12,258 research outputs found
Epilogue
Factors that may have been decisive in turning Rancho Santa Ana Botanic Garden into a successful establishment of botanical teaching and a garden devoted to the conservation and showcasing of the native California flora are put forward. In addition to the enthusiasm and tenacity of its founder, Susanna Bixby Bryant, inspiration and advice came from several other key figures, notably Carl Brandt Wolf, Ernest Braunton, Willis Linn Jepson, and Theodore Payne
Time Series Analysis in Flight Flutter Testing at the Air Force Flight Test Center: Concepts and Results
The Air Force Flight Test Center (AFFTC) flight flutter facility is described. Concepts of using a minicomputer-based time series analyzer and a modal analysis software package for flight flutter testing are examined. The results of several evaluations of the software package are given. The reasons for employing a minimum phase concept in analyzing response only signals are discussed. The use of a Laplace algorithm is shown to be effective for the modal analysis of time histories in flutter testing. Sample results from models and flight tests are provided. The limitations inherent in time series analysis methods are discussed, and the need for effective noise reduction techniques is noted. The use of digital time series analysis techniques in flutter testing is shown to be fast, accurate, and cost effective
Second constant of motion for two-dimensional positronium in a magnetic field
Recent numerical work indicates that the classical motion of positronium in a
constant magnetic field does not exhibit chaotic behavior if the system is
confined to two dimensions. One would therefore expect this system to possess a
second constant of the motion in addition to the total energy. In this paper we
construct a generalization of the Laplace-Runge-Lenz vector and show that a
component of this vector is a constant of the motion.Comment: 4 pages, no figure
The Years 1960–1977
In the years 1960–1977, Rancho Santa Ana Botanic Garden fully embraces its role as teaching institution and as advocate and guardian of the native California flora. Expansion of the living collection, landscaping of the grounds, public education, herbarium and library activities, and publication output are detailed. To accommodate a growing number of graduate students, the faculty—consisting of Richard K. Benjamin, Sherwin Carlquist, and Lee. W. Lenz—is joined by Peter H. Raven, Ronald Scogin, John P. Simon, and Robert F. Thorne
In the Beginning
This article traces the early history of Rancho Santa Ana Botanic Garden, California, starting ca. 1867 with the PortolĂ Expedition. The expedition was the first to record the site where the botanic garden later came to be located, in Santa Ana Canyon, northeastern Orange County. Successive changes in land ownership eventually led to the Bixby family purchasing the land in 1875. Susanna Bixby Bryant, the founder of Rancho Santa Ana Botanic Garden, acquired the land in 1925
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