Stable isotopes back-track the origin of alabaster from the 'Ulrich Epitaph', Güstrow, Germany

Science.gov (United States)

Böttcher, Michael E.; Fuchs, Arnold; Gehre, Matthias; Krempler, Michael; Cooper, Anthony H.

2017-04-01

Natural calcium sulphate minerals (like gypsum, in the variety of 'alabaster') have been used for a long time for art and ornamental works despite its high solubility in aqueous solution due to its easy way of recovery and handling. To identify different European source provenances, geochemical and stable isotope forensic methods have been applied, thereby defining historical pathways of trade. A detailed geochemical characterization of both alabaster samples from the monument and potential sources is a pre-requisite for a backtracking material sources. Several tracers have been tested in the past identifiying the coupled sulfur and oxygen isotope composition of the sulfate molecule in the evaporite minerals to be highly characteristic. In the present study, we analyzed the stable sulfur and oxygen isotope composition of raw alabaster from the famous Ulrich Epithaph in Güstrow, Northeastern Germany, and compared the results with new measurements from one of the major European contributors of alabaster in the 16th century, the Cellaston quarry, Derbyshire (England) and literature data for further potential Spanish and Frensh source quarries (Kloppmann et a., 2014; Archaeometry, 56). We found that the stable sulfur and oxygen isotope signatures of alabaster from the Ulrich Epitaph indicate the origin from the Upper Triassic (Keuper) evaporites of the English Cellaston quarry and are not related to other potential alabaster sources. This further illustrates the alabaster trade way between England and Germany in the late 16th century.

Medidas ultrasonográficas del espesor conjunto de la unión útero-placentaria en yeguas criollas colombianas

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Fernando Emilio Vega Díaz

2013-04-01

Full Text Available En el trabajo se determinaron los valores ultrasonográficos del espesor conjunto de la unión úteroplacentaria (ECUP, desde el cuarto mes hasta el final de la gestación, en 20 yeguas criollas colombianas, con edades entre 4 y 8 años y un promedio de peso de 348 kg, para un total de 640 mediciones en cada examen. Para el efecto se hicieron exámenes transrectal y transabdominal con transductor lineal de 6.0 MHz y transductor convexo R40 de 3.5 MHz, respectivamente. Durante el periodo de gestación se encontraron diferencias (P £ 0.05 entre los parámetros ECUP y divergencias cuando se compararon con los resultados reportados en hembras equinas de otras razas. La media de los valores ECUP incrementó con la edad gestacional; para la transrectal se encontró un mínimo de 3.1 ± 1.28 mm y un máximo de 7.3 ± 2.22 mm, y para transabdominal estos valores fueron de 6.3 ± 1.28 mm y 14.3 ± 2.22 mm.

Evaluación ultrasonográfica del espesor conjunto útero placentario en yeguas de raza de tiro Ardenés, Región de Valparaíso, Chile

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Jorge Lohse

2016-03-01

Full Text Available El presente estudio se realizó con el objetivo de estandarizar medidas de espesor conjunto útero placentario (ECUP, en yeguas de raza Ardenes entre el 5° y último mes de gestación siendo el primer estudio de esta medición en esta raza de tipo de tiro, éste fue desarrollado en un haras de la región de Valparaiso, Chile. Un total de 61 yeguas gestantes, clínicamente sanas de raza Ardenés, escogidas al azar y con edades que fluctuaron entre 4 a 18 años, fueron ecografiadas por vía transrectal, para determinar el ECUP, lo cual fue realizado por un solo examinador durante la temporada de parición 2009-2010. La medición de dicho parámetro se realizó con equipo de ultrasonografía análogo, con un transductor lineal de frecuencia 6.0/8.0 MHz. Este procedimiento se repitió 3 veces y con estas medidas se obtuvo un promedio individual. Los resultados fueron descritos en promedios y desviación estándar. Los valores obtenidos en promedio para cada mes son los siguientes: 3,75 mm al 5° mes (121 a 150 días; 3,98 mm al 6° mes (151 a 180 días; 4,02 mm al 7° mes (181 a 210 días; 4,50 mm al 8° mes (211 a 240 días; 4,71 mm al 9° mes (241 a 270 días; 5,02 mm al 10° mes (271 a 300 días; 8,10 mm al 11er mes (301-330 días; 9,73 mm al 12° mes (331 a 360 días. Se concluye que no hubo una variación significativa en el grosor del ECUP en los distintos meses del segundo tercio de gestación, y tampoco hay mayor diferencia comparando estas mediciones con otras razas equinas mencionado en la literatura.

Aborto en una yegua debido a mellizos, ¿porque conviene reducirlos manualmente?: reporte de un caso - Abortion in a Mare caused by twins pregnancy, the convenience of the manual reduction of one of the twins. A case report

OpenAIRE

González del Pino, Francisco Javier.

2010-01-01

ResumenEl artículo describe el caso clínico de un cuadro de aborto en un yegua deraza Peruano de Paso de 10 años de edad, debido a una preñez de mellizoscon fijación bicornual. La misma fue diagnosticada en forma precozmediante ecografía transrectal, pero su desenlace final en un abortoindeseable se debió a que el propietario del animal, no quiso su resoluciónmediante la técnica de reducción manual de uno de los mellizos.SummaryThis article describes a clinical case of an abortion in a 10 yea...

The team from ALICE DAQ (Data acquisition) involved in the 7th ALICE data challenge. First row: Sylvain Chapeland, Ulrich Fuchs, Pierre Vande Vyvre, Franco Carena Second row: Wisla Carena, Irina MAKHLYUEVA , Roberto Divia

CERN Multimedia

Claudia Marcelloni

2007-01-01

The team from ALICE DAQ (Data acquisition) involved in the 7th ALICE data challenge. First row: Sylvain Chapeland, Ulrich Fuchs, Pierre Vande Vyvre, Franco Carena Second row: Wisla Carena, Irina MAKHLYUEVA , Roberto Divia

Coal Resources and reserves in the sectors of El Hoyo - Quilcace, El Vergel and Yeguas - Limoncito, Municipalities of The Tambo and Patia, Cauca; Recursos y reservas de carbon en los sectores de El Hoyo - Quilcace, El Vergel y Yeguas - Limoncito, Municipios de El Tambo y Patia, Cauca

Energy Technology Data Exchange (ETDEWEB)

Rodriguez G, Gabriel; Celada A, Carlos Mario; Becerra B, Javier Eduardo; Alvarez Q, Silvia Ines; Guerrero G, German; Valderrama C, Gladys; Barajas Q, Maribel

1999-07-01

The surface exploration carried out during 1998, whose results are added those obtained in 1994, they have allowed to gather an information that leads to a first evaluation of the carboniferous resources present in the Sectors of El Hoyo-Quilcace, El Vergel and Yeguas-Limoncito belonging to the Carboniferous area of The Tambo-Patia. According to the concepts, classification approaches and dispositions of the System of Classification of coal Resources and Reserves of ECOCARBON, they were calculated and they ordered in categories the volumes of coal. The total figures of the basic reserves and resources, calculated in the entirety of the referred sectors, ascend to 1.967.061 tons in the category of measures reserves; 5.965.533 tons in the category of indicates reserves; 12.268.418 tons in the category of inferred reserves. 4.415.939 tons in the category of measured resources; 13.099.071 tons in the category of indicates resources; 18.455.711 tons in the category of inferred resources. The heating power in humid base free of mineral matters varies on the average between 6.588 and 7.354 calories. The content of ashy in dry base varies on the average between 8.12 and 18.04%. The content in total sulfur in dry base varies on the average between 0.84 and 2.32%.

Coal Resources and reserves in the sectors of El Hoyo - Quilcace, El Vergel and Yeguas - Limoncito, Municipalities of The Tambo and Patia, Cauca

International Nuclear Information System (INIS)

Rodriguez G, Gabriel; Celada A, Carlos Mario; Becerra B, Javier Eduardo; Alvarez Q, Silvia Ines; Guerrero G, German; Valderrama C, Gladys; Barajas Q, Maribel

1999-01-01

The surface exploration carried out during 1998, whose results are added those obtained in 1994, they have allowed to gather an information that leads to a first evaluation of the carboniferous resources present in the Sectors of El Hoyo-Quilcace, El Vergel and Yeguas-Limoncito belonging to the Carboniferous area of The Tambo-Patia. According to the concepts, classification approaches and dispositions of the System of Classification of coal Resources and Reserves of ECOCARBON, they were calculated and they ordered in categories the volumes of coal. The total figures of the basic reserves and resources, calculated in the entirety of the referred sectors, ascend to 1.967.061 tons in the category of measures reserves; 5.965.533 tons in the category of indicates reserves; 12.268.418 tons in the category of inferred reserves. 4.415.939 tons in the category of measured resources; 13.099.071 tons in the category of indicates resources; 18.455.711 tons in the category of inferred resources. The heating power in humid base free of mineral matters varies on the average between 6.588 and 7.354 calories. The content of ashy in dry base varies on the average between 8.12 and 18.04%. The content in total sulfur in dry base varies on the average between 0.84 and 2.32%

Proceso de sensibilización y empoderamiento local frente al uso sostenible del suelo en la microcuenca El Limón, cuencas altas Sabana Yegua, República Dominicana

Directory of Open Access Journals (Sweden)

Maldané Cuello Espinosa

2011-05-01

Full Text Available Este artículo trata el desarrollo de un proceso de sensibilización y empoderamiento por parte de los productores y productoras agrícolas de la microcuenca El Limón, dentro del complejo de cuencas que alimentan a la presa Sabana Yegua, en República Dominicana. La metodología implementada en el proceso se basa en un enfoque participativo local, que a su vez está basado en el modelo de Acción Ambiental Positiva (AAP, el cual incluye los elementos de habilidades y procedimientos, conceptos, empoderamiento y actitudes. En el escrito se presenta la aplicación de este enfoque y los productos obtenidos del proceso de sensibilización y empoderamiento. Dentro de los resultados se incluye la adopción de prácticas sostenibles del recurso suelo, donde se desarrollan prácticas de conservación, con el fin de reducir la degradación a la que está expuesto el mencionado recurso. El objetivo es que los productores logren interiorizar y experimentar la importancia de proteger el suelo en términos económicos y ambientales.

[Klaus Militzer. Polyethnizität und Migration in Baltischen Städten. In: Kurt-Ulrich Jäschke/Christhardt Schrenk (Hgg.): Vieler Völker Städte (=Quellen und Forschungen zur Geschichte der Stadt Heilbronn; 21). Heilbronn, 2012. S. 101-116] / Denn

Index Scriptorium Estoniae

Hormuth, Dennis

2014-01-01

Arvustus: Klaus Militzer. Polyethnizität und Migration in Baltischen Städten. In: Kurt-Ulrich Jäschke/Christhardt Schrenk (Hgg.): Vieler Völker Städte (=Quellen und Forschungen zur Geschichte der Stadt Heilbronn; 21). Heilbronn, 2012. S. 101-116

Capacidad de uso de las tierras en la microcuenca El Limón, complejo de cuencas Sabana Yegua, República Dominicana Land use capacity in the mini watershed El Limón, Sabana Yegua Watershed Complex, Dominican Republic

Directory of Open Access Journals (Sweden)

Maldané Cuello Espinoza

2013-03-01

Full Text Available Este estudio aborda el análisis biofísico de las tierras en la microcuenca El Limón, en el complejo de Cuencas Altas de Sabana Yegua en República Dominicana. El objetivo del ensayo fue determinar la capacidad de uso de las tierras considerando las limitaciones del suelo, el clima y la geomorfología que presenta. Se propone una serie de prácticas de manejo como opciones para reducir la erosión, mejorar el suelo y acondicionar los caminos, lo que permitiría mantener condiciones favorables para el manejo racional del sistema. De esa forma, con este objetivo se establecen y se integran por primera vez en una cuenca del país varios elementos limitantes para con su identificación proponer prácticas apropiadas que controlen el problema de degradación acelerada que experimenta el área bajo estudio. Para ello, se determinaron parámetros fundamentales, los cuales abarcan factores de erosión, suelo, drenaje y clima, en función de lo que establece la metodología MAG/FAO/UNED (1996, la cual se usa en Costa Rica para determinar la capacidad de uso de las tierras y ha sido adaptada al área objeto de este estudio. Esta metodología integra clases de tierras que van desde la I hasta la VIII según la frecuencia y grado de las limitantes que se identifican. Para su aplicación en la microcuenca El Limón, se han incluido otros parámetros físicos que no contemplan dicha metodología, tales como la densidad aparente del suelo y los parámetros climáticos de lluvia y temperatura, estos últimos con el fin de establecer la zona de vida del área. Se pudo determinar que las clases de tierras en la microcuenca El Limón van desde la III hasta la VIII, las cuales son aptas para protección, sistemas forestales y agroforestería. De igual manera, se estableció que las mayores limitantes que se presentan son las concernientes a la erosión y al drenaje del suelo. Para frenar y corregir los efectos de estas limitantes, las prácticas de manejo

Applying the criteria of Ulrich and Brockbank for the assessment of the role of human resources as a strategic business partner in a mining company

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Lize de Bruyn

2009-10-01

Full Text Available The aim of this study was to apply the 14 criteria of Ulrich and Brockbank for the assessment of the movement of a human-resource function from its current development phase to a strategic business-partner role. A qualitative method, based on casing, was adopted as the research strategy. Data were collected from members of the human-resource forum of an organisation through a semi-structured focus group, individual interviews and solicited document reviews. The collected data were analysed through open coding or thematic analyses. Findings indicated that the organisation’s human-resource function was moving from operational human-resource service provision to a more strategic focus.

Better P-curves: Making P-curve analysis more robust to errors, fraud, and ambitious P-hacking, a Reply to Ulrich and Miller (2015).

Science.gov (United States)

Simonsohn, Uri; Simmons, Joseph P; Nelson, Leif D

2015-12-01

When studies examine true effects, they generate right-skewed p-curves, distributions of statistically significant results with more low (.01 s) than high (.04 s) p values. What else can cause a right-skewed p-curve? First, we consider the possibility that researchers report only the smallest significant p value (as conjectured by Ulrich & Miller, 2015), concluding that it is a very uncommon problem. We then consider more common problems, including (a) p-curvers selecting the wrong p values, (b) fake data, (c) honest errors, and (d) ambitiously p-hacked (beyond p < .05) results. We evaluate the impact of these common problems on the validity of p-curve analysis, and provide practical solutions that substantially increase its robustness. (c) 2015 APA, all rights reserved).

Evaluation of the reliability and construct validity of test of gross motor development-2 (Ulrich 2 in children of Semnan province

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Mohammad Ali Soltanian

2012-12-01

Full Text Available Introduction: The purpose of this study was to assess the validity and reliability of the second edition of test of gross motor development (TGMD-2; Ulrich in 7-11 aged children of Semnan province, Iran.Materials and Methods: TGMD-2 measures 12 fundamental movement skills divided evenly into locomotor and object control subtests. 1277 children (651 girls and 626 boys aged from seven to eleven years were participated.Results: Cronbach's alpha coefficients for the two subtests were ranged from 0.60 to 0.78, and test-retest reliability was from 0.86 to 0.89. Two-factor structure of TGMD-2 and proper assignment of skills to locomotor and object control factors were supported for our population.Conclusion: Based on our findings, we conclude that the TGMD-2 is an appropriate tool to examine the gross motor skills in this population

‘Everything is autobiographical’: Hans-Ulrich Treichel’s idiolect in Lost (1999

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Philip van der Merwe

2014-12-01

Full Text Available Joachim Dicks writes in his review on Hans-Ulrich Treichel’s latest novel, Frühe Störung,that the author shows continuity by having developed in all of his books a unique and unmistakeable style that he calls ‘the so-called Treichel sound’. Treichel’s style, tone and mixture of thematic concerns in all of his eleven works of prose from Von Leib und Seele: Berichte up to Frühe Störung are indeed recognisable as distinctively Treichel, but has remained an unexplored terrain. The question therefore arises: What is the nature of the so-called ‘Treichel sound’ or his idiolect? Lost is a case in point with regard to Treichel’s idiolect: the narration includes factual historical and autobiographic information that represents both an ‘official life’ and a ‘carnival’, i.e. his representations of lives are determined by two aspects of theworld: the aspect of the piety of seriousness and by the aspect of laughter. This article firstly focuses on the theoretical possibility of using ‘serious’ factual autobiographic and historical information in combination with humour. The most prominent idiolectic traits of Treichel’soeuvre are then introduced, also in order to provide a context for the following discussion of Lost. Here it becomes apparent that Treichel’s humour has a tragicomical and derisive effect with regard to the narrator’s depiction of his childhood, family experiences and his cultural context. The microcosmic family context and the macrocosmic national and international contexts as they were formed because of the Second World War has lead to a loss of the narrator’s identity. The result of Treichel’s manner of dealing with serious contents that includes humour is the creation of a self-concept that can be described as self-exploratory,honest or confessional, self-centred, humorous and critical of German society - and these are also key features of Treichel’s idiolect. This article thus argues that the

Research Skills for the Future: Research Workforce Under the Spotlight

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Eva Dobozy

2013-01-01

Full Text Available The value and training needs of the future research workforce is under the spotlight. In this article, I take up Ulrich and Dash's (2013 somewhat provocative invitation to engage in discussion and debate about current and future research. In my three-tiered response, I first discuss Ulrich and Dash's article, followed by my own observations about the APEC/Deloitte (2010 research report: "Skills and Competencies Needed in the Research Field: Objectives 2020," and finally, I explore, in some detail, challenges of building a twentyfirst-century research workforce.

Uranium favorability of late Eocene through Pliocene rocks of the South Texas Coastal Plain

Energy Technology Data Exchange (ETDEWEB)

Quick, J.V.; Thomas, N.G.; Brogdon, L.D.; Jones, C.A.; Martin, T.S.

1977-02-01

The results of a subsurface uranium favorability study of Tertiary rocks (late Eocene through Pliocene) in the Coastal Plain of South Texas are given. In ascending order, these rock units include the Yegua Formation, Jackson Group, Frio Clay, Catahoula Tuff, Oakville Sandstone, and Goliad Sand. The Vicksburg Group, Anahuac Formation, and Fleming Formation were not considered because they have unfavorable lithologies. The Yegua Formation, Jackson Group, Frio Clay, Catahoula Tuff, Oakville Sandstone, and Goliad Sand contain sandstones that may be favorable uranium hosts under certain environmental and structural conditions. All except the Yegua are known to contain ore-grade uranium deposits. Yegua and Jackson sandstones are found in strand plain-barrier bar systems that are aligned parallel to depositional and structural strike. These sands grade into shelf muds on the east, and lagoonal sediments updip toward the west. The lagoonal sediments in the Jackson are interrupted by dip-aligned fluvial systems. In both units, favorable areas are found in the lagoonal sands and in sands on the updip side of the strand-plain system. Favorable areas are also found along the margins of fluvial systems in the Jackson. The Frio and Catahoula consist of extensive alluvial-plain deposits. Favorable areas for uranium deposits are found along the margins of the paleo-channels where favorable structural features and numerous optimum sands are present. The Oakville and Goliad Formations consist of extensive continental deposits of fluvial sandstones. In large areas, these fluvial sandstones are multistoried channel sandstones that form very thick sandstone sequences. Favorable areas are found along the margins of the channel sequences. In the Goliad, favorable areas are also found on the updip margin of strand-plain sandstones where there are several sandstones of optimum thickness.

Uranium favorability of late Eocene through Pliocene rocks of the South Texas Coastal Plain

International Nuclear Information System (INIS)

Quick, J.V.; Thomas, N.G.; Brogdon, L.D.; Jones, C.A.; Martin, T.S.

1977-02-01

The results of a subsurface uranium favorability study of Tertiary rocks (late Eocene through Pliocene) in the Coastal Plain of South Texas are given. In ascending order, these rock units include the Yegua Formation, Jackson Group, Frio Clay, Catahoula Tuff, Oakville Sandstone, and Goliad Sand. The Vicksburg Group, Anahuac Formation, and Fleming Formation were not considered because they have unfavorable lithologies. The Yegua Formation, Jackson Group, Frio Clay, Catahoula Tuff, Oakville Sandstone, and Goliad Sand contain sandstones that may be favorable uranium hosts under certain environmental and structural conditions. All except the Yegua are known to contain ore-grade uranium deposits. Yegua and Jackson sandstones are found in strand plain-barrier bar systems that are aligned parallel to depositional and structural strike. These sands grade into shelf muds on the east, and lagoonal sediments updip toward the west. The lagoonal sediments in the Jackson are interrupted by dip-aligned fluvial systems. In both units, favorable areas are found in the lagoonal sands and in sands on the updip side of the strand-plain system. Favorable areas are also found along the margins of fluvial systems in the Jackson. The Frio and Catahoula consist of extensive alluvial-plain deposits. Favorable areas for uranium deposits are found along the margins of the paleo-channels where favorable structural features and numerous optimum sands are present. The Oakville and Goliad Formations consist of extensive continental deposits of fluvial sandstones. In large areas, these fluvial sandstones are multistoried channel sandstones that form very thick sandstone sequences. Favorable areas are found along the margins of the channel sequences. In the Goliad, favorable areas are also found on the updip margin of strand-plain sandstones where there are several sandstones of optimum thickness

A tribute to Ulrich Heber (1930-2016) for his contribution to photosynthesis research: understanding the interplay between photosynthetic primary reactions, metabolism and the environment.

Science.gov (United States)

Dietz, Karl-Josef; Krause, G Heinrich; Siebke, Katharina; Krieger-Liszkay, Anja

2018-07-01

The dynamic and efficient coordination of primary photosynthetic reactions with leaf energization and metabolism under a wide range of environmental conditions is a fundamental property of plants involving processes at all functional levels. The present historical perspective covers 60 years of research aiming to understand the underlying mechanisms, linking major breakthroughs to current progress. It centers on the contributions of Ulrich Heber who had pioneered novel concepts, fundamental methods, and mechanistic understanding of photosynthesis. An important first step was the development of non-aqueous preparation of chloroplasts allowing the investigation of chloroplast metabolites ex vivo (meaning that the obtained results reflect the in vivo situation). Later on, intact chloroplasts, retaining their functional envelope membranes, were isolated in aqueous media to investigate compartmentation and exchange of metabolites between chloroplasts and external medium. These studies elucidated metabolic interaction between chloroplasts and cytoplasm during photosynthesis. Experiments with isolated intact chloroplasts clarified that oxygenation of ribulose-1.5-bisphosphate generates glycolate in photorespiration. The development of non-invasive optical methods enabled researchers identifying mechanisms that balance electron flow in the photosynthetic electron transport system avoiding its over-reduction. Recording chlorophyll a (Chl a) fluorescence allowed one to monitor, among other parameters, thermal energy dissipation by means of 'nonphotochemical quenching' of the excited state of Chl a. Furthermore, studies both in vivo and in vitro led to basic understanding of the biochemical mechanisms of freezing damage and frost tolerance of plant leaves, to SO 2 tolerance of tree leaves and dehydrating lichens and mosses.

Performance: travestismos y política en las crónicas de Pedro Lemebel

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Regina Vanesa Cellino

2015-08-01

Full Text Available En este trabajo se indagará sobre la relación que existe entre las crónicas urbanas de Pedro Lemebel, La esquina es mi corazón (1995 y Loco afán. Crónicas de sidario (1996, en el contexto de la posdictadura chilena, y su participación en las performances de Las Yeguas del Apocalipsis, a las que consideramos una articulación entre cuerpo, política y teatralidad. Este texto parte de las siguientes preguntas: ¿Qué afinidad/es hay entre las crónicas literarias de Lemebel y las performances de Las Yeguas del Apocalipsis? ¿Qué relación existe entre el cuerpo, la homosexualidad, el travestismo y la performance? ¿Cómo se manifiesta ese vínculo en las crónicas de Pedro Lemebel? 

A dynamic neural field model of temporal order judgments.

Science.gov (United States)

Hecht, Lauren N; Spencer, John P; Vecera, Shaun P

2015-12-01

Temporal ordering of events is biased, or influenced, by perceptual organization-figure-ground organization-and by spatial attention. For example, within a region assigned figural status or at an attended location, onset events are processed earlier (Lester, Hecht, & Vecera, 2009; Shore, Spence, & Klein, 2001), and offset events are processed for longer durations (Hecht & Vecera, 2011; Rolke, Ulrich, & Bausenhart, 2006). Here, we present an extension of a dynamic field model of change detection (Johnson, Spencer, Luck, & Schöner, 2009; Johnson, Spencer, & Schöner, 2009) that accounts for both the onset and offset performance for figural and attended regions. The model posits that neural populations processing the figure are more active, resulting in a peak of activation that quickly builds toward a detection threshold when the onset of a target is presented. This same enhanced activation for some neural populations is maintained when a present target is removed, creating delays in the perception of the target's offset. We discuss the broader implications of this model, including insights regarding how neural activation can be generated in response to the disappearance of information. (c) 2015 APA, all rights reserved).

Ulrich Beck : riskiühiskond / Ulrich Beck ; tõlk. Külli-Riin Tigasson

Index Scriptorium Estoniae

Beck, Ulrich

2004-01-01

Katkend raamatust "Risikogesellschaft". Autori hinnangul on tänapäeval poliitikute roll ühiskonna arengu otsustamisel kahanenud, sest võtmelise tähtsusega otsuseid teevad teadlased ja äriühingute juhid. Poliitika ja mittepoliitika vahetavad kohad

Kõigepealt tuleb moraal / Bernd Ulrich

Index Scriptorium Estoniae

Ulrich, Bernd

2007-01-01

Autor selgitab, et kliimamuutused asetavad inimkonna enneolematusse olukorda, mis tingib meie eluviisi ja majanduse radikaalse muutuse. Keskkonnapoliitikas osutuvad idealistid realistideks, kes on juba ammu teinud ettepanekuid kliimamuutuste vältimiseks

Kriisi fataalne oht / Ulrich Beck

Index Scriptorium Estoniae

Beck, Ulrich

2009-01-01

Sotsioloogi arvates peitub praeguses majanduskriisis võimalus tuua Euroopa Liit uutele alustele, võttes aluseks printsiibi, et poliitika on rahvuslikul tasemel seda edukam, mida euroopalikum, kosmopoliitlikum ta on

2333-IJBCS-Article-Ulrich Maloueki

African Journals Online (AJOL)

hp

Activité antioxydante par le radical 1,1- diphényl-2-picrylhydrazyle (DPPH). Un composé à activité antioxydante mis en présence du radical libre DPPH. (couleur violet), vire en jaune en donnant un proton au radical. Evaluation qualitative par chromatographie sur couche mince (CCM). La réalisation de la CCM a été.

Synthesizing Graphene Production with Polymeric Injection Molding for Enhancing EMI Shielding Effectiveness of Plastics

Science.gov (United States)

2017-09-01

Ulrich, Karl T., and Steven D. Eppinger. 2012. Product Design and Development, 5th ed. New York: McGraw-Hill Irwin. Warner, Jamie H., Franziska Schaffel...of tasks that an organization or business generally follows to transform a thought or idea of a product to a manufactured good. In the early stages...established product design and development processes. Karl Ulrich and Steven Eppinger (2012) state that one of the initial steps in the opportunity

15th Kassel symposium energy systems technology. Renewable energy sources and E-mobility. Proceedings; 15. Kasseler Symposium Energie-Systemtechnik. Erneuerbare Energien und E-Mobilitaet. Tagungsband

Energy Technology Data Exchange (ETDEWEB)

NONE

2010-07-01

Within the 15th Kassel symposium of power system engineering from 23th to 24th September, 2010, in Kassel (Federal Republic of Germany) the following lectures were held: (1) Transformation of energy systems and electromobility (Juergen Schmid); (2) Electromobility and renewable energies - scenarios and perspectives (Michael Weinhold); (3) Fraunhofer systems research electromobility (Ulrich Buller); (4) Renewable energies and electromobility - research promotion of the BMU (Alexander Folz); (5) Lithium ion batteries - a key component for electric vehicles (Klaus Brandt); (6) Virtual batteries and electromobility (Peter Caselitz); (7) Integration of electric vehicles into the grid - grid-to-vehicle (Zbigeniew Styczynski); (8) Intelligent grid interfaces for electric vehicles (Ulrich Reker); (9) Contactless grid connection of electric vehicles (Ulrich Reker); (10) Current converters for electric vehicles (Peter Zacharias); (11) Vehicle to grid communication interface (Joerg Heuer); (12) Business models electromobility (Anke Weidlich); (13) Hydrogen and electromobility - a future model? (Hubert Landinger).

Perturbative corrections for approximate inference in gaussian latent variable models

DEFF Research Database (Denmark)

Opper, Manfred; Paquet, Ulrich; Winther, Ole

2013-01-01

Expectation Propagation (EP) provides a framework for approximate inference. When the model under consideration is over a latent Gaussian field, with the approximation being Gaussian, we show how these approximations can systematically be corrected. A perturbative expansion is made of the exact b...... illustrate on tree-structured Ising model approximations. Furthermore, they provide a polynomial-time assessment of the approximation error. We also provide both theoretical and practical insights on the exactness of the EP solution. © 2013 Manfred Opper, Ulrich Paquet and Ole Winther....

Metrics of Justice. A Sundial's Nomological Figuration.

Science.gov (United States)

Behrmann, Carolin

2015-01-01

This paper examines a polyhedral dial from the British Museum made by the instrument maker Ulrich Schniep, and discusses the status of multifunctional scientific instruments. It discerns a multifaceted iconic meaning considering different dimensions such as scientific functionality (astronomy), the complex allegorical figure of Justice (iconography), and the representation of the sovereign (politics), the court and the Kunstkammer of Albrecht v of Bavaria. As a numen mixtum the figure of "Justicia" touches different fields that go far beyond pure astronomical measurement and represents the power of the ruler as well as the rules of economic justice.

Globalisme og hegemonisk tænkning i sprogpolitiken

DEFF Research Database (Denmark)

Haberland, Hartmut

2010-01-01

A distinction is introduced between globalization as a historical process, globality as its result at any given time, and globalism, which according to Ulrich Beck is “the view that the world market eliminates or supplants political action”. English, it is claimed, is rather the language of globa......A distinction is introduced between globalization as a historical process, globality as its result at any given time, and globalism, which according to Ulrich Beck is “the view that the world market eliminates or supplants political action”. English, it is claimed, is rather the language...... of consent. This is illustrated with a few examples from recent Danish language policy discourse....

76 FR 19998 - Supplemental Funding Under the Food and Drug Administration Pediatric Device Consortia Grant Program

Science.gov (United States)

2011-04-11

...: Linda C. Ulrich, Office of Orphan Products Development, Food and Drug Administration, 10903 New... projects through the development process, including product identification, prototype design, device...

Frecuencia y causas de mortalidad en caballos pura sangre inglés de carreras en el hipódromo "La Rinconada", Caracas, Venezuela

OpenAIRE

Morales, Abelardo; García, Francisco; Gomez, Marian; Leal, Luis; López, Pedro; Planas, Gilberto; Rodríguez, Carlos; Vallejo, Mariela; Morales, María

2010-01-01

Este trabajo describe la frecuencia y causas de muerte súbita o que conllevaron a la eutanasia de caballos de carreras Pura Sangre Inglés del Hipódromo “La Rinconada” en Caracas, Venezuela. Se estudiaron 129 casos de mortalidad, 69 en caballos y 60 en yeguas, de una población de 1900 equinos durante el año 2009, mediante necropsia y análisis hematológicos, bacteriológicos e histopatológicos. La mortalidad anual fue por lo tanto 7% con un promedio mensual de 11 equinos muertos. La frecuencia d...

[Johann...] / Jacek Wijaczka

Index Scriptorium Estoniae

Wijaczka, Jacek

2003-01-01

Rets. rmt.: Ulrich Müller. Johann Lohmüller und seine livländische Chronik "Warhaftig Histori". Lüneburg : Verlag Nordostdeutsches Kulturwerk, 2001 (Schriften der Baltischen Historischen Kommission. Bd. 10)

Tthe covenant in Ulrich Huber's enlightened theology, jurisprudence ...

African Journals Online (AJOL)

... of God's law), and the secular social contract theories stemming from the early Enlightenment. This investigation gains value as a result of its emphasis on the prominence of the covenant in the inextricably linked disciplines of theology, jurisprudence and political theory; as well as its revitalisation of the complicated nature

Avalik kiri Euroopa tulevikust / Anthony Giddens, Ulrich Beck

Index Scriptorium Estoniae

Giddens, Anthony

2005-01-01

Autorid kutsuvad üles mõtlema Euroopa Liidust mitte kui "lõpetamata (rahvus)riigist" või "poolikust föderaalriigist", vaid pigem kui uuelaadsest kosmopoliitsest projektist. Kui Euroopa soovib, et teda maailmas kuulda võetaks, siis ei saa me deklareerida laienemise lõppemist ega loobuda EL-i juhtimismudeli muutmisest

Modernismi kaduvuse kogemus = The Experience of Transience in Modern Architecture / Thomas Bruns

Index Scriptorium Estoniae

Bruns, Thomas

2007-01-01

Saksa Demokraatliku Vabariigi aegse moodsa arhitektuuri kadumisest Berliinis. Alexanderplatzi teletorni korrastamine, nüüd lammutatud hooned: kohvik "Vahtraleht" (arhitekt Ulrich Müther, 1970), "Vabariigi palee", Radisson SAS hotell, eksperimentaalhoone Mollstrasse 31

Geschichtswissenschaftliche Perspektiven der Frühneuzeitforschung

OpenAIRE

Burkhardt, Johannes

2010-01-01

Geschichtswissenschaftliche Perspektiven der Frühneuzeitforschung. - In: Macht und Recht / Ulrich Lappenküper ... (Hrsg.). - Paderborn u.a. : Schöningh, 2010. - S. 33-51. - (Otto-von-Bismarck-Stiftung: Wissenschaftliche Reihe ; 13)

Kontrolli ja vaatluse all / Jaanus Noormets

Index Scriptorium Estoniae

Noormets, Jaanus

2007-01-01

Florian Henckel von Donnersmarcki mängufilm "Teiste elu" ("Das Leben der Anderen") : peaosas Ulrich Mühe : Saksamaa 2006. Lisatud nimekiri "Üleilmne Oscar" parima võõrkeelse filmi viimase 10 aasta Oscarite kohta

Preliminary study of uranium favorability of the Wilcox and Claiborne Groups (Eocene) in Texas

International Nuclear Information System (INIS)

Wilbert, W.P.; Templain, C.J.

1978-01-01

Rocks of the Wilcox and Claiborne Groups crop out in the Texas Gulf Coastal Plain and are represented by a series of sands and shales which reflect oscillation of the strandline. The Wilcox Group (lower Eocene), usually undifferentiated in Texas, consists of very fine sands and clays and abundant lignite. The Claiborne Group (middle Eocene) comprises, in ascending order, Carrizo Sand, Reklaw Formation (clay), Queen City Sand, Weches Formation (clay), Sparta Sand, Cook Mountain Formation (clay), and Yegua Formation (sand). Fluvial systems of the Wilcox and Claiborne Groups exist in east Texas and trend perpendicular to the present coastline. In central Texas, sand bodies are parallel to the present coastline and are strand-plain, barrier-bar systems. Since the time of deposition of the Queen City Sand, a significant fluvial sand buildup occurred in the area of the present Rio Grande embayment where the marine clays pinch out. Known occurrences of mineral matter in the Wilcox and Claiborne (up to the Yegua) are limited to lignite (particularly in the Wilcox), cannel coal in the upper Claiborne, and hydrocarbons throughout. No uranium mineralization is known, and no uranium is likely to be discovered in the Claiborne and Wilcox. Approximately 50 surface samples and many gamma-ray logs showed no significant anomalies. The sands are very good potential host rocks, but no uranium source was discovered. During deposition of the Wilcox and Claiborne Groups, there was no volcanism to serve as a source of uranium (as with the prolific occurrences in the younger rocks of south Texas); also, Precambrian crystalline rocks in the Llano uplift were not exposed

Community lab kunstihoones ja Arsenales / Harry Liivrand

Index Scriptorium Estoniae

Liivrand, Harry, 1961-

2003-01-01

Taani kaasaegse kunsti näitus "Projekt" Tallinna Kunstihoones, kus osalevad EKA üliõpilased ja külalised Lätist. Kuraatorite Molly Nesbiti, Hans Ulrich Obristi ja Rirkrit Tiravanija projekt "Utopia Station" Veneetsia biennaalil

Pop / Erkki Luuk

Index Scriptorium Estoniae

Luuk, Erkki, 1971-

2003-01-01

Heliplaatidest: Ulrich Schnauss "A Strangely Isolated Place", James Brown "Motherlode", Saian Supa Crew "X-Raisions - International Version", Erinevad esitajad "Animatrix: The Album", Tindersticks "Waiting For The Moon", Fallacy "Blackmarket Boy", Qeen "Live at Wembley '86"

At R209

CERN Multimedia

1977-01-01

Side view of R209, showing a large muon chamber in front of the Iron toroid magnet. Gunter Feilhauer is looking down from top of the magnet. Ulrich Becker (left), Lars Leistam (right) stand on the floor.

African Sociological Review / Revue Africaine de Sociologie - Vol 19 ...

African Journals Online (AJOL)

Les Jeux Video en Negroculture : Contribution a Une Anthropologie de La Solidarite Chez Les Jeunes du Cameroun · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. Paul Ulrich Otye Elom, 77-87 ...

HRM, technology and innovation: new HRM competences for old business challenges?

NARCIS (Netherlands)

Bondarouk, Tatiana; Marsman, Eline; Rekers, Marc; Bondarouk, Tanya; Olivas-Luján, Mguel R.

2014-01-01

Purpose: The goal of this chapter is to explore the requirements modern companies expect of HR professionals’ competences. Design/Methodology/Approach: Departing from the widely acknowledged HR competence studies of Ulrich and associates, we extended them with the continuous learning competence

Euroopa parim film näitab punase võimu olemust / Heli Meisterson

Index Scriptorium Estoniae

Meisterson, Heli

2006-01-01

Euroopa Filmiakadeemia andis Euroopa 2006.a. parima filmi auhinna sakslase Florian Henckel von Donnersmarcki filmile "Teiste elu" ("Das Leben der Anderen"), mille peaosaline Ulrich Mühe sai parima meesnäitleja auhinna. F. Henckel von Donnersmarck sai ka stsenaristi auhinna

Lisandusi Eesti homoajaloole

Index Scriptorium Estoniae

1999-01-01

1998. a. lõpul Hamburgis ilmunud Bernd-Ulrich Hergemölleri koostatud saksa homoleksikon "Biographisches Lexikon zur Geschichte von Freundesliebe und mann-männlicher Sexualität im deutschen Sprachraum" toob ära ka artikli Otto Magnus von Stackelbergist (1786-1837)

Integrality in codimension one

DEFF Research Database (Denmark)

Thorup, Anders

2014-01-01

The paper from 2001 by Simis, Ulrich, and Vasconcelos contained deep results on codimension, multiplicity and integral extensions. The results and the ideas of the paper led to substantial simplifications in the treatment of the exceptional fiber of a conormal space, considered previously...

Zum Stand und den Perspektiven der allgemeinsprachlichen ...

African Journals Online (AJOL)

Mev. R.B. Ruthven

so dass man nicht weiß, wie die Aktualität der gegenwärtigen slowenischen ...... zu wa23 in Abb. 1 gehören; Abkürzungen: A. = ABSTRAKTE; H = HIERAR-. CHISCHE ...... Ulrich, Stefan Evert, Egbert Lehmann und Christian Rohrer (Hrsg.).

Resonance – Journal of Science Education | Indian Academy of ...

Indian Academy of Sciences (India)

Home; Journals; Resonance – Journal of Science Education; Volume 15; Issue 5. Mycocepurus smithii - A Sex-less, Male-less Society. Ruchira Sen Ulrich G Mueller. Research News Volume 15 Issue 5 May 2010 pp 459-461. Fulltext. Click here to view fulltext PDF. Permanent link:

Intellectual History

DEFF Research Database (Denmark)

In the 5 Questions book series, this volume presents a range of leading scholars in Intellectual History and the History of Ideas through their answers to a brief questionnaire. Respondents include Michael Friedman, Jacques le Goff, Hans Ulrich Gumbrecht, Jonathan Israel, Phiip Pettit, John Pocock...

Kunstnik kannatab ja lõpetab traagiliselt / Sigrid Saarep

Index Scriptorium Estoniae

Saarep, Sigrid, 1963-

2009-01-01

Prantsuse naivistlikust maalikunstnikust Séraphine Louis', kunstnikunimega Séraphine de Senlis, saksa kunstikriitikust ja kollektsionäärist Wilhelm Uhdest ning Prantsusmaa- Belgia 2008. a. eluloofilmist "Séraphine", režissöör Martin Provost, nimiosas Yolande Moreau, kunstikriitik Wilhelm Uhde rollis Ulrich Tukur

Жанна дАрк с кистью вместо меча / Борис Тух

Index Scriptorium Estoniae

Тух, Борис, 1946-

2009-01-01

Prantsuse naivistlikust maalikunstnikust Séraphine Louis', kunstnikunimega Séraphine de Senlis, saksa kunstikriitikust ja kollektsionäärist Wilhelm Uhdest ning Prantsusmaa- Belgia 2008. a. eluloofilmist "Séraphine", režissöör Martin Provost, nimiosas Yolande Moreau, kunstikriitik Wilhelm Uhde rollis Ulrich Tukur

Speaking with a Commonality Language: A Lexicon for System and Component Development

Science.gov (United States)

2007-01-01

Abdullahil Azeem, “Impact of Commonality and Flexibility on Manufacturing Performance: A Simulation Study,” International Journal of Production Economics , Vols...Cycle Costs of Products,” International Journal of Production Economics , Vols. 60–61, April 1999, pp. 109–116. Robertson, David, and Karl Ulrich

The "Self-Interested" Woman Academic: A Consideration of Beck's Model of the "Individualised Individual"

Science.gov (United States)

Skelton, Christine

2005-01-01

The work of Ulrich Beck, particularly his concept of the "individualised individual", is increasingly cited by educational social scientists. As yet, there have been few empirical investigations that consider how applicable and relevant is the notion of the "individualised individual" in understanding how people make sense of…

Tacita Deani ajadokumendid kunstina / Kaire Nurk

Index Scriptorium Estoniae

Nurk, Kaire, 1960-

2003-01-01

Tacita Deani (sündinud 1965 Canterburys, elab ja töötab Berliinis) loomingust. Kunstnik on spetsialiseerunud ajale, Veneetsia bienaalil esines ta Francesco Bonami ja Daniel Birnbaumi kureeritud projektis "Ritardi e Revoluzioni" ning Hans-Ulrich Obristi projektis "Utopia Station". Ajast huvitatud eesti kunstnikust Erki Kasemetsast

Lutshshi film Jevropõ raskrõvajet sut Shtazi / Heli Meisterson

Index Scriptorium Estoniae

Meisterson, Heli

2006-01-01

Euroopa Filmiakadeemia andis Euroopa 2006.a. parima filmi auhinna sakslase Florian Henckel von Donnersmarcki filmile "Teiste elu" ("Das Leben der Anderen"), mille peaosaline Ulrich Mühe sai parima meesnäitleja auhinna. F. Henckel von Donnersmarck sai ka stsenaristi auhinna. Lisatud Euroopa 2006.a. filmiauhinna saajate nimekiri

Tõsielust midagi jaburamat ei ole / Kristjan Ots

Index Scriptorium Estoniae

Ots, Kristjan

2004-01-01

PÖFFi filme - mängufilmid "Kadudega tuleb arvestada" ("Mit Verlust ist zu Rechnen") : režissöör Ulrich Seidl : Austria 1992 ja "Tş̌ehhi unelm" ("Česky sen") : režissöörid Vit Klusak ja Filip Remunda : Tšehhi 2004

Disability and the Open City.

Science.gov (United States)

Gleeson, Brendan

2001-01-01

Contributes to the social theorization of physical access for people with disabilities by critically exploring how Ulrich Beck's "reflexive modernisation" thesis might be applied to the geographical understanding of disability. Demonstrates how Beck's theoretical framework can be used to enrich people's understanding of the genesis and mediation…

Cine-Club

CERN Document Server

CERN Ciné-Club

2010-01-01

Thursday 10 June 2010 at 20:30 Main Auditorium Family Life By: Ken Loach (UK, 1971) 105 min. With: Sandy Ratcliff, Grace Cave, Bill Dean, Malcolm Tierney, Michael Riddall   A nineteen-year old London girl received agressive psychiatric treatments for her schizophrenic behaviour by a doctor who still wants her family to insure the guard of the child without any regards to the facts that it is this family who’s agravating her situation.....   * * * * * * * Thursday 17 June 2010 at 20:30 Main Auditorium Das Leben der Anderen (The Lives of Others) By: Florian Henckel von Donnersmarck (Germany, 2006) With: Martina Gedeck, Ulrich Mühe, Sebastian Koch, Ulrich Tukur, Thomas Thieme Academy Award, Best Foreign Language Film 2007 In the early 1980s, the successful dramatist Georg Dreyman and his longtime companion Christa-Maria Sieland, a popular actress, are big intellectual stars in the socialist state, although they secretly don’t always think loyal to the party ...

Overwhelming Force - A Persistent Concept in US Military Thinking

DEFF Research Database (Denmark)

Ulrich, Philip Christian

calls the “Civil War Concept”, based on overwhelming numbers in personnel and material superiority. The US Army followed this concept, and the entire US military for that matter, until the Vietnam War. Before the Vietnam War the concept was changed in order to limit the risk to ground forces......In his book, The Army and Vietnam, Andrew F. Krepinevich, Jr. concludes that the US defeat in Vietnam was partially a result of the US Army’s focus on conventional warfare, what he calls the “Army Concept”. But where does this Army Concept evolve from? In his brief, Philip Ulrich traces the origins...... of the Army Concept back to the American Civil War, and the lessons that the US Army took from that war. These lessons led to a strict adherence in the US Army to the concept of overwhelming force, designed to overwhelm the enemy. Initially the lessons of the Civil War became the basis for what Philip Ulrich...

Climate change challenges for SEA

DEFF Research Database (Denmark)

Larsen, Sanne Vammen

This paper takes a theoretical perspective on the challenges that climate changes pose for SEA. The theoretical framework used is the sociologist Ulrich Beck’s theory of risk society and the aspects that characterise this society. Climate change is viewed as a risk, and the theory is used to derive...

From Iron Cage to Pigeon House: The Birth of Reflexive Authority

NARCIS (Netherlands)

Hoogenboom, M.J.M.; Ossewaarde, Marinus R.R.

2005-01-01

In recent years, Weber’s image of the ‘iron cage’ has been challenged by the sociologists Ulrich Beck and Anthony Giddens. They claim that this image no longer applies to the late modern world we are entering. In the late modern era, individuals, institutions and organizations have become or will

Interview mit Benoît Godin

Directory of Open Access Journals (Sweden)

Ulrich Ufer

2018-03-01

Full Text Available In this interview for TATuP, conducted at the Institut national de la recherche scientifique in Montreál, Benoît Godin responds to Ulrich Ufer’s questions about the history of the concept of innovation and its uses in present and past discourses on social change.

Relation between Radio Polarization and Spectral Index of Blazars ...

Indian Academy of Sciences (India)

Introduction. Blazars are a very special class of extragalactic objects showing some special proper- ties, including rapid variability, high and variability polarization, high luminosity and superluminal motion, etc. Their optical variability timescales can cover a range of hours to years from radio to γ-rays (Fan et al. 2004; Ulrich ...

How Are New Behavioral Forms and Functions Introduced during Ontogenesis? Commentary.

Science.gov (United States)

Wolff, Peter H.

1991-01-01

Comments on Thelen and Ulrich's monograph in this issue. Examines theoretical and empirical sections and findings, concluding that the authors have taken a major step forward by introducing the dynamic systems perspective to the study of behavioral coordination in infants, thus opening the way for experimental investigation of phenomena that could…

Pop / Tõnis Kahu

Index Scriptorium Estoniae

Kahu, Tõnis, 1962-

2007-01-01

Heliplaatidest: Free Tallinn Trio "Full Moon", Whitesnake "1987 - 20th Anniversary Special Edition", Maroon5 "It Won't Be Soon Before Long", Uku Kuut "Santa Monica", The Afgan Whigs "Unbreakable (A Retrospective 1990-2006)", Various Artists "Box of Dub: Dubstep and Future Dub", Kubichek! "Not Enough Night", Ulrich Schnauss "Goodbye"

Le fabbriche del cioccolato : settore e impresa in Germania, Svizzera e Italia tra il tardo '800 e la Prima Guerra Mondiale

OpenAIRE

CHIAPPARINO, Francesco

1995-01-01

Defence date: 28 April 1995 Examining Board: Prof. Albert Carreras (Universitat Pompeu Fabra, Barcelona, supervisore) ; Prof. Peter Hertner (IUE, supervisore esterno) ; Prof. René Leboutte (IUE) ; Prof. Ulrich Wengenroth (Technische Universität, München) ; Prof.ssa Vera Zamagni (Università di Bologna) First made available online: 30 August 2016

Gender Differences in Fundamental Motor Skill Development in Disadvantaged Preschoolers from Two Geographical Regions

Science.gov (United States)

Goodway, Jacqueline D.; Robinson, Leah E.; Crowe, Heather

2010-01-01

This study examined the influence of gender and region on object control (OC) and locomotor skill development. Participants were 275 midwestern African American and 194 southwestern Hispanic preschool children who were disadvantaged. All were evaluated on the Test of Gross Motor Development-2 (Ulrich, 2000). Two, 2 Gender (girls, boys) x 2 Region…

156 -- 15 Dec 2009 [final version].indd

African Journals Online (AJOL)

15 Des 2009 ... ABSTRACT. Intertextuality – encyclopedia and archaeology: Matthew's presentation of Jesus as saviour. This article aims to explore and to apply what Gérard Genette refers to as kinds of transtextual relationships and what Ulrich Luz, in his application of these insights to the Gospel of Matthew, calls the ...

