, diagnosis, and management of BA. PMID:24174804

  10. Currently available antitussives.

    Science.gov (United States)

    Dicpinigaitis, Peter V

    2009-04-01

    Cough is among the most common complaints for which patients seek medical attention. Acute cough, usually due to a viral upper respiratory tract infection, generates a huge expenditure on prescription and over-the-counter cough and cold preparations worldwide. Most of these agents, however, have not been shown to be more effective than placebo in adequately performed clinical trials. The goal of management in chronic cough is treatment of its underlying cause. However, certain situations will necessitate cough suppressant therapy for symptomatic relief. Unfortunately, currently available antitussives, such as the opioids, are not consistently effective, or achieve therapeutic effect at the expense of unpleasant or intolerable side effects. Safer and more effective cough suppressants are desperately needed. Potential novel antitussives will need to be evaluated in properly formulated clinical trials, measuring relevant subjective and objective end points in appropriate subject populations. PMID:18771744

  11. Transungual permeation: current insights.

    Science.gov (United States)

    Bhuptani, Ronak S; Deshpande, Ketaki M; Patravale, Vandana B

    2016-08-01

    Nail disorders are beyond cosmetic concern; besides discomfort in the performance of daily chores, they disturb patients psychologically and affect their quality of life. Fungal nail infection (onychomycosis) is the most prevalent nail-related disorder affecting a major population worldwide. Overcoming the impenetrable nail barrier is the toughest challenge for the development of efficacious topical ungual formulation. Sophisticated techniques such as iontophoresis and photodynamic therapy have been proven to improve transungual permeation. This article provides an updated and concise discussion regarding the conventional approach and upcoming novel approaches focused to alter the nail barrier. A comprehensive description regarding preformulation screening techniques for the identification of potential ungual enhancers is also described in this review while highlighting the current pitfalls for the development of ungual delivery. PMID:26419676

  12. Brain abscess: Current management

    Directory of Open Access Journals (Sweden)

    Hernando Alvis-Miranda

    2013-01-01

    Full Text Available Brain abscess (BA is defined as a focal infection within the brain parenchyma, which starts as a localized area of cerebritis, which is subsequently converted into a collection of pus within a well-vascularized capsule. BA must be differentiated from parameningeal infections, including epidural abscess and subdural empyema. The BA is a challenge for the neurosurgeon because it is needed good clinical, pharmacological, and surgical skills for providing good clinical outcomes and prognosis to BA patients. Considered an infrequent brain infection, BA could be a devastator entity that easily left the patient into dead. The aim of this work is to review the current concepts regarding epidemiology, pathophysiology, etiology, clinical presentation, diagnosis, and management of BA.

  13. Perihilar cholangiocarcinoma: Current therapy

    Institute of Scientific and Technical Information of China (English)

    Wei; Zhang; Lu-Nan; Yan

    2014-01-01

    Perihilar cholangiocarcinoma, which is a rare primary malignancy, originates from the epithelial cells of the bile duct. Usually invading the periductal tissues and the lymph nodes, perihilar cholangiocarcinoma is commonly diagnosed in the advanced stage of the disease and has a dismal prognosis. Currently, complete hepatectomy is the primary therapy for curing this disease. Perioperative assessment and available surgical procedures can be considered for achieving a negative margin resection, which is associated with long-term survival and better quality of life. For patients with unresectable cholangiocarcinoma, several palliative treatments have been demonstrated to produce a better outcome; and liver transplantation for selected patients with perihilar cholangiocarcinoma is promising and desirable. However, the role of palliative treatments and liver transplantation was controversial and requires more evidence and substantial validity from multiple institutions. In this article, we summarize the data from multiple institutions and discuss the resectability, mortality, morbidity and outcome with different approaches.

  14. Current Management of Pemphigus

    Directory of Open Access Journals (Sweden)

    Soner Uzun

    2012-09-01

    Full Text Available Corticosteroids decreased the mortality rates of pemphigus as dramatically, and they are still the baseline treatment and cornerstone of pemphigus management. Systemic corticosteroids, in combination with adjuvant corticosteroid-sparing immunosuppressive drugs, are the conventional therapy for pemphigus. However, because of both refractory patients and the serious side effects of immunosuppressive drugs, the treatment of pemphigus patients is still challenging. Although they have limited evidence, more recently, monoclonal anti-CD20 antibody, rituximab, high-dose intravenous immunoglobulins and immunoadsorption have been established as additional successful therapeutic options. In this article both conventional therapies and most current treatment strategies for pemphigus are reviewed on the basis of clinical experiences. (Turk J Dermatol 2012; 6: 91-101

  15. Bioartificial liver: current status.

    Science.gov (United States)

    Pless, G; Sauer, I M

    2005-11-01

    Liver failure remains a life-threatening syndrome. With the growing disparity between the number of suitable donor organs and the number of patients awaiting transplantation, efforts have been made to optimize the allocation of organs, to find alternatives to cadaveric liver transplantation, and to develop extracorporeal methods to support or replace the function of the failing organ. An extracorporeal liver support system has to provide the main functions of the liver: detoxification, synthesis, and regulation. The understanding that the critical issue of the clinical syndrome in liver failure is the accumulation of toxins not cleared by the failing liver led to the development of artificial filtration and adsorption devices (artificial liver support). Based on this hypothesis, the removal of lipophilic, albumin-bound substances, such as bilirubin, bile acids, metabolites of aromatic amino acids, medium-chain fatty acids, and cytokines, should be beneficial to the clinical course of a patient in liver failure. Artificial detoxification devices currently under clinical evaluation include the Molecular Adsorbent Recirculating System (MARS), Single-Pass Albumin Dialysis (SPAD), and the Prometheus system. The complex tasks of regulation and synthesis remain to be addressed by the use of liver cells (bioartificial liver support). The Extracorporeal Liver Assist Device (ELAD), HepatAssist, Modular Extracorporeal Liver Support system (MELS), and the Amsterdam Medical Center Bioartificial Liver (AMC-BAL) are bioartificial systems. This article gives a brief overview on these artificial and bioartificial devices and discusses remaining obstacles.

  16. Osteomyelitis: a current challenge

    Directory of Open Access Journals (Sweden)

    Luciana Souza Jorge

    2010-06-01

    Full Text Available Over the last 30 years, the pathogenesis of osteomyelitis has almost been totally elucidated, and many factors responsible for the persistence of this infection have been identified. Numerous antimicrobial agents with distinct spectrums of action, pharmacokinetics, and pharmacodynamics have been used in its treatment. Surgical techniques, including muscle grafts, the Ilizarov technique, and antibiotic bone cements, have been applied. However, bone infections are still a challenge. Despite the importance of isolation and identification of microorganisms to determine the antimicrobial treatment of bone infections, there are few systematic national studies about the etiological profile of these diseases. This article describes the current knowledge of osteomyelitis and summarizes published national data based on the experience of different Orthopedic and Traumatology Services. In general, S. aureus was described as an important etiological agent; however, the difference in design of national studies makes a comparison between the prevalence of bone infection, the associated risk factors, and the different therapeutic approaches difficult. In conclusion, effort is necessary in order to stimulate systematic national studies in different Orthopedics and Traumatology Services to obtain a better consensus on preventive measures and therapies of bone infections.

  17. Sustainable winegrowing: current perspectives

    Directory of Open Access Journals (Sweden)

    Mariani A

    2015-05-01

    Full Text Available Angela Mariani,1 Antonella Vastola2 1Department of Economic and Legal Studies, University Parthenope, Naples, 2School of Agricultural, Forestry, Food and Environmental Sciences, University of Basilicata, Potenza, Italy Abstract: The winegrowing sector worldwide is strongly committed to improving environmental and social sustainability. The aim of this work, based on a literature review, is to highlight current sustainability perspectives and the related main issues. There is a broad consensus that the challenge to achieve a greater spread of sustainable practices is to enhance environmental and social sustainability while maintaining economic viability. From the producers' point of view, the priority is to bridge the still substantial knowledge gaps in terms of perceived environmental benefits, economic benefits, and costs. Thus, an increased research effort focusing on the costs and benefits of different winegrowing practices and technical assistance with implementation might support their diffusion. Moreover, targeted marketing strategies are needed to: enhance consumers' involvement and their attitude toward sustainable wine; improve understanding and use of sustainable labels and claims; and raise awareness of some environmental credentials of wine packaging, mainly with reference to lightweight glass bottles. Keywords: winegrower, sustainability, wine, consumer, marketing strategies

  18. Current ADC Linker Chemistry.

    Science.gov (United States)

    Jain, Nareshkumar; Smith, Sean W; Ghone, Sanjeevani; Tomczuk, Bruce

    2015-11-01

    The list of ADCs in the clinic continues to grow, bolstered by the success of first two marketed ADCs: ADCETRIS® and Kadcyla®. Currently, there are 40 ADCs in various phases of clinical development. However, only 34 of these have published their structures. Of the 34 disclosed structures, 24 of them use a linkage to the thiol of cysteines on the monoclonal antibody. The remaining 10 candidates utilize chemistry to surface lysines of the antibody. Due to the inherent heterogeneity of conjugation to the multiple lysines or cysteines found in mAbs, significant research efforts are now being directed toward the production of discrete, homogeneous ADC products, via site-specific conjugation. These site-specific conjugations may involve genetic engineering of the mAb to introduce discrete, available cysteines or non-natural amino acids with an orthogonally-reactive functional group handle such as an aldehyde, ketone, azido, or alkynyl tag. These site-specific approaches not only increase the homogeneity of ADCs but also enable novel bio-orthogonal chemistries that utilize reactive moieties other than thiol or amine. This broadens the diversity of linkers that can be utilized which will lead to better linker design in future generations of ADCs.

  19. Renal autotransplantation: current perspectives.

    Science.gov (United States)

    Stewart, B H; Banowsky, L H; Hewitt, C B; Straffon, R A

    1976-01-01

    Autotransplantation, with or without an extracorporeal renal operation, has been done 39 times in 37 patients. Indications for the procedure included severe ureteral injury in 4 patients, failed supravesical diversion in 2, renal carcinoma in a solitary kidney in 1, renovascular hypertension in 1 and donor arterial reconstruction before renal transplantation in 29. Success was obtained in all but 2 procedures, both of which involved previously operated kidneys with severe inflammation and adhesions involving the renal pelvis and pedicle. Based on our experience and a review of currently available literature we believe that renal autotransplantation and extracorporeal reconstruction can provide the best solution for patients with severe renovascular and ureteral disease not correctable by conventional operative techniques. The technique can be of particular value in removing centrally located tumors in solitary kidneys and in preparing donor kidneys with abnormal arteries for renal transplantation. The role of autotransplantation in the management of advanced renal trauma and calculus disease is less clear. A long-term comparison of patients treated by extracorporeal nephrolithotomy versus conventional lithotomy techniques will be necessary before a conclusion is reached in these disease categories.

  20. [Current management of epilepsy].

    Science.gov (United States)

    Mizobuchi, Masahiro

    2013-09-01

    Epilepsy is one of the most common neurological disorders. Global neurological knowledge is essential for differential diagnosis of epileptic syndromes due to the diversity of ictal semiology, causes and syndromes. Neurologists play an important role in planning the medical care for patients with epilepsy, as medication is the most fundamental therapeutic strategy. Some patients with early-onset epilepsy require joint care by pediatric neurologists, those with intractable epilepsy by neurosurgeons, and those with psychological comorbidity by psychiatrists, and neurologists should play a coordinating role. While there is a great need for neurologists to participate in epilepsy care, neurologists in Japan currently do not participate substantially in the epilepsy management system. It is necessary to train more neurologists who can provide epilepsy care and conduct basic and clinical research on epilepsy by providing continuous education on epilepsy for general neurologists as well as pre- and post-graduate medical students. Most of the patients who require long-term treatment experience many medical problems and social handicaps, such as adverse effects of medication, social stigma, educational disadvantages and difficulties in obtaining driver's license. To improve the quality of life of patients with epilepsy, it is desirable to build broad medical-social networks participated by patients, doctors, neurological nurses, psychologists, social workers, school teachers, managers of employment support facilities and care givers.

  1. [Current management of epilepsy].

    Science.gov (United States)

    Mizobuchi, Masahiro

    2013-09-01

    Epilepsy is one of the most common neurological disorders. Global neurological knowledge is essential for differential diagnosis of epileptic syndromes due to the diversity of ictal semiology, causes and syndromes. Neurologists play an important role in planning the medical care for patients with epilepsy, as medication is the most fundamental therapeutic strategy. Some patients with early-onset epilepsy require joint care by pediatric neurologists, those with intractable epilepsy by neurosurgeons, and those with psychological comorbidity by psychiatrists, and neurologists should play a coordinating role. While there is a great need for neurologists to participate in epilepsy care, neurologists in Japan currently do not participate substantially in the epilepsy management system. It is necessary to train more neurologists who can provide epilepsy care and conduct basic and clinical research on epilepsy by providing continuous education on epilepsy for general neurologists as well as pre- and post-graduate medical students. Most of the patients who require long-term treatment experience many medical problems and social handicaps, such as adverse effects of medication, social stigma, educational disadvantages and difficulties in obtaining driver's license. To improve the quality of life of patients with epilepsy, it is desirable to build broad medical-social networks participated by patients, doctors, neurological nurses, psychologists, social workers, school teachers, managers of employment support facilities and care givers. PMID:24018740

  2. ALMA Pipeline: Current Status

    Science.gov (United States)

    Shinnaga, H.; Humphreys, E.; Indebetouw, R.; Villard, E.; Kern, J.; Davis, L.; Miura, R. E.; Nakazato, T.; Sugimoto, K.; Kosugi, G.; Akiyama, E.; Muders, D.; Wyrowski, F.; Williams, S.; Lightfoot, J.; Kent, B.; Momjian, E.; Hunter, T.; ALMA Pipeline Team

    2015-12-01

    The ALMA Pipeline is the automated data reduction tool that runs on ALMA data. Current version of the ALMA pipeline produces science quality data products for standard interferometric observing modes up to calibration process. The ALMA Pipeline is comprised of (1) heuristics in the form of Python scripts that select the best processing parameters, and (2) contexts that are given for book-keeping purpose of data processes. The ALMA Pipeline produces a "weblog" that showcases detailed plots for users to judge how each step of calibration processes are treated. The ALMA Interferometric Pipeline was conditionally accepted in March 2014 by processing Cycle 0 and Cycle 1 data sets. From Cycle 2, ALMA Pipeline is used for ALMA data reduction and quality assurance for the projects whose observing modes are supported by the ALMA Pipeline. Pipeline tasks are available based on CASA version 4.2.2, and the first public pipeline release called CASA 4.2.2-pipe has been available since October 2014. One can reduce ALMA data both by CASA tasks as well as by pipeline tasks by using CASA version 4.2.2-pipe.

  3. Non-inductive current probe

    DEFF Research Database (Denmark)

    Bak, Christen Kjeldahl

    1977-01-01

    The current probe described is a low-cost, shunt resistor for monitoring current pulses in e.g., pulsed lasers. Rise time is......The current probe described is a low-cost, shunt resistor for monitoring current pulses in e.g., pulsed lasers. Rise time is...

  4. Theme: Staying Current--Horticulture.

    Science.gov (United States)

    Shry, Carroll L., Jr.; And Others

    1986-01-01

    This theme issue on staying current in horticulture includes articles on sex equity in horticulture, Future Farmers of America, career opportunities in horticulture, staying current with your school district's needs, staying current in horticulture instruction, staying current with landscape trade associations, emphasizing the basics in vocational…

  5. Muscle dysmorphia: current insights

    Directory of Open Access Journals (Sweden)

    Tod D

    2016-08-01

    than currently exists. Future work will help clinicians assist a group of people whose quality of life and health are placed at risk by their muscular preoccupation. Keywords: psychopathology, mental health, body image, self-perceptions 

  6. Muscle dysmorphia: current insights.

    Science.gov (United States)

    Tod, David; Edwards, Christian; Cranswick, Ieuan

    2016-01-01

    Since 1997, there has been increasing research focusing on muscle dysmorphia, a condition underpinned by people's beliefs that they have insufficient muscularity, in both the Western and non-Western medical and scientific communities. Much of this empirical interest has surveyed nonclinical samples, and there is limited understanding of people with the condition beyond knowledge about their characteristics. Much of the existing knowledge about people with the condition is unsurprising and inherent in the definition of the disorder, such as dissatisfaction with muscularity and adherence to muscle-building activities. Only recently have investigators started to explore questions beyond these limited tautological findings that may give rise to substantial knowledge advances, such as the examination of masculine and feminine norms. There is limited understanding of additional topics such as etiology, prevalence, nosology, prognosis, and treatment. Further, the evidence is largely based on a small number of unstandardized case reports and descriptive studies (involving small samples), which are largely confined to Western (North American, British, and Australian) males. Although much research has been undertaken since the term "muscle dysmorphia" entered the psychiatric lexicon in 1997, there remains tremendous scope for knowledge advancement. A primary task in the short term is for investigators to examine the extent to which the condition exists among well-defined populations to help determine the justification for research funding relative to other public health issues. A greater variety of research questions and designs may contribute to a broader and more robust knowledge base than currently exists. Future work will help clinicians assist a group of people whose quality of life and health are placed at risk by their muscular preoccupation.

  7. Lead toxicity: Current concerns

    Energy Technology Data Exchange (ETDEWEB)

    Goyer, R.A. (Univ. of Western Ontario, London (Canada))

    1993-04-01

    Over the 20-year period since the first issue of Environmental Health Perspectives was published, there has been considerable progress in the understanding of the potential toxicity of exposure to lead. Many of these advances have been reviewed in published symposia, conferences, and review papers in EHP. This brief review identifies major advances as well as a number of current concerns that present opportunities for prevention and intervention strategies. The major scientific advance has been the demonstration that blood lead (PbB) levels of 10-15 micrograms/dL in newborn and very young infants result in cognitive and behavioral deficits. Further support for this observation is being obtained by prospective or longitudinal studies presently in progress. The mechanism(s) for the central nervous system effects of lead is unclear but involve lead interactions within calcium-mediated intracellular messenger systems and neurotransmission. Effects of low-level lead exposure on blood pressure, particularly in adult men, may be related to the effect of lead on calcium-mediated control of vascular smooth muscle contraction and on the renin-angiotensin system. Reproductive effects of lead have long been suspected, but low-level effects have not been well studied. Whether lead is a carcinogen or its association with renal adenocarcinoma is a consequence of cystic nephropathy is uncertain. Major risk factors for lead toxicity in children in the United States include nutrition, particularly deficiencies of essential metals, calcium, iron, and zinc, and housing and socioeconomic status. A goal for the year 2000 is to reduce prevalence of blood lead levels exceeding 15 micrograms/dL. 97 refs.

  8. Fahr's disease: current perspectives

    Directory of Open Access Journals (Sweden)

    Tai XY

    2015-07-01

    Full Text Available Xin You Tai, Amit BatlaUCL Institute of Neurology, Queen Square, London, UKAbstract: Based on original descriptions of brain calcification by Theodor Fahr, brain calcification, and more specifically basal ganglia calcification, is referred to as Fahr's syndrome. Recent identification of genetic mutations has concerted the description of this erstwhile heterogeneous condition which we refer to here as Fahr's disease. Fahr's disease refers to idiopathic calcification of the basal ganglia without a secondary (non-genetic cause. Idiopathic basal ganglia calcification (IBGC is another term, which offers a more accurate description of this condition. Within the last 2 years, genetic mutations for IBGC have been described in SLC20A2, PDGFB, and PDGFRB. These findings broaden our understanding of the pathophysiology and encourage a search for specific treatment options in this rare but disabling condition. Clinically, parkinsonism, dystonia, and other movement disorders are the most common clinical features, but psychiatric features can predominate. Cases with confirmed genetic mutations reveal new clinical features linked with Fahr's disease, such as headaches. Computed tomography or magnetic resonance imaging is usually the trigger for suspecting Fahr's disease and important for identifying the calcification pattern. Symmetric calcification of the globus pallidus, thalamus, and dentate nucleus is the most common pattern in IBGC, but other parts of the brain such as the cerebellum are involved. Treatment of Fahr's disease is currently limited and is largely symptomatic. A better understanding of this condition in light of genetic findings is important to improve the clinical diagnosis and develop specific treatment options.Keywords: Fahr's disease, basal ganglia calcification, parkinsonism, calcium

  9. Magnesium Diboride Current Leads

    Science.gov (United States)

    Panek, John

    2010-01-01

    A recently discovered superconductor, magnesium diboride (MgB2), can be used to fabricate conducting leads used in cryogenic applications. Dis covered to be superconducting in 2001, MgB2 has the advantage of remaining superconducting at higher temperatures than the previously used material, NbTi. The purpose of these leads is to provide 2 A of electricity to motors located in a 1.3 K environment. The providing environment is a relatively warm 17 K. Requirements for these leads are to survive temperature fluctuations in the 5 K and 11 K heat sinks, and not conduct excessive heat into the 1.3 K environment. Test data showed that each lead in the assembly could conduct 5 A at 4 K, which, when scaled to 17 K, still provided more than the required 2 A. The lead assembly consists of 12 steelclad MgB2 wires, a tensioned Kevlar support, a thermal heat sink interface at 4 K, and base plates. The wires are soldered to heavy copper leads at the 17 K end, and to thin copper-clad NbTi leads at the 1.3 K end. The leads were designed, fabricated, and tested at the Forschungszentrum Karlsruhe - Institut foer Technische Physik before inclusion in Goddard's XRS (X-Ray Spectrometer) instrument onboard the Astro-E2 spacecraft. A key factor is that MgB2 remains superconducting up to 30 K, which means that it does not introduce joule heating as a resistive wire would. Because the required temperature ranges are 1.3-17 K, this provides a large margin of safety. Previous designs lost superconductivity at around 8 K. The disadvantage to MgB2 is that it is a brittle ceramic, and making thin wires from it is challenging. The solution was to encase the leads in thin steel tubes for strength. Previous designs were so brittle as to risk instrument survival. MgB2 leads can be used in any cryogenic application where small currents need to be conducted at below 30 K. Because previous designs would superconduct only at up to 8 K, this new design would be ideal for the 8-30 K range.

  10. Experimental observation of neoclassical currents

    International Nuclear Information System (INIS)

    The parallel and perpendicular equilibrium currents have been experimentally studied in the Levitated Octupole, with toroidal field. Observations of the spatial structure, collisionality and toroidal field dependence of the complete current and the ion portion of the current are presented. Experimentally measured currents are compared to neoclassical current distributions calculated for the actual machine geometry. Measurements of the total plasma parallel current for absolute-MHD-stable flux surfaces (inside the separatrix) agree well with theory, showing the bootstrap and Pfirsch-Schlueter currents as predicted by neoclassical transport theory. On average-MHD-stable flux surfaces (outside the separatrix) there is more parallel current than predicted by theory, though the spatial structure is correct. Separate measurements of the ion parallel and perpendicular currents agree with theory, showing the lack of measurable ion poloidal rotation in all situations

  11. Charm current-current correlators in twisted mass lattice QCD

    International Nuclear Information System (INIS)

    The current correlator method has been shown to be a practical tool to extract the charm quark mass and strong coupling constant from Lattice QCD data as an alternative to the sum rule approach using experimental electron-positron annihilation cross section data. We report on the progress of an investigation of charm current-current correlators in Nf=2 Twisted Mass Lattice QCD. Upon determining the temporal moments of the current correlators we compare to the low-energy expansion of the moments in perturbative QCD and calculate the charm quark mass and strong coupling constant and in case of the vector current correlator directly compare both methods. (orig.)

  12. Steering Multiple Reverse Current into Unidirectional Current in Deterministic Ratchets

    Institute of Scientific and Technical Information of China (English)

    韦笃取; 罗晓曙; 覃英华

    2011-01-01

    Recent investigations have shown that with varying the amplitude of the external force, the deterministic ratchets exhibit multiple current reversals, which are undesirable in certain circumstances. To control the multiple reverse current to unidirectional current, an adaptive control law is presented inspired from the relation between multiple reversaJs current and the chaos-periodic/quasiperiodic transition of the transport velocity. The designed controller can stabilize the transport velocity of ratchets to steady state and suppress any chaos-periodic/quasiperiodic transition, namely, the stable transport in ratchets is achieved, which makes the current sign unchanged.

  13. Representations of twisted current algebras

    OpenAIRE

    Lau, Michael

    2013-01-01

    We use evaluation representations to give a complete classification of the finite-dimensional simple modules of twisted current algebras. This generalizes and unifies recent work on multiloop algebras, current algebras, equivariant map algebras, and twisted forms.

  14. Drug Establishments Current Registration Site

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Drug Establishments Current Registration Site (DECRS) is a database of current information submitted by drug firms to register establishments (facilities) which...

  15. Exchange currents in nuclear physics

    International Nuclear Information System (INIS)

    Starting from Adler's low-energy theorem for the soft pion production amplitudes the predictions of the meson exchange currents theory for the nuclear physics are discussed. The results are reformulated in terms of phenomenological lagrangians. This method allows one to pass naturally to the more realistic case of hard mesons. The predictions are critically compared with the existing experimental data. The main processes in which vector isovector exchange currents, vector isoscalar exchange currents and axial exchange currents take place are pointed out

  16. Active inrush-current limiter

    Science.gov (United States)

    Kichak, R. A.

    1977-01-01

    By stretching turn-on time from approximately 1 to 200 ms, effects of inrush current (and of associated large current spikes) and current rate of rise (dl/dt) are made potentially less severe. Limiter arrangement consists of time-variable impedance connected in series between input dc power source return and power circuit of converter.

  17. Mathematical Modelling of Turbidity Currents

    Science.gov (United States)

    Fay, G. L.; Fowler, A.; Howell, P.

    2011-12-01

    A turbidity current is a submarine sediment flow which propagates downslope through the ocean into the deep sea. Turbidity currents can occur randomly and without much warning and consequently are hard to observe and measure. The driving force in a turbidity current is the presence of sediment in the current - gravity acts on the sediment in suspension, causing it to move downstream through the ocean water. A phenomenon known as ignition or autosuspension has been observed in turbidity currents in submarine canyons, and it occurs when a current travelling downslope gathers speed as it erodes sediment from the sea floor in a self-reinforcing cycle. Using the turbidity current model of Parker et al. (Journal of Fluid Mechanics, 1986) we investigate the evolution of a 1-D turbidity current as it moves downstream. To seek a better understanding of the dynamics of flow as the current evolves in space and time, we present analytical results alongside computed numerical solutions, incorporating entrainment of water and erosion and deposition of sediment. We consider varying slope functions and inlet conditions and attempt to predict when the current will become extinct. We examine currents which are in both supercritical and subcritical flow regimes and consider the dynamics of the flow as the current switches regime.

  18. Flow tracing based on current

    Institute of Scientific and Technical Information of China (English)

    蔡兴国; 曹海龙

    2001-01-01

    Analyses the flow tracing based on power flow, points out that the detachment of reactive power and active power is unrealiable and concludes that the current is the real basic of flow tracing,and proposes the new flow tracing model based on current, which devides the current into active current and reactive current, analyses the theory about the matrix to deal with the precision and realization of the flow tracing, and then proposes a new pricing model by fixed rate and marginal rate, which keeps not only economy information such as congestion cost in marginal cost based pricing, but also benefits to make both ends meet.

  19. HLS bunch current measurement system

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Bunch current is an important parameter for studying the injection fill-pattern in the storage ring and the instability threshold of the bunch, and the bunch current monitor also is an indispensable tool for the top-up injection. A bunch current measurement (BCM) system has been developed to meet the needs of the upgrade project of Hefei Light Source (HLS). This paper presents the layout of the BCM system. The system based on a high-speed digital oscilloscope can be used to measure the bunch current and synchronous phase shift. To obtain the absolute value of bunch-by-bunch current, the calibration coefficient is measured and analyzed. Error analysis shows that the RMS of bunch current is less than 0.01 mA when bunch current is about 5 mA, which can meet project requirement.

  20. TOKAMAK EQUILIBRIA WITH CENTRAL CURRENT HOLES AND NEGATIVE CURRENT DRIVE

    Energy Technology Data Exchange (ETDEWEB)

    CHU, M.S.; PARKS, P.B.

    2002-06-01

    OAK B202 TOKAMAK EQUILIBRIA WITH CENTRAL CURRENT HOLES AND NEGATIVE CURRENT DRIVE. Several tokamak experiments have reported the development of a central region with vanishing currents (the current hole). Straightforward application of results from the work of Greene, Johnson and Weimer [Phys. Fluids, 3, 67 (1971)] on tokamak equilibrium to these plasmas leads to apparent singularities in several physical quantities including the Shafranov shift and casts doubts on the existence of this type of equilibria. In this paper, the above quoted equilibrium theory is re-examined and extended to include equilibria with a current hole. It is shown that singularities can be circumvented and that equilibria with a central current hole do satisfy the magnetohydrodynamic equilibrium condition with regular behavior for all the physical quantities and do not lead to infinitely large Shafranov shifts. Isolated equilibria with negative current in the central region could exist. But equilibria with negative currents in general do not have neighboring equilibria and thus cannot have experimental realization, i.e. no negative currents can be driven in the central region.

  1. Ionization tube simmer current circuit

    Science.gov (United States)

    Steinkraus, Jr., Robert F.

    1994-01-01

    A highly efficient flash lamp simmer current circuit utilizes a fifty percent duty cycle square wave pulse generator to pass a current over a current limiting inductor to a full wave rectifier. The DC output of the rectifier is then passed over a voltage smoothing capacitor through a reverse current blocking diode to a flash lamp tube to sustain ionization in the tube between discharges via a small simmer current. An alternate embodiment of the circuit combines the pulse generator and inductor in the form of an FET off line square wave generator with an impedance limited step up output transformer which is then applied to the full wave rectifier as before to yield a similar simmer current.

  2. Buoyancy driven rotating boundary currents

    CERN Document Server

    Yecko, P A

    1997-01-01

    The structure of boundary currents formed from intermediately dense water introduced into a rotating, stably stratified, two-layer environment is investigated in a series of laboratory experiments, performed for Froude numbers ranging from 0.01 to 1. The thickness and streamwise velocity profiles in quasi-steady currents are measured using a pH activated tracer (thymol blue) and found to compare favorably to simplified analytic solutions and numerical models. Currents flowing along sloping boundaries in a stratified background exhibit robust stability at all experimental Froude numbers. Such stability is in sharp contrast to the unequivocal instability of such currents flowing against vertical boundaries, or of currents flowing along slopes in a uniform background. The presence of a variety of wave mechanisms in the ambient medium might account for the slower and wider observed structures and the stability of the currents, by effecting the damping of disturbances through wave radiation.

  3. Current Research Information in Europe

    OpenAIRE

    van Dijk, A.; GreyNet, Grey Literature Network Service

    1994-01-01

    Current Research Information is defined here as descriptive information on ongoing scientific research (who, what, where). When a research project has started, the outside world can generally find information about it in Current Research information sources, then in the GL and towards the end of the project in the white literature. Compared to bibliographic databases, Current Research databases are searched by only a limited group of users. To enhance usage of this type of information, two po...

  4. Noninductive current drive in tokamaks

    International Nuclear Information System (INIS)

    Various current drive mechanisms may be grouped into four classes: (1) injection of energetic particle beams; (2) launching of rf waves; (3) hybrid schemes, which are combinations of various rf schemes (rf plus beams, rf and/or beam plus ohmic heating, etc.); and (4) other schemes, some of which are specific to reactor plasma conditions requiring the presence of alpha particle or intense synchrotron radiation. Particle injection schemes include current drive by neutral beams and relativistic electron beams. The rf schemes include current drive by the lower hybrid (LH) waves, the electron waves, the waves in the ion cyclotron range of frequencies, etc. Only a few of these approaches, however, have been tested experimentally, with the broadest data base available for LH waves. Included in this report are (1) efficiency criteria for current drive, (2) current drive by neutral beam injection, (3) LH current drive, (4) electron cyclotron current drive, (5) current drive by ion cyclotron waves - minority species heating, and (6) current drive by other schemes (such as hybrids and low frequency waves)

  5. Electron Locking in Current Drive

    Science.gov (United States)

    McCollam, K. J.; Jarboe, T. R.; Nelson, B. A.; Orvis, D. J.; Raman, R.; Redd, A. J.; Smith, R. J.; Nagata, M.; Uyama, T.

    2000-10-01

    The traveling n=1, m~= q_edge magnetic distortion observed in the Helicity Injected Torus (HIT-II) during coaxial helicity injection (CHI) is responsible for some current profile relaxation. A model for electromotive current drive, called the electron locking model, can account for the results of current drive experiments in both the HIT-II and the original HIT devices. The most relevant of these results involve the the frequencies and directions of the mode itself, the E× B drift, and the electric current drift. In spherical tokamaks with CHI, electrode and coil polarities can be changed to control the relative directions of these drifts. Results from HIT-II experiments with different polarities are shown. These point out the character n=1, m~= q_edge mode, and suggest its role in CHI current drive. The electron locking model is presented, and is also discussed in the context of mean field electrodynamics. This model might also be applied to other types of current drive, such as rotating magnetic field (RMF) current drive, oscillating field current drive (OFCD), steady inductive helicity injection (SIHI), or Ohmic current drive in a reversed field pinch (RFP). These examples are discussed.

  6. DC-Compensated Current Transformer.

    Science.gov (United States)

    Ripka, Pavel; Draxler, Karel; Styblíková, Renata

    2016-01-01

    Instrument current transformers (CTs) measure AC currents. The DC component in the measured current can saturate the transformer and cause gross error. We use fluxgate detection and digital feedback compensation of the DC flux to suppress the overall error to 0.15%. This concept can be used not only for high-end CTs with a nanocrystalline core, but it also works for low-cost CTs with FeSi cores. The method described here allows simultaneous measurements of the DC current component. PMID:26805830

  7. Nuclear Current and Magnetic Rotation

    Institute of Scientific and Technical Information of China (English)

    PENG Jing; XING Li-Feng

    2009-01-01

    The magnetic rotational bands based on the configuration πh211/2 ⊕Vh-211/2 in 142 Gd are investigated with the newly developed tilted axis cranking relativistic mean field (RMF) theory with and without nuclear current.The effect of the nuclear current is discussed by comparing the total Routhians,single particle levels,electromagnetic transition probabilities B(M1) and B(E2) in self-consistent tilted axis cranking RMF calculation with those obtained without the nuclear current.The nuclear currents are found to play an important role in the magnetic rotation of nuclei.

  8. DC-Compensated Current Transformer.

    Science.gov (United States)

    Ripka, Pavel; Draxler, Karel; Styblíková, Renata

    2016-01-20

    Instrument current transformers (CTs) measure AC currents. The DC component in the measured current can saturate the transformer and cause gross error. We use fluxgate detection and digital feedback compensation of the DC flux to suppress the overall error to 0.15%. This concept can be used not only for high-end CTs with a nanocrystalline core, but it also works for low-cost CTs with FeSi cores. The method described here allows simultaneous measurements of the DC current component.

  9. Anomalous-viscosity current drive

    Science.gov (United States)

    Stix, T.H.; Ono, M.

    1986-04-25

    The present invention relates to a method and apparatus for maintaining a steady-state current for magnetically confining the plasma in a toroidal magnetic confinement device using anomalous viscosity current drive. A second aspect of this invention relates to an apparatus and method for the start-up of a magnetically confined toroidal plasma.

  10. Electronic measurements of ionization currents

    Energy Technology Data Exchange (ETDEWEB)

    Hutyra, F.; Knapp, K.; Gregor, J. (Tesla, Premysleni (Czechoslovakia). Vyzkumny Ustav Pristroju Jaderne Techniky)

    1982-02-01

    Measurements are discussed of very low currents from ionization chambers. The currents range between 10/sup -15/ and 10/sup -9/ A. Two methods are discussed. A description is given of a dynamic and a semiconductor electrometers. Both meters are parts of dosimetric instruments for monitoring the dose rate (NB 9201) and the neutron-gamma mixed radiation dose rate (NDK 601).

  11. Multispacecraft current estimates at swarm

    DEFF Research Database (Denmark)

    Dunlop, M. W.; Yang, Y.-Y.; Yang, J.-Y.;

    2015-01-01

    orbit the use oftime-shifted positions allow stable estimates of current density to be made and can verify temporal effects aswell as validating the interpretation of the current components as arising predominantly from field-alignedcurrents. In the case of four-spacecraft configurations we can resolve...

  12. Investigation of Current Driven Loudspeakers

    DEFF Research Database (Denmark)

    Schneider, Henrik; Agerkvist, Finn T.; Knott, Arnold;

    2015-01-01

    and current drive. A multi tone test signal is used in the evaluation of the driving schemes since it resembles audio signals to a higher degree than the signals used in total harmonic distortion and intermodulation distortion test methods. It is found that current drive is superior over voltage drive in a 5...

  13. Eddy current manual, volume 2

    International Nuclear Information System (INIS)

    This report on eddy current testing is divided into three sections: (a) Demonstration of Basic Principles, (b) Practical (Laboratory) Tests and, (c) Typical Certification Questions. It is intended to be used as a supplement to ΣEddy Current Manual, Volume 1Σ (AECL-7523) during CSNDT Foundation Level II and III courses

  14. Current in wave driven plasmas

    Energy Technology Data Exchange (ETDEWEB)

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

    1985-06-01

    A theory for the generation of current in a toroidal plasma by radio-frequency waves is presented. The effect of an opposing electric field is included, allowing the case of time varying currents to be studied. The key quantities that characterize this regime are identified and numerically calculated. Circuit equations suitable for use in ray-tracing and transport codes are given.

