When Dijkstra Meets Vanishing Point: A Stereo Vision Approach for Road Detection.

Science.gov (United States)

Zhang, Yigong; Su, Yingna; Yang, Jian; Ponce, Jean; Kong, Hui

2018-05-01

In this paper, we propose a vanishing-point constrained Dijkstra road model for road detection in a stereo-vision paradigm. First, the stereo-camera is used to generate the u- and v-disparity maps of road image, from which the horizon can be extracted. With the horizon and ground region constraints, we can robustly locate the vanishing point of road region. Second, a weighted graph is constructed using all pixels of the image, and the detected vanishing point is treated as the source node of the graph. By computing a vanishing-point constrained Dijkstra minimum-cost map, where both disparity and gradient of gray image are used to calculate cost between two neighbor pixels, the problem of detecting road borders in image is transformed into that of finding two shortest paths that originate from the vanishing point to two pixels in the last row of image. The proposed approach has been implemented and tested over 2600 grayscale images of different road scenes in the KITTI data set. The experimental results demonstrate that this training-free approach can detect horizon, vanishing point, and road regions very accurately and robustly. It can achieve promising performance.

Moose models with vanishing S parameter

International Nuclear Information System (INIS)

Casalbuoni, R.; De Curtis, S.; Dominici, D.

2004-01-01

In the linear moose framework, which naturally emerges in deconstruction models, we show that there is a unique solution for the vanishing of the S parameter at the lowest order in the weak interactions. We consider an effective gauge theory based on K SU(2) gauge groups, K+1 chiral fields, and electroweak groups SU(2) L and U(1) Y at the ends of the chain of the moose. S vanishes when a link in the moose chain is cut. As a consequence one has to introduce a dynamical nonlocal field connecting the two ends of the moose. Then the model acquires an additional custodial symmetry which protects this result. We examine also the possibility of a strong suppression of S through an exponential behavior of the link couplings as suggested by the Randall Sundrum metric

On the vanishing rate of smooth CR functions

Directory of Open Access Journals (Sweden)

Giuseppe Della Sala

2014-01-01

Full Text Available Let be a lineally convex hypersurface of ℂⁿ of finite type, 0∈. Then there exist non-trivial smooth CR functions on that are flat at 0, i.e. whose Taylor expansion about 0 vanishes identically. Our aim is to characterize the rate at which flat CR functions can decrease without vanishing identically. As it turns out, non-trivial CR functions cannot decay arbitrarily fast, and a possible way of expressing the critical rate is by comparison with a suitable exponential of the modulus of a local peak function.

Vanishing theorems and effective results in algebraic geometry

International Nuclear Information System (INIS)

Demailly, J.P.; Goettsche, L.; Lazarsfeld, R.

2001-01-01

The School on Vanishing Theorems and Effective Results in Algebraic Geometry took place in ICTP, Trieste from 25 April 2000 to 12 May 2000. It was organized by J. P. Demailly (Universite de Grenoble I) and R. Lazarsfeld (University of Michigan). The main topics considered were vanishing theorems, multiplyer ideal sheaves and effective results in algebraic geometry, tight closure, geometry of higher dimensional projective and Kahler manifolds, hyperbolic algebraic varieties. The school consisted of two weeks of lectures and one week of conference. This volume contains the lecture notes of most of the lectures in the first two weeks

Vanishing theorems and effective results in algebraic geometry

Energy Technology Data Exchange (ETDEWEB)

Demailly, J P [Universite de Grenoble (France); Goettsche, L [Abdus Salam International Centre for Theoretical Physics, Trieste (Italy); Lazarsfeld, R [University of Michigan (United States)

2001-12-15

The School on Vanishing Theorems and Effective Results in Algebraic Geometry took place in ICTP, Trieste from 25 April 2000 to 12 May 2000. It was organized by J. P. Demailly (Universite de Grenoble I) and R. Lazarsfeld (University of Michigan). The main topics considered were vanishing theorems, multiplyer ideal sheaves and effective results in algebraic geometry, tight closure, geometry of higher dimensional projective and Kahler manifolds, hyperbolic algebraic varieties. The school consisted of two weeks of lectures and one week of conference. This volume contains the lecture notes of most of the lectures in the first two weeks.

Non-vanishing of Taylor coefficients and Poincaré series

DEFF Research Database (Denmark)

O'Sullivan, C.; Risager, Morten S.

2013-01-01

We prove recursive formulas for the Taylor coefficients of cusp forms, such as Ramanujan's Delta function, at points in the upper half-plane. This allows us to show the non-vanishing of all Taylor coefficients of Delta at CM points of small discriminant as well as the non-vanishing of certain...... Poincaré series. At a "generic" point, all Taylor coefficients are shown to be non-zero. Some conjectures on the Taylor coefficients of Delta at CM points are stated....

Vanishing points detection using combination of fast Hough transform and deep learning

Science.gov (United States)

Sheshkus, Alexander; Ingacheva, Anastasia; Nikolaev, Dmitry

2018-04-01

In this paper we propose a novel method for vanishing points detection based on convolutional neural network (CNN) approach and fast Hough transform algorithm. We show how to determine fast Hough transform neural network layer and how to use it in order to increase usability of the neural network approach to the vanishing point detection task. Our algorithm includes CNN with consequence of convolutional and fast Hough transform layers. We are building estimator for distribution of possible vanishing points in the image. This distribution can be used to find candidates of vanishing point. We provide experimental results from tests of suggested method using images collected from videos of road trips. Our approach shows stable result on test images with different projective distortions and noise. Described approach can be effectively implemented for mobile GPU and CPU.

Three theorems on near horizon extremal vanishing horizon geometries

Directory of Open Access Journals (Sweden)

S. Sadeghian

2016-02-01

Full Text Available EVH black holes are Extremal black holes with Vanishing Horizon area, where vanishing of horizon area is a result of having a vanishing one-cycle on the horizon. We prove three theorems regarding near horizon geometry of EVH black hole solutions to generic Einstein gravity theories in diverse dimensions. These generic gravity theories are Einstein–Maxwell-dilaton-Λ theories, and gauged or ungauged supergravity theories with U(1 Maxwell fields. Our three theorems are: (1 The near horizon geometry of any EVH black hole has a three dimensional maximally symmetric subspace. (2 If the energy momentum tensor of the theory satisfies strong energy condition either this 3d part is an AdS3, or the solution is a direct product of a locally 3d flat space and a d−3 dimensional part. (3 These results extend to the near horizon geometry of near-EVH black holes, for which the AdS3 part is replaced with BTZ geometry.

‘Vanishing embryo syndrome’ in IVF/ICSI

DEFF Research Database (Denmark)

Hvidtjørn, Dorte; Grove, Jakob; Schendel, Diana

2005-01-01

BACKGROUND: In a Danish population-based cohort study assessing the risk of cerebral palsy in children bornafter IVF, we made some interesting observations regarding ‘vanishing co-embryos’. METHODS andRESULTS: All live-born children born in Denmark from 1 January 1995 to 31 December 2000 were...... included inthis analysis. The children conceived by IVF/ICSI (9444) were identified through the IVF Register, the childrenconceived without IVF/ICSI (395 025) were identified through The Danish Medical Birth Register. Main outcomemeasure was the incidence of cerebral palsy. Within the IVF/ICSI children we...... found indications of an increasedrisk of cerebral palsy in those children resulting from pregnancies, where the number of embryos transferred washigher than the number of children born. CONCLUSIONS: The association between vanishing embryo syndromeand incidence of cerebral palsy following IVF requires...

Mangghuer Embroidery: A Vanishing Tradition

OpenAIRE

Aila Pullinen

2015-01-01

Aila Pullinen. 2015. Mangghuer Embroidery: A Vanishing Tradition IN Gerald Roche and CK Stuart (eds) Asian Highlands Perspectives 36: Mapping the Monguor, 178-188, 301-332. Visits were undertaken in the years 2001 and 2002 to Minhe Hui and Mangghuer (Tu) Autonomous County, Haidong Municipality, Qinghai Province, China to research and document Mangghuer embroidery. This research is summarized in terms of the history of Mangghuer embroidery, tools and materials, embroidery techniques, embr...

Tight closure and vanishing theorems

International Nuclear Information System (INIS)

Smith, K.E.

2001-01-01

Tight closure has become a thriving branch of commutative algebra since it was first introduced by Mel Hochster and Craig Huneke in 1986. Over the past few years, it has become increasingly clear that tight closure has deep connections with complex algebraic geometry as well, especially with those areas of algebraic geometry where vanishing theorems play a starring role. The purpose of these lectures is to introduce tight closure and to explain some of these connections with algebraic geometry. Tight closure is basically a technique for harnessing the power of the Frobenius map. The use of the Frobenius map to prove theorems about complex algebraic varieties is a familiar technique in algebraic geometry, so it should perhaps come as no surprise that tight closure is applicable to algebraic geometry. On the other hand, it seems that so far we are only seeing the tip of a large and very beautiful iceberg in terms of tight closure's interpretation and applications to algebraic geometry. Interestingly, although tight closure is a 'characteristic p' tool, many of the problems where tight closure has proved useful have also yielded to analytic (L2) techniques. Despite some striking parallels, there had been no specific result directly linking tight closure and L∼ techniques. Recently, however, the equivalence of an ideal central to the theory of tight closure was shown to be equivalent to a certain 'multiplier ideal' first defined using L2 methods. Presumably, deeper connections will continue to emerge. There are two main types of problems for which tight closure has been helpful: in identifying nice structure and in establishing uniform behavior. The original algebraic applications of tight closure include, for example, a quick proof of the Hochster-Roberts theorem on the Cohen-Macaulayness of rings of invariants, and also a refined version of the Brianqon-Skoda theorem on the uniform behaviour of integral closures of powers of ideals. More recent, geometric

Leukoencephalopathy With Vanishing White Matter: A Review

NARCIS (Netherlands)

Bugiani, M.; Boor, I.; Powers, J.M.; Scheper, G.C.; van der Knaap, M.S.

2010-01-01

Vanishing white matter (VWM) is one of the most prevalent inherited childhood leukoencephalopathies, but this may affect people ofall ages, including neonates and adults. It is a progressive disorder clinically dominated by cerebellar ataxia and in which minor stress conditions, such as fever or

Leukoencephalopathy with vanishing white matter: a review

NARCIS (Netherlands)

Bugiani, Marianna; Boor, Ilja; Powers, James M.; Scheper, Gert C.; van der Knaap, Marjo S.

2010-01-01

Vanishing white matter (VWM) is one of the most prevalent inherited childhood leukoencephalopathies, but this may affect people of all ages, including neonates and adults. It is a progressive disorder clinically dominated by cerebellar ataxia and in which minor stress conditions, such as fever or

On vanishing of vacuum energy for superstrings

International Nuclear Information System (INIS)

Morozov, A.; Perelomov, A.

1986-01-01

Hypothesis, concerning the structure of formulae for vacuum diagrams in the first-quantized superstring theory is proposed. The analytical measure in the integration over moduli space is proportional to the sum over spin structures on Riemann surfaces and vanishes because of the Riemann identities for Θ-constants

Natural occupation numbers: When do they vanish?

NARCIS (Netherlands)

Giesbertz, K.J.H.; Van Leeuwen, R.

The non-vanishing of the natural orbital (NO) occupation numbers of the one-particle density matrix of many-body systems has important consequences for the existence of a density matrix-potential mapping for nonlocal potentials in reduced density matrix functional theory and for the validity of the

Neutrino mass matrices with vanishing determinant

International Nuclear Information System (INIS)

Chauhan, Bhag C.; Pulido, Joao; Picariello, Marco

2006-01-01

We investigate the prospects for neutrinoless double beta decay, texture zeros. and equalities between neutrino mass matrix elements in scenarios with vanishing determinant mass matrices for vanishing and finite θ 13 mixing angles in normal and inverse mass hierarchies. For normal hierarchy and both zero and finite θ 13 it is found that neutrinoless double beta decay cannot be observed by any of the present or next generation experiments, while for inverse hierarchy it is, on the contrary, accessible to experiments. Regarding texture zeros and equalities between mass matrix elements, we find that in both normal and inverse hierarchies with θ 13 =0 no texture zeros nor any such equalities can exist apart from the obvious ones. For θ 13 ≠0 some texture zeros become possible. In normal hierarchy two texture zeros occur if 8.1x10 -2 ≤sinθ 13 ≤9.1x10 -2 while in inverse hierarchy three are possible, one with sinθ 13 ≥7x10 -3 and two others with sinθ 13 ≥0.18. All equalities between mass matrix elements are impossible with θ 13 ≠0

Vanishing twins: a predictor of small-for-gestational age in IVF singletons

DEFF Research Database (Denmark)

Pinborg, Anja; Lidegaard, Ojvind; Freiesleben, Nina la Cour

2007-01-01

The purpose of this study was to assess the effect of a vanishing twin on the risk of being small-for-gestational age (SGA) in in vitro fertilization (IVF) singletons.......The purpose of this study was to assess the effect of a vanishing twin on the risk of being small-for-gestational age (SGA) in in vitro fertilization (IVF) singletons....

Near horizon structure of extremal vanishing horizon black holes

Directory of Open Access Journals (Sweden)

S. Sadeghian

2015-11-01

Full Text Available We study the near horizon structure of Extremal Vanishing Horizon (EVH black holes, extremal black holes with vanishing horizon area with a vanishing one-cycle on the horizon. We construct the most general near horizon EVH and near-EVH ansatz for the metric and other fields, like dilaton and gauge fields which may be present in the theory. We prove that (1 the near horizon EVH geometry for generic gravity theory in generic dimension has a three dimensional maximally symmetric subspace; (2 if the matter fields of the theory satisfy strong energy condition either this 3d part is AdS3, or the solution is a direct product of a locally 3d flat space and a d−3 dimensional part; (3 these results extend to the near horizon geometry of near-EVH black holes, for which the AdS3 part is replaced with BTZ geometry. We present some specific near horizon EVH geometries in 3, 4 and 5 dimensions for which there is a classification. We also briefly discuss implications of these generic results for generic (gauged supergravity theories and also for the thermodynamics of near-EVH black holes and the EVH/CFT proposal.

Genetics Home Reference: leukoencephalopathy with vanishing white matter

Science.gov (United States)

... Torres C, Pröschel C. EIF2B5 mutations compromise GFAP+ astrocyte generation in vanishing white matter leukodystrophy. Nat Med. ... of Medicine Lister Hill National Center for Biomedical Communications 8600 Rockville Pike, Bethesda, MD 20894, USA HONCode ...

Ursodeoxycholic acid treatment of vanishing bile duct syndromes

NARCIS (Netherlands)

Pusl, Thomas; Beuers, Ulrich

2006-01-01

Vanishing bile duct syndromes (VBDS) are characterized by progressive loss of small intrahepatic ducts caused by a variety of different diseases leading to chronic cholestasis, cirrhosis, and premature death from liver failure. The majority of adult patients with VBDS suffer from primary biliary

The vanishing twin: a major determinant of infant outcome in IVF singleton births

DEFF Research Database (Denmark)

Pinborg, Anja; Lidegaard, Ojvind; Andersen, Anders Nyboe

2006-01-01

This article attempts to assess the frequency of vanishing twins in assisted reproductive and spontaneously conceived pregnancies, including in-vitro fertilization (IVF), and its impact on the live-born surviving twin.......This article attempts to assess the frequency of vanishing twins in assisted reproductive and spontaneously conceived pregnancies, including in-vitro fertilization (IVF), and its impact on the live-born surviving twin....

Consequences of vanishing twins in IVF/ICSI pregnancies

DEFF Research Database (Denmark)

Pinborg, Anja Bisgaard; Lidegaard, Ojvind; la Cour Freiesleben, Nina

2005-01-01

Spontaneous reductions are a possible cause of the increased morbidity in IVF singletons. The aim of this study was to assess incidence rates of spontaneous reductions in IVF/ICSI twin pregnancies and to compare short- and long-term morbidity in survivors of a vanishing co-twin with singletons...

The vanishing discount problem and viscosity Mather measures. Part 2: boundary value problems

OpenAIRE

Ishii, Hitoshi; Mitake, Hiroyoshi; Tran, Hung V.

2016-01-01

In arXiv:1603.01051 (Part 1 of this series), we have introduced a variational approach to studying the vanishing discount problem for fully nonlinear, degenerate elliptic, partial differential equations in a torus. We develop this approach further here to handle boundary value problems. In particular, we establish new representation formulas for solutions of discount problems, critical values, and use them to prove convergence results for the vanishing discount problems.

On the monoaxial stabilization of a rigid body under vanishing restoring torque

Science.gov (United States)

Aleksandrov, A. Yu.; Aleksandrova, E. B.; Tikhonov, A. A.

2018-05-01

The problem of monoaxial stabilization of a rigid body is studied. It is assumed that a linear time-invariant dissipative torque and a time-varying restoring torque vanishing as time increases act on the body. Both the case of linear restoring torque and that of essentially nonlinear one are considered. With the aid of the decomposition method, conditions are obtained under which we can guarantee the asymptotic stability of an equilibrium position of the body despite the vanishing of the restoring torque. A numerical simulation is provided to demonstrate the effectiveness of our theoretical results.

Type 1,1-operators defined by vanishing frequency modulation

DEFF Research Database (Denmark)

Johnsen, Jon

2009-01-01

This paper presents a general definition of pseudo-differential operators of type 1,1; the definition is shown to be the largest one that is both compatible with negliible operators and stable under vanishing frequency modulation. Elaborating counter-examples of Ching, Hörmander and Parenti...

Hodgkin's lymphoma-related vanishing bile duct syndrome: A case report and literature review

Directory of Open Access Journals (Sweden)

Kiong-Ming Wong

2013-11-01

Full Text Available We report the case of a 38-year-old man who developed vanishing bile duct syndrome in association with Hodgkin's lymphoma. He was noted to have cervical lymphadenopathy and marked elevation of total serum bilirubin at diagnosis. He achieved complete remission with normalization of serum bilirubin after eight courses of Adriamycin, bleomycin, vinblastine, and dacarbazine chemotherapy followed with autologous hematopoietic cell transplantation. Consecutive liver biopsies performed at diagnosis and at the stage of complete remission revealed the disappearance and regeneration of interlobular bile ducts, respectively. Our case provides pathological evidence that Hodgkin's lymphoma-related vanishing bile duct syndrome is a reversible bile duct injury disease. Bilirubin is a reliable serum marker to monitor the treatment response of these cases. The mechanism to develop hyperbilirubinemia with vanishing bile duct in such a case of Hodgkin's lymphoma remains to be studied. A literature review was carried out.

So It Vanished: Art, Taboo and Shared Space in Contemporary Aotearoa New Zealand

Directory of Open Access Journals (Sweden)

Jonathan Barrett

2013-04-01

Full Text Available In February 2012, The Dowse Art Museum in Lower Hutt, near Wellington, planned to host So It Vanishes, an exhibition by acclaimed Mexican artist Teresa Margolles, whose often shocking works seek to highlight how dispensable human life has become in the parts of Mexico riven by drugs wars. Margolles’s installation would have used infinitesimal amounts of morgue water in a bubble mixture dispensed into an empty, silent room in the same building that sacred Māori treasures are housed. The incorporation of water used to wash corpses in So It Vanishes, particularly in proximity to cultural treasures, would have been deeply offensive, indeed dangerous, for Māori people. Following objections, the exhibition was cancelled. This article analyses the cancellation of So It Vanishes and seeks to answer whether and how transgressive art and indigenous beliefs may be reconciled in contemporary Aotearoa New Zealand.

Type 1,1-operators defined by vanishing frequency modulation

DEFF Research Database (Denmark)

Johnsen, Jon

This paper presents a general definition of pseudo-differential operators of type 1,1; the definition is shown to be the largest one that is both compatible with negligible operators and stable under vanishing frequency modulation. Elaborating counter-examples of Ching andHörmander, type 1...

Toward Modeling Limited Plasticity in Ceramic Materials

National Research Council Canada - National Science Library

Grinfeld, Michael; Schoenfeld, Scott E; Wright, Tim W

2008-01-01

The characteristic features of many armor-related ceramic materials are the anisotropy on the micro-scale level and the very limited, though non-vanishing, plasticity due to limited number of the planes for plastic slip...

The "vanishing follicle" in women with low number of developing follicles during assisted reproduction.

Science.gov (United States)

Younis, Johnny S; Yakovi, Shiran; Izhaki, Ido; Haddad, Sami; Ben-Ami, Moshe

2018-01-01

To investigate the occurrence of the "vanishing follicle" phenomenon in women with low number of developing follicles in assisted reproduction. Women with ≤ 6 follicles on the day of hCG administration with ≥ 14mm diameter were prospectively studied. Primary outcome measures were disappearance of ≥14mm and all-diameter follicles on the day of oocyte pick-up compared to the day of hCG administration. Among the 120 women recruited, 95 were found eligible and completed the study. The "vanishing follicle" phenomenon occurred in 3.1% (95% confidence level: 0.7%-9.0%) and 18.9% (95% confidence level: 11.6%-28.3%) of cases affecting ≥14mm and all-diameter follicles, respectively. In all cases, mid-late follicular serum LH and P levels remained within normal follicular phase range and trans-vaginal scan did not show signs of ovulation. Markedly, the main significant difference between the study and control groups in the ≥14mm follicle group was serum E 2 level on the day of hCG administration; median (Interquartile range), corresponding to 395 (382.0-405.5) versus 823.0 (544.5-1291.0) pg/mL, respectively (P=0.04). The same trend was encountered in all-diameter vanishing follicles group but it did not reach significance. Interestingly, in all-diameter vanishing group, chronic smoking and the P/E 2 ratio on the hCG day were significantly higher than controls. Post hoc multiple logistic regression analysis of data in accordance with the Bologna criteria reveled that antral follicle count was found to significantly affect the development of the "vanishing follicle" phenomenon. The "vanishing follicle" phenomenon occasionally occurs in women with low number of developing follicles during assisted reproduction with no signs of ovulation. Our preliminary findings suggest that this phenomenon may be related to exhausted ovarian reserve however, an early-unrecognized LH elevation could not be ruled out. Copyright © 2017 Elsevier B.V. All rights reserved.

Vanishing dissipation limit for the Navier-Stokes-Fourier system

Czech Academy of Sciences Publication Activity Database

Feireisl, Eduard

2016-01-01

Roč. 14, č. 6 (2016), s. 1535-1551 ISSN 1539-6746 EU Projects: European Commission(XE) 320078 - MATHEF Institutional support: RVO:67985840 Keywords : inviscid limit * compressible fluid * Navier–Stokes–Fourier system Subject RIV: BA - General Mathematics Impact factor: 1.425, year: 2016 http://intlpress.com/site/pub/pages/journals/items/cms/content/vols/0014/0006/a004/index.html

An application of stress energy tensor to the vanishing theorem of differential forms

Directory of Open Access Journals (Sweden)

Kairen Cai

1988-01-01

Full Text Available The author applies the stress energy of differential forms to study the vanishing theorems of the Liouville type. It is shown that for a large class of underlying manifolds such as the Euclidean n-space, the complex n-space, and the complex hyperbolic space form, if any vector bundle valued p-form with conservative stress energy tensor is of finite norm or slowly divergent norm, then the p-form vanishes. This generalizes the recent results due to Hu and Sealey.

Vanishing of local non-Gaussianity in canonical single field inflation

Science.gov (United States)

Bravo, Rafael; Mooij, Sander; Palma, Gonzalo A.; Pradenas, Bastián

2018-05-01

We study the production of observable primordial local non-Gaussianity in two opposite regimes of canonical single field inflation: attractor (standard single field slow-roll inflation) and non attractor (ultra slow-roll inflation). In the attractor regime, the standard derivation of the bispectrum's squeezed limit using co-moving coordinates gives the well known Maldacena's consistency relation fNL = 5 (1‑ns) / 12. On the other hand, in the non-attractor regime, the squeezed limit offers a substantial violation of this relation given by fNL = 5/2. In this work we argue that, independently of whether inflation is attractor or non-attractor, the size of the observable primordial local non-Gaussianity is predicted to be fNLobs = 0 (a result that was already understood to hold in the case of attractor models). To show this, we follow the use of the so-called Conformal Fermi Coordinates (CFC), recently introduced in the literature. These coordinates parametrize the local environment of inertial observers in a perturbed FRW spacetime, allowing one to identify and compute gauge invariant quantities, such as n-point correlation functions. Concretely, we find that during inflation, after all the modes have exited the horizon, the squeezed limit of the 3-point correlation function of curvature perturbations vanishes in the CFC frame, regardless of the inflationary regime. We argue that such a cancellation should persist after inflation ends.

The vanishing volume of D = 4 superspace

Energy Technology Data Exchange (ETDEWEB)

Bossard, Guillaume, E-mail: bossard@cpht.polytechnique.f [Ecole Polytechnique (CNRS), Palaiseau Cedex (France). Centre de Physique Theorique; Howe, P.S., E-mail: paul.howe@kcl.ac.u [University of London (United Kingdom). King' s College. Dept. of Mathematics; Stelle, K.S., E-mail: stelle@imperial.ac.u [Imperial College London (United Kingdom). Theoretical Physics Group; Vanhove, Pierre, E-mail: pierre.vanhove@cea.f [University of California, Santa Barbara, CA (United States). Kavli Inst. for Theoretical Physics

2011-07-01

The volume of on-shell D = 4, N = 8 superspace is shown to vanish. Despite this, it is shown that there is a fully supersymmetric and duality-invariant candidate {nabla}{sup 8}R{sup 4} counterterm corresponding to an anticipated seven-loop logarithmic divergence in D = 4. We construct this counterterm explicitly and also give the complete nonlinear extension of the 1=8-BPS {nabla}{sup 6}R{sup 4} invariant. Similar results are derived for N = 4; 5 and 6. (author)

vanishing bone disease in a tertiary teaching hospital in uganda

African Journals Online (AJOL)

prior to the above presentation and review of systems were unremarkable. General examination revealed a ... syndrome or disease, massive osteolysis, disappearing bone disease, vanishing bone disease, idiopathic ... patient symptoms and anatomic location. Medical treatment involves, radiation therapy, anti-osteoclastic.

Astrocytes are central in the pathomechanisms of vanishing white matter

NARCIS (Netherlands)

Dooves, Stephanie; Bugiani, Marianna; Postma, Nienke L.; Polder, Emiel; Land, Niels; Horan, Stephen T.; van Deijk, Anne-Lieke F.; van de Kreeke, Aleid; Jacobs, Gerbren; Vuong, Caroline; Klooster, Jan; Kamermans, Maarten; Wortel, Joke; Loos, Maarten; Wisse, Lisanne E.; Scheper, Gert C.; Abbink, Truus E. M.; Heine, Vivi M.; van der Knaap, Marjo S.

2016-01-01

Vanishing white matter (VWM) is a fatal leukodystrophy that is caused by mutations in genes encoding subunits of eukaryotic translation initiation factor 2B (eIF2B). Disease onset and severity are codetermined by genotype. White matter astrocytes and oligodendrocytes are almost exclusively affected;

Vanishing of Littlewood-Richardson polynomials is in P

OpenAIRE

Adve, Anshul; Robichaux, Colleen; Yong, Alexander

2017-01-01

J. DeLoera-T. McAllister and K. D. Mulmuley-H. Narayanan-M. Sohoni independently proved that determining the vanishing of Littlewood-Richardson coefficients has strongly polynomial time computational complexity. Viewing these as Schubert calculus numbers, we prove the generalization to the Littlewood-Richardson polynomials that control equivariant cohomology of Grassmannians. We construct a polytope using the edge-labeled tableau rule of H. Thomas-A. Yong. Our proof then combines a saturation...

Quad-Rotor Helicopter Autonomous Navigation Based on Vanishing Point Algorithm

Directory of Open Access Journals (Sweden)

Jialiang Wang

2014-01-01

Full Text Available Quad-rotor helicopter is becoming popular increasingly as they can well implement many flight missions in more challenging environments, with lower risk of damaging itself and its surroundings. They are employed in many applications, from military operations to civilian tasks. Quad-rotor helicopter autonomous navigation based on the vanishing point fast estimation (VPFE algorithm using clustering principle is implemented in this paper. For images collected by the camera of quad-rotor helicopter, the system executes the process of preprocessing of image, deleting noise interference, edge extracting using Canny operator, and extracting straight lines by randomized hough transformation (RHT method. Then system obtains the position of vanishing point and regards it as destination point and finally controls the autonomous navigation of the quad-rotor helicopter by continuous modification according to the calculated navigation error. The experimental results show that the quad-rotor helicopter can implement the destination navigation well in the indoor environment.

Vanishing of cohomology over Cohen–Macaulay rings

DEFF Research Database (Denmark)

Christensen, Lars Winther; Holm, Henrik Granau

2012-01-01

A 2003 counterexample to a conjecture of Auslander brought attention to a family of rings—colloquially called AC rings—that satisfy a natural condition on vanishing of cohomology. Several results attest to the remarkable homological properties of AC rings, but their definition is barely operational......, and it remains unknown if they form a class that is closed under typical constructions in ring theory. In this paper, we study transfer of the AC property along local homomorphisms of Cohen–Macaulay rings. In particular, we show that the AC property is preserved by standard procedures in local algebra. Our...

On the Sen limit squared

OpenAIRE

Fullwood, James; Wang, Dongxu

2018-01-01

We introduce a class of F-theory vacua whose smooth elliptic fibers admit a vanishing $j$-invariant, and construct a weak coupling limit associated with such vacua which we view as the `square' of the Sen limit. We find that while Sen's limit is naturally viewed as an orientifold theory, the universal tadpole relation which equates the D3 charge between the associated F-theory compactification and the limit we construct suggests that perhaps the limiting theory is in fact an oriented theory c...

On weighted hardy inequalities on semiaxis for functions vanishing at the endpoints

Directory of Open Access Journals (Sweden)

Stepanov Vladimir

1997-01-01

Full Text Available We study the weighted Hardy inequalities on the semiaxis of the form for functions vanishing at the endpoints together with derivatives up to the order . The case is completely characterized.

Wave instabilities in nonlinear Schrödinger systems with non vanishing background

KAUST Repository

Trillo, Stefano; Gongora, J. S. Totero; Fratalocchi, Andrea

2014-01-01

We investigate wave collapse in the generalized nonlinear Schrödinger (NLS) equation and in the presence of a non vanishing background. Through the use of virial identities, we establish a new criterion for blow-up.

Vanishing twin syndrome among ART singletons and pregnancy outcomes.

Science.gov (United States)

Magnus, Maria C; Ghaderi, Sara; Morken, Nils-Halvdan; Magnus, Per; Bente Romundstad, Liv; Skjærven, Rolv; Wilcox, Allen J; Eldevik Håberg, Siri

2017-11-01

Among babies born by ART, do singleton survivors of a vanishing twin have lower birth weight than other singletons? Vanishing twin syndrome (VTS) was associated with lower birth weight among ART singletons; a sibship analysis indicated that the association was not confounded by maternal characteristics that remain stable between deliveries. Previous studies indicate that ART singletons with VTS have increased risk of adverse pregnancy outcomes, compared with other ART singletons. The potential contribution of unmeasured maternal background characteristics has been unclear. This was a Norwegian population-based registry study, including 17 368 mothers with 20 410 ART singleton deliveries between January 1984 and December 2013. The study population included 17 291 ART singletons without VTS, 638 ART singletons with VTS and 2418 ART singletons with uncertain vanishing twin status. We estimated differences in birth weight and gestational age comparing ART singletons with VTS first to all ART singletons without VTS, and subsequently to their ART siblings without VTS, using random- and fixed-effects linear regression, respectively. The corresponding comparisons for the associations with preterm birth and small for gestational age (SGA) were conducted using random-and fixed-effects logistic regression. The sibling analysis of preterm birth included 587 discordant siblings, while the sibling analysis of SGA included 674 discordant siblings. ART singletons with VTS had lower birth weight when compared to all ART singletons without VTS, with an adjusted mean difference (95% CI) of -116 g (-165, -67). When we compared ART singletons with VTS to their ART singletons sibling without VTS, the adjusted mean difference was -112 g (-209, -15). ART singletons with VTS also had increased risk of being born SGA, with an adjusted odds ratio (OR) (95% CI) of 1.48 (1.07, 2.03) compared to all ART singletons without VTS, and 2.79 (1.12, 6.91) in the sibship analyses. ART singletons with

BULK THERMODYNAMICS AND CHARGE FLUCTUATIONS AT NON-VANISHING BARYON DENSITY

International Nuclear Information System (INIS)

MIAO, C.; SCHMIDT, C.

2007-01-01

We present results on bulk thermodynamic quantities as well as net baryon number, strangeness and electric charge fluctuations in QCD at non-zero density and temperature obtained from lattice calculations with almost physical quark masses for two values of the lattice cut-off aT = 1/4 and 1/6. We show that with our improved p4fa3-action the cut-off effects are under control when using lattices with a temporal extent of 6 or larger and that the contribution to the equation of state, which is due to a finite chemical potential is small for μ q /T < 1. Moreover, at vanishing chemical potential, i.e. under conditions almost realized at RHIC and the LHC, quartic fluctuations of net baryon number and strangeness are large in a narrow temperature interval characterizing the transition region from the low to high temperature phase. At non-zero baryon number density, strangeness fluctuations are enhanced and correlated to fluctuations of the net baryon number. If strangeness is furthermore forced to vanish, as it may be the case in systems created in heavy ion collisions, strangeness fluctuations are significantly smaller than baryon number fluctuations

VANISHING CALCIFICATION OF THE BRAIN IN AN INFANT AFTER OPEN-HEART-SURGERY

NARCIS (Netherlands)

BEGEER, JH; RUTGERS, AWF; VENCKEN, LM; HOORNTJE, TM; MEUZELAAR, JJ; WOLTERSOMZWIERZYNSKA, BD

1991-01-01

Neurological complications after cardiac operations with the aid of cardiopulmonary bypass and hypothermia are well known. A 6 months-old child is described with severe neurological complications after cardiac surgery for Fallots tetralogy. On the CT scan cortical calcification was seen to vanish.

Anti-levitation of Landau levels in vanishing magnetic fields

Science.gov (United States)

Pan, W.; Baldwin, K. W.; West, K. W.; Pfeiffer, L. N.; Tsui, D. C.

Soon after the discovery of the quantum Hall effects in two-dimensional electron systems, the question on the fate of the extended states in a Landau level in vanishing magnetic (B) field arose. Many theoretical models have since been proposed, and experimental results remain inconclusive. In this talk, we report experimental observation of anti-levitation behavior of Landau levels in vanishing B fields (down to as low as B 58 mT) in a high quality heterojunction insulated-gated field-effect transistor (HIGFET). We observed that, in the Landau fan diagram of electron density versus magnetic field, the positions of the magneto-resistance minima at Landau level fillings ν = 4, 5, 6 move below the ``traditional'' Landau level line to lower electron densities. This clearly differs from what was observed in the earlier experiments where in the same Landau fan plot the density moved up. Our result strongly supports the anti-levitation behavior predicted recently. Moreover, the even and odd Landau level filling states show quantitatively different behaviors in anti-levitation, suggesting that the exchange interactions, which are important at odd fillings, may play a role. SNL is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energys National Nuclear Security Administration under contract DE-AC04-94AL85000.

Compactification over coset spaces with torsion and vanishing cosmological constant

Energy Technology Data Exchange (ETDEWEB)

Batakis, N.A.; Farakos, K.; Koutsoumbas, G.; Zoupanos, G.; Kapetanakis, D.

1989-04-13

We consider the compactification of ten-dimensional Einstein-Yang-Mills theories over non-symmetric, six-dimensional homogeneous coset spaces with torsion. We examine the Einstein-Yang-Mills equations of motion requiring vanishing cosmological constant at ten and four dimensions and we present examples of compactifying solutions. It appears that the introduction of more than one radii in the coset space, when possible, may be mandatory for the existence of compactifying solutions.

Compactification over coset spaces with torsion and vanishing cosmological constant

International Nuclear Information System (INIS)

Batakis, N.A.

1989-01-01

We consider the compactification of ten-dimensional Einstein-Yang-Mills theories over non-symmetric, six-dimensional homogeneous coset spaces with torsion. We examine the Einstein-Yang-Mills equations of motion requiring vanishing cosmological constant at ten and four dimensions and we present examples of compactifying solutions. It appears that the introduction of more than one radii in the coset space, when possible, may be mandatory for the existence of compactifying solutions. (orig.)

Local invariants vanishing on stationary horizons: a diagnostic for locating black holes.

Science.gov (United States)

Page, Don N; Shoom, Andrey A

2015-04-10

Inspired by the example of Abdelqader and Lake for the Kerr metric, we construct local scalar polynomial curvature invariants that vanish on the horizon of any stationary black hole: the squared norms of the wedge products of n linearly independent gradients of scalar polynomial curvature invariants, where n is the local cohomogeneity of the spacetime.

Design of a projection display screen with vanishing color shift for rear-projection HDTV

Science.gov (United States)

Liu, Xiu; Zhu, Jin-lin

1996-09-01

Using bi-convex cylinder lens with matrix structure, the transmissive projection display screen with high contrast and wider viewing angle has been widely used in large rear projection TV and video projectors, it obtained a inhere color shift and puzzled the designer of display screen for RGB projection tube in-line adjustment. Based on the method of light beam racing, the general software of designing projection display screen has been developed and the computer model of vanishing color shift for rear projection HDTV has bee completed. This paper discussed the practical designing method to vanish the defect of color shift and mentioned the relations between the primary optical parameters of display screen and relative geometry sizes of lens' surface. The distributions of optical gain to viewing angle and the influences on engineering design are briefly analyzed.

Metrics with vanishing quantum corrections

International Nuclear Information System (INIS)

Coley, A A; Hervik, S; Gibbons, G W; Pope, C N

2008-01-01

We investigate solutions of the classical Einstein or supergravity equations that solve any set of quantum corrected Einstein equations in which the Einstein tensor plus a multiple of the metric is equated to a symmetric conserved tensor T μν (g αβ , ∂ τ g αβ , ∂ τ ∂ σ g αβ , ...,) constructed from sums of terms, the involving contractions of the metric and powers of arbitrary covariant derivatives of the curvature tensor. A classical solution, such as an Einstein metric, is called universal if, when evaluated on that Einstein metric, T μν is a multiple of the metric. A Ricci flat classical solution is called strongly universal if, when evaluated on that Ricci flat metric, T μν vanishes. It is well known that pp-waves in four spacetime dimensions are strongly universal. We focus attention on a natural generalization; Einstein metrics with holonomy Sim(n - 2) in which all scalar invariants are zero or constant. In four dimensions we demonstrate that the generalized Ghanam-Thompson metric is weakly universal and that the Goldberg-Kerr metric is strongly universal; indeed, we show that universality extends to all four-dimensional Sim(2) Einstein metrics. We also discuss generalizations to higher dimensions

A combinatorial method for the vanishing of the Poisson brackets of an integrable Lotka-Volterra system

International Nuclear Information System (INIS)

Itoh, Yoshiaki

2009-01-01

The combinatorial method is useful to obtain conserved quantities for some nonlinear integrable systems, as an alternative to the Lax representation method. Here we extend the combinatorial method and introduce an elementary geometry to show the vanishing of the Poisson brackets of the Hamiltonian structure for a Lotka-Volterra system of competing species. We associate a set of points on a circle with a set of species of the Lotka-Volterra system, where the dominance relations between points are given by the dominance relations between the species. We associate each term of the conserved quantities with a subset of points on the circle, which simplifies to show the vanishing of the Poisson brackets

Smooth massless limit of field theories

International Nuclear Information System (INIS)

Fronsdal, C.

1980-01-01

The massless limit of Fierz-Pauli field theories, describing fields with fixed mass and spin interacting with external sources, is examined. Results are obtained for spins, 1, 3/2, 2 and 3 using conventional models, and then for all half-integral spins in a relatively model-independent manner. It is found that the massless limit is smooth provided that the sources satisfy certain conditions. In the massless limit these conditions reduce to the conservation laws required by internal consistency of massless field theory. Smoothness simply requires that quantities that vanish in the massless case approach zero in a certain well-defined manner. (orig.)

String theory in polar coordinates and the vanishing of the one-loop Rindler entropy

Energy Technology Data Exchange (ETDEWEB)

Mertens, Thomas G. [Joseph Henry Laboratories, Princeton University,Princeton, NJ 08544 (United States); Verschelde, Henri [Ghent University, Department of Physics and Astronomy,Krijgslaan, 281-S9, 9000 Gent (Belgium); Zakharov, Valentin I. [ITEP, B. Cheremushkinskaya 25, Moscow, 117218 (Russian Federation); Moscow Inst Phys & Technol,Dolgoprudny, Moscow Region, 141700 (Russian Federation); School of Biomedicine, Far Eastern Federal University,Sukhanova str 8, Vladivostok 690950 (Russian Federation)

2016-08-19

We analyze the string spectrum of flat space in polar coordinates, following the small curvature limit of the SL(2,ℝ)/U(1) cigar CFT. We first analyze the partition function of the cigar itself, making some clarifications of the structure of the spectrum that have escaped attention up to this point. The superstring spectrum (type 0 and type II) is shown to exhibit an involution symmetry, that survives the small curvature limit. We classify all marginal states in polar coordinates for type II superstrings, with emphasis on their links and their superconformal structure. This classification is confirmed by an explicit large τ{sub 2} analysis of the partition function. Next we compare three approaches towards the type II genus one entropy in Rindler space: using a sum-over-fields strategy, using a Melvin model approach as in http://dx.doi.org/10.1007/JHEP05(2015)106 and finally using a saddle point method on the cigar partition function. In each case we highlight possible obstructions and motivate that the correct procedures yield a vanishing result: S=0. We finally discuss how the QFT UV divergences of the fields in the spectrum disappear when computing the free energy and entropy using Euclidean techniques.

Vanishing calcification of the brain in an infant after open heart surgery

Energy Technology Data Exchange (ETDEWEB)

Begeer, J.H.; Rutgers, A.W.F. (Groningen Univ. Hospital (Netherlands). Dept. of Child Neurology); Vencken, L.M. (Groningen Univ. Hospital (Netherlands). Dept. of Neuroradiology); Hoorntje, T.M. (Groningen Univ. Hospital (Netherlands). Dept. of Pediatrics); Meuzelaar, J.J. (Groningen Univ. Hospital (Netherlands). Dept. of Thoracic Surgery); Woltersom-Zwierzynska, B.D. (Groningen Univ. Hospital (Netherlands). Dept. of Anaesthesia)

1991-08-01

Neurological complications after cardiac operations with the aid of cardiopulmonary bypass and hypothermia are well known. A 6 months-old child is described with severe neurological complications after cardiac surgery for Fallots tetralogy. On the CT scan cortical calcification was seen to vanish. Such calcification has not been reported in similar patients. Possible causes are discussed but the precise pathophysiology of this phenomenon remains unclear. (orig.).

Vanishing calcification of the brain in an infant after open heart surgery

International Nuclear Information System (INIS)

Begeer, J.H.; Rutgers, A.W.F.; Vencken, L.M.; Hoorntje, T.M.; Meuzelaar, J.J.; Woltersom-Zwierzynska, B.D.

1991-01-01

Neurological complications after cardiac operations with the aid of cardiopulmonary bypass and hypothermia are well known. A 6 months-old child is described with severe neurological complications after cardiac surgery for Fallots tetralogy. On the CT scan cortical calcification was seen to vanish. Such calcification has not been reported in similar patients. Possible causes are discussed but the precise pathophysiology of this phenomenon remains unclear. (orig.)

A vanishing diffusion limit in a nonstandard system of phase field equations

Czech Academy of Sciences Publication Activity Database

Colli, P.; Gilardi, G.; Krejčí, Pavel; Sprekels, J.

2014-01-01

Roč. 3, č. 2 (2014), s. 257-275 ISSN 2163-2480 R&D Projects: GA ČR GAP201/10/2315 Institutional support: RVO:67985840 Keywords : nonstandard phase field system * nonlinear partial differential equations * asympotic limit Subject RIV: BA - General Mathematics Impact factor: 0.373, year: 2014 http://aimsciences.org/journals/displayArticlesnew.jsp?paperID=9918

Vanishing quantum vacuum energy in eleven-dimensional supergravity on the round seven-sphere

International Nuclear Information System (INIS)

Inami, T.; Yamagishi, K.

1984-01-01

Quantum corrections to the vacuum energy are evaluated at one-loop order in eleven-dimensional supergravity on the round seven-sphere S 7 and are shown to vanish. The cancellation is also shown for all ultraviolet poles at z = 11/2, 10/2,..., corresponding to divergences of eleventh and lower powers of momentum cut-off Λ. (orig.)

The story of antimatter matter's vanished twin

CERN Document Server

Borissov, Guennadi

2018-01-01

Each elementary particle contained within every known substance has an almost identical twin called its antiparticle. Existing data clearly indicate that equal numbers of particles and antiparticles were initially created soon after the birth of the universe. Despite this, all objects around us, as well as all the stars in all the known galaxies, are made of particles, while antiparticles have almost completely vanished. The reasons behind this disappearance are not yet fully known. Uncovering them will allow us to not only penetrate much deeper into the structure of matter, but also to understand the secret mechanisms that determine the genesis and development of our immense universe. That is why explaining the mystery of the missing antimatter is currently considered to be one of the main tasks of particle physics. This book tells the story of all the achievements in solving the problem of the missing antiparticles including the latest developments in the field. It is written by Prof. Guennadi Borissov, an...

The “Axial” (“Vanishing Axis” Perspective

Directory of Open Access Journals (Sweden)

Daniel Sofron

2015-11-01

Full Text Available The present paper approaches the axial perspective, a method of spatial representation that precedes the invention of the Renaissance geometrical perspective. Despite being typical to ancient Greek and Roman art, the axial perspective can also be identified during the Middle Ages and the early Renaissance period and it represents the first form of systematic convergence of parallel lines. At the same time, the paper presents Erwin Panofsky's theories on this spatial suggestion method. Trying to offer it a scientific foundation, the researcher builds a system that he calls "the vanishing axis perspective" and puts forward a series of arguments in favour of the existence of such a perspective. Although the axial perspectival constructions imply awkward superimpositions of planes that might seem geometrically inaccurate, this method of spatial structuring of the image constitutes an important stage in the process of identifying solutions for the faithful reproduction of concrete reality and an essential stepin the development process of thevanishing point perspective.

Vanishing Ponds and Regional Water Resources in Taoyuan, Taiwan

Directory of Open Access Journals (Sweden)

Yuei-An Liou

2015-01-01

Full Text Available Taiwan has a Subtropic to Tropical climate, but its precipitation varies widely in response to seasonal effects and weather events such as Typhoon and Meiyu systems. Precipitation must be held back in reservoirs to provide and regulate sufficient water supply. Balancing the irregular precipitation and increasing water demands generates tremendous pressure on water resources management for the water stored in the Shihmen Reservoir, which is the major unitary water supply system in the Greater Taoyuan Area. Such pressure will be significantly enlarged due to the huge 17 billion USD Taoyuan Aerotropolis Project. In earlier days many small artificial ponds (a common terminology in this article, including irrigation ponds, fishery ponds and others, were built to cope with water shortages in Taoyuan County. These small storage ponds provided a solution that resolved seasonal precipitation shortages. Unfortunately, these ponds have been vanishing one after another one due to regional industrialization and urbanization in recent decades and less than 40% of them still remain today. There is great urgency and importance to investigating the link between vanishing ponds and water resources management. Remote sensing technology was used in this study to monitor the environmental consequences in the Taoyuan area by conducting multi-temporal analysis on the changes in water bodies, i.e., ponds. SPOT satellite images taken in 1993, 2003, and 2010 were utilized to analyze and assess the importance of small-scale ponds as water conservation facilities. It was found that, during the seventeen years from 1993 - 2010, the number of irrigation ponds decreased by 35.94%. These ponds can reduce the burden on the major reservoir and increase the water recycling rate if they are properly conserved. They can also improve rainfall interception and surface detention capabilities, and provide another planning advantage for regional water management.

Vanishing "tattoo" multisensor for biomedical diagnostics

Science.gov (United States)

Moczko, E.; Meglinski, I.; Piletsky, S.

2008-02-01

Currently, precise non-invasive diagnostics systems for the real-time multi detection and monitoring of physiological parameters and chemical analytes in the human body are urgently required by clinicians, physiologists and bio-medical researchers. We have developed a novel cost effective smart 'vanishing tattoo' (similar to temporary child's tattoos) consisting of environmental-sensitive dyes. Painlessly impregnated into the skin the smart tattoo is capable of generating optical/fluorescence changes (absorbance, transmission, reflectance, emission and/or luminescence within UV, VIS or NIR regions) in response to physical or chemical changes. These changes allow the identification of colour pattern changes similar to bar-code scanning. Such a system allows an easy, cheap and robust comprehensive detection of various parameters and analytes in a small volume of sample (e.g. variations in pH, temperature, ionic strength, solvent polarity, presence of redox species, surfactants, oxygen). These smart tattoos have possible applications in monitoring the progress of disease and transcutaneous drug delivery. The potential of this highly innovative diagnostic tool is wide and diverse and can impact on routine clinical diagnostics, general therapeutic management, skin care and cosmetic products testing as well as fundamental physiological investigations.

Unusual case of a vanishing bronchus of the left allograft in a lung transplant recipient

Directory of Open Access Journals (Sweden)

Don Hayes

2013-01-01

Full Text Available We present an interesting case of a complete vanishing of the left main bronchus in a lung transplant recipient who had a successful outcome due to acute respiratory support with venovenous extracorporeal membrane oxygenation in order to perform airway dilation.

''Vanishing theorem'' for a positive holomorphic vector bundle of undefined rank

International Nuclear Information System (INIS)

Le Potier, J.

1974-01-01

Let M ba a compact complex manifold of dimension n and let E→M be a holomorphic vector bundle over M. Theorem: If E is positive of rank r and if Hsup(p,q)(M,E) is the cohomology of type (p,q) of M with values in E, then Hsup(p,q)(M,E) = O as soon as p+q >=n+r. If r = 1, this is the ''precise vanishing theorem'' due to Kodaira and Nakano; the present paper contains a proof of the general case

Vanishing Lung Syndrome in a Patient with HIV Infection and Heavy Marijuana Use

Directory of Open Access Journals (Sweden)

Basheer Tashtoush

2014-01-01

Full Text Available Vanishing lung syndrome (VLS is a rare and distinct clinical syndrome that usually affects young men. VLS leads to severe progressive dyspnea and is characterized by extensive, asymmetric, peripheral, and predominantly upper lobe giant lung bullae. Case reports have suggested an additive role of marijuana use in the development of this disease in young male tobacco smokers. We herein report a case of a 65-year-old Hispanic male previously diagnosed with severe emphysema and acquired immune deficiency syndrome (AIDS, with a history of intravenous heroin use and active marijuana smoking who presents to the emergency department with severe progressive shortness of breath he was found to have multiple large subpleural bullae occupying more than one-third of the hemithorax on chest computerized tomography (CT, characteristic of vanishing lung syndrome. The patient was mechanically ventilated and later developed a pneumothorax requiring chest tube placement and referral for surgical bullectomy. Surgical bullectomy has shown high success rates in alleviating the debilitating symptoms and preventing the life threatening complications of this rare syndrome. This case further emphasizes the importance of recognizing VLS in patients with severe emphysema and heavy marijuana smoking.

Analysis and numerical simulation of compressible two-phase flows using relaxation methods. Contribution to the treatment of vanishing phases

International Nuclear Information System (INIS)

Saleh, K.