Officership And The Profession: A Selected Bibliography

Science.gov (United States)

2013-09-01

General." Rolling Stone , July 2010, 91-97, 120-121. ProQuest; Rehkopf, Donald G., Jr., and Marybeth P. Ulrich. "Commentary and Reply: On ’The General...51-55. ProQuest Marble , Andrew. "How Are Great Leaders Made? Lessons from the Career of General John Shalikashvili (1936-2011)." Joint Force

Internal Drivers of External Flexibility: A Detailed Analysis

Science.gov (United States)

2007-08-14

and Stephen Swartz for giving me the opportunity to obtain my Ph. D.. Dave Ulrich, Basilio Perez, Kevin James, and Pete Cabrera were my first USAF...Arndt, and Scott Grawe , I couldn’t have made it without you. Elten Briggs was the “senior” doctoral student when I arrived and when he graduated I saw

Methods in Lexicography and Dictionary Research

African Journals Online (AJOL)

user

Access Structures in Printed Dictionaries. Gouws,. Rufus H., Ulrich Heid, Wolfgang Schweickard and Herbert Ernst Wiegand (Eds.). 2013: 110-149. Wiegand, Herbert Ernst and Mª Teresa Fuentes Morán. 2010. Estructuras lexicográficas. Aspectos centrales de una teoría de la forma del diccionario. Colección Lexicografía 2.

Intertekstualiteit – ensiklopedie en argeologie: Matteus se ...

African Journals Online (AJOL)

Intertextuality – encyclopedia and archaeology: Matthew's presentation of Jesus as saviour This article aims to explore and to apply what Gérard Genette refers to as kinds of transtextual relationships and what Ulrich Luz, in his application of these insights to the Gospel of Matthew, calls the encyclopaedia of the author or the ...

Enhancing New Product Development (NPD Portfolio Performance by Shaping the Development Funnel

Directory of Open Access Journals (Sweden)

Paulo Soares Figueiredo

2012-12-01

Full Text Available New product development (NPD projects are typically managed through a series of screens, or gates, where ideas compete for resources. Ideas are carved into projects, and these projects are reviewed, and approved or terminated through the screening process so that only the best performing projects continue to subsequent stages of design, development and testing, and are released into the market place (Krishnan and Ulrich 2001; Terwiesch and Ulrich 2009. Most large innovative organizations deal with more than one NPD project at a time and typically engage in product pipeline management (PPM, where a set of active projects are evaluated together while they traverse through a sequence of such screens. Key decisions in a R&D pipeline are: screen thresholds, complexity of projects, resource allocation and capacity adjustment biases. We explore the impact of structural and behavioral aspects of these decisions through a simulation based analysis of a pharmaceutical dataset. Results establish concave relationships between value created at the end of pipeline and the resource allocation and complexity allocation biases, indicating optimizability and a limit for front loading practices.

Moskva, lootuse ja lootusetuse dialektika / Reet Varblane

Index Scriptorium Estoniae

Varblane, Reet, 1952-

2005-01-01

Moskva I rahvusvaheline kaasaja kunsti biennaal "Lootuse dialektika" endises Lenini muuseumis 28. I-28. II. Kuraatorid Joseph Backstein, Daniel Birnbaum, Nicolas Bourriaud, Iara Boubnova, Rosa Martinez ja Hans Ulrich Obrist. Kunstnike Keskmajas eksponeeritud Marat Gelmani kuraatoriprojekti "Venemaa 2" Moskva linnakohtusse kaebamisest õigeusklike poolt. 2. III toimunud kohtuistungist Sahharovi keskuse näituse "Ettevaatust religioon!" korraldajate tegevuse asjus

Using games as a teaching strategy.

Science.gov (United States)

Glendon, Kellie; Ulrich, Debbie

2005-07-01

Both of these games are relatively easy to develop and are fun ways for faculty to challenge students and provide immediate feedback so students can assess their own comprehension and, consequently, their need for further study (Ulrich & Glendon, 2005). Teacher-delivered factual material is often tedious and boring, while games are highly motivating and accomplish the same objectives.

The Gross Motor Skills of Children with Mild Learning Disabilities

Science.gov (United States)

Nonis, Karen P.; Jernice, Tan Sing Yee

2014-01-01

Many international studies have examined the gross motor skills of children studying in special schools while local studies of such nature are limited. This study investigated the gross motor skills of children with Mild Learning Disabilities (MLD; n = 14, M age = 8.93 years, SD = 0.33) with the Test of Gross Motor Development-2 (TGMD-2, Ulrich,…

Nanotechnology and the Developing World: Lab-on-Chip Technology for Health and Environmental Applications

Science.gov (United States)

Mehta, Michael D.

2008-01-01

This article argues that advances in nanotechnology in general, and lab-on-chip technology in particular, have the potential to benefit the developing world in its quest to control risks to human health and the environment. Based on the "risk society" thesis of Ulrich Beck, it is argued that the developed world must realign its science and…

Stasi luuramine pälvis 25 aastat hiljem Euroopa filmiauhinna / A. L.

Index Scriptorium Estoniae

A. L.

2006-01-01

Euroopa Filmiakadeemia andis Euroopa 2006.a. parima filmi auhinna sakslase Florian Henckel von Donnersmarcki filmile "Teiste elu" ("Das Leben der Anderen"), mille peaosaline Ulrich Mühe sai parima meesnäitleja auhinna. Parim režissöör oli Pedro Almodovar, kelle filmi "Volver" näitleja Penelope Cruz sai ka parima naisnäitleja auhinna

Rammens udkrængning

DEFF Research Database (Denmark)

Thygesen, Mads

2006-01-01

for projektet, dvs. hvordan Waltz og hendes kompagni har ladet sig inspirere af kulturteoretikere som Jean Baudrillard, Pierre Bourdieu og Ulrich Beck. Dernæst følger to afsnit om installationens centrale greb, som jeg med inspiration fra værkets titel har valgt at benævne »rammens udkrængning«. I denne del af...

Ära tee, tee! = Do not do it, do it! / Rebeka Põldsam

Index Scriptorium Estoniae

Põldsam, Rebeka, 1989-

2016-01-01

Margit Säde-Lehni kuraatorinäitus "DOings & kNOTs. Kunst ja/või instruktsioon" Tallinna Kunstihoones. Lähtepunktiks on Hans Ulrich Obristi 1993. a. algatatud projekt „Do it”. Kunstihoonesse on kutsutud 20 kunstnikku/rühmitust üle Euroopa, et tõlgendada kellegi teise jäetud instruktsioone ja teha nende järgi uusi teoseid

Highlights from e-EPS: EPS and EuChems are joining forces

CERN Multimedia

2013-01-01

e-EPS News is an addition to the CERN Bulletin line-up, showcasing articles from e-EPS – the European Physical Society newsletter – as part of a collaboration between the two publications.   On the occasion of the EPS Council 2013 in Strasbourg, a memorandum of understanding was signed between the European Association for Chemical and Molecular Societies (EuCheMS) and the European Physical Society (EPS) by presidents Ulrich Schubert and Luisa Cifarelli. EuCheMS and EPS share many objectives, such as community building, scientific excellence, communication and representation of their respective members to European policy makers. The two societies recognise that issues in many fields such as education, publication, support for basic sciences and frontier research are similar in their respective disciplines. They wish to combine efforts in developing and presenting common standpoints to their mutual benefit as European representatives in chemistry ...

Powerhouse in the foliage; Kraftwerk im Blattwerk

Energy Technology Data Exchange (ETDEWEB)

Roesch, Harald

2010-07-01

Photosynthesis, a veritable stroke of genius on the part of nature, makes the existence of higher life forms possible. If it can be optimized, it may be able to make an even greater contribution to the resolution of future energy problems. Manajit Hayer-Hartl and Ulrich Hartl are currently working on this possibility at the Max Planck Institute of Biochemistry in Martinsried. (orig.)

The "Individualized" (Woman) in the Academy: Ulrich Beck, Gender and Power

Science.gov (United States)

Skelton, Christine

2005-01-01

This article considers the tensions and struggles that exist between men and women and between women and women in the academic workplace. The research reported here is a small-scale case study of 22 academic women from two generations who were interviewed about their career experiences. The theoretical framework is materialist feminism and draws…

Physical Plant Design and Engineering Controls to Reduce Hospital-Acquired Infections

Directory of Open Access Journals (Sweden)

JM Conly

2006-01-01

Full Text Available The importance of the environment as a reservoir for microorganisms implicated in disease transmission in the hospital setting has been increasingly recognized, especially with respect to dialysis units, ventilation in specialized areas, and the proper use of disinfectants (1. Inherent within the environmental setting is the importance of physical plant design. Several studies have underscored the importance of optimizing design standards to maximize patient and health care worker (HCW safety, including the prevention of hospital-acquired infections in patients (2-6. Ulrich et al (7 recently completed an evidence-based review, entitled 'The role of the physical environment in the hospital of the 21st century: A once-in-a-lifetime opportunity', for the Center for Health Design in California (USA, which was funded by the Robert Wood Johnson Foundation. Ulrich and colleagues identified over 600 studies that examined the hospital environment and its effects on staff effectiveness, patient safety, patient and family stress, quality and costs. They suggested that one of the important elements in improving patient safety is the reduction of the risk of hospital-acquired infections through improved facility design.

2007 Winter meeting - nuclear power in a relationship of tension between politics, society, and the economy

International Nuclear Information System (INIS)

Anon.

2007-01-01

Some 300 interested representatives of the power industry, industry at large, politics, administration, science and research met in Berlin on February 7 and 8, 2007 by invitation of the Deutsches Atomforum e.V. to exchange ideas and experience at the '2007 Winter Meeting'. This year's event was dedicated to the basic conditions underlying the use of nuclear power in Germany, Europe and worldwide. Seven contributions and statements by representatives from politics, industry, and society reflected a broad spectrum of divergent aspects and opinions about the topic of the meeting. Hans-Ulrich Joerges (stern, Berlin) chaired a discussion among Baerbel Hoehn (MP, Alliance 90/The Greens), Dr. Gerd Jaeger (RWE Power AG, Essen), Herbert Reul (MEP, energy policy spokesman of the CDU/CSU group of the European Parliament), and Prof. Dr.-Ing. Ulrich Wagner (Munich Technical University) about current and future aspects of power supply with or without nuclear energy. At the beginning of the year, the '2007 Winter Meeting' offered an interesting start of the debates accompanying this year's climate discussions, the problems associated with gas and oil deliveries from Russia, and the goal to adopt politically a sustainable energy program in the course of the year. (orig.)

Nickel-based materials and high-alloy, special stainless steels. 2. new rev. and enl. ed.

International Nuclear Information System (INIS)

Heubner, U.; Brill, U.; Hoffmann, T.; Jasner, M.; Kirchheiner, R.; Koecher, R.; Richter, H.; Rockel, M.; White, F.

1993-01-01

The book is intended as a source of information on nickel-based materials and special stainless steels and apart from the up-to-date materials data presents information on recent developments and knowledge gained, so that it may be a valuable aid to materials engineers looking for cost-effective resolutions of their materials problems in the chemical process industry, power plant operation, and high-temperature applications. The book presents eight individual contributions entitled as follows: (1) Nickel-base alloys and high-alloy, special stainless steels. - Materials survey and data sheets (Ulrich Heubner). (2) Corrosion of nickel-base alloys and special stainless steels (Manfred Rockel). (3) Welding of nickel-base alloys and high-alloy, special stainless steels (Theo Hoffmann). (4) High-temperature resistant materials (Ulrich Brill). (5) Application and processing of nickel-base materials in the chemical process industry and in pollution abatement equipment (Reiner Koecher). (6) Selected examples of applications of nickel-base materials in chemical plant (Manfred Jasner, Frederick White). (7) Applications of nickel-base alloys and special stainless steels in power plant. (8) The use of nickel-base alloys and stainless steels in pollution abatement processes (R. Kirchheiner). (orig./MM). 151 figs., 226 refs [de

Christian Joerges and Ernst-Ulrich Petersmann (eds., Constitutionalism: Multilevel Trade Governance and International Economic Law (Hart Publishing: Studies in International Trade Law, 2011

Directory of Open Access Journals (Sweden)

Rachael L. Johnstone

2012-03-01

Full Text Available Constitutionalism, Multilevel Trade Governance and International Economic Law is a second issue of a 2006 text of the same name. It brings together an impressive collection of international scholarship exploring international economic law in light of constitutional theory with many well-established experts in the field alongside some relatively junior and highly promising scholars.

Pilot Scale Production and Testing of a Recombinant Staphylococcal Enterotoxin (SEB) Triple Mutant

Science.gov (United States)

2017-09-01

Polymerase Chain Reaction . J. Food Prot. 2000, 63, (4), 479–488. 6. Ulrich, R.G.; Olson, M.A.; Bavari, S. Development of Engineered Vaccines...TR-1471 9. SPONSORING / MONITORING AGENCY NAME(S) AND ADDRESS(ES) Joint Program Executive Office for Chemical and Biological Defense, Joint Project...distribution unlimited. 13. SUPPLEMENTARY NOTES 14. ABSTRACT: The use of chemically or thermally inactivated biothreat toxins in detection

Euroopa asi / Jaanus Noormets

Index Scriptorium Estoniae

Noormets, Jaanus

2006-01-01

Euroopa Filmiakadeemia andis Euroopa 2006.a. parima filmi auhinna sakslase Florian Henckel von Donnersmarcki filmile "Teiste elu" ("Das Leben der Anderen"), mille peaosaline Ulrich Mühe sai parima meesnäitleja auhinna. Parim režissöör oli Pedro Almodovar, kelle filmi "Volver" näitleja Penelope Cruz sai ka parima naisnäitleja auhinna. Lisatud nimekiri "Valik tänavusi Euroopa filmiauhindade võitjaid

Environmental law. 2. rev. and enl. ed.; Umweltrecht

Energy Technology Data Exchange (ETDEWEB)

Koch, H.J. (ed.) [Hamburg Univ. (Germany). Forschungsstelle Umweltrecht

2007-07-01

The text book under consideration already is addressed to lawyers and students of jurisprudence. It enables an introduction into the general environmental law and consists of sixteen autonomous chapters: (a) International law in the field of ecology (Matthias Buck, Roda Verheyen); (b) European and national environmental constitutional law (Johannes Caspar); (c) General environmental administrative law (Ulrich Ramsauer); (d) Pollution abatement law (Hans-Joachim Koch); (e) Water protection law (Silke Laskowski, Cornelia Ziehm); (f) Recycling economy law and waste management law (Martin Dieckmann, Moritz Reese); (g) Nature conservation law (Christian Maass, Peter Schuette); (h) Soil conservation law and contaminated sites law (Nikolaus Herrmann); (i) Energy legal regulations as an instrument of environmental protection (Wolfgang Ewer); (j) Atomic energy law (Klaus Jankowski); (k) Genetic engineering law (Ursula Prall); (l) Law of hazardous materials (Eckhard Pache); (m) Environmental law in planning law (Nikolaus Hermann); (n) Environment and traffic (Philipp Hermann, Ekkehard Hofmann); (o) Agriculture and ecology (Ulf-Henning Moeker); (p) Liberal trade and environmental protection (Matthias Buck).

Two significant experiences related to radon in a high risk area in Spain

International Nuclear Information System (INIS)

Sainz, C.; Gutierrez-Villanueva, J.-L.; Fuente, I.; Quindos, L.; Soto, J.; Quindos-Poncela, L.S.; Arteche, J.-L.

2010-01-01

Radon is a natural radioactive gas and it is currently accepted as being responsible for lung cancer in some cases. One of the most important sources of indoor radon is from the soil. The RADON content of soil is also a very important factor to be taken into account. The natural radiation map of Spain (MARNA) classifies the country into three regions with different levels of natural gamma radiation. There are some areas in Spain with high levels of natural radiation one of those is the province of Salamanca. Western part of this province presents a population of 20 000 inhabitants and 7% of the houses have an indoor radon concentration above 400 Bq·m -3 . In this high risk area, the village of Villar de la Yegua is of special interest: 11% of the houses in this village have an indoor radon level below 400 Bq·m -3 , 89% have above 400 Bq·m -3 and 71% of the houses have a radon concentration above 1000 Bq·m -3 . An old uranium mine site close to this village has been selected for the construction of an experimental pilot house. It is a two story house located in the place with a very high 226 Ra concentration in soil. Radon in soil at 1 m depth has an average level of 250 kBq·m -3 . We present in this work the characteristics of the experimental unit located in this high risk area and we describe the zone where one of the Spanish villages with the highest radon concentration is located. This is a very interesting place for further research on indoor radon concentration and it is a unique opportunity of testing radon monitors, radon passive detectors and remedial actions for the mitigation of radon in real conditions. It is common to carry out intercomparison exercises under laboratory conditions. Nonetheless, it is not so common to develop these exercises in real conditions as we have in the experimental unit we present here. We offer in this work the possibility for other research groups of testing their equipment in this unit and we also show the evolution of

Simultaneous Vascular Targeting and Tumor Targeting of Cerebral Breast Cancer Metastases Using a T-Cell Receptor Mimic Antibody

Science.gov (United States)

2014-05-01

in May 2013, the difference between nude mice (which lack T- cells , but still have a partially functional adaptive and innate immune system) and NSG...Mangada J, Greiner DL, Handgretinger R. Human lymphoid and myeloid cell development in NOD/LtSz-scid IL2R gamma null mice engrafted with mobilized human...Targeting of Cerebral Breast Cancer Metastases Using a T- Cell Receptor Mimic Antibody PRINCIPAL INVESTIGATOR: Ulrich Bickel

Solar Observations on Magneto-Convection

Science.gov (United States)

1989-05-31

Technical Library National Solar Observatory Sunspot, NM 88349 Karl - Schwarzschild -Strasse 1 8046 Garching bei Mundhen Solar Observations On Magneto...Schmidt, Hermann-Ulrich Schmidt, Hans-Christoph Thomas (eds.) Max-Planck-Institut fir Physik und Astrophysik Institut fiur Astrophysik Karl ... Schwarzschild -St-. 1 D-8046 Garching, FklG 14TIS CRiA.&l DTIC TA. U~Jar,iou8:ed B ......... ... Distribution I -- Availability COcý----- Avail and or Dist special

Cryptogenic transient ischemic attack after nose blowing: association of huge atrial septal aneurysm with patent foramen ovale as potential cause

OpenAIRE

Lotze, Ulrich; Kirsch, Uwe; Ohlow, Marc-Alexander; Scholle, Thorsten; Leonhardi, Jochen; Lauer, Bernward; Oltmanns, Gerhard; Schmidt, Hendrik

2013-01-01

Ulrich Lotze,1 Uwe Kirsch,1 Marc-Alexander Ohlow,2 Thorsten Scholle,3 Jochen Leonhardi,3 Bernward Lauer,2 Gerhard Oltmanns,4 Hendrik Schmidt5,6 1Department of Internal Medicine, DRK Krankenhaus Sondershausen, Sondershausen, Germany; 2Department of Cardiology, Zentralklinik Bad Berka, Bad Berka, Germany; 3Institute of Diagnostic and Interventional Radiology, Zentralklinik Bad Berka, Germany; 4Department of Internal Medicine, DRK Krankenhaus Sömmerda; Sömmerda, Germany; 5Depar...

11. Textbeispiele

OpenAIRE

Kunze, Rolf-Ulrich

2017-01-01

11.1 Seminararbeit zum Thema eines Seminarvortrags: Otto von Bismarck als preußischer Gesandter am Deutschen Bund in Frankfurt am Main, 1851-1859 Warum Bismarck? Man muß gar nicht auf den aus der Zeitgeschichte kommenden sozialgeschichtlichen Siegeszug des biographischen Genre seit einigen Jahren verweisen, um die seit ihren Anfängen offen zu Tage liegenden biographisch-strukturgeschichtlichen Defizite der makrotheoretisch-reduktionistischen politischen Sozialgeschichte Hans-Ulrich Wehlers un...

Risk Aversion: As Perceived by U.S. and Swedish Officers

Science.gov (United States)

2011-06-10

marginalized traditional morality . (Furedi 1997, 153f) The value of risk aversion means to not put people at risk and to regulate behavior. The main...difference compared to traditional morality lies in the individualistic orientation of risk aversion (Furedi 1997, 163) Ulrich Beck German Professor of...that distinguishes one group of people from another (Hofstede 2005, 3ff). Studying differences in culture demands a position of cultural relativism

ULUSLARARASI İLİŞKİLERDE BAŞARISIZ DEVLETLER SORUNSALI VE BU SORUNSALIN ULUSLARARASI HUKUKA ETKİLERİ

OpenAIRE

Özalp, Osman N.

2014-01-01

Kavramlarla ilgili bkz. Zartman, I. William (Hg.): Collapsed States: The Disintegration and Restoration of Legitimate Authority, Boulder: Lynne Rienner, 1995; Rotberg, Robert I.: The Failure and Collapse of Nation-States: Breakdown, Prevention and Repair, in: Beisheim, Marianna/Schuppert, Gunnar F.: Staatszerfall und Governance. Baden Baden: Nomos 2007, s. 59-97; Helman, Gerald B./Ratner, Steven B.: Saving Failed States, in: Foreign Policy, 1992 (89), 3-20; Schneckener, Ulrich (Ed.): Fra...

Identification of Solar Events Responsible for ICMEs at 1AU - Estimation of Chirality and Helicity

Science.gov (United States)

Ulrich, Roger K.; tran, Tham; Riley, Pete

2017-08-01

We start with the table of identified interplanetary magnetic clouds provided by the WIND/SWI project at https://wind.gsfc.nasa.gov/mfi/mag_cloud_S1.html .Our procedure uses the following steps:1) We take candidates observed during the HMI era from the above catalogue.2) We average cloud start and end times.3) We subtract an estimated travel time to get an origin time.4) We find a halo or partial halo CME near the origin time using the CDAW catalogue.5) We estimate a quadrant for the solar event from the CME shape.6) We use the jHelioviewer on AIA 173 differences with a 5 minute cadence to find an ejected loop near the origin time.7) We place the foot points near the locations of maxima and minima of Br (i.e. the strongest fields of opposite sign).8) We find the field gradients such as (curl B)r at these points.The above steps have been applied to the 37 clouds listed in the MFI table for the period 2011 to 2012 with the result that only 7 clouds could be identified and clearly associated with solar surface origination points. The MFI table includes an estimation of the cloud chirality. Transverse magnetic fields on the solar surface can be determinedfrom the observations of the HMI instrument on the SDO spacecraft in two different ways: the standard HMI pipeline or the Ulrich - Boyden method. The Ulrich - Boyden method gives the correct chirality for all 7 cases while the standard pipeline gives the correct chirality for 6 of the 7 clouds.The clouds are belowAR Solar Source HelicityMFI Number Source Day/Hr Coord Pred Obs129 11158 11/02/15:02:24 S22W09-S18W18 L L133 11226 11/06/01:18:36 S21E19-S19E15 R R134 11226-11227 11/06/02:07:41 S20E26-S21E16 R R138 11289-11293 11/09/13:23:12 N23W13-N17W23 L L148 11504 12/06/14:14:12 S16E11-S16E03 R R154 11560-11561 12/09/02:04:00 N01W04-N05W11 L L161 11610 12/11/10:05:12 S24E11-S20E07 R RThis research has been supported by NASA through award NNX15AF39G to Predictive Science, Inc. and subaward to UCLA

Spatial attention does improve temporal discrimination.

Science.gov (United States)

Chica, Ana B; Christie, John

2009-02-01

It has recently been stated that exogenous attention impairs temporal-resolution tasks (Hein, Rolke, & Ulrich, 2006; Rolke, Dinkelbach, Hein, & Ulrich, 2008; Yeshurun, 2004; Yeshurun & Levy, 2003). In comparisons of performance on spatially cued trials versus neutral cued trials, the results have suggested that spatial attention decreases temporal resolution. However, when performance on cued and uncued trials has been compared in order to equate for cue salience, typically speed-accuracy trade-offs (SATs) have been observed, making the interpretation of the results difficult. In the present experiments, we aimed at studying the effect of spatial attention in temporal resolution while using a procedure to control for SATs. We controlled reaction times (RTs) by constraining the time to respond, so that response decisions would be made within comparable time windows. The results revealed that when RT was controlled, performance was impaired for cued trials as compared with neutral trials, replicating previous findings. However, when cued and uncued trials were compared, performance was actually improved for cued trials as compared with uncued trials. These results suggest that SAT effects may have played an important role in the previous studies, because when they were controlled and measured, the results reversed, revealing that exogenous attention does improve performance on temporal-resolution tasks.

Captivity mark as Foundation of Civil Liability for Risk in Prol Consumer

Directory of Open Access Journals (Sweden)

Fernando Antônio de Vasconcelos

2016-06-01

Full Text Available The postmodern society can be seen as risk society. From the Ulrich Beck’s idea that the acquired knowledge allows the current development model, but its generates uncontrollable risks, this study attempts to make a validation of trademark captivity theory as the basis for civil liability for risk. The strength of the brands as fundamental goals in today’s economic process is seen as a vector of liability for consumers as a vulnerable class. The difficulty of consumers in the process of accountability for damages suffered in their relations is still present. The supply process is complex and is formed by a network arrangements which stresses the consumer’s vulnerability. The trademark captivity allows the identification of an economic group participants by sharing the brand. The proposal in this article, is to strengthen the idea of   captivity mark as accountability paradigm from the brand with the theory of risk, examining its feasibility framing the sole paragraph of Article 927 of the Brazilian Civil Code.The methodology will be based on a legal-economic aspect and depart from an inductive analysis and bibliographic surveys, with the theoretical framework of Ulrich Beck, Antonny Giddens and Claudia Lima Marques.

Advanced Integrated Fuel/Combustion Systems

Science.gov (United States)

2004-01-01

ineffective in the T63, even at concentrations up to 40 times the recommended value. Additive companies were informed about the performance of their...M. (1996): NASA RP- 1385. • Toepke, S. (1999): Boeing Company , Personal Correspondence. • Ulrich, G.D. (1971): Comb. Sci. Tech., Vol. 4, pp. 47-58...temperature (K) THC = total hydrocarbons UNICORN = UNsteady Ignition and COmbustion with ReactioNs V = reactor volume (mL) WSR = well-stirred reactor

Africa - Israel - Africa Return-migration experiences of African labour migrants

OpenAIRE

Galia Sabar

2013-01-01

This paper analyses homecoming experiences of African labour migrants who lived in Israel and returned home. Using qualitative research methodologies, I discerned what factors - material and non-material - determine the relative success of the return process. Focusing on these factors’ effects, I offer a new understanding of labour migrants’ homecoming experiences: those who are “content,” “readjusting,” or “lost. Following Ulrich Beck's (2006) analysis of cosmopolitanism, I suggest that thes...

The fifth annual ALICE Industrial Awards ceremony on 9 March, 2007.

CERN Multimedia

2007-01-01

The ALICE collaboration presents Quantum Corp with an award for the high performance cluster file system (StorNext) for the ALICE DAQ system, and for their outstanding cooperation in implementing the software.From left to right: Jurgen Schukraft (ALICE Spokesperson), Pierre vande Vyvre (ALICE DAQ), Hans Boggild (ALICE), Ewan Johnston (Quantum Corp.), Derek Barrilleaux (Quantum Corp.), Lance Hukill (Quantum Corp.), Ulrich Fuchs (ALICE DAQ), Catherine Decosse (ALICE) and Roberto Divia (ALICE DAQ).

Thirteenth International Workshop on Principles of Diagnosis (DX-2002)

Science.gov (United States)

2002-05-01

91 Suárez, Antonio J., 165 Szemethy, Tivadar, 7 Tatar, Mugur, 65 Torasso, Pietro , 43 Torta, Gianluca, 43 Travé-Massuyés, Louise, 106 Weiss, Ulrich...Washio Osaka University, Japan Marina Zanella Universitá di Brescia, Italy Feng Zhao Xerox PARC, USA II Foreword The Thirteenth International Workshop...dynamic and temporal systems, distribution and abstraction, and non-symbolic methods of di - agnosis. They bear witness to the continuing existence of

Proceedings: NATO CCMS (Committee on the Challenges of Modern Society) Seminar Blue Book 159, Preservation of Flora and Fauna in Military Training Areas Held in Soesterberg, Netherlands on 28-30 November 1984

Science.gov (United States)

1987-01-01

CONSERVATION MEASURES AND CULTIVATION ON MILITARY TRAINING AREAS... .o...o......, ..... **.. 99 Ulrich V. Coler PROTECTION OF SPECIES AND BIOTOPES ON MTAs.o...stone cliffs. The climate is coastal and there are very few species of beast and bird of prey. Most of the land side is cultivated for agricultural or...experimentations, trainings, etc.) and the checks carried out and going on at present on waste waters from the ecotoxicological point of view, are

Swarming Mechanisms in the Yellow Fever Mosquito: Aggregation Pheromones are Involved in the Mating Behavior of Aedes aegypti

Science.gov (United States)

2014-12-01

behavior of Aedes aegypti Emadeldin Y. Fawaz1, Sandra A. Allan2, Ulrich R. Bernier2, Peter J. Obenauer3, and Joseph W. Diclaro II1 1Vector Biology... Aedes aegypti swarming behavior and identified associated chemical cues. Novel evidence is provided that Ae. aegypti females aggregate by means of...the isolated aggregation pheromones in controlling Ae. aegypti. Journal of Vector Ecology 39 (2): 347-354. 2014. Keyword Index: Aedes aegypti, swarm

Study of alternative strategies to the task clarification activity of the market-pull product development process model

OpenAIRE

Motte, Damien

2009-01-01

A very large majority of the current product development process models put forward in textbooks present a homogenous structure, what Ulrich & Eppinger [1] call the market-pull model, presented as a generic one, while other possible product development process models are merely seen as variants. This paper focuses on the task clarification and derived activities (mainly the systematic search for customer needs through market study and the supplementary development costs it entails) and in...

The Ukrainian Crisis and European Security: Implications for the United States and U.S. Army

Science.gov (United States)

2015-01-01

14 Chris Giles and Stefan Wagstyl, “IMF Warns of Third Eurozone Recession Since Finan- cial Crisis,” Financial Times, October 8, 2014. 15 Ulrich...Jones, and Kathrin Hille, “Russian Air Incursions Rattle Baltic States,” Financial Times, September 25, 2014. 25 Andrew Higgins , “Tensions Surge in...Opening of the Munich Security Conference, January 31, 2014. Giles, Chris , and Stefan Wagstyl, “IMF Warns of Third Eurozone Recession Since Financial

PROF. ULRICH GERHARD LAUTS (1787— 1865). In sy studie „De ...

African Journals Online (AJOL)

Test

In sy studie „De beteekenis van 1813 voor Nederlands geestelijke beschaving"') het die .... af te lê. Daarna het hulle hul eed nog weer bevestig om trou te bly aan ..... L. 'n ver dedigende skrywe aan die Minister gestuur na aanleiding van 'n twis met die militêre geneesheer („Rijksarchief," Dept. van Marine. Prof. U. G..

Canadian company innovates dam repair

International Nuclear Information System (INIS)

Anon.

2000-01-01

Successful repair without any downtime, of the Sabana Yegua power and irrigation structure in the western Dominican Republic by Aquatic Sciences Ltd., a St. Catherine, Ontario-based underwater specialist company, is discussed. The structure was damaged by Hurricane George last when when rising water levels damaged a major valve in the control gate chamber. The repair strategy designed by Aquatic Sciences used a remotely operated vehicle with a mechanical arm for minor tasks which placed a specially-made plug into the inlet pipe. The work was completed in one week, saving the utility company a great deal of money by making it possible to make the repairs remotely in the gate chamber without having to drain the tunnel, as would have been necessary had the repair been completed manually. The remotely operated vehicles use a scanning sonar as well as light to find their way. They are particularly well adapted to work underwater under low-visibility conditions

Atmospheric dispersion calculations in a low mountain area

International Nuclear Information System (INIS)

Schmid, S.

1987-01-01

The applicability of the Gaussian model for assessing the short-range environmental exposure from an emission source in a topographically inhomogeneous terrain is tested. An atmospheric dispersion model of general applicability is used, which is based on results of hydrodynamic flow models. Approaches for turbulence and radiation parameterization are tested by means of a vertically one-dimensional flow model. In order to introduce the effects of the topography in the boundary-layer simulations, the three-dimensional mesoscale model (Ulrich) is applied. The two models are verified by way of episode simulation using wind profile measurements. The differences in the models' results are to show the topographic influence. The calculated flow fields serve as input to a randomwalk model applied for calculating ground-level concentration fields in the vicinity of an emission source. The Gaussian model underestimates the pollution under stable conditions. Convectivity conditions may change the effective source hight through vertical effects caused by orography which, depending on the direction of free flow, leads to an increase or decrease of pollutant concentration at ground level. Applying the more complex dispersion model, the concentration maxima under stable conditions are closer to the source by a factor five, and under unstable conditions about one and a half times more remote. (orig./HP) [de

Regulatory change and monetary policy

OpenAIRE

Bank for International Settlements

2015-01-01

Report submitted by a Working Group established by the Committee on the Global Financial System and the Markets Committee. The Group was chaired by Ulrich Bindseil (European Central Bank) and William R Nelson (Federal Reserve Board). Financial regulation is evolving, as policymakers seek to strengthen the financial system in order to make it more robust and resilient. Changes in the regulatory environment are likely to have an impact on financial system structure and on the behaviour of finan...

Field transformations to multivalued fields

Energy Technology Data Exchange (ETDEWEB)

Kleinert, H [Institut fuer Theoretische Physik, Arnimallee 14, D-14195 Berlin (Germany)

2007-05-15

Changes of field variables may lead to multivalued fields which do not satisfy the Schwarz integrability conditions. Their quantum field theory needs special care as is shown in an application to the superfluid and superconducting phase transitions.

Stress Exposure, Food Intake, and Emotional State

Science.gov (United States)

Ulrich-Lai, Yvonne M.; Fulton, Stephanie; Wilson, Mark; Petrovich, Gorica; Rinaman, Linda

2016-01-01

This manuscript summarizes the proceedings of the symposium entitled, “Stress, Palatable Food and Reward”, that was chaired by Drs. Linda Rinaman and Yvonne Ulrich-Lai at the 2014 Neurobiology of Stress Workshop held in Cincinnati, OH. This symposium comprised research presentations by four neuroscientists whose work focuses on the biological bases for complex interactions among stress, food intake and emotion. First, Dr. Ulrich-Lai describes her rodent research exploring mechanisms by which the rewarding properties of sweet palatable foods confer stress relief. Second, Dr. Stephanie Fulton discusses her work in which excessive, long-term intake of dietary lipids, as well as their subsequent withdrawal, promotes stress-related outcomes in mice. Third, Dr. Mark Wilson describes his group’s research examining the effects of social hierarchy-related stress on food intake and diet choice in group-housed female rhesus macaques, and compared the data from monkeys to results obtained in analogous work using rodents. Lastly, Dr. Gorica Petrovich discusses her research program that is aimed at defining cortical–amygdalar–hypothalamic circuitry responsible for curbing food intake during emotional threat (i.e., fear anticipation) in rats. Their collective results reveal the complexity of physiological and behavioral interactions that link stress, food intake and emotional state, and suggest new avenues of research to probe the impact of genetic, metabolic, social, experiential, and environmental factors. PMID:26303312

Stress exposure, food intake and emotional state.

Science.gov (United States)

Ulrich-Lai, Yvonne M; Fulton, Stephanie; Wilson, Mark; Petrovich, Gorica; Rinaman, Linda

2015-01-01

This manuscript summarizes the proceedings of the symposium entitled, "Stress, Palatable Food and Reward", that was chaired by Drs. Linda Rinaman and Yvonne Ulrich-Lai at the 2014 Neurobiology of Stress Workshop held in Cincinnati, OH. This symposium comprised research presentations by four neuroscientists whose work focuses on the biological bases for complex interactions among stress, food intake and emotion. First, Dr Ulrich-Lai describes her rodent research exploring mechanisms by which the rewarding properties of sweet palatable foods confer stress relief. Second, Dr Stephanie Fulton discusses her work in which excessive, long-term intake of dietary lipids, as well as their subsequent withdrawal, promotes stress-related outcomes in mice. Third, Dr Mark Wilson describes his group's research examining the effects of social hierarchy-related stress on food intake and diet choice in group-housed female rhesus macaques, and compared the data from monkeys to results obtained in analogous work using rodents. Finally, Dr Gorica Petrovich discusses her research program that is aimed at defining cortical-amygdalar-hypothalamic circuitry responsible for curbing food intake during emotional threat (i.e. fear anticipation) in rats. Their collective results reveal the complexity of physiological and behavioral interactions that link stress, food intake and emotional state, and suggest new avenues of research to probe the impact of genetic, metabolic, social, experiential and environmental factors on these interactions.

IRRS: The CSN under the microscope; Mision IRRS: el CSN bajo el microscopio

Energy Technology Data Exchange (ETDEWEB)

Salome, M.

2008-07-01

Throughout the two weeks from January 28th to February 8th an international team of experts, appointed by the IAEA and led by Ulrich Schmocker from Switzerland, carried out a detailed study of the CSN. The objective of the IRRS mission, which was performed in response to a request from the Council itself, was to analyse the structure and operation of the Spanish regulatory body in order to determine its strengths and weaknesses and to suggest measures to improve its management. (Author)

IRRS: The CSN under the microscope

International Nuclear Information System (INIS)

Salome, M.

2008-01-01

Throughout the two weeks from January 28th to February 8th an international team of experts, appointed by the IAEA and led by Ulrich Schmocker from Switzerland, carried out a detailed study of the CSN. The objective of the IRRS mission, which was performed in response to a request from the Council itself, was to analyse the structure and operation of the Spanish regulatory body in order to determine its strengths and weaknesses and to suggest measures to improve its management. (Author)

LC/MS/MS data analysis of the human uterine smooth muscle S-nitrosoproteome fingerprint in pregnancy, labor, and preterm labor

Directory of Open Access Journals (Sweden)

Craig C. Ulrich

2015-09-01

Full Text Available The data described in this article is the subject of an article in the American Journal of Physiology: Cell Physiology, titled “The Human Uterine Smooth Muscle S-nitrosoproteome Fingerprint in Pregnancy, Labor, and Preterm Labor” (doi:10.1152/ajpcell.00198.2013 (Ulrich et al., 2013 [1]. The data described is a large scale mass spectrometry data set that defines the human uterine smooth muscle S-nitrosoproteome differences among laboring, non-laboring, preterm laboring tissue after treatment with S-nitrosoglutathione.

A Rotational and Axial Motion System Load Frame Insert for In Situ High Energy X-Ray Studies (Postprint)

Science.gov (United States)

2015-09-08

Paul A. Shade, Jay C. Schuren, and Todd J. Turner AFRL/RX Basil Blank PulseRay Peter Kenesei, Kurt Goetze, Ulrich Lienert, and Jonathan Almer...AFRL/RX 2) Basil Blank – PulseRay (continued on page 2) 5d. PROJECT NUMBER 4349 5e. TASK NUMBER 0001 5f...2015) A rotational and axial motion system load frame insert for in situ high energy x-ray studies Paul A. Shade,1,a) Basil Blank,2 Jay C. Schuren,1,b

Seitsmes palverändur on professor Volker Sellin / Kalev Vilgats

Index Scriptorium Estoniae

Vilgats, Kalev

2009-01-01

Pärnust pärit valgustusaja mõtleja Carl Gustav Jochmanni 220. sünniaastapäeva tähistamine Pärnu raekojas. Loenguid pidasid professorid dr. Ulrich Kronauer ja dr. Volker Sellin Saksamaalt. Seitsmenda Pärnu akadeemilise palveränduri märgi sai dr. Volker Sellin. Akadeemilise palverändurimärgi on saanud väljaspool Eestit Pärnu ajaloo uurimist toetanud või siit pärit väljapaistvate tegelaste pärandit tutvustanud õpetlased

Risk, Rationality and Nudging in Late Modern Society: Understanding the dynamics of the climate crisis

OpenAIRE

Jakobsen, Terne Sasha Thorn

2016-01-01

This study seeks to explore and explain how nudge theory may contribute to the understanding of thedynamics of the climate crisis in a ‘world risk society’. It is based on Ulrich Beck’s theory of a worldrisk society and unfolds through the combination of theories about risk, rationality and behaviour thatare ultimately brought together in relation to the climate crisis. A critical realistic perspective andmethod is taken to explore three hypothetical premises: 1) That the climate crisis is a ...

Leveling the Playing Field: Assessment of Gross Motor Skills in Low Socioeconomic Children to their Higher Socioeconomic Counterparts

Directory of Open Access Journals (Sweden)

Megan M. Adkins

2017-07-01

Full Text Available Background: Fundamental movements (FM of children influence the willingness to engage in physical activity (PA. Thus, proper FM skills are the foundation for a lifespan of PA. Objective: This study examined what factors may affect children’s PA in relation to FM pattern capabilities. Methods: The study examined the influence of SES when three low-income schools were provided additional PA opportunities on days PE was not taught. FM patterns in relation to object control (OC and locomotor skill (LC development were evaluated on K (n = 871, 1st (n = 893, and 2nd graders (n = 829 using the Test of Gross Motor Development-2 (TGMD-2 instrument (Ulrich, 2000. Schools were dichotomized and categorized as being low SES (n = 2008 and high SES (n = 578 status. Results: A significant relationship was revealed with LC (r = 0.264; p = 0.001, OC (r = 0.171; p = 0.001, and total TGMD-2 (r = 0.264; p = 0.001. Low and high SES schools significantly improved overall TGMD-2 scores. High SES schools children were significantly higher in LC [F, (2, 1272 = 29.31, p = 0.001], OC [F, (2, 1272 = 23.14, p = 0.001], and total TGMD-2 [F, (1, 1272 = 38.11, p = 0.001]. Conclusion: Low SES schools need to concentrate on PA-based activities to engage students in FM patterns, to help narrow the gap in FM capabilities. In addition, the increase in PA opportunities for lower SES schools could positively impact brain function, cardiovascular fitness, and overall well-being.

An electric field in a gravitational field

International Nuclear Information System (INIS)

Harpaz, Amos

2005-01-01

The behaviour of an electric field in a gravitational field is analysed. It is found that due to the mass (energy) of the electric field, it is subjected to gravity and it falls in the gravitational field. This fall curves the electric field, a stress force (a reaction force) is created, and the interaction of this reaction force with the static charge gives rise to the creation of radiation

A happy marriage. In his private home, heating systems expert Ulrich Krausscombines photovoltaic power generation and geothermal heat; Eine glueckliche Verbindung. Heizungsfachmann Ulrich Krauss kombiniert in seinem Haus Photovoltaik und Erdwaerme

Energy Technology Data Exchange (ETDEWEB)

Simons, Kristina; Krause, Matthias B.

2010-11-15

The contribution presents a private home with photovoltaic cells installed on the garage roof and with geothermal heating. In spite of unfavourable boundary conditions, the solar modules produce more electric power than the geothermal heat pump consumes. (orig.)

Tripolar electric field Structure in guide field magnetic reconnection

Science.gov (United States)

Fu, Song; Huang, Shiyong; Zhou, Meng; Ni, Binbin; Deng, Xiaohua

2018-03-01

It has been shown that the guide field substantially modifies the structure of the reconnection layer. For instance, the Hall magnetic and electric fields are distorted in guide field reconnection compared to reconnection without guide fields (i.e., anti-parallel reconnection). In this paper, we performed 2.5-D electromagnetic full particle simulation to study the electric field structures in magnetic reconnection under different initial guide fields (Bg). Once the amplitude of a guide field exceeds 0.3 times the asymptotic magnetic field B0, the traditional bipolar Hall electric field is clearly replaced by a tripolar electric field, which consists of a newly emerged electric field and the bipolar Hall electric field. The newly emerged electric field is a convective electric field about one ion inertial length away from the neutral sheet. It arises from the disappearance of the Hall electric field due to the substantial modification of the magnetic field and electric current by the imposed guide field. The peak magnitude of this new electric field increases linearly with the increment of guide field strength. Possible applications of these results to space observations are also discussed.

Tripolar electric field Structure in guide field magnetic reconnection

Directory of Open Access Journals (Sweden)

S. Fu

2018-03-01

Full Text Available It has been shown that the guide field substantially modifies the structure of the reconnection layer. For instance, the Hall magnetic and electric fields are distorted in guide field reconnection compared to reconnection without guide fields (i.e., anti-parallel reconnection. In this paper, we performed 2.5-D electromagnetic full particle simulation to study the electric field structures in magnetic reconnection under different initial guide fields (Bg. Once the amplitude of a guide field exceeds 0.3 times the asymptotic magnetic field B0, the traditional bipolar Hall electric field is clearly replaced by a tripolar electric field, which consists of a newly emerged electric field and the bipolar Hall electric field. The newly emerged electric field is a convective electric field about one ion inertial length away from the neutral sheet. It arises from the disappearance of the Hall electric field due to the substantial modification of the magnetic field and electric current by the imposed guide field. The peak magnitude of this new electric field increases linearly with the increment of guide field strength. Possible applications of these results to space observations are also discussed.

Studies of national research performance: A case of ‘methodological nationalism’ and ‘zombie science’?

DEFF Research Database (Denmark)

Sørensen, Mads P.; Schneider, Jesper Wiborg

2017-01-01

The analytical point of departure in this paper is the ongoing debate, initiated by Ulrich Beck, on methodological nationalism within the social sciences. Based on a comprehensive study of research collaboration and mobility of researchers this paper discusses possible traces of methodological...... with researchers in other countries. The national research institutions are increasingly transnationalised due to the growing mobility of researchers. Based on an examination of all the papers registered in the Thompson Reuter’s Web of Science database we follow the development in research collaboration...

Individualization of poverty?

DEFF Research Database (Denmark)

Bak, Carsten Kronborg

2015-01-01

The German Sociologist Ulrich Beck is best known for his book “Risk Society” which has been discussed extensively; however Beck’s claims about modern poverty have not received the same attention among poverty researchers. The individualization perspective views poverty as a relatively transient...... phenomenon and the democratization perspective views the risk of poverty as spread equally in the population. Both perspectives challenge the mainstream tradition of class analysis, and therefore both view poverty as largely independent of traditional stratification factors. In this article, I argue...

An initial model of the computation viewpoint for a spatial data infrastructure

CSIR Research Space (South Africa)

Cooper, Antony K

2007-08-01

Full Text Available of the 21st International Cartographic Conference, Durban S. Africa, CD-ROM. Delgado T (2005), "Infraestructuras de Datos Espaciales en países de bajo desarrollo económico. Implementación en Cuba", Tesis de doctorado, ITM "José Martí", 143 pp. Groot R..., Landesvermessungsamt Nordrhein-Westfalen, ulrich.dueren@lverma.nrw.de, Jan Hjelmager, Kort & Matrikelstyrelsen, jnh@kms.dk, Michel Huet, International Hydrographic Bureau, pac@ihb.mc, Petr Rapant, VSB-Technical University of Ostrava, petr.rapant@vsb.cz, Abbas...

Footwear and locomotor skill performance in preschoolers.

Science.gov (United States)

Robinson, Leah E; Rudisill, Mary E; Weimar, Wendi H; Breslin, Casey M; Shroyer, Justin F; Morera, Maria

2011-10-01

The effect of footwear on locomotor skill performance was examined. 12 children (4 boys, 8 girls; M age = 56.3 mo., SD = 3.3) served as participants. Participants were randomly assigned to perform the locomotor subscale of Ulrich's Test of Gross Motor Development in two shoe conditions (Condition 1: Stride Rite athletic shoes, and Condition 2: flip flop sandals). Children scored significantly higher when wearing athletic shoes than flip-flop sandals. This finding is relevant for motor performance and safety in physical education and movement programs.

