7,321 research outputs found
Galaxy-Targeting Approach Optimized for Finding the Radio Afterglows of Gravitational Wave Sources
Kilonovae and radio afterglows of neutron star merger events have been
identified as the two most promising counterparts, of these gravitational wave
sources, that can provide arcsecond localization. While several new and
existing optical search facilities have been dedicated to finding kilonovae,
factors such as dust obscuration and the daytime sky may thwart these searches
in a significant fraction of gavitational wave events. Radio-only searches,
being almost immune to these factors, are equally capable of finding the
counterparts and in fact offer a complementary discovery approach, despite the
modest fields of view for many of the present-day radio interferometers. Such
interferometers will be able to carry out competitive searches for the
electromagnetic counterparts through the galaxy targeting approach. Adapting
and improving on an existing algorithm by Rana et al. 2017. we present here a
method that optimizes the placement of radio antenna pointings, integration
time, and antenna slew. We simulate 3D gravitational wave localizations to find
the efficacy of our algorithm; with substantial improvements in slew overhead
and containment probability coverage, our algorithm performs significantly
better than simple galaxy-rank-ordered observations. We propose that telescopes
such as the Very Large Array, MeerKAT, Australia Telescope Compact Array and
the Gaint Meterwave Radio Telescope, having fields of view 1 deg
and searching for the counterparts of nearby GW events over tens of square
degrees or larger, will especially benefit from this optimized galaxy-targeting
approach for electromagnetic counterpart searches.Comment: 13 pages, 7 figures, Submitted to Ap
Fluctuation relations for heat engines in time-periodic steady states
A fluctuation relation for heat engines (FRHE) has been derived recently. In
the beginning, the system is in contact with the cooler bath. The system is
then coupled to the hotter bath and external parameters are changed cyclically,
eventually bringing the system back to its initial state, once the coupling
with the hot bath is switched off. In this work, we lift the condition of
initial thermal equilibrium and derive a new fluctuation relation for the
central system (heat engine) being in a time-periodic steady state (TPSS).
Carnot's inequality for classical thermodynamics follows as a direct
consequence of this fluctuation theorem even in TPSS. For the special cases of
the absence of hot bath and no extraction of work, we obtain the integral
fluctuation theorem for total entropy and the generalized exchange fluctuation
theorem, respectively. Recently microsized heat engines have been realized
experimentally in the TPSS. We numerically simulate the same model and verify
our proposed theorems.Comment: 9 page
Hospice and Oncology Nurses’ Perspectives on Legalizing Physician-Assisted Suicide in California: A Pilot Study
People are living with congenital anomalies, chronic diseases, and disabilities. It is universally agreed upon that every human being has a right to life, however, there is no unanimous decision regarding the right to death. Of the hospice nurses and social workers in Oregon, two-thirds of them reported having a patient ask them about the PAS option (Miller, Harvath, Ganzini, Goy, Delorit, & Jackson, 2004) California, Oregon, Vermont, and Washington have all legalized physician-assisted suicide through legislation. California’s law, the right to death passed on September 11th, 2015. The purpose of this research study is to examine hospice and oncology nurses’ perspectives of Physician-Assisted Suicide. Current research is inconclusive. Further research is necessary to understand how nurse\u27s religion or spiritual framwork affects attitudes, what are ethical alternatives, and what are common perceptions of PAS, etc. This research was guided by the research question; how do hospice and oncology nurses describe the positive and negative aspects of PAS? According to the American Nurses Association (ANA) Code of Ethics for Nurses with Interpretive Statements (2001), “the nurse should not participate in assisted suicide. Such an act is in violation of the Code for Nurses with Interpretive Statements and the ethical traditions of the profession. Nurses, individually and collectively, have an obligation to provide comprehensive and compassionate end-of-life care which includes the promotion of comfort and the relief of pain, and at times, foregoing life-sustaining treatments”. Yet, the same passage states that nurses must intervene to relieve pain and suffering of the dying patient, even if the interventions hasten death
Recommended from our members
Leveraging legacy codes to distributed problem solving environments: A web service approach
This paper describes techniques used to leverage high performance legacy codes as CORBA components to a distributed problem solving environment. It first briefly introduces the software architecture adopted by the environment. Then it presents a CORBA oriented wrapper generator (COWG) which can be used to automatically wrap high performance legacy codes as CORBA components. Two legacy codes have been wrapped with COWG. One is an MPI-based molecular dynamic simulation (MDS) code, the other is a finite element based computational fluid dynamics (CFD) code for simulating incompressible Navier-Stokes flows. Performance comparisons between runs of the MDS CORBA component and the original MDS legacy code on a cluster of workstations and on a parallel computer are also presented. Wrapped as CORBA components, these legacy codes can be reused in a distributed computing environment. The first case shows that high performance can be maintained with the wrapped MDS component. The second case shows that a Web user can submit a task to the wrapped CFD component through a Web page without knowing the exact implementation of the component. In this way, a user’s desktop computing environment can be extended to a high performance computing environment using a cluster of workstations or a parallel computer
Evaporation Channel as a Tool to Study Fission Dynamics
The dynamics of the fission process is expected to affect the evaporation
residue cross section because of the fission hindrance due to the nuclear
viscosity. Systems of intermediate fissility constitute a suitable environment
for testing such hypothesis, since they are characterized by evaporation
residue cross sections comparable or larger than the fission ones. Observables
related to emitted charged particle, due to their relatively high emission
probability, can be used to put stringent constraints on models describing the
excited nucleus decay and to recognize the effects of fission dynamics. In this
work model simulations are compared with the experimental data collected via
the ^{32}S + ^{100}Mo reaction at E_{lab}= 200 MeV. By comparing an extended
set of evaporation channel observables the limits of the statistical model and
the large improvement coming by using a dynamical model are evidenced. The
importance of using a large angular covering apparatus to extract the
observable is stressed. The opportunity to measure more sensitive observables
by a new detection device in operation at LNL are also discussed.Comment: v1: 7 pages, 6 figure
- …