2012-01-01

This thesis deals with the Baer-Nunziato two-phase flow model. The main objective of this work is to propose some techniques to cope with phase vanishing regimes which produce important instabilities in the model and its numerical simulations. Through analysis and simulation methods using Suliciu relaxation approximations, we prove that in these regimes, the solutions can be stabilised by introducing some extra dissipation of the total mixture entropy. In a first approach, called the Eulerian approach, the exact resolution of the relaxation Riemann problem provides an accurate entropy-satisfying numerical scheme, which turns out to be much more efficient in terms of CPU-cost than the classical and very simple Rusanov's scheme. Moreover, the scheme is proved to handle the vanishing phase regimes with great stability. The scheme, first developed in 1D, is then extended in 3D and implemented in an industrial code developed by EDF. The second approach, called the acoustic splitting approach, considers a separation of fast acoustic waves from slow material waves. The objective is to avoid the resonance due to the interaction between these two types of waves, and to allow an implicit treatment of the acoustics, while material waves are explicitly discretized. The resulting scheme is very simple and allows to deal simply with phase vanishing. The originality of this work is to use new dissipative closure laws for the interfacial velocity and pressure, in order to control the solutions of the Riemann problem associated with the acoustic step, in the phase vanishing regimes. (author)

Coset space compactification of the field theory limit of a heterotic string

Energy Technology Data Exchange (ETDEWEB)

Foda, O.; Helayel-Neto, J.A.

1986-07-01

The D = 10 - E/sub 8/xE/sub 8/ field theory limit of the heterotic string is compactified on the non-symmetric coset space Sp(4)/SU(2) xU(1) that is known in the limit of decoupled gravity to give three standard fermion generations, with SU(5)xSU(3)sub(F)xU(1)sub(F) as a gauge group in D = 4. Allowing for non-vanishing fermion bilinear condensates, and assuming the conventional form of the supersymmetry transformations, the presence of a family of N = 1 supersymmetric background field configurations is proved. This requires the non-compact space to be flat: (Minkowski)/sup 4/, while the 3-form Hsub(MNP) is non-vanishing and proportional to the torsion on the internal manifold. All equations of motion, including that of the dilation, are satisfied.

Existence of the passage to the limit of an inviscid fluid.

Science.gov (United States)

Goldobin, Denis S

2017-11-24

In the dynamics of a viscous fluid, the case of vanishing kinematic viscosity is actually equivalent to the Reynolds number tending to infinity. Hence, in the limit of vanishing viscosity the fluid flow is essentially turbulent. On the other hand, the Euler equation, which is conventionally adopted for the description of the flow of an inviscid fluid, does not possess proper turbulent behaviour. This raises the question of the existence of the passage to the limit of an inviscid fluid for real low-viscosity fluids. To address this question, one should employ the theory of turbulent boundary layer near an inflexible boundary (e.g., rigid wall). On the basis of this theory, one can see how the solutions to the Euler equation become relevant for the description of the flow of low-viscosity fluids, and obtain the small parameter quantifying accuracy of this description for real fluids.

Generalized conditions for the distributional zero-mass limit of renormalized Feynman amplitudes in Minkowski space

International Nuclear Information System (INIS)

Manoukian, E.B.

1986-01-01

Generalized conditions (rules) are set up for the existence of the distributional zero-mass limit of renormalized Feynman amplitudes in Minkowski space. These rules are generalizations of rules that have been set up earlier by us and hence are applicable to a larger class of graphs. The study is very general as the vanishing masses are led to vanish at different rates. All subtractions of renormalization are carried out directly in momentum space, about the origin, with the degree of divergence of a subtraction coinciding with the dimensionality of the corresponding subdiagram

A coset space compactification of the field theory limit of a heterotic string

International Nuclear Information System (INIS)

Foda, O.; Helayel-Neto, J.A.

1986-01-01

The D = 10 - E 8 xE 8 field theory limit of the heterotic string is compactified on the non-symmetric coset space Sp(4)/SU(2) xU(1) that is known in the limit of decoupled gravity to give three standard fermion generations, with SU(5)xSU(3)sub(F)xU(1)sub(F) as a gauge group in D = 4. Allowing for non-vanishing fermion bilinear condensates, and assuming the conventional form of the supersymmetry transformations, the presence of a family of N = 1 supersymmetric background field configurations is proved. This requires the non-compact space to be flat: (Minkowski) 4 , while the 3-form Hsub(MNP) is non-vanishing and proportional to the torsion on the internal manifold. All equations of motion, including that of the dilation, are satisfied. (author)

A coset-space compactification of the field-theory limit of a heterotic string

International Nuclear Information System (INIS)

Foda, O.; Helayel-Neto, J.A.

1985-06-01

The D=10-E 8 xE 8 field-theory limit of the heterotic string is compactified on the non-symmetric coset-space Sp(4)/SU(2)xU(1), that is known - in the limit of decoupled gravity - to give 3 standard fermion generations, with SU(5)xSU(3)sub(F)xU(1)sub(F) as a gauge group in D=4. Allowing for non-vanishing fermion-bilinear condensates, and assuming the conventional form of the supersymmetry transformations, we prove the presence of a family of N=1 supersymmetric background field configurations. This requires the non-compact space to be flat: (Minkowski) 4 , while the 3-form Hsub(MNP) is non-vanishing, and proportional to the torsion on the internal manifold. All equations of motion - including that of the dilaton - are satisfied. (author)

More on non-supersymmetric asymmetric orbifolds with vanishing cosmological constant

International Nuclear Information System (INIS)

Sugawara, Yuji; Wada, Taiki

2016-01-01

We explore various non-supersymmetric type II string vacua constructed based on asymmetric orbifolds of tori with vanishing cosmological constant at the one loop. The string vacua we present are modifications of the models studied in http://dx.doi.org/10.1007/JHEP02(2016)184, of which orbifold group is just generated by a single element. We especially focus on two types of modifications: (i) the orbifold twists include different types of chiral reflections not necessarily removing massless Rarita-Schwinger fields in the 4-dimensional space-time, (ii) the orbifold twists do not include the shift operator. We further discuss the unitarity and stability of constructed non-supersymmetric string vacua, with emphasizing the common features of them.

Vanishing auxiliary variables in PPS sampling - with applications in microscopy

DEFF Research Database (Denmark)

Andersen, Ina Trolle; Hahn, Ute; Jensen, Eva B. Vedel

Recently, non-uniform sampling has been suggested in microscopy to increase efficiency. More precisely, sampling proportional to size (PPS) has been introduced where the probability of sampling a unit in the population is proportional to the value of an auxiliary variable. Unfortunately, vanishing...... auxiliary variables are a common phenomenon in microscopy and, accordingly, part of the population is not accessible, using PPS sampling. We propose a modification of the design, for which an optimal solution can be found, using a model assisted approach. The optimal design has independent interest...... in sampling theory. We verify robustness of the new approach by numerical results, and we use real data to illustrate the applicability....

Inviscid limit of stochastic damped 2D Navier–Stokes equations

International Nuclear Information System (INIS)

Bessaih, Hakima; Ferrario, Benedetta

2014-01-01

We consider the inviscid limit of the stochastic damped 2D Navier–Stokes equations. We prove that, when the viscosity vanishes, the stationary solution of the stochastic damped Navier–Stokes equations converges to a stationary solution of the stochastic damped Euler equation and that the rate of dissipation of enstrophy converges to zero. In particular, this limit obeys an enstrophy balance. The rates are computed with respect to a limit measure of the unique invariant measure of the stochastic damped Navier–Stokes equations. (paper)

The quasi-abelian limit

International Nuclear Information System (INIS)

Fried, H.M.; Avan, J.

2000-01-01

A new, non-perturbative, eikonal method called the ''quasi abelian limit'' (QAL) is suggested for high energy quark (nucleon) scattering involving the exchange of all possible, non-interacting, non-abelian gluons (mesons). With this method, those functional integrals defining, e.g., the exchange of color coordinates in quark-quark scattering, are replaced by a finite number of quadratures over a subset of their coordinates. Mathematically, this procedure is not rigourous, because an unjustified interchange of limits has been performed; physically, it corresponds to the observation that the non-perturbative sum over all color-moment fluctuations can vanish at arbitrarily high energies. The QAL generates a result in agreement with a corrected, ''contiguity'' calculation, when the latter is summed over all perturbative orders. (orig.)

On weighted hardy inequalities on semiaxis for functions vanishing at the endpoints

Directory of Open Access Journals (Sweden)

Vladimir Stepanov

1997-01-01

Full Text Available We study the weighted Hardy inequalities on the semiaxis of the form ‖Fu‖2≤C‖F(kv‖2  (1 for functions vanishing at the endpoints together with derivatives up to the order k−1. The case k=2 is completely characterized.

Vanishing tattoo multi-sensor for biomedical diagnostics

Science.gov (United States)

Moczko, E.; Meglinski, I.; Piletsky, S.

2008-04-01

Currently, precise non-invasive diagnostics systems for the real-time multi detection and monitoring of physiological parameters and chemical analytes in the human body are urgently required by clinicians, physiologists and bio-medical researchers. We have developed a novel cost effective smart 'vanishing tattoo' (similar to temporary child's tattoos) consisting of environmental-sensitive dyes. Painlessly impregnated into the skin the smart tattoo is capable of generating optical/fluorescence changes (absorbance, transmission, reflectance, emission and/or luminescence within UV, VIS or NIR regions) in response to physical or chemical changes. These changes allow the identification of colour pattern changes similar to bar-code scanning. Such a system allows an easy, cheap and robust comprehensive detection of various parameters and analytes in a small volume of sample (e.g. variations in pH, temperature, ionic strength, solvent polarity, presence of redox species, surfactants, oxygen). These smart tattoos have possible applications in monitoring the progress of disease and transcutaneous drug delivery. The potential of this highly innovative diagnostic tool is wide and diverse and can impact on routine clinical diagnostics, general therapeutic management, skin care and cosmetic products testing as well as fundamental physiological investigations.

Upper limit on NUT charge from the observed terrestrial Sagnac effect

Science.gov (United States)

Kulbakova, A.; Karimov, R. Kh; Izmailov, R. N.; Nandi, K. K.

2018-06-01

The exact Sagnac delay in the Kerr–Taub–NUT (Newman–Unti–Tamburino) spacetime is derived in the equatorial plane for non-geodesic as well as geodesic circular orbits. The resulting formula, being exact, can be directly applied to motion in the vicinity of any spinning object including black holes but here we are considering only the terrestrial case since observational data are available. The formula reveals that, in the limit of spin , the delay does not vanish. This fact is similar to the non-vanishing of Lense–Thirring precession under even though the two effects originate from different premises. Assuming a reasonable input that the Kerr–Taub–NUT corrections are subsumed in the average residual uncertainty in the measured Sagnac delay, we compute upper limits on the NUT charge n. It is found that the upper limits on n are far larger than the Earth’s gravitational mass, which has not been detected in observations, implying that the Sagnac effect cannot constrain n to smaller values near zero. We find a curious difference between the delays for non-geodesic and geodesic clock orbits and point out its implication for the well known ‘twin paradox’ of special relativity.

A large deviations approach to limit theory for heavy-tailed time series

DEFF Research Database (Denmark)

Mikosch, Thomas Valentin; Wintenberger, Olivier

2016-01-01

and vanishing in some neighborhood of the origin. We study a variety of such functionals, including large deviations of random walks, their suprema, the ruin functional, and further derive weak limit theory for maxima, point processes, cluster functionals and the tail empirical process. One of the main results...

The Poynting vector of a charged magnetic dipole: two limiting cases

Energy Technology Data Exchange (ETDEWEB)

Sod-Hoffs, J; Manko, V S [Departamento de Fisica, Centro de Investigacion y de Estudios Avanzados del I.P.N., A.P. 14-740, 07000 Mexico D.F. (Mexico)

2007-11-15

We consider the Poynting vector of two exact solutions describing a charged magnetized non-rotating mass in the following limiting cases: (i) m{sup 2} = q{sup 2}, and (ii) m = 0. Whereas the former limit leads to a non-vanishing Poynting vector only for one of the solutions, the latter limit in both solutions results in non-zero expressions of the azimuthal component of the Poynting vector, thus providing evidence that Bonnor's frame-dragging effect takes place even in the case of a charged massless magnetic dipole.

The parity-preserving massive QED3: Vanishing β-function and no parity anomaly

Directory of Open Access Journals (Sweden)

O.M. Del Cima

2015-11-01

Full Text Available The parity-preserving massive QED3 exhibits vanishing gauge coupling β-function and is parity and infrared anomaly free at all orders in perturbation theory. Parity is not an anomalous symmetry, even for the parity-preserving massive QED3, in spite of some claims about the possibility of a perturbative parity breakdown, called parity anomaly. The proof is done by using the algebraic renormalization method, which is independent of any regularization scheme, based on general theorems of perturbative quantum field theory.

No evidence that polymorphisms of the vanishing white matter disease genes are risk factors in multiple sclerosis

NARCIS (Netherlands)

Pronk, J.C.; Scheper, G.C.; Andel, R.J.; van Berkel, C.G.M.; Polman, C.H.; Uitdehaag, B.M.J.; van der Knaap, M.S.

2008-01-01

Febrile infections are known to cause exacerbations in the white matter disorders 'vanishing white matter' (VWM) and multiple sclerosis (MS). We hypothesized that polymorphisms in EIF2B1-5, the genes involved in VWM, might be risk factors for the development of MS or temperature sensitivity in

Texture one zero Dirac neutrino mass matrix with vanishing determinant or trace condition

Science.gov (United States)

Singh, Madan

2018-06-01

In the light of non-zero and relatively large value of rector mixing angle (θ13), we have performed a detailed analysis of texture one zero neutrino mass matrix Mν in the scenario of vanishing determinant/trace conditions, assuming the Dirac nature of neutrinos. In both the scenarios, normal mass ordering is ruled out for all the six possibilities of Mν, however for inverted mass ordering, only two are found to be viable with the current neutrino oscillation data at 3σ confidence level. Numerical and some approximate analytical results are presented.

Vanishing bone disease of the orbital roof: now you see it, now you don't

International Nuclear Information System (INIS)

Dharsono, Ferry; Van Heerden, Jolandi; McAuliffe, William; Ardakani, Nima M.; Franconi, Catherine; Honeybul, Stephen; Lind, Christopher R.

2014-01-01

We describe a rare case of vascularised orbital roof and calvarial erosions with an associated venous malformation. In the absence of infection, malignancy, trauma and eosinophillic granuloma, the closest previously described entity is vanishing bone disease. Computed tomography (CT), MRI, catheter angiography and pathology were all important in the diagnostic workup to enable surgical planning for biopsy and reconstruction. Ongoing CT and MRI follow-up imaging will determine future treatment planning.

Vanishing lung syndrome: the importance of the high-resolution CT in its diagnostic

International Nuclear Information System (INIS)

Rodriguez Cerezo, M.I.; Porres Azcona, E.; Pina Insausti, L.; Inchusta Sarasibar, M.I.; Mellado Rodriguez, M.

1995-01-01

Vanishing lung syndrome, also referred to as idiopathic giant bullions emphysema is a dissolver that has yet to be fully characterized. It is considered a different entry from classic pulmonary emphysema. It is characterized by the presence of large bullae associated with some type of emphysema. High-resolution CT is the best imaging technique to identify the underlying type of emphysema and it helps to determine the viability of the nonbullous lung. We present the case of an asymptomatic patient in whom the diagnosis was suspected on the basis of plain chest X ray and was confirmed by high-resolution CT. 13 refs

Emerging quasi-0D states at vanishing total entropy of the 1D hard sphere system: A coarse-grained similarity to the car parking problem

Science.gov (United States)

Frusawa, Hiroshi

2014-05-01

A coarse-grained system of one-dimensional (1D) hard spheres (HSs) is created using the Delaunay tessellation, which enables one to define the quasi-0D state. It is found from comparing the quasi-0D and 1D free energy densities that a frozen state due to the emergence of quasi-0D HSs is thermodynamically more favorable than fluidity with a large-scale heterogeneity above crossover volume fraction of ϕc=e/(1+e)=0.731⋯ , at which the total entropy of the 1D state vanishes. The Delaunay-based lattice mapping further provides a similarity between the dense HS system above ϕc and the jamming limit in the car parking problem.

Emerging quasi-0D states at vanishing total entropy of the 1D hard sphere system: A coarse-grained similarity to the car parking problem

International Nuclear Information System (INIS)

Frusawa, Hiroshi

2014-01-01

A coarse-grained system of one-dimensional (1D) hard spheres (HSs) is created using the Delaunay tessellation, which enables one to define the quasi-0D state. It is found from comparing the quasi-0D and 1D free energy densities that a frozen state due to the emergence of quasi-0D HSs is thermodynamically more favorable than fluidity with a large-scale heterogeneity above crossover volume fraction of ϕ c =e/(1+e)=0.731⋯ , at which the total entropy of the 1D state vanishes. The Delaunay-based lattice mapping further provides a similarity between the dense HS system above ϕ c and the jamming limit in the car parking problem.

Vanishing Shear Viscosity Limit in the Magnetohydrodynamic Equations

Science.gov (United States)

Fan, Jishan; Jiang, Song; Nakamura, Gen

2007-03-01

We study an initial boundary value problem for the equations of plane magnetohydrodynamic compressible flows, and prove that as the shear viscosity goes to zero, global weak solutions converge to a solution of the original equations with zero shear viscosity. As a by-product, this paper improves the related results obtained by Frid and Shelukhin for the case when the magnetic effect is neglected.

Vanishing corrections on intermediate scale and implications for unification of forces

International Nuclear Information System (INIS)

Parida, M.K.

1996-02-01

In two-step breakings of a class of grand unified theories including SO(10), we prove a theorem showing that the scale (M I ) where the Pati-Salam gauge symmetry with parity breaks down to the standard gauge group, has vanishing corrections due to all sources emerging from higher scales (μ > M I ) such as the one-loop and all higher-loop effects, the GUT-threshold, gravitational smearing, and string threshold effects. Implications of such a scale for the unification of gauge couplings with small Majorana neutrino masses are discussed. In string inspired SO(10), we show that M I ≅ 5 x 10 12 GeV, needed for neutrino masses, with the GUT scale M U ≅ M str can be realized provided certain particle states in the predicted spectrum are light. (author). 28 refs, 1 tab

Vanishing of the vacuum amplitude of heterotic string compactified on a tensor product of N=2 superconformal models

International Nuclear Information System (INIS)

Kei Ito.

1988-07-01

The vacuum amplitude of heterotic string compactified on a tensor product of nine copies of c=1, N=2 superconformal models is shown to vanish due to a generalized Riemann's theta identity associated with the 12x12 matrix identity t BB=6 2 I 12 , identity B ij =-5(i=j), 1(i≠j). (author). 4 refs

The Vanished Child: An inquiry into figures and their modes of appearance

Directory of Open Access Journals (Sweden)

Bertrand Gervais

2010-12-01

Full Text Available Sophie Calle's texts are elaborate devices that facilitate the production of figures, of complex symbolic entities. In fact, her work enables us to better understand how figures emerge and unfold in the imaginary. Thus, we find in her Disparitions (Disappearances, a startling figure, which we can name the "Vanished Child". I will present this figure and explain how it stems from the description of a painting by Rembrandt, stolen at the Gardner Museum in Boston. I will start by identifying some of the essential processes implied in the identification of a figure, and, to do so, I will give two short examples, drawn from Witold Gombrowicz and Don DeLillo. Then, after having described in details the figure of the Vanished Child, I will argue, following the French art historian Georges Didi-Huberman in his reading of Walter Benjamin, that figures are auratic objects. Dans ses textes, Sophie Calle emploie des techniques détaillées qui facilitent la production de figures, d'entités symboliques complexes. Son œuvre nous permet effectivement de mieux comprendre comment les figures émergent et se déploient dans l'imaginaire. Ainsi, nous trouvons dans ses Disparitions (Disappearances une figure surprenante que nous pouvons désigner comme « l'enfant disparu ». Je présenterai cette figure en expliquant comment elle découle de la description d'un tableau de Rembrandt volé au musée Gardner à Boston. J'identifierai d'abord quelques-uns des procédés essentiels à l'identification d'une figure, et pour ce faire je donnerai deux exemples, tirés des œuvres de Witold Gombrowicz et Don DeLillo. Puis je décrirai de façon détaillée la figure de l'enfant disparu, avant de démontrer le caractère auratique des figures à partir de la lecture de Walter Benjamin qu'exécute l'historien de l'art français Georges Didi-Huberman.

Multiloop amplitudes and vanishing theorems using the pure spinor formalism for the superstring

International Nuclear Information System (INIS)

Berkovits, Nathan

2004-01-01

A ten-dimensional super-Poincare covariant formalism for the superstring was recently developed which involves a BRST operator constructed from superspace matter variables and a pure spinor ghost variable. A super-Poincare covariant prescription was defined for computing tree amplitudes and was shown to coincide with the standard RNS prescription. In this paper, picture-changing operators are used to define functional integration over the pure spinor ghosts and to construct a suitable b ghost. A super-Poincare covariant prescription is then given for the computation of N-point multiloop amplitudes. One can easily prove that massless N-point multiloop amplitudes vanish for N 4 terms in the effective action receive no perturbative contributions above one loop. (author)

A comparison of automatic and intentional instructions when using the method of vanishing cues in acquired brain injury.

Science.gov (United States)

Riley, Gerard A; Venn, Paul

2015-01-01

Thirty-four participants with acquired brain injury learned word lists under two forms of vanishing cues - one in which the learning trial instructions encouraged intentional retrieval (i.e., explicit memory) and one in which they encouraged automatic retrieval (which encompasses implicit memory). The automatic instructions represented a novel approach in which the cooperation of participants was actively sought to avoid intentional retrieval. Intentional instructions resulted in fewer errors during the learning trials and better performance on immediate and delayed retrieval tests. The advantage of intentional over automatic instructions was generally less for those who had more severe memory and/or executive impairments. Most participants performed better under intentional instructions on both the immediate and the delayed tests. Although those who were more severely impaired in both memory and executive function also did better with intentional instructions on the immediate retrieval test, they were significantly more likely to show an advantage for automatic instructions on the delayed test. It is suggested that this pattern of results may reflect impairments in the consolidation of intentional memories in this group. When using vanishing cues, automatic instructions may be better for those with severe consolidation impairments, but otherwise intentional instructions may be better.

On the zero mass limit of the non linear sigma model in four dimensions

International Nuclear Information System (INIS)

Gomes, M.; Koeberle, R.

The existence of the zero mass limit for the non-linear sigma-model in four dimensions is shown to all orders in renormalized perturbation theory. The main ingredient in the proof is the imposition of many current axial vector Ward identities and the tool used is Lowenstein's momentum-space subtraction procedure. Instead of introducing anisotropic symmetry breaking mass terms, which do not vanish in the symmetry limit, it is necessary to allow for 'soft' anisotropic derivative coupling in order to obtain the correct Ward indentities [pt

'Vanishing' structural effects of temperature in polymer glasses close to the glass-transition temperature

International Nuclear Information System (INIS)

Shantarovich, V.P.; Suzuki, T.; Ito, Y.; Yu, R.S.; Kondo, K.; Yampolskii, Yu. P.; Alentiev, A.Yu.

2007-01-01

Positron annihilation lifetime (PAL) measurements were used for observation of structural effects of temperature in polystyrene (PS), super-cross-linked polystyrene networks (CPS), and in polyimides (PI) below and in the vicinity of glass-transition temperature T g . 'Vanishing' of these structural effects in the repeating cycles of the temperature controlled PAL experiments due to the slow relaxation processes in different conditions and details of chemical structure is demonstrated. Obtained results illustrate complex, dependent on thermal history, inhomogeneous character of the glass structure. In fact, structure of some polymer glasses is changing continuously. Calculations of the number density of free volume holes in these conditions are discussed

The Lagrangian Multiplier Method of Finding Upper and Lower Limits to Critical Stresses of Clamped Plates

Science.gov (United States)

1946-01-01

geometrica ~ boundary condi- tions of the problem. (2) The energy of the load-plate system is computed for this deflection surface and is then minimized...and interpolating to find the k that makes the seriw vanish. The correct value of m is that which gives the lowest value of k. For two half waves (m=2...the square plate, the present rekdively simple upper- and lower-limit calcula- tions show that his est,imatd limit of error is correct for this case

Brane solutions sourced by a scalar with vanishing potential and classification of scalar branes

Energy Technology Data Exchange (ETDEWEB)

Cadoni, Mariano [Dipartimento di Fisica, Università di Cagliari,Cittadella Universitaria, 09042 Monserrato (Italy); INFN, Sezione di Cagliari,Cagliari (Italy); Franzin, Edgardo [Dipartimento di Fisica, Università di Cagliari,Cittadella Universitaria, 09042 Monserrato (Italy); INFN, Sezione di Cagliari,Cagliari (Italy); CENTRA, Departamento de Física, Instituto Superior Técnico, Universidade de Lisboa,Avenida Rovisco Pais 1, 1049 Lisboa (Portugal); Serra, Matteo [Dipartimento di Matematica, Sapienza Università di Roma,Piazzale Aldo Moro 2, 00185 Roma (Italy)

2016-01-20

We derive exact brane solutions of minimally coupled Einstein-Maxwell-scalar gravity in d+2 dimensions with a vanishing scalar potential and we show that these solutions are conformal to the Lifshitz spacetime whose dual QFT is characterized by hyperscaling violation. These solutions, together with the AdS brane and the domain wall sourced by an exponential potential, give the complete list of scalar branes sourced by a generic potential having simple (scale-covariant) scaling symmetries not involving Galilean boosts. This allows us to give a classification of both simple and interpolating brane solution of minimally coupled Einstein-Maxwell-scalar gravity having no Schrödinger isometries, which may be very useful for holographic applications.

Dynamical vanishing of the order parameter in a confined Bardeen-Cooper-Schrieffer Fermi gas after an interaction quench

Science.gov (United States)

Hannibal, S.; Kettmann, P.; Croitoru, M. D.; Axt, V. M.; Kuhn, T.

2018-01-01

We present a numerical study of the Higgs mode in an ultracold confined Fermi gas after an interaction quench and find a dynamical vanishing of the superfluid order parameter. Our calculations are done within a microscopic density-matrix approach in the Bogoliubov-de Gennes framework which takes the three-dimensional cigar-shaped confinement explicitly into account. In this framework, we study the amplitude mode of the order parameter after interaction quenches starting on the BCS side of the BEC-BCS crossover close to the transition and ending in the BCS regime. We demonstrate the emergence of a dynamically vanishing superfluid order parameter in the spatiotemporal dynamics in a three-dimensional trap. Further, we show that the signal averaged over the whole trap mirrors the spatiotemporal behavior and allows us to systematically study the effects of the system size and aspect ratio on the observed dynamics. Our analysis enables us to connect the confinement-induced modifications of the dynamics to the pairing properties of the system. Finally, we demonstrate that the signature of the Higgs mode is contained in the dynamical signal of the condensate fraction, which, therefore, might provide a new experimental access to the nonadiabatic regime of the Higgs mode.

Exponential vanishing of the ground-state gap of the quantum random energy model via adiabatic quantum computing

Science.gov (United States)

Adame, J.; Warzel, S.

2015-11-01

In this note, we use ideas of Farhi et al. [Int. J. Quantum. Inf. 6, 503 (2008) and Quantum Inf. Comput. 11, 840 (2011)] who link a lower bound on the run time of their quantum adiabatic search algorithm to an upper bound on the energy gap above the ground-state of the generators of this algorithm. We apply these ideas to the quantum random energy model (QREM). Our main result is a simple proof of the conjectured exponential vanishing of the energy gap of the QREM.

Exponential vanishing of the ground-state gap of the quantum random energy model via adiabatic quantum computing

International Nuclear Information System (INIS)

Adame, J.; Warzel, S.

2015-01-01

In this note, we use ideas of Farhi et al. [Int. J. Quantum. Inf. 6, 503 (2008) and Quantum Inf. Comput. 11, 840 (2011)] who link a lower bound on the run time of their quantum adiabatic search algorithm to an upper bound on the energy gap above the ground-state of the generators of this algorithm. We apply these ideas to the quantum random energy model (QREM). Our main result is a simple proof of the conjectured exponential vanishing of the energy gap of the QREM

Turbulence closure: turbulence, waves and the wave-turbulence transition – Part 1: Vanishing mean shear

Directory of Open Access Journals (Sweden)

H. Z. Baumert

2009-03-01

Full Text Available This paper extends a turbulence closure-like model for stably stratified flows into a new dynamic domain in which turbulence is generated by internal gravity waves rather than mean shear. The model turbulent kinetic energy (TKE, K balance, its first equation, incorporates a term for the energy transfer from internal waves to turbulence. This energy source is in addition to the traditional shear production. The second variable of the new two-equation model is the turbulent enstrophy (Ω. Compared to the traditional shear-only case, the Ω-equation is modified to account for the effect of the waves on the turbulence time and space scales. This modification is based on the assumption of a non-zero constant flux Richardson number in the limit of vanishing mean shear when turbulence is produced exclusively by internal waves. This paper is part 1 of a continuing theoretical development. It accounts for mean shear- and internal wave-driven mixing only in the two limits of mean shear and no waves and waves but no mean shear, respectively.

The new model reproduces the wave-turbulence transition analyzed by D'Asaro and Lien (2000b. At small energy density E of the internal wave field, the turbulent dissipation rate (ε scales like ε~E². This is what is observed in the deep sea. With increasing E, after the wave-turbulence transition has been passed, the scaling changes to ε~E¹. This is observed, for example, in the highly energetic tidal flow near a sill in Knight Inlet. The new model further exhibits a turbulent length scale proportional to the Ozmidov scale, as observed in the ocean, and predicts the ratio between the turbulent Thorpe and Ozmidov length scales well within the range observed in the ocean.

Vanishing current hysteresis under competing nuclear spin pumping processes in a quadruplet spin-blockaded double quantum dot

Energy Technology Data Exchange (ETDEWEB)

Amaha, S., E-mail: s-amaha@riken.jp [Quantum Spin Information Project, Japan Science and Technology Agency, ICORP, 3-1, Morinosato Wakamiya, Atsugi-shi, Kanagawa 243-0198 (Japan); Quantum Functional System Research Group, RIKEN Center for Emergent Matter Science, RIKEN, 3-1 Wako-shi, Saitama 351-0198 (Japan); Hatano, T. [Quantum Spin Information Project, Japan Science and Technology Agency, ICORP, 3-1, Morinosato Wakamiya, Atsugi-shi, Kanagawa 243-0198 (Japan); Department of Physics, Tohoku University, Sendai-shi, Miyagi 980-8578 (Japan); Tarucha, S. [Quantum Spin Information Project, Japan Science and Technology Agency, ICORP, 3-1, Morinosato Wakamiya, Atsugi-shi, Kanagawa 243-0198 (Japan); Quantum Functional System Research Group, RIKEN Center for Emergent Matter Science, RIKEN, 3-1 Wako-shi, Saitama 351-0198 (Japan); Department of Applied Physics, School of Engineering, University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan); Gupta, J. A.; Austing, D. G. [National Research Council of Canada, M50, Montreal Road, Ottawa, Ontario K1A 0R6 (Canada)

2015-04-27

We investigate nuclear spin pumping with five-electron quadruplet spin states in a spin-blockaded weakly coupled vertical double quantum dot device. Two types of hysteretic steps in the leakage current are observed on sweeping the magnetic field and are associated with bidirectional polarization of nuclear spin. Properties of the steps are understood in terms of bias-voltage-dependent conditions for the mixing of quadruplet and doublet spin states by the hyperfine interaction. The hysteretic steps vanish when up- and down-nuclear spin pumping processes are in close competition.

Scaling limit of deeply virtual Compton scattering

Energy Technology Data Exchange (ETDEWEB)

A. Radyushkin

2000-07-01

The author outlines a perturbative QCD approach to the analysis of the deeply virtual Compton scattering process {gamma}{sup *}p {r_arrow} {gamma}p{prime} in the limit of vanishing momentum transfer t=(p{prime}{minus}p){sup 2}. The DVCS amplitude in this limit exhibits a scaling behavior described by a two-argument distributions F(x,y) which specify the fractions of the initial momentum p and the momentum transfer r {equivalent_to} p{prime}{minus}p carried by the constituents of the nucleon. The kernel R(x,y;{xi},{eta}) governing the evolution of the non-forward distributions F(x,y) has a remarkable property: it produces the GLAPD evolution kernel P(x/{xi}) when integrated over y and reduces to the Brodsky-Lepage evolution kernel V(y,{eta}) after the x-integration. This property is used to construct the solution of the one-loop evolution equation for the flavor non-singlet part of the non-forward quark distribution.

New limits on neutrino magnetic moment through nonvanishing 13-mixing

Science.gov (United States)

Guzzo, M. M.; de Holanda, P. C.; Peres, O. L. G.

2018-05-01

The relatively large value of the neutrino mixing angle θ13 set by recent measurements allows us to use solar neutrinos to set a limit on the neutrino magnetic moment involving the second and third flavor families, μ23. The existence of a random magnetic field in the solar convective zone can produce a significant antineutrino flux when a nonvanishing neutrino magnetic moment is assumed. Even if we consider a vanishing neutrino magnetic moment involving the first family, electron antineutrinos are indirectly produced through the mixing between the first and third families and μ23≠0 . Using KamLAND limits on the solar flux of electron antineutrino, we set the limit μ23behavior of solar magnetic fields. This is the first time that a limit on μ23 has been established in the literature directly from neutrino interactions with magnetic fields, and, interestingly enough, is comparable with the limits on the neutrino magnetic moment involving the first family and with the ones coming from modifications to the electroweak cross section.

Grafting and Poisson Structure in (2+1)-Gravity with Vanishing Cosmological Constant

Science.gov (United States)

Meusburger, C.

2006-09-01

We relate the geometrical construction of (2+1)-spacetimes via grafting to phase space and Poisson structure in the Chern-Simons formulation of (2+1)-dimensional gravity with vanishing cosmological constant on manifolds of topology mathbb{R} × S_g, where S g is an orientable two-surface of genus g>1. We show how grafting along simple closed geodesics λ is implemented in the Chern-Simons formalism and derive explicit expressions for its action on the holonomies of general closed curves on S g .We prove that this action is generated via the Poisson bracket by a gauge invariant observable associated to the holonomy of λ. We deduce a symmetry relation between the Poisson brackets of observables associated to the Lorentz and translational components of the holonomies of general closed curves on S g and discuss its physical interpretation. Finally, we relate the action of grafting on the phase space to the action of Dehn twists and show that grafting can be viewed as a Dehn twist with a formal parameter θ satisfying θ2 = 0.

Angiomatosis of bone and soft tissue: A spectrum of disease from diffuse lymphangiomatosis to vanishing bone disease in young patients

International Nuclear Information System (INIS)

Aviv, R.I.; McHugh, K.; Hunt, J.

2001-01-01

The application of cross-sectional imaging in the investigation of patients with angiomatosis reveals that lymphangiomatosis and vanishing bone disease should not be considered as separate entities, but rather as a spectrum of disease. We present a pictorial review of eight patients demonstrating the manifestations of soft tissue and bony involvement. We highlight a subgroup of patients with chyloid pleural effusions who have a poor prognosis. Aviv, R. I. et al. (2001)

The unified approach to integrable relativistic equations: Soliton solutions over non-vanishing backgrounds - 1

International Nuclear Information System (INIS)

Barashenkov, I.V.; Getmanov, B.S.; Kovtun, V.E.

1992-01-01

The scheme for unified description of integrable relativistic massive systems provides an inverse scattering formalism that covers universally all (1+1)- dimensional systems of this kind. In this work we construct the N-soliton solution (over an arbitrary background) for some generic system which is associated with the sl(2,C) case of the scheme and whose reductions include the complex sine-Gordon equation, the massive Thirring model and other equations, both in the Euclidean and Minkowski spaces. Thus the N-soliton solutions for all these systems emerge in a unified form differing only in the type of constraints imposed on their parameters. In an earlier paper the case of the zero background was considered while here we concentrate on the case of the non-vanishing constant background i.e., on the N-kink solutions. (author). 18 refs

Approach to the thermodynamic limit in lattice QCD at μ≠0

International Nuclear Information System (INIS)

Splittorff, K.; Verbaarschot, J. J. M.

2008-01-01

The expectation value of the complex phase factor of the fermion determinant is computed to leading order in the p expansion of the chiral Lagrangian. The computation is valid for μ π /2 and determines the dependence of the sign problem on the volume and on the geometric shape of the volume. In the thermodynamic limit with L i →∞ at fixed temperature 1/L 0 , the average phase factor vanishes. In the low temperature limit where L i /L 0 is fixed as L i becomes large, the average phase factor approaches 1 for μ π /2. The results for a finite volume compare well with lattice results obtained by Allton et al. After taking appropriate limits, we reproduce previously derived results for the ε regime and for one-dimensional QCD. The distribution of the phase itself is also computed

Concentration and limit behaviors of stationary measures

Science.gov (United States)

Huang, Wen; Ji, Min; Liu, Zhenxin; Yi, Yingfei

2018-04-01

In this paper, we study limit behaviors of stationary measures of the Fokker-Planck equations associated with a system of ordinary differential equations perturbed by a class of multiplicative noise including additive white noise case. As the noises are vanishing, various results on the invariance and concentration of the limit measures are obtained. In particular, we show that if the noise perturbed systems admit a uniform Lyapunov function, then the stationary measures form a relatively sequentially compact set whose weak∗-limits are invariant measures of the unperturbed system concentrated on its global attractor. In the case that the global attractor contains a strong local attractor, we further show that there exists a family of admissible multiplicative noises with respect to which all limit measures are actually concentrated on the local attractor; and on the contrary, in the presence of a strong local repeller in the global attractor, there exists a family of admissible multiplicative noises with respect to which no limit measure can be concentrated on the local repeller. Moreover, we show that if there is a strongly repelling equilibrium in the global attractor, then limit measures with respect to typical families of multiplicative noises are always concentrated away from the equilibrium. As applications of these results, an example of stochastic Hopf bifurcation and an example with non-decomposable ω-limit sets are provided. Our study is closely related to the problem of noise stability of compact invariant sets and invariant measures of the unperturbed system.

Molecular dynamics study on atomic elastic stiffness in Si under tension: homogenization by external loading and its limit

International Nuclear Information System (INIS)

Yashiro, K; Fujihara, M

2012-01-01

As a series of studies that discuss the onset of inelastic deformation based on atomic elastic stiffness (AES), we investigated the AES in silicon by the Tersoff interatomic potential. For a comprehensive discussion including the effect of structural inhomogeneity by surface and grain boundaries, we performed tensile simulations on bulk/nanowire of Si single crystal, laminate bulk/bamboo nanowire with Σ5 twist grain boundary under a very low temperature (T = 1 K). Not only the stress–strain response, but also the AESs at each atom point, B ij α , were evaluated numerically by Δσ i α /Δε j (Voigt notation) against local strain perturbation. The deviation of detB ij α vanishes/diminishes by tension both in the homogeneous case of bulk perfect lattice and inhomogeneous ones with surface and grain boundaries; however, there is a certain limit for the homogenization. That is, the subtle deviation of AES in the perfect bulk vanishes by tension but it increases again like an onset of resonance, showing precursor stress decrease just before the unstable stress drop. In the inhomogeneous cases, we demonstrated that the near-zero AESs at the initial structural defects, e.g. surface or grain boundary, do not change but the positive AESs of other stable atoms approach zero by tension. When these distributions overlap each other, the standard deviation of AES increases again as if it were the first homogenization limit. However, the real homogenization starts at that point; that is, the AES distribution changes its shape to have a single peak at the detB ij α =0 border, suggesting that the difference of initial defects and other stable part vanishes before the system instability. (paper)

Remarks on a Class of Nonlinear Schrödinger Equations with Potential Vanishing at Infinity

Directory of Open Access Journals (Sweden)

Hongbo Zhu

2013-01-01

Full Text Available We study the following nonlinear Schrödinger equation −Δu+V(xu=K(xf(u,  x∈ℝN,  u∈H1(ℝN, where the potential V(x vanishes at infinity. Working in weighted Sobolev space, we obtain the ground states of problem ( under a Nahari type condition. Furthermore, if V(x,K(x are radically symmetric with respect to x∈ℝN, it is shown that problem ( has a positive solution with some more general growth conditions of the nonlinearity. Particularly, if f(u=up, then the growth restriction σ≤p≤N+2/N-2 in Ambrosetti et al. (2005 can be relaxed to σ~≤p≤N+2/N-2, where σ~<σ if 0<β<α<2.

The MSSM with large tan(beta) beyond the decoupling limit

International Nuclear Information System (INIS)

Hofer, L.; Scherer, D.; Nierste, U.

2009-01-01

If the parameter tan(beta) of the MSSM is large, enhanced loop corrections must be resumed to all orders in perturbation theory. We perform this resummation for flavour-diagonal and flavour-violating tan-beta-enhanced corrections without resorting to the decoupling limit, in which the MSSM is reduced to an effective 2HDM. Our results enable us to clarify the dependence of the resumed expressions on the renormalization scheme and to cover two new classes of processes with supersymmetric particles, which are both intractable with the conventional effective-2HDM method: The first class are collider processes with external supersymmetric particles; the second class are loop processes which vanish in the decoupling limit of supersymmetry. Applying the resummation formulae to FCNC processes in B physics, we find an interesting new effect in observables in which the chromomagnetic effective operator is important. (author)

Vanishing honey bees: Is the dying of adult worker bees a consequence of short telomeres and premature aging?

Science.gov (United States)

Stindl, Reinhard; Stindl, Wolfgang

2010-10-01

Einstein is often quoted to have said that without the bee, mankind would have but 4years to live. It is highly unlikely that he made this comment, which was even mentioned in a Lancet article on honey bees. However, the current vanishing of the bees can have serious consequences for human health, because 35% of the human diet is thought to benefit from pollination. Colony collapse disorder (CCD) in honey bees is characterized by the rapid decline of the adult bee population, leaving the brood and the queen poorly or completely unattended, with no dead bodies in or around the hive. A large study found no evidence that the presence or amount of any individual pesticide or infectious agent occurred more frequently or abundantly in CCD-affected colonies. The growing consensus is that honey bees are suffering from comprised immune systems, which allow various infectious pathogens to invade. The question remains, what causes immunosuppression in many colonies of Apis mellifera in North America and Europe? Telomeres are protective DNA structures located at eukaryotic chromosome tips that shorten in the somatic tissues of animals with age. Lifelong tissue regeneration takes place in Apis mellifera, and worker bees have been shown to senesce. In humans, a vast amount of literature has accumulated on exhausted telomere reserves causing impaired tissue regeneration and age-associated diseases, specifically cancer and immunosuppression. Therefore, we propose a new causative mechanism for the vanishing of the bees: critically short telomeres in long-lived winter bees. We term this the telomere premature aging syndrome. Copyright 2010 Elsevier Ltd. All rights reserved.

On the vanishing of multiloop contributions to the 0-, 1-, 2-, 3-point functions in the Green-Schwarz formalism for heterotic strings

International Nuclear Information System (INIS)

Kallosh, R.; Morosov, A.

1988-01-01

We analyse the structure of insertions arising in multiloop calculations in the first-quantized version of the Green-Schwarz formalism. We show that at least four constant zero modes of grassmannian Θ-fields related to space-time supersymmetry are not removed by insertions. The occurrence of these zero modes straightforwardly leads to non-renormalization theorems, which imply that all 0-, 1-, 2-, 3-point functions vanish. (orig.)

The limits of the Bohm criterion in collisional plasmas

International Nuclear Information System (INIS)

Valentini, H.-B.; Kaiser, D.

2015-01-01

The sheath formation within a low-pressure collisional plasma is analysed by means of a two-fluid model. The Bohm criterion takes into account the effects of the electric field and the inertia of the ions. Numerical results yield that these effects contribute to the space charge formation, only, if the collisionality is lower than a relatively small threshold. It follows that a lower and an upper limit of the drift speed of the ions exist where the effects treated by Bohm can form a sheath. This interval becomes narrower as the collisionality increases and vanishes at the mentioned threshold. Above the threshold, the sheath is mainly created by collisions and the ionisation. Under these conditions, the sheath formation cannot be described by means of Bohm like criteria. In a few references, a so-called upper limit of the Bohm criterion is stated for collisional plasmas where the momentum equation of the ions is taken into account, only. However, the present paper shows that this limit results in an unrealistically steep increase of the space charge density towards the wall, and, therefore, it yields no useful limit of the Bohm velocity

Vanishing De Vega annuloplasty for functional tricuspid regurgitation.

Science.gov (United States)

Duran, C M; Kumar, N; Prabhakar, G; Ge, Z; Bianchi, S; Gometza, B

1993-10-01

pulmonary arteriolar resistance can be adequately treated by a vanishing De Vega annuloplasty, which will stent the tricuspid anulus for about 4 months.

On non-conformal limit of the AGT relations

International Nuclear Information System (INIS)

Marshakov, A.; Mironov, A.; Morozov, A.

2009-01-01

The Seiberg-Witten prepotentials for N=2 SUSY gauge theories with N f c fundamental multiplets are obtained from conformal N f =2N c theory by decoupling 2N c -N f multiplets of heavy matter. This procedure can be lifted to the level of Nekrasov functions with arbitrary background parameters ε 1 and ε 2 . The AGT relations imply that similar limit exists for conformal blocks (or, for generic N c >2, for the blocks in conformal theories with W N c chiral algebra). We consider the limit of the four-point function explicitly in the Virasoro case of N c =2, by bringing the dimensions of external states to infinity. The calculation is performed entirely in terms of representation theory for the Virasoro algebra and reproduces the answers conjectured in [D. Gaiotto, (arXiv:0908.0307)] with the help of the brane-compactification analysis and computer simulations. In this limit, the conformal block involving four external primaries, corresponding to the theory with vanishing beta-function, turns either into a 2-point or 3-point function, with certain coherent rather than primary external states.

A notable difference between ideal gas and infinite molar volume limit of van der Waals gas

International Nuclear Information System (INIS)

Liu, Q H; Shen, Y; Bai, R L; Wang, X

2010-01-01

The van der Waals equation of state does not sufficiently represent a gas unless a thermodynamic potential with two proper and independent variables is simultaneously determined. The limiting procedures under which the behaviour of the van der Waals gas approaches that of an ideal gas are letting two van der Waals coefficients be zero rather than letting the molar volume become infinitely large; otherwise, the partial derivative of internal energy with respect to pressure at a fixed temperature does not vanish.

A notable difference between ideal gas and infinite molar volume limit of van der Waals gas

Science.gov (United States)

Liu, Q. H.; Shen, Y.; Bai, R. L.; Wang, X.

2010-05-01

The van der Waals equation of state does not sufficiently represent a gas unless a thermodynamic potential with two proper and independent variables is simultaneously determined. The limiting procedures under which the behaviour of the van der Waals gas approaches that of an ideal gas are letting two van der Waals coefficients be zero rather than letting the molar volume become infinitely large; otherwise, the partial derivative of internal energy with respect to pressure at a fixed temperature does not vanish.

Limits of slow light in photonic crystals

DEFF Research Database (Denmark)

Pedersen, Jesper Goor; Xiao, Sanshui; Mortensen, N. Asger

2008-01-01

in the group velocity acquiring a finite value above zero at the band-gap edges while attaining uperluminal values within the band gap. Simple scalings of the minimum and maximum group velocities with the imaginary part of the dielectric function or, equivalently, the linewidth of the broadened states......While ideal photonic crystals would support modes with a vanishing group velocity, state-of-the-art structures have still only provided a slow down by roughly two orders of magnitude. We find that the induced density of states caused by lifetime broadening of the electromagnetic modes results...... are presented. The results obtained are entirely general and may be applied to any effect which results in a broadening of the electromagnetic states, such as loss, disorder, and finite-size effects. This significantly limits the reduction in group velocity attainable via photonic crystals....

Vanishing Lung Syndrome: Compound Effect of Tobacco and Marijuana Use on the Development of Bullous Lung Disease – A Joint Effort

OpenAIRE

Wiesel, Shimshon; Siddiqui, Faraz; Khan, Tahir; Hossri, Sami; El-Sayegh, Dany

2017-01-01

Marijuana use has been increasing across the United States due to its legalization as both a medicinal and recreational product. A small number of case reports have described a pathological entity called vanishing lung syndrome (VLS), which is a rare bullous lung disease usually caused by tobacco smoking. Recent case reports have implicated marijuana in the development of VLS. We present a case of a 47-year-old man, who presented to our hospital with shortness of breath, fevers and a producti...

EFFECT OF DIFFERENT K2 HPO4, NaCl LEVELS AND TWO DIFFERENT TEMPARATURES ON SOME EMULSION PROPERTIES OF GOAT MEAT

OpenAIRE

Mustafa KARAKAYA; Hüsnü Yusuf GÖKALP; Ramazan BAYRAK

1996-01-01

Different levels of K2 HPO4 (0.00 %, 0.25 % and 0.50 %) and NaCl (2.5 % and 3.0 %) were added into goat meat, at the two different temperatures (11o C and 18o C) in order to investigate the emulsion properties in the model emulsion system. Emulsion capacity (EK), emulsion viscocity (EV), emulsion stability ratio (ES), the ratio of separated water (ESO) and oil (EYO) ratio from the emulsion, and the emulsion pH were determined. K2 HPO4 and NaCl levels and the oil temperatures have significant ...

Predicting Sediment Thickness on Vanished Ocean Crust Since 200 Ma

Science.gov (United States)

Dutkiewicz, A.; Müller, R. D.; Wang, X.; O'Callaghan, S.; Cannon, J.; Wright, N. M.

2017-12-01

Tracing sedimentation through time on existing and vanished seafloor is imperative for constraining long-term eustasy and for calculating volumes of subducted deep-sea sediments that contribute to global geochemical cycles. We present regression algorithms that incorporate the age of the ocean crust and the mean distance to the nearest passive margin to predict sediment thicknesses and long-term decompacted sedimentation rates since 200 Ma. The mean sediment thickness decreases from ˜220 m at 200 Ma to a minimum of ˜140 m at 130 Ma, reflecting the replacement of old Panthalassic ocean floor with young sediment-poor mid-ocean ridges, followed by an increase to ˜365 m at present-day. This increase reflects the accumulation of sediments on ageing abyssal plains proximal to passive margins, coupled with a decrease in the mean distance of any parcel of ocean crust to the nearest passive margin by over 700 km, and a doubling of the total passive margin length at present-day. Mean long-term sedimentation rates increase from ˜0.5 cm/ky at 160 Ma to over 0.8 cm/ky today, caused by enhanced terrigenous sediment influx along lengthened passive margins, superimposed by the onset of ocean-wide carbonate sedimentation. Our predictive algorithms, coupled to a plate tectonic model, provide a framework for constraining the seafloor sediment-driven eustatic sea-level component, which has grown from ˜80 to 210 m since 120 Ma. This implies a long-term sea-level rise component of 130 m, partly counteracting the contemporaneous increase in ocean basin depth due to progressive crustal ageing.

Entropy production of a Brownian ellipsoid in the overdamped limit.

Science.gov (United States)

Marino, Raffaele; Eichhorn, Ralf; Aurell, Erik

2016-01-01

We analyze the translational and rotational motion of an ellipsoidal Brownian particle from the viewpoint of stochastic thermodynamics. The particle's Brownian motion is driven by external forces and torques and takes place in an heterogeneous thermal environment where friction coefficients and (local) temperature depend on space and time. Our analysis of the particle's stochastic thermodynamics is based on the entropy production associated with single particle trajectories. It is motivated by the recent discovery that the overdamped limit of vanishing inertia effects (as compared to viscous fricion) produces a so-called "anomalous" contribution to the entropy production, which has no counterpart in the overdamped approximation, when inertia effects are simply discarded. Here we show that rotational Brownian motion in the overdamped limit generates an additional contribution to the "anomalous" entropy. We calculate its specific form by performing a systematic singular perturbation analysis for the generating function of the entropy production. As a side result, we also obtain the (well-known) equations of motion in the overdamped limit. We furthermore investigate the effects of particle shape and give explicit expressions of the "anomalous entropy" for prolate and oblate spheroids and for near-spherical Brownian particles.

