FM/CW radar system

An FM/CW radar system is presented with improved noise discrimination in which the received signal is multiplied by a sample of the transmitted signal, and the product signal is employed to deflect a laser beam as a function of frequency. The position of the beam is thus indicative of a discrete frequency, and it is detected by the frequency encoded positions of an array of photodiodes. The outputs of the photodiodes are scanned, then threshold detected, and used to obtain the range and velocity of a target

1993 Grain Sorghum Performance Trials

Grain sorghum hybrids grown under 1993 environmental conditions are evaluated in this report. Tables include 1993 grain yields in pounds per acre adjusted to 14% moisture content, and 1992-93 2-year yield averages, test weight, and plant height. Results in this report were obtained from the Plant Science Department, Crop Performance Testing Program, Agricultural Experiment Station, South Dakota State University

1991 Grain Sorghum Performance Trials

The relative performance of grain sorghum hybrids grown under similar environmental conditions in 1991 is evaluated in this report. The accompanying tables include grain yields in pounds per acre, test weight, moisture percentages of threshed grain sorghum immediately after first frost, and other related information. Performance records of entries harvested in 1991 and available 2-year averages are also presented. The trials reported were conducted under the Plant Science Department programs in Crop Performance Testing, Agricultural Experiment Station, South Dakota State University

1992 Grain Sorghum Performance Trials

Grain sorghum hybrids grown under similar environmental conditions in 1992 are evaluated in this report. Tables include 1992 grain yields in pounds per acre adjusted to 14% moisture content, 1991-92 2-year yield averages, test weight, plant height, and stalk lodging score. Results in this report were obtained from the Plant Science Department Crop Performance Testing Program

Sunflowers in South Dakota

Domestic sunflower culture was established in the United States after 1880 following introduction of improved varieties that had been developed in Europe before 1600. The Indians in Virginia were using native variety sunflowers for food in 1586, and in New England sunflower oil was being used as a hair dressing in 1615. During the early 1900\u27s sunflowers were grown in the Northern Great Plains states and prairie provinces of Canada as a silage crop. Sunflowers as an oilseed crop have been grown commercially in Canada since 1943 and in Minnesota since 1947. Commercial birdfeed production in Minnesota began in 1952. Since then, 70% of the harvest has been utilized as bird feed, while 30% has been used for human consumption. Production for oil gained new interest in 1966 when varieties from Russia were introduced which ranged from 40% to 50% oil in their small, black, thin-hulled seed. Although sunflowers are adapted to most of the climates and cultivated soils of the United States and Canada, the risk of sunflower moth damage has limited the sunflower growing area to the Red River Valley and adjacent counties. However, the development of insecticides now permit the growing area to be expanded

The interface between the stellar wind and interstellar medium around R Cassiopeiae revealed by far-infrared imaging

The circumstellar dust shells of intermediate initial-mass (about 1 to 8 solar masses) evolved stars are generated by copious mass loss during the asymptotic giant branch phase. The density structure of their circumstellar shell is the direct evidence of mass loss processes, from which we can investigate the nature of mass loss. We used the AKARI Infrared Astronomy Satellite and the Spitzer Space Telescope to obtain the surface brightness maps of an evolved star R Cas at far-infrared wavelengths, since the temperature of dust decreases as the distance from the star increases and one needs to probe dust at lower temperatures, i.e., at longer wavelengths. The observed shell structure and the star's known proper motion suggest that the structure represents the interface regions between the dusty wind and the interstellar medium. The deconvolved structures are fitted with the analytic bow shock structure to determine the inclination angle of the bow shock cone. Our data show that (1) the bow shock cone of 1 - 5 x 10^-5 solar masses (dust mass) is inclined at 68 degrees with respect to the plane of the sky, and (2) the dust temperature in the bow shock cone is raised to more than 20 K by collisional shock interaction in addition to the ambient interstellar radiation field. By comparison between the apex vector of the bow shock and space motion vector of the star we infer that there is a flow of interstellar medium local to R Cas whose flow velocity is at least 55.6 km/s, consistent with an environment conducive to dust heating by shock interactions.Comment: 7 pages, 2 figures, accepted for publication in Astronomy and Astrophysic

Derivatives of 1-phenyl-3-methylpyrazol-2-in-5-thione and their oxygen analogues in the crystalline phase and their tautomeric transformations in solutions and in the gas phase

1-Phenyl-3-methylpyrazol-2-in-5-thione, crystallised from methanol, was shown to exist in the tautomeric NH-form, stabilised by intermolecular NH···S hydrogen bonds. In solutions, however, the molecule is found predominantly as the SH-tautomer, accompanied (in low-polar solvents) by a small amount of the CH-tautomer. 1-Phenyl-3-methyl-4-benzoylpyrazol-2-in-5-thione occurs in the crystal as well as in solution in the SH-tautomeric form, stabilised by an intramolecular SH···O bridge. In dimethylsulfoxide solution indications were found for an additional SH-tautomer in a conformation lacking the intramolecular H-bridge. The structure of 1-phenyl-3-methylpyrazol-2-in-5-one was redetermined by X-ray single crystal diffraction at 120°K in order to obtain more accurate geometry and hydrogen bonding parameters. © 2001 Elsevier Science B.V. All rights reserved

X Her and TX Psc: Two cases of ISM interaction with stellar winds observed by Herschel

The asymptotic giant branch (AGB) stars X Her and TX Psc have been imaged at 70 and 160 microns with the PACS instrument onboard the Herschel satellite, as part of the large MESS (Mass loss of Evolved StarS) Guaranteed Time Key Program. The images reveal an axisymmetric extended structure with its axis oriented along the space motion of the stars. This extended structure is very likely to be shaped by the interaction of the wind ejected by the AGB star with the surrounding interstellar medium (ISM). As predicted by numerical simulations, the detailed structure of the wind-ISM interface depends upon the relative velocity between star+wind and the ISM, which is large for these two stars (108 and 55 km/s for X Her and TX Psc, respectively). In both cases, there is a compact blob upstream whose origin is not fully elucidated, but that could be the signature of some instability in the wind-ISM shock. Deconvolved images of X Her and TX Psc reveal several discrete structures along the outermost filaments, which could be Kelvin-Helmholtz vortices. Finally, TX Psc is surrounded by an almost circular ring (the signature of the termination shock?) that contrasts with the outer, more structured filaments. A similar inner circular structure seems to be present in X Her as well, albeit less clearly.Comment: 11 pages, Astronomy & Astrophysics, in pres