6,063 research outputs found
Absolute Properties of the Eclipsing Binary Star V501 Herculis
V501 Her is a well detached G3 eclipsing binary star with a period of
8.597687 days for which we have determined very accurate light and
radial-velocity curves by using robotic telescopes. Results of these data
indicate that the component stars have masses of 1.269 +/- 0.004 and 1.211 +/-
0.003 solar masses, radii of 2.001 +/- 0.003 and 1.511 +/- 0.003 solar radii,
and temperatures of 5683 +/- 100K and 5720 +/- 100K, respectively. Comparison
with the Yonsei-Yale series of evolutionary models results in good agreement at
an age of about 5.1 Gyr for a somewhat metal rich composition. Those models
indicate that the more massive, larger, slightly cooler star is just beyond
core hydrogen exhaustion while the less massive, smaller, slightly hotter star
has not quite reached core hydrogen exhaustion. The orbit is not yet
circularized, and the components are rotating at or near their
pseudosynchronous velocities. The distance to the system is 420 +/- 30 pc
Fast readout of a single Cooper-pair box using its quantum capacitance
We have fabricated a single Cooper-pair box (SCB) together with an on-chip
lumped element resonator. By utilizing the quantum capacitance of the SCB, its
state can be read out by detecting the phase of a radio-frequency (rf) signal
reflected off the resonator. The resonator was optimized for fast readout. By
studying quasiparticle tunneling events in the SCB, we have characterized the
performance of the readout and found that we can perform a single shot parity
measurement in approximately 50 ns. This is an order of magnitude faster than
previously reported measurements.Comment: 7 pages, 5 figure
Negligence—Guest Statute—Owner as a Guest—Wife as a Guest
In Naphtali v. Lafazan, defendant and his wife accepted the invitation of plaintiffs, husband and wife, to accompany them on a pleasure trip in an auto owned by plaintiff-husband. It was understood that the expenses of operating the auto were to be borne by plaintiff-husband. As the party proceeded along an Ohio highway, with the defendant driving, the auto left the highway and overturned, injuring the plaintiffs. Suit was instituted in New York, alleging defendant’s ordinary negligence and praying damages for the injuries sustained. Defendant relied upon the Ohio Guest Statute, arguing that plaintiffs were “guests” in the auto and therefore could not recover in the absence of proof of defendant\u27s gross negligence. Two interesting questions were thus presented: (1) Was the plaintiff-owner a “guest” in his own auto, and (2) was the owner’s wife a “guest”? Though there were no Ohio cases in point, the New York Supreme Court held, inter alia, that the owner might recover on proof of defendant’s ordinary negligence, as it was not the intention of the Ohio Legislature to make an owner a “guest” in his own auto. On complicated reasoning, however, plaintiff-wife was found to be a guest and was denied recovery, since there was no proof of defendant’s gross negligence
Negligence—Guest Statute—Owner as a Guest—Wife as a Guest
In Naphtali v. Lafazan, defendant and his wife accepted the invitation of plaintiffs, husband and wife, to accompany them on a pleasure trip in an auto owned by plaintiff-husband. It was understood that the expenses of operating the auto were to be borne by plaintiff-husband. As the party proceeded along an Ohio highway, with the defendant driving, the auto left the highway and overturned, injuring the plaintiffs. Suit was instituted in New York, alleging defendant’s ordinary negligence and praying damages for the injuries sustained. Defendant relied upon the Ohio Guest Statute, arguing that plaintiffs were “guests” in the auto and therefore could not recover in the absence of proof of defendant\u27s gross negligence. Two interesting questions were thus presented: (1) Was the plaintiff-owner a “guest” in his own auto, and (2) was the owner’s wife a “guest”? Though there were no Ohio cases in point, the New York Supreme Court held, inter alia, that the owner might recover on proof of defendant’s ordinary negligence, as it was not the intention of the Ohio Legislature to make an owner a “guest” in his own auto. On complicated reasoning, however, plaintiff-wife was found to be a guest and was denied recovery, since there was no proof of defendant’s gross negligence
Absolute dimensions of the early F-type eclipsing binary V506 Ophiuchi
We report extensive differential V-band photometry and high-resolution
spectroscopic observations of the early F-type, 1.06-day detached eclipsing
binary V506 Oph. The observations along with times of minimum light from the
literature are used to derive a very precise ephemeris and the physical
properties for the components, with the absolute masses and radii being
determined to 0.7% or better. The masses are 1.4153 +/- 0.0100 M(Sun) and
1.4023 +/- 0.0094 M(sun) for the primary and secondary, the radii are 1.725 +/-
0.010 R(Sun) and 1.692 +/- 0.012 R(Sun), and the effective temperatures 6840
+/- 150 K and 6780 +/- 110 K, respectively. The orbit is circular and the stars
are rotating synchronously. The accuracy of the radii and temperatures is
supported by the resulting distance estimate of 564 +/- 30 pc, in excellent
agreement with the value implied by the trigonometric parallax listed in the
Gaia/DR2 catalog. Current stellar evolution models from the MIST series for a
composition of [Fe/H] = -0.04 match the properties of both stars in V506 Oph
very well at an age of 1.83 Gyr, and indicate they are halfway through their
core hydrogen-burning phase.Comment: Accepted for publication in The Astrophysical Journal, 8 pages in
emulateapj format including figures and tables. Tables 3, 5, and 6 available
only electronically from the Journa
Absolute dimensions of the unevolved F-type eclipsing binary BT Vulpeculae
We report extensive differential V-band photometry and high-resolution
spectroscopy for the 1.14 day, detached, double-lined eclipsing binary BT Vul
(F0+F7). Our radial-velocity monitoring and light curve analysis lead to
absolute masses and radii of M1 = 1.5439 +/- 0.0098 MSun and R1 = 1.536 +/-
0.018 RSun for the primary, and M2 = 1.2196 +/- 0.0080 MSun and R2 = 1.151 +/-
0.029 RSun for the secondary. The effective temperatures are 7270 +/- 150 K and
6260 +/- 180 K, respectively. Both stars are rapid rotators, and the orbit is
circular. A comparison with stellar evolution models from the MIST series shows