Flavor symmetry in the large Nc limit

International Nuclear Information System (INIS)

Karl, G.; Washington Univ., Seattle, WA; Lipkin, H.J.; Washington Univ., Seattle, WA

1991-01-01

An essential difference between two-flavor and three-flavor descriptions of baryons in large N c QCD is discussed in detail. For N c ≥3 a state with the SU(3) flavor quantum numbers of the proton must contain a number of strange quarks n s ≥(N c -3)/3, while a state with no strange quarks must have extra hypercharge Y-1 = 3/N c -1. The extra strangeness or extra hypercharge which vanishes for N c = 3 is spurious for the physical proton. This problem does not arise in two-flavor QCD, where the flavor-SU(2) Skyrmion may give a good approximation for nucleon-pion physics at low energies below strangeness threshold. But any nucleon model with SU(3) flavor symmetry which is interpreted as arising from the large N c limit in QCD can lead to erroneous conclusions about the spin and flavor structure of the proton. 12 refs

Evaluating Small Sphere Limit of the Wang-Yau Quasi-Local Energy

Science.gov (United States)

Chen, Po-Ning; Wang, Mu-Tao; Yau, Shing-Tung

2018-01-01

In this article, we study the small sphere limit of the Wang-Yau quasi-local energy defined in Wang and Yau (Phys Rev Lett 102(2):021101, 2009, Commun Math Phys 288(3):919-942, 2009). Given a point p in a spacetime N, we consider a canonical family of surfaces approaching p along its future null cone and evaluate the limit of the Wang-Yau quasi-local energy. The evaluation relies on solving an "optimal embedding equation" whose solutions represent critical points of the quasi-local energy. For a spacetime with matter fields, the scenario is similar to that of the large sphere limit found in Chen et al. (Commun Math Phys 308(3):845-863, 2011). Namely, there is a natural solution which is a local minimum, and the limit of its quasi-local energy recovers the stress-energy tensor at p. For a vacuum spacetime, the quasi-local energy vanishes to higher order and the solution of the optimal embedding equation is more complicated. Nevertheless, we are able to show that there exists a solution that is a local minimum and that the limit of its quasi-local energy is related to the Bel-Robinson tensor. Together with earlier work (Chen et al. 2011), this completes the consistency verification of the Wang-Yau quasi-local energy with all classical limits.

Isospin effects on the system mass dependence of nuclear stopping around the energy of vanishing flow

Science.gov (United States)

Jain, Anupriya; Kumar, Suneel

2014-10-01

We study the effect of isospin degree of freedom on nuclear stopping throughout the mass range 50 and 350 for two sets of isotopic systems with N/Z ≈ 1.5 and 1.8, as well as isobaric systems with N/Z = 1.0 and 1.4. Analysis is carried out at incident energies below, at, and above the energy of vanishing flow (EVF) using the isospin-dependent quantum molecular dynamics model. Our findings reveal that nuclear stopping does not show any particular behavior at the EVF. Moreover, system size effects dominate the isospin effects throughout the range of colliding geometry. The Coulomb effects, however, become important at peripheral geometry. The comparative study of the counterbalancing of Coulomb and mean field by removing the nucleon-nucleon collisions and symmetry potential clearly indicates the dominance of nucleon-nucleon cross-section over the Coulomb repulsions. Moreover, the theoretical results presented in this manuscript for the set of reactions can be experimentally verified.

Isospin effects on the system mass dependence of nuclear stopping around the energy of vanishing flow

International Nuclear Information System (INIS)

Jain, Anupriya; Kumar, Suneel

2014-01-01

We study the effect of isospin degree of freedom on nuclear stopping throughout the mass range 50 and 350 for two sets of isotopic systems with N/Z ≈ 1.5 and 1.8, as well as isobaric systems with N/Z = 1.0 and 1.4. Analysis is carried out at incident energies below, at, and above the energy of vanishing flow (EVF) using the isospin-dependent quantum molecular dynamics model. Our findings reveal that nuclear stopping does not show any particular behavior at the EVF. Moreover, system size effects dominate the isospin effects throughout the range of colliding geometry. The Coulomb effects, however, become important at peripheral geometry. The comparative study of the counterbalancing of Coulomb and mean field by removing the nucleon–nucleon collisions and symmetry potential clearly indicates the dominance of nucleon–nucleon cross-section over the Coulomb repulsions. Moreover, the theoretical results presented in this manuscript for the set of reactions can be experimentally verified. (paper)

Acute vanishing bile duct syndrome after therapy with cephalosporin, metronidazole, and clotrimazole: A case report.

Science.gov (United States)

Zhao, Zonghao; Bao, Lei; Yu, Xiaolan; Zhu, Chuanlong; Xu, Jing; Wang, Yu; Yin, Ming; Li, Yi; Li, Wenting

2017-09-01

Vanishing bile duct syndrome (VBDS) consists of a series of diseases characterized by the loss of >50% bile duct in portal areas. Many factors are associated with VBDS including infections, neoplasms, and drugs. Antibiotic is one of the most frequently reported causes of VBDS. A 29-year-old female was admitted because of liver injury for over 3 months. Tests for viruses that can cause hepatitis and autoantibodies were all negative. She was prescribed with antibiotics approximately a week before liver injury while there was no history of alcohol consumption. Liver biopsy demonstrated a loss of intrahepatic bile duct in most of the portal tracts. This patient was treated with ursodeoxycholic acid, polyene phosphatidylcholine, and bicyclol. Most importantly, the treatments in our hospital were proved by the ethics committee of Department of Infectious Disease, Anhui Provincial Hospital. The symptoms were improved. She is still under treatment. VBDS is rare but can be severe. A liver biopsy offers an important evidence for the diagnosis of VBDS, especially for those with a history of susceptible drugs taking.

EFFECT OF DIFFERENT K2 HPO4, NaCl LEVELS AND TWO DIFFERENT TEMPARATURES ON SOME EMULSION PROPERTIES OF GOAT MEAT

Directory of Open Access Journals (Sweden)

Mustafa KARAKAYA

1996-03-01

Full Text Available Different levels of K2 HPO4 (0.00 %, 0.25 % and 0.50 % and NaCl (2.5 % and 3.0 % were added into goat meat, at the two different temperatures (11o C and 18o C in order to investigate the emulsion properties in the model emulsion system. Emulsion capacity (EK, emulsion viscocity (EV, emulsion stability ratio (ES, the ratio of separated water (ESO and oil (EYO ratio from the emulsion, and the emulsion pH were determined. K2 HPO4 and NaCl levels and the oil temperatures have significant effect (p

Casimir effect: The classical limit

International Nuclear Information System (INIS)

Feinberg, J.; Mann, A.; Revzen, M.

2001-01-01

We analyze the high temperature (or classical) limit of the Casimir effect. A useful quantity which arises naturally in our discussion is the 'relative Casimir energy', which we define for a configuration of disjoint conducting boundaries of arbitrary shapes, as the difference of Casimir energies between the given configuration and a configuration with the same boundaries infinitely far apart. Using path integration techniques, we show that the relative Casimir energy vanishes exponentially fast in temperature. This is consistent with a simple physical argument based on Kirchhoff's law. As a result the 'relative Casimir entropy', which we define in an obviously analogous manner, tends, in the classical limit, to a finite asymptotic value which depends only on the geometry of the boundaries. Thus the Casimir force between disjoint pieces of the boundary, in the classical limit, is entropy driven and is governed by a dimensionless number characterizing the geometry of the cavity. Contributions to the Casimir thermodynamical quantities due to each individual connected component of the boundary exhibit logarithmic deviations in temperature from the behavior just described. These logarithmic deviations seem to arise due to our difficulty to separate the Casimir energy (and the other thermodynamical quantities) from the 'electromagnetic' self-energy of each of the connected components of the boundary in a well defined manner. Our approach to the Casimir effect is not to impose sharp boundary conditions on the fluctuating field, but rather take into consideration its interaction with the plasma of 'charge carriers' in the boundary, with the plasma frequency playing the role of a physical UV cutoff. This also allows us to analyze deviations from a perfect conductor behavior

Limitation of the Mellin transform for small angle scattering by nearly spherical particles

International Nuclear Information System (INIS)

Melone, S.; Puliti, P.

1983-01-01

An analysis of the limit of validity of the Mellin transform when applied to small angle scattering curves produced by nearly spherical particles, i.e. by ellipsoids of semi-axes, a, a, va, was performed. The width of the assumed Gaussian distribution for the v values was used as a parameter. When this width tends to zero the inaccuracy of the Mellin transform vanishes as expected. However the inaccuracy becomes appreciable for large values of the width. In spite of this, the total volume fraction and the average radius of the scattering particles is also obtained by the Mellin transform with very high accuracy for large values of the width of the Gaussian distribution. (orig.)

Office hysteroscopic treatment of a vanishing external uterine orifice in a postmenopausal woman with an obstetrical history of 44 abortions

Directory of Open Access Journals (Sweden)

Maurizio Guida

2015-11-01

Full Text Available Cervical stenosis, defined as cervical scarring of variable degree, represents a significant anatomical impediment to hysteroscopic procedures. Acquired cervical stenoses are more common than congenital forms and they are mainly associated with aging, estrogen–progesteron drugs, cervical trauma or carcinoma. The overcoming of cervical stenosis at office hysteroscopy is challenging and it often fails requiring the scheduling of the patient for an in-patient treatment under general anesthesia. We report the office hysteroscopy treatment of a vanishing external uterine orifice in a postmenopausal woman with an ultrasonographic report of a heterogeneous and thick endometrium suggestive of endometrial pathology, focusing on the main surgical steps to perform an adequate management.

Similarities and differences between infantile and early childhood onset vanishing white matter disease.

Science.gov (United States)

Zhou, Ling; Zhang, Haihua; Chen, Na; Zhang, Zhongbin; Liu, Ming; Dai, Lifang; Wang, Jingmin; Jiang, Yuwu; Wu, Ye

2018-06-01

Vanishing white matter disease (VWM) is one of the most prevalent inherited leukoencephalopathies in childhood. Infantile VWM is more severe but less understood than the classic early childhood type. We performed a follow-up study on 14 infantile and 26 childhood patients to delineate the natural history and neuroimaging features of VWM. Infantile and childhood patients shared similarities in the incidence of epileptic seizure (35.7 vs. 38.5%) and episodic aggravation (92.9 vs. 84.6%). Developmental delay before disease onset was more common in infantile patients. Motor disability was earlier and more severe in infantile VWM. In survivors with disease durations of 1-3 years, the Gross Motor Function Classification System (GMFCS) was classified as IV-V in 66.7% of infantile and only 29.4% of childhood patients. Kaplan-Meier survival curve analysis indicated that the 5-year survival rates were 21.6 and 91.3% in infantile and childhood VWM, respectively. In terms of MRI, infantile patients showed more extensive involvement and earlier rarefaction, with more common involvement of subcortical white matter, internal capsule, brain stem and dentate nuclei of the cerebellum. Restricted diffusion was more diffuse or extensive in infantile patients. In addition, four novel mutations were identified. In conclusion, we identified some similarities and differences in the natural history and neuroimaging features between infantile and early childhood VWM.

A note on the post-Newtonian limit of quasi-local energy expressions

International Nuclear Information System (INIS)

Frauendiener, Jörg; Szabados, László B

2011-01-01

An 'effective' quasi-local energy expression, motivated by the (relativistically corrected) Newtonian theory, is introduced in exact general relativity as the volume integral of all the source terms in the field equation for the Newtonian potential in static spacetimes. In particular, we exhibit a new post-Newtonian correction in the source term in the field equation for the Newtonian gravitational potential. In asymptotically flat spacetimes, this expression tends to the Arnowitt-Deser-Misner energy at spatial infinity as a monotonically decreasing set function. We prove its positivity in spherically symmetric spacetimes under certain energy conditions, and that its vanishing characterizes flatness. We argue that any physically acceptable quasi-local energy expression should behave qualitatively like this 'effective' energy expression in this limit. (paper)

Super-mercuryphobic and hydrophobic diamond surfaces with hierarchical structures: Vanishment of the contact angle hysteresis with mercury

International Nuclear Information System (INIS)

Escobar, Juan V.; Garza, Cristina; Alonso, Juan Carlos; Castillo, Rolando

2013-01-01

Increased roughness is known to enhance the natural wetting properties of surfaces, making them either more hydrophobic or more hydrophilic. In this work we study the wetting properties of water and mercury drops in contact with boron doped diamond films with progressively increased surface roughnesses. We show how thermal oxidation of a microcrystalline film creates pyramids decorated with sub-micron protrusions that turn its naturally mercuryphobic surface into super-mercuryphobic. With this liquid, we observe the vanishment of the contact angle hysteresis that is expected for rough surfaces as the contact angle approaches 180, making small drops of mercury roll along out of the surface at an apparent zero tilt-angle. In contrast, the incorporation of nano-globules on the oxidized surface through a silanization process is necessary to increase the hydrophobic properties of the film for which the contact angle with water reaches 138°. The wetting states that dominate in each case are discussed.

Super-mercuryphobic and hydrophobic diamond surfaces with hierarchical structures: Vanishment of the contact angle hysteresis with mercury

Energy Technology Data Exchange (ETDEWEB)

Escobar, Juan V., E-mail: escobar@fisica.unam.mx [Instituto de Física, Universidad Nacional Autónoma de México, PO Box 20-364, DF, México, 01000 (Mexico); Garza, Cristina, E-mail: cgarza@fisica.unam.mx [Instituto de Física, Universidad Nacional Autónoma de México, PO Box 20-364, DF, México, 01000 (Mexico); Alonso, Juan Carlos, E-mail: alonso@unam.mx [Instituto de Investigaciones en Materiales, Universidad Nacional Autónoma de México, PO Box 70-360, DF, México, 04510 (Mexico); Castillo, Rolando, E-mail: rolandoc@fisica.unam.mx [Instituto de Física, Universidad Nacional Autónoma de México, PO Box 20-364, DF, México, 01000 (Mexico)

2013-05-15

Increased roughness is known to enhance the natural wetting properties of surfaces, making them either more hydrophobic or more hydrophilic. In this work we study the wetting properties of water and mercury drops in contact with boron doped diamond films with progressively increased surface roughnesses. We show how thermal oxidation of a microcrystalline film creates pyramids decorated with sub-micron protrusions that turn its naturally mercuryphobic surface into super-mercuryphobic. With this liquid, we observe the vanishment of the contact angle hysteresis that is expected for rough surfaces as the contact angle approaches 180, making small drops of mercury roll along out of the surface at an apparent zero tilt-angle. In contrast, the incorporation of nano-globules on the oxidized surface through a silanization process is necessary to increase the hydrophobic properties of the film for which the contact angle with water reaches 138°. The wetting states that dominate in each case are discussed.

Breakdown of quasiparticle picture in the low-density limit of the 1D Hubbard model

International Nuclear Information System (INIS)

Qin Shaojin; Qian Tiezheng; Su Zhaobin

1995-03-01

Using the finite-size scaling of results obtained by exact diagonalization, we study the low-density limit of the one-dimensional Hubbard model. Calculating the quasiparticle weight, we demonstrate that for a given particle number N and system size L, there always exists a crossover point U c separating the Fermi-liquid (U c ) and non-Fermi-liquid (U > U c ) regimes (U is the Hubbard repulsion). We find that for a fixed N, U c is inversely proportional to L, keeping U c L/t constant (with t as the hopping integral), as L is large enough. It follows that in the low-density (in fact vanishing density) limit L → ∞, U c → 0, so the system is always in non-Fermi-liquid regime as long as U > 0. We show that our numerical results are consistent with the Bethe ansatz solution. (author). 11 refs, 3 figs

[Association between homozygous c.318A>GT mutation in exon 2 of the EIF2B5 gene and the infantile form of vanishing white matter leukoencephalopathy].

Science.gov (United States)

Esmer, Carmen; Blanco Hernández, Gabriela; Saavedra Alanís, Víctor; Reyes Vaca, Jorge Guillermo; Bravo Oro, Antonio

Vanishing white matter disease is one of the most frequent leukodystrophies in childhood with an autosomal recessive inheritance. A mutation in one of the genes encoding the five subunits of the eukaryotic initiation factor 2 (EIF2B5) is present in 90% of the cases. The diagnosis can be accomplished by the clinical and neuroradiological findings and molecular tests. We describe a thirteen-month-old male with previous normal neurodevelopment, who was hospitalized for vomiting, hyperthermia and irritability. On examination, cephalic perimeter and cranial pairs were normal. Hypotonia, increased muscle stretching reflexes, generalized white matter hypodensity on cranial tomography were found. Fifteen days after discharge, he suffered minor head trauma presenting drowsiness and focal seizures. Magnetic resonance showed generalized hypointensity of white matter. Vanishing white matter disease was suspected, and confirmed by sequencing of the EIF2B5 gene, revealing a homozygous c.318A> T mutation in exon 2. Subsequently, visual acuity was lost and cognitive and motor deterioration was evident. The patient died at six years of age due to severe pneumonia. This case contributes to the knowledge of the mutational spectrum present in Mexican patients and allows to extend the phenotype associated to this mutation. Copyright © 2017. Publicado por Masson Doyma México S.A.

Leucoencefalopatia megalencefálica com substância branca evanescente e cistos subcorticais Megalencephalic leukoencephalopathy with vanishing white matter and cystic formation

Directory of Open Access Journals (Sweden)

Hélio Araújo Oliveira

2004-12-01

Full Text Available Apresentamos três casos de leucoencefalopatia megalencefálica com substancia branca evanescente e cistos subcorticais, diagnosticados através da ressonância nuclear magnética.Os casos estudados apresentam quadro clinico e radiológico de acordo com os critérios diagnósticos estabelecidos na descrição inicial desta enfermidade. São discutidos os aspectos clínicos e neuroradiológicos.We present three cases of megalencephalic leukoencephalopathy with vanishing white matter and cystic formation in both temporal lobes, diagnosed through magnetic resonance imaging. All the cases presented clinical and radiological aspects according to the diagnostic criteria that were established in the initial description of the syndrome. Clinical and radiological aspects are discussed.

Vanishing Viscosity Approach to the Compressible Euler Equations for Transonic Nozzle and Spherically Symmetric Flows

Science.gov (United States)

Chen, Gui-Qiang G.; Schrecker, Matthew R. I.

2018-04-01

We are concerned with globally defined entropy solutions to the Euler equations for compressible fluid flows in transonic nozzles with general cross-sectional areas. Such nozzles include the de Laval nozzles and other more general nozzles whose cross-sectional area functions are allowed at the nozzle ends to be either zero (closed ends) or infinity (unbounded ends). To achieve this, in this paper, we develop a vanishing viscosity method to construct globally defined approximate solutions and then establish essential uniform estimates in weighted L p norms for the whole range of physical adiabatic exponents γ\\in (1, ∞) , so that the viscosity approximate solutions satisfy the general L p compensated compactness framework. The viscosity method is designed to incorporate artificial viscosity terms with the natural Dirichlet boundary conditions to ensure the uniform estimates. Then such estimates lead to both the convergence of the approximate solutions and the existence theory of globally defined finite-energy entropy solutions to the Euler equations for transonic flows that may have different end-states in the class of nozzles with general cross-sectional areas for all γ\\in (1, ∞) . The approach and techniques developed here apply to other problems with similar difficulties. In particular, we successfully apply them to construct globally defined spherically symmetric entropy solutions to the Euler equations for all γ\\in (1, ∞).

A global limit load solution for plates with surface cracks under combined end force and cross-thickness bending

International Nuclear Information System (INIS)

Lei Yuebao; Fox, Mike J.H.

2011-01-01

A global limit load solution for rectangular surface cracks in plates under combined end force and cross-thickness bending is derived, which allows any combination of positive/negative end force and positive/negative cross-thickness moment. The solution is based on the net-section plastic collapse concept and, therefore, gives limit load values based on the Tresca yielding criterion. Solutions for both cases with and without crack face contact are derived when whole or part of the crack is located in the compressive stress zone. From the solution, particular global limit load solutions for plates with extended surface cracks and through-thickness cracks under the same loading conditions are obtained. The solution is consistent with the limit load solution for surface cracks in plates under combined tension and positive bending due to Goodall and Webster and Lei when both the applied end force and bending moment are positive. The solution reduces to the limit load solution for plain plates under combined end force and cross-thickness bending when the crack vanishes. - Highlights: → A global limit load solution for plates with surface cracks in plates is derived. → Combined positive/negative end force and positive/negative cross-thickness moment are considered. → The solution is based on the net-section plastic collapse concept.

Time-independent limit of a creep-recovery constitutive equation

International Nuclear Information System (INIS)

Chang, S.J.

1984-01-01

The effect of strain recovery is taken into consideration in ORNL efforts to establish unified constitutive equations for time-dependent plastic deformation for metals at elevated temperatures. Representation by internal state variables and Rice's flow potential are under consideration. Here the growth law for the internal state variables is discussed and interpreted in terms of a generalized form of the kinematic hardening condition of Prager. The yield condition is obtained from the flow potential representation of the inelastic strain rate. A consistency condition is derived from the yield condition and leads to a flow rule which assumes a slightly general form as compared with that of the classical plasticity due to the effect of strain recovery and the time-dependent property of the yield condition. Based on this representation, the time-independent limit is discussed. From a vanishing effect of recovery and a rate-independent limit for the yield condition at low temperature, this flow rule reduces to the well-known form of time-independent plasticity with a kinematic hardening condition. The duration of time (the characteristic time) required for the inelastic strain to reach its saturated value is defined for the inelastic loading condition. It provides the measure of a minimum duration of time which is required for a valid approximation made by the time-independent plasticity model

Limiting procedure T→ infinity in the Hill method for quasi-energetic states

International Nuclear Information System (INIS)

Melikyan, A.O.; Simonyan, K.Kh.

1980-01-01

A connection between the quasi-energetic states of a quantum system in a time-periodic field when the period tends to infinity and the nonstationary states in a nonperiodic field vanishing at t→infinity is established

Renormalization group functions of the φ4 theory in the strong coupling limit: Analytical results

International Nuclear Information System (INIS)

Suslov, I. M.

2008-01-01

The previous attempts of reconstructing the Gell-Mann-Low function β(g) of the φ 4 theory by summing perturbation series give the asymptotic behavior β(g) = β ∞ g in the limit g → ∞, where α = 1 for the space dimensions d = 2, 3, 4. It can be hypothesized that the asymptotic behavior is β(g) ∼ g for all d values. The consideration of the zero-dimensional case supports this hypothesis and reveals the mechanism of its appearance: it is associated with vanishing of one of the functional integrals. The generalization of the analysis confirms the asymptotic behavior β(g) ∼ g in the general d-dimensional case. The asymptotic behaviors of other renormalization group functions are constant. The connection with the zero-charge problem and triviality of the φ 4 theory is discussed

The capacity of black holes to transmit quantum information

International Nuclear Information System (INIS)

Brádler, Kamil; Adami, Christoph

2014-01-01

We study the properties of the quantum information transmission channel that emerges from the quantum dynamics of particles interacting with a black hole horizon. We calculate the quantum channel capacity in two limiting cases where a single-letter capacity is known to exist: the limit of perfectly reflecting and perfectly absorbing black holes. We find that the perfectly reflecting black hole channel is closely related to the Unruh channel and that its capacity is non-vanishing, allowing for the perfect reconstruction of quantum information outside of the black hole horizon. We also find that the complementary channel (transmitting entanglement behind the horizon) is entanglement-breaking in this case, with vanishing capacity. We then calculate the quantum capacity of the black hole channel in the limit of a perfectly absorbing black hole and find that this capacity vanishes, while the capacity of the complementary channel is non-vanishing instead. Rather than inviting a new crisis for quantum physics, this finding instead is in accordance with the quantum no-cloning theorem, because it guarantees that there are no space-like surfaces that contain both the sender’s quantum state and the receiver’s reconstructed quantum state

The capacity of black holes to transmit quantum information

Energy Technology Data Exchange (ETDEWEB)

Brádler, Kamil [Department of Astronomy and Physics, Saint Mary’s University,Halifax, Nova Scotia, B3H 3C3 (Canada); Adami, Christoph [Department of Physics and Astronomy, Michigan State University,East Lansing, MI 48824 (United States)

2014-05-21

We study the properties of the quantum information transmission channel that emerges from the quantum dynamics of particles interacting with a black hole horizon. We calculate the quantum channel capacity in two limiting cases where a single-letter capacity is known to exist: the limit of perfectly reflecting and perfectly absorbing black holes. We find that the perfectly reflecting black hole channel is closely related to the Unruh channel and that its capacity is non-vanishing, allowing for the perfect reconstruction of quantum information outside of the black hole horizon. We also find that the complementary channel (transmitting entanglement behind the horizon) is entanglement-breaking in this case, with vanishing capacity. We then calculate the quantum capacity of the black hole channel in the limit of a perfectly absorbing black hole and find that this capacity vanishes, while the capacity of the complementary channel is non-vanishing instead. Rather than inviting a new crisis for quantum physics, this finding instead is in accordance with the quantum no-cloning theorem, because it guarantees that there are no space-like surfaces that contain both the sender’s quantum state and the receiver’s reconstructed quantum state.

Vanishing of T sub c and appearance of quantum paraelectricity in KD sub 2 PO sub 4 and KH sub 2 PO sub 4 under high pressure

CERN Document Server

Endo, S; Tokunaga, M

2002-01-01

The temperature dependences of the dielectric constants of the hydrogen-bond ferroelectrics KH sub 2 PO sub 4 (KDP) and KD sub 2 PO sub 4 (DKDP) were measured under high hydrostatic pressure. Their ferroelectric transition temperatures T sub c monotonically decreased with increasing pressure and the ferroelectric state vanished at p sub c : 1.7 GPa for KDP and 6.1 GPa for DKDP. On the other hand, the Curie constant remained finite at p sub c , which indicates that the ferroelectric phase transition at high pressure is of displacive type. At pressures around p sub c , quantum paraelectricity was observed in KDP and DKDP.

The Limited Capacity of Sleep-Dependent Memory Consolidation

Directory of Open Access Journals (Sweden)

Gordon B Feld

2016-09-01

Full Text Available Sleep supports memory consolidation. However, the conceptually important influence of the amount of items encoded in a memory test on this effect has not been investigated. In two experiments, participants (n=101 learned lists of word-pairs varying in length (40, 160, 320 word-pairs in the evening before a night of sleep (sleep group or of sleep deprivation (wake group. After 36 h (including a night allowing recovery sleep retrieval was tested. Compared with wakefulness, post-learning sleep enhanced retention for the 160 word-pair condition (p < 0.01, importantly, this effect completely vanished for the 320 word-pair condition. This result indicates a limited capacity for sleep-dependent memory consolidation, which is consistent with an active system consolidation view on sleep’s role for memory, if it is complemented by processes of active forgetting and/or gist abstraction. Whereas the absolute benefit from sleep should have increased with increasing amounts of successfully encoded items, if sleep only passively protected memory from interference. Moreover, the finding that retention performance was significantly diminished for the 320 word-pair condition compared to the 160 word-pair condition in the sleep group, makes it tempting to speculate that with increasing loads of information encoded during wakefulness, sleep might favour processes of forgetting over consolidation.

Dimensional expansion for the Ising limit of quantum field theory

International Nuclear Information System (INIS)

Bender, C.M.; Boettcher, S.

1993-01-01

A recently proposed technique, called dimensional expansion, uses the space-time dimension D as an expansion parameter to extract nonperturbative results in quantum field theory. Here we apply dimensional-expansion methods to examine the Ising limit of a self-interacting scalar field theory. We compute the first few coefficients in the dimensional expansion of γ 2n , the renormalized 2n-point Green's function at zero momentum, for n=2, 3, 4, and 5. Because the exact results for γ 2n are known at D=1 we can compare the predictions of the dimensional expansion at this value of D. We find typical accuracies of less than 5%. The radius of convergence of the dimensional expansion for γ 2n appears to be 2n/(n-1). As a function of the space-time dimension D, γ 2n appears to rise monotonically with increasing D and we conjecture that it becomes infinite at D=2n/(n-1). We presume that for values of D greater than this critical value γ 2n vanishes identically because the corresponding φ 2n scalar quantum field theory is free for D>2n/(n-1)

Monte Carlo study of one hole in a quantum antiferromagnet

International Nuclear Information System (INIS)

Sorella, S.

1992-01-01

Using the standard Quantum Monte Carlo technique for the Hubbard model, I present here a numerical investigation of the hole propagation in a Quantum Antiferromagnet. The calculation is very well stabilized, using selected sized systems and special use of the trial wavefunction that satisfy the close shell condition in presence of an arbitrarily weak Zeeman magnetic field, vanishing in the thermodynamic limit. In this paper the author investigates the question of vanishing or nonvanishing quasiparticle weight, in order to clarify whether the Mott insulator should behave just as conventional insulator with an upper and lower Hubbard band. By comparing the present finite size scaling with several techniques predicting a finite quasiparticle weight the data seem more consistent with a vanishing quasiparticle weight, i.e., as recently suggested by P.W. Anderson the Hubbard-Mott insulator should be characterized by non-trivial excitations which cannot be interpreted in a simple quasi-particle picture. However it cannot be excluded, based only on numerical grounds, that a very small but non vanishing quasiparticle weight should survive in the thermodynamic limit

Bolometer tomography at the density limit of the HDH mode in the W7-AS stellarator

International Nuclear Information System (INIS)

Giannone, L; Brakel, R; Burhenn, R; Ehmler, H; Feng, Y; Grigull, P; McCormick, K; Wagner, F; Baldzuhn, J; Igitkhanov, Y; Knauer, J; Nishimura, K; Pasch, E; Peterson, B J; Ramasubramanian, N; Rust, N; Weller, A; Werner, A

2003-01-01

The installation of divertor plates in the W7-AS stellarator has allowed attainment of a high energy confinement regime at high density, where the radiation profiles reached steady state. In this regime, the radial profile of the radiated power is hollow. Raising the density to the point where the radiated power approached the input power led to plasma detachment and a decrease in diamagnetic energy. This defines the density limit in a stellarator and a scaling law for this maximum density can be heuristically derived on the basis of power balance considerations. The installation of two bolometer cameras away from the divertor plates and three bolometer cameras in the vicinity of the divertor plates has provided insight into the features of high density operation of a divertor in a stellarator. In the main chamber, tomographic inversion at the density limit has shown that a poloidally asymmetric radiation profile developed as the density limit was approached. In the divertor, radiation in front of the divertor plates occurred while the plasma was attached and this radiation zone vanished at plasma detachment. Steady state discharges of up to 1.5 s have been achieved for neutral beam injection power of up to 2 MW. A precursor to a spontaneous transition out of the high confinement regime has been identified

Failure strains and proposed limit strains for an reactor pressure vessel under severe accident conditions

International Nuclear Information System (INIS)

Krieg, R.

2005-01-01

The local failure strains of essential design elements of a reactor vessel are investigated. The size influence of the structure is of special interest. Typical severe accident conditions including elevated temperatures and dynamic loads are considered. The main part of work consists of test families with specimens under uniaxial and biaxial load. Within one test family the specimen geometry and the load conditions are similar, but the size is varied up to reactor dimensions. Special attention is given to geometries with a hole or a notch causing non-uniform stress and strain distributions typical for the reactor vessel. A key problem is to determine the local failure strain. Here suitable methods had to be developed including the so-called 'vanishing gap method', and the 'forging die method'. They are based on post-test geometrical measurements of the fracture surfaces and reconstructions of the related strain fields using finite element models. The results indicate that stresses versus dimensionless deformations are approximately size independent up to failure for specimens of similar geometry under similar load conditions. Local failure strains could be determined. The values are rather high and size dependent. Statistical evaluation allow the proposal of limit strains which are also size dependent. If these limit strains are not exceeded, the structures will not fracture

No need for a social cue! A masked magician can also trick the audience in the vanishing ball illusion.

Science.gov (United States)

Thomas, Cyril; Didierjean, André

2016-01-01

In the vanishing ball illusion (VBI), a magician throws a ball up in the air twice, after which he pretends to toss it up again, when in fact it remains secretly concealed in his hand. Observers perceive an imaginary ball disappearing into the air. According to Kuhn and Land (2006), the VBI during the fake throw is mediated by the magician's gaze and/or head direction (also called "social cues") as he looks toward the imaginary ball. The aim of this article is to test an alternative interpretation. According to our hypothesis, the magician's social cues are not essential to the VBI. We compared the numbers of participants experiencing the VBI when the magician's social cues were directed toward the illusory ball and when the magician's social cues were either hidden behind a black mask (Exp. 1) or stationary (Exp. 2). The results showed that the number of observers experiencing the VBI was high (almost two-thirds of the participants), regardless of whether the magician's social cueing was directed toward the illusion, hidden behind a mask, or stationary. In a third experiment (Exp. 3), we replicated Kuhn and Land's initial results and attempted to further explain their "anti-illusion" social-cue effect. This study confirms that social cueing is not required in the VBI: Its presence did not increase the number of participants experiencing the illusion.

Conribution to the study of spontaneous breakdown of the chiral symmetry in gauge theories

International Nuclear Information System (INIS)

Gamonal, R.

1984-01-01

In the framework of quantum chromodynamics, we have been interested in the order parameters for the breakdown of the non-abelian chiral symmetry. Using the functional integral representation in the euclidean formalism, we have performed the fermionic integration after having inverted the chiral limit and the integration over gluonic fields. So, we were led to look for what gauge field configurations, the fermionic integrand has a non-vanishing chiral limit. We have been able to show, in a general manner, that the generating functional of all the order parameters vanishes in the chiral limit for the gauge field configurations which lead to a discrete spectrum for the Dirac operator around zero. For those leading to a continuous spectrum from the zero eigenvalue, the existence of a non-vanishing infra-red limit for the spectral density of the Dirac operator is crucial. We have exhibited gauge field configurations which give such a behaviour. Nevertheless, our analysis reveals the necessity to get a degeneracy for the zero modes belonging to the continuum of the Dirac operator. We have been able to demonstrate, for the class of gluonic fields, previously considered, an absence of degeneracy [fr

Localized solutions for a nonlocal discrete NLS equation

International Nuclear Information System (INIS)

Ben, Roberto I.; Cisneros Ake, Luís; Minzoni, A.A.; Panayotaros, Panayotis

2015-01-01

We study spatially localized time-periodic solutions of breather type for a cubic discrete NLS equation with a nonlocal nonlinearity that models light propagation in a liquid crystal waveguide array. We show the existence of breather solutions in the limit where both linear and nonlinear intersite couplings vanish, and in the limit where the linear coupling vanishes with arbitrary nonlinear intersite coupling. Breathers of this nonlocal regime exhibit some interesting features that depart from what is seen in the NLS breathers with power nonlinearity. One property we see theoretically is the presence of higher amplitude at interfaces between sites with zero and nonzero amplitude in the vanishing linear coupling limit. A numerical study also suggests the presence of internal modes of orbitally stable localized modes. - Highlights: • Show existence of spatially localized solutions in nonlocal discrete NLS model. • Study spatial properties of localized solutions for arbitrary nonlinear nonlocal coupling. • Present numerical evidence that nonlocality leads to internal modes around stable breathers. • Present theoretical and numerical evidence for amplitude maxima at interfaces

Localized solutions for a nonlocal discrete NLS equation

Energy Technology Data Exchange (ETDEWEB)

Ben, Roberto I. [Instituto de Desarrollo Humano, Universidad Nacional de General Sarmiento, J.M. Gutiérrez 1150, 1613 Los Polvorines (Argentina); Cisneros Ake, Luís [Department of Mathematics, ESFM, Instituto Politécnico Nacional, Unidad Profesional Adolfo López Mateos Edificio 9, 07738 México D.F. (Mexico); Minzoni, A.A. [Depto. Matemáticas y Mecánica, I.I.M.A.S.-U.N.A.M., Apdo. Postal 20-726, 01000 México D.F. (Mexico); Panayotaros, Panayotis, E-mail: panos@mym.iimas.unam.mx [Depto. Matemáticas y Mecánica, I.I.M.A.S.-U.N.A.M., Apdo. Postal 20-726, 01000 México D.F. (Mexico)

2015-09-04

We study spatially localized time-periodic solutions of breather type for a cubic discrete NLS equation with a nonlocal nonlinearity that models light propagation in a liquid crystal waveguide array. We show the existence of breather solutions in the limit where both linear and nonlinear intersite couplings vanish, and in the limit where the linear coupling vanishes with arbitrary nonlinear intersite coupling. Breathers of this nonlocal regime exhibit some interesting features that depart from what is seen in the NLS breathers with power nonlinearity. One property we see theoretically is the presence of higher amplitude at interfaces between sites with zero and nonzero amplitude in the vanishing linear coupling limit. A numerical study also suggests the presence of internal modes of orbitally stable localized modes. - Highlights: • Show existence of spatially localized solutions in nonlocal discrete NLS model. • Study spatial properties of localized solutions for arbitrary nonlinear nonlocal coupling. • Present numerical evidence that nonlocality leads to internal modes around stable breathers. • Present theoretical and numerical evidence for amplitude maxima at interfaces.

Generalized 3D Zernike functions for analytic construction of band-limited line-detecting wavelets

NARCIS (Netherlands)

Janssen, A.J.E.M.

2015-01-01

We consider 3D versions of the Zernike polynomials that are commonly used in 2D in optics and lithography. We generalize the 3D Zernike polynomials to functions that vanish to a prescribed degree $\\alpha\\geq0$ at the rim of their supporting ball $\\rho\\leq1$. The analytic theory of the 3D generalized

Conserved charge fluctuations at vanishing and non-vanishing chemical potential

Science.gov (United States)

Karsch, Frithjof

2017-11-01

Up to 6th order cumulants of fluctuations of net baryon-number, net electric charge and net strangeness as well as correlations among these conserved charge fluctuations are now being calculated in lattice QCD. These cumulants provide a wealth of information on the properties of strong-interaction matter in the transition region from the low temperature hadronic phase to the quark-gluon plasma phase. They can be used to quantify deviations from hadron resonance gas (HRG) model calculations which frequently are used to determine thermal conditions realized in heavy ion collision experiments. Already some second order cumulants like the correlations between net baryon-number and net strangeness or net electric charge differ significantly at temperatures above 155 MeV in QCD and HRG model calculations. We show that these differences increase at non-zero baryon chemical potential constraining the applicability range of HRG model calculations to even smaller values of the temperature.

Second-order transport, quasinormal modes and zero-viscosity limit in the Gauss-Bonnet holographic fluid

Energy Technology Data Exchange (ETDEWEB)

Grozdanov, Sašo [Instituut-Lorentz for Theoretical Physics, Leiden University, Niels Bohrweg 2, Leiden 2333 CA (Netherlands); Starinets, Andrei O. [Rudolf Peierls Centre for Theoretical Physics, University of Oxford, 1 Keble Road, Oxford OX1 3NP (United Kingdom)

2017-03-30

Gauss-Bonnet holographic fluid is a useful theoretical laboratory to study the effects of curvature-squared terms in the dual gravity action on transport coefficients, quasinormal spectra and the analytic structure of thermal correlators at strong coupling. To understand the behavior and possible pathologies of the Gauss-Bonnet fluid in 3+1 dimensions, we compute (analytically and non-perturbatively in the Gauss-Bonnet coupling) its second-order transport coefficients, the retarded two- and three-point correlation functions of the energy-momentum tensor in the hydrodynamic regime as well as the relevant quasinormal spectrum. The Haack-Yarom universal relation among the second-order transport coefficients is violated at second order in the Gauss-Bonnet coupling. In the zero-viscosity limit, the holographic fluid still produces entropy, while the momentum diffusion and the sound attenuation are suppressed at all orders in the hydrodynamic expansion. By adding higher-derivative electromagnetic field terms to the action, we also compute corrections to charge diffusion and identify the non-perturbative parameter regime in which the charge diffusion constant vanishes.

Can quantum transition state theory be defined as an exact t = 0+ limit?

Science.gov (United States)

Jang, Seogjoo; Voth, Gregory A.

2016-02-01

that the t → 0+ limit of the new rate expression vanishes in the exact quantum limit.

Limited Effects of Set Shifting Training in Healthy Older Adults

Directory of Open Access Journals (Sweden)

Petra Grönholm-Nyman

2017-03-01

Full Text Available Our ability to flexibly shift between tasks or task sets declines in older age. As this decline may have adverse effects on everyday life of elderly people, it is of interest to study whether set shifting ability can be trained, and if training effects generalize to other cognitive tasks. Here, we report a randomized controlled trial where healthy older adults trained set shifting with three different set shifting tasks. The training group (n = 17 performed adaptive set shifting training for 5 weeks with three training sessions a week (45 min/session, while the active control group (n = 16 played three different computer games for the same period. Both groups underwent extensive pre- and post-testing and a 1-year follow-up. Compared to the controls, the training group showed significant improvements on the trained tasks. Evidence for near transfer in the training group was very limited, as it was seen only on overall accuracy on an untrained computerized set shifting task. No far transfer to other cognitive functions was observed. One year later, the training group was still better on the trained tasks but the single near transfer effect had vanished. The results suggest that computerized set shifting training in the elderly shows long-lasting effects on the trained tasks but very little benefit in terms of generalization.

Scaling laws, renormalization group flow and the continuum limit in non-compact lattice QED

International Nuclear Information System (INIS)

Goeckeler, M.; Horsley, R.; Rakow, P.; Schierholz, G.; Sommer, R.

1992-01-01

We investigate the ultra-violet behavior of non-compact lattice QED with light staggered fermions. The main question is whether QED is a non-trivial theory in the continuum limit, and if not, what is its range of validity as a low-energy theory. Perhaps the limited range of validity could offer an explanation of why the fine-structure constant is so small. Non-compact QED undergoes a second-order chiral phase transition at strong coupling, at which the continuum limit can be taken. We examine the phase diagram and the critical behavior of the theory in detail. Moreover, we address the question as to whether QED confines in the chirally broken phase. This is done by investigating the potential between static external charges. We then compute the renormalized charge and derive the Callan-Symanzik β-function in the critical region. No ultra-violet stable zero is found. Instead, we find that the evolution of charge is well described by renormalized perturbation theory, and that the renormalized charge vanishes at the critical point. The consequence is that QED can only be regarded as a cut-off theory. We evaluate the maximum value of the cut-off as a function of the renormalized charge. Next, we compute the masses of fermion-antifermion composite states. The scaling behavior of these masses is well described by an effective action with mean-field critical exponents plus logarithmic corrections. This indicates that also the matter sector of the theory is non-interacting. Finally, we investigate and compare the renormalization group flow of different quantities. Altogether, we find that QED is a valid theory only for samll renormalized charges. (orig.)

Extremal rotating black holes in the near-horizon limit: Phase space and symmetry algebra

Directory of Open Access Journals (Sweden)

G. Compère

2015-10-01

Full Text Available We construct the NHEG phase space, the classical phase space of Near-Horizon Extremal Geometries with fixed angular momenta and entropy, and with the largest symmetry algebra. We focus on vacuum solutions to d dimensional Einstein gravity. Each element in the phase space is a geometry with SL(2,R×U(1d−3 isometries which has vanishing SL(2,R and constant U(1 charges. We construct an on-shell vanishing symplectic structure, which leads to an infinite set of symplectic symmetries. In four spacetime dimensions, the phase space is unique and the symmetry algebra consists of the familiar Virasoro algebra, while in d>4 dimensions the symmetry algebra, the NHEG algebra, contains infinitely many Virasoro subalgebras. The nontrivial central term of the algebra is proportional to the black hole entropy. The conserved charges are given by the Fourier decomposition of a Liouville-type stress-tensor which depends upon a single periodic function of d−3 angular variables associated with the U(1 isometries. This phase space and in particular its symmetries can serve as a basis for a semiclassical description of extremal rotating black hole microstates.

Infantile onset Vanishing White Matter disease associated with a novel EIF2B5 variant, remarkably long life span, severe epilepsy, and hypopituitarism.

Science.gov (United States)

Woody, April L; Hsieh, David T; McIver, Harkirtin K; Thomas, Linda P; Rohena, Luis

2015-04-01

Vanishing White Matter disease (VWM) is an inherited progressive leukoencephalopathy caused by mutations in the genes EIF2B1-5, which encode for the 5 subunits of the eukaryotic initiation factor 2B (eIF2B), a regulator of protein synthesis. VWM typically presents with acute neurological decline following febrile infections or minor head trauma, and subsequent progressive neurological and cognitive regression. There is a varied clinical spectrum of VWM, with earlier onset associated with more severe phenotypes. Brain magnetic resonance imaging is usually diagnostic with diffusely abnormal white matter, progressing over time to cystic degeneration. We are reporting on a patient with infantile onset VWM associated with three heterozygous missense variants in EIF2B5, including a novel missense variant on exon 6 of EIF2B5 (D262N), as well as an interstitial duplication at 7q21.12. In addition, our case is unusual because of a severe epilepsy course, a novel clinical finding of hypopituitarism manifested by hypothyroidism and adrenal insufficiency, and a prolonged life span with current age of survival of 4 years and 11 months. © 2015 Wiley Periodicals, Inc.

A Vanishing Act

DEFF Research Database (Denmark)

la Cour, Anders; Hecht, Janus; Stilling, Maria Kirstine

2016-01-01

The use of information and communication technology (ICT) has played an important role in the reforms that have taken place in Western welfare societies over the past two decades. ICT is regarded as a way to provide transparency and information exchange among providers, users and politicians....... This has also been the case for healthcare services in elderly home care, where ICT has been deployed to enable information exchange, knowledge sharing and documentation of delivered services. This article explores the extent to which the popular personal digital assistant (PDA) contributes to these types...... of activities in the provision of elderly home care services in Copenhagen, Denmark. We argue that despite the PDA’s promising potential to provide increased transparency concerning the delivery of services, it has had the opposite effect. Rather than creating transparency, the PDA has become a tool for hiding...

Fractional energy states of strongly-interacting bosons in one dimension

DEFF Research Database (Denmark)

Zinner, Nikolaj Thomas; G. Volosniev, A.; V. Fedorov, D.

2014-01-01

We study two-component bosonic systems with strong inter-species and vanishing intra-species interactions. A new class of exact eigenstates is found with energies that are {\\it not} sums of the single-particle energies with wave functions that have the characteristic feature that they vanish over...... than three particles. The states can be probed using the same techniques that have recently been used for fermionic few-body systems in quasi-1D.......We study two-component bosonic systems with strong inter-species and vanishing intra-species interactions. A new class of exact eigenstates is found with energies that are {\\it not} sums of the single-particle energies with wave functions that have the characteristic feature that they vanish over...... extended regions of coordinate space. This is demonstrated in an analytically solvable model for three equal mass particles, two of which are identical bosons, which is exact in the strongly-interacting limit. We numerically verify our results by presenting the first application of the stochastic...

Absence of high-temperature ballistic transport in the spin-1/2 XXX chain within the grand-canonical ensemble

Directory of Open Access Journals (Sweden)

J.M.P. Carmelo

2017-01-01

Full Text Available Whether in the thermodynamic limit, vanishing magnetic field h→0, and nonzero temperature the spin stiffness of the spin-1/2 XXX Heisenberg chain is finite or vanishes within the grand-canonical ensemble remains an unsolved and controversial issue, as different approaches yield contradictory results. Here we provide an upper bound on the stiffness and show that within that ensemble it vanishes for h→0 in the thermodynamic limit of chain length L→∞, at high temperatures T→∞. Our approach uses a representation in terms of the L physical spins 1/2. For all configurations that generate the exact spin-S energy and momentum eigenstates such a configuration involves a number 2S of unpaired spins 1/2 in multiplet configurations and L−2S spins 1/2 that are paired within Msp=L/2−S spin–singlet pairs. The Bethe-ansatz strings of length n=1 and n>1 describe a single unbound spin–singlet pair and a configuration within which n pairs are bound, respectively. In the case of n>1 pairs this holds both for ideal and deformed strings associated with n complex rapidities with the same real part. The use of such a spin 1/2 representation provides useful physical information on the problem under investigation in contrast to often less controllable numerical studies. Our results provide strong evidence for the absence of ballistic transport in the spin-1/2 XXX Heisenberg chain in the thermodynamic limit, for high temperatures T→∞, vanishing magnetic field h→0 and within the grand-canonical ensemble.

Modelling of Magma Density and Viscocity Changes and Their Influences towards the Characteristic of Kelud Volcano Eruption

Directory of Open Access Journals (Sweden)

Hanik Humaida

2014-06-01

Full Text Available DOI: 10.17014/ijog.v6i4.129The effusive eruption of Kelud Volcano in 2007 was different from the previous ones, which in general were more explosive. Among others, density and viscosity are factors that determine the type of eruption. Therefore, the study on the difference of the recent eruption style based on the density and viscosity of magma was carried out. The method used in this study was based on geochemical analysis of the rock and then a modeling was established by using the above parameter. The study on the explosive eruption was emphasized on the data of 1990 eruption, whereas the effusive eruption was based on the data of 2007 eruption. The result shows that the magma viscosity of Kelud Volcano depend on the H O concentration as one of the volatile compound in magma, and temperature which gives the exponential equation. The higher the increase of H O content the smaller the value of its viscosity as well as the higher the temperature. The H O content in silica fluid can break the polymer bond of the silica fluid, because a shorter polymer will produce a lower viscosity. The density of the silica content of Kelud Volcano ranges between andesitic and basaltic types, but andesite is more likely. The fluid density of the material of 1990 eruption is different from 2007 eruption. Compared to the 2007, the 1990 eruption material gave a lower density value in its silica fluid than that of the 2007 one. The low density value of the silica fluid of the 1990 eruption material was reflecting a more acid magma. The level of density value of silica fluid depends on its temperature. At the temperature of 1073 K the density of the 1990 Kelud magma is 2810 kg/m3 and the 2007 magma is 2818 kg/m3, whereas at a temperature of 1673 K, the density is 2672 kg/m3 and 2682 kg/m3 of the 1990 and 2007 eruptions respectively. A modeling by using an ideal gas law of Henry’s Law illustrated that the ascent of Kelud’s magma to the surface may cause changes in it’s physical properties. The evolution of the flow pressure in the conduit is characterized by three different areas; based of the conduit until the pressure is saturated, then at the level between release and fragmentation, and then the level above the fragmentation, that implicates the decrease in the wall friction.

The effect of modified potato flour substitution on the organoleptics characteristics of toddler biscuit

Science.gov (United States)

Cakrawati, Dewi; Rahmawati, Puji

2016-04-01

Toddler biscuit is complementary food given to infants to help meet their nutritional needs. This research was undertaken to develop toddler biscuit with subtitution of physically modified potato flour. There were two puposes of the research, first to know the characteristics of physically modification on potato flour; secondly to know biscuit characteristics with modified potato flour substitution. There were two factor analysis in the development of biscuit; first factor was pre heating mehods and substitution rate. The research was conducted with experimental method using split plot design. The functional properties on modified potato flour as swelling capacity, water absorption capacity, solubility and viscocity were analyzed. Organoleptic analysis using quality hedonic test showed no interaction between potato starch modification and concentration of modified potato flour. Quality hedonic test showed all toddler biscuit socred in the range of “slightly like” to “like moderately”. Modifying potato starch by boiling and steaming with flour concentration of 30% producing toddler biscuit with organoleptic characteristics acceptable according to the panelists.

Absence of high-temperature ballistic transport in the spin-1/2 XXX chain within the grand-canonical ensemble

Science.gov (United States)

Carmelo, J. M. P.; Prosen, T.

2017-01-01

Whether in the thermodynamic limit, vanishing magnetic field h → 0, and nonzero temperature the spin stiffness of the spin-1/2 XXX Heisenberg chain is finite or vanishes within the grand-canonical ensemble remains an unsolved and controversial issue, as different approaches yield contradictory results. Here we provide an upper bound on the stiffness and show that within that ensemble it vanishes for h → 0 in the thermodynamic limit of chain length L → ∞, at high temperatures T → ∞. Our approach uses a representation in terms of the L physical spins 1/2. For all configurations that generate the exact spin-S energy and momentum eigenstates such a configuration involves a number 2S of unpaired spins 1/2 in multiplet configurations and L - 2 S spins 1/2 that are paired within Msp = L / 2 - S spin-singlet pairs. The Bethe-ansatz strings of length n = 1 and n > 1 describe a single unbound spin-singlet pair and a configuration within which n pairs are bound, respectively. In the case of n > 1 pairs this holds both for ideal and deformed strings associated with n complex rapidities with the same real part. The use of such a spin 1/2 representation provides useful physical information on the problem under investigation in contrast to often less controllable numerical studies. Our results provide strong evidence for the absence of ballistic transport in the spin-1/2 XXX Heisenberg chain in the thermodynamic limit, for high temperatures T → ∞, vanishing magnetic field h → 0 and within the grand-canonical ensemble.

