1,154 research outputs found
A three-dimensional electrostatic actuator with a locking mechanism for a new generation of atom chips
A micromachined three-dimensional electrostatic actuator that is optimized for aligning and tuning optical microcavities on atom chips is presented. The design of the 3D actuator is outlined in detail, and its characteristics are verified by analytical calculations and finite element modelling. Furthermore, the fabrication process of the actuation device is described and preliminary fabrication results are shown. The actuation in the chip plane which is used for mirror positioning has a working envelope of 17.5 ?m. The design incorporates a unique locking mechanism which allows the out-of-plane actuation that is used for cavity tuning to be carried out once the in-plane actuation is completed. A maximum translation of 7 ?m can be achieved in the out-of-plane direction
Reducing the Overlap Between Machiavellianism and Subclinical Psychopathy: The M7 and P7 Scales
Machiavellianism (Mach) and subclinical psychopathy are two widely studied antagonistic personality traits with distinct theoretical conceptualizations. Mach is conceptualized by strategic deviousness, cynicism, and pragmatic morality, whereas subclinical psychopathy is conceptualized by impulsive antisocial tendencies, callousness, and rule-breaking. However, existing measures of the two traits are typically highly correlated and have very similar nomological networks. Notably, even though psychopathy scales should be more strongly positively associated with antisocial impulsivity and more strongly negatively associated with conscientiousness than Mach scales, existing Mach and psychopathy scales tend to be similarly related to these constructs. We created a new Mach scale, the M7, and a new psychopathy scale, the P7, by selecting items from existing Mach and psychopathy scales on the basis of the correlations of these items with antisocial impulsivity and conscientiousness. Across three studies (combined N = 4,607), the M7 and P7 showed acceptable to good psychometric properties in terms of closeness to unidimensionality, measurement precision, temporal stability, measurement invariance across language and gender groups, and convergent and discriminant validity (nomological network, self-other agreement, and interpersonal perceptions in group interactions). Most importantly, the new scales assess clearly distinct latent traits that are more in line with their theoretical conceptualizations than established scales are
The Early Palomar Program (1950-1955) for the Discovery of Classical Novae in M81: Analysis of the Spatial Distribution, Magnitude Distribution, and Distance Suggestion
Data obtained in the 1950-1955 Palomar campaign for the discovery of
classical novae in M81 are set out in detail. Positions and apparent B
magnitudes are listed for the 23 novae that were found. There is modest
evidence that the spatial distribution of the novae does not track the B
brightness distribution of either the total light or the light beyond an
isophotal radius that is 70\arcsec from the center of M81. The nova
distribution is more extended than the aforementioned light, with a significant
fraction of the sample appearing in the outer disk/spiral arm region. We
suggest that many (perhaps a majority) of the M81 novae that are observed at
any given epoch (compared with say years ago) are daughters of
Population I interacting binaries. The conclusion that the present day novae
are drawn from two population groups, one from low mass white dwarf secondaries
of close binaries identified with the bulge/thick disk population, and the
other from massive white dwarf secondaries identified with the outer thin
disk/spiral arm population, is discussed. We conclude that the M81 data are
consistent with the two population division as argued previously from (1) the
observational studies on other grounds by Della Valle et al. (1992, 1994),
Della Valle & Livio (1998), and Shafter et al. (1996) of nearby galaxies, (2)
the Hatano et al. (1997a,b) Monte Carlo simulations of novae in M31 and in the
Galaxy, and (3) the Yungelson et al. (1997) population synthesis modeling of
nova binaries. Two different methods of using M81 novae as distance indicators
give a nova distance modulus for M81 as , consistent with the
Cepheid modulus that is the same value.Comment: 24 pages, 7 figures, accepted to PAS
Comprehensive summary and retrospective evaluation of prognostic scores for patients with newly diagnosed brain metastases treated with upfront radiosurgery in a modern patient collective
X-rays Studies of the Solar System
X-ray observatories contribute fundamental advances in Solar System studies
by probing Sun-object interactions, developing planet and satellite surface
composition maps, probing global magnetospheric dynamics, and tracking
astrochemical reactions. Despite these crucial results, the technological
limitations of current X-ray instruments hinder the overall scope and impact
for broader scientific application of X-ray observations both now and in the
coming decade. Implementation of modern advances in X-ray optics will provide
improvements in effective area, spatial resolution, and spectral resolution for
future instruments. These improvements will usher in a truly transformative era
of Solar System science through the study of X-ray emission.Comment: White paper submitted to Astro2020, the Astronomy and Astrophysics
Decadal Surve
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