  15. Magnetic Materials for Current Transformers

    CERN Document Server

    Aguilera, S; Ruffieux, P

    2013-01-01

    At CERN, the circulating beam current measurement is provided by two types of transformers, the Direct Current Current Transformers (DCCT) and the Fast Beam Current Transformers (FBCT). Each type of transformer requires different magnetic characteristics regarding parameters such as permeability, coercivity and shape of the magnetization curve. Each transformer is built based on toroidal cores of a magnetic material which gives these characteristics. For example, DCCTs consist of three cores, two for the measurement of the DC component and one for the AC component. In order to study the effect of changes in these parameters on the current transformers, several interesting raw materials based on their as-cast properties were selected with the annealing process used to tune their properties for the individual needs of each transformer. First annealing tests show that the magnetization curve, and therefore the permeability, of the material can be modified, opening the possibility for building and studying a vari...

  16. The influence of convective current generator on the global current

    Directory of Open Access Journals (Sweden)

    V. N. Morozov

    2006-01-01

    Full Text Available The mathematical generalization of classical model of the global circuit with taking into account the convective current generator, working in the planetary boundary layer was considered. Convective current generator may be interpreted as generator, in which the electromotive force is generated by processes, of the turbulent transport of electrical charge. It is shown that the average potential of ionosphere is defined not only by the thunderstorm current generators, working at the present moment, but by the convective current generator also. The influence of the convective processes in the boundary layer on the electrical parameters of the atmosphere is not only local, but has global character as well. The numerical estimations, made for the case of the convective-unstable boundary layer demonstrate that the increase of the average potential of ionosphere may be of the order of 10% to 40%.

  17. Charm current-current correlators in twisted mass lattice QCD

    International Nuclear Information System (INIS)

    The charm quark mass and the strong coupling constant are two of the fundamental parameters of the Standard Model and the precision of their determination has been continuously enhanced by higher order perturbative QCD calculations combined with more precise experimental data from e+-e-scattering as well as non-perturbative lattice calculations. As opposed to using experimental data to include non-perturbative effects, lattice QCD is not confined to the vector current correlator alone but additionally allows for an extension to the axial vector, scalar and pseudoscalar current correlators giving rise to a larger number of operators to extract the desired parameters from. We study the moments of the diverse charm current-current correlators in the framework of twisted mass lattice QCD with two light dynamical quarks. By matching lattice QCD results to continuum perturbation theory the strong coupling constant and the charm quark mass are extracted and compared to QCD sum rule and previous lattice calculations.

  18. Relationships between Geomagnetic Induced Currents and Field Aligned Currents

    Science.gov (United States)

    Waters, C. L.; Barnett, R.; Anderson, B. J.; Gjerloev, J. W.; Korth, H.; Barnes, R. J.

    2015-12-01

    Geomagnetic Induced Currents (GICs) appear in the ground due to time varying magnetic fields that occur during periods of enhanced geomagnetic activity. The resultant time varying electric fields at Earth's surface drive very low frequency, currents through electricity supply transformers which reduces transforming capacity. In extreme cases, electricity supply grids can collapse as multiple transformers are affected. GICs have larger magnitudes at auroral latitudes and should be related to the field aligned current (FAC) and auroral ionosphere currents systems. At ground locations under the regions between upward and downward FACs, the GIC related fields show a direct relationship with the time derivative of the FACs. This allows a conversion factor between FAC and GIC magnitudes. Examples of the relationship between FAC and GIC related fields are presented using data derived from the Active Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE) and SuperMAG.

  19. Current in open quantum systems.

    Science.gov (United States)

    Gebauer, Ralph; Car, Roberto

    2004-10-15

    We show that a dissipative current component is present in the dynamics generated by a Liouville-master equation, in addition to the usual component associated with Hamiltonian evolution. The dissipative component originates from coarse graining in time, implicit in a master equation, and needs to be included to preserve current continuity. We derive an explicit expression for the dissipative current in the context of the Markov approximation. Finally, we illustrate our approach with a simple numerical example, in which a quantum particle is coupled to a harmonic phonon bath and dissipation is described by the Pauli master equation. PMID:15524960

  20. Record current in the LHC

    CERN Multimedia

    On 19 December, just before CERN's end-of-year break, Sector 4-5, which had been cooled to 1.9 K, beat the LHC current record for 2007. The current was raised to 8500 amperes in the main magnets. The current of the dipole circuit was repeatedly ramped up and quenches were provoked. The magnets were maintained at 4.5 K over the holiday period so that they could be quickly brought back down to the nominal temperature after the shutdown. The testing of the sector has now resumed.

  1. FEMA Current Disaster Declarations -shp

    Data.gov (United States)

    Department of Homeland Security — This dataset lists the current Disaster Declarations in Shapefile. This data was compiled and distributed by FEMA Mapping and Analysis Center (MAC). Metadata file...

  2. Acoustoelectric current for composite fermions

    Science.gov (United States)

    Bergli, J.; Galperin, Y. M.

    2001-07-01

    The acoustoelectric current for composite fermions in a two-dimensional electron gas (2DEG) close to the half-filled Landau level is calculated in the random phase approximation. The Boltzmann equation is used to find the nonequilibrium distribution of composite fermions to second order in the acoustic field. It is shown that the oscillating Chern-Simons field created by the induced density fluctuations in the 2DEG is important for the acoustoelectric current. This leads to a violation of the Weinreich relation between the acoustoelectric current and acoustic intensity. The deviations from the Weinreich relation can be detected by measuring the angle between the longitudinal and the Hall components of the acoustoelectric current. This departure from the Weinreich relation gives additional information on the properties of the composite fermion fluid.

  3. High current gain transistor laser

    Science.gov (United States)

    Liang, Song; Qiao, Lijun; Zhu, Hongliang; Wang, Wei

    2016-06-01

    A transistor laser (TL), having the structure of a transistor with multi-quantum wells near its base region, bridges the functionality gap between lasers and transistors. However, light emission is produced at the expense of current gain for all the TLs reported up to now, leading to a very low current gain. We propose a novel design of TLs, which have an n-doped InP layer inserted in the emitter ridge. Numerical studies show that a current flow aperture for only holes can be formed in the center of the emitter ridge. As a result, the common emitter current gain can be as large as 143.3, which is over 15 times larger than that of a TL without the aperture. Besides, the effects of nonradiative recombination defects can be reduced greatly because the flow of holes is confined in the center region of the emitter ridge.

  4. NOAA NOS SOS, EXPERIMENTAL - Currents

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA NOS SOS server is part of the IOOS DIF SOS Project. The stations in this dataset have currents data. *These services are for testing and evaluation use...

  5. Electric current abroad, 1991 edition

    Science.gov (United States)

    1991-07-01

    The characteristics are listed, for the information of U.S. manufacturers and exporters and individuals living or traveling abroad, of electric current available and the type of attachment plugs used in principal cities throughout the world. The characteristics of electric current-type (alternating or direct current), number of phases, frequency (hertz), and voltage found in major foreign cities are listed. In addition, the stability of the frequency and the number of wires to a commercial or residential installation are given where available. The current characteristics and other data furnished relate to domestic and commercial service only. It does not include special commercial installations involving relatively high voltage requirements nor does it refer to any industrial installations.

  6. Electric Current Abroad, 1991 Edition

    Energy Technology Data Exchange (ETDEWEB)

    1991-07-01

    The publication lists, for the information of U.S. manufacturers and exporters and individuals living or traveling abroad, the characteristics of electric current available and the type of attachment plugs used in principal cities throughout the world. The characteristics of electric current-type (alternating or direct current), number of phases, frequency (hertz), and voltage-found in major foreign cities are listed. In addition, the stability of the frequency and the number of wires to a commercial or residential installation are given where available. The current characteristics and other data furnished relate to domestic and commercial service only. It does not include special commercial installations involving relatively high voltage requirements nor does it refer to any industrial installations.

  7. Five currents of organizational psychology

    DEFF Research Database (Denmark)

    Nickelsen, Niels Christian Mossfeldt

    2016-01-01

    Organizational psychology may be seen as consisting of a number of mutually conflictual currents developed over several decades. This article discusses five currents in organizational psychology that have both been dominant in Scandinavia and have had particular significance in relation...... to the field of organizational development: The social psychological, the socio-technical, the humanistic, the work psychological and the social constructionist currents. Central arguments and works from leading scholars are discussed. It is argued that although treated differently the notions of the small...... group, group dynamics, resistance to change and process consultation constitute pivotal and through going tenets in all the currents. These notions, it is argued, link the discipline of organizational psychology together into a mutually discordant, but anyway relatively consistent research area...

  8. Current-Induced Membrane Discharge

    OpenAIRE

    Andersen, MB; Soestbergen, van, M Michiel; A Mani; Bruus, H.; Biesheuvel, PM; Bazant, MZ

    2012-01-01

    Possible mechanisms for overlimiting current (OLC) through aqueous ion-exchange membranes (exceeding diffusion limitation) have been debated for half a century. Flows consistent with electro-osmotic instability have recently been observed in microfluidic experiments, but the existing theory neglects chemical effects and remains to be quantitatively tested. Here, we show that charge regulation and water self-ionization can lead to OLC by “current-induced membrane discharge” (CIMD), even in the...

  9. CURRENT ACCOUNTING DEVELOPMENTS IN KOSOVO

    OpenAIRE

    NEXHMIE VOKSHI; MIHANE BERISHA-NAMANI

    2011-01-01

    For the study of the developments in accounting in Kosovo and its prospects, it is necessary to review the current situation of the developments in accounting, the recognition and acceptance of accounting standards. It is clear that the actual and perspective development level in an affected by many factors, such as social, cultural, etc. Therefore, the main aim of the research work in this study is to give an overview of the current developments of accounting in Kosovo. To obtain the require...

  10. The bivariate current status model

    OpenAIRE

    Groeneboom, P.

    2013-01-01

    For the univariate current status and, more generally, the interval censoring model, distribution theory has been developed for the maximum likelihood estimator (MLE) and smoothed maximum likelihood estimator (SMLE) of the unknown distribution function, see, e.g., [12], [7], [4], [5], [6], [10], [11] and [8]. For the bivariate current status and interval censoring models distribution theory of this type is still absent and even the rate at which we can expect reasonable estimators to converge...

  11. Submesoscale currents in the ocean

    OpenAIRE

    Mcwilliams, James C.

    2016-01-01

    This article is a perspective on the recently discovered realm of submesoscale currents in the ocean. They are intermediate-scale flow structures in the form of density fronts and filaments, topographic wakes and persistent coherent vortices at the surface and throughout the interior. They are created from mesoscale eddies and strong currents, and they provide a dynamical conduit for energy transfer towards microscale dissipation and diapycnal mixing. Consideration is given to their generatio...

  12. Current devices of respiratory physiotherapy

    OpenAIRE

    Hristara-Papadopoulou, A; Tsanakas, J; Diomou, G; Papadopoulou, O.

    2008-01-01

    In recent years patients with respiratory diseases use various devices, which help the removal of mucus from the airways and the improvement of pulmonary function. The aim of the present study is to determine the effectiveness of the current devices of respiratory physiotherapy, as it comes from the review of literature. The current devices of physiotherapy for patients with respiratory diseases, are presented as an alternative therapy method or a supplemental therapy and they can motivate pa...

  13. Spin currents in metallic nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Czeschka, Franz Dominik

    2011-09-05

    A pure spin current, i.e., a flow of angular momentum without accompanying net charge current, is a key ingredient in the field of spintronics. In this thesis, we experimentally investigated two different concepts for pure spin current sources suggested by theory. The first is based on a time-dependent magnetization precession which ''pumps'' a pure spin current into an adjacent non-magnetic conductor. Our experiments quantitatively corroborated important predictions expected theoretically for this approach, including the dependence of the spin current on the sample geometry and the microwave power. Even more important, we could show for the first time that the spin pumping concept is viable in a large variety of ferromagnetic materials and that it only depends on the magnetization damping. Therefore, our experiments established spin pumping as generic phenomenon and demonstrated that it is a powerful way to generate pure spin currents. The second theoretical concept is based on the conversion of charge currents into spin currents in non-magnetic nanostructures via the spin Hall effect. We experimentally investigated this approach in H-shaped, metallic nanodevices, and found that the predictions are linked to requirements not realizable with the present experimental techniques, neither in sample fabrication nor in measurement technique. Indeed, our experimental data could be consistently understood by a spin-independent transport model describing the transition from diffusive to ballistic transport. In addition, the implementation of advanced fabrication and measurement techniques allowed to discover a new non-local phenomenon, the non-local anisotropic magnetoresistance. Finally, we also studied spin-polarized supercurrents carried by spin-triplet Cooper pairs. We found that low resistance interfaces are a key requirement for further experiments in this direction. (orig.)

  14. Spheromak Impedance and Current Amplification

    Energy Technology Data Exchange (ETDEWEB)

    Fowler, T K; Hua, D D; Stallard, B W

    2002-01-31

    It is shown that high current amplification can be achieved only by injecting helicity on the timescale for reconnection, {tau}{sub REC}, which determines the effective impedance of the spheromak. An approximate equation for current amplification is: dI{sub TOR}{sup 2}/dt {approx} I{sup 2}/{tau}{sub REC} - I{sub TOR}{sup 2}/{tau}{sub closed} where I is the gun current, I{sub TOR} is the spheromak toroidal current and {tau}{sub CLOSED} is the ohmic decay time of the spheromak. Achieving high current amplification, I{sub TOR} >> I, requires {tau}{sub REC} <<{tau}{sub CLOSED}. For resistive reconnection, this requires reconnection in a cold zone feeding helicity into a hot zone. Here we propose an impedance model based on these ideas in a form that can be implemented in the Corsica-based helicity transport code. The most important feature of the model is the possibility that {tau}{sub REC} actually increases as the spheromak temperature increases, perhaps accounting for the ''voltage sag'' observed in some experiments, and a tendency toward a constant ratio of field to current, B {proportional_to} I, or I{sub TOR} {approx} I. Program implications are discussed.

  15. BOOK REVIEW: The Current Comparator

    Science.gov (United States)

    Petersons, Oskars

    1989-01-01

    This 120-page book is a concise, yet comprehensive, clearly-written and well-illustrated monograph that covers the subject matter from basic principles through design, construction and calibration details to the principal applications. The book will be useful, as a primer, to the uninitiated and, as a reference book to the practitioner involved with transformer-type ratio devices. The length of the book and the style of presentation will not overburden any informed reader. The described techniques and the cited references are primarily from the work at the National Research Council, Canada (NRC). Any omissions, however, are not serious with respect to coverage of the subject matter, since most of the development work has been done at NRC. The role of transformers and transformer-like devices for establishing accurate voltage and current ratios has been recognized for over half a century. Transformer techniques were much explored and developed in the fifties and sixties for accuracy levels suitable for standards laboratories. Three-winding voltage transformers were developed for scaling of impedances in connection with the calculable Thompson Lampard capacitor; three-winding current transformers or current comparators were initially explored for the calibration of current transformers and later for specialized impedance measurements. Extensive development of the current comparator and its applications has been and is still being conducted at the NRC by a team that was started and, until his retirement, led by N L Kusters. The team is now led by W J M Moore. He and P N Miljanic, the authors of this book, have had the principal roles in the development of the current comparator. It is fortunate for the field of metrology that considerabe resources and a talented group of researchers were available to do this development along with mechanisms that were available to transfer this technology to a private sector instrument manufacturer and, thus, disseminate it world wide

  16. Displacement currents in geoelectromagnetic problems

    Science.gov (United States)

    Mogilatov, Vladimir; Goldman, Mark; Persova, Marina; Soloveichik, Yury

    2014-06-01

    The influence of displacement currents in conventional geoelectromagnetic (GEM) methods using unimodal transversal electric (TE) or multimodal TE and TM (transversal magnetic) fields is only significant at very high frequencies in the frequency domain or at extremely early times in the time domain. The transient process in the latter includes three stages: the propagation through air, the propagation through earth and the diffusion within the earth. The influence of displacement currents is significant mainly during the former two stages, normally up to several tens to a few hundreds of nanoseconds. The behavior is essentially different in novel GEM methods using a vertical electric dipole (VED) or circular electric dipole (CED) sources of unimodal TM-fields. Under certain geoelectric conditions, the influence of displacement currents in these methods might be crucial at late times as well. This happens, if the model consists of insulating layers. In the absence of displacement currents, such layers would totally mask underlying structures. However, TM-fields including displacement currents depend on geoelectric parameters below insulating layers at late times.

  17. Application of fault current limiters

    Energy Technology Data Exchange (ETDEWEB)

    Neumann, A.

    2007-11-30

    This report presents the results of a study commissioned by the Department for Business, Enterprise and Industry (BERR; formerly the Department of Trade and Industry) into the application of fault current limiters in the UK. The study reviewed the current state of fault current limiter (FCL) technology and regulatory position in relation to all types of current limiters. It identified significant research and development work with respect to medium voltage FCLs and a move to high voltage. Appropriate FCL technologies being developed include: solid state breakers; superconducting FCLs (including superconducting transformers); magnetic FCLs; and active network controllers. Commercialisation of these products depends on successful field tests and experience, plus material development in the case of high temperature superconducting FCL technologies. The report describes FCL techniques, the current state of FCL technologies, practical applications and future outlook for FCL technologies, distribution fault level analysis and an outline methodology for assessing the materiality of the fault level problem. A roadmap is presented that provides an 'action agenda' to advance the fault level issues associated with low carbon networks.

  18. Digitally compensated beam current transformer

    CERN Document Server

    Kesselman, Martin

    2005-01-01

    The Spallation Neutron Source (SNS) is being built by a collaboration of six laboratories. Beam current monitors (BCMs) will be used to record the current of H-minus and H-plus beams ranging from 15 mA (tune-up in the Front End and Linac) to over 60A fully accumulated in the Ring and dumped to the load as a single pulse in the Ring to Beam Target (RTBT). The time structure of these beams ranges from 645ns "mini" bunches at the 1.05 MHz ring revolution rate, to an overall 1 ms long macro-pulse. The requirements for the BCMs will depend upon their location within the system. The need to measure individual mini-pulses, examine the characteristics of the chopper edge, as well as the longer average current pulse of the macropulse, or long duration pulses during Linac tuning place wide requirements upon the response of current transformers. To obtain the desired accuracy and resolution, current transformers must have less than 1 ns rise time and droops of 0.1 %/ms. This places a significant design burden on the cur...

  19. Current pulse shaping of the load current on PTS

    Science.gov (United States)

    Xia, Minghe; Li, Fengping; Ji, Ce; Wei, Bing; Feng, Shuping; Wang, Meng; Xie, Weiping

    2016-02-01

    The typical rise time of PTS machine is ˜110 ns with about 10 MA peak current under short pulse mode when all 24 modules discharge simultaneously. By distributing the trigger times of 12 laser beams logically and adjusting the statues of the pulse output switches, longer rise-time pulse can be obtained on the PTS facility. Based on the required pulse shape, whole circuit simulations will be used to calculate the trigger times of each laser triggering gas switch and the status of the pulse output switches. The rise time of the current is determined by the time difference between the first and last trigged laser triggering gas switches. In order to trigger the laser triggering gas switch, sufficient laser power is needed to be sent into the gap of the gas switches. The gas pressure and voltage difference on the two electrodes of the gas switches also affect the triggering of the gas switches, and the voltage added on the gas switch is determined by its transition time. Traditionally the trigger time difference should be less than the transition time of the two neighboring modules. A new simulation model of PTS shows one can break this transition time limits. Series of current pulse shaping experiments have been investigated on the PTS (Primary Test Stand). As results, more than 5 MA peak current were successfully achieved on the load with a rise time of 600 ns. This study and experiments of the pulse shaping on PTS demonstrate the adaptable ability of the PTS for offering different waveform of mega ampere current pulse for different research purpose.

  20. Current pulse shaping of the load current on PTS

    Directory of Open Access Journals (Sweden)

    Minghe Xia

    2016-02-01

    Full Text Available The typical rise time of PTS machine is ∼110 ns with about 10 MA peak current under short pulse mode when all 24 modules discharge simultaneously. By distributing the trigger times of 12 laser beams logically and adjusting the statues of the pulse output switches, longer rise-time pulse can be obtained on the PTS facility. Based on the required pulse shape, whole circuit simulations will be used to calculate the trigger times of each laser triggering gas switch and the status of the pulse output switches. The rise time of the current is determined by the time difference between the first and last trigged laser triggering gas switches. In order to trigger the laser triggering gas switch, sufficient laser power is needed to be sent into the gap of the gas switches. The gas pressure and voltage difference on the two electrodes of the gas switches also affect the triggering of the gas switches, and the voltage added on the gas switch is determined by its transition time. Traditionally the trigger time difference should be less than the transition time of the two neighboring modules. A new simulation model of PTS shows one can break this transition time limits. Series of current pulse shaping experiments have been investigated on the PTS (Primary Test Stand. As results, more than 5 MA peak current were successfully achieved on the load with a rise time of 600 ns. This study and experiments of the pulse shaping on PTS demonstrate the adaptable ability of the PTS for offering different waveform of mega ampere current pulse for different research purpose.

  1. Magnetoelectric control of spin currents

    Science.gov (United States)

    Gómez, J. E.; Vargas, J. M.; Avilés-Félix, L.; Butera, A.

    2016-06-01

    The ability to control the spin current injection has been explored on a hybrid magnetoelectric system consisting of a (011)-cut ferroelectric lead magnesium niobate-lead titanate (PMNT) single crystal, a ferromagnetic FePt alloy, and a metallic Pt. With this PMNT/FePt/Pt structure we have been able to control the magnetic field position or the microwave excitation frequency at which the spin pumping phenomenon between FePt and Pt occurs. We demonstrate that the magnetoelectric heterostructure operating in the L-T (longitudinal magnetized-transverse polarized) mode couples the PMNT crystal to the magnetostrictive FePt/Pt bilayer, displaying a strong magnetoelectric coefficient of ˜140 Oe cm kV-1. Our results show that this mechanism can be effectively exploited as a tunable spin current intensity emitter and open the possibility to create an oscillating or a bistable switch to effectively manipulate spin currents.

  2. Turbulent lock release gravity current

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The time evolution of a turbulent lock release gravity current, formed by a finite volume ofhomogeneous fluid released instantaneously into another fluid of slightly lower density, was studied byexperimental measurements of the density structure via elaborate digital image processing and by a nu-merical simulation of the flow and mixing using a two-equation turbulence model. The essential fact thatthe gravity current passes through an initial slumping phase in which the current head advances steadilyand a second self-similar phase in which the front velocity decreases like the negative third power of thetime after release is satisfactorily presented by the laboratory observation. An overall entrainment ratioproportional to the distance from the release point is found by the numerical simulation. The renormal-ization group (RNG) k- ε model for Reynolds-stress closure is validated to characterize the gravitycurrent with transitional and localized turbulence.

  3. Remote field eddy current testing

    Energy Technology Data Exchange (ETDEWEB)

    Cheong, Y. M.; Jung, H. K.; Huh, H.; Lee, Y. S.; Shim, C. M

    2001-03-01

    The state-of-art technology of the remote field eddy current, which is actively developed as an electromagnetic non-destructive testing tool for ferromagnetic tubes, is described. The historical background and recent R and D activities of remote-field eddy current technology are explained including the theoretical development of remote field eddy current, such as analytical and numerical approach, and the results of finite element analysis. The influencing factors for actual applications, such as the effect of frequency, magnetic permeability, receiving sensitivity, and difficulties of detection and classification of defects are also described. Finally, two examples of actual application, 1) the gap measurement between pressure tubes and calandria tube in CANDU reactor and, 2) the detection of defects in the ferromagnetic heat exchanger tubes, are described. The future research efforts are also included.

  4. Transungual drug delivery: current status.

    Science.gov (United States)

    Elkeeb, Rania; AliKhan, Ali; Elkeeb, Laila; Hui, Xiaoying; Maibach, Howard I

    2010-01-15

    Topical therapy is highly desirable in treating nail disorders due to its localized effects, which results in minimal adverse systemic events and possibly improved adherence. However, the effectiveness of topical therapies is limited by minimal drug permeability through the nail plate. Current research on nail permeation that focuses on altering the nail plate barrier by means of chemical treatments, penetration enhancers as well as physical and mechanical methods is reviewed. A new method of nail sampling is examined. Finally limitations of current ungual drug permeability studies are briefly discussed. PMID:19819318

  5. Current Flows in Pulsar Magnetospheres

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The global structure of .current flows in pulsar magnetosphere is investigated, with rough calculations of the circuit elements. It is emphasized that the potential of the critical field lines (the field lines that intersect the null surface at the light cylinder radius) should be the same as that of interstellar medium, and that pulsars whose rotation axes and magnetic dipole axes are parallel should be positively charged, in order to close the pulsar's current flows. The statistical relation between the radio luminosity and pulsar's electric charge (or the spindown power) may hint that the millisecond pulsars could be low-mass bare strange stars.

  6. Transungual drug delivery: current status.

    Science.gov (United States)

    Elkeeb, Rania; AliKhan, Ali; Elkeeb, Laila; Hui, Xiaoying; Maibach, Howard I

    2010-01-15

    Topical therapy is highly desirable in treating nail disorders due to its localized effects, which results in minimal adverse systemic events and possibly improved adherence. However, the effectiveness of topical therapies is limited by minimal drug permeability through the nail plate. Current research on nail permeation that focuses on altering the nail plate barrier by means of chemical treatments, penetration enhancers as well as physical and mechanical methods is reviewed. A new method of nail sampling is examined. Finally limitations of current ungual drug permeability studies are briefly discussed.

  7. Micromachined optical fiber current sensor

    OpenAIRE

    Heredero, R. L.; Fernández de Caleya, Ramón; Guerrero, Héctor; Losantos Viñolas, Pedro; Acero, M.C.; Esteve, J.

    1999-01-01

    We describe a micromachined optical fiber current sensor. The sensing element consists of a squared silicon membrane (8 mm long and 20 μm thick) that has a cylindrical permanent magnet (NdFeB alloy, 3-mm diameter, 1.5 mm high) fixed on its central region. This structure allows the permanent magnet to vibrate in the presence of the magnetic field gradient generated by an ac. A linear relation between the electrical current and the magnet displacement was measured with white-light interferometr...

  8. Current therapies for premature ejaculation.

    Science.gov (United States)

    Gur, Serap; Kadowitz, Philip J; Sikka, Suresh C

    2016-07-01

    Premature ejaculation (PE) subjectively affects 20-30% of men globally. Until recently, understanding of PE was hampered by the absence of a widely accepted definition, paucity of evidence-based clinical studies, and the absence of an appropriate animal model. Here, we elaborate on the current definition of PE, its pathogenesis, currently available therapies, and future treatment prospects. Most treatments for PE are 'off-label' and include selective serotonin reuptake inhibitors (SSRIs), topical anesthetics, tramadol, and phosphodiesterase type 5 (PDE5) inhibitors. Such knowledge of the benefit and limitations of each treatment will help to direct future drug design and formulations.

  9. Eddy current inspection of tubing

    International Nuclear Information System (INIS)

    The Experimental research work carried out to develop a Eddy current testing equipment is described. Search coils with ferrite or air cores were used and the obtained results are discussed. Valuable information was gained from a improved channel in which a direct measure of the defect and the reference signal phase difference is obtained. Artificial defect used to evaluate resolution and sensitivity were produced by electro-machining and mechanical means. Finned SAP tubing was tested in a routine basis with the described equipment and the results plotted. Basic and theoretical considerations on the Eddy current testing technique are given in the last section of this report. (Author)

  10. Current therapies for premature ejaculation.

    Science.gov (United States)

    Gur, Serap; Kadowitz, Philip J; Sikka, Suresh C

    2016-07-01

    Premature ejaculation (PE) subjectively affects 20-30% of men globally. Until recently, understanding of PE was hampered by the absence of a widely accepted definition, paucity of evidence-based clinical studies, and the absence of an appropriate animal model. Here, we elaborate on the current definition of PE, its pathogenesis, currently available therapies, and future treatment prospects. Most treatments for PE are 'off-label' and include selective serotonin reuptake inhibitors (SSRIs), topical anesthetics, tramadol, and phosphodiesterase type 5 (PDE5) inhibitors. Such knowledge of the benefit and limitations of each treatment will help to direct future drug design and formulations. PMID:27179987

  11. Current issues with research support

    Energy Technology Data Exchange (ETDEWEB)

    Russell, W.T.

    1996-03-01

    It would be difficult to condense current issues in nuclear reactor regulation to just a few minutes. So, let me start off by saying that I have not tried to give a comprehensive listing of issues that are currently facing the reactor program, but rather to select those that I thought were relevant as they relate to research activities. Use of probabilistic risk assessment in regulatory decisions; materials aging issues concerning steam generators and reactor vessels; high burnup fuels; accident management; and digital instrumentation and control, are just a sampling of the important issues that I want to talk about.

  12. Current Trends in Language Teaching

    Science.gov (United States)

    Revue des Langues Vivantes, 1975

    1975-01-01

    Examines the effects of Chomsky's theories of linguistics and language acquisition on language teaching methodology, specifically on the use of the audio-lingual method. Current trends in methodology move in two basic directions: 1) towards relaxation of the tighter restrictions of the audio-lingual method, and 2) towards development of techniques…

  13. Current Issues in Maritime Health

    DEFF Research Database (Denmark)

    Wagtmann, Maria Anne

    2008-01-01

     In the early part of 2008, Maria Anne Wagtmann had the opportunity to interview the former president of the International Maritime Health Association, Dr. Tim Carter, in London about a number of current maritime health issues. In this interview, Dr. Tim Carter, who is cur­rently employed as the ...

  14. Current management of oral cancer

    Institute of Scientific and Technical Information of China (English)

    Robert Ord

    2008-01-01

    @@ This presentation will summarize some of the current areas of interest in the management of oral cancer. The presentation will be divided into a brief review of epidemiology and diagnosis, with a more extensive discussion regarding the controversial areas in surgery and a review of the adjuvant roles of radiation and chemotherapy.

  15. Noether currents for BF gravity

    International Nuclear Information System (INIS)

    The conservation laws and currents for BF theory in four spacetime dimensions and BF gravity corresponding with their Lagrangian local gauge symmetries (local Lorentz transformations and diffeomorphisms) are computed using Noether's theorem. The physical meaning of the Noether charges that arise from the conservation laws is not explored

  16. Current-Induced Membrane Discharge

    NARCIS (Netherlands)

    Baeko Andersen, M.; Soestbergen, M.; Mani, A.; Bruus, H.; Biesheuvel, P.M.; Bazant, M.Z.

    2012-01-01

    Possible mechanisms for overlimiting current (OLC) through aqueous ion-exchange membranes (exceeding diffusion limitation) have been debated for half a century. Flows consistent with electro-osmotic instability have recently been observed in microfluidic experiments, but the existing theory neglects

  17. Current-Induced Membrane Discharge

    DEFF Research Database (Denmark)

    Andersen, Mathias Bækbo; van Soestbergen, M.; Mani, A.;

    2012-01-01

    neglects chemical effects and remains to be quantitatively tested. Here, we show that charge regulation and water self-ionization can lead to OLC by "current-induced membrane discharge'' (CIMD), even in the absence of fluid flow, in ion-exchange membranes much thicker than the local Debye screening length...

  18. Chiral Electroweak Currents in Nuclei

    CERN Document Server

    Riska, D O

    2016-01-01

    The development of the chiral dynamics based description of nuclear electroweak currents is reviewed. Gerald E. (Gerry) Brown's role in basing theoretical nuclear physics on chiral Lagrangians is emphasized. Illustrative examples of the successful description of electroweak observables of light nuclei obtained from chiral effective field theory are presented.

  19. Biodiesel: Current Trends and Properties

    Science.gov (United States)

    Biodiesel, an alternative to petroleum-derived diesel fuel, is defined as the mono-alkyl esters of vegetable oils and animal fats. Several current issues affecting biodiesel that are briefly discussed include the role of new feedstocks in meeting increased demand for biodiesel and circumventing the...

  20. The Current Conjuncture in Theory.

    Science.gov (United States)

    Sprinker, Michael

    1989-01-01

    Describes the current debate in literary study between the humanist/historicist and the anti-humanist/anti-historicist perspectives. Examines the political dimensions of this debate, including its relationship to Marxist theory and deconstruction. Asserts that literary texts are productions of ideology and that literary study should inquire into…

  1. The Current in a Wire

    Science.gov (United States)

    Thompson, Keith

    2009-01-01

    This little problem arose because I was frustrated with the standard electromagnetism texts, which show the magnetic field due to a current-bearing wire outside the wire [proportional to] 1/r and inside [proportional to] r. However, they never point out that the moving electrons must be influenced by the magnetic field created by the other moving…

  2. Current trends and future directions

    DEFF Research Database (Denmark)

    Harboe, Peter G.; Madsen, Sabine; Svejvig, Per

    2012-01-01

    This book is an attempt to gather current state-of-the-art research on project management from multiple universities and university colleges in Denmark. This chapter first discuss a literature review of Danish and Scandinavian research on project management thereby complementing the short review...

  3. Eddy current thickness measurement apparatus

    Energy Technology Data Exchange (ETDEWEB)

    Rosen, Gary J.; Sinclair, Frank; Soskov, Alexander; Buff, James S.

    2015-06-16

    A sheet of a material is disposed in a melt of the material. The sheet is formed using a cooling plate in one instance. An exciting coil and sensing coil are positioned downstream of the cooling plate. The exciting coil and sensing coil use eddy currents to determine a thickness of the solid sheet on top of the melt.

  4. Universal bounds on current fluctuations

    Science.gov (United States)

    Pietzonka, Patrick; Barato, Andre C.; Seifert, Udo

    2016-05-01

    For current fluctuations in nonequilibrium steady states of Markovian processes, we derive four different universal bounds valid beyond the Gaussian regime. Different variants of these bounds apply to either the entropy change or any individual current, e.g., the rate of substrate consumption in a chemical reaction or the electron current in an electronic device. The bounds vary with respect to their degree of universality and tightness. A universal parabolic bound on the generating function of an arbitrary current depends solely on the average entropy production. A second, stronger bound requires knowledge both of the thermodynamic forces that drive the system and of the topology of the network of states. These two bounds are conjectures based on extensive numerics. An exponential bound that depends only on the average entropy production and the average number of transitions per time is rigorously proved. This bound has no obvious relation to the parabolic bound but it is typically tighter further away from equilibrium. An asymptotic bound that depends on the specific transition rates and becomes tight for large fluctuations is also derived. This bound allows for the prediction of the asymptotic growth of the generating function. Even though our results are restricted to networks with a finite number of states, we show that the parabolic bound is also valid for three paradigmatic examples of driven diffusive systems for which the generating function can be calculated using the additivity principle. Our bounds provide a general class of constraints for nonequilibrium systems.

  5. DC superconducting fault current limiter

    Science.gov (United States)

    Tixador, P.; Villard, C.; Cointe, Y.

    2006-03-01

    There is a lack of satisfying solutions for fault currents using conventional technologies, especially in DC networks, where a superconducting fault current limiter could play a very important part. DC networks bring a lot of advantages when compared to traditional AC ones, in particular within the context of the liberalization of the electric market. Under normal operation in a DC network, the losses in the superconducting element are nearly zero and only a small, i.e. a low cost, refrigeration system is then required. The absence of zero crossing of a DC fault current favourably accelerates the normal zone propagation. The very high current slope at the time of the short circuit in a DC grid is another favourable parameter. The material used for the experiments is YBCO deposited on Al2O3 as well as YBCO coated conductors. The DC limitation experiments are compared to AC ones at different frequencies (50-2000 Hz). Careful attention is paid to the quench homogenization, which is one of the key issues for an SC FCL. The University of Geneva has proposed constrictions. We have investigated an operating temperature higher than 77 K. As for YBCO bulk, an operation closer to the critical temperature brings a highly improved homogeneity in the electric field development. The material can then absorb large energies without degradation. We present tests at various temperatures. These promising results are to be confirmed over long lengths.

  6. Imposed currents in galvanic cells

    NARCIS (Netherlands)

    Biesheuvel, P.M.; Soestbergen, M.; Bazant, M.Z.

