Misc. Pub. 85-4

Paper copies in Archives, Acc #:2013-0059Soils have been surveyed in various parts of Alaska to meet resource -development needs since territorial days. These surveys have been conducted and published by the National Cooperative Soil Survey since 1952 and are a joint effort of the United States Department of Agriculture Soil Conservation Service and the Alaska Agricultural Experiment Station. Initially, government agencies were the major users of such soil surveys because land ownership was controlled almost entirely by government agencies. However, the demand for soils and geographic information increased substantially as population increased and urban areas grew following the discovery of oil on the Kenai Peninsula during the 1950s and on the North Slope in the late 1960s. Interest also heightened when the state gained titles to a large portion of land following statehood in 1959. The National Cooperative Soil Survey (NCSS) published many soil surveys for areas of intensive land use or potential land development. These soil surveys often are underutilized or misused. This publication, "Soil Survey and Its Use in Alaska," was developed over three years based on my field reviews of NCSS activities in Alaska as well as on my discussions with users of soil surveys regarding questions and problems arising from using the reports. In this publication, soil surveys and their use in Alaska are reviewed and discussed.Preface -- Introduction: What is Soil? Early Works, Current Status, Table 1: Status of National Cooperative Soil Survey (NCSS) in Alaska (Dec. 1984), National Cooperative Soil Survey -- How Soil Surveys are Made -- How Soils are Classified and Named: Soil Classification, Map Units -- The Use of Soil Survey: Soil: A Valuable Resources, General Resource Planning, Regional Land-Use or Watershed Planning, Community Planning, Agricultural Development, Engineering Interpretation, Environmental Protection, Recreation and Wildlife Management, Other Potential Uses in Alaska -- Problems and Questions About Soil Surveys: Map Scale and Order of Survey, Map Unit Inclusion, Table 2: General guidelines for identifying intensity of soil surveys, Land Capability Classification, Misuse of Soil Surveys, Over-Interpretation of Soil Surveys, Automated Data-Processing in Soil Survey, Taxonomic Unit vx. Map Unit, Soil Survey Report Format, Soil Mapping on the Arctic Slope -- Future Challenges of NCSS in Alaska -- Conclusions -- Reference

Trajectory optimization for the National Aerospace Plane

The primary objective of this research is to develop an efficient and robust trajectory optimization tool for the optimal ascent problem of the National Aerospace Plane (NASP). This report is organized in the following order to summarize the complete work: Section two states the formulation and models of the trajectory optimization problem. An inverse dynamics approach to the problem is introduced in Section three. Optimal trajectories corresponding to various conditions and performance parameters are presented in Section four. A midcourse nonlinear feedback controller is developed in Section five. Section six demonstrates the performance of the inverse dynamics approach and midcourse controller during disturbances. Section seven discusses rocket assisted ascent which may be beneficial when orbital altitude is high. Finally, Section eight recommends areas of future research

Analytical solutions to constrained hypersonic flight trajectories

The flight trajectory of aerospace vehicles subject to a class of path constraints is considered. The constrained dynamics is shown to be a natural two-time-scale system. Asymptotic analytical solutions are obtained. Problems of trajectory optimization and guidance can be dramatically simplified with these solutions. Applications in trajectory design for an aerospace plane strongly support the theoretical development

Gutzwiller Approximation in Degenerate Hubbard Models

Degenerate Hubbard models are studied using the Generalized-Gutzwiller-Approximation. It is found that the metal-insulator transition occurs at a finite correlation $U_c$ when the average number of electrons per lattice site is an integer. The critical $U_c$ depends sensitively on both the band degeneracy $N$ and the filling $x$. A derivation is presented for the general expression of $U_c(x,N)$ which reproduces all previously known Gutzwiller solutions, including that of the Boson Hubbard model. Effects of the lattice structure on the metal-insulator transition and the effective mass are discussed.Comment: RevTex file with 2 figures included, 12 page

An inverse dynamics approach to trajectory optimization for an aerospace plane

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