731 research outputs found
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Definition of total bootstrap current in tokamaks
Alternative definitions of the total bootstrap current are compared. An analogous comparison is given for the ohmic and auxiliary currents. It is argued that different definitions than those usually employed lead to simpler analyses of tokamak operating scenarios
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Plasma confinement theory and transport simulation
The objectives continue to be: (1) to advance the transport studies of tokamaks, including development and maintenance of the Magnetic Fusion Energy Database, and (2) to provide theoretical interpretation, modeling and equilibrium and stability for TEXT-Upgrade. Recent publications and reports, and conference presentations of the Fusion Research Center theory group are listed
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Plasma confinement theory and transport simulation. Final report, October 1, 1988--October 31, 1994
The objectives of the Fusion Research Center Theory Program are: (1) to advance the transport studies of tokamaks, including development and maintenance of the Magnetic Fusion Energy Database, and (2) to provide theoretical interpretation, modeling and equilibrium and stability studies for the TEXT-Upgrade tokamak. Publications and reports and conference presentations for the grant period are listed. Work is described in five basic categories: (A) magnetic fusion energy database; (B) computational support and numerical modeling; (C) support for TEXT-upgrade and diagnostics; (D) transport studies; and (E) Alfven waves
Value of beef performance records
"Individual performance records are useful for selecting superior performing cows and bulls and for culling undesirable animals from the herd. The Missouri Beef Cattle Improvement Programs are available to beef cattle breeders through local University of Missouri extension centers. · Flexibility of the programs helps both purebred and commercial breeders in their selection and breeding programs. The cow-calf man can use these programs as tools to check the performance of each animal from birth until it is added to the herd or slaughtered. By using these programs, you can evaluate an individual animal's genetic merit within a herd. This is important since new genes are not created and herd superiority comes from measuring economic traits and selecting genetically superior individuals."--First page.John W. Massey, James E. Ross, and D. W. Vogt (Department of Animal Science, College of Agriculture)Revised 2/85/8
Petrography and Geochemistry of Metals in Almahata Sitta Ureilites
Ureilites are ultramafic achondrites, predominantly composed of olivine and pyroxenes with accessory carbon, metal and sulfide. The majority of ureilites are believed to represent the mantle of the ureilite parent body (UPB) [1]. Although ureilites have lost much of their original metal [2], the metal that remains retains a record of the formative processes. Almahata Sitta is predominantly composed of unbrecciated ureilites with a wide range of silicate compositions [3,4]. As a fall it presents a rare opportunity to examine fresh ureilite metal in-situ, and analyzing their highly siderophile element (HSE) ratios gives clues to their formation. Bulk siderophile element analyses of Almahata Sitta fall within the range observed in other ureilites [5]. We have examined the metals in seven ureilitic samples of Almahata Sitta (AS) and one associated chondrite fragment (AS#25)
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Petrologic and oxygen-isotopic investigations of eucritic and anomalous mafic achondrites
The most common asteroidal igneous meteorites are eucrite-type basalts and gabbros rocks composed of ferroan pigeonite and augite, calcic plagioclase, silica, ilmenite, troilite, Ca-phosphate, chromite and Fe-metal. These rocks are thought to have formed on a single asteroid along with howardites and diogenites (HEDs). However, Northwest Africa (NWA) 011 is mineralogically identical to eucrites, but has an O-isotopic composition distinct from them and was derived from a different asteroid. Modern analyses with higher precision have shown that some eucrites have smaller O-isotopic differences that are nevertheless well-resolved from the group mean
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Compact tokamak reactors part 2 (numerical results)
The authors describe a numerical optimization scheme for fusion reactors. The particular application described is to find the smallest copper coil spherical tokamak, although the numerical scheme is sufficiently general to allow many other problems to be solved. The solution to the steady state energy balance is found by first selecting the fixed variables. The range of all remaining variables is then selected, except for the temperature. Within the specified ranges, the temperature which satisfies the power balance is then found. Tests are applied to determine that remaining constraints are satisfied, and the acceptable results then stored. Results are presented for a range of auxiliary current drive efficiencies and different scaling relationships; for the range of variables chosen the machine encompassing volume increases or remains approximately unchanged as the aspect ratio is reduced
Synthetic- and bio-polymer use for runoff water quality management in irrigation agriculture
Low concentrations of synthetic- or bio-polymers in irrigation water can nearly eliminate
sediment, N, ortho- and total-P, DOM, pesticides, micro-organisms, and weed seed from runoff. These
environmentally safe polymers are employed in various sensitive uses including food processing, animal
feeds, and potable water purification. The most common synthetic polymer is anionic, high purity
polyacrylamide (PAM), which typically provides 70-90% contaminant elimination. Excellent results are
achieved adding only 10 ppm PAM to irrigation water, applying 1 -2 kg ha. -1 per irrigation, costing
12 kg -1 . Biopolymers are less effective. Using twice or higher concentrations, existing biopolymers
are ,r=60% effective as PAM, at 2 - 3 times the cost. A half million ha of US irrigated land use PAM for
erosion control and runoff protection. The practice is spreading rapidly in the US and worldwide. Interest
in development of biopolymer surrogates for PAM is high. If the supply of cheap natural gas (raw material
for PAM synthesis) diminishes, industries may seek alternative polymers. Also "green" perceptions and
preferences favor biopolymers for certain application
Synthetic- and Bio-polymer use for runoff water quality management in irrigated agriculture
Low concentrations of synthetic- or bio-polymers in irrigation water can nearly eliminate sediment, N,
ortho- and total-P, DOM, pesticides, micro-organisms, and weed seed from runoff. These environmentally safe
polymers are employed in various sensitive uses including food processing, animal feeds, and potable water
purification. The most common synthetic polymer is anionic, high purity polyacrylamide (PAM), which typically
provides 70-90% contaminant elimination. Excellent results are achieved adding only 10 ppm PAM to irrigation
water, applying 1-2 kg ha-lper irrigation, costing 12 kg-1. Biopolymers are less effective, but show promise; they
include starch co-polymers, microfibril suspensions, chitin, polysaccharides and protein derivatives. Using twice or
higher concentrations, existing biopolymers are ~60% effective as PAM, at 2-3 times the cost kg-1. A half million ha
of US irrigated land use PAM for erosion control and runoff protection. The practice is spreading rapidly in the US
and worldwide. Interest in development of biopolymer surrogates for PAM is high. If the supply of cheap natural gas
(raw material for PAM synthesis) diminishes, industries may seek alternative polymers. Also "green" perceptions and
preferences favor biopolymers for certain applications. More complete history, user/technical information and
bibliography are found at
Phocine Distemper Outbreak, the Netherlands, 2002
During the 2002 phocine distemper epidemic, 2,284 seals, primarily harbor seals (Phoca vitulina), were found stranded along the Dutch coast. Stranding pattern varied with age, sex, state of decomposition, wind, and location. Cumulative proportion of deaths (54%) was comparable to that in the first reported epidemic in 1988
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