    2009-01-01

    We analyze the steady-state behavior of a general mathematical model for reversible galvanic cells, such as redox flow cells, reversible solid oxide fuel cells, and rechargeable batteries. We consider not only operation in the galvanic discharging mode, spontaneously generating a positive current ag

  7. Eddy current manual: v.1

    International Nuclear Information System (INIS)

    This training and reference manual was assembled to provide those involved in eddy current testing with both the fundamental principles of the technique as well as the knowledge to deal with often complicated test results. A non-rigorous approach is used to simplify complex physical phenomena. Emphasis is placed on proper choice of test frequency and signal interpretation. Defect detection and diagnosis receive particular attention. Design and construction of probes are covered extensively since probes play a key role in eddy current testing. The advantages and limitations of various probe types are discussed. Electromagnetic theory, instrumentation, test methods and signal analysis are covered. Simplified derivations of probe response to test parameters are presented to develop a basic understanding of eddy current behaviour. Eddy current signals are presented on impedance plane diagrams throughout the manual since this is the most common display on modern, general purpose instruments. The use of Σphase lagΣ in signal analysis is covered in detail. To supplement theory, practical examples are presented to develop proficiency in performing inspections, and to illustrate how basic principles are applied to diagnose real signals

  8. Eddy current testing, volume 1

    International Nuclear Information System (INIS)

    This training and reference manual was assembled to provide those involved in eddy current testing with both the fundamental principles of the technique as well as the knowledge to deal with often complicated test results. A non-rigorous approach is used to simplify complex physical phenomena. Emphasis is placed on proper choice of test frequency and interpretation. Defect detection and diagnosis receive particular attention. Design and construction of probes are covered extensively since probes play a key role in eddy current testing. The advantages and limitations of various probe types are discussed. Electromagnetic theory, instrumentation, test methods and signal analysis are covered. Simplified derivations of probe response to test parameters are presented to develop a basic understanding of eddy current behaviour. Eddy current signals are presented on impedance plane diagrams throughout the manual since this is the most common display on modern, general purpose instruments. The use of 'phase leg' in signal analysis is covered in detail. To supplement theory, practical examples are presented to develop proficiency in performing inspections, and to illustrate how basic principles are applied to diagnose real signals

  9. Mechanical generation of spin current

    Directory of Open Access Journals (Sweden)

    Mamoru eMatsuo

    2015-07-01

    Full Text Available We focus the recent results on spin-current generation from mechanical motion such as rigid rotation and elastic deformations. Spin transport theory in accelerating frames is constructed by using the low energy expansion of the generally covariant Dirac equation. Related issues on spin-manipulation by mechanical rotation are also discussed.

  10. Plasma current profile shaping with rf-current drive

    Energy Technology Data Exchange (ETDEWEB)

    Ehst, D.A.; Evans, K. Jr.

    1985-01-01

    Calculations of rf current drive in a toroidal geometry are presented. The result is self-consistent in that the tokamak magnetic field generated by the rf-driven current is used to compute the wave trajectory and spatial damping in the plasma. In the next section we derive the quasilinear theory in an axisymmetric torus. In Section 3 we describe a numerical solution to this problem and investigate rf-generated equilibria in a reactor-relevant geometry (A = 6.0; major radius, R/sub 0/ = 5.25 m; elongation k = 1.6; triangular boundary). By suitably adjusting the rf/plasma parameters a wide range of equilibria can be created. Although we have not optimized our rf-generated equilibria (in particular, we are limited at present to a narrow spectrum) we find evidence that equilibria can be sustained which should lead to attractive tokamak reactors.

  11. Power voltage current convertor using quasi complementary MOSFET current mirrors.

    Science.gov (United States)

    Maclachlan, R A; Riviere, C N

    2011-10-13

    A voltage current convertor is described having a quasi complementary class AB architecture that is particularly suited to implementation using discrete power MOSFETs. High-voltage mirror designs are presented, enabling the construction of sources with kilovolt compliance range, tens of watts of output power and greater than 100 kHz bandwidth. GΩ output impedance and distortion below 1% can be obtained with no trimming or transistor matching. PMID:22312182

  12. Submesoscale currents in the ocean

    Science.gov (United States)

    2016-01-01

    This article is a perspective on the recently discovered realm of submesoscale currents in the ocean. They are intermediate-scale flow structures in the form of density fronts and filaments, topographic wakes and persistent coherent vortices at the surface and throughout the interior. They are created from mesoscale eddies and strong currents, and they provide a dynamical conduit for energy transfer towards microscale dissipation and diapycnal mixing. Consideration is given to their generation mechanisms, instabilities, life cycles, disruption of approximately diagnostic force balance (e.g. geostrophy), turbulent cascades, internal-wave interactions, and transport and dispersion of materials. At a fundamental level, more questions remain than answers, implicating a programme for further research. PMID:27279778

  13. Nanorobotics current approaches and techniques

    CERN Document Server

    Ferreira, Antoine

    2013-01-01

    Nanorobot devices now perform a wide variety of tasks at the nanoscale in a wide variety of fields including but not limited to fields such as manufacturing, medicine, supply chain, biology, and outer space. Nanorobotics: Current Approaches and Techniques is a comprehensive overview of this interdisciplinary field with a wide ranging discussion that includes nano-manipulation and industrial nanorobotics, nanorobotics in biology and medicine, nanorobotic sensing, navigation and swarm behavior, and protein and DNA-based nanorobotics. Also included is the latest on topics such as bio-nano-actuators and propulsion and navigation of nanorobotic systems using magnetic fields. Nanorobotics: Current Approaches and Techniques is an ideal book for scientists, researchers, and engineers actively involved in applied and robotic research and development.

  14. CURRENT ACCOUNTING DEVELOPMENTS IN KOSOVO

    Directory of Open Access Journals (Sweden)

    NEXHMIE VOKSHI

    2011-04-01

    Full Text Available For the study of the developments in accounting in Kosovo and its prospects, it is necessary to review the current situation of the developments in accounting, the recognition and acceptance of accounting standards. It is clear that the actual and perspective development level in an affected by many factors, such as social, cultural, etc. Therefore, the main aim of the research work in this study is to give an overview of the current developments of accounting in Kosovo. To obtain the required information, 400 respondents have been chosen through a questionnaire designed for this purpose1. The respondents operate in different branches, they work in small, medium and large enterprises, insurance companies, banks, and while some of them are independent accountants and employees in the tax authorities. The data obtained are processed and analyzed from two aspects: the aspect of descriptive statistics reflected through histograms, and econometric aspect of reflecting through econometric models.

  15. Solid-state current transformer

    Science.gov (United States)

    Farnsworth, D. L. (Inventor)

    1976-01-01

    A signal transformation network which is uniquely characterized to exhibit a very low input impedance while maintaining a linear transfer characteristic when driven from a voltage source and when quiescently biased in the low microampere current range is described. In its simplest form, it consists of a tightly coupled two transistor network in which a common emitter input stage is interconnected directly with an emitter follower stage to provide virtually 100 percent negative feedback to the base input of the common emitter stage. Bias to the network is supplied via the common tie point of the common emitter stage collector terminal and the emitter follower base stage terminal by a regulated constant current source, and the output of the circuit is taken from the collector of the emitter follower stage.

  16. Current status of rotavirus vaccines

    Institute of Scientific and Technical Information of China (English)

    Ching-Min Wang; Shou-Chien Chen; Kow-Tong Chen

    2015-01-01

    Background: Rotaviruses remain the major cause of childhood diarrheal disease worldwide and of diarrheal deaths of infants and children in developing countries. The huge burden of childhood rotavirus-related diarrhea in the world continues to drive the remarkable pace of vaccine development. Data sources: Research articles were searched using terms "rotavirus" and "rotavirus vaccine" in MEDLINE and PubMed. Articles not published in the English language, articles without abstracts, and opinion articles were excluded from the review. After preliminary screening, all articles were reviewed and synthesized to provide an overview of current vaccines and vaccination programs. Results: In this review of the global rotavirus vaccines and vaccination programs, the principles of rotavirus vaccine development and the efficacy of the currently licensed vaccines from both developed and developing countries were summarized. Conclusions: Rotavirus is a common cause of diarrhea in children in both developed and developing countries. Rotavirus vaccination is a cost-effective measure to prevent rotavirus diarrhea.

  17. Current Concept of Geometrical Accuracy

    Directory of Open Access Journals (Sweden)

    Görög Augustín

    2014-06-01

    Full Text Available Within the solving VEGA 1/0615/12 research project "Influence of 5-axis grinding parameters on the shank cutter´s geometric accuracy", the research team will measure and evaluate geometrical accuracy of the produced parts. They will use the contemporary measurement technology (for example the optical 3D scanners. During the past few years, significant changes have occurred in the field of geometrical accuracy. The objective of this contribution is to analyse the current standards in the field of geometric tolerance. It is necessary to bring an overview of the basic concepts and definitions in the field. It will prevent the use of outdated and invalidated terms and definitions in the field. The knowledge presented in the contribution will provide the new perspective of the measurement that will be evaluated according to the current standards.

  18. Bootstrap Current in Spherical Tokamaks

    Institute of Scientific and Technical Information of China (English)

    王中天; 王龙

    2003-01-01

    Variational principle for the neoclassical theory has been developed by including amomentum restoring term in the electron-electron collisional operator, which gives an additionalfree parameter maximizing the heat production rate. All transport coefficients are obtained in-cluding the bootstrap current. The essential feature of the study is that the aspect ratio affects thefunction of the electron-electron collision operator through a geometrical factor. When the aspectratio approaches to unity, the fraction of circulating particles goes to zero and the contribution toparticle flux from the electron-electron collision vanishes. The resulting diffusion coefficient is inrough agreement with Hazeltine. When the aspect ratio approaches to infinity, the results are inagreement with Rosenbluth. The formalism gives the two extreme cases a connection. The theoryis particularly important for the calculation of bootstrap current in spherical tokamaks and thepresent tokamaks, in which the square root of the inverse aspect ratio, in general, is not small.

  19. Currents in supersymmetric field theories

    CERN Document Server

    Derendinger, Jean-Pierre

    2016-01-01

    A general formalism to construct and improve supercurrents and source or anomaly superfields in two-derivative N=1 supersymmetric theories is presented. It includes arbitrary gauge and chiral superfields and a linear superfield coupled to gauge fields. These families of supercurrent structures are characterized by their energy-momentum tensors and R currents and they display a specific relation to the dilatation current of the theory. The linear superfield is introduced in order to describe the gauge coupling as a background (or propagating) field. Supersymmetry does not constrain the dependence on this gauge coupling field of gauge kinetic terms and holomorphicity restrictions are absent. Applying these results to an effective (Wilson) description of super-Yang-Mills theory, matching or cancellation of anomalies leads to an algebraic derivation of the all-order NSVZ beta function.

  20. Current concepts in maxillofacial imaging

    Energy Technology Data Exchange (ETDEWEB)

    Boeddinghaus, Rudolf [Perth Radiological Clinic, 127 Hamersley Road, Subiaco, Western Australia 6008 (Australia)], E-mail: rboeddinghaus@perthradclinic.com.au; Whyte, Andy [Perth Radiological Clinic, 127 Hamersley Road, Subiaco, Western Australia 6008 (Australia)], E-mail: awhyte@perthradclinic.com.au

    2008-06-15

    A review of state-of-the-art maxillofacial imaging is presented. Current imaging techniques include intra-oral radiographs, dental panoramic tomography, multidetector helical computed tomography, cone-beam computed tomography (CBCT) and magnetic resonance imaging (MRI). The commonest conditions encountered in clinical radiological practice are reviewed, including maxillofacial deformities, complicated dental impactions, maxillofacial trauma, jaw lesions (cysts, neoplasms, fibro-osseous lesions (FOLs) and infections), and temporomandibular joint pathology. Pre-operative assessment for dental implant placement is also briefly reviewed.

  1. High PRF high current switch

    Science.gov (United States)

    Moran, Stuart L.; Hutcherson, R. Kenneth

    1990-03-27

    A triggerable, high voltage, high current, spark gap switch for use in pu power systems. The device comprises a pair of electrodes in a high pressure hydrogen environment that is triggered by introducing an arc between one electrode and a trigger pin. Unusually high repetition rates may be obtained by undervolting the switch, i.e., operating the trigger at voltages much below the self-breakdown voltage of the device.

  2. Current concepts in maxillofacial imaging

    International Nuclear Information System (INIS)

    A review of state-of-the-art maxillofacial imaging is presented. Current imaging techniques include intra-oral radiographs, dental panoramic tomography, multidetector helical computed tomography, cone-beam computed tomography (CBCT) and magnetic resonance imaging (MRI). The commonest conditions encountered in clinical radiological practice are reviewed, including maxillofacial deformities, complicated dental impactions, maxillofacial trauma, jaw lesions (cysts, neoplasms, fibro-osseous lesions (FOLs) and infections), and temporomandibular joint pathology. Pre-operative assessment for dental implant placement is also briefly reviewed

  3. Classification of simple current invariants

    CERN Document Server

    Gato-Rivera, Beatriz

    1992-01-01

    We summarize recent work on the classification of modular invariant partition functions that can be obtained with simple currents in theories with a center (Z_p)^k with p prime. New empirical results for other centers are also presented. Our observation that the total number of invariants is monodromy-independent for (Z_p)^k appears to be true in general as well. (Talk presented in the parallel session on string theory of the Lepton-Photon/EPS Conference, Geneva, 1991.)

  4. Social networks user: current research

    Directory of Open Access Journals (Sweden)

    Agadullina E.R.

    2015-12-01

    Full Text Available The purpose of this article is to review current research studies focusing on the users of Facebook and their behaviors in social networks. This review is organized into two sections: 1 social-demographic characteristics (Age, Gender, Nationality; 2 personality characteristics (Neuroticism, Extraversion, Openness-to-Experience, Agreeableness, Conscientiousness, Narcissism, Self-esteem. The results showed that the information in the personal profile and online behavior are strongly connected with socio-demographic and personality characteristics

  5. Classification of Simple Current Invariants

    CERN Document Server

    Gato-Rivera, Beatriz

    1991-01-01

    We summarize recent work on the classification of modular invariant partition functions that can be obtained with simple currents in theories with a center (Z_p)^k with p prime. New empirical results for other centers are also presented. Our observation that the total number of invariants is monodromy-independent for (Z_p)^k appears to be true in general as well. (Talk presented in the parallel session on string theory of the Lepton-Photon/EPS Conference, Geneva, 1991.)

  6. Management of insomnia: current trends

    OpenAIRE

    Rimple Jeet Kaur; Sneha R. Ambwani; Bharati Mehta

    2014-01-01

    Insomnia is one of the most commonly occurring sleep disorders worldwide. With increased prevalence of insomnia the demand of the people seeking pharmacological treatment for this disease is continuously increasing. Numerous options are currently available for its treatment and with our increased understanding of the neurophysiological factors involved in the insomnia continuous research is being conducted to seek newer pharmacological treatments. Recent advancement in treatment of insomnia i...

  7. Current therapy for Parkinson's disease

    OpenAIRE

    A. V. Obukhova

    2014-01-01

    The main goal of therapy for Parkinson's disease (PD) is to correct dopamine deficiency in the nigrostriatal system. Levodopa preparations and dopamine receptor agonists (DRAs) that are prescribed with regards to patient age and disease severity are mainly used now. Notwithstanding the fact that levodopa preparations are the gold standard of therapy, their long-term use gives rise to complications as motor fluctuations and drug-induced dyskinesias. The currently available DRAs are the drugs o...

  8. Social networks user: current research

    OpenAIRE

    Agadullina E.R.

    2015-01-01

    The purpose of this article is to review current research studies focusing on the users of Facebook and their behaviors in social networks. This review is organized into two sections: 1) social-demographic characteristics (Age, Gender, Nationality); 2) personality characteristics (Neuroticism, Extraversion, Openness-to-Experience, Agreeableness, Conscientiousness, Narcissism, Self-esteem). The results showed that the information in the personal profile and online behavior are strongly connect...

  9. Reconciling current approaches to blindsight

    DEFF Research Database (Denmark)

    Overgaard, Morten; Mogensen, Jesper

    2015-01-01

    After decades of research, blindsight is still a mysterious and controversial topic in consciousness research. Currently, many researchers tend to think of it as an ideal phenomenon to investigate neural correlates of consciousness, whereas others believe that blindsight is in fact a kind of degr...... evidence. We propose that the REF-CON model (Overgaard & Mogensen, 2014) may work as such a model. © 2014 Elsevier Inc. All rights reserved....

  10. Current Concept of Geometrical Accuracy

    OpenAIRE

    Görög Augustín; Görögová Ingrid

    2014-01-01

    Within the solving VEGA 1/0615/12 research project "Influence of 5-axis grinding parameters on the shank cutter´s geometric accuracy", the research team will measure and evaluate geometrical accuracy of the produced parts. They will use the contemporary measurement technology (for example the optical 3D scanners). During the past few years, significant changes have occurred in the field of geometrical accuracy. The objective of this contribution is to analyse the current standards in the fiel...

  11. Ultrasound Current Source Density Imaging

    OpenAIRE

    Olafsson, Ragnar; Witte, Russell S.; Huang, Sheng-Wen; O’Donnell, Matthew

    2008-01-01

    Surgery to correct severe heart arrhythmias usually requires detailed maps of the cardiac activation wave prior to ablation. The pinpoint electrical mapping procedure is laborious and limited by its spatial resolution (5–10 mm). We propose ultrasound current source density imaging (UCSDI), a direct 3-D imaging technique that potentially facilitates existing mapping procedures with superior spatial resolution. The technique is based on a pressure-induced change in resistivity known as the acou...

  12. Biofield Science: Current Physics Perspectives

    OpenAIRE

    Kafatos, Menas C.; Chevalier, Gaétan; Chopra, Deepak; Hubacher, John; Kak, Subhash; Theise, Neil D.

    2015-01-01

    This article briefly reviews the biofield hypothesis and its scientific literature. Evidence for the existence of the biofield now exists, and current theoretical foundations are now being developed. A review of the biofield and related topics from the perspective of physical science is needed to identify a common body of knowledge and evaluate possible underlying principles of origin of the biofield. The properties of such a field could be based on electromagnetic fields, coherent states, bi...

  13. Current uses of ophthalmic lasers.

    OpenAIRE

    O'Neill, D; GREGSON, R; McHugh, D

    1992-01-01

    Current laser treatments are quick, relatively painless, and well tolerated. Some ophthalmic techniques can be performed only by laser while others have a lower morbidity than alternative treatments. Peripheral retinal photocoagulation and focal photocoagulation now offer greatly improved visual prognosis for diabetic patients with proliferative diabetic retinopathy or diabetic macular disease. Selected cases of macular degeneration may be treated by focal laser photocoagulation. The role of ...

  14. Current practice for pulmonary hypertension

    Institute of Scientific and Technical Information of China (English)

    Toru Satoh

    2014-01-01

    Objective To investigate the current practice of pulmonary hypertension including current epidemiology,diagnosis and treatment.Data sources The review was based on data obtained from the published articles and guidelines.Study selection Articles with high level of evidence or current best evidence in each issue were selected to be reviewed.Results Overall prevalence of pulmonary hypertension was 0.3% to 6% with left heart disease occupying the most proportion,followed by pulmonary disease,pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension.In diagnosis,a flow diagram of diagnosis of pulmonary hypertension,differential diagnosis of pulmonary hypertension and how to determine the severity of pulmonary hypertension are explained including recent development of magnetic resonance imaging and gene abnormality study on bone morphogenetic protein receptor Ⅱ.In treatment,newlydeveloped pulmonary vasodilators and the way to use them are shown to treat pulmonary hypertension.Conclusion Safer and more effective treatment algorithm and basic researches and clinical trials are warranted to be explored.

  15. Female pattern alopecia: current perspectives.

    Science.gov (United States)

    Levy, Lauren L; Emer, Jason J

    2013-01-01

    Hair loss is a commonly encountered problem in clinical practice, with men presenting with a distinctive pattern involving hairline recession and vertex balding (Norwood-Hamilton classification) and women exhibiting diffuse hair thinning over the crown (increased part width) and sparing of the frontal hairline (Ludwig classification). Female pattern hair loss has a strikingly overwhelming psychological effect; thus, successful treatments are necessary. Difficulty lies in successful treatment interventions, as only two medications - minoxidil and finasteride - are approved for the treatment of androgenetic alopecia, and these medications offer mediocre results, lack of a permanent cure, and potential complications. Hair transplantation is the only current successful permanent option, and it requires surgical procedures. Several other medical options, such as antiandrogens (eg, spironolactone, oral contraceptives, cyproterone, flutamide, dutasteride), prostaglandin analogs (eg, bimatoprost, latanoprost), and ketoconazole are reported to be beneficial. Laser and light therapies have also become popular despite the lack of a profound benefit. Management of expectations is crucial, and the aim of therapy, given the current therapeutic options, is to slow or stop disease progression with contentment despite patient expectations of permanent hair regrowth. This article reviews current perspectives on therapeutic options for female pattern hair loss. PMID:24039457

  16. Female pattern alopecia: current perspectives

    Directory of Open Access Journals (Sweden)

    Levy LL

    2013-08-01

    Full Text Available Lauren L Levy, Jason J Emer Department of Dermatology, Mount Sinai School of Medicine, New York, NY, USA Abstract: Hair loss is a commonly encountered problem in clinical practice, with men presenting with a distinctive pattern involving hairline recession and vertex balding (Norwood-Hamilton classification and women exhibiting diffuse hair thinning over the crown (increased part width and sparing of the frontal hairline (Ludwig classification. Female pattern hair loss has a strikingly overwhelming psychological effect; thus, successful treatments are necessary. Difficulty lies in successful treatment interventions, as only two medications – minoxidil and finasteride – are approved for the treatment of androgenetic alopecia, and these medications offer mediocre results, lack of a permanent cure, and potential complications. Hair transplantation is the only current successful permanent option, and it requires surgical procedures. Several other medical options, such as antiandrogens (eg, spironolactone, oral contraceptives, cyproterone, flutamide, dutasteride, prostaglandin analogs (eg, bimatoprost, latanoprost, and ketoconazole are reported to be beneficial. Laser and light therapies have also become popular despite the lack of a profound benefit. Management of expectations is crucial, and the aim of therapy, given the current therapeutic options, is to slow or stop disease progression with contentment despite patient expectations of permanent hair regrowth. This article reviews current perspectives on therapeutic options for female pattern hair loss. Keywords: androgenetic alopecia, female pattern hair loss, minoxidil, finasteride, antiandrogens, spironolactone

  17. Reconnection in thin current sheets

    Science.gov (United States)

    Tenerani, Anna; Velli, Marco; Pucci, Fulvia; Rappazzo, A. F.

    2016-05-01

    It has been widely believed that reconnection is the underlying mechanism of many explosive processes observed both in nature and laboratory, but the question of reconnection speed and initial trigger have remained mysterious. How is fast magnetic energy release triggered in high Lundquist (S) and Reynolds (R) number plasmas?It has been shown that a tearing mode instability can grow on an ideal timescale, i.e., independent from the the Lundquist number, once the current sheet thickness becomes thin enough, or rather the inverse aspect ratio a/L reaches a scale a/L~S-1/3. As such, the latter provides a natural, critical threshold for current sheets that can be formed in nature before they disrupt in a few Alfvén time units. Here we discuss the transition to fast reconnection extended to simple viscous and kinetic models and we propose a possible scenario for the transition to explosive reconnection in high-Lundquist number plasmas, that we support with fully nonlinear numerical MHD simulations of a collapsing current sheet.

  18. Internet gaming addiction: current perspectives

    Science.gov (United States)

    Kuss, Daria J

    2013-01-01

    In the 2000s, online games became popular, while studies of Internet gaming addiction emerged, outlining the negative consequences of excessive gaming, its prevalence, and associated risk factors. The establishment of specialized treatment centers in South-East Asia, the US, and Europe reflects the growing need for professional help. It is argued that only by understanding the appeal of Internet gaming, its context, and neurobiologic correlates can the phenomenon of Internet gaming addiction be understood comprehensively. The aim of this review is to provide an insight into current perspectives on Internet gaming addiction using a holistic approach, taking into consideration the mass appeal of online games, the context of Internet gaming addiction, and associated neuroimaging findings, as well as the current diagnostic framework adopted by the American Psychiatric Association. The cited research indicates that the individual’s context is a significant factor that marks the dividing line between excessive gaming and gaming addiction, and the game context can gain particular importance for players, depending on their life situation and gaming preferences. Moreover, the cultural context is significant because it embeds the gamer in a community with shared beliefs and practices, endowing their gaming with particular meaning. The cited neuroimaging studies indicate that Internet gaming addiction shares similarities with other addictions, including substance dependence, at the molecular, neurocircuitry, and behavioral levels. The findings provide support for the current perspective of understanding Internet gaming addiction from a disease framework. The benefits of an Internet gaming addiction diagnosis include reliability across research, destigmatization of individuals, development of efficacious treatments, and the creation of an incentive for public health care and insurance providers. The holistic approach adopted here not only highlights empirical research that

  19. Power quality issues current harmonics

    CERN Document Server

    Mikkili, Suresh

    2015-01-01

    Power Quality Issues: Current Harmonics provides solutions for the mitigation of power quality problems related to harmonics. Focusing on active power filters (APFs) due to their excellent harmonic and reactive power compensation in two-wire (single phase), three-wire (three-phase without neutral), and four-wire (three-phase with neutral) AC power networks with nonlinear loads, the text:Introduces the APF technology, describing various APF configurations and offering guidelines for the selection of APFs for specific application considerationsCompares shunt active filter (SHAF) control strategi

  20. Topics in current aerosol research

    CERN Document Server

    Hidy, G M

    1971-01-01

    Topics in Current Aerosol Research deals with the fundamental aspects of aerosol science, with emphasis on experiment and theory describing highly dispersed aerosols (HDAs) as well as the dynamics of charged suspensions. Topics covered range from the basic properties of HDAs to their formation and methods of generation; sources of electric charges; interactions between fluid and aerosol particles; and one-dimensional motion of charged cloud of particles. This volume is comprised of 13 chapters and begins with an introduction to the basic properties of HDAs, followed by a discussion on the form

  1. Short, high current electrodynamic tether

    OpenAIRE

    Savich, N.A.; Sanmartín Losada, Juan Ramón

    1994-01-01

    An electrodynamic tether experiment, to be carried out in the Russian spacecraft Almaz, is proposed. A 10 km tether would be deployed downwards; the lower 8 km would be nonconductive, the upper 2 km would be conductive, bare, and 2.2 mm in diameter, and would act as a thruster, with power supply at the top. This hybrid arrangement allows for other, onelectrodynamic experiments,reducing costs; it also limits the induced electromotive force, reducing the power to be handled. The current-volt...

  2. Transient eddy current flow metering

    Science.gov (United States)

    Forbriger, J.; Stefani, F.

    2015-10-01

    Measuring local velocities or entire flow rates in liquid metals or semiconductor melts is a notorious problem in many industrial applications, including metal casting and silicon crystal growth. We present a new variant of an old technique which relies on the continuous tracking of a flow-advected transient eddy current that is induced by a pulsed external magnetic field. This calibration-free method is validated by applying it to the velocity of a spinning disk made of aluminum. First tests at a rig with a flow of liquid GaInSn are also presented.

  3. Transient eddy current flow metering

    CERN Document Server

    Forbriger, Jan

    2015-01-01

    Measuring local velocities or entire flow rates in liquid metals or semiconductor melts is a notorious problem in many industrial applications, including metal casting and silicon crystal growth. We present a new variant of an old technique which relies on the continuous tracking of a flow-advected transient eddy current that is induced by a pulsed external magnetic field. This calibration-free method is validated by applying it to the velocity of a spinning disk made of aluminum. First tests at a rig with a flow of liquid GaInSn are also presented.

  4. Nerve lesioning with direct current

    Science.gov (United States)

    Ravid, E. Natalie; Shi Gan, Liu; Todd, Kathryn; Prochazka, Arthur

    2011-02-01

    Spastic hypertonus (muscle over-activity due to exaggerated stretch reflexes) often develops in people with stroke, cerebral palsy, multiple sclerosis and spinal cord injury. Lesioning of nerves, e.g. with phenol or botulinum toxin is widely performed to reduce spastic hypertonus. We have explored the use of direct electrical current (DC) to lesion peripheral nerves. In a series of animal experiments, DC reduced muscle force by controlled amounts and the reduction could last several months. We conclude that in some cases controlled DC lesioning may provide an effective alternative to the less controllable molecular treatments available today.

  5. Current Science: Some early history

    OpenAIRE

    Krishnan, Riki; Balaram, P.

    2007-01-01

    1932, the year in which Current Science was born, saw the world in the midst of transition. Europe, then the centre of science had the First World War well behind it and was purposefully heading towards the Second War. The demand for selfgovernance and independence in India was rapidly zaining ground. The major revolution in atomic physics had already reached its high point. C. V. Raman had announced the discovery of the ‘Raman effect’ in 1928 and had been recognized with the Nobel Prize, in ...

  6. Detection of neutral current events

    International Nuclear Information System (INIS)

    The topics investigated in the course of the study can be broadly divided into three classes: (i) Inclusive measurements of the scattered electron for the determination of structure functions, scaling violations, deltaL/deltaT and weak interaction effects. (ii) Exclusive measurements of the current jet (momentum, energy, particle composition) for the study of fragmentation functions, for search of new particles, new quarks and QCD effects in the jet. (iii) Search for heavy leptons by detection and identification of their decay products. (orig.)

  7. Xerostomia: current streams of investigation.

    Science.gov (United States)

    Quock, Ryan L

    2016-07-01

    Xerostomia is the subjective feeling of dry mouth, and it is often related to salivary hypofunction. Besides medication-related salivary hypofunction, Sjögren syndrome and head-and-neck radiation are two common etiologies that have garnered considerable attention. Approaches to treating and/or preventing salivary hypofunction in patients with these conditions will likely incorporate gene therapy, stem cell therapy, and tissue engineering. Advances in these disciplines are central to current research in the cure for xerostomia and will be key to eventual treatment. PMID:27189896

  8. Current algebra; Algebre des courants

    Energy Technology Data Exchange (ETDEWEB)

    Jacob, M. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1967-07-01

    The first three chapters of these lecture notes are devoted to generalities concerning current algebra. The weak currents are defined, and their main properties given (V-A hypothesis, conserved vector current, selection rules, partially conserved axial current,...). The SU (3) x SU (3) algebra of Gell-Mann is introduced, and the general properties of the non-leptonic weak Hamiltonian are discussed. Chapters 4 to 9 are devoted to some important applications of the algebra. First one proves the Adler- Weisberger formula, in two different ways, by either the infinite momentum frame, or the near-by singularities method. In the others chapters, the latter method is the only one used. The following topics are successively dealt with: semi leptonic decays of K mesons and hyperons, Kroll- Ruderman theorem, non leptonic decays of K mesons and hyperons ( {delta}I = 1/2 rule), low energy theorems concerning processes with emission (or absorption) of a pion or a photon, super-convergence sum rules, and finally, neutrino reactions. (author) [French] La premiere partie de ce cours (trois premiers chapitres), traite des generalites concernant l'algebre de courants. Apres une definition rapide des courants faibles et un rappel de leurs proprietes (hypothese V-A, conservation du courant vecteur, regles de selection, courant axial partiellement conserve,...), l'on introduit l'algebre de Gell-Mann SU (3) x SU (3), et discute les proprietes generales de l'Hamiltonien faible non leptonique. Les chapitres IV a IX sont consacres a des applications importantes de l'algebre des courants. En premier lieu l'on demontre la formule de Adler et Weisberger, par deux methodes differentes, celle dite du repere de moment infini et celle des singularites proches. Cette derniere est seule utilisee dans la suite. Puis, l'on traite successivement les problemes suivants: desintegrations semi-leptoniques des mesons K et des hyperons, theoreme de Kroll

  9. Internet gaming addiction: current perspectives

    Directory of Open Access Journals (Sweden)

    Kuss DJ

    2013-11-01

    Full Text Available Daria J KussPsychology Research and Behavior Management, Birmingham City University, Birmingham, UKAbstract: In the 2000s, online games became popular, while studies of Internet gaming addiction emerged, outlining the negative consequences of excessive gaming, its prevalence, and associated risk factors. The establishment of specialized treatment centers in South-East Asia, the US, and Europe reflects the growing need for professional help. It is argued that only by understanding the appeal of Internet gaming, its context, and neurobiologic correlates can the phenomenon of Internet gaming addiction be understood comprehensively. The aim of this review is to provide an insight into current perspectives on Internet gaming addiction using a holistic approach, taking into consideration the mass appeal of online games, the context of Internet gaming addiction, and associated neuroimaging findings, as well as the current diagnostic framework adopted by the American Psychiatric Association. The cited research indicates that the individual's context is a significant factor that marks the dividing line between excessive gaming and gaming addiction, and the game context can gain particular importance for players, depending on their life situation and gaming preferences. Moreover, the cultural context is significant because it embeds the gamer in a community with shared beliefs and practices, endowing their gaming with particular meaning. The cited neuroimaging studies indicate that Internet gaming addiction shares similarities with other addictions, including substance dependence, at the molecular, neurocircuitry, and behavioral levels. The findings provide support for the current perspective of understanding Internet gaming addiction from a disease framework. The benefits of an Internet gaming addiction diagnosis include reliability across research, destigmatization of individuals, development of efficacious treatments, and the creation of an incentive

  10. Psychiatry beyond the current paradigm.

    LENUS (Irish Health Repository)

    Bracken, Pat

    2012-12-01

    A series of editorials in this Journal have argued that psychiatry is in the midst of a crisis. The various solutions proposed would all involve a strengthening of psychiatry\\'s identity as essentially \\'applied neuroscience\\'. Although not discounting the importance of the brain sciences and psychopharmacology, we argue that psychiatry needs to move beyond the dominance of the current, technological paradigm. This would be more in keeping with the evidence about how positive outcomes are achieved and could also serve to foster more meaningful collaboration with the growing service user movement.

  11. DESY: Handling persistent eddy currents

    International Nuclear Information System (INIS)

    The vanishing electrical resistance of superconducting coils as well as their ability to provide magnetic fields far beyond those of saturated iron is the main motivation behind the push to use superconducting technology in big new proton accelerators. But this advantage can turn into a drawback at low excitations when the eddy currents - induced in any electromagnet when the field is changed - do not decay, but continue to flow. Preparations for the proton ring of the HERA electron-proton collider nearing completion at the German DESY Laboratory in Hamburg have borne this in mind

  12. Current considerations on teenage pregnancy

    Directory of Open Access Journals (Sweden)

    Camila Cristina Manfré

    2011-03-01

    Full Text Available Teenage pregnancy has acquired significant proportions. It is estimated that 20 to 25% of all pregnant women in Brazil are teenagers. The present study, through an analysis of the current literature, examines the main aspects involving pregnancy during adolescence, along with its consequences on the life of young mothers, their children and social environment. We conclude that the efforts of health care professionals, parents and educators are crucial to increase awareness of adolescent sexuality. The application of this knowledge is a way to prevent teen pregnancy, thus avoiding the harmful effects on young mothers and their children.

  13. Sinoprobe Datacenter Development: Current Status

    Science.gov (United States)

    Guan, Y.; Dong, S.; Chen, Z.; Chen, G.; Cheng, M.

    2011-12-01

    The project of the Sinoprobe datacenter development is to build new IT infrastructures needed to store, visualize and manage all the data acquired by SinoProbe program.The SinoProbe data center is designed using service-oriented architecture (SOA) principles. More specifically, service component architecture (SCA) is used to implement sinoprobe data services. It also uses various advanced technologies such as Java/JEE for the platform, PostgresSQL/PostGIS for the data storage, ApacheDS for LDAP, CoachDB for the medadata storage, GeoServer for the GIS services, ExtJs and OpenLayer for the Ajax framework, and Apache Shiro for the security framework. Through the integration and development of various technologies used, the major services of the datacenter system are implemented including the security infrastructure services (user authentication and authorization), metadata services, data warehouse stores, data services, GIS services, and web portal. There are also visualization components including the development of a virtual globe to replace the currently used Google Earth. This poster presents the current status of the SinoProbe data center development, and the detailed discussion of the system.

  14. Past and Current Climate Change

    Science.gov (United States)

    Mercedes Rodríguez Ruibal, Ma

    2014-05-01

    In 1837 the Swiss geologist and palaeontologist Louis Agassiz was the first scientist to propose the existence of an ice age in the Earth's past. Nearly two centuries after discussing global glacial periods... while the average global temperature is rising very quickly because of our economic and industrial model. In tribute to these pioneers, we have selected a major climate change of the past as the Snowball Earth and, through various activities in the classroom, compared to the current anthropogenic climate change. First, we include multiple geological processes that led to a global glaciation 750 million years ago as the decrease in the atmospheric concentration of greenhouse gases such as CO2 and CH4, the effect of climate variations in solar radiation due to emissions of volcanic dust and orbital changes (Milankovitch cycles), being an essential part of this model the feedback mechanism of the albedo of the ice on a geological scale. Moreover, from simple experiments and studies in the classroom this time we can compare the past with the current anthropogenic global warming we are experiencing and some of its consequences, highlighting that affect sea level rise, increased extreme and effects on health and the biosphere weather.

  15. Current procedural terminology; a primer.

    Science.gov (United States)

    Hirsch, Joshua A; Leslie-Mazwi, Thabele M; Nicola, Gregory N; Barr, Robert M; Bello, Jacqueline A; Donovan, William D; Tu, Raymond; Alson, Mark D; Manchikanti, Laxmaiah

    2015-04-01

    In 1966, The American Medical Association (AMA) working with multiple major medical specialty societies developed an iterative coding system for describing medical procedures and services using uniform language, the Current Procedural Terminology (CPT) system. The current code set, CPT IV, forms the basis of reporting most of the services performed by healthcare providers, physicians and non-physicians as well as facilities allowing effective, reliable communication among physician and other providers, third parties and patients. This coding system and its maintenance has evolved significantly since its inception, and now goes well beyond its readily perceived role in reimbursement. Additional roles include administrative management, tracking new and investigational procedures, and evolving aspects of 'pay for performance'. The system also allows for local, regional and national utilization comparisons for medical education and research. Neurointerventional specialists use CPT category I codes regularly--for example, 36,215 for first-order cerebrovascular angiography, 36,216 for second-order vessels, and 37,184 for acute stroke treatment by mechanical means. Additionally, physicians add relevant modifiers to the CPT codes, such as '-26' to indicate 'professional charge only,' or '-59' to indicate a distinct procedural service performed on the same day. PMID:24589819

  16. Current knowledge on esophageal atresia

    Institute of Scientific and Technical Information of China (English)

    Paulo Fernando Martins Pinheiro; Ana Cristina Sim(o)es e Silva; Regina Maria Pereira

    2012-01-01

    Esophageal atresia (EA) with or without tracheoesophageal fistula (TEF) is the most common congenital anomaly of the esophagus.The improvement of survival observed over the previous two decades is multifactorial and largely attributable to advances in neonatal intensive care,neonatal anesthesia,ventilatory and nutritional support,antibiotics,early surgical intervention,surgical materials and techniques.Indeed,mortality is currently limited to those cases with coexisting severe life-threatening anomalies.The diagnosis of EA is most commonly made during the first 24 h of life but may occur either antenatally or may be delayed.The primary surgical correction for EA and TEF is the best option in the absence of severe malformations.There is no ideal replacement for the esophagus and the optimal surgical treatment for patients with long-gap EA is still controversial.The primary complications during the postoperative period are leak and stenosis of the anastomosis,gastro-esophageal reflux,esophageal dysmotility,fistula recurrence,respiratory disorders and deformities of the thoracic wall.Data regarding long-term outcomes and follow-ups are limited for patients following EA/TEF repair.The determination of the risk factors for the complicated evolution following EA/TEF repair may positively impact long-term prognoses.Much remains to be studied regarding this condition.This manuscript provides a literature review of the current knowledge regarding EA.

