6,723 research outputs found
Evaluation of thermal insulation materials
Data was obtained on silicone-bonded fiberglass, isocyanurate foam, and two dozen other insulators. Materials were selected to withstand heat sterilization, outer space, and the Martian atmosphere. Significant environmental parameters were vibration, landing shock, and launch venting
Diversity and Abundance of Club and Coral Fungi in the Upper Lane Cove Valley
The Kingdom Fungi are central players in the ecology and biogeochemistry of terrestrial ecosystems. Despite this importance, the diversity, distribution and abundance of fungal species are poorly known. Here, we undertook an intensive survey of club and coral fungi in the Upper Lane Cove Valley, Sydney, Australia. Over a two-year period, we collected more than 1100 specimens, and identified these to genus using a combination of DNA barcoding and morphology. The majority of specimens did not match any sequences in GenBank at more than 95% similarity, meaning that many of these fungi are either poorly represented in DNA databases, or are potentially novel species. A number of hotspots for fungal diversity and abundance were identified, largely along creek lines draining southwest through coachwood dominated vegetation. Notably, these hotspots all lie outside the adjacent Lane Cove National Park
Two-mirror Schwarzschild aplanats. Basic relations
It is shown that the theory of aplanatic two-mirror telescopes developed by
Karl Schwarzschild in 1905 leads to the unified description both the prefocal
and the postfocal systems. The class of surfaces in the ZEMAX optical program
has been properly extended to ascertain the image quality in exact
Schwarzschild aplanats. A comparison of Schwarzschild aplanats with approximate
Ritchey-Chretien and Gregory-Maksutov aplanatic telescopes reveals a noticeable
advantage of the former at fast focal ratio of the system.Comment: 19 page
Asymmetric emission of high energy electrons in the two-dimensional hydrodynamic expansion of large xenon clusters irradiated by intense laser fields
Energy spectra and angular distributions have been measured of electrons that
are emitted upon disassembly of following irradiation by intense
(10 W cm) laser pulses whose durations are varied over
the 100-2200 fs range. The cluster explosion dynamics occur in the hydrodynamic
regime. Electron emission is found to be unexpectedly asymmetric and exhibits a
resonance when the laser pulse duration is 1 ps. These results are
rationalized by extending the hydrodynamic model to also take into account the
force that the light field exerts on the polarization charge that is induced on
surface of the cluster. We show that the magnitude of this electrostrictive
force is comparable to those of Coulombic and the hydrodynamic forces, and it
exhibits resonance behavior. Contrary to earlier understanding, we find that
low-energy electrons are connected to the resonance in energy absorption by the
cluster. The high-energy electrons seem to be produced by a mechanism that is
not so strongly influenced by the resonance.Comment: 1 Revtex file, 8 figs. in eps forma
The effects of benzopyrene and safrole on biphenyl 2-hydroxylase and other drug-metabolizing enzymes
Impact of proctoring on success rates for percutaneous revascularisation of coronary chronic total occlusions.
OBJECTIVE: To assess the impact of proctoring for chronic total occlusion (CTO) percutaneous coronary intervention (PCI) in six UK centres. METHODS: We retrospectively analysed 587 CTO procedures from six UK centres and compared success rates of operators who had received proctorship with success rates of the same operators before proctorship (pre-proctored) and operators in the same institutions who had not been proctored (non-proctored). There were 232 patients in the pre-proctored/non-proctored group and 355 patients in the post-proctored group. Complexity was assessed by calculating the Japanese CTO (JCTO) score for each case. RESULTS: CTO PCI success was greater in the post-proctored compared with the pre-proctored/non-proctored group (77.5% vs 62.1%, p<0.0001). In more complex cases where JCTOâ„2, the difference in success was greater (70.7% vs 49.5%, p=0.0003). After proctoring, there was an increase in CTO PCI activity in centres from 2.5% to 3.5%, p<0.0001 (as a proportion of total PCI), and the proportion of very difficult cases with JCTO score â„3 increased from 15.3% (35/229) to 29.7% (105/354), p<0.0001. CONCLUSIONS: Proctoring resulted in an increase in procedural success for CTO PCI, an increase in complex CTO PCI and an increase in total CTO PCI activity. Proctoring may be a valuable way to improve access to CTO PCI and the likelihood of procedural success
Spectroscopy of Ti and the systematic behavior of low energy octupole states in Ca and Ti isotopes
Excited states of the nucleus Ti have been studied, via both
inverse-kinematics proton scattering and one-neutron knockout from Ti by
a liquid hydrogen target, using the GRETINA -ray tracking array.
Inelastic proton-scattering cross sections and deformation lengths have been
determined. A low-lying octupole state has been tentatively identified in
Ti for the first time. A comparison of results on low-energy
octupole states in the neutron-rich Ca and Ti isotopes with the results of
Random Phase Approximation calculations demonstrates that the observed
systematic behavior of these states is unexpected.Comment: 7 pages, 8 figure
The ATLAS SCT grounding and shielding concept and implementation
This paper presents a complete description of Virgo, the French-Italian gravitational wave detector. The detector, built at Cascina, near Pisa (Italy), is a very large Michelson interferometer, with 3 km-long arms. In this paper, following a presentation of the physics requirements, leading to the specifications for the construction of the detector, a detailed description of all its different elements is given. These include civil engineering infrastructures, a huge ultra-high vacuum (UHV) chamber (about 6000 cubic metres), all of the optical components, including high quality mirrors and their seismic isolating suspensions, all of the electronics required to control the interferometer and for signal detection. The expected performances of these different elements are given, leading to an overall sensitivity curve as a function of the incoming gravitational wave frequency. This description represents the detector as built and used in the first data-taking runs. Improvements in different parts have been and continue to be performed, leading to better sensitivities. These will be detailed in a forthcoming paper
Spectroscopy of Ti and the systematic behavior of low energy octupole states in Ca and Ti isotopes
Excited states of the nucleus Ti have been studied, via both
inverse-kinematics proton scattering and one-neutron knockout from Ti by
a liquid hydrogen target, using the GRETINA -ray tracking array.
Inelastic proton-scattering cross sections and deformation lengths have been
determined. A low-lying octupole state has been tentatively identified in
Ti for the first time. A comparison of results on low-energy
octupole states in the neutron-rich Ca and Ti isotopes with the results of
Random Phase Approximation calculations demonstrates that the observed
systematic behavior of these states is unexpected.Comment: 7 pages, 8 figure
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