Reply to "Comment on 'Calculations for the one-dimensional soft Coulomb problem and the hard Coulomb limit' ".

Science.gov (United States)

Gebremedhin, Daniel H; Weatherford, Charles A

2015-02-01

This is a response to the comment we received on our recent paper "Calculations for the one-dimensional soft Coulomb problem and the hard Coulomb limit." In that paper, we introduced a computational algorithm that is appropriate for solving stiff initial value problems, and which we applied to the one-dimensional time-independent Schrödinger equation with a soft Coulomb potential. We solved for the eigenpairs using a shooting method and hence turned it into an initial value problem. In particular, we examined the behavior of the eigenpairs as the softening parameter approached zero (hard Coulomb limit). The commenters question the existence of the ground state of the hard Coulomb potential, which we inferred by extrapolation of the softening parameter to zero. A key distinction between the commenters' approach and ours is that they consider only the half-line while we considered the entire x axis. Based on mathematical considerations, the commenters consider only a vanishing solution function at the origin, and they question our conclusion that the ground state of the hard Coulomb potential exists. The ground state we inferred resembles a δ(x), and hence it cannot even be addressed based on their argument. For the excited states, there is agreement with the fact that the particle is always excluded from the origin. Our discussion with regard to the symmetry of the excited states is an extrapolation of the soft Coulomb case and is further explained herein.

Measure-valued solutions to the complete Euler system revisited

Science.gov (United States)

Březina, Jan; Feireisl, Eduard

2018-06-01

We consider the complete Euler system describing the time evolution of a general inviscid compressible fluid. We introduce a new concept of measure-valued solution based on the total energy balance and entropy inequality for the physical entropy without any renormalization. This class of so-called dissipative measure-valued solutions is large enough to include the vanishing dissipation limits of the Navier-Stokes-Fourier system. Our main result states that any sequence of weak solutions to the Navier-Stokes-Fourier system with vanishing viscosity and heat conductivity coefficients generates a dissipative measure-valued solution of the Euler system under some physically grounded constitutive relations. Finally, we discuss the same asymptotic limit for the bi-velocity fluid model introduced by H.Brenner.

Vanishing testes syndrome-related osteoporosis and high cardio-metabolic risk in an adult male with long term untreated hypergonadotropic hypogonadism.

Science.gov (United States)

Carsote, Mara; Capatina, Cristina; Valea, Ana; Dumitrascu, Anda

2016-02-01

The male hypogonadism-related bone mass loss is often under diagnosed. Peak bone mass is severely affected if the hypogonadism occurs during puberty and is left untreated. We present an interesting; almost bizarre case of a male with non-functional testes early during childhood and undiagnosed and untreated hypogonadism until his fifth decade of life. Forty six year male is referred for goitre, complaining of back pain. Phenotype suggested intersexuality: gynoid proportions, micropenis, no palpable testes into the scrotum, no facial or truncal hair. His medical history had been unremarkable until the previous year when primary hypothyroidism was diagnosed and levothyroxine replacement was initiated. Later, he was diagnosed with ischemic heart disease, with inaugural unstable angina. On admission, the testosterone was 0.2 ng/mL (normal: 1.7-7.8 ng/mL), FSH markedly increased (56 mUI/mL), with normal adrenal axis, and TSH (under thyroxine replacement). High bone turnover markers, and blood cholesterol, and impaired glucose tolerance were diagnosed. The testes were not present in the scrotum. Abdominal computed tomography suggested bilateral masses of 1.6 cm diameter within the abdominal fat that were removed but no gonadal tissue was confirmed histopathologically. Vanishing testes syndrome was confirmed. The central DXA showed lumbar bone mineral density of 0.905 g/cm2, Z-score of -2.9SD. The spine profile X-Ray revealed multiple thoracic vertebral fractures. Alendronate therapy together with vitamin D and calcium supplements and trans-dermal testosterone were started. Four decades of hypogonadism associate increased cardiac risk, as well as decreased bone mass and high fracture risk.

Surface terms and dual formulations of gauge theories

International Nuclear Information System (INIS)

Mecklenburg, W.; Mizrachi, L.

1982-09-01

Previously proposed duality transformations for a pure non-Abelian gauge theory are carried out for a Yang Mills theory with non-vanishing theta parameter. We argue that the theory is no longer self-dual even in the weak coupling limit, as there is a surface term generated by the duality transformation. This surface term has non-zero Pontryagin index hence it gets contributions from instanton type configurations only. However, it does vanish for monopoles and vortices, therefore for this set of configurations self-duality is maintained in the weak coupling region. (author)

The Ising model in the scaling limit as model for the description of elementary particles

International Nuclear Information System (INIS)

Weinzierl, W.

1981-01-01

In this thesis a possible way is stepped over which starts from the derivation of a quantum field theory from simplest statistical degrees of freedom, as for instance in a two-level system. On a model theory, the Ising model in (1+1) dimensions the idea is explained. In this model theory two particle-interpretable quantum fields arise which can be constructed by a basic field which parametrizes the local dynamics in a simplest way. This so called proliferation is further examined. For the proliferation of the basic field a conserved quantity, a kind of parity is necessary. The stability of both particle fields is a consequence of this conservation law. For the identification of the ''particle-interpretable'' fields the propagators of the order and disorder parameter field are calculated and discussed. An effective Hamiltonian in this particle fields is calculated. As further aspect of this transition from the statistical system to quantum field theory the dimensional transmutation and the closely to this connected mass renormalization is examined. The relation between spin systems in the critical region and fermionic field theories is explained. Thereby it results that certain fermionic degrees of freedom of the spin system vanish in the scaling limit. The ''macroscopically'' relevant degrees of freedom constitute a relativistic Majorana field. (orig./HSI) [de

Palaeolimnological evidence of vulnerability of Lake Neusiedl (Austria) toward climate related changes since the last "vanished-lake" stage.

Science.gov (United States)

Tolotti, Monica; Milan, Manuela; Boscaini, Adriano; Soja, Gerhard; Herzig, Alois

2013-04-01

The palaeolimnological reconstruction of secular evolution of Euroepan Lakes with key socio-economical relevance respect to large (climate change) and local scale (land use, tourism) environmental changes, represents one of the objectives of the project EuLakes (European Lakes Under Environmental Stressors, Supporting lake governance to mitigate the impact of climate change, Reg. N. 2CE243P3), launched in 2010 within the Central European Inititiative. The project consortium comprises lakes of different morphology and prevalent human uses, including the meso-eutrophic Lake Neusiedl, the largest Austrian lake (total area 315 km2), and the westernmost shallow (mean depth 1.2 m) steppe lake of the Euro-Asiatic continent. The volume of Lake Neusiedl can potentially change over the years, in relation with changing balance between atmospheric precipitation and lake water evapotranspiration. Changing water budget, together with high lake salinity and turbidity, have important implications over the lake ecosystem. This contribution illustrates results of the multi-proxi palaeolimnological reconstruction of ecologial changes occurred in Lake Neusiedl during the last ca. 140 years, i.e. since the end of the last "vanished-lake" stage (1865-1871). Geochemical and biological proxies anticipate the increase in lake productivity of ca. 10 years (1950s) respect to what reported in the literature. Diatom species composition indicate a biological lake recovery in the late 1980s, and suggest a second increment in lake productivity since the late 1990s, possibly in relation with the progressive increase in the nitrogen input from agriculture. Abundance of diatoms typical of brackish waters indicated no significant long-term change in lake salinity, while variations in species toleranting dessiccation confirm the vulnerability of Lake Neusiedl toward climate-driven changes in the lake water balance. This fragility is aggravated by the the semi-arid climate conditions of the catchemnt

Generalized 3D Zernike functions for analytic construction of band-limited line-detecting wavelets

OpenAIRE

Janssen, Augustus J. E. M.

2015-01-01

We consider 3D versions of the Zernike polynomials that are commonly used in 2D in optics and lithography. We generalize the 3D Zernike polynomials to functions that vanish to a prescribed degree $\\alpha\\geq0$ at the rim of their supporting ball $\\rho\\leq1$. The analytic theory of the 3D generalized Zernike functions is developed, with attention for computational results for their Fourier transform, Funk and Radon transform, and scaling operations. The Fourier transform of generalized 3D Zern...

D walls and junctions in supersymmetric gluodynamics in the large N limit suggest the existence of heavy hadrons

International Nuclear Information System (INIS)

Gabadadze, Gregory; Shifman, Mikhail

2000-01-01

A number of arguments exists that the ''minimal'' Bogomol'nyi-Prasad-Sommerfeld (BPS) wall width in large-N supersymmetric gluodynamics vanishes as 1/N. There is a certain tension between this assertion and the fact that the mesons coupled to λλ have masses O(N 0 ). To reconcile these facts we argue that there should exist additional solitonlike states with masses scaling as N. The BPS walls must be ''made'' predominantly of these heavy states which are coupled to λλ stronger than the conventional mesons. The tension of the BPS wall junction scales as N 2 , which serves as an additional argument in favor of the 1/N scaling of the wall width. The heavy states can be thought of as solitons of the corresponding closed string theory. They are related to certain fivebranes in the M-theory construction. We study the issue of the wall width in toy models which capture some features of supersymmetric gluodynamics. We speculate that the special hadrons with mass scaling as N should also exist in the large-N limit of nonsupersymmetric gluodynamics. (c) 2000 The American Physical Society

Vanishing White Matter Disease

Science.gov (United States)

... the ovaries, which can result in lack of menstrual periods, fertility problems and early menopause. Mental decline ... manner. This means that both parents carry one copy of a mutated eIF2B gene and pass it ...

Paperless or vanishing society

Science.gov (United States)

Turner Luke, Joy

2002-06-01

In the 1940s color photography became available and within a few years, extremely popular. As people switched from black and white photographs made with the old metallic silver process to the new color films, pictures taken to record their lives and families began a slow disappearing act. The various color processes, coupled with the substrates they were printed on, affected their longevity, but many color photographs taken from the late 1950s through the 1970s, and even into the 1980s, faded not only when exposed to the light, but also when stored in the dark. Henry Wilhelm's excellent book 'The Permanence and Care of Color Photographs' documents this history in detail. Today we are making another transition in the storage of pictures and information. There are questions about the longevity of different types of digital storage, and also of the images printed by various types of inkjet printers, or by laser printers using colored toners. Very expensive and very beautiful works of art produced on Iris printers are appearing in art exhibitions. Some of these are referred to as Giclee prints and are offered on excellent papers. Artists are told the prints will last a lifetime; and if by change they don't it is only necessary to make another print. Henry Wilhelm has begun to test and rate these images for lightfastness; however, his test method was developed for examining longevity in colored photographs. It is of interest to find out how these prints will hold up in the tests required for fine art materials. Thus far companies producing digital inks and printers have not invested the time and money necessary to develop an American Society for Testing and Materials (ASTM) standard method for evaluating the lightfastness of digital prints. However, it is possible to use ASTM D 5383, Standard Practice for Visual Determination of the Lightfastness of Art Materials by Art Technologists, to pinpoint colors that will fade in a short time, even though the test is not as severe as ASTM D 4303, which is used to rate the lightfastness of artists's paint.

Vanishing tumor in pregnancy

Directory of Open Access Journals (Sweden)

M V Vimal

2012-01-01

Full Text Available A patient with microprolactinoma, who had two successful pregnancies, is described for management issues. First pregnancy was uneventful. During the second pregnancy, the tumor enlarged to macroprolactinoma with headache and blurring of vision which was managed successfully with bromocriptine. Post delivery, complete disappearance of the tumor was documented.

Vanishing tumor in pregnancy

Science.gov (United States)

Vimal, M. V.; Budyal, Sweta; Kasliwal, Rajeev; Jagtap, Varsha S.; Lila, Anurag R.; Bandgar, Tushar; Menon, Padmavathy; Shah, Nalini S.

2012-01-01

A patient with microprolactinoma, who had two successful pregnancies, is described for management issues. First pregnancy was uneventful. During the second pregnancy, the tumor enlarged to macroprolactinoma with headache and blurring of vision which was managed successfully with bromocriptine. Post delivery, complete disappearance of the tumor was documented. PMID:23226664

An asymptotic formula for the free energy density of ideal quantum gases

International Nuclear Information System (INIS)

Mackowiak, J.

1988-01-01

It is shown that the expressions for the free energy density of ideal quantum gases in the canonical and grand canonical ensembles, are identical up to additive terms which vanish in the thermodynamic limit. (orig.)

Differential calculus for q-deformed twistors

International Nuclear Information System (INIS)

Akulov, V.P.; Duplij, S.A.; Chitov, V.V.

1998-01-01

Brief type of q-deformed differential calculus at light cone with using of twistor representation is suggested. Commutative relations between coordinates and moments are obtained. Considered quasiclassical limit gives exact form of vanish from mass shell

Finite-time singularities and flow regularization in a hydromagnetic shell model at extreme magnetic Prandtl numbers

International Nuclear Information System (INIS)

Nigro, G; Carbone, V

2015-01-01

Conventional surveys on the existence of singularities in fluid systems for vanishing dissipation have hitherto tried to infer some insight by searching for spatial features developing in asymptotic regimes. This approach has not yet produced a conclusive answer. One of the difficulties preventing us from getting a definitive answer is the limitations of direct numerical simulations which do not yet have a high enough resolution so far as to properly describe spatial fine structures in asymptotic regimes. In this paper, instead of searching for spatial details, we suggest seeking a principle, that would be able to discriminate between singular or not-singular behavior, among the integral and purely dynamical properties of a fluid system. We investigate the singularities developed by a hydromagnetic shell model during the magnetohydrodynamic turbulent cascade. Our results show that when the viscosity is equal to the magnetic diffusivity (unit magnetic Prandtl number) singularities appear in a finite time. A complex behavior is observed at extreme magnetic Prandtl numbers. In particular, the singularities persist in the limit of vanishing viscosity, while a complete regularization is observed in the limit of vanishing diffusivity. This dynamics is related to differences between the magnetic and the kinetic energy cascades towards small scales. Finally a comparison between the three-dimensional and the two-dimensional cases leads to conjecture that the existence of singularities may be related to the conservation of different ideal invariants. (paper)

Fermionic field perturbations of a three-dimensional Lifshitz black hole in conformal gravity

Energy Technology Data Exchange (ETDEWEB)

Gonzalez, P.A. [Facultad de Ingenieria y Ciencias, Universidad Diego Portales, Santiago (Chile); Vasquez, Yerko; Villalobos, Ruth Noemi [Universidad de La Serena, Departamento de Fisica y Astronomia, Facultad de Ciencias, La Serena (Chile)

2017-09-15

We study the propagation of massless fermionic fields in the background of a three-dimensional Lifshitz black hole, which is a solution of conformal gravity. The black-hole solution is characterized by a vanishing dynamical exponent. Then we compute analytically the quasinormal modes, the area spectrum, and the absorption cross section for fermionic fields. The analysis of the quasinormal modes shows that the fermionic perturbations are stable in this background. The area and entropy spectrum are evenly spaced. In the low frequency limit, it is observed that there is a range of values of the angular momentum of the mode that contributes to the absorption cross section, whereas it vanishes in the high frequency limit. In addition, by a suitable change of variables a gravitational soliton can also be obtained and the stability of the quasinormal modes are studied and ensured. (orig.)

Invited talk: Deep Learning Meets Physics

CERN Multimedia

CERN. Geneva

2018-01-01

Deep Learning has emerged as one of the most successful fields of machine learning and artificial intelligence with overwhelming success in industrial speech, text and vision benchmarks. Consequently it evolved into the central field of research for IT giants like Google, facebook, Microsoft, Baidu, and Amazon. Deep Learning is founded on novel neural network techniques, the recent availability of very fast computers, and massive data sets. In its core, Deep Learning discovers multiple levels of abstract representations of the input. The main obstacle to learning deep neural networks is the vanishing gradient problem. The vanishing gradient impedes credit assignment to the first layers of a deep network or to early elements of a sequence, therefore limits model selection. Major advances in Deep Learning can be related to avoiding the vanishing gradient like stacking, ReLUs, residual networks, highway networks, and LSTM. For Deep Learning, we suggested self-normalizing neural networks (SNNs) which automatica...

The Cosmological Constant and Domain Walls in Orientifold Field Theories and N=1 Gluodynamics

CERN Document Server

Armoni, Adi

2003-01-01

We discuss domain walls and vacuum energy density (cosmological constant) in N=1 gluodynamics and in non-supersymmetric large N orientifold field theories which have been recently shown to be planar equivalent (in the boson sector) to N=1 gluodynamics. A relation between the vanishing force between two parallel walls and vanishing cosmological constant is pointed out. This relation may explain why the cosmological constant vanishes in the orientifold field theory at leading order although the hadronic spectrum of this theory does not contain fermions in the limit N-->infinity. The cancellation is among even and odd parity bosonic contributions, due to NS-NS and R-R cancellations in the annulus amplitude of the underlying string theory. We use the open-closed string channel duality to describe interaction between the domain walls which is interpreted as the exchange of composite ``dilatons'' and ``axions'' coupled to the walls. Finally, we study some planar equivalent pairs in which both theories in the parent...

Topological transport from a black hole

Directory of Open Access Journals (Sweden)

Dmitry Melnikov

2018-03-01

Full Text Available In this paper the low temperature zero-frequency transport in a 2+1-dimensional theory dual to a dyonic black hole is discussed. It is shown that transport exhibits topological features: the transverse electric and heat conductivities satisfy the Wiedemann–Franz law of free electrons; the direct heat conductivity is measured in units of the central charge of CFT2+1, while the direct electric conductivity vanishes; the thermoelectric conductivity is non-zero at vanishing temperature, while the O(T behavior, controlled by the Mott relation, is subleading. Provided that the entropy of the black hole, and the dual system, is non-vanishing at T=0, the observations indicate that the dyonic black hole describes a ħ→0 limit of a highly degenerate topological state, in which the black hole charge measures the density of excited non-abelian quasiparticles. The holographic description gives further evidence that non-abelian nature of quasiparticles can be determined by the low temperature behavior of the thermoelectric transport.

Transport in ratchets with single-file constraint

Indian Academy of Sciences (India)

file diffusion” in the literature. Anomaly in protein molecule diffusion on a cell ... tic media [20]. The rectification effect vanishes in the adiabatically slow modulation limit and optimizes in a driving frequency range. In other related work on flash-.

7 CFR 1400.204 - Limited partnerships, limited liability partnerships, limited liability companies, corporations...

Science.gov (United States)

2010-01-01

... 7 Agriculture 10 2010-01-01 2010-01-01 false Limited partnerships, limited liability partnerships..., limited liability partnerships, limited liability companies, corporations, and other similar legal entities. (a) A limited partnership, limited liability partnership, limited liability company, corporation...

Anticavitation and Differential Growth in Elastic Shells

KAUST Repository

Moulton, Derek E.; Goriely, Alain

2010-01-01

infinite growth or resorption is imposed at the inner surface of the shell. However, void collapse can occur in a limiting sense when radial and circumferential growth are properly balanced. Growth functions which diverge or vanish at a point arise

Ground states of a spin-boson model

International Nuclear Information System (INIS)

Amann, A.

1991-01-01

Phase transition with respect to ground states of a spin-boson Hamiltonian are investigated. The spin-boson model under discussion consists of one spin and infinitely many bosons with a dipole-type coupling. It is shown that the order parameter of the model vanishes with respect to arbitrary ground states if it vanishes with respect to ground states obtained as (biased) temperature to zero limits of thermic equilibrium states. The ground states of the latter special type have been investigated by H. Spohn. Spohn's respective phase diagrams are therefore valid for arbitrary ground states. Furthermore, disjointness of ground states in the broken symmetry regime is examined

When the asymptotic limit offers no advantage in the local-operations-and-classical-communication paradigm

Science.gov (United States)

Fu, Honghao; Leung, Debbie; Mančinska, Laura

2014-05-01

We consider bipartite LOCC, the class of operations implementable by local quantum operations and classical communication between two parties. Surprisingly, there are operations that can be approximated to arbitrary precision but are impossible to implement exactly if only a finite number of messages are exchanged. This significantly complicates the analysis of what can or cannot be approximated with LOCC. Toward alleviating this problem, we exhibit two scenarios in which allowing vanishing error does not help. The first scenario is implementation of projective measurements with product measurement operators. The second scenario is the discrimination of unextendable product bases on two three-dimensional systems.

Universal restrictions to the conversion of heat into work derived from the analysis of the Nernst theorem as a uniform limit

International Nuclear Information System (INIS)

Martin-Olalla, Jose Maria; Luna, Alfredo Rey de

2003-01-01

We revisit the relationship between the Nernst theorem and the Kelvin-Planck statement of the second law. We propose that the exchange of entropy uniformly vanishes as the temperature goes to zero. The analysis of this assumption shows that is equivalent to the fact that the compensation of a Carnot engine scales with the absorbed heat so that the Nernst theorem should be embedded in the statement of the second law

PENGARUH UMUR PANEN RUMPUT LAUT Eucheuma cottonii TERHADAP SIFAT FISIK, KIMIA DAN FUNGSIONAL KARAGENAN Effect of Harvest Time of Seaweed Eucheuma cottonii on Physical, Chemical and Fungsional Properties of Carra- geenan

Directory of Open Access Journals (Sweden)

Djagal W. Marseno

2012-05-01

Full Text Available The aim of this study was to evaluate the effect of different harvesting times of Eucheuma cottonii on both physical, chemical and functional properties of carrageenan. Seaweed Eucheuma cottonii was obtained from water territorial of Tablolong Kupang. The study was carried out into two steps. The first step was to investigate the effect of harvesting time of 30, 45, and 60 days after planting on physical and chemical properties of obtained carrageenan. The second step was to study the effect of functional properties of obtained carrageenan on viscocity and the stability of tomato sauce. The results showed that seaweed which was harvested in 45 days after planting has good physical and chemical properties of carrageenan in term of moisture 12.45 %; protein 5.03 %; extract ether 1.40 %; ash 21.29 %; carbohy- drate 72.28 %; sulphate 19.69 %; and crude extract 48.20 %. The obtained carrageenan at concentration of 1,5%, also give highest viscocity of 11.50-45 cps and gel strength of 0.8961-4.0709 kg/cm2. Further identification show that the obtained carrageenan produced was classified as kappa carrageenan and at 0,2 % (w/v was able to stabilize tomato sauce up to 86 % and viscosity of 60 cps after 2 weeks of storage at room temperature. ABSTRAK Tujuan penelitian adalah mengkaji sifat fisik dan kimia karagenan yang diperoleh dari rumput laut Eucheuma cot- tonii pada umur panen yang berbeda dari perairan Tablolong Kupang dan mengetahui sifat fungsionalnya sebagai stabilizer dan thickener dalam saos tomat. Penelitian diawali dengan menanam rumput laut pada interval tanam yang berbeda, sehingga pada saat panen yang bersamaan diperoleh rumput laut dengan umur yang berbeda yaitu 30, 45,60 hari. Tahap berikutnya adalah ekstraksi dan karakterisasi karaginan yang dihasilkan, kemudian aplikasi karaginan yang diperoleh untuk menjaga stabilitas viskositas saos tomat pada konsentrasi karagenan (0,1 %, 0,15 %, 0,2 % b/v. Hasil penelitian menunjukkan bahwa

Scaling of the polarization amplitude in quantum many-body systems in one dimension

Science.gov (United States)

Kobayashi, Ryohei; Nakagawa, Yuya O.; Fukusumi, Yoshiki; Oshikawa, Masaki

2018-04-01

Resta proposed a definition of the electric polarization in one-dimensional systems in terms of the ground-state expectation value of the large gauge transformation operator. Vanishing of the expectation value in the thermodynamic limit implies that the system is a conductor. We study Resta's polarization amplitude (expectation value) in the S =1 /2 XXZ chain and its several generalizations, in the gapless conducting Tomonaga-Luttinger liquid phase. We obtain an analytical expression in the lowest-order perturbation theory about the free fermion point (XY chain) and an exact result for the Haldane-Shastry model with long-range interactions. We also obtain numerical results, mostly using the exact diagonalization method. We find that the amplitude exhibits a power-law scaling in the system size (chain length) and vanishes in the thermodynamic limit. On the other hand, the exponent depends on the model even when the low-energy limit is described by the Tomonaga-Luttinger liquid with the same Luttinger parameter. We find that a change in the exponent occurs when the Umklapp term(s) are eliminated, suggesting the importance of the Umklapp terms.

Gravitating monopole-antimonopole chains and vortex rings

International Nuclear Information System (INIS)

Kleihaus, Burkhard; Kunz, Jutta; Shnir, Yasha

2005-01-01

We construct monopole-antimonopole chain and vortex solutions in Yang-Mills-Higgs theory coupled to Einstein gravity. The solutions are static, axially symmetric, and asymptotically flat. They are characterized by two integers (m,n) where m is related to the polar angle and n to the azimuthal angle. Solutions with n=1 and n=2 correspond to chains of m monopoles and antimonopoles. Here the Higgs field vanishes at m isolated points along the symmetry axis. Larger values of n give rise to vortex solutions, where the Higgs field vanishes on one or more rings, centered around the symmetry axis. When gravity is coupled to the flat space solutions, a branch of gravitating monopole-antimonopole chain or vortex solutions arises and merges at a maximal value of the coupling constant with a second branch of solutions. This upper branch has no flat space limit. Instead in the limit of vanishing coupling constant it either connects to a Bartnik-McKinnon or generalized Bartnik-McKinnon solution, or, for m>4, n>4, it connects to a new Einstein-Yang-Mills solution. In this latter case further branches of solutions appear. For small values of the coupling constant on the upper branches, the solutions correspond to composite systems, consisting of a scaled inner Einstein-Yang-Mills solution and an outer Yang-Mills-Higgs solution

Large-Nc quantum chromodynamics and harmonic sums

Indian Academy of Sciences (India)

2012-06-08

Jun 8, 2012 ... This has led us to consider a class of analytic number theory .... The self-energy function LR(Q2) in the chiral limit vanishes order by order in QCD ... the 1/Nc expansion, the Goldstone loop corrections are subleading and, ...

Short-distance Schwinger-mechanism and chiral symmetry

DEFF Research Database (Denmark)

McGady, David A.; Brogård, Jon

2017-01-01

rates depend only on the ratio between the capacitor plate separation, $\\ell$, and the length-scale of the force-field, $\\ell_F$. Chirality ensures that fermion production smoothly vanishes with $\\ell/\\ell_F$. Scalar pair production though diverges exponentially quickly in this limit. The same limit...... of the smooth tanh-potential does not diverge; divergences seem tied to singularities in current and charge densities....

A search for the electric dipole moment of the neutron

International Nuclear Information System (INIS)

Lobashev, V.M.

1982-01-01

The experimental search for the electric dipole moment of the neutron, a possible manifestation of CP violation is reviewed. The existence of non-vanishing electric dipole moment of the neutron is predicted by different theories but the recent experiments are not sensitive enough to distinguish between the theories. The latest experimental limits and the expected results on limits of new, planned experiments are discussed. (D.Gy.)

A comment on compactification of M-theory on an (almost) light-like circle

International Nuclear Information System (INIS)

Bilal, A.

1998-01-01

In perturbative quantum field theory the limit of compactification on an almost light-like circle has recently been shown to be plagued by divergences. We argue that the light-like limit for M-theory probably is free of such divergences due to, among others, the existence of the wrapping modes of the membranes. To illustrate this, we consider superstring theory compactified on an almost light-like circle. Specifically, we compute a one-loop four-point amplitude in type II theory. As is well known, if the external states have vanishing momenta in the compact dimension, the divergence in the light-like limit is even stronger than in field theory. However, in the case of present interest, where these external momenta are non-vanishing, there is a subtle compensation and the resulting amplitude has a well defined and finite light-like limit. The net effect of taking the light-like limit is to replace the integration over one of the moduli of the four-punctured torus by a sum over a discrete modulus taking values in a finite lattice on the torus. The same result can also be obtained from a suitably ''Wick rotated'' amplitude computed directly with a compact light-like circle. (orig.)

Geometric Thermodynamics: Black Holes and the Meaning of the Scalar Curvature

Directory of Open Access Journals (Sweden)

Miguel Ángel García-Ariza

2014-12-01

Full Text Available In this paper we show that the vanishing of the scalar curvature of Ruppeiner-like metrics does not characterize the ideal gas. Furthermore, we claim through an example that flatness is not a sufficient condition to establish the absence of interactions in the underlying microscopic model of a thermodynamic system, which poses a limitation on the usefulness of Ruppeiner’s metric and conjecture. Finally, we address the problem of the choice of coordinates in black hole thermodynamics. We propose an alternative energy representation for Kerr-Newman black holes that mimics fully Weinhold’s approach. The corresponding Ruppeiner’s metrics become degenerate only at absolute zero and have non-vanishing scalar curvatures.

The hype cycle in 3D displays: inherent limits of autostereoscopy

Science.gov (United States)

Grasnick, Armin

2013-06-01

Since a couple of years, a renaissance of 3dimensional cinema can be observed. Even though the stereoscopy was quite popular within the last 150 years, the 3d cinema has disappeared and re-established itself several times. The first boom in the late 19th century stagnated and vanished after a few years of success, the same happened again in 50's and 80's of the 20th century. With the commercial success of the 3d blockbuster "Avatar" in 2009, at the latest, it is obvious that the 3d cinema is having a comeback. How long will it last this time? There are already some signs of a declining interest in 3d movies, as the discrepancy between expectations and the results delivered becomes more evident. From the former hypes it is known: After an initial phase of curiosity (high expectations and excessive fault tolerance), a phase of frustration and saturation (critical analysis and subsequent disappointment) will follow. This phenomenon is known as "Hype Cycle" The everyday experienced evolution of technology has conditioned the consumers. The expectation "any technical improvement will preserve all previous properties" cannot be fulfilled with present 3d technologies. This is an inherent problem of stereoscopy and autostereoscopy: The presentation of an additional dimension caused concessions in relevant characteristics (i.e. resolution, brightness, frequency, viewing area) or leads to undesirable physical side effects (i.e. subjective discomfort, eye strain, spatial disorientation, feeling of nausea). It will be verified that the 3d apparatus (3d glasses or 3d display) is also the source for these restrictions and a reason for decreasing fascination. The limitations of present autostereoscopic technologies will be explained.

Captivate the customer or vanish

International Nuclear Information System (INIS)

Regis, J.

1994-01-01

Throughout its expansion program in the 1960s and its energy efficiency programs in the 1970s and 1980s, Hydro-Quebec had a satisfactory proportion of satisfied customers. However, at the end of the 1980s, the utility's customer satisfaction rating slipped below 50% for the first time. Hydro-Quebec's first response was to re-establish transmission system reliability. Service interruptions per customer were reduced from 10 h/y in 1989 to just over 4 h in 1993. Starting in 1990, the utility devised a strategy aimed at fully integrated quality management, with customer service as the top priority. A series of performance commitments was adopted which pinpointed 27 specific targets, each linked to a specific activity; of those targets, 16 are directly related to customer service. A training plan was developed which makes the customer the focus of every action taken by a Hydro-Quebec employee, and office hours have been reorganized in response to constantly evolving customer needs. A courtesy call strategy has been adopted to anticipate customer expectations before they are expressed. Highly personalized and accurately targeted informational tools have been developed for each customer category and a toll-free energy efficiency hotline has been established. Energy efficiency publications are distributed to business and residential customers. Satisfaction with Hydro-Quebec activities rose from 77% in 1992 to 93% in 1993, and credibility in energy efficiency rose from 73% to 85%. A new project being investigated is an electronic superhighway with a variety of customer applications including home automation, load and meter telecontrol, telebilling, and direct payment

Interacting quantum wires: A possible explanation for the 0.7 anomalous conductance

International Nuclear Information System (INIS)

Malard, M.; Schmeltzer, D.; Kuklov, A.

2009-01-01

We investigate an effective one-dimensional conducting channel considering both the contact umklapp and the Coulomb electron-electron interaction. We show that, at low electronic density, the proximity to the Wigner crystal reproduces the anomaly in conductance at 0.7G 0 . The crucial ingredient of our theory is the fact that the gate voltage acts as a bias controlling the intensity of the umklapp term. At large gate voltages, the umklapp vanishes and we obtain a conducting quantum wire with a perfect conductance. At low gate voltages, the Wigner crystal is pinned by the umklapp term, giving rise to an insulating behavior with vanishing conductance. This crossover pattern has a transition point which can be identified with the anomalous conductance around 0.7G 0 . This picture is obtained within the framework of a renormalization group calculation. The conductance static regime is achieved by taking first the limit of finite length and then the limit of zero frequency.

Annihilation diagrams in two-body nonleptonic decays of charmed mesons

International Nuclear Information System (INIS)

Bedaque, P.; Das, A.; Mathur, V.S.

1994-06-01

In the pole-dominance model for the two-body nonleptonic decays of charmed mesons D → PV and D → VV, it is shown that the contributions of the intermediate pseudoscalar and the axial-vector meson poles cancel each other in the annihilation diagrams in the chiral limit. In the same limit, the annihilation diagrams for the D → PP decays vanish independently. (author). 6 refs, 3 figs

Distinct Nature of Static and Dynamic Magnetic Stripes in Cuprate Superconductors

DEFF Research Database (Denmark)

Jacobsen, H.; Holm, S. L.; Lăcătuşu, M. E.

2018-01-01

We present detailed neutron scattering studies of the static and dynamic stripes in an optimally doped high-Temperature superconductor, La2CuO4+y. We observe that the dynamic stripes do not disperse towards the static stripes in the limit of vanishing energy transfer. Therefore, the dynamic stripes...

Breakdown of the Siegert theorem and the many-body charge density operators

International Nuclear Information System (INIS)

Hyuga, H.; Ohtsubo, H.

1978-01-01

The exchange charge density operator is studied in the two-boson exchange model with consistent treatment of the exchange current and nuclear wave functions. A non-vanishing exchange charge density operator even in the static limit, which leads to the breakdown of the Siegert theorem, is found. (Auth.)

Transition radiation of ultrarelativistic neutral particles

International Nuclear Information System (INIS)

Grimus, W.; Neufeld, H.

1994-10-01

We perform a quantum theoretical calculation of transition radiation by neutral particles with spin 1/2 equipped with magnetic moments and/or electric dipole moments. The limit of vanishing masses is treated exactly for arbitrary refraction index. Finally we apply our result to the solar neutrino flux. (author)

Boundary description of Planckian scattering in curved spacetimes

NARCIS (Netherlands)

Arcioni, G.; Haro, S. de; O'Loughlin, M.

2001-01-01

We show that for an eikonal limit of gravity in a space-time of any dimension with a non-vanishing cosmological constant, the Einstein - Hilbert action reduces to a boundary action. This boundary action describes the interaction of shock-waves up to the point ofevolution at which the forward

Critical behavior of the compact 3D U(1) theory in the limit of zero spatial coupling

International Nuclear Information System (INIS)

Borisenko, O; Gravina, M; Papa, A

2008-01-01

Critical properties of the compact three-dimensional U(1) lattice gauge theory are explored at finite temperatures on an asymmetric lattice. For vanishing value of the spatial gauge coupling one obtains an effective two-dimensional spin model which describes the interaction between Polyakov loops. We study numerically the effective spin model for N t = 1,4,8 on lattices with spatial extent ranging from L = 64 to 256. Our results indicate that the finite temperature U(1) lattice gauge theory belongs to the universality class of the two-dimensional XY model, thus supporting the Svetitsky–Yaffe conjecture

Casimir free energy of dielectric films: classical limit, low-temperature behavior and control.

Science.gov (United States)

Klimchitskaya, G L; Mostepanenko, V M

2017-07-12

The Casimir free energy of dielectric films, both free-standing in vacuum and deposited on metallic or dielectric plates, is investigated. It is shown that the values of the free energy depend considerably on whether the calculation approach used neglects or takes into account the dc conductivity of film material. We demonstrate that there are material-dependent and universal classical limits in the former and latter cases, respectively. The analytic behavior of the Casimir free energy and entropy for a free-standing dielectric film at low temperature is found. According to our results, the Casimir entropy goes to zero when the temperature vanishes if the calculation approach with neglected dc conductivity of a film is employed. If the dc conductivity is taken into account, the Casimir entropy takes the positive value at zero temperature, depending on the parameters of a film, i.e. the Nernst heat theorem is violated. By considering the Casimir free energy of SiO 2 and Al 2 O 3 films deposited on a Au plate in the framework of two calculation approaches, we argue that physically correct values are obtained by disregarding the role of dc conductivity. A comparison with the well known results for the configuration of two parallel plates is made. Finally, we compute the Casimir free energy of SiO 2 , Al 2 O 3 and Ge films deposited on high-resistivity Si plates of different thicknesses and demonstrate that it can be positive, negative and equal to zero. The effect of illumination of a Si plate with laser light is considered. Possible applications of the obtained results to thin films used in microelectronics are discussed.

Casimir free energy of dielectric films: classical limit, low-temperature behavior and control

Science.gov (United States)

Klimchitskaya, G. L.; Mostepanenko, V. M.

2017-07-01

The Casimir free energy of dielectric films, both free-standing in vacuum and deposited on metallic or dielectric plates, is investigated. It is shown that the values of the free energy depend considerably on whether the calculation approach used neglects or takes into account the dc conductivity of film material. We demonstrate that there are material-dependent and universal classical limits in the former and latter cases, respectively. The analytic behavior of the Casimir free energy and entropy for a free-standing dielectric film at low temperature is found. According to our results, the Casimir entropy goes to zero when the temperature vanishes if the calculation approach with neglected dc conductivity of a film is employed. If the dc conductivity is taken into account, the Casimir entropy takes the positive value at zero temperature, depending on the parameters of a film, i.e. the Nernst heat theorem is violated. By considering the Casimir free energy of SiO2 and Al2O3 films deposited on a Au plate in the framework of two calculation approaches, we argue that physically correct values are obtained by disregarding the role of dc conductivity. A comparison with the well known results for the configuration of two parallel plates is made. Finally, we compute the Casimir free energy of SiO2, Al2O3 and Ge films deposited on high-resistivity Si plates of different thicknesses and demonstrate that it can be positive, negative and equal to zero. The effect of illumination of a Si plate with laser light is considered. Possible applications of the obtained results to thin films used in microelectronics are discussed.

Nonlinear mode coupling in rotating stars and the r-mode instability in neutron stars

International Nuclear Information System (INIS)

Schenk, A.K.; Arras, P.; Flanagan, E.E.; Teukolsky, S.A.; Wasserman, I.

2002-01-01

entirely and the coupling of two r modes to one hybrid, or r-g rotational, mode vanishes to zeroth order in rotation frequency. The coupling of any three rotational modes vanishes to zeroth order in compressibility and in Ω. In nonzero-buoyancy stars, coupling of the r modes to each other vanishes to zeroth order in Ω. Couplings to regular modes (those modes whose frequencies are finite in the limit Ω→0), such as f modes, are not zero, but since the natural frequencies of these modes are relatively large in the slow rotation limit compared to those of the r modes, energy transfer to those modes is not expected to be efficient

Limits on fundamental limits to computation.

Science.gov (United States)

Markov, Igor L

2014-08-14

An indispensable part of our personal and working lives, computing has also become essential to industries and governments. Steady improvements in computer hardware have been supported by periodic doubling of transistor densities in integrated circuits over the past fifty years. Such Moore scaling now requires ever-increasing efforts, stimulating research in alternative hardware and stirring controversy. To help evaluate emerging technologies and increase our understanding of integrated-circuit scaling, here I review fundamental limits to computation in the areas of manufacturing, energy, physical space, design and verification effort, and algorithms. To outline what is achievable in principle and in practice, I recapitulate how some limits were circumvented, and compare loose and tight limits. Engineering difficulties encountered by emerging technologies may indicate yet unknown limits.

Vanishing bone disease (Gorham′s disease - A rare occurrence of unknown etiology

Directory of Open Access Journals (Sweden)

Sumit Ray

2012-01-01

Full Text Available A 20-year-old male patient presented with painful swelling around left elbow joint. Radiographic examination revealed osteolytic lesion with pathological fracture of lower end of humerus and upper radius. Upper end of ulna was completely absent along with bony erosion. Histopathology of the bony tissue revealed hemangioma-like lesion composed of vascular channels lined by benign endothelium replacing bone. The diagnosis of Gorham′s massive osteolysis was made. Gorham′s disease is a benign self-limiting condition affecting any age, may involve any part of the skeleton and is characterized by replacement of bone by hemangiomatous tissue resulting in formation of lesions exhibiting massive osteolysis, which may be to the extent of disappearance of the affected bone in radiograph. This nonhereditary case was not associated with nephropathy, which is often a coexistent condition. The case is being reported for its rarity.

Partnerships – Limited partnerships and limited liability limited partnerships

OpenAIRE

Henning, Johan J.

2000-01-01

Consideration of the Limited Liability Partnership Act 2000 which introduced a new corporate entity, carrying the designations “partnership” and “limited” which allow members to limit their liability whilst organising themselves internally as a partnership. Article by Professor Johan Henning (Director of the Centre for Corporate Law and Practice, IALS and Dean of the Faculty of Law, University of the Free State, South Africa). Published in Amicus Curiae - Journal of the Institute of Advanced ...

The limitation and modification of flux-limited diffusion theory

International Nuclear Information System (INIS)

Liu Chengan; Huang Wenkai

1986-01-01

The limitation of various typical flux-limited diffusion theory and advantages of asymptotic diffusion theory with time absorption constant are analyzed and compared. The conclusions are as following: Though the flux-limited problem in neutron diffusion theory are theoretically solved by derived flux-limited diffusion equation, it's going too far to limit flux due to the inappropriate assumption in deriving flux-limited diffusion equation. The asymptotic diffusion theory with time absorption constant has eliminated the above-mentioned limitation, and it is more accurate than flux-limited diffusion theory in describing neutron transport problem

Pramana – Journal of Physics | Indian Academy of Sciences

Indian Academy of Sciences (India)

... Bose–Einstein condensation temperature by treating the gas cloud as a canonical ensemble of non-interacting classical particles. The static structure factor is found to vanish ∝ q 2 in the long-wavelength limit. We also incorporate a relaxation mechanism phenomenologically by including a stochastic friction force to study ...

Current limiters

Energy Technology Data Exchange (ETDEWEB)

Loescher, D.H. [Sandia National Labs., Albuquerque, NM (United States). Systems Surety Assessment Dept.; Noren, K. [Univ. of Idaho, Moscow, ID (United States). Dept. of Electrical Engineering

1996-09-01

The current that flows between the electrical test equipment and the nuclear explosive must be limited to safe levels during electrical tests conducted on nuclear explosives at the DOE Pantex facility. The safest way to limit the current is to use batteries that can provide only acceptably low current into a short circuit; unfortunately this is not always possible. When it is not possible, current limiters, along with other design features, are used to limit the current. Three types of current limiters, the fuse blower, the resistor limiter, and the MOSFET-pass-transistor limiters, are used extensively in Pantex test equipment. Detailed failure mode and effects analyses were conducted on these limiters. Two other types of limiters were also analyzed. It was found that there is no best type of limiter that should be used in all applications. The fuse blower has advantages when many circuits must be monitored, a low insertion voltage drop is important, and size and weight must be kept low. However, this limiter has many failure modes that can lead to the loss of over current protection. The resistor limiter is simple and inexpensive, but is normally usable only on circuits for which the nominal current is less than a few tens of milliamperes. The MOSFET limiter can be used on high current circuits, but it has a number of single point failure modes that can lead to a loss of protective action. Because bad component placement or poor wire routing can defeat any limiter, placement and routing must be designed carefully and documented thoroughly.

The refractive index of curved spacetime II: QED, Penrose limits and black holes

International Nuclear Information System (INIS)

Hollowood, Timothy J.; Shore, Graham M.; Stanley, Ross J.

2009-01-01

This work considers the way that quantum loop effects modify the propagation of light in curved space. The calculation of the refractive index for scalar QED is reviewed and then extended for the first time to QED with spinor particles in the loop. It is shown how, in both cases, the low frequency phase velocity can be greater than c, as found originally by Drummond and Hathrell, but causality is respected in the sense that retarded Green functions vanish outside the lightcone. A 'phenomenology' of the refractive index is then presented for black holes, FRW universes and gravitational waves. In some cases, some of the polarization states propagate with a refractive index having a negative imaginary part indicating a potential breakdown of the optical theorem in curved space and possible instabilities.

Beam-limiting and radiation-limiting interlocks

International Nuclear Information System (INIS)

Macek, R.J.

1996-01-01

This paper reviews several aspects of beam-limiting and radiation- limiting interlocks used for personnel protection at high-intensity accelerators. It is based heavily on the experience at the Los Alamos Neutron Science Center (LANSCE) where instrumentation-based protection is used extensively. Topics include the need for ''active'' protection systems, system requirements, design criteria, and means of achieving and assessing acceptable reliability. The experience with several specific devices (ion chamber-based beam loss interlock, beam current limiter interlock, and neutron radiation interlock) designed and/or deployed to these requirements and criteria is evaluated

Stability properties of the Euler-Korteweg system with nonmonotone pressures

KAUST Repository

Giesselmann, Jan

2016-12-21

We establish a relative energy framework for the Euler-Korteweg system with non-convex energy. This allows us to prove weak-strong uniqueness and to show convergence to a Cahn-Hilliard system in the large friction limit. We also use relative energy to show that solutions of Euler-Korteweg with convex energy converge to solutions of the Euler system in the vanishing capillarity limit, as long as the latter admits sufficiently regular strong solutions.

Material limitations on the detection limit in refractometry.

Science.gov (United States)

Skafte-Pedersen, Peder; Nunes, Pedro S; Xiao, Sanshui; Mortensen, Niels Asger

2009-01-01

We discuss the detection limit for refractometric sensors relying on high-Q optical cavities and show that the ultimate classical detection limit is given by min {Δn} ≳ η, with n + iη being the complex refractive index of the material under refractometric investigation. Taking finite Q factors and filling fractions into account, the detection limit declines. As an example we discuss the fundamental limits of silicon-based high-Q resonators, such as photonic crystal resonators, for sensing in a bio-liquid environment, such as a water buffer. In the transparency window (λ ≳ 1100 nm) of silicon the detection limit becomes almost independent on the filling fraction, while in the visible, the detection limit depends strongly on the filling fraction because the silicon absorbs strongly.

Oliver Sacks: Our Correspondence About Twins/Twin Research: Vanishing Twins Syndrome; Discordant Sex in MZ Twins; Pregnancy Outcomes in IVF and ICSI Conceived Twins/Print and Media: Superfetated Twins; Twins Discordant for Smoking; Twins in Fashion; Yale University Twin Hockey Players; Conjoined Twin-Visiting Professor.

Science.gov (United States)

Segal, Nancy L

2017-08-01

The late neurologist and author, Oliver Sacks, published an insightful 1986 review of Marjorie Wallace's book, The Silent Twins, in the New York Times. Taking exception to his assertion about Sir Francis Galton, I wrote a letter to the Times' editor. The letter was unpublished, but it brought a wonderful response from Sacks himself that is reproduced and examined. Next, brief reviews of twin research concerning the vanishing twin syndrome (VTS), discordant sex in a monozygotic (MZ) twin pair, and multiple pregnancy outcomes from assisted reproductive technology (ART) are presented. This section is followed by popular coverage of superfetated twins, smoking-discordant co-twins, twins in fashion, Yale University twin hockey players, and a visiting professor who was a conjoined twin.

Material Limitations on the Detection Limit in Refractometry

Directory of Open Access Journals (Sweden)

Niels Asger Mortensen

2009-10-01

Full Text Available We discuss the detection limit for refractometric sensors relying on high-Q optical cavities and show that the ultimate classical detection limit is given by min {Δn} ≳ η with n + iη being the complex refractive index of the material under refractometric investigation. Taking finite Q factors and filling fractions into account, the detection limit declines. As an example we discuss the fundamental limits of silicon-based high-Q resonators, such as photonic crystal resonators, for sensing in a bio-liquid environment, such as a water buffer. In the transparency window (λ ≳ 1100 nm of silicon the detection limit becomes almost independent on the filling fraction, while in the visible, the detection limit depends strongly on the filling fraction because the silicon absorbs strongly.

Material Limitations on the Detection Limit in Refractometry

OpenAIRE

Skafte-Pedersen, Peder; Nunes, Pedro S.; Xiao, Sanshui; Mortensen, Niels Asger

2009-01-01

We discuss the detection limit for refractometric sensors relying on high-Q optical cavities and show that the ultimate classical detection limit is given by min {Δn} ≳ η with n + iη being the complex refractive index of the material under refractometric investigation. Taking finite Q factors and filling fractions into account, the detection limit declines. As an example we discuss the fundamental limits of silicon-based high-Q resonators, such as photonic crystal resonators, for sensing in a...

The standard Higgs-model on the lattice

International Nuclear Information System (INIS)

Montvay, I.

1985-06-01

Some recent Monte Carlo calcuations in the SU(2) Higgs-model with a scalar doublet field are reviewed. Questions about the dependence on the scalar self-coupling are discussed in the framework of a strong self-coupling expansion. The numerical results are consistent with an asymptotically free continuum limit at vanishing bare gauge coupling. (orig.)

High scale parity invariance as a solution to the SUSY CP problem ...

Indian Academy of Sciences (India)

It is shown that if the supersymmetric Standard Model (MSSM) emerges as the low energy limit of a high scale left–right symmetric gauge structure, the number of uncontrollable CP violating phases of MSSM are drastically reduced. In particular it guarantees the vanishing of the dangerous phases that were at the root of the ...

Semileptonic B → D** decays in lattice QCD: a feasability

Energy Technology Data Exchange (ETDEWEB)

Atoui, M.; Morenas, V. [Unite Mixte de Recherche 6533 CNRS/IN2P3, Universite Blaise Pascal, Laboratoire de Physique Corpusculaire de Clermont-Ferrand, Campus des Cezeaux, 24 avenue des Landais, BP 80026, Aubiere Cedex (France); Blossier, B.; Pene, O. [Unite Mixte de Recherche 8627 du Centre National de la Recherche Scientifique et Universite Paris-Sud XI, Laboratoire de Physique Theorique, Orsay Cedex (France); Petrov, K. [Inria Saclay, Batiment Alan Turing, Palaiseau (France)

2015-08-15

We compute the decays B → D{sub 0}{sup *} and B → D{sub 2}{sup *} with finite masses for the b and c quarks. We first discuss the spectral properties of both the B meson as a function of its momentum and the D{sub 0}{sup *} and D{sub 2}{sup *} at rest. We compute the theoretical formulae leading to the decay amplitudes from the three-point and two-point correlators. We then compute the amplitudes at zero recoil of B → D{sub 0}{sup *}, which turns out not to be vanishing contrary to what happens in the heavy quark limit. This opens the possibility to get better agreement with experiment. To improve the continuum limit we have added a set of data with smaller lattice spacing. The B → D{sub 2}{sup *} vanishes at zero recoil and we show a convincing signal but only slightly more than 1 sigma from 0. In order to reach quantitatively significant results we plan to exploit fully smaller lattice spacings as well as another lattice regularisation. (orig.)

