1,967 research outputs found
The quantum duality principle
The "quantum duality principle" states that the quantization of a Lie
bialgebra - via a quantum universal enveloping algebra (QUEA) - provides also a
quantization of the dual Lie bialgebra (through its associated formal Poisson
group) - via a quantum formal series Hopf algebra (QFSHA) - and, conversely, a
QFSHA associated to a Lie bialgebra (via its associated formal Poisson group)
yields a QUEA for the dual Lie bialgebra as well; more precisely, there exist
functors QUEA --> QFSHA and QFSHA --> QUEA, inverse of each other, such that in
either case the Lie bialgebra associated to the target object is the dual of
that of the source object. Such a result was claimed true by Drinfeld, but
seems to be unproved in literature: we give here a complete detailed proof of
it.Comment: 19 pages, AMS-TeX file. The paper has been entirely re-written: in
particular, we add a discussion of the possible generalisation of the main
result to the infinite dimensional case. This is the author's file of the
final version (after the refereeing process), as sent for publicatio
A fail safe laser activated switch used as an emergency control link at the Langley Vortex Research Facility
A fail safe light activated switch was used as an emergency control link at the Langley Vortex Research Facility. In this facility aircraft models were towed through a still air test chamber by a gasoline powered vehicle which was launched from one end of a 427-meter track and attained velocities to 31 m/sec in the test chamber. A 5 mW HeNe laser with a mechanical copper provided a connecting link with the moving tow vehicle on which a silicon photodiode receiver with a specially designed amplifier provided a fail safe switching action. This system provided an emergency means of stopping the vehicle by turning off the laser to interrupt the power to the vehicle ignition and brake release systems
Characteristics of capacitor-type micrometeoroid flux detectors when impacted with simulated micrometeoroids
A series of impact tests are described and data presented which characterize the operation of the capacitor-type micrometeoroid flux detectors used on the Meteoroid Technology Satellite (MTS). Capacitor-type detectors with silicon dioxide dielectric thickness of 0.4 and 1.0 microns were tested in the micrometeoroid impact simulator at the Langley Research Center, a 4-MV Van de Graaff electrostatic accelerator. The carbonyl iron projectiles were from 0.5 to 5.0 microns in diameter with velocities from 4 to 10.0 km/sec. The detector bias voltage was varied from -20 to -60 V; some tests were at detector temperatures of 90 C to -100 C; and the angle of impact varied from 0 deg to 75 deg from the normal to the detector. These tests showed that: (1) the detector operation is reliable when the bias voltage is greater than 30 V; (2) after an impact the detector returns to its original condition with an insignificant loss of active area; and (3) the sensitivity of the detector is inversely proportional to the detector thickness. The test results suggest a theoretical model in which the signal is an arc triggered by the impacting projectile, and the detector bias voltage must be high enough to insure that an arc will form
Subsoil Moisture Levels a Concern for Northwest Iowa 2012 Crops
The northwest Iowa fall survey of subsoil moisture completed by Iowa State University in November shows well below average amount of subsoil moisture. Subsoil moisture levels are checked in the fall in many northwest Iowa counties through this survey
Subsoil Moisture Levels are Still a Concern for 2012 Crops
The Iowa State University spring survey of subsoil moisture in northwest Iowa indicates below normal amounts of subsoil moisture in most areas. The exception was near Rossie where the subsoil moisture was 1.3 inches above normal. Subsoil moisture levels are surveyed in pre-determined areas each spring and fall
Twisting algebras using non-commutative torsors
Non-commutative torsors (equivalently, two-cocycles) for a Hopf algebra can
be used to twist comodule algebras. After surveying and extending the
literature on the subject, we prove a theorem that affords a presentation by
generators and relations for the algebras obtained by such twisting. We give a
number of examples, including new constructions of the quantum affine spaces
and the quantum tori.Comment: 27 pages. Masuoka is a new coauthor. Introduction was revised.
Sections 1 and 2 were thoroughly restructured. The presentation theorem in
Section 3 is now put in a more general framework and has a more general
formulation. Section 4 was shortened. All examples (quantum affine spaces and
tori, twisting of SL(2), twisting of the enveloping algebra of sl(2)) are
left unchange
Deep-Tillage Study—Northwest Research Farm
A deep-tillage study was started during the fall of 2003 to evaluate the effects of deep (~20 in.) preplant tillage on corn and soybean yields
Soybean Fungicide Phytotoxicity Study, Northwest Research Farm
This study was done to evaluate the potential leaf burn (phytotoxicity) of two fungicides on 32 commonly grown soybean varieties. These 32 varieties represented diverse genetic backgrounds and ranged in maturity from late maturity group (MG) 0 to late MG II. Most of the varieties were in the late MG I to early MG II maturity range and would be commonly grown in northern Iowa
Soybean Fungicide Demonstration at the Northwest Iowa Research Farm
Eleven different fungicide treatments were evaluated on soybean at the Northwest Research Farm in 2006. The fungicides were evaluated because of the threat of Asian soybean rust and the potential yield benefit that fungicides may provide without the presence of leaf disease
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