1,315 research outputs found
A General Formula for Black Hole Gravitational Wave Kicks
Although the gravitational wave kick velocity in the orbital plane of
coalescing black holes has been understood for some time, apparently
conflicting formulae have been proposed for the dominant out-of-plane kick,
each a good fit to different data sets. This is important to resolve because it
is only the out-of-plane kicks that can reach more than 500 km/s and can thus
eject merged remnants from galaxies. Using a different ansatz for the
out-of-plane kick, we show that we can fit almost all existing data to better
than 5 %. This is good enough for any astrophysical calculation, and shows that
the previous apparent conflict was only because the two data sets explored
different aspects of the kick parameter space.Comment: 14 pages
Fertilizer inspection, analysis and use, 1942
Cover title.Includes bibliographical references
3C236: Radio Source, Interrupted?
We present new HST STIS/MAMA near-UV images and archival WFPC2 V and R band
images which reveal the presence of four star forming regions in an arc along
the edge of the dust lane in the giant (4 Mpc) radio galaxy 3C236. Two of the
star forming regions are relatively young with ages of order 1E7 yr, while the
other two are older with ages of order 1E8 - 1E9 yr which is comparable to the
estimated age of the giant radio source. Based on dynamical and spectral aging
arguments, we suggest that the fuel supply to the AGN was interrupted for 1E7
yr and has now been restored, resulting in the formation of the inner 2 kpc
scale radio source. This time scale is similar to that of the age of the
youngest of the star forming regions. We suggest that the transport of gas in
the disk is non-steady and that this produces both the multiple episodes of
star formation in the disk as well as the multiple epochs of radio source
activity. If the inner radio source and the youngest star forming region are
related by the same event of gas transport, the gas must be transported from
the hundreds of pc scale to the sub-parsec scale on a time scale of 1E7 yr,
which is similar to the dynamical time scale of the gas on the hundreds of pc
scales
12.グルタミン酸ナトリウムはglucagon like peptide-1の食後早期の分泌を促進し, 食後血糖の上昇を抑制する
The purpose of this study was to compare the growth and nutritional status of infants fed different diets, some of whom received a low-fat formula. Beginning at four to six months of age, 101 infants were fed whole cow\u27s milk, one of two low-fat follow-up formulas, or a standard infant formula until 12 months of age. Weight, recumbent length, and head circumference were measured at one-month intervals. Analyses of status (values at an age) for all examinations showed no significant differences among the feeding groups in status for weight or recumbent length, but there were significant differences in head circumference for boys and for girls after adjustments for the initial values. Head circumferences were smaller in those fed whole cow\u27s milk and relatively large in those fed follow-up formula, but these differences were small and not of clinical significance. Comparisons with national reference data showed growth in weight, recumbent length, and head circumference was normal regardless of feeding group. These results indicate that, during the second half year of infancy, the use of lower fat concentrations in the follow-up formulas did not retard growth in weight, recumbent length, or head circumference
Automation-Induced Complacency Potential: Development and Validation of a New Scale
Complacency, or sub-optimal monitoring of automation performance, has been cited as a contributing factor in numerous major transportation and medical incidents. Researchers are working to identify individual differences that correlate with complacency as one strategy for preventing complacency-related accidents. Automation-induced complacency potential is an individual difference reflecting a general tendency to be complacent across a wide variety of situations which is similar to, but distinct from trust. Accurately assessing complacency potential may improve our ability to predict and prevent complacency in safety-critical occupations. Much past research has employed an existing measure of complacency potential. However, in the 25 years since that scale was published, our conceptual understanding of complacency itself has evolved, and we propose that an updated scale of complacency potential is needed. The goal of the present study was to develop, and provide initial validation evidence for, a new measure of automation-induced complacency potential that parallels the current conceptualization of complacency. In a sample of 475 online respondents, we tested 10 new items and found that they clustered into two separate scales: Alleviating Workload (which focuses on attitudes about the use of automation to ease workloads) and Monitoring (which focuses on attitudes toward monitoring of automation). Alleviating workload correlated moderately with the existing complacency potential rating scale, while monitoring did not. Further, both the alleviating workload and monitoring scales showed discriminant validity from the previous complacency potential scale and from similar constructs, such as propensity to trust. In an initial examination of criterion-related validity, only the monitoring-focused scale had a significant relationship with hypothetical complacency (r = -0.42, p < 0.01), and it had significant incremental validity over and above all other individual difference measures in the study. These results suggest that our new monitoring-related items have potential for use as a measure of automation-induced complacency potential and, compared with similar scales, this new measure may have unique value
Bostonia: The Boston University Alumni Magazine. Volume 18
Founded in 1900, Bostonia magazine is Boston University's main alumni publication, which covers alumni and student life, as well as university activities, events, and programs
Colour reconnection in e+e- -> W+W- at sqrt(s) = 189 - 209 GeV
The effects of the final state interaction phenomenon known as colour
reconnection are investigated at centre-of-mass energies in the range sqrt(s) ~
189-209 GeV using the OPAL detector at LEP. Colour reconnection is expected to
affect observables based on charged particles in hadronic decays of W+W-.
Measurements of inclusive charged particle multiplicities, and of their angular
distribution with respect to the four jet axes of the events, are used to test
models of colour reconnection. The data are found to exclude extreme scenarios
of the Sjostrand-Khoze Type I (SK-I) model and are compatible with other
models, both with and without colour reconnection effects. In the context of
the SK-I model, the best agreement with data is obtained for a reconnection
probability of 37%. Assuming no colour reconnection, the charged particle
multiplicity in hadronically decaying W bosons is measured to be (nqqch) =
19.38+-0.05(stat.)+-0.08 (syst.).Comment: 30 pages, 9 figures, Submitted to Euro. Phys. J.
Search for the Standard Model Higgs Boson with the OPAL Detector at LEP
This paper summarises the search for the Standard Model Higgs boson in e+e-
collisions at centre-of-mass energies up to 209 GeV performed by the OPAL
Collaboration at LEP. The consistency of the data with the background
hypothesis and various Higgs boson mass hypotheses is examined. No indication
of a signal is found in the data and a lower bound of 112.7GeV/C^2 is obtained
on the mass of the Standard Model Higgs boson at the 95% CL.Comment: 51 pages, 21 figure
Recommended from our members
Emission Control Research to Enable Fuel Efficiency: Department of Energy Heavy Vehicle Technologies
The Office of Heavy Vehicle Technologies supports research to enable high-efficiency diesel engines to meet future emissions regulations, thus clearing the way for their use in light trucks as well as continuing as the most efficient powerplant for freight-haulers. Compliance with Tier 2 rules and expected heavy duty engine standards will require effective exhaust emission controls (after-treatment) for diesels in these applications. DOE laboratories are working with industry to improve emission control technologies in projects ranging from application of new diagnostics for elucidating key mechanisms, to development and tests of prototype devices. This paper provides an overview of these R and D efforts, with examples of key findings and developments
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