Charged black holes in a generalized scalar–tensor gravity model

Directory of Open Access Journals (Sweden)

Yves Brihaye

2017-09-01

Full Text Available We study 4-dimensional charged and static black holes in a generalized scalar–tensor gravity model, in which a shift symmetry for the scalar field exists. For vanishing scalar field the solution corresponds to the Reissner–Nordström (RN solution, while solutions of the full scalar-gravity model have to be constructed numerically. We demonstrate that these black holes support Galilean scalar hair up to a maximal value of the scalar–tensor coupling that depends on the value of the charge and can be up to roughly twice as large as that for uncharged solutions. The Hawking temperature TH of the hairy black holes at maximal scalar–tensor coupling decreases continuously with the increase of the charge and reaches TH=0 for the highest possible charge that these solutions can carry. However, in this limit, the scalar–tensor coupling needs to vanish. The limiting solution hence corresponds to the extremal RN solution, which does not support regular Galilean scalar hair due to its AdS2×S2 near-horizon geometry.

The return of the King: No-Scale F-SU(5

Directory of Open Access Journals (Sweden)

Tianjun Li

2017-01-01

Full Text Available We revisit the viable parameter space in No-Scale F-SU(5, examining the Grand Unified Theory within the context of the prevailing gluino mass limits established by the LHC. The satisfaction of both the No-Scale boundary condition and the experimentally measured Standard Model (SM like Higgs boson mass requires a lower limit on the gluino mass in the model space of about 1.9 TeV, which maybe not coincidentally is the current LHC supersymmetry search bound. This offers a plausible explanation as to why a supersymmetry signal has thus far not been observed at the LHC. On the contrary, since the vector-like flippon particles are relatively heavy due to the strict condition that the supersymmetry breaking soft term Bμ must vanish at the unification scale, we also cannot address the recently vanished 750 GeV diphoton resonance at the 13 TeV LHC. Therefore, No-Scale F-SU(5 returns as a King after the spurious 750 GeV diphoton excess was gone with the wind.

First- and second-order metal-insulator phase transitions and topological aspects of a Hubbard-Rashba system

Science.gov (United States)

Marcelino, Edgar

2017-05-01

This paper considers a model consisting of a kinetic term, Rashba spin-orbit coupling and short-range Coulomb interaction at zero temperature. The Coulomb interaction is decoupled by a mean-field approximation in the spin channel using field theory methods. The results feature a first-order phase transition for any finite value of the chemical potential and quantum criticality for vanishing chemical potential. The Hall conductivity is also computed using the Kubo formula in a mean-field effective Hamiltonian. In the limit of infinite mass the kinetic term vanishes and all the phase transitions are of second order; in this case the spontaneous symmetry-breaking mechanism adds a ferromagnetic metallic phase to the system and features a zero-temperature quantization of the Hall conductivity in the insulating one.

The physical boundary Hilbert space and volume operator in the Lorentzian new spin-foam theory

International Nuclear Information System (INIS)

Ding You; Rovelli, Carlo

2010-01-01

A covariant spin-foam formulation of quantum gravity has been recently developed, characterized by a kinematics which appears to match well the one of canonical loop quantum gravity. In this paper we reconsider the implementation of the constraints that defines the model. We define in a simple way the boundary Hilbert space of the theory, introducing a slight modification of the embedding of the SU(2) representations into the SL(2,C) ones. We then show directly that all constraints vanish on this space in a weak sense. The vanishing is exact (and not just in the large quantum number limit). We also generalize the definition of the volume operator in the spin-foam model to the Lorentzian signature and show that it matches the one of loop quantum gravity, as in the Euclidean case.

Logamediate Inflation in f ( T ) Teleparallel Gravity

Energy Technology Data Exchange (ETDEWEB)

Rezazadeh, Kazem; Karami, Kayoomars [Department of Physics, University of Kurdistan, Pasdaran Street, P.O. Box 66177-15175, Sanandaj (Iran, Islamic Republic of); Abdolmaleki, Asrin, E-mail: rezazadeh86@gmail.com [Research Institute for Astronomy and Astrophysics of Maragha (RIAAM), P.O. Box 55134-441, Maragha (Iran, Islamic Republic of)

2017-02-20

We study logamediate inflation in the context of f ( T ) teleparallel gravity. f ( T )-gravity is a generalization of the teleparallel gravity which is formulated on the Weitzenbock spacetime, characterized by the vanishing curvature tensor (absolute parallelism) and the non-vanishing torsion tensor. We consider an f ( T )-gravity model which is sourced by a canonical scalar field. Assuming a power-law f ( T ) function in the action, we investigate an inflationary universe with a logamediate scale factor. Our results show that, although logamediate inflation is completely ruled out by observational data in the standard inflationary scenario based on Einstein gravity, it can be compatible with the 68% confidence limit joint region of Planck 2015 TT,TE,EE+lowP data in the framework of f ( T )-gravity.

Production of electroweak bosons at colliders

Indian Academy of Sciences (India)

of diboson production are usually framed as comparison of measured couplings to SM predictions and interpreted as limits on ... the Standard Model, λγ and λZ vanish, while the others have a value of 1. ... small (Wγ) or zero (Zγ) as these final states are predominantly produced by initial- and final-state radiation of photons.

On the ground state of a model for compressed helium

NARCIS (Netherlands)

Seldam, C.A. ten; Groot, S.R. de

1952-01-01

In the problem of the “compressed helium atom”, the boundary condition that the wave function ψ must vanish at infinity (r = ∞), is replaced by: ψ = 0 at a finite r = r0. This problem is solved by a variational method, which for the limiting case of the free atom (r0 → ∞) coincides with one of

Opening up to Native Speaker Norms: The Use of /?/ in the Speech of Canadian French Immersion Students

Science.gov (United States)

Nadasdi, Terry; Vickerman, Alison

2017-01-01

Our study examines the extent to which French immersion students use lax /?/ in the same linguistic context as native speakers of Canadian French. Our results show that the lax variant is vanishingly rare in the speech of immersion students and is used by only a small minority of individuals. This is interpreted as a limitation of French immersion…

The analytical solution of wake-fields in an elliptical pillbox cavity

International Nuclear Information System (INIS)

Yang, J.S.; Chen, K.W.

1991-01-01

The wake potential of a bunch of relativistic charged particles traversing an elliptical pillbox cavity is derived analytically in the limit of vanishing aperture. It is found that the resonant modes of an elliptical cavity can be expressed in terms of Mathieu functions. Calculation results are presented and compared with numerical ones. (author) 10 refs., 10 figs., 2 tabs

Thermodynamic limit for coherence-limited solar power conversion

Science.gov (United States)

Mashaal, Heylal; Gordon, Jeffrey M.

2014-09-01

The spatial coherence of solar beam radiation is a key constraint in solar rectenna conversion. Here, we present a derivation of the thermodynamic limit for coherence-limited solar power conversion - an expansion of Landsberg's elegant basic bound, originally limited to incoherent converters at maximum flux concentration. First, we generalize Landsberg's work to arbitrary concentration and angular confinement. Then we derive how the values are further lowered for coherence-limited converters. The results do not depend on a particular conversion strategy. As such, they pertain to systems that span geometric to physical optics, as well as classical to quantum physics. Our findings indicate promising potential for solar rectenna conversion.

Contracting bubbles in Hele-Shaw cells with a power-law fluid

International Nuclear Information System (INIS)

McCue, Scott W; King, John R

2011-01-01

The problem of bubble contraction in a Hele-Shaw cell is studied for the case in which the surrounding fluid is of power-law type. A small perturbation of the radially symmetric problem is first considered, focussing on the behaviour just before the bubble vanishes, it being found that for shear-thinning fluids the radially symmetric solution is stable, while for shear-thickening fluids the aspect ratio of the bubble boundary increases. The borderline (Newtonian) case considered previously is neutrally stable, the bubble boundary becoming elliptic in shape with the eccentricity of the ellipse depending on the initial data. Further light is shed on the bubble contraction problem by considering a long thin Hele-Shaw cell: for early times the leading-order behaviour is one-dimensional in this limit; however, as the bubble contracts its evolution is ultimately determined by the solution of a Wiener–Hopf problem, the transition between the long thin limit and the extinction limit in which the bubble vanishes being described by what is in effect a similarity solution of the second kind. This same solution describes the generic (slit-like) extinction behaviour for shear-thickening fluids, the interface profiles that generalize the ellipses that characterize the Newtonian case being constructed by the Wiener–Hopf calculation

The Fermion boson interaction within the linear sigma model at finite temperature

International Nuclear Information System (INIS)

Caldas, H.C.G.

2000-01-01

We study the interaction of massless bosons at finite temperature. Specifically, we calculate the self-energy of massless fermions due to interaction with massless bosons at high temperature, which is the region where thermal effects are maximal. The calculations are concentrated in the limit of vanishing fermion three momentum and after considering the effective boson dressed mass, we obtain the damping rate of the fermion. It is shown that in the limit k O 2 T + g 3 T. (author)

Collective magnetic behaviors of Fe-Ag nanostructured thin films above the percolation limit

International Nuclear Information System (INIS)

Alonso, J.; Fdez-Gubieda, M. L.; Barandiaran, J. M.; Svalov, A.; Sarmiento, G.; Fernandez Barquin, L.; Pedro, I. de; Orue, I.

2009-01-01

The magnetic behavior of sputtered and pulsed laser deposited (PLD) Fe x Ag 100-x thin films with 27≤x≤55 has been studied by means of ac and dc magnetic measurements. Sputtered samples present a continuous decrease in the magnetization, down to 310 K for x=30, where a magnetic transition into a superparamagnetic state with the presence of dipolar interactions is observed. The ac susceptibility measurements indicate that this transition resembles that of three dimensional glassy systems. Sputtered samples with higher concentration of Fe present a similar but slower thermal evolution of magnetization. PLD samples with x≥50 show a Curie-Weiss-type transition above ∼200 K triggered by direct exchange interactions. As the temperature decreases, the system behaves like a ferromagnet and below ∼75 K, a transition into a cluster-glass state appears. As the composition decreases, these phenomena vanish

Who Will Replace Those Vanishing Execs?

Science.gov (United States)

Geber, Beverly

2000-01-01

Many top-level managers are retiring early. Programs to prepare their replacements have been scaled back. Many companies are offering phased retirement plans, redesigning jobs, and paying for spouses to go along on business trips to keep their managers a little longer. (JOW)

Electromagnetic fields with vanishing quantum corrections

Czech Academy of Sciences Publication Activity Database

Ortaggio, Marcello; Pravda, Vojtěch

2018-01-01

Roč. 779, 10 April (2018), s. 393-395 ISSN 0370-2693 R&D Projects: GA ČR GA13-10042S Institutional support: RVO:67985840 Keywords : nonlinear electrodynamics * quantum corrections Subject RIV: BA - General Mathematics OBOR OECD: Applied mathematics Impact factor: 4.807, year: 2016 https://www.sciencedirect.com/science/article/pii/S0370269318300327?via%3Dihub

Electromagnetic fields with vanishing quantum corrections

Czech Academy of Sciences Publication Activity Database

Ortaggio, Marcello; Pravda, Vojtěch

2018-01-01

Roč. 779, 10 April (2018), s. 393-395 ISSN 0370-2693 R&D Projects: GA ČR GA13-10042S Institutional support: RVO:67985840 Keywords : nonlinear electrodynamics * quantum corrections Subject RIV: BA - General Mathematics OBOR OECD: Applied mathematics Impact factor: 4.807, year: 2016 https://www. science direct.com/ science /article/pii/S0370269318300327?via%3Dihub

Vanishing Species: The Planet in Crisis

Indian Academy of Sciences (India)

Permanent link: https://www.ias.ac.in/article/fulltext/reso/015/04/0321-0336. Keywords. Species; mass extinction; biotic crisis; hotspot. Author Affiliations. Uttam Saikia1 Narayan Sharma Abhijit Das. High Altitude Zoology Field Station, Zoological Survey of India, Saproon, Solan, H.P.173211. Resonance – Journal of Science ...

Electromagnetic fields with vanishing quantum corrections

Science.gov (United States)

Ortaggio, Marcello; Pravda, Vojtěch

2018-04-01

We show that a large class of null electromagnetic fields are immune to any modifications of Maxwell's equations in the form of arbitrary powers and derivatives of the field strength. These are thus exact solutions to virtually any generalized classical electrodynamics containing both non-linear terms and higher derivatives, including, e.g., non-linear electrodynamics as well as QED- and string-motivated effective theories. This result holds not only in a flat or (anti-)de Sitter background, but also in a larger subset of Kundt spacetimes, which allow for the presence of aligned gravitational waves and pure radiation.

Vanishing microwave effects : influence of heterogeneity

NARCIS (Netherlands)

Dressen, M.H.C.L.; Kruijs, van de B.H.P.; Meuldijk, J.; Vekemans, J.A.J.M.; Hulshof, L.A.

2007-01-01

A consistent setup of experiments has been conducted to demonstrate an enhanced reaction rate under microwave irradiation as compared to conventional heating, i.e. a real microwave effect. It was found that addition of a cosolvent, diminishing the heterogeneous character of the reaction mixture,

Electromagnetic fields with vanishing scalar invariants

Czech Academy of Sciences Publication Activity Database

Ortaggio, Marcello; Pravda, Vojtěch

2016-01-01

Roč. 33, č. 11 (2016), s. 115010 ISSN 0264-9381 R&D Projects: GA ČR GA13-10042S Institutional support: RVO:67985840 Keywords : electromagnetic fields * n-dimensional spacetime * Einstein-Maxwell equations Subject RIV: BA - General Mathematics Impact factor: 3.119, year: 2016 http://dx.doi.org/10.1088/0264-9381/33/11/115010

Vanishing Species: The Planet in Crisis

Indian Academy of Sciences (India)

IAS Admin

world. The living world today in essence is a reflection of the past .... of the pathogen is still sketchy, but it is suspected that they may produce toxin or affect the passage of moisture .... The illegal trade of .... could lead to the collapse of the economies of many societies and ... erty that can be integrated into agricultural crops.

Penser aux/les limites de nos limites

Directory of Open Access Journals (Sweden)

Jacques Lévy

2010-12-01

Full Text Available Le mot « frontière » a beaucoup de succès, dans son sens propre mais plus encore comme métaphore d’une multitude de réalités qui ont à voir avec les limites, c’est-à-dire avec notre propension à découper le monde en objets séparables. Mais on constate une grande indétermination entre concept et métaphore et un usage trop facile de mélanges entre ceux-ci. Il faut donc d’abord admettre que la matérialité n’est qu’une des composantes de notre monde, mais que l’immatériel n’est pas l’irréel, le simulé ou le métaphorique. Après un détour par une théorie des limites et ses limites et une distinction entre le topographique (continu et le topologique (discontinu appliquée à l’intérieur et aux limites d’une aire, deux exemples sont développés qui visent à montrer que, si l’on trouve des frontières, ce n’est pas forcément là où on les attend et que l’appréciation juste de la place des frontières suppose la prise en compte de bien d’autres considérations que la seule limitation volontaire et brutale du franchissement d’une ligne imaginaire tracée au sol.Think about limits and the limits of our limitsThe word “boundary” has been very successful in its literal sense but even more so as a metaphor of a multitude of realities involving limits, that is, with regards to our tendency to divide the world into separable objects. However, one can observe a considerable uncertainty between the concept and the metaphor and an utilisation too easy of various mixtures of them. It becomes necessary therefore to first admit that materiality is only one of the components of our world whilst the immaterial is not unreal, simulated or metaphoric. After a detour consisting of examining a theory of limits and its limits and making the distinction between the topographic (continuous and the topologic (discontinuous applied to the interior and the limits of an area, two examples are developed which aim to

ICRF power limitation relation to density limit in ASDEX

International Nuclear Information System (INIS)

Ryter, F.

1992-01-01

Launching high ICRF power into ASDEX plasmas required good antenna-plasma coupling. This could be achieved by sufficient electron density in front of the antennas i.e. small antenna-plasma distance (1-2 cm) and moderate to high line-averaged electron density compared to the density window in ASDEX. These are conditions eventually close to the density limit. ICRF heated discharges terminated by plasma disruptions caused by the RF pulse limited the maximum RF power which can be injected into the plasma. The disruptions occurring in these cases have clear phenomenological similarities with those observed in density limit discharges. We show in this paper that the ICRF-power limitation by plasma disruptions in ASDEX was due to reaching the density limit. (orig.)

ICRF power limitation relation to density limit in ASDEX

International Nuclear Information System (INIS)

Ryter, F.

1992-01-01

Launching high ICRF power into ASDEX plasmas required good antenna-plasma coupling. This could be achieved by sufficient electron density in front of the antennas i.e. small antenna-plasma distance (1-2 cm) and moderate to high line-averaged electron density compared to the density window in ASDEX. These are conditions eventually close to the density limit. ICRF heated discharges terminated by plasma disruptions caused by the RF pulse limited the maximum RF power which can be injected into the plasma. The disruptions occurring in these cases have clear phenomenological similarities with those observed in density limit discharges. We show in this paper that the ICRF-power limitation by plasma disruptions in ASDEX was due to reaching the density limit. (author) 3 refs., 3 figs

Experimentally Manipulating Items Informs on the (Limited Construct and Criterion Validity of the Humor Styles Questionnaire

Directory of Open Access Journals (Sweden)

Willibald Ruch

2017-04-01

Full Text Available How strongly does humor (i.e., the construct-relevant content in the Humor Styles Questionnaire (HSQ; Martin et al., 2003 determine the responses to this measure (i.e., construct validity? Also, how much does humor influence the relationships of the four HSQ scales, namely affiliative, self-enhancing, aggressive, and self-defeating, with personality traits and subjective well-being (i.e., criterion validity? The present paper answers these two questions by experimentally manipulating the 32 items of the HSQ to only (or mostly contain humor (i.e., construct-relevant content or to substitute the humor content with non-humorous alternatives (i.e., only assessing construct-irrelevant context. Study 1 (N = 187 showed that the HSQ affiliative scale was mainly determined by humor, self-enhancing and aggressive were determined by both humor and non-humorous context, and self-defeating was primarily determined by the context. This suggests that humor is not the primary source of the variance in three of the HQS scales, thereby limiting their construct validity. Study 2 (N = 261 showed that the relationships of the HSQ scales to the Big Five personality traits and subjective well-being (positive affect, negative affect, and life satisfaction were consistently reduced (personality or vanished (subjective well-being when the non-humorous contexts in the HSQ items were controlled for. For the HSQ self-defeating scale, the pattern of relationships to personality was also altered, supporting an positive rather than a negative view of the humor in this humor style. The present findings thus call for a reevaluation of the role that humor plays in the HSQ (construct validity and in the relationships to personality and well-being (criterion validity.

Experimentally Manipulating Items Informs on the (Limited) Construct and Criterion Validity of the Humor Styles Questionnaire.

Science.gov (United States)

Ruch, Willibald; Heintz, Sonja

2017-01-01

How strongly does humor (i.e., the construct-relevant content) in the Humor Styles Questionnaire (HSQ; Martin et al., 2003) determine the responses to this measure (i.e., construct validity)? Also, how much does humor influence the relationships of the four HSQ scales, namely affiliative, self-enhancing, aggressive, and self-defeating, with personality traits and subjective well-being (i.e., criterion validity)? The present paper answers these two questions by experimentally manipulating the 32 items of the HSQ to only (or mostly) contain humor (i.e., construct-relevant content) or to substitute the humor content with non-humorous alternatives (i.e., only assessing construct-irrelevant context). Study 1 ( N = 187) showed that the HSQ affiliative scale was mainly determined by humor, self-enhancing and aggressive were determined by both humor and non-humorous context, and self-defeating was primarily determined by the context. This suggests that humor is not the primary source of the variance in three of the HQS scales, thereby limiting their construct validity. Study 2 ( N = 261) showed that the relationships of the HSQ scales to the Big Five personality traits and subjective well-being (positive affect, negative affect, and life satisfaction) were consistently reduced (personality) or vanished (subjective well-being) when the non-humorous contexts in the HSQ items were controlled for. For the HSQ self-defeating scale, the pattern of relationships to personality was also altered, supporting an positive rather than a negative view of the humor in this humor style. The present findings thus call for a reevaluation of the role that humor plays in the HSQ (construct validity) and in the relationships to personality and well-being (criterion validity).

Supersymmetry of noncompact MQCD-like membrane instantons and heat kernel asymptotics

International Nuclear Information System (INIS)

Belani, Kanishka; Kaura, Payal; Misra, Aalok

2006-01-01

We perform a heat kernel asymptotics analysis of the nonperturbative superpotential obtained from wrapping of an M2-brane around a supersymmetric noncompact three-fold embedded in a (noncompact) G 2 -manifold as obtained, the three-fold being the one relevant to domain walls in Witten's MQCD, in the limit of small 'ζ', a complex constant that appears in the Riemann surfaces relevant to defining the boundary conditions for the domain wall in MQCD. The MQCD-like configuration is interpretable, for small but non-zero ζ as a noncompact/'large open membrane instanton, and for vanishing ζ, as the type IIA D0-brane (for vanishing M-theory circle radius). We find that the eta-function Seeley de-Witt coefficients vanish, and we get a perfect match between the zeta-function Seeley de-Witt coefficients (up to terms quadratic in ζ) between the Dirac-type operator and one of the two Laplace-type operators figuring in the superpotential. Given the dissimilar forms of the bosonic and the square of the fermionic operators, this is an extremely nontrivial check, from a spectral analysis point of view, of the expected residual supersymmetry for the nonperturbative configurations in M-theory considered in this work

Squashed, magnetized black holes in D = 5 minimal gauged supergravity

Science.gov (United States)

Blázquez-Salcedo, Jose Luis; Kunz, Jutta; Navarro-Lérida, Francisco; Radu, Eugen

2018-02-01

We construct a new class of black hole solutions in five-dimensional Einstein-Maxwell-Chern-Simons theory with a negative cosmological constant. These configurations are cohomogeneity-1, with two equal-magnitude angular momenta. In the generic case, they possess a non-vanishing magnetic potential at infinity with a boundary metric which is the product of time and a squashed three-dimensional sphere. Both extremal and non-extremal black holes are studied. The non-extremal black holes satisfying a certain relation between electric charge, angular momenta and magnitude of the magnetic potential at infinity do not trivialize in the limit of vanishing event horizon size, becoming particle-like (non-topological) solitonic configurations. Among the extremal black holes, we show the existence of a new one-parameter family of supersymmetric solutions, which bifurcate from a critical Gutowski-Reall configuration.

Conformal higher spin scattering amplitudes from twistor space

Energy Technology Data Exchange (ETDEWEB)

Adamo, Tim [Blackett Laboratory, Imperial College, London, SW7 2AZ (United Kingdom); Hähnel, Philipp; McLoughlin, Tristan [School of Mathematics, Trinity College Dublin, College Green, Dublin 2 (Ireland)

2017-04-04

We use the formulation of conformal higher spin (CHS) theories in twistor space to study their tree-level scattering amplitudes, finding expressions for all three-point (MHV)-bar amplitudes and all MHV amplitudes involving positive helicity conformal gravity particles and two negative helicity higher spins. This provides the on-shell analogue for the covariant coupling of CHS fields to a conformal gravity background. We discuss the restriction of the theory to a ghost-free unitary subsector, analogous to restricting conformal gravity to general relativity with a cosmological constant. We study the flat-space limit and show that the restricted amplitudes vanish, supporting the conjecture that in the unitary sector the S-matrix of CHS theories is trivial. However, by appropriately rescaling the amplitudes we find non-vanishing results which we compare with chiral flat-space higher spin theories.

Conformal higher spin scattering amplitudes from twistor space

International Nuclear Information System (INIS)

Adamo, Tim; Hähnel, Philipp; McLoughlin, Tristan

2017-01-01

We use the formulation of conformal higher spin (CHS) theories in twistor space to study their tree-level scattering amplitudes, finding expressions for all three-point (MHV)-bar amplitudes and all MHV amplitudes involving positive helicity conformal gravity particles and two negative helicity higher spins. This provides the on-shell analogue for the covariant coupling of CHS fields to a conformal gravity background. We discuss the restriction of the theory to a ghost-free unitary subsector, analogous to restricting conformal gravity to general relativity with a cosmological constant. We study the flat-space limit and show that the restricted amplitudes vanish, supporting the conjecture that in the unitary sector the S-matrix of CHS theories is trivial. However, by appropriately rescaling the amplitudes we find non-vanishing results which we compare with chiral flat-space higher spin theories.

Quench limits

International Nuclear Information System (INIS)

Sapinski, M.

2012-01-01

With thirteen beam induced quenches and numerous Machine Development tests, the current knowledge of LHC magnets quench limits still contains a lot of unknowns. Various approaches to determine the quench limits are reviewed and results of the tests are presented. Attempt to reconstruct a coherent picture emerging from these results is taken. The available methods of computation of the quench levels are presented together with dedicated particle shower simulations which are necessary to understand the tests. The future experiments, needed to reach better understanding of quench limits as well as limits for the machine operation are investigated. The possible strategies to set BLM (Beam Loss Monitor) thresholds are discussed. (author)

The three-photon vertex

International Nuclear Information System (INIS)

Delbourgo, R.

1976-01-01

Owing to weak interactions, the three-photon vertex is non-zero. From gauge invariance and symmetry requirements, it is proved that the C = -1P = - 1 vertex amplitudes are at least of order q 7 in the limit of soft photon momentum q and that if any two photons are placed on mass shell the form factors vanish identically. (author)

Measure-valued solutions to the complete Euler system revisited

Czech Academy of Sciences Publication Activity Database

Březina, J.; Feireisl, Eduard

2018-01-01

Roč. 69, č. 3 (2018), č. článku 57. ISSN 0044-2275 EU Projects: European Commission(XE) 320078 - MATHEF Institutional support: RVO:67985840 Keywords : Euler system * measure-valued solution * vanishing dissipation limit Subject RIV: BA - General Mathematics OBOR OECD: Pure mathematics Impact factor: 1.687, year: 2016 https://link.springer.com/article/10.1007/s00033-018-0951-8

Looking for a gift of Nature: Hadron loops and hybrid mixing

International Nuclear Information System (INIS)

Close, Frank; Thomas, Christopher

2009-01-01

We investigate how coupling of valence q qbar to meson pairs can modify the properties of conventional q qbar and hybrid mesons. In a symmetry limit the mixing between hybrids and conventional q qbar with the same J PC is shown to vanish. Flavor mixing between heavy and light q qbar due to meson loops is shown to be dual to the

Irregular wave functions of a hydrogen atom in a uniform magnetic field

Science.gov (United States)

Wintgen, D.; Hoenig, A.

1989-01-01

The highly excited irregular wave functions of a hydrogen atom in a uniform magnetic field are investigated analytically, with wave function scarring by periodic orbits considered quantitatively. The results obtained confirm that the contributions of closed classical orbits to the spatial wave functions vanish in the semiclassical limit. Their disappearance, however, is slow. This discussion is illustrated by numerical examples.

The limiting current in a one-dimensional situation: Transition from a space charge limited to magnetically limited flow

International Nuclear Information System (INIS)

Kumar, Raghwendra; Biswas, Debabrata

2008-01-01

For a nonrelativistic electron beam propagating in a cylindrical drift tube, it is shown that the limiting current density does not saturate to the electrostatic one-dimensional (1D) estimate with increasing beam radius. Fully electromagnetic particle-in-cell (PIC) simulation studies show that beyond a critical aspect ratio, the limiting current density is lower than the 1D electrostatic prediction. The lowering in the limiting current density is found to be due to the transition from the space charge limited to magnetically limited flow. An adaptation of Alfven's single particle trajectory method is used to estimate the magnetically limited current as well as the critical radius beyond which the flow is magnetically limited in a drift tube. The predictions are found to be in close agreement with PIC simulations

Abrasion-set limits on Himalayan gravel flux.

Science.gov (United States)

Dingle, Elizabeth H; Attal, Mikaël; Sinclair, Hugh D

2017-04-26

Rivers sourced in the Himalayan mountain range carry some of the largest sediment loads on the planet, yet coarse gravel in these rivers vanishes within approximately 10-40 kilometres on entering the Ganga Plain (the part of the North Indian River Plain containing the Ganges River). Understanding the fate of gravel is important for forecasting the response of rivers to large influxes of sediment triggered by earthquakes or storms. Rapid increase in gravel flux and subsequent channel bed aggradation (that is, sediment deposition by a river) following the 1999 Chi-Chi and 2008 Wenchuan earthquakes reduced channel capacity and increased flood inundation. Here we present an analysis of fan geometry, sediment grain size and lithology in the Ganga Basin. We find that the gravel fluxes from rivers draining the central Himalayan mountains, with upstream catchment areas ranging from about 350 to 50,000 square kilometres, are comparable. Our results show that abrasion of gravel during fluvial transport can explain this observation; most of the gravel sourced more than 100 kilometres upstream is converted into sand by the time it reaches the Ganga Plain. These findings indicate that earthquake-induced sediment pulses sourced from the Greater Himalayas, such as that following the 2015 Gorkha earthquake, are unlikely to drive increased gravel aggradation at the mountain front. Instead, we suggest that the sediment influx should result in an elevated sand flux, leading to distinct patterns of aggradation and flood risk in the densely populated, low-relief Ganga Plain.

Extremal dyonic black holes in D=4 Gauss-Bonnet gravity

International Nuclear Information System (INIS)

Chen, C.-M.; Gal'tsov, Dmitri V.; Orlov, Dmitry G.

2008-01-01

We investigate extremal dyon black holes in the Einstein-Maxwell-dilaton theory with higher curvature corrections in the form of the Gauss-Bonnet density coupled to the dilaton. In the same theory without the Gauss-Bonnet term the extremal dyon solutions exist only for discrete values of the dilaton coupling constant a. We show that the Gauss-Bonnet term acts as a dyon hair tonic enlarging the allowed values of a to continuous domains in the plane (a,q m ) where q m is the magnetic charge. In the limit of the vanishing curvature coupling (a large magnetic charge) the dyon solutions obtained tend to the Reissner-Nordstroem solution but not to the extremal dyons of the Einstein-Maxwell-dilaton theory. Both solutions have the same dependence of the horizon radius in terms of charges. The entropy of new dyonic black holes interpolates between the Bekenstein-Hawking value in the limit of the large magnetic charge (equivalent to the vanishing Gauss-Bonnet coupling) and twice this value for the vanishing magnetic charge. Although an expression for the entropy can be obtained analytically using purely local near-horizon solutions, its interpretation as the black hole entropy is legitimate only once the global black hole solution is known to exist, and we obtain numerically the corresponding conditions on the parameters. Thus, a purely local analysis is insufficient to fully understand the entropy of the curvature-corrected black holes. We also find dyon solutions which are not asymptotically flat, but approach the linear dilaton background at infinity. They describe magnetic black holes on the electric linear dilaton background.

Translation-aware semantic segmentation via conditional least-square generative adversarial networks

Science.gov (United States)

Zhang, Mi; Hu, Xiangyun; Zhao, Like; Pang, Shiyan; Gong, Jinqi; Luo, Min

2017-10-01

Semantic segmentation has recently made rapid progress in the field of remote sensing and computer vision. However, many leading approaches cannot simultaneously translate label maps to possible source images with a limited number of training images. The core issue is insufficient adversarial information to interpret the inverse process and proper objective loss function to overcome the vanishing gradient problem. We propose the use of conditional least squares generative adversarial networks (CLS-GAN) to delineate visual objects and solve these problems. We trained the CLS-GAN network for semantic segmentation to discriminate dense prediction information either from training images or generative networks. We show that the optimal objective function of CLS-GAN is a special class of f-divergence and yields a generator that lies on the decision boundary of discriminator that reduces possible vanished gradient. We also demonstrate the effectiveness of the proposed architecture at translating images from label maps in the learning process. Experiments on a limited number of high resolution images, including close-range and remote sensing datasets, indicate that the proposed method leads to the improved semantic segmentation accuracy and can simultaneously generate high quality images from label maps.

Discrete Frenet frame, inflection point solitons, and curve visualization with applications to folded proteins

Science.gov (United States)

Hu, Shuangwei; Lundgren, Martin; Niemi, Antti J.

2011-06-01

We develop a transfer matrix formalism to visualize the framing of discrete piecewise linear curves in three-dimensional space. Our approach is based on the concept of an intrinsically discrete curve. This enables us to more effectively describe curves that in the limit where the length of line segments vanishes approach fractal structures in lieu of continuous curves. We verify that in the case of differentiable curves the continuum limit of our discrete equation reproduces the generalized Frenet equation. In particular, we draw attention to the conceptual similarity between inflection points where the curvature vanishes and topologically stable solitons. As an application we consider folded proteins, their Hausdorff dimension is known to be fractal. We explain how to employ the orientation of Cβ carbons of amino acids along a protein backbone to introduce a preferred framing along the backbone. By analyzing the experimentally resolved fold geometries in the Protein Data Bank we observe that this Cβ framing relates intimately to the discrete Frenet framing. We also explain how inflection points (a.k.a. soliton centers) can be located in the loops and clarify their distinctive rôle in determining the loop structure of folded proteins.

Material limitations on the detection limit in refractometry

DEFF Research Database (Denmark)

Skafte-Pedersen, Peder; Nunes, Pedro; Xiao, Sanshui

2009-01-01

We discuss the detection limit for refractometric sensors relying on high-Q optical cavities and show that the ultimate classical detection limit is given by min {Δn} ≳ η with n + iη being the complex refractive index of the material under refractometric investigation. Taking finite Q factors and...

CONNECTING THE VANISHING FLORA, FAUNA AND ITS RELATION TO THE INDIAN REMOVAL POLICY AS SEEN IN COOPERS THE LEATHERSTOCKING TALES

Directory of Open Access Journals (Sweden)

Ceisy Nita Wuntu

2016-02-01

Full Text Available This study aims at connecting the vanishing flora, fauna and its Relation to the Indian removal policy in Coopers The Leatherstocking Tales. This research applies an American Studies interdisciplinary principle supplemented by the myth and symbol theory proposed by Henry Nash Smith. Smith claimed the importance of imaginative works in revealing American culture. He declared that the historical, anthropological and cultural, sociological, and ecological data as covered in this research can be equipped by data from imaginative works. Hence, in this research, those data are presented integratedly in their context of past and present. In this research, in order to highlight environmental matters in Coopers The Leatherstocking Tales, the analysis covers the data above that are integrated with the data revealed in The Leatherstocking Tales as a whole by employing the concept of ecocriticism. The spirit of the immigrants to have a better life in the new world, stimulated by its rich, lush and beautiful circumstances, in fact, is not an aim of a sustainable life. The desire to improve their life is not enough without using and treating its environment wisely as well as facing it with the environmental conservation paradigm. The spirit of doing the exploitation is a consequence of western humanism value. The reason of coming to America to avoid the population density as well as the competition of life cannot be attained when the immigrants experience the same population density and harsh competition as in their old world and when the beautiful nature disappears, the forests become cities, the tranquility becomes noisy and crowded, and the people experience the uncomfortable life that many kinds of conflict can follow. It is not on the right path when they cannot maintain the grandeur of nature, because they are not directing their way to the right, sustainable way of life as alerted and meant by Cooper. Ecologically, the superabundance of the land when

The finite temperature QCD phase transition and the thermodynamic equation of state. An investigation employing lattice QCD with Nf=2 twisted mass quarks

International Nuclear Information System (INIS)

Burger, Florian

2012-01-01

In this thesis we report about an investigation of the finite temperature crossover/phase transition of quantum chromodynamics and the evaluation of the thermodynamic equation of state. To this end the lattice method and the Wilson twisted mass discretisation of the quark action are used. This formulation is known to have an automatic improvement of lattice artifacts and thus an improved continuum limit behaviour. This work presents first robust results using this action for the non-vanishing temperature case. We investigate the chiral limit of the two flavour phase transition with several small values of the pion mass in order to address the open question of the order of the transition in the limit of vanishing quark mass. For the currently simulated pion masses in the range of 300 to 700 MeV we present evidence that the finite temperature transition is a crossover transition rather than a genuine phase transition. The chiral limit is investigated by comparing the scaling of the observed crossover temperature with the mass including several possible scenarios. Complementary to this approach the chiral condensate as the order parameter for the spontaneous breaking of chiral symmetry is analysed in comparison with the O(4) universal scaling function which characterises a second order transition. With respect to thermodynamics the equation of state is obtained from the trace anomaly employing the temperature integral method which provides the pressure and energy density in the crossover region. The continuum limit of the trace anomaly is studied by considering several values of N τ and the tree-level correction technique.

HOME Income Limits

Data.gov (United States)

Department of Housing and Urban Development — HOME Income Limits are calculated using the same methodology that HUD uses for calculating the income limits for the Section 8 program. These limits are based on HUD...

Quantum distribution function of nonequilibrium system

International Nuclear Information System (INIS)

Sogo, Kiyoshi; Fujimoto, Yasushi.

1990-03-01

A path integral representation is derived for the Wigner distribution function of a nonequilibrium system coupled with heat bath. Under appropriate conditions, the Wigner distribution function approaches an equilibrium distribution, which manifests shifting and broadening of spectral lines due to the interaction with heat bath. It is shown that the equilibrium distribution becomes the quantum canonical distribution in the vanishing coupling constant limit. (author)

Hydrodynamic equations for electrons in graphene obtained from the maximum entropy principle

Energy Technology Data Exchange (ETDEWEB)

Barletti, Luigi, E-mail: luigi.barletti@unifi.it [Dipartimento di Matematica e Informatica “Ulisse Dini”, Università degli Studi di Firenze, Viale Morgagni 67/A, 50134 Firenze (Italy)

2014-08-15

The maximum entropy principle is applied to the formal derivation of isothermal, Euler-like equations for semiclassical fermions (electrons and holes) in graphene. After proving general mathematical properties of the equations so obtained, their asymptotic form corresponding to significant physical regimes is investigated. In particular, the diffusive regime, the Maxwell-Boltzmann regime (high temperature), the collimation regime and the degenerate gas limit (vanishing temperature) are considered.

Consistency relation and inflaton field redefinition in the δN formalism

Energy Technology Data Exchange (ETDEWEB)

Domènech, Guillem [Center for Gravitational Physics, Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto 606-8502 (Japan); Gong, Jinn-Ouk, E-mail: jinn-ouk.gong@apctp.org [Asia Pacific Center for Theoretical Physics, Pohang 37673 (Korea, Republic of); Department of Physics, Postech, Pohang 37673 (Korea, Republic of); Sasaki, Misao [Center for Gravitational Physics, Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto 606-8502 (Japan)

2017-06-10

We compute for general single-field inflation the intrinsic non-Gaussianity due to the self-interactions of the inflaton field in the squeezed limit. We recover the consistency relation in the context of the δN formalism, and argue that there is a particular field redefinition that makes the intrinsic non-Gaussianity vanishing, thus improving the estimate of the local non-Gaussianity using the δN formalism.

Polaron in the dilute critical Bose condensate

Science.gov (United States)

Pastukhov, Volodymyr

2018-05-01

The properties of an impurity immersed in a dilute D-dimensional Bose gas at temperatures close to its second-order phase transition point are considered. Particularly by means of the 1/N-expansion, we calculate the leading-order polaron energy and the damping rate in the limit of vanishing boson–boson interaction. It is shown that the perturbative effective mass and the quasiparticle residue diverge logarithmically in the long-length limit, signalling the non-analytic behavior of the impurity spectrum and pole-free structure of the polaron Green’s function in the infrared region, respectively.

Magnus force in discrete and continuous two-dimensional superfluids

International Nuclear Information System (INIS)

Gecse, Z.; Khlebnikov, S.

2005-01-01

Motion of vortices in two-dimensional superfluids in the classical limit is studied by solving the Gross-Pitaevskii equation numerically on a uniform lattice. We find that, in the presence of a superflow directed along one of the main lattice periods, vortices move with the superflow on fine lattices but perpendicular to it on coarse ones. We interpret this result as a transition from the full Magnus force in a Galilean-invariant limit to vanishing effective Magnus force in a discrete system, in agreement with the existing experiments on vortex motion in Josephson junction arrays

Inverse Limits

CERN Document Server

Ingram, WT

2012-01-01

Inverse limits provide a powerful tool for constructing complicated spaces from simple ones. They also turn the study of a dynamical system consisting of a space and a self-map into a study of a (likely more complicated) space and a self-homeomorphism. In four chapters along with an appendix containing background material the authors develop the theory of inverse limits. The book begins with an introduction through inverse limits on [0,1] before moving to a general treatment of the subject. Special topics in continuum theory complete the book. Although it is not a book on dynamics, the influen

Robust test limits

NARCIS (Netherlands)

Albers, Willem/Wim; Kallenberg, W.C.M.; Otten, G.D.

1997-01-01

Because of inaccuracies of the measurement process inspection of manufactured parts requires test limits which are more strict than the given specification limits. Test limits derived under the assumption of normality for product characteristics turn out to violate the prescribed bound on the

JET pump limiter

International Nuclear Information System (INIS)

Sonnenberg, K.; Deksnis, E.; Shaw, R.; Reiter, D.

1988-01-01

JET plans to install two pump limiter modules which can be used for belt-limiter, inner-wall and X-point discharges and, also, for 1-2s as the main limiter. A design is presented which is compatible with two diagnostic systems, and which allows partial removal of the pump limiter to provide access for remote-handling operations. The high heat-flux components are initially cooled during a pulse. Heat is removed between discharges by radiation and pressure contacts to a water-cooled support structure. The pumping edge will be made of annealed pyrolytic graphite. Exhaust efficiency has been estimated, for a 1-d edge model, using a Monte-Carlo calculation of neutral gas transport. When the pump limiter is operated together with other wall components we expect an efficiency of ≅ 5% (2.5 x 10 21 part/s). As a main limiter the efficiency increases to about 10%. (author)

Moving toroidal limiter

International Nuclear Information System (INIS)

Ikuta, Kazunari; Miyahara, Akira.

1983-06-01

The concept of the limiter-divertor proposed by Mirnov is extended to a toroidal limiter-divertor (which we call moving toroidal limiter) using the stream of ferromagnetic balls coated with a low Z materials such as plastics, graphite and ceramics. An important advantage of the use of the ferromagnetic materials would be possible soft landing of the balls on a catcher, provided that the temperature of the balls is below Curie point. Moreover, moving toroidal limiter would work as a protector of the first wall not only against the vertical movement of plasma ring but also against the violent inward motion driven by major disruption because the orbit of the ball in the case of moving toroidal limiter distributes over the small major radius side of the toroidal plasma. (author)

Threshold limit values, permissible exposure limits, and feasibility: The bases for exposure limits in the United States

International Nuclear Information System (INIS)

Rappaport, S.M.

1993-01-01

The development of exposure limits in the United States has always relied heavily upon the threshold limit values (TLVs) developed by the American Conference of Governmental Industrial Hygienists (ACGIH). In fact, the TLVs were adopted as official exposure limits by the Occupational Safety and Health Administration (OSHA) in 1972 and 1989. Given the continuing importance of the ACGIH limits, this paper compares the basis of the TLVs with that employed by OSHA de novo in its 12 new permissible exposure limits (PELs). Using benzene as an example, it is shown that OSHA's new PELs have been established following a rigorous assessment of the inherent risks and the feasibility of instituting the limit. The TLVs, on the other hand, have been developed by ad hoc procedures and appear to have traditionally reflected levels thought to be achievable at the time. However, this might be changing. Analysis of the historical reductions of TLVs, for 27 substances on the 1991-1992 list of intended changes, indicates smaller reductions in the past (median reduction of 2.0-2.5-fold between 1946 and 1988) compared to those currently being observed (median reduction of 7.5-fold between 1989 and 1991). Further analysis suggests a more aggressive policy of the ACGIH regarding TLVs for carcinogens but not for substances that produce effects other than cancer. Regardless of whether the basis of the TLVs has changed recently, it would take a relatively long time for the impact of any change to be felt, since the median age of the 1991-1992 TLVs is 16.5 years, and 75% of these limits are more than 10 years old. The implications of OSHA's continued reliance on the TLVs as a means of updating its PELs are discussed, and four alternatives are presented to the ACGIH regarding the future of its activities related to exposure limits. It is concluded that new mechanisms are needed for OSHA to update its PELs in a timely fashion so that the TLVs will not be adopted by default in the future

Tokamak pump limiters

International Nuclear Information System (INIS)

Conn, R.W.

1984-05-01

Recent experiments with a scoop limiter without active internal pumping have been carried out in the PDX tokamak with up to 6MW of auxiliary neutral beam heating. Experiments have also been done with a rotating head pump limiter in the PLT tokamak in conjunction with RF plasma heating. Extensive experiments have been done in the ISX-B tokamak and first experiments have been completed with the ALT-I limiter in TEXTOR. The pump limiter modules in these latter two machines have internal getter pumping. Experiments in ISX-B are with ohmic and auxiliary neutral beam heating. The results in ISX-B and TEXTOR show that active density control and particle removal is achieved with pump limiters. In ISX-B, the boundary layer (or scape-off layer) plasma partially screens the core plasma from gas injection. In both ISX-B and TEXTOR, the pressure internal to the module scales linearly with plasma density but in ISX-B, with neutral beam injection, a nonlinear increase is observed at the highest densities studied. Plasma plugging is the suspected cause. Results from PDX suggest that a region may exist in which core plasma energy confinement improves using a pump limiter during neutral beam injection. Asymmetric radial profiles and an increased edge electron temperature are observed in discharges with improved confinement. The injection of small amounts of neon into ISX-B has more clearly shown an improved electron core energy confinement during neutral beam injection. While carried out with a regular limiter, this Z-mode of operation is ideal for use with pump limiters and should be a way to achieve energy confinement times similar to values for H-mode tokamak plasmas. The implication of all these results for the design of a reactor pump limiter is described

Tokamak pump limiters

International Nuclear Information System (INIS)

Conn, R.W.; California Univ., Los Angeles

1984-01-01

Recent experiments with a scoop limiter without active internal pumping have been carried out in the PDX tokamak with up to 6 MW of auxiliary neutral beam heating. Experiments have also been performed with a rotating head pump limiter in the PLT tokamak in conjunction with RF plasma heating. Extensive experiments have been done in the ISX-B tokamak and first experiments have been completed with the ALT-I limiter in TEXTOR. The pump limiter modules in these latter two machines have internal getter pumping. Experiments in ISX-B are with ohmic and auxiliary neutral beam heating. The results in ISX-B and TEXTOR show that active density control and particle removal is achieved with pump limiters. In ISX-B, the boundary layer (or scrape-off layer) plasma partially screens the core plasma from gas injection. In both ISX-B and TEXTOR, the pressure internal to the module scales linearly with plasma density but in ISX-B, with neutral beam injection, a nonlinear increase is observed at the highest densities studied. Plasma plugging is the suspected cause. Results from PDX suggest that a regime may exist in which core plasma energy confinement improves using a pump limiter during neutral beam injection. Asymmetric radial profiles and an increased edge electron temperature are observed in discharges with improved confinement. The injection of small amounts of neon into ISX-B has more clearly shown an improved electron core energy confinement during neutral beam injection. While carried out with a regular limiter, this 'Z-mode' of operation is ideal for use with pump limiters and should be a way to achieve energy confinement times similar to values for H-mode tokamak plasmas. The implication of all these results for the design of a reactor pump limiter is described. (orig.)

Absence of ballistic charge transport in the half-filled 1D Hubbard model

Science.gov (United States)

Carmelo, J. M. P.; Nemati, S.; Prosen, T.

2018-05-01

Whether in the thermodynamic limit of lattice length L → ∞, hole concentration mηz = - 2 Sηz/L = 1 -ne → 0, nonzero temperature T > 0, and U / t > 0 the charge stiffness of the 1D Hubbard model with first neighbor transfer integral t and on-site repulsion U is finite or vanishes and thus whether there is or there is no ballistic charge transport, respectively, remains an unsolved and controversial issue, as different approaches yield contradictory results. (Here Sηz = - (L -Ne) / 2 is the η-spin projection and ne =Ne / L the electronic density.) In this paper we provide an upper bound on the charge stiffness and show that (similarly as at zero temperature), for T > 0 and U / t > 0 it vanishes for mηz → 0 within the canonical ensemble in the thermodynamic limit L → ∞. Moreover, we show that at high temperature T → ∞ the charge stiffness vanishes as well within the grand-canonical ensemble for L → ∞ and chemical potential μ →μu where (μ -μu) ≥ 0 and 2μu is the Mott-Hubbard gap. The lack of charge ballistic transport indicates that charge transport at finite temperatures is dominated by a diffusive contribution. Our scheme uses a suitable exact representation of the electrons in terms of rotated electrons for which the numbers of singly occupied and doubly occupied lattice sites are good quantum numbers for U / t > 0. In contrast to often less controllable numerical studies, the use of such a representation reveals the carriers that couple to the charge probes and provides useful physical information on the microscopic processes behind the exotic charge transport properties of the 1D electronic correlated system under study.

Dose limits

International Nuclear Information System (INIS)

Fitoussi, L.

1987-12-01

The dose limit is defined to be the level of harmfulness which must not be exceeded, so that an activity can be exercised in a regular manner without running a risk unacceptable to man and the society. The paper examines the effects of radiation categorised into stochastic and non-stochastic. Dose limits for workers and the public are discussed

Quantum games with decoherence

International Nuclear Information System (INIS)

Flitney, A P; Abbott, D

2005-01-01

A protocol for considering decoherence in quantum games is presented. Results for two-player, two-strategy quantum games subject to decoherence are derived and some specific examples are given. Decoherence in other types of quantum games is also considered. As expected, the advantage that a quantum player achieves over a player restricted to classical strategies is diminished for increasing decoherence but only vanishes in the limit of maximum decoherence

Families of superintegrable Hamiltonians constructed from exceptional polynomials

International Nuclear Information System (INIS)

Post, Sarah; Tsujimoto, Satoshi; Vinet, Luc

2012-01-01

We introduce a family of exactly-solvable two-dimensional Hamiltonians whose wave functions are given in terms of Laguerre and exceptional Jacobi polynomials. The Hamiltonians contain purely quantum terms which vanish in the classical limit leaving only a previously known family of superintegrable systems. Additional, higher-order integrals of motion are constructed from ladder operators for the considered orthogonal polynomials proving the quantum system to be superintegrable. (paper)

NLO corrections to power suppressed contributions to anti B → X{sub c}l anti ν

Energy Technology Data Exchange (ETDEWEB)

Mannel, Thomas; Pivovarov, Alexei A.; Rosenthal, Denis [Theoretische Physik 1, Naturwissenschaftlich-Technische Fakultaet, Universitaet Siegen, Walter-Flex-Strasse 3, D-57068 Siegen (Germany)

2015-07-01

We present the results of a calculation of the perturbative QCD corrections for the semileptonic inclusive width of a heavy flavored meson. Within the Heavy Quark Expansion we analytically compute the QCD correction to the coefficient of power suppressed contribution of chromo-magnetic operator in the limit of vanishing mass of the final state quark. The important phenomenological applications are decays of bottom mesons, and to the less extent, charmed mesons.

The light bound states of N=1 supersymmetric SU(3) Yang-Mills theory on the lattice

Science.gov (United States)

Ali, Sajid; Bergner, Georg; Gerber, Henning; Giudice, Pietro; Montvay, Istvan; Münster, Gernot; Piemonte, Stefano; Scior, Philipp

2018-03-01

In this article we summarise our results from numerical simulations of N=1 supersymmetric Yang-Mills theory with gauge group SU(3). We use the formulation of Curci and Veneziano with clover-improved Wilson fermions. The masses of various bound states have been obtained at different values of the gluino mass and gauge coupling. Extrapolations to the limit of vanishing gluino mass indicate that the bound states form mass-degenerate supermultiplets.

Criticality of the D=2 anisotropic quantum Heisenberg model

International Nuclear Information System (INIS)

Caride, A.O.; Tsallis, C.; Zanette, S.I.

1983-01-01

Within a real space renormalization group framework, the square-lattice spin-1/2 Heisenberg ferromagnet in the presence of an Ising-like anisotropy is discussed. The controversial point on how T sub(c) vanishes in the isotropic Heisenberg limit is analyzed: quite strong evidence is presented favoring a continuous function of anisotropy. The crossover from the isotropic Heisenberg model to the pure Ising one is exhibited. (Author) [pt

Turn-on delay of QD and QW laser diodes: What is the difference?

