715 research outputs found
Toolset for Visual Creative Conflict Management
Conflict is neuro-physiologically processed by emotional faculties of the humanbrain, similarly to pain processing (Lack & Bogacz, 2012). Pain causes an away-reflex , and so does conflict. Most of us, therefore, try to avoid pain and likewise conflict. Some of us are drawn into conflict, either as an active party or a referee, against our will, while others of us must handle conflict as a matter of life role. Because of this away-reflex to conflict, we often try to resolve conflict in a single step in order to get it over with as quickly as possible. Many people expect to resolve a conflict in a single intervention (Elliott, d\u27Estrée & Kaufman, 2003). When that doesn\u27t work, our emotional response is amplified, typically including frustration, anger, and withdrawal. This project aims to provide a toolset that transitions a user\u27s handling of conflict from their emotional faculties to their logical faculties, overcoming the away-reflex. It also provides a visual representation of the conflict, which allows a conflict manager to logically plot and manage a multi-step resolution process with improved potential for long term results over the get-it-over-quickly single-step reflex. And, it comprises an open framework to which an expanding number of resources can be added to bolster a conflict manager\u27s understanding of all parties\u27 concerns, personalities, motivations, fears, and to enable the conflict manager to generate new ideas using Creative Problem Solving, and increase influence and persuasiveness
Exoplanets imaging with a Phase-Induced Amplitude Apodization Coronagraph - I. Principle
Using 2 aspheric mirrors, it is possible to apodize a telescope beam without
losing light or angular resolution: the output beam is produced by
``remapping'' the entrance beam to produce the desired light intensity
distribution in a new pupil. We present the Phase-Induced Amplitude Apodization
Coronagraph (PIAAC) concept, which uses this technique, and we show that it
allows efficient direct imaging of extrasolar terrestrial planets with a
small-size telescope in space. The suitability of the PIAAC for exoplanet
imaging is due to a unique combination of achromaticity, small inner working
angle (about 1.5 ), high throughput, high angular resolution and
large field of view. 3D geometrical raytracing is used to investigate the
off-axis aberrations of PIAAC configurations, and show that a field of view of
more than 100 in radius is available thanks to the correcting
optics of the PIAAC. Angular diameter of the star and tip-tilt errors can be
compensated for by slightly increasing the size of the occulting mask in the
focal plane, with minimal impact on the system performance. Earth-size planets
at 10 pc can be detected in less than 30s with a 4m telescope. Wavefront
quality requirements are similar to classical techniques.Comment: 35 pages, 16 figures, Accepted for publication in Ap
Capacity Improvement of Large, Two Stage Diaphragm Compressor
Case StudyTwo stage diaphragm compressor is used to pressurize a process gas stream. As delivered, compressor produced less than 75% of the required flow rate at the specified suction and discharge conditions. Improvement Goal: Increase capacity to deliver minimum required flow to the process. An improvement effort was initiated. This presentation covers the improvements made to the compressor which resulted in a capacity increase to 98% of the design flow rate. The OEM was integral to this process and provided the engineering and shop time to implement the improvements
Simultaneous Exoplanet Characterization and deep wide-field imaging with a diffractive pupil telescope
High-precision astrometry can identify exoplanets and measure their orbits
and masses, while coronagraphic imaging enables detailed characterization of
their physical properties and atmospheric compositions through spectroscopy. In
a previous paper, we showed that a diffractive pupil telescope (DPT) in space
can enable sub-microarcsecond accuracy astrometric measurements from wide-field
images by creating faint but sharp diffraction spikes around the bright target
star. The DPT allows simultaneous astrometric measurement and coronagraphic
imaging, and we discuss and quantify in this paper the scientific benefits of
this combination for exoplanet science investigations: identification of
exoplanets with increased sensitivity and robustness, and ability to measure
planetary masses to high accuracy. We show how using both measurements to
identify planets and measure their masses offers greater sensitivity and
provides more reliable measurements than possible with separate missions, and
therefore results in a large gain in mission efficiency. The combined
measurements reliably identify potentially habitable planets in multiple
systems with a few observations, while astrometry or imaging alone would
require many measurements over a long time baseline. In addition, the combined
measurement allows direct determination of stellar masses to percent-level
accuracy, using planets as test particles. We also show that the DPT maintains
the full sensitivity of the telescope for deep wide-field imaging, and is
therefore compatible with simultaneous scientific observations unrelated to
