65,147 research outputs found
Blunting the Spike: the CV Minimum Period
The standard picture of CV secular evolution predicts a spike in the CV
distribution near the observed short-period cutoff P_0 ~ 78 min, which is not
observed. We show that an intrinsic spread in minimum (`bounce') periods P_b
resulting from a genuine difference in some parameter controlling the evolution
can remove the spike without smearing the sharpness of the cutoff. The most
probable second parameter is different admixtures of magnetic stellar wind
braking (at up to 5 times the GR rate) in a small tail of systems, perhaps
implying that the donor magnetic field strength at formation is a second
parameter specifying CV evolution. We suggest that magnetic braking resumes
below the gap with a wide range, being well below the GR rate in most CVs, but
significantly above it in a small tail.Comment: 5 pages, 4 figures; accepted for publication in MNRA
Black Hole Winds
We show that black holes accreting at or above the Eddington rate probably
produce winds which are optically thick in the continuum, whether in quasars or
X-ray binaries. The photospheric radius and outflow speed are proportional to
\mo^2 and \mo^-1 respectively, where \mo is the mass outflow rate. The outflow
momentum rate is always of order L_Edd/c. Blackbody emission from these winds
may provide the big blue bump in some quasars and AGN, as well as ultrasoft
X-ray components in ULXs.Comment: 3 pages, no figures; MNRAS, in press (with minor corrections applied
TAG user's manual
Transient Analysis Generator /TAG/ program for automatic circuit analysis of transient and steady state behavior of large class of electrical network
Component modeling handbook
Handbook on nonlinear mathematical models for electronic component
Role of the community matron in advance care planning and ‘do not attempt CPR’ decision-making: a qualitative study
The community matron (CM) is often the key worker caring for patients with chronic, life-limiting, long-term conditions, but these patients are not always recognised as palliative cases. This study explored the experiences of CMs with regard to advance care planning (ACP) and ‘do not attempt cardiopulmonary resuscitation’ (DNACPR) decision-making to understand whether or not they felt adequately prepared for this aspect of their role, and why. Qualitative data were generated from six CMs using a broad interpretive phenomenological approach. Face-to-face recorded interviews were analysed using template analysis. The study found that although participants faced complex ethical situations around ACP and DNACPR almost on a daily basis, none had received any formal training despite the emphasis on training in national and local guidelines. Participants often struggled to get their patients accepted on to the Gold Standards Framework. The research found variability and complexity of cases to be the main barriers to clear identification of the palliative phase
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