2,788 research outputs found
Mars Observer
The Mars Observer Mission will deliver a single spacecraft to Mars for an extended orbital study of the planet's surface, atmosphere, and gravitational and magnetic fields. A flight profile is given, and information is presented in tabular form on the following topics: Deep Space Network support; compatibility tests, frequency assignments, telemetry, command, and tracking support responsibility
Conservation tillage : costs and returns (1993)
This publication briefly describes tillage systems and estimates costs and returns on a typical farm.Reviewed October 1, 1993
CPT- and B-Violation: The p-pbar Sector
The CPT symmetry of relativistic quantum field theory requires the total
lifetimes of particles and antiparticles be equal. Detection of pbar lifetime
shorter than tau_p > O(10^32) yr would signal breakdown of CPT invariance, in
combination with B-violation. The best current limit on tau_pbar, inferred from
cosmic ray measurements, is about one Myr, placing lower limits on
CPT-violating scales that depend on the exact mechanism. Paths to CPT breakdown
within and outside ordinary quantum mechanics are sketched. Many of the
limiting CPT-violating scales in pbar decay lie within the weak-to-Planck
range.Comment: 6 pages, LaTeX, .sty file included; based on contribution to CPT98
Conference; minor changes, accepted by Mod. Phys. Lett.
Triticum mosaic: a new wheat disease in Kansas
De Wolf, Erick and Dallas Seifers, Triticum Mosaic: A New Wheat Disease in Kansas, Manhattan, Kansas, Kansas State University, August 2008
Dallas Bower: a producer for television's early years, 1936-39
Having worked in the film industry as a sound technician and then director, Dallas Bower (1907-99) was appointed in 1936 as one of two senior producers at the start of the BBC Television service. Over the next three years Bower produced as well as directed many ground-breaking live programmes, including the opening-day broadcast on 2 November 1936; the BBC Television Demonstration Film (1937, his only surviving pre-war production); a modern-dress Julius Caesar (1938), in uniforms suggestive of a Fascist disctatorship; Act II of Tristan and Isolde (1938); Patrick Hamilton’s play Rope (1939), utilising extended single camera-shots camera-shots; numerous ballets, among them Checkmate (1938); and ambitious outside broadcasts from the film studios at Denham and Pinewood.
Developing the working practices of producing for the theatre, film industry and radio, Bower was a key figure in defining the role of the creative television producer at the start of the medium. Among his innovations, according to his unpublished autobiographical fragment ‘Playback’ (written 1995), was the introduction of a drawn studio plan for the four cameras employed in all live broadcasts from Alexandra Palace.
Using Bower’s writings (among them his 1936 book Plan for Cinema), his BECTU History Project interview, the BBC Written Archives and contemporary industry coverage, this article reconstructs the early development of the role of staff television producer in order to consider the questions of autonomy, agency and institutional constraints at the BBC in the pre-war years
Comparison of steer behavior when housed in a deep-bedded hoop barn versus an open feedlot with shelter
The use of hoop barns as an alternative housing system for beef cattle has not been widely researched. The objectives of this study were to determine the main effects of behavior of steers 1) over winter and summer, 2) when housed in either a hoop barn or a conventional feedlot, and 3) interactions between season and housing system. A total of 960 crossbredBos taurus steers were used [August 2006 to April 2008 (2 winter and 2 summer trials)]. Steers were housed in either 1 deep-bedded hoop barn (n = 12 pens; 4.65 m2/steer) or 1 open feedlot with shelter (n = 12 pens; 14.7 m2/steer). Steers were ear tagged, implanted, and weighed (414 ± 36 kg) on arrival and allotted to treatments that were balanced for source, BW, and hide color. Behavioral data (3 postures and 2 behaviors) were collected using a 10-min live scan. The experimental unit for behavior was a pen of steers. Behavioral data were arcsine transformed to achieve a normal distribution. There were no (P \u3e 0.05) differences for time spent at bunk or waterer for steers between housing treatments. Steers housed in an open feedlot with shelter spent less time lying and more time standing and walking (P \u3c 0.05) compared with steers housed in a hoop barn. There were no (P = 0.32) differences between seasons for standing. Steers spent more time at the bunk (P \u3c 0.0001) and waterer (P \u3c 0.0001) in the summer compared with the winter. In the winter, steers engaged in more lying (P = 0.0002) and walking (P \u3c 0.0001). Overall, steers stood less (P = 0.006) and spent more time lying (P = 0.024) when housed in a hoop barn than in the open feedlot with shelter regardless of season. Steers housed in the open feedlot with shelter walked more (P \u3c 0.0001) than steers housed in the hoop barn and walked more (P \u3c 0.0001) in winter than in summer months (6 vs. 3%). There were no (P \u3e 0.05) differences in time spent at bunk and waterer between housing systems within season, but time spent at the waterer and bunk decreased (P \u3c 0.05) for both housing systems during the winter. In conclusion, housing 40 steers per pen in a cornstalk-bedded hoop barn at 4.65m2/steer does not result in adverse behavioral alterations and can be considered as a housing alternative for finishing steers in the Midwestern United States when compared with steers fed in an open feedlot with shelter provided
A New Limit on the Antiproton Lifetime
Measurements of the cosmic ray pbar/p ratio are compared to predictions from
an inhomogeneous disk-diffusion model of pbar production and propagation within
the Galaxy, combined with a calculation of the modulation of the interstellar
cosmic ray spectra as the particles propagate through the heliosphere to the
Earth. The predictions agree with the observed pbar/p spectrum. Adding a finite
pbar lifetime to the model, we obtain the limit tau_pbar > 0.8 Myr (90 % C.L.).Comment: 13 pages, 3 encapsulated Postscript figures, uses AASTeX; accepted by
Astrophysical Journal; minor change
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