International Nuclear Information System (INIS)

Sokolovskii, G S; Dudelev, V V; Kolykhalova, E D; Deryagin, A G; Maximov, M V; Nadtochiy, A M; Kuchinskii, V I; Mikhrin, S S; Livshits, D A; Viktorov, E A; Erneux, T

2013-01-01

Turn-on delay of laser diodes with quantum-sized active media is investigated both theoretically and experimentally. In this research we show the striking difference in turn-on delay of quantum dot and quantum well laser diodes: With quantum-well lasers turn on delay tends to zero in the limit of high pumping, while with quantum dot lasers turn-on delay has the non-vanishing component which is independent of pumping

On the assumption of vanishing temperature fluctuations at the wall for heat transfer modeling

Science.gov (United States)

Sommer, T. P.; So, R. M. C.; Zhang, H. S.

1993-01-01

Boundary conditions for fluctuating wall temperature are required for near-wall heat transfer modeling. However, their correct specifications for arbitrary thermal boundary conditions are not clear. The conventional approach is to assume zero fluctuating wall temperature or zero gradient for the temperature variance at the wall. These are idealized specifications and the latter condition could lead to an ill posed problem for fully-developed pipe and channel flows. In this paper, the validity and extent of the zero fluctuating wall temperature condition for heat transfer calculations is examined. The approach taken is to assume a Taylor expansion in the wall normal coordinate for the fluctuating temperature that is general enough to account for both zero and non-zero value at the wall. Turbulent conductivity is calculated from the temperature variance and its dissipation rate. Heat transfer calculations assuming both zero and non-zero fluctuating wall temperature reveal that the zero fluctuating wall temperature assumption is in general valid. The effects of non-zero fluctuating wall temperature are limited only to a very small region near the wall.

QCD at Zero Baryon Density and the Polyakov Loop Paradox

CERN Document Server

Kratochvila, S; Forcrand, Ph. de

2006-01-01

We compare the grand canonical partition function at fixed chemical potential mu with the canonical partition function at fixed baryon number B, formally and by numerical simulations at mu=0 and B=0 with four flavours of staggered quarks. We verify that the free energy densities are equal in the thermodynamic limit, and show that they can be well described by the hadron resonance gas at T T_c. Small differences between the two ensembles, for thermodynamic observables characterising the deconfinement phase transition, vanish with increasing lattice size. These differences are solely caused by contributions of non-zero baryon density sectors, which are exponentially suppressed with increasing volume. The Polyakov loop shows a different behaviour: for all temperatures and volumes, its expectation value is exactly zero in the canonical formulation, whereas it is always non-zero in the commonly used grand-canonical formulation. We clarify this paradoxical difference, and show that the non-vanishing Polyakov loop e...

Kinetic features of interchange turbulence

International Nuclear Information System (INIS)

Sarazin, Y; Grandgirard, V; Fleurence, E; Garbet, X; Ghendrih, Ph; Bertrand, P; Depret, G

2005-01-01

Non-linear gyrokinetic simulations of the interchange instability are discussed. The semi-Lagrangian numerical scheme allows one to address two critical points achieved with simulations lasting several confinement times: an accurate statistical analysis of the fluctuations and the back reaction of the turbulence on equilibrium profiles. Zonal flows are found to quench a 2D + 1D interchange turbulence when one of the species has a vanishing response to zonal modes. Conversely, when streamers dominate, the equilibrium profiles are found to be stiff. In the non-linear regime and steady-state turbulence, the distribution function exhibits a significant departure from a Maxwellian distribution. This property is characterized by an expansion on generalized Laguerre functions with a slow decay of the series of moments. This justifies the use of gyrokinetic simulations since a standard fluid approach, based on a limited number of moments, would certainly require a complex closure so as to take into account the impact of these non-vanishing high order moments

Vanishing large ovarian cyst with thyroxine therapy

OpenAIRE

Dharmshaktu, Pramila; Kutiyal, Aditya; Dhanwal, Dinesh

2013-01-01

Summary A 21-year-old female patient recently diagnosed with severe hypothyroidism was found to have a large ovarian cyst. In view of the large ovarian cyst, she was advised to undergo elective laparotomy in the gynaecology department. She was further evaluated in our medical out-patient department (OPD), and elective surgery was withheld. She was started on thyroxine replacement therapy, and within a period of 4 months, the size of the cyst regressed significantly, thereby improving the cond...

Vanishing large ovarian cyst with thyroxine therapy.

Science.gov (United States)

Dharmshaktu, Pramila; Kutiyal, Aditya; Dhanwal, Dinesh

2013-01-01

A 21-year-old female patient recently diagnosed with severe hypothyroidism was found to have a large ovarian cyst. In view of the large ovarian cyst, she was advised to undergo elective laparotomy in the gynaecology department. She was further evaluated in our medical out-patient department (OPD), and elective surgery was withheld. She was started on thyroxine replacement therapy, and within a period of 4 months, the size of the cyst regressed significantly, thereby improving the condition of the patient significantly. This case report highlights the rare and often missed association between hypothyroidism and ovarian cysts. Although very rare, profound hypothyroidism that can cause ovarian cysts in an adult should always be kept in the differential diagnosis to avoid unnecessary ovarian surgery. Hypothyroidism should be considered in the differential diagnosis of adult females presenting with multicystic ovarian tumours.Adequate thyroid hormone replacement therapy can prevent these patients from undergoing unnecessary and catastrophic ovarian resection.Surgical excision should be considered only when adequate thyroid replacement therapy fails to resolve ovarian enlargement.In younger women with ovarian cysts, it is also desirable to avoid unnecessary surgery so as to not compromise fertility in the future.

Transverse correlation vanishing due to phase aberrations

CSIR Research Space (South Africa)

Godin, T

2011-06-01

Full Text Available of the effects of each aberration on the ratio Sp ?? / , the following condition are imposed: 0max3max2max1 )()()( ??????? === . (9) It is assumed that the phase aberration is set in the beam-waist plane of radius mmW 5.10 = . Arbitrarily, the value... of max? is fixed to twice the incident beam width, 0max 2W=? , where the intensity is only 0.03% of the on-axis value. In the following we will express the aberration 0? in number of equivalent wavelengths given by the ratio )2/(00 pi...

Impacts of generalized uncertainty principle on black hole thermodynamics and Salecker-Wigner inequalities

International Nuclear Information System (INIS)

Tawfik, A.

2013-01-01

We investigate the impacts of Generalized Uncertainty Principle (GUP) proposed by some approaches to quantum gravity such as String Theory and Doubly Special Relativity on black hole thermodynamics and Salecker-Wigner inequalities. Utilizing Heisenberg uncertainty principle, the Hawking temperature, Bekenstein entropy, specific heat, emission rate and decay time are calculated. As the evaporation entirely eats up the black hole mass, the specific heat vanishes and the temperature approaches infinity with an infinite radiation rate. It is found that the GUP approach prevents the black hole from the entire evaporation. It implies the existence of remnants at which the specific heat vanishes. The same role is played by the Heisenberg uncertainty principle in constructing the hydrogen atom. We discuss how the linear GUP approach solves the entire-evaporation-problem. Furthermore, the black hole lifetime can be estimated using another approach; the Salecker-Wigner inequalities. Assuming that the quantum position uncertainty is limited to the minimum wavelength of measuring signal, Wigner second inequality can be obtained. If the spread of quantum clock is limited to some minimum value, then the modified black hole lifetime can be deduced. Based on linear GUP approach, the resulting lifetime difference depends on black hole relative mass and the difference between black hole mass with and without GUP is not negligible

The exited hexagon reloaded

Energy Technology Data Exchange (ETDEWEB)

Bartels, Joachim [Hamburg Univ. (Germany). II. Inst. fuer Theoretische Physik; Kotanski, Jan; Schomerus, Volker; Sprenger, Martin [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

2013-11-15

This work revisits the computation of six-gluon scattering amplitudes in the high energy limit of strongly coupled N=4 supersymmetric Yang-Mills theory. It is based on previous studies in which we showed that the amplitude simplifies in the Regge regime and outlined an efficient computational scheme. By exploiting a symmetry of the underlying equations we are now able to argue that a term we had seen in preliminary numerical studies must vanish identically. The derived formula for the Regge limit of the 6-gluon scattering amplitude at strong coupling differs from the one we had conjectured previously.

Statistical mechanics of free particles on space with Lie-type noncommutativity

Energy Technology Data Exchange (ETDEWEB)

Shariati, Ahmad; Khorrami, Mohammad; Fatollahi, Amir H, E-mail: shariati@mailaps.or, E-mail: mamwad@mailaps.or, E-mail: ahfatol@gmail.co [Department of Physics, Alzahra University, Tehran 1993891167 (Iran, Islamic Republic of)

2010-07-16

Effects of Lie-type noncommutativity on thermodynamic properties of a system of free identical particles are investigated. A definition for finite volume of the configuration space is given, and the grandcanonical partition function in the thermodynamic limit is calculated. Two possible definitions for the pressure are discussed, which are equivalent when the noncommutativity vanishes. The thermodynamic observables are extracted from the partition function. Different limits are discussed where either the noncommutativity or the quantum effects are important. Finally, specific cases are discussed where the group is SU(2) or SO(3), and the partition function of a nondegenerate gas is calculated.

The exited hexagon reloaded

International Nuclear Information System (INIS)

Bartels, Joachim

2013-11-01

This work revisits the computation of six-gluon scattering amplitudes in the high energy limit of strongly coupled N=4 supersymmetric Yang-Mills theory. It is based on previous studies in which we showed that the amplitude simplifies in the Regge regime and outlined an efficient computational scheme. By exploiting a symmetry of the underlying equations we are now able to argue that a term we had seen in preliminary numerical studies must vanish identically. The derived formula for the Regge limit of the 6-gluon scattering amplitude at strong coupling differs from the one we had conjectured previously.

Screening of electron electric dipole moment through the Foldy-Wouthuysen representation

Directory of Open Access Journals (Sweden)

M M Ettefaghi

2015-07-01

Full Text Available The existent of the intrinsic electric dipole moments (EDM lead to CP violation in a physical system. In the non-relativistic and point like limits, the effects of them in atoms are canceled which is well-known as Schiff screening effects. It is why that the energy shift due to the EDM is proportional to the expectation value of which vanishes in non-relativistic limit. In this paper, using Foldy-Wouthuysen representation we remove the odd terms (those terms mix the positive and negative energy solutions up to order and then study the Schiff screening effects.

Detector limitations, STAR

Energy Technology Data Exchange (ETDEWEB)

Underwood, D. G.

1998-07-13

Every detector has limitations in terms of solid angle, particular technologies chosen, cracks due to mechanical structure, etc. If all of the presently planned parts of STAR [Solenoidal Tracker At RHIC] were in place, these factors would not seriously limit our ability to exploit the spin physics possible in RHIC. What is of greater concern at the moment is the construction schedule for components such as the Electromagnetic Calorimeters, and the limited funding for various levels of triggers.

Advanced limiters for ISX

International Nuclear Information System (INIS)

Mioduszewski, P.K.; Edmonds, P.H.; Sheffield, J.

1982-01-01

Continuous removal of heat and particles becomes a vital necessity in future steady-state fusion devices. The pump limiter seems to be an attractive concept to combine these two tasks. On ISX, various schemes of pump limiters are being explored with the final goal to furnish the ISX--C device with a pump limiter to handle heat removal and particle control in steady state. The emphasis of the present paper is on pump limiters based on ballistic particle collection. If this concept turns out to be successful in supplying sufficient pumping efficiency, it may be possible to design pump limiters without a leading edge. Analytical calculations of the particle collection efficiency are given for various limiter configurations. Pumping efficiencies of approximately 4--10%, depending on the specific configuration, seem to be feasible and should be sufficient for steady-state operation. Initial experimental results on pump limiter studies in ISX--B confirm the calculated collection efficiencies. By measuring the ion saturation current to the limiter blade and the pressure buildup simultaneously, we found a correlation between the incident particle flux and the pressure rise that agrees well with a simple model

Agent-based models for latent liquidity and concave price impact

Science.gov (United States)

Mastromatteo, Iacopo; Tóth, Bence; Bouchaud, Jean-Philippe

2014-04-01

We revisit the "ɛ-intelligence" model of Tóth et al. [Phys. Rev. X 1, 021006 (2011), 10.1103/PhysRevX.1.021006], which was proposed as a minimal framework to understand the square-root dependence of the impact of meta-orders on volume in financial markets. The basic idea is that most of the daily liquidity is "latent" and furthermore vanishes linearly around the current price, as a consequence of the diffusion of the price itself. However, the numerical implementation of Tóth et al. (2011) was criticized as being unrealistic, in particular because all the "intelligence" was conferred to market orders, while limit orders were passive and random. In this work, we study various alternative specifications of the model, for example, allowing limit orders to react to the order flow or changing the execution protocols. By and large, our study lends strong support to the idea that the square-root impact law is a very generic and robust property that requires very few ingredients to be valid. We also show that the transition from superdiffusion to subdiffusion reported in Tóth et al. (2011) is in fact a crossover but that the original model can be slightly altered in order to give rise to a genuine phase transition, which is of interest on its own. We finally propose a general theoretical framework to understand how a nonlinear impact may appear even in the limit where the bias in the order flow is vanishingly small.

PENGGUNAAN KOMBINASI KUNYIT (Curcuma domestica DAN JAHE (Zingiber officinale BENTUK ENKAPSULASI DAN TANPA ENKAPSULASI TERHADAP KARAKTERISTIK USUS DAN MIKROFLORA USUS AYAM PEDAGING

Directory of Open Access Journals (Sweden)

Muhammad Halim Natsir

2016-03-01

Full Text Available The purpose of this research was to examine the use of curcuma (curcuma domestica and ginger (Zingiber officinale combinations with encapsulated and not Encapsulated on intestinal histological and Intestinal Microflora in broiler. The materials used in this research were 180 day-old broiler chicks, flour and encapsulated turmeric and ginger mixture. The encapsulants used were maltodextrin (75 %: casein 25 % and adding BHT 0.075 % from extract of 10 % turmeric and ginger mixture. The methods used a Laboratory experiment of a Completely Randomized Design with 9 treatments (P0 = control feed, namely 2 forms of turmeric and ginger mixture. (flour and encapsulated with 4 levels (0.2; 0.4; 0.6 and 0.8%. The results showed that use of turmeric and ginger mixture in the form of non-encapsulation and encapsulation significantly improved (P<0.01 pH, viscocity of digesta and the number of villi, but showed a no significant difference on villi height, and the number of bacteria (LAB, Lactobacillus, sp, E Coli and salmonella Sp.. It is concluded that the use of turmeric and ginger mixture of encapsulated form provides better results than the form of non- encapsulation with the optimum level of 0.8%. Therefore using encapsulated form in 0.8% of the combined turmeric and ginger in broiler diet is recommended.   (Key words: Broiler, Encapsulation, Ginger, Histological, Microflora, Turmeric

Derivation of the Lifshitz-Matsubara sum formula for the Casimir pressure between metallic plane mirrors

Science.gov (United States)

Guérout, R.; Lambrecht, A.; Milton, K. A.; Reynaud, S.

2014-10-01

We carefully reexamine the conditions of validity for the consistent derivation of the Lifshitz-Matsubara sum formula for the Casimir pressure between metallic plane mirrors. We recover the usual expression for the lossy Drude model but not for the lossless plasma model. We give an interpretation of this new result in terms of the modes associated with the Foucault currents, which play a role in the limit of vanishing losses, in contrast to common expectations.

Asymptotic behavior of the mean square displacement of the Brownian parametric oscillator near the singular point

International Nuclear Information System (INIS)

Tashiro, Tohru

2009-01-01

A parametric oscillator with damping driven by white noise is studied. The mean square displacement (MSD) in the long-time limit is derived analytically for the case that the static force vanishes, which was not treated in the past work (Tashiro and Morita 2007 Physica A 377 401). The formula is asymptotic but is applicable to a general periodic function. On the basis of this formula, some periodic functions reducing MSD remarkably are proposed

Quarkonium spectral function in medium at next-to-leading order for any quark mass

International Nuclear Information System (INIS)

Burnier, Yannis

2015-01-01

The vector channel spectral function at zero spatial momentum is calculated at next-to-leading order in thermal QCD for any quark mass. It corresponds to the imaginary part of the massive quark contribution to the photon polarisation tensor. The spectrum shows a well-defined transport peak in contrast to both the heavy quark limit studied previously, where the low frequency domain is exponentially suppressed at this order, and the naive massless case where it vanishes at leading order and diverges at next-to-leading order. From our general expressions, the massless limit can be taken and we show that no divergences occur if done carefully. Finally, we compare the massless limit to results from lattice simulations. (orig.)

LANSCE beam current limiter

International Nuclear Information System (INIS)

Gallegos, F.R.

1996-01-01

The Radiation Security System (RSS) at the Los Alamos Neutron Science Center (LANSCE) provides personnel protection from prompt radiation due to accelerated beam. Active instrumentation, such as the Beam Current Limiter, is a component of the RSS. The current limiter is designed to limit the average current in a beam line below a specific level, thus minimizing the maximum current available for a beam spill accident. The beam current limiter is a self-contained, electrically isolated toroidal beam transformer which continuously monitors beam current. It is designed as fail-safe instrumentation. The design philosophy, hardware design, operation, and limitations of the device are described

Scrape-off layer based modelling of the density limit in beryllated JET limiter discharges

International Nuclear Information System (INIS)

Borrass, K.; Campbell, D.J.; Clement, S.; Vlases, G.C.

1993-01-01

The paper gives a scrape-off layer based interpretation of the density limit in beryllated JET limiter discharges. In these discharges, JET edge parameters show a complicated time evolution as the density limit is approached and the limit is manifested as a non-disruptive density maximum which cannot be exceeded by enhanced gas puffing. The occurrence of Marfes, the manner of density control and details of recycling are essential elements of the interpretation. Scalings for the maximum density are given and compared with JET data. The relation to disruptive density limits, previously observed in JET carbon limiter discharges, and to density limits in divertor discharges is discussed. (author). 18 refs, 10 figs, 1 tab

Preliminary disposal limits, plume interaction factors, and final disposal limits

Energy Technology Data Exchange (ETDEWEB)

Flach, G. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2018-01-11

In the 2008 E-Area Performance Assessment (PA), each final disposal limit was constructed as the product of a preliminary disposal limit and a plume interaction factor. The following mathematical development demonstrates that performance objectives are generally expected to be satisfied with high confidence under practical PA scenarios using this method. However, radionuclides that experience significant decay between a disposal unit and the 100-meter boundary, such as H-3 and Sr-90, can challenge performance objectives, depending on the disposed-of waste composition, facility geometry, and the significance of the plume interaction factor. Pros and cons of analyzing single disposal units or multiple disposal units as a group in the preliminary disposal limits analysis are also identified.

Altruism and Reproductive Limitations

Directory of Open Access Journals (Sweden)

Carey J. Fitzgerald

2009-04-01

Full Text Available We examined how different types of reproductive limitations — functional (schizoid personality disorder and schizophrenia, physical (malnutrition, and sexual (bisexuality and homosexuality — influenced altruistic intentions toward hypothetical target individuals of differing degrees of relatedness (r = 0, .25, and .50. Participants were 312 undergraduate students who completed a questionnaire on altruism toward hypothetical friends, half-siblings, and siblings with these different types of reproductive limitations. Genetic relatedness and reproductive limitations did not influence altruistic decision-making when the cost of altruism was low but did as the cost of altruism increased, with participants being more likely to help a sibling over a half-sibling and a half-sibling over a friend. Participants also indicated they were more likely to help a healthy (control person over people with a reproductive limitation. Of the three types of reproductive limitations, functional limitations had the strongest effect on altruistic decision-making, indicating that people were less likely to help those who exhibit abnormal social behavior.

Power limit and quality limit of natural circulation reactor

International Nuclear Information System (INIS)

Zhao Guochang; Ma Changwen

1997-01-01

The circulation characteristics of natural circulation reactor in boiling regime are researched. It is found that, the circulation mass flow rate and the power have a peak value at a mass quality respectively. Therefore, the natural circulation reactor has a power limit under certain technological condition. It can not be increased steadily by continually increasing the mass quality. Corresponding to this, the mass quality of natural circulation reactor has a reasonable limit. The relations between the maximum power and the reactor parameters, such as the resistance coefficient, the working pressure and so on, are analyzed. It is pointed out that the power limit of natural circulation reactor is about 1000 MW at present technological condition. Taking the above result and low quality stability experimental result into account, the authors recommend that the reasonable mass quality of natural circulation reactor working in boiling regime is from 2% to 3% under the researched working pressure

Compliance of feed limits, does not mean compliance of food limits

Directory of Open Access Journals (Sweden)

van Raamsdonk LWD.

2009-01-01

Full Text Available The carry-over of contaminants from feed to animal food products is an important aspect of the animal production chain. For a proper containment, limits for feed as well food products are fixed for a series of chemicals, e.g. dioxins and dioxin-like PCBs, lead, cadmium, some chlorinated pesticides, and aflatoxin B1 (and its metabolite M1 in milk. The relationship between feed and food limits is an important issue. An ideal goal is to assure that compliance to a feed limits automatically results in compliance to food limits. In order to collect information about this relationship, several simulation models and a large database on transfer factors have been developed. An optimal choice between either a model or an application of data from the Transfer Database is based on both the knowledge level, and on the circumstances of the specific situation. To reach and validate such an optimal choice an Expert System Carry-Over is currently in development, containing four different modules: 1 the different calculation models and the Transfer Database, 2 a decision tree for choosing the optimal strategy, 3 data tables indicating knowledge levels of compound/animal/product parameters, and 4 supporting databases containing information on consumption and composition of daily diets, animal parameters, and amounts of (daily production. Calculations indicate that for dioxins compliance to feed levels does not necessarily mean that food limits are complied as well. Besides an estimation of the compliance to limits, the expert system is a tool for feed related risk assessments, and for planning of future research.

Liberty through limits: The bill of rights as limited government provisions

Directory of Open Access Journals (Sweden)

Patrick M. Garry

2013-04-01

Full Text Available Under the modern view, individual autonomy has become the primary if not exclusive focus of the Bill of Rights. But the Bill of Rights came about not because of a desire to preserve individual autonomy, nor to insulate the individual from the democratic community. The impetus for the Bill of Rights arose from the same set of concerns that motivated the original Constitution. These concerns involved creating the appropriate structures so as to keep the new central government in check. The Bill of Rights sought to further ensure that the federal government would have limited power and operate in a limited role. Not only does this limited government model coincide with the original intent underlying the Bill of Rights, but it also provides for a more objective and manageable application. Under an individual autonomy view of the Bill of Rights, courts must define the ingredients necessary for such autonomy. However, this endeavor is fraught with ambiguity, and courts must constantly pit the individual against democratic society. But under the limited government model, the judicial role is more objective. Instead of trying to define an ambiguous individual autonomy, courts simply need to focus on whether a particular right is needed so as to maintain limited government. In addition, the limited government model does not put the Bill of Rights in conflict with democratic society. Instead, it just uses the Bill of Rights to maintain a check on government, just as the original Constitution seeks to do.

Be-limiter experiment on ISX

International Nuclear Information System (INIS)

Mioduszewski, P.K.

1984-01-01

The relevance of this experiment to the JET experiment is described. Data on the following issues are given: (1) thermo-mechanical properties of the Be-limiter; (2) particle flow to limiter; (3) heat flow to the limiter; (4) limiter-plasma-wall interaction; (5) plasma properties/operation; (6) active control of plasma-limiter operation; and (7) fault conditions

Determination and Interpretation of Characteristic Limits for Radioactivity Measurements: Decision Threshhold, Detection Limit and Limits of the Confidence Interval

International Nuclear Information System (INIS)

2017-01-01

Since 2004, the environment programme of the IAEA has included activities aimed at developing a set of procedures for analytical measurements of radionuclides in food and the environment. Reliable, comparable and fit for purpose results are essential for any analytical measurement. Guidelines and national and international standards for laboratory practices to fulfil quality assurance requirements are extremely important when performing such measurements. The guidelines and standards should be comprehensive, clearly formulated and readily available to both the analyst and the customer. ISO 11929:2010 is the international standard on the determination of the characteristic limits (decision threshold, detection limit and limits of the confidence interval) for measuring ionizing radiation. For nuclear analytical laboratories involved in the measurement of radioactivity in food and the environment, robust determination of the characteristic limits of radioanalytical techniques is essential with regard to national and international regulations on permitted levels of radioactivity. However, characteristic limits defined in ISO 11929:2010 are complex, and the correct application of the standard in laboratories requires a full understanding of various concepts. This publication provides additional information to Member States in the understanding of the terminology, definitions and concepts in ISO 11929:2010, thus facilitating its implementation in Member State laboratories.

Near horizon extremal Myers–Perry black holes and integrability of associated conformal mechanics

Directory of Open Access Journals (Sweden)

Tigran Hakobyan

2017-09-01

Full Text Available We investigate dynamics of probe particles moving in the near-horizon limit of (2N+1-dimensional extremal Myers–Perry black hole with arbitrary rotation parameters. We observe that in the most general case with non-equal non-vanishing rotational parameters the system admits separation of variables in N-dimensional ellipsoidal coordinates. This allows us to find solution of the corresponding Hamilton–Jacobi equation and write down the explicit expressions of Liouville constants of motion.

Spectral Approximation for Ergodic CMV Operators with an Application to Quantum Walks

OpenAIRE

Fillman, Jake; Ong, Darren C.; Vandenboom, Tom

2017-01-01

We establish concrete criteria for fully supported absolutely continuous spectrum for ergodic CMV matrices and purely absolutely continuous spectrum for limit-periodic CMV matrices. We proceed by proving several variational estimates on the measure of the spectrum and the vanishing set of the Lyapunov exponent for CMV matrices, which represent CMV analogues of results obtained for Schr\\"odinger operators due to Y.\\ Last in the early 1990s. Having done so, we combine those estimates with resul...

Frequency and temperature dependent mobility of a charged carrier and randomly interrupted strand

International Nuclear Information System (INIS)

Kumar, N.; Jayannavar, A.M.

1981-05-01

Randomly interrupted strand model of a one-dimensional conductor is considered. Exact analytical expression is obtained for the temperature dependent as mobility for a finite segment drawn at random, taking into account the reflecting barriers at the two open ends. The real part of mobility shows a broad resonance as a function of both frequency and tempeature, and vanishes quadratically in the dc limit. The frequency (temperature) maximum shifts to higher values for higher temperatures (frequencies). (author)

Comparison of second-order impact line shifts

International Nuclear Information System (INIS)

Griem, H.R.; Iglesias, C.A.; Boercker, D.B.

1991-01-01

The second-order impact shifts in hydrogen obtained from the Baranger formalism are compared with those from a kinetic theory approach. The resulting Δn=0 contributions to the shift from the two theories are shown to be identical, except for the neglect of electron-electron correlations in the Baranger formalism. It is also shown that some care is required in taking the classical limit for the perturbing electrons, or else the shift from Δn=0 interactions vanishes

Equivalence of massive propagator distance and mathematical distance on graphs

International Nuclear Information System (INIS)

Filk, T.

1992-01-01

It is shown in this paper that the assignment of distance according to the massive propagator method and according to the mathematical definition (length of minimal path) on arbitrary graphs with a bound on the degree leads to equivalent large scale properties of the graph. Especially, the internal scaling dimension is the same for both definitions. This result holds for any fixed, non-vanishing mass, so that a really inequivalent definition of distance requires the limit m → 0

Transient localization in the kicked Rydberg atom

OpenAIRE

Persson, E.; Fürthauer, S.; Wimberger, S.; Burgdörfer, J.

2006-01-01

We investigate the long-time limit of quantum localization of the kicked Rydberg atom. The kicked Rydberg atom is shown to possess in addition to the quantum localization time $\\tau_L$ a second cross-over time $t_D$ where quantum dynamics diverges from classical dynamics towards increased instability. The quantum localization is shown to vanish as either the strength of the kicks at fixed principal quantum number or the quantum number at fixed kick strength increases. The survival probability...

R-current six-point correlators in AdS5 supergravity

International Nuclear Information System (INIS)

Bartels, J.; Kotanski, J.; Mischler, A.M.

2009-12-01

Within the conjectured duality between N=4 super Yang-Mills and Anti-deSitter string theory, the BFKL Pomeron of the gauge theory corresponds to the graviton mode of the dual string. As a first step towards analyzing multigraviton exchange, we investigate R-current six-point functions within the supergravity approximation. We compute the analogue of diffractive scattering, and we analyze the triple Regge limit. In the supergravity approximation the triple graviton vertex is found to vanish. (orig.)

Diphoton and diboson probes of fermiophobic Higgs bosons at the LHC

International Nuclear Information System (INIS)

Delgado, Antonio; Garcia-Pepin, Mateo; Quirós, Mariano; Santiago, José; Vega-Morales, Roberto

2016-01-01

Extensions of the Standard Model Higgs sector with electroweak charged scalars can possess exotic ‘Higgs’ bosons with vanishing or suppressed couplings to Standard Model fermions. These ‘fermiophobic’ scalars, which cannot be produced via gluon fusion, are constrained by LHC measurements of the 125 GeV Higgs boson to have a small vacuum expectation value. This implies that vector boson fusion and associated vector boson production are in general suppressed rendering conventional Higgs searches insensitive. However, Drell-Yan Higgs pair production, which is not present in the SM, can be sizeable even in the limit of vanishing exotic Higgs vacuum expectation value. We utilize this to show that diphoton searches at 8 TeV LHC already rule out a large class of neutral fermiophobic Higgs bosons below ∼110 GeV. This includes fermiophobic scalars found in two Higgs doublet as well as Higgs triplet and Georgi-Machacek type models. Our results extend the only relevant limit on fermiophobic Higgs bosons obtained by a recent CDF analysis of 4γ+X Tevatron data. Furthermore, diphoton limits are independent of the decay of the second Higgs boson and thus apply even for degenerate masses in contrast to the CDF search. We also find that if the fermiophobic Higgs has very enhanced couplings to photons, masses as large as ∼150 GeV can be ruled out while if these couplings are somehow highly suppressed, masses below ∼90 GeV can still be ruled out. Finally, we show that WW and ZZ diboson searches may serve as complementary probes for masses above the diphoton limit up to ∼250 GeV and discuss prospects at 13 TeV LHC.

Numerical Limit Analysis:

DEFF Research Database (Denmark)

Damkilde, Lars

2007-01-01

Limit State analysis has a long history and many prominent researchers have contributed. The theoretical foundation is based on the upper- and lower-bound theorems which give a very comprehensive and elegant formulation on complicated physical problems. In the pre-computer age Limit State analysis...... also enabled engineers to solve practical problems within reinforced concrete, steel structures and geotechnics....

Limits to Inclusion

Science.gov (United States)

Hansen, Janne Hedegaard

2012-01-01

In this article, I will argue that a theoretical identification of the limit to inclusion is needed in the conceptual identification of inclusion. On the one hand, inclusion is formulated as a vision that is, in principle, limitless. On the other hand, there seems to be an agreement that inclusion has a limit in the pedagogical practice. However,…

FED pumped limiter configuration issues

International Nuclear Information System (INIS)

Haines, J.R.; Fuller, G.M.

1983-01-01

Impurity control in the Fusion Engineering Device (FED) is provided by a toroidal belt pumped limiter. Limiter design issues addressed in this paper are (1) poloidal location of the limiter belt, (2) shape of the limiter surface facing the plasma, and (3) whether the belt is pumped from one or both sides. The criteria used for evaluation of limiter configuration features were sensitivity to plasma-edge conditions and ease of maintenance and fabrication. The evaluation resulted in the selection of a baseline FED limiter that is located at the bottom of the device and has a flat surface with a single leading edge

FED pumped limiter configuration issues

International Nuclear Information System (INIS)

Haines, J.R.; Fuller, G.M.

1983-01-01

Impurity control in the Fusion Engineering Device (FED) is provided by a toroidal belt pumped limiter. Limiter design issues addressed in this paper are (1) poloidal location of the limiter belt, (2) shape of the limiter surface facing the plasma, and (3) whether the belt is pumped from one or both sides. The criteria used for evaluation of limiter configuration features were sensitivity to plasma edge conditions and ease of maintenance and fabrication. The evaluation resulted in the selection of a baseline FED limiter that is located at the bottom of the device and has a flat surface with a single leading edge

Thermal-hydraulic limitations on water-cooled limiters

International Nuclear Information System (INIS)

Cha, Y.S.; Misra, B.

1984-08-01

An assessment of the cooling requirements for fusion reactor components, such as the first wall and limiter/divertor, was carried out using pressurized water as the coolant. In order to establish the coolant operating conditions, a survey of the literature on departure from nucleate boiling, critical heat flux, asymmetrical heating and heat transfer augmentation techniques was carried out. The experimental data and the empirical correlations indicate that thermal protection for the fusion reactor components based on current design concepts can be provided with an adequate margin of safety without resorting to either high coolant velocities, excessive coolant pressures, or heat transfer augmentation techniques. If, however, the future designs require heat transfer enhancement techniques, experimental verification would be necessary since no data on heat transfer augmentation techniques exist for complex geometries, especially under asymmetrically heated conditions. Since the data presented herein concern primarily thermal protection, the final design should consider other factors such as thermal stresses, temperature limits, and fatigue

Time-limited optimal dynamics beyond the Quantum Speed Limit

DEFF Research Database (Denmark)

Gajdacz, Miroslav; Das, Kunal K.; Arlt, Jan

2015-01-01

The quantum speed limit sets the minimum time required to transfer a quantum system completely into a given target state. At shorter times the higher operation speed has to be paid with a loss of fidelity. Here we quantify the trade-off between the fidelity and the duration in a system driven......-off expressed in terms of the direct Hilbert velocity provides a robust prediction of the quantum speed limit and allows to adapt the control optimization such that it yields a predefined fidelity. The results are verified numerically in a multilevel system with a constrained Hamiltonian, and a classification...

Modeling Complex Time Limits

Directory of Open Access Journals (Sweden)

Oleg Svatos

2013-01-01

Full Text Available In this paper we analyze complexity of time limits we can find especially in regulated processes of public administration. First we review the most popular process modeling languages. There is defined an example scenario based on the current Czech legislature which is then captured in discussed process modeling languages. Analysis shows that the contemporary process modeling languages support capturing of the time limit only partially. This causes troubles to analysts and unnecessary complexity of the models. Upon unsatisfying results of the contemporary process modeling languages we analyze the complexity of the time limits in greater detail and outline lifecycles of a time limit using the multiple dynamic generalizations pattern. As an alternative to the popular process modeling languages there is presented PSD process modeling language, which supports the defined lifecycles of a time limit natively and therefore allows keeping the models simple and easy to understand.

Interference and memory capacity limitations.

Science.gov (United States)

Endress, Ansgar D; Szabó, Szilárd

2017-10-01

Working memory (WM) is thought to have a fixed and limited capacity. However, the origins of these capacity limitations are debated, and generally attributed to active, attentional processes. Here, we show that the existence of interference among items in memory mathematically guarantees fixed and limited capacity limits under very general conditions, irrespective of any processing assumptions. Assuming that interference (a) increases with the number of interfering items and (b) brings memory performance to chance levels for large numbers of interfering items, capacity limits are a simple function of the relative influence of memorization and interference. In contrast, we show that time-based memory limitations do not lead to fixed memory capacity limitations that are independent of the timing properties of an experiment. We show that interference can mimic both slot-like and continuous resource-like memory limitations, suggesting that these types of memory performance might not be as different as commonly believed. We speculate that slot-like WM limitations might arise from crowding-like phenomena in memory when participants have to retrieve items. Further, based on earlier research on parallel attention and enumeration, we suggest that crowding-like phenomena might be a common reason for the 3 major cognitive capacity limitations. As suggested by Miller (1956) and Cowan (2001), these capacity limitations might arise because of a common reason, even though they likely rely on distinct processes. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Topological charge on the lattice: a field theoretical view of the geometrical approach

International Nuclear Information System (INIS)

Rastelli, L.; Rossi, P.; Vicari, E.

1997-01-01

We construct sequences of ''field theoretical'' lattice topological charge density operators which formally approach geometrical definitions in 2D CP N-1 models and 4D SU(N) Yang-Mills theories. The analysis of these sequences of operators suggests a new way of looking at the geometrical method, showing that geometrical charges can be interpreted as limits of sequences of field theoretical (analytical) operators. In perturbation theory, renormalization effects formally tend to vanish along such sequences. But, since the perturbative expansion is asymptotic, this does not necessarily lead to well-behaved geometrical limits. It indeed leaves open the possibility that non-perturbative renormalizations survive. (orig.)

The Fermion boson interaction within the linear sigma model at finite temperature

Energy Technology Data Exchange (ETDEWEB)

Caldas, H.C.G. [Fundacao de Ensino Superior de Sao Joao del Rei (FUNREI), MG (Brazil). Dept. de Ciencias Naturais (DCNAT)

2000-07-01

We study the interaction of massless bosons at finite temperature. Specifically, we calculate the self-energy of massless fermions due to interaction with massless bosons at high temperature, which is the region where thermal effects are maximal. The calculations are concentrated in the limit of vanishing fermion three momentum and after considering the effective boson dressed mass, we obtain the damping rate of the fermion. It is shown that in the limit k{sub O} <

Quantum phase slips and voltage fluctuations in superconducting nanowires

Energy Technology Data Exchange (ETDEWEB)

Semenov, Andrew G. [I.E. Tamm Department of Theoretical Physics, P.N. Lebedev Physics Institute, Moscow (Russian Federation); National Research University Higher School of Economics, Moscow (Russian Federation); Zaikin, Andrei D. [I.E. Tamm Department of Theoretical Physics, P.N. Lebedev Physics Institute, Moscow (Russian Federation); Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), Karlsruhe (Germany)

2017-06-15

We argue that quantum phase slips (QPS) may generate non-equilibrium voltage fluctuations in superconducting nanowires. In the low frequency limit we evaluate all cumulants of the voltage operator which obey Poisson statistics and show a power law dependence on the external bias. We specifically address quantum shot noise which power spectrum S{sub Ω} may depend non-monotonously on temperature. In the long wire limit S{sub Ω} decreases with increasing frequency Ω and vanishes beyond a threshold value of Ω at T → 0. Our predictions can be directly tested in future experiments with superconducting nanowires. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Performance limitations at ISABELLE

International Nuclear Information System (INIS)

Keil, E.

1975-01-01

The transverse stability of coasting beams in the planned ISABELLE storage rings was studied. The beam--beam tune shift limitation at 0.005 can be avoided, and a computer simulation seems to show 0.005 is a pessimistic limit. For beams of reasonable smoothness on the edge, the actual limit should be somewhat higher. Some coupling effects due to the beam--beam interaction are also examined

Limit loads in nozzles

International Nuclear Information System (INIS)

Zouain, N.

1983-01-01

The static method for the evaluation of the limit loads of a perfectly elasto-plastic structure is presented. Using the static theorem of Limit Analysis and the Finite Element Method, a lower bound for the colapso load can be obtained through a linear programming problem. This formulation if then applied to symmetrically loaded shells of revolution and some numerical results of limit loads in nozzles are also presented. (Author) [pt

Solubility limits on radionuclide dissolution

Energy Technology Data Exchange (ETDEWEB)

Kerrisk, J.F.

1984-12-31

This paper examines the effects of solubility in limiting dissolution rates of a number of important radionuclides from spent fuel and high-level waste. Two simple dissolution models were used for calculations that would be characteristics of a Yucca Mountain repository. A saturation-limited dissolution model, in which the water flowing through the repository is assumed to be saturated with each waste element, is very conservative in that it overestimates dissolution rates. A diffusion-limited dissolution model, in which element-dissolution rates are limited by diffusion of waste elements into water flowing past the waste, is more realistic, but it is subject to some uncertainty at this time. Dissolution rates of some elements (Pu, Am, Sn, Th, Zr, Sm) are always limited by solubility. Dissolution rates of other elements (Cs, Tc, Np, Sr, C, I) are never solubility limited; their release would be limited by dissolution of the bulk waste form. Still other elements (U, Cm, Ni, Ra) show solubility-limited dissolution under some conditions. 9 references, 3 tables.

Topological susceptibility with a single light quark flavour

Science.gov (United States)

Frison, Julien; Kitano, Ryuichiro; Yamada, Norikazu

2018-03-01

One of the historical suggestions to tackle the strong CP problem is to take the up quark mass to zero while keeping md finite. The θ angle is then supposed to become irrelevant, i.e. the topological susceptibility vanishes. However, the definition of the quark mass is scheme-dependent and identifying the mu = 0 point is not trivial, in particular with Wilson-like fermions. More specifically, up to our knowledge there is no theoretical argument guaranteeing that the topological susceptibility exactly vanishes when the PCAC mass does. We will present our recent progresses on the empirical check of this property using Nf = 1 + 2 flavours of clover fermions, where the lightest fermion is tuned very close to muPCAC= 0 and the mass of the other two is kept of the order of magnitude of the physical ms. This choice is indeed expected to amplify any unknown non-perturbative effect caused by mu ≠ md. The simulation is repeated for several βs and those results, although preliminary, give a hint about what happens in the continuum limit.

First trimester prenatal screening among women pregnant after IVF/ICSI

DEFF Research Database (Denmark)

Anne Cathrine, Gjerris; Tabor, Ann; Loft, Anne

2012-01-01

BACKGROUND Prenatal screening and diagnosis of chromosomal abnormalities especially Down's syndrome in IVF pregnancies are complicated by higher maternal age, a high multiple pregnancy rate, a high risk of a vanishing twin and an increased risk of chromosomal abnormalities, particularly in pregna......BACKGROUND Prenatal screening and diagnosis of chromosomal abnormalities especially Down's syndrome in IVF pregnancies are complicated by higher maternal age, a high multiple pregnancy rate, a high risk of a vanishing twin and an increased risk of chromosomal abnormalities, particularly...... in pregnancies after ICSI. The aim of the present systematic review was to evaluate the findings of first trimester screening for chromosomal abnormalities in IVF/ICSI singleton and twin pregnancies. METHODS A systematic MESH-term search in MEDLINE using PubMed and the Cochrane Library was performed until May...... 2011, with no earlier date limit. RESULTS The electronic search retrieved 562 citations, 96 of which were evaluated in detail and 57 were then excluded for not meeting the selection criteria. A total of 61 articles were finally selected for review. Our analysis of the data shows that, for IVF...

One-loop effective lagrangians after matching

Energy Technology Data Exchange (ETDEWEB)

Aguila, F. del; Santiago, J. [Universidad de Granada, Departamento de Fisica Teorica y del Cosmos and CAFPE, Granada (Spain); Kunszt, Z. [ETH Zuerich, Institute for Theoretical Physics, Zuerich (Switzerland)

2016-05-15

We discuss the limitations of the covariant derivative expansion prescription advocated to compute the one-loop Standard Model (SM) effective lagrangian when the heavy fields couple linearly to the SM. In particular, one-loop contributions resulting from the exchange of both heavy and light fields must be explicitly taken into account through matching because the proposed functional approach alone does not account for them. We review a simple case with a heavy scalar singlet of charge -1 to illustrate the argument. As two other examples where this matching is needed and this functional method gives a vanishing result, up to renormalization of the heavy sector parameters, we re-evaluate the one-loop corrections to the T-parameter due to a heavy scalar triplet with vanishing hypercharge coupling to the Brout-Englert-Higgs boson and to a heavy vector-like quark singlet of charged 2/3 mixing with the top quark, respectively. In all cases we make use of a new code for matching fundamental and effective theories in models with arbitrary heavy field additions. (orig.)

Reactor limit control system

International Nuclear Information System (INIS)

Rubbel, F.E.

1982-01-01

The very extensive use of limitations in the operational field between protection system and closed-loop controls is an important feature of German understanding of operational safety. The design of limitations is based on very large activities in the computational field but mostly on the high level of the plant-wide own commissioning experience of a turnkey contractor. Limitations combine intelligence features of closed-loop controls with the high availability of protection systems. (orig.)

Magnetic shielding of a limiter

International Nuclear Information System (INIS)

Brevnov, N.N.; Stepanov, S.B.; Khimchenko, L.N.; Matthews, G.F.; Goodal, D.H.J.

1991-01-01

Localization of plasma interaction with material surfaces in a separate chamber, from where the escape of impurities is hardly realized, i.e. application of magnetic divertors or pump limiters, is the main technique for reduction of the impurity content in a plasma. In this case, the production of a divertor configuration requires a considerable power consumption and results in a less effective utilization of the magnetic field volume. Utilization of a pump limiter, for example the ICL-type, under tokamak-reactor conditions would result in the extremely high and forbidden local heat loadings onto the limiter surface. Moreover, the magnetically-shielded pump limiter (MSL) was proposed to combine positive properties of the divertor and the pump limiter. The idea of magnetic shielding is to locate the winding with current inside the limiter head so that the field lines of the resultant magnetic field do not intercept the limiter surface. In this case the plasma flows around the limiter leading edges and penetrates into the space under the limiter. The shielding magnetic field can be directed either counter the toroidal field or counter the poloidal one of a tokamak, dependent on the concrete diagram of the device. Such a limiter has a number of advantages: -opportunity to control over the particle and impurity recycling without practical influence upon the plasma column geometry, - perturbation of a plasma column magnetic configuration from the side of such a limiter is less than that from the side of the divertor coils. The main deficiency is the necessity to locate active windings inside the discharge chamber. (author) 5 refs., 3 figs

Relativistic tidal properties of neutron stars

International Nuclear Information System (INIS)

Damour, Thibault; Nagar, Alessandro

2009-01-01

We study the various linear responses of neutron stars to external relativistic tidal fields. We focus on three different tidal responses, associated to three different tidal coefficients: (i) a gravito-electric-type coefficient Gμ l =[length] 2l+1 measuring the lth-order mass multipolar moment GM a 1 ...a l induced in a star by an external lth-order gravito-electric tidal field G a 1 ...a l ; (ii) a gravito-magnetic-type coefficient Gσ l =[length] 2l+1 measuring the lth spin multipole moment GS a 1 ...a l induced in a star by an external lth-order gravito-magnetic tidal field H a 1 ...a l ; and (iii) a dimensionless 'shape' Love number h l measuring the distortion of the shape of the surface of a star by an external lth-order gravito-electric tidal field. All the dimensionless tidal coefficients Gμ l /R 2l+1 , Gσ l /R 2l+1 , and h l (where R is the radius of the star) are found to have a strong sensitivity to the value of the star's 'compactness'c≡GM/(c 0 2 R) (where we indicate by c 0 the speed of light). In particular, Gμ l /R 2l+1 ∼k l is found to strongly decrease, as c increases, down to a zero value as c is formally extended to the 'black hole (BH) limit'c BH =1/2. The shape Love number h l is also found to significantly decrease as c increases, though it does not vanish in the formal limit c→c BH , but is rather found to agree with the recently determined shape Love numbers of black holes. The formal vanishing of μ l and σ l as c→c BH is a consequence of the no-hair properties of black holes. This vanishing suggests, but in no way proves, that the effective action describing the gravitational interactions of black holes may not need to be augmented by nonminimal worldline couplings.

Doublet III limiter performance and implications for mechanical design and material selection for future limiters

International Nuclear Information System (INIS)

Sabado, M.M.; Marcus, F.B.; Trester, P.W.; Wesley, J.C.

1979-10-01

The plasma limiter system for Doublet III is described. Initially, high-Z materials, Ta-10W for the primary limiter and Mo for the backup limiters, were selected as the most attractive metallic candidates from the standpoint of thermal and structural properties. For the purpose of evaluating the effect of material Z on plasma performance, the nonmagnetic, Ni-base alloy Inconel X-750 was selected for a medium-Z limiter material. Graphite, a low-Z material, will likely be the next limiter material for evaluation. Design and material selection criteria for the different Z ranges are presented. The performance of the high-Z limiters in Doublet III is reviewed for an operation period that included approximately 5000 plasma shots. Changes in surface appearance and metallurgical changes are characterized. Discussion is presented on how and to what extent the high-Z elements affected the performance of the plasma based on theory and measurements in Doublet III. The fabrication processes for the Inconel X-750 limiters are summarized, and, last, observations on early performance of the Inconel limiters are described

Doublet III limiter performance and implications for mechanical design and material selection for future limiters

Energy Technology Data Exchange (ETDEWEB)

Sabado, M.M.; Marcus, F.B.; Trester, P.W.; Wesley, J.C.

1979-10-01

The plasma limiter system for Doublet III is described. Initially, high-Z materials, Ta-10W for the primary limiter and Mo for the backup limiters, were selected as the most attractive metallic candidates from the standpoint of thermal and structural properties. For the purpose of evaluating the effect of material Z on plasma performance, the nonmagnetic, Ni-base alloy Inconel X-750 was selected for a medium-Z limiter material. Graphite, a low-Z material, will likely be the next limiter material for evaluation. Design and material selection criteria for the different Z ranges are presented. The performance of the high-Z limiters in Doublet III is reviewed for an operation period that included approximately 5000 plasma shots. Changes in surface appearance and metallurgical changes are characterized. Discussion is presented on how and to what extent the high-Z elements affected the performance of the plasma based on theory and measurements in Doublet III. The fabrication processes for the Inconel X-750 limiters are summarized, and, last, observations on early performance of the Inconel limiters are described. (MOW)

FUEL CASK IMPACT LIMITER VULNERABILITIES

International Nuclear Information System (INIS)

Leduc, D.; England, J.; Rothermel, R.

2009-01-01

Cylindrical fuel casks often have impact limiters surrounding just the ends of the cask shaft in a typical 'dumbbell' arrangement. The primary purpose of these impact limiters is to absorb energy to reduce loads on the cask structure during impacts associated with a severe accident. Impact limiters are also credited in many packages with protecting closure seals and maintaining lower peak temperatures during fire events. For this credit to be taken in safety analyses, the impact limiter attachment system must be shown to retain the impact limiter following Normal Conditions of Transport (NCT) and Hypothetical Accident Conditions (HAC) impacts. Large casks are often certified by analysis only because of the costs associated with testing. Therefore, some cask impact limiter attachment systems have not been tested in real impacts. A recent structural analysis of the T-3 Spent Fuel Containment Cask found problems with the design of the impact limiter attachment system. Assumptions in the original Safety Analysis for Packaging (SARP) concerning the loading in the attachment bolts were found to be inaccurate in certain drop orientations. This paper documents the lessons learned and their applicability to impact limiter attachment system designs

Limit cycles in quantum systems

Energy Technology Data Exchange (ETDEWEB)

Niemann, Patrick

2015-04-27

In this thesis we investigate Limit Cycles in Quantum Systems. Limit cycles are a renormalization group (RG) topology. When degrees of freedom are integrated out, the coupling constants flow periodically in a closed curve. The presence of limit cycles is restricted by the necessary condition of discrete scale invariance. A signature of discrete scale invariance and limit cycles is log-periodic behavior. The first part of this thesis is concerned with the study of limit cycles with the similarity renormalization group (SRG). Limit cycles are mainly investigated within conventional renormalization group frameworks, where degrees of freedom, which are larger than a given cutoff, are integrated out. In contrast, in the SRG potentials are unitarily transformed and thereby obtain a band-diagonal structure. The width of the band structure can be regarded as an effective cutoff. We investigate the appearance of limit cycles in the SRG evolution. Our aim is to extract signatures as well as the scaling factor of the limit cycle. We consider the 1/R{sup 2}-potential in a two-body system and a three-body system with large scattering lengths. Both systems display a limit cycle. Besides the frequently used kinetic energy generator we apply the exponential and the inverse generator. In the second part of this thesis, Limit Cycles at Finite Density, we examine the pole structure of the scattering amplitude for distinguishable fermions at zero temperature in the medium. Unequal masses and a filled Fermi sphere for each fermion species are considered. We focus on negative scattering lengths and the unitary limit. The properties of the three-body spectrum in the medium and implications for the phase structure of ultracold Fermi gases are discussed.