  17. High Critical Current Coated Conductors

    Energy Technology Data Exchange (ETDEWEB)

    Paranthaman, M. P.; Selvamanickam, V. (SuperPower, Inc.)

    2011-12-27

    One of the important critical needs that came out of the DOE’s coated conductor workshop was to develop a high throughput and economic deposition process for YBCO. Metal-organic chemical vapor deposition (MOCVD) technique, the most critical steps in high technical micro fabrications, has been widely employed in semiconductor industry for various thin film growth. SuperPower has demonstrated that (Y,Gd)BCO films can be deposited rapid with world record performance. In addition to high critical current density with increased film thickness, flux pinning properties of REBCO films needs to be improved to meet the DOE requirements for various electric-power equipments. We have shown that doping with Zr can result in BZO nanocolumns, but at substantially reduced deposition rate. The primary purpose of this subtask is to develop high current density MOCVD-REBCO coated conductors based on the ion-beam assisted (IBAD)-MgO deposition process. Another purpose of this subtask is to investigate HTS conductor design optimization (maximize Je) with emphasis on stability and protection issues, and ac loss for REBCO coated conductors.

  18. Geomagnetically induced currents in Europe

    Directory of Open Access Journals (Sweden)

    Viljanen Ari

    2014-03-01

    Full Text Available Statistics of geomagnetically induced currents (GIC in the European high-voltage power grids based on 1-min geomagnetic recordings in 1996–2008 and on 1-D models of the ground conductivity have been derived in the EURISGIC project (European Risk from Geomagnetically Induced Currents. The simplified yet realistic power grid model indicates that large GIC can occur anywhere in Europe. However, geomagnetic variations are clearly larger in North Europe, so it is the likely region of significant GIC events. Additionally, there are areas in the North with especially low ground conductivities, which further tend to increase GIC. The largest modelled GIC values at single substations in 1996–2008 are about 400 A in the Nordic Countries, about 100 A in the British Isles, about 80 A in the Baltic Countries, and less than 50 A in Central and South Europe. The largest GIC event in the period studied is the Halloween storm on 29–30 October 2003, and the next largest ones occurred on 15 July 2000 and 9 November 2004.

  19. Current status of Japanese detectors

    CERN Document Server

    Tatsumi, Daisuke; Arai, Koji; Nakagawa, Noriyasu; Agatsuma, Kazuhiro; Yamazaki, Toshitaka; Fukushima, Mitsuhiro; Fujimoto, Masa-Katsu; Takamori, Akiteru; Bertolini, Alessandro; Sannibale, Virginio; DeSalvo, Riccardo; Marka, Szabolcs; Ando, Masaki; Tsubono, Kimio; Akutsu, Tomomi; Yamamoto, Kazuhiro; Ishitsuka, Hideki; Uchiyama, Takashi; Miyoki, Shinji; Ohashi, Masatake; Kuroda, Kazuaki; Awaya, Norichika; Kanda, Nobuyuki; Araya, Akito; Telada, Souichi; Tomaru, Takayuki; Haruyama, Tomiyoshi; Yamamoto, Akira; Sato, Nobuaki; Suzuki, Toshitaka; Shintomi, Takakazu

    2007-01-01

    Current status of TAMA and CLIO detectors in Japan is reported in this article. These two interferometric gravitational-wave detectors are being developed for the large cryogenic gravitational wave telescope (LCGT) which is a future plan for detecting gravitational wave signals at least once per year. TAMA300 is being upgraded to improve the sensitivity in low frequency region after the last observation experiment in 2004. To reduce the seismic noises, we are installing new seismic isolation system, which is called TAMA Seismic Attenuation System, for the four test masses. We confirmed stable mass locks of a cavity and improvements of length and angular fluctuations by using two SASs. We are currently optimizing the performance of the third and fourth SASs. We continue TAMA300 operation and R&D studies for LCGT. Next data taking in the summer of 2007 is planned. CLIO is a 100-m baseline length prototype detector for LCGT to investigate interferometer performance in cryogenic condition. The key features of...

  20. [Current Approaches in Cancer Immunotherapy].

    Science.gov (United States)

    Otáhal, P; Trněný, M

    2015-01-01

    Methods of cancer immunotherapy have finally entered clinical medicine after years of preclinical research. Currently, there are several methods, which have proven to be very effective even in cases of incurable cancer. Antitumor monoclonal antibodies are among major therapeutic anti-cancer drugs and have been successfully used for many ears. Novel group of antibodies are immunomodulatory antibodies which can break tumor -specific immune tolerance and induce regression of tumors by nonspecific activation of immune system. Bispecific antibodies represent a novel class of anticancer agents which can induce expansion of T cells in vivo, blinatumomab is an example of such agents and is currently available for the treatment of acute B -cell leukemia. Cellular immunotherapy is also very effective, especially the use of Chimeric receptor modified T-cells for the therapy of B- cell lymphoproliferative diseases. Although it is a very complicated and expensive method, it is highly effective approach which can induce remission even in previously hopeless conditions. The goal of this article is to explain the basic principles of cancer immunotherapy and summarize the newest findings in this field.

  1. Current conveyors variants, applications and hardware implementations

    CERN Document Server

    Senani, Raj; Singh, A K

    2015-01-01

    This book serves as a single-source reference to Current Conveyors and their use in modern Analog Circuit Design. The authors describe the various types of current conveyors discovered over the past 45 years, details of all currently available, off-the-shelf integrated circuit current conveyors, and implementations of current conveyors using other, off-the-shelf IC building blocks. Coverage includes prominent bipolar/CMOS/Bi-CMOS architectures of current conveyors, as well as all varieties of starting from third generation current conveyors to universal current conveyors, their implementations and applications. •Describes all commercially available off-the-shelf IC current conveyors, as well as hardware implementations of current conveyors using other off-the-shelf ICs; • Describes numerous variants of current conveyors evolved over the past forty five years; • Describes a number of Bipolar/CMOS/Bi-CMOS architectures of current conveyors, along with their characteristic features; • Includes a comprehe...

  2. Rosacea: current state of epidemiology.

    Science.gov (United States)

    Tan, Jerry; Berg, Mats

    2013-12-01

    Case definitions are critical in epidemiologic research. However, modern disease indicators must now consider complex data from gene-based research along with traditional clinical parameters. Rosacea is a skin disorder with multiple signs and symptoms. In individuals, these features may be multiple or one may predominate. While studies on the epidemiology of rosacea have previously been sparse, there has been a recent increase in research activity. A broader body of epidemiological information that includes a greater variety of countries beyond Northern Europe and general population-based demographics is needed. As there are operational issues in current case definitions of rosacea subtypes--rationalization and standardization--universal consistent applications in future research is also imperative. Further improvement in disease definition combining new research information along with clinical pragmatism should increase the accuracy of rosacea case ascertainment and facilitate further epidemiological research.

  3. Biofield Science: Current Physics Perspectives.

    Science.gov (United States)

    Kafatos, Menas C; Chevalier, Gaétan; Chopra, Deepak; Hubacher, John; Kak, Subhash; Theise, Neil D

    2015-11-01

    This article briefly reviews the biofield hypothesis and its scientific literature. Evidence for the existence of the biofield now exists, and current theoretical foundations are now being developed. A review of the biofield and related topics from the perspective of physical science is needed to identify a common body of knowledge and evaluate possible underlying principles of origin of the biofield. The properties of such a field could be based on electromagnetic fields, coherent states, biophotons, quantum and quantum-like processes, and ultimately the quantum vacuum. Given this evidence, we intend to inquire and discuss how the existence of the biofield challenges reductionist approaches and presents its own challenges regarding the origin and source of the biofield, the specific evidence for its existence, its relation to biology, and last but not least, how it may inform an integrated understanding of consciousness and the living universe.

  4. Electroconvulsive Therapy: A Current Review

    Directory of Open Access Journals (Sweden)

    Gokben Hizli Sayar

    2014-06-01

    Full Text Available Most of the electroconvulsive therapy guidelines state that severe major depression with psychotic features, manic delirium, or catatonia are conditions where there is a clear consensus favoring early electroconvulsive therapy. The decision to administer electroconvulsive therapy is based on an evaluation of the risks and benefits for the individual patient and involves a combination of factors, including psychiatric diagnosis, type and severity of symptoms, prior treatment history and response, identification of possible alternative treatment options, and consumer preference. In this review history, mechanisms of action, side effects that have been referenced in the literature and clinical experience are discussed. [Psikiyatride Guncel Yaklasimlar - Current Approaches in Psychiatry 2014; 6(2.000: 107-125

  5. Optical currents in vector fields

    DEFF Research Database (Denmark)

    Angelsky, O. V.; Gorsky, M. P.; Maksimyak, P. P.;

    2011-01-01

    The influence of phase relations and the degree of mutual coherence of superimposing waves in the arrangements of twowave superposition on the characteristics of the microparticle's motion has been analyzed. The prospects of studying temporal coherence using the proposed approach are made. For th....... For the first time, we have shown experimentally the possibility of diagnostics the optical currents in liquids caused by polarization characteristics of an optical field alone, using test metallic particles of nanoscale.......The influence of phase relations and the degree of mutual coherence of superimposing waves in the arrangements of twowave superposition on the characteristics of the microparticle's motion has been analyzed. The prospects of studying temporal coherence using the proposed approach are made...

  6. Current Developments in Cognitive Linguistics

    Institute of Scientific and Technical Information of China (English)

    Dirk Geeraerts

    2008-01-01

    After 30 years of theoretical development, we need to address the question whether the internal evolution of Cognitive Linguistics can be synthesized: what are the fundamental underlying trends in Cognitive Linguistics, and how do they shape the current developments within Cognitive Linguistics? This paper argues that Cognitive Linguistics is essentially characterized by a gradual recontextualization of the grammar. First, the development of 20th century grammar is characterized by a succession of a decontextualizing and a recontextualizing movement. Second, the various stages in the development of Cognitive Linguistics involve the gradual recovery of the various types of context that were discarded by generative grammar. These involve the experiential and embodied context of meaning in natural Language, the pragmatic context of actual language usage, and the social and cultural context of language as a shared code.

  7. Familial Mediterranean fever: current perspectives.

    Science.gov (United States)

    Sönmez, Hafize Emine; Batu, Ezgi Deniz; Özen, Seza

    2016-01-01

    Familial Mediterranean fever (FMF) is the most frequent monogenic autoinflammatory disease, and it is characterized by recurrent attacks of fever and polyserositis. The disease is associated with mutations in the MEFV gene encoding pyrin, which causes exaggerated inflammatory response through uncontrolled production of interleukin 1. The major long-term complication of FMF is amyloidosis. Colchicine remains the principle therapy, and the aim of treatment is to prevent acute attacks and the consequences of chronic inflammation. With the evolution in the concepts about the etiopathogenesis and genetics of the disease, we have understood that FMF is more complicated than an ordinary autosomal recessive monogenic disorder. Recently, recommendation sets have been generated for interpretation of genetic testing and genetic diagnosis of FMF. Here, we have reviewed the current perspectives in FMF in light of recent recommendations. PMID:27051312

  8. HIGH CURRENT COAXIAL PHOTOMULTIPLIER TUBE

    Science.gov (United States)

    Glass, N.W.

    1960-01-19

    A medium-gain photomultiplier tube having high current output, fast rise- time, and matched output impedance was developed. The photomultiplier tube comprises an elongated cylindrical envelope, a cylindrical anode supported at the axis of the envelope, a plurality of elongated spaced opaque areas on the envelope, and a plurality of light admitting windows. A photo-cathode is supported adjacent to each of the windows, and a plurality of secondary emissive dynodes are arranged in two types of radial arrays which are alternately positioned to fill the annular space between the anode and the envelope. The dynodes are in an array being radially staggered with respect to the dynodes in the adjacent array, the dynodes each having a portion arranged at an angle with respect to the electron path, such that electrons emitted by each cathode undergo multiplication upon impingement on a dynode and redirected flight to the next adjacent dynode.

  9. Current perspectives on reflux laryngitis.

    Science.gov (United States)

    Asaoka, Daisuke; Nagahara, Akihito; Matsumoto, Kenshi; Hojo, Mariko; Watanabe, Sumio

    2014-12-01

    Laryngopharyngeal reflux (LPR) is an extraesophageal manifestation of gastroesophageal reflux disease (GERD). With the increase of GERD patients, the importance of LPR is acknowledged widely. However, the pathophysiology of LPR is not understood completely and the diagnostic criteria for LPR remain controversial. Unfortunately, a gold standard diagnostic test for reflux laryngitis is not available. Recently, an experimental animal model for reflux laryngitis was developed to investigate the pathophysiology of reflux laryngitis. An empirical trial of lifestyle modification and proton pump inhibitor therapy is a reasonable approach for LPR symptoms. Alternatives after failure with aggressive medical treatment are limited and multichannel intraluminal impedance and pH monitoring is currently the best alternative to detect nonacid reflux. Additional prospective and evidence-based research is anticipated.

  10. Current Ideas about Prebiological Compartmentalization

    Directory of Open Access Journals (Sweden)

    Pierre-Alain Monnard

    2015-04-01

    Full Text Available Contemporary biological cells are highly sophisticated dynamic compartment systems which separate an internal volume from the external medium through a boundary, which controls, in complex ways, the exchange of matter and energy between the cell’s interior and the environment. Since such compartmentalization is a fundamental principle of all forms of life, scenarios have been elaborated about the emergence of prebiological compartments on early Earth, in particular about their likely structural characteristics and dynamic features. Chemical systems that consist of potentially prebiological compartments and chemical reaction networks have been designed to model pre-cellular systems. These systems are often referred to as “protocells”. Past and current protocell model systems are presented and compared. Since the prebiotic formation of cell-like compartments is directly linked to the prebiotic availability of compartment building blocks, a few aspects on the likely chemical inventory on the early Earth are also summarized.

  11. Collagen cross linking: Current perspectives

    Directory of Open Access Journals (Sweden)

    Srinivas K Rao

    2013-01-01

    Full Text Available Keratoconus is a common ectatic disorder occurring in more than 1 in 1,000 individuals. The condition typically starts in adolescence and early adulthood. It is a disease with an uncertain cause and its progression is unpredictable, but in extreme cases, vision deteriorates and can require corneal transplant surgery. Corneal collagen cross-linking (CCL with riboflavin (C3R is a recent treatment option that can enhance the rigidity of the cornea and prevent disease progression. Since its inception, the procedure has evolved with newer instrumentation, surgical techniques, and is also now performed for expanded indications other than keratoconus. With increasing experience, newer guidelines regarding optimization of patient selection, the spectrum of complications and their management, and combination procedures are being described. This article in conjunction with the others in this issue, will try and explore the uses of collagen cross-linking (CXL in its current form.

  12. Rotating concave eddy current probe

    Science.gov (United States)

    Roach, Dennis P.; Walkington, Phil; Rackow, Kirk A.; Hohman, Ed

    2008-04-01

    A rotating concave eddy current probe for detecting fatigue cracks hidden from view underneath the head of a raised head fastener, such as a buttonhead-type rivet, used to join together structural skins, such as aluminum aircraft skins. The probe has a recessed concave dimple in its bottom surface that closely conforms to the shape of the raised head. The concave dimple holds the probe in good alignment on top of the rivet while the probe is rotated around the rivet's centerline. One or more magnetic coils are rigidly embedded within the probe's cylindrical body, which is made of a non-conducting material. This design overcomes the inspection impediment associated with widely varying conductivity in fastened joints.

  13. Current status of intrahepatic cholangiocarcinoma

    Institute of Scientific and Technical Information of China (English)

    Jian Yang; Lu-Nan Yan

    2008-01-01

    Intrahepatlc cholangiocarcinoma (ICC) is a rare primary liver cancer with a global increasing trend in recent years. Symptoms tend to be vague and insidious in development, often are diagnosed at an advanced stage when only palliative approaches can be used with a median survival rate of months. Comparing with HCC, ICC tends to spread to lymph nodes early, and is rarely limited to the regional lymph nodes, with a frequent postoperative recurrence. Surgery is the only choice of curative therapy for ICC, but recently no consensus has been established for operation. Thus, more data from multiple centers and more cases are needed. Generally speaking, current adjunctive therapy cannot clearly improve survival. Further research is needed to find more effective radio- and chemotherapeutic regimens.

  14. EDITORIAL: MUSLIM WORLD CURRENT ISSUES

    Directory of Open Access Journals (Sweden)

    Editor Al-Jami'ah: Journal of Islamic Studies

    2006-01-01

    Full Text Available Globalisation has proofed its self as a very spectacular phenomenon until no one may deny its impacts, but on the other hand, it reflexively suggests localization of the global. In this context, religion is not exclusion. It remains believed however, that religion still has its formula for solving the problems that emerged from globalisation. Scholars have devoted attempts to propose new ideas for this challenge. Local interpretations of symbols representing “global” Islam, for instance, increasingly grow in line with the growth of Islamic revival. This has drawn very much attention and responses from Muslims, whether to protest against or support for the new idea. The present edition of the journal is designed to more deeply explore the current issues from Muslim world, whether as very local phenomena or in a more global context.

  15. Current trends in plant breeding

    International Nuclear Information System (INIS)

    The current world population is 6 billion and it is likely to reach 7 billion in 2010 and 8 billion 2025. Sufficient food must be produced for the ever increasing human population. The available suitable land for intensive agriculture is limited. We have to produce more food from less land, pesticide, labour and water resources. Hence, increase in crop productivity are essential to feed the world in the next century. Plant breeding provides the avenue to increase the food production to feed the growing world population. Development of a cultivar involves (I) Construction of a genetic model (II) creating a gene pool (III) selection among plants and (IV) testing the selected genotypes for adaptation to the biotic and abiotic environments (Frey, 1999). This paper discusses the trends in plant breeding using the oil palm as a model. It covers (i) genetic resources (ii) physiological traits (III) exploitation of genotype x environment interaction (IV) oil palm clones, and (v) biotechnology application. (Author)

  16. CURRENT CONCEPTS IN ACL RECONSTRUCTION

    Directory of Open Access Journals (Sweden)

    Freddie H. Fu

    2008-09-01

    Full Text Available Current Concepts in ACL Reconstruction is a complete reference text composed of the most thorough collection of topics on the ACL and its surgical reconstruction compiled, with contributions from some of the world's experts and most experienced ACL surgeons. Various procedures mentioned throughout the text are also demonstrated in an accompanying video CD-ROM. PURPOSE Composing a single, comprehensive and complete information source on ACL including basic sciences, clinical issues, latest concepts and surgical techniques, from evaluation to outcome, from history to future, editors and contributors have targeted to keep the audience pace with the latest concepts and techniques for the evaluation and the treatment of ACL injuries. FEATURES The text is composed of 27 chapters in 6 sections. The first section is mostly about basic sciences, also history of the ACL, imaging, clinical approach to adolescent and pediatric patients are subjected. In the second section, Graft Choices and Arthroscopy Portals for ACL Reconstruction are mentioned. The third section is about the technique and the outcome of the single-bundle ACL reconstruction. The fourth chapter includes the techniques and outcome of the double-bundle ACL reconstruction. In the fifth chapter revision, navigation technology, rehabilitation and the evaluation of the outcome of ACL reconstruction is subjected. The sixth/the last chapter is about the future advances to reach: What We Have Learned and the Future of ACL Reconstruction. AUDIENCE Orthopedic residents, sports traumatology and knee surgery fellows, orthopedic surgeons, also scientists in basic sciences or clinicians who are studying or planning a research on ACL forms the audience group of this book. ASSESSMENT This is the latest, the most complete and comprehensive textbook of ACL reconstruction produced by the editorial work up of two pioneer and masters "Freddie H. Fu MD and Steven B. Cohen MD" with the contribution of world

  17. Biofield Science: Current Physics Perspectives.

    Science.gov (United States)

    Kafatos, Menas C; Chevalier, Gaétan; Chopra, Deepak; Hubacher, John; Kak, Subhash; Theise, Neil D

    2015-11-01

    This article briefly reviews the biofield hypothesis and its scientific literature. Evidence for the existence of the biofield now exists, and current theoretical foundations are now being developed. A review of the biofield and related topics from the perspective of physical science is needed to identify a common body of knowledge and evaluate possible underlying principles of origin of the biofield. The properties of such a field could be based on electromagnetic fields, coherent states, biophotons, quantum and quantum-like processes, and ultimately the quantum vacuum. Given this evidence, we intend to inquire and discuss how the existence of the biofield challenges reductionist approaches and presents its own challenges regarding the origin and source of the biofield, the specific evidence for its existence, its relation to biology, and last but not least, how it may inform an integrated understanding of consciousness and the living universe. PMID:26665039

  18. Current treatments for radiation retinopathy

    Energy Technology Data Exchange (ETDEWEB)

    Giuliari, Gian Paolo; Simpson, E. Rand (Princess Margaret Hospital, Univ. of Toronto, Dept. of Ophthalmology and Vision Sciences, Toronto (Canada)), e-mail: gpgiuliari@gmail.com; Sadaka, Ama (Schepens Eye Research Inst., Boston, MA (United States)); Hinkle, David M. (Massachusetts Eye Research and Surgery Institution, Cambridge, MA (United States))

    2011-01-15

    Background. To review the currently available therapeutic modalities for radiation retinopathy (RR), including newer investigational interventions directed towards specific aspects of the pathophysiology of this refractory complication. Methods. A review of the literature encompassing the pathogenesis of RR and the current therapeutic modalities available was performed. Results. RR is a chronic and progressive condition that results from exposure to any source of radiation. It might be secondary to radiation treatment of intraocular tumors such as choroidal melanomas, retinoblastomas, and choroidal metastasis, or from unavoidable exposure to excessive radiation from the treatment of extraocular tumors like cephalic, nasopharyngeal, orbital, and paranasal malignancies. After the results of the Collaborative Ocular Melanoma Study, most of the choroidal melanomas are being treated with plaque brachytherapy increasing by that the incidence of this radiation complication. RR has been reported to occur in as many as 60% of eyes treated with plaque radiation, with higher rates associated with larger tumors. Initially, the condition manifests as a radiation vasculopathy clinically seen as microaneurysms and telangiectasis, with posterior development of retinal hard exudates and hemorrhages, macular edema, neovascularization and tractional retinal detachment. Regrettably, the management of these eyes remains limited. Photodynamic therapy, laser photocoagulation, oral pentoxyphylline and hyperbaric oxygen have been attempted as treatment modalities with inconclusive results. Intravitreal injections of anti-vascular endothelial growth factor such as bevacizumab, ranibizumab and pegaptanib sodium have been recently used, also with variable results. Discussion. RR is a common vision threatening complication following radiation therapy. The available therapeutic options are limited and show unsatisfactory results. Further large investigative studies are required for developing

  19. The current efficiency during the cathodic period of reversing current in copper powder deposition and the overall current efficiency

    Directory of Open Access Journals (Sweden)

    N. D. NIKOLIC

    2003-09-01

    Full Text Available The current efficiency during the cathodic period of reversing current in copper powder deposition was determined by measuring the quantity of hydrogen evolved. The diagrams from which the instantaneous and average current efficiencies for copper deposition can be extracted for any deposition time up to 30 min are given. A procedure for the calculation of the overall current efficiency is proposed.

  20. Archaeometry: changes and current trends

    Directory of Open Access Journals (Sweden)

    Montero Ruiz, Ignacio

    2007-06-01

    Full Text Available This paper looks through the definition of the term Archaeometry and its different meanings since the first use of the term in the1950s to the present. It is also concerned with the historical background of Archaeometry, its evolution throughout recent decades and the fields currently covered by this new area of knowledge, which must be understood within the limits of archaeology. In addition, a bibliometric analysis has served to show in depth the trends of archaeometric studies and to assess their role in current archaeological research. Finally, some ideas on the particular knowledge generated by Archaeometry as well as its future and immediate perspectives are also discussed.  

    Este trabajo realiza un recorrido por la definición del término Arqueometría y las distintas acepciones que ha ido teniendo desde su aparición en la década de los 50 del siglo pasado hasta el presente. También se profundiza en los antecedentes históricos, en la evolución acaecida en las últimas décadas y en los campos de actuación cubiertos en la actualidad por esta nueva área de conocimiento, cuyo desarrollo no puede entenderse al margen de la propia arqueología. Un análisis bibliométrico ha servido además para conocer en profundidad las tendencias en este tipo de estudios arqueométricos y valorar el papel que juegan en la investigación arqueológica actual. Por último, se discuten algunas ideas sobre las particulares características del conocimiento generado por la Arqueometría, así como su futuro y perspectivas más inmediatas.

  1. Current status of zirconia restoration.

    Science.gov (United States)

    Miyazaki, Takashi; Nakamura, Takashi; Matsumura, Hideo; Ban, Seiji; Kobayashi, Taira

    2013-10-01

    During the past decade, zirconia-based ceramics have been successfully introduced into the clinic to fabricate fixed dental prostheses (FDPs), along with a dental computer-aided/computer-aided manufacturing (CAD/CAM) system. In this article (1) development of dental ceramics, (2) the current status of dental CAD/CAM systems, (3) CAD/CAM and zirconia restoration, (4) bond between zirconia and veneering ceramics, (5) bond of zirconia with resin-based luting agents, (6) surface finish of zirconia restoration and antagonist enamel wear, and (7) clinical evaluation of zirconia restoration are reviewed. Yttria partially stabilized tetragonal zirconia polycrystalline (Y-TZP) showed better mechanical properties and superior resistance to fracture than other conventional dental ceramics. Furthermore, ceria-stabilized tetragonal zirconia polycrystalline and alumina nanocomposites (Ce-TZP/A) had the highest fracture toughness and had resistance to low-temperature aging degradation. Both zirconia-based ceramics have been clinically available as an alternative to the metal framework for fixed dental prostheses (FDPs). Marginal adaptation of zirconia-based FDPs is acceptable for clinical application. The most frequent clinical complication with zirconia-based FDPs was chipping of the veneering porcelain that was affected by many factors. The mechanism for the bonding between zirconia and veneering ceramics remains unknown. There was no clear evidence of chemical bonding and the bond strength between zirconia and porcelain was lower than that between metal and porcelain. There were two alternatives proposed that might avoid chipping of veneering porcelains. One was hybrid-structured FDPs comprising CAD/CAM-fabricated porcelain parts adhering to a CAD/CAM fabricated zirconia framework. Another option was full-contour zirconia FDPs using high translucent zirconia. Combined application of silica coating and/or silane coupler, and 10-methacryloyloxydecyl dihydrogen phosphate is

  2. Current trends of banking innovations

    Directory of Open Access Journals (Sweden)

    A.M. Karminskiy

    2013-06-01

    Full Text Available The current stage of the global banking system development takes place in an increasingly competitive environment and unstable financial markets. One of the key factors of bank's successful development is a policy of continuous innovative behavior. Nowadays innovation is a key factor of bankingnstability, competitiveness and sustainable growth.The aim of the article. The main goal of this article is to examine key trends of banking innovations and innovative in Russia. Experience in the development of new banking products, services and technologies in the Russian market is mainly based on international practice. Noteworthy is the fact that Russian banks take over not only the successful practice of new product lines, but also information technology as well as key methodological aspects of bank management and the technological aspects related the business processes.The results of the analysis. Innovative policy in the credit institution must not take place spontaneously. The positive effect of innovation can be achieved only if there is the possibility of managing the innovation process, which is not possible without a clearly highlighted definition and characteristics of banking innovation, which at least would allow distinguishing of innovation and modification. The paper describes the main aspects of the morphology of banking innovation with the detailed classification depended on the variety of attributes from its origin to the direction of action and highlights the major trends of current banking innovation, such as:development of information and cyber technology (and hence the possibility of the emergence of computational complexity and risk prediction models, the development of information security tools,etc.;implementation of customer-oriented model as the best practice;optimization of its own business processes.The article shows a number of real examples of each kind of banking innovation including the innovations in the non

  3. Influenza: A current medical problem

    Directory of Open Access Journals (Sweden)

    Bojić Ivanko

    2007-01-01

    Full Text Available Introduction. Acute respiratory infections are the most common infections in the human population. Among them, virus infections, especially those caused by influenza viruses, have an important place. Type A influenza. Type A influenza virus caused three epidemics during the last century. A high percetage of deceased in pandemics of 1918, and 1919 were young, healthy persons, with many of the deaths due to an unusually severe, hemorrhagic pneumonia. At the end of 2003, and the beginning of 2004, an epidemic emerged in South East Asia of poultry influenza caused by animal (avian virus. Later it spread to the human population, with a high death rate of 73% and with a possibility of interhuman transmission. This review article provides an overview of the clinical manifestations, laboratory findings and chest radiographs. Apart from the symptomatic and supportive therapy, there are antiviral drugs and corticosteriods. Conclusion. The use of vaccine containing subtypes of virus hemagglutinins and neuraminidase from an influenza virus currently infecting the population has a great importance. .

  4. Current advances in orthodontic pain.

    Science.gov (United States)

    Long, Hu; Wang, Yan; Jian, Fan; Liao, Li-Na; Yang, Xin; Lai, Wen-Li

    2016-01-01

    Orthodontic pain is an inflammatory pain that is initiated by orthodontic force-induced vascular occlusion followed by a cascade of inflammatory responses, including vascular changes, the recruitment of inflammatory and immune cells, and the release of neurogenic and pro-inflammatory mediators. Ultimately, endogenous analgesic mechanisms check the inflammatory response and the sensation of pain subsides. The orthodontic pain signal, once received by periodontal sensory endings, reaches the sensory cortex for pain perception through three-order neurons: the trigeminal neuron at the trigeminal ganglia, the trigeminal nucleus caudalis at the medulla oblongata and the ventroposterior nucleus at the thalamus. Many brain areas participate in the emotion, cognition and memory of orthodontic pain, including the insular cortex, amygdala, hippocampus, locus coeruleus and hypothalamus. A built-in analgesic neural pathway-periaqueductal grey and dorsal raphe-has an important role in alleviating orthodontic pain. Currently, several treatment modalities have been applied for the relief of orthodontic pain, including pharmacological, mechanical and behavioural approaches and low-level laser therapy. The effectiveness of nonsteroidal anti-inflammatory drugs for pain relief has been validated, but its effects on tooth movement are controversial. However, more studies are needed to verify the effectiveness of other modalities. Furthermore, gene therapy is a novel, viable and promising modality for alleviating orthodontic pain in the future. PMID:27341389

  5. Aktuelles Vaterschaftsrecht Current Paternity Law

    Directory of Open Access Journals (Sweden)

    Silvia C. Groppler

    2004-07-01

    Full Text Available Das Fachbuch enthält eine sehr vollständige Übersicht über die Entwicklung und die derzeitige rechtliche Situation im Bereich der Vaterschaftsfeststellung und -anfechtung. Das Buch ist in erster Linie für Praktiker/-innen geschrieben, also insbesondere für Familienrichter/-innen, Jugend- und Standesämter sowie für Anwälte und Anwältinnen, die auf dem Gebiet des Vaterschaftsrechts tätig sind. Es ist aber auch geeignet für all diejenigen, die juristisch mit Vaterschaftsproblemen zu tun haben und sich einen fundierten Überblick verschaffen wollen bzw. das Buch als Nachschlagewerk zu einzelnen Problemfeldern des Vaterschaftsrechts nutzen wollen.This specialized book contains a complete overview of the development and current legal situation in the area of the determination and contestation of paternity. The book is primarily written for practitioners, especially for family judges, youth and registry offices, as well as for male and female lawyers who work in the field of paternity law. But it is also suitable for those who deal with legal paternity problems and would like to gain a sound overview, i.e. would like to use the book as a reference work for specific problem areas of paternity law.

  6. Burning mouth syndrome: Current concepts.

    Science.gov (United States)

    Nasri-Heir, Cibele; Zagury, Julyana Gomes; Thomas, Davis; Ananthan, Sowmya

    2015-01-01

    Burning mouth syndrome (BMS) is a chronic pain condition. It has been described by the International Headache Society as "an intra-oral burning or dysesthetic sensation, recurring daily for more than 2 h/day for more than 3 months, without clinically evident causative lesions." BMS is frequently seen in women in the peri-menopausal and menopausal age group in an average female/male ratio of 7:1. The site most commonly affected is the anterior two-thirds of the tongue. The patient may also report taste alterations and oral dryness along with the burning. The etiopathogenesis is complex and is not well-comprehended. The more accepted theories point toward a neuropathic etiology, but the gustatory system has also been implicated in this condition. BMS is frequently mismanaged, partly because it is not well-known among healthcare providers. Diagnosis of BMS is made after other local and systemic causes of burning have been ruled out as then; the oral burning is the disease itself. The management of BMS still remains a challenge. Benzodiazepines have been used in clinical practice as the first-line medication in the pharmacological management of BMS. Nonpharmacological management includes cognitive behavioral therapy and complementary and alternative medicine (CAM). The aim of this review is to familiarize healthcare providers with the diagnosis, pathogenesis, and general characteristics of primary BMS while updating them with the current treatment options to better manage this group of patients. PMID:26929531

  7. Current work in energy analysis

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-03-01

    This report describes the work performed at Berkeley Lab most recently. One of the Labs accomplishments is the publication of Scenarios of US Carbon Reductions, an analysis of the potential of energy technologies to reduce carbon emissions in the US. This analysis is described and played a key role in shaping the US position on climate change in the Kyoto Protocol negotiations. The Labs participation in the fundamental characterization of the climate change issue by the IPCC is described. Described also is a study of leaking electricity, which is stimulating an international campaign for a one-watt ceiling for standby electricity losses from appliances. This ceiling has the potential to save two-thirds of the 5% of US residential electricity currently expended on standby losses. The 54 vignettes contained in the report summarize results of research activities ranging in scale from calculating the efficacy of individual lamp ballasts to estimating the cost-effectiveness of the national Energy Star{reg_sign} labeling program, and ranging in location from a scoping study of energy-efficiency market transformation in California to development of an energy-efficiency project in the auto parts industry in Shandong Province, China.

  8. BGG reciprocity for current algebras

    CERN Document Server

    Bennett, Matthew; Manning, Nathan

    2011-01-01

    We study the category $\\cal I_{\\gr}$ of graded representations with finite--dimensional graded pieces for the current algebra $\\lie g\\otimes\\bc[t]$ where $\\lie g$ is a simple Lie algebra. This category has many similarities with the category $\\cal O$ of modules for $\\lie g$ and in this paper, we formulate and study an analogue of the famous BGG duality. We recall the definition of the projective and simple objects in $\\cal I_{\\gr}$ which are indexed by dominant integral weights. The role of the Verma modules is played by a family of modules called the global Weyl modules. We show that in the case when $\\lie g$ is of type $\\lie{sl}_2$, the projective module admits a flag in which the successive quotients are finite direct sums of global Weyl modules. The multiplicity with which a particular Weyl module occurs in the flag is determined by the multiplicity of a Jordan--Holder series for a closely associated family of modules, called the local Weyl modules. We conjecture that the result remains true for arbitrary...

  9. Current clinical approach to achalasia

    Institute of Scientific and Technical Information of China (English)

    Alexander J Eckardt; Volker F Eckardt

    2009-01-01

    Idiopathic achalasia is a rare primary motility disorder of the esophagus.The classical features are incomplete relaxation of a frequently hypertensive lower esophageal sphincter (LES) and a lack of peristalsis in the tubular esophagus.These motor abnormalities lead to dysphagia,stasis,regurgitation,weight loss,or secondary respiratory complications.Although major strides have been made in understanding the pathogenesis of this rare disorder,including a probable autoimmune mediated destruction of inhibitory neurons in response to an unknown insult in genetically susceptible individuals,a definite trigger has not been identified.The diagnosis of achalasia is suggested by clinical features and confirmed by further diagnostic tests,such as esophagogastroduodenoscopy (EGD),manometry or barium swallow.These studies are not only used to exclude pseudoachalasia,but also might help to categorize the disease by severity or clinical subtype.Recent advances in diagnostic methods,including high resolution manometry (HRM),might allow prediction of treatment responses.The primary treatments for achieving long-term symptom relief are surgery and endoscopic methods.Although limited high-quality data exist,it appears that laparoscopic Heller myotomy with partial fundoplication is superior to endoscopic methods in achieving long-term relief of symptoms in the majority of patients.However,the current clinical approach to achalasia will depend not only on patients' characteristics and clinical subtypes of the disease,but also on local expertise and patient preferences.

