7,951 research outputs found
A Unitarity-Conserving Higgs Inflation Model
Scalar field models of inflation based on a large nonminimal coupling to
gravity xi, in particular, Higgs inflation, may violate unitarity at an energy
scale ~ M_p / xi << M_p. In this case the model is incomplete at energy scales
relevant to inflation. Here we propose a new unitarity-conserving model of
Higgs inflation. The completion of the theory is achieved via additional
interactions which are proportional to products of the derivatives of the Higgs
doublet. The resulting model differs from the original version of Higgs
inflation in its prediction for the spectral index, with a classical value n =
0.974. In the case of a nonsupersymmetric model, quantum corrections are likely
to strongly modify the tree-level potential, suggesting that supersymmetry or a
gauge singlet scalar inflaton is necessary for a completely successful model.Comment: 5 pages, published versio
Method of carbonizing polyacrylonitrile fibers
This invention relates to a method of carbonizing polyacrylonitrile fibers by exposing the fibers at an elevated temperature to an oxidizing atmosphere; then exposing the oxidized fibers to an atmosphere of an inert gas such as nitrogen containing a carbonaceous material such as acetylene. The fibers are preferably treated with an organic compound, for example benzoic acid, before the exposure to an oxidizing atmosphere. The invention also relates to the resulting fibers. The treated fibers have enhanced tensile strength
Cobalt improves nickel hydroxide electrodes for batteries
Positive nickel hydroxide electrodes containing 20 mole percent of cobalt hydroxide are more efficient than when impregnated to the same degree by weight with nickel hydroxide alone. Charge-acceptance and oxygen-evolution tests indicate cobalt electrodes are more efficient than plain positive nickel hydroxide electrodes at all rates of charge
An investigation of the nickel oxide electrode
Optimum concentration of cobalt doping of nickel oxide electrodes and structural studies of electrod
Investigation of battery active nickel oxides Final report
Identification and characterization of battery active compound structures formed on nickel oxide electrode during charging and dischargin
Evaluation of the Strecker synthesis as a source of amino acids on carbonaceous chondrites
The Strecker synthesis (SS) has been proposed as the source of amino acids (AA) formed during aqueous alteration of carbonaceous chondrites. It is postulated that the aldehyde and ketone precursors of the meteoritic AA originated in interstellar syntheses and accreted on the meteorite parent body along with other reactant species in cometesimal ices. The SS has been run with formaldehyde, acetyldehyde, propionaldehyde, acetone, and methyl ketone as starting materials. To study the effect of minerals on the reaction, the SS was run in the presence and absence of dust from the Allende meteorite using deuterated aldehydes and ketones as starting materials. The products were studied by GC/MS. With the exception of glycine, the retention of deuterium in the AA was greater than 90 pct. Some D exchange with water does occur, however, and determination of the rate of exchange as a function of pH and temperature may allow some bounds to be placed on the duration of parent body aqueous alteration. The retention of D by the AA under conditions studied thus far is consistent with the model that a SS starting from interstellar aldehydes and ketones led to the production of meteoritic AA
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