167 research outputs found
2015 AQ Summit: Research Update by Steve Von Vogt
A presentation covering how composite materials are currently used in some sectors, and how they could be utilized in the aquaculture sector
Systemic: A Testbed For Characterizing the Detection of Extrasolar Planets. I. The Systemic Console Package
We present the systemic Console, a new all-in-one, general-purpose software
package for the analysis and combined multiparameter fitting of Doppler radial
velocity (RV) and transit timing observations. We give an overview of the
computational algorithms implemented in the Console, and describe the tools
offered for streamlining the characterization of planetary systems. We
illustrate the capabilities of the package by analyzing an updated radial
velocity data set for the HD128311 planetary system. HD128311 harbors a pair of
planets that appear to be participating in a 2:1 mean motion resonance. We show
that the dynamical configuration cannot be fully determined from the current
data. We find that if a planetary system like HD128311 is found to undergo
transits, then self-consistent Newtonian fits to combined radial velocity data
and a small number of timing measurements of transit midpoints can provide an
immediate and vastly improved characterization of the planet's dynamical state.Comment: 10 pages, 5 figures, accepted for publication on PASP. Additional
material at http://www.ucolick.org/~smeschia/systemic.ph
A determination of the spin-orbit alignment of the anomalously dense planet orbiting HD 149026
We report 35 radial velocity measurements of HD 149026 taken with the Keck Telescope. Of these measurements, 15
were made during the transit of the companion planet HD 149026b, which occurred on 2005 June 25. These velocities
provide a high-cadence observation of the Rossiter-McLaughlin effect, the shifting of photospheric line profiles that occurs when a planet occults a portion of the rotating stellar surface. We combine these radial velocities with previously published radial velocity and photometric data sets and derive a composite best-fit model for the star-planet system. This model confirms and improves previously published orbital parameters, including the remarkably small planetary radius, the planetary mass, and the orbital inclination, found to be Rp/RJup = 0.718 ± 0.065, Mp/MJup = 0.352 ± 0.025, and I = 86.1° ± 1.4°, respectively. Together the planetary mass and radius determinations imply a mean planetary density
of 1.18(-0.30)(+0.38)g cm(-3). The new data also allow for the determination of the angle between the apparent stellar equator and the orbital plane, which we constrain to be λ = -12° ± 15°
A Quasi-Stationary Solution to Gliese 436b's Eccentricity
We investigate the possibility that the large orbital eccentricity of the
transiting Neptune-mass planet Gliese 436b is maintained in the face of tidal
dissipation by a second planet in the system. We find that the currently
observed configuration can be understood if Gliese 436b and a putative
companion have evolved to a quasi-stationary fixed point in which the planets'
orbital apses are co-linear and in which secular variations in the orbital
eccentricities of the two planets have been almost entirely damped out. We
adopt an octopole-order secular theory based on a Legendre expansion in the
semi-major axis ratio to delineate well-defined regions of (P_c, M_c, e_c)
space that can be occupied by a perturbing companion. We incorporate the
evolutionary effect of tidal dissipation into our secular model of the system,
and solve the resulting initial value problems for a large sample of the
allowed configurations. We then polish the stationary configurations derived
from secular theory with full numerical integrations. We present our results in
the form of candidate companion planets to Gliese 436b. For these candidates,
radial velocity half-amplitudes, K_c, are of order 3 m/s, and the maximum
amplitude of orbit-to-orbit transit timing variations are of order Delta t=1 s
to Delta t=5s. For the particular example case of a perturber with orbital
period, P_c=40 d, mass, M_c=8.5 M_Earth, and eccentricity, e_c=0.58, we confirm
our semi-analytic calculations with a full numerical 3-body integration of the
orbital decay that includes tidal damping and spin evolution. Additionally, we
discuss the possibility of many-perturber stationary configurations, utilizing
modified Laplace-Lagrange secular theory.Comment: 25 pages, 7 figures. Accepted for publication in the Astrophysical
Journa
Real-time vocal emotion recognition in artistic installations and interactive storytelling: Experiences and lessons learnt from CALLAS and IRIS
Most emotion recognition systems still rely exclusively on prototypical emotional vocal expressions that may be uniquely assigned to a particular class. In realistic applications, there is, however, no guarantee that emotions are expressed in a prototypical manner. In this paper, we report on challenges that arise when coping with non-prototypical emotions in the context of the CALLAS project and the IRIS network. CALLAS aims to develop interactive art installations that respond to the multimodal emotional input of performers and spectators in real-time. IRIS is concerned with the development of novel technologies for interactive storytelling. Both research initiatives represent an extreme case of non-prototypicality since neither the stimuli nor the emotional responses to stimuli may be considered as prototypical. 1
