Enhanced soils information systems from advances in computer technology

Information is being requested with increasing frequency for location, quality, and quantity of soil properties, processes and interactions with various natural resources.

Advancements in computer technology such as increased storage capabilities, faster processing speeds, improved database management systems, geographic information systems, and telecommunications have made it possible to provide more information in a more timely manner, and in formats better suited to user needs.

These advancements also make it possible for the National Cooperative Soil Survey (NCSS) program to continue evolving in the scientific pursuit of understanding and communicating soil-landscape relationships and their interpretations.

In an effort to take advantage of the advances in technologies, and to better respond to increased user needs, the United States Department of Agriculture Soil Conservation Service (SCS) is developing a new National Soil Information System (NASIS).

NASIS is intended to provide a number of new capabilities for the users of the system. Among these capabilities are the maintenance of individual observation data within the system and the capability to relate these individual observations and spatial variability of soil properties to individual delineated areas on soil maps. NASIS will also provide for the interpretation of individual components of map units as well as what were formerly included soils within the map units.

With increases in capabilities coupled with increases in user needs for soil information, the NCSS has the opportunity as well as the responsibility to continually review practices, procedures and concepts in light of new technologies to assure that they are not based on prior constraints that these new technologies may have erased.     

The percolation phase transition in sea Ice

Sea ice exhibits a marked transition in its fluid transport properties at a critical brine volume fraction pc of about 5 percent, or temperature Tc of about -5 degreesC for salinity of 5 parts per thousand. For temperatures warmer than Tc, brine carrying heat and nutrients can move through the ice, whereas for colder temperatures the ice is impermeable. This transition plays a key role in the geophysics, biology, and remote sensing of sea ice. Percolation theory can be used to understand this critical behavior of transport in sea ice. The similarity of sea ice microstructure to compressed powders is used to theoretically predict pc of about 5 percent.     

X-ray Absorption Spectroscopic Investigation of Sulfur Sites in Coal: Organic Sulfur Identification

High-resolution x-ray absorption spectroscopy was used to probe the chemical and structural environments of sulfur in coal. Measurement of the sulfur Kedge spectra down to 2472.0 electron volts under nonvacuum conditions was made possible in an all-helium path, and a Stern-Heald type ion chamber was used for fluorescence detection. For a number of selected sulfur-containing minerals and organic model compounds, results show that near-edge spectral features are diagnostic for sulfur in specific organic moieties such as thiols, disulfides, and various heterocyclics, as well as in mineral sulfide and sulfate phases. The spectrum of a model system containing 35 percent iron pyrite and 65 percent benzothiophene was found to match the observed spectral features of a bituminous coal from the eastern United States.