19,443 research outputs found
Using ForeCAT Deflections and Rotations to Constrain the Early Evolution of CMEs
To accurately predict the space weather effects of coronal mass ejection
(CME) impacts at Earth one must know if and when a CME will impact Earth, and
the CME parameters upon impact. Kay et al. (2015b) presents Forecasting a CME's
Altered Trajectory (ForeCAT), a model for CME deflections based on the magnetic
forces from the background solar magnetic field. Knowing the deflection and
rotation of a CME enables prediction of Earth impacts, and the CME orientation
upon impact. We first reconstruct the positions of the 2008 April 10 and the
2012 July 12 CMEs from the observations. The first of these CMEs exhibits
significant deflection and rotation (34 degrees deflection and 58 degrees
rotation), while the second shows almost no deflection or rotation (<3 degrees
each). Using ForeCAT, we explore a range of initial parameters, such as the CME
location and size, and find parameters that can successfully reproduce the
behavior for each CME. Additionally, since the deflection depends strongly on
the behavior of a CME in the low corona (Kay et al. (2015a, 2015b)), we are
able to constrain the expansion and propagation of these CMEs in the low
corona.Comment: accepted in Ap
Using foreCAT deflections and rotations to constrain the early evolution of CMEs
To accurately predict the space weather effects of the impacts of coronal mass ejection (CME) at Earth one must know if and when a CME will impact Earth and the CME parameters upon impact. In 2015 Kay et al. presented Forecasting a CME's Altered Trajectory (ForeCAT), a model for CME deflections based on the magnetic forces from the background solar magnetic field. Knowing the deflection and rotation of a CME enables prediction of Earth impacts and the orientation of the CME upon impact. We first reconstruct the positions of the 2010 April 8 and the 2012 July 12 CMEs from the observations. The first of these CMEs exhibits significant deflection and rotation (34° deflection and 58° rotation), while the second shows almost no deflection or rotation (<3° each). Using ForeCAT, we explore a range of initial parameters, such as the CME's location and size, and find parameters that can successfully reproduce the behavior for each CME. Additionally, since the deflection depends strongly on the behavior of a CME in the low corona, we are able to constrain the expansion and propagation of these CMEs in the low corona.C.K.'s research was supported by an appointment to the NASA Postdoctoral Program at NASA GSFC, administered by the Universities Space Research Association under contract with NASA. A.V. acknowledges support from JHU/APL. R.C.C. acknowledges the support of NASA contract S-136361-Y to NRL. The SECCHI data are produced by an international consortium of the NRL, LMSAL, and NASA GSFC (USA), RAL and Univ. of Birmingham (UK), MPS (Germany), CSL (Belgium), IOTA and IAS (France). (JHU/APL; S-136361-Y - NASA)Published versio
Perfect State Transfer: Beyond Nearest-Neighbor Couplings
In this paper we build on the ideas presented in previous works for perfectly
transferring a quantum state between opposite ends of a spin chain using a
fixed Hamiltonian. While all previous studies have concentrated on
nearest-neighbor couplings, we demonstrate how to incorporate additional terms
in the Hamiltonian by solving an Inverse Eigenvalue Problem. We also explore
issues relating to the choice of the eigenvalue spectrum of the Hamiltonian,
such as the tolerance to errors and the rate of information transfer.Comment: 8 pages, 2 figures. Reorganised, more detailed derivations provided
and section on rate of information transfer adde
Reducing Stigma toward the Transgender Community: An Evaluation of a Humanizing and Perspective-Taking Intervention
Transgender (TG) individuals are an understudied group at high risk of experiencing discrimination and associated adverse mental health outcomes (IOM, 2011). Although many studies demonstrate that contact reduces negative attitudes toward out-groups, few studies have examined the link between contact and attitudes toward the TG community (Hill & Willoughby, 2005; Walchet al., 2012). This study represents one of the first attempts to understand how to effectively reduce stigma toward the TG community. Results indicate that education alone is not enough to change attitudes; in fact, there is some evidence that associating transgenderism with psychopathology may heighten stigma. Consistent with prior research on stigma towards the mentally ill, the current study suggests that both exposure to intimate media depictions of the “other” (Reinke et al., 2004) and perspective-taking (Mann & Himelein, 2008) could strengthen educational campaigns designed to combat stigma
Semiclassical initial value calculations of collinear helium atom
Semiclassical calculations using the Herman-Kluk initial value treatment are
performed to determine energy eigenvalues of bound and resonance states of the
collinear helium atom. Both the configuration (where the classical motion
is fully chaotic) and the configuration (where the classical dynamics is
nearly integrable) are treated. The classical motion is regularized to remove
singularities that occur when the electrons collide with the nucleus. Very good
agreement is obtained with quantum energies for bound and resonance states
calculated by the complex rotation method.Comment: 24 pages, 3 figures. Submitted to J. Phys.
'She's like a daughter to me': insights into care, work and kinship from rural Russia
This article draws on ethnographic research into a state-funded homecare service in rural Russia. The article discusses intersections between care, work and kinship in the relationships between homecare workers and their elderly wards and explores the ways in which references to kinship, as a means of authenticating paid care and explaining its emotional content, reinforce public and private oppositions while doing little to relieve the tensions and conflicts of care work. The discussion brings together detailed empirical insights into local ideologies and practices as a way of generating new theoretical perspectives, which will be of relevance beyond the particular context of study
- …