Gauge fields in a torsion field

International Nuclear Information System (INIS)

Rosu, Ion

2004-01-01

In this paper we analyse the motion and the field equations in a non-null curvature and torsion space. In this 4-n dimensional space, the connection coefficients are γ bc a = 1/2S bc a + 1/2T bc a, where S bc a is the symmetrical part and T bc a are the components of the torsion tensor. We will consider that all the fields depend on x = x α , α = 1,2,3,4 and do not depend on y = y k , k=1,2,...,n. The factor S bc a depends on the components of the metric tensor g αβ (x) and on the gauge fields A ν s 0 (x) and the components of the torsion depend only on the gauge fields A ν s 0 (x). We take into consideration the particular case for which the geodesic equations coincide with the motion equations in the presence of the gravitational and the gauge fields. In this case the field equations are Einstein equations in a 4-n dimensional space. We show that both the geodesic equations and the field equations can be obtained from a variational principle. (author)

Application of Surface Geophysical Methods, With Emphasis on Magnetic Resonance Soundings, to Characterize the Hydrostratigraphy of the Brazos River Alluvium Aquifer, College Station, Texas, July 2006 - A Pilot Study

Science.gov (United States)

Shah, Sachin D.; Kress, Wade H.; Legchenko, Anatoly

2007-01-01

The U.S. Geological Survey, in cooperation with the Texas Water Development Board, used surface geophysical methods at the Texas A&M University Brazos River Hydrologic Field Research Site near College Station, Texas, in a pilot study, to characterize the hydrostratigraphic properties of the Brazos River alluvium aquifer and determine the effectiveness of the methods to aid in generating an improved ground-water availability model. Three non-invasive surface geophysical methods were used to characterize the electrical stratigraphy and hydraulic properties and to interpret the hydrostratigraphy of the Brazos River alluvium aquifer. Two methods, time-domain electromagnetic (TDEM) soundings and two-dimensional direct-current (2D-DC) resistivity imaging, were used to define the lateral and vertical extent of the Ships clay, the alluvium of the Brazos River alluvium aquifer, and the underlying Yegua Formation. Magnetic resonance sounding (MRS), a recently developed geophysical method, was used to derive estimates of the hydrologic properties including percentage water content and hydraulic conductivity. Results from the geophysics study demonstrated the usefulness of combined TDEM, 2D-DC resistivity, and MRS methods to reduce the need for additional boreholes in areas with data gaps and to provide more accurate information for ground-water availability models. Stratigraphically, the principal finding of this study is the relation between electrical resistivity and the depth and thickness of the subsurface hydrostratigraphic units at the site. TDEM data defined a three-layer electrical stratigraphy corresponding to a conductor-resistor-conductor that represents the hydrostratigraphic units - the Ships clay, the alluvium of the Brazos River alluvium aquifer, and the Yegua Formation. Sharp electrical boundaries occur at about 4 to 6 and 20 to 22 meters below land surface based on the TDEM data and define the geometry of the more resistive Brazos River alluvium aquifer

Quantized fields in external field. Pt. 2

International Nuclear Information System (INIS)

Bellissard, J.

1976-01-01

The case of a charged scalar field is considered first. The existence of the corresponding Green's functions is proved. For weak fields, as well as pure electric or scalar external fields, the Bogoliubov S-operator is shown to be unitary, covariant, causal up-to-a-phase. These results are generalised to a class of higher spin quantized fields, 'nicely' coupled to external fields, which includes the Dirac theory, and in the case of minimal and magnetic dipole coupling, the spin one Petiau-Duffin-Kemmer theory. (orig.) [de

Wake fields and wake field acceleration

International Nuclear Information System (INIS)

Bane, K.L.F.; Wilson, P.B.; Weiland, T.

1984-12-01

In this lecture we introduce the concepts of wake fields and wake potentials, examine some basic properties of these functions, show how they can be calculated, and look briefly at a few important applications. One such application is wake field acceleration. The wake field accelerator is capable of producing the high gradients required for future very high energy e + e - linear colliders. The principles of wake field acceleration, and a brief description of experiments in progress in this area, are presented in the concluding section. 40 references, 27 figures

User requirements for information systems in nuclear medicine

Energy Technology Data Exchange (ETDEWEB)

Todd-Pokropek, A. (University Coll., London (United Kingdom)); Vauramo, E.; Sippo-Tujunen, I. (Helsinki City Health Dept. (Finland)); Cosgriff, P. (Pilgrim Hospital, Boston (UK)); Britton, K. (Saint Bartholomew' s Hospital, London (United Kingdom))

1992-05-01

In the field of COST cooperation (COST = European Cooperation in the Field of Scientific and Technical Research) a project B2 for Quality Assurance in Nuclear Medicine Software has been established. In a memorandum of understanding setting up this project, user requirements were to be defined for the hardware and software used for data acquisition, processing and presentation. A subgroup of the management committee of COST B2 were interested in the Advanced Informatics in Medicine, AIM, task T-734 'Quality Assurance of Medical Software', and the AIM Project 'A 1034', coordinated by Dr. K. Britton, was initiated. The initial drafts of this document were written in Helsinki during 1988-1990, and submitted for comment by the members of the management committee of COST B2. These comments were integrated in the text and this document was finalized by the UK group so as to make it available for international discussion. It is anticipated that, after appropriate international discussion, these User Requirements for Information Systems in Nuclear Medicine will be adopted by the management committee of COST B2 as a COST document. Towards these ends, a working group chaired by Dr Britton, including the British and Finnish teams and Ulrich Noelpp from Switzerland, was appointed by the management committee of COST B2 in April 1990. (Author).

User requirements for information systems in nuclear medicine

International Nuclear Information System (INIS)

Todd-Pokropek, A.; Vauramo, E.; Sippo-Tujunen, I.; Cosgriff, P.; Britton, K.

1992-01-01

In the field of COST cooperation (COST = European Cooperation in the Field of Scientific and Technical Research) a project B2 for Quality Assurance in Nuclear Medicine Software has been established. In a memorandum of understanding setting up this project, user requirements were to be defined for the hardware and software used for data acquisition, processing and presentation. A subgroup of the management committee of COST B2 were interested in the Advanced Informatics in Medicine, AIM, task T-734 'Quality Assurance of Medical Software', and the AIM Project 'A 1034', coordinated by Dr. K. Britton, was initiated. The initial drafts of this document were written in Helsinki during 1988-1990, and submitted for comment by the members of the management committee of COST B2. These comments were integrated in the text and this document was finalized by the UK group so as to make it available for international discussion. It is anticipated that, after appropriate international discussion, these User Requirements for Information Systems in Nuclear Medicine will be adopted by the management committee of COST B2 as a COST document. Towards these ends, a working group chaired by Dr Britton, including the British and Finnish teams and Ulrich Noelpp from Switzerland, was appointed by the management committee of COST B2 in April 1990. (Author)

Qualities of Inpatient Hospital Rooms: Patients' Perspectives.

Science.gov (United States)

Devlin, Ann Sloan; Andrade, Cláudia Campos; Carvalho, Diana

2016-04-01

The aim of this qualitative study was to investigate what design features of hospital rooms are valued by inpatients. Little research has explored how patients evaluate the physical environment of their hospital rooms. Most responses are captured by the Hospital Consumer Assessment of Healthcare Providers and Systems survey, which includes only two questions about the physical environment. Two hundred thirty-six orthopedic patients (78 in the United States and 158 in Portugal) listed three features of their hospital room that influenced their level of satisfaction with their hospital stay, indicating whether the feature was positive or negative. The comments were more positive (71.4%) than negative (28.6%). Using the framework of supportive design from Ulrich, over half the comments (64.31%) could be categorized in one of the three dimensions: 33.2% (positive distraction), 22.4% (perceived control), and 6.0% (social support). This total includes Internet (2.7%), which could be categorized as either social support or positive distraction. Comments called "other aspects" focused on overall environmental appraisals, cleanliness, and functionality and maintenance. The majority of comments could be accommodated by Ulrich's theory, but it is noteworthy that other aspects emerge from patients' comments and affect their experience. Cross-cultural differences pointed to the greater role of light and sun for Portuguese patients and health status whiteboard for U.S. Qualitative research can add significantly to our understanding of the healthcare experience and may inform design decisions. © The Author(s) 2015.

Nuclear waste - where to go?; Atommuell - wohin?

Energy Technology Data Exchange (ETDEWEB)

Dornsiepen, Ulrich

2015-07-01

The question of the final di9sposal of nuclear waste is a problem of international importance. The solution of the problem is of increasing urgency; the discussion is controversial and implies a lot of emotions. In Germany there is consensus that the nuclear wastes have to be disposed within the country in deep geological formations. This kind of final disposal is predominantly a geological problem and has to be solved from the geological point of view. The geologist Ulrich Dornsiepen presents the problems of the final disposal in an objective way without ideology and generally understandable. Such a presentation is necessary since the public information and participation is demanded but the open geological questions and their scientific solutions are never explained for the public. [German] Die Frage der endgueltigen Lagerung von Atommuell ist ein Problem von nationaler Tragweite, dessen Loesung immer dringender wird, bisher aber sehr kontrovers diskutiert wird und mit vielen Emotionen verknuepft ist. Es besteht in Deutschland ein Konsens, diese Abfaelle innerhalb der Landesgrenzen dauerhaft in tief liegenden Gesteinsschichten abzulagern. Diese Art der Endlagerung ist aber in erster Linie ein geologisches Problem und so auch nur von geologischer Seite her zu loesen. Daher stellt der Geologe Ulrich Dornsiepen die Problematik der Endlagerung objektiv, ideologiefrei und allgemein verstaendlich dar. Ein solches Hoerbuch ist dringend noetig, da zwar die Information und Beteiligung breiter, betroffener Bevoelkerungsteile eingefordert, aber niemals versucht wird, die offenen geologischen Fragen und ihre wissenschaftliche Loesung verstaendlich zu machen.

A field-sweep/field-lock system for superconducting magnets--Application to high-field EPR.

Science.gov (United States)

Maly, Thorsten; Bryant, Jeff; Ruben, David; Griffin, Robert G

2006-12-01

We describe a field-lock/field-sweep system for the use in superconducting magnets. The system is based on a commercially available field mapping unit and a custom designed broad-band 1H NMR probe. The NMR signal of a small water sample is used in a feedback loop to set and control the magnetic field to high accuracy. The current instrumental configuration allows field sweeps of +/-0.4 T and a resolution of up to 10(-5) T (0.1 G) and the performance of the system is demonstrated in a high-field electron paramagnetic resonance (EPR) application. The system should also be of utility in other experiments requiring precise and reproducible sweeps of the magnetic field such as DNP, ENDOR or PELDOR.

A Field-Sweep/Field-Lock System for Superconducting Magnets-Application to High-Field EPR

Science.gov (United States)

Maly, Thorsten; Bryant, Jeff; Ruben, David; Griffin, Robert G.

2007-01-01

We describe a field-lock/field-sweep system for the use in superconducting magnets. The system is based on a commercially available field mapping unit and a custom designed broad-band 1H-NMR probe. The NMR signal of a small water sample is used in a feedback loop to set and control the magnetic field to high accuracy. The current instrumental configuration allows field sweeps of ± 0.4 T and a resolution of up to 10-5 T (0.1 G) and the performance of the system is demonstrated in a high-field electron paramagnetic resonance (EPR) application. The system should also be of utility in other experiments requiring precise and reproducible sweeps of the magnetic field such as DNP, ENDOR or PELDOR. PMID:17027306

Matching tomographic IMRT fields with static photon fields

International Nuclear Information System (INIS)

Sethi, A.; Leybovich, L.; Dogan, N.; Emami, B.

2001-01-01

The matching of abutting radiation fields presents a challenging problem in radiation therapy. Due to sharp penumbra of linear accelerator beams, small (1-2 mm) errors in field positioning can lead to large (>30%) hot or cold spots in the abutment region. With head and neck immobilization devices (thermoplastic mask/aquaplast) an average setup error of 3 mm has been reported. Therefore hot or cold spots approaching 50% of the prescription dose may occur along the matchline. Although abutting radiation fields have been investigated for static fields, there is no reported study regarding matching of tomographic IMRT and static fields. Compared to static fields, the matching of tomographic IMRT fields with static fields is more complicated. Since IMRT and static fields are planned on separate treatment planning computers, the dose in the abutment region is not specified. In addition, commonly used techniques for matching fields, such as feathering of junctions, are not practical. We have developed a method that substantially reduces dose inhomogeneity in the abutment region. In this method, a 'buffer zone' around the matchline was created and was included as part of the target for both IMRT and static field plans. In both fields, a small dose gradient (≤3%/mm) in the buffer zone was created. In the IMRT plan, the buffer zone was divided into three sections with dose varying from 83% to 25% of prescription dose. The static field dose profile was modified using either a specially designed physical (hard) or a dynamic (soft) wedge. When these modified fields were matched, the combined dose in the abutment region varied by ≤10% in the presence of setup errors spanning 4 mm (±2 mm) when the hard wedge was used and 10 mm (±5 mm) with the soft wedge

InfiniBand-Experiences at the Forschungszentrum Karlsruhe

International Nuclear Information System (INIS)

Schwickerath, Ulrich; Heiss, Andreas

2006-01-01

The Institute for Scientific Computing (IWR) at the Forschungszentrum Karlsruhe has been evaluating the InfiniBand [InfiniBand Trade Association, InfiniBand Architecture Specification, Release 1.0, October 24, 2000] technology since end of the year 2002. The performance of the interconnect has been tested on different platforms and architectures using MPI. Sequential file transfer performance was measured with the RFIO protocol running on native InfiniBand [Ulrich Schwickerath, Andreas Heiss, Nucl. Instr. and Meth. A 534 (2004) 130, http://www.fzk.de/infiniband], and a newly developed InfiniBand-enabled version of the XROOTD

La gestión del talento humano y su aporte estratégico en los objetivos organizacionales del Servicio de Rentas Internas, con sustento en el Cuadro de Mando del Talento Humano

OpenAIRE

Toapanta Guambi, Álvaro Hernán

2013-01-01

147 hojas : ilustraciones, 29 x 21 cm + CD-ROM 5055 La presente tesis tiene el propósito de evidenciar el aporte estratégico de la gestión del Talento Humano en la consecución de los objetivos organizacionales sustentado en el cuadro de mando de talento humano para una institución pública, basado en el conocimiento de los 7 pasos para medir la influencia del talento humano de (Becker, Huselid, and Ulrich, 2001) y cuadro de mando para instituciones públicas. El esquema desarrollado en es...

Inspiration in the Act of Reading

DEFF Research Database (Denmark)

Zeller, Kinga

2016-01-01

In German-language theology, Professor Ulrich H. J. Körtner’s theory of inspiration, as it relates to the Bible reader’s perspective, is well known. His attempt to gain fruitful insights from contemporary literary hermeneutics while linking them to theological concerns makes his approach a valued...... yet not uncontroversial example of a reception-aesthetics twist on the Lutheran sola Scriptura. This article presents Körtner’s hermeneutical considerations with special regard to inspiration related to the Bible reader’s perspective and shows how this approach may be related to some aspects...

Field theories with subcanonical fields

International Nuclear Information System (INIS)

Bigi, I.I.Y.

1976-01-01

The properties of quantum field theories with spinor fields of dimension less than the canonical value of 3/2 are studied. As a starting point for the application of common perturbation theory we look for the linear version of these theories. A gange-interaction is introduced and with the aid of power counting the renormalizability of the theory is shown. It follows that in the case of a spinor-field with negative dimension renormalization can only be attained if the interaction has a further symmetry. By this symmetry the theory is determined in an unequivocal way. The gange-interaction introduced in the theory leads to a spontaneous breakdown of scale invariance whereby masses are produced. At the same time the spinor-field operators can now be separated in two orthogonal sections with opposite norm. It is proposed to use the section with negative (positive) norm to describe hadrons (leptons) respectively. (orig./WL) [de

Tripolar electric field Structure in guide field magnetic reconnection

OpenAIRE

S. Fu; S. Huang; M. Zhou; B. Ni; X. Deng

2018-01-01

It has been shown that the guide field substantially modifies the structure of the reconnection layer. For instance, the Hall magnetic and electric fields are distorted in guide field reconnection compared to reconnection without guide fields (i.e., anti-parallel reconnection). In this paper, we performed 2.5-D electromagnetic full particle simulation to study the electric field structures in magnetic reconnection under different initial guide fields (Bg). Once the amplit...

Gravitational Field Shielding by Scalar Field and Type II Superconductors

Directory of Open Access Journals (Sweden)

Zhang B. J.

2013-01-01

Full Text Available The gravitational field shielding by scalar field and type II superconductors are theoret- ically investigated. In accord with the well-developed five-dimensional fully covariant Kaluza-Klein theory with a scalar field, which unifies the Einsteinian general relativity and Maxwellian electromagnetic theory, the scalar field cannot only polarize the space as shown previously, but also flatten the space as indicated recently. The polariza- tion of space decreases the electromagnetic field by increasing the equivalent vacuum permittivity constant, while the flattening of space decreases the gravitational field by decreasing the equivalent gravitational constant. In other words, the scalar field can be also employed to shield the gravitational field. A strong scalar field significantly shield the gravitational field by largely decreasing the equivalent gravitational constant. According to the theory of gravitational field shielding by scalar field, the weight loss experimentally detected for a sample near a rotating ceramic disk at very low tempera- ture can be explained as the shielding of the Earth gravitational field by the Ginzburg- Landau scalar field, which is produced by the type II superconductors. The significant shielding of gravitational field by scalar field produced by superconductors may lead to a new spaceflight technology in future.

Heliophysics: Evolving Solar Activity and the Climates of Space and Earth

Science.gov (United States)

Schrijver, Carolus J.; Siscoe, George L.

2012-01-01

Preface; 1. Interconnectedness in heliophysics Carolus J. Schrijver and George L. Siscoe; 2. Long-term evolution of magnetic activity of Sun-like stars Carolus J. Schrijver; 3. Formation and early evolution of stars and proto-planetary disks Lee W. Hartmann; 4. Planetary habitability on astronomical time scales Donald E. Brownlee; 5. Solar internal flows and dynamo action Mark S. Miesch; 6. Modeling solar and stellar dynamos Paul Charbonneau; 7. Planetary fields and dynamos Ulrich R. Christensen; 8. The structure and evolution of the 3D solar wind John T. Gosling; 9. The heliosphere and cosmic rays J. Randy Jokipii; 10. Solar spectral irradiance: measurements and models Judith L. Lean and Thomas N. Woods; 11. Astrophysical influences on planetary climate systems Juerg Beer; 12. Evaluating the drivers of Earth's climate system Thomas J. Crowley; 13. Ionospheres of the terrestrial planets Stanley C. Solomon; 14. Long-term evolution of the geospace climate Jan J. Sojka; 15. Waves and transport processes in atmospheres and oceans Richard L. Walterscheid; 16. Solar variability, climate, and atmospheric photochemistry Guy P. Brasseur, Daniel Marsch and Hauke Schmidt; Appendix I. Authors and editors; List of illustrations; List of tables; Bibliography; Index.

On vector fields having properties of Reeb fields

OpenAIRE

Hajduk, Boguslaw; Walczak, Rafal

2011-01-01

We study constructions of vector fields with properties which are characteristic to Reeb vector fields of contact forms. In particular, we prove that all closed oriented odd-dimensional manifold have geodesible vector fields.

On Jacobi-fields

International Nuclear Information System (INIS)

Bruening, E.

1981-01-01

The concept of a Jacobi-field is introduced as such a field for which the field-operators have the form of a generalized Jacobi-matrix with respect to the n-field-sector decomposition of the state-space. It is argued that the class of Jacobi-fields is of interest for relativistic quantum field theory for two reasons: (a) Jacobi-fields allow a direct association of particles (charges etc.) with fields. The concept of (generalized) creation- and annihilation-operators is thus available. (b) Jacobi-fields belong to that class of fields which can be characterized in terms of finitely many vacuum expectation values. A characterization of Jacobi-fields in terms of continuity and hermiticity properties of their system of vacuum expectation values is derived. Furthermore it is argued that all examples of relativistic quantum fields in a four-dimensional space-time are Jacobi-fields. This is evident for generalized free fields and Wick-powers of free fields, but is also true for a class of generalized Wick-powers of generalized free fields. (Auth.)

Mees, kes mängis head natsi / Ulrich Tukur ; intervjueerinud Maria Ulfsak-Šeripova

Index Scriptorium Estoniae

Tukur, Ulrich, 1957-

2010-01-01

Festivali "Uus saksa kino" raames on oodata Eestisse saksa kino elavat klassikut, kel kandev roll Michael Haneke auhinnatud filmis "Valge pael" ja nimosa filmis "John Rabe" (Saksamaa-Hiina-Prantsusmaa 2009)

Negative Feelings as Emotional Enhancement in Cinema: The Case of Ulrich Seidl's Paradise Trilogy

NARCIS (Netherlands)

Laine, T.; Hauskeller, M.; Philbeck, T.D.; Carbonell, C.D.; Carbonell, CD

2015-01-01

In everyday life, negative feelings such as shame, horror and disgust, are emotions one rather wants to discard than to cherish. Just think of the way in which people aspire at ‘improving’ their emotional makeup by means of Prozac and other mood enhancers in order to get rid of their undesirable

Field Science--the Nature and Utility of Scientific Fields.

Science.gov (United States)

Casadevall, Arturo; Fang, Ferric C

2015-09-08

Fields are the fundamental sociological units of science. Despite their importance, relatively little has been written about their emergence, composition, structure, and function in the scientific enterprise. This essay considers the nature of fields and their important role in maintaining information and providing normative standards for scientific work. We suggest that fields arise naturally as a consequence of increasing information and scientific specialization. New fields tend to emerge as research communities grow, which may reflect biologically determined optima for the size of human groups. The benefits of fields include the organization of scientists with similar interests into communities that collectively define the next important problems to pursue. In the discipline of microbiology, fields are often organized on the basis of phylogenetic differences between microorganisms being studied. Although fields are essential to the proper functioning of science, their emergence can restrict access by outsiders and sustain dogmas that hinder progress. We suggest mechanisms to improve the functioning of scientific fields and to promote interdisciplinary interaction between fields. Copyright © 2015 Casadevall and Fang.

Optimal field splitting for large intensity-modulated fields

International Nuclear Information System (INIS)

Kamath, Srijit; Sahni, Sartaj; Ranka, Sanjay; Li, Jonathan; Palta, Jatinder

2004-01-01

The multileaf travel range limitations on some linear accelerators require the splitting of a large intensity-modulated field into two or more adjacent abutting intensity-modulated subfields. The abutting subfields are then delivered as separate treatment fields. This workaround not only increases the treatment delivery time but it also increases the total monitor units (MU) delivered to the patient for a given prescribed dose. It is imperative that the cumulative intensity map of the subfields is exactly the same as the intensity map of the large field generated by the dose optimization algorithm, while satisfying hardware constraints of the delivery system. In this work, we describe field splitting algorithms that split a large intensity-modulated field into two or more intensity-modulated subfields with and without feathering, with optimal MU efficiency while satisfying the hardware constraints. Compared to a field splitting technique (without feathering) used in a commercial planning system, our field splitting algorithm (without feathering) shows a decrease in total MU of up to 26% on clinical cases and up to 63% on synthetic cases

A general field-covariant formulation of quantum field theory

International Nuclear Information System (INIS)

Anselmi, Damiano

2013-01-01

In all nontrivial cases renormalization, as it is usually formulated, is not a change of integration variables in the functional integral, plus parameter redefinitions, but a set of replacements, of actions and/or field variables and parameters. Because of this, we cannot write simple identities relating bare and renormalized generating functionals, or generating functionals before and after nonlinear changes of field variables. In this paper we investigate this issue and work out a general field-covariant approach to quantum field theory, which allows us to treat all perturbative changes of field variables, including the relation between bare and renormalized fields, as true changes of variables in the functional integral, under which the functionals Z and W=lnZ behave as scalars. We investigate the relation between composite fields and changes of field variables, and we show that, if J are the sources coupled to the elementary fields, all changes of field variables can be expressed as J-dependent redefinitions of the sources L coupled to the composite fields. We also work out the relation between the renormalization of variable-changes and the renormalization of composite fields. Using our transformation rules it is possible to derive the renormalization of a theory in a new variable frame from the renormalization in the old variable frame, without having to calculate it anew. We define several approaches, useful for different purposes, in particular a linear approach where all variable changes are described as linear source redefinitions. We include a number of explicit examples. (orig.)

Two field formulation of closed string field theory

International Nuclear Information System (INIS)

Bogojevic, A.R.

1990-09-01

A formulation of closed string field theory is presented that is based on a two field action. It represents a generalization of Witten's Chern-Simons formulation of 3d gravity. The action contains only 3 string interactions and no string field truncations, unlike the previous non-polynomial action of Zwiebach. The two field action is found to follow from a purely cubic, background independent action similar to the one for open strings. (orig.)

Field Model: An Object-Oriented Data Model for Fields

Science.gov (United States)

Moran, Patrick J.

2001-01-01

We present an extensible, object-oriented data model designed for field data entitled Field Model (FM). FM objects can represent a wide variety of fields, including fields of arbitrary dimension and node type. FM can also handle time-series data. FM achieves generality through carefully selected topological primitives and through an implementation that leverages the potential of templated C++. FM supports fields where the nodes values are paired with any cell type. Thus FM can represent data where the field nodes are paired with the vertices ("vertex-centered" data), fields where the nodes are paired with the D-dimensional cells in R(sup D) (often called "cell-centered" data), as well as fields where nodes are paired with edges or other cell types. FM is designed to effectively handle very large data sets; in particular FM employs a demand-driven evaluation strategy that works especially well with large field data. Finally, the interfaces developed for FM have the potential to effectively abstract field data based on adaptive meshes. We present initial results with a triangular adaptive grid in R(sup 2) and discuss how the same design abstractions would work equally well with other adaptive-grid variations, including meshes in R(sup 3).

Trapped field recovery of bulk superconductor magnets by static field magnetization

Energy Technology Data Exchange (ETDEWEB)

Deng, Z., E-mail: zigang@kaiyodai.ac.jp [Laboratory of Applied Physics, Department of Marine Electronics and Mechanical Engineering, Tokyo University of Marine Science and Technology, Tokyo 135-8533 (Japan); Tsuzuki, K.; Miki, M.; Felder, B.; Hara, S.; Izumi, M. [Laboratory of Applied Physics, Department of Marine Electronics and Mechanical Engineering, Tokyo University of Marine Science and Technology, Tokyo 135-8533 (Japan)

2011-11-15

A series of initial trapped fields after ZFC or FC magnetization are used to simulate the attenuated trapped field. It is possible and easy to recover the lost trapped field and regain the best trapped field performance as before. In the re-magnetization process, the initial magnetic flux inside the bulk magnets will help to recover the trapped field. The optimum recovery field is recommended to be 2.5 times the saturation field of the bulk at LN2 temperature. Thanks to the trapped field of bulk high-temperature superconductors, they can be used as field-pole magnets in the high temperature superconducting (HTS) rotating machines. For example, an output power of 10 kW at 720 rpm was realized by an average trapped field of 0.56 T of eight melt-textured GdBa{sub 2}Cu{sub 3}O{sub y} (Gd-123) bulks at liquid nitrogen temperature in TUMSAT in 2004. Similarly to the HTS machines involving 1G or 2G wires, the trapped field of the bulk is possibly sensitive and even can be attenuated by the AC component field during the operation. Hence, it is necessary to recover the trapped field once being decreased to some extent in the practical application. From this point, we have investigated the trapped field recovery of HTS bulk magnets by static field magnetization in the paper. A series of different initial trapped fields after zero-field-cooling or field-cooling magnetization are used to simulate the attenuated trapped field. By comparing the trapped field peak and its distribution, the trapped field was found to be able to recover by the static field magnetization method with a stronger excitation field and the initial trapped flux inside the bulk also has an influence on the recovery process. The optimum recovery field was found to be about 2.5 times the saturated trapped field of the bulk at liquid nitrogen temperature, by which the bulk can regain the former best trapped field performance.

How fields vary.

Science.gov (United States)

Krause, Monika

2018-03-01

Field theorists have long insisted that research needs to pay attention to the particular properties of each field studied. But while much field-theoretical research is comparative, either explicitly or implicitly, scholars have only begun to develop the language for describing the dimensions along which fields can be similar to and different from each other. In this context, this paper articulates an agenda for the analysis of variable properties of fields. It discusses variation in the degree but also in the kind of field autonomy. It discusses different dimensions of variation in field structure: fields can be more or less contested, and more or less hierarchical. The structure of symbolic oppositions in a field may take different forms. Lastly, it analyses the dimensions of variation highlighted by research on fields on the sub- and transnational scale. Post-national analysis allows us to ask how fields relate to fields of the same kind on different scales, and how fields relate to fields on the same scale in other national contexts. It allows us to ask about the role resources from other scales play in structuring symbolic oppositions within fields. A more fine-tuned vocabulary for field variation can help us better describe particular fields and it is a precondition for generating hypotheses about the conditions under which we can expect to observe fields with specified characteristics. © London School of Economics and Political Science 2017.

fields

Directory of Open Access Journals (Sweden)

Brad J. Arnold

2014-07-01

Full Text Available Surface irrigation, such as flood or furrow, is the predominant form of irrigation in California for agronomic crops. Compared to other irrigation methods, however, it is inefficient in terms of water use; large quantities of water, instead of being used for crop production, are lost to excess deep percolation and tail runoff. In surface-irrigated fields, irrigators commonly cut off the inflow of water when the water advance reaches a familiar or convenient location downfield, but this experience-based strategy has not been very successful in reducing the tail runoff water. Our study compared conventional cutoff practices to a retroactively applied model-based cutoff method in four commercially producing alfalfa fields in Northern California, and evaluated the model using a simple sensor system for practical application in typical alfalfa fields. These field tests illustrated that the model can be used to reduce tail runoff in typical surface-irrigated fields, and using it with a wireless sensor system saves time and labor as well as water.

MAGNETIC FIELD MEASUREMENTS FOR FAST-CHANGING MAGNETIC FIELDS

International Nuclear Information System (INIS)

2004-01-01

Several recent applications for fast ramped magnets have been found that require rapid measurement of the field quality during the ramp. (In one instance, accelerator dipoles will be ramped at 1 T/sec, with measurements needed to the accuracy typically required for accelerators.) We have built and tested a new type of magnetic field measuring system to meet this need. The system consists of 16 stationary pickup windings mounted on a cylinder. The signals induced in the windings in a changing magnetic field are sampled and analyzed to obtain the field harmonics. To minimize costs, printed circuit boards were used for the pickup windings and a combination of amplifiers and ADPs used for the voltage readout system. New software was developed for the analysis. Magnetic field measurements of a model dipole developed for the SIS200 accelerator at GSI are presented. The measurements are needed to insure that eddy currents induced by the fast ramps do not impact the field quality needed for successful accelerator operation

Magnetic field reconnexion in a sheared field

International Nuclear Information System (INIS)

Ugai, M.

1981-01-01

A nonlinear development of the Petschek mode in a sheared magnetic field where there is a field component Bsub(z) along an X line is numerically studied. It is found that finite-amplitude intermediate waves, adjacent to the slow shock, may eventually stand in the quasi-steady configuration; on the other hand, the fundamental characteristics of the Petschek-mode development are scarcely influenced, either qualitatively or quantitatively, by the Bsub(z) field. (author)

Nothing Risked, Nothing Gained: Richard Powers' Gain and the Horizon of Risk

Directory of Open Access Journals (Sweden)

Aaron Jaffe

2010-02-01

Full Text Available Cet article interprète Gain, sixième roman de Richard Powers, à la lumière du concept de « seconde modernité » proposé par le sociologue allemand Ulrich Beck. Ce concept souligne la dissémination du risque et la manière dont celle-ci invalide les marchés conclus par la « première modernité » entre l’avenir et le présent, entre l’intérieur du corps et l’extérieur. Cet article entend montrer que Beck fournit un cadre interprétatif utile à la compréhension de ces rapports, hors des impasses catégorielles que suscite l’opposition entre les deux régimes narratifs à l’œuvre dans le texte : le récit biographique, local et individuel, de la maladie de Laura Rowen Bodey, et l’histoire collective de l’entreprise Clare devenue conglomérat.This essay interprets Richard Powers' sixth novel Gain with reference to the German sociologist Ulrich Beck's concept of “second modernity.” The concept underscores the dispersal of risk and how it shreds promissory notes understood in “first modernity” between the future and present and the insides and outsides of the body. It argues that Beck supplies an apt interpretive framework for understanding these relationships and overcoming the categorical impasses between the two narrative words at work in Power's novel, the biographical situatedness of Laura Rowen Bodey's illness and the corporate history of the Clare conglomerate.

Comparison between 3D conventional techniques, field-in-field and electronic tissue compensation for mantle fields planning

International Nuclear Information System (INIS)

Martins, Lais P.; Silva, Leonardo P.; Trindade, Cassia; Garcia, Paulo L.; Santos, Maira R.; Batista, Delano V.S.

2012-01-01

External radiotherapy treatment for Hodgkin's lymphoma over diaphragm region requires large radiation fields with protections applied to larynx, humerus head and lungs. The size and shape of the field, which covers different depths, make it difficult to distribute a homogeneous dose. Techniques such as field-in-field and electronic tissue compensation may be used to make dose homogeneous and compensate the obliquity from the tissue. Three types of planning were performed for diagnose of nodular sclerosis Hodgkin's lymphoma: one plan with two fields, AP-PA (AP plan), another with four fields field-in- field (FF plan), and a third one with two fields and electronic tissue compensation (ETC plan). Results showed better gradient, cover of PTV and dose distribution for the ETC plan, besides the advantage from this technique of does not require protection blocks. In the meanwhile, AP and FF plans require simpler dosimetry and fewer MU. Related to the uniformity of dose distribution, AP plan showed hot areas in the neck region, FF plan showed hot areas in the shoulder region and ETC plan showed most uniform distribution without hot areas. The electronic tissue compensation is a useful tool for large and shaped fields as the mantle field, however higher MU and complex dosimetry should be taken in account. (author)

Trapped field recovery of bulk superconductor magnets by static field magnetization

Science.gov (United States)

Deng, Z.; Tsuzuki, K.; Miki, M.; Felder, B.; Hara, S.; Izumi, M.

2011-11-01

Thanks to the trapped field of bulk high-temperature superconductors, they can be used as field-pole magnets in the high temperature superconducting (HTS) rotating machines. For example, an output power of 10 kW at 720 rpm was realized by an average trapped field of 0.56 T of eight melt-textured GdBa2Cu3Oy (Gd-123) bulks at liquid nitrogen temperature in TUMSAT in 2004. Similarly to the HTS machines involving 1G or 2G wires, the trapped field of the bulk is possibly sensitive and even can be attenuated by the AC component field during the operation. Hence, it is necessary to recover the trapped field once being decreased to some extent in the practical application. From this point, we have investigated the trapped field recovery of HTS bulk magnets by static field magnetization in the paper. A series of different initial trapped fields after zero-field-cooling or field-cooling magnetization are used to simulate the attenuated trapped field. By comparing the trapped field peak and its distribution, the trapped field was found to be able to recover by the static field magnetization method with a stronger excitation field and the initial trapped flux inside the bulk also has an influence on the recovery process. The optimum recovery field was found to be about 2.5 times the saturated trapped field of the bulk at liquid nitrogen temperature, by which the bulk can regain the former best trapped field performance.

Field electron emission spectrometer combined with field ion/electron microscope as a field emission laboratory

International Nuclear Information System (INIS)

Shkuratov, S.I.; Ivanov, S.N.; Shilimanov, S.N.

1996-01-01

The facility, combining the field ion microscope, field electron emission microscope and field electron emission spectrometer, is described. Combination of three methodologies makes it possible to carry out the complete cycle of emission studies. Atom-plane and clean surface of the studied samples is prepared by means of field evaporation of the material atom layers without any thermal and radiation impact. This enables the study of atom and electron structure of clean surface of the wide range materials, the study whereof through the field emission methods was previously rather difficult. The temperature of the samples under study changes from 75 up to 2500 K. The energy resolution of the electron analyzer equals 30 MeV. 19 refs., 10 figs

Tracing Utopia in 'Utopia Station'

DEFF Research Database (Denmark)

Schwarzbart, Judith

This paper will discuss how avant-garde rhetoric and working methods are used to rethink exhibition-making in the wake of the ‘relational aesthetics’ and visual art of the 90s. With Utopia Station curated by Molly Nesbit, Hans Ulrich Obrist, and Rirkrit Tiravanija as key example, we will look...... at the many layers of discourse, ‘thinking-in-process’ and collaboration. These processes led to particular presentational formats (display) and architectural frameworks for activities, and gave way to a variety of other material and situated performative modes of audience encounters. Here, we can trace avant...

Globalización y política

Directory of Open Access Journals (Sweden)

Mate, Reyes

2000-09-01

Full Text Available Not Available

Ulrich Beck es un nombre obligado en el tema de la globalización, con títulos tan conocidos como Politik der Globalisierung, aparecido en 1998, ¿Qué es la globalización?, en 1997, Segunda Modernidad, en 1996, La sociedad del riesgo, en 1986. Lo que a continuación pretendo es una exposición de sus reflexiones políticas y morales sobre la globalización económica, seguidas de unas breves consideraciones críticas.

Conflits et conflictualités

Directory of Open Access Journals (Sweden)

2010-12-01

Full Text Available Conflits de proximitéLe premier panel du séminaire s’est articulé autour du conflit de proximité. Ouvert par une introduction consacrée aux liens entre voisinage et violence, il a apporté deux illustrations à travers deux études de cas : à l’échelle d’une institution culturelle franco-allemande d’abord, puis au sein d’une communauté sociale particulière.La communication de Ulrich Bielefeld, intitulée « Proximité et violence », envisage le voisinage comme champ d’émergence du conflit, au sens ...

Introducing Systems Approaches

Science.gov (United States)

Reynolds, Martin; Holwell, Sue

Systems Approaches to Managing Change brings together five systems approaches to managing complex issues, each having a proven track record of over 25 years. The five approaches are: System Dynamics (SD) developed originally in the late 1950s by Jay Forrester Viable Systems Model (VSM) developed originally in the late 1960s by Stafford Beer Strategic Options Development and Analysis (SODA: with cognitive mapping) developed originally in the 1970s by Colin Eden Soft Systems Methodology (SSM) developed originally in the 1970s by Peter Checkland Critical Systems Heuristics (CSH) developed originally in the late 1970s by Werner Ulrich

EFECTOS DE LA GLOBALIZACIÓN EN LAS VIDAS PROFESIONALES DEL PROFESORADO

Directory of Open Access Journals (Sweden)

Antonio Bolivar Botía

2009-11-01

Full Text Available This paper examines some of the problems associated with how globalization is reshaping the teaacher's professional lives, focusing on their effect on the crisis in secondary teachers' professional identity. Globalization, as Ulrich Beck points out, is experienced as a new modernity. School crisis and its professionals is associated with the crisis of modernity. Teaching in the knowledge society involves the following paradox: in loco parentis, restructuring teaching work, individualization and recognition deficits, performativity and professional practice. Finally, it offers some guidelines to reaffirm the role of schools and teachers in the new globalized modernity.

ENTRIA workshop: Emotions in the implementation of a final nuclear disposal site; ENTRIA-Werkstattgespraech: ''Emotionen bei der Realisierung eines Endlagers fuer Atommuell''

Energy Technology Data Exchange (ETDEWEB)

Kattau, Alke [Technische Univ. Braunschweig (Germany). Inst. fuer Rechtswissenschaften

2016-08-15

On 21 June 2016, prior to the publication of the report of the Commission Storage of High Radioactive Waste, ''Emotions in the realisation of a repository for nuclear waste'' were the topic of a workshop. The workshop was organised in the context of the Federal Ministry of Education and Research (BMBF) interdisciplinary research platform ENTRIA. In his opening remarks, Prof.Dr. Ulrich Smeddinck (Institute of Law of the University of Braunschweig) noticed, that emotions have been neglected in the scientific analysis so far, but fears and feelings to be considered with a special view.

ENTRIA workshop: Emotions in the implementation of a final nuclear disposal site

International Nuclear Information System (INIS)

Kattau, Alke

2016-01-01

On 21 June 2016, prior to the publication of the report of the Commission Storage of High Radioactive Waste, ''Emotions in the realisation of a repository for nuclear waste'' were the topic of a workshop. The workshop was organised in the context of the Federal Ministry of Education and Research (BMBF) interdisciplinary research platform ENTRIA. In his opening remarks, Prof.Dr. Ulrich Smeddinck (Institute of Law of the University of Braunschweig) noticed, that emotions have been neglected in the scientific analysis so far, but fears and feelings to be considered with a special view.

Overwhelming Force - A Persistent Concept in US Military Thinking

DEFF Research Database (Denmark)

Ulrich, Philip Christian

In the second brief in the series Overwhelming Force – A Persistent Concept in US Military Thinking, Philip Chr. Ulrich analyzes how the US Army reacted to the defeat in the Vietnam War. The US Army wanted to avoid operations, which might lead to a long term engagement in stability operations......, as engagement in such operations were seen as the reason for the defeat in Vietnam. The US Army also chose to exclude stability operations and counterinsurgency from its doctrines and teachings. Instead, the US Army chose to focus on conventional war, supplemented by an increasing fascination with technology...

Lydon, Ghislaine — On Trans-Saharan Trails: Islamic Law, Trade Networks, and Cross-Cultural Exchange in Nineteenth-Century Western Africa

Directory of Open Access Journals (Sweden)

Judith Scheele

2013-06-01

Full Text Available Le livre de Ghislaine Lydon ouvre un nouveau chapitre dans les recherches historiques sur le Sahara. L’auteure reprend certes un sujet classique : le commerce transsaharien. Mais elle l’étudie à partir de sources locales qui, malgré leur richesse et leur abondance, n’ont jusqu’ici que trop peu attiré l’intérêt des chercheurs des universités occidentales – à l’exception de quelques travaux isolés tels ceux de Paul Pascon au Maroc, d’Ulrich Haarmann en Libye, ou de Rainer Osswald en Mauritanie....

STS-55 MS1/PLC Ross and Payload Specialist Walter work in SL-D2 module

Science.gov (United States)

1993-01-01

STS-55 Mission Specialist 1 (MS1) and Payload Commander (PLC) Jerry L. Ross floats near cycle ergometer and Rack 9 Anthrorack (AR) (Human Physiology Laboratory) as German Payload Specialist 1 Ulrich Walter reviews a checklist in front of Rack 11 Experiment Rack. These experiment stations and the crewmembers are in the shirt-sleeve environment of the Spacelab Deutsche 2 (SL-D2) science module onboard the Earth-orbiting Columbia, Orbiter Vehicle (OV) 102. In the background is the SL-D2 aft end cone. Behind Ross and Walter is Rack 12 Experiment Rack with Baroreflex (BA).

Some notions on urbanity

DEFF Research Database (Denmark)

Grønlund, Bo

According to International Federation of Housing and Planning the majority of the population of the planet will be urban in 2007. That definition of the urban, however, is based on zombie categories, to speak as Ulrich Beck. Urbanization and urban areas as we normally understand them are concepts...... of 'the first modernity'. Nowadays, in 'the second modernity', we have instead to aks: where in the city do you really find urbanity? A large part of what statistically is called urban areas lack urban quality and visible urban life. In the space syntax community urbanity is basically understood...

Sensitivity-based virtual fields for the non-linear virtual fields method

Science.gov (United States)

Marek, Aleksander; Davis, Frances M.; Pierron, Fabrice

2017-09-01

The virtual fields method is an approach to inversely identify material parameters using full-field deformation data. In this manuscript, a new set of automatically-defined virtual fields for non-linear constitutive models has been proposed. These new sensitivity-based virtual fields reduce the influence of noise on the parameter identification. The sensitivity-based virtual fields were applied to a numerical example involving small strain plasticity; however, the general formulation derived for these virtual fields is applicable to any non-linear constitutive model. To quantify the improvement offered by these new virtual fields, they were compared with stiffness-based and manually defined virtual fields. The proposed sensitivity-based virtual fields were consistently able to identify plastic model parameters and outperform the stiffness-based and manually defined virtual fields when the data was corrupted by noise.

Field in field technique in two-dimensional planning for whole brain irradiation; Tecnica field in field em planejamentos bidimensionais para irradiacao de cerebro total

Energy Technology Data Exchange (ETDEWEB)

Castro, A.L.S.; Campos, T.P.R., E-mail: radioterapia.andre@gmail.com [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte (Brazil). Departamento de Engenharia Nuclear

2016-11-01

Radiotherapy is the most used clinical method used for brain metastases treatment, the most frequent secondary tumors provided by breast, lung and melanomas as primary origin. The protocols often use high daily doses and, depending on the irradiation technique there is high probability of complications in health tissues. In order to minimize adverse effects, it is important the dosimetric analysis of three-dimensional radiotherapy planning through tomographic images or, concerning to the 2D simulations, by the application of techniques that optimize dose distribution by increasing the homogeneity. The study aimed to compare the 2D and 3D conformal planning for total brain irradiation in a individual equivalent situation and evaluate the progress of these planning applying the field in field technique. The methodology consisted of simulating a two-dimensional planning, reproduce it on a set of tomographic images and compare it with the conformal plan for two fields and four fields (field in field). The results showed no significant difference between 2D and 3D planning for whole brain irradiation, and the field in field technique significantly improved the dose distribution in brain volume compared with two fields for the proposal situation. As conclusion, the two-dimensional plane for the four fields described was viable for whole brain irradiation in the treatment of brain metastases at the proposal situation. (author)

Magnetic Field

DEFF Research Database (Denmark)

Olsen, Nils

2015-01-01

he Earth has a large and complicated magnetic field, the major part of which is produced by a self-sustaining dynamo operating in the fluid outer core. Magnetic field observations provide one of the few tools for remote sensing the Earth’s deep interior, especially regarding the dynamics...... of the fluid flow at the top of the core. However, what is measured at or near the surface of the Earth is the superposition of the core field and fields caused by magnetized rocks in the Earth’s crust, by electric currents flowing in the ionosphere, magnetosphere, and oceans, and by currents induced...... in the Earth by time-varying external fields. These sources have their specific characteristics in terms of spatial and temporal variations, and their proper separation, based on magnetic measurements, is a major challenge. Such a separation is a prerequisite for remote sensing by means of magnetic field...

Ambient Field Analysis at Groningen Gas Field

Science.gov (United States)

Spica, Z.; Nakata, N.; Beroza, G. C.

2016-12-01

We analyze continuous ambient-field data at Groningen gas field (Netherlands) through cross-correlation processing. The Groningen array is composed of 75 shallow boreholes with 6 km spacing, which contain a 3C surface accelerometer and four 5-Hz 3C borehole geophones spaced at 50 m depth intervals. We successfully retrieve coherent waves from ambient seismic field on the 9 components between stations. Results show high SNR signal in the frequency range of 0.125-1 Hz, and the ZZ, ZR, RZ, RR and TT components show much stronger wave energy than other components as expected. This poster discuss the different type of waves retrieved, the utility of the combination of borehole and surface observations, future development as well as the importance to compute the 9 components of the Green's tensor to better understand the wave field propriety with ambient noise.

Invariant gauge families inherent in Abelian-gauge field theory. [Scalar dipole ghost field, free-field equations

Energy Technology Data Exchange (ETDEWEB)

Yokoyama, Kan-ichi; Kubo, Reijiro

1974-12-01

The framework of the Nakanishi-Lautrup formalism should be enlarged by introducing a scalar dipole ghost field B(x), which is called gauge on field, together with its pair field. By taking free Lagrangian density, Free-field equations can be described. The vacuum is defined by using a neutral vector field U..mu..(x). The state-vector space is generated by the adjoining conjugates of U..mu..sup((+))(x), and auxiliary fields B(x), B/sub 1/(x) and B/sub 2/(x), which were introduced in the form of the Lagrangian density. The physical states can be defined by the supplementary conditions of the form B/sub 1/sup((+))(x) 1 phys>=B/sub 2/sup((+))(x) 1 phys>=0. It is seen that all the field equations and all the commutators are kept form-invariant, and that the gauge parameter ..cap alpha.. is transformed into ..cap alpha..' given by ..cap alpha..'=..cap alpha..+lambda, with epsilon unchanged. The Lagrangian density is specified only by the gauge invariant parameter epsilon. The gauge structure of theory has universal meaning over whole Abelian-gauge field. C-number gauge transformation and the gauge structure in the presence of interaction are also discussed.

Internal magnetic field measurements in a translating field-reversed configuration

International Nuclear Information System (INIS)

Armstrong, W.T.; Chrien, R.E.; McKenna, K.F.; Rej, D.J.; Sherwood, E.G.; Siemon, R.E.; Tuszewski, M.

1984-01-01

Magnetic field probes have been employed to study the internal field structure of Field-Reversed Configurations (FRCs) translating past the probes in the FRX-C/T device. Internal closed flux surfaces can be studied in this manner with minimal perturbation because of the rapid transit of the plasma (translational velocity v/sub z/ approx. 10 cm/μs). Data have been taken using a low-field (5 kG), 5-mtorr-D 2 gas-puff mode of operation in the FRC source coil which yields an initial plasma density of approx. 1 x 10 15 cm -3 and x/sub s/ approx. 0.04. FRCs translate from the approx. 25 cm radius source coil into a 20 cm radius metal translation vessel. Two translation conditions are studied: (1) translation into a 4 kG guide field (matched guide-field case), resulting in similar plasma parameters but with x/sub s/ approx. .45, and (2) translation into a 1 kG guide field (reduced guide-field case), resulting in expansion of the FRC to conditions of density approx. 3 x 10 14 , external field B 0 approx. 2 kG and x/sub s/ approx. 0.7. The expected reversed B/sub z/ structure is observed in both cases. However, the field measurements indicate a possible sideways offset of the FRC from the machine axis in the matched case. There is also evidence of island structure in the reduced guide-field case. Fluctuating levels of B/sub theta/ are ovserved with amplitudes less than or equal to B 0 /3 in both cases. Field measurements on the FRC symmetry axis in the reduced guide-field case indicate β on the separatrix of β/sub s/ approx. = 0.3 (indexed to the external field) has been achieved. This decrease of β/sub s/ with increased x/sub s/ is expected, and desirable for improved plasma confinement

Hydrogen Field Test Standard: Laboratory and Field Performance

Science.gov (United States)

Pope, Jodie G.; Wright, John D.

