Algebraic Monte Carlo precedure reduces statistical analysis time and cost factors

Algebraic Monte Carlo procedure statistically analyzes performance parameters in large, complex systems. The individual effects of input variables can be isolated and individual input statistics can be changed without having to repeat the entire analysis

Commercialization of the land remote sensing system: An examination of mechanisms and issues

In September 1982 the Secretary of Commerce was authorized (by Title II of H.R. 5890 of the 97th Congress) to plan and provide for the management and operation of the civil land remote sensing satellite systems, to provide for user fees, and to plan for the transfer of the ownership and operation of future civil operational land remote sensing satellite systems to the private sector. As part of the planning for transfer, a number of approaches were to be compared including wholly private ownership and operation of the system by an entity competitively selected, mixed government/private ownership and operation, and a legislatively-chartered privately-owned corporation. The results of an analysis and comparison of a limited number of financial and organizational approaches for either transfer of the ownership and operation of the civil operational land remote sensing program to the private sector or government retention are presented

File Editing on the HP3000 for the SEDIMOT II Computer Model

Since the release of the SEDIMOT II model, the Agricultural Engineering Department has taught approximately 300 consulting and mining engineers, reclamation specialists, government agency personnel, and academia. The program is being used on all types of computer systems, company owned as well as time sharing vendors. Over 50 firms are using the HP3000 system of the College of Agriculture at the University of Kentucky under arrangements with the Institute for Mining and Minerals Research, Office of Informational Services and Technical Liaison

Global Positioning System Applications

The space-based Navstar Global Positioning System (GPS), which is scheduled to achieve full operational status by late 1988, will consist of 18 active satellites placed around six orbital rings at 10,898 nautical miles above the earth. Every other ring will contain an extra satellite that will function as an active on-orbit spare. This regular and precise constellation of GPS satellites will provide continuous, three-dimensional global navigation coverage to users worldwide. Average positioning accuracies of 15 meters or less are anticipated by the military. This extraordinary precision has been demonstrated repeatedly under field-test conditions in both the United States and Western Europe. Other tests indicate that relative (differential) navigation, which employs user sets rigged to communicate their navigation solution to one another, can achieve substantially better results. Relative errors of only 1 or 2 meters have been demonstrated with existing equipment under realistic field-test conditions

Field Method for Measuring Mobile/Immobile Water Content and Solute Transfer Rate Coefficient

Numerous field and laboratory studies have documented the occurrence of preferential transport of solutes due to a fraction of the soil water being immobile and not taking part in the transport process. Domain models have been developed that describe these processes, but before we can apply them routinely, we need methods for measuring the required model parameters, particularly the fraction of immobile water to total water θlm/θ and the exchange coefficient between the mobile and immobile domains, α. We developed a field method for measuring both θlm/θ and α. The method uses a sequence of conservative anionic tracers consisting of Br−, pentafluorobenzoate, o-trifluoromethylbenzoate, and 2,6-difluorobenzoate infiltrated with time through a tension infiltrometer. Previous studies have confirmed that these tracers have very similar transport properties in a wide range of soils. The method was applied to an undisturbed loam and a greenhouse soil as an initial test of the approach. Calculated θim/θ fractions averaged 0.69 and ranged from 0.25 to 0.98, while calculated α values averaged 0.0081 h−1 and ranged from 0.0030 to 0.021 h−1. These values compare well with values reported earlier by other investigators. The method is simple and allows routine measurement of transport properties of field soils. The method can also be used to validate the applicability of domain models to specific soils

Immobile Water Content and Mass Exchange Coefficient of a Field Soil

Determining the preferential flow characteristics of a soil is important because agrichemicals can contaminate groundwater via preferential flow pathways. A model that predicts solute transport due to preferential flow is the mobile-immobile solute transport model, which partitions the total water content (θ, m3 m−3) into a mobile fraction (θm) and an immobile fraction (θim). Recently, an in situ method was proposed for determining the mobile-immobile model parameters of θim and mass exchange coefficient (α) between the fractions by using a tension infiltrometer to apply a series of four fluorobenzoate tracers. The objective of this study was to test the in situ technique at 47 sites along a transect in a ridge-till corn (Zea mays L.) field of Nicollet soil (fine-loamy, mixed, mesic Aquic Hapludoll). The immobile fraction (θim /θ) ranged from 0.394 to 0.952 with a median of 0.622. The mass exchange coefficient ranged from 0.000237 to 0.00481 min−1 with a median of 0.00123 min−1. These values are similar in magnitude and range to values reported by other investigators, and they follow the same relationships. The values of θim/θ and α along the transect indicated no obvious spatial trends or spatial correlations. Significant linear correlations did exist between α and soil water flux, α and θim, and θ and θim

Shear History Extensional Rheology Experiment: A Proposed ISS Experiment

The Shear History Extensional Rheology Experiment (SHERE) is a proposed International Space Station (ISS) glovebox experiment designed to study the effect of preshear on the transient evolution of the microstructure and viscoelastic tensile stresses for monodisperse dilute polymer solutions. Collectively referred to as Boger fluids, these polymer solutions have become a popular choice for rheological studies of non-Newtonian fluids and are the non-Newtonian fluid used in this experiment. The SHERE hardware consists of the Rheometer, Camera Arm, Interface Box, Cabling, Keyboard, Tool Box, Fluid Modules, and Stowage Tray. Each component will be described in detail in this paper. In the area of space exploration, the development of in-situ fabrication and repair technology represents a critical element in evolution of autonomous exploration capability. SHERE has the capability to provide data for engineering design tools needed for polymer parts manufacturing systems to ensure their rheological properties have not been impacted in the variable gravity environment and this will be briefly addressed