Apparent Contact Angle and Contact Angle Hysteresis on Liquid Infused Surfaces

OpenAIRE

Semprebon, Ciro; McHale, Glen; Kusumaatmaja, Halim

2016-01-01

We theoretically investigate the apparent contact angle and contact angle hysteresis of a droplet placed on a liquid infused surface. We show that the apparent contact angle is not uniquely defined by material parameters, but also has a strong dependence on the relative size between the droplet and its surrounding wetting ridge formed by the infusing liquid. We derive a closed form expression for the contact angle in the limit of vanishing wetting ridge, and compute the correction for small b...

The Hodge structure of semiample hypersurfaces and a generalization of the monomial-divisor mirror map

OpenAIRE

Mavlyutov, Anvar R.

2000-01-01

We solved the long-standing problem of describing the cohomology ring of semiample hypersurfaces in complete simplicial toric varieties. Also, the monomial-divisor mirror map is generalized to a map between the whole Picard group and the space of infinitesimal deformations for a mirror pair of Calabi-Yau hypersurfaces. This map is compatible with certain vanishing limiting products of the subrings of the chiral rings, on which the ring structure is related to a product of the roots of $A$-typ...

Subtracted Dispersion Relations for In-medium Meson Correlators in QCD Sum Rules

Energy Technology Data Exchange (ETDEWEB)

Florkowski, W; Broniowski, W [The H. Niewodniczanski Institute of Nuclear Physics, Cracow (Poland)

1999-01-01

We analyze subtracted dispersion relations for meson correlators at finite baryon density and temperature. Such relations are needed for QCD sum rules. We point out that importance of scattering terms, as well as finite, well-defined subtraction constants. Both are necessary for consistency, in particular for the equality of the longitudinal and transverse correlators in the limit of the vanishing three-momentum of mesons relative to the medium. We present detailed calculations in various mesonic channels of the Fermi gas of nucleons. (author)

Quantum cybernetics: a new perspective for Nelson's stochastic theory, nonlocality, and the Klein-Gordon equation

Science.gov (United States)

Grössing, Gerhard

2002-04-01

The Klein-Gordon equation is shown to be equivalent to coupled partial differential equations for a sub-quantum Brownian movement of a “particle”, which is both passively affected by, and actively affecting, a diffusion process of its generally nonlocal environment. This indicates circularly causal, or “cybernetic”, relationships between “particles” and their surroundings. Moreover, in the relativistic domain, the original stochastic theory of Nelson is shown to hold as a limiting case only, i.e., for a vanishing quantum potential.

On 3D Minimal Massive Gravity

CERN Document Server

Alishahiha, Mohsen; Naseh, Ali; Shirzad, Ahmad

2014-12-03

We study linearized equations of motion of the newly proposed three dimensional gravity, known as minimal massive gravity, using its metric formulation. We observe that the resultant linearized equations are exactly the same as that of TMG by making use of a redefinition of the parameters of the model. In particular the model admits logarithmic modes at the critical points. We also study several vacuum solutions of the model, specially at a certain limit where the contribution of Chern-Simons term vanishes.

Finite size effects and chiral symmetry breaking in quenched three-dimensional QED

International Nuclear Information System (INIS)

Hands, S.; Kogut, J.B.

1990-01-01

Finite size effects and the chiral condensate are studied in three-dimensional QED by the Lanczos and the conjugate-gradient algorithms. Very substantial finite size effects are observed, but studies on L 3 lattices with L ranging from 8 to 80 indicate the development of a non-vanishing chiral condensate in the continuum limit of the theory. The systematics of the finite size effects and the fermion mass dependence in the conjugate-gradient algorithm are clarified in this extensive study. (orig.)

Instanton superfield calculations for SU(N) SQCD in the Higgs phase

International Nuclear Information System (INIS)

Fuchs, J.

1987-01-01

We present a superfield formalism for instanton calculations in SQCD with arbitrary numbers N, M of colors and flavors and with non-vanishing classical scalar expectation values. Various correlators can be computed economically. In the limit of large expectation values the results are in full agreement with clustering and other general arguments. For M=N-1 a superpotential is shown to be generated at the one-instanton level; this fixes the values of the scalars without use of the Konishi anomaly. (orig.)

Limit analysis via creep

International Nuclear Information System (INIS)

Taroco, E.; Feijoo, R.A.

1981-07-01

In this paper it is presented a variational method for the limit analysis of an ideal plastic solid. This method has been denominated as Modified Secundary Creep and enables to find the collapse loads through a minimization of a functional and a limit process. Given an ideal plastic material it is shown how to determinate the associated secundary creep constitutive equation. Finally, as an application, it is found the limit load in an pressurized von Mises rigid plastic sphere. (Author) [pt

Term limits and the tobacco industry.

Science.gov (United States)

Apollonio, Dorie E; Glantz, Stanton A; Bero, Lisa A

2014-03-01

In the 1990s several American states passed term limits on legislators with the stated intention of reducing the influence of wealthy industries on career legislators. Although term limits in the United States do not have a direct relationship to public health, the tobacco industry anticipated that term limits could have indirect effects by either limiting or expanding industry influence. We detail the strategy of the tobacco industry in the wake of term limits using internal tobacco company documents and a database of campaign contributions made to legislators in term limited states between 1988 and 2002. Despite some expectations that term limits would limit tobacco industry access to state legislators, term limits appear to have had the opposite effect. Copyright © 2013 Elsevier Ltd. All rights reserved.

Destructive operations--a vanishing art in modern obstetrics: 25 year experience at a tertiary care center in India.

Science.gov (United States)

Sikka, Pooja; Chopra, Seema; Kalpdev, Arun; Jain, Vanita; Dhaliwal, Lakhbir

2011-05-01

Destructive operations have a limited role in modern day obstetrics. In the developed countries, obstetrics has become so advanced that these instruments have actually been put away. However, in developing countries like India, these procedures have a limited role where obstructed labor still continues to plague thousands of women every year and accounts for 8% of maternal deaths. This study was planned to define the changing role of destructive operations in obstetrics over the years as more number of abdominal deliveries are conducted in modern day obstetrics than these procedures. A retrospective analysis of destructive operations performed at the Post Graduate Institute of Medical Education and Research (PGIMER), Chandigarh, India, over a span of 25 years, between 1983 and 2007, was carried out. Of a total of 85,952 deliveries in PGIMER in these 25 years, there were 25,474 cesarean deliveries (29.63%), and 8,826 (10.26%) operative vaginal deliveries. The total number of destructive operations performed was 230 (0.26%). There were 202 craniotomies (87.8%), 13 decapitations (5.7%), 8 eviscerations (3.6%) and 7 cleidotomies (2.9%). There should be an individualized approach to each case of obstructed labor. The health care provider has to decide on the options available to him to deliver the mother by the safest route without causing morbidity and mortality. If the fetus is dead, a destructive procedure can be considered in place of abdominal-route delivery which carries considerable risk to the debilitated mother in neglected labor.

Spherically Symmetric Geometries in f(T) and f(R) Gravitational Theories

International Nuclear Information System (INIS)

Nashed, Gamal G. L.

2015-01-01

Using the well know relation between Ricci scalar, R, and torsion scalar, T, that is, R=-T-2∇_αT"α, we show that, for any spherically symmetric spacetime whose (i) scalar torsion vanishing, that is, T=T_μ_ν"αS_α"μ"ν=0 or (ii) total derivative term, that is, ∇_αT"α with T"α is the contraction of the torsion, vanishing, or (iii) the combination of scalar torsion and total derivative term vanishing, could be solution for f(T) and f(R) gravitational theories.

QCD Green's Functions and Phases of Strongly-Interacting Matter

Directory of Open Access Journals (Sweden)

Schaefer B.J.

2011-04-01

Full Text Available After presenting a brief summary of functional approaches to QCD at vanishing temperatures and densities the application of QCD Green's functions at non-vanishing temperature and vanishing density is discussed. It is pointed out in which way the infrared behavior of the gluon propagator reflects the (de-confinement transition. Numerical results for the quark propagator are given thereby verifying the relation between (de--confinement and dynamical chiral symmetry breaking (restoration. Last but not least some results of Dyson-Schwinger equations for the color-superconducting phase at large densities are shown.

Force Limit System

Science.gov (United States)

Pawlik, Ralph; Krause, David; Bremenour, Frank

2011-01-01

The Force Limit System (FLS) was developed to protect test specimens from inadvertent overload. The load limit value is fully adjustable by the operator and works independently of the test system control as a mechanical (non-electrical) device. When a test specimen is loaded via an electromechanical or hydraulic test system, a chance of an overload condition exists. An overload applied to a specimen could result in irreparable damage to the specimen and/or fixturing. The FLS restricts the maximum load that an actuator can apply to a test specimen. When testing limited-run test articles or using very expensive fixtures, the use of such a device is highly recommended. Test setups typically use electronic peak protection, which can be the source of overload due to malfunctioning components or the inability to react quickly enough to load spikes. The FLS works independently of the electronic overload protection.

Novel limiter pump topologies

International Nuclear Information System (INIS)

Schultz, J.H.

1981-01-01

The use of limiter pumps as the principle plasma exhaust system of a magnetic confinement fusion device promises significant simplification, when compared to previously investigating divertor based systems. Further simplifications, such as the integration of the exhaust system with a radio frequency heating system and with the main reactor shield and structure are investigated below. The integrity of limiters in a reactor environment is threatened by many mechanisms, the most severe of which may be erosion by sputtering. Two novel topolgies are suggested which allow high erosion without limiter failure

Novel limiter pump topologies

International Nuclear Information System (INIS)

Schultz, J.H.

1981-01-01

The use of limiter pumps as the principle plasma exhaust system of a magnetic confinement fusion device promises significant simplification, when compared to previously investigating divertor based systems. Further simplifications, such as the integration of the exhaust system with a radio frequency heating system and with the main reactor shield and structure are investigated below. The integrity of limiters in a reactor environment is threatened by many mechanisms, the most severe of which may be erosion by sputtering. Two novel topologies are suggested which allow high erosion without limiter failure

Inflation from a ripple on a vanishing potential

Science.gov (United States)

Enqvist, K.; Nanopoulos, D. V.; Quiros, M.

1985-09-01

We propose a very simple model of inflation having essentially one free parameter, the value of which is fixed by the amplitude and scale independence of energy density fluctuations. The model, based on the maximally symmetric supergravity with SU(n,1) manifold, has an asymptotically flat inflaton potential. All inflationary conditions can be satisfied without any fine-tuning and all mass parameters can be O(MPI). Present address: Department of Theoretical Physics, University of Michigan, Ann Arbor, MI 48109, USA.

Social Learning Theory: A Vanishing or Expanding Presence?

Science.gov (United States)

Stuart, Richard B.

1989-01-01

Reviews history and current status of social learning theory (SLT) including present conflict between "cognitive behaviorists" within the movement. Makes suggestions on how to resolve conflict in a way that will further secure the future role of SLT. Offers prescription for adoption of a multifaceted "indirect" approach to…

The Essence of Nonclassicality: Non-Vanishing Signal Deficit

Science.gov (United States)

Aravinda, S.; Srikanth, R.

2015-12-01

Nonclassical properties of correlations- like unpredictability, no-cloning and uncertainty- are known to follow from two assumptions: nonlocality and no-signaling. For two-input-two-output correlations, we derive these properties from a single, unified assumption: namely, the excess of the communication cost over the signaling in the correlation. This is relevant to quantum temporal correlations, resources to simulate quantum correlations and extensions of quantum mechanics. We generalize in the context of such correlations the nonclassicality result for nonlocal-nonsignaling correlations (Masanes et al., Phys. Rev. A 73, 012112 (2006)) and the uncertainty bound on nonlocality (Oppenheim and Wehner, Science 330(6007), 1072 (2010)), when the no-signaling condition is relaxed.

The Vanishing Indian Reappears in the College Curriculum.

Science.gov (United States)

Kidwell, Clara Sue

The first Native American studies programs, created in the rising political consciousness of the late 1960s and early 1970s, arose from a rejection of traditional curricula and challenged stereotypes of Indians and their history. During the 1980s, Native studies programs became vehicles to recruit and retain American Indian students, reflecting…

The Vanishing Native Reappears in the College Curriculum.

Science.gov (United States)

Kidwell, Clara Sue

1991-01-01

A review of the history of American Indian studies in the college curriculum traces the political, demographic, academic, and social changes affecting American Indian roles. The recent revival of native American studies and the emergence of graduation requirements in ethnic studies are seen as both beneficial and risky. (MSE)

Vanishing species: things weong between man and nature

NARCIS (Netherlands)

Jacobs, M.

1980-01-01

Loss of species is the key issue of conservation. Contrary to misuse of land which is visible to anybody with eyes to see, the issue of extinction is sly, treacherous, and open to clear perception only for experts. It touches on quality, and reaches far out in time: hard things to grasp for

‘Vanishing cities’: can urban costs explain deindustrialization?

Czech Academy of Sciences Publication Activity Database

Goryunov, Maxim; Kokovin, S.

2016-01-01

Roč. 95, č. 3 (2016), s. 633-651 ISSN 1056-8190 Institutional support: RVO:67985998 Keywords : city size * urban hierarchies * agglomeration Subject RIV: AH - Economics Impact factor: 1.272, year: 2016

Metrics, Business Plans, and the Vanishing Public Good

Science.gov (United States)

Tuchman, Gaye

2011-01-01

For at least 30 years, professional work has been changing. Even such once-elite professionals as doctors, lawyers, and professors have become subject to significant control. Single-practitioner medical practices have given way to group practices subject to the rules of insurance plans; lawyers join mammoth firms where paralegals time the steps…

Vanishing Voices: The Extinction of the World's Languages.

Science.gov (United States)

Nettle, Daniel; Romaine, Suzanne

This book holds that the evolution of the mind has given rise to great diversity of language and culture, each going along with a distinct adaptation to life specific ecosystems or geographical areas. Much like the wealth of plant and animal species is essential to biodiversity and ecological balance, diversity in the world's languages is vital to…

‘Vanishing cities’: can urban costs explain deindustrialization?

Czech Academy of Sciences Publication Activity Database

Goryunov, Maxim; Kokovin, S.

2016-01-01

Roč. 95, č. 3 (2016), s. 633-651 ISSN 1056-8190 Institutional support: PRVOUK-P23 Keywords : city size * urban hierarchies * agglomeration Subject RIV: AH - Economics Impact factor: 1.272, year: 2016

Modelling of a vanishing Hawaiin stream with DHSVM

NARCIS (Netherlands)

Verger, R.P.; Augustijn, Dionysius C.M.; Booij, Martijn J.; Fares, A.; Erdbrink, C.D.; van Os, A.G.

2008-01-01

Several Hawaiian streams show downward trends in stream flow. In this study Makaha Stream is investigated as an example. Three possible reasons are commonly mentioned for the discharge reduction: groundwater pumping, decreasing rainfall, and changes in vegetation. The effect of these factors on

History Reviving the Erased Voice of the Vanished

Directory of Open Access Journals (Sweden)

Ki Hoon Lee

2016-06-01

Full Text Available Jung Byung-joon. Hyŏn aellisŭ wa kŭ ŭi sidae: Yŏksa e hwipssŭllyŏgan pigŭk ŭi kyŏnggyein 현앨리스와 그의 시대: 역사에 휩쓸려간 비극의 경계인 [Alice Hyun and her days: The tragic marginal one swept away by history]. Seoul: Dolbegae, 2015. ISBN: 978-89-7199-651-5. Alice Hyun and Her Days is an excellent new work that restores the life and thoughts of a Korean American socialist intellectual and independence activist and her family. It also presents the history of Korean social movements through elaborate historical research and analyses covering an extensive amount of data. The author, Jung Byung-joon, has previously published excellent papers and books on modern Korean history and has received important academic awards for his books.... As with Jung’s other work, this book is a superb academic achievement and an intriguing read that captivates its readers...

The Pampas are vanishing under water | IDRC - International ...

International Development Research Centre (IDRC) Digital Library (Canada)

"But, based on the current situation, trees would have to be planted on more than ... hiding the fields behind the trees if we don't change our agricultural model, ... the CONICET and INTA teams also advocate a return to extensive cattle grazing.

Finite element limit analysis based plastic limit pressure solutions for cracked pipes

International Nuclear Information System (INIS)

Shim, Do Jun; Huh, Nam Su; Kim, Yun Jae; Kim, Young Jin

2002-01-01

Based on detailed FE limit analyses, the present paper provides tractable approximations for plastic limit pressure solutions for axial through-wall cracked pipe; axial (inner) surface cracked pipe; circumferential through-wall cracked pipe; and circumferential (inner) surface cracked pipe. Comparisons with existing analytical and empirical solutions show a large discrepancy in circumferential short through-wall cracks and in surface cracks (both axial and circumferential). Being based on detailed 3-D FE limit analysis, the present solutions are believed to be the most accurate, and thus to be valuable information not only for plastic collapse analysis of pressurised piping but also for estimating non-linear fracture mechanics parameters based on the reference stress approach

Characteristics of chiral anomaly in view of various applications

Science.gov (United States)

Fujikawa, Kazuo

2018-01-01

In view of the recent applications of chiral anomaly to various fields beyond particle physics, we discuss some basic aspects of chiral anomaly which may help deepen our understanding of chiral anomaly in particle physics also. It is first shown that Berry's phase (and its generalization) for the Weyl model H =vFσ →.p →(t ) assumes a monopole form at the exact adiabatic limit but deviates from it off the adiabatic limit and vanishes in the high frequency limit of the Fourier transform of p →(t ) for bounded |p →(t )|. An effective action, which is consistent with the nonadiabatic limit of Berry's phase, combined with the Bjorken-Johnson-Low prescription, gives normal equal-time space-time commutators and no chiral anomaly. In contrast, an effective action with a monopole at the origin of the momentum space, which describes Berry's phase in the precise adiabatic limit but fails off the adiabatic limit, gives anomalous space-time commutators and a covariant anomaly to the gauge current. We regard this anomaly as an artifact of the postulated monopole and not a consequence of Berry's phase. As for the recent application of the chiral anomaly to the description of effective Weyl fermions in condensed matter and nuclear physics, which is closely related to the formulation of lattice chiral fermions, we point out that the chiral anomaly for each species doubler separately vanishes for a finite lattice spacing, contrary to the common assumption. Instead, a general form of pair creation associated with the spectral flow for the Dirac sea with finite depth takes place. This view is supported by the Ginsparg-Wilson fermion, which defines a single Weyl fermion without doublers on the lattice and gives a well-defined index (anomaly) even for a finite lattice spacing. A different use of anomaly in analogy to the partially conserved axial-vector current is also mentioned and could lead to an effect without fermion number nonconservation.

Limit lines for risk

International Nuclear Information System (INIS)

Cox, D.C.; Baybutt, P.

1982-01-01

Approaches to the regulation of risk from technological systems, such as nuclear power plants or chemical process plants, in which potential accidents may result in a broad range of adverse consequences must take into account several different aspects of risk. These include overall or average risk, accidents posing high relative risks, the rate at which accident probability decreases with increasing accident consequences, and the impact of high frequency, low consequence accidents. A hypothetical complementary cumulative distribution function (CCDF), with appropriately chosen parametric form, meets all these requirements. The Farmer limit line, by contrast, places limits on the risks due to individual accident sequences, and cannot adequately account for overall risk. This reduces its usefulness as a regulatory tool. In practice, the CCDF is used in the Canadian nuclear licensing process, while the Farmer limit line approach, supplemented by separate qualitative limits on overall risk, is employed in the United Kingdom

Tokamak plasma interaction with limiters

International Nuclear Information System (INIS)

Pitcher, C.S.

1987-11-01

The importance of plasma purity is first discussed in terms of the general requirements of controlled thermonuclear fusion. The tokamak approach to fusion and its inherent problem of plasma contamination are introduced. A main source of impurities is due to the bombardment of the limiter by energetic particles and thus the three main aspects of the plasma-limiter interaction are reviewed, boundary plasma conditions, fuelling/recycling and impurity production. The experiments, carried out on the DITE tokamak at Culham Laboratory, UK, investigated these three topics and the results are compared with predicted behaviour; new physical phenomena are presented in all three areas. Simple one-dimensional fluid equations are found to adequately describe the SOL plasma, except in regard to the pre-sheath electric field and ambipolarity; that is, the electric field adjacent to the limiter surface appears to be weak and the associated plasma flow can be non-ambipolar. Recycling of fuel particles from the limiter is observed to be near unity at all times. The break-up behaviour of recycled and gas puffed D 2 molecules is dependent on the electron temperature, as expected. Impurity production at the limiter is chemical erosion of graphite being negligible. Deposition of limiter and wall-produced impurities is found on the limiter. The spatial distributions of impurities released from the limiter are observed and are in good agreement with a sputtered atom transport code. Finally, preliminary experiments on the transport of impurity ions along field lines away from the limiter have been performed and compared with simple analytic theory. The results suggest that the pre-sheath electric field in the SOL is much weaker than the simple fluid model would predict

Approaching the Shockley-Queisser limit: General assessment of the main limiting mechanisms in photovoltaic cells

International Nuclear Information System (INIS)

Vossier, Alexis; Gualdi, Federico; Dollet, Alain; Ares, Richard; Aimez, Vincent

2015-01-01

In principle, the upper efficiency limit of any solar cell technology can be determined using the detailed-balance limit formalism. However, “real” solar cells show efficiencies which are always below this theoretical value due to several limiting mechanisms. We study the ability of a solar cell architecture to approach its own theoretical limit, using a novel index introduced in this work, and the amplitude with which the different limiting mechanisms affect the cell efficiency is scrutinized as a function of the electronic gap and the illumination level to which the cell is submitted. The implications for future generations of solar cells aiming at an improved conversion of the solar spectrum are also addressed

Departures from scaling in SU(2) lattice gauge theory

International Nuclear Information System (INIS)

Gutbrod, F.

1987-01-01

High statistics Monte Carlo Data in SU(2) lattice gauge theory are presented. At β = 2.6 and β = 2.7 large deviations form scaling are observed for Creutz ratios, when 12 4 and 24 4 lattice data are compared. There is a trend towards a restauration of asymptotic scaling with increasing β, which vanishes if at the higher value of β larger loops are considered than at lower β. The static qanti q-potential and an upper limit for the string tension are given. (orig.)

Deconfinement transition and flux-string models

International Nuclear Information System (INIS)

Momen, A.; Rosenzweig, C.

1997-01-01

Flux-string models can be used to study the deconfining phase transition. In this paper, we study the models proposed by Patel. We also study the large N c limits of Patel model. To discuss the validity of the mean field theory results, the one-loop Coleman-Weinberg effective potential is calculated for N c =3. We argue that the quantum corrections vanish at large N c when the energy of the so-called baryonic vertices scale with N c . copyright 1997 The American Physical Society

Fluid boundary of a viscoplastic Bingham flow for finite solid deformations

OpenAIRE

Thual , Olivier; Lacaze , Laurent

2010-01-01

International audience; The modelling of viscoplastic Bingham fluids often relies on a rheological constitutive law based on a "plastic rule function" often identical to the yield criterion of the solid state. It is also often assumed that this plastic rule function vanishes at the boundary between the solid and fluid states, based on the fact that it is true in the limit of small deformations of the solid state or for simple yield criteria. We show that this is not the case for finite deform...

An asymptotically consistent approximant for the equatorial bending angle of light due to Kerr black holes

Science.gov (United States)

Barlow, Nathaniel S.; Weinstein, Steven J.; Faber, Joshua A.

2017-07-01

An accurate closed-form expression is provided to predict the bending angle of light as a function of impact parameter for equatorial orbits around Kerr black holes of arbitrary spin. This expression is constructed by assuring that the weak- and strong-deflection limits are explicitly satisfied while maintaining accuracy at intermediate values of impact parameter via the method of asymptotic approximants (Barlow et al 2017 Q. J. Mech. Appl. Math. 70 21-48). To this end, the strong deflection limit for a prograde orbit around an extremal black hole is examined, and the full non-vanishing asymptotic behavior is determined. The derived approximant may be an attractive alternative to computationally expensive elliptical integrals used in black hole simulations.

Circular orbits in cosmic string and Schwarzschild-AdS spacetime with Fermi-Walker transport

International Nuclear Information System (INIS)

Bakke, K.; Furtado, C.; Carvalho, A.M. de

2009-01-01

In this paper we discuss the Fermi-Walker transport of vectors along orbits in cosmic string and Schwarzschild-AdS spacetimes. We analyze the influence of acceleration on these holonomies. An effect similar to Thomas precession is observed within the process of Fermi-Walker transport along these circular orbits which are studied in the limit of vanishing cosmological constant in Schwarzschild-AdS case; also we obtain Fermi-Walker transport in a Schwarzschild background. In the case of a Schwarzschild spacetime, we analyze the quantized band holonomy invariance. In the limit of zero acceleration we recover the well-known results for holonomy matrix obtained by parallel transport in all these spacetimes. (orig.)

On the quantum analogue of Galileo's leaning tower experiment

International Nuclear Information System (INIS)

Ali, Md Manirul; Majumdar, A S; Home, Dipankar; Pan, Alok Kumar

2006-01-01

The quantum analogue of Galileo's leaning tower experiment is revisited using wave packets evolving under the gravitational potential. We first calculate the position detection probabilities for particles projected upwards against gravity around the classical turning point and also around the point of initial projection, which exhibit mass dependence at both these points. We then compute the mean arrival time of freely falling particles using the quantum probability current, which also turns out to be mass dependent. The mass dependence of both the position detection probabilities and the mean arrival time vanish in the limit of large mass. Thus, compatibility between the weak equivalence principle and quantum mechanics is recovered in the macroscopic limit of the latter

A note on hypoplastic yielding

OpenAIRE

Nader, José Jorge

2010-01-01

This note discusses briefly the definition of yield surface in hypoplasticity in connection with the physical notion of yielding. The relation of yielding with the vanishing of the material time derivative of the stress tensor and the vanishing of the corotational stress rate is investigated.

Plane wave limits and T-duality

International Nuclear Information System (INIS)

Guven, R.

2000-04-01

The Penrose limit is generalized to show that, any leading order solution of the low-energy field equations in any one of the five string theories has a plane wave solution as a limit. This limiting procedure takes into account all the massless fields that may arise and commutes with the T-duality so that any dual solution has again a plane wave limit. The scaling rules used in the limit are unique and stem from the scaling property of the D = 11 supergravity action. Although the leading order dual solutions need not be exact or supersymmetric, their plane wave limits always preserve some portion of the Poincare supersymmetry and solve the relevant field equations in all powers of the string tension parameter. Further properties of the limiting procedure are discussed. (author)

Limitations of Human Visual Working Memory

OpenAIRE

Wesenick, Maria-Barbara

2004-01-01

The present empirical study investigates limitations of human visual working memory (VWM). The experiments of the present work involve the experimental paradigm of change detection using simple geometrical objects in the form of rectangles of different colour, length, and orientation. It can be shown, that a limited performance in the temporary storage of visual information has multiple sources. Limitations of VWM can be attributed to a limited capacity or a limited duration, but also to limi...

The Advanced Limiter Test-I (ALT-I) variable-geometry pump limiter module

International Nuclear Information System (INIS)

Pontau, A.E.; Malinowski, M.E.; Ver Berkmoes, A.A.; Guthrie, S.E.; Watson, R.D.; Goebel, D.M.; Campbell, G.A.

1984-01-01

The ALT-I variable geometry module has been designed to address many of the issues not previously settled by earlier experiments. The goal is to study the basic processes involved in pump limiter operation as well as demonstrate its utility and effect on the plasma. The flexibility and extensive instrumentation of ALT-I will offer a unique opportunity to parameterize operation and facilitate the engineering design of future pump limiters. (orig.)

Pump limiter studies in Tore Supra

International Nuclear Information System (INIS)

Chatelier, M.; Bonnel, P.; Bruneau, J.L.; Gil, C.; Grisolia, C.; Loarer, T.; Martin, G.; Pegourie, B.; Rodriguez, L.

1991-01-01

The aim of the Tore Supra pump limiter program is to study particle exhaust with a pump limiter system in long-pulse discharges with continuous pellet fueling and strong auxiliary heating. The pump limiter system consists of six vertical modules, located at the bottom of the machine, and one horizontal module at the outer midplane. The instrumentation of the limiter included pressure gauges, a residual gas analyser Langmuir probes, a spectrometer and water calorimeters. Initial results in low-density discharges, with the outboard limiter only, showed a modest effect on the plasma density, while large exhaust fluxes were measured in the pump limiter, without any external fueling

Passive fault current limiting device

Science.gov (United States)

Evans, Daniel J.; Cha, Yung S.

1999-01-01

A passive current limiting device and isolator is particularly adapted for use at high power levels for limiting excessive currents in a circuit in a fault condition such as an electrical short. The current limiting device comprises a magnetic core wound with two magnetically opposed, parallel connected coils of copper, a high temperature superconductor or other electrically conducting material, and a fault element connected in series with one of the coils. Under normal operating conditions, the magnetic flux density produced by the two coils cancel each other. Under a fault condition, the fault element is triggered to cause an imbalance in the magnetic flux density between the two coils which results in an increase in the impedance in the coils. While the fault element may be a separate current limiter, switch, fuse, bimetal strip or the like, it preferably is a superconductor current limiter conducting one-half of the current load compared to the same limiter wired to carry the total current of the circuit. The major voltage during a fault condition is in the coils wound on the common core in a preferred embodiment.

Energy–pressure relation for low-dimensional gases

Directory of Open Access Journals (Sweden)

Francesco Mancarella

2014-10-01

Full Text Available A particularly simple relation of proportionality between internal energy and pressure holds for scale-invariant thermodynamic systems (with Hamiltonians homogeneous functions of the coordinates, including classical and quantum – Bose and Fermi – ideal gases. One can quantify the deviation from such a relation by introducing the internal energy shift as the difference between the internal energy of the system and the corresponding value for scale-invariant (including ideal gases. After discussing some general thermodynamic properties associated with the scale-invariance, we provide criteria for which the internal energy shift density of an imperfect (classical or quantum gas is a bounded function of temperature. We then study the internal energy shift and deviations from the energy–pressure proportionality in low-dimensional models of gases interpolating between the ideal Bose and the ideal Fermi gases, focusing on the Lieb–Liniger model in 1d and on the anyonic gas in 2d. In 1d the internal energy shift is determined from the thermodynamic Bethe ansatz integral equations and an explicit relation for it is given at high temperature. Our results show that the internal energy shift is positive, it vanishes in the two limits of zero and infinite coupling (respectively the ideal Bose and the Tonks–Girardeau gas and it has a maximum at a finite, temperature-depending, value of the coupling. Remarkably, at fixed coupling the energy shift density saturates to a finite value for infinite temperature. In 2d we consider systems of Abelian anyons and non-Abelian Chern–Simons particles: as it can be seen also directly from a study of the virial coefficients, in the usually considered hard-core limit the internal energy shift vanishes and the energy is just proportional to the pressure, with the proportionality constant being simply the area of the system. Soft-core boundary conditions at coincident points for the two-body wavefunction introduce

Energy–pressure relation for low-dimensional gases

International Nuclear Information System (INIS)

Mancarella, Francesco; Mussardo, Giuseppe; Trombettoni, Andrea

2014-01-01

A particularly simple relation of proportionality between internal energy and pressure holds for scale-invariant thermodynamic systems (with Hamiltonians homogeneous functions of the coordinates), including classical and quantum – Bose and Fermi – ideal gases. One can quantify the deviation from such a relation by introducing the internal energy shift as the difference between the internal energy of the system and the corresponding value for scale-invariant (including ideal) gases. After discussing some general thermodynamic properties associated with the scale-invariance, we provide criteria for which the internal energy shift density of an imperfect (classical or quantum) gas is a bounded function of temperature. We then study the internal energy shift and deviations from the energy–pressure proportionality in low-dimensional models of gases interpolating between the ideal Bose and the ideal Fermi gases, focusing on the Lieb–Liniger model in 1d and on the anyonic gas in 2d. In 1d the internal energy shift is determined from the thermodynamic Bethe ansatz integral equations and an explicit relation for it is given at high temperature. Our results show that the internal energy shift is positive, it vanishes in the two limits of zero and infinite coupling (respectively the ideal Bose and the Tonks–Girardeau gas) and it has a maximum at a finite, temperature-depending, value of the coupling. Remarkably, at fixed coupling the energy shift density saturates to a finite value for infinite temperature. In 2d we consider systems of Abelian anyons and non-Abelian Chern–Simons particles: as it can be seen also directly from a study of the virial coefficients, in the usually considered hard-core limit the internal energy shift vanishes and the energy is just proportional to the pressure, with the proportionality constant being simply the area of the system. Soft-core boundary conditions at coincident points for the two-body wavefunction introduce a length scale

Subsubleading soft theorems of gravitons and dilatons in the bosonic string

International Nuclear Information System (INIS)

Vecchia, Paolo Di; Marotta, Raffaele; Mojaza, Matin

2016-01-01

Starting from the amplitude with an arbitrary number of massless closed states of the bosonic string, we compute the soft limit when one of the states becomes soft to subsubleading order in the soft momentum expansion, and we show that when the soft state is a graviton or a dilaton, the full string amplitude can be expressed as a soft theorem through subsubleading order. It turns out that there are string corrections to the field theoretical limit in the case of a soft graviton, while for a soft dilaton the string corrections vanish. We then show that the new soft theorems, including the string corrections, can be simply obtained from the exchange diagrams where the soft state is attached to the other external states through the three-point string vertex of three massless states. In the soft-limit, the propagator of the exchanged state is divergent, and at tree-level these are the only divergent contributions to the full amplitude. However, they do not form a gauge invariant subset and must be supplemented with extra non-singular terms. The requirement of gauge invariance then fixes the complete amplitude through subsubleading order in the soft expansion, reproducing exactly what one gets from the explicit calculation in string theory. From this it is seen that the string corrections at subsubleading order arise as a consequence of the three-point amplitude having string corrections in the bosonic string. When specialized to a soft dilaton, it remarkably turns out that the string corrections vanish and that the non-singular piece of the subsubleading term of the dilaton soft theorem is the generator of space-time special conformal transformation.

ALT-I pump limiter experiments

International Nuclear Information System (INIS)

Goebel, D.M.; Conn, R.W.; Campbell, G.A.

1987-09-01

Results from the ALT-I pump limiter experiments in TEXTOR are presented. ALT-I has demonstrated control of the plasma density in a high recycling tokamak by pumping up to 15% of the core efflux. The closed pump limiter designs with restricted entrance geometries to reduce the backflow of neutral gas to the plasma remove over 50% of the ion flux incident on the collection slot. Up to 80% of the entrance ion flux is removed when the edge electron temperature is less than 10 eV and plasma-neutral gas interactions are minimized inside the limiter. Results from a 3-D Monte Carlo neutral gas transport code agree closely with these experimental results. The compound curvature of the head is found to distribute the heat over the surface as predicted in the original designs. Impurity removal experiments demonstrate that significant helium exhaust can be achieved with a pump limiter. During ohmic heating in TEXTOR, the energy and particle confinement times are proportional to the line averaged core density. With ICRH auxiliary heating, tau/sub E/ follow L-mode scaling independent of particle removal by the pump limiter. Pump limiter operation does not directly modify the SOL plasma density and electron temperature, but controls the core plasma density by changing the global recycling at the boundary. The global particle confinement, the particle flux to the limiter, and the edge electron temperature follow the changes in the core density and auxiliary heating power. 25 refs

Lacunary Fourier Series and a Qualitative Uncertainty Principle for ...

Indian Academy of Sciences (India)

We define lacunary Fourier series on a compact connected semisimple Lie group . If f ∈ L 1 ( G ) has lacunary Fourier series and vanishes on a non empty open subset of , then we prove that vanishes identically. This result can be viewed as a qualitative uncertainty principle.

Saffman-Taylor fingers with kinetic undercooling

KAUST Repository

Gardiner, Bennett P. J.

2015-02-23

© 2015 American Physical Society. The mathematical model of a steadily propagating Saffman-Taylor finger in a Hele-Shaw channel has applications to two-dimensional interacting streamer discharges which are aligned in a periodic array. In the streamer context, the relevant regularization on the interface is not provided by surface tension but instead has been postulated to involve a mechanism equivalent to kinetic undercooling, which acts to penalize high velocities and prevent blow-up of the unregularized solution. Previous asymptotic results for the Hele-Shaw finger problem with kinetic undercooling suggest that for a given value of the kinetic undercooling parameter, there is a discrete set of possible finger shapes, each analytic at the nose and occupying a different fraction of the channel width. In the limit in which the kinetic undercooling parameter vanishes, the fraction for each family approaches 1/2, suggesting that this "selection" of 1/2 by kinetic undercooling is qualitatively similar to the well-known analog with surface tension. We treat the numerical problem of computing these Saffman-Taylor fingers with kinetic undercooling, which turns out to be more subtle than the analog with surface tension, since kinetic undercooling permits finger shapes which are corner-free but not analytic. We provide numerical evidence for the selection mechanism by setting up a problem with both kinetic undercooling and surface tension and numerically taking the limit that the surface tension vanishes.

Persistence of the gapless spin liquid in the breathing kagome Heisenberg antiferromagnet

Science.gov (United States)

Iqbal, Yasir; Poilblanc, Didier; Thomale, Ronny; Becca, Federico

2018-03-01

The nature of the ground state of the spin S =1 /2 Heisenberg antiferromagnet on the kagome lattice with breathing anisotropy (i.e., with different superexchange couplings J▵ and J▿ within elementary up- and down-pointing triangles) is investigated within the framework of Gutzwiller projected fermionic wave functions and Monte Carlo methods. We analyze the stability of the U(1 ) Dirac spin liquid with respect to the presence of fermionic pairing that leads to a gapped Z2 spin liquid. For several values of the ratio J▿/J▵ , the size scaling of the energy gain due to the pairing fields and the variational parameters are reported. Our results show that the energy gain of the gapped spin liquid with respect to the gapless state either vanishes for large enough system size or scales to zero in the thermodynamic limit. Similarly, the optimized pairing amplitudes (responsible for opening the spin gap) are shown to vanish in the thermodynamic limit. Our outcome is corroborated by the application of one and two Lanczos steps to the gapless and gapped wave functions, for which no energy gain of the gapped state is detected when improving the quality of the variational states. Finally, we discuss the competition with the "simplex" Z2 resonating-valence-bond spin liquid, valence-bond crystal, and nematic states in the strongly anisotropic regime, i.e., J▿≪J▵ .

Saffman-Taylor fingers with kinetic undercooling

KAUST Repository

Gardiner, Bennett P. J.; McCue, Scott W.; Dallaston, Michael C.; Moroney, Timothy J.

2015-01-01

© 2015 American Physical Society. The mathematical model of a steadily propagating Saffman-Taylor finger in a Hele-Shaw channel has applications to two-dimensional interacting streamer discharges which are aligned in a periodic array. In the streamer context, the relevant regularization on the interface is not provided by surface tension but instead has been postulated to involve a mechanism equivalent to kinetic undercooling, which acts to penalize high velocities and prevent blow-up of the unregularized solution. Previous asymptotic results for the Hele-Shaw finger problem with kinetic undercooling suggest that for a given value of the kinetic undercooling parameter, there is a discrete set of possible finger shapes, each analytic at the nose and occupying a different fraction of the channel width. In the limit in which the kinetic undercooling parameter vanishes, the fraction for each family approaches 1/2, suggesting that this "selection" of 1/2 by kinetic undercooling is qualitatively similar to the well-known analog with surface tension. We treat the numerical problem of computing these Saffman-Taylor fingers with kinetic undercooling, which turns out to be more subtle than the analog with surface tension, since kinetic undercooling permits finger shapes which are corner-free but not analytic. We provide numerical evidence for the selection mechanism by setting up a problem with both kinetic undercooling and surface tension and numerically taking the limit that the surface tension vanishes.

Massive gravity from bimetric gravity

International Nuclear Information System (INIS)

Baccetti, Valentina; Martín-Moruno, Prado; Visser, Matt

2013-01-01

We discuss the subtle relationship between massive gravity and bimetric gravity, focusing particularly on the manner in which massive gravity may be viewed as a suitable limit of bimetric gravity. The limiting procedure is more delicate than currently appreciated. Specifically, this limiting procedure should not unnecessarily constrain the background metric, which must be externally specified by the theory of massive gravity itself. The fact that in bimetric theories one always has two sets of metric equations of motion continues to have an effect even in the massive gravity limit, leading to additional constraints besides the one set of equations of motion naively expected. Thus, since solutions of bimetric gravity in the limit of vanishing kinetic term are also solutions of massive gravity, but the contrary statement is not necessarily true, there is no complete continuity in the parameter space of the theory. In particular, we study the massive cosmological solutions which are continuous in the parameter space, showing that many interesting cosmologies belong to this class. (paper)

LANSCE Beam Current Limiter (XL)

International Nuclear Information System (INIS)

Gallegos, F.R.; Hall, M.J.

1997-01-01

The Radiation Security System (RSS) at the Los Alamos Neutron Science Center (LANSCE) is an engineered safety system that provides personnel protection from prompt radiation due to accelerated proton beams. The Beam Current Limiter (XL), as an active component of the RSS, limits the maximum average current in a beamline, thus the current available for a beam spill accident. Exceeding the pre-set limit initiates action by the RSS to mitigate the hazard (insertion of beam stoppers in the low energy beam transport). The beam limiter is an electrically isolated, toroidal transformer and associated electronics. The device was designed to continuously monitor beamline currents independent of any external timing. Fail-safe operation was a prime consideration in its development. Fail-safe operation is defined as functioning as intended (due to redundant circuitry), functioning with a more sensitive fault threshold, or generating a fault condition. This report describes the design philosophy, hardware, implementation, operation, and limitations of the device

Limits to magnetic resonance microscopy

International Nuclear Information System (INIS)

Glover, Paul; Mansfield, Peter

2002-01-01

The last quarter of the twentieth century saw the development of magnetic resonance imaging (MRI) grow from a laboratory demonstration to a multi-billion dollar worldwide industry. There is a clinical body scanner in almost every hospital of the developed nations. The field of magnetic resonance microscopy (MRM), after mostly being abandoned by researchers in the first decade of MRI, has become an established branch of the science. This paper reviews the development of MRM over the last decade with an emphasis on the current state of the art. The fundamental principles of imaging and signal detection are examined to determine the physical principles which limit the available resolution. The limits are discussed with reference to liquid, solid and gas phase microscopy. In each area, the novel approaches employed by researchers to push back the limits of resolution are discussed. Although the limits to resolution are well known, the developments and applications of MRM have not reached their limit. (author)

Quasilocal energy for three-dimensional massive gravity solutions with chiral deformations of AdS{sub 3} boundary conditions

Energy Technology Data Exchange (ETDEWEB)

Garbarz, Alan, E-mail: alan-at@df.uba.ar [Departamento de Física, Universidad de Buenos Aires FCEN-UBA, IFIBA-CONICET, Ciudad Universitaria, Pabellón I, 1428, Buenos Aires, Argentina and Instituto de Física de La Plata, Universidad Nacional de La Plata IFLP-UNLP, C.C. 67 (Argentina); Giribet, Gaston, E-mail: gaston-at@df.uba.ar, E-mail: af.goya-at@df.uba.ar; Goya, Andrés, E-mail: gaston-at@df.uba.ar, E-mail: af.goya-at@df.uba.ar [Departamento de Física, Universidad de Buenos Aires FCEN-UBA, IFIBA-CONICET, Ciudad Universitaria, Pabellón I, 1428, Buenos Aires (Argentina); Leston, Mauricio, E-mail: mauricio-at@iafe.uba.ar [Instituto de Astronomía y Física del Espacio IAFE-CONICET, Ciudad Universitaria, C.C. 67 Suc. 28, 1428, Buenos Aires (Argentina)

2015-03-26

We consider critical gravity in three dimensions; that is, the New Massive Gravity theory formulated about Anti-de Sitter (AdS) space with the specific value of the graviton mass for which it results dual to a two-dimensional conformai field theory with vanishing central charge. As it happens with Kerr black holes in four-dimensional critical gravity, in three-dimensional critical gravity the Bañados-Teitelboim-Zanelli black holes have vanishing mass and vanishing angular momentum. However, provided suitable asymptotic conditions are chosen, the theory may also admit solutions carrying non-vanishing charges. Here, we give simple examples of exact solutions that exhibit falling-off conditions that are even weaker than those of the so-called Log-gravity. For such solutions, we define the quasilocal stress-tensor and use it to compute conserved charges. Despite the drastic deformation of AdS{sub 3} asymptotic, these solutions have finite mass and angular momentum, which are shown to be non-zero.

Nonlinear (super)symmetries and amplitudes

Energy Technology Data Exchange (ETDEWEB)

Kallosh, Renata [Physics Department, Stanford University,382 Via Pueblo Mall, Stanford, CA 94305-4060 (United States)

2017-03-07

There is an increasing interest in nonlinear supersymmetries in cosmological model building. Independently, elegant expressions for the all-tree amplitudes in models with nonlinear symmetries, like D3 brane Dirac-Born-Infeld-Volkov-Akulov theory, were recently discovered. Using the generalized background field method we show how, in general, nonlinear symmetries of the action, bosonic and fermionic, constrain amplitudes beyond soft limits. The same identities control, for example, bosonic E{sub 7(7)} scalar sector symmetries as well as the fermionic goldstino symmetries. We present a universal derivation of the vanishing amplitudes in the single (bosonic or fermionic) soft limit. We explain why, universally, the double-soft limit probes the coset space algebra. We also provide identities describing the multiple-soft limit. We discuss loop corrections to N≥5 supergravity, to the D3 brane, and the UV completion of constrained multiplets in string theory.

Multi-monopoles and magnetic bags

International Nuclear Information System (INIS)

Bolognesi, Stefano

2006-01-01

By analogy with the multi-vortices, we show that also multi-monopoles become magnetic bags in the large n limit. This simplification allows us to compute the spectrum and the profile functions by requiring the minimization of the energy of the bag. We consider in detail the case of the magnetic bag in the limit of vanishing potential and we find that it saturates the Bogomol'nyi bound and there is an infinite set of different shapes of allowed bags. This is consistent with the existence of a moduli space of solutions for the BPS multi-monopoles. We discuss the string theory interpretation of our result and also the relation between the 't Hooft large n limit of certain supersymmetric gauge theories and the large n limit of multi-monopoles. We then consider multi-monopoles in the cosmological context and provide a mechanism that could lead to their production

Limiting characteristics of the superconducting fault current limiter applied to the neutral line of conventional transformer

International Nuclear Information System (INIS)

Im, I.G.; Choi, H.S.; Jung, B.I.

2013-01-01

Highlights: •Fault current limiter was used a high-speed interrupter. •High-speed interrupter was operated to bypass to the current limiter line. •The size of the fault current was limited to about 80% after the fault occurred. •The fault current was limited quickly within a half-cycle after the fault occurred. -- Abstract: The increased electricity demands influenced by the recent industrial development make the electric power distribution system more comprehensive, and the risks are high to cause failures to steady state electric line due to the extended range of fault at the time of fault occurrence. Also, the high performance and the high precision electric appliances that sensitive to switching surge and fault current expose vulnerability of reduced life span and increased fault occurrence ratio. Therefore, this thesis analyzed the fault limiting characteristics by the fault types by applying the superconducting fault current limiter to the neutral line of the transformer in order to reduce the fault currents that flow such high performance appliances. A current transformer (CT) that detects the fault current in the simulated power distribution system, a switching control system that is self-developed and a transformer are used in constructing a circuit. When a fault occurs, the initial fault current is restricted by the superconducting fault current limiter and simultaneously detours the fault current by operating the SCR contact of the switching control system through the detection by CT. This thesis analyzed the limiting characteristics of the superconducting fault current limiter that are applied to the neutral line of the transformer by the fault types

Limiting characteristics of the superconducting fault current limiter applied to the neutral line of conventional transformer

Energy Technology Data Exchange (ETDEWEB)

Im, I.G., E-mail: asiligo@gmail.com; Choi, H.S., E-mail: hyosang@chosun.ac.kr; Jung, B.I.

2013-11-15

Highlights: •Fault current limiter was used a high-speed interrupter. •High-speed interrupter was operated to bypass to the current limiter line. •The size of the fault current was limited to about 80% after the fault occurred. •The fault current was limited quickly within a half-cycle after the fault occurred. -- Abstract: The increased electricity demands influenced by the recent industrial development make the electric power distribution system more comprehensive, and the risks are high to cause failures to steady state electric line due to the extended range of fault at the time of fault occurrence. Also, the high performance and the high precision electric appliances that sensitive to switching surge and fault current expose vulnerability of reduced life span and increased fault occurrence ratio. Therefore, this thesis analyzed the fault limiting characteristics by the fault types by applying the superconducting fault current limiter to the neutral line of the transformer in order to reduce the fault currents that flow such high performance appliances. A current transformer (CT) that detects the fault current in the simulated power distribution system, a switching control system that is self-developed and a transformer are used in constructing a circuit. When a fault occurs, the initial fault current is restricted by the superconducting fault current limiter and simultaneously detours the fault current by operating the SCR contact of the switching control system through the detection by CT. This thesis analyzed the limiting characteristics of the superconducting fault current limiter that are applied to the neutral line of the transformer by the fault types.

Smoothness of limit functors

Indian Academy of Sciences (India)

Abstract. Let S be a scheme. Assume that we are given an action of the one dimen- sional split torus Gm,S on a smooth affine S-scheme X. We consider the limit (also called attractor) subfunctor Xλ consisting of points whose orbit under the given action. 'admits a limit at 0'. We show that Xλ is representable by a smooth ...

The JET belt limiter tiles

International Nuclear Information System (INIS)

Deksnis, E.

1988-09-01

The belt limiter system, comprising two full toroidal rings of limiter tiles, was installed in JET in 1987. In consists of water-cooled fins with the limiter material in form of tile inbetween. The tiles are designed to absorb heat fluxes during irradiation without the surface temperature exceeding 2000 0 C and to radiate this heat between pulses to the water cooled sink whose temperature is lower than that of the vacuum vessel. An important feature of the design is to maximise the area of the radiating surface facing the water cooled fin. This leads to a tile depth much greater than the width of the tile facing the heat flux. Limiter tiles intercept particles flowing out of the plasma through the area between the two belt limiter rings and through remaining surface area of the plasma column. Power deposition to a limiter tile depends strongly on the shape of the plasma, the edge plasma properties as well as on the surface profile of the tiles. This paper will discuss the methodology that was followed in producing an optimized surface profile of the tiles. This shaped profile has the feature that the resulting power deposition profile is roughly similar for a wide range of plasma parameters. (author)

The role of collective self-gravity in the nonlinear evolution of viscous overstability in Saturn's rings.

Science.gov (United States)

Lehmann, Marius; Schmidt, Jürgen; Salo, Heikki

2017-06-01

We investigate the influence of collective self-gravity forces on the nonlinear evolution of the viscous overstability in Saturn's dense rings. Local N-body simulations, incorporating vertical and radial collective self-gravity are performed. Vertical self-gravity is mimicked through an increased frequency of vertical oscillations, while radial self-gravity is approximated by solving the Poisson equation for a thin disk in Fourier space. Direct particle-particle forces are omitted, while the magnitude of radial self gravity is controlled by assigning a variable surface mass density to the system's homogeneous ground state. We compare our simulations with large-scale isothermal and non-isothermal hydrodynamic model calculations, including radial self-gravity and employing transport coefficients derived in Salo et al. (2001). We concentrate on optical depths τ=1.5-2, appropriate to model Saturn's dense rings. Our isothermal and non isothermal hydrodynamic results in the limit of vanishing self-gravity compare very well with the studies of Latter&Ogilvie (2010) and Rein&latter (2013), respectively.With non-vanishing radial self-gravity we find that the wavelengths of saturated overstable wave trains are located in close vicinity of the local minimum of the nonlinear dispersion relation for a particular surface density. Good agreement is found between non-isothermal hydrodynamics and N-body simulations for disks with strong radial self-gravity, while the largest deviations occur for a weak but non-vanishing self-gravity.The resulting saturation wavelengths of the viscous overstability for moderate and strong radial self-gravity (λ~ 200-300m) agree reasonably well with the length scale of periodic micro structure in Saturn's inner A and B ring, as found by Cassini.