2015-01-01

The National Institute of Standards and Technology (NIST) developed a prototype field test standard (FTS) that incorporates three test methods that could be used by state weights and measures inspectors to periodically verify the accuracy of retail hydrogen dispensers, much as gasoline dispensers are tested today. The three field test methods are: 1) gravimetric, 2) Pressure, Volume, Temperature (PVT), and 3) master meter. The FTS was tested in NIST's Transient Flow Facility with helium gas and in the field at a hydrogen dispenser location. All three methods agree within 0.57 % and 1.53 % for all test drafts of helium gas in the laboratory setting and of hydrogen gas in the field, respectively. The time required to perform six test drafts is similar for all three methods, ranging from 6 h for the gravimetric and master meter methods to 8 h for the PVT method. The laboratory tests show that 1) it is critical to wait for thermal equilibrium to achieve density measurements in the FTS that meet the desired uncertainty requirements for the PVT and master meter methods; in general, we found a wait time of 20 minutes introduces errors methods, respectively and 2) buoyancy corrections are important for the lowest uncertainty gravimetric measurements. The field tests show that sensor drift can become a largest component of uncertainty that is not present in the laboratory setting. The scale was calibrated after it was set up at the field location. Checks of the calibration throughout testing showed drift of 0.031 %. Calibration of the master meter and the pressure sensors prior to travel to the field location and upon return showed significant drifts in their calibrations; 0.14 % and up to 1.7 %, respectively. This highlights the need for better sensor selection and/or more robust sensor testing prior to putting into field service. All three test methods are capable of being successfully performed in the field and give equivalent answers if proper sensors without drift are

Electric fields and field-aligned current generation in the magnetosphere

International Nuclear Information System (INIS)

Alexeev, I.I.; Belenkaya, E.S.; Kalegaev, V.V.; Lyutov, Yu.G.

1993-01-01

The authors present a calculation of the electric potential, field-aligned currents, and plasma convection caused by the penetration of the solar wind electric field into the magnetosphere. Ohm's law and the continuity equation of ionospheric currents are used. It is shown that the large-scale convection system is reversed in the plasma sheet flanks. In this region the plasma flow is antisunward earthward of the neutral line and sunward tailward of it. The interplanetary magnetic field (IMF) B z dependences on the dimension of the magnetopause open-quotes windowsclose quotes which are intersected by open field lines, on the potential drop across the polar cap, and on the distance to the neutral line are determined. Because of the IMF effect and the effect of seasonal or daily variations of the geomagnetic field which violate its symmetry relative to the equatorial plane, there may arise a potential drop along field lines which causes field-aligned currents. The values and directions of these currents, the field-aligned potential drop, and a self-consistent solution for the potential at the ionosphere level for high field-aligned conductivity have been determined. 41 refs., 7 figs

Comparison between 3D conventional techniques, field-in-field and electronic tissue compensation for mantle fields planning; Comparacao entre tecnica 3D convencional, field-in-field e compensacao eletronica para planejamento de manto

Energy Technology Data Exchange (ETDEWEB)

Martins, Lais P.; Silva, Leonardo P.; Trindade, Cassia; Garcia, Paulo L.; Santos, Maira R.; Batista, Delano V.S., E-mail: pm.lais@gmail.com [Instituto Nacional de Cancer (INCA), Rio de Janeiro, RJ (Brazil)

2012-12-15

External radiotherapy treatment for Hodgkin's lymphoma over diaphragm region requires large radiation fields with protections applied to larynx, humerus head and lungs. The size and shape of the field, which covers different depths, make it difficult to distribute a homogeneous dose. Techniques such as field-in-field and electronic tissue compensation may be used to make dose homogeneous and compensate the obliquity from the tissue. Three types of planning were performed for diagnose of nodular sclerosis Hodgkin's lymphoma: one plan with two fields, AP-PA (AP plan), another with four fields field-in- field (FF plan), and a third one with two fields and electronic tissue compensation (ETC plan). Results showed better gradient, cover of PTV and dose distribution for the ETC plan, besides the advantage from this technique of does not require protection blocks. In the meanwhile, AP and FF plans require simpler dosimetry and fewer MU. Related to the uniformity of dose distribution, AP plan showed hot areas in the neck region, FF plan showed hot areas in the shoulder region and ETC plan showed most uniform distribution without hot areas. The electronic tissue compensation is a useful tool for large and shaped fields as the mantle field, however higher MU and complex dosimetry should be taken in account. (author)

Cosmic Magnetic Fields

Science.gov (United States)

Sánchez Almeida, J.; Martínez González, M. J.

2018-05-01

Magnetic fields play an important role in many astrophysical processes. They are difficult to detect and characterize since often their properties have to be inferred through interpreting the polarization of the light. Magnetic fields are also challenging to model and understand. Magnetized plasmas behave following highly non-linear differential equations having no general solution, so that every astrophysical problem represents a special case to be studied independently. Hence, magnetic fields are often an inconvenient subject which is overlooked or simply neglected (the elephant in the room, as they are dubbed in poster of the school). Such difficulty burdens the research on magnetic fields, which has evolved to become a very technical subject, with many small disconnected communities studying specific aspects and details. The school tried to amend the situation by providing a unifying view of the subject. The students had a chance to understand the behavior of magnetic fields in all astrophysical contexts, from cosmology to the Sun, and from starbursts to AGNs. The school was planed to present a balanced yet complete review of our knowledge, with excursions into the unknown to point out present and future lines of research. The subject of Cosmic Magnetic Fields was split into seven different topics: cosmic magnetic field essentials, solar magnetic fields, stellar magnetic fields, the role of magnetic fields on AGN feedback, magnetic fields in galaxies, magnetic fields in galaxy clusters and at larger scales, and primordial magnetic fields and magnetic fields in the early Universe. The corresponding lectures were delivered by seven well known and experienced scientists that have played key roles in the major advances of the field during the last years: F. Cattaneo, P. Judge, O. Kochukhov, R. Keppens, R. Beck, K. Dolag, and F. Finelli. Their lectures were recorded and are freely available at the IAC website: http://iactalks.iac.es/talks/serie/19.

Integrated field modelling[Oil and gas fields

Energy Technology Data Exchange (ETDEWEB)

Nazarian, Bamshad

2002-07-01

This research project studies the feasibility of developing and applying an integrated field simulator to simulate the production performance of an entire oil or gas field. It integrates the performance of the reservoir, the wells, the chokes, the gathering system, the surface processing facilities and whenever applicable, gas and water injection systems. The approach adopted for developing the integrated simulator is to couple existing commercial reservoir and process simulators using available linking technologies. The simulators are dynamically linked and customised into a single hybrid application that benefits from the concept of open software architecture. The integrated field simulator is linked to an optimisation routine developed based on the genetic algorithm search strategies. This enables optimisation of the system at field level, from the reservoir to the process. Modelling the wells and the gathering network is achieved by customising the process simulator. This study demonstrated that the integrated simulation improves current capabilities to simulate the performance of the entire field and optimise its design. This is achieved by evaluating design options including spread and layout of the wells and gathering system, processing alternatives, reservoir development schemes and production strategies. Effectiveness of the integrated simulator is demonstrated and tested through several field-level case studies that discuss and investigate technical problems relevant to offshore field development. The case studies cover topics such as process optimisation, optimum tie-in of satellite wells into existing process facilities, optimal well location and field layout assessment of a high pressure high temperature deepwater oil field. Case study results confirm the viability of the total field simulator by demonstrating that the field performance simulation and optimal design were obtained in an automated process with treasonable computation time. No significant

Impact of local electrostatic field rearrangement on field ionization

Science.gov (United States)

Katnagallu, Shyam; Dagan, Michal; Parviainen, Stefan; Nematollahi, Ali; Grabowski, Blazej; Bagot, Paul A. J.; Rolland, Nicolas; Neugebauer, Jörg; Raabe, Dierk; Vurpillot, François; Moody, Michael P.; Gault, Baptiste

2018-03-01

Field ion microscopy allows for direct imaging of surfaces with true atomic resolution. The high charge density distribution on the surface generates an intense electric field that can induce ionization of gas atoms. We investigate the dynamic nature of the charge and the consequent electrostatic field redistribution following the departure of atoms initially constituting the surface in the form of an ion, a process known as field evaporation. We report on a new algorithm for image processing and tracking of individual atoms on the specimen surface enabling quantitative assessment of shifts in the imaged atomic positions. By combining experimental investigations with molecular dynamics simulations, which include the full electric charge, we confirm that change is directly associated with the rearrangement of the electrostatic field that modifies the imaging gas ionization zone. We derive important considerations for future developments of data reconstruction in 3D field ion microscopy, in particular for precise quantification of lattice strains and characterization of crystalline defects at the atomic scale.

Potential of Field Education as Signature Pedagogy: The Field Director Role

Science.gov (United States)

Lyter, Sharon C.

2012-01-01

In light of the assertion that field education is the signature pedagogy of social work education, this Internet-based study explores field director demographics and questions the fulfillment of this potential, examining BSW and MSW field education through the lens of the field director position. Field directors (159) and deans/directors (150)…

Engineering field theory

CERN Document Server

Baden Fuller, A J

2014-01-01

Engineering Field Theory focuses on the applications of field theory in gravitation, electrostatics, magnetism, electric current flow, conductive heat transfer, fluid flow, and seepage.The manuscript first ponders on electric flux, electrical materials, and flux function. Discussions focus on field intensity at the surface of a conductor, force on a charged surface, atomic properties, doublet and uniform field, flux tube and flux line, line charge and line sink, field of a surface charge, field intensity, flux density, permittivity, and Coulomb's law. The text then takes a look at gravitation

Wide-field fundus autofluorescence corresponds to visual fields in chorioretinitis patients

Directory of Open Access Journals (Sweden)

Seidensticker F

2011-11-01

Full Text Available Florian Seidensticker1, Aljoscha S Neubauer1, Tamer Wasfy1,2, Carmen Stumpf1, Stephan R Thurau1,*, Anselm Kampik1, Marcus Kernt1,*1Department of Ophthalmology, Ludwig-Maximilians-University, Munich, Germany; 2Department of Ophthalmology, Tanta University, Tanta, Egypt *Both authors contributed equally to this workBackground and objectives: Detection of peripheral fundus autofluorescence (FAF using conventional scanning laser ophthalmoscopes (SLOs is difficult and requires pupil dilation. Here we evaluated the diagnostic properties of wide-field FAF detected by a two-laser wavelength wide-field SLO in uveitis patients.Study design/materials and methods: Observational case series of four patients suffering from different types of posterior uveitis/chorioretinitis. Wide-field FAF images were compared to visual fields. Panretinal FAF was detected by a newly developed SLO, which allows FAF imaging of up to 200° of the retina in one scan without the need for pupil dilation. Visual fields were obtained by Goldmann manual perimetry.Results: Findings from wide-field FAF imaging showed correspondence to visual field defects in all cases.Conclusion: Wide-field FAF allowed the detection of visual field defect-related alterations of the retinal pigment epithelium in all four uveitis cases.Keywords: fundus autofluorescence (FAF, Optomap, wide-field scanning laser ophthalmoscopy, imaging, uveitis, visual field

Accelerating field step-up transformer in wake-field accelerators

International Nuclear Information System (INIS)

Chojnacki, E.; Gai, W.; Schoessow, P.; Simpson, J.

1991-01-01

In the wake-field scheme of particle acceleration, a short, intense drive bunch of electrons passes through a slow-wave structure, leaving behind high rf power in its wake field. The axial accelerating electric field associated with the rf can be quite large, > 100 MeV/m, and is used to accelerate a much less intense ''witness'' beam to eventual energies > 1 TeV. The rf power is deposited predominantly in the fundamental mode of the structure, which, for dielectric-lined waveguide as used at Argonne, is the TM 01 mode. In all likelihood on the field amplitude will be limited only by rf breakdown of the dielectric material, the limit of which is currently unknown in the short time duration, high frequency regime of wake-field acceleration operation. To obtain such strong electric fields with given wake-field rf power, the dimensions of the dielectric-lined waveguide have to be fairly small, OD of the order of a cm and ID of a few mm, and this gives rise to the generation of strong deflection modes with beam misalignment. While a scheme exists to damp such deflection modes on a bunch-to-bunch time scale, head-tail beam deflection could still be a problem and BNS damping as well as FODO focusing are incomplete cures. Presented here are details of a scheme by which the rf power is generated by in a large-diameter wake-field tube, where deflection mode generation by the intense drive beam is tolerable, and then fed into a small-diameter acceleration tube where the less intense witness beam is accelerated by the greatly enhanced axial electric field. The witness beam generates little deflection-mode power itself, even in the small acceleration tube, thus a final high-quality, high-energy electron beam is produced

Background Independent Open String Field Theory and Constant B-Field

OpenAIRE

Nemeschansky, D.; Yasnov, V.

2000-01-01

We calculate the background independent action for bosonic and supersymmetric open string field theory in a constant B-field. We also determine the tachyon effective action in the presence of constant B-field.

Acceleration of auroral particles by magnetic-field aligned electric fields

International Nuclear Information System (INIS)

Block, L.P.

1988-01-01

Measurements on the S3-3 and Viking satellites appear to show that at least a large fraction of magnetic field-aligned potential drops are made up of multiple double layers. Solitons and double layers in U-shaped potential structures give rise to spiky electric fields also perpendicular to the magnetic field in agreement with satellite measurements. The large scale potential structures associated with inverted V-events are built up of many similar short-lived structures on a small scale. Viking measurements indicate that electric fields parallel to the magnetic field are almost always directed upward

Selfdecomposable Fields

DEFF Research Database (Denmark)

Barndorff-Nielsen, Ole E.; Sauri, Orimar; Szozda, Benedykt

In the present paper we study selfdecomposability of random fields, as defined directly rather than in terms of finite-dimensional distributions. The main tools in our analysis are the master Lévy measure and the associated Lévy-Itô representation. We give the dilation criterion for selfdecomposa......In the present paper we study selfdecomposability of random fields, as defined directly rather than in terms of finite-dimensional distributions. The main tools in our analysis are the master Lévy measure and the associated Lévy-Itô representation. We give the dilation criterion...... for selfdecomposability analogous to the classical one. Next, we give necessary and sufficient conditions (in terms of the kernel functions) for a Volterra field driven by a Lévy basis to be selfdecomposable. In this context we also study the so-called Urbanik classes of random fields. We follow this with the study...... of existence and selfdecomposability of integrated Volterra fields. Finally, we introduce infinitely divisible field-valued Lévy processes, give the Lévy-Itô representation associated with them and study stochastic integration with respect to such processes. We provide examples in the form of Lévy...

Selfdecomposable Fields

DEFF Research Database (Denmark)

Barndorff-Nielsen, Ole E.; Sauri, Orimar; Szozda, Benedykt

In the present paper we study selfdecomposability of random fields, as defined directly rather than in terms of finite-dimensional distributions. The main tools in our analysis are the master L\\'evy measure and the associated L\\'evy-It\\^o representation. We give the dilation criterion for selfdec......In the present paper we study selfdecomposability of random fields, as defined directly rather than in terms of finite-dimensional distributions. The main tools in our analysis are the master L\\'evy measure and the associated L\\'evy-It\\^o representation. We give the dilation criterion...... for selfdecomposability analogous to the classical one. Next, we give necessary and sufficient conditions (in terms of the kernel functions) for a Volterra field driven by a L\\'evy basis to be selfdecomposable. In this context we also study the so-called Urbanik classes of random fields. We follow this with the study...... of existence and selfdecomposability of integrated Volterra fields. Finally, we introduce infinitely divisible field-valued L\\'evy processes, give the L\\'evy-It\\^o representation associated with them and study stochastic integration with respect to such processes. We provide examples in the form of L...

Suppression of sound radiation to far field of near-field acoustic communication system using evanescent sound field

Science.gov (United States)

Fujii, Ayaka; Wakatsuki, Naoto; Mizutani, Koichi

2016-01-01

A method of suppressing sound radiation to the far field of a near-field acoustic communication system using an evanescent sound field is proposed. The amplitude of the evanescent sound field generated from an infinite vibrating plate attenuates exponentially with increasing a distance from the surface of the vibrating plate. However, a discontinuity of the sound field exists at the edge of the finite vibrating plate in practice, which broadens the wavenumber spectrum. A sound wave radiates over the evanescent sound field because of broadening of the wavenumber spectrum. Therefore, we calculated the optimum distribution of the particle velocity on the vibrating plate to reduce the broadening of the wavenumber spectrum. We focused on a window function that is utilized in the field of signal analysis for reducing the broadening of the frequency spectrum. The optimization calculation is necessary for the design of window function suitable for suppressing sound radiation and securing a spatial area for data communication. In addition, a wide frequency bandwidth is required to increase the data transmission speed. Therefore, we investigated a suitable method for calculating the sound pressure level at the far field to confirm the variation of the distribution of sound pressure level determined on the basis of the window shape and frequency. The distribution of the sound pressure level at a finite distance was in good agreement with that obtained at an infinite far field under the condition generating the evanescent sound field. Consequently, the window function was optimized by the method used to calculate the distribution of the sound pressure level at an infinite far field using the wavenumber spectrum on the vibrating plate. According to the result of comparing the distributions of the sound pressure level in the cases with and without the window function, it was confirmed that the area whose sound pressure level was reduced from the maximum level to -50 dB was

Prequantum classical statistical field theory: background field as a source of everything?

International Nuclear Information System (INIS)

Khrennikov, Andrei

2011-01-01

Prequantum classical statistical field theory (PCSFT) is a new attempt to consider quantum mechanics (QM) as an emergent phenomenon, cf. with De Broglie's 'double solution' approach, Bohmian mechanics, stochastic electrodynamics (SED), Nelson's stochastic QM and its generalization by Davidson, 't Hooft's models and their development by Elze. PCSFT is a comeback to a purely wave viewpoint on QM, cf. with early Schrodinger. There is no quantum particles at all, only waves. In particular, photons are simply wave-pulses of the classical electromagnetic field, cf. SED. Moreover, even massive particles are special 'prequantum fields': the electron field, the neutron field, and so on. PCSFT claims that (sooner or later) people will be able to measure components of these fields: components of the 'photonic field' (the classical electromagnetic field of low intensity), electronic field, neutronic field, and so on. At the moment we are able to produce quantum correlations as correlations of classical Gaussian random fields. In this paper we are interested in mathematical and physical reasons of usage of Gaussian fields. We consider prequantum signals (corresponding to quantum systems) as composed of a huge number of wave-pulses (on very fine prequantum time scale). We speculate that the prequantum background field (the field of 'vacuum fluctuations') might play the role of a source of such pulses, i.e., the source of everything.

Accuracy limits of the equivalent field method for irregular photon fields

International Nuclear Information System (INIS)

Sanz, Dario Esteban

2002-01-01

A mathematical approach is developed to evaluate the accuracy of the equivalent field method using basic clinical photon beam data. This paper presents an analytical calculation of dose errors arising when field equivalencies, calculated at a certain reference depth, are translated to other depths. The phantom scatter summation is expressed as a Riemann-Stieltjes integral and two categories of irregular fields are introduced: uniform and multiform. It is shown that multiform fields produce errors whose magnitudes are nearly twice those corresponding to uniform fields in extreme situations. For uniform field shapes, the maximum, local, relative dose errors, when the equivalencies are calculated at 10 cm depth on the central axis and translated to a depth of 30 cm, are 3.8% and 8.8% for 6 MV and cobalt-60 photon beams, respectively. In terms of maximum dose those errors are within 1-2%. This supports the conclusion that the equivalencies between rectangular fields, which are examples of uniform fields, are applicable to dose ratio functions irrespective of beam energy. However, the magnitude of such errors could be of importance when assessing the exit dose for in vivo monitoring. This work provides a better understanding of the influence of the irregular field shapes on the accuracy of the equivalent field method. (author)

Field Campaign Guidelines

Energy Technology Data Exchange (ETDEWEB)

Voyles, J. W. [DOE ARM Climate Research Facility, Washington, DC (United States); Chapman, L. A. [DOE ARM Climate Research Facility, Washington, DC (United States)

2015-12-01

This document establishes a common set of guidelines for the Atmospheric Radiation Measurement (ARM) Climate Research Facility for planning, executing, and closing out field campaigns. The steps that guide individual field campaigns are described in the Field Campaign Tracking System and are specifically tailored to meet the scope of each field campaign.

Field quality issues in iron-dominated dipoles at low fields

International Nuclear Information System (INIS)

Brown, B.C.

1996-10-01

In order to help assess the usable dynamic range of iron-dominated dipoles, field shape data at low field on several Fermi-lab accelerator dipole designs are presented. Emphasis is placed on the systematic and random values of the low field sextupole since it is the first ''allowed'' field error. The Main Injector dipoles provide four times smaller sextupole and more than 20 times less sextupole hysteresis than earlier designs for the Main Ring

Quantum field theory

International Nuclear Information System (INIS)

Ryder, L.H.

1985-01-01

This introduction to the ideas and techniques of quantum field theory presents the material as simply as possible and is designed for graduate research students. After a brief survey of particle physics, the quantum theory of scalar and spinor fields and then of gauge fields, is developed. The emphasis throughout is on functional methods, which have played a large part in modern field theory. The book concludes with a bridge survey of ''topological'' objects in field theory and assumes a knowledge of quantum mechanics and special relativity

Earth's electric field

International Nuclear Information System (INIS)

Kelley, M.C.

1978-01-01

The earth becomes charged during thunderstorm activity and discharges through the weak conducting atmosphere. Balloon and rocket studies infer that a high altitude electric field penetrates virtually unattenuated through the atmosphere, at least as far as balloon heights. The field has two primary sources. At low and mid latitudes, interaction between the earth's magnetic field and the neutral wind creates electric fields. At latitudes above 60 0 , the high altitude electrical structure is dominated by the interaction between the solar wind and the earth's magnetic field. The auroral light is emitted by atmospheric atoms and molecules excited by electrons with potentials of many thousands volts. The potentials are induced by the solar wind. Recent satellite data shows that the electrons get this energy by passing through a localized electric field about 6000 km above the auroral zone. Several rocket and satellite experiments used to study the earth's electric field are discussed

) Ima Field: A Type Marginal Field-Challenges and Prospects

International Nuclear Information System (INIS)

Afolabi, T. J.

2003-01-01

The IMA Field is located in the south-eastern Niger Delta in approximately 30' of water. Discovered in 1972 by Japan Petroleum, commercial accumulation was not established until 1994 by the AMNI/Abacan Joint Venture, with the drilling of ima-3 well, which discovered the major reservoirs in the C and D sands. Recoverable Reserve of 48MMBO. Ten wells have been drilled on the IMA structure to date, with a cumulative production of 16 Million barrels of condensates.The IMA Field is a typical Niger Delta rollover anticlinal structure trending northeast southwest with a regional tilt to the northeast. The major trapping mechanism is the anticline.The sediments of IMA Field are Miocene Agbada Fm. They are deltaic deposits with high sand/shale ratio. The reservoirs are loosely compacted sandstones with porosity values ranging from 21% to 27% while permeability is generally measured in darcies.The development of IMA Field posed financial and logistical challenges since the partners had decided to fast track this process, and since neither had the resources to drill the development wells, assemble/install the crude processing and storage facilities; a mixture of debt financing and contractor financing arrangements were made.The prospects in IMA Field are to be found in early realisation of the limitations of a marginal field, particularly the management of cash flow. Workers and field development funding is financed by current production. Appraisal and exploration drilling within the same lease have required equity financing (participation)

Phase field

International Nuclear Information System (INIS)

Radhakrishnan, B.; Gorti, S.B.; Clarno, K.; Tonks, M.R.

2015-01-01

In this work, the phase-field method and its application to microstructure evolution in reactor fuel and clad are discussed. The examples highlight the capability of the phase-field method to capture evolution processes that are influenced by both thermal and elastic stress fields that are caused by microstructural changes in the solid-state. The challenges that need to be overcome before the technique can become predictive and material-specific are discussed. (authors)

Field emission electronics

CERN Document Server

Egorov, Nikolay

2017-01-01

This book is dedicated to field emission electronics, a promising field at the interface between “classic” vacuum electronics and nanotechnology. In addition to theoretical models, it includes detailed descriptions of experimental and research techniques and production technologies for different types of field emitters based on various construction principles. It particularly focuses on research into and production of field cathodes and electron guns using recently developed nanomaterials and carbon nanotubes. Further, it discusses the applications of field emission cathodes in new technologies such as light sources, flat screens, microwave and X-ray devices.

Use of along-track magnetic field differences in lithospheric field modelling

DEFF Research Database (Denmark)

Kotsiaros, Stavros; Finlay, Chris; Olsen, Nils

2015-01-01

. Experiments in modelling the Earth's lithospheric magnetic field with along-track differences are presented here as a proof of concept. We anticipate that use of such along-track differences in combination with east–west field differences, as are now provided by the Swarm satellite constellation......We demonstrate that first differences of polar orbiting satellite magnetic data in the along-track direction can be used to obtain high resolution models of the lithospheric field. Along-track differences approximate the north–south magnetic field gradients for non-polar latitudes. In a test case......, using 2 yr of low altitude data from the CHAMP satellite, we show that use of along-track differences of vector field data results in an enhanced recovery of the small scale lithospheric field, compared to the use of the vector field data themselves. We show that the along-track technique performs...

Rapid change of field line connectivity and reconnection in stochastic magnetic fields

International Nuclear Information System (INIS)

Huang, Yi-Min; Bhattacharjee, A.; Boozer, Allen H.

2014-01-01

Magnetic fields without a direction of continuous symmetry have the generic feature that neighboring field lines exponentiate away from each other and become stochastic, and hence the ideal constraint of preserving magnetic field line connectivity becomes exponentially sensitive to small deviations from ideal Ohm's law. The idea of breaking field line connectivity by stochasticity as a mechanism for fast reconnection is tested with numerical simulations based on reduced magnetohydrodynamics equations with a strong guide field line-tied to two perfectly conducting end plates. Starting from an ideally stable force-free equilibrium, the system is allowed to undergo resistive relaxation. Two distinct phases are found in the process of resistive relaxation. During the quasi-static phase, rapid change of field line connectivity and strong induced flow are found in regions of high field line exponentiation. However, although the field line connectivity of individual field lines can change rapidly, the overall pattern of field line mapping appears to deform gradually. From this perspective, field line exponentiation appears to cause enhanced diffusion rather than reconnection. In some cases, resistive quasi-static evolution can cause the ideally stable initial equilibrium to cross a stability threshold, leading to formation of intense current filaments and rapid change of field line mapping into a qualitatively different pattern. It is in this onset phase that the change of field line connectivity is more appropriately designated as magnetic reconnection. Our results show that rapid change of field line connectivity appears to be a necessary, but not a sufficient condition for fast reconnection.

The Swarm Initial Field Model for the 2014 Geomagnetic Field

Science.gov (United States)

Olsen, Nils; Hulot, Gauthier; Lesur, Vincent; Finlay, Christopher C.; Beggan, Ciaran; Chulliat, Arnaud; Sabaka, Terence J.; Floberghagen, Rune; Friis-Christensen, Eigil; Haagmans, Roger

2015-01-01

Data from the first year of ESA's Swarm constellation mission are used to derive the Swarm Initial Field Model (SIFM), a new model of the Earth's magnetic field and its time variation. In addition to the conventional magnetic field observations provided by each of the three Swarm satellites, explicit advantage is taken of the constellation aspect by including east-west magnetic intensity gradient information from the lower satellite pair. Along-track differences in magnetic intensity provide further information concerning the north-south gradient. The SIFM static field shows excellent agreement (up to at least degree 60) with recent field models derived from CHAMP data, providing an initial validation of the quality of the Swarm magnetic measurements. Use of gradient data improves the determination of both the static field and its secular variation, with the mean misfit for east-west intensity differences between the lower satellite pair being only 0.12 nT.

Classical field theory

CERN Document Server

Franklin, Joel

2017-01-01

Classical field theory, which concerns the generation and interaction of fields, is a logical precursor to quantum field theory, and can be used to describe phenomena such as gravity and electromagnetism. Written for advanced undergraduates, and appropriate for graduate level classes, this book provides a comprehensive introduction to field theories, with a focus on their relativistic structural elements. Such structural notions enable a deeper understanding of Maxwell's equations, which lie at the heart of electromagnetism, and can also be applied to modern variants such as Chern–Simons and Born–Infeld. The structure of field theories and their physical predictions are illustrated with compelling examples, making this book perfect as a text in a dedicated field theory course, for self-study, or as a reference for those interested in classical field theory, advanced electromagnetism, or general relativity. Demonstrating a modern approach to model building, this text is also ideal for students of theoretic...

Field-Induced Rheology in Uniaxial and Biaxial Fields

International Nuclear Information System (INIS)

MARTIN, JAMES E.

1999-01-01

Steady and oscillatory shear 3-D simulations of electro- and magnetorheology in uniaxial and biaxial fields are presented, and compared to the predictions of the chain model. These large scale simulations are three dimensional, and include the effect of Brownian motion. In the absence of thermal fluctuations, the expected shear thinning viscosity is observed in steady shear, and a striped phase is seen to rapidly form in a uniaxial field, with a shear slip zone in each sheet. However, as the influence of Brownian motion increases, the fluid stress decreases, especially at lower Mason numbers, and the striped phase eventually disappears, even when the fluid stress is still high. In a biaxial field, an opposite trend is seen, where Brownian motion decreases the stress most significantly at higher Mason numbers. to account for the uniaxial steady shear data they propose a microscopic chain model of the role played by thermal fluctuations on the rheology of ER and MR fluids that delineates the regimes where an applied field can impact the fluid viscosity, and gives an analytical prediction for the thermal effect. In oscillatory shear, a striped phase again appears in uniaxial field, at strain amplitudes greater than(approx) 0.15, and the presence of a shear slip zone creates strong stress nonlinearities at low strain amplitudes. In a biaxial field, a shear slip zone is not created, and so the stress nonlinearities develop only at expected strain amplitudes. The nonlinear dynamics of these systems is shown to be in good agreement with the Kinetic Chain Model

Novel Electrochemical Phenomena in Magnetic Fields(Research in High Magnetic Fields)

OpenAIRE

Mogi, Iwao; Kamiko, Masao

1996-01-01

Recent two topics are given of electrochemical studies in steady magnetic fields at the High Field Laboratory of Tohoku University. One is the magnetic-field-induced diffusion-limited-aggregation in the pattern formation of silver electrodeposits . The other is the magnetic field effect on the learning effect in a dopant-exchange process of an organic conducting polymer polypyrrole.

Orbital effect of the magnetic field in dynamical mean-field theory

Science.gov (United States)

Acheche, S.; Arsenault, L.-F.; Tremblay, A.-M. S.

2017-12-01

The availability of large magnetic fields at international facilities and of simulated magnetic fields that can reach the flux-quantum-per-unit-area level in cold atoms calls for systematic studies of orbital effects of the magnetic field on the self-energy of interacting systems. Here we demonstrate theoretically that orbital effects of magnetic fields can be treated within single-site dynamical mean-field theory with a translationally invariant quantum impurity problem. As an example, we study the one-band Hubbard model on the square lattice using iterated perturbation theory as an impurity solver. We recover the expected quantum oscillations in the scattering rate, and we show that the magnetic fields allow the interaction-induced effective mass to be measured through the single-particle density of states accessible in tunneling experiments. The orbital effect of magnetic fields on scattering becomes particularly important in the Hofstadter butterfly regime.

Pulsed magnetic field generation suited for low-field unilateral nuclear magnetic resonance systems

Science.gov (United States)

Gaunkar, Neelam Prabhu; Selvaraj, Jayaprakash; Theh, Wei-Shen; Weber, Robert; Mina, Mani

2018-05-01

Pulsed magnetic fields can be used to provide instantaneous localized magnetic field variations. In presence of static fields, pulsed field variations are often used to apply torques and in-effect to measure behavior of magnetic moments in different states. In this work, the design and experimental performance of a pulsed magnetic field generator suited for low static field nuclear magnetic resonance (NMR) applications is presented. One of the challenges of low bias field NMR measurements is low signal to noise ratio due to the comparable nature of the bias field and the pulsed field. Therefore, a circuit is designed to apply pulsed currents through an inductive load, leading to generation of pulsed magnetic fields which can temporarily overpower the effect of the bias field on magnetic moments. The designed circuit will be tuned to operate at the precession frequency of 1H (protons) placed in a bias field produced by permanent magnets. The designed circuit parameters may be tuned to operate under different bias conditions. Therefore, low field NMR measurements can be performed for different bias fields. Circuit simulations were used to determine design parameters, corresponding experimental measurements will be presented in this work.

Effective field theories

International Nuclear Information System (INIS)

Mack, G.; Kalkreuter, T.; Palma, G.; Speh, M.

1992-05-01

Effective field theories encode the predictions of a quantum field theory at low energy. The effective theory has a fairly low utraviolet cutoff. As a result, loop corrections are small, at least if the effective action contains a term which is quadratic in the fields, and physical predictions can be read straight from the effective Lagrangean. Methods will be discussed how to compute an effective low energy action from a given fundamental action, either analytically or numerically, or by a combination of both methods. Basically, the idea is to integrate out the high frequency components of fields. This requires the choice of a 'blockspin', i.e. the specification af a low frequency field as a function of the fundamental fields. These blockspins will be fields of the effective field theory. The blockspin need not be a field of the same type as one of the fundamental fields, and it may be composite. Special features of blockspin in nonabelian gauge theories will be discussed in some detail. In analytical work and in multigrid updating schemes one needs interpolation kernels A from coarse to fine grid in addition to the averaging kernels C which determines the blockspin. A neural net strategy for finding optimal kernels is presented. Numerical methods are applicable to obtain actions of effective theories on lattices of finite volume. The special case of a 'lattice' with a single site (the constraint effective potential) is of particular interest. In a higgs model, the effective action reduces in this case to the free energy, considered as a function of a gauge covariant magnetization. Its shape determines the phase structure of the theory. Its loop expansion with and without gauge fields can be used to determine finite size corrections to numerical data. (orig.)

On field line resonances of hydromagnetic Alfven waves in dipole magnetic field

International Nuclear Information System (INIS)

Chen, Liu; Cowley, S.C.

1989-07-01

Using the dipole magnetic field model, we have developed the theory of field line resonances of hydromagnetic Alfven waves in general magnetic field geometries. In this model, the Alfven speed thus varies both perpendicular and parallel to the magnetic field. Specifically, it is found that field line resonances do persist in the dipole model. The corresponding singular solutions near the resonant field lines as well as the natural definition of standing shear Alfven eigenfunctions have also been systematically derived. 11 refs

Unitary field theories

International Nuclear Information System (INIS)

Bergmann, P.G.

1980-01-01

A problem of construction of the unitary field theory is discussed. The preconditions of the theory are briefly described. The main attention is paid to the geometrical interpretation of physical fields. The meaning of the conceptions of diversity and exfoliation is elucidated. Two unitary field theories are described: the Weyl conformic geometry and Calitzy five-dimensioned theory. It is proposed to consider supersymmetrical theories as a new approach to the problem of a unitary field theory. It is noted that the supergravitational theories are really unitary theories, since the fields figuring there do not assume invariant expansion

On Point - But Going Where?

DEFF Research Database (Denmark)

Ulrich, Philip Christian

2012-01-01

strategy. The problem for the US Army in regards to the overall shift in focus towards the Asia-Pacific region, is that it has to adapt to a secondary role, supporting the US Navy and US Air Force, after being in the lead for 10 years in US overseas operations. The second development is a doctrinal......Philip Ulrich argues that there are two developments going on in the US Army, as a result of the new strategic situation. The first development is a result of the overall shift in US strategy towards the Asia-Pacific region, and how the US Army is seeking to define its role in the new grand...

A bordo do “Tapete Voador”: Histórias e Aprendizagem no 1º Ciclo do Ensino Básico

OpenAIRE

Francisco, Inês

2014-01-01

O presente relatório científico surgiu no âmbito da Prática do Ensino Supervisionada (PES), no âmbito do Mestrado em Educação Pré-escolar e Ensino do 1º Ciclo do E. Básico na Escola Superior de Educadores de Infância Maria Ulrich. Este visa refletir o percurso da prática pedagógica e o que foi observado durante a mesma, numa turma de 1º e 2º ano do 1º Ciclo do Ensino Básico (CEB), mas também descrever o estudo realizado para responder a problemática que emergiu naquele contexto...

Mediar a presença nas artes visuais, ou, sobre o gesto e o sensível

OpenAIRE

Silva, João Paulo Andrade da

2018-01-01

Este trabalho investiga em que medida o conceito de presença em Hans Ulrich Gumbrecht pode subsidiar o campo da mediação em artes visuais. O estudo parte do pressuposto que a obra de arte enquanto forma poética abre espaço para uma relação com a substância do mundo. Ao mesmo tempo, instaura uma situação de tensão com a dimensão de sentido proposta pela hermenêutica. Trata-se de um contraponto à situação delineada por Jonathan Crary e Walter Benjamin sobre dois traços da modernidade: o surgime...

Retrieving Storm Electric Fields From Aircraft Field Mill Data. Part 2; Applications

Science.gov (United States)

Koshak, W. J.; Mach, D. M.; Christian, H. J.; Stewart, M. F.; Bateman, M. G.

2005-01-01

The Lagrange multiplier theory and "pitch down method" developed in Part I of this study are applied to complete the calibration of a Citation aircraft that is instrumented with six field mill sensors. When side constraints related to average fields are used, the method performs well in computer simulations. For mill measurement errors of 1 V/m and a 5 V/m error in the mean fair weather field function, the 3-D storm electric field is retrieved to within an error of about 12%. A side constraint that involves estimating the detailed structure of the fair weather field was also tested using computer simulations. For mill measurement errors of 1 V/m, the method retrieves the 3-D storm field to within an error of about 8% if the fair weather field estimate is typically within 1 V/m of the true fair weather field. Using this side constraint and data from fair weather field maneuvers taken on 29 June 2001, the Citation aircraft was calibrated. The resulting calibration matrix was then used to retrieve storm electric fields during a Citation flight on 2 June 2001. The storm field results are encouraging and agree favorably with the results obtained from earlier calibration analyses that were based on iterative techniques.

Fractal vector optical fields.

Science.gov (United States)

Pan, Yue; Gao, Xu-Zhen; Cai, Meng-Qiang; Zhang, Guan-Lin; Li, Yongnan; Tu, Chenghou; Wang, Hui-Tian

2016-07-15

We introduce the concept of a fractal, which provides an alternative approach for flexibly engineering the optical fields and their focal fields. We propose, design, and create a new family of optical fields-fractal vector optical fields, which build a bridge between the fractal and vector optical fields. The fractal vector optical fields have polarization states exhibiting fractal geometry, and may also involve the phase and/or amplitude simultaneously. The results reveal that the focal fields exhibit self-similarity, and the hierarchy of the fractal has the "weeding" role. The fractal can be used to engineer the focal field.

Functional visual fields: relationship of visual field areas to self-reported function.

Science.gov (United States)

Subhi, Hikmat; Latham, Keziah; Myint, Joy; Crossland, Michael D

2017-07-01

The aim of this study is to relate areas of the visual field to functional difficulties to inform the development of a binocular visual field assessment that can reflect the functional consequences of visual field loss. Fifty-two participants with peripheral visual field loss undertook binocular assessment of visual fields using the 30-2 and 60-4 SITA Fast programs on the Humphrey Field Analyser, and mean thresholds were derived. Binocular visual acuity, contrast sensitivity and near reading performance were also determined. Self-reported overall and mobility function were assessed using the Dutch ICF Activity Inventory. Greater visual field loss (0-60°) was associated with worse self-reported function both overall (R 2 = 0.50; p function (R 2 = 0.61, p function in multiple regression analyses. Superior and inferior visual field areas related similarly to mobility function (R 2 = 0.56, p function in multiple regression analysis. Mean threshold of the binocular visual field to 60° eccentricity is a good predictor of self-reported function overall, and particularly of mobility function. Both the central (0-30°) and peripheral (30-60°) mean threshold are good predictors of self-reported function, but the peripheral (30-0°) field is a slightly better predictor of mobility function, and should not be ignored when considering functional consequences of field loss. The inferior visual field is a slightly stronger predictor of perceived overall and mobility function than the superior field. © 2017 The Authors Ophthalmic & Physiological Optics © 2017 The College of Optometrists.

Magnetic field systems employing a superconducting D.C. field coil

International Nuclear Information System (INIS)

Bartram, T.C.; Hazell, P.A.

1977-01-01

Method and equipment for transferring energy to or from a direct-current superconducting field coil to change the magnetic field generated by the coil in which a second direct-current superconducting coil is used as a storage coil, and energy transfer between the field coil and the storage coil is effected automatically in dependence upon a control program. Preferably, the control program acts upon a variable transformer which is coupled by respective rectifier/inverters to the field and storage coils and also serves for intital supply of energy to the coils

Plasma behaviors in the open field region of reversed-field theta-pinch

International Nuclear Information System (INIS)

Aso, Yoshiyuki; Hirano, Keiichi.

1983-03-01

A characteristic behavior of the plasma in an open field region of reversed field theta pinch has been studied with the guide field (GF) which extends the field line along the axial direction. The experimental result suggests that the rotaional instability may be induced in FRC after the plasma touches the wall at the ends of the open field. (author)

Visual field

Science.gov (United States)

... your visual field. How the Test is Performed Confrontation visual field exam. This is a quick and ... to achieve this important distinction for online health information and services. Learn more about A.D.A. ...

Detection of electric field around field-reversed configuration plasma

International Nuclear Information System (INIS)

Ikeyama, Taeko; Hiroi, Masanori; Nogi, Yasuyuki; Ohkuma, Yasunori

2010-01-01

Electric-field probes consisting of copper plates are developed to measure electric fields in a vacuum region around a plasma. The probes detect oscillating electric fields with a maximum strength of approximately 100 V/m through a discharge. Reproducible signals from the probes are obtained with an unstable phase dominated by a rotational instability. It is found that the azimuthal structure of the electric field can be explained by the sum of an n=2 mode charge distribution and a convex-surface electron distribution on the deformed separatrix at the unstable phase. The former distribution agrees with that anticipated from the diamagnetic drift motions of plasma when the rotational instability occurs. The latter distribution suggests that an electron-rich plasma covers the separatrix.

Magnetic response to applied electrostatic field in external magnetic field

Energy Technology Data Exchange (ETDEWEB)

Adorno, T.C. [Universidade de Sao Paulo, Instituto de Fisica, Caixa Postal 66318, Sao Paulo, SP (Brazil); University of Florida, Department of Physics, Gainesville, FL (United States); Gitman, D.M. [Universidade de Sao Paulo, Instituto de Fisica, Caixa Postal 66318, Sao Paulo, SP (Brazil); Tomsk State University, Department of Physics, Tomsk (Russian Federation); Shabad, A.E. [P. N. Lebedev Physics Institute, Moscow (Russian Federation)

2014-04-15

We show, within QED and other possible nonlinear theories, that a static charge localized in a finite domain of space becomes a magnetic dipole, if it is placed in an external (constant and homogeneous) magnetic field in the vacuum. The magnetic moment is quadratic in the charge, depends on its size and is parallel to the external field, provided the charge distribution is at least cylindrically symmetric. This magneto-electric effect is a nonlinear response of the magnetized vacuum to an applied electrostatic field. Referring to the simple example of a spherically symmetric applied field, the nonlinearly induced current and its magnetic field are found explicitly throughout the space; the pattern of the lines of force is depicted, both inside and outside the charge, which resembles that of a standard solenoid of classical magnetostatics. (orig.)

Finite discrete field theory

International Nuclear Information System (INIS)

Souza, Manoelito M. de

1997-01-01

We discuss the physical meaning and the geometric interpretation of implementation in classical field theories. The origin of infinities and other inconsistencies in field theories is traced to fields defined with support on the light cone; a finite and consistent field theory requires a light-cone generator as the field support. Then, we introduce a classical field theory with support on the light cone generators. It results on a description of discrete (point-like) interactions in terms of localized particle-like fields. We find the propagators of these particle-like fields and discuss their physical meaning, properties and consequences. They are conformally invariant, singularity-free, and describing a manifestly covariant (1 + 1)-dimensional dynamics in a (3 = 1) spacetime. Remarkably this conformal symmetry remains even for the propagation of a massive field in four spacetime dimensions. We apply this formalism to Classical electrodynamics and to the General Relativity Theory. The standard formalism with its distributed fields is retrieved in terms of spacetime average of the discrete field. Singularities are the by-products of the averaging process. This new formalism enlighten the meaning and the problem of field theory, and may allow a softer transition to a quantum theory. (author)

The role of magnetic-field-aligned electric fields in auroral acceleration

International Nuclear Information System (INIS)

Block, L.P.; Faelthammar, C.G.

1990-01-01

Electric field measurements on the Swedish satellite Viking have confirmed and extended earlier observations on S3-3 and provided further evidence of the role of dc electric fields in auroral acceleration processes. On auroral magnetic field lines the electric field is strongly fluctuating both transverse and parallel to the magnetic field. The significance of these fluctuations for the auroral acceleration process is discussed. A definition of dc electric fields is given in terms of their effects on charged particles. Fluctuations below several hertz are experienced as dc by typical auroral electrons if the acceleration length is a few thousand kilometers. For ions the same is true below about 0.1 Hz. The magnetic-field-aligned (as well as the transverse) component of the electric field fluctuations has a maximum below 1 Hz, in a frequency range that appears as dc to the electrons but not to the ions. This allows it to cause a selective acceleration, which may be important in explaining some of the observed characteristics of auroral particle distributions. The electric field observations on Viking support the conclusion that magnetic-field-aligned potential drops play an important role in auroral acceleration, in good agreement with particle observations boht on Viking and on the DE satellites. They also show that a large part, or even all, of the accelerating potential drop may be accounted for by numerous weak (about a volt) electric double layers, in agreement with earlier observations on the S3-3 satellite and with an early theoretical suggestion by L. Block

Blockspin transformations for finite temperature field theories with gauge fields

International Nuclear Information System (INIS)

Kerres, U.

1996-08-01

A procedure is proposed to study quantum field theories at zero or at finite temperature by a sequence of real space renormalization group (RG) or blockspin transformations. They transform to effective theories on coarser and coarser lattices. The ultimate aim is to compute constraint effective potentials, i.e. the free energy as a function of suitable order parameters. From the free energy one can read off the thermodynamic behaviour of the theory, in particular the existence and nature of phase transitions. In a finite temperature field theory one begins with either one or a sequence of transformations which transform the original theory into an effective theory on a three-dimensional lattice. Its effective action has temperature dependent coefficients. Thereafter one may proceed with further blockspin transformations of the three-dimensional theory. Assuming a finite volume, this can in principle be continued until one ends with a lattice with a single site. Its effective action is the constraint effective potential. In each RG-step, an integral over the high frequency part of the field, also called the fluctuation field, has to be performed. This is done by perturbation theory. It requires the knowledge of bare fluctuation field propagators and of interpolation operators which enter into the vertices. A detailed examination of these quantities is presented for scalar fields, abelian gauge fields and for Higgs fields, finite temperature is admitted. The lattice perturbation theory is complicated because the bare lattice propagators are complicated. This is due to a partial loss of translation invariance in each step. Therefore the use of translation invariant cutoffs in place of a lattice is also discussed. In case of gauge fields this is only possible as a continuum version of the blockspin method. (orig.)

Gravitation and vacuum field

International Nuclear Information System (INIS)

Tevikyan, R.V.

1986-01-01

This paper presents equations that describe particles with spins s = 0, 1/2, 1 completely and which also describe 2s + 2 limiting fields as E → ∞. It is shown that the ordinary Hilbert-Einstein action for the gravitation field must be augmented by the action for the Bose vacuum field. This means that one must introduce in the gravitational equations a cosmological term proportional to the square of the strength of the Bose vacuum field. It is shown that the theory of gravitation describes three realities: matter, field, and vacuum field. A new form of matter--the vacuum field--is introduced into field theory

Echoes from the Field: An Ethnographic Investigation of Outdoor Science Field Trips

Science.gov (United States)

Boxerman, Jonathan Zvi

As popular as field trips are, one might think they have been well-studied. Nonetheless, field trips have not been heavily studied, and little research has mapped what actually transpires during field trips. Accordingly, to address this research gap, I asked two related research questions. The first question is a descriptive one: What happens on field trips? The second question is explanatory: What field trip events are memorable and why? I employed design research and ethnographic methodologies to study learning in naturally occurring contexts. I collaborated with middle-school science teachers to design and implement more than a dozen field trips. The field trips were nested in particular biology and earth sciences focal units. Students were tasked with making scientific observations in the field and then analyzing this data during classroom activities. Audio and video recording devices captured what happened during the field trips, classroom activities and discussions, and the interviews. I conducted comparative microanalysis of videotaped interactions. I observed dozens of events during the field trips that reverberated across time and place. I characterize the features of these events and the objects that drew interest. Then, I trace the residue across contexts. This study suggests that field trips could be more than one-off experiences and have the potential to be resources to seed and enrich learning and to augment interest in the practice of science.

