843 research outputs found
Planetary rover technology development requirements
Planetary surface (including lunar) mobility and sampling capability is required to support proposed future National Aeronautics and Space Administration (NASA) solar system exploration missions. The NASA Office of Aeronautics and Space Technology (OAST) is addressing some of these technology needs in its base research and development program, the Civil Space Technology Initiative (CSTI) and a new technology initiative entitled Pathfinder. The Pathfinder Planetary Rover (PPR) and Sample Acquisition, Analysis and Preservation (SAAP) programs will develop and validate the technologies needed to enable both robotic and piloted rovers on various planetary surfaces. The technology requirements for a planetary roving vehicle and the development plans of the PPR and SAAP programs are discussed
Characterization of organic matter in the Torridonian using Raman spectroscopy
We gratefully acknowledge two anonymous reviewers for their constructive comments on an earlier version of this manuscript. Earth System Evolution and Early Life: a Celebration of the Work of Martin Brasier. ed. / A. T. Brasier; D. McIlroy; N. McLoughlin. 978-1-78620-279-6Peer reviewedPostprintPostprintPostprintPostprintPostprintPostprintPostprintPostprintPostprin
M-Dwarf Fast Rotators and the Detection of Relatively Young Multiple M-Star Systems
We have searched the Kepler light curves of ~3900 M-star targets for evidence
of periodicities that indicate, by means of the effects of starspots, rapid
stellar rotation. Several analysis techniques, including Fourier transforms,
inspection of folded light curves, 'sonograms', and phase tracking of
individual modulation cycles, were applied in order to distinguish the
periodicities due to rapid rotation from those due to stellar pulsations,
eclipsing binaries, or transiting planets. We find 178 Kepler M-star targets
with rotation periods, P_rot, of < 2 days, and 110 with P_rot < 1 day. Some 30
of the 178 systems exhibit two or more independent short periods within the
same Kepler photometric aperture, while several have three or more short
periods. Adaptive optics imaging and modeling of the Kepler pixel response
function for a subset of our sample support the conclusion that the targets
with multiple periods are highly likely to be relatively young physical binary,
triple, and even quadruple M star systems. We explore in detail the one object
with four incommensurate periods all less than 1.2 days, and show that two of
the periods arise from one of a close pair of stars, while the other two arise
from the second star, which itself is probably a visual binary. If most of
these M-star systems with multiple periods turn out to be bound M stars, this
could prove a valuable way of discovering young hierarchical M-star systems;
the same approach may also be applicable to G and K stars. The ~5% occurrence
rate of rapid rotation among the ~3900 M star targets is consistent with spin
evolution models that include an initial contraction phase followed by magnetic
braking, wherein a typical M star can spend several hundred Myr before spinning
down to periods longer than 2 days.Comment: 17 pages, 12 figures, 2 tables; accepted for publication in The
Astrophysical Journa
Raman spectral shifts in naturally faulted rocks
Acknowledgements. We thank Colin Taylor at UoA for help in sample preparation.This study was supported by the School of Geosciences at the University of Aberdeen and in part by the NERC Centre for Doctoral Training in Oil & Gas (Grant Number: NE/R01051x/1).Peer reviewedPublisher PD
Quantum conductance problems and the Jacobi ensemble
In one dimensional transport problems the scattering matrix is decomposed
into a block structure corresponding to reflection and transmission matrices at
the two ends. For a random unitary matrix, the singular value probability
distribution function of these blocks is calculated. The same is done when
is constrained to be symmetric, or to be self dual quaternion real, or when
has real elements, or has real quaternion elements. Three methods are used:
metric forms; a variant of the Ingham-Seigel matrix integral; and a theorem
specifying the Jacobi random matrix ensemble in terms of Wishart distributed
matrices.Comment: 10 page
Increased Depth of Cellular Imaging in the Intact Lung Using Far-Red and Near-Infrared Fluorescent Probes
Scattering of shorter-wavelength visible light limits the
fluorescence imaging depth of thick specimens such as whole
