32,614 research outputs found
Fire extinguishment in oxygen enriched atmospheres
Current state-of-the-art of fire suppression and extinguishment techniques in oxygen enriched atmosphere is reviewed. Four classes of extinguishment action are considered: cooling, separation of reactants, dilution or removal of fuel, and use of chemically reactive agents. Current practice seems to show preference for very fast acting water spray applications to all interior surfaces of earth-based chambers. In space, reliance has been placed on fire prevention methods through the removal of ignition sources and use of nonflammable materials. Recommendations are made for further work related to fire suppression and extinguishment in oxygen enriched atmospheres, and an extensive bibliography is appended
Organic slug control using Phasmarhabditis hermaphrodita
Phasmarhabditis hermaphrodita is a lethal slug parasitic nematode that has been formulated into an effective biological control agent called NemaslugÂź. We investigated the possibility of using different application methods of P. hermaphrodita to reduce cost and the number of nematodes applied. We also compared P. hermaphrodita with a new slug pellet called FerramolÂź, which is available for use on organic farms
An analysis of aircraft accidents involving fires
All U. S. Air Carrier accidents between 1963 and 1974 were studied to assess the extent of total personnel and aircraft damage which occurred in accidents and in accidents involving fire. Published accident reports and NTSB investigators' factual backup files were the primary sources of data. Although it was frequently not possible to assess the relative extent of fire-caused damage versus impact damage using the available data, the study established upper and lower bounds for deaths and damage due specifically to fire. In 12 years there were 122 accidents which involved airframe fires. Eighty-seven percent of the fires occurred after impact, and fuel leakage from ruptured tanks or severed lines was the most frequently cited cause. A cost analysis was performed for 300 serious accidents, including 92 serious accidents which involved fire. Personal injury costs were outside the scope of the cost analysis, but data on personnel injury judgements as well as settlements received from the CAB are included for reference
Electron Transport and Hot Phonons in Carbon Nanotubes
We demonstrate the key role of phonon occupation in limiting the high-field
ballistic transport in metallic carbon nanotubes. In particular, we provide a
simple analytic formula for the electron transport scattering length, that we
validate by accurate first principles calculations on (6,6) and (11,11)
nanotubes. The comparison of our results with the scattering lengths fitted
from experimental I-V curves indicates the presence of a non-equilibrium
optical phonon heating induced by electron transport. We predict an effective
temperature for optical phonons of thousands Kelvin.Comment: 4 pages, 1 figur
Coherent and generalized intelligent states for infinite square well potential and nonlinear oscillators
This article is an illustration of the construction of coherent and
generalized intelligent states which has been recently proposed by us for an
arbitrary quantum system . We treat the quantum system submitted to the
infinite square well potential and the nonlinear oscillators. By means of the
analytical representation of the coherent states \`{a} la Gazeau-Klauder and
those \`{a} la Klauder-Perelomov, we derive the generalized intelligent states
in analytical ways
Automatic structures for semigroup constructions
We survey results concerning automatic structures for semigroup
constructions, providing references and describing the corresponding automatic
structures. The constructions we consider are: free products, direct products,
Rees matrix semigroups, Bruck-Reilly extensions and wreath products.Comment: 22 page
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