Omnigenous magnetic fields

International Nuclear Information System (INIS)

Stupakov, G.V.

1982-01-01

In omnigenous magnetic fields particles' drift surfaces coincide with plasma magnetic surfaces. In this paper we formulate equations of omnigenous magnetic fields in natural curvilinear coordinates. An analysis of fields which are omnigenous only in the paraxial approximation is presented. (author)

Random Fields

Science.gov (United States)

Vanmarcke, Erik

1983-03-01

Random variation over space and time is one of the few attributes that might safely be predicted as characterizing almost any given complex system. Random fields or "distributed disorder systems" confront astronomers, physicists, geologists, meteorologists, biologists, and other natural scientists. They appear in the artifacts developed by electrical, mechanical, civil, and other engineers. They even underlie the processes of social and economic change. The purpose of this book is to bring together existing and new methodologies of random field theory and indicate how they can be applied to these diverse areas where a "deterministic treatment is inefficient and conventional statistics insufficient." Many new results and methods are included. After outlining the extent and characteristics of the random field approach, the book reviews the classical theory of multidimensional random processes and introduces basic probability concepts and methods in the random field context. It next gives a concise amount of the second-order analysis of homogeneous random fields, in both the space-time domain and the wave number-frequency domain. This is followed by a chapter on spectral moments and related measures of disorder and on level excursions and extremes of Gaussian and related random fields. After developing a new framework of analysis based on local averages of one-, two-, and n-dimensional processes, the book concludes with a chapter discussing ramifications in the important areas of estimation, prediction, and control. The mathematical prerequisite has been held to basic college-level calculus.

Electric field confinement effect on charge transport in organic field-effect transistors

NARCIS (Netherlands)

Li, X.; Kadashchuk, A.; Fishchuk, I.I.; Smaal, W.T.T.; Gelinck, G.H.; Broer, D.J.; Genoe, J.; Heremans, P.; Bässler, H.

2012-01-01

While it is known that the charge-carrier mobility in organic semiconductors is only weakly dependent on the electric field at low fields, the experimental mobility in organic field-effect transistors using silylethynyl-substituted pentacene is found to be surprisingly field dependent at low

Electric field with bipolar structure during magnetic reconnection without a guide field

Science.gov (United States)

Guo, Jun

2014-05-01

We present a study on the polarized electric field during the collisionless magnetic reconnection of antiparallel fields using two dimensional particle-in-cell simulations. The simulations demonstrate clearly that electron holes and electric field with bipolar structure are produced during magnetic reconnection without a guide field. The electric field with bipolar structure can be found near the X-line and on the separatrix and the plasma sheet boundary layer, which is consistent with the observations. These structures will elongate electron's time staying in the diffusion region. In addition, the electric fields with tripolar structures are also found in our simulation.

Merging of magnetic fields with field-aligned plasma flow components

International Nuclear Information System (INIS)

Mitchell, H.G. Jr.; Kan, J.R.

1978-01-01

The Sonnerup merging model for an incompressible plasma is extended to allow a flow component along the field lines in the inflow regions. Solutions are found to exist as long as the difference between the quantities B. V for the two inflow regions does not exceed a critical magnitude dependent on the inflow field magnitudes and plasma densities. All such solutions satisfy Vasyliunas' definition of merging, but some classes of solution have radically altered geometries, i.e. geometries in which the inflow regions are much smaller than the outflow regions. The necessary but not sufficient condition for these unusual geometries is that the field-aligned flow component in at least one inflow region be super-Alfvenic. A solution for the case of a vacuum field in one inflow region is obtained in which any flow velocity is allowed in the non-vacuum inflow region, although super-Alfvenic flow can still result in an unusual geometry. For symmetric configurations, the usual geometry, that of Petschek and Sonnerup, is retained as long as both field-aligned flow components in the inflow regions are less than twice the inflow Alfven speed. For the case of a vacuum field on one side and fields approximating the boundary between the solar wind and the earth's dayside magnetosphere, the usual geometry is retained for flow less than about 2.5 times the local Alfven speed. (author)

Overlay control methodology comparison: field-by-field and high-order methods

Science.gov (United States)

Huang, Chun-Yen; Chiu, Chui-Fu; Wu, Wen-Bin; Shih, Chiang-Lin; Huang, Chin-Chou Kevin; Huang, Healthy; Choi, DongSub; Pierson, Bill; Robinson, John C.

2012-03-01

Overlay control in advanced integrated circuit (IC) manufacturing is becoming one of the leading lithographic challenges in the 3x and 2x nm process nodes. Production overlay control can no longer meet the stringent emerging requirements based on linear composite wafer and field models with sampling of 10 to 20 fields and 4 to 5 sites per field, which was the industry standard for many years. Methods that have emerged include overlay metrology in many or all fields, including the high order field model method called high order control (HOC), and field by field control (FxFc) methods also called correction per exposure. The HOC and FxFc methods were initially introduced as relatively infrequent scanner qualification activities meant to supplement linear production schemes. More recently, however, it is clear that production control is also requiring intense sampling, similar high order and FxFc methods. The added control benefits of high order and FxFc overlay methods need to be balanced with the increased metrology requirements, however, without putting material at risk. Of critical importance is the proper control of edge fields, which requires intensive sampling in order to minimize signatures. In this study we compare various methods of overlay control including the performance levels that can be achieved.

Conformal invariant quantum field theory and composite field operators

International Nuclear Information System (INIS)

Kurak, V.

1976-01-01

The present status of conformal invariance in quantum field theory is reviewed from a non group theoretical point of view. Composite field operators dimensions are computed in some simple models and related to conformal symmetry

Channel-closing effects in strong-field ionization by a bicircular field

Science.gov (United States)

Milošević, D. B.; Becker, W.

2018-03-01

Channel-closing effects, such as threshold anomalies and resonantlike intensity-dependent enhancements in strong-field ionization by a bicircular laser field are analyzed. A bicircular field consists of two coplanar corotating or counter-rotating circularly polarized fields having different frequencies. For the total detachment rate of a negative ion by a bicircular field we observe threshold anomalies and explain them using the Wigner threshold law and energy and angular momentum conservation. For the corotating bicircular case, these effects are negligible, while for the counter-rotating case they are pronounced and their position depends on the magnetic quantum number of the initial state. For high-order above-threshold ionization of rare-gas atoms by a counter-rotating bicircular laser field we observe very pronounced intensity-dependent enhancements. We find all four types of threshold anomalies known from collision theory. Contrary to the case of linear polarization, channel-closing effects for a bicircular field are visible also in the cutoff region of the electron energy spectrum, which is explained using quantum-orbit theory.

The Coriolis field

Science.gov (United States)

Costa, L. Filipe; Natário, José

2016-05-01

We present a pedagogical discussion of the Coriolis field, emphasizing its not-so-well-understood aspects. We show that this field satisfies the field equations of the so-called Newton-Cartan theory, a generalization of Newtonian gravity that is covariant under changes of arbitrarily rotating and accelerated frames. Examples of solutions of this theory are given, including the Newtonian analogue of the Gödel universe. We discuss how to detect the Coriolis field by its effect on gyroscopes, of which the gyrocompass is an example. Finally, using a similar framework, we discuss the Coriolis field generated by mass currents in general relativity, and its measurement by the gravity probe B and LAGEOS/LARES experiments.

Field-aligned currents during northward interplanetary magnetic field: Morphology and causes

DEFF Research Database (Denmark)

Vennerstrøm, Susanne; Moretto, T.; Rastatter, L.

2005-01-01

[1] We present the results of a global MHD simulation of solar wind magnetosphere interaction during northward IMF. In particular, we emphasize the effect of the IMF By component on the reconnection geometry and the mapping along field lines to the polar ionosphere, through field-aligned currents....... We find that the existence and geometry of the polar cap is closely connected to the IMF By component. During strictly northward IMF the simulated magnetosphere can remain essentially closed because the solar wind field lines reconnect in both hemispheres, thereby creating newly reconnected closed...... both on open and closed field lines and are created by the shear of the newly reconnected field lines against the mantle field as they are convected tailward by the solar wind. When the IMF rotates from northward toward east, the magnetospheric mapping regions of the NBZ currents likewise rotates...

Macroscopic electrical field distribution and field-induced surface stresses of needle-shaped field emitters

Energy Technology Data Exchange (ETDEWEB)

Moy, Charles K.S., E-mail: charles.moy@sydney.edu.au [Australian Centre for Microscopy and Microanalysis, The University of Sydney, Sydney, NSW 2006 (Australia); ARC Centre of Excellence for Design in Light Metals, The University of Sydney, Sydney, NSW 2006 (Australia); School of Civil Engineering, The University of Sydney, Sydney, NSW 2006 (Australia); Ranzi, Gianluca [ARC Centre of Excellence for Design in Light Metals, The University of Sydney, Sydney, NSW 2006 (Australia); School of Civil Engineering, The University of Sydney, Sydney, NSW 2006 (Australia); Petersen, Timothy C. [Australian Centre for Microscopy and Microanalysis, The University of Sydney, Sydney, NSW 2006 (Australia); Ringer, Simon P. [Australian Centre for Microscopy and Microanalysis, The University of Sydney, Sydney, NSW 2006 (Australia); ARC Centre of Excellence for Design in Light Metals, The University of Sydney, Sydney, NSW 2006 (Australia)

2011-05-15

One major concern since the development of the field ion microscope is the mechanical strength of the specimens. The macroscopic shape of the imaging tip greatly influences field-induced stresses and there is merit in further study of this phenomenon from a classical perspective. Understanding the geometrical, as opposed to localized electronic, factors that affect the stress might improve the quality and success rate of atom probe experiments. This study uses macroscopic electrostatic principles and finite element modelling to investigate field-induced stresses in relation to the shape of the tip. Three two-dimensional idealized models are considered, namely hyperbolic, parabolic and sphere-on-orthogonal-cone; the shapes of which are compared to experimental tips prepared by electro-polishing. Three dimensional morphologies of both a nano-porous and single-crystal aluminium tip are measured using electron tomography to quantitatively test the assumption of cylindrical symmetry for electro-polished tips. The porous tip was prepared and studied to demonstrate a fragile specimen for which such finite element studies could determine potential mechanical failure, prior to any exhaustive atom probe investigation. -- Research highlights: {yields} We use electrostatic principles and finite element to model field-induced stresses. {yields} We study two-dimensional idealized needle-shaped field emitters. {yields} Stress distribution of hyperbolic, parabolic and sphere-on-orthogonal-cone tips mapped. {yields} Electron tomography to obtain the morphology of three-dimensional aluminium tips. {yields} Studies of the morphology of the porous tip demonstrate a fragile specimen.

Field-In-Field Technique With Intrafractionally Modulated Junction Shifts for Craniospinal Irradiation

International Nuclear Information System (INIS)

Yom, Sue S.; Frija, Erik K. C.; Mahajan, Anita; Chang, Eric; Klein, Kelli C.; Shiu, Almon; Ohrt, Jared; Woo, Shiao

2007-01-01

Purpose: To plan craniospinal irradiation with 'field-in-field' (FIF) homogenization in combination with daily, intrafractional modulation of the field junctions, to minimize the possibility of spinal cord overdose. Methods and Materials: Lateral cranial fields and posterior spinal fields were planned using a forward-planned, step-and-shoot FIF technique. Field junctions were automatically modulated and custom-weighted for maximal homogeneity within each treatment fraction. Dose-volume histogram analyses and film dosimetry were used to assess results. Results: Plan inhomogeneity improved with FIF. Planning with daily modulated junction shifts provided consistent dose delivery during each fraction of treatment across the junctions. Modulation minimized the impact of a 5-mm setup error at the junction. Film dosimetry confirmed that no point in the junction exceeded the anticipated dose. Conclusions: Field-in-field planning and modulated junction shifts improve the homogeneity and consistency of daily dose delivery, simplify treatment, and reduce the impact of setup errors

Retrieving Storm Electric Fields from Aircrfaft Field Mill Data: Part II: Applications

Science.gov (United States)

Koshak, William; Mach, D. M.; Christian H. J.; Stewart, M. F.; Bateman M. G.

2006-01-01

The Lagrange multiplier theory developed in Part I of this study is applied to complete a relative calibration of a Citation aircraft that is instrumented with six field mill sensors. When side constraints related to average fields are used, the Lagrange multiplier method performs well in computer simulations. For mill measurement errors of 1 V m(sup -1) and a 5 V m(sup -1) error in the mean fair-weather field function, the 3D storm electric field is retrieved to within an error of about 12%. A side constraint that involves estimating the detailed structure of the fair-weather field was also tested using computer simulations. For mill measurement errors of 1 V m(sup -l), the method retrieves the 3D storm field to within an error of about 8% if the fair-weather field estimate is typically within 1 V m(sup -1) of the true fair-weather field. Using this type of side constraint and data from fair-weather field maneuvers taken on 29 June 2001, the Citation aircraft was calibrated. Absolute calibration was completed using the pitch down method developed in Part I, and conventional analyses. The resulting calibration matrices were then used to retrieve storm electric fields during a Citation flight on 2 June 2001. The storm field results are encouraging and agree favorably in many respects with results derived from earlier (iterative) techniques of calibration.

Manipulation of positron orbits in a dipole magnetic field with fluctuating electric fields

Science.gov (United States)

Saitoh, H.; Horn-Stanja, J.; Nißl, S.; Stenson, E. V.; Hergenhahn, U.; Pedersen, T. Sunn; Singer, M.; Dickmann, M.; Hugenschmidt, C.; Stoneking, M. R.; Danielson, J. R.; Surko, C. M.

2018-01-01

We report the manipulation of positron orbits in a toroidal dipole magnetic field configuration realized with electric fields generated by segmented electrodes. When the toroidal circulation motion of positrons in the dipole field is coupled with time-varying electric fields generated by azimuthally segmented outer electrodes, positrons undergo oscillations of their radial positions. This enables quick manipulation of the spatial profiles of positrons in a dipole field trap by choosing appropriate frequency, amplitude, phase, and gating time of the electric fields. According to numerical orbit analysis, we applied these electric fields to positrons injected from the NEPOMUC slow positron facility into a prototype dipole field trap experiment with a permanent magnet. Measurements with annihilation γ-rays clearly demonstrated the efficient compression effects of positrons into the strong magnetic field region of the dipole field configuration. This positron manipulation technique can be used as one of essential tools for future experiments on the formation of electron-positron plasmas.

MR equipment acquisition strategies: low-field or high-field scanners

International Nuclear Information System (INIS)

Marti-Bonmati, L.; Kormano, M.

1997-01-01

Magnetic resonance (MR) field strength is one of the key aspects to consider when purchasing MR equipment. Other aspects include the gradient system, coil design, computer and pulse sequence availability, purchase cost, local reimbursement policies, and current opinion within the medical community. Our objective here is to evaluate the decision-influencing aspects of the MR market, with a focus on some specific areas such as high resolution studies, examination times, special techniques, instrumentation, open design magnets, costs and reimbursement policies, academic and industrial interests, contrast media, clinical efficacy, and finally, clinicians' preferences. Certainly the advantage of high-field is a higher signal-to-noise ratio and improved resolution. With a high-field unit, higher spatial resolution images and higher temporal resolution images can be obtained. Typical imaging times needed to produce clinically diagnostic images are about 3 times longer at 0.1 T than at 1.0 or 1.5 T. High-field-related advanced techniques, such as functional imaging, spectroscopy and microscopy, may become clinically useful in the near future. As long as there is an unlimited demand for MR examinations, it appears financially profitable to run a high-field system, despite the associated higher costs. However, if demand for MR becomes saturated, low-field systems will cause less financial strain on the reimbursement organisation and service provider. Recent emphasis on cost containment, the development of interventional techniques, the increased use of MR for patients in intensive care and operating suites, the deployment of magnets in office suites, and the development of new magnet configurations, all favour the supplementary use of low-field systems. Hence, MR units of all field strengths have a role in radiology. (orig.)

Quantum noise in the mirror–field system: A field theoretic approach

International Nuclear Information System (INIS)

Hsiang, Jen-Tsung; Wu, Tai-Hung; Lee, Da-Shin; King, Sun-Kun; Wu, Chun-Hsien

2013-01-01

We revisit the quantum noise problem in the mirror–field system by a field-theoretic approach. Here a perfectly reflecting mirror is illuminated by a single-mode coherent state of the massless scalar field. The associated radiation pressure is described by a surface integral of the stress-tensor of the field. The read-out field is measured by a monopole detector, from which the effective distance between the detector and mirror can be obtained. In the slow-motion limit of the mirror, this field-theoretic approach allows to identify various sources of quantum noise that all in all leads to uncertainty of the read-out measurement. In addition to well-known sources from shot noise and radiation pressure fluctuations, a new source of noise is found from field fluctuations modified by the mirror’s displacement. Correlation between different sources of noise can be established in the read-out measurement as the consequence of interference between the incident field and the field reflected off the mirror. In the case of negative correlation, we found that the uncertainty can be lowered than the value predicted by the standard quantum limit. Since the particle-number approach is often used in quantum optics, we compared results obtained by both approaches and examine its validity. We also derive a Langevin equation that describes the stochastic dynamics of the mirror. The underlying fluctuation–dissipation relation is briefly mentioned. Finally we discuss the backreaction induced by the radiation pressure. It will alter the mean displacement of the mirror, but we argue this backreaction can be ignored for a slowly moving mirror. - Highlights: ► The quantum noise problem in the mirror–field system is re-visited by a field-theoretic approach. ► Other than the shot noise and radiation pressure noise, we show there are new sources of noise and correlation between them. ► The noise correlations can be used to suppress the overall quantum noise on the mirror. �

Quantum noise in the mirror-field system: A field theoretic approach

Energy Technology Data Exchange (ETDEWEB)

Hsiang, Jen-Tsung, E-mail: cosmology@gmail.com [Department of Physics, National Dong-Hwa University, Hua-lien, Taiwan, ROC (China); Wu, Tai-Hung [Department of Physics, National Dong-Hwa University, Hua-lien, Taiwan, ROC (China); Lee, Da-Shin, E-mail: dslee@mail.ndhu.edu.tw [Department of Physics, National Dong-Hwa University, Hua-lien, Taiwan, ROC (China); King, Sun-Kun [Institutes of Astronomy and Astrophysics, Academia Sinica, Taipei, Taiwan, ROC (China); Wu, Chun-Hsien [Department of Physics, Soochow University, Taipei, Taiwan, ROC (China)

2013-02-15

We revisit the quantum noise problem in the mirror-field system by a field-theoretic approach. Here a perfectly reflecting mirror is illuminated by a single-mode coherent state of the massless scalar field. The associated radiation pressure is described by a surface integral of the stress-tensor of the field. The read-out field is measured by a monopole detector, from which the effective distance between the detector and mirror can be obtained. In the slow-motion limit of the mirror, this field-theoretic approach allows to identify various sources of quantum noise that all in all leads to uncertainty of the read-out measurement. In addition to well-known sources from shot noise and radiation pressure fluctuations, a new source of noise is found from field fluctuations modified by the mirror's displacement. Correlation between different sources of noise can be established in the read-out measurement as the consequence of interference between the incident field and the field reflected off the mirror. In the case of negative correlation, we found that the uncertainty can be lowered than the value predicted by the standard quantum limit. Since the particle-number approach is often used in quantum optics, we compared results obtained by both approaches and examine its validity. We also derive a Langevin equation that describes the stochastic dynamics of the mirror. The underlying fluctuation-dissipation relation is briefly mentioned. Finally we discuss the backreaction induced by the radiation pressure. It will alter the mean displacement of the mirror, but we argue this backreaction can be ignored for a slowly moving mirror. - Highlights: Black-Right-Pointing-Pointer The quantum noise problem in the mirror-field system is re-visited by a field-theoretic approach. Black-Right-Pointing-Pointer Other than the shot noise and radiation pressure noise, we show there are new sources of noise and correlation between them. Black-Right-Pointing-Pointer The noise

Quantized Dirac field interacting with a classical Maxwell field

International Nuclear Information System (INIS)

Kolsrud, M.

1987-10-01

The S operator for the quantized and the s matrix for the unquantized Dirac field, both fields interacting with an unquantized Maxwell field, are shown to be related in the following way: S=exp(-ic†kc) and s=exp(-ik). Here c is the column matrix of the particle operators, and k is a Hermitian matrix. With splitting of c into an electron and a positron part, a corresponding factorization of S is performed. Exact expressions for the probability amplitude for various electron and/or positron processes are then obtained

Climate Change at the Poles: Research Immersion Experience at Bellingshausen, Antarctica

Science.gov (United States)

Alexeev, V. A.; Repina, I. A.; Baeseman, J. L.; Fernandoy, F.; Bart, S.

2010-12-01

We brought a party of 15 scientists, graduate students, and educators to King George Island, the largest of the South Shetland Islands, just off the Antarctic Peninsula, for an international workshop on Antarctica and global climate change in January 2010. Participants included professors, young scientists and graduate students from the Obukhov Institute of Atmospheric Physics, the University of Maryland, the University of Wisconsin, and the Michigan Technological University. Lindsay Bartholomew, an education and outreach specialist at the Museum of Science and Industry in Chicago connected the workshop via video and Internet with an audience of museum visitors. Scientists living and working at Bellingshausen, including Hans-Ulrich Peter, an eminent ecologist from Jena University (Germany), and Bulat Movlyudov (Institute of Geography, Moscow), a distinguished glaciologist, participated in the workshop. Field trips led by Peter and Movlyudov and others were made by day and lectures were held by night. Professors and graduate students made cutting-edge presentations on such subjects as permafrost, glaciology, and global climate models. Three workshop teams conducted field research projects at the foot of the Bellingshausen Dome icecap - two on carbon cycling and one on permafrost. Major funding sources for the workshop included the Russian Foundation for Basic Research (Russia), Wilderness Research Foundation (USA), NSF, University of Wisconsin at Stevens Point, Alfred Wegener Institute (Germany) and Museum for Science and Industry (Chicago). INACH, the Chilean Antarctic Institute, and IAU, the Uruguayan Antarctic Institute, provided air charter services. On King George Island, our group was billeted at Russia’s Bellingshausen science station.

User requirements for information systems in nuclear medicine.

Science.gov (United States)

Todd-Pokropek, A; Vauramo, E; Cosgriff, P; Sippo-Tujunen, I; Britton, K

1992-05-01

In the field of COST cooperation (COST = European Cooperation in the Field of Scientific and Technical Research) a project B2 for Quality Assurance in Nuclear Medicine Software has been established. In a memorandum of understanding setting up this project, user requirements were to be defined for the hardware and software used for data acquisition, processing and presentation. A subgroup of the management committee of COST B2 were interested in the Advanced Informatics in Medicine, AIM, task T-734 'Quality Assurance of Medical Software', and the AIM Project 'A 1034', coordinated by Dr K. Britton, was initiated. The initial drafts of this document were written in Helsinki during 1988-1990, and submitted for comment by the members of the management committee of COST B2. These comments were integrated in the text and this document was finalized by the UK group so as to make it available for international discussion. It is anticipated that, after appropriate international discussion, these User Requirements for Information Systems in Nuclear Medicine will be adopted by the management committee of COST B2 as a COST document. Towards these ends, a working group chaired by Dr Britton, including the British and Finnish teams and Ulrich Noelpp from Switzerland, was appointed by the management committee of COST B2 in April 1990. While writing it we have had the pleasure of working with referees from different European hospitals in many countries. We are happy to thank all of them for their valuable contributions.

Superconductivity in Strong Magnetic Field (Greater Than Upper Critical Field)

International Nuclear Information System (INIS)

Tessema, G.X.; Gamble, B.K.; Skove, M.J.; Lacerda, A.H.; Mielke, C.H.

1998-01-01

The National High Magnetic Field Laboratory, funded by the National Science Foundation and other US federal Agencies, has in recent years built a wide range of magnetic fields, DC 25 to 35 Tesla, short pulse 50 - 60 Tesla, and quasi-continuous 60 Tesla. Future plans are to push the frontiers to 45 Tesla DC and 70 to 100 Tesla pulse. This user facility, is open for national and international users, and creates an excellent tool for materials research (metals, semiconductors, superconductors, biological systems ..., etc). Here we present results of a systematic study of the upper critical field of a novel superconducting material which is considered a promising candidate for the search for superconductivity beyond H c2 as proposed by several new theories. These theories predict that superconductors with low carrier density can reenter the superconducting phase beyond the conventional upper critical field H c2 . This negates the conventional thinking that superconductivity and magnetic fields are antagonistic

Covariant electromagnetic field lines

Science.gov (United States)

Hadad, Y.; Cohen, E.; Kaminer, I.; Elitzur, A. C.

2017-08-01

Faraday introduced electric field lines as a powerful tool for understanding the electric force, and these field lines are still used today in classrooms and textbooks teaching the basics of electromagnetism within the electrostatic limit. However, despite attempts at generalizing this concept beyond the electrostatic limit, such a fully relativistic field line theory still appears to be missing. In this work, we propose such a theory and define covariant electromagnetic field lines that naturally extend electric field lines to relativistic systems and general electromagnetic fields. We derive a closed-form formula for the field lines curvature in the vicinity of a charge, and show that it is related to the world line of the charge. This demonstrates how the kinematics of a charge can be derived from the geometry of the electromagnetic field lines. Such a theory may also provide new tools in modeling and analyzing electromagnetic phenomena, and may entail new insights regarding long-standing problems such as radiation-reaction and self-force. In particular, the electromagnetic field lines curvature has the attractive property of being non-singular everywhere, thus eliminating all self-field singularities without using renormalization techniques.

Gauge theories of Yang-Mills vector fields coupled to antisymmetric tensor fields

International Nuclear Information System (INIS)

Anco, Stephen C.

2003-01-01

A non-Abelian class of massless/massive nonlinear gauge theories of Yang-Mills vector potentials coupled to Freedman-Townsend antisymmetric tensor potentials is constructed in four space-time dimensions. These theories involve an extended Freedman-Townsend-type coupling between the vector and tensor fields, and a Chern-Simons mass term with the addition of a Higgs-type coupling of the tensor fields to the vector fields in the massive case. Geometrical, field theoretic, and algebraic aspects of the theories are discussed in detail. In particular, the geometrical structure mixes and unifies features of Yang-Mills theory and Freedman-Townsend theory formulated in terms of Lie algebra valued curvatures and connections associated to the fields and nonlinear field strengths. The theories arise from a general determination of all possible geometrical nonlinear deformations of linear Abelian gauge theory for one-form fields and two-form fields with an Abelian Chern-Simons mass term in four dimensions. For this type of deformation (with typical assumptions on the allowed form considered for terms in the gauge symmetries and field equations), an explicit classification of deformation terms at first-order is obtained, and uniqueness of deformation terms at all higher orders is proven. This leads to a uniqueness result for the non-Abelian class of theories constructed here

Determination of the saturation magnetization, anisotropy field, mean field interaction, and switching field distribution for nanocrystalline hard magnets

International Nuclear Information System (INIS)

McCallum, R. William

2005-01-01

For a uniaxial nanocrystalline magnetic material, the determination of the saturation magnetization, M s , requires measurements of the magnetization at fields which exceed the anisotropy field. For a typical RE-Tm compound, where RE=rare earth and Tm=transition metal, this may require fields above 7 T if the approach to saturation law is used. However for an isotropic material composed of a random distribution of non-interacting uniaxial grains, both M s and the anisotropy filed, H a , may be determined by fitting the Stoner-Wohlfarth (SW) model (Philos. Trans. Roy. Soc. 240 (1948) 599) to the reversible part of the demagnetization curve in the first quadrant. Furthermore, using the mean field interaction model of Callen, Liu and Cullen [2], a quantitative measure of the interaction strength for interacting particles may be determined. In conjunction with an analytical fit to the first quadrant demagnetization curve of the SW model, this allows M s , H a and the mean field interaction constant of a nanocrystalline magnet to be determined from measurements below 5 T. Furthermore, comparison of the model solution for the reversible magnetization with experimental data in the 2nd and 3rd quadrants allows the accurate determination of the switching field distribution. In many cases the hysteresis loop may be accurately described by a normal distribution of switching fields

Extraction of the Electric Field in Field Plate Assisted RESURF Devices

NARCIS (Netherlands)

Boksteen, B.K.; Dhar, S.; Heringa, A.; Koops, G.E.J.; Hueting, Raymond Josephus Engelbart

2012-01-01

It has previously been reported that the lateral electric field (Ex) in the drain extension of thin SOI HV (700V) field plate assisted RESURF devices can be extracted from their ID-VD characteristics in the subthreshold regime. In this work the prerequisites for valid field extraction and the

Field emitters with low turn on electric field based on carbon fibers

International Nuclear Information System (INIS)

Wang Qilong; Mu Hui; Zhang Xiaobing; Lei Wei; Wang Jinchan; Zhao Hongping

2007-01-01

Field emitters of vertical carbon fibers on a silicon substrate are fabricated by catalytic chemical vapor deposition. After an ageing process of 150 min, field emission measurement of the fibers is carried out in a vacuum chamber with a base pressure of 5.0 x 10 -4 Pa. The experimental results display that field emission performance of the carbon fibers depends strongly on the vacuum level during the experiments. After the field emission measurement, damage to the carbon fiber field emitters is observed from the scanning electron microscopic images

Far field acceleration

International Nuclear Information System (INIS)

Fernow, R.C.

1995-07-01

Far fields are propagating electromagnetic waves far from their source, boundary surfaces, and free charges. The general principles governing the acceleration of charged particles by far fields are reviewed. A survey of proposed field configurations is given. The two most important schemes, Inverse Cerenkov acceleration and Inverse free electron laser acceleration, are discussed in detail

Mosquitoes and other aquatic insects in fallow field biotopes and rice paddy fields.

Science.gov (United States)

Ohba, S Y; Matsuo, T; Takagi, M

2013-03-01

Fallow field biotopes that develop from abandoned rice fields are man-made wetlands that provide new habitats for various aquatic animals. Although consideration of such biotopes generally focuses on their positive aspects, this study evaluated the negative aspects of establishing fallow field biotopes with regard to mosquito breeding sites. To determine whether fallow field biotopes become breeding habitats for vector mosquitoes, we evaluated mosquito fauna in fallow field biotopes and adjacent rice fields. We found larvae of Anopheles lesteri, Anopheles sinensis and Culex tritaeniorhynchus (all: Diptera: Culicidae) in the biotopes. Although abundances of mosquito larvae in the biotopes and rice fields were statistically similar, mosquito abundances in rice fields increased dramatically in August when the water level reduced after the rainy season. The abundance and variety of the mosquitoes' natural predators were greater in biotopes than in rice fields because the former are a permanent and stable aquatic environment. A generalized linear mixed model showed a negative effect of predator diversity on mosquito larvae abundance in both habitats. Although fallow field biotopes become breeding habitats for vector mosquitoes, establishing biotopes from fallow fields in order to protect various aquatic animals, including mosquito insect predators, may help to control mosquito breeding. © 2012 The Royal Entomological Society.

Low-field MRI can be more sensitive than high-field MRI

Science.gov (United States)

Coffey, Aaron M.; Truong, Milton L.; Chekmenev, Eduard Y.

2013-12-01

MRI signal-to-noise ratio (SNR) is the key factor for image quality. Conventionally, SNR is proportional to nuclear spin polarization, which scales linearly with magnetic field strength. Yet ever-stronger magnets present numerous technical and financial limitations. Low-field MRI can mitigate these constraints with equivalent SNR from non-equilibrium ‘hyperpolarization' schemes, which increase polarization by orders of magnitude independently of the magnetic field. Here, theory and experimental validation demonstrate that combination of field independent polarization (e.g. hyperpolarization) with frequency optimized MRI detection coils (i.e. multi-turn coils using the maximum allowed conductor length) results in low-field MRI sensitivity approaching and even rivaling that of high-field MRI. Four read-out frequencies were tested using samples with identical numbers of 1H and 13C spins. Experimental SNRs at 0.0475 T were ∼40% of those obtained at 4.7 T. Conservatively, theoretical SNRs at 0.0475 T 1.13-fold higher than those at 4.7 T were possible despite an ∼100-fold lower detection frequency, indicating feasibility of high-sensitivity MRI without technically challenging, expensive high-field magnets. The data at 4.7 T and 0.0475 T was obtained from different spectrometers with different RF probes. The SNR comparison between the two field strengths accounted for many differences in parameters such as system noise figures and variations in the probe detection coils including Q factors and coil diameters.

Near-field and far-field modeling of scattered surface waves. Application to the apertureless scanning near-field optical microscopy

International Nuclear Information System (INIS)

Muller, J.; Parent, G.; Fumeron, S.; Jeandel, G.; Lacroix, D.

2011-01-01

The detection of surface waves through scanning near-field optical microscopy (SNOM) is a promising technique for thermal measurements at very small scales. Recent studies have shown that electromagnetic waves, in the vicinity of a scattering structure such as an atomic force microscopy (AFM) tip, can be scattered from near to far-field and thus detected. In the present work, a model based on the finite difference time domain (FDTD) method and the near-field to far-field (NFTFF) transformation for electromagnetic waves propagation is presented. This model has been validated by studying the electromagnetic field of a dipole in vacuum and close to a dielectric substrate. Then simulations for a tetrahedral tip close to an interface are presented and discussed.

Electron-Cloud Wake Fields

CERN Document Server

Rumolo, Giovanni

2002-01-01

The electron cloud gives rise to coherent and incoherent single-bunch wake fields, both in the longitudinal and in the transverse direction, and to coherent coupled-bunch wakes. These wake fields can be computed using the simulation programs ECLOUD and HEADTAIL developed at CERN. We present the wake fields simulated for the LHC beam in the CERN SPS and at injection into the LHC in different magnetic field configurations (field-free region, dipole, and solenoid), where the magnetic field affects both the elec-tron motion during a bunch passage and the overall electron distribution in the beam pipe.

Forces in electromagnetic field and gravitational field

OpenAIRE

Weng, Zihua

2008-01-01

The force can be defined from the linear momentum in the gravitational field and electromagnetic field. But this definition can not cover the gradient of energy. In the paper, the force will be defined from the energy and torque in a new way, which involves the gravitational force, electromagnetic force, inertial force, gradient of energy, and some other new force terms etc. One of these new force terms can be used to explain why the solar wind varies velocity along the magnetic force line in...

Magnetic Field Effects on the Plume of a Diverging Cusped-Field Thruster

KAUST Repository

Matlock, Taylor

2010-07-25

The Diverging Cusped-Field Thruster (DCFT) uses three permanent ring magnets of alternating polarity to create a unique magnetic topology intended to reduce plasma losses to the discharge chamber surfaces. The magnetic field strength within the DCFT discharge chamber (up to 4 kG on axis) is much higher than in thrusters of similar geometry, which is believed to be a driving factor in the high measured anode efficiencies. The field strength in the near plume region is large as well, which may bear on the high beam divergences measured, with peaks in ion current found at angles of around 30-35 from the thruster axis. Characterization of the DCFT has heretofore involved only one magnetic topology. It is then the purpose of this study to investigate changes to the near-field plume caused by altering the shape and strength of the magnetic field. A thick magnetic collar, encircling the thruster body, is used to lower the field strength outside of the discharge chamber and thus lessen any effects caused by the external field. Changes in the thruster plume with field topology are monitored by the use of normal Langmuir and emissive probes interrogating the near-field plasma. Results are related to other observations that suggest a unified conceptual framework for the important near-exit region of the thruster.

Narrowing the field

DEFF Research Database (Denmark)

Knudsen, Bo Nissen

characteristics and the sequence of information in the series. Adding to the challenge is the macrostructural variation: The areas covered in printed form are covered with shifting principles of selecting the names to be published. Finding the right balance between letting the algorithms structure this complex....... As of now, no less than 45 different database fields have been found necessary to structure the information found in a single place-name entry – some fields mandatory, some nonmandatory. And using a relational database structure, some fields have multiple occurrences within one entry (i.e. multiple source...... forms for one entry a.s.f.). Having made the conscious decision to split up the information into so many categories (i.e. fields) – instead of employing a broad 'other information' field – sophisticated algorithms have been developed in order to identify information category from typographical...

Out-of-Field Cell Survival Following Exposure to Intensity-Modulated Radiation Fields

International Nuclear Information System (INIS)

Butterworth, Karl T.; McGarry, Conor K.; Trainor, Colman; O'Sullivan, Joe M.; Hounsell, Alan R.; Prise, Kevin M.

2011-01-01

Purpose: To determine the in-field and out-of-field cell survival of cells irradiated with either primary field or scattered radiation in the presence and absence of intercellular communication. Methods and Materials: Cell survival was determined by clonogenic assay in human prostate cancer (DU145) and primary fibroblast (AGO1552) cells following exposure to different field configurations delivered using a 6-MV photon beam produced with a Varian linear accelerator. Results: Nonuniform dose distributions were delivered using a multileaf collimator (MLC) in which half of the cell population was shielded. Clonogenic survival in the shielded region was significantly lower than that predicted from the linear quadratic model. In both cell lines, the out-of-field responses appeared to saturate at 40%-50% survival at a scattered dose of 0.70 Gy in DU-145 cells and 0.24 Gy in AGO1522 cells. There was an approximately eightfold difference in the initial slopes of the out-of-field response compared with the α-component of the uniform field response. In contrast, cells in the exposed part of the field showed increased survival. These observations were abrogated by direct physical inhibition of cellular communication and by the addition of the inducible nitric oxide synthase inhibitor aminoguanidine known to inhibit intercellular bystander effects. Additional studies showed the proportion of cells irradiated and dose delivered to the shielded and exposed regions of the field to impact on response. Conclusions: These data demonstrate out-of-field effects as important determinants of cell survival following exposure to modulated irradiation fields with cellular communication between differentially irradiated cell populations playing an important role. Validation of these observations in additional cell models may facilitate the refinement of existing radiobiological models and the observations considered important determinants of cell survival.

Dynamical Mean Field Approximation Applied to Quantum Field Theory

CERN Document Server

Akerlund, Oscar; Georges, Antoine; Werner, Philipp

2013-12-04

We apply the Dynamical Mean Field (DMFT) approximation to the real, scalar phi^4 quantum field theory. By comparing to lattice Monte Carlo calculations, perturbation theory and standard mean field theory, we test the quality of the approximation in two, three, four and five dimensions. The quantities considered in these tests are the critical coupling for the transition to the ordered phase and the associated critical exponents nu and beta. We also map out the phase diagram in four dimensions. In two and three dimensions, DMFT incorrectly predicts a first order phase transition for all bare quartic couplings, which is problematic, because the second order nature of the phase transition of lattice phi^4-theory is crucial for taking the continuum limit. Nevertheless, by extrapolating the behaviour away from the phase transition, one can obtain critical couplings and critical exponents. They differ from those of mean field theory and are much closer to the correct values. In four dimensions the transition is sec...

Background field coils for the High Field Test Facility

International Nuclear Information System (INIS)

Zbasnik, J.P.; Cornish, D.N.; Scanlan, R.M.; Jewell, A.M.; Leber, R.L.; Rosdahl, A.R.; Chaplin, M.R.

1980-01-01

The High Field Test Facility (HFTF), presently under construction at LLNL, is a set of superconducting coils that will be used to test 1-m-o.d. coils of prototype conductors for fusion magnets in fields up to 12 T. The facility consists of two concentric sets of coils; the outer set is a stack of Nb-Ti solenoids, and the inner set is a pair of solenoids made of cryogenically-stabilized, multifilamentary Nb 3 Sn superconductor, developed for use in mirror-fusion magnets. The HFTF system is designed to be parted along the midplane to allow high-field conductors, under development for Tokamak fusion machines, to be inserted and tested. The background field coils were wound pancake-fashion, with cold-welded joints at both the inner and outer diameters. Turn-to-turn insulation was fabricated at LLNL from epoxy-fiberglass strip. The coils were assembled and tested in our 2-m-diam cryostat to verify their operation

Nonperturbative construction of massive Yang-Mills fields without the Higgs field

Science.gov (United States)

Kondo, Kei-Ichi

2013-01-01

In order to understand the so-called decoupling solution for gluon and ghost propagators in QCD, we give a nonperturbative construction of a massive vector field describing a non-Abelian massive spin-one particle, which has the correct physical degrees of freedom and is invariant under a modified Becchi-Rouet-Stora-Tyutin transformation, in a massive Yang-Mills model without the Higgs field, i.e., the Curci-Ferrari model. The resulting non-Abelian massive vector boson field is written by using a nonlinear but local transformation from the original fields in the Curci-Ferrari model. As an application, we write down a local mass term for the Yang-Mills field and a dimension-two condensate, which are exactly invariant under the modified Becchi-Rouet-Stora-Tyutin transformation, Lorentz transformation, and color rotation.

Polarimetry of random fields

Science.gov (United States)

Ellis, Jeremy

On temporal, spatial and spectral scales which are small enough, all fields are fully polarized. In the optical regime, however, instantaneous fields can rarely be examined, and, instead, only average quantities are accessible. The study of polarimetry is concerned with both the description of electromagnetic fields and the characterization of media a field has interacted with. The polarimetric information is conventionally presented in terms of second order field correlations which are averaged over the ensemble of field realizations. Motivated by the deficiencies of classical polarimetry in dealing with specific practical situations, this dissertation expands the traditional polarimetric approaches to include higher order field correlations and the description of fields fluctuating in three dimensions. In relation to characterization of depolarizing media, a number of fourth-order correlations are introduced in this dissertation. Measurements of full polarization distributions, and the subsequent evaluation of Stokes vector element correlations and Complex Degree of Mutual Polarization demonstrate the use of these quantities for material discrimination and characterization. Recent advancements in detection capabilities allow access to fields near their sources and close to material boundaries, where a unique direction of propagation is not evident. Similarly, there exist classical situations such as overlapping beams, focusing, or diffusive scattering in which there is no unique transverse direction. In this dissertation, the correlation matrix formalism is expanded to describe three dimensional electromagnetic fields, providing a definition for the degree of polarization of such a field. It is also shown that, because of the dimensionality of the problem, a second parameter is necessary to fully describe the polarimetric properties of three dimensional fields. Measurements of second-order correlations of a three dimensional field are demonstrated, allowing the

Unified field theory

International Nuclear Information System (INIS)

Prasad, R.

1975-01-01

Results of researches into Unified Field Theory over the past seven years are presented. The subject is dealt with in chapters entitled: the choice of affine connection, algebraic properties of the vector fields, field laws obtained from the affine connection based on the path integral method, application to quantum theory and cosmology, interpretation of physical theory in terms of geometry. (U.K.)

Pair-breaking effects by parallel magnetic field in electric-field-induced surface superconductivity

International Nuclear Information System (INIS)

Nabeta, Masahiro; Tanaka, Kenta K.; Onari, Seiichiro; Ichioka, Masanori

2016-01-01

Highlights: • Zeeman effect shifts superconducting gaps of sub-band system, towards pair-breaking. • Higher-level sub-bands become normal-state-like electronic states by magnetic fields. • Magnetic field dependence of zero-energy DOS reflects multi-gap superconductivity. - Abstract: We study paramagnetic pair-breaking in electric-field-induced surface superconductivity, when magnetic field is applied parallel to the surface. The calculation is performed by Bogoliubov-de Gennes theory with s-wave pairing, including the screening effect of electric fields by the induced carriers near the surface. Due to the Zeeman shift by applied fields, electronic states at higher-level sub-bands become normal-state-like. Therefore, the magnetic field dependence of Fermi-energy density of states reflects the multi-gap structure in the surface superconductivity.

Muonium spin exchange as a Poisson process: magnetic field dependence in transverse fields

International Nuclear Information System (INIS)

Senba, Masayoshi; British Columbia Univ., Vancouver, BC

1993-01-01

The muonium spin exchange has been investigated as a function of transverse magnetic field strength, where the Poisson nature of collisions is exploited to simplify the calculation. In intermediate fields where the so-called two-frequency muonium signal is observed, the muonium relaxation due to spin exchange is 1.5 times faster than in low fields. In even higher fields, the observed relaxation rate drops back to the low field value. Since the relaxation rate due to a chemical reaction is field independent, such a distinct field dependence in spin exchange can be used in distinguishing experimentally spin exchange from chemical reactions. The time evolution of the muon spin polarization in the presence of muonium spin exchange has been expressed in a simple analytical closed form. (author)

Mixed-symmetry fields in AdS(5), conformal fields, and AdS/CFT

Energy Technology Data Exchange (ETDEWEB)

Metsaev, R.R. [Department of Theoretical Physics, P.N. Lebedev Physical Institute,Leninsky prospect 53, Moscow 119991 (Russian Federation)

2015-01-15

Mixed-symmetry arbitrary spin massive, massless, and self-dual massive fields in AdS(5) are studied. Light-cone gauge actions for such fields leading to decoupled equations of motion are constructed. Light-cone gauge formulation of mixed-symmetry anomalous conformal currents and shadows in 4d flat space is also developed. AdS/CFT correspondence for normalizable and non-normalizable modes of mixed-symmetry AdS fields and the respective boundary mixed-symmetry anomalous conformal currents and shadows is studied. We demonstrate that the light-cone gauge action for massive mixed-symmetry AdS field evaluated on solution of the Dirichlet problem amounts to the light-cone gauge 2-point vertex of mixed-symmetry anomalous shadow. Also we show that UV divergence of the action for mixed-symmetry massive AdS field with some particular value of mass parameter evaluated on the Dirichlet problem amounts to the action of long mixed-symmetry conformal field, while UV divergence of the action for mixed-symmetry massless AdS field evaluated on the Dirichlet problem amounts to the action of short mixed-symmetry conformal field. We speculate on string theory interpretation of a model which involves short low-spin conformal fields and long higher-spin conformal fields.

Field Report

DEFF Research Database (Denmark)

Gorm Hansen, Louise Lyngfeldt

2012-01-01

This field report expresses perfectly the kind of confusion almost all of us experience when entering the field. How do we know whether what we’re doing is “right” or not? What in particular should we record when we don’t have time to write down everything among all the myriad impressions thrusting...

Working in the magnetic field of ultrahigh field MRI

International Nuclear Information System (INIS)

Leitgeb, N.; Gombotz, H.

2013-01-01

Development of magnetic resonance imaging (MRI) device technology continues to increase the static magnetic flux densities applied and consequently leads to considerably increased occupational exposure. This has already made it necessary to review limits of occupational exposure and to postpone European legal regulations for occupational exposure to electromagnetic fields. This raises the question whether and if so which adverse health effects and health risks might be associated with occupational exposure to MRI ultra-high static magnetic fields. Based on a survey on interaction mechanisms recommendations and safety rules are presented to help minimize adverse health effects of emerging ultra-high field MRI. (orig.) [de

Quantized fields in interaction with external fields. Pt. 1

International Nuclear Information System (INIS)

Bellissard, J.

1975-01-01

We consider a massive, charged, scalar quantized field interacting with an external classical field. Guided by renormalized perturbation theory we show that whenever the integral equations defining the Feynman or retarded or advanced interaction kernel possess non perturbative solutions, there exists an S-operator which satisfies, up to a phase, the axioms of Bogoliubov, and is given for small external fields by a power series which converges on coherent states. Furthermore this construction is shown to be equivalent to the one based on the Yang-Kaellen-Feldman equation. This is a consequence of the relations between chronological and retarded Green's functions which are described in detail. (orig.) [de

A Unified Field Theory of Gravity, Electromagnetism, and the Yang-Mills Gauge Field

Directory of Open Access Journals (Sweden)

Suhendro I.

2008-01-01

Full Text Available In this work, we attempt at constructing a comprehensive four-dimensional unified field theory of gravity, electromagnetism, and the non-Abelian Yang-Mills gauge field in which the gravitational, electromagnetic, and material spin fields are unified as intrinsic geometric objects of the space-time manifold S4 via the connection, with the general- ized non-Abelian Yang-Mills gauge field appearing in particular as a sub-field of the geometrized electromagnetic interaction.

Vector optical fields with polarization distributions similar to electric and magnetic field lines.

Science.gov (United States)

Pan, Yue; Li, Si-Min; Mao, Lei; Kong, Ling-Jun; Li, Yongnan; Tu, Chenghou; Wang, Pei; Wang, Hui-Tian

2013-07-01

We present, design and generate a new kind of vector optical fields with linear polarization distributions modeling to electric and magnetic field lines. The geometric configurations of "electric charges" and "magnetic charges" can engineer the spatial structure and symmetry of polarizations of vector optical field, providing additional degrees of freedom assisting in controlling the field symmetry at the focus and allowing engineering of the field distribution at the focus to the specific applications.

Field Trips. Beginnings Workshop.

Science.gov (United States)

Cartwright, Sally; Aronson, Susan S.; Stacey, Susan; Winbush, Olga

2001-01-01

Five articles highlight benefits and organization of field trips: (1) "Field Trips Promote Child Learning at Its Best"; (2) "Planning for Maximum Benefit, Minimum Risk"; (3) "Coaching Community Hosts"; (4) "The Story of a Field Trip: Trash and Its Place within Children's Learning and Community"; and (5) "Field Trip Stories and Perspectives" (from…

Strong Magnetic Field Characterisation

Science.gov (United States)

2012-04-01

an advertised surface field of approximately 0.5 T were used to supply the static magnetic field source. The disc magnet had a diameter of 50 mm and... colour bar indicates the magnetic field strength set to an arbitrary 0.25 T. The white area has a field >0.25 T. The size of the arrow is proportional...9 shows the magnetic field strength along a slice in the XZ plane. The colours represent the total UNCLASSIFIED 10 UNCLASSIFIED DSTO-TR-2699

Hyperbolic-symmetry vector fields.

