4,799 research outputs found
On the Axisymmetric Force-Free Pulsar Magnetosphere
We investigate the axisymmetric magnetosphere of an aligned rotating magnetic
dipole surrounded by an ideal force-free plasma. We concentrate on the magnetic
field structure around the point of intersection of the separatrix between the
open and closed field-line regions and the equatorial plane. We first study the
case where this intersection point is located at the Light Cylinder. We find
that in this case the separatrix equilibrium condition implies that all the
poloidal current must return to the pulsar in the open-field region, i.e., that
there should be no finite current carried by the separatrix/equator current
sheet. We then perform an asymptotic analysis of the pulsar equation near the
intersection point and find a unique self-similar solution; however, a Light
Surface inevitably emerges right outside the Light Cylinder. We then perform a
similar analysis for the situation where the intersection point lies somewhere
inside the Light Cylinder, in which case a finite current flowing along the
separatrix and the equator is allowed. We find a very simple behavior in this
case, characterized by a 90-degree angle between the separatrix and the equator
and by finite vertical field in the closed-field region. Finally, we discuss
the implications of our results for global numerical studies of pulsar
magnetospheres.Comment: 31 pages, including 5 figure
On Airy Solutions of the Second Painleve Equation
In this paper, we discuss Airy solutions of the second Painleve equation and two related equations, the Painleve XXXIV equation and the Jimbo-Miwa-Okamoto sigma form of second Painleve equation, are discussed. It is shown that solutions which depend only on the Airy function Ai(z) have a completely difference structure to those which involve a linear combination of the Airy functions Ai(z) and Bi(z). For all three equations, the special solutions that depend only on inline image are tronquƩe solutions, i.e., they have no poles in a sector of the complex plane. Further, for both inline image and SII, it is shown that among these tronquƩe solutions there is a family of solutions that have no poles on the real axis
Nucleon-deuteron scattering with the JISP16 potential
The nucleon-nucleon J-matrix Inverse Scattering Potential JISP16 is applied
to elastic nucleon-deuteron (Nd) scattering and the deuteron breakup process at
the lab. nucleon energies up to 135 MeV. The formalism of the Faddeev equations
is used to obtain 3N scattering states. We compare predictions based on the
JISP16 force with data and with results based on various NN interactions: the
CD Bonn, the AV18, the chiral force with the semi-local regularization at the
5th order of the chiral expansion and with low-momentum interactions obtained
from the CD Bonn force as well as with the predictions from the combination of
the AV18 NN interaction and the Urbana IX 3N force. JISP16 provides a
satisfactory description of some observables at low energies but strong
deviations from data as well as from standard and chiral potential predictions
with increasing energy. However, there are also polarization observables at low
energies for which the JISP16 predictions differ from those based on the other
forces by a factor of two. The reason for such a behavior can be traced back to
the P-wave components of the JISP16 force. At higher energies the deviations
can be enhanced by an interference with higher partial waves and by the
properties of the JISP16 deuteron wave function. In addition, we compare the
energy and angular dependence of predictions based on the JISP16 force with the
results of the low-momentum forces obtained with different values of the
momentum cutoff parameter. We found that such low-momentum forces can be
employed to interpret the Nd elastic scattering data only below some specific
energy which depends on the cutoff parameter. Since JISP16 is defined in a
finite oscillator basis, it has properties similar to low momentum interactions
and its application to the description of Nd scattering data is limited to a
low momentum transfer region.Comment: 26 pages, 12 eps figures; Version accepted to Phys. Rev. C: text is
shortened, few figures regarding the nucleon-deuteron elastic scattering
observables are removed but a short discussion of the nucleon induced
deuteron breakup cross section is added. Conclusions remain unchange
New Bifunctional Antioxidants : In tramolecular Synergistic Effects between Benzofuranol and Thiopropionate Group, Part II
The antioxidant activities of benzofuranols and chromanols with methyl, methyl thiomethyl and thiopropionate groups were evaluated for the oxidation of tetralin at 61 and 140ā. The antioxidants tested showed almost the same behaviour for the oxidation of tetralin initiated by an azo initiator at 61ā. However, benzofuranol and chromanol with a thiopropionate group at the meta position of the OH group were shown to improve antioxidant activity at high temperature to a greater extent than the methyl and methyl thiomethyl groups
Communication with Families in the Last Days of a Patientās Life and Optimal Delivery of a Death Pronouncement
Communicating with family members is critically important when a severely ill patient is experiencing their last few days of life. However, healthcare professionals (HCPs) have limited opportunities to learn effective and respectful ways to perform this communication. In recent decades, significant effort has been put forth to identify the phenomena that indicate the last hours and days of life and the optimal methods to deliver a death pronouncement, which will potentially help HCPs communicate compassionately with family members throughout the dying process. In this chapter, we will review the literature regarding the phenomena that indicate the last hours and days of life and the death pronouncement. Furthermore, we will discuss clinical implications derived from those articles and future research perspectives
Alkali-metal-induced Fermi level and two dimensional electrons at cleaved InAs(110) surfaces
Low-temperature Hall measurements have been performed on two-dimensional
electron gases (2DEGs) induced by deposition of Cs or Na on in situ cleaved
surfaces of p-type InAs. The surface donor level, at which the Fermi energy of
the 2DEG is pinned, is calculated from the observed saturation surface electron
density using a surface potential determined self-consistently. The results are
compared to those of previous photoelectron spectroscopy measurements.Comment: 3 pages, 4 figure
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