organs. In this study, we report the use of four newly synthesized
near-infrared and far-red fluorescence probes
(excitation/emission, in nm: 644/670; 683/707; 786/814; 824/834)
to image tumor cells in the subpleural vasculature of the intact
rat lungs. Transpelural imaging of tumor cells labeled with
long-wavelength probes and expressing green fluorescent protein
(GFP; excitation/emission 488/507 nm) was done in the intact rat
lung after perfusate administration or intravenous injection. Our
results show that the average optimum imaging depth for the
long-wavelength probes is higher (27.8 ± 0.7
μm) than for GFP (20 ± 0.5
μm; p = 0.008; n = 50), corresponding to a
40% increase in the volume of tissue accessible for
high-resolution imaging. The maximum depth of cell visualization
was significantly improved with the novel dyes (36.4 ± 1
μm from the pleural surface) compared with GFP (30.1 ± 0.5
μm; p = 0.01; n = 50). Stable binding of the long-wavelength
vital dyes to the plasma membrane also permitted in vivo tracking
of injected tumor cells in the pulmonary vasculature. These probes
offer a significant improvement in the imaging quality of in situ
biological processes in the deeper regions of intact lungs
Observations of reservoir quality alteration in proximity to igneous intrusions for two distinct sandstones units in Scotland
Acknowledgements We thank the reviewers and editor for their helpful comments which greatly improved this manuscript. Thanks to John Still from the University of Aberdeen (ACEMAC ) for guidance with SEM/EDS, Colin Taylor for MICP tests and Walter Ritchie for making thin sections. Lorenza Sardisco and Jonathan Wilkins at X-Ray Minerals for XRD analysis and Prof. M.J. Wilson from the James Hutton Institute for valuable discussion of XRD results. Dave Healy acknowledges the support of the Natural Environment Research Council (NERC, UK) through the award NE/N003063/1 ‘Quantifying the Anisotropy of Permeability in Stressed Rock’.Peer reviewedPostprin
Raman Spectroscopy : an effective thermal marker in low temperature carbonaceous fold-thrust belts
Special Publication title- Fold and Thrust Belts: Structural Style, Evolution and Exploration Acknowledgments Z. Crawford and A. Marpino were funded through the University of Aberdeen, School of Geosciences for MGeol and MSc project work. Bond, Butler and Watkins were supported through the Fold-Thrust Research Group, sponsored by Oil Search, Santos and Interoil.Peer reviewedPostprintPostprintPostprintPostprintPostprintPostprintPostprintPostprin
Making Oil From Magma
Volume title: Application of Analytical Techniques to Petroleum Systems Acknowledgements The authors would like to thank W. Meredith and F. Bebb for constructive reviews that greatly improved this manuscript. S. Bowden is thanked for useful discussions on earlier drafts. Finally, we would like to thank P. Dowey for his editorial management of this volume. Funding M. Duffy is supported by a School of Geosciences Scholarship and N. Mark is supported by JX Nippon Exploration & Production (UK) as part of the Volcanic Margin Research Consortium Phase 2.Peer reviewedPostprintPostprin
Ten-fold spectral resolution boosting using TEDI at the Mt. Palomar NIR Triplespec spectrograph
An optical technique called "interferometric spectral reconstruction" (ISR) is capable of increasing a spectrograph's resolution and stability by large factors, well beyond its classical limits. We have demonstrated a 6- to 11-fold increase in the Triplespec effective spectral resolution (R=2,700) to achieve R=16,000 at 4100 cm-^(1) to 30,000 at 9600 cm^(-1) by applying special Fourier processing to a series of exposures with different delays (optical path differences) taken with the TEDI interferometer and the near-infrared Triplespec spectrograph at the Mt. Palomar Observatory 200 inch telescope. The TEDI is an externally dispersed interferometer (EDI) used for Doppler radial velocity measurements on M-stars, and now also used for ISR. The resolution improvement is observed in both stellar and telluric features simultaneously over the entire spectrograph bandwidth (0.9-2.45 μm). By expanding the delay series, we anticipate achieving resolutions of R=45,000 or more. Since the delay is not continuously scanned, the technique is advantageous for measuring time-variable phenomena or in varying conditions (e.g. planetary fly-bys). The photon limited signal to noise ratio can be 100 times better than a classic Fourier Transform Spectrometer (FTS) due to the benefit of dispersion
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