  10. Current status of converter steelmaking

    Energy Technology Data Exchange (ETDEWEB)

    Oghbasialasie, H.; Holappa, L.

    1995-12-31

    This literature work is mainly focusing on the mechanisms of modern converter steelmaking and related with the evaluation of converter technology applied during the last decades and further to the future. The history of steelmaking has been briefly reviewed from bloomeries and early-steelmaking processes to the progress of modern converter process. The pneumatic converter processes were developed in the 1850`s and thereafter the basis for the rapid growth of steel industries was established for the next 100 years. The world production of steel has not continuously grown but fluctuating quite much. It reached 723 Mt in 1994. The production is believed to grow the forecast for the year 2003 being approximately 800 Mt. Electric arc furnace production is estimated to reach 280 Mt by 2003, and BOFIOH will reach 520 Mt by 2003. The current status of the converter steelmaking process is briefly described both on its theoretical bases and practical technological progresses. Developments which significantly improve the process are briefly discussed. Several more recent developments such as combined oxygen blowing process, increased scrap melting, post combustion and hot metal pretreatment are discussed. The future progress will be in further development of these process characteristics as well as in eventual emerging of the continuous converter process. (author)

  11. Malaria vaccine: a current perspective

    Directory of Open Access Journals (Sweden)

    Shobhona Sharma

    2008-02-01

    Full Text Available The observation that inactivated Plasmodium sporozoites could protect against malaria is about a hundred years old. However, systematic demonstration of protection using irradiated sporozoites occurred in the nineteen-sixties, providing the impetus for the development of a malaria vaccine. In 1983, the circumsporozoite protein (CSP, a major sporozoite surface antigen, became the first Plasmodium gene to be cloned, and a CSP-based vaccine appeared imminent. Today, 25 years later, we are still without an effective malaria vaccine, despite considerable information regarding the genomics and proteomics of the malaria parasites. Although clinical immunity to malaria has been well-documented in adults living in malaria endemic areas, our understanding of the host-immune responses operating in such malaria immune persons remains poor, and limits the development of immune control of the disease. Currently, several antigen and adjuvant combinations have entered clinical trials, in which efficacy against experimental sporozoite challenge and/or exposure to natural infection is evaluated. This review collates information on the recent status of the field. Unresolved challenges facing the development of a malaria vaccine are also discussed.

  12. Management of insomnia: current trends

    Directory of Open Access Journals (Sweden)

    Rimple Jeet Kaur

    2014-04-01

    Full Text Available Insomnia is one of the most commonly occurring sleep disorders worldwide. With increased prevalence of insomnia the demand of the people seeking pharmacological treatment for this disease is continuously increasing. Numerous options are currently available for its treatment and with our increased understanding of the neurophysiological factors involved in the insomnia continuous research is being conducted to seek newer pharmacological treatments. Recent advancement in treatment of insomnia is the introduction of non-benzodiazepine hypnotic medications such as zaleplon, zolpidem, and eszopiclone. Ramelteon, a melatonin agonist, is also helpful for sleep initiation diffi culties. Tri-cyclic antidepressants have long been used for insomnia but use has been limited by unwanted anticholinergic side-effects. A hypocretin/orexin antagonist MK-4035 is presently in clinical trials. Serotonin antagonists and inverse agonists are being investigated for their usefulness in insomnia; newer research examining other mechanisms of action suggest that agents which modulate the histaminergic, serotonergic, melontonergic, and hypocretin/orexin and perhaps gamma-aminobutyric acid B systems could play a promising role in management of insomnia. [Int J Basic Clin Pharmacol 2014; 3(2.000: 272-276

  13. Cranial MRI: Current clinical applications

    International Nuclear Information System (INIS)

    Human MR images were first published by the Nottingham group in 1980. Since that time, there have been steady improvements in image quality and significant reductions in imaging time. After initial studies by the Hammersmith group in London, investigators at UCSF published studies comparing CT with MR, clearly demonstrating the higher sensitivity of MR to pathologic intracranial processes. Since that time, several investigators have demonstrated the efficacy of MR in the evaluation of a wide range of intracranial pathologic processes, including neoplasms, demyelinating disease, trauma, and congenital abnormalities. In the authors' studies comparing MR with CT in 400 consecutive cases of suspected CNS pathology, MR detected abnormalities which were not seen on CT in 30 percent of these cases. MR has become established as the imaging modality of choice in the evaluation of a broad range of CNS abnormalities and is rapidly being implemented not only at university medical centers but also in community hospitals and free-standing clinics. This chapter deals with fundamental principles of MR image interpretation and provides insight into current clinical indications for MR in intracranial disorders

  14. Current ethical issues in IVF.

    Science.gov (United States)

    Grobstein, C; Flower, M

    1985-12-01

    This article has briefly reviewed the range of public policy issues and ethical questions raised with respect to IVF. It then discussed selected issues that are now under policy debate and decision. Given the wide acceptance of IVF as a medical procedure for married couples, what variants might also be ethically defensible? IVF for unmarried couples appears defensible under specific conditions that are equally applicable to married couples. Involvement of third parties (gamete donation and gestational surrogacy) is more complex and needs case by case examination. Sperm donation appears to generate little that is ethically new when coupled with IVF but requires the same care and concern as AID. Egg or embryo donation, however, does raise new ethical questions that need close attention and continuing analysis. Freezing of human embryos also breaks new ethical ground, particularly in the options it generates beyond a narrowly defined medical domain. Certain of these options are better not undertaken without further public policy decision. Improvement of current procedures and techniques through effective clinical trials can be ethically carried out in terms of scientific and medical perspectives. However, efforts in this direction will be more effective if undertaken within a public policy framework that clearly defines acceptability during a transitional period of confidence-building. PMID:3833444

  15. REACH and nanomaterials: current status

    International Nuclear Information System (INIS)

    New challenges for regulators are emerging about a specific assessment and appropriate management of the potential risks of nanomaterials. In the framework of European legislation on chemicals, Regulation (EC) No. 1907/2006 REACH aims to ensure the safety of human health and the environment through the collection of information on the physico-chemical characteristics of the substances and on their profile (eco) toxicological and the identification of appropriate risk management linked to 'exposure to these substances without impeding scientific progress and the competitiveness of industry. In order to cover the current shortage of information on the safety of nanomaterials and tackle the acknowledged legal vacuum, are being a rich activities, carried out both by regulators both by stake holders, and discussions on the proposals for adapting the European regulatory framework for chemicals . The European Commission is geared to strengthen the REACH Regulation by means of updates of its annexes. The importance of responding to the regulatory requirements has highlighted the need for cooperation between European organizations, scientists and industries to promote and ensure the safe use of nanomaterials.

  16. Current treatment of ulcerative colitis

    Institute of Scientific and Technical Information of China (English)

    JohannesMeier; AndreasSturm

    2011-01-01

    Ulcerative colitis (UC) is a chronic disease featuring re- current inflammation of the colonic mucosa. The goal of medical treatment is to rapidly induce a steroid-free remission while at the same time preventing complica- tions of the disease itself and its treatment. The choice of treatment depends on severity, localization and the course of the disease. For proctitis, topical therapy with 5-aminosalicylic acid (5-ASA) compounds is used. More extensive or severe disease should be treated with oral and local 5-ASA compounds and corticosteroids to induce remission. Patients who do not respond to this treatment require hospitalization. Intravenous steroids or, when refractory, calcineurin inhibitors (cyclosporine, tacrolimus), tumor necrosis factor-α antibodies (infliximab) or immunomodulators (azathioprine, 6-mercaptopurine) are then called for. Indications for emergency surgery include refractory toxic megacolon, perforation, and continuous severe colorectal bleeding. Close collaboration between gastroenterologist and surgeon is mandatory in order not to delay surgical therapy when needed. This article is intended to give a general, practice-orientated overview of the key issues in ulcerative colitis treatment. Recommendations are based on published consensus guidelines derived from national and international guidelines on the treatment of ulcerative colitis.

  17. Rhegmatogenous retinal detachment: current opinion

    Directory of Open Access Journals (Sweden)

    T. A. Avanesova

    2015-01-01

    Full Text Available Rhegmatogenous retinal detachment (RRD is a severe ocular disorder which requires prompt treatment to prevent low vision and blindness. It is also a significant socio-economic problem as 84% of RDD patients are able-bodied. RRD grading systems (including current Machemer grading system, risk factors, and pathogenesis are reviewed. The role of proliferative vitreoretinopathy in RDD pathogenesis and recurrence is described. Macula involvement determines RDD outcome. Optical coherence tomography (OCT provides the study of retina anatomy and the analysis of parameters that affect post-op best corrected visual acuity, i.e., defects of the junction between inner segments and outer segments (IS/OS, the integrity of external (ELM and internal limiting membrane (ILM, outer nuclear layer thickness (ONLT etc. Fluorescent angiography allows to understand the reasons for low vision in anatomically successful RDD surgery. Scleral buckling, balloon buckling, pneumatic retinopexy, vitrectomy, cryopexy, and laser coagulation are important tools in surgical armamentarium. In recent years, vitrectomy is growing in popularity for RDD treatment. Criteria for procedure selection and surgical success rate in phakic and pseudophakic eyes are discussed. The outcomes of vitrectomy with air/gas and silicone oil tamponade are compared. Bimanual vitrectomy benefits are discussed. 

  18. Current trends in geomorphological mapping

    Science.gov (United States)

    Seijmonsbergen, A. C.

    2012-04-01

    Geomorphological mapping is a world currently in motion, driven by technological advances and the availability of new high resolution data. As a consequence, classic (paper) geomorphological maps which were the standard for more than 50 years are rapidly being replaced by digital geomorphological information layers. This is witnessed by the following developments: 1. the conversion of classic paper maps into digital information layers, mainly performed in a digital mapping environment such as a Geographical Information System, 2. updating the location precision and the content of the converted maps, by adding more geomorphological details, taken from high resolution elevation data and/or high resolution image data, 3. (semi) automated extraction and classification of geomorphological features from digital elevation models, broadly separated into unsupervised and supervised classification techniques and 4. New digital visualization / cartographic techniques and reading interfaces. Newly digital geomorphological information layers can be based on manual digitization of polygons using DEMs and/or aerial photographs, or prepared through (semi) automated extraction and delineation of geomorphological features. DEMs are often used as basis to derive Land Surface Parameter information which is used as input for (un) supervised classification techniques. Especially when using high-res data, object-based classification is used as an alternative to traditional pixel-based classifications, to cluster grid cells into homogeneous objects, which can be classified as geomorphological features. Classic map content can also be used as training material for the supervised classification of geomorphological features. In the classification process, rule-based protocols, including expert-knowledge input, are used to map specific geomorphological features or entire landscapes. Current (semi) automated classification techniques are increasingly able to extract morphometric, hydrological

  19. Persistent current in a magnetized Rashba ring

    Institute of Scientific and Technical Information of China (English)

    Zhang Lin; Wang Jun

    2011-01-01

    We theoretically study the persistent currents flowing in a Rashba quantum ring subjected to the Rashba spinorbit interaction.By introducing uniform or nonuniform magnetization into the ring,we find that a nonzero persistent charge current circulates in the ring,which stems from the original equilibrium spin current due to the Rashba spinorbit interaction.Because of broken time reversal symmetry,the two oppositely flowing spin-up and spin-down charge currents of the equilibrium spin current are no longer equal,and so a net persistent charge current can flow in the system.It is also found that the persistent current can be modulated by the Fermi energy,the Rashba spin-orbit interaction strength and the magnetization in the ring.Moreover,the magnetization perpendicular to the ring plane can optimize the current.The persistent current flowing in the ring is a manifestation of the nonzero equilibrium spin current existing in the ring.

  20. Current therapy of hilar cholangiocarcinoma

    Institute of Scientific and Technical Information of China (English)

    Stephanie HiuYan Lau; WanYee Lau

    2012-01-01

    BACKGROUND: Hilar cholangiocarcinoma (HC) is an adeno-carcinoma of the extrahepatic biliary tree arising from the main left or right hepatic ducts or their confluence. This tumor is still considered to be difficult to treat or to cure. DATA SOURCES: We reviewed the medical literature on HC. Relevant and updated information on this tumor was analyzed in a concise and easy-to-read manner. The article is not intended to be a systematic review, but an extensive search was conducted on PubMed and MEDLINE using the keywords "hilar cholangiocarcinoma" and "Klatskin tumor" until July 2011. RESULTS: The selection and the timing of management options for patients with HC are determined by the degree of certainty of the diagnosis, the general condition of the patients, the underlying liver function and the stage of the disease. Current treatment of HC can be divided into curative and palliative treatment. For the curative treatment, local excision should only be used on small tumors which are confined to the bile duct wall and Bismuth I papillary carcinoma. Partial hepatectomy should be combined with caudate lobe resection and porta-hepatis lymph node dissection. The results of these major resections can be improved with portal vein embolization, and staging laparoscopy and laparoscopic ultrasound. The role of preoperative biliary drainage is controversial. Autotransplantation for HC gave disappointing results while the Mayo Protocol of chemoradiation for selecting patients with unresectable HC for orthotopic liver transplantation has been widely accepted. Palliative treatment included bypass surgery, endoscopic or percutaneous stenting, photodynamic therapy, intraluminal brachytherapy, and external radiation and systemic therapy. CONCLUSIONS: Adequate surgery with R0 resection should be the main goal of treatment. For patients with unresectable HC, treatment aims to improve the quality and quantity of their survival.

  1. An isolated current monitor for iontophoresis.

    Science.gov (United States)

    Hauser, S E; Cohen, S A

    1976-01-01

    An inexpensive isolated current monitor has been developed as an effort to minimize stimulus artifact in experimental systems which include iontophoresis as the source of stimulus. The monitor becomes an element of the iontophoresis circuit, but provides an output voltage isolated from the iontophoresis current. The voltage is proportional to the iontophoresis current and will represent currents of 1/2 nA to 5 muA. It is this ability to detect minute currents that is valuable in iontophoresis measurements.

  2. Current Concepts of Maternal Nutrition

    Science.gov (United States)

    Lowensohn, Richard I.; Stadler, Diane D.; Naze, Christie

    2016-01-01

    Background A nutrient-rich maternal diet before and during pregnancy is associated with improved fetal health, more appropriate birth weight, and increased rates of maternal and infant survival. Physicians need a better understanding of the role of diet in shaping fetal outcomes. Given this background, we reviewed and summarized articles on maternal nutrition found in MEDLINE since 1981, written in English, and limited to human subjects. For the Offspring Maternal diets high in sugar and fat lead to an increased incidence of metabolic syndrome, diabetes, and cardiovascular disease later in life. Folic acid should be supplemented prior to conception and continued through at least the first 28 days of fetal life to prevent neural tube defects, and vitamin C should be given to women who smoke to lower the incidence of asthma and wheezing in the children. Iodine deficiency is increasing, and iodine should be included in prenatal supplements. If the maternal hemoglobin is 7 g/dL or more, there is no evidence that iron supplementation is needed. Fish intake during pregnancy is protective against atopic outcomes, whereas high-meat diets contribute to elevated adult blood pressure and hypersecretion of cortisol. For the Mother Calcium supplementation lowers the risk of preeclampsia and hypertensive disease in pregnancy. Conclusions Given the limits of our current knowledge, a diet rich in whole grains, fruits, vegetables, and selected fish is desirable for the best outcomes. Diets high in sugar and fat lead to higher rates of diabetes, metabolic syndrome, and cardiovascular disease. Folic acid, iodine, and calcium in all pregnant women and vitamin C in smokers are the only supplements so far shown to be of value for routine use. The physician treating a pregnant woman should be ready to advise a healthy diet for the benefit of the fetus. Target Audience Obstetricians and gynecologists, family physicians Learning Objectives After participating in this activity, the

  3. [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

  4. rasdaman Array Database: current status

    Science.gov (United States)

    Merticariu, George; Toader, Alexandru

    2015-04-01

    rasdaman (Raster Data Manager) is a Free Open Source Array Database Management System which provides functionality for storing and processing massive amounts of raster data in the form of multidimensional arrays. The user can access, process and delete the data using SQL. The key features of rasdaman are: flexibility (datasets of any dimensionality can be processed with the help of SQL queries), scalability (rasdaman's distributed architecture enables it to seamlessly run on cloud infrastructures while offering an increase in performance with the increase of computation resources), performance (real-time access, processing, mixing and filtering of arrays of any dimensionality) and reliability (legacy communication protocol replaced with a new one based on cutting edge technology - Google Protocol Buffers and ZeroMQ). Among the data with which the system works, we can count 1D time series, 2D remote sensing imagery, 3D image time series, 3D geophysical data, and 4D atmospheric and climate data. Most of these representations cannot be stored only in the form of raw arrays, as the location information of the contents is also important for having a correct geoposition on Earth. This is defined by ISO 19123 as coverage data. rasdaman provides coverage data support through the Petascope service. Extensions were added on top of rasdaman in order to provide support for the Geoscience community. The following OGC standards are currently supported: Web Map Service (WMS), Web Coverage Service (WCS), and Web Coverage Processing Service (WCPS). The Web Map Service is an extension which provides zoom and pan navigation over images provided by a map server. Starting with version 9.1, rasdaman supports WMS version 1.3. The Web Coverage Service provides capabilities for downloading multi-dimensional coverage data. Support is also provided for several extensions of this service: Subsetting Extension, Scaling Extension, and, starting with version 9.1, Transaction Extension, which

  5. Conservation of Supergravity Currents from Matrix Theory

    CERN Document Server

    Van Raamsdonk, M

    1999-01-01

    In recent work by Kabat and Taylor, certain Matrix theory quantities have been identified with the spatial moments of the supergravity stress-energy tensor, membrane current, and fivebrane current. In this note, we determine the relations between these moments required by current conservation, and prove that these relations hold as exact Matrix Theory identities at finite N. This establishes conservation of the effective supergravity currents (averaged over the compact circle). In addition, the constraints of current conservation allow us to deduce Matrix theory quantities corresponding to moments of the spatial current of the longitudinal fivebrane charge, not previously identified.

  6. Bifurcation of Jovian magnetotail current sheet

    Directory of Open Access Journals (Sweden)

    P. L. Israelevich

    2006-07-01

    Full Text Available Multiple crossings of the magnetotail current sheet by a single spacecraft give the possibility to distinguish between two types of electric current density distribution: single-peaked (Harris type current layer and double-peaked (bifurcated current sheet. Magnetic field measurements in the Jovian magnetic tail by Voyager-2 reveal bifurcation of the tail current sheet. The electric current density possesses a minimum at the point of the Bx-component reversal and two maxima at the distance where the magnetic field strength reaches 50% of its value in the tail lobe.

  7. Overview of current chelation practices

    Directory of Open Access Journals (Sweden)

    Y. Aydinok

    2011-12-01

    , should provide long-term survival and quality of life for patients with iron loading anemias. The goal of this review is to summarize current concepts in iron chelation therapies based on the considerable amount of prospective data obtained by clinical studies. 去铁胺 (DFO)是自20世纪80年以来输血引起铁过载的参考标准疗法。 虽然它是一种高效的铁螯合剂,但是去铁胺皮下给药的遵从性问题依旧是主要问题。 口服螯合剂去铁酮(DFP)在北美没有销售许可证,但是,它在1994年获得印度许可,1999年欧洲联盟(EU)批准授予去铁酮销售许可证,特别是当去铁胺不足、无法忍受或无法接受时,去铁酮可用于重型地中海贫血患者。 还可获得关于在6岁至10岁之间的儿童身上使用去铁酮的有限数据,但是没有关于在6岁以下儿童身上使用去铁酮的数据。 随后美国食品和药品管理局(FDA)和欧洲药品管理局(EMA)分别在2005年和2006年批准口服螯合剂去铁酮作为第一疗法来治疗2岁以上输血引起铁过载的患者。 铁螯合的主要目的是将身体铁维持在安全水平,但一旦铁累积起来,铁螯合的目标是把组织铁降低到安全级别,这是一个缓慢的过程。 确定螯合剂的螯合方案、剂量和频率管理的主要依据是身体铁负担、心肌铁的状态和输血铁负载速率。 适当监控螯合对测量特殊方案的反应速率和提供计量调整来加强螯合效果和避免毒效尤其重要。 由于一些因素,诸如:螯合剂的吸收和代谢,螯合方案的效果可能呈现个别变化。 耐受性和遵从性也是影响螯合反应的个别变量。 了解螯合剂的优点和局限性,准确确定铁过载患者的螯合需求以及设计毒效更小但效果更优的个性化螯合方案,可以向铁过载贫血患者提供长期的生存和生活质量。 此次调研的目的是在临床研究获得的相当数

  8. Noise Properties of CMOS Current Conveyors

    DEFF Research Database (Denmark)

    Bruun, Erik

    1996-01-01

    The definition of the current conveyor is presented and it is shown how different generations of current conveyors can all be combined into a single definition of a multiple-output second generation current conveyor (CCII). Next, noise sources are introduced into the model, and a general noise...... model for the current conveyor is established. This model is used for the analysis of selected examples of current conveyor based operational amplifier configurations and the relative merits with respect to the noise performance of these configurations are discussed. Finally, the noise model...... is developed for a CMOS current conveyor implementation, and optimization strategies for noise reduction are discussed. It is concluded that a class AB implementation provides more flexibility than does a class A configuration. In both cases it is essential to design low noise current mirrors and current...

  9. Anomalous bootstrap current due to drift waves

    International Nuclear Information System (INIS)

    An anomalous parallel current driven by radial flux in tokamak is discussed. Drift waves, which cause an anomalous cross field diffusion, can generate a parallel current in a sheared magnetic field, if the fluctuation level has radial dependence. (author)

  10. The Current State of Music Therapy Theory?

    DEFF Research Database (Denmark)

    Bonde, Lars Ole

    2015-01-01

    An essay on themes from Ken Aigen (2014): "The Study of Music Therapy. Current Issues and Concepts"......An essay on themes from Ken Aigen (2014): "The Study of Music Therapy. Current Issues and Concepts"...

  11. Development of Multichannel Eddy Current Testing Instrument

    International Nuclear Information System (INIS)

    Four main techniques of electromagnetic testing are used for commercial applications: eddy current testing, alternating current field testing, magnetic flux leakage testing and remote field testing. Eddy current testing is a nondestructive evaluation method, which makes eddy current flow on a specimen by applying driving pulse to eddy current probe coil, by using eddy current testing device, and makes the change of eddy current which is dependently caused by flaws, material characteristics, testing condition, receiving through eddy current, and analyzes material properties, flaws, status on the specimen. Application of EC instrumentation varies widely in industry from the identification of metal heat treatment to the inspection of steam generator tubing in nuclear power plants. In this study, we have designed multichannel EC instrument which can be applicable to the NDE of the tube in heat exchanger for electric power facility, chemistry, and military industry, and finally confirmed the proper function of EC instrumentation

  12. Neutral-current x-distributions

    Science.gov (United States)

    Friedman, J. I.; Kendall, H. W.; Bogert, D.; Burnstein, R.; Fisk, R.; Fuess, S.; Bofill, J.; Busza, W.; Eldridge, T.; Abolins, M.; Brock, R.; et al.

    1984-06-01

    The role of the semi leptonic neutral current interaction as a probe of nucleon structure is examined. Previous measurements of neutral current x-distributions are reviewed, and new results from the Fermilab - MIT - MSU collaboration are presented.

  13. Direct images of semi-meromorphic currents

    OpenAIRE

    Andersson, Mats; Wulcan, Elizabeth

    2014-01-01

    We introduce a calculus for direct images of semi-meromorphic currents. We also provide results on the behaviour of these currents under the action of holomorphic differential operators and interior multiplication by holomorphic vector fields.

  14. Improving Current Balance In Parallel MOSFET's

    Science.gov (United States)

    Niedra, Janis M.

    1992-01-01

    Simple circuit makes currents more nearly equal. Addition of diodes and adjustable-tap resistor increases operating range over which drain currents in two unmatched power MOSFET's brought more nearly into balance.

  15. [Current malaria situation in Turkmenistan].

    Science.gov (United States)

    Amangel'diev, K A

    2001-01-01

    Malaria is one of the main health problems facing most developing countries having a hot climate. It is a problem in Turkmenistan. The country is situated in Central Asia, north of the Kopetdag mountains, between the Caspian Sea to the west and the Amu-Darya river to the east. Turkmenistan stretches for a distance of 1,100 km from west to east and 650 km from north to south. It borders Kazakhstan in the north, Uzbekistan in the east and north-east, Iran in the south, and Afghanistan in the south-east. Seven malaria vector species are found in Turkmenistan, the main ones being Anopheles superpictus, An. pulcherrimus, and An. martinius. The potentially endemic area consists of the floodplains of the Tejen and Murgab rivers, with a long chain of reservoirs built along them. In 1980 most cases of imported malaria were recorded in military personnel who had returned from service in Afghanistan. In the past years, only tertian (Plasmodium vivax) malaria has been recorded and there have been no death from malaria over that period. In the Serkhetabad (Gushgi) district there are currently 5 active foci of malaria infection, with a population of 22,000 people. In 1999, forty nine cases of P. vivax malaria were recorded in Turkmenistan. Of them, 36 cases, including 4 children under 14 years were diagnosed for the first time while 13 were relapses. There were 88 fewer cases than those in the previous year (by a factor of 2.8). There were 17 more cases of imported malaria than those in 1998 (by a factor of 1.7), most of which occurred in the foci of malaria infection (Serkhetabad, Tagtabazar, and Kerki districts), in the city of Ashkhabat and in Lebap, Dashkhovuz and Akhal Regions. The emergence of indigenous malaria in the border areas was due to the importation of the disease at intervals by infected mosquitoes flying in from neighbouring countries (e.g. Afghanistan), the lack of drugs to treat the first cases and the lack of alternative insecticides. Most patients suffer

  16. Topological Orbital Angular Momentum Hall Current

    OpenAIRE

    Hu, Jiangping

    2005-01-01

    We show that there is a fundamental difference between spin Hall current and orbital angular momentum Hall current in Rashba- Dresselhaus spin orbit coupling systems. The orbital angular momentum Hall current has a pure topological contribution which is originated from the existence of magnetic flux in momentum space while there is no such topological nature for the spin Hall current. Moreover, we show that the orbital Hall conductance is always larger than the spin Hall conductance in the pr...

  17. Nuclear electromagnetic currents from chiral EFT

    International Nuclear Information System (INIS)

    Using the method of unitary transformation in combination with chiral effective field theory we derive the pion exchange contributions to the two-nucleon electromagnetic current. A formal definition of the current operator in this scheme and the power counting is presented. We discuss the implications of additional unitary transformations that have to be present to ensure the renormalizability of the one-pion exchange current. Further, we give explicit and compact results for the current in coordinate-space.

  18. Aquantis Ocean Current Turbine Development Project Report

    Energy Technology Data Exchange (ETDEWEB)

    Fleming, Alex J.

    2014-08-23

    The Aquantis® Current Plane (“C-Plane”) technology developed by Dehlsen Associates, LLC (DA) and Aquantis, Inc. is an ocean current turbine designed to extract kinetic energy from ocean currents. The technology is capable of achieving competitively priced base-load, continuous, and reliable power generation from a source of renewable energy not before possible in this scale or form.

  19. Circuit Controls Turn-On Current

    Science.gov (United States)

    Holmes, K. G.

    1972-01-01

    Single choke used in primary circuit with diode arrangement, maintaining dc current flow through choke and setting up a unidirectional magnetic field, limits turn-on current of transformer-rectifier power supply. Technique reduces number and weight of components and minimizes effect of initial inrush surge current on source.

  20. Inrush-Current Limiter And Bus Isolator

    Science.gov (United States)

    Dolland, Carlisle R.

    1994-01-01

    Electronic circuit protects electrical power bus and source of power against excessive current demands. Circuit intended for use with power-consuming electronic system drawing pulsed currents and including capacitor bank as low-impedance secondary source from which pulsed currents drawn.

  1. High Precision Current Measurement for Power Converters

    CERN Document Server

    Cerqueira Bastos, M

    2015-01-01

    The accurate measurement of power converter currents is essential to controlling and delivering stable and repeatable currents to magnets in particle accelerators. This paper reviews the most commonly used devices for the measurement of power converter currents and discusses test and calibration methods.

  2. High Precision Current Measurement for Power Converters

    OpenAIRE

    Bastos, M. Cerqueira

    2016-01-01

    The accurate measurement of power converter currents is essential to controlling and delivering stable and repeatable currents to magnets in particle accelerators. This paper reviews the most commonly used devices for the measurement of power converter currents and discusses test and calibration methods.

  3. 49 CFR 236.733 - Current, foreign.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Current, foreign. 236.733 Section 236.733 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Current, foreign. A term applied to stray electric currents which may affect a signaling system, but...

  4. The Current Status of STEM Education Research

    Science.gov (United States)

    Brown, Josh

    2012-01-01

    This paper explores the current Science, Technology, Engineering and Mathematics (STEM) education research base through an analysis of articles from eight journals focused on the STEM disciplines. Analyzed are both practitioner and research publications to determine the current scope of STEM education research, where current STEM education…

  5. Harmonic Current Predictors for Wind Turbines

    Directory of Open Access Journals (Sweden)

    Shun-Yu Chan

    2013-03-01

    Full Text Available The harmonic impact caused by wind turbines should be carefully investigated before wind turbines are interconnected. However, the harmonic currents of wind turbines are not easily predicted due to the variations of wind speed. If the harmonic current outputs can be predicted accurately, the harmonic impact of wind turbines and wind farms for power grids can be analyzed efficiently. Therefore, this paper analyzes the harmonic current characteristics of wind turbines and investigates the feasibility of developing harmonic current predictors. Field measurement, data sorting, and analysis are conducted for wind turbines. Two harmonic current predictors are proposed based on the measured harmonic data. One is the Auto-Regressive and Moving Average (ARMA-based harmonic current predictor, which can be used for real-time prediction. The other is the stochastic harmonic current predictor considering the probability density distributions of harmonic currents. It uses the measured harmonic data to establish the probability density distributions of harmonic currents at different wind speeds, and then uses them to implement a long-term harmonic current prediction. Test results use the measured data to validate the forecast ability of these two harmonic current predictors. The ARMA-based predictor obtains poor performance on some harmonic orders due to the stochastic characteristics of harmonic current caused by the variations of wind speed. Relatively, the prediction results of stochastic harmonic current predictor show that the harmonic currents of a wind turbine in long-term operation can be effectively analyzed by the established probability density distributions. Therefore, the proposed stochastic harmonic current predictor is helpful in predicting and analyzing the possible harmonic problems during the operation of wind turbines and wind farms.

  6. EXTRACTION OF INTERNAL TIDE FROM CURRENT

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    In order to extract the internal tidal current from the current data which is not measured from the sea surface to the bottom, a data processing method is developed. It is based on the fact that the internal wave currents above and below the sharp thermocline are inverse in direction. This method is a practical extension to that proposed by Shu (1985) that can be only used to quite ideal current data. The ADCP data collected on the South China Sea is then processed by this method. The internal tidal current is successfully extracted.

  7. Ohm's law for a current sheet

    Science.gov (United States)

    Lyons, L. R.; Speiser, T. W.

    1985-01-01

    The paper derives an Ohm's law for single-particle motion in a current sheet, where the magnetic field reverses in direction across the sheet. The result is considerably different from the resistive Ohm's law often used in MHD studies of the geomagnetic tail. Single-particle analysis is extended to obtain a self-consistency relation for a current sheet which agrees with previous results. The results are applicable to the concept of reconnection in that the electric field parallel to the current is obtained for a one-dimensional current sheet with constant normal magnetic field. Dissipated energy goes directly into accelerating particles within the current sheet.

  8. The universal definition of spin current.

    Science.gov (United States)

    An, Z; Liu, F Q; Lin, Y; Liu, C

    2012-01-01

    The spin current, orbit angular momentum current and total angular momentum current in a tensor form have been universally defined according to the quantum electrodynamics. Their conservation quantities and the continuity equations have been discussed in different cases. Non-relativistic approximation forms are deduced in order to explain their physical meanings, and to analyze some experimental results. The spin current of helical edge states in HgTe/CdTe quantum wells is calculated to demonstrate the properties of the spin current of the two dimensional quantum spin-Hall system. A generalized spin-orbit coupling term in the semiconducting media is deduced based on the theory of the electrodynamics in the moving media. It is recommended to use the effective total angular momentum current instead of the pure spin current to describe the distribution of polarization and the transport properties in spintronics. PMID:22563522

  9. Electric current arising from unpolarized polyvinyl formal

    Indian Academy of Sciences (India)

    P K Khare; P L Jain; R K Pandey

    2000-10-01

    An appreciable electric current is observed in a system consisting of a polyvinyl formal (PVF) film in a sandwich configuration, in the temperature range 30–110°C. The maximum value of the current during first heating is found to be of the order of 10–10 A and its thermograms exhibit one transition (i.e. current peak) at around 60°C. The position of the current peak in thermal spectrum shifts with the heating rate. A temperature dependence of the open circuit voltage is also observed. The activation energy of the process responsible for the current is determined. The magnitude of the current is more in the case of dissimilar electrode systems. It is proposed that the electric current arising from unpolarized metal–polymer–metal system is a water activated phenomenon, which is influenced by the transitional changes of the polymer.

  10. Current measurement method for characterization of fast switching power semiconductors with Silicon Steel Current Transformer

    DEFF Research Database (Denmark)

    Li, Helong; Beczkowski, Szymon; Munk-Nielsen, Stig;

    2015-01-01

    This paper proposes a novel current measurement method with Silicon Steel Current Transformer (SSCT) for the characterization of fast switching power semiconductors. First, the existing current sensors for characterization of fast switching power semiconductors are experimentally evaluated...

  11. Discrimination of Inrush Currents from Faults Current in Power Transformers using Gravitational Search Algorithm (GSA)

    OpenAIRE

    Mohamad Kazem Daryabari; Mahmoud Ebadian; Alireza Moradi

    2011-01-01

    The magnetizing inrush current phenomenon is a large transient condition, which occurs when a transformer is energized. The inrush current magnitude may be as high as ten times of transformer rated current that causes mal-operation of protection systems. Indeed, the similarity between signatures of Inrush current and internal fault condition make this failure. So, for safe running of a transformer, it is necessary to distinguish inrush current from fault currents. In this project, an Artifici...

  12. Vacuum Dielectric Recovery Characteristics of a Novel Current Limiting Circuit Breaker Base on Artificial Current Zero

    Institute of Scientific and Technical Information of China (English)

    JIANG Zhuangxian; ZHUANG Jinwu; WANG Chen; WU Jin; LIU Luhui

    2012-01-01

    A novel current limiting circuit breaker employs zero current switching method in cutting off DC current, which gives out a reverse impulsive current towards a high speed vacuum interrupter and force the current down to zero. This kind of breaker is simply in structure and can act in a very short time with high current limiting capability, and therefore it has a long electric life and is extremely suitable to be installed in a DC electrical system as a fault orotection utility.

  13. Current diffusion in rail-gun conductors

    International Nuclear Information System (INIS)

    A method has been developed to analyze one- and two-dimensional, nonlinear current diffusion in rail-gun conductors. A nonlinear current-diffusion equation that accounts for the temperature dependence of electrical conductivity has been developed from Maxwell's equations. A finite-difference heat-transfer computer program was adapted to solve the current-diffusion and thermal-diffusion problems for rail-gun conductors in one and two dimensions. The nonlinear current-diffusion equation was also extended to account for the magnetic-field dependence of the magnetic permeability, thus allowing ferromagnetic materials to be considered. A one-dimensional finite-difference technique was developed for ferromagnetic materials. Two one-dimensional test problems that compare results with other analyses are discussed. A series of calculations of current density and rail temperature was done for various size rectangular rails. One analysis of current diffusion in a ferromagnetic material was also performed

  14. Computational thermodynamics in electric current metallurgy

    DEFF Research Database (Denmark)

    Bhowmik, Arghya; Qin, R.S.

    2015-01-01

    A priori derivation for the extra free energy caused by the passing electric current in metal is presented. The analytical expression and its discrete format in support of the numerical calculation of thermodynamics in electric current metallurgy have been developed. This enables the calculation...... of electric current distribution, current induced temperature distribution and free energy sequence of various phase transitions in multiphase materials. The work is particularly suitable for the study of magnetic materials that contain various magnetic phases. The latter has not been considered in literature....... The method has been validated against the analytical solution of current distribution and experimental observation of microstructure evolution. It provides a basis for the design, prediction and implementation of the electric current metallurgy. The applicability of the theory is discussed in the derivations....

  15. A review of the quantum current standard

    Science.gov (United States)

    Kaneko, Nobu-Hisa; Nakamura, Shuji; Okazaki, Yuma

    2016-03-01

    The electric current, voltage, and resistance standards are the most important standards related to electricity and magnetism. Of these three standards, only the ampere, which is the unit of electric current, is an International System of Units (SI) base unit. However, even with modern technology, relatively large uncertainty exists regarding the generation and measurement of current. As a result of various innovative techniques based on nanotechnology and novel materials, new types of junctions for quantum current generation and single-electron current sources have recently been proposed. These newly developed methods are also being used to investigate the consistency of the three quantum electrical effects, i.e. the Josephson, quantum Hall, and single-electron tunneling effects, which are also known as ‘the quantum metrology triangle’. This article describes recent research and related developments regarding current standards and quantum-metrology-triangle experiments.