Science.gov (United States)

Gao, Xu-Zhen; Pan, Yue; Cai, Meng-Qiang; Li, Yongnan; Tu, Chenghou; Wang, Hui-Tian

2015-12-14

We present and construct a new kind of orthogonal coordinate system, hyperbolic coordinate system. We present and design a new kind of local linearly polarized vector fields, which is defined as the hyperbolic-symmetry vector fields because the points with the same polarization form a series of hyperbolae. We experimentally demonstrate the generation of such a kind of hyperbolic-symmetry vector optical fields. In particular, we also study the modified hyperbolic-symmetry vector optical fields with the twofold and fourfold symmetric states of polarization when introducing the mirror symmetry. The tight focusing behaviors of these vector fields are also investigated. In addition, we also fabricate micro-structures on the K9 glass surfaces by several tightly focused (modified) hyperbolic-symmetry vector fields patterns, which demonstrate that the simulated tightly focused fields are in good agreement with the fabricated micro-structures.

RFID Antenna Near-field Characterization Using a New 3D Magnetic Field Probe

Directory of Open Access Journals (Sweden)

Kassem Jomaa

2017-05-01

Full Text Available In this paper the design of a new 3D magnetic field (H-field probe with a near-field scanning system is presented, then the near electromagnetic fields radiated by a Library RFID system is characterized. The proposed system is developed in order to determine the magnetic near-field emitted by electronic devices. The designed isotropic H-field probe consists of three orthogonal and identical loops each of diameter of 6 mm having 3 turns. The antenna factor of the designed probe is presented for a frequency range from 10 MHz to 1 GHz. The designed probe is tested and validated using a standard passive circuit as a device under test. An RFID reader antenna is also designed and simulated on HFSS (high frequency structural simulator and the radiated magnetic field, obtained by simulations, is then compared to the real measured one above the fabricated circuit. The obtained levels are checked if they satisfy the European and ICNIRP Electromagnetic Fields Guidelines.

Representation of magnetic fields with toroidal topology in terms of field-line invariants

International Nuclear Information System (INIS)

Lewis, H.R.

1990-01-01

Beginning with Boozer's representation of magnetic fields with toroidal topology [Phys. Fluids 26, 1288 (1983)], a general formalism is presented for the representation of any magnetic field with toroidal topology in terms of field-line invariants. The formalism is an application to the magnetic field case of results developed recently by Lewis et al. (submitted for publication to J. Phys. A) for arbitrary time-dependent Hamiltonian systems with one degree of freedom. Every magnetic field with toroidal topology can be associated with time-dependent Hamiltonian systems with one degree of freedom and every time-dependent Hamiltonian system with one degree of freedom can be associated with magnetic fields with toroidal topology. In the Hamiltonian context, given any particular function I(q,p,t), Lewis et al. derived those Hamiltonians for which I(q,p,t) is an invariant. In addition, for each of those Hamiltonians, they derived a function canonically conjugate to I(q,p,t) that is also an invariant. They applied this result to the case where I(q,p,t) is expressed as a function of two canonically conjugate functions. This general Hamiltonian formalism provides a basis for representing magnetic fields with toroidal topology in terms of field-line invariants. The magnetic fields usually contain plasma with flow and anisotropic pressure. A class of fields with or without rotational symmetry is identified for which there are magnetic surfaces. The formalism is developed for application to the case of vacuum magnetic fields

A Unified Field Theory of Gravity, Electromagnetism, and theA Unified Field Theory of Gravity, Electromagnetism, and the Yang-Mills Gauge Field

Directory of Open Access Journals (Sweden)

Suhendro I.

2008-01-01

Full Text Available In this work, we attempt at constructing a comprehensive four-dimensional unified field theory of gravity, electromagnetism, and the non-Abelian Yang-Mills gauge field in which the gravitational, electromagnetic, and material spin fields are unified as intrinsic geometric objects of the space-time manifold $S_4$ via the connection, with the generalized non-Abelian Yang-Mills gauge field appearing in particular as a sub-field of the geometrized electromagnetic interaction.

Towers of Function Fields over Non-prime Finite Fields

DEFF Research Database (Denmark)

Bassa, Alp; Beelen, Peter; Garcia, Arnaldo

2015-01-01

Over all non-prime finite fields, we construct some recursive towers of function fields with many rational places. Thus we obtain a substantial improvement on all known lower bounds for Ihara’s quantity A(ℓ), for ℓ = pn with p prime and n > 3 odd. We relate the explicit equations to Drinfeld modu...

The Galactic magnetic fields

International Nuclear Information System (INIS)

Han Jinlin

2006-01-01

A good progress has been made on studies of Galactic magnetic fields in last 10 years. I describe what we want to know about the Galactic magnetic fields, and then review we current knowledge about magnetic fields in the Galactic disk, the Galactic halo and the field strengths. I also listed many unsolved problems on this area

Black holes, magnetic fields and particle creation. [Quantum field theory

Energy Technology Data Exchange (ETDEWEB)

Gibbons, G W [Cambridge Univ. (UK). Dept. of Applied Mathematics and Theoretical Physics

1976-10-01

Wald has given a classical argument suggesting that a rotating black hole immersed in a uniform magnetic field B will acquire a charge Q = 2JB where J is the angular momentum of the hole. The note contains a quantum field theoretic treatment of this process. For fields B greater than B/sub 0/ = 4 x 10/sup 13/ G the black hole will rapidly emit charged particles to achieve the equilibrium value. If B is less than the critical value the charge will remain zero.

Electromagnetic fields and their impacts

Science.gov (United States)

Prša, M. A.; Kasaš-Lažetić, K. K.

2018-01-01

The main goal of this paper is to briefly recall some different electromagnetic field definitions, some macroscopic sources of electromagnetic fields, electromagnetic fields classification regarding time dependences, and the ways of field determination in concrete cases. After that, all the mechanisms of interaction between electromagnetic field and substance, on atomic level, are described in details. Interaction between substance and electric field is investigated separately from the substance and magnetic field interaction. It is demonstrated that, in all cases of the unique electromagnetic field, total interaction can be treated as a superposition of two separated interactions. Finally, the main electromagnetic fields surrounding us is cited and discussed.

Disintegration and field evaporation of thiolate polymers in high electric fields

International Nuclear Information System (INIS)

Nickerson, B.S.; Karahka, M.; Kreuzer, H.J.

2015-01-01

High electrostatic fields cause major changes in polymers, structural (e.g. electrostriction) and electronic (e.g. reduction of the “band gap” with final metallization). Using density functional theory we have studied field effects on amino-alkane-thiols and perfluoro-alkane-thiols adsorbed on a metal substrate. Our results agree well with the APT fragmentation spectra obtained by Stoffers, Oberdorfer and Schmitz and shed light on disintegration pathways. We demonstrate that in SAMs the HOMO/LUMO gap is again reduced as a function of the field strength and vanishes at evaporation. We also follow the field dependence of the dielectric constant and polarizability. - Highlights: • Simple model of thiolate polymers is used to understand trends leading to field evaporation. • Potential energy curves followed by dipole moment, electric polarizability and dielectric constant are examined. • Features including coil, tilt and electrostriction are featured alongside evaporated species and HOMO/LUMO gap.

Disintegration and field evaporation of thiolate polymers in high electric fields

Energy Technology Data Exchange (ETDEWEB)

Nickerson, B.S., E-mail: brenden.nickerson@dal.ca; Karahka, M.; Kreuzer, H.J.

2015-12-15

High electrostatic fields cause major changes in polymers, structural (e.g. electrostriction) and electronic (e.g. reduction of the “band gap” with final metallization). Using density functional theory we have studied field effects on amino-alkane-thiols and perfluoro-alkane-thiols adsorbed on a metal substrate. Our results agree well with the APT fragmentation spectra obtained by Stoffers, Oberdorfer and Schmitz and shed light on disintegration pathways. We demonstrate that in SAMs the HOMO/LUMO gap is again reduced as a function of the field strength and vanishes at evaporation. We also follow the field dependence of the dielectric constant and polarizability. - Highlights: • Simple model of thiolate polymers is used to understand trends leading to field evaporation. • Potential energy curves followed by dipole moment, electric polarizability and dielectric constant are examined. • Features including coil, tilt and electrostriction are featured alongside evaporated species and HOMO/LUMO gap.

Geophysical Field Theory

International Nuclear Information System (INIS)

Eloranta, E.

2003-11-01

The geophysical field theory includes the basic principles of electromagnetism, continuum mechanics, and potential theory upon which the computational modelling of geophysical phenomena is based on. Vector analysis is the main mathematical tool in the field analyses. Electrostatics, stationary electric current, magnetostatics, and electrodynamics form a central part of electromagnetism in geophysical field theory. Potential theory concerns especially gravity, but also electrostatics and magnetostatics. Solid state mechanics and fluid mechanics are central parts in continuum mechanics. Also the theories of elastic waves and rock mechanics belong to geophysical solid state mechanics. The theories of geohydrology and mass transport form one central field theory in geophysical fluid mechanics. Also heat transfer is included in continuum mechanics. (orig.)

Quark pair creation in color electric fields and effects of magnetic fields

International Nuclear Information System (INIS)

Tanji, Noato

2010-01-01

The time evolution of a system where a uniform and classical SU(3) color electric field and quantum fields of quarks interact with each other is studied focusing on non-perturbative pair creation and its back reaction. We characterize a color direction of an electric field in a gauge invariant way, and investigate its dependence. Momentum distributions of created quarks show plasma oscillation as well as quantum effects such as the Pauli blocking and interference. Pressure of the system is also calculated, and we show that pair creation moderates degree of anisotropy of pressure. Furthermore, enhancement of pair creation and induction of chiral charge under a color magnetic field which is parallel to an electric field are discussed.

Mean fields and self consistent normal ordering of lattice spin and gauge field theories

International Nuclear Information System (INIS)

Ruehl, W.

1986-01-01

Classical Heisenberg spin models on lattices possess mean field theories that are well defined real field theories on finite lattices. These mean field theories can be self consistently normal ordered. This leads to a considerable improvement over standard mean field theory. This concept is carried over to lattice gauge theories. We construct first an appropriate real mean field theory. The equations determining the Gaussian kernel necessary for self-consistent normal ordering of this mean field theory are derived. (orig.)

Magnetic Field Calculator

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The Magnetic Field Calculator will calculate the total magnetic field, including components (declination, inclination, horizontal intensity, northerly intensity,...

Stray-field-induced Faraday contributions in wide-field Kerr microscopy and -magnetometry

International Nuclear Information System (INIS)

Markó, D.; Soldatov, I.; Tekielak, M.; Schäfer, R.

2015-01-01

The magnetic domain contrast in wide-field Kerr microscopy on bulk specimens can be substantially distorted by non-linear, field-dependent Faraday rotations in the objective lens that are caused by stray-field components emerging from the specimen. These Faraday contributions, which were detected by Kerr-magnetometry on grain-oriented iron–silicon steel samples, are thoroughly elaborated and characterized. They express themselves as a field-dependent gray-scale offset to the domain contrast and in highly distorted surface magnetization curves if optically measured in a wide field Kerr microscope. An experimental method to avoid such distortions is suggested. In the course of these studies, a low-permeability part in the surface magnetization loop of slightly misoriented (110)-surfaces in iron–silicon sheets was discovered that is attributed to demagnetization effects in direction perpendicular to the sheet surface. - Highlights: • Magnetizing a finite sample in a Kerr microscope leads to sample-generated stray-fields. • They cause non-linear, field- and position-dependent Faraday rotations in the objective. • This leads to a modulation of the Kerr contrast and to distorted MOKE loops. • A method to compensate these Faraday rotations is presented

Continuum gauge fields from lattice gauge fields

International Nuclear Information System (INIS)

Goeckeler, M.; Kronfeld, A.S.; Schierholz, G.; Wiese, U.J.

1993-01-01

On the lattice some of the salient features of pure gauge theories and of gauge theories with fermions in complex representations of the gauge group seem to be lost. These features can be recovered by considering part of the theory in the continuum. The prerequisite for that is the construction of continuum gauge fields from lattice gauge fields. Such a construction, which is gauge covariant and complies with geometrical constructions of the topological charge on the lattice, is given in this paper. The procedure is explicitly carried out in the U(1) theory in two dimensions, where it leads to simple results. (orig.)

Stuff we love: Afeto, Presença e Materialidade no Design de Livros

Directory of Open Access Journals (Sweden)

Larissa Andrioli

2014-11-01

Full Text Available The present article aims to discuss the materiality of the book through graphic design. It begins with two different ways of looking at the object: the emotional design approach by Donald Norman (complemented by Antonio Damasio’s affects theory and the production of presence approach by Hans Ulrich Gumbrecht. To understand how those theories can be related and how they can apply to books, one of the sections is dedicated to describing the haptic qualities of three books. By contrasting a traditional book with two books whose design explores their tactile materiality, this article tries to understand how the physical embodiment of the book influences our perception of art through affective interactions.

JOINT ADVISORY APPEALS BOARD

CERN Multimedia

Human Resources Division

2001-01-01

The Joint Advisory Appeals Board was convened to examine the appeal lodged by Mr Neil Calder, Mrs Sudeshna Datta Cockerill, Mrs Andrée Fontbonne, Mrs Moniek Laurent and Mr Ulrich Liptow with regard to membership in the Pension Fund under the period with a Paid Associate contract, appeals dealt with on a collective basis. As the appellants have not objected, the report of the Board and the final decision of the Director-General are brought to the notice of the personnel in accordance with Article R VI 1.20 of the Staff Regulations. The relevant documents will therefore be posted on the notice boards of the Administration Building (N° 60) from 10 to 31 August 2001.

Trabajando en modo multitarea: Cuellos de botella en la decisión y en la acción

Directory of Open Access Journals (Sweden)

Susana Ruiz Fernández

2011-11-01

Full Text Available ¿Cómo funciona el sistema cognitivo cuando debe realizar dos tareas simultáneamente? Los modelos de cuello de botella proponen que se puede realizar solamente una selección de respuesta a la vez. El estudio de Ulrich y cols. (2006 sugiere que tampoco se puede realizar más de una ejecución motora simultáneamente. Es decir, existen dos cuellos de botella en el sistema, uno cuando se selecciona y otro cuando se ejecuta la respuesta. Estos resultados pueden ayudar a aumentar la seguridad en tareas de riesgo, además de a optimizar recursos, aumentando la eficiencia, a la hora de realizar tareas complejas.

Is the cosmopolitanization of science emerging in China?

Science.gov (United States)

Zhang, Joy Yueyue

2010-12-01

China is one among many other countries that have recognised the necessity in aligning national scientific progress with that of global development. As China is striding along the path of scientific development with determination and initial success, a key concern confronted by international scientific community is how China, a rising scientific power, will transform existing global scientific atlas. Based on a project carried out in six Chinese cities between 2006 to 2009, this paper mainly employs Ulrich Beck's cosmopolitan theory in examining China's life sciences' development in the last decade to investigate how Chinese stakeholders have developed a (cosmopolitan) sensibility to rival ways of scientific reasoning, and in what way, Chinese stakeholders have contributed to the cosmopolitanization of science.

Dime qué número ves y te diré dónde miras después

Directory of Open Access Journals (Sweden)

Juan José Rahona

2011-01-01

Full Text Available Un reciente estudio de la Universidad Complutense de Madrid y la Universidad de Tübingen (Ruiz Fernández, Rahona, Hervás, Vázquez y Ulrich, en prensa ha encontrado que la magnitud de un número puede influir en la dirección de la mirada hacia las imágenes que siguen a ese número. El procedimiento (tarea de libre elección y el material usado (rostros humanos sugieren que, en circunstancias más cercanas a la realidad, la magnitud de un número al que se ha atendido puede tener una influencia observable en los patrones de exploración visual del individuo.

Electric Field Imaging

Data.gov (United States)

National Aeronautics and Space Administration — NDE historically has focused technology development in propagating wave phenomena with little attention to the field of electrostatics and emanating electric fields....

Gauge fields and inflation

Science.gov (United States)

Maleknejad, A.; Sheikh-Jabbari, M. M.; Soda, J.

2013-07-01

The isotropy and homogeneity of the cosmic microwave background (CMB) favors “scalar driven” early Universe inflationary models. However, gauge fields and other non-scalar fields are far more common at all energy scales, in particular at high energies seemingly relevant to inflation models. Hence, in this review we consider the role and consequences, theoretical and observational, that gauge fields can have during the inflationary era. Gauge fields may be turned on in the background during inflation, or may become relevant at the level of cosmic perturbations. There have been two main classes of models with gauge fields in the background, models which show violation of the cosmic no-hair theorem and those which lead to isotropic FLRW cosmology, respecting the cosmic no-hair theorem. Models in which gauge fields are only turned on at the cosmic perturbation level, may source primordial magnetic fields. We also review specific observational features of these models on the CMB and/or the primordial cosmic magnetic fields. Our discussions will be mainly focused on the inflation period, with only a brief discussion on the post inflationary (p)reheating era. Large field models: The initial value of the inflaton field is large, generically super-Planckian, and it rolls slowly down toward the potential minimum at smaller φ values. For instance, chaotic inflation is one of the representative models of this class. The typical potential of large-field models has a monomial form as V(φ)=V0φn. A simple analysis using the dynamical equations reveals that for number of e-folds Ne larger than 60, we require super-Planckian initial field values,5φ0>3M. For these models typically ɛ˜η˜Ne-1. Small field models: Inflaton field is initially small and slowly evolves toward the potential minimum at larger φ values. The small field models are characterized by the following potential V(φ)=V0(1-(), which corresponds to a Taylor expansion about the origin, but more realistic

Fields, symmetries, and quarks

International Nuclear Information System (INIS)

Mosel, U.

1989-01-01

'Fields, symmetries, and quarks' covers elements of quantum field theory, symmetries, gauge field theories and phenomenological descriptions of hadrons, with special emphasis on topics relevant to nuclear physics. It is aimed at nuclear physicists in general and at scientists who need a working knowledge of field theory, symmetry principles of elementary particles and their interactions and the quark structure of hadrons. The book starts out with an elementary introduction into classical field theory and its quantization. As gauge field theories require a working knowledge of global symmetries in field theories this topic is then discussed in detail. The following part is concerned with the general structure of gauge field theories and contains a thorough discussion of the still less widely known features of Non-Abelian gauge field theories. Quantum Chromodynamics (QCD), which is important for the understanding of hadronic matter, is discussed in the next section together with the quark compositions of hadrons. The last two chapters give a detailed discussion of phenomenological bag-models. The MIT bag is discussed, so that all theoretical calculations can be followed step by step. Since in all other bag-models the calculational methods and steps are essentially identical, this chapter should enable the reader to actually perform such calculations unaided. A last chapter finally discusses the topological bag-models which have become quite popular over the last few years. (orig.)

Free bosonic string field theory without supplementary fields

International Nuclear Information System (INIS)

Embacher, F.

1987-01-01

A covariant local action for free bosonic string fields is constructed without the use of supplementary fields. The open string case is treated in detail. Up to a mathematical conjecture which is likely to hold it is shown that the Virasoro constraints arise as a special choice of gauge. The kinetic operator turns out to be extremely simple, the gauge transformation law arising rather implicitly. The case of closed strings is briefly discussed. 25 refs. (Author)

Scalar field dark matter and the Higgs field

Directory of Open Access Journals (Sweden)

O. Bertolami

2016-08-01

Full Text Available We discuss the possibility that dark matter corresponds to an oscillating scalar field coupled to the Higgs boson. We argue that the initial field amplitude should generically be of the order of the Hubble parameter during inflation, as a result of its quasi-de Sitter fluctuations. This implies that such a field may account for the present dark matter abundance for masses in the range 10−6–10−4eV, if the tensor-to-scalar ratio is within the range of planned CMB experiments. We show that such mass values can naturally be obtained through either Planck-suppressed non-renormalizable interactions with the Higgs boson or, alternatively, through renormalizable interactions within the Randall–Sundrum scenario, where the dark matter scalar resides in the bulk of the warped extra-dimension and the Higgs is confined to the infrared brane.

Improvement of dose distribution of esophageal irradiation using the field-within-a-field technique

International Nuclear Information System (INIS)

Iwai, Tsugunori; Okabe, Keigo; Yamato, Hidetada; Murakami, Jyunji; Nakazawa, Yasuo; Kato, Mitsuyoshi

2002-01-01

The wide radiation field for mediastinal dose distribution should be inhomogeneous with the usual simple opposed beam irradiation. The purpose of this study was to improve the dose distribution of the mediastinum using a conventional planning system with a dose-volume histogram (DVH) and the field-in-field technique. Three-dimensional (3D) dose distribution is obtained in bilateral opposed-field irradiation. An overdose area obtained from the 3D dose distribution is defined and reprojected into the irradiation field. A new reduced field is created by removing the reprojected overdose area. A 3D dose distribution is again obtained and compared with the results from first one. Procedures were repeated until each of the target volumes was within ±5% of the prescribed dose and the irradiation volume within 107% or less of the prescribed dose. From the DVH analysis, our field-within-a-field technique resulted in a more uniform dose distribution within the conventional planning. The field-within-a-field technique involves many parameters, and an inverse planning algorithm is suitable for computation. However, with our method, the forward planning system is adequate for planning, at least in a relatively straightforward planning system such as bilateral opposed fields therapy. (author)

Managergehälter als Gegenstand europäischer und staatlicher Regulierung / Ulrich Jan Schröder

Index Scriptorium Estoniae

Schröder, Ulrich Jan

2016-01-01

Investeerimispankurite lisatasudest. Tegevjuhtide, juhatuste ja järelevalvenõukogude töö hüvitamise regulatsioonist ELi (nt direktiiv 2013/36/EL) ja Saksa õiguses. Hüvitiste regulatsiooni põhiõiguslikest piiridest

End-shorting and electric field in edge plasmas with application to field-reversed configurations

International Nuclear Information System (INIS)

Steinhauer, Loren C.

2002-01-01

The shorting of open field lines where they intersect external boundaries strongly modifies the transverse electric field all along the field lines. The modified electric field is found by an extension of the familiar Boltzmann relation for the electric potential. This leads to a prediction of the electric drift. Flow generation by electrical shorting is applied here to three aspects of elongated field-reversed configurations: plasma rotation rate; the particle-loss spin-up mechanism; and the sustainability of the rotating magnetic field current drive method

Simulated workplace neutron fields

International Nuclear Information System (INIS)

Lacoste, V.; Taylor, G.; Rottger, S.

2011-01-01

The use of simulated workplace neutron fields, which aim at replicating radiation fields at practical workplaces, is an alternative solution for the calibration of neutron dosemeters. They offer more appropriate calibration coefficients when the mean fluence-to-dose equivalent conversion coefficients of the simulated and practical fields are comparable. Intensive Monte Carlo modelling work has become quite indispensable for the design and/or the characterization of the produced mixed neutron/photon fields, and the use of Bonner sphere systems and proton recoil spectrometers is also mandatory for a reliable experimental determination of the neutron fluence energy distribution over the whole energy range. The establishment of a calibration capability with a simulated workplace neutron field is not an easy task; to date only few facilities are available as standard calibration fields. (authors)

Non-potential Field Formation in the X-shaped Quadrupole Magnetic Field Configuration

Energy Technology Data Exchange (ETDEWEB)

Kawabata, Y.; Shimizu, T. [Department of Earth and Planetary Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Inoue, S., E-mail: kawabata.yusuke@ac.jaxa.jp [Max-Planck-Institute for Solar System Research, Justus-von-Liebig-Weg 3 D-37077 Göttingen (Germany)

2017-06-20

Some types of solar flares are observed in X-shaped quadrupolar field configuration. To understand the magnetic energy storage in such a region, we studied non-potential field formation in an X-shaped quadrupolar field region formed in the active region NOAA 11967, which produced three X-shaped M-class flares on 2014 February 2. Nonlinear force-free field modeling was applied to a time series of vector magnetic field maps from the Solar Optical Telescope on board Hinode and the Helioseismic and Magnetic Imager on board the Solar Dynamics Observatory . Our analysis of the temporal three-dimensional magnetic field evolution shows that the sufficient free energy had already been stored more than 10 hr before the occurrence of the first M-class flare and that the storage was observed in a localized region. In this localized region, quasi-separatrix layers (QSLs) started to develop gradually from 9 hr before the first M-class flare. One of the flare ribbons that appeared in the first M-class flare was co-spatial with the location of the QSLs, suggesting that the formation of the QSLs is important in the process of energy release. These QSLs do not appear in the potential field calculation, indicating that they were created by the non-potential field. The formation of the QSLs was associated with the transverse photospheric motion of the pre-emerged flux and the emergence of a new flux. This observation indicates that the occurrence of the flares requires the formation of QSLs in the non-potential field in which free magnetic energy is stored in advance.

The effect of quadrupole fields on particle confinement in a field-reversed mirror

International Nuclear Information System (INIS)

McColl, D.B.; Berk, H.L.; Hammer, J.; Morse, E.C.

1982-01-01

A particle simulation code has been modified to simulate particle loss caused by quadrupole magnetic fields on a field-reversed mirror plasma device. Since analytic fields are chosen for the equilibrium, the numerical algorithm is highly accurate for long-time integrations of particle orbits. The resultant particle loss due to the quadrupole fields can be competitive with collisional loss in the device

Magnetic Fields Versus Gravity

Science.gov (United States)

Hensley, Kerry

2018-04-01

Deep within giant molecular clouds, hidden by dense gas and dust, stars form. Unprecedented data from the Atacama Large Millimeter/submillimeter Array (ALMA) reveal the intricate magnetic structureswoven throughout one of the most massive star-forming regions in the Milky Way.How Stars Are BornThe Horsehead Nebulasdense column of gas and dust is opaque to visible light, but this infrared image reveals the young stars hidden in the dust. [NASA/ESA/Hubble Heritage Team]Simple theory dictates that when a dense clump of molecular gas becomes massive enough that its self-gravity overwhelms the thermal pressure of the cloud, the gas collapses and forms a star. In reality, however, star formation is more complicated than a simple give and take between gravity and pressure. Thedusty molecular gas in stellar nurseries is permeated with magnetic fields, which are thought to impede the inward pull of gravity and slow the rate of star formation.How can we learn about the magnetic fields of distant objects? One way is by measuring dust polarization. An elongated dust grain will tend to align itself with its short axis parallel to the direction of the magnetic field. This systematic alignment of the dust grains along the magnetic field lines polarizes the dust grains emission perpendicular to the local magnetic field. This allows us to infer the direction of the magnetic field from the direction of polarization.Magnetic field orientations for protostars e2 and e8 derived from Submillimeter Array observations (panels a through c) and ALMA observations (panels d and e). Click to enlarge. [Adapted from Koch et al. 2018]Tracing Magnetic FieldsPatrick Koch (Academia Sinica, Taiwan) and collaborators used high-sensitivity ALMA observations of dust polarization to learn more about the magnetic field morphology of Milky Way star-forming region W51. W51 is one of the largest star-forming regions in our galaxy, home to high-mass protostars e2, e8, and North.The ALMA observations reveal

Electric fields in the magnetosphere

International Nuclear Information System (INIS)

Falthammar, C.G.

1989-01-01

Electric field measurements on the satellites GEOS-1, GEOS-2, ISEE-1, and Viking have extended the empirical knowledge of electric fields in space so as to include the outer regions of the magnetosphere. While the measurements confirm some of the theoretically expected properties of the electric fields, they also reveal unexpected features and a high degree of complexity and variability. The existence of a magnetospheric dawn-to-dusk electric field, as expected on the basis of extrapolation from low altitude measurements, is confirmed in an average sense. However, the actual field exhibits large spatial and temporal variations, including strong fields of inductive origin. At the magnetopause, the average (dawn-to-dusk directed) tangential electric field component is typically obscured by irregular fluctuations of larger amplitude. The magnetic-field aligned component of the electric field, which is of particular importance for ionosphere-magnetosphere coupling and for auroral acceleration, is even now very difficult to measure directly. However, the data from electric field measurements provide further support for the conclusion, based on a variety of evidence, that a non-vanishing magnetic-field aligned electric field exists in the auroral acceleration region

Comparison study of toroidal-field divertors for a compact reversed-field pinch reactor

International Nuclear Information System (INIS)

Bathke, C.G.; Krakowski, R.A.; Miller, R.L.

1985-01-01

Two divertor configurations for the Compact Reversed-Field Pinch Reactor (CRFPR) based on diverting the minority (toroidal) field have been reported. A critical factor in evaluating the performance of both poloidally symmetric and bundle divertor configurations is the accurate determination of the divertor connection length and the monitoring of magnetic islands introduced by the divertors, the latter being a three-dimensional effect. To this end the poloidal-field, toroidal-field, and divertor coils and the plasma currents are simulated in three dimensions for field-line tracings in both the divertor channel and the plasma-edge regions. The results of this analysis indicate a clear preference for the poloidally symmetric toroidal-field divertor. Design modifications to the limiter-based CRFPR design that accommodate this divertor are presented

Analysis of Surface Electric Field Measurements from an Array of Electric Field Mills

Science.gov (United States)

Lucas, G.; Thayer, J. P.; Deierling, W.

2016-12-01

Kennedy Space Center (KSC) has operated an distributed array of over 30 electric field mills over the past 18 years, providing a unique data set of surface electric field measurements over a very long timespan. In addition to the electric field instruments there are many meteorological towers around KSC that monitor the local meteorological conditions. Utilizing these datasets we have investigated and found unique spatial and temporal signatures in the electric field data that are attributed to local meteorological effects and the global electric circuit. The local and global scale influences on the atmospheric electric field will be discussed including the generation of space charge from the ocean surf, local cloud cover, and a local enhancement in the electric field that is seen at sunrise.

Low field-low cost: Can low-field magnetic resonance systems replace high-field magnetic resonance systems in the diagnostic assessment of multiple sclerosis patients?

International Nuclear Information System (INIS)

Ertl-Wagner, B.B.; Reith, W.; Sartor, K.

2001-01-01

As low-field MR imaging is becoming a widely used imaging technique, we aimed at a prospective assessment of differences in imaging quality between low- and high-field MR imaging in multiple sclerosis patients possibly interfering with diagnostic or therapeutic decision making. Twenty patients with clinically proven multiple sclerosis were examined with optimized imaging protocols in a 1.5- and a 0.23-T MR scanner within 48 h. Images were assessed independently by two neuroradiologists. No statistically significant interrater discrepancies were observed. A significantly lower number of white matter lesions could be identified in low-field MR imaging both on T1- and on T2-weighted images (T2: high field 700, low field 481; T1: high field 253, low field 177). A total of 114 enhancing lesions were discerned in the high-field MR imaging as opposed to 45 enhancing lesions in low-field MR imaging. Blood-brain barrier disruption was identified in 11 of 20 patients in the high-field MR imaging, but only in 4 of 20 patients in low-field MR imaging. Since a significantly lower lesion load is identified in low-field MR imaging than in high-field MR imaging, and blood-brain barrier disruption is frequently missed, caution must be exercised in interpreting a normal low-field MR imaging scan in a patient with clinical signs of multiple sclerosis and in interpreting a scan without enhancing lesions in a patient with known multiple sclerosis and clinical signs of exacerbation. (orig.)

Elliptic-symmetry vector optical fields.

Science.gov (United States)

Pan, Yue; Li, Yongnan; Li, Si-Min; Ren, Zhi-Cheng; Kong, Ling-Jun; Tu, Chenghou; Wang, Hui-Tian

2014-08-11

We present in principle and demonstrate experimentally a new kind of vector fields: elliptic-symmetry vector optical fields. This is a significant development in vector fields, as this breaks the cylindrical symmetry and enriches the family of vector fields. Due to the presence of an additional degrees of freedom, which is the interval between the foci in the elliptic coordinate system, the elliptic-symmetry vector fields are more flexible than the cylindrical vector fields for controlling the spatial structure of polarization and for engineering the focusing fields. The elliptic-symmetry vector fields can find many specific applications from optical trapping to optical machining and so on.

Wake field accelerators

International Nuclear Information System (INIS)

Wilson, P.B.

1986-02-01

In a wake field accelerator a high current driving bunch injected into a structure or plasma produces intense induced fields, which are in turn used to accelerate a trailing charge or bunch. The basic concepts of wake field acceleration are described. Wake potentials for closed cavities and periodic structures are derived, as are wake potentials on a collinear path with a charge distribution. Cylindrically symmetric structures excited by a beam in the form of a ring are considered

Mapping and correcting respiration-induced field changes in the brain using fluorine field probes

DEFF Research Database (Denmark)

Andersen, Mads; Madsen, Kristoffer; Hanson, Lars G.

2014-01-01

strength values from signal phase by linear fitting. Ahead of imaging, the field probe positions were determined for each subject, by applying known gradients in all three dimensions while measuring with the field probes. Experiments: Measurements were performed in 4 male subjects instructed to hold...... software was updated with f0 and first order shim values, before the acquisition of every volume. Evaluation: To assess whether the dynamic field changes were captured by the field probe data, the field probe fitted fields were subtracted from the scanner B0 maps to model shimming. We then assessed whether......Purpose. Breathing induced dynamic B0 field perturbations in the head can lead to artefacts in ultra-high field MR by causing line broadening in spectroscopy and signal dropout, ghosting, displacement artifacts and blurring in imaging. It has recently been proposed to continuously stabilize...

Heisenberg representation for secondary-quantized fields in nonstationary external fields and dielectric nonlinear medium

International Nuclear Information System (INIS)

Lobashev, A.A.; Mostepanenko, V.M.

1993-01-01

Heisenberg formalism is developed for creation-annihilation operators of quantum fields propagating in nonstationary external fields. Quantum fields with spin 0,1/2, 1 are considered in the presence of such external fields as electromagnetic, scalar and the field of nonstationary dielectric properties of nonlinear medium. Elliptic operator parametrically depending on time is constructed. In Heisenberg representation field variables are decomposed over eigenfunction of this operator. The relation between Heisenberg creation-annihilation operators and the operators obtained in the frame of diagonalization of Hamiltonian with Bogoliubov transformations is set up

National Uranium Resource Evaluation: Crystal City Quadrangle, Texas

International Nuclear Information System (INIS)

Greimel, T.C.

1982-08-01

The uranium resources of the Crystal City Quadrangle, Texas, were evaluated to a depth of 1500 m using surface and subsurface geologic information. Uranium occurrences reported in the literature, in reports of the US Atomic Energy Commission and the US Geological Survey Computerized Resources Information Bank, were located, described, and sampled. Geochemical anomalies interpreted from hydrogeochemical and stream-sediment reconnaissance were also investigated and sampled in detail. Areas of uranium favorability in the subsurface were located through interpretation of lithofacies patterns and structure derived from electric-log data. Gamma-ray well logs and results of geochemical sample analyses were used as supportive data in locating these areas. Fifteen surface and subsurface favorable areas were delineated in the quadrangle. Eight are in fluvial and genetically associated facies of the Pliocene Goliad Sandstone, Miocene Oakville Sandstone, Miocene Catahoula Tuff, and Oligocene Frio Clay. One area encompasses strand plain-barrier bar, fluvial-deltaic, and lagoonal-margin facies of the Eocene Jackson Group. Two areas are in strand plain-barrier bar and probable fluvial facies of the Eocene Yegua Formation. Four areas are in fluvial-deltaic, barrier-bar, and lagoonal-margin facies of the Eocene Queen City Formation and stratigraphically equivalent units. Seventeen geologic units are considered unfavorable, and seven are unevaluated due to lack of data

Oscillating field current drive for reversed field pinch discharges

International Nuclear Information System (INIS)

Schoenberg, K.F.; Gribble, R.F.; Baker, D.A.

1984-06-01

Oscillating Field Current Drive (OFCD), also known as F-THETA pumping, is a steady-state current-drive technique proposed for the Reversed Field Pinch (RFP). Unlike other current-drive techniques, which employ high-technology, invasive, and power intensive schemes using radio frequency or neutral particle injection, F-THETA pumping entails driving the toroidal and poloidal magnetic field circuits with low-frequency (audio) oscillating voltage sources. Current drive by this technique is a consequence of the strong nonlinear plasma coupling in the RFP. Because of its low frequency and efficient plasma coupling, F-THETA pumping shows excellent promise as a reactor-relevant current-drive technique. A conceptual and computational study of this concept, including its experimental and reactor relevance, is explored in this paper

Multi-valued fields

CERN Document Server

Ershov, Yuri L

2001-01-01

For more than 30 years, the author has studied the model-theoretic aspects of the theory of valued fields and multi-valued fields. Many of the key results included in this book were obtained by the author whilst preparing the manuscript. Thus the unique overview of the theory, as developed in the book, has been previously unavailable. The book deals with the theory of valued fields and mutli-valued fields. The theory of Prüfer rings is discussed from the `geometric' point of view. The author shows that by introducing the Zariski topology on families of valuation rings, it is possible to distinguish two important subfamilies of Prüfer rings that correspond to Boolean and near Boolean families of valuation rings. Also, algebraic and model-theoretic properties of multi-valued fields with near Boolean families of valuation rings satisfying the local-global principle are studied. It is important that this principle is elementary, i.e., it can be expressed in the language of predicate calculus. The most important...

String field theory

International Nuclear Information System (INIS)

Kaku, M.

1987-01-01

In this article, the authors summarize the rapid progress in constructing string field theory actions, such as the development of the covariant BRST theory. They also present the newer geometric formulation of string field theory, from which the BRST theory and the older light cone theory can be derived from first principles. This geometric formulation allows us to derive the complete field theory of strings from two geometric principles, in the same way that general relativity and Yang-Mills theory can be derived from two principles based on global and local symmetry. The geometric formalism therefore reduces string field theory to a problem of finding an invariant under a new local gauge group they call the universal string group (USG). Thus, string field theory is the gauge theory of the universal string group in much the same way that Yang-Mills theory is the gauge theory of SU(N). The geometric formulation places superstring theory on the same rigorous group theoretical level as general relativity and gauge theory

A 0.5 Tesla Transverse-Field Alternating Magnetic Field Demagnetizer

Science.gov (United States)

Schillinger, W. E.; Morris, E. R.; Finn, D. R.; Coe, R. S.

2015-12-01

We have built an alternating field demagnetizer that can routinely achieve a maximum field of 0.5 Tesla. It uses an amorphous magnetic core with an air-cooled coil. We have started with a 0.5 T design, which satisfies most of our immediate needs, but we can certainly achieve higher fields. In our design, the magnetic field is transverse to the bore and uniform to 1% over a standard (25 mm) paleomagnetic sample. It is powered by a 1 kW power amplifier and is compatible with our existing sample handler for automated demagnetization and measurement (Morris et al., 2009). It's much higher peak field has enabled us to completely demagnetize many of the samples that previously we could not with commercial equipment. This capability is especially needed for high-coercivity sedimentary and igneous rocks that contain magnetic minerals that alter during thermal demagnetization. It will also enable detailed automated demagnetization of high coercivity phases in extraterrestrial samples, such as native iron, iron-alloy and sulfide minerals that are common in lunar rocks and meteorites. Furthermore, it has opened the door for us to use the rock-magnetic technique of component analysis, using coercivity distributions derived from very detailed AF demagnetization of NRM and remanence produced in the laboratory to characterize the magnetic mineralogy of sedimentary rocks. In addition to the many benefits this instrument has brought to our own research, a much broader potential impact is to replace the transverse coils in automated AF demagnetization systems, which typically are limited to peak fields around 0.1 T.

Magnetic field screens

International Nuclear Information System (INIS)

Mansfield, P.; Turner, R.; Chapman, B.L.W.; Bowley, R.M.

1990-01-01

A screen for a magnetic coil, for producing, for example, a homogeneous, gradient or RF field in nuclear magnetic resonance imaging, is described. It is provided by surround the coil with a set of electrical conductors. The currents within the conductors are controlled in such a manner that the field is neutralised in a specific region of space. The current distribution within the conductors is determined by calculating the current within a hypothetical superconductive shield which would have the effect of neutralising the field, the current through the conductors thereby being a substitute for the superconductive shield. The conductors may be evenly spaced and connected in parallel, their resistances being determined by thickness or composition to provide the desired current, or they may carry equal currents but be differently spaced. A further set or sets of controlled conductors outside the first set may ensure that the first set does not upset the field from the NMR coil. The shield may selectively reflect certain fields while transmitting others and may prevent acoustic vibration e.g. when switching gradient fields. An RF coil arrangement may consist of two orthogonal coils, one coil within the other for use as a transmit/receive set or as a double resonance transmitter; a shield between the coils is in series with, and formed from the same winding as, the inner coil. (author)

Understanding Vector Fields.

Science.gov (United States)

Curjel, C. R.

1990-01-01

Presented are activities that help students understand the idea of a vector field. Included are definitions, flow lines, tangential and normal components along curves, flux and work, field conservation, and differential equations. (KR)

Gauge structure of neutral-vector field theory. [Massive vector fields, massless limits

Energy Technology Data Exchange (ETDEWEB)

Kubo, R; Yokoyama, [Hiroshima univ., Takehara (Japan). Research Inst. for Theoretical Physics

1975-03-01

General aspects of gauge structure of neutral-vector field theory are investigated from an extended standpoint, where massive vector fields are treated in a form corresponding to the electromagnetic fields in a general gauge formalism reported previously. All results obtained are shown to have unique massless limits. It is shown that a generalized q-number gauge transformation for fields makes the theory invariant in cooperation with a simultaneous transformation for relevant gauge parameters. A method of differentiation with respect to a gauge variable is found to clarify some essential features of the gauge structure. Two possible types of gauge structure also emerge correspondingly to the massless case. A neutral-vector field theory proposed in a preceding paper is included in the present framework as the most preferable case.

Massive fields as systematics for single field inflation

Energy Technology Data Exchange (ETDEWEB)

Jiang, Hongliang; Wang, Yi, E-mail: hjiangag@connect.ust.hk, E-mail: phyw@ust.hk [Department of Physics, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong (China)

2017-06-01

During inflation, massive fields can contribute to the power spectrum of curvature perturbation via a dimension-5 operator. This contribution can be considered as a bias for the program of using n {sub s} and r to select inflation models. Even the dimension-5 operator is suppressed by Λ = M {sub p} , there is still a significant shift on the n {sub s} - r diagram if the massive fields have m ∼ H . On the other hand, if the heavy degree of freedom appears only at the same energy scale as the suppression scale of the dimension-5 operator, then significant shift on the n {sub s} - r diagram takes place at m =Λ ∼ 70 H , which is around the inflationary time-translation symmetry breaking scale. Hence, the systematics from massive fields pose a greater challenge for future high precision experiments for inflationary model selection. This result can be thought of as the impact of UV sensitivity to inflationary observables.

Neutron dosemeter responses in workplace fields and the implications of using realistic neutron calibration fields

International Nuclear Information System (INIS)

Thomas, D.J.; Horwood, N.; Taylor, G.C.

1999-01-01

The use of realistic neutron calibration fields to overcome some of the problems associated with the response functions of presently available dosemeters, both area survey instruments and personal dosemeters, has been investigated. Realistic calibration fields have spectra which, compared to conventional radionuclide source based calibration fields, more closely match those of the workplace fields in which dosemeters are used. Monte Carlo simulations were performed to identify laboratory systems which would produce appropriate workplace-like calibration fields. A detailed analysis was then undertaken of the predicted under- and over-responses of dosemeters in a wide selection of measured workplace field spectra assuming calibration in a selection of calibration fields. These included both conventional radionuclide source calibration fields, and also several proposed realistic calibration fields. The present state of the art for dosemeter performance, and the possibilities of improving accuracy by using realistic calibration fields are both presented. (author)

Quantum particle in a potential well field and in an electric field

International Nuclear Information System (INIS)

Gyunter, U.; Olejnik, V.P.

1990-01-01

Solutions of the Dirac equation in the field of δ-like potential well with arbitrary symmetry and in uniform electric field were obtained and analyzed. It is shown that wave function and energy of electron in bound state in the absence of electric field depend sufficiently on the type of potential well symmetry. 1 ref

Stochastic spin-one massive field

International Nuclear Information System (INIS)

Lim, S.C.

1984-01-01

Stochastic quantization schemes of Nelson and Parisi and Wu are applied to a spin-one massive field. Unlike the scalar case Nelson's stochastic spin-one massive field cannot be identified with the corresponding euclidean field even if the fourth component of the euclidean coordinate is taken as equal to the real physical time. In the Parisi-Wu quantization scheme the stochastic Proca vector field has a similar property as the scalar field; which has an asymptotically stationary part and a transient part. The large equal-time limit of the expectation values of the stochastic Proca field are equal to the expectation values of the corresponding euclidean field. In the Stueckelberg formalism the Parisi-Wu scheme gives rise to a stochastic vector field which differs from the massless gauge field in that the gauge cannot be fixed by the choice of boundary condition. (orig.)

Magnetic islands at the field reversal surface in reversed field pinches

International Nuclear Information System (INIS)

Pinsker, R.I.; Reiman, A.H.

1985-09-01

In the reversed field pinch (RFP), magnetic field perturbations having zero poloidal mode number and any toroidal mode number are resonant at the field reversal surface. Such perturbations are a particular threat to the RFP because of their weak radial dependence at low toroidal mode number, and because the toroidal field ripple is essentially of this type. The widths of the resulting islands are calculated in this paper. The self-consistent plasma response is included through the assumption that the plasma relaxes to a Taylor force-free state. The connection with linear tearing mode theory is established for those limits where arbitrarily large islands result from infinitesimal perturbations. Toroidal effects are considered, and application of the theory to RFP experiments is discussed

Cosmological magnetic fields - V

Indian Academy of Sciences (India)

Magnetic fields seem to be everywhere that we can look in the universe, from our own ... The field tensor is observer-independent, while the electric and magnetic .... based on string theory [11], in which vacuum fluctuations of the field are ...

Linearized interactions of scalar and vector fields with the higher spin field in AdSD

International Nuclear Information System (INIS)

Mkrtchyan, K.

2011-01-01

The explicit form of linearized gauge and generalized 'Weyl invariant' interactions of scalar and general higher even spin fields in the AdS D space is reviewed. Also a linearized interaction of vector field with general higher even spin gauge field is obtained. It is shown that the gauge-invariant action of linearized vector field interacting with the higher spin field also includes the whole tower of invariant actions for couplings of the same vector field with the gauge fields of smaller even spin

Field Geology/Processes

Science.gov (United States)

Allen, Carlton; Jakes, Petr; Jaumann, Ralf; Marshall, John; Moses, Stewart; Ryder, Graham; Saunders, Stephen; Singer, Robert

1996-01-01

The field geology/process group examined the basic operations of a terrestrial field geologist and the manner in which these operations could be transferred to a planetary lander. Four basic requirements for robotic field geology were determined: geologic content; surface vision; mobility; and manipulation. Geologic content requires a combination of orbital and descent imaging. Surface vision requirements include range, resolution, stereo, and multispectral imaging. The minimum mobility for useful field geology depends on the scale of orbital imagery. Manipulation requirements include exposing unweathered surfaces, screening samples, and bringing samples in contact with analytical instruments. To support these requirements, several advanced capabilities for future development are recommended. Capabilities include near-infrared reflectance spectroscopy, hyper-spectral imaging, multispectral microscopy, artificial intelligence in support of imaging, x ray diffraction, x ray fluorescence, and rock chipping.

Earth's Magnetic Field

DEFF Research Database (Denmark)

This volume provides a comprehensive view on the different sources of the geomagnetic field both in the Earth’s interior and from the field’s interaction with the terrestrial atmosphere and the solar wind. It combines expertise from various relevant areas of geomagnetic and near Earth space...... research with the aim to better characterise the state and dynamics of Earth’s magnetic field. Advances in the exploitation of geomagnetic observations hold a huge potential not only for an improved quantitative description of the field source but also for a better understanding of the underlying processes...... and space observations, and on state-of-the-art empirical models and physics-based simulations. Thus, it provides an in-depth overview over recent achievements, current limitations and challenges, and future opportunities in the field of geomagnetism and space sciences....

Magnetic field sensor for isotropically sensing an incident magnetic field in a sensor plane

Science.gov (United States)

Pant, Bharat B. (Inventor); Wan, Hong (Inventor)

2001-01-01

A magnetic field sensor that isotropically senses an incident magnetic field. This is preferably accomplished by providing a magnetic field sensor device that has one or more circular shaped magnetoresistive sensor elements for sensing the incident magnetic field. The magnetoresistive material used is preferably isotropic, and may be a CMR material or some form of a GMR material. Because the sensor elements are circular in shape, shape anisotropy is eliminated. Thus, the resulting magnetic field sensor device provides an output that is relatively independent of the direction of the incident magnetic field in the sensor plane.

Magnetic field measuring system for remapping the ORIC magnetic field

International Nuclear Information System (INIS)

Mosko, S.W.; Hudson, E.D.; Lord, R.S.; Hensley, D.C.; Biggerstaff, J.A.

