1,315 research outputs found
Letter from Joseph Swift to Alden Partridge, 11 September 1813
No full textAlthough Partridge had been appointed Professor of Engineering, Swift prefers he continue in his role as Professor of Mathematics until the Spring and the arrival of Andrew Ellicott.Transcription by Cameron Myette and Alison Horner. Transcriptions are subject to human error
Description of West Point cadet uniform, 20 June 1813
No full textProvides sketch and description of cadet uniform approved by Swift and the Secretary of War.Transcription by Cameron Myette and Alison Horner. Transcriptions are subject to human error
Letter from Joseph Swift to Alden Partridge, 21 November 1812.
No full textWishes Alden Partridge to contract with workmen on materials and labor for erecting buildings at West Point.Transcription by Cameron Myette and Alison Horner. Transcriptions are subject to human error
Correlated X-ray/ultraviolet/optical variability in the very low mass AGN NGC 4395
No full textWe report the results of a 1-yr Swift X-ray/ultraviolet (UV)/optical programme monitoring the dwarf Seyfert nucleus in NGC4395 in 2008-2009. The UV/optical flux from the nucleus was found to vary dramatically over the monitoring period, with a similar pattern of variation in each of the observed UV/optical bands (spanning 1900-5500 Å). In particular, the luminosity of NGC4395 in the 1900 Å band changed by more than a factor of 8 over the monitoring period. The fractional variability was smaller in the UV/optical bands than that seen in the X-rays, with the X-ray/optical ratio increasing with increasing flux. Pseudo-instantaneous flux measurements in the X-ray and each UV/optical band were well correlated, with cross-correlation coefficients of ≥0.7, significant at 99.9per cent confidence. Archival Swift observations from 2006 sample the intra-day X-ray/optical variability on NGC4395. These archival data show a very strong correlation between the X-ray and b bands, with a cross-correlation coefficient of 0.84 (significant at >99per cent confidence). The peak in the cross-correlation function is marginally resolved and asymmetric, suggesting that X-rays lead the b band, but by ≤1h. In response to recent (2011 August) very high X-ray flux levels from NGC4395 we triggered Swift target of opportunity observations, which sample the intra-hour X-ray/UV variability. These observations indicate, albeit with large uncertainties, a lag of the 1900 Å band behind the X-ray flux of ∼400s. The tight correlation between the X-ray and UV/optical lightcurves, together with the constraints we place on the lag time-scale, is consistent with the UV/optical variability of NGC4395 being primarily due to reprocessing of X-ray photons by the accretion disc
Distribution and evolution of starspots on the RS CVn binary II Pegasi in 2004
No full textThis work is supported by National Natural Science Foundation of China through grants Nos. 10373023, 10773027 and 11333006, Chinese Academy of Sciences through project KJCX2-YW-T24.We present Doppler images of RS CVn-type binary II Peg based on two data sets obtained in 2004 February and November. In order to improve signal-to-noise ratio and reliability,we apply least-squares deconvolution technique to calculate average profiles from 2032 photospheric absorption lines. Both of the resulting surface images show a wide latitude distribution of starspots. Most spots are concentrated at a high-latitude belt above 60° and a low-latitude belt near equator. The starspots evolved dramatically between two observing runs, which may indicate shorter time-scale evolution in this epoch, especially for low-latitude belt. There is no stable preferred active longitude that can be found in our images. We also find out a possible phenomenon that the intermediate-latitude spot migrated poleward and merged with the high-latitude spot to make it stronger, which may reveal a more complex behaviour of starspots on II Peg. A potential change of orbital ephemeris zero-point was detected. This may imply an orbital period change of II Peg like other active close binaries.Peer reviewe
Preparation and crystal structure of 3-(1-naphthylmethyl)-3-chlorodiazirine
No full textPT: J; CR: 1974, INT TABLES XRAY CRYS, V4 BATTAGLIA R, 1980, Z NATURFORSCH B, V35, P719 CAMERON TS, 1979, ACTA CRYSTALLOGR B, V35, P749 GERMAIN G, 1971, ACTA CRYSTALLOGR A, V27, P368 GRAHAM WH, 1965, J AM CHEM SOC, V87, P4396 HEINE HW, 1983, SMALL RING HETEROCYC, V2, P547 HENCHER JL, 1967, J AM CHEM SOC, V89, P5527 KISCH H, 1987, CHEM DIAZIRINES, CH10 LIU MTH, 1982, CHEM SOC REV, V11, P127 MOFFAT JB, 1978, CHEM DIAZONIUM DIA 1 PIERCE L, 1962, J AM CHEM SOC, V84, P2651 SCHARPEN LH, 1969, J CHEM PHYS, V50, P2063 SCHMITZ E, 1979, ADV HETEROCYCL CHEM, V24, P63 SHELDRICK GM, 1976, SHELX 76 PROGRAM CRY WOLLRAB JE, 1968, J CHEM PHYS, V49, P2405 WOLLRAB JE, 1969, J CHEM PHYS, V51, P1585 WOLLRAB JE, 1970, J CHEM PHYS, V53, P1543; NR: 17; TC: 11; J9: J ORG CHEM; PG: 3; GA: M3719Source type: Electronic(1
Long-term wind-driven X-ray spectral variability of NGC 1365 with Swift
No full textWe present long-term (months–years) X-ray spectral variability of the Seyfert 1.8 galaxy NGC 1365 as observed by Swift, which provides well-sampled observations over a much longer time-scale (six years) and a much larger flux range than is afforded by other observatories. At very low luminosities, the spectrum is very soft, becoming rapidly harder as the luminosity increases and then, above a particular luminosity, softening again. At a given flux level, the scatter in hardness ratio is not very large, meaning that the spectral shape is largely determined by the luminosity. The spectra were therefore summed in luminosity bins and fitted with a variety of models. The best-fitting model consists of two power laws, one unabsorbed and another, more luminous, which is absorbed. In this model, we find a range of intrinsic 0.5–10.0 keV luminosities of approximately 1.1–3.5 erg s?1, and a very large range of absorbing columns, of approximately 1022–1024 cm?2. Interestingly, we find that the absorbing column decreases with increasing luminosity, but that this result is not due to changes in ionization. We suggest that these observations might be interpreted in terms of a wind model in which the launch radius varies as a function of ionizing flux and disc temperature and therefore moves out with increasing accretion rate, i.e. increasing X-ray luminosity. Thus, depending on the inclination angle of the disc relative to the observer, the absorbing column may decrease as the accretion rate goes up. The weaker, unabsorbed, component may be a scattered component from the wind
Prevention and management of falls: falling into place?
No full text This article considers the broad international status of falls prevention research and evidence-based guidance, and highlights the apparent discrepancy between information and implementation, with an emphasis on the need for delivery systems. The case is made for the dissemination of a broader concept of the phenomenon of age-associated falls, for its outworking in the resolution of outstanding research topics and, in particular, for the achievement of a robust, networked, economical service delivery model to drive standards forward. The current window of opportunity for progress in falls prevention may prove crucial to the future of cost–effective healthcare in the context of demographic change. </jats:p
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