  16. Absolute geostrophic currents in global tropical oceans

    Science.gov (United States)

    Yang, Lina; Yuan, Dongliang

    2016-11-01

    A set of absolute geostrophic current (AGC) data for the period January 2004 to December 2012 are calculated using the P-vector method based on monthly gridded Argo profiles in the world tropical oceans. The AGCs agree well with altimeter geostrophic currents, Ocean Surface Current Analysis-Real time currents, and moored current-meter measurements at 10-m depth, based on which the classical Sverdrup circulation theory is evaluated. Calculations have shown that errors of wind stress calculation, AGC transport, and depth ranges of vertical integration cannot explain non-Sverdrup transport, which is mainly in the subtropical western ocean basins and equatorial currents near the Equator in each ocean basin (except the North Indian Ocean, where the circulation is dominated by monsoons). The identified non-Sverdrup transport is thereby robust and attributed to the joint effect of baroclinicity and relief of the bottom (JEBAR) and mesoscale eddy nonlinearity.

  17. 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 ...

  18. A review of the quantum current standard

    International Nuclear Information System (INIS)

    The electric current, voltage, and resistance standards are the most important standards related to electricity and magnetism. Of these three standards, only the ampere, which is the unit of electric current, is an International System of Units (SI) base unit. However, even with modern technology, relatively large uncertainty exists regarding the generation and measurement of current. As a result of various innovative techniques based on nanotechnology and novel materials, new types of junctions for quantum current generation and single-electron current sources have recently been proposed. These newly developed methods are also being used to investigate the consistency of the three quantum electrical effects, i.e. the Josephson, quantum Hall, and single-electron tunneling effects, which are also known as ‘the quantum metrology triangle’. This article describes recent research and related developments regarding current standards and quantum-metrology-triangle experiments. (topical review)

  19. Controlling local currents in molecular junctions

    CERN Document Server

    Yadalam, Hari Kumar

    2016-01-01

    The effect of non-equilibrium constraints and dephasing on the circulating currents in molecular junctions are analyzed. Circulating currents are manifestations of quantum effects and can be induced either by externally applied bias or an external magnetic field through the molecular system. In symmetric Aharonov-Bohm ring, bond currents have two contributions, bias driven and magnetic field driven. We analyze the competition between these two contributions and show that, as a consequence, current through one of the branches can be completely suppressed. We then study the effect of asymmetry (as a result of chemical substitution) on the current pathways inside the molecule and study asymmetry induced circulating currents (without magnetic field) by tuning the coupling strength of the substituent (at finite bias).

  20. Eddy current analysis in fusion devices

    International Nuclear Information System (INIS)

    In magnetic fusion devices, particularly tokamaks and reversed field pinch (RFP) experiments, time-varying magnetic fields are in intimate contact with electrically conducting components of the device. Induced currents, fields, forces, and torques result. This note reviews the analysis of eddy current effects in the following systems: Interaction of a tokamak plasma with the eddy currents in the first wall, blanket, and shield (FWBS) systems; Eddy currents in a complex but two-dimensional vacuum vessel, as in TFTR, JET, and JT-60; Eddy currents in the FWBS system of a tokamak reactor, such as NET, FER, or ITER; and Eddy currents in a RFP shell. The cited studies are chosen to be illustrative, rather than exhaustive. 42 refs

  1. Konstruktion av current conveyors via makromodellering

    OpenAIRE

    Hjalmarsson, Erik

    2004-01-01

    A current conveyor is an active building block that can be used to implement most active and passive components. It differs from the operation amplifier in that it uses current instead of voltage. The current conveyor also has significantly higher voltage gain over a broader frequency range. To simplify the construction of analogue circuits and increase the construction efficiency it is desirable to use a top-down methodology. This means that the whole system is partitioned into a hierarchy ...

  2. Worst Asymmetrical Short-Circuit Current

    DEFF Research Database (Denmark)

    Arana Aristi, Iván; Holmstrøm, O; Grastrup, L;

    2010-01-01

    In a typical power plant, the production scenario and the short-circuit time were found for the worst asymmetrical short-circuit current. Then, a sensitivity analysis on the missing generator values was realized in order to minimize the uncertainty of the results. Afterward the worst asymmetrical...... short-circuit current was analyzed in order to compare the results with the allowable DC current component based in the IEC. Finally the normal operating condition for the power plant was modeled....

  3. Current fluctuations in stochastic lattice gases.

    Science.gov (United States)

    Bertini, L; De Sole, A; Gabrielli, D; Jona-Lasinio, G; Landim, C

    2005-01-28

    We study current fluctuations in lattice gases in the macroscopic limit extending the dynamic approach for density fluctuations developed in previous articles. More precisely, we establish a large deviation theory for the space-time fluctuations of the empirical current which include the previous results. We then estimate the probability of a fluctuation of the average current over a large time interval. It turns out that recent results by Bodineau and Derrida [Phys. Rev. Lett. 92, 180601 (2004)

  4. Does the Current Account Still Matter?

    OpenAIRE

    Maurice Obstfeld

    2012-01-01

    Do global current account imbalances still matter in a world of deep international financial markets where gross two-way financial flows often dwarf the net flows measured in the current account? Contrary to a complete markets or 'consenting adults' view of the world, large current account imbalances, while very possibly warranted by fundamentals and welcome, can also signal elevated macroeconomic and financial stresses, as was arguably the case in the mid-2000s. Furthermore, the increasingly...

  5. Salt taste inhibition by cathodal current

    OpenAIRE

    Hettinger, Thomas P.; Frank, Marion E.

    2009-01-01

    Effects of cathodal current, which draws cations away from the tongue and drives anions toward the tongue, depend on the ionic content of electrolytes through which the current is passed. To address the role of cations and anions in human salt tastes, cathodal currents of −40 to −80 µA were applied to human subjects’ tongues through supra-threshold salt solutions. The salts were sodium chloride, sodium bromide, potassium chloride, ammonium chloride, calcium chloride, sodium nitrate, sodium su...

  6. Power threshold for neutral beam current drive

    International Nuclear Information System (INIS)

    For fully noninductive current drive in tokamaks using neutral beams, there is a power and density threshold condition, setting a minimum value for P3/2/n2. If this condition is not met, stationary state cannot occur, and a tokamak discharge will collapse. This is a consequence of the coupling between current and electron temperature, or between current drive efficiency and energy confinement time. 4 figs

  7. Current practice in tailings ponds risk assessment

    OpenAIRE

    Pytel, Witold

    2010-01-01

    Current practice for risk assessment posed by surface tailings/waste storage facilities is presented. This involves current legislation and regulations applied in EU countries and over the world and the basics concerned with tailings impoundments design as well. It was proved that a current activity at the existing tailings impoundment structures is presently confined rather to field measurements, monitoring and surveillance understood as a basic source for a “real time risk assessment”.

  8. A constant current source for extracellular microiontophoresis.

    Science.gov (United States)

    Walker, T; Dillman, N; Weiss, M L

    1995-12-01

    A sophisticated constant-current source suitable for extracellular microiontophoresis of tract-tracing substances, such as Phaseolus vulgaris leucoagglutinin, Biocytin or Fluoro-Gold, is described. This design uses a flyback switched-mode power supply to generate controllable high-voltage and operational amplifier circuitry to regulate current and provide instrumentation. Design features include a fast rise time, +/- 2000 V supply (stable output in current and voltage monitoring, and separate pumping and holding current settings. Three features of this constant-current source make it especially useful for extracellular microiontophoresis. First, the output voltage monitor permits one to follow changes in the microelectrode resistance during current injection. Second, the voltage-limit (or out-of-compliance) indicator circuitry will sound an alarm when the iontophoretic pump is unable to generate the desired current, such as when the micropipette is blocked. Third, the high-compliance voltage power supply insures up to +/- 20 microA of current through 100 M omega resistance. This device has proven itself to be a reliable constant-current source for extracellular microiontophoresis in the laboratory. PMID:8788057

  9. Josephson current in parallel SFS junctions

    Science.gov (United States)

    Ioselevich, Pavel; Ostrovsky, Pavel; Fominov, Yakov; Feigelman, Mikhail

    We study a Josephson junction between superconductors connected by two parallel ferromagnetic arms. If the ferromagnets are fully polarised, supercurrent can only flow via Cooper pair splitting between the differently polarised arms. The disorder-average current is suppressed, but mesoscopic fluctuations lead to a significant typical current. We extract the typical current from a current-current correlator. The current is proportional to sin2 α / 2 , where α is the angle between the polarisations of the two arms, revealing the spin dependence of crossed Andreev reflection. Compared to an SNS device of the same geometry, the typical SFS current is small by a factor determined by the properties of the superconducting leads alone. The current is insensitive to the flux threading the area between the ferromagnetic arms of the junction. However, if the ferromagnetic arms are replaced by metal with magnetic impurities, or partially polarised ferromagnets, the Josephson current starts depending on the flux with a period of h / e , i.e. twice the superconducting flux quantum.

  10. Tubular solid oxide fuel cell current collector

    Science.gov (United States)

    Bischoff, Brian L.; Sutton, Theodore G.; Armstrong, Timothy R.

    2010-07-20

    An internal current collector for use inside a tubular solid oxide fuel cell (TSOFC) electrode comprises a tubular coil spring disposed concentrically within a TSOFC electrode and in firm uniform tangential electrical contact with the electrode inner surface. The current collector maximizes the contact area between the current collector and the electrode. The current collector is made of a metal that is electrically conductive and able to survive under the operational conditions of the fuel cell, i.e., the cathode in air, and the anode in fuel such as hydrogen, CO, CO.sub.2, H.sub.2O or H.sub.2S.

  11. Theory of current-drive in plasmas

    International Nuclear Information System (INIS)

    The continuous operation of a tokamak fusion reactor requires, among other things, a means of providing continuous toroidal current. Such operation is preferred to the conventional pulsed operation, where the plasma current is induced by a time-varying magnetic field. A variety of methods has been proposed to provide continuous current, including methods which utilize particle beams or radio frequency waves in any of several frequency regimes. Currents as large as half a mega-amp have now been produced in the laboratory by such means, and experimentation in these techniques has now involved major tokamak facilities worldwide

  12. SHORT CIRCUIT CURRENT LIMITER IN AC NETWORK

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Short circuit is a serious fault in power network.Some novelcircuit topologies of current limiter using power electronic technology have been developed,which can limit the fault current to any desired level without much penalty.The operating principle and control strategies of such current limiters are discussed in detail.Simulation and experimental results are given to verify the performance of the current limiter,which can meet the requirements set for locations of bus tie,feeder,as well as the main transformer in the distribution network.

  13. Current distribution characteristics of superconducting parallel circuits

    International Nuclear Information System (INIS)

    In order to increase the current carrying capacity of the current path of the superconducting magnet system, the portion of parallel circuits such as insulated multi-strand cables or parallel persistent current switches (PCS) are made. In superconducting parallel circuits of an insulated multi-strand cable or a parallel persistent current switch (PCS), the current distribution during the current sweep, the persistent mode, and the quench process were investigated. In order to measure the current distribution, two methods were used. (1) Each strand was surrounded with a pure iron core with the air gap. In the air gap, a Hall probe was located. The accuracy of this method was deteriorated by the magnetic hysteresis of iron. (2) The Rogowski coil without iron was used for the current measurement of each path in a 4-parallel PCS. As a result, it was shown that the current distribution characteristics of a parallel PCS is very similar to that of an insulated multi-strand cable for the quench process

  14. Hybrid high direct current circuit interrupter

    Science.gov (United States)

    Rockot, J.H.; Mikesell, H.E.; Jha, K.N.

    1998-08-11

    A device and a method are disclosed for interrupting very high direct currents (greater than 100,000 amperes) and simultaneously blocking high voltages (greater than 600 volts). The device utilizes a mechanical switch to carry very high currents continuously with low loss and a silicon controlled rectifier (SCR) to bypass the current around the mechanical switch while its contacts are separating. A commutation circuit, connected in parallel with the SCR, turns off the SCR by utilizing a resonant circuit to divert the SCR current after the switch opens. 7 figs.

  15. Magnetopause current as seen by Cluster

    Directory of Open Access Journals (Sweden)

    M. W. Dunlop

    2005-03-01

    Full Text Available The four-spacecraft, magnetic field measurements on Cluster can be combined to produce an accurate determination of the electric current in the magnetopause boundary during stable magnetopause crossings. For events that are planar on the scale of the spacecraft configuration, the thickness of the current layer can be accurately estimated from its magnetic profile at each spacecraft and the corresponding boundary crossing times. The latter, give a determination of boundary motion relative to the Cluster array. We use the estimates of all these properties, for a range of spacecraft separation distances, to show, firstly, that the estimate of electric current density is representative even when the spatial scale of the configuration of Cluster spacecraft approaches the thickness of the current layer. Secondly, we show that the estimated current lies in the plane of the boundary and demonstrate this for crossings occurring during large-scale ripples on the magnetopause. Thirdly, we show that the magnitude of the current is accurately represented, averaged over the extent of the current layer, by comparing to the change in the boundary-parallel magnetic field component divided by the estimated current layer thickness. We demonstrate this last point using a range of crossings each having a different thickness and crossing speed, different changes in the magnetic field component and different current densities.

  16. Origin of axial current in scyllac

    International Nuclear Information System (INIS)

    The origin of the axial current observed in Scyllac (a high beta stellarator experiment) is discussed. A shaped coil and/or helical winding produce rotational transform which links magnetic lines of force to the plasma column and the axial current is induced electromagnetically. This phenomenon is inherent in a pulsed high-beta stellarator. The rotational transform produced by the induced axial current is much smaller than that associated with the l = 1, 0 equilibrium fields. The effect of the axial current on the equilibrium and stability of the plasma column is thus small. It is also shown that the magnetic field shear near a plasma surface is very strong

  17. Interhemispheric Field-Aligned Currents: Simulation Results

    Science.gov (United States)

    Lyatsky, Sonya

    2016-04-01

    We present simulation results of the 3-D magnetosphere-ionosphere current system including the Region 1, Region 2, and interhemispheric (IHC) field-aligned currents flowing between the Northern and Southern conjugate ionospheres in the case of asymmetry in ionospheric conductivities in two hemispheres (observed, for instance, during the summer-winter seasons). We also computed the maps of ionospheric and equivalent ionospheric currents in two hemispheres. The IHCs are an important part of the global 3-D current system in high-latitude ionospheres. These currents are especially significant during summer and winter months. In the winter ionosphere, they may be comparable and even exceed both Region 1 and Region 2 field-aligned currents. An important feature of these interhemispheric currents is that they link together processes in two hemispheres, so that the currents observed in one hemisphere can provide us with information about the currents in the opposite hemisphere. Despite the significant role of these IHCs in the global 3-D current system, they have not been sufficiently studied yet. The main results of our research may be summarized as follows: 1) In winter hemisphere, the IHCs may significantly exceed and be a substitute for the local Region 1 and Region 2 currents; 2) The IHCs may strongly affect the magnitude, location, and direction of the ionospheric and equivalent ionospheric currents (especially in the nightside winter auroral ionosphere). 3) The IHCs in winter hemisphere may be, in fact, an important (and sometimes even major) source of the Westward Auroral Electrojet, observed in both hemispheres during substorm activity. The study of the contribution from the IHCs into the total global 3-D current system allows us to improve the understanding and forecasting of geomagnetic, auroral, and ionospheric disturbances in two hemispheres. The results of our studies of the Interhemispheric currents are presented in papers: (note: for publications my last

  18. Hybrid Current Lead Design of HTS SMES

    Science.gov (United States)

    Ge, T.; Ren, L.; He, Q.; Jiao, F.; Dong, H.; Jin, T.; Zhou, S.

    In application of Superconducting magnetic energy storage device (SMES), current lead represents a key development component. This paper will focus on parameters and structure design of hybrid high-temperature superconductor (HTS) current lead in a SMES with 100 kJ/100 kW class. Based on the theoretical analysis, finite element simulation (FEA) has been used. It studies the thermal influence of variable cross-sectional area, HTS material and the connection between current lead and cryocooler. Some improvements have been proposed to reduce heat losses. At the end of this paper, a whole procedure about hybrid current lead design is given.

  19. Charged particle beam current monitoring tutorial

    International Nuclear Information System (INIS)

    A tutorial presentation is made on topics related to the measurement of charged particle beam currents. The fundamental physics of electricity and magnetism pertinent to the problem is reviewed. The physics is presented with a stress on its interpretation from an electrical circuit theory point of view. The operation of devices including video pulse current transformers, direct current transformers, and gigahertz bandwidth wall current style transformers is described. Design examples are given for each of these types of devices. Sensitivity, frequency response, and physical environment are typical parameters which influence the design of these instruments in any particular application. Practical engineering considerations, potential pitfalls, and performance limitations are discussed

  20. Current-voltage curve of a bipolar membrane at high current density

    NARCIS (Netherlands)

    Aritomi, T.; Boomgaard, van den Th.; Strathmann, H.

    1996-01-01

    The potential drop across a bipolar membrane was measured as a function of the applied current density. As a result, an inflection point was observed in the obtained current-voltage curve at high current density. This inflection point indicates that at high current densities water supply from outsid

  1. An Optimal Current Observer for Predictive Current Controlled Buck DC-DC Converters

    OpenAIRE

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

    2014-01-01

    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 t...

  2. Forces and torques between nonintersecting straight currents

    Science.gov (United States)

    Binder, P.-M.; Cross, Felicity; Silva, J. K.

    2016-07-01

    We analyse two very long current-carrying straight wires that point in arbitrary directions without touching. We find general expressions for the forces and torques for arbitrary points on one wire due to the other. This allows us to make calculations for the overall forces and torques and statements about the stability of parallel and anti-parallel current arrangements.

  3. 33 CFR 117.127 - Current River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Current River. 117.127 Section 117.127 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Arkansas § 117.127 Current River. The draws of...

  4. 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

  5. Current drive induced by intermittent trapping

    Energy Technology Data Exchange (ETDEWEB)

    Nakach, R. [Association Euratom-CEA, CEA/Cadarache, Dept. de Recherches sur la Fusion Controlee (DRFC), 13 - Saint-Paul-lez-Durance (France); Gell, Y. [CET, Israel (Israel)

    1999-02-01

    We propose a mechanism for driving a current in a dispersive plasma based on intermittent trapping of electrons in a ponderomotive well generated by two- counterpropagating electron cyclotron waves. By choosing properly the parameters of the system, this mechanism is expected to induce a high efficiency current drive. (authors)

  6. A quasilinear formulation of turbulence driven current

    Energy Technology Data Exchange (ETDEWEB)

    McDevitt, C. J.; Tang, Xian-Zhu; Guo, Zehua [Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

    2014-02-15

    Non-inductive current drive mechanisms, such as the familiar neoclassical bootstrap current correspond to an essential component to the realization of steady state tokamak operation. In this work, we discuss a novel collisionless mechanism through which a mean plasma current may be driven in the presence of microturbulence. In analogy with the traditional neoclassical bootstrap current drive mechanism, in which the collisional equilibrium established between trapped and passing electrons results in the formation of a steady state plasma current, here we show that resonant scattering of electrons by drift wave microturbulence provides an additional means of determining the equilibrium between trapped and passing electrons. The resulting collisionless equilibrium is shown to result in the formation of an equilibrium current whose magnitude is a function of the thermodynamic forces. A mean field formulation is utilized to incorporate the above components into a unified framework through which both collisional as well as collisionless current drive mechanisms may be self-consistently treated. Utilizing a linearized Fokker-Planck collision operator, the plasma current in the presence of both collisions as well as turbulent stresses is computed, allowing for the relative strength of these two mechanisms to be quantified as a function of collisionality and fluctuation amplitude.

  7. A quasilinear formulation of turbulence driven current

    Science.gov (United States)

    McDevitt, C. J.; Tang, Xian-Zhu; Guo, Zehua

    2014-02-01

    Non-inductive current drive mechanisms, such as the familiar neoclassical bootstrap current correspond to an essential component to the realization of steady state tokamak operation. In this work, we discuss a novel collisionless mechanism through which a mean plasma current may be driven in the presence of microturbulence. In analogy with the traditional neoclassical bootstrap current drive mechanism, in which the collisional equilibrium established between trapped and passing electrons results in the formation of a steady state plasma current, here we show that resonant scattering of electrons by drift wave microturbulence provides an additional means of determining the equilibrium between trapped and passing electrons. The resulting collisionless equilibrium is shown to result in the formation of an equilibrium current whose magnitude is a function of the thermodynamic forces. A mean field formulation is utilized to incorporate the above components into a unified framework through which both collisional as well as collisionless current drive mechanisms may be self-consistently treated. Utilizing a linearized Fokker-Planck collision operator, the plasma current in the presence of both collisions as well as turbulent stresses is computed, allowing for the relative strength of these two mechanisms to be quantified as a function of collisionality and fluctuation amplitude.

  8. Multiple Currents in the Gulf Stream System

    OpenAIRE

    Fuglister, F. C.

    2011-01-01

    A new interpretation of the accumulated temperature and salinity data from the Gulf Stream Area indicates that the System is made up of a series of overlapping currents. These currents are separated by relatively weak countercurrents. Data from a recent survey are presented as supporting this hypothesis.DOI: 10.1111/j.2153-3490.1951.tb00804.x

  9. Frequency analysis of DC tolerant current transformers

    International Nuclear Information System (INIS)

    This article deals with wide frequency range behaviour of DC tolerant current transformers that are usually used in modern static energy meters. In this application current transformers must comply with European and International Standards in their accuracy and DC tolerance. Therefore, the linear DC tolerant current transformers and double core current transformers are used in this field. More details about the problems of these particular types of transformers can be found in our previous works. Although these transformers are designed mainly for power distribution network frequency (50/60 Hz), it can be interesting to understand their behaviour in wider frequency range. Based on this knowledge the new generations of energy meters with measuring quality of electric energy will be produced. This solution brings better measurement of consumption of nonlinear loads or measurement of non-sinusoidal voltage and current sources such as solar cells or fuel cells. The determination of actual power consumption in such energy meters is done using particular harmonics component of current and voltage. We measured the phase and ratio errors that are the most important parameters of current transformers, to characterize several samples of current transformers of both types

  10. Recent Advances in Studies of Current Noise

    OpenAIRE

    Blanter, Ya. M.

    2005-01-01

    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.

  11. Numerical modeling of transformer inrush currents

    Science.gov (United States)

    Cardelli, E.; Faba, A.

    2014-02-01

    This paper presents an application of a vector hysteresis model to the prediction of the inrush current due the arbitrary initial excitation of a transformer after a fault. The approach proposed seems promising in order to predict the transient overshoot in current and the optimal time to close the circuit after the fault.

  12. Numerical modeling of transformer inrush currents

    Energy Technology Data Exchange (ETDEWEB)

    Cardelli, E. [Department of Industrial Engineering, University of Perugia, I-06125 Perugia (Italy); Center for Electric and Magnetic Applied Research (Italy); Faba, A., E-mail: faba@unipg.it [Department of Industrial Engineering, University of Perugia, I-06125 Perugia (Italy); Center for Electric and Magnetic Applied Research (Italy)

    2014-02-15

    This paper presents an application of a vector hysteresis model to the prediction of the inrush current due the arbitrary initial excitation of a transformer after a fault. The approach proposed seems promising in order to predict the transient overshoot in current and the optimal time to close the circuit after the fault.

  13. Enhancing critical current density of cuprate superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Chaudhari, Praveen

    2015-06-16

    The present invention concerns the enhancement of critical current densities in cuprate superconductors. Such enhancement of critical current densities include using wave function symmetry and restricting movement of Abrikosov (A) vortices, Josephson (J) vortices, or Abrikosov-Josephson (A-J) vortices by using the half integer vortices associated with d-wave symmetry present in the grain boundary.

  14. Current and Future Flight Operating Systems

    Science.gov (United States)

    Cudmore, Alan

    2007-01-01

    This viewgraph presentation reviews the current real time operating system (RTOS) type in use with current flight systems. A new RTOS model is described, i.e. the process model. Included is a review of the challenges of migrating from the classic RTOS to the Process Model type.

  15. Designer's Casebook: current-mode minimax circuit

    NARCIS (Netherlands)

    Wassenaar, Roelof F.

    1992-01-01

    The minimum-maximum (minimax) circuit selects the minimum and maximum of two input currents. Four transistors in matched pairs are operated in the saturation region. Because the behavior of the circuit is based on matched devices and is independent of the relationship between the drain current and t

  16. Coastal Currents with Along-Track Interferometry

    NARCIS (Netherlands)

    Greidanus, H.S.F.; Bree, R.J.P. van; Huising, E.J.; Vogelzang, J.; Vaessen, E.M.J.

    1999-01-01

    Airborne radar along-track interferometric measurements of a coastal area with a complex tidal flow pattern are analyzed. The results are compared with a current field computed from a tidal model. Using wave-current interaction modeling, a radar backscatter image is simulated based on the measured c

  17. K130 beam current measurement system

    Science.gov (United States)

    Gustafsson, J.; Kotilainen, P.; Hänninen, V.; Liukkonen, E.; Kaski, K.

    1994-03-01

    A measurement system for very low currents, developed to be used in the K130 cyclotron at University of Jyväskylä, is described. The beam intensity measurement is implemented with a current preamplifier and signal multiplexor. The measurement is controlled and visualised with a commercial data acquisition card integrated in a PC.

  18. K130 beam current measurement system

    Energy Technology Data Exchange (ETDEWEB)

    Gustafsson, J. (Microelectronics Lab., Tampere Univ. of Technology (Finland)); Kotilainen, P. (Microelectronics Lab., Tampere Univ. of Technology (Finland)); Haenninen, V. (Jyvaeskylae Univ. (Finland). Dept. of Physics); Liukkonen, E. (Jyvaeskylae Univ. (Finland). Dept. of Physics); Kaski, K. (Microelectronics Lab., Tampere Univ. of Technology (Finland))

    1994-03-22

    A measurement system for very low currents, developed to be used in the K130 cyclotron at University of Jyvaeskylae, is described. The beam intensity measurement is implemented with a current preamplifier and signal multiplexor. The measurement is controlled and visualised with a commercial data acquisition card integrated in a PC. (orig.)

  19. Circle Points Discharge Tube Current Controller

    Institute of Scientific and Technical Information of China (English)

    Meng Jinjia; Meng Lisheng

    2005-01-01

    Circle points discharge tube current controller is a new type device to limit theoutput of high voltage discharge current. Circle points uniform corona discharge to form airionization current in the discharge tube. On the outside, even if the discharge electrode is sparkdischarging or the two discharge electrodes are short circuited, the air ionization current in the tuberemains within a stable range, and there is no spark discharge. In this case, when the dischargecurrent only increases slightly, the requirement to limited current is obtained. By installing thecontroller at a discharge pole with a small power but high voltage supply, we can realize the shiftbetween the continuous spark line discharge and corona discharge. This provides a new simpledevice for spark discharge research and is a supplement to the Townsend discharge experiment.

  20. Transformation of spin current by antiferromagnetic insulators

    Science.gov (United States)

    Khymyn, Roman; Lisenkov, Ivan; Tiberkevich, Vasil S.; Slavin, Andrei N.; Ivanov, Boris A.

    2016-06-01

    It is demonstrated theoretically that a thin layer of an anisotropic antiferromagnetic (AFM) insulator can effectively conduct spin current through the excitation of a pair of evanescent AFM spin wave modes. The spin current flowing through the AFM is not conserved due to the interaction between the excited AFM modes and the AFM lattice and, depending on the excitation conditions, can be either attenuated or enhanced. When the phase difference between the excited evanescent modes is close to π /2 , there is an optimum AFM thickness for which the output spin current reaches a maximum, which can significantly exceed the magnitude of the input spin current. The spin current transfer through the AFM depends on the ambient temperature and increases substantially when temperature approaches the Néel temperature of the AFM layer.

  1. Entropy current for non-relativistic fluid

    CERN Document Server

    Banerjee, Nabamita; Jain, Akash; Roychowdhury, Dibakar

    2014-01-01

    We study transport properties of a parity-odd, non-relativistic charged fluid in presence of background electric and magnetic fields. To obtain stress tensor and charged current for the non-relativistic system we start with the most generic relativistic fluid, living in one higher dimension and reduce the constituent equations along the light-cone direction. We also reduce the equation satisfied by the entropy current of the relativistic theory and obtain a consistent entropy current for the non-relativistic system (we call it "canonical form" of the entropy current). Demanding that the non-relativistic fluid satisfies the second law of thermodynamics we impose constraints on various first order transport coefficients. For parity even fluid, this is straight forward; it tells us positive definiteness of different transport coefficients like viscosity, thermal conductivity, electric conductivity etc. However for parity-odd fluid, canonical form of the entropy current fails to confirm the second law of thermody...

  2. 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.

  3. Renormalization of the Vector Current in QED

    CERN Document Server

    Collins, J C; Wise, M B; Collins, John C.; Manohar, Aneesh V.; Wise, Mark B.

    2006-01-01

    It is commonly asserted that the electromagnetic current is conserved and therefore is not renormalized. Within QED we show (a) that this statement is false, (b) how to obtain the renormalization of the current to all orders of perturbation theory, and (c) how to correctly define an electron number operator. The current mixes with the four-divergence of the electromagnetic field-strength tensor. The true electron number operator is the integral of the time component of the electron number density, but only when the current differs from the MSbar-renormalized current by a definite finite renormalization. This happens in such a way that Gauss's law holds: the charge operator is the surface integral of the electric field at infinity. The theorem extends naturally to any gauge theory.

  4. Three phase voltage source converter current analysis

    International Nuclear Information System (INIS)

    The proposed rectifier system consists of a three-phase diode bridge circuit as a main power circuit, A C reactors, and an additional circuit, which serves as an active filter with low switching frequencies and forced-commutation circuit for the diodes. These papers describe the operation principle, analysis of the waveforms of input voltage and current, the calculated of A C input current, multiple phase-shifted systems, and the experimental result. Avery conventional method was employed to analyze the input current equation; in that, the ripple output was neglected. The theory developed in this paper was verified twice; by calculation result and experiments. The calculated A C input the simple program using the algorithm of current equations calculated current waveforms presented in this paper. A switching circuit has been added to the diode rectifier, serving as an active filter and a forced-commutation circuit for diodes systems

  5. Quench properties of high current superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Garber, M; Sampson, W B

    1980-01-01

    A technique has been developed which allows the simultaneous determination of most of the important parameters of a high current superconductor. The critical current, propagation velocity, normal state resistivity, magnetoresistance, and enthalpy are determined as a function of current and applied field. The measurements are made on non-inductive samples which simulate conditions in full scale magnets. For wide, braided conductors the propagation velocity was found to vary approximately quadratically with current in the 2 to 5 kA region. A number of conductors have been tested including some Nb/sub 3/Sn braids which have critical currents in excess of 10 kA at 5 T, 4.2 K.

  6. Deep boundary current disintegration in Drake Passage

    Science.gov (United States)

    Brearley, J. Alexander; Sheen, Katy L.; Naveira Garabato, Alberto C.; Smeed, David A.; Speer, Kevin G.; Thurnherr, Andreas M.; Meredith, Michael P.; Waterman, Stephanie

    2014-01-01

    The fate of a deep boundary current that originates in the Southeast Pacific and flows southward along the continental slope of South America is elucidated. The current transports poorly ventilated water of low salinity (a type of Pacific Deep Water, PDW), into Drake Passage. East of Drake Passage, the boundary current breaks into fresh anticyclonic eddies, nine examples of which were observed in mooring data from December 2009 to March 2012. The observed eddies appear to originate mainly from a topographic separation point close to 60°W, have typical diameters of 20-60 km and accompanying Rossby numbers of 0.1-0.3. These features are likely to be responsible for transporting PDW meridionally across the Antarctic Circumpolar Current, explaining the near homogenization of Circumpolar Deep Water properties downstream of Drake Passage. This mechanism of boundary current breakdown may constitute an important process in the Southern Ocean overturning circulation.

  7. EFFECTS OF WAVE-CURRENT INTERACTIONS ON BOTTOM STRESS AND CURRENTS

    Institute of Scientific and Technical Information of China (English)

    Yin Bao-shu; Yang De-zhou; Lin Xiang; Hou Yi-jun; Cheng Ming-hua; Will Perrie

    2003-01-01

    This paper presents a high-resolution (2′×2′) numerical model of coastal coupled wave-current interaction with explicit consideration of the effects of wave-current interaction on bottom stress. For two selected storms with measured data in the Yellow River coastal area of the Bohai Sea, it is shown that the bottom stress calculated by using a coupled wave-current model is increased, as one would expect, compared with the bottom stress computed with an uncoupled current model. Moreover, the current velocity field is also changed, but the corresponding current directions show less influence in the two simulations. The extents of changes in bottom stress and current velocity vary with storm intensities. The results further imply that the coupled wave-current model should be used as the basis for simulating the current velocity and sea level in the near shore region.

  8. Programmable, very low noise current source

    Science.gov (United States)

    Scandurra, G.; Cannatà, G.; Giusi, G.; Ciofi, C.

    2014-12-01

    We propose a new approach for the realization of very low noise programmable current sources mainly intended for application in the field of low frequency noise measurements. The design is based on a low noise Junction Field Effect Transistor (JFET) acting as a high impedance current source and programmability is obtained by resorting to a low noise, programmable floating voltage source that allows to set the sourced current at the desired value. The floating voltage source is obtained by exploiting the properties of a standard photovoltaic MOSFET driver. Proper filtering and a control network employing super-capacitors allow to reduce the low frequency output noise to that due to the low noise JFET down to frequencies as low as 100 mHz while allowing, at the same time, to set the desired current by means of a standard DA converter with an accuracy better than 1%. A prototype of the system capable of supplying currents from a few hundreds of μA up to a few mA demonstrates the effectiveness of the approach we propose. When delivering a DC current of about 2 mA, the power spectral density of the current fluctuations at the output is found to be less than 25 pA/√Hz at 100 mHz and less than 6 pA/√Hz for f > 1 Hz, resulting in an RMS noise in the bandwidth from 0.1 to 10 Hz of less than 14 pA.

  9. LEDA beam diagnostics instrumentation: Beam current measurement

    International Nuclear Information System (INIS)

    The Low Energy Demonstration Accelerator (LEDA) facility located at Los Alamos National Laboratory (LANL) accelerates protons to an energy of 6.7 MeV and current of 100 mA operating in either a pulsed or cw mode. Two types of current measurements are used. The first is an AC or pulsed-current measurement which uses three LANL built toroids. They are placed in the beamline in such a way as to measure important transmission parameters and act as a differential current-loss machine protection system. The second system is a DC current measurement used to measure cw beam characteristics and uses toroids from Bergoz Inc. There are two of these systems, so they can also be used for transmission measurements. The AC system uses custom processing electronics whereas the DC system uses a modified Bergoz registered electronics system. Both systems feature data acquisition via a series of custom TMS320C40 Digital Signal Processing (DSP) boards. Of special interest to this paper is the operation of these systems, the calibration technique, the differential current loss measurements and fast-protection processing, current droop characteristics for the AC system, and existing system noise levels. This paper will also cover the DSP system operations and their interaction with the main accelerator control system

  10. Eddy current analysis in JT-60

    International Nuclear Information System (INIS)

    In response to the demands from a mechanical design and a control analysis of plasma position, current and shape, intensive numerical and analytical eddy current studies have been made in JT-60 project. The numerical results of eddy current analysis in JT-60 multi-torus system using the numerical code EDDYMULT which was newly developed in JAERI are presented. Taking into account the mutual coupling between a vacuum vessel, toroidal coils, support plates and a central column, the eigen functions of eddy current defined in the entire multi-torus system were obtained by the method of modal analysis. In order to confirm the validity of our numerical code, the model experiments were carried out and satisfactory agreement between the experimental and the numerical results was obtained. Volt-second loss of ohmic heating circuit due to the eddy current and the transient shape of equilibrium field including the eddy current field during regular start-up of plasma were numerically calculated in JT-60 multi-torus system. The application to the advanced study based on a modern control theory was discussed in particular on controlling a plasma position including the eddy current effect in the actual geometry. (author)

  11. Current density and continuity in discretized models

    International Nuclear Information System (INIS)

    Discrete approaches have long been used in numerical modelling of physical systems in both research and teaching. Discrete versions of the Schroedinger equation employing either one or several basis functions per mesh point are often used by senior undergraduates and beginning graduate students in computational physics projects. In studying discrete models, students can encounter conceptual difficulties with the representation of the current and its divergence because different finite-difference expressions, all of which reduce to the current density in the continuous limit, measure different physical quantities. Understanding these different discrete currents is essential and requires a careful analysis of the current operator, the divergence of the current and the continuity equation. Here we develop point forms of the current and its divergence valid for an arbitrary mesh and basis. We show that in discrete models currents exist only along lines joining atomic sites (or mesh points). Using these results, we derive a discrete analogue of the divergence theorem and demonstrate probability conservation in a purely localized-basis approach.