exoplanets. We conclude that astrometry, coronagraphy, and deep wide-field
imaging can be performed simultaneously on a single telescope without
significant negative impact on the performance of any of the three techniques.Comment: 15 pages, 6 figures. This second paper, following the paper
describing the diffractive pupil telescope (DPT) astrometric technique, shows
how simultaneous astrometry and coronagraphy observations, enabled by the DPT
concept, constrain the orbital parameters and mass of exoplanet
Conceptual Design of the Coronagraphic High Angular Resolution Imaging Spectrograph (CHARIS) for the Subaru Telescope
Recent developments in high-contrast imaging techniques now make possible
both imaging and spectroscopy of planets around nearby stars. We present the
conceptual design of the Coronagraphic High Angular Resolution Imaging
Spectrograph (CHARIS), a lenslet-based, cryogenic integral field spectrograph
(IFS) for imaging exoplanets on the Subaru telescope. The IFS will provide
spectral information for 140x140 spatial elements over a 1.75 arcsecs x 1.75
arcsecs field of view (FOV). CHARIS will operate in the near infrared (lambda =
0.9 - 2.5 microns) and provide a spectral resolution of R = 14, 33, and 65 in
three separate observing modes. Taking advantage of the adaptive optics systems
and advanced coronagraphs (AO188 and SCExAO) on the Subaru telescope, CHARIS
will provide sufficient contrast to obtain spectra of young self-luminous
Jupiter-mass exoplanets. CHARIS is in the early design phases and is projected
to have first light by the end of 2015. We report here on the current
conceptual design of CHARIS and the design challenges
CHARIS Science: Performance Simulations for the Subaru Telescope's Third-Generation of Exoplanet Imaging Instrumentation
We describe the expected scientific capabilities of CHARIS, a high-contrast
integral-field spectrograph (IFS) currently under construction for the Subaru
telescope. CHARIS is part of a new generation of instruments, enabled by
extreme adaptive optics (AO) systems (including SCExAO at Subaru), that promise
greatly improved contrasts at small angular separation thanks to their ability
to use spectral information to distinguish planets from quasistatic speckles in
the stellar point-spread function (PSF). CHARIS is similar in concept to GPI
and SPHERE, on Gemini South and the Very Large Telescope, respectively, but
will be unique in its ability to simultaneously cover the entire near-infrared
, , and bands with a low-resolution mode. This extraordinarily broad
wavelength coverage will enable spectral differential imaging down to angular
separations of a few , corresponding to 0.\!\!''1. SCExAO
will also offer contrast approaching at similar separations,
0.\!\!''1--0.\!\!''2. The discovery yield of a CHARIS survey will
depend on the exoplanet distribution function at around 10 AU. If the
distribution of planets discovered by radial velocity surveys extends unchanged
to 20 AU, observations of 200 mostly young, nearby stars targeted
by existing high-contrast instruments might find 1--3 planets. Carefully
optimizing the target sample could improve this yield by a factor of a few,
while an upturn in frequency at a few AU could also increase the number of
detections. CHARIS, with a higher spectral resolution mode of , will
also be among the best instruments to characterize planets and brown dwarfs
like HR 8799 cde and And b.Comment: 13 pages, 7 figures, proceedings from SPIE Montrea
Towards an optimal aiming for molten salt power towers
Finding a suitable aiming strategy for receivers of power towers can be challenging, especially for receivers using molten salt as heat transfer fluid as the allowable flux density decreases dramatically with increasing salt temperature. In this paper a very fast, steady-state model for the molten salt receiver is presented. This model is combined with a ray-tracing software and a metaheuristic optimization procedure. The thermal model is used to calculate the actual temperature and mass flow in the receiver which are then used to calculate the operational limits for the flux density. It is demonstrated that such an optimized aiming strategy can outperform a parameter based aiming strategies by more than 2%
Mountain Rivers Reveal the Earthquake Hazard of Geologic Faults in Silicon Valley
The 1989, Mw = 6.9 Loma Prieta earthquake resulted in tens of lives lost and cost California almost 3% of its gross domestic product. Despite widespread damage, the earthquake did not clearly rupture the surface, challenging the identification and characterization of these hidden hazards. Here, we show that they can be illuminated by inverting fluvial topography for slip-and moment accrual-rates—fundamental components in earthquake hazard assessments—along relief-generating geologic faults. We applied this technique to thrust faults bounding the mountains along the western side of Silicon Valley in the San Francisco Bay Area, and discovered that these structures may be capable of generating a Mw = 6.9 earthquake every 250–300 years based on moment accrual rates. This method may be deployed broadly to evaluate seismic hazard in developing regions with limited geological and geophysical information
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