77,283 research outputs found
Polarizabilities of Si^{2+}: a benchmark test of theory and experiment
We have calculated electric-dipole polarizabilities of the 3s^2 ^1S_0, 3s3p
^3P_0, and 3s3p ^1P_1 states of the Si^{2+} ion using recently developed
configuration interaction + all-order method. Detailed evaluation of the
uncertainties of the final results is carried out. Our value for the ground
state electric-dipole polarizability 11.670(13) a.u. is in excellent agreement
with the resonant excitation Stark ionization spectroscopy value 11.669(9) a.u.
[Komara et al., J. Phys. B 38, 87 (2005); Mitroy, Phys. Rev. A 78, 052515
(2008)]. This work represents the most precise benchmark test to date of theory
and experiment in divalent atoms. The near cancellation of the ns^2 ^1S_0
ground state and the lowest nsnp ^3P_0 polarizabilities previously observed in
B+, Al+, In+, Tl+, and Pb^{2+} is also found in Si^{2+} ion.Comment: 6 page
Milton Keynes - preliminary estimates of regional traffic flows in 1981
The Milton Keynes Development Corporation and their planning
consultants have asked the College Transport Group to investigate the
scale of likely regional traffic flows into and out of Milton Keynes.
At this stage the emphasis is on providing information for the preparation
of a Master Plan for the city itself, rather than detailed traffic
estimates for planning transport systems in the surrounding region.
Population estimates for 1981 have been obtained from County
Councils for areas within a 20 mile radius of the new city, and the
proportions attracted to Milton Keynes for work and shopping assessed
using gravity model techniques. Separate estimates have been made of
work journeys from the city to regional employment and to London.
Possible upper and lower limits to these forecasts are included to
account for many uncertainties in the absolute and relative growth of
population, employment and shopping opportunities in the city itself and
in the surrounding region. The results are presented as traffic flews
into and out of octant sectors around the city. Flows to the east are
greater than to the west with work trip flows of the order of 2,500 person
trips each way in the most heavily loaded sectors. A 1981 city population
of 150,000 is likely to produce at least 1,500 daily commuters to London
using the fast rail service, with an additional 200 commuters from the region
using Milton Keynes railway station
Development of fuel cell electrodes Semiannual report, 30 Jun. 1966 - 30 Dec. 1966
Fuel cell using circulating liquid electrolyte and water removal by transpiration through porous electrode
Light transport and general aviation aircraft icing research requirements
A short term and a long term icing research and technology program plan was drafted for NASA LeRC based on 33 separate research items. The specific items listed resulted from a comprehensive literature search, organized and assisted by a computer management file and an industry/Government agency survey. Assessment of the current facilities and icing technology was accomplished by presenting summaries of ice sensitive components and protection methods; and assessments of penalty evaluation, the experimental data base, ice accretion prediction methods, research facilities, new protection methods, ice protection requirements, and icing instrumentation. The intent of the research plan was to determine what icing research NASA LeRC must do or sponsor to ultimately provide for increased utilization and safety of light transport and general aviation aircraft
New records, nomenclatural changes, and taxonomic notes for select North American leaf beetles (Coleoptera: Chrysomelidae)