A Sub-Saturn Mass Planet Orbiting HD 3651
We report precise Doppler velocities of HD 3651 obtained at Lick and Keck Observatories. The velocities reveal evidence of a planetary companion with an orbital period of 62.23 ± 0.03 days, an eccentricity of 0.63 ± 0.04, and a velocity semiamplitude of 15.9 ± 1.7 m s-1. With an assumed mass of 0.79 Mâ for this K0 V star, we derive M sin i = 0.20MJ and a semimajor axis of 0.284 AU. The star is chromospherically inactive, with log R = -5.01, and 10 years of observations at Fairborn Observatory show it to be photometrically stable to better than 0.001 mag. In particular, there is no photometric variability on the 62.23 day radial velocity period to a limit of 0.0002 mag, supporting the planetary interpretation of the radial velocity variability. Photometric transits of the planetary companion across the star are ruled out with a probability of 87%
Implications of climate targets on oil production and fiscal revenues in Latin America and the Caribbean
While many governments rely on oil production and exports for fiscal revenues, the global energy transition driven by climate policy and technological change makes future demand and prices uncertain. We propose a framework to explore prospects for oil production, public revenues from oil, and unexploited oil reserves under hundreds of future energy transitions scenarios, following robust decision making principles. We apply it to Latin American and the Caribbean, a developing region that exports half its oil production and faces fiscal constraints. We use the BUEGO (Bottom-Up Economic and Geological Oil field production) model to simulate field development and production decisions globally. We find that oil production in the region over the next 15 years is highly sensitive to the impact of global climate action on oil prices and to the strategies of large global producers, while choices around oil fiscal regimes have limited impact. Also, 66 to 81% of proved, probable and possible reserves will remain unused by 2035. Finally, cumulative fiscal and nonfiscal revenues from oil would be 2.7-6.8 trillion if reserves were strongly exploited. Our findings confirm that governments need to diversify their fiscal revenues away from dependency on oil production
Resilience in Nonmetropolitan Nebraska: Capacity to Overcome Disasters and Hardships. 2020 Nebraska Rural Poll Results
The definition of resilience is the capacity to recover quickly from difficulties. Synonyms include toughness, perseverance and grit. Last springâs severe weather events and this yearâs ongoing COVID-19 pandemic are likely testing the resilience of rural Nebraskans. Given that, how do rural Nebraskans rate their communities on dimensions that measure their resiliency? How confident are they that the federal government or local emergency management authorities can contain infectious disease outbreaks? How do they rate their ability to help their community handle adversities? How prepared are rural Nebraskans to deal with financial emergencies? This paper provides a detailed analysis of these questions. This report details 1,979 responses to the 2020 Nebraska Rural Poll, the 25th annual effort to understand rural Nebraskansâ perceptions. Respondents were asked a series of questions about resilience. Comparisons are made among different respondent subgroups, that is, comparisons by age, occupation, region, etc. Based on these analyses, some key findings emerged:
âą Most rural Nebraskans agree that their community contains most elements of resilience: trust among residents, ability to overcome an emergency situation, residents working together to improve the community, people that help each other, community information sharing and community priority and goal setting.
âą Rural Nebraskans are less likely to say their community treats everyone fairly, actively plans for future disasters, trusts public officials, and look at its successes and failures to learn from the past.
âą Most rural Nebraskans agree that infectious diseases will have a major impact in the country in the next few years.
âą Most rural Nebraskans assume that there will be limits on what federal and local governments can do to contain a widespread infectious disease outbreak.
âą Most rural Nebraskans believe they can help improve their communities when something bad happens and can take setbacks in their communityâs progress in stride.
âą Savings, credit card(s) and a bank loan are the most accessible sources of emergency funds for rural Nebraskans
Exploring the Nebraska Rural Poll, 2020
The Nebraska Rural Poll was initiated in 1996. Over the past 24 years, input has been gathered from over 64,000 nonmetropolitan Nebraskans. 102 separate reports have been produced covering 31 unique topics
Trend Analysis
Subgroup Comparisons
Some questions have been repeated at various intervals of tim
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