1977-01-01

The Holifield Heavy Ion Research Facility will integrate a new 25 MV tandem electrostatic acccelerator into the existing cyclotron laboratory which includes the Oak Ridge Isochronous Cyclotron (ORIC). Computations of ion paths for beam injection from the new tandem into ORIC require field mapping in the regions traversed by the beam. Additional field data is also desired for the higher levels (approx.19 kG) now used for most heavy ion beams. The magnetic field measurement system uses 39 flip coil/current integrator sets with computer controlled data scanning. The coils are spaced radially at 1 inch intervals in an arm which can be rotated azimuthally in 2 degree increments. The entire flip coil assembly can be shifted to larger radii to measure fields beyond the pole boundary. Temperature stabilization of electronic circuitry permits a measurement resolution of +-1 gauss over a dynamic range of +-25,000 gauss. The system will process a scan of 8000 points in about one hour

Multivector field formulation of Hamiltonian field theories: equations and symmetries

Energy Technology Data Exchange (ETDEWEB)

Echeverria-Enriquez, A.; Munoz-Lecanda, M.C.; Roman-Roy, N. [Departamento de Matematica Aplicada y Telematica, Edificio C-3, Campus Norte UPC, Barcelona (Spain)

1999-12-03

We state the intrinsic form of the Hamiltonian equations of first-order classical field theories in three equivalent geometrical ways: using multivector fields, jet fields and connections. Thus, these equations are given in a form similar to that in which the Hamiltonian equations of mechanics are usually given. Then, using multivector fields, we study several aspects of these equations, such as the existence and non-uniqueness of solutions, and the integrability problem. In particular, these problems are analysed for the case of Hamiltonian systems defined in a submanifold of the multimomentum bundle. Furthermore, the existence of first integrals of these Hamiltonian equations is considered, and the relation between Cartan-Noether symmetries and general symmetries of the system is discussed. Noether's theorem is also stated in this context, both the 'classical' version and its generalization to include higher-order Cartan-Noether symmetries. Finally, the equivalence between the Lagrangian and Hamiltonian formalisms is also discussed. (author)

Effective theories of single field inflation when heavy fields matter

CERN Document Server

Achucarro, Ana; Hardeman, Sjoerd; Palma, Gonzalo A; Patil, Subodh P

2012-01-01

We compute the low energy effective field theory (EFT) expansion for single-field inflationary models that descend from a parent theory containing multiple other scalar fields. By assuming that all other degrees of freedom in the parent theory are sufficiently massive relative to the inflaton, it is possible to derive an EFT valid to arbitrary order in perturbations, provided certain generalized adiabaticity conditions are respected. These conditions permit a consistent low energy EFT description even when the inflaton deviates off its adiabatic minimum along its slowly rolling trajectory. By generalizing the formalism that identifies the adiabatic mode with the Goldstone boson of this spontaneously broken time translational symmetry prior to the integration of the heavy fields, we show that this invariance of the parent theory dictates the entire non-perturbative structure of the descendent EFT. The couplings of this theory can be written entirely in terms of the reduced speed of sound of adiabatic perturbat...

Magnetostriction of field-structured magnetoelastomers.

Energy Technology Data Exchange (ETDEWEB)

Gulley, Gerald L. (Dominican University, River Forest, IL); Read, Douglas H.; Martin, James Ellis; Huber, Dale L.; Anderson, Robert Alan; Frankamp, Benjamin L.

2005-12-01

Field-structured magnetic particle composites are an important new class of materials that have great potential as both sensors and actuators. These materials are synthesized by suspending magnetic particles in a polymeric resin and subjecting these to magnetic fields while the resin polymerizes. If a simple uniaxial magnetic field is used, the particles will form chains, yielding composites whose magnetic susceptibility is enhanced along a single direction. A biaxial magnetic field, comprised of two orthogonal ac fields, forms particle sheets, yielding composites whose magnetic susceptibility is enhanced along two principal directions. A balanced triaxial magnetic field can be used to enhance the susceptibility in all directions, and biased heterodyned triaxial magnetic fields are especially effective for producing composites with a greatly enhanced susceptibility along a single axis. Magnetostriction is quadratic in the susceptibility, so increasing the composite susceptibility is important to developing actuators that function well at modest fields. To investigate magnetostriction in these field-structured composites we have constructed a sensitive, constant-stress apparatus capable of 1 ppm strain resolution. The sample geometry is designed to minimize demagnetizing field effects. With this apparatus we have demonstrated field-structured composites with nearly 10,000 ppm strain.

Rapid core field variations during the satellite era: Investigations using stochastic process based field models

DEFF Research Database (Denmark)

Finlay, Chris; Olsen, Nils; Gillet, Nicolas

We present a new ensemble of time-dependent magnetic field models constructed from satellite and observatory data spanning 1997-2013 that are compatible with prior information concerning the temporal spectrum of core field variations. These models allow sharper field changes compared to tradition...... physical hypotheses can be tested by asking questions of the entire ensemble of core field models, rather than by interpreting any single model.......We present a new ensemble of time-dependent magnetic field models constructed from satellite and observatory data spanning 1997-2013 that are compatible with prior information concerning the temporal spectrum of core field variations. These models allow sharper field changes compared to traditional...... regularization methods based on minimizing the square of second or third time derivative. We invert satellite and observatory data directly by adopting the external field and crustal field modelling framework of the CHAOS model, but apply the stochastic process method of Gillet et al. (2013) to the core field...

Single-shot imaging with higher-dimensional encoding using magnetic field monitoring and concomitant field correction.

Science.gov (United States)

Testud, Frederik; Gallichan, Daniel; Layton, Kelvin J; Barmet, Christoph; Welz, Anna M; Dewdney, Andrew; Cocosco, Chris A; Pruessmann, Klaas P; Hennig, Jürgen; Zaitsev, Maxim

2015-03-01

PatLoc (Parallel Imaging Technique using Localized Gradients) accelerates imaging and introduces a resolution variation across the field-of-view. Higher-dimensional encoding employs more spatial encoding magnetic fields (SEMs) than the corresponding image dimensionality requires, e.g. by applying two quadratic and two linear spatial encoding magnetic fields to reconstruct a 2D image. Images acquired with higher-dimensional single-shot trajectories can exhibit strong artifacts and geometric distortions. In this work, the source of these artifacts is analyzed and a reliable correction strategy is derived. A dynamic field camera was built for encoding field calibration. Concomitant fields of linear and nonlinear spatial encoding magnetic fields were analyzed. A combined basis consisting of spherical harmonics and concomitant terms was proposed and used for encoding field calibration and image reconstruction. A good agreement between the analytical solution for the concomitant fields and the magnetic field simulations of the custom-built PatLoc SEM coil was observed. Substantial image quality improvements were obtained using a dynamic field camera for encoding field calibration combined with the proposed combined basis. The importance of trajectory calibration for single-shot higher-dimensional encoding is demonstrated using the combined basis including spherical harmonics and concomitant terms, which treats the concomitant fields as an integral part of the encoding. © 2014 Wiley Periodicals, Inc.

The Swarm Initial Field Model for the 2014 geomagnetic field

DEFF Research Database (Denmark)

Olsen, Nils; Hulot, Gauthier; Lesur, Vincent

2015-01-01

agreement (up to at least degree 60) with recent field models derived from CHAMP data, providing an initial validation of the quality of the Swarm magnetic measurements. Use of gradient data improves the determination of both the static field and its secular variation, with the mean misfit for East...

The Virtual Fields Method Extracting Constitutive Mechanical Parameters from Full-field Deformation Measurements

CERN Document Server

Pierron, Fabrice

2012-01-01

The Virtual Fields Method: Extracting Constitutive Mechanical Parameters from Full-field Deformation Measurements is the first book on the Virtual Fields Method (VFM), a technique to identify materials mechanical properties from full-field measurements. Firmly rooted with extensive theoretical description of the method, the book presents numerous examples of application to a wide range of materials (composites, metals, welds, biomaterials) and situations (static, vibration, high strain rate). The authors give a detailed training section with examples of progressive difficulty to lead the reader to program the VFM and include a set of commented Matlab programs as well as GUI Matlab-based software for more general situations. The Virtual Fields Method: Extracting Constitutive Mechanical Parameters from Full-field Deformation Measurements is an ideal book for researchers, engineers, and students interested in applying the VFM to new situations motivated by their research.  

Complex Polynomial Vector Fields

DEFF Research Database (Denmark)

Dias, Kealey

vector fields. Since the class of complex polynomial vector fields in the plane is natural to consider, it is remarkable that its study has only begun very recently. There are numerous fundamental questions that are still open, both in the general classification of these vector fields, the decomposition...... of parameter spaces into structurally stable domains, and a description of the bifurcations. For this reason, the talk will focus on these questions for complex polynomial vector fields.......The two branches of dynamical systems, continuous and discrete, correspond to the study of differential equations (vector fields) and iteration of mappings respectively. In holomorphic dynamics, the systems studied are restricted to those described by holomorphic (complex analytic) functions...

Gauge field copies

International Nuclear Information System (INIS)

Bollini, C.G.; Giambiagi, J.J.; Tiomno, J.

1979-01-01

The construction of field strength copies without any gauge constraint is discussed. Several examples are given, one of which is not only a field strength copy but also (at the same time) a 'current copy'. (author) [pt

A novel background field removal method for MRI using projection onto dipole fields (PDF).

Science.gov (United States)

Liu, Tian; Khalidov, Ildar; de Rochefort, Ludovic; Spincemaille, Pascal; Liu, Jing; Tsiouris, A John; Wang, Yi

2011-11-01

For optimal image quality in susceptibility-weighted imaging and accurate quantification of susceptibility, it is necessary to isolate the local field generated by local magnetic sources (such as iron) from the background field that arises from imperfect shimming and variations in magnetic susceptibility of surrounding tissues (including air). Previous background removal techniques have limited effectiveness depending on the accuracy of model assumptions or information input. In this article, we report an observation that the magnetic field for a dipole outside a given region of interest (ROI) is approximately orthogonal to the magnetic field of a dipole inside the ROI. Accordingly, we propose a nonparametric background field removal technique based on projection onto dipole fields (PDF). In this PDF technique, the background field inside an ROI is decomposed into a field originating from dipoles outside the ROI using the projection theorem in Hilbert space. This novel PDF background removal technique was validated on a numerical simulation and a phantom experiment and was applied in human brain imaging, demonstrating substantial improvement in background field removal compared with the commonly used high-pass filtering method. Copyright © 2011 John Wiley & Sons, Ltd.

Development and applications of NMR [nuclear magnetic resonance] in low fields and zero field

International Nuclear Information System (INIS)

Bielecki, A.

1987-05-01

This dissertation is about nuclear magnetic resonance (NMR) spectroscopy in the absence of applied magnetic fields. NMR is usually done in large magnetic fields, often as large as can be practically attained. The motivation for going the opposite way, toward zero field, is that for certain types of materials, particularly powdered or polycrystalline solids, the NMR spectra in zero field are easier to interpret than those obtained in high field. 92 refs., 60 figs., 1 tab

Large field-of-view transmission line resonator for high field MRI

DEFF Research Database (Denmark)

Zhurbenko, Vitaliy; Johannesson, Kristjan Sundgaard; Boer, Vincent

2016-01-01

Transmission line resonators is often a preferable choice for coils in high field magnetic resonance imaging (MRI), because they provide a number of advantages over traditional loop coils. The size of such resonators, however, is limited to shorter than half a wavelength due to high standing wave....... Achieved magnetic field distribution is compared to the conventional transmission line resonator. Imaging experiments are performed using 7 Tesla MRI system. The developed resonator is useful for building coils with large field-of-view....

Thermo field dynamics: a quantum field theory at finite temperature

International Nuclear Information System (INIS)

Mancini, F.; Marinaro, M.; Matsumoto, H.

1988-01-01

A brief review of the theory of thermo field dynamics (TFD) is presented. TFD is introduced and developed by Umezawa and his coworkers at finite temperature. The most significant concept in TFD is that of a thermal vacuum which satisfies some conditions denoted as thermal state conditions. The TFD permits to reformulate theories at finite temperature. There is no need in an additional principle to determine particle distributions at T ≠ 0. Temperature and other macroscopic parameters are introduced in the definition of the vacuum state. All operator formalisms used in quantum field theory at T=0 are preserved, although the field degrees of freedom are doubled. 8 refs

Covariant field equations in supergravity

Energy Technology Data Exchange (ETDEWEB)

Vanhecke, Bram [KU Leuven, Institute for Theoretical Physics, Leuven (Belgium); Ghent University, Faculty of Physics, Gent (Belgium); Proeyen, Antoine van [KU Leuven, Institute for Theoretical Physics, Leuven (Belgium)

2017-12-15

Covariance is a useful property for handling supergravity theories. In this paper, we prove a covariance property of supergravity field equations: under reasonable conditions, field equations of supergravity are covariant modulo other field equations. We prove that for any supergravity there exist such covariant equations of motion, other than the regular equations of motion, that are equivalent to the latter. The relations that we find between field equations and their covariant form can be used to obtain multiplets of field equations. In practice, the covariant field equations are easily found by simply covariantizing the ordinary field equations. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Covariant field equations in supergravity

International Nuclear Information System (INIS)

Vanhecke, Bram; Proeyen, Antoine van

2017-01-01

Covariance is a useful property for handling supergravity theories. In this paper, we prove a covariance property of supergravity field equations: under reasonable conditions, field equations of supergravity are covariant modulo other field equations. We prove that for any supergravity there exist such covariant equations of motion, other than the regular equations of motion, that are equivalent to the latter. The relations that we find between field equations and their covariant form can be used to obtain multiplets of field equations. In practice, the covariant field equations are easily found by simply covariantizing the ordinary field equations. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Generalized field-transforming metamaterials

International Nuclear Information System (INIS)

Tretyakov, Sergei A; Nefedov, Igor S; Alitalo, Pekka

2008-01-01

In this paper, we introduce a generalized concept of field-transforming metamaterials, which perform field transformations defined as linear relations between the original and transformed fields. These artificial media change the fields in a prescribed fashion in the volume occupied by the medium. We show what electromagnetic properties of transforming medium are required. The coefficients of these linear functions can be arbitrary scalar functions of position and frequency, which makes the approach quite general and opens a possibility to realize various unusual devices.

Room Acoustical Fields

CERN Document Server

Mechel, Fridolin

2013-01-01

This book presents the theory of room acoustical fields and revises the Mirror Source Methods for practical computational use, emphasizing the wave character of acoustical fields.  The presented higher methods include the concepts of “Mirror Point Sources” and “Corner sources which allow for an excellent approximation of complex room geometries and even equipped rooms. In contrast to classical description, this book extends the theory of sound fields describing them by their complex sound pressure and the particle velocity. This approach enables accurate descriptions of interference and absorption phenomena.

Robotics Potential Fields

Directory of Open Access Journals (Sweden)

Jordi Lucero

2009-01-01

Full Text Available This problem was to calculate the path a robot would take to navigate an obstacle field and get to its goal. Three obstacles were given as negative potential fields which the robot avoided, and a goal was given a positive potential field that attracted the robot. The robot decided each step based on its distance, angle, and influence from every object. After each step, the robot recalculated and determined its next step until it reached its goal. The robot's calculations and steps were simulated with Microsoft Excel.

Nonlocal continuum field theories

CERN Document Server

2002-01-01

Nonlocal continuum field theories are concerned with material bodies whose behavior at any interior point depends on the state of all other points in the body -- rather than only on an effective field resulting from these points -- in addition to its own state and the state of some calculable external field. Nonlocal field theory extends classical field theory by describing the responses of points within the medium by functionals rather than functions (the "constitutive relations" of classical field theory). Such considerations are already well known in solid-state physics, where the nonlocal interactions between the atoms are prevalent in determining the properties of the material. The tools developed for crystalline materials, however, do not lend themselves to analyzing amorphous materials, or materials in which imperfections are a major part of the structure. Nonlocal continuum theories, by contrast, can describe these materials faithfully at scales down to the lattice parameter. This book presents a unif...

Stochastic-field cavitation model

International Nuclear Information System (INIS)

Dumond, J.; Magagnato, F.; Class, A.

2013-01-01

Nonlinear phenomena can often be well described using probability density functions (pdf) and pdf transport models. Traditionally, the simulation of pdf transport requires Monte-Carlo codes based on Lagrangian “particles” or prescribed pdf assumptions including binning techniques. Recently, in the field of combustion, a novel formulation called the stochastic-field method solving pdf transport based on Eulerian fields has been proposed which eliminates the necessity to mix Eulerian and Lagrangian techniques or prescribed pdf assumptions. In the present work, for the first time the stochastic-field method is applied to multi-phase flow and, in particular, to cavitating flow. To validate the proposed stochastic-field cavitation model, two applications are considered. First, sheet cavitation is simulated in a Venturi-type nozzle. The second application is an innovative fluidic diode which exhibits coolant flashing. Agreement with experimental results is obtained for both applications with a fixed set of model constants. The stochastic-field cavitation model captures the wide range of pdf shapes present at different locations

Stochastic-field cavitation model

Science.gov (United States)

Dumond, J.; Magagnato, F.; Class, A.

2013-07-01

Nonlinear phenomena can often be well described using probability density functions (pdf) and pdf transport models. Traditionally, the simulation of pdf transport requires Monte-Carlo codes based on Lagrangian "particles" or prescribed pdf assumptions including binning techniques. Recently, in the field of combustion, a novel formulation called the stochastic-field method solving pdf transport based on Eulerian fields has been proposed which eliminates the necessity to mix Eulerian and Lagrangian techniques or prescribed pdf assumptions. In the present work, for the first time the stochastic-field method is applied to multi-phase flow and, in particular, to cavitating flow. To validate the proposed stochastic-field cavitation model, two applications are considered. First, sheet cavitation is simulated in a Venturi-type nozzle. The second application is an innovative fluidic diode which exhibits coolant flashing. Agreement with experimental results is obtained for both applications with a fixed set of model constants. The stochastic-field cavitation model captures the wide range of pdf shapes present at different locations.

Development of field-wide risk based remediation objectives for an aging oil field : Devon Canada Swan Hills Field

Energy Technology Data Exchange (ETDEWEB)

Brewster, M.; North, C.; Leighton-Boyce, G. [WorleyParsons Komex, Calgary, AB (Canada); Moore, D. [Devon Canada Corp., Calgary, AB (Canada)

2006-07-01

The development of field-wide risk based remediation objectives for the aging Devon Canada Swan Hills oil field was examined along with the key components of the closure strategy. These included source removal to the extent practical, long term monitoring, and achievable risk-based remedial objectives that were appropriate to the remote boreal forest setting of the Swan Hills field. A two stage approach was presented. The first stage involved a field wide background framework which included defining areas of common physical and ecological setting and developing appropriate exposure scenarios. The second stage involved site-specific risk assessments which included adjusting for site-specific conditions and an early demonstration project to prove the concept. A GIS approach was used to identify areas of common physical and ecological setting including: physiography; surface water; land use; vegetation ecozones; surficial and bedrock geology; and water well use. Species lists were compiled for vegetation, terrestrial wildlife (mammals, birds, amphibians), and aquatic species (fish and invertebrates). Major contaminant sources, problem formulation, vegetation bioassays, invertebrate bioassays, black spruce emergence, and guideline development were other topics covered during the presentation. Last, a summary of progress was presented. A field-wide review and development of risk zones and site-specific risk assessment has been completed. A regulatory review is underway. tabs., figs.

Entropy for the Quantized Field in the Atom-Field Interaction: Initial Thermal Distribution

Directory of Open Access Journals (Sweden)

Luis Amilca Andrade-Morales

2016-09-01

Full Text Available We study the entropy of a quantized field in interaction with a two-level atom (in a pure state when the field is initially in a mixture of two number states. We then generalise the result for a thermal state; i.e., an (infinite statistical mixture of number states. We show that for some specific interaction times, the atom passes its purity to the field and therefore the field entropy decreases from its initial value.

Ultra-Low Field SQUID-NMR using LN2 Cooled Cu Polarizing Field coil

Science.gov (United States)

Demachi, K.; Kawagoe, S.; Ariyoshi, S.; Tanaka, S.

2017-07-01

We are developing an Ultra-Low Field (ULF) Magnetic Resonance Imaging (MRI) system using a High-Temperature Superconductor superconducting quantum interference device (HTS rf-SQUID) for food inspection. The advantages of the ULF-NMR (Nuclear Magnetic Resonance) / MRI as compared with a conventional high field MRI are that they are compact and of low cost. In this study, we developed a ULF SQUID-NMR system using a polarizing coil to measure fat of which relaxation time T1 is shorter. The handmade polarizing coil was cooled by liquid nitrogen to reduce the resistance and accordingly increase the allowable current. The measured decay time of the polarizing field was 40 ms. The measurement system consisted of the liquid nitrogen cooled polarizing coil, a SQUID, a Cu wound flux transformer, a measurement field coil for the field of 47 μT, and an AC pulse coil for a 90°pulse field. The NMR measurements were performed in a magnetically shielded room to reduce the environmental magnetic field. The size of the sample was ϕ35 mm × L80 mm. After applying a polarizing field and a 90°pulse, an NMR signal was detected by the SQUID through the flux transformer. As a result, the NMR spectra of fat samples were obtained at 2.0 kHz corresponding to the measurement field Bm of 47 μT. The T1 relaxation time of the mineral oil measured in Bm was 45 ms. These results suggested that the ULF-NMR/MRI system has potential for food inspection.

Geomagnetic field, global pattern

OpenAIRE

Macmillan, Susan

2011-01-01

The geomagnetic field is generated in the fluid outer core region of the Earth by electrical currents flowing in the slowly moving molten iron. In addition to sources in the Earth’s core, the geomagnetic field observable on the Earth’s surface has sources in the crust and in the ionosphere and magnetosphere. The signal from the core dominates, accounting for over 95% of the field at the Earth’s surface. The geomagnetic field varies on a range of scales, both temporal and spatial; the...

The Juno Magnetic Field Investigation

DEFF Research Database (Denmark)

Connerney, J. E. P.; Benn, Mathias; Bjarnø, Jonas Bækby

2017-01-01

The Juno Magnetic Field investigation (MAG) characterizes Jupiter’s planetary magnetic field and magnetosphere, providing the first globally distributed and proximate measurements of the magnetic field of Jupiter. The magnetic field instrumentation consists of two independent magnetometer sensor ...

Development of hard X-ray dark-field microscope using full-field optics

International Nuclear Information System (INIS)

Takano, Hidekazu; Azuma, Hiroaki; Shimomura, Sho; Tsuji, Takuya; Tsusaka, Yoshiyuki; Kagoshima, Yasushi

2016-01-01

We develop a dark-field X-ray microscope using full-field optics based on a synchrotron beamline. Our setup consists of a condenser system and a microscope objective with an angular acceptance larger than that of the condenser. The condenser system is moved downstream from its regular position such that the focus of the condenser is behind the objective. The dark-field microscope optics are configured by excluding the converging beam from the condenser at the focal point. The image properties of the system are evaluated by observing and calculating a Siemens star test chart with 10 keV X-rays. Our setup allows easy switching to bright-field imaging. (author)

In vivo field-cycling relaxometry using an insert coil for magnetic field offset.

Science.gov (United States)

Pine, Kerrin J; Goldie, Fred; Lurie, David J

2014-11-01

The T(1) of tissue has a strong dependence on the measurement magnetic field strength. T(1) -dispersion could be a useful contrast parameter, but is unavailable to clinical MR systems which operate at fixed magnetic field strength. The purpose of this work was to implement a removable insert magnet coil for field-cycling T(1) -dispersion measurements on a vertical-field MRI scanner, by offsetting the static field over a volume of interest. An insert magnet coil was constructed for use with a whole-body sized 59 milli-Tesla (mT) vertical-field, permanent-magnet based imager. The coil has diameter 38 cm and thickness 6.1 cm and a homogeneous region (± 5%) of 5 cm DSV, offset by 5 cm from the coil surface. Surface radiofrequency (RF) coils were also constructed. The insert coil was used in conjunction with a surface RF coil and a volume-localized inversion-recovery pulse sequence to plot T(1) -dispersion in a human volunteer's forearm over a range of field strengths from 1 mT to 70 mT. T(1) -dispersion measurements were demonstrated on a fixed-field MRI scanner, using an insert coil. This demonstrates the feasibility of relaxation dispersion measurements on an otherwise conventional MR imager, facilitating the exploitation of T(1) -dispersion contrast for enhanced diagnosis. Copyright © 2013 Wiley Periodicals, Inc.

Self-field effects on electron dynamics in free-electron lasers with axial magnetic field

International Nuclear Information System (INIS)

Mirzanejhad, S.; Maraghechi, B.; Mohsenpour, T.

2004-01-01

A self-consistent method for the analysis of self-magnetic field for a free-electron laser with a one-dimensional helical wiggler and an axial guide magnetic field is presented. The equilibrium orbits and their stability, under the influence of self-electric and self-magnetic fields, are analyzed. New unstable orbits, in the first part of the Group I orbits and in the resonance region of the Group II orbits, are found. It is shown that an increase in the defocusing effect of self-fields will widen the unstable orbits. An anomalous self-field regime is found where an increase in the defocusing effect of self-fields can have stabilizing effect on the resonance region

Refractive waveguide non-mechanical beam steering (NMBS) in the MWIR

Science.gov (United States)

Myers, Jason D.; Frantz, Jesse A.; Spillmann, Christopher M.; Bekele, Robel Y.; Kolacz, Jakub; Gotjen, Henry; Naciri, Jawad; Shaw, Brandon; Sanghera, Jas S.

2018-02-01

Beam steering is a crucial technology for a number of applications, including chemical sensing/mapping and light detection and ranging (LIDAR). Traditional beam steering approaches rely on mechanical movement, such as the realignment of mirrors in gimbal mounts. The mechanical approach to steering has several drawbacks, including large size, weight and power usage (SWAP), and frequent mechanical failures. Recently, alternative non-mechanical approaches have been proposed and developed, but these technologies do not meet the demanding requirements for many beam steering applications. Here, we highlight the development efforts into a particular non-mechanical beam steering (NMBS) approach, refractive waveguides, for application in the MWIR. These waveguides are based on an Ulrich-coupled slab waveguide with a liquid crystal (LC) top cladding; by selectively applying an electric field across the liquid crystal through a prismatic electrode, steering is achieved by creating refraction at prismatic interfaces as light propagates through the device. For applications in the MWIR, we describe a versatile waveguide architecture based on chalcogenide glasses that have a wide range of refractive indices, transmission windows, and dispersion properties. We have further developed robust shadow-masking methods to taper the subcladding layers in the coupling region. We have demonstrated devices with >10° of steering in the MWIR and a number of advantageous properties for beam steering applications, including low-power operation, compact size, and fast point-to-point steering.

Magnetic fields in diffuse media

CERN Document Server

Pino, Elisabete; Melioli, Claudio

2015-01-01

This volume presents the current knowledge of magnetic fields in diffuse astrophysical media. Starting with an overview of 21st century instrumentation to observe astrophysical magnetic fields, the chapters cover observational techniques, origin of magnetic fields, magnetic turbulence, basic processes in magnetized fluids, the role of magnetic fields for cosmic rays, in the interstellar medium and for star formation. Written by a group of leading experts the book represents an excellent overview of the field. Nonspecialists will find sufficient background to enter the field and be able to appreciate the state of the art.

Vector Fields on Product Manifolds

OpenAIRE

Kurz, Stefan

2011-01-01

This short report establishes some basic properties of smooth vector fields on product manifolds. The main results are: (i) On a product manifold there always exists a direct sum decomposition into horizontal and vertical vector fields. (ii) Horizontal and vertical vector fields are naturally isomorphic to smooth families of vector fields defined on the factors. Vector fields are regarded as derivations of the algebra of smooth functions.

Magnetic fields, velocity fields and brightness in the central region of the Solar disk

Energy Technology Data Exchange (ETDEWEB)

Tsap, T T

1978-01-01

The longitudinal magnetic fields, velocity fields and brightness at the center of the Solar disk are studied. Observations of the magnetic field, line-of-sight velocities and brightness have been made with the doublemagnetograph of the Crimean astrophysical observatory. It is found that the average magnetic field strength recorded in the iron line lambda 5233 A is 18 Gs for the elements of N-polarity and 23 Gs for the elements of S-polarity. The magnetic elements with the field strength more than 200 Gs are observed in some of the cases. There is a close correlation between the magnetic field distribution in the lambda 5250 A FeI and D/sub 1/ Na I lines and between the magnetic field in the lambda 5250 A and brightness in the K/sub 3/CaII line. The dimensions of the magnetic elements in the lambda and D/sub 1/NaI lines are equal. The comparison of the magnetic field with the radial velocity recorded in the lambda 5250 and 5233 A lines has shown that radial velocities are close to zero in the regions of maximum longitudinal magnetic field. The chromospheric network-like pattern is observed in the brightness distribution of ten different spectral lines.

Interaction of the geomagnetic field with northward interplanetary magnetic field

Science.gov (United States)

Bhattarai, Shree Krishna

The interaction of the solar wind with Earth's magnetic field causes the transfer of momentum and energy from the solar wind to geospace. The study of this interaction is gaining significance as our society is becoming more and more space based, due to which, predicting space weather has become more important. The solar wind interacts with the geomagnetic field primarily via two processes: viscous interaction and the magnetic reconnection. Both of these interactions result in the generation of an electric field in Earth's ionosphere. The overall topology and dynamics of the magnetosphere, as well as the electric field imposed on the ionosphere, vary with speed, density, and magnetic field orientation of the solar wind as well as the conductivity of the ionosphere. In this dissertation, I will examine the role of northward interplanetary magnetic field (IMF) and discuss the global topology of the magnetosphere and the interaction with the ionosphere using results obtained from the Lyon-Fedder-Mobarry (LFM) simulation. The electric potentials imposed on the ionosphere due to viscous interaction and magnetic reconnection are called the viscous and the reconnection potentials, respectively. A proxy to measure the overall effect of these potentials is to measure the cross polar potential (CPP). The CPP is defined as the difference between the maximum and the minimum of the potential in a given polar ionosphere. I will show results from the LFM simulation showing saturation of the CPP during periods with purely northward IMF of sufficiently large magnitude. I will further show that the viscous potential, which was assumed to be independent of IMF orientation until this work, is reduced during periods of northward IMF. Furthermore, I will also discuss the implications of these results for a simulation of an entire solar rotation.

Digital archaeology field recording in the 4th dimension: ArchField C++ a 4D GIS for digital field work

KAUST Repository

Smith, Neil; Howland, Matthew; Levy, Thomas E.

2016-01-01

With the rapid adoption of laser scanning and photogrammetry among the archaeological community the creation of point cloud `data scaffolds' and digital documentation of archaeological sites is now becoming common. In field excavations, however, the continual exposure of archaeological layers requires a digital toolset in which to record, categorize and spatially locate artifacts, installations, and loci within a site's daily 3D or aerial scan. We present ArchField C++, the latest version of our digital field recording software that enables real-time digital GIS 3D Top Plan production within a rendering engine designed for visualizing massive 3D datasets. ArchField directly connects to Total Stations and our RTK GPS units to record sub-centimeter measurements for artifacts, scanning markers, loci boundaries, and camera positions. The processing pipeline enables the generation of publishable orthographic and perspective maps from the first day of excavation to the last. As a backend it uses a PostGIS database and the ability to export and import various vector, raster, DEM and 3D datasets that can be hosted by on-line geo-referenced databases. We present the application of ArchField C++ to our 2014 field excavations of the early Iron Age site of Khirbat al-Jariyah located in Southern Jordan.

Digital archaeology field recording in the 4th dimension: ArchField C++ a 4D GIS for digital field work

KAUST Repository

Smith, Neil

2016-02-25

With the rapid adoption of laser scanning and photogrammetry among the archaeological community the creation of point cloud `data scaffolds\\' and digital documentation of archaeological sites is now becoming common. In field excavations, however, the continual exposure of archaeological layers requires a digital toolset in which to record, categorize and spatially locate artifacts, installations, and loci within a site\\'s daily 3D or aerial scan. We present ArchField C++, the latest version of our digital field recording software that enables real-time digital GIS 3D Top Plan production within a rendering engine designed for visualizing massive 3D datasets. ArchField directly connects to Total Stations and our RTK GPS units to record sub-centimeter measurements for artifacts, scanning markers, loci boundaries, and camera positions. The processing pipeline enables the generation of publishable orthographic and perspective maps from the first day of excavation to the last. As a backend it uses a PostGIS database and the ability to export and import various vector, raster, DEM and 3D datasets that can be hosted by on-line geo-referenced databases. We present the application of ArchField C++ to our 2014 field excavations of the early Iron Age site of Khirbat al-Jariyah located in Southern Jordan.

Effective quantum field theories

International Nuclear Information System (INIS)

Georgi, H.M.

1993-01-01

The most appropriate description of particle interactions in the language of quantum field theory depends on the energy at which the interactions are studied; the description is in terms of an ''effective field theory'' that contains explicit reference only to those particles that are actually important at the energy being studied. The various themes of the article are: local quantum field theory, quantum electrodynamics, new physics, dimensional parameters and renormalizability, socio-dynamics of particle theory, spontaneously broken gauge theories, scale dependence, grand unified and effective field theories. 2 figs

Time-localized projectors in string field theory with an E-field

International Nuclear Information System (INIS)

Maccaferri, C.; Scherer Santos, R.J.; Tolla, D.D.

2005-01-01

We extend the analysis of Bonora et al. [hep-th/0409063] to the case of a constant electric field turned on the world volume and on a transverse direction of a D-brane. We show that time localization is still obtained by inverting the discrete eigenvalues of the lump solution. The lifetime of the unstable soliton is shown to depend on two free parameters: the b parameter and the value of the electric field. As a by-product, we construct the normalized diagonal basis of the star algebra in the B μν -field background

Magnetic resonance of field-frozen and zero-field-frozen magnetic fluids

International Nuclear Information System (INIS)

Pereira, A.R.; Pelegrini, F.; Neto, K. Skeff; Buske, N.; Morais, P.C.

2004-01-01

In this study magnetic resonance was used to investigate magnetic fluid samples frozen under zero and non-zero (15 kG) external fields. The magnetite-based sample containing 2x10 17 particle/cm 3 was investigated from 100 to 400 K. Analysis of the temperature dependence of the resonance field revealed bigger magnetic structures in the frozen state than in the liquid phase. Also, differences in the mesoscopic organization in the frozen state may explain the data obtained from samples frozen under zero and non-zero fields

Multiple fields in stochastic inflation

Energy Technology Data Exchange (ETDEWEB)

Assadullahi, Hooshyar [Institute of Cosmology & Gravitation, University of Portsmouth,Dennis Sciama Building, Burnaby Road, Portsmouth, PO1 3FX (United Kingdom); Firouzjahi, Hassan [School of Astronomy, Institute for Research in Fundamental Sciences (IPM),P.O. Box 19395-5531, Tehran (Iran, Islamic Republic of); Noorbala, Mahdiyar [Department of Physics, University of Tehran,P.O. Box 14395-547, Tehran (Iran, Islamic Republic of); School of Astronomy, Institute for Research in Fundamental Sciences (IPM),P.O. Box 19395-5531, Tehran (Iran, Islamic Republic of); Vennin, Vincent; Wands, David [Institute of Cosmology & Gravitation, University of Portsmouth,Dennis Sciama Building, Burnaby Road, Portsmouth, PO1 3FX (United Kingdom)

2016-06-24

Stochastic effects in multi-field inflationary scenarios are investigated. A hierarchy of diffusion equations is derived, the solutions of which yield moments of the numbers of inflationary e-folds. Solving the resulting partial differential equations in multi-dimensional field space is more challenging than the single-field case. A few tractable examples are discussed, which show that the number of fields is, in general, a critical parameter. When more than two fields are present for instance, the probability to explore arbitrarily large-field regions of the potential, otherwise inaccessible to single-field dynamics, becomes non-zero. In some configurations, this gives rise to an infinite mean number of e-folds, regardless of the initial conditions. Another difference with respect to single-field scenarios is that multi-field stochastic effects can be large even at sub-Planckian energy. This opens interesting new possibilities for probing quantum effects in inflationary dynamics, since the moments of the numbers of e-folds can be used to calculate the distribution of primordial density perturbations in the stochastic-δN formalism.

Unbalanced field RF electron gun

Science.gov (United States)

Hofler, Alicia

2013-11-12

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

Control of the radial electric field shear by modification of the magnetic field configuration in LHD

International Nuclear Information System (INIS)

Ida, K.; Yoshinuma, M.; Yokoyama, M.

2005-01-01

Control of the radial electric field, E r , is considered to be important in helical plasmas, because the radial electric field and its shear are expected to reduce neoclassical and anomalous transport, respectively. In general, the radial electric field can be controlled by changing the collisionality, and positive or negative electric fields have been obtained by decreasing or increasing the electron density, respectively. Although the sign of the radial electric field can be controlled by changing the collisionality, modification of the magnetic field is required to achieve further control of the radial electric field, especially to produce a strong radial electric field shear. In the Large Helical Device (LHD) the radial electric field profiles are shown to be controlled by the modification of the magnetic field by (1) changing the radial profile of the effective helical ripples, ε h (2) creating a magnetic island with an external perturbation field coil and (3) changing the local island divertor coil current

Control of the radial electric field shear by modification of the magnetic field configuration in LHD

International Nuclear Information System (INIS)

Ida, K.; Yoshinuma, M.; Yokoyama, M.

2005-01-01

Control of the radial electric field, E γ , is considered to be important in helical plasmas, because the radial electric field and its shear are expected to reduce neoclassical and anomalous transport, respectively. In general, the radial electric field can be controlled by changing the collisionality, and positive or negative electric field have been obtained by decreasing or increasing the electron density, respectively. Although the sign of the radial electric field can be controlled by changing the collisionality, modification of the magnetic field is required to achieve further control of the radial electric field, especially producing a strong radial electric field shear. In the Large Helical Device (LHD) the radial electric field profiles are shown to be controlled by the modification of the magnetic field by 1) changing the radial profile of the helical ripples, ε h , 2) creating a magnetic island with an external perturbation field coil and 3) changing the local island divertor coil current. (author)

Toroidal magnetic field system for a 2-MA reversed-field pinch experiment

International Nuclear Information System (INIS)

Melton, J.G.; Linton, T.W.

1983-01-01

The engineering design of the toroidal magnetic field (TF) system for a 2-MA Reversed-Field Pinch experiment (ZT-H) is described. ZT-H is designed with major radius 2.15 meters, minor radius 0.40 meters, and a peak toroidal magnetic field of 0.85 Tesla. The requirement for highly uniform fields, with spatial ripple <0.2% leads to a design with 72 equally spaced circular TF coils, located at minor radius 0.6 meters, carrying a maximum current of 9.0 MA. The coils are driven by a 12-MJ capacitor bank which is allowed to ring in order to aid the reversal of magnetic field. A stress analysis is presented, based upon calculated hoop tension, centering force, and overturning moment, treating these as a combination of static loads and considering that the periodic nature of the loading causes little amplification. The load transfer of forces and moments is considered as a stress distribution resisted by the coils, support structures, wedges, and the structural shell

The logarithmic conformal field theories

International Nuclear Information System (INIS)

Rahimi Tabar, M.R.; Aghamohammadi, A.; Khorrami, M.

1997-01-01

We study the correlation functions of logarithmic conformal field theories. First, assuming conformal invariance, we explicitly calculate two- and three-point functions. This calculation is done for the general case of more than one logarithmic field in a block, and more than one set of logarithmic fields. Then we show that one can regard the logarithmic field as a formal derivative of the ordinary field with respect to its conformal weight. This enables one to calculate any n-point function containing the logarithmic field in terms of ordinary n-point functions. Finally, we calculate the operator product expansion (OPE) coefficients of a logarithmic conformal field theory, and show that these can be obtained from the corresponding coefficients of ordinary conformal theory by a simple derivation. (orig.)

Field testing a soil site field guide for Allegheny hardwoods

Science.gov (United States)

S.B. Jones

1991-01-01

A site quality evaluation decision model, developed for Allegheny hardwoods on the non-glaciated Allegheny Plateau of Pennsylvania and New York, was field tested by International Paper (IP) foresters and the author, on sites within the region of derivation and on glaciated sites north and west of the Wisconsin drift line. Results from the field testing are presented...

Complex Polynomial Vector Fields

DEFF Research Database (Denmark)

The two branches of dynamical systems, continuous and discrete, correspond to the study of differential equations (vector fields) and iteration of mappings respectively. In holomorphic dynamics, the systems studied are restricted to those described by holomorphic (complex analytic) functions...... or meromorphic (allowing poles as singularities) functions. There already exists a well-developed theory for iterative holomorphic dynamical systems, and successful relations found between iteration theory and flows of vector fields have been one of the main motivations for the recent interest in holomorphic...... vector fields. Since the class of complex polynomial vector fields in the plane is natural to consider, it is remarkable that its study has only begun very recently. There are numerous fundamental questions that are still open, both in the general classification of these vector fields, the decomposition...

Nanosecond field emitted and photo-field emitted current pulses from ZrC tips

International Nuclear Information System (INIS)

Ganter, R.; Bakker, R.J.; Gough, C.; Paraliev, M.; Pedrozzi, M.; Le Pimpec, F.; Rivkin, L.; Wrulich, A.

2006-01-01

In order to find electron sources with low thermal emittance, cathodes based on single tip field emitter are investigated. Maximum peak current, measured from single tip in ZrC with a typical apex radius around 1 μm, are presented. Voltage pulses of 2 ns duration and up to 50 kV amplitude lead to field emission current up to 470 mA from one ZrC tip. Combination of high applied electric field with laser illumination gives the possibility to modulate the emission with laser pulses. Nanoseconds current pulses have been emitted with laser pulses at 1064 nm illuminating a ZrC tip under high-DC electric field. The dependence of photo-field emitted current with the applied voltage can be explained by the Schottky effect

A Compact RFID Reader Antenna for UHF Near-Field and Far-Field Operations

Directory of Open Access Journals (Sweden)

Lai Xiao zheng

2013-01-01

Full Text Available A compact loop antenna is presented for mobile ultrahigh frequency (UHF radio frequency identification (RFID application. This antenna, printed on a 0.8 mm thick FR4 substrate with a small size of 31 mm × 31 mm, achieves good impedance bandwidth from 897 to 928 MHz, which covers USA RFID Band (902–928 MHz. The proposed loop configuration, with a split-ring resonator (SRR coupled inside it, demonstrates strong and uniform magnetic field distribution in the near-field antenna region. Its linearly polarized radiation pattern provides available far-field gain. Finally, the reading capabilities of antenna are up to 56 mm for near-field and 1.05 m for far-field UHF RFID operations, respectively.

Nanosecond field emitted and photo-field emitted current pulses from ZrC tips

Energy Technology Data Exchange (ETDEWEB)

Ganter, R. [Paul Scherrer Institut, Villigen, CH 5232 (Switzerland)]. E-mail: romain.ganter@psi.ch; Bakker, R.J. [Paul Scherrer Institut, Villigen, CH 5232 (Switzerland); Gough, C. [Paul Scherrer Institut, Villigen, CH 5232 (Switzerland); Paraliev, M. [Paul Scherrer Institut, Villigen, CH 5232 (Switzerland); Pedrozzi, M. [Paul Scherrer Institut, Villigen, CH 5232 (Switzerland); Le Pimpec, F. [Paul Scherrer Institut, Villigen, CH 5232 (Switzerland); Rivkin, L. [Paul Scherrer Institut, Villigen, CH 5232 (Switzerland); Wrulich, A. [Paul Scherrer Institut, Villigen, CH 5232 (Switzerland)

2006-09-15

In order to find electron sources with low thermal emittance, cathodes based on single tip field emitter are investigated. Maximum peak current, measured from single tip in ZrC with a typical apex radius around 1 {mu}m, are presented. Voltage pulses of 2 ns duration and up to 50 kV amplitude lead to field emission current up to 470 mA from one ZrC tip. Combination of high applied electric field with laser illumination gives the possibility to modulate the emission with laser pulses. Nanoseconds current pulses have been emitted with laser pulses at 1064 nm illuminating a ZrC tip under high-DC electric field. The dependence of photo-field emitted current with the applied voltage can be explained by the Schottky effect.

High field MRI in the diagnosis of multiple sclerosis: high field-high yield?

International Nuclear Information System (INIS)

Wattjes, Mike P.; Barkhof, Frederik

2009-01-01

Following the approval of the U.S. Food and Drug Administration (FDA), high field magnetic resonance imaging (MRI) has been increasingly incorporated into the clinical setting. Especially in the field of neuroimaging, the number of high field MRI applications has been increased dramatically. Taking advantage on increased signal-to-noise ratio (SNR) and chemical shift, higher magnetic field strengths offer new perspectives particularly in brain imaging and also challenges in terms of several technical and physical consequences. Over the past few years, many applications of high field MRI in patients with suspected and definite multiple sclerosis (MS) have been reported including conventional and quantitative MRI methods. Conventional pulse sequences at 3 T offers higher lesion detection rates when compared to 1.5 T, particularly in anatomic regions which are important for the diagnosis of patients with MS. MR spectroscopy at 3 T is characterized by an improved spectral resolution due to increased chemical shift allowing a better quantification of metabolites. It detects significant axonal damage already in patients presenting with clinically isolated syndromes and can quantify metabolites of special interest such as glutamate which is technically difficult to quantify at lower field strengths. Furthermore, the higher susceptibility and SNR offer advantages in the field of functional MRI and diffusion tensor imaging. The recently introduced new generation of ultra-high field systems beyond 3 T allows scanning in submillimeter resolution and gives new insights into in vivo MS pathology on MRI. The objectives of this article are to review the current knowledge and level of evidence concerning the application of high field MRI in MS and to give some ideas of research perspectives in the future. (orig.)

Field error lottery

Energy Technology Data Exchange (ETDEWEB)

Elliott, C.J.; McVey, B. (Los Alamos National Lab., NM (USA)); Quimby, D.C. (Spectra Technology, Inc., Bellevue, WA (USA))

1990-01-01

The level of field errors in an FEL is an important determinant of its performance. We have computed 3D performance of a large laser subsystem subjected to field errors of various types. These calculations have been guided by simple models such as SWOOP. The technique of choice is utilization of the FELEX free electron laser code that now possesses extensive engineering capabilities. Modeling includes the ability to establish tolerances of various types: fast and slow scale field bowing, field error level, beam position monitor error level, gap errors, defocusing errors, energy slew, displacement and pointing errors. Many effects of these errors on relative gain and relative power extraction are displayed and are the essential elements of determining an error budget. The random errors also depend on the particular random number seed used in the calculation. The simultaneous display of the performance versus error level of cases with multiple seeds illustrates the variations attributable to stochasticity of this model. All these errors are evaluated numerically for comprehensive engineering of the system. In particular, gap errors are found to place requirements beyond mechanical tolerances of {plus minus}25{mu}m, and amelioration of these may occur by a procedure utilizing direct measurement of the magnetic fields at assembly time. 4 refs., 12 figs.

The Emerging Strategic Entrepreneurship Field

DEFF Research Database (Denmark)

Foss, Nicolai Juul; Lyngsie, Jacob

The field of strategic entrepreneurship is a fairly recent one. Its central idea is that opportunity-seeking and advantage-seeking — the former the central subject of the entrepreneurship field, the latter the central subject of the strategic management field — are processes that need...... to be considered jointly. The purpose of this brief chapter is to explain the emergence of SE theory field in terms of a response to research gaps in the neighboring fields of entrepreneurship and strategic management; describe the main tenets of SE theory; discuss its relations to neighboring fields; and finally...

Unidirectional magnetoelectric-field multiresonant tunneling

International Nuclear Information System (INIS)

Kamenetskii, E O; Hollander, E; Joffe, R; Shavit, R

2015-01-01

Unidirectional multi-resonant tunneling of the magnetoelectric (ME) field excitations through a subwavelength (regarding the scales of regular electromagnetic radiation) vacuum or isotropic-dielectric regions has been observed in two-port microwave structures having a quasi-2D ferrite disk with magnetic dipolar mode (MDM) oscillations. The excitations manifest themselves as Fano-resonance peaks in the scattering-matrix parameters at the stationary states of the MDM spectrum. The ME near-field excitations are quasimagnetostatic fields ∇-vector × H-vector =0 with non-zero helicity parameter: F=(1/(16π))Im{ E-vector ⋅( ∇-vector × E-vector ) ∗ }. Topological phase properties of ME fields are determined by edge chiral currents of MDM oscillations. We show that while for a given direction of a bias magnetic field (in other words, for a given direction of time), the ME field excitations are considered as ‘forward’ tunneling processes, in the opposite direction of a bias magnetic field (the opposite direction of time), there are ‘backward’ tunneling processes. Unidirectional ME field resonant tunneling is observed due to the distinguishable topology of the ‘forward’ and ‘backward’ ME field excitations. We establish a close connection between the Fano-resonance unidirectional tunneling and the topology of the ME fields in different microwave structures. (paper)

Field errors in the RFX magnetic field configuration

International Nuclear Information System (INIS)

Bellina, F.; Campostrini, P.P.; Chitarin, G.; Fauri, M.; Zaccaria, P.L.

