3,120 research outputs found
Stochastic Analysis of Subcritical Amplification of Magnetic Energy in a Turbulent Dynamo
We present and analyze a simplified stochastic dynamo model
which is designed to assess the influence of additive and multiplicative
noises, non-normality of dynamo equation, and nonlinearity of the %
effect and turbulent diffusivity, on the generation of a large-scale magnetic
field in the subcritical case. Our model incorporates random fluctuations in
the parameter and additive noise arising from the small-scale
fluctuations of magnetic and turbulent velocity fields. We show that the noise
effects along with non-normality can lead to the stochastic amplification of
the magnetic field even in the subcritical case. The criteria for the
stochastic instability during the early kinematic stage are established and the
critical value for the intensity of multiplicative noise due to fluctuations is found. We obtain numerical solutions of non-linear stochastic
differential equations and find the series of phase transitions induced by
random fluctuations in the parameter.Comment: 21pages,7 figure
Superconducting Magnetization above the Irreversibility Line in Tl2Ba2CuO6
Piezolever torque magnetometry has been used to measure the magnetization of
superconducting Tl2Ba2CuO6. Three crystals with different levels of oxygen
overdoping were investigated in magnetic fields up to 10 Tesla. In all cases,
the magnetization above the irreversibility line was found to depart from the
behaviour M ~ ln(Hc2/H) of a simple London-like vortex liquid. In particular,
for a strongly overdoped (Tc = 15K) crystal, the remnant superconducting order
above the irreversibility line is characterized by a linear diamagnetic
response (M ~ H) that persists well above Tc and also up to the highest field
employed.Comment: RevTeX, 11 pages, 7 encapsulated PostScript figures, submitted to
Physical Review
Whither Critical Masculinity Studies? Notes on Inclusive Masculinity Theory, Postfeminism, and Sexual Politics
Inclusive masculinity theory has recently been proposed as a new approach to theo- rizing contemporary masculinities. Focusing particularly on the work of the theory’s key exponent, Eric Anderson, this article offers a critical reading of inclusive masculinity theory in relation to the context of contemporary postfeminism. Building on feminist scholarship that analyzes the emergence of a distinctive postfeminist sensibility within the academy, I consider how inclusive masculinity theory both reflects and reproduces certain logics of postfeminism. My central concern is the manner in which this scho- larship deemphasizes key issues of sexual politics and promotes a discourse of optimism about men, masculinities, and social change. Against this view, I argue that critical masculinity studies must foreground the analysis of gendered power relations and posit that the interrogation of contemporary postfeminism is critical to this endeavor
Schema therapy for emotional dysregulation: Theoretical implication and clinical applications
The term emotional dysregulation refers to an impaired ability to regulate unwanted
emotional states. Scientific evidence supports the idea that emotional dysregulation
underlies several psychological disorders as, for example: personality disorders, bipolar
disorder type II, interpersonal trauma, anxiety disorders, mood disorders and posttraumatic
stress disorder. Emotional dysregulation may derive from early interpersonal
traumas in childhood. These early traumatic events create a persistent sensitization of
the central nervous system in relation to early life stressing events. For this reason,
some authors suggest a common endophenotypical origin across psychopathologies.
In the last 20 years, cognitive behavioral therapy has increasingly adopted an interactiveontogenetic
view to explain the development of disorders associated to emotional
dysregulation. Unfortunately, standard Cognitive Behavior Therapy (CBT) methods are
not useful in treating emotional dysregulation. A CBT-derived new approach called
Schema Therapy (ST), that integrates theory and techniques from psychodynamic and
emotion focused therapy, holds the promise to fill this gap in cognitive literature. In this
model, psychopathology is viewed as the interaction between the innate temperament
of the child and the early experiences of deprivation or frustration of the subject\u2019s
basic needs. This deprivation may lead to develop early maladaptive schemas (EMS),
and maladaptive Modes. In the present paper we point out that EMSs and Modes
are associated with either dysregulated emotions or with dysregulatory strategies that
produce and maintain problematic emotional responses. Thanks to a special focus on
the therapeutic relationship and emotion focused-experiential techniques, this approach
successfully treats severe emotional dysregulation. In this paper, we make several
comparisons between the main ideas of ST and the science of emotion regulation, and
we present how to conceptualize pathological phenomena in terms of failed regulation
and some of the ST strategies and techniques to foster successful regulation in patients
Social Efficiency in Microfinance Institutions: Identifying How to Improve It
This article analyzes the determinants for social and economic efficiency in Microfinance Institutions using a Seemingly Unrelated Regression. We find two factors that improve their relative efficiency: legal status and target market; however, age and scale are not clear determinants. The main contribution of this paper is to engage MFIs to achieve the desired social efficiency without giving up economic efficiency as the two can be complementary; moreover, it is possible to be efficient as an NBFI/NGO with small size and low-end target, at least. The paper is a new contribution in line with the so-called paradox of social cost
Nonlinear Hydrodynamics of Disentangled Flux-Line Liquids
In this paper we use non-Gaussian hydrodynamics to study the magnetic
response of a flux-line liquid in the mixed state of a type-II superconductor.
Both the derivation of our model, which goes beyond conventional Gaussian flux
liquid hydrodynamics, and its relationship to other approaches used in the
literature are discussed. We focus on the response to a transverse tilting
field which is controlled by the tilt modulus, c44, of the flux array. We show
that interaction effects can enhance c44 even in infinitely thick clean
materials. This enhancement can be interpreted as the appearance of a
disentangled flux-liquid fraction. In contrast to earlier work, our theory
incorporates the nonlocality of the intervortex interaction in the field
direction. This nonlocality is crucial for obtaining a nonvanishing
renormalization of the tilt modulus in the thermodynamic limit of thick
samples.Comment: 20 pages, 3 figures (submitted to PRB
Vortex Line Fluctuations in Model High Temperature Superconductors
We carry out Monte Carlo simulations of the uniformly frustrated 3d XY model
as a model for vortex line fluctuations in a high Tc superconductor. A density
of vortex lines of f=1/25 is considered. We find two sharp phase transitions.
The low T phase is an ordered vortex line lattice. The high T normal phase is a
vortex line liquid with much entangling, cutting, and loop excitations. An
intermediate phase is found which is characterized as a vortex line liquid of
disentangled lines. In this phase, the system displays superconducting
properties in the direction parallel to the magnetic field, but normal behavior
in planes perpendicular to the magnetic field.Comment: 38 pages, LaTeX 15 figures (upon request to
[email protected]
Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector
A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results
Measurement of the production of a W boson in association with a charm quark in pp collisions at √s = 7 TeV with the ATLAS detector
The production of a W boson in association with a single charm quark is studied using 4.6 fb−1 of pp collision data at s√ = 7 TeV collected with the ATLAS detector at the Large Hadron Collider. In events in which a W boson decays to an electron or muon, the charm quark is tagged either by its semileptonic decay to a muon or by the presence of a charmed meson. The integrated and differential cross sections as a function of the pseudorapidity of the lepton from the W-boson decay are measured. Results are compared to the predictions of next-to-leading-order QCD calculations obtained from various parton distribution function parameterisations. The ratio of the strange-to-down sea-quark distributions is determined to be 0.96+0.26−0.30 at Q 2 = 1.9 GeV2, which supports the hypothesis of an SU(3)-symmetric composition of the light-quark sea. Additionally, the cross-section ratio σ(W + +c¯¯)/σ(W − + c) is compared to the predictions obtained using parton distribution function parameterisations with different assumptions about the s−s¯¯¯ quark asymmetry
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