excellent agreement with these determinations, for a composition of [Fe/H] =
+0.08 and an age of 350 Myr. The two components of BT Vul are very near the
zero-age main sequence.Comment: 9 pages in emulateapj format, including tables and figures. Accepted
for publication in The Astrophysical Journa
Photon generation in an electromagnetic cavity with a time-dependent boundary
We report the observation of photon generation in a microwave cavity with a
time-dependent boundary condition. Our system is a microfabricated quarter-wave
coplanar waveguide cavity. The electrical length of the cavity is varied using
the tunable inductance of a superconducting quantum interference device. It is
measured in the quantum regime, where the temperature is significantly less
than the resonance frequency (~ 5 GHz). When the length is modulated at
approximately twice the static resonance frequency, spontaneous oscillations of
the cavity field are observed. Time-resolved measurements of the dynamical
state of the cavity show multiple stable states. The behavior is well described
by theory. Connections to the dynamical Casimir effect are discussed.Comment: 5 pages, 3 Figure
The quadruple-lined, doubly-eclipsing system V482 Persei
We report spectroscopic and differential photometric observations of the
A-type system V482 Per that reveal it to be a rare hierarchical quadruple
system containing two eclipsing binaries. One has the previously known orbital
period of 2.4 days and a circular orbit, and the other a period of 6 days, a
slightly eccentric orbit (e = 0.11), and shallow eclipses only 2.3% deep. The
two binaries revolve around their common center of mass in a highly elongated
orbit (e = 0.85) with a period of 16.67 yr. Radial velocities are measured for
all components from our quadruple-lined spectra, and are combined with the
light curves and with measurements of times of minimum light for the 2.4 day
binary to solve for the elements of the inner and outer orbits simultaneously.
The line-of-sight inclination angles of the three orbits are similar,
suggesting they may be close to coplanar. The available observations appear to
indicate that the 6 day binary experiences significant retrograde apsidal
motion in the amount of about 60 degrees per century. We derive absolute masses
for the four stars good to better than 1.5%, along with radii with formal
errors of 1.1% and 3.5% for the 2.4 day binary and about 9% for the 6 day
binary. A comparison of these and other physical properties with current
stellar evolution models gives excellent agreement for a metallicity of [Fe/H]
= -0.15 and an age of 360 Myr.Comment: 15 pages in emulateapj format, including figures and tables. Accepted
for publication in The Astrophysical Journa
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Passion or delusion: middle managers constructing new meanings of work
Recently, organization scholars have called for a need to re-think managerial leadership so as to take into account the "mundane", the key activity of which is "influencing expectations, meanings, and values about what is desirable and necessary related to everyday work" (Sveningsson et. al., 2012: 84). In other words, mundane leaders can be seen as sense makers (Weick, 1995) and sense givers (Gioia and
Chittipeddi 1991). Managerial leadership has also been described as event-driven actions arising mostly from unforeseen happenings (Holmberg and Tyrstrup, 2010). A study of site managers in construction
depicted their leadership as a "muddling through", i.e. they skilfully solve problems as these inevitably
crop up, and they try to be everywhere at the same time Styhre, 2012). We argue that muddling through
also puts high demands on site managers' abilities and possibilities of coping with and balancing their
work, family and personal life. The purpose of this paper is to explore what mundane leadership and muddling through actually mean for managerial leaders in construction from a wider perspective than their work. In other words, what
does muddling through mean in terms of coping with work and family and life in general. This paper contributes empirical examples from 37 in-depth interviews with site managers, foremen and supervisor in a large number of construction organisations. We draw on practice theories to explore and analyse the data, and argue that mundane leaders are indeed both organizational sense makers and
sense givers, the linkers of the strategic with the operational, the cohesion that generates coherence.
All the site managers interviewed were passionate about their work, but deplored organisational and institutional constraints, which mostly obstructed rather than supported or facilitated their work. Sense-making and sense-giving roles demand presence, flexibility, experience, hindsight, judgment and improvisation, which in turn, and over time, often result in exhaustion and stress, and leave little energy over for family and life outside work. We conclude that the "mundane" activities of middle managers are
far from trivial; they demand leadership competences that require fostering and nurturing. Today there is little support for middle-managerial leaders and little training of the competences that they need the nmost
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Workaholics on site! Sustainability of site managers' work situations?
Site-managerial practice in construction has been depicted as a 'muddling through', being everywhere at the same time and skilfully solving problems as these crop up. The purpose of this paper is to explore work patterns and related well-being implications of site managers in construction. Drawing on the work-life stories of 21 site managers, which have been analysed using narrative analysis we argue that muddling through put high demands on these managers' abilities and possibilities of coping with and balancing their work situations. In all the accounts, several features of workaholism were identified as driving forces, often leading to negative well-being symptoms. The site managers were passionate about their work, but deplored organisational and institutional constraints, which mostly obstructed rather than supported or facilitated their work. This resulted in periods of exhaustion and stress, leaving little energy over for family and life outside work. We conclude that the warnings we perceive concerning the unsustainable work situations of site managers warrant further research
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