4,183 research outputs found
Applications systems verification and transfer project. Volume 4: Operational applications of satellite snow cover observations. Colorado Field Test Center
The study was conducted on six watersheds ranging in size from 277 km to 3460 km in the Rio Grande and Arkansas River basins of southwestern Colorado. Six years of satellite data in the period 1973-78 were analyzed and snowcover maps prepared for all available image dates. Seven snowmapping techniques were explored; the photointerpretative method was selected as the most accurate. Three schemes to forecast snowmelt runoff employing satellite snowcover observations were investigated. They included a conceptual hydrologic model, a statistical model, and a graphical method. A reduction of 10% in the current average forecast error is estimated when snowcover data in snowmelt runoff forecasting is shown to be extremely promising. Inability to obtain repetitive coverage due to the 18 day cycle of LANDSAT, the occurrence of cloud cover and slow image delivery are obstacles to the immediate implementation of satellite derived snowcover in operational streamflow forecasting programs
Sunflower Seeds in Rations for Beef Cattle
In 1981, North Dakota was the US leader in sunflower seed production. Prior research on sunflower seeds did not indicate the nutritional value of hybrid flowers with oil content. The article covers three trials. Steers that received sunflowers gained weight more quickly. Their coats were richer and fuller. However, there is a cap of 1 pond of oil seeds per day without inferring with their digestive systems. Those heifers fed three pounds of sunflower seed never consumed as much feed. It was concluded that sunflowers should be fed as an energy supplement rather than a protein supplement. While high in protein, high oil sunflower seeds were a poor protein supplement for cattle
Library Design in Combinatorial Chemistry by Monte Carlo Methods
Strategies for searching the space of variables in combinatorial chemistry
experiments are presented, and a random energy model of combinatorial chemistry
experiments is introduced. The search strategies, derived by analogy with the
computer modeling technique of Monte Carlo, effectively search the variable
space even in combinatorial chemistry experiments of modest size. Efficient
implementations of the library design and redesign strategies are feasible with
current experimental capabilities.Comment: 5 pages, 3 figure
The IRAS bright galaxy sample. II - The sample and luminosity function
A complete sample of 324 extragalactic objects with 60 μm flux densities greater than 5.4 Jy has been selected from the IRAS catalogs. Only one of these objects can be classified morphologically as a Seyfert nucleus; the others are all galaxies. The median distance of the galaxies in the sample is ~ 30 Mpc, and the median luminosity vL,(60 μm) is ~ 2 x 10^(10) L_☉ . This infrared selected sample is much more "infrared active" than optically selected galaxy samples. The range in far-infrared luminosities of the galaxies in the sample is 10^8 L_☉ -2 x 10^(12) L_☉ The far-infrared luminosities of the sample galaxies appear to be independent of the optical luminosities, suggesting a separate luminosity component. As previously found, a correlation exists between 60 μm/100 μm flux density ratio and
far-infrared luminosity. The mass of interstellar dust required to produce the far-infrared radiation corresponds to a mass of gas of 108-10^(10) M_☉ for normal gas to dust ratios. This is comparable to the mass of the interstellar medium in most galaxies. The infrared luminous galaxies are found to be an important component of extraglactic objects, being the
most numerous objects in the local universe at luminosities L > 10^(11) L_☉, and producing a luminosity density of ~ that of the observed starlight in normal galaxies. Approximately 60%-80% of the far-infrared luminosity of the local universe is likely attributed to recent or ongoing star formation. If the infrared active phase (L_(FIR) > 10^(11) L_☉ ) is a nonrecurring event of duration less than 108 yr in galaxy evolution, then more than
10%, and perhaps all of the galaxies with blue luminosities greater than 10^(10) L_☉ must undergo such an event
Evaluation of the Global Multi-Resolution Terrain Elevation Data 2010 (GMTED2010) Using ICESat Geodetic Control
Supported by NASA's Earth Surface and Interior (ESI) Program, we are producing a global set of Ground Control Points (GCPs) derived from the Ice, Cloud and land Elevation Satellite (ICESat) altimetry data. From February of 2003, to October of 2009, ICESat obtained nearly global measurements of land topography (+/- 86deg latitudes) with unprecedented accuracy, sampling the Earth's surface at discrete approx.50 m diameter laser footprints spaced 170 m along the altimetry profiles. We apply stringent editing to select the highest quality elevations, and use these GCPs to characterize and quantify spatially varying elevation biases in Digital Elevation Models (DEMs). In this paper, we present an evaluation of the soon to be released Global Multi-resolution Terrain Elevation Data 2010 (GMTED2010). Elevation biases and error statistics have been analyzed as a function of land cover and relief. The GMTED2010 products are a large improvement over previous sources of elevation data at comparable resolutions. RMSEs for all products and terrain conditions are below 7 m and typically are about 4 m. The GMTED2010 products are biased upward with respect to the ICESat GCPs on average by approximately 3 m
The luminosity function and space density of the most luminous galaxies in the IRAS survey
The local space density of galaxies with 60 μm luminosity greater than VL_v (60 μm) ≳ 10^(10) L_☉ is derived from a sample of bright galaxies detected in the IRAS survey. The sample is complete to 5 Jy at 60 μm and covers one-quarter of the sky. With a maximum redshift in the sample of 0.081, this sample represents a survey of the infrared characteristics for infrared bright galaxies in the local universe. The space density is described by p(L) ≈ 1.7 X 10^(-3) (L/10^(10) L_☉)-2 Mpc^(-3) over the range 10^(10) L_☉ 10^(10) L_☉ undergo a period of extreme infrared activity
Web Site Metadata
The currently established formats for how a Web site can publish metadata about a site's pages, the robots.txt file and sitemaps, focus on how to provide information to crawlers about where to not go and where to go on a site. This is sufficient as input for crawlers, but does not allow Web sites to publish richer metadata about their site's structure, such as the navigational structure. This paper looks at the availability of Web site metadata on today's Web in terms of available information resources and quantitative aspects of their contents. Such an analysis of the available Web site metadata not only makes it easier to understand what data is available today; it also serves as the foundation for investigating what kind of information retrieval processes could be driven by that data, and what additional data could be provided by Web sites if they had richer data formats to publish metadata
- …