  12. Ultrastable low-noise current amplifier

    CERN Document Server

    Drung, Dietmar; Becker, Ulrich; Scherer, Hansjörg; Ahlers, Franz Josef

    2014-01-01

    An ultrastable low-noise current amplifier (ULCA) is presented. The ULCA is a non-cryogenic instrument based on specially designed operational amplifiers and resistor networks. It involves two stages, the first providing a 1000-fold current gain and the second performing a current-to-voltage conversion via an internal 1 MOhm reference resistor or, optionally, an external standard resistor. The ULCA's transfer coefficient is extremely stable versus time, temperature and current amplitude within the full dynamic range of +/-5 nA. A low noise level of 2.4 fA/sqrt(Hz) helps to keep averaging times low at small input currents. A cryogenic current comparator is used to calibrate both input current gain and output transresistance, providing traceability to the quantum Hall effect. Typically, within one day after calibration, the uncertainty contribution from short-term fluctuations of the transresistance is below one part in 10^7. The long-term stability is expected to be better than one part in 10^5 over a year. A ...

  13. Current assisted superplastic forming of titanium alloy

    Directory of Open Access Journals (Sweden)

    Wang Guofeng

    2015-01-01

    Full Text Available Current assisted superplastic forming combines electric heating technology and superplastic forming technology, and can overcome some shortcomings of traditional superplastic forming effectively, such as slow heating rate, large energy loss, low production efficiency, etc. Since formability of titanium alloy at room temperature is poor, current assisted superplastic forming is suitable for titanium alloy. This paper mainly introduces the application of current assisted superplastic forming in the field of titanium alloy, including forming technology of double-hemisphere structure and bellows.

  14. On the formation of current ripples

    DEFF Research Database (Denmark)

    Bartholdy, Jesper; Ernstsen, Verner Brandbyge; Flemming, Burg W.;

    2015-01-01

    For grain sizes finer than coarse sand, the first flow-transverse bedforms to develop are current ripples. Although numerous studies have analysed different aspects of bedform morphodynamics, to date no comprehensive physical explanation for the formation of ripples has been given. We offer...... such an explanation based on a virtual boundary layer concept, and present a model predicting ripple height on the basis of grain size, current velocity and water depth. The model contradicts the conventional view of current ripples as bedforms not scaling with flow depth. Furthermore, it confirms the dependence...

  15. 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.

  16. Burnout current density of bismuth nanowires

    Science.gov (United States)

    Cornelius, T. W.; Picht, O.; Müller, S.; Neumann, R.; Völklein, F.; Karim, S.; Duan, J. L.

    2008-05-01

    Single bismuth nanowires with diameters ranging from 100nmto1μm were electrochemically deposited in ion track-etched single-pore polycarbonate membranes. The maximum current density the wires are able to carry was investigated by ramping up the current until failure occurred. It increases by three to four orders of magnitude for nanowires embedded in the template compared to bulk bismuth and rises with diminishing diameter. Simulations show that the wires are heated up electrically to the melting temperature. Since the surface-to-volume ratio rises with diminishing diameter, thinner wires dissipate the heat more efficiently to the surrounding polymer matrix and, thus, can tolerate larger current densities.

  17. Current-driven phenomena in nanoelectronics

    CERN Document Server

    Seideman, Tamar

    2010-01-01

    Consisting of ten chapters written by some of the world's leaders in the field, this book combines experimental, theoretical and numerical studies of current-driven phenomena in the nanoscale. The topics covered range from single-molecule, site-specific nanochemistry induced by a scanning tunneling microscope, through inelastic tunneling spectroscopy and current-induced heating, to current-triggered molecular machines. The various chapters focus on experimental and numerical method development, the description of specific systems, and new ideas and novel phenomena.

  18. Superconducting fault current limiter for railway transport

    International Nuclear Information System (INIS)

    A resistive switching superconducting fault current limiter (SFCL) for DC networks with voltage of 3.5 kV and nominal current of 2 kA is developed. The SFCL consists of two series-connected units: block of superconducting modules and high-speed vacuum breaker with total disconnection time not more than 8 ms. The results of laboratory tests of superconducting SFCL modules in current limiting mode are presented. The recovery time of superconductivity is experimentally determined. The possibility of application of SFCL on traction substations of Russian Railways is considered

  19. Probable Values of Current Solar Cycle Peak

    Directory of Open Access Journals (Sweden)

    V. M. Silbergleit

    2012-01-01

    Full Text Available An analysis of multiple linear regression method applied to solar cycles 4 to 23 using lagged values of smoothed monthly mean sunspot numbers as independent variables is presented. According to that, the amplitude of current solar cycle 24 is estimated providing a quantitative prediction result. Our adjustment shows that the current cycle would have a sunspot peak less than the biggest one observed during the cycle 19 giving an additional support to the declination in solar activity which is currently happening.

  20. Superconducting fault current limiter for railway transport

    Energy Technology Data Exchange (ETDEWEB)

    Fisher, L. M., E-mail: LMFisher@niitfa.ru; Alferov, D. F.; Akhmetgareev, M. R.; Budovskii, A. I.; Evsin, D. V.; Voloshin, I. F.; Kalinov, A. V. [National Technical Physics and Automation Research Institute (Russian Federation)

    2015-12-15

    A resistive switching superconducting fault current limiter (SFCL) for DC networks with voltage of 3.5 kV and nominal current of 2 kA is developed. The SFCL consists of two series-connected units: block of superconducting modules and high-speed vacuum breaker with total disconnection time not more than 8 ms. The results of laboratory tests of superconducting SFCL modules in current limiting mode are presented. The recovery time of superconductivity is experimentally determined. The possibility of application of SFCL on traction substations of Russian Railways is considered.

  1. Stabilization of tearing mode by current drive

    Institute of Scientific and Technical Information of China (English)

    WANG Zhong-tian; SHI Man-li; MAO Guo-ping; ZHAO Shan-zhong; ZHENG Xiao-hu

    2004-01-01

    The major disruption limits the operation of present tokamaks. Experimental evidences point out that the growth of tearing modes or the magnetic islands is primarily responsible for the occurrence. Taking the non-inductive current drive effects into account, a set of 3D nonlinear equation is derived. It is shown from simulation that the growth of the magnetic island is suppressed effectively by RF current drive. It is consistent with recent experiments on the HL-1 tokamak in which the plasma is stabilized by an RF current drive.

  2. Current saturation in submillimeter wave varactors

    Science.gov (United States)

    Kollberg, Erik L.; Tolmunen, T. J.; Frerking, Margaret A.; East, Jack R.

    1992-01-01

    In semiconductor devices the speed of electrons cannot exceed certain limits. This phenomenon will affect varactor multipliers as well as other high frequency devices where the RF current through the active part of the device is primarily displacement current. Hence, 'saturation' of the varactor output power is expected at some point. This phenomenon is discussed in some detail and shown to severely deteriorate the multiplier performance at higher frequencies. Single barrier varactors should have an advantage over GaAs Schottky diode varactors because they can be fabricated on InAs and stacked in a series array, allowing for lower current densities and higher power handling.

  3. Physics of the magnetotail current sheet

    Energy Technology Data Exchange (ETDEWEB)

    Chen, J. (Beam Physics Branch, Plasma Physics Division, Naval Research Laboratory, Washington, D.C. 20375 (United States))

    1993-07-01

    The Earth's magnetotail plays an important role in the solar-wind--magnetosphere coupling. At the midplane of the magnetotail is a current sheet where the dominant magnetic field component reverses sign. The charged particle motion in and near the current sheet is collisionless and nonintegrable, exhibiting chaotic scattering. The current understanding of the dynamical properties of the charged particle motion is discussed. In particular, the relationships between particle dynamics and global attributes of the system are elucidated. Geometrical properties of the phase space determine important physical observables on both micro- and macroscales.

  4. Current lead for cryogenic electrical devices

    International Nuclear Information System (INIS)

    Current lead for cryogenic electrical devices is described. The current lead comprises a gas-proof vessel with a located current-carrying element in it and an insulator. The element is realized in a form of packet with parallel arranged and interconnected foils and flattened brainds. With the purpose to improve heat exchange with the cooling gas, cross section size decrease and construction simplification, the gas-proof vessel is formed by extreme packet foils and welded surfaces of latteral faces, foils and raids

  5. Eddy-Current Monitoring Of Composite Layups

    Science.gov (United States)

    Fox, Robert L.; Buckley, John D.

    1993-01-01

    Eddy-current-probe apparatus used to determine predominant orientations of fibers in fiber/matrix composite materials. Apparatus nondestructive, noninvasive means for monitoring composite prepregs and layups during fabrication to ensure predictable and repeatable mechanical properties of finished composite panels. Consists essentially of electromagnet coil wrapped around horseshoe-shaped powdered-iron or ferrite ore. Optionally, capacitor included in series or parallel with coil to form resonant circuit. Impedance monitor excites radio-frequency current in coil and measures impedance of probe circuit. Affected by whatever material placed near ends of core, where material intercepts alternating magnetic field excited in core by current in coil.

  6. Current drive and sustain experiments with the bootstrap current in JT-60

    International Nuclear Information System (INIS)

    The current drive and sustain experiments with the neoclassical bootstrap current are performed in the JT-60 tokamak. It is shown that up to 80% of total plasma current is driven by the bootstrap current in extremely high βp regime (βp = 3.2) and the current drive product Ip (bootstrap) n-bareRp up to 4.4 x 1019 MAm-2 has been attained with the bootstrap current. The experimental resistive loop voltages are compared with the calculations using the neoclassical resistivity with and without the bootstrap current and the Spitzer resistivity for a wide range of the plasma current (Ip = 0.5 -2 MA) and the poloidal beta (βp = 0.1 - 3.2). The calculated resistive loop voltage is consistent with the neoclassical prediction including the bootstrap current. Current sustain with the bootstrap current is tested by terminating the Ip feedback control during the high power neutral beam heating. An enhancement of the L/R decay time than those expected from the plasma resistivity with measured Te and Zeff has been confirmed experimentally supporting the large non-inductive current in the plasma and is consistent with the neoclassical prediction. A new technique to calculate the bootstrap current in multi-collisionality regime for finite aspect ratio tokamak has bee developed. The neoclassical bootstrap current is calculated directly through the force balance equations between viscous and friction forces according to the Hirshman-Sigmar theory. The bootstrap current driven by the fast ion component is also included. Ballooning stability of the high βp plasma are analyzed using the current profiles including the bootstrap current. The plasma pressure is close to the ballooning limit in high βp discharges. (author)

  7. Eddy current testing with high penetration

    International Nuclear Information System (INIS)

    The low-frequency eddy current testing method is used when penetration into very deep layers is required. The achievable penetration depth is determined among other parameters by the lowest testing frequency that can be realised together with the eddy current sensor. When using inductive sensors, the measuring effect declines proportional to the lowering frequency (induction effect). Further reduction of testing frequency requires other types of sensors, as e.g. the GMR (Giant Magnetic Resistance), which achieves a constant measuring sensitivity down to the steady field. The multi-frequency eddy current testing method MFEC 3 of IZFP described here can be operated using three different scanning frequencies at a time. Two variants of eddy current probes are used in this case. Both have an inductive winding at their emitters, of the type of a measuring probe. The receiver end is either also an inductive winding, or a magnetic field-responsive resistance (GMR). (orig./CB)

  8. Currents in the Eastern Irish Sea

    International Nuclear Information System (INIS)

    Low level radioactive waste is discharged from the nuclear re-processing plant at Sellafield, Cumbria. Its movement away from the discharge point is determined by the Irish Sea's dynamics, both for the soluble compounds and for those compounds which become attached to the sediment. Near Sellafield the tidal currents are weak and parallel to the shore, becoming stronger east/west to the north and south of the Isle of Man. Wind driven currents near Sellafield are predominantly north-westward, strongest near the coast, and oppose the other low frequency currents. Hence, the soluble effluent will initially be dispersed parallel to the shore by the weak tidal currents, moving episodically, southeastward during weak winds and northwestward during storms. Eventually it will leave the Irish Sea, flowing northward through the North Channel. (author)

  9. Equivalent Resistance in Pulse Electric Current Sintering

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The sintering resistance for conductive TiB2 and non-conductive Al2O3 as well as empty die during pulse current sintering were investigated in this paper.Equivalent resistances were measured by current and valtage during sintering the conductive and non-conductive materials in the same conditions.It is found that the current paths for conductive are different from those for non-conductive materials.For non-conductive materials,sintering resistances are influenced by powder sizes and heating rates,which indicates that pulse current has some interaction with non-conductive powders.For conductive TiB2,sintering resistances are influenced by heating rates and ball-milling time,which indicates the effect of powders activated by spark.

  10. The Current Status of Galaxy Formation

    OpenAIRE

    Silk, Joe; Mamon, Gary A.

    2012-01-01

    Understanding galaxy formation is one of the most pressing issues in cosmology. We review the current status of galaxy formation from both an observational and a theoretical perspective, and summarise the prospects for future advances.

  11. Simulation of Gravity Currents Using VOF Model

    Institute of Scientific and Technical Information of China (English)

    邹建锋; 黄钰期; 应新亚; 任安禄

    2002-01-01

    By the Volume of Fluid (VOF) multiphase flow model two-dimensional gravity currents with three phases including air are numerically simulated in this article. The necessity of consideration of turbulence effect for high Reynolds numbers is demonstrated quantitatively by LES (the Large Eddy Simulation) turbulence model. The gravity currents are simulated for h ≠ H as well as h = H, where h is the depth of the gravity current before the release and H is the depth of the intruded fluid. Uprising of swell occurs when a current flows horizontally into another lighter one for h ≠ H. The problems under what condition the uprising of swell occurs and how long it takes are considered in this article. All the simulated results are in reasonable agreement with the experimental results available.

  12. Redefining the Concept of Spin Current

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    @@ A group of physicists headed by CAS scientist questioned the validity of the conventional definition of spin current and proposed a new one.Their work was published in a recent issue of the US journal Physical Review Letters.

  13. Current filaments in turbulent magnetized plasmas

    DEFF Research Database (Denmark)

    Martines, E.; Vianello, N.; Sundkvist, D.;

    2009-01-01

    gradient region of a fusion plasma confined in reversed field pinch configuration and in a density gradient region in the Earth magnetosphere are measured and compared, showing that in both environments they can be attributed to drift-Alfvén vortices. Current structures associated with reconnection events......Direct measurements of current density perturbations associated with non-linear phenomena in magnetized plasmas can be carried out using in situ magnetic measurements. In this paper we report such measurements for three different kinds of phenomena. Current density fluctuations in the edge density...... measured in a reversed field pinch plasma and in the magnetosheath are detected and compared. Evidence of current filaments occurring during ELMs in an H-mode tokamak plasma is displayed....

  14. First metatarsophalangeal joint arthrodesis: current fixation options.

    Science.gov (United States)

    Moon, Jared L; McGlamry, Michael C

    2011-04-01

    This article reviews the current literature on first metatarsophalangeal joint arthrodesis rates using various forms of fixation, as well as reviewing biomechanical studies comparing the strengths of the different fixation options that are available.

  15. Superconducting Current Leads for Cryogenic Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Space flight cryocoolers will be able to handle limited heat loads at their expected operating temperatures and the current leads may be the dominant contributor to...

  16. Electromagnetic currents induced by color fields

    CERN Document Server

    Tanji, Naoto

    2015-01-01

    The quark production in classical color fields is investigated with a focus on the induction of an electromagnetic current by produced quarks. We show that the SU(2) and the SU(3) theories lead significantly different results for the electromagnetic current. In uniform SU(2) color fields, the net electromagnetic current is not generated, while for SU(3) the net current is induced depending on the color direction of background fields. Also the numerical study of the quark production in inhomogeneous color fields is done. Motivated by gauge field configurations provided by the color glass condensate framework, we introduce an ensemble of randomly distributed color electric fluxtubes. The spectrum of photons emitted from the quarks by a classical process is shown.

  17. Combined Digital Electronic Current and Voltage Transducer

    Institute of Scientific and Technical Information of China (English)

    段雄英; 邹积岩; 等

    2002-01-01

    A high-performance current and voltage measurement system has been developed in power system.The system is composed of two parts:one current measurement element and one voltage measurement element.A Rogowski coil and a capacitive voltage divider are used respectively for the line current and voltage measurements.Active electronic components are used to modulate signal,and power supply for these components is drawn from power line via an auxiliary current transformer,Measurement signal is transmitted y optical fibers,which is resistant to electromagnetic induction and noise,With careful design and the use of digital signal processing technology,the whole system can meet 0.5% accuracy for metering and provides large dynamic range coupled with good accuracy for protective relaying use.

  18. Recognizing limitations in eddy current testing

    International Nuclear Information System (INIS)

    This paper addresses known limitations and constraints in eddy current nondestructive testing. Incomplete appreciation for eddy current limitations is believed to have contributed to both under-utilization and misapplication of the technique. Neither situation need arise if known limitations are recognized. Some, such as the skin depth effect, are inherent to electromagnetic test methods and define the role of eddy current testing. Others can be overcome with available technology such as surface probes to find circumferential cracks in tubes and magnetic saturation of ferromagnetic alloys to eliminate permeability effects. The variables responsible for limitations in eddy current testing are discussed and where alternative approaches exist, these are presented. Areas with potential for further research and development are also identified

  19. Current frontiers in systemic sclerosis pathogenesis

    NARCIS (Netherlands)

    Ciechomska, Marzena; van Laar, Jacob; O'Reilly, Steven

    2015-01-01

    Systemic sclerosis is an autoimmune disease characterised by vascular dysfunction, impaired angiogenesis, inflammation and fibrosis. There is no currently accepted disease-modifying treatment with only autologous stem cell transplant showing clinically meaningful benefit. The lack of treatment optio

  20. Leakage current measurement in transformerless PV inverters

    DEFF Research Database (Denmark)

    Kerekes, Tamas; Sera, Dezso; Mathe, Laszlo

    2012-01-01

    Photovoltaic (PV) installations have seen a huge increase during the last couple of years. Transformerless PV inverters are gaining more share of the total inverter market, due to their high conversion efficiency, small weight and size. Nevertheless safety should have an important role in case...... of these tranformerless systems, due to the missing galvanic isolation. Leakage and fault current measurement is a key issue for these inverter topologies to be able to comply with the required safety standards. This article presents the test results of two different current measurement sensors that were suggested...... to be used in commercial PV inverters for the measurement of leakage and fault ground currents. The German VDE0126–1–1 standard gives the limit for fault and leakage ground currents and all grid connected PV inverters have to comply with these limits and disconnect from the grid in case of a fault....

  1. Employee Training: Current Trends, Future Challenges.

    Science.gov (United States)

    Gorovitz, Elizabeth

    1983-01-01

    Issues currently affecting employee training are the impact of high technology, worker adaptability, the communications revolution, job satisfaction, underinvestment in human capital, demographic shifts, and interest in productivity improvement. (SK)

  2. 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.

  3. Electric Current Systems in Solar Active Regions

    Science.gov (United States)

    LaBonte, B. J.; Mickey, D. L.

    2000-05-01

    The first study to show the persistence of local field-aligned current systems in active regions was reported by Pevtsov, Canfield, and Metcalf (Astrophys. J., 425, L117, 1994). Their work was limited to a sample of complex, flare-productive regions because of the sensitivity limit of the data from the Haleakala Stokes Polarimeter. I report here on a new survey of active regions with the Imaging Vector Magnetograph (IVM) at Mees Solar Observatory. The IVM data permit a look at current systems in simpler, more typical active regions, because of better sensitivity, temporal sampling, spatial resolution and field-of-view. Small scale current systems are commonly seen. Transport of current systems by advective processes is commonly seen over times of hours. This work was supported by NASA grant NAG5-4941 and by a subcontract with LMSAL in support of NASA contract NAS8-40801 for YOHKOH SXT.

  4. Public Budget Database - Governmental receipts 1962-Current

    Data.gov (United States)

    Executive Office of the President — This file contains governmental receipts for 1962 through the current budget year, as well as four years of projections. It can be used to reproduce many of the...

  5. On Active Current Selection for Lagrangian Profilers

    Directory of Open Access Journals (Sweden)

    J. Jouffroy

    2013-01-01

    Full Text Available Autonomous Lagrangian profilers are now widely used as measurement and monitoring platforms, notably in observation programs as Argo. In a typical mode of operation, the profilers drift passively at their parking depthbefore making a vertical profile to go back to the surface. This paperpresents simple and computationally-efficient control strategies to activelyselect and use ocean currents so that a profiler can autonomously reach adesired destination. After briefly presenting a typical profiler andpossible mechanical modifications for a coastal environment, we introducesimple mathematical models for the profiler and the currents it will use. Wethen present simple feedback controllers that, using the direction of thecurrents and taking into account the configuration of the environment(coastal or deep-sea, is able to steer the profiler to any desiredhorizontal location. To illustrate the approach, a few results are presentedusing both simulated currents and real current velocity profiles from theNorth Sea.

  6. Full-wave current conveyor precision rectifier

    Directory of Open Access Journals (Sweden)

    Đukić Slobodan R.

    2008-01-01

    Full Text Available A circuit that provides precision rectification of small signal with low temperature sensitivity for frequencies up to 100 kHz without waveform distortion is presented. It utilizes an improved second type current conveyor based on current-steering output stage and biased silicon diodes. The use of a DC current source to bias the rectifying diodes provides higher temperature stability and lower DC offset level at the output. Proposed design of the precision rectifier ensures good current transfer linearity in the range that satisfy class A of the amplifier and good voltage transfer characteristic for low level signals. Distortion during the zero crossing of the input signal is practically eliminated. Design of the proposed rectifier is realized with standard components.

  7. Medicare Current Beneficiary Survey - Limited Data Set

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Medicare Current Beneficiary Survey (MCBS) is a continuous, multipurpose survey of a representative national sample of the Medicare population. There are two...

  8. Nuclear standards: current issues and future trends

    International Nuclear Information System (INIS)

    A summary of the important issues that currently face the nuclear standards field is presented and a discussion of how each of these issues is being resolved is given. The economic benefits that properly developed standards produce are listed

  9. Critical current densities in superconducting materials

    Indian Academy of Sciences (India)

    P Chaddah

    2003-02-01

    We discuss recent research in the area of critical current densities $(J_C)$ in superconductors. This shall cover recent work on newly discovered superconductors, as well as on the magnetic-field dependence of $J_C$.

  10. Transformer current sensor for superconducting magnetic coils

    Science.gov (United States)

    Shen, Stewart S.; Wilson, C. Thomas

    1988-01-01

    A transformer current sensor having primary turns carrying a primary current for a superconducting coil and secondary turns only partially arranged within the primary turns. The secondary turns include an active winding disposed within the primary turns and a dummy winding which is not disposed in the primary turns and so does not experience a magnetic field due to a flow of current in the primary turns. The active and dummy windings are wound in opposite directions or connected in series-bucking relationship, and are exposed to the same ambient magnetic field. Voltages which might otherwise develop in the active and dummy windings due to ambient magnetic fields thus cancel out. The resultant voltage is purely indicative of the rate of change of current flowing in the primary turns.

  11. Programmable Second-Generation Current-Conveyor With Variable Current Gain

    OpenAIRE

    Abdulrafeeq Abdulshakoor; Abdulrahman Khalaf Al-Ali; Muhammad Taher Abuelma'atti

    1995-01-01

    A new programmable second-generation current-conveyor is proposed. The proposed circuit uses a commercially available second-generation current-conveyor and one operational transconductance amplifier. Simulation results confirming the presented theory are included.

  12. My Opinion of the Current World Security

    Institute of Scientific and Technical Information of China (English)

    YuSui; WangWei

    2005-01-01

    What the current world is most concerned about is the situation of security. Without security, it is not to mention economic construction, nor peaceful development, nor people living and working in peace and contentment. All countries in the world are no exception in thisregard. This article will deal briefly with the questions of whether the current world is secure, where the threats to the world security come from and how these threats are coped with.

  13. Current-Enhanced Quantum Well Solar Cells

    Institute of Scientific and Technical Information of China (English)

    LOU Chao-Gang; SUN Qiang; XU Jun; ZHANG Xiao-Bing; LEI Wei; WANG Bao-Ping; CHEN Wen-Jun; QIAO Zai-Xiang

    2006-01-01

    We present the experimental results that demonstrate the enhancement of the short-circuit current of quantum well solar cells. The spectral response shows that the introduction of quantum wells extends the absorption spectrum of solar cells. The current densities under different truncated spectrums significantly increase, showing that quantum well solar cells are suitable to be the middle cells of GaInP/GaAs/Ge triple-junction solar cells to increase their overall conversion efficiency.

  14. RETAIL BANKING BUSINESS: CURRENT STATE ANDSPECIFIC FEATURES

    OpenAIRE

    Faizova Guzel Refkadovna

    2013-01-01

    The role and importance of the retail banking business in the banking sector continueto grow. The current state of the retail banking business is considered and specific features of this area in the face of growing demand for banking products and services by the public and interest from lending institutions are identified by the article.Purpose: Research of current state of retail banking business and detection specific features of this area.Methodology: In the process of analysis and researc...

  15. Transformation of spin current by antiferromagnetic insulators

    OpenAIRE

    Khymyn, Roman; Lisenkov, Ivan; Tiberkevich, Vasil S.; Slavin, Andrei N.; Ivanov, Boris A.

    2015-01-01

    It is demonstrated theoretically that a thin layer of an anisotropic antiferromagnetic (AFM) insulator can effectively conduct spin current by excitation of a pair of evanescent AFM spin wave modes. The spin current flowing through the AFM is not conserved due to the interaction between the excited AFM modes and the AFM lattice, and, depending on the excitation conditions, can be either attenuated or enhanced. When the phase difference between the excited evanescent modes is close to $\\pi/2$,...

  16. Barotropic instability in the West Spitsbergen Current

    Science.gov (United States)

    Teigen, S. H.; Nilsen, F.; Gjevik, B.

    2010-07-01

    Barotropic instability in the shoreward branch of the West Spitsbergen Current is investigated on the basis of data from an array of current meter moorings along 78.83°N, across the upper continental slope and shelf break west of Svalbard. The slowly varying background current profile is modeled as an along-slope, asymmetric jet anchored to the shelf break. Numerical linear stability analyses are performed on the idealized current profile and topography, revealing the characteristic period, wavelength, and growth rate of unstable vorticity waves. Detailed analysis of the ambient current profile in 2007-2008 shows that unstable conditions are present during ˜40% of the 10 month measurement record, depending on the localization, width, and amplitude of the current jet. The resulting vorticity waves are localized at the shelf break and are able to exchange water masses across the oceanic Arctic front. Typical wavelengths and periods are 20-40 km and 40-70 h, respectively. Wavelet, coherence, and complex demodulation analyses of the current meter data confirm that transient signals of similar periodicity as predicted by the stability analysis exist in the data record, prominently during the winter and spring months. Estimates of the heat loss contribution from isopycnal diffusion reach 1.4 TW during the time intervals when unstable vorticity waves are active at the shelf break, implying that the dynamics of the West Spitsbergen Current play a significant role in the cooling process of the Atlantic water on the way to the Arctic Ocean. This cooling corresponds to an along-shelf cooling rate of -0.08°C per 100 km.

  17. Nonperturbative features of the axial current

    CERN Document Server

    Kopeliovich, B Z; Siddikov, M

    2013-01-01

    In this paper we study the nonperturbative structure of the axial current and evaluate the two-point distribution amplitudes $\\int d\\xi\\, e^{-iq...\\xi}$ in the framework of the instanton vacuum model in the leading order in $\\mathcal{O}(N_{c})$. We perform a direct numerical test of the relations between the axial current and the pion distribution amplitudes, imposed by PCAC, and found excellent agreement.

  18. How does relativity affect magnetically induced currents?

    Science.gov (United States)

    Berger, R J F; Repisky, M; Komorovsky, S

    2015-09-21

    Magnetically induced probability currents in molecules are studied in relativistic theory. Spin-orbit coupling (SOC) enhances the curvature and gives rise to a previously unobserved current cusp in AuH or small bulge-like distortions in HgH2 at the proton positions. The origin of this curvature is magnetically induced spin-density arising from SOC in the relativistic description. PMID:26243659

  19. Charm Changing Neutral Currents and Supersymmetry

    OpenAIRE

    Lau, Kwong

    2003-01-01

    Flavor changing neutral currents (FCNCs) in the charm system are highly suppressed in the standard model (SM). The theoretical strategies used to suppress FCNCs induced by supersymmetry in the strange and beauty systems need not apply to the charm system. The charm changing neutral current decay D^0-> mu^+ mu^- is studied phenomenologically in the framework of supersymmetric extensions of the standard model. It is found that the decay branching ratio can be enhanced to about 10^{-10}, by havi...

  20. Eddy Current Sensor for Tissue Conductivity Measurement

    OpenAIRE

    Tanha, Milad

    2013-01-01

    Electrical conductivity of the tissue can be measured via eddy current sensor and it can be used to distinguish cancerous tissue from healthy tissue. The conductivity of healthy and cancerous tissues is different due to the strong correlation between necrosis in tumor and the associated membrane breakdown [10]. Three types of similar electronic set ups with different components based on eddy current technique  were investigated to measure electrical properties of tissue in vitro as well as te...

  1. Government consumption expenditures and the current account

    OpenAIRE

    Michele Cavallo

    2005-01-01

    This paper distinguishes between two components of government consumption, expenditure on final goods and expenditure on hours, and compares the effects of changes in these two on the current account. I find that changes in government expenditure on hours do not directly affect the current account and that their impact is considerably smaller than the impact produced by changes in government expenditure on final goods. These findings indicate that considering government consumption as entirel...

  2. Spin-current induced electric field

    OpenAIRE

    Sun, QF; Guo, H; Wang, J

    2003-01-01

    We theoretically investigate properties of the induced electric field of a steady-state spin-current without charge current, using an 'equivalent magnetic charge' method. Several general formula for the induced electric field are derived which play the role of 'Biot-Savart law' and 'Ampere's law.' Conversely, a moving spin is affected by an external electric field and we derive an expression for the interaction torque.

  3. Dark current model for ILC main linac

    Energy Technology Data Exchange (ETDEWEB)

    Solyak, N.; Romanov, G.; Mokhov, N.V.; /Fermilab; Eidelman, Y.; /Novosibirsk, IYF; Tam, Wai-Ming; /Indiana U.

    2008-06-01

    In the ILC Main Linac, the dark current electrons, generated in SRF cavity can be accelerated to hundreds of MeV before being kicked out by quadrupoles and thus will originate electromagnetic cascade showers in the surrounding materials. Some of the shower secondaries can return back into vacuum and be re-accelerated again. The preliminary results of simulation of the dark current generation in ILC cavity, its dynamics in linac are discussing in this paper.

  4. Current efficiency in the chlorate cell process

    Directory of Open Access Journals (Sweden)

    Spasojević Miroslav D.

    2014-01-01

    Full Text Available A mathematical model has been set up for current efficiency in a chlorate cell acting as an ideal electrochemical tubular reactor with a linear increase in hypochlorite concentration from the entrance to the exit. Good agreement was found between the results on current efficiency experimentally obtained under simulated industrial chlorate production conditions and the theoretical values provided by the mathematical model. [Projekat Ministarstva nauke Republike Srbije, br. 172057 i br. 172062

  5. On the Early History of Current Algebra

    OpenAIRE

    Pietschmann, Herbert.

    2011-01-01

    The history of Current Algebra is reviewed up to the appearance of the Adler-Weisberger sum rule. Particular emphasis is given to the role current algebra played for the historical struggle in strong interaction physics of elementary particles between the S-matrix approach based on dispersion relations and field theory. The question whether there are fundamental particles or all hadrons are bound or resonant states of one another played an important role in this struggle and is thus also rega...

  6. Boundary Conditions in an Electric Current Contact

    OpenAIRE

    Titov, O. Yu.; Giraldo, J.; Gurevich, Yu. G.

    2002-01-01

    In most electronic devices, electric current of both types (electrons and holes) flows through a junction. Usually the boundary conditions have been formulated exclusively for open circuit. The boundary conditions proposed here bypass this limitation by the first time, as far as we are aware. Besides, these new boundary conditions correctly describe current flow in a circuit, i.e., closed circuit conditions, which are the usual operation conditions for electronic devices and for the measureme...

  7. Entropy current for non-relativistic fluid

    Science.gov (United States)

    Banerjee, Nabamita; Dutta, Suvankar; Jain, Akash; Roychowdhury, Dibakar

    2014-08-01

    We study transport properties of a parity-odd, non-relativistic charged fluid in presence of background electric and magnetic fields. To obtain stress tensor and charged current for the non-relativistic system we start with the most generic relativistic fluid, living in one higher dimension and reduce the constituent equations along the light-cone direction. We also reduce the equation satisfied by the entropy current of the relativistic theory and obtain a consistent entropy current for the non-relativistic system (we call it "canonical form" of the entropy current). Demanding that the non-relativistic fluid satisfies the second law of thermodynamics we impose constraints on various first order transport coefficients. For parity even fluid, this is straight forward; it tells us positive definiteness of different transport coefficients like viscosity, thermal conductivity, electric conductivity etc. However for parity-odd fluid, canonical form of the entropy current fails to confirm the second law of thermodynamics. Therefore, we need to add two parity-odd vectors to the entropy current with arbitrary coefficients. Upon demanding the validity of second law, we see that one can fix these two coefficients exactly.

  8. Modelling current voltage characteristics of practical superconductors

    International Nuclear Information System (INIS)

    Based on recent experimental results, and in the light of fundamental physical properties of the magnetic flux in type-II superconductors, we introduce a practical expression for the material law to be applied in numerical modelling of superconducting applications. Focusing on the computational side, in this paper, previous theory is worked out, so as to take the celebrated form of a power-law-like dependence for the current voltage characteristic. However, contrary to the common approach in numerical studies, this proposal suits the general situation of current density flow with components either parallel or perpendicular to the local magnetic field, and different constraints applying on each component. Mathematically, the theory is generated from an elliptic locus defined in terms of the current density vector components. From the physical side, this contour establishes the boundary for the onset of entropy production related to overcritical current flow in different conditions. The electric field is obtained by partial differentiation and points perpendicular to the ellipse. Some numerical examples, inspired by the geometry of a two-layer helical counter-wound cable are provided. Corrections to the widespread use of the implicit isotropic assumption (physical properties only depend on the modulus of the current density vector) are discussed, and essentially indicate that the current carrying capacity of practical systems may be underestimated by using such simplification. (paper)

  9. Efficiency studies of high frequency current drive

    International Nuclear Information System (INIS)

    Pulsed high power free-electron-lasers (FELs) offer new possibilities for the current drive in tokamaks. High intensity FELs apply to the excitation of nonlinear wave-wave processes, such as beat-waves (BW) and stimulated Raman scattering (SRS), in which large phase velocity (vph>>ve) electrostatic modes are generated. These can accelerate resonant electrons to high parallel velocities v||∼vph, which produces a slowly decaying current. Furthermore, the fast electrons with v||>>v are not toroidally trapped into banana orbits. The operation at high frequencies provides for the FEL beam an easy access into the plasma centre. This makes possible to suppress sawtooth activity by profile control and to expand the operational limits in parameter space. Raman and beat-wave methods apply particularly well to bootstrap current seeding, which may considerably enhance the overall current drive efficiency. Both Raman forward (SRS-F) and backward (SRS-B) scattering can be applied to current drive. At high, reactor relevant temperatures SRS-F is the dominant process, because SRS-B is suppressed due to heavy damping of the plasma wave. At temperatures of a few keV, SRS-B dominates because of its short gain length. In this report we shall estimate the current drive efficiency at temperatures relevant for MTX and for a tokamak reactor. We shall also consider the dependence of the efficiency on the peak intensity of FEL in these two cases. (author) 8 refs., 2 figs., 1 tab

  10. Steadiness in Dilute Pyroclastic Density Currents

    Science.gov (United States)

    Andrews, B. J.

    2015-12-01

    Pyroclastic density currents (PDCs) are often unsteady, as evidenced by direct observations of dilute lobes or jets emerging from the fronts of larger currents and by deposits that indicate transient transport and depositional regimes. We used scaled experiments to investigate unsteadiness in dilute PDCs. The experimental currents were run in an 8.5x6.1x2.6 m tank and comprised heated or ambient temperature 20-μm talc powder turbulently suspended in air. Experiments were scaled such that densimetric and thermal Richardson numbers, Froude number, and particle Stokes and settling numbers were dynamically similar to natural dilute PDCs. Although the experiment Reynolds numbers are substantially lower than those of natural PDCs, the experiments are fully turbulent. Experiments were observed with video and high-speed cameras and high-frequency thermocouples. Currents were generated with total eruption durations of 100 s. Unsteadiness in source conditions was produced by interrupting supply for intervals, t, with durations of 1, 2.5, 5, and 10 s in the experimental runs at 35 and 70 s. When t3t>τ, unsteadiness decays such that at a distance of ~4Ut, the currents are again steady. Applied to natural dilute PDCs, our results suggest that currents and their resulting deposits, will only show evidence of unsteadiness if they are disrupted for many seconds and those breaks may "heal" over distances of 100s of meters.

  11. Fast control technique based on peak current mode control of the output capacitor current

    OpenAIRE

    Alou Cervera, Pedro; García Suárez, Oscar; Oliver Ramírez, Jesús Angel; Cobos Márquez, José Antonio; Viejo de Frutos, Miriam del

    2010-01-01

    The control proposed and analyzed in this paper is based on the peak current mode control of the output capacitor current of a Buck converter. The output capacitor current loop provides fast dynamic response to the control since it behaves as a feed-forward of the load current while the voltage loop provides accurate steady state regulation. A simulation oriented averaged model of the proposed control has been developed to design the external voltage loop. As shown in simulations, with the co...