1987-01-01

Several factors can jeopardize the desired field configuration in the plasma region of a toroidal machine, namely: the wrong positioning of the coil conductors; the displacement of the coils due to the deflection of the mechanical structure; the currents in the busbars feeding the coils; the ferromagnetic materials around the machine; and the eddy currents in any conducting loop in the neighbourhood of the machine. This paper describes the various methods used for evaluating the effects of each item listed above and the technical solutions which have been adopted, case by case, in order to comply with the requirements on the field errors

Conformal field theory with two kinds of Bosonic fields and two linear dilatons

International Nuclear Information System (INIS)

Kamani, Davoud

2010-01-01

We consider a two-dimensional conformal field theory which contains two kinds of the bosonic degrees of freedom. Two linear dilaton fields enable to study a more general case. Various properties of the model such as OPEs, central charge, conformal properties of the fields and associated algebras will be studied. (author)

A corotation electric field model of the Earth derived from Swarm satellite magnetic field measurements

Science.gov (United States)

Maus, Stefan

2017-08-01

Rotation of the Earth in its own geomagnetic field sets up a primary corotation electric field, compensated by a secondary electric field of induced electrical charges. For the geomagnetic field measured by the Swarm constellation of satellites, a derivation of the global corotation electric field inside and outside of the corotation region is provided here, in both inertial and corotating reference frames. The Earth is assumed an electrical conductor, the lower atmosphere an insulator, followed by the corotating ionospheric E region again as a conductor. Outside of the Earth's core, the induced charge is immediately accessible from the spherical harmonic Gauss coefficients of the geomagnetic field. The charge density is positive at high northern and southern latitudes, negative at midlatitudes, and increases strongly toward the Earth's center. Small vertical electric fields of about 0.3 mV/m in the insulating atmospheric gap are caused by the corotation charges located in the ionosphere above and the Earth below. The corotation charges also flow outward into the region of closed magnetic field lines, forcing the plasmasphere to corotate. The electric field of the corotation charges further extends outside of the corotating regions, contributing radial outward electric fields of about 10 mV/m in the northern and southern polar caps. Depending on how the magnetosphere responds to these fields, the Earth may carry a net electric charge.

Pulsed electric fields

Science.gov (United States)

The concept of pulsed electric fields (PEF) was first proposed in 1967 to change the behavior or microorganisms. The electric field phenomenon was identified as membrane rupture theory in the 1980s. Increasing the membrane permeability led to the application of PEF assisted extraction of cellular co...

Magnetic field line Hamiltonian

International Nuclear Information System (INIS)

Boozer, A.H.

1985-02-01

The basic properties of the Hamiltonian representation of magnetic fields in canonical form are reviewed. The theory of canonical magnetic perturbation theory is then developed and applied to the time evolution of a magnetic field embedded in a toroidal plasma. Finally, the extension of the energy principle to tearing modes, utilizing the magnetic field line Hamiltonian, is outlined

Effects of the reconnection electric field on crescent electron distribution functions in asymmetric guide field reconnection

Science.gov (United States)

Bessho, N.; Chen, L. J.; Hesse, M.; Wang, S.

2017-12-01

In asymmetric reconnection with a guide field in the Earth's magnetopause, electron motion in the electron diffusion region (EDR) is largely affected by the guide field, the Hall electric field, and the reconnection electric field. The electron motion in the EDR is neither simple gyration around the guide field nor simple meandering motion across the current sheet. The combined meandering motion and gyration has essential effects on particle acceleration by the in-plane Hall electric field (existing only in the magnetospheric side) and the out-of-plane reconnection electric field. We analyze electron motion and crescent-shaped electron distribution functions in the EDR in asymmetric guide field reconnection, and perform 2-D particle-in-cell (PIC) simulations to elucidate the effect of reconnection electric field on electron distribution functions. Recently, we have analytically expressed the acceleration effect due to the reconnection electric field on electron crescent distribution functions in asymmetric reconnection without a guide field (Bessho et al., Phys. Plasmas, 24, 072903, 2017). We extend the theory to asymmetric guide field reconnection, and predict the crescent bulge in distribution functions. Assuming 1D approximation of field variations in the EDR, we derive the time period of oscillatory electron motion (meandering + gyration) in the EDR. The time period is expressed as a hybrid of the meandering period and the gyro period. Due to the guide field, electrons not only oscillate along crescent-shaped trajectories in the velocity plane perpendicular to the antiparallel magnetic fields, but also move along parabolic trajectories in the velocity plane coplanar with magnetic field. The trajectory in the velocity space gradually shifts to the acceleration direction by the reconnection electric field as multiple bounces continue. Due to the guide field, electron distributions for meandering particles are bounded by two paraboloids (or hyperboloids) in the

Biological effects of electromagnetic fields and recently updated safety guidelines for strong static magnetic fields

International Nuclear Information System (INIS)

Yamaguchi-Sekino, Sachiko; Sekino, Masaki; Ueno, Shoogo

2011-01-01

Humans are exposed daily to artificial and naturally occurring magnetic fields that originate from many different sources. We review recent studies that examine the biological effects of and medical applications involving electromagnetic fields, review the properties of static and pulsed electromagnetic fields that affect biological systems, describe the use of a pulsed electromagnetic field in combination with an anticancer agent as an example of a medical application that incorporates an electromagnetic field, and discuss the recently updated safety guidelines for static electromagnetic fields. The most notable modifications to the 2009 International Commission on Non-Ionizing Radiation Protection guidelines are the increased exposure limits, especially for those who work with or near electromagnetic fields (occupational exposure limits). The recommended increases in exposure were determined using recent scientific evidence obtained from animal and human studies. Several studies since the 1994 publication of the guidelines have examined the effects on humans after exposure to high static electromagnetic fields (up to 9.4 tesla), but additional research is needed to ascertain further the safety of strong electromagnetic fields. (author)

Error field considerations for BPX

International Nuclear Information System (INIS)

LaHaye, R.J.

1992-01-01

Irregularities in the position of poloidal and/or toroidal field coils in tokamaks produce resonant toroidal asymmetries in the vacuum magnetic fields. Otherwise stable tokamak discharges become non-linearly unstable to disruptive locked modes when subjected to low level error fields. Because of the field errors, magnetic islands are produced which would not otherwise occur in tearing mode table configurations; a concomitant reduction of the total confinement can result. Poloidal and toroidal asymmetries arise in the heat flux to the divertor target. In this paper, the field errors from perturbed BPX coils are used in a field line tracing code of the BPX equilibrium to study these deleterious effects. Limits on coil irregularities for device design and fabrication are computed along with possible correcting coils for reducing such field errors

Some stochastic techniques in quantization, new developments in Markov fields and quantum fields

International Nuclear Information System (INIS)

Albeverio, S.; Zegarlinski, B.

1990-01-01

In these lectures we intend to discuss a few recent developments in the area of interactions between quantum fields and Markow fields in which we have been involved. We stress particularly developments involving techniques of stochastic analysis and where mathematical results have been obtained. In sections 1 and 2 we discuss recent developments in the study and applications of the theory of Dirichlet forms in its relations with quantum mechanics and quantum field theory. In our opinion, this theory provides a natural setting for the study of the singular stochastic processes associated with quantum theory. In section 3 we discuss a recent rigorous construction of a convergent simplicial approximation to quantum fields. We look upon these developments as a first step towards a mathematical realization, at least in 2 space-time dimensions, of a convergent 'Regge-calculus', and as first steps to the mathematical control of more general models (like e.g. models involving actions of Chern-Simons type) in the continuum. In Sect. 4 we discuss applications of some stochastic techniques to the study of gauge fields and Higgs fields, mainly in 2 space time dimensions and certain non linear electromagnetic-type fields in 4-space-time dimensions. (orig./HSI)

Grand partition function in field theory with applications to sine-Gordon field theory

International Nuclear Information System (INIS)

Samuel, S.

1978-01-01

Certain relativistic field theories are shown to be equivalent to the grand partition function of an interacting gas. Using the physical insight given by this analogy many field-theoretic results are obtained, particularly for the sine-Gordon field theory. The main results are enumerated in the summary to which the reader is referred

Effects of Resonant Helical Field on Toroidal Field Ripple in IR-T1 Tokamak

Science.gov (United States)

Mahdavipour, B.; Salar Elahi, A.; Ghoranneviss, M.

2018-02-01

The toroidal magnetic field which is created by toroidal coils has the ripple in torus space. This magnetic field ripple has an importance in plasma equilibrium and stability studies in tokamak. In this paper, we present the investigation of the interaction between the toroidal magnetic field ripple and resonant helical field (RHF). We have estimated the amplitude of toroidal field ripples without and with RHF (with different q = m/n) ( m = 2, m = 3, m = 4, m = 5, m = 2 & 3, n = 1) using “Comsol Multiphysics” software. The simulations show that RHF has effects on the toroidal ripples.

Dielectrics in electric fields

CERN Document Server

Raju, Gorur G

2003-01-01

Discover nontraditional applications of dielectric studies in this exceptionally crafted field reference or text for seniors and graduate students in power engineering tracks. This text contains more than 800 display equations and discusses polarization phenomena in dielectrics, the complex dielectric constant in an alternating electric field, dielectric relaxation and interfacial polarization, the measurement of absorption and desorption currents in time domains, and high field conduction phenomena. Dielectrics in Electric Fields is an interdisciplinary reference and text for professionals and students in electrical and electronics, chemical, biochemical, and environmental engineering; physical, surface, and colloid chemistry; materials science; and chemical physics.

Dual double field theory

Energy Technology Data Exchange (ETDEWEB)

Bergshoeff, Eric A. [Centre for Theoretical Physics, University of Groningen,Nijenborgh 4, 9747 AG Groningen (Netherlands); Hohm, Olaf [Simons Center for Geometry and Physics, Stony Brook University,Stony Brook, NY 11794-3636 (United States); Penas, Victor A. [Centre for Theoretical Physics, University of Groningen,Nijenborgh 4, 9747 AG Groningen (Netherlands); Riccioni, Fabio [INFN - Sezione di Roma, Dipartimento di Fisica, Università di Roma “La Sapienza”,Piazzale Aldo Moro 2, 00185 Roma (Italy)

2016-06-06

We present the dual formulation of double field theory at the linearized level. This is a classically equivalent theory describing the duals of the dilaton, the Kalb-Ramond field and the graviton in a T-duality or O(D,D) covariant way. In agreement with previous proposals, the resulting theory encodes fields in mixed Young-tableau representations, combining them into an antisymmetric 4-tensor under O(D,D). In contrast to previous proposals, the theory also requires an antisymmetric 2-tensor and a singlet, which are not all pure gauge. The need for these additional fields is analogous to a similar phenomenon for “exotic' dualizations, and we clarify this by comparing with the dualizations of the component fields. We close with some speculative remarks on the significance of these observations for the full non-linear theory yet to be constructed.

Magnetic fields in cosmology

International Nuclear Information System (INIS)

Madsen, M.S.

1989-01-01

The possible role of a large-scale relic magnetic field in the history of the Universe is considered. The perturbation of the cosmic microwave back-ground radiation on large angular scales due to a homogeneous magnetic field is estimated in a simple relativistic model. This allows corresponding limits to be placed on the magnitude of any such large-scale relic magnetic field at the present time. These limits are essentially the strongest which can be set on the largest scales. A corresponding bound is obtained by use of the requirement that the field should not spoil the predictions of primordial nucleosynthesis. It is noted that the existence of large-scale cosmic magnetic fields would circumvent the limits previously set - also on the basis of nucleosynthesis considerations - on the large-scale anisotropy now present in the Universe. (author)

Quality for quantum free fields

International Nuclear Information System (INIS)

Leyland, Pen; Roberts, John; Testard, Daniel; Centre National de la Recherche Scientifique, 13 - Marseille

1978-07-01

A proof is given concerning duality for the free neutral scalar boson field (abstract duality). Then real subspaces of a complex Hilbert space and the Von Neumann algebra associated with real subspaces are considered. Lastly duality for free fields (free electromagnetic field and free scalar field of any mass) is studied

The earth's magnetic field

International Nuclear Information System (INIS)

Merrill, R.T.

1983-01-01

After a historical introduction in Chapter 1, the more traditional aspects of geomagnetism relating to the present field and historical observations are presented in Chapter 2. The various methods and techniques and theoretical background of palaeomagnetism are given in Chapter 3. Chapters 4, 5 and 6 present the results of palaeomagnetic and archaeomagnetic studies in three topics. Chapter 4 relates to studies of the geomagnetic field roughly back to about 50,000 years ago. Chapter 5 is about reversals of the geomagnetic field and Chapter 6 presents studies of the field for times older than 50,000 years and on the geological time scale of millions or hundreds of millions of years. Chapters 7, 8 and 9 provide insight into dynamo theory. Chapter 7 is essentially a non-mathematical attempt to explain the physical basis of dynamo theories to palaeomagnetists. This is followed in Chapter 8 by a more advanced theoretical treatment. Chapter 9 explains theoretical aspects of secular variation and the origin of reversals of the geomagnetic field. Chapter 10 is our attempt to relate theory to experiment and vice versa. The final two chapters consider the magnetic fields of the moon, sun, planets and meteorites, in an attempt to determine the necessary and sufficient conditions for magnetic field generation in large solar system bodies. (author)

DRAPING OF THE INTERSTELLAR MAGNETIC FIELD OVER THE HELIOPAUSE: A PASSIVE FIELD MODEL

International Nuclear Information System (INIS)

Isenberg, Philip A.; Forbes, Terry G.; Möbius, Eberhard

2015-01-01

As the local interstellar plasma flows past our heliosphere, it is slowed and deflected around the magnetic obstacle of the heliopause. The interstellar magnetic field, frozen into this plasma, then becomes draped around the heliopause in a characteristic manner. We derive the analytical solution for this draped magnetic field in the limit of weak field intensity, assuming an ideal potential flow around the heliopause, which we model as a Rankine half-body. We compare the structure of the model magnetic field with observed properties of the Interstellar Boundary Explorer (IBEX) ribbon and with in situ observations at the Voyager 1 spacecraft. We find reasonable qualitative agreement, given the idealizations of the model. This agreement lends support to the secondary ENA model of the IBEX ribbon and to the interpretation that Voyager 1 has crossed the heliopause. We also predict that the magnetic field measured by Voyager 2 after it crosses the heliopause will not be significantly rotated away from the direction of the undisturbed interstellar field

Politics of aviation fields

Science.gov (United States)

Vivent, Jacques

1922-01-01

In short, the "politics of aviation" lies in a few propositions: the need of having as large a number of fields as possible and of sufficient area; the utilization of the larger part of the existing military fields; the selection of uncultivated or unproductive fields, whenever technical conditions permit; ability to disregard (save in exceptional cases) objections of an agricultural nature.

ZEPHYR - poloidal field system

International Nuclear Information System (INIS)

Seidel, U.

1982-04-01

The basics of the poloidal field system of the ZEPHYR experiment are considered. From the physical data the requirements for the poloidal field are derived. Hence an appropriate coil configuration consisting of coil locations and corresponding currents is obtained. A suitable electrical circuit feeding the coils is described. A preliminary assessment of the dynamic control of the poloidal field system is given. (orig.)

Effect of radial electric field inhomogeneity on anomalous cross field plasma flux in Heliotron/Torsatron

International Nuclear Information System (INIS)

Yamagishi, Tomejiro; Sanuki, Heiji.

1996-01-01

Anomalous cross field plasma fluxes induced by the electric field fluctuations has been evaluated in a rotating plasma with shear flow in a helical system. The anomalous ion flux is evaluated by the contribution from ion curvature drift resonance continuum in the test particle model. The radial electric field induces the Doppler frequency shift which disappears in the frequency integrated anomalous flux. The inhomogeneity of the electric field (shear flow effect), however, induces a new force term in the flux. The curvature drift resonance also induces a new force term '/ which, however, did not make large influence in the ion flux in the CHS configuration. The shear flow term in the flux combined with the electric field in neoclassical flux reduces to a first order differential equation which governs the radial profile of the electric field. Numerical results indicate that the shear flow effect is important for the anomalous cross field flux and for determination of the radial electric field particularly in the peripheral region. (author)

Studies in quantum field theory

International Nuclear Information System (INIS)

Bender, C.M.; Mandula, J.E.; Shrauner, J.E.

1982-01-01

Washington University is currently conducting research in many areas of high energy theoretical and mathematical physics. These areas include: strong-coupling approximation; classical solutions of non-Abelian gauge theories; mean-field approximation in quantum field theory; path integral and coherent state representations in quantum field theory; lattice gauge calculations; the nature of perturbation theory in large orders; quark condensation in QCD; chiral symmetry breaking; the l/N expansion in quantum field theory; effective potential and action in quantum field theories, including QCD

Neural fields theory and applications

CERN Document Server

Graben, Peter; Potthast, Roland; Wright, James

2014-01-01

With this book, the editors present the first comprehensive collection in neural field studies, authored by leading scientists in the field - among them are two of the founding-fathers of neural field theory. Up to now, research results in the field have been disseminated across a number of distinct journals from mathematics, computational neuroscience, biophysics, cognitive science and others. Starting with a tutorial for novices in neural field studies, the book comprises chapters on emergent patterns, their phase transitions and evolution, on stochastic approaches, cortical development, cognition, robotics and computation, large-scale numerical simulations, the coupling of neural fields to the electroencephalogram and phase transitions in anesthesia. The intended readership are students and scientists in applied mathematics, theoretical physics, theoretical biology, and computational neuroscience. Neural field theory and its applications have a long-standing tradition in the mathematical and computational ...

Chameleons with Field Dependent Couplings

CERN Document Server

Brax, Philippe; Mota, David F; Nunes, Nelson J; Winther, Hans A

2010-01-01

Certain scalar-tensor theories exhibit the so-called chameleon mechanism, whereby observational signatures of scalar fields are hidden by a combination of self-interactions and interactions with ambient matter. Not all scalar-tensor theories exhibit such a chameleon mechanism, which has been originally found in models with inverse power run-away potentials and field independent couplings to matter. In this paper we investigate field-theories with field-dependent couplings and a power-law potential for the scalar field. We show that the theory indeed is a chameleon field theory. We find the thin-shell solution for a spherical body and investigate the consequences for E\\"ot-Wash experiments, fifth-force searches and Casimir force experiments. Requiring that the scalar-field evades gravitational tests, we find that the coupling is sensitive to a mass-scale which is of order of the Hubble scale today.

ATLAS cavern magnetic field calculations

International Nuclear Information System (INIS)

Vorojtsov, S.B.; Vorozhtsov, A.S.; Butin, F.; Price, M.

2000-01-01

A new approach has been adopted in an attempt to produce a complete ATLAS cavern B-field map using a more precise methodological approach (variable magnetisation, depending on the external field) and the latest design taking into account of the structural elements. The basic idea was to produce a dedicated basic TOSCA model and then to insert a series of ferromagnetic structure elements to monitor the perturbative effect on the basic field map. Eventually, it was found: the bedplate field perturbation is an order of magnitude above the permissible level; manufacturing of the bedplates from nonmagnetic material or careful evaluation of their field contribution in the event reconstruction codes is required; the field value at the rack positions is higher than the permissible one; the final position of racks should be chosen taking into account the detailed magnetic field distribution

Chameleons with field-dependent couplings

International Nuclear Information System (INIS)

Brax, Philippe; Bruck, Carsten van de; Mota, David F.; Winther, Hans A.; Nunes, Nelson J.

2010-01-01

Certain scalar-tensor theories exhibit the so-called chameleon mechanism, whereby observational signatures of scalar fields are hidden by a combination of self-interactions and interactions with ambient matter. Not all scalar-tensor theories exhibit such a chameleon mechanism, which has been originally found in models with inverse power runaway potentials and field-independent couplings to matter. In this paper we investigate field theories with field-dependent couplings and a power-law potential for the scalar field. We show that the theory indeed is a chameleon field theory. We find the thin-shell solution for a spherical body and investigate the consequences for Eoet-Wash experiments, fifth-force searches and Casimir-force experiments. Requiring that the scalar field evades gravitational tests, we find that the coupling is sensitive to a mass scale which is of order of the Hubble scale today.

One biquaternion model of electro-gravimagnetic field. Field analogues of Newton laws

OpenAIRE

Alexeyeva, Lyudmila A.

2007-01-01

Using the biquaternions algebra with involution and mutual quaternional gradients the equations of one model of electro-gravimagnetic (EGM) field are constructed on the base of Hamilton form of Maxwell equations. For this field the hypothesis of equivalence of magnetic charge to gravitational mass is implied. The equations of interaction of generated by different charges and currents EGM-fields are built. On its base the analogies of three Newton's laws are obtained. The laws of transformatio...

On a Correlation between the Ionospheric Electric Field and the Time Derivative of the Magnetic Field

Directory of Open Access Journals (Sweden)

R. R. Ilma

2012-01-01

Full Text Available A correlation of the ionospheric electric field and the time derivative of the magnetic field was noticed over thirty years ago and has yet to be explained. Here we report on another set of examples during the superstorm of November 2004. The electric field in the equatorial ionosphere, measured with the Jicamarca incoherent scatter radar, exhibited a 3 mV/m electric field pulse that was not seen in the interplanetary medium. It was, however, accompanied by a correlation with the time derivative of the magnetic field measured at two points in Peru. Our inclination was to assume that the field was inductive. However, the time scale of the pulse was too short for the magnetic field to penetrate the crust of the Earth. This means that the area threaded by ∂B/∂t was too small to create the observed electric field by induction. We suggest that the effect was caused by a modulation of the ring current location relative to the Earth due to the electric field. This electric field is required, as the magnetic field lines are considered frozen into the plasma in the magnetosphere. The closer location of the ring current to the Earth in turn increased the magnetic field at the surface.

Killing vector fields in three dimensions: a method to solve massive gravity field equations

Energy Technology Data Exchange (ETDEWEB)

Guerses, Metin, E-mail: gurses@fen.bilkent.edu.t [Department of Mathematics, Faculty of Sciences, Bilkent University, 06800 Ankara (Turkey)

2010-10-21

Killing vector fields in three dimensions play an important role in the construction of the related spacetime geometry. In this work we show that when a three-dimensional geometry admits a Killing vector field then the Ricci tensor of the geometry is determined in terms of the Killing vector field and its scalars. In this way we can generate all products and covariant derivatives at any order of the Ricci tensor. Using this property we give ways to solve the field equations of topologically massive gravity (TMG) and new massive gravity (NMG) introduced recently. In particular when the scalars of the Killing vector field (timelike, spacelike and null cases) are constants then all three-dimensional symmetric tensors of the geometry, the Ricci and Einstein tensors, their covariant derivatives at all orders, and their products of all orders are completely determined by the Killing vector field and the metric. Hence, the corresponding three-dimensional metrics are strong candidates for solving all higher derivative gravitational field equations in three dimensions.

Linear Response of Field-Aligned Currents to the Interplanetary Electric Field

DEFF Research Database (Denmark)

Weimer, D. R.; R. Edwards, T.; Olsen, Nils

2017-01-01

Many studies that have shown that the ionospheric, polar cap electric potentials (PCEP) exhibit a “saturation” behavior in response to the level of the driving by the solar wind. As the magnitude of the interplanetary magnetic field (IMF) and electric field (IEF) increase, the PCEP response...... of the field-aligned currents (FAC) with the solar wind/magnetosphere/ionosphere system has a role. As the FAC are more difficult to measure, their behavior in response to the level of the IEF has not been investigated as thoroughly. In order to resolve the question of whether or not the FAC also exhibit...... saturation, we have processed the magnetic field measurements from the Ørsted, CHAMP, and Swarm missions, spanning more than a decade. As the amount of current in each region needs to be known, a new technique is used to separate and sum the current by region, widely known as R0, R1, and R2. These totals...

Quantum fields in curved space

International Nuclear Information System (INIS)

Birrell, N.D.; Davies, P.C.W.

1982-01-01

The book presents a comprehensive review of the subject of gravitational effects in quantum field theory. Quantum field theory in Minkowski space, quantum field theory in curved spacetime, flat spacetime examples, curved spacetime examples, stress-tensor renormalization, applications of renormalization techniques, quantum black holes and interacting fields are all discussed in detail. (U.K.)

Introduction to gauge field theory

International Nuclear Information System (INIS)

Bailin, David; Love, Alexander

1986-01-01

The book is intended as an introduction to gauge field theory for the postgraduate student of theoretical particle physics. The topics discussed in the book include: path integrals, classical and quantum field theory, scattering amplitudes, feynman rules, renormalisation, gauge field theories, spontaneous symmetry breaking, grand unified theory, and field theories at finite temperature. (UK)

Planetary science. Low-altitude magnetic field measurements by MESSENGER reveal Mercury's ancient crustal field.

Science.gov (United States)

Johnson, Catherine L; Phillips, Roger J; Purucker, Michael E; Anderson, Brian J; Byrne, Paul K; Denevi, Brett W; Feinberg, Joshua M; Hauck, Steven A; Head, James W; Korth, Haje; James, Peter B; Mazarico, Erwan; Neumann, Gregory A; Philpott, Lydia C; Siegler, Matthew A; Tsyganenko, Nikolai A; Solomon, Sean C

2015-05-22

Magnetized rocks can record the history of the magnetic field of a planet, a key constraint for understanding its evolution. From orbital vector magnetic field measurements of Mercury taken by the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft at altitudes below 150 kilometers, we have detected remanent magnetization in Mercury's crust. We infer a lower bound on the average age of magnetization of 3.7 to 3.9 billion years. Our findings indicate that a global magnetic field driven by dynamo processes in the fluid outer core operated early in Mercury's history. Ancient field strengths that range from those similar to Mercury's present dipole field to Earth-like values are consistent with the magnetic field observations and with the low iron content of Mercury's crust inferred from MESSENGER elemental composition data. Copyright © 2015, American Association for the Advancement of Science.

Matching IMRT fields with static photon field in the treatment of head-and-neck cancer

International Nuclear Information System (INIS)

Li, Jonathan G.; Liu, Chihray; Kim, Siyong; Amdur, Robert J.; Palta, Jatinder R.

2005-01-01

Radiation treatment with intensity-modulated radiation therapy (IMRT) for head-and-neck cancer usually involves treating the superior aspects of the target volume with intensity-modulated (IM) fields, and the inferior portion of the target volume (the low neck nodes) with a static anterior-posterior field (commonly known as the low anterior neck, or LAN field). A match line between the IM and the LAN fields is created with possibly large dose inhomogeneities, which are clinically undesirable. We propose a practical method to properly match these fields with minimal dependence on patient setup errors. The method requires mono-isocentric setup of the IM and LAN fields with half-beam blocks as defined by the asymmetric jaws. The inferior jaws of the IM fields, which extend ∼1 cm inferiorly past the isocenter, are changed manually before patient treatment, so that they match the superior jaw of the LAN field at the isocenter. The matching of these fields therefore does not depend on the particular treatment plan of IMRT and depends only on the matching of the asymmetric jaws. Measurements in solid water phantom were performed to verify the field-matching technique. Dose inhomogeneities of less than 5% were obtained in the match-line region. Feathering of the match line is done twice during the course of a treatment by changing the matching jaw positions superiorly at 3-mm increments each time, which further reduces the dose inhomogeneity. Compared to the method of including the lower neck nodes in the IMRT fields, the field-matching technique increases the delivery efficiency and significantly reduces the total treatment time

Magnetic field of Mercury

International Nuclear Information System (INIS)

Jackson, D.J.; Beard, D.B.

1977-01-01

The geomagnetic field, suitably scaled down and parameterized, is shown to give a very good fit to the magnetic field measurements taken on the first and third passes of the Mariner 10 space probe past Mercury. The excellence of the fit to a reliable planetary magnetospheric model is good evidence that the Mercury magnetosphere is formed by a simple, permanent, intrinsic planetary magnetic field distorted by the effects of the solar wind. The parameters used for a best fit to all the data are (depending slightly on the choice of data) 2.44--2.55 for the ratio of Mercury's magnetic field strength at the subsolar point to that of the earth's subsolar point field (this results in a dipole moment of 170 γR/sub M/ 3 (R/sub M/ is Mercury Radius), i.e., 2.41 x 10 22 G cm 3 in the same direction as the earth's dipole), approx.-113 γR/sub M/ 4 for the planetary quadrupole moment parallel to the dipole moment, 10degree--17degree for the tilt of the planet dipole toward the sun, 4.5degree for the tilt of the dipole toward dawn, and 2.5degree--7.6degree aberration angle for the shift in the tail axis from the planet-sun direction because of the planet's orbital velocity. The rms deviation overall for the entire data set compared with the theoretical fitted model for the magnetic field strength was 17 γ (approx.4% of the maximum field measured). If the data from the first pass that show presumed strong time variations are excluded, the overall rms deviation for the field magnitude is only 10 γ

Field theory and strings

International Nuclear Information System (INIS)

Bonara, L.; Cotta-Ramusino, P.; Rinaldi, M.

1987-01-01

It is well-known that type I and heterotic superstring theories have a zero mass spectrum which correspond to the field content of N=1 supergravity theory coupled to supersymmetric Yang-Mills theory in 10-D. The authors study the field theory ''per se'', in the hope that simple consistency requirements will determine the theory completely once one knows the field content inherited from string theory. The simplest consistency requirements are: N=1 supersymmetry; and absence of chiral anomalies. This is what the authors discuss in this paper here leaving undetermined the question of the range of validity of the resulting field theory. As is known, a model of N=1 supergravity (SUGRA) coupled to supersymmetric Yang-Mills (SYM) theory was known in the form given by Chapline and Manton. The coupling of SUGRA to SYM was determined by the definition of the ''field strength'' 3-form H in this paper

Self-generation of magnetic fields

International Nuclear Information System (INIS)

Dolan, T.J.

2000-01-01

The stars generate self-magnetic fields on large spatial scales and long time scales,and laser-produced plasmas generate intense self-magnetic fields on very short spatial and time scales. Two questions are posed : (1) Could a self-magnetic field be generated in a laboratory plasma with intermediate spatial and time scales? (2) If a self-magnetic field were generated,would it evolve towards a minimum energy state? If the answers turned out to be affirmative,then self-magnetic fields could possibly have interesting applications

Light-cone AdS/CFT-adapted approach to AdS fields/currents, shadows, and conformal fields

Energy Technology Data Exchange (ETDEWEB)

Metsaev, R.R. [Department of Theoretical Physics, P.N. Lebedev Physical Institute, Leninsky prospect 53, Moscow 119991 (Russian Federation)

2015-10-16

Light-cone gauge formulation of fields in AdS space and conformal field theory in flat space adapted for the study of AdS/CFT correspondence is developed. Arbitrary spin mixed-symmetry fields in AdS space and arbitrary spin mixed-symmetry currents, shadows, and conformal fields in flat space are considered on an equal footing. For the massless and massive fields in AdS and the conformal fields in flat space, simple light-cone gauge actions leading to decoupled equations of motion are found. For the currents and shadows, simple expressions for all 2-point functions are also found. We demonstrate that representation of conformal algebra generators on space of currents, shadows, and conformal fields can be built in terms of spin operators entering the light-cone gauge formulation of AdS fields. This considerably simplifies the study of AdS/CFT correspondence. Light-cone gauge actions for totally symmetric arbitrary spin long conformal fields in flat space are presented. We apply our approach to the study of totally antisymmetric (one-column) and mixed-symmetry (two-column) fields in AdS space and currents, shadows, and conformal fields in flat space.

Electromagnetic fields in biological systems

National Research Council Canada - National Science Library

Lin, James C

2012-01-01

"Focusing on exposure, induced fields, and absorbed energy, this volume covers the interaction of electromagnetic fields and waves with biological systems, spanning static fields to terahertz waves...

Closed string field theory

International Nuclear Information System (INIS)

Strominger, A.

1987-01-01

A gauge invariant cubic action describing bosonic closed string field theory is constructed. The gauge symmetries include local spacetime diffeomorphisms. The conventional closed string spectrum and trilinear couplings are reproduced after spontaneous symmetry breaking. The action S is constructed from the usual ''open string'' field of ghost number minus one half. It is given by the associator of the string field product which is non-vanishing because of associativity anomalies. S does not describe open string propagation because open string states associate and can thereby be shifted away. A field theory of closed and open strings can be obtained by adding to S the cubic open string action. (orig.)

Geomagnetic field of earth

International Nuclear Information System (INIS)

Delipetrev, Marjan; Delipetrev, Blagoj; Panovska, Sanja

2008-01-01

In this paper is introduced the theory of geomagnetic field of the Earth. A homogenous and isotropic sphere is taken for a model of Earth with a bar magnet at its center as a magnetic potential. The understanding of the real origin of geomagnetic field produced from differential rotation of inner core with respect to the outer core of Earth is here presented. Special attention is given to the latest observed data of the established net of geomagnetic repeat stations in the Republic of Macedonia. Finally, the maps of elements of geomagnetic field and the equation for calculation of normal magnetic field of Earth are provided. (Author)

Gauge fields

International Nuclear Information System (INIS)

Itzykson, C.

1978-01-01

In these notes the author provides some background on the theory of gauge fields, a subject of increasing popularity among particle physicists (and others). Detailed motivations and applications which are covered in the other lectures of this school are not presented. In particular the application to weak interactions is omitted by referring to the introduction given by J. Ilipoulos a year ago (CERN Report 76-11). The aim is rather to stress those aspects which suggest that gauge fields may play some role in a future theory of strong interactions. (Auth.)

Field Markup Language: biological field representation in XML.

Science.gov (United States)

Chang, David; Lovell, Nigel H; Dokos, Socrates

2007-01-01

With an ever increasing number of biological models available on the internet, a standardized modeling framework is required to allow information to be accessed or visualized. Based on the Physiome Modeling Framework, the Field Markup Language (FML) is being developed to describe and exchange field information for biological models. In this paper, we describe the basic features of FML, its supporting application framework and its ability to incorporate CellML models to construct tissue-scale biological models. As a typical application example, we present a spatially-heterogeneous cardiac pacemaker model which utilizes both FML and CellML to describe and solve the underlying equations of electrical activation and propagation.

Field type, trap type and field-edge characteristics affect Rhagoletis mendax captures in lowbush blueberries.

Science.gov (United States)

Renkema, Justin M; Cutler, G Christopher; Gaul, Sonia O

2014-11-01

Blueberry maggot, Rhagoletis mendax Curran (Diptera: Tephritidae), is the most important pest of blueberries in eastern North America. Insecticide use in fruit-bearing lowbush blueberry fields could be reduced with management strategies focused on vegetative fields. Fly distribution and fruit infestation levels were assessed where fruit-bearing and vegetative fields adjoin and along forested edges of vegetative fields. Along adjoining edges, immature female flies were captured in fruiting fields and mature females in vegetative fields throughout the season. Male fly captures and fruit infestation levels were greater at 5 m than at 30 m from the edge. Along forested edges, fly captures were best predicted by densities of ripe lowbush blueberries and large coniferous trees. Maggot infestation level in lowbush blueberries was best predicted by blueberry density and small deciduous trees. Bunchberry, Cornus canadensis L., was the only non-crop host in which blueberry maggot was found. We have shown that relatively high numbers of flies occur in vegetative fields and at edges of fruiting fields. Ripe blueberries and certain vegetation in forested edges affect fly distribution and probably maintain populations. These results may help to predict where controls for blueberry maggot should be targeted and suggest that management strategies focused on vegetative fields and field edges may be worthwhile. © 2013 Society of Chemical Industry.

Aspects of the Antisymmetric Tensor Field

Science.gov (United States)

Lahiri, Amitabha

1991-02-01

With the possible exception of gravitation, fundamental interactions are generally described by theories of point particles interacting via massless gauge fields. Since the advent of string theories the picture of physical interaction has changed to accommodate one in which extended objects interact with each other. The generalization of the gauge theories to extended objects leads to theories of antisymmetric tensor fields. At scales corresponding to present-day laboratory experiments one expects to see only point particles, their interactions modified by the presence of antisymmetric tensor fields in the theory. Therefore, in order to establish the validity of any theory with antisymmetric tensor fields one needs to look for manifestations of these fields at low energies. The principal problem of gauge theories is the failure to provide a suitable explanation for the generation of masses for the fields in the theory. While there is a known mechanism (spontaneous symmetry breaking) for generating masses for both the matter fields and the gauge fields, the lack of experimental evidence in support of an elementary scalar field suggests that one look for alternative ways of generating masses for the fields. The interaction of gauge fields with an antisymmetric tensor field seems to be an attractive way of doing so, especially since all indications point to the possibility that there will be no remnant degrees of freedom. On the other hand the interaction of such a field with black holes suggest an independent way of verifying the existence of such fields. In this dissertation the origins of the antisymmetric tensor field are discussed in terms of string theory. The interaction of black holes with such a field is discussed next. The last chapter discusses the effects of an antisymmetric tensor field on quantum electrodynamics when the fields are minimally coupled.

Non-perturbative background field calculations

International Nuclear Information System (INIS)

Stephens, C.R.; Department of Physics, University of Utah, Salt Lake City, Utah 84112)

1988-01-01

New methods are developed for calculating one loop functional determinants in quantum field theory. Instead of relying on a calculation of all the eigenvalues of the small fluctuation equation, these techniques exploit the ability of the proper time formalism to reformulate an infinite dimensional field theoretic problem into a finite dimensional covariant quantum mechanical analog, thereby allowing powerful tools such as the method of Jacobi fields to be used advantageously in a field theory setting. More generally the methods developed herein should be extremely valuable when calculating quantum processes in non-constant background fields, offering a utilitarian alternative to the two standard methods of calculation: perturbation theory in the background field or taking the background field into account exactly. The formalism developed also allows for the approximate calculation of covariances of partial differential equations from a knowledge of the solutions of a homogeneous ordinary differential equation. copyright 1988 Academic Press, Inc

Non-perturbative background field calculations

Science.gov (United States)

Stephens, C. R.

1988-01-01

New methods are developed for calculating one loop functional determinants in quantum field theory. Instead of relying on a calculation of all the eigenvalues of the small fluctuation equation, these techniques exploit the ability of the proper time formalism to reformulate an infinite dimensional field theoretic problem into a finite dimensional covariant quantum mechanical analog, thereby allowing powerful tools such as the method of Jacobi fields to be used advantageously in a field theory setting. More generally the methods developed herein should be extremely valuable when calculating quantum processes in non-constant background fields, offering a utilitarian alternative to the two standard methods of calculation—perturbation theory in the background field or taking the background field into account exactly. The formalism developed also allows for the approximate calculation of covariances of partial differential equations from a knowledge of the solutions of a homogeneous ordinary differential equation.

The Archaeomagnetic Field and the Historical Field: Never the Twain Shall Meet?

OpenAIRE

A. Lodge; Monika Korte; R. Holme

2008-01-01

We compare predictions of the geomagnetic field in Europe from 1590 to 1800 AD from a field model from archaeomagnetic data in Europe, developed for archaeomagnetic dating and from the historical field model gufm1 (Jackson et al., 2000). A consistent discrepancy pre-1800 AD is observed in inclination (I), with gufm1 producing higher values of I than those predicted from archaeomagnetic data. Between 1590 and 1800 AD there are 354 archaeomagnetic data and 133 historical data; in general, the a...

On the generally invariant Lagrangians for the metric field and other tensor fields

International Nuclear Information System (INIS)

Novotny, J.

1978-01-01

The Krupka and Trautman method for the description of all generally invariant functions of the components of geometrical object fields is applied to the invariants of second degree of the metrical field and other tensor fields. The complete system of differential identities fulfilled by the invariants mentioned is found and it is proved that these invariants depend on the tensor quantities only. (author)

Las yeguas marismeñas de Doñana: naturaleza, tradición e identidades sociales en un espacio protegido

Directory of Open Access Journals (Sweden)

Murphy, Michael D.

2002-12-01

Full Text Available The breeding of Andalusia's feral marsh horses stands out among other examples of Doñana National Park's extraordinary legacy of social and cultural traditions. This is so not only because of its importance as a venerable livestock management system, unique and vibrant still despite being surprisingly little known and scarecly studied, but also because it constitutes a notable example of the contributions that Andalusian culture has made to the rest of the world. Marsh animal husbandry is, without a doubt, the cultural matrix out of which developed the livestock traditions of the Americas. By situating this cultural complex within an International comparative framework, we argue that the human involvement with Doñana's feral horses may be distinguished from other similar cases in the world because their care and maintenance has been converted, to an extraordinary degree, into a central element of the local culture. Highly emotional social processes are involved in the construction and maintenance of a collective social identity that expresses itself in perennial conflicts with the authorities of the Park over its feral horses.

Entre el extraordinario legado de tradiciones sociales y culturales del Parque Nacional de Doñana (Suroeste de Andalucía sobresale la cría de caballos marismeños asilvestrados, no sólo por su importancia como práctica ganadera ancestral, viva e insólita, sorprendentemente poco conocida y apenas estudiada, sino también porque constituye un ejemplo eminente de las contribuciones de la cultura andaluza al resto del mundo. La ganadería marismeña es, sin duda, la matriz cultural de las tradiciones ganaderas de América. En este artículo se aborda su análisis dentro de un marco comparativo internacional del que se deduce que lo que verdaderamente distingue la cría de los caballos marismeños de otros casos paralelos en el mundo es haberse convertido en un elemento central de la cultura local, mediante emotivos procesos sociales de construcción y mantenimiento de la identidad comunitaria, en medio de reiterados conflictos con las autoridades oficiales del Parque.

Rydberg atoms in strong fields

International Nuclear Information System (INIS)

Kleppner, D.; Tsimmerman, M.

1985-01-01

Experimental and theoretical achievements in studying Rydberg atoms in external fields are considered. Only static (or quasistatic) fields and ''one-electron'' atoms, i.e. atoms that are well described by one-electron states, are discussed. Mainly behaviour of alkali metal atoms in electric field is considered. The state of theoretical investigations for hydrogen atom in magnetic field is described, but experimental data for atoms of alkali metals are presented as an illustration. Results of the latest experimental and theoretical investigations into the structure of Rydberg atoms in strong fields are presented

Moving Field Guides

Science.gov (United States)

Cassie Meador; Mark Twery; Meagan. Leatherbury

2011-01-01

The Moving Field Guides (MFG) project is a creative take on site interpretation. Moving Field Guides provide an example of how scientific and artistic endeavors work in parallel. Both begin with keen observations that produce information that must be analyzed, understood, and interpreted. That interpretation then needs to be communicated to others to complete the...

Mean field games

KAUST Repository

Gomes, Diogo A.

2014-01-06

In this talk we will report on new results concerning the existence of smooth solutions for time dependent mean-field games. This new result is established through a combination of various tools including several a-priori estimates for time-dependent mean-field games combined with new techniques for the regularity of Hamilton-Jacobi equations.

Mean field games

KAUST Repository

Gomes, Diogo A.

2014-01-01

In this talk we will report on new results concerning the existence of smooth solutions for time dependent mean-field games. This new result is established through a combination of various tools including several a-priori estimates for time-dependent mean-field games combined with new techniques for the regularity of Hamilton-Jacobi equations.

Editorial

Directory of Open Access Journals (Sweden)

Sylvia De Castro Korgi

2018-01-01

Full Text Available Desde el Jardín de Freud is indexed and the following databases and catalogs: Academic Keys - Academic Journals, Academic Search Premier, BIBLAT, CIRC, CLASE, Dialnet, DOAJ, EBSCO Host, EBSCO Discovery Service, Emerging Sources Citation Index, EZB - Elektronische Zeitschriftenbibliothek (Electronic Journals Library, Fuente Académica Plus, Google Scholar, Journal Scholar Metrics - España, Latin America & Iberian Database, LATINDEX (Directorio y Catálogo, LatinREV, MIAR, ProQuest Central, ProQuest Central K-12, REBIUN, REDIB, Research Library, Ulrich's Periodical Directory and Biblioteca virtual Luis Ángel Arango.

Calculation and reduction of the sound emissions of overhead power lines

International Nuclear Information System (INIS)

Straumann, U.

2007-01-01

In this dissertation, Ulrich Straumann of the Swiss Federal Institute of Technology in Zurich, Switzerland, discusses the reduction of sound emissions from overhead power lines. Corona-discharges occur during wet weather or when foggy or icing conditions prevail. Apart from these wide-band crackling noises, low-frequency, tonal emissions also occur. The CONOR (Corona Noise Reduction) project examined these emissions at a frequency of twice the mains frequency and looked for economically feasible solutions to the problems caused by them. The source of these emissions and the mechanisms causing them are discussed. Also, ways of calculating their strength are presented. The effects of varying cable geometry and construction are discussed, as are hydrophilic coatings that could be used to reduce sound emissions.

Nuclear waste - where to go?

International Nuclear Information System (INIS)

Dornsiepen, Ulrich

2015-01-01

The question of the final di9sposal of nuclear waste is a problem of international importance. The solution of the problem is of increasing urgency; the discussion is controversial and implies a lot of emotions. In Germany there is consensus that the nuclear wastes have to be disposed within the country in deep geological formations. This kind of final disposal is predominantly a geological problem and has to be solved from the geological point of view. The geologist Ulrich Dornsiepen presents the problems of the final disposal in an objective way without ideology and generally understandable. Such a presentation is necessary since the public information and participation is demanded but the open geological questions and their scientific solutions are never explained for the public. [de

Violence and Contemporaneity

Directory of Open Access Journals (Sweden)

Irme Salete Bonamigo

2008-01-01

Full Text Available This article discusses the etymological meaning of the term violence, analyzes the multiple possibilities of the definition and practices considered violent today. Contemporaneity is understood through a reference to Ulrich Beck’s theory of the global society of risks, which allows conceiving violence as contemporaneous configurations, linked to imprevisibility and to the risks that compose the current world. It identifies the emerging discourse of security as a possibility to mobilize people and legitimize practices of vigilance and social control, constituting a strategy of access and maintenance of the power of governing a municipality, state or nation. The paper presents some theoretical-methodological proposals for the study of contemporary violence, based on the study conducted and on the sociology of actor-network.

Refuse and the 'Risk Society': The Political Ecology of Risk in Inter-war Britain.

Science.gov (United States)

Cooper, Timothy; Bulmer, Sarah

2013-05-01

This article responds to current critiques of Ulrich Beck's 'risk society' thesis by historians of science and medicine. Those who have engaged with the concept of risk society have been content to accept the fundamental categories of Beck's analysis. In contrast, we argue that Beck's risk society thesis underplays two key themes. First, the role of capitalist social relations as the driver of technological change and the transformation of everyday life; and second, the ways in which hegemonic discourses of risk can be appropriated and transformed by counter-hegemonic forces. In place of 'risk society', we propose an approach based upon a 'political ecology of risk', which emphasises the social relations that are fundamental to the everyday politics of environmental health.

Stochastic quantization of Proca field

International Nuclear Information System (INIS)

Lim, S.C.

1981-03-01

We discuss the complications that arise in the application of Nelson's stochastic quantization scheme to classical Proca field. One consistent way to obtain spin-one massive stochastic field is given. It is found that the result of Guerra et al on the connection between ground state stochastic field and the corresponding Euclidean-Markov field extends to the spin-one case. (author)

Analysis of a high brightness photo electron beam with self field and wake field effects

International Nuclear Information System (INIS)

Parsa, Z.

1991-01-01

High brightness sources are the basic ingredients in the new accelerator developments such as Free-Electron Laser experiments. The effects of the interactions between the highly charged particles and the fields in the accelerating structure, e.g. R.F., Space charge and Wake fields can be detrimental to the beam and the experiments. We present and discuss the formulation used, some simulation and results for the Brookhaven National Laboratory high brightness beam that illustrates effects of the accelerating field, space charge forces (e.g. due to self field of the bunch), and the wake field (e.g. arising from the interaction of the cavity surface and the self field of the bunch)

Finite fields and applications

CERN Document Server

Mullen, Gary L

2007-01-01

This book provides a brief and accessible introduction to the theory of finite fields and to some of their many fascinating and practical applications. The first chapter is devoted to the theory of finite fields. After covering their construction and elementary properties, the authors discuss the trace and norm functions, bases for finite fields, and properties of polynomials over finite fields. Each of the remaining chapters details applications. Chapter 2 deals with combinatorial topics such as the construction of sets of orthogonal latin squares, affine and projective planes, block designs, and Hadamard matrices. Chapters 3 and 4 provide a number of constructions and basic properties of error-correcting codes and cryptographic systems using finite fields. Each chapter includes a set of exercises of varying levels of difficulty which help to further explain and motivate the material. Appendix A provides a brief review of the basic number theory and abstract algebra used in the text, as well as exercises rel...

Electromagnetic fields and cancer

International Nuclear Information System (INIS)

Singh, Neeta; Mathur, R.; Behari, J.

1997-01-01

Several studies in recent years have raised the possibility that exposure to electromagnetic fields (EMFs) may be hazardous to human health, in particular by promotion or initiation of cancer. Recent reports have indicated increased cancer risk from industrial and domestic exposure to environmental ELF fields and to RF fields that are amplitude modulated at ELF. EMF fields have been reported to affect biological systems in various ways, affecting changes in the morphology and or functional behavior of cells, which have been observed in a variety of tissues. Although the mechanism of interaction of EMFs with living cells are not known, it has been proposed that they have multiple effects and can affect cell signalling, including modification of plasma membrane permeability and ion transport. Our findings suggest that EMFs can affect post translational modification of proteins such as poly ADP-ribosylation by epigenetic mechanism and that the effect of EMFs are highly specific regarding both the cell type and the frequency and amplification of the applied field. (author)

Conformal generally covariant quantum field theory. The scalar field and its Wick products

Energy Technology Data Exchange (ETDEWEB)

Pinamonti, N. [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik

2008-06-15