209 research outputs found
The NStED Exoplanet Transit Survey Service
The NASA Star and Exoplanet Database (NStED) is a general purpose stellar
archive with the aim of providing support for NASA's planet finding and
characterization goals, stellar astrophysics, and the planning of NASA and
other space missions. There are two principal components of NStED: a database
of (currently) 140,000 nearby stars and exoplanet-hosting stars, and an archive
dedicated to high-precision photometric surveys for transiting exoplanets. We
present a summary of the latter component: the NStED Exoplanet Transit Survey
Service (NStED-ETSS), along with its content, functionality, tools, and user
interface. NStED-ETSS currently serves data from the TrES Survey of the Kepler
Field as well as dedicated photometric surveys of four stellar clusters.
NStED-ETSS aims to serve both the surveys and the broader astronomical
community by archiving these data and making them available in a homogeneous
format. Examples of usability of ETSS include investigation of any
time-variable phenomena in data sets not studied by the original survey team,
application of different techniques or algorithms for planet transit
detections, combination of data from different surveys for given objects,
statistical studies, etc. NStED-ETSS can be accessed at
\tt{http://nsted.ipac.caltech.edu}Comment: To appear in the Proceedings of the 253rd IAU Symposium: "Transiting
Planets", May 2008, Cambridge, MA. 4 pages, 2 figure
Unconventional PDV applications: detecting plasma and radiation
Author Institution: Sandia National LaboratoriesSlides presented at the 2018 Photonic Doppler Velocimetry (PDV) Users Workshop, Drury Plaza Hotel, Santa Fe, New Mexico, May 16-18, 2018
Iron oxide and water paste rheology and its effect on low adhesion in the wheel/rail interface
The “wet-rail” phenomenon results in low adhesion between wheel and rail throughout the year, occurring transiently on a slightly wet, or drying railhead. It has been previously proposed that it is caused by a mixture of iron oxides and small amounts of water (from dew or precipitation) on the railhead that form a friction reducing paste. This paper outlines a novel combination of rheology, modelling and experimental work using a twin disc test rig to determine how the rheology of this iron oxide paste affects adhesion. The yield strength of different types of iron oxides, along with solid oxide fraction of the friction reducing paste, was assessed and used as an input into an “adhesion model” for assessing water and oxide suspensions. The rheological and modelling results were compared against very low adhesion recorded in twin disc experimental validation when simulating the wet-rail phenomenon
The LAEX and NASA portals for CoRoT public data
* Aims. We describe here the main functionalities of the LAEX (Laboratorio de
Astrofisica Estelar y Exoplanetas/Laboratory for Stellar Astrophysics and
Exoplanets) and NASA portals for CoRoT Public Data. The CoRoT archive at LAEX
was opened to the community in January 2009 and is managed in the framework of
the Spanish Virtual Observatory. NStED (NASA Star and Exoplanet Database)
serves as the CoRoT portal for the US astronomical community. NStED is a
general purpose stellar and exoplanet archive with the aim of providing support
for NASA planet finding and characterisation goals, and the planning and
support of NASA and other space missions. CoRoT data at LAEX and NStED can be
accessed at http://sdc.laeff.inta.es/corotfa/ and
http://nsted.ipac.caltech.edu,respectively.
* Methods. Based on considerable experience with astronomical archives, the
aforementioned archives are designed with the aim of delivering science-quality
data in a simple and efficient way.
* Results. LAEX and NStED not only provide access to CoRoT Public Data but
furthermore serve a variety of observed and calculated astrophysical data. In
particular, NStED provides scientifically validated information on stellar and
planetary data related to the search for and characterization of extrasolar
planets, and LAEX makes any information from Virtual Observatory services
available to the astronomical community.Comment: Accepted for publication in Astronomy & Astrophysic
The NASA Exoplanet Archive: Data and Tools for Exoplanet Research
We describe the contents and functionality of the NASA Exoplanet Archive, a
database and tool set funded by NASA to support astronomers in the exoplanet
community. The current content of the database includes interactive tables
containing properties of all published exoplanets, Kepler planet candidates,
threshold-crossing events, data validation reports and target stellar
parameters, light curves from the Kepler and CoRoT missions and from several
ground-based surveys, and spectra and radial velocity measurements from the
literature. Tools provided to work with these data include a transit ephemeris
predictor, both for single planets and for observing locations, light curve
viewing and normalization utilities, and a periodogram and phased light curve
service. The archive can be accessed at
http://exoplanetarchive.ipac.caltech.edu.Comment: Accepted for publication in the Publications of the Astronomical
Society of the Pacific, 4 figure
The Automated Palomar 60-Inch Telescope
We have converted the Palomar 60-inch telescope (P60) from a classical night
assistant-operated telescope to a fully robotic facility. The automated system,
which has been operational since September 2004, is designed for moderately
fast (t <~ 3 minutes) and sustained (R <~ 23 mag) observations of gamma-ray
burst afterglows and other transient events. Routine queue-scheduled
observations can be interrupted in response to electronic notification of
transient events. An automated pipeline reduces data in real-time, which is
then stored on a searchable web-based archive for ease of distribution. We
describe here the design requirements, hardware and software upgrades, and
lessons learned from roboticization. We present an overview of the current
system performance as well as plans for future upgrades.Comment: Accepted in PASP; 26 pages, 7 figures; high resolution version at
http://www.srl.caltech.edu/~cenko/public/papers/p60.p
Covalent enzyme coupling on cellulose acetate membranes for glucose sensor development
International audienceMethods for immobilizing glucose oxidase (GOx) on cellulose acetate (CA) membranes are compared. The optimal method involves covalent coupling of bovine serum albumin (BSA) to CA membrane and a subsequent reaction of the membrane with GOx, which has previously been activated with an excess of p-benzoquinone. This coupling procedure is fairly reproducible and allows the preparation of thin membranes (5-20 µm) showing high surface activities (1-3 U/cm2) which are stable over a period of 1-3 months. Electrochemical and radiolabeling experiments show that enzyme inactivation as a result of immobilization is negligible. A good correlation between surface activity of membranes and their GOx load is observed
Electrospun Polyurethane Fibers for Absorption of Volatile Organic Compounds from Air
Electrospun polyurethane fibers for removal of volatile organic compounds (VOC) from air with rapid VOC absorption and desorption have been developed. Polyurethanes based on 4,4-methylenebis(phenylisocyanate) (MDI) and aliphatic isophorone diisocyanate as the hard segments and butanediol and tetramethylene glycol as the soft segments were electrospun from their solutions in N,N-dimethylformamide to form micrometer-sized fibers. Although activated carbon possessed a many-fold higher surface area than the polyurethane fiber meshes, the sorption capacity of the polyurethane fibers was found to be similar to that of activated carbon specifically designed for vapor adsorption. Furthermore, in contrast to VOC sorption on activated carbon, where complete regeneration of the adsorbent was not possible, the polyurethane fibers demonstrated a completely reversible absorption and desorption, with desorption obtained by a simple purging with nitrogen at room temperature. The fibers possessed a high affinity toward toluene and chloroform, but aliphatic hexane lacked the necessary strong attractive interactions with the polyurethane chains and therefore was less strongly absorbed. The selectivity of the polyurethane fibers toward different vapors, along with the ease of regeneration, makes them attractive materials for VOC filtration.Boeing CompanyNetherlands Organisation for Scientific Research (NWO) (Talent Scholarship
- …