  12. Short-Circuit Withstand Current Rating for Low Voltage Switchgear : Short-Circuit Current Rating (SCCR)

    OpenAIRE

    Schütt, Matthias

    2016-01-01

    The subject of this thesis was to observe the short-circuit currents at electrical distribution boards. The purpose was to investigate different methods of protecting switchgears from dam-ages caused by short-circuit currents. Manufactures of switchgears need to indicate the rated short-circuit withstand current of their assembly. This thesis is presenting methods of defining the right value of the short-circuit withstand current. This thesis presents theoretical information about the cau...

  13. INVESTIGATION OF BLOCKING ALGORITHM FOR TRANSFORMER CURRENT PROTECTIONS IN MAGNETIZING INRUSH CURRENT MODES

    Directory of Open Access Journals (Sweden)

    A. N. Kuzovlev

    2014-01-01

    Full Text Available Presents investigations on blocking  algorithm for transformer  current  protections  during magnetizing  inrush  current. The investigations have shown that the algorithm has high sensitivity and reliably determines magnetizing  inrush current modes.

  14. Ring current development during high speed streams

    Science.gov (United States)

    Jordanova, V. K.; Matsui, H.; Puhl-Quinn, P. A.; Thomsen, M. F.; Mursula, K.; Holappa, L.

    2009-07-01

    Episodes of southward (Bzdynamics with a CME-driven storm of similar strength during 22-23 April 2001. We use our kinetic ring current-atmosphere interactions model (RAM), and investigate the mechanisms responsible for trapping particles and for causing their loss. Ring current evolution depends on the interplay of time-dependent inflow of plasma from the magnetotail, particle acceleration and loss (mainly due to charge exchange) along adiabatic drift paths, and outflow of plasma from the dayside magnetopause; all of these processes are incorporated in our model. We compare results from simulations using a newly developed, Cluster data based, University of New Hampshire inner magnetospheric electric field (UNH-IMEF) convection model with simulations using a Volland-Stern (V-S) type convection model. We find that, first, periods of increased magnetospheric convection coinciding with enhancements of plasma sheet density are needed for strong ring current buildup. Second, during the HSS-driven storm the convection potential from UNH-IMEF model is highly variable and causes sporadic shallow injections resulting in a weak ring current. The long period of enhanced convection during the CME-driven storm causes a continuous ion injection penetrating to lower L shells and stronger ring current buildup. V-S model predicts larger ring current injection during both storms. Third, the RAM driven by either convection model underestimates the total ring current energy during the recovery phase of the HSS storm, thus indicating that additional injections from substorm-induced electric fields and/or radial diffusion are needed to better reproduce its several-day long geomagnetic activity.

  15. Current carriers in the near-earth cross-tail current sheet during substorm growth phase

    Science.gov (United States)

    Mitchell, D. G.; Williams, D. J.; Huang, C. Y.; Frank, L. A.; Russell, C. T.

    1990-01-01

    Throughout most of the growth phase of a substorm, the cross-tail current at x about -10 Re can be supplied by the curvature drift of a bi-directional field aligned distribution of 1 keV electrons. Just prior to its local disruption after substorm onset, the cross-tail current in the now thin (about 400 km) current sheet is carried by the cross-tail serpentine motion of non-adiabatic ions (Speiser, 1965). The instability of this latter current leads to the local disruption of the near-earth current sheet.

  16. 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

    2014-01-01

    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.

  17. An Optimal Current Observer for Predictive Current Controlled Buck DC-DC Converters

    Directory of Open Access Journals (Sweden)

    Run Min

    2014-05-01

    Full Text Available 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.

  18. 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

    2014-01-01

    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. PMID:24854061

  19. Low-voltage, wide-range, current-controlled DC current generator

    Science.gov (United States)

    Mathew, M.; Hart, B. L.; Hayatleh, K.; Lidgey, F. J.

    2011-08-01

    Operating from a 1 V rail supply, a proposed CMOS current-controlled DC current generator can function as a repeater, attenuator or amplifier over the input current range, 1 µA to 1 mA, with a current-transfer ratio accuracy better than 1% using IBM technology, characterised by a process with a 0.13 µm minimum feature size. In repeater mode, the incremental output resistance exceeds 30 MΩ for an output current of 500 µA at an output voltage of 0.20 V, and exceeds 1 MΩ for an output current of 1 mA at an output voltage of 0.22 V. For zero input current, the circuit dissipation is 117 µW.

  20. 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.

  1. Rip current monitoring using GPS buoy system

    Science.gov (United States)

    Song, DongSeob; Kim, InHo; Kang, DongSoo

    2014-05-01

    The occurrence of rip current in the Haeundae beach, which is one of the most famous beaches in South Korea, has been threatening beach-goers security in summer season annually. Many coastal scientists have been investigating rip currents by using field observations and measurements, laboratory measurements and wave tank experiments, and computer and numerical modeling. Rip current velocity is intermittent and may rapidly increase within minutes due to larger incoming wave groups or nearshore circulation instabilities. It is important to understand that changes in rip current velocity occur in response to changes in incoming wave height and period as well as changes in water level. GPS buoys have been used to acquire sea level change data, atmospheric parameters and other oceanic variables in sea for the purposes of vertical datum determination, tide correction, radar altimeter calibration, ocean environment and marine pollution monitoring. Therefore, we adopted GPS buoy system for an experiment which is to investigate rip current velocity; it is sporadic and may quickly upsurge within minutes due to larger arriving wave groups or nearshore flow uncertainties. In this study, for high accurate positioning of buy equipment, a Satellite Based Argumentation System DGPS data logger was deployed to investigate within floating object, and it can be acquired three-dimensional coordinate or geodetic position of buoy with continuous NMEA-0183 protocol during 24 hours. The wave height measured by in-situ hydrometer in a cross-shore array clearly increased before and after occurrence of rip current, and wave period also was lengthened around an event. These results show that wave height and period correlate reasonably well with long-shore current interaction in the Haeundae beach. Additionally, current meter data and GPS buoy data showed that rip current velocities, about 0.2 m/s, may become dangerously strong under specific conditions. Acknowledgement This research was

  2. Current Distribution in Wide YBCO Tapes

    Science.gov (United States)

    Carrera, M.; Granados, X.; Amorós, J.; Puig, T.; Obradors, X.

    The need of a better mechanical behaviour and the stabilization of coated conductors for applications, as Magnets, cables or Fault Current Limiters, has motivated the lamination of tapes with stainless steel or copper alloys, increasing so the elastic modulus of the conductors and their mechanical performance. Some of the stainless steels used are magnetic, thus introducing some perturbations of the current flow when energizing the conductor. In order to detect these possible perturbations, the magnetic self field in the surface of the tape has been explored by Hall mapping technique at several current loads in a monotonically driven cyclic sequence. By increasing current steps when loading up, crossing the critical field threshold, and decreasing down to remanent state. Deviation from the expected magnetic map has been observed. In this work, we will report on the resulting measurements, and the current flow is calculated by solving the inverse problem for a 12 mm wide stainless steel reinforced Coated Conductor tape. We discuss on the likely origin of the observed perturbations.

  3. Microstructure cantilever beam for current measurement

    Directory of Open Access Journals (Sweden)

    M.T.E. Khan

    2010-01-01

    Full Text Available Most microelectromechanical systems (MEMS sensors are based on the microcantilever technology, which uses a broad range of design materials and structures. The benefit ofMEMStechnology is in developing devices with a lower cost, lower power consumption, higher performance and greater integration. A free-end cantilever beam with a magnetic material mass has been designed using MEMS software tools. The magnetic material was used to improve the sensitivity of the cantilever beam to an externally-applied magnetic field. The cantilever was designed to form a capacitance transducer, which consisted of variable capacitance where electrical and mechanical energies were exchanged. The aim of this paper was to analyse the system design of the microcantilever when subjected to a magnetic field produced by a current-carrying conductor. When the signal, a sinusoidal current with a constant frequency, was applied, the cantilever beam exhibited a vibration motion along the vertical axis when placed closer to the line current. This motion created corresponding capacitance changes and generated a voltage output proportional to the capacitive change in the signal-processing circuitry attached to the microcantilever. The equivalent massspring system theory was used to describe and analyse the effect of the natural frequency of the system vibrations and motion due to the applied magnetic field, in a single-degree of freedom. The main application of this microcantilever is in current measurements to develop a non-contact current sensor mote.

  4. Interactions between domain walls and spin currents

    Science.gov (United States)

    Klaui, M.; Laufenberg, M.; Backes, D.; Buhrer, W.; Rudiger, U.; Vila, L.; Vouille, C.; Faini, G.

    2006-03-01

    A promising novel approach for switching magnetic nanostructures is current-induced domain wall propagation (CIDP), where due to a spin torque effect, electrons transfer angular momentum to a head-to-head domain wall and thereby push it in the direction of the electron flow without any externally applied fields. This effect has been observed with a variety of techniques including MFM [1] and spin polarized scanning electron microscopy [2] to directly observe current-induced domain wall propagation in ferromagnetic nanostructures and magnetoresistance measurements to systematically probe the critical current densities as a function of the geometry [3]. The observed wall velocities and critical current densities, where wall motion sets in at room temperature, do not agree well with theoretical 0K calculations [4]. We have therefore measured the critical current densities as a function of the sample temperature. We find that the spin torque effect becomes more efficient at low temperatures, which could account for some of the observed discrepancies between the 300K experiment and the 0K simulation. [1] A. Yamaguchi et al., Phys. Rev. Lett. 92, 77205 (2004); [2] M. Klaui et al., PRL 95, 26601 (2005); [3] M. Klaui et al., PRL 94, 106601 (2005); [4] A. Thiaville et al., EPL 69, 990 (2005); G. Tatara et al., APL 86, 252509 (2005);

  5. Mapping turbidity currents using seismic oceanography

    Directory of Open Access Journals (Sweden)

    E. A. Vsemirnova

    2011-08-01

    Full Text Available Using a combination of seismic oceanographic and physical oceanographic data acquired across the Faroe-Shetland Channel we present evidence of a turbidity current that transports suspended sediment along the western boundary of the Channel. We focus on reflections observed on seismic data close to the sea-bed on the Faroese side of the Channel below 900m. Forward modelling based on independent physical oceanographic data show that thermohaline structure does not explain these near sea-bed reflections but they are consistent with optical backscatter data, dry matter concentrations from water samples and from seabed sediment traps. Hence we conclude that an impedance contrast in water column caused by turbidity currents is strong enough to be seen in seismic sections and this provides a new way to visualise this type of current and its lateral structure. By inverting the seismic data we estimate a sediment concentration in the turbidity current, present at the time of the survey, of 45 ± 25 mg l−1. We believe this is the first direct observation of a turbidity current using Seismic Oceanography.

  6. Astrocytic actions on extrasynaptic neuronal currents

    Directory of Open Access Journals (Sweden)

    Balazs ePal

    2015-12-01

    Full Text Available In the last few decades, knowledge about astrocytic functions has significantly increased. It was demonstrated that astrocytes are not passive elements of the central nervous system, but active partners of neurons. There is a growing body of knowledge about the calcium excitability of astrocytes, the actions of different gliotransmitters and their release mechanisms, as well as the participation of astrocytes in the regulation of synaptic functions and their contribution to synaptic plasticity. However, astrocytic functions are even more complex than being a partner of the 'tripartite synapse', as they can influence extrasynaptic neuronal currents either by releasing substances or regulating ambient neurotransmitter levels. Several types of currents or changes of membrane potential with different kinetics and via different mechanisms can be elicited by astrocytic activity. Astrocyte-dependent phasic or tonic, inward or outward currents were described in several brain areas. Such currents, together with the synaptic actions of astrocytes, can contribute to neuromodulatory mechanisms, neurosensory and –secretory processes, cortical oscillatory activity, memory and learning or overall neuronal excitability. This mini-review is an attempt to give a brief summary of astrocyte-dependent extrasynaptic neuronal currents and their possible functional significance.

  7. New York Times Current News Physics Applications

    Science.gov (United States)

    Cise, John

    2010-03-01

    Since 2007 I have been using NYTimes current News articles rich in graphics and physics variables for developing edited one page web (http://CisePhysics.homestead.com/files/NYT.htm) physics questions based on current events in the news. The NYTimes home page listed above contains currently ten pages with about 40 one page current edited News related physics articles per page containing: rich graphics, graphic editions by the author, edited articles, introduction to a question, questions, and answers. I use these web pages to introduce new physics concepts to students with current applications of concepts in the news. I also use these one page physics applications as pop quizzes and extra credit for students. As news happens(e.g. the 2010 Vancouver Olympics) I find the physics applications in the NYTimes articles and generate applications and questions. These new one page applications with questions are added to the home page: http://CisePhysics.homestead.com/files/NYT.htm The newest pages start with page 10 and work back in time to 9, 8, etc. The ten web pages with about 40 news articles per page are arranged in the traditional manner: vectors, kinematics, projectiles, Newton, Work & Energy, properties of matter, fluids, temperature, heat, waves, and sound. This site is listed as a resource in AAPT's Compadre site.

  8. Tilted loop currents in cuprate superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Yakovenko, Victor M., E-mail: yakovenk@physics.umd.edu

    2015-03-01

    The paper briefly surveys theoretical models for the polar Kerr effect (PKE) and time-reversal symmetry breaking in the pseudogap phase of cuprate superconductors. By elimination, the most promising candidate is the tilted loop-current model, obtained from the Simon–Varma model by tilting one triangular loop up and another one down toward the apical oxygens. The model is consistent with the PKE, spin-polarized neutron scattering, and optical anisotropy measurements. Spontaneous currents in this model flow between the in-plane and apical oxygens in such a manner that each oxygen belongs to one current loop. This loop-current pattern is similar to the spin order in the magnetoelectric antiferromagnet Cr{sub 2}O{sub 3}, where the PKE is observed experimentally. By analogy, it should be possible to train the PKE sign in the cuprates magnetoelectrically. Several experiments are proposed to confirm the loop-current order: the magnetic-field-induced polarity, the nonlinear anomalous Hall effect, and the second-harmonic generation.

  9. The current interruption process in vacuum analysis of the currents and voltages of current-zero measurements

    NARCIS (Netherlands)

    van Lanen, E.P.A.

    2008-01-01

    The circuit breaker helps protecting vulnerable equipment in a power network from hazardous short-circuit currents by isolating a fault, when it occurs. They perform this task by extinguishing a plasma arc that appears as soon as the breaker's contacts separate, and through which the short-circuit c

  10. Predicting the importance of current papers.

    Energy Technology Data Exchange (ETDEWEB)

    Klavans, Richard (SciTech Strategies, Inc., Berwyn, PA); Boyack, Kevin W.

    2005-01-01

    This article examines how well one can predict the importance of a current paper (a paper that is recently published in the literature). We look at three factors--journal importance, reference importance and author reputation. Citation-based measures of importance are used for all variables. We find that journal importance is the best predictor (explaining 22.3% out of a potential 29.1% of the variance in the data), and that this correlation value varies significantly by discipline. Journal importance is a better predictor of citation in Computer Science than in any other discipline. While the finding supports the present policy of using journal impact statistics as a surrogate for the importance of current papers, it calls into question the present policy of equally weighting current documents in text-based analyses. We suggest that future researchers take into account the expected importance of a document when attempting to describe the cognitive structure of a field.

  11. Direct current power delivery system and method

    Science.gov (United States)

    Zhang, Di; Garces, Luis Jose; Dai, Jian; Lai, Rixin

    2016-09-06

    A power transmission system includes a first unit for carrying out the steps of receiving high voltage direct current (HVDC) power from an HVDC power line, generating an alternating current (AC) component indicative of a status of the first unit, and adding the AC component to the HVDC power line. Further, the power transmission system includes a second unit for carrying out the steps of generating a direct current (DC) voltage to transfer the HVDC power on the HVDC power line, wherein the HVDC power line is coupled between the first unit and the second unit, detecting a presence or an absence of the added AC component in the HVDC power line, and determining the status of the first unit based on the added AC component.

  12. Wall current monitor for SPring-8 linac

    International Nuclear Information System (INIS)

    A fast rise time, broad band width and wide dynamic range wall current monitor was developed for SPring-8 linac. The performances are a rise time of ∼250ps, an effective impedance of 1.4Ω (output of ∼1.4V/A) and a bandwidth of 18kHz-2GHz. From a result of examination using 40ns electron beam, a significant change of effective impedance was not observed when a peak current was changed up to 12A or when a beam was moved by 8mm in a vacuum pipe. A circuit model that includes a core inductor loop was constructed. Using this model effective impedance and band width were calculated and compared to measured ones. They agreed very well except one part. In consequence the mechanism of wall current monitor can be explained by means of this model. (author)

  13. Quadrant I description of current conditions

    International Nuclear Information System (INIS)

    In accordance with the requirements of the Consent Decree issued by the Ohio Attorney General's office on August 29, 1989 and with the RCRA Section 3008(h) Consent Order issued by the US Environmental Protection Agency, Region V (USEPA) on September 29, 1989, this report, which provides a Description of Current Conditions within Quadrant I of the Portsmouth Gaseous Diffusion Plant (PORTS) located in Piketon, Ohio, has been developed and submitted for approval. The objectives of this report are to provide data concerning: (1) the current state of knowledge of the environmental setting of Quadrant I of PORTS including ground water, surface water, soil and air; and (2) the extent of known, potential and suspected contamination of these segments of the environment in Quadrant I of the facility. This report is the initial step in the comprehensive RCRA Facility Investigation (RFI) currently underway at PORTS, and will provide a foundation for all subsequent activities related to the RFI in Quadrant I

  14. Kinetics of current formation in molecular diode

    International Nuclear Information System (INIS)

    Based on the kinetic theory of election transfer in low-dimensional molecular systems, the formation of transient and stationary currents in a system 'electrode l-molecule-electrode 2' (molecular diode) is studied for different regimes of charge transmission. In the framework of the HOMO-LUMO molecular model, a situation is considered where the current formation is initiated either by molecule photoexcitation or by change of interelectrode voltage bias. It is found that the distant (tunnel) inelastic electron transfer plays a crucial role in changing molecular electronic states and, as a result, in generating transmission channels for hopping (sequential) and distant (direct) current components. The effect of inelastic tunneling is especially pronounced in the condition of resonant electron transmission.

  15. Diffuser Augmented Horizontal Axis Tidal Current Turbines

    Directory of Open Access Journals (Sweden)

    Nasir Mehmood

    2012-09-01

    Full Text Available The renewal energy technologies are increasingly popular to ensure future energy sustenance and address environmental issues. The tides are enormous and consistent untapped resource of renewable energy. The growing interest in exploring tidal energy has compelling reasons such as security and diversity of supply, intermittent but predictable and limited social and environmental impacts. The tidal energy industry is undergoing an increasing shift towards diffuser augmented turbines. The reason is the higher power output of diffuser augmented turbines compared to conventional open turbines. The purpose of this study is to present a comprehensive review of diffuser augmented horizontal axis tidal current turbines. The components, relative advantages, limitations and design parameters of diffuser augmented horizontal axis tidal current turbines are presented in detail. CFD simulation of NACA 0016 airfoil is carried out to explore its potential for designing a diffuser. The core issues associated with diffuser augmented horizontal axis tidal current turbines are also discussed.

  16. Pulse current enhanced electrodialytic soil remediation

    DEFF Research Database (Denmark)

    Sun, Tian R.; Ottosen, Lisbeth M.; Jensen, Pernille E.

    2012-01-01

    extent depending on the pulse frequency. The experiment with the frequency of 16 cycles per day showed the best restoration of equilibrium and lowest energy consumption. The energy consumption per removed heavy metals was lower in pulse current experiments than constant current and increased...... in a dramatic decrease in energy consumption, but this change impeded the acidification process and thus the removal of heavy metals decreased significantly. (C) 2012 Elsevier B.V. All rights reserved.......Energy consumption is an important factor influencing the cost of electrodialytic soil remediation (EDR). It has been indicated that the pulse current (in low frequency range) could decrease the energy consumption during EDR. This work is focused on the comparison of energy saving effect...

  17. Current and Future Parts Management at NASA

    Science.gov (United States)

    Sampson, Michael J.

    2011-01-01

    This presentation provides a high level view of current and future electronic parts management at NASA. It describes a current perspective of the new human space flight direction that NASA is beginning to take and how that could influence parts management in the future. It provides an overview of current NASA electronic parts policy and how that is implemented at the NASA flight Centers. It also describes some of the technical challenges that lie ahead and suggests approaches for their mitigation. These challenges include: advanced packaging, obsolescence and counterfeits, the global supply chain and Commercial Crew, a new direction by which NASA will utilize commercial launch vehicles to get astronauts to the International Space Station.

  18. The Euler current and parity odd transport

    CERN Document Server

    Golkar, Siavash; Son, Dam T

    2014-01-01

    For a spacetime of odd dimensions endowed with a unit vector field, we introduce a new topological current that is identically conserved and whose charge is equal to the Euler character of the even dimensional spacelike foliations. The existence of this current allows us to introduce new Chern-Simons-type terms in the effective field theories describing relativistic quantum Hall states and (2+1) dimensional superfluids. Using effective field theory, we calculate various correlation functions and identify transport coefficients. In the quantum Hall case, this current provides the natural relativistic generalization of the Wen-Zee term, required to characterize the shift and Hall viscosity in quantum Hall systems. For the superfluid case this term is required to have nonzero Hall viscosity and to describe superfluids with non s-wave pairing.

  19. Variable energy constant current accelerator structure

    Science.gov (United States)

    Anderson, O.A.

    1988-07-13

    A variable energy, constant current ion beam accelerator structure is disclosed comprising an ion source capable of providing the desired ions, a pre-accelerator for establishing an initial energy level, a matching/pumping module having means for focusing means for maintaining the beam current, and at least one main accelerator module for continuing beam focus, with means capable of variably imparting acceleration to the beam so that a constant beam output current is maintained independent of the variable output energy. In a preferred embodiment, quadrupole electrodes are provided in both the matching/pumping module and the one or more accelerator modules, and are formed using four opposing cylinder electrodes which extend parallel to the beam axis and are spaced around the beam at 90/degree/ intervals with opposing electrodes maintained at the same potential. 12 figs., 3 tabs.

  20. Gravitational wave astronomy: the current status

    CERN Document Server

    Blair, David; Zhao, Chunnong; Wen, Linqing; Chu, Qi; Fang, Qi; Cai, RongGen; Gao, JiangRui; Lin, XueChun; Liu, Dong; Wu, Ling-An; Zhu, ZongHong; Reitze, David H; Arai, Koji; Zhang, Fan; Flaminio, Raffaele; Zhu, Xingjiang; Hobbs, George; Manchester, Richard N; Shannon, Ryan M; Baccigalupi, Carlo; Xu, Peng; Bian, Xing; Cao, Zhoujian; Chang, ZiJing; Dong, Peng; Gong, XueFei; Huang, ShuangLin; Ju, Peng; Luo, ZiRen; Qiang, Li'E; Tang, WenLin; Wan, XiaoYun; Wang, Yue; Xu, ShengNian; Zhang, YunLong; Zhang, HaiPeng; Lau, Yun-Kau; Ni, Wei-Tou

    2016-01-01

    In the centenary year of Einstein's General Theory of Relativity, this paper reviews the current status of gravitational wave astronomy across a spectrum which stretches from attohertz to kilohertz frequencies. Sect. 1 of this paper reviews the historical development of gravitational wave astronomy from Einstein's first prediction to our current understanding the spectrum. It is shown that detection of signals in the audio frequency spectrum can be expected very soon, and that a north-south pair of next generation detectors would provide large scientific benefits. Sect. 2 reviews the theory of gravitational waves and the principles of detection using laser interferometry. The state of the art Advanced LIGO detectors are then described. These detectors have a high chance of detecting the first events in the near future. Sect. 3 reviews the KAGRA detector currently under development in Japan, which will be the first laser interferometer detector to use cryogenic test masses. Sect. 4 of this paper reviews gravit...

  1. An Alternative to Maxwell's Displacement Current

    CERN Document Server

    Wolsky, Alan M

    2014-01-01

    Though sufficient for local conservation of charge, we show that Maxwells displacement current is not necessary. An alternative to the Ampere Maxwell equation is exhibited and the alternative s electric and magnetic fields and scalar and vector potentials are expressed in terms of the charge and current densities. The alternative describes a theory in which action is instantaneous and so may provide a good approximation to Maxwells equations where and when the finite speed of light can be neglected. The result is reminiscent of the Darwin approximation which arose from the study classical charged point particles to order (v/c)2 in the Lagrangian. Unlike Darwin, this approach does not depend on the constitution of the electric current. Instead, this approach grows from a straightforward revision of the Ampere Equation which revision enforces the local conservation of charge.

  2. Cognitive impairment and preferences for current health

    Directory of Open Access Journals (Sweden)

    Tsevat Joel

    2009-01-01

    Full Text Available Abstract Background We assessed preferences for current health using the visual analogue scale (VAS, standard gamble (SG, time trade-off (TTO, and willingness to pay (WTP in patients with cerebral aneurysms, a population vulnerable to cognitive deficits related to aneurysm bleeding or treatment. Methods We measured VAS, SG, TTO, and WTP values for current health in 165 outpatients with cerebral aneurysms. We assessed cognitive impairment with the Mini Mental State Examination (MMSE; scores Results Eleven patients (7% had MMSE scores Conclusion Cognitive impairment is associated with lower preferences for current health in patients with cerebral aneurysms. Cognitively impaired patients have poor inter-preference test correlations and different response distributions compared to unimpaired patients.

  3. Spin currents in TFT-Josephson junction

    International Nuclear Information System (INIS)

    The spin of the Cooper pair in a triplet superconductor provides a new degree of freedom in Josephson junction physics. This can be accessed by using a magnetically-active tunneling barrier, leading to a rich variety of unconventional Josephson effects. Because of the triplet state of the pairing wavefunction, triplet superconductor junctions in general also display a Josephson spin current, which can flow even when the equilibrium charge current is vanishing. Using the quasiclassical Green's function theory, we have examined the more general situation of a magnetically-active barrier which does not conserve the spin of a tunneling Cooper-pair. We demonstrate that the Josephson spin currents on either side of the barrier need not be identical, with the magnitude, sign and orientation all allowed to differ. Not only do our calculations enhance the physical understanding of transport through triplet superconductor junctions, but they also open the possibility of novel spintronic Josephson devices.

  4. Does bipolar pacemaker current activate blood platelets?

    DEFF Research Database (Denmark)

    Gjesdal, Grunde; Hansen, Annebirthe Bo; Brandes, Axel

    2009-01-01

    platelets and muscle cells contain actin and myosin filaments, and both cells are activated following calcium influx. Muscle cells open their calcium channels and contract when exposed to an electric current. Current through a bipolar pacemaker lead will expose a small volume of blood, including platelets...... to the pacemaker can. METHODS: Platelet-rich plasma was prepared from two healthy subjects. Platelet reactivity to the agonist ADP was tested in paired samples in an aggregometer in a case/control setup. RESULTS: Eighteen of 46 tested pairs of platelet-rich plasma showed increased reactivity in the paced sample......; 26 were unchanged while two showed decreased reactivity in the paced sample. Using a two-sided sign test, the null hypothesis was rejected (P = 0.0004). CONCLUSIONS: The study demonstrates increased reactivity to ADP in platelets exposed in vitro to stimulation by pacemaker current. The clinical...

  5. Current understanding of the aeronomy of Mars

    Science.gov (United States)

    Nagy, Andrew F.; Grebowsky, Joseph M.

    2015-12-01

    This paper provides a short overview of our current understanding of the upper atmosphere/ionosphere of Mars including the escaping neutral atmosphere to space that plays a key role in the current state of the Mars upper atmosphere. The proper definition of the word "aeronomy" relates to the upper atmosphere where ionization is important. Currently there is a paucity of measurements of the internal physical structure of the Martian upper atmosphere/ionosphere. Much that we know has been deduced from theoretical models that predict many more things than thus far measured. The newest Mars orbital missions, the US MAVEN and Indian MOM missions, just beginning their science analyses, will provide the measurements needed to fully characterize the aeronomy of Mars.

  6. Improving the lattice axial vector current

    CERN Document Server

    Horsley, R; Perlt, H; Rakow, P E L; Schierholz, G; Schiller, A; Zanotti, J M

    2015-01-01

    For Wilson and clover fermions traditional formulations of the axial vector current do not respect the continuum Ward identity which relates the divergence of that current to the pseudoscalar density. Here we propose to use a point-split or one-link axial vector current whose divergence exactly satisfies a lattice Ward identity, involving the pseudoscalar density and a number of irrelevant operators. We check in one-loop lattice perturbation theory with SLiNC fermion and gauge plaquette action that this is indeed the case including order $O(a)$ effects. Including these operators the axial Ward identity remains renormalisation invariant. First preliminary results of a nonperturbative check of the Ward identity are also presented.

  7. Meson exchange and neutral weak currents

    Energy Technology Data Exchange (ETDEWEB)

    Beck, D.H. [Univ. of Illinois, Urbana, IL (United States)

    1994-04-01

    Measurements of parity-violating electron scattering asymmetries to determine weak neutral currents in nuclei will be effected by the presence of meson exchange currents. Present low momentum transfer calculations, based on a flavor independent framework, show these effects to be small. In general, however, as the momentum transfer increases to values typical of deep-inelastic scattering, fragmentation functions show a clear flavor dependence. It is suggested that a good experimental starting point for understanding the flavor dependence of meson production and exchange currents is the Q{sup 2} dependence of parity-violating asymmetry in inclusive single pion electroproduction. A CEBAF facility with doubled energy is necessary to approach momentum transfers where this process begins to scale.

  8. About Eddy Currents in Induction Melting Processes

    Directory of Open Access Journals (Sweden)

    Gafiţa Nicolae-Bogdan

    2008-05-01

    Full Text Available In this paper we present a method forcomputing the eddy currents in induction meltingprocesses for non-ferrous alloys. We take intoconsideration the situation when only the crucible ismoving, inside the coils. This fact makes differentialcomputation methods to be hard to apply, because isnecessary to generate a new mesh and a new systemmatrix for every for every new position of the cruciblerelated to the coils. Integral methods cancel thisdrawback because the mesh is generated only for thedomains with eddy currents. For integral methods, themesh and the inductance matrix remain unchangedduring the movement of the crucible; only the free termsof the equation system will change.

  9. Current situation and industrialization of Taiwan nanotechnology

    International Nuclear Information System (INIS)

    Nanotechnology is projected to be a very promising field, and the impact of nanotechnology on society is increasingly significant as the research funding and manufactured goods increase exponentially. A clearer picture of Taiwan's current and future nanotechnology industry is an essential component for future planning. Therefore, this investigation studies the progress of industrializing nanotechnology in Taiwan by surveying 150 companies. Along with understanding Taiwan's current nanotechnology industrialization, this paper also suggests ways to promote Taiwan's nanotechnology. The survey results are summarized and serve as the basis for planning a nanotechnology industrialization strategy

  10. Development of high current electron beam generator

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Byeong Cheol; Lee, Jong Min; Kim, Sun Kook [and others

    1997-05-01

    A high-current electron beam generator has been developed. The energy and the average current of the electron beam are 2 MeV and 50 mA, respectively. The electron beam generator is composed of an electron gun, RF acceleration cavities, a 260-kW RF generator, electron beam optics components, and control system, etc. The electron beam generator will be used for the development of a millimeter-wave free-electron laser and a high average power infrared free-electron laser. The machine will also be used as a user facility in nuclear industry, environment industry, semiconductor industry, chemical industry, etc. (author). 15 tabs., 85 figs.

  11. Transcranial direct current stimulation--update 2011.

    Science.gov (United States)

    Nitsche, Michael A; Paulus, Walter

    2011-01-01

    Non-invasive brain stimulation with weak direct currents (transcranial direct current stimulation (tDCS)) has emerged as one of the major tools to induce neuroplastic cortical excitability alterations in humans since its (re-) introduction to the arsenal of plasticity-inducing brain stimulation tools. In this review, we gather newly emerged knowledge about the effect of tDCS on brain function in both, basic and applied research. This overview will deliver an update of the last two years of research, because especially during this time numerous important studies were published covering the above-mentioned fields. PMID:22085959

  12. Plasma current resonance in asymmetric toroidal systems

    Energy Technology Data Exchange (ETDEWEB)

    Hazeltine, R. D. [Institute for Fusion Studies, University of Texas at Austin, Austin, Texas 78712 (United States); Catto, Peter J. [Plasma Science and Fusion Center, Massachusetts Institute of Technology, 167 Albany Street, Cambridge, Massachusetts 02139 (United States)

    2015-09-15

    The well-known singularity in the magnetic differential equation for plasma current in an asymmetric toroidal confinement system is resolved by including in the pressure tensor corrections stemming from finite Larmor radius. The result provides an estimate of the amplitude of spikes in the parallel current that occur on rational magnetic surfaces. Resolution of the singularity is shown to depend on both the ambipolarity condition—the requirement of zero surface-averaged radial current—and the form of the magnetic differential equation near the rational surface.

  13. Premature ejaculation: current and future treatments

    Institute of Scientific and Technical Information of China (English)

    Levent Gurkan; Matthew Oommen; Wayne J. G. Hellstrom

    2008-01-01

    Premature ejaculation (PE) is recognized to be the most common male sexual disorder. PE provides difficulties for professionals who treat this condition because there is neither a universally accepted definition nor a medication approved by the Food and Drug Administration (FDA). Despite these shortcomings, physicians continue to diagnose their patients with PE according to major guidelines and treat them with either behavioral therapies or off-label medications. This review focuses on current and emerging treatment options and medications for PE. Advantages and limitations of each treatment option are discussed in the light of current published peer-reviewed literature.

  14. Peltier Current Leads with conical configuration

    Science.gov (United States)

    Hakimi, I.; Nikulshin, Y.; Wolfus, S.; Yeshurun, Y.

    2016-04-01

    Current leads in cryogenic systems are a major heat source which eventually affects the entire system. It has been shown in recent years that Peltier elements are useful in reducing incoming heat into the cold system. In this article we present a new tapered cone-like configuration of the Peltier Current Leads which increases the power saving. This configuration is compared to the standard cylindrical configuration utilizing advanced ANSYS simulations. The simulations show an additional power saving of 4% when using the tapered lead configuration.

  15. Entropy current formalism for supersymmetric theories

    Directory of Open Access Journals (Sweden)

    L. Andrianopoli

    2015-03-01

    Full Text Available The recent developments in fluid/gravity correspondence give a new impulse to the study of fluid dynamics of supersymmetric theories. In that respect, the entropy current formalism requires some modifications in order to be adapted to supersymmetric theories and supergravities. We formulate a new entropy current in superspace with the properties: 1 it is conserved off-shell for non-dissipative fluids, 2 it is invariant under rigid supersymmetry transformations, 3 it is covariantly closed in local supersymmetric theories, 4 it reduces to its bosonic expression on space–time.

  16. Eddy current inspection of mildly ferromagnetic tubing

    International Nuclear Information System (INIS)

    The past decade has seen the development of eddy current probes for inspection of the mildly ferro-magnetic alloy Monel 400. Due to the rapid advances in permanent magnet technology similar probes have been upgraded to magnetically saturate, and hence inspect, the duplex stainless steel Sandvik 3RE60, which has saturation induction more than twice that of Monel 400. Prototypes of these probes have been tested in three ways: saturation capability, quality of typical eddy current data, and ability to eliminate permeability induced signals. Successful laboratory testing, potential applications, and limitations of these type probes are discussed

  17. Stability of alternating current gliding arcs

    DEFF Research Database (Denmark)

    Kusano, Yukihiro; Salewski, Mirko; Leipold, Frank;

    2014-01-01

    A gliding arc is a quenched plasma that can be operated as a non-thermal plasma at atmospheric pressure and that is thus suitable for large-scale plasma surface treatment. For its practical industrial use the discharge should be extended stably in ambient air. A simple analytical calculation based...... on Ohm’s law indicates that the critical length of alternating current (AC) gliding arc discharge columns can be larger than that of a corresponding direct current (DC) gliding arc. This finding is supported by previously published images of AC and DC gliding arcs. Furthermore, the analysis shows...

  18. The early history of current Algebra

    Science.gov (United States)

    Pietschmann, Herbert

    2011-07-01

    The history of Current Algebra is reviewed up to the appearance of the Adler-Weisberger sum rule. Particular emphasis is given to the role of current algebra in the historical struggle in strong interaction physics of elementary particles between field theory and the S-matrix approach based on dispersion relations. The question as to whether some particles are truly fundamental or all hadrons are bound or resonant states of one another played an important role in this struggle and is thus also regarded.

  19. Magnet current regulation in the SSC

    International Nuclear Information System (INIS)

    This paper investigates the transient response, the stability and the regulation characteristics of a system designed to power the SSC magnets. Considering the magnet system as a transmission line, the performance of the regulation system was investigated under perturbations on the voltage power supply and changes in the current reference. The influence of the damping resistors on the transient reponse was included. Differential current transductors were included to minimize the tracking errors between the electrically isolated sectors. A comparison was made for the two cases, with and without the differential loops. System performance was investigated during ramping of the magnets and during steady state full field operation

  20. Current status of neutron scattering in Thailand

    International Nuclear Information System (INIS)

    The current neutron powder diffractometer at the Thai Research Reactor-1/M1 (TRR-1/M1) has been modified from the obsolete neutron diffractometer which had been used during 1968-1975. The upgraded diffractometer has medium resolution and is appropriate for studying samples with small unit cell dimensions and training university students in the field of neutron scattering. This paper describes the current activities of neutron scattering research in Thailand as well as a new research reactor for enlarging the perspectives of its utilization in the future. (author)