1,851 research outputs found
Whole body measurement systems
A system for measuring the volume and volume variations of a human body under zero gravity conditions is disclosed. An enclosed chamber having a defined volume and arranged for receiving a human body is provided with means for infrasonically varying the volume of the chamber. The changes in volume produce resultant changes in pressure, and under substantially isentropic conditions, an isentropic relationship permits a determination of gas volume which, in turn, when related to total chamber volume permits a determination of the body volume. By comparison techniques, volume changes of a human independent of gravity conditions can be determined
An extended XMM-Newton observation of the Seyfert galaxy NGC 4051. II. Soft X-ray emission from a limb-brightened shell of post-shock gas
An extended XMM-Newton observation of the Seyfert I galaxy NGC 4051 in 2009
revealed a complex absorption spectrum, with a wide range of outflow velocities
and ionisation states.The main velocity and ionisation structure was
interpreted in Paper I in terms of a decelerating, recombining flow resulting
from the shocking of a still higher velocity wind colliding with the ISM or
slower moving ejecta. The high sensitivity of the XMM-Newton observation also
revealed a number of broad emission lines, all showing evidence of
self-absorption near the line cores. The line profiles are found here to be
consistent with emission from a limb-brightened shell of post-shock gas
building up ahead of the contact discontinuity. While the broad emission lines
remain quasi-constant as the continuum flux changes by an order of magnitude,
recombination continua of several H- and He-like ions are found to vary in
response to the continuum, providing an important key to scaling the ionised
flow.Comment: Accepted for publication in MNRA
Historical review of financial equity in Missouri : 1993 foundation formula and amendments
The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file.Title from title screen of research.pdf file (viewed on December 12, 2007)Vita.Thesis (Ed. D.) University of Missouri-Columbia 2007.Outstanding Schools Act (OSA) Foundation Funding Formula and subsequent revisions on the equity of statewide educational funding. This research considered the revenue per student per penny of property tax levy, the revenue per student, and the legislative decision to guarantee a minimum (hold harmless) payment per student to analyze whether funding for Missouri public schools was more equitable than the pre-1993 OSA formula. Specific fiscal years from 1998-99 through 2005-06 were selected for analysis. The horizontal equity statistics of coefficient of variation, federal range ratio, and McLoone Index were calculated and tracked for the selected years. These measures were applied to the data for all districts and to the data for non-hold harmless districts. The results of this study were compared to the pre-OSA (1992-93) statistics reported in the 1999 Missouri Department of Elementary and Secondary Education study. Data for all years selected compared to the pre-OSA year of 1992-93 showed improved equity for all districts and for non-hold harmless districts on both the revenue per student per penny of tax rate basis and on a revenue per student basis using the coefficient of variation and the federal range ratio. All years, except 2005-06, showed improved equity using the McLoone Index. All statistics analyzed demonstrated dramatically greater improved equity for non-hold harmless districts than for all districts.Includes bibliographical reference
Quasar 3C 298: a test-case for meteoritic nanodiamond 3.5 µm emission
Aims. We calculate the dust emission expected at 3.43 and 3.53 µm if meteoritic (i.e. hydrogenated) nanodiamonds are responsible for most of the far-UV break observed in quasars.
Methods. We integrate the UV flux that hydrogenated nanodiamonds must absorb to reproduce the far-UV break. Based on laboratory spectra of H-terminated diamond surfaces, we analyse the radiative energy budget and derive theoretically the IR emission profiles expected for possible C-H surface stretch modes of the diamonds.
Results. Using as test case a spectrum of 3C 298 provided by the Spitzer Observatory, we do not find evidence of these emission bands.
Conclusions. While diamonds without surface adsorbates remain a viable candidate for explaining the far-UV break observed in quasars, hydrogenated nanodiamonds appear to be ruled out, as they would give rise to IR emission bands, which have not been observed so far
Nitrous oxide emissions from 2008 to 2012 for agricultural lands in the conterminous United States
The soil N2O emissions data for the conterminous United States were generated by the DayCent ecosystem model using the crop and land-use histories for survey locations in the USDA-NRCS National Resources Inventory (NRI). The model also requires weather and soils data. Daily maximum/minimum temperature and precipitation data are based on gridded weather data from the PRISM Climate Data product. Soils data are obtained from Soil Survey Geographic Database (SSURGO). See Del Grosso et al. (2022) and US-EPA (2020) for more details about the simulations. Atmospheric inversions were conducted using the CarbonTracker Langrage framework (Nevison et al. 2018). These results provide total N2O fluxes for the domain using atmospheric observations and an inverse modeling, and are compared to the DayCent emissions to confirm seasonal patterns, particularly the role of freeze-thaw events in driving pulses of N2O emissions from agricultural lands.Nitrous oxide (N2O) is an important greenhouse gas (GHG) that also contributes to depletion of ozone in the stratosphere. Agricultural soils account for about 60% of anthropogenic N2O emissions. Most national GHG reporting to the UN Framework Convention on Climate Change assumes nitrogen (N) additions drive emissions during the growing season, but soil freezing and thawing during spring is also an important driver in cold climates. We show that both atmospheric inversions and newly implemented bottom-up modeling approaches exhibit large N2O pulses in the northcentral region of the United States during early spring and this increases annual N2O emissions from croplands and grasslands reported in the national GHG inventory by 11%. Considering this, emission accounting in cold climate regions is very likely under-estimated in most national reporting frameworks. Current commitments related to the Paris Agreement and COP 26 emphasize reductions of carbon compounds. Assuming these targets are met, the importance of accurately accounting and mitigating N2O increases once CO2 and CH4 are phased out. Hence, the N2O emission under-estimate introduces additional risks into meeting long term climate goals.US Forest Service 18-CR-11242305-109, US Department of Agriculture (USDA) UV-B Monitoring and Research Program, Colorado State University, under USDA National Institute of Food and Agriculture Grant 2016-34263-25763, and the USDA GHG and DayCent modeling NACA agreements (58-3012-9-012 and 58-3012-1-015
Studying Conceptual Models for Publishing Library Data to the Semantic Web
This thesis studies the library data and the way that linked data technologies may affect libraries. The thesis aims to contribute to the research regarding the devel-opment and implementation of a framework for the integration of bibliographic data in the semantic web. It seeks to make sound propositions for the interopera-bility of conceptual bibliographic models, as well as for future library systems and search environments integrating bibliographic information
Chandra Observations of the X-ray Narrow-Line Region in NGC 4151
We present the first high-resolution X-ray spectrum of the Seyfert 1.5 galaxy
NGC 4151. Observations with the Chandra High Energy Transmission Grating
Spectrometer reveal a spectrum dominated by narrow emission lines from a
spatially resolved (1.6 kpc), highly ionized nebula. The X-ray narrow-line
region is composite, consisting of both photoionized and collisionally ionized
components. The X-ray emission lines have similar velocities, widths, and
spatial extent to the optical emission lines, showing that they arise in the
same region. The clouds in the narrow-line region must contain a large range of
ionization states in order to explain both the optical and X-ray photoionized
emission. Chandra data give the first direct evidence of X-ray line emission
from a hot plasma (T~1e7 K) which may provide pressure confinement for the
cooler (T=3e4 K) photoionized clouds.Comment: 13 pages, 3 figures, to be published in Astrophysical Journal Letter
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