On the Limitations of Biological Knowledge

Science.gov (United States)

Dougherty, Edward R; Shmulevich, Ilya

2012-01-01

Scientific knowledge is grounded in a particular epistemology and, owing to the requirements of that epistemology, possesses limitations. Some limitations are intrinsic, in the sense that they depend inherently on the nature of scientific knowledge; others are contingent, depending on the present state of knowledge, including technology. Understanding limitations facilitates scientific research because one can then recognize when one is confronted by a limitation, as opposed to simply being unable to solve a problem within the existing bounds of possibility. In the hope that the role of limiting factors can be brought more clearly into focus and discussed, we consider several sources of limitation as they apply to biological knowledge: mathematical complexity, experimental constraints, validation, knowledge discovery, and human intellectual capacity. PMID:23633917

UV DRIVEN EVAPORATION OF CLOSE-IN PLANETS: ENERGY-LIMITED, RECOMBINATION-LIMITED, AND PHOTON-LIMITED FLOWS

International Nuclear Information System (INIS)

Owen, James E.; Alvarez, Marcelo A.

2016-01-01

We have investigated the evaporation of close-in exoplanets irradiated by ionizing photons. We find that the properties of the flow are controlled by the ratio of the recombination time to the flow timescale. When the recombination timescale is short compared to the flow timescale, the flow is in approximate local ionization equilibrium with a thin ionization front where the photon mean free path is short compared to the flow scale. In this “recombination-limited” flow the mass-loss scales roughly with the square root of the incident flux. When the recombination time is long compared to the flow timescale the ionization front becomes thick and encompasses the entire flow with the mass-loss rate scaling linearly with flux. If the planet's potential is deep, then the flow is approximately “energy-limited”; however, if the planet's potential is shallow, then we identify a new limiting mass-loss regime, which we term “photon-limited.” In this scenario, the mass-loss rate is purely limited by the incoming flux of ionizing photons. We have developed a new numerical approach that takes into account the frequency dependence of the incoming ionizing spectrum and performed a large suite of 1D simulations to characterize UV driven mass-loss around low-mass planets. We find that the flow is “recombination-limited” at high fluxes but becomes “energy-limited” at low fluxes; however, the transition is broad occurring over several orders of magnitude in flux. Finally, we point out that the transitions between the different flow types do not occur at a single flux value but depend on the planet's properties, with higher-mass planets becoming “energy-limited” at lower fluxes

Further limitations on nuclear testing

International Nuclear Information System (INIS)

Brown, P.S.

1991-11-01

This document addresses a number of subjects related to further constraints on nuclear testing, briefly discussing each of the following topics: the current political situation, the kinds of steps that might next be taken in test limitations and the impacts of further testing limits, the need for a test ban readiness program, some issues related to verification, and the possibility of confidence building measures as alternative, or near-term, steps to further test limitations

Classical and sequential limit analysis revisited

Science.gov (United States)

Leblond, Jean-Baptiste; Kondo, Djimédo; Morin, Léo; Remmal, Almahdi

2018-04-01

Classical limit analysis applies to ideal plastic materials, and within a linearized geometrical framework implying small displacements and strains. Sequential limit analysis was proposed as a heuristic extension to materials exhibiting strain hardening, and within a fully general geometrical framework involving large displacements and strains. The purpose of this paper is to study and clearly state the precise conditions permitting such an extension. This is done by comparing the evolution equations of the full elastic-plastic problem, the equations of classical limit analysis, and those of sequential limit analysis. The main conclusion is that, whereas classical limit analysis applies to materials exhibiting elasticity - in the absence of hardening and within a linearized geometrical framework -, sequential limit analysis, to be applicable, strictly prohibits the presence of elasticity - although it tolerates strain hardening and large displacements and strains. For a given mechanical situation, the relevance of sequential limit analysis therefore essentially depends upon the importance of the elastic-plastic coupling in the specific case considered.

Physics considerations for the FED limiter

International Nuclear Information System (INIS)

Howe, H.C.

1981-07-01

The physics of the scrapeoff plasma and its interaction with a pumping limiter is reviewed. The governing equations for heat and particle transport in the scrapeoff are solved analytically with several simplifying assumptions. The assumed scrapeoff model is widely used and is presented here for completeness. From the solution, a shape for the limiter is derived which has a uniform heat loading on the front surface. The assumed crossfield transport coefficient is varied to examine the sensitivity of the heat loading to variations in plasma scrapeoff thickness. The heat flux to the limiter leading edge is an extremely sensitive function of variations in scrapeoff thickness, and we argue that uncertainties in the plasma crossfield transport preclude derivation of a believable limiter shape. We also discuss the problems involved with an edgeless, perforated limiter and with a global limiter. Finally, a solution is proposed using a flat-plate limiter with the heat flux to the leading edge controlled by major radius motion of the plasma

Hydrodynamic Limit of Multiple SLE

Science.gov (United States)

Hotta, Ikkei; Katori, Makoto

2018-04-01

Recently del Monaco and Schleißinger addressed an interesting problem whether one can take the limit of multiple Schramm-Loewner evolution (SLE) as the number of slits N goes to infinity. When the N slits grow from points on the real line R in a simultaneous way and go to infinity within the upper half plane H, an ordinary differential equation describing time evolution of the conformal map g_t(z) was derived in the N → ∞ limit, which is coupled with a complex Burgers equation in the inviscid limit. It is well known that the complex Burgers equation governs the hydrodynamic limit of the Dyson model defined on R studied in random matrix theory, and when all particles start from the origin, the solution of this Burgers equation is given by the Stieltjes transformation of the measure which follows a time-dependent version of Wigner's semicircle law. In the present paper, first we study the hydrodynamic limit of the multiple SLE in the case that all slits start from the origin. We show that the time-dependent version of Wigner's semicircle law determines the time evolution of the SLE hull, K_t \\subset H\\cup R, in this hydrodynamic limit. Next we consider the situation such that a half number of the slits start from a>0 and another half of slits start from -a exact solutions, we will discuss the universal long-term behavior of the multiple SLE and its hull K_t in the hydrodynamic limit.

TFTR movable limiter instrumentation and controls

International Nuclear Information System (INIS)

Frankenberg, J.; Collins, D.; Kaufmann, D.; Mamoun, A.

1983-01-01

The TFTR movable limiter is a single poloidal limiter located within one 18 /SUP o/ segment of the vacuum vessel. It consists of three (3) interconnected inconel backing plates covered with titanium carbide coated graphite tiles. The backing plates are positioned by three independent screw drive actuators. Cooling water is fed through the horizontal port cover to tubes brazed onto the backs of the backing plates. Thermocouples monitor the limiter temperature. (1) and more fully described in refs. (1) and (2). The positioning actuators are driven by independently controlled DC servo motors, controlled either locally or from CICADA. Drive motor shaft position is monitored by chain driven encoders and potentiometers. Limiter blade position can be varied to suit any plasma within the operating range. CICADA is programmed to keep the limiter stroke within safe operating limits. A microprocessor duplicates the CICADA protective function allowing limiter operation without CICADA. The potentiometer signal is sent to an analog computer, which safeguards the limiter against failure of the encoders or the micro-processor. Cooling water flows through the limiter in 3 separate paths, one for each blade. The flow rate and temperature rise through each loop are measured accurately to allow CICADA to calculate the heat into each blade. The water system is also interlocked and alarmed to prevent dumping of water into the vacuum vessel

Algebraic entropy for differential-delay equations

OpenAIRE

Viallet, Claude M.

2014-01-01

We extend the definition of algebraic entropy to a class of differential-delay equations. The vanishing of the entropy, as a structural property of an equation, signals its integrability. We suggest a simple way to produce differential-delay equations with vanishing entropy from known integrable differential-difference equations.

Metamorphosis

Science.gov (United States)

Balch, Stephen H.

2012-01-01

One thing history's torrent appears to be sweeping away is, ironically, the study of its most productive wellspring, Western civilization. "The Vanishing West", a report the National Association of Scholars released in May 2011, documents the extent of this vanishing. The traditional Western civilization survey requirement, commonplace only…

48 CFR 1417.402 - Limitations.

Science.gov (United States)

2010-10-01

... CONTRACT TYPES SPECIAL CONTRACTING METHODS Leader Company Contracting 1417.402 Limitations. Use of leader company contracting for a product, subject to the limitations in FAR 17.402, shall require advance...

Adjusting estimative prediction limits

OpenAIRE

Masao Ueki; Kaoru Fueda

2007-01-01

This note presents a direct adjustment of the estimative prediction limit to reduce the coverage error from a target value to third-order accuracy. The adjustment is asymptotically equivalent to those of Barndorff-Nielsen & Cox (1994, 1996) and Vidoni (1998). It has a simpler form with a plug-in estimator of the coverage probability of the estimative limit at the target value. Copyright 2007, Oxford University Press.

Greybody factors of massive charged fermionic fields in a charged two-dimensional dilatonic black hole

Energy Technology Data Exchange (ETDEWEB)

Becar, Ramon [Universidad Catolica de Temuco, Departamento de Ciencias Matematicas y Fisicas, Temuco (Chile); Gonzalez, P.A. [Universidad Diego Portales, Facultad de Ingenieria, Santiago (Chile); Saavedra, Joel [Pontificia Universidad Catolica de Valparaiso, Instituto de Fisica, Valparaiso (Chile); Vasquez, Yerko [Universidad de La Serena, Departamento de Fisica, Facultad de Ciencias, La Serena (Chile)

2015-02-01

We study massive charged fermionic perturbations in the background of a charged two-dimensional dilatonic black hole, and we solve the Dirac equation analytically. Then we compute the reflection and transmission coefficients and the absorption cross section for massive charged fermionic fields, and we show that the absorption cross section vanishes at the low- and high-frequency limits. However, there is a range of frequencies where the absorption cross section is not null. Furthermore, we study the effect of the mass and electric charge of the fermionic field over the absorption cross section. (orig.)

Jets in QCD Media: Onset of Color Decoherence

International Nuclear Information System (INIS)

Mehtar-Tani, Y.; Salgado, C.A.; Tywoniuk, K.

2011-01-01

We report on recent studies of the phenomenon of color decoherence of jets in QCD media. The effect is most clearly observed in the radiation pattern of a quark-antiquark antenna, created in the same quantum state, traversing a dense color deconfined plasma. Multiple scattering with the medium color charges gradually destroys the coherence of the antenna. In the limit of opaque media this ultimately leads to independent radiation off the antenna constituents. Accordingly, radiation off the total charge vanishes implying a memory loss effect induced by the medium. (authors)

Lifshitz-Matsubara sum formula for the Casimir pressure between magnetic metallic mirrors

Science.gov (United States)

Guérout, R.; Lambrecht, A.; Milton, K. A.; Reynaud, S.

2016-02-01

We examine the conditions of validity for the Lifshitz-Matsubara sum formula for the Casimir pressure between magnetic metallic plane mirrors. As in the previously studied case of nonmagnetic materials [Guérout et al., Phys. Rev. E 90, 042125 (2014), 10.1103/PhysRevE.90.042125], we recover the usual expression for the lossy model of optical response, but not for the lossless plasma model. We also show that the modes associated with the Foucault currents play a crucial role in the limit of vanishing losses, in contrast to expectations.

Transport of a Bose gas in 1D disordered lattices at the fluid-insulator transition.

Science.gov (United States)

Tanzi, Luca; Lucioni, Eleonora; Chaudhuri, Saptarishi; Gori, Lorenzo; Kumar, Avinash; D'Errico, Chiara; Inguscio, Massimo; Modugno, Giovanni

2013-09-13

We investigate the momentum-dependent transport of 1D quasicondensates in quasiperiodic optical lattices. We observe a sharp crossover from a weakly dissipative regime to a strongly unstable one at a disorder-dependent critical momentum. In the limit of nondisordered lattices the observations suggest a contribution of quantum phase slips to the dissipation. We identify a set of critical disorder and interaction strengths for which such critical momentum vanishes, separating a fluid regime from an insulating one. We relate our observation to the predicted zero-temperature superfluid-Bose glass transition.

Transient Splenial Lesion of Corpus Callosum Associated with Antiepileptic Drug: Conventional and Diffusion-weighted Magnetic Resonance Images

Energy Technology Data Exchange (ETDEWEB)

Hakyemez, B.; Erdogan, C.; Yildirim, N.; Gokalp, G.; Parlak, M. [Uludag Univ. Medical School, Bursa (Turkey). Dept. of Radiology

2005-11-01

Transient focal lesions of splenium of corpus callosum can be seen as a component of many central nervous system diseases, including antiepileptic drug toxicity. The conventional magnetic resonance (MR) findings of the disease are characteristic and include ovoid lesions with high signal intensity at T2-weighted MRI. Limited information exists about the diffusion-weighted MRI characteristics of these lesions vanishing completely after a period of time. We examined the conventional, FLAIR, and diffusion-weighted MR images of a patient complaining of depressive mood and anxiety disorder after 1 year receiving antiepileptic medication.

Casimir effect and the quantum vacuum

International Nuclear Information System (INIS)

Jaffe, R.L.

2005-01-01

In discussions of the cosmological constant, the Casimir effect is often invoked as decisive evidence that the zero-point energies of quantum fields are ''real.'' On the contrary, Casimir effects can be formulated and Casimir forces can be computed without reference to zero-point energies. They are relativistic, quantum forces between charges and currents. The Casimir force (per unit area) between parallel plates vanishes as α, the fine structure constant, goes to zero, and the standard result, which appears to be independent of α, corresponds to the α→∞ limit

Onset of color decoherence for soft gluon radiation in a medium

Science.gov (United States)

Mehtar-Tani, Y.; Salgado, C. A.; Tywoniuk, K.

2011-12-01

We report on recent studies of the phenomenon of color decoherence in jets in QCD media. The effect is most clearly observed in the radiation pattern of a quark-antiquark antenna, created in the same quantum state, traversing a dense color deconfined plasma. Multiple scattering with the medium color charges gradually destroys the coherence of the antenna. In the limit of opaque media, this ultimately leads to independent radiation off the antenna constituents. Accordingly, radiation off the total charge vanishes implying a memory loss effect induced by the medium.

Spin relaxation in nanowires by hyperfine coupling

International Nuclear Information System (INIS)

Echeverria-Arrondo, C.; Sherman, E.Ya.

2012-01-01

Hyperfine interactions establish limits on spin dynamics and relaxation rates in ensembles of semiconductor quantum dots. It is the confinement of electrons which determines nonzero hyperfine coupling and leads to the spin relaxation. As a result, in nanowires one would expect the vanishing of this effect due to extended electron states. However, even for relatively clean wires, disorder plays a crucial role and makes electron localization sufficient to cause spin relaxation on the time scale of the order of 10 ns. (copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Magnus expansion for laser-matter interaction: Application to generic few-cycle laser pulses

DEFF Research Database (Denmark)

Klaiber, Michael; Dimitrovski, Darko; Briggs, John S.

2009-01-01

We treat the interaction of an atom with a short intense few-cycle laser pulse by the use of the Magnus expansion of the time-evolution operator. Terms of the Magnus expansion up to the third order in the pulse duration are evaluated explicitly, and expressions for the transition probability...... of the Magnus approximation are in excellent agreement with time-dependent transition probabilities obtained from accurate ab initio numerical calculations. However, the limitation of the Magnus expansion for pulses having both vanishing momentum and position shifts is demonstrated also....

Dynamic retardation corrections to the mass spectrum of heavy quarkonia

International Nuclear Information System (INIS)

Kopalejshvili, T.; Rusetskij, A.

1996-01-01

In the framework of the Logunov-Tavkhelidze quasipotential approach the first-order retardation corrections to the heavy quarkonia mass spectrum are calculated with the use of the stationary wave boundary condition in the covariant kernel of the Bethe-Salpeter equation. As has been expected, these corrections turn out to be small for all low-lying heavy meson states and vanish in the heavy quark limit (m Q →∞). The comparison of the suggested approach to the calculation of retardation corrections with others, known in literature, is carried out. 22 refs., 1 tab

The British Nuclear Fuels Limited (Payment and Loan Limit) Order 1976 No.1298

International Nuclear Information System (INIS)

1976-01-01

Sections 11(4) and 12(1) of the Atomic Energy Authority Act 1971 authorise the Secretary of State for Energy (with the consent of the Treasury) to subscribe for shares in British Nuclear Fuels Limited and (with the approval of the Treasury) to make loans to the Company. Section 13 of the Act imposes an overall limit on the total amounts which may be paid or lent to that Company by the Secretary of State or by the United Kingdom Atomic Energy Authority, or both collectively, of Pound 50 million, which may be increased to such greater sum not exceeding Pound 75 million as may be specified by the Secretary of State by order. This Order increases the limit to Pound 75 million. (G.B.) [fr

Hydrodynamic mobility of a sphere moving on the centerline of an elastic tube

Science.gov (United States)

Daddi-Moussa-Ider, Abdallah; Lisicki, Maciej; Gekle, Stephan

2017-11-01

Elastic channels are an important component of many soft matter systems, in which hydrodynamic interactions with confining membranes determine the behavior of particles in flow. In this work, we derive analytical expressions for Green's functions associated with a point-force (Stokeslet) directed parallel or perpendicular to the axis of an elastic cylindrical channel exhibiting resistance against shear and bending. We then compute the leading order self- and pair mobility functions of particles on the cylinder axis, finding that the mobilities are primarily determined by membrane shear and that bending does not play a significant role. In the quasi-steady limit of vanishing frequency, the particle self- and pair mobilities near a no-slip hard cylinder are recovered only if the membrane possesses a non-vanishing shear rigidity. We further compute the membrane deformation, finding that deformation is generally more pronounced in the axial (radial) directions, for the motion along (perpendicular to) the cylinder centerline, respectively. Our analytical calculations for Green's functions in an elastic cylinder can serve as a fundamental building block for future studies and are verified by fully resolved boundary integral simulations where very good agreement is obtained.

Chiral current generation in QED by longitudinal photons

Energy Technology Data Exchange (ETDEWEB)

Acosta Avalo, J.L., E-mail: jlacosta@instec.cu [Instituto Superior de Tecnologías y Ciencias Aplicadas (INSTEC), Ave Salvador Allende, No. 1110, Vedado, La Habana 10400 (Cuba); Pérez Rojas, H., E-mail: hugo@icimaf.cu [Instituto de Cibernética, Matemática y Física (ICIMAF), Calle E esq 15, No. 309, Vedado, La Habana 10400 (Cuba)

2016-08-15

We report the generation of a pseudovector electric current having imbalanced chirality in an electron–positron strongly magnetized gas in QED. It propagates along the external applied magnetic field B as a chiral magnetic effect in QED. It is triggered by a perturbative electric field parallel to B, associated to a pseudovector longitudinal mode propagating along B. An electromagnetic chemical potential was introduced, but our results remain valid even when it vanishes. A nonzero fermion mass was assumed, which is usually considered vanishing in the literature. In the quantum field theory formalism at finite temperature and density, an anomaly relation for the axial current was found for a medium of massive fermions. It bears some analogy to the Adler–Bell–Jackiw anomaly. From the expression for the chiral current in terms of the photon self-energy tensor in a medium, it is obtained that electrons and positrons scattered by longitudinal photons (inside the light cone) contribute to the chiral current, as well as the to pair creation due to longitudinal photons (out of light cone). In the static limit, an electric pseudovector current is obtained in the lowest Landau level.

Chiral current generation in QED by longitudinal photons

Directory of Open Access Journals (Sweden)

J.L. Acosta Avalo

2016-08-01

Full Text Available We report the generation of a pseudovector electric current having imbalanced chirality in an electron–positron strongly magnetized gas in QED. It propagates along the external applied magnetic field B as a chiral magnetic effect in QED. It is triggered by a perturbative electric field parallel to B, associated to a pseudovector longitudinal mode propagating along B. An electromagnetic chemical potential was introduced, but our results remain valid even when it vanishes. A nonzero fermion mass was assumed, which is usually considered vanishing in the literature. In the quantum field theory formalism at finite temperature and density, an anomaly relation for the axial current was found for a medium of massive fermions. It bears some analogy to the Adler–Bell–Jackiw anomaly. From the expression for the chiral current in terms of the photon self-energy tensor in a medium, it is obtained that electrons and positrons scattered by longitudinal photons (inside the light cone contribute to the chiral current, as well as the to pair creation due to longitudinal photons (out of light cone. In the static limit, an electric pseudovector current is obtained in the lowest Landau level.

The density limit in JET diverted plasmas

Energy Technology Data Exchange (ETDEWEB)

Campbell, D J; Clement, S; Gottardi, N; Gowers, C; Harbour, P; Loarte, A; Horton, L; Lingertat, J; Lowry, C G; Saibene, G; Stamp, M; Stork, D [Commission of the European Communities, Abingdon (United Kingdom). JET Joint Undertaking; Monk, R [Royal Holloway Coll., London (United Kingdom). Dept. of Physics

1994-07-01

In JET limiter plasmas the density limit is associated with radiated power fractions of 100% and, in plasmas with carbon limiters, it is invariably disruptive. However, in discharges with solid beryllium limiters the limit is identified with the formation of a MARFE and disruptions are less frequent. In addition, the improved conditioning of the vessel arising from the use of beryllium has significantly improved the density limit scaling, so that the maximum density rises with the square root of the input power. In diverted plasmas several confinement regimes exist, making the characterization of the density limit more complex. While the density limit in L-mode plasmas is generally disruptive, the limit in ELMy and ELM-free H-modes generally prompts a return to the L-mode and a disruption is not inevitable. The density limit does rise with the increasing power, but the L-to-H transition complicates the analysis. Nevertheless, at low plasma currents (<2 MA), densities significantly above the Greenwald limit can be achieved, while at higher currents power handling limitations have constrained the range of density which can be achieved. (authors). 7 refs., 4 figs.

Vacuum currents in braneworlds on AdS bulk with compact dimensions

Science.gov (United States)

Bellucci, S.; Saharian, A. A.; Vardanyan, V.

2015-11-01

The two-point function and the vacuum expectation value (VEV) of the current density are investigated for a massive charged scalar field with arbitrary curvature coupling in the geometry of a brane on the background of AdS spacetime with partial toroidal compactification. The presence of a gauge field flux, enclosed by compact dimensions, is assumed. On the brane the field obeys Robin boundary condition and along compact dimensions periodicity conditions with general phases are imposed. There is a range in the space of the values for the coefficient in the boundary condition where the Poincaré vacuum is unstable. This range depends on the location of the brane and is different for the regions between the brane and AdS boundary and between the brane and the horizon. In models with compact dimensions the stability condition is less restrictive than that for the AdS bulk with trivial topology. The vacuum charge density and the components of the current along non-compact dimensions vanish. The VEV of the current density along compact dimensions is a periodic function of the gauge field flux with the period equal to the flux quantum. It is decomposed into the boundary-free and brane-induced contributions. The asymptotic behavior of the latter is investigated near the brane, near the AdS boundary and near the horizon. It is shown that, in contrast to the VEVs of the field squared an denergy-momentum tensor, the current density is finite on the brane and vanishes for the special case of Dirichlet boundary condition. Both the boundary-free and brane-induced contributions vanish on the AdS boundary. The brane-induced contribution vanishes on the horizon and for points near the horizon the current is dominated by the boundary-free part. In the near-horizon limit, the latter is connected to the corresponding quantity for a massless field in the Minkowski bulk by a simple conformal relation. Depending on the value of the Robin coefficient, the presence of the brane can either

Information Processing and Limited Liability

OpenAIRE

Bartosz Mackowiak; Mirko Wiederholt

2012-01-01

Decision-makers often face limited liability and thus know that their loss will be bounded. We study how limited liability affects the behavior of an agent who chooses how much information to acquire and process in order to take a good decision. We find that an agent facing limited liability processes less information than an agent with unlimited liability. The informational gap between the two agents is larger in bad times than in good times and when information is more costly to process.

Effluent release limits, sources and control

International Nuclear Information System (INIS)

Swindell, G.E.

1977-01-01

Objectives of radiation protection in relation to releases. Environmental transfer models for radionuclides. Relationship between releases, environmental levels and doses to persons. Establishment of release limits: Limits based on critical population group concept critical pathway analysis and identification of critical group. Limits based on optimization of radiation protection individual dose limits, collective doses and dose commitments 1) differential cost benefit analysis 2) authorized and operational limits taking account of future exposures. Monitoring of releases to the environment: Objectives of effluent monitoring. Typical sources and composition of effluents; design and operation of monitoring programmes; recording and reporting of monitoring results; complementary environmental monitoring. (orig.) [de

Does the QCD vacuum build up a colour chemical potential dynamically?

International Nuclear Information System (INIS)

Sailer, K.; Greiner, W.

1998-01-01

The one-loop effective theory is found for QCD assuming an overcritical homogeneous gluon vector potential background that corresponds to a non-vanishing colour chemical potential. It is found that the vacuum is unstable against building up a non-vanishing colour chemical potential for sufficiently large number of flavours. (author)

Limitations on blanket performance

International Nuclear Information System (INIS)

Malang, S.

1999-01-01

The limitations on the performance of breeding blankets in a fusion power plant are evaluated. The breeding blankets will be key components of a plant and their limitations with regard to power density, thermal efficiency and lifetime could determine to a large degree the attractiveness of a power plant. The performance of two rather well known blanket concepts under development in the frame of the European Blanket Programme is assessed and their limitations are compared with more advanced (and more speculative) concepts. An important issue is the question of which material (structure, breeder, multiplier, coatings) will limit the performance and what improvement would be possible with a 'better' structural material. This evaluation is based on the premise that the performance of the power plant will be limited by the blankets (including first wall) and not by other components, e.g. divertors, or the plasma itself. However, the justness of this premise remains to be seen. It is shown that the different blanket concepts cover a large range of allowable power densities and achievable thermal efficiencies, and it is concluded that there is a high incentive to go for better performance in spite of possibly higher blanket cost. However, such high performance blankets are usually based on materials and technologies not yet developed and there is a rather high risk that the development could fail. Therefore, it is explained that a part of the development effort should be devoted to concepts where the materials and technologies are more or less in hand in order to ensure that blankets for a DEMO reactor can be developed and tested in a given time frame. (orig.)

Prediction Model of Mechanical Extending Limits in Horizontal Drilling and Design Methods of Tubular Strings to Improve Limits

Directory of Open Access Journals (Sweden)

Wenjun Huang

2017-01-01

Full Text Available Mechanical extending limit in horizontal drilling means the maximum horizontal extending length of a horizontal well under certain ground and down-hole mechanical constraint conditions. Around this concept, the constrained optimization model of mechanical extending limits is built and simplified analytical results for pick-up and slack-off operations are deduced. The horizontal extending limits for kinds of tubular strings under different drilling parameters are calculated and drawn. To improve extending limits, an optimal design model of drill strings is built and applied to a case study. The results indicate that horizontal extending limits are underestimated a lot when the effects of friction force on critical helical buckling loads are neglected. Horizontal extending limits firstly increase and tend to stable values with vertical depths. Horizontal extending limits increase faster but finally become smaller with the increase of horizontal pushing forces for tubular strings of smaller modulus-weight ratio. Sliding slack-off is the main limit operation and high axial friction is the main constraint factor constraining horizontal extending limits. A sophisticated installation of multiple tubular strings can greatly inhibit helical buckling and increase horizontal extending limits. The optimal design model is called only once to obtain design results, which greatly increases the calculation efficiency.

Size Dependent Orientation of Knudsen Force

KAUST Repository

Zhu, Taishan

2012-03-03

Knudsen force acting on a heated microbeam adjacent to a cold substrate in a rarefied gas is a mechanical force created by unbalanced thermal gradients. The measured force has its direction pointing towards the side with a lower thermal gradient and its magnitude vanishes in both continuum and free-molecule limits. In our previous study, negative Knudsen forces were discovered at the high Knudsen regime before diminishing in the free-molecule limit. Such a phenomenon was however not observed in the experiment. In this paper, the existence of such a negative Knudsen force is further confirmed using both numerical simulation and theoretical analysis. The asymptotic order of the Knudsen force near the collisionless limit is analyzed and the analytical expression of its leading term is provided, from which approaches for the enhancement of negative Knudsen forces are proposed. Copyright © 2012 by ASME.

Enhanced Detectability of Community Structure in Multilayer Networks through Layer Aggregation.

Science.gov (United States)

Taylor, Dane; Shai, Saray; Stanley, Natalie; Mucha, Peter J

2016-06-03

Many systems are naturally represented by a multilayer network in which edges exist in multiple layers that encode different, but potentially related, types of interactions, and it is important to understand limitations on the detectability of community structure in these networks. Using random matrix theory, we analyze detectability limitations for multilayer (specifically, multiplex) stochastic block models (SBMs) in which L layers are derived from a common SBM. We study the effect of layer aggregation on detectability for several aggregation methods, including summation of the layers' adjacency matrices for which we show the detectability limit vanishes as O(L^{-1/2}) with increasing number of layers, L. Importantly, we find a similar scaling behavior when the summation is thresholded at an optimal value, providing insight into the common-but not well understood-practice of thresholding pairwise-interaction data to obtain sparse network representations.

The Limits of Exercise Physiology

DEFF Research Database (Denmark)

Gabriel, Brendan M; Zierath, Juleen R

2017-01-01

Many of the established positive health benefits of exercise have been documented by historical discoveries in the field of exercise physiology. These investigations often assess limits: the limits of performance, or the limits of exercise-induced health benefits. Indeed, several key findings have...... been informed by studying highly trained athletes, in addition to healthy or unhealthy people. Recent progress has been made in regard to skeletal muscle metabolism and personalized exercise regimes. In this perspective, we review some of the historical milestones of exercise physiology, discuss how...

Theory of limit cycles

CERN Document Server

Ye, Yan-Qian; Lo, Chi Y

1986-01-01

Over the past two decades the theory of limit cycles, especially for quadratic differential systems, has progressed dramatically in China as well as in other countries. This monograph, updating the 1964 first edition, includes these recent developments, as revised by eight of the author's colleagues in their own areas of expertise. The first part of the book deals with limit cycles of general plane stationary systems, including their existence, nonexistence, stability, and uniqueness. The second section discusses the global topological structure of limit cycles and phase-portraits of quadratic systems. Finally, the last section collects important results that could not be included under the subject matter of the previous two sections or that have appeared in the literature very recently. The book as a whole serves as a reference for college seniors, graduate students, and researchers in mathematics and physics.

Quantity and quality limit detritivore growth: mechanisms revealed by ecological stoichiometry and co-limitation theory.

Science.gov (United States)

Halvorson, Halvor M; Sperfeld, Erik; Evans-White, Michelle A

2017-12-01

Resource quantity and quality are fundamental bottom-up constraints on consumers. Best understood in autotroph-based systems, co-occurrence of these constraints may be common but remains poorly studied in detrital-based systems. Here, we used a laboratory growth experiment to test limitation of the detritivorous caddisfly larvae Pycnopsyche lepida across a concurrent gradient of oak litter quantity (food supply) and quality (phosphorus : carbon [P:C ratios]). Growth increased simultaneously with quantity and quality, indicating co-limitation across the resource gradients. We merged approaches of ecological stoichiometry and co-limitation theory, showing how co-limitation reflected shifts in C and P acquisition throughout homeostatic regulation. Increased growth was best explained by elevated consumption rates and improved P assimilation, which both increased with elevated quantity and quality. Notably, C assimilation efficiencies remained unchanged and achieved maximum 18% at low quantity despite pronounced C limitation. Detrital C recalcitrance and substantive post-assimilatory C losses probably set a minimum quantity threshold to achieve positive C balance. Above this threshold, greater quality enhanced larval growth probably by improving P assimilation toward P-intensive growth. We suggest this interplay of C and P acquisition contributes to detritivore co-limitation, highlighting quantity and quality as potential simultaneous bottom-up controls in detrital-based ecosystems, including under anthropogenic change like nutrient enrichment. © 2017 by the Ecological Society of America.

Safety and design limits

International Nuclear Information System (INIS)

Shishkov, L. K.; Gorbaev, V. A.; Tsyganov, S. V.

2007-01-01

The paper touches upon the issues of NPP safety ensuring at the stage of fuel load design and operation by applying special limitations for a series of parameters, that is, design limits. Two following approaches are compared: the one used by west specialists for the PWR reactor and the Russian approach employed for the WWER reactor. The closeness of approaches is established, differences that are mainly peculiarities of terms are noted (Authors)

Determination of the Meteor Limiting Magnitude

Science.gov (United States)

Kingery, A.; Blaauw, R.; Cooke, W. J.

2016-01-01

The limiting meteor magnitude of a meteor camera system will depend on the camera hardware and software, sky conditions, and the location of the meteor radiant. Some of these factors are constants for a given meteor camera system, but many change between meteor shower or sporadic source and on both long and short timescales. Since the limiting meteor magnitude ultimately gets used to calculate the limiting meteor mass for a given data set, it is important to have an understanding of these factors and to monitor how they change throughout the night, as a 0.5 magnitude uncertainty in limiting magnitude translates to a uncertainty in limiting mass by a factor of two.

Anomalies and the Large N Limit

International Nuclear Information System (INIS)

Agarwal, A.; Akant, L.

2003-01-01

Operator algebra aspects of the Large N limit of Bosonic vector models are analyzed. It is shown that the Large N limit is a classical theory, and a general method, based on defromation quatization, for calculating the Poisson algebra of dynamical observables in the limiting classical theory is presented. The Poisson algebra of O(N) invariant observables of Bosonic vector models is constructed in this approach, and is shown to be a central extension of the Symplectic Lie algebra. The relation of the central term to anomalies is discussed. A comparision of the classical theories obtained in the Large N limit and that in the small (ℎ/2π) limit is also presented

Survey of beam-beam limitations

International Nuclear Information System (INIS)

Courant, E.; Cornacchia, M.; Donald, M.M.R.; Evans, L.R.; Tazzari, S.; Wilson, E.J.N.

1979-01-01

The effect of beam-beam interaction is known to limit the luminosity of electron-positron storage rings and will, no doubt, limit the proton-antiproton collision scheme for the SPS. While theorists are struggling to explain this phenomenon it is more instructive to list their failures than their rather limited successes, in the hope that experiments may emerge which will direct their endeavors. The search for a description of a nonlinear system as it approaches the limit in which ordered motion breaks down, is the nub of the problem. It has engaged many fine mathematical intellects for decades and will no doubt continue to do so long after ISABELLE, the p antip and LEP are past achievements. Empirical scaling laws are emerging which relate electron machines to each other but their extrapolation to proton machines remain a very speculative exercise. Experimental data on proton limits is confined to one machine, the ISR, which does not normally suffer the beam-beam effect and where it must be artificially induced or simulated. This machine is also very different in important ways from the p antip collider. The gloomy picture which has emerged recently is that the fixed limits which were conventionally assumed for proton and electron machines can only be said to be valid for the machines which engendered them - the best guess that could be made at the time. They are very difficult to extrapolate to other sets of parameters

Density limit investigations near and significantly above the Greenwald limit on the tokamaks TEXTOR-94 and RTP

International Nuclear Information System (INIS)

Rapp, J.; Koslowski, H.R.; Pospieszczyk, A.; Salzedas, F.; Vries, P.C. de; Schueller, F.C.; Hokin, S.; Messiaen, A.M.

2001-01-01

Ignition scenarios like those developed for ITER require plasma densities which will be close or above the Greenwald limit. Generally it is observed that exceeding this limit may lead to a degradation of plasma confinement or to a violent end of the discharge. The achievable density limit and the related processes, such as radiative instabilities and MHD phenomena, which eventually lead to disruption, have been investigated in the limiter tokamaks TEXTOR-94 and RTP. (author)

The estimation of derived limits

International Nuclear Information System (INIS)

Harrison, N.T.; Bryant, P.M.; Clarke, R.H.; Morley, F.

1979-08-01

In practical radiation protection, it is often necessary to calculate limits of intake of radionuclides associated with various quantities; such limits are needed, for example, to assess the adequacy of the control of environmental contamination. In publication 26 of the International Commission on Radiological Protection (ICRP), these limits, when related to the basic limits of dose-equivalent by a defined model, are referred to as Derived Limits (DLs). In the present report the principles to be adopted by the Board in calculating DLs to be recommended for general application within the United Kingdom are outlined. DLs will be recommended for a wide range of radionuclides and for circumstances relevant to the workplace, and, more frequently, the general environment. The latter will include DLs in foodstuffs and associated environmental materials, such as soil and grass, and DLs for discharges from stacks. DLs will be related to dose equivalents for workers or members of the public for stochastic or non-stochastic effects as appropriate. Consideration will be given to relevant data on radiosensitivity, metabolism and dosimetry for children and to the physicochemical forms of radionuclides. (author)

Penrose limits and RG flows

International Nuclear Information System (INIS)

Gimon, Eric G.; Sonnenschein, Jacob; Pando Zayas, Leopoldo A.

2002-01-01

The Penrose-Gueven limit simplifies a given supergravity solution into a pp-wave background. Aiming at clarifying its relation to renormalization group flow we study the Penrose-Guven limit of supergravity backgrounds that are dual to non-conformal gauge theories. The resulting backgrounds fall in a class simple enough that the quantum particle is exactly solvable. We propose a map between the effective time-dependent quantum mechanical problem and the RG flow in the gauge theory. As a testing ground we consider explicitly two Penrose limits of the infrared fixed point of the Pilch-Warner solution. We analyze the corresponding gauge theory picture and write down the operators which are the duals of the low lying string states. We also address RG flows of a different nature by considering the Penrose-Gueven limit of a stack of N D p branes. We note that in the far IR (for p<3)the limit generically has negative mass-squared. This phenomenon signals, in the world sheet picture, the necessity to transform to another description. In this regard, we consider explicitly the cases of M2 from D2 and F1 from D1. (author)

Up in smoke: vanishing evidence of tobacco disparities in the Institute of Medicine's report on sexual and gender minority health.

Science.gov (United States)

Lee, Joseph G L; Blosnich, John R; Melvin, Cathy L

2012-11-01

The Institute of Medicine (IOM) released a groundbreaking report on lesbian, gay, bisexual, and transgender (LGBT) health in 2011, finding limited evidence of tobacco disparities. We examined IOM search terms and used 2 systematic reviews to identify 71 articles on LGBT tobacco use. The IOM omitted standard tobacco-related search terms. The report also omitted references to studies on LGBT tobacco use (n = 56), some with rigorous designs. The IOM report may underestimate LGBT tobacco use compared with general population use.

Superconducting dc fault current limiter

International Nuclear Information System (INIS)

Cointe, Y.

2007-12-01

Within the framework of the electric power market liberalization, DC networks have many interests compared to alternative ones, but their protections need to use new systems. Superconducting fault current limiters enable by an overstepping of the critical current to limit the fault current to a preset value, lower than the theoretical short-circuit current. For these applications, coated conductors offer excellent opportunities. We worked on the implementation of these materials and built a test bench. We carried out limiting experiments to estimate the quench homogeneity at various short-circuit parameters. An important point is the temperature measurement by deposited sensors on the ribbon, results are in good correlation with the theoretical models. Improved quench behaviours for temperatures close to the critical temperature have been confirmed. Our results enable to better understand the limitation mechanisms of coated conductors. (author)

The Limits to Giving Back

Directory of Open Access Journals (Sweden)

Jade S. Sasser

2014-07-01

Full Text Available In this thematic section, authors consider the limitations on giving back that they faced in field research, or saw others face. For some authors, their attempts at giving back were severely limited by the scope of their projects, or their understandings of local cultures or histories. For others, very specific circumstances and historical interventions of foreigners in certain places can limit how and to what extent a researcher is able to have a reciprocal relationship with the participating community. Some authors, by virtue of their lesser positions of power relative to those that they were studying, simply decided not to give back to those communities. In each article it becomes apparent that how and in what ways people give back is unique (and limited both to their personal values and the contexts in which they do research.

Limited Releases of Krsko NPP

International Nuclear Information System (INIS)

Breznik, B.; Kovac, A.

2001-01-01

Full text: Krsko Nuclear Power Plant is about 700 MW Pressurised Water Reactor plant located in Slovenia close to the border with Croatia. The authorised limit for the radioactive releases is basically set to 50 μSv effective dose per year to the members of the public. There is also additional limitation of total activities released in a year and concentration. The poster presents the effluents of the year 2000 and evaluated dose referring to the limits and to the natural and other sources of radiation around the plant. (author)

Solutions of weakened field equations in Gödel space-time

Directory of Open Access Journals (Sweden)

Aditya Mani Mishra

2019-04-01

Full Text Available We have solved Weakened field equations, collected work of Lovelock for cylindrically symmetric G¨odel type spacetime. A comparative study of these solutions to solution of Einstein’s field equation have shown. Conformality of Gödel spacetime has discussed with vanishing and non-vanishing scalar curvature of the spacetime.

Approach to DOE threshold guidance limits

International Nuclear Information System (INIS)

Shuman, R.D.; Wickham, L.E.

1984-01-01

The need for less restrictive criteria governing disposal of extremely low-level radioactive waste has long been recognized. The Low-Level Waste Management Program has been directed by the Department of Energy (DOE) to aid in the development of a threshold guidance limit for DOE low-level waste facilities. Project objectives are concernd with the definition of a threshold limit dose and pathway analysis of radionuclide transport within selected exposure scenarios at DOE sites. Results of the pathway analysis will be used to determine waste radionuclide concentration guidelines that meet the defined threshold limit dose. Methods of measurement and verification of concentration limits round out the project's goals. Work on defining a threshold limit dose is nearing completion. Pathway analysis of sanitary landfill operations at the Savannah River Plant and the Idaho National Engineering Laboratory is in progress using the DOSTOMAN computer code. Concentration limit calculations and determination of implementation procedures shall follow completion of the pathways work. 4 references

Charter Halibut Limited Access Program

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This limited access system limits the number of charter vessels that may participate in the guided sport fishery for halibut in area 2C and 3A. NMFS issues a charter...

An asymptotically consistent approximant for the equatorial bending angle of light due to Kerr black holes

International Nuclear Information System (INIS)

Barlow, Nathaniel S; Faber, Joshua A; Weinstein, Steven J

2017-01-01

An accurate closed-form expression is provided to predict the bending angle of light as a function of impact parameter for equatorial orbits around Kerr black holes of arbitrary spin. This expression is constructed by assuring that the weak- and strong-deflection limits are explicitly satisfied while maintaining accuracy at intermediate values of impact parameter via the method of asymptotic approximants (Barlow et al 2017 Q. J. Mech. Appl. Math . 70 21–48). To this end, the strong deflection limit for a prograde orbit around an extremal black hole is examined, and the full non-vanishing asymptotic behavior is determined. The derived approximant may be an attractive alternative to computationally expensive elliptical integrals used in black hole simulations. (paper)

12 CFR 24.4 - Investment limits.

Science.gov (United States)

2010-01-01

... 12 Banks and Banking 1 2010-01-01 2010-01-01 false Investment limits. 24.4 Section 24.4 Banks and... ENTITIES, COMMUNITY DEVELOPMENT PROJECTS, AND OTHER PUBLIC WELFARE INVESTMENTS § 24.4 Investment limits. (a) Limits on aggregate outstanding investments. A national bank's aggregate outstanding investments under...

N-limited or N and P co-limited indications in the surface waters of three Mediterranean basins

Science.gov (United States)

Tanaka, T.; Thingstad, T. F.; Christaki, U.; Colombet, J.; Cornet-Barthaux, V.; Courties, C.; Grattepanche, J.-D.; Lagaria, A.; Nedoma, J.; Oriol, L.; Psarra, S.; Pujo-Pay, M.; van Wambeke, F.

2010-11-01

The limiting nutrient for the pelagic microbial food web in the Mediterranean Sea was investigated in the nutrient manipulated microcosms during summer 2008. Surface waters were collected into 12 carboys at a center of anticyclonic eddy at the Western Basin, the Ionian Basin, and the Levantine Basin, respectively. As compared to the Redfield ratio, the ratio of N to P in the collected waters was always smaller in the dissolved inorganic fraction but higher in both dissolved and particulate organic fractions. Four different treatments in triplicates (addition of ammonium, phosphate, a combination of both, and the unamended control) were set up for the carboys. Responses of chemical and biological parameters in these different treatments were measured during the incubation (3-4 days). Temporal changes of turnover time of phosphate and ATP, and alkaline phosphatase activity during the incubation suggested that the phytoplankton and heterotrophic prokaryotes (Hprok) communities were not purely P-limited at any studied stations. Statistical comparison between the treatments for a given parameter measured at the end of the incubation did not find pure P-limitation in any chemical and biological parameters at three study sites. Primary production was consistently limited by N, and Hprok growth was not limited by N nor P in the Western Basin, but N-limited in the Ionian Basin, and N and P co-limited in the Levantine Basin. Our results demonstrated the gap between biogeochemical features and biological responses in terms of the limiting nutrient. We question the general notion that Mediterranean surface waters are limited by P alone during the stratified period.

Density limit experiments on FTU

International Nuclear Information System (INIS)

Pucella, G.; Tudisco, O.; Apicella, M.L.; Apruzzese, G.; Artaserse, G.; Belli, F.; Boncagni, L.; Botrugno, A.; Buratti, P.; Calabrò, G.; Castaldo, C.; Cianfarani, C.; Cocilovo, V.; Dimatteo, L.; Esposito, B.; Frigione, D.; Gabellieri, L.; Giovannozzi, E.; Bin, W.; Granucci, G.

2013-01-01

One of the main problems in tokamak fusion devices concerns the capability to operate at a high plasma density, which is observed to be limited by the appearance of catastrophic events causing loss of plasma confinement. The commonly used empirical scaling law for the density limit is the Greenwald limit, predicting that the maximum achievable line-averaged density along a central chord depends only on the average plasma current density. However, the Greenwald density limit has been exceeded in tokamak experiments in the case of peaked density profiles, indicating that the edge density is the real parameter responsible for the density limit. Recently, it has been shown on the Frascati Tokamak Upgrade (FTU) that the Greenwald density limit is exceeded in gas-fuelled discharges with a high value of the edge safety factor. In order to understand this behaviour, dedicated density limit experiments were performed on FTU, in which the high density domain was explored in a wide range of values of plasma current (I p = 500–900 kA) and toroidal magnetic field (B T = 4–8 T). These experiments confirm the edge nature of the density limit, as a Greenwald-like scaling holds for the maximum achievable line-averaged density along a peripheral chord passing at r/a ≃ 4/5. On the other hand, the maximum achievable line-averaged density along a central chord does not depend on the average plasma current density and essentially depends on the toroidal magnetic field only. This behaviour is explained in terms of density profile peaking in the high density domain, with a peaking factor at the disruption depending on the edge safety factor. The possibility that the MARFE (multifaced asymmetric radiation from the edge) phenomenon is the cause of the peaking has been considered, with the MARFE believed to form a channel for the penetration of the neutral particles into deeper layers of the plasma. Finally, the magnetohydrodynamic (MHD) analysis has shown that also the central line

Bioenergy Sorghum Crop Model Predicts VPD-Limited Transpiration Traits Enhance Biomass Yield in Water-Limited Environments.

Science.gov (United States)

Truong, Sandra K; McCormick, Ryan F; Mullet, John E

2017-01-01

Bioenergy sorghum is targeted for production in water-limited annual cropland therefore traits that improve plant water capture, water use efficiency, and resilience to water deficit are necessary to maximize productivity. A crop modeling framework, APSIM, was adapted to predict the growth and biomass yield of energy sorghum and to identify potentially useful traits for crop improvement. APSIM simulations of energy sorghum development and biomass accumulation replicated results from field experiments across multiple years, patterns of rainfall, and irrigation schemes. Modeling showed that energy sorghum's long duration of vegetative growth increased water capture and biomass yield by ~30% compared to short season crops in a water-limited production region. Additionally, APSIM was extended to enable modeling of VPD-limited transpiration traits that reduce crop water use under high vapor pressure deficits (VPDs). The response of transpiration rate to increasing VPD was modeled as a linear response until a VPD threshold was reached, at which the slope of the response decreases, representing a range of responses to VPD observed in sorghum germplasm. Simulation results indicated that the VPD-limited transpiration trait is most beneficial in hot and dry regions of production where crops are exposed to extended periods without rainfall during the season or to a terminal drought. In these environments, slower but more efficient transpiration increases biomass yield and prevents or delays the exhaustion of soil water and onset of leaf senescence. The VPD-limited transpiration responses observed in sorghum germplasm increased biomass accumulation by 20% in years with lower summer rainfall, and the ability to drastically reduce transpiration under high VPD conditions could increase biomass by 6% on average across all years. This work indicates that the productivity and resilience of bioenergy sorghum grown in water-limited environments could be further enhanced by development

7 CFR 52.3185 - Moisture limits.

Science.gov (United States)

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false Moisture limits. 52.3185 Section 52.3185 Agriculture... United States Standards for Grades of Dried Prunes Moisture, Uniformity of Size, Defects § 52.3185 Moisture limits. Dried prunes shall not exceed the moisture limits for the applicable grades and kind and...

Subcritical limits for special fissile actinides

International Nuclear Information System (INIS)

Clark, H.K.

1980-01-01

Critical masses and subcritical mass limits in oxide-water mixtures were calculated for actinide nuclides other than 233 U, 235 U, and 239 Pu that have an odd number of neutrons in the nucleus: S/sub n/ transport theory was used together with cross sections, drawn from the GLASS multigroup library, developed to provide accurate forecasts of actinide production at Savannah River. The subcritical limits are 201 g for 241 Pu, 13 g for 242 /sup m/Am, 90 g for 243 Cm, 30 g for 245 Cm, 900 g for 247 Cm, 10 g for 249 Cf, and 5 g for 251 Cf. Association of 241 Pu with an equal mass of 240 Pu increases the 241 Pu limit to a value greater than that for pure 239 Pu. Association of 242 /sup m/Am with 241 Am increases the limit for the mixture to that for dry, theoretical density AmO 2 at isotopic concentrations of 242 /sup m/Am less than approx. 6%. Association of 245 Cm with 244 Cm increases the limit according to the formula 30 + 0.3 244 Cm/ 245 Cm up to the limit for dry CmO 2 . A limiting mass of 8.15 kg for plutonium containing at least 67% 238 Pu as oxide was calculated that applies (provided 240 Pu exceeds 241 Pu) with no limit on moderation. 1 figure, 5 tables

Model for movement of molten limiter material during the ISX-B beryllium limiter experiment

International Nuclear Information System (INIS)

Langley, R.A.; England, A.C.; Edmonds, P.H.; Hogan, J.T.; Neilson, G.H.

1986-01-01

A model is proposed for the movement and erosion of limiter material during the Beryllium Limiter Experiment performed on the ISX-B Tokamak. This model is consistent with observed experimental results and plasma operational characteristics. Conclusions drawn from the model can provide an understanding of erosion mechanisms, thereby contributing to the development of future design criteria. (author)

47 CFR 73.1725 - Limited time.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 4 2010-10-01 2010-10-01 false Limited time. 73.1725 Section 73.1725... Rules Applicable to All Broadcast Stations § 73.1725 Limited time. (a) Operation is applicable only to... stations on the channel. (b) No authorization will be granted for: (1) A new limited time station; (2) A...

29 CFR 4050.11 - Limitations.

Science.gov (United States)

2010-07-01

... missing participants. (b) Limitation on benefit value. The total actuarial present value of all benefits... Relating to Labor (Continued) PENSION BENEFIT GUARANTY CORPORATION PLAN TERMINATIONS MISSING PARTICIPANTS § 4050.11 Limitations. (a) Exclusive benefit. The benefits provided for under this part will be the only...