New records, nomenclatural changes and taxonomic notes are presented for select North American leaf beetles (Coleoptera: Chrysomelidae). The following genera are newly recorded from the United States: Nesaecrepida Blake, 1964; Acallepitrix Bechyne, 1959; Margaridisa Bechyne, 1958; Parchicola Bechyne and Springlova de Bechyne, 1975; (all Galerucinae: Alticini); and Demotina Baly, 1874 (Eumolpinae). The following species are newly recorded from the United States: Neolema dorsalis (Olivier, 1791) (Criocerinae); Charidotella bifossulata Boheman, 1855 (Hispinae: Cassidini); Syphrea flauicollis (Jacoby, 1884) (Galerucinae: Alticini); and Promecosoma inflatum Lefevre, 1877, and Demotina modesta Baly, 1874 (Eumolpinae). The following new synonymies are proposed: Deloyala clauata, var. diuersicollis Schaeffer, 1925, transferred from synonymy with Plagiometriona clauata (Fabricius, 1798) to synonymy withP. clauata testudinaria (Boheman, 1855); Chrysomela hybrida Say, 1824, downgraded from subspecies of Calligrapha lunata (Fabricius, 1787) to full synonym of CaZZigrapha lunata (Fabricius); Chrysomela casta Rogers, 1856, downgraded from subspecies of Zygogramma suturalis (Fabricius, 1775) to full synonym of Zygogrammasuturalis (Fabricius); Trirhabdagurneyi Blake, 1951, downgraded to synonym of Trirhabda caduca Horn, 1893; Scelida mimula Wilcox, 1965, downgraded to synonym of Scelida nigricornis (Jacoby, 1888); Exoracalifornica Wilcox, 1953, downgraded to synonym of Pte leon breuicornis (Jacoby, 1887); alaeothonaarizonensis Blake, 1950, downgraded to synonym ofLupraea discrepans (Schaeffer, 1932); Haltica nigritula Linell, 1898, downgraded to synonym of Nesaecrepida asphalt ina (Suffrian, 1868); Cryptocephalus reinhardi Sundman, 1965, downgraded to synonym of Cryptocephalus nwtabilis Melsheimer, 1847. The tribes Chalepini Wiese, 1910, and Uroplatini Weise, 1910 (Hispinae), are synonymized, and both of these family-group names are recognized as nomina protecta. The family-group name Octotomites Chapuis, 1875, is recognized as a nomen oblitum. Coptocycla testudinaria Boheman, 1855, is downgraded from specific status to a subspecies of Plagiometriona clauata (Fabricius, 1798); Cassida bicolor (Fabricius, 1798) is recognized as a valid subspecies of Charidotellasexpunctata (Fabricius). The genus Hemiphrynus Horn, 1889, is removed from synonymy with Phrynocepha and reinstated as a valid genus; Rhabdopterus weisei (Schaeffer, 1920) is removed from synonymy with Rhabdopterus praetextus (Say) and reinstated as a valid species. The following new combinations are proposed: Synetocephalus wallacei (Wilcox, 1965), transferred from Pseudoluperus; Nesaecrepida infuscata (Schaeffer, 1906), transferred from Monomacra; Acallepitrix nitens (Horn, 1889), transferred from Epitrix; Margaridisa atriuentris (Melsheimer, 1847), transferred from Hornaltica; Parchicola iris (Olivier, 1808) and P. tibialis (Olivier, 1808), transferred from Monomacra; and Coleothorpa panochensis (Gilbert, 1981), transferred from Coscinoptera; Promecosoma arizonae (Crotch, 1873), transferred from Metaxyonycha; Tymnes chrysis (Olivier, 1808), T. oregonensis (Crotch, 1873), and T. thaleia (Blake, 1977), transferred from Colaspis. The following new replacement name is proposed: Triarius nigroflaulls, for Luperodes flauoniger Blake, 1942 (not Laboissiere, 1925). The identities of Griburius equestris (Olivier, 1808) and G. laruatlls (Newman, 1840) are discussed
An Evidence Based Time-Frequency Search Method for Gravitational Waves from Pulsar Glitches
We review and expand on a Bayesian model selection technique for the
detection of gravitational waves from neutron star ring-downs associated with
pulsar glitches. The algorithm works with power spectral densities constructed
from overlapping time segments of gravitational wave data. Consequently, the
original approach was at risk of falsely identifying multiple signals where
only one signal was present in the data. We introduce an extension to the
algorithm which uses posterior information on the frequency content of detected
signals to cluster events together. The requirement that we have just one
detection per signal is now met with the additional bonus that the belief in
the presence of a signal is boosted by incorporating information from adjacent
time segments.Comment: 6 pages, 4 figures, submitted to AMALDI 7 proceeding
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