29,842 research outputs found
Current Status of the MiniBooNE Experiment
MiniBooNE is an experiment designed to refute or confirm the LSND anti-nu_mu
-> anti-nu_e oscillation result. MiniBooNE will look for oscillations of nu_mu
-> nu_e in a closed-box appearance analysis. MiniBooNE began collecting data in
2002, and is expected to continue data taking through 2005. Current MiniBooNE
results are presented.Comment: 3 pages, 2 figures. Proceedings for talk presented at the Meeting of
the Division of Particles and Fields (DPF2004). Proceedings will be published
as a supplement in the International Journal of Modern Physics
Freshwater Mussel Shells as Indicators of Seasonal Occupation of Archaeological Sites: Review of the Method
Seasonal occupation of sites and utilization of resources by aborigines is a subject of growing importance to prehistoric archeologists; however, relatively few satisfactory techniques are available for making the necessary determinations. Recent research in New Zealand has indicated the potential value of bivalve mollusks in subsistence-settlement pattern studies. A method for seasonal dating of prehistoric sites involving growth ring analysis of freshwater mussel shells and the potential application of this method in Ozark archeology are discussed
Physiological Aspects of Genetics
A considerable amount of evidence indicates that desoxyribonucleic acid is capable of duplicating itself, a property also possessed by genes. (By a self-duplicating material, we mean one which plays some essential role in its own production.) Watson & Crick (1) have proposed a new structure for desoxyribonucleic acid which not only takes into account the existing analytical and x-ray diffraction data but also seems capable of explaining the mechanism of duplication. Their model consists of two helical chains coiled around the same axis, the purine and pyrimidine bases on the inside, the phosphate groups on the outside. The chains are held together by hydrogen bonds between the bases, the adenine residues of either chain being bonded specifically to thymine in the other, and similarly guanine to cytosine. The sequence of bases along one chain is not restricted, but once fixed the sequence along the other chain is determined. This complementarity, which is the most novel feature of the structure, suggests that duplication takes place by separation of the two chains, followed by the synthesis of its complement alongside each chain. The model is supported by recent x-ray diffraction studies (2, 3)
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Encapsulated thermoacoustic projector based on freestanding carbon nanotube film
A suspended nanotube film (or films) producing sound by means of the thermoacoustic (TA) effect is encapsulated between two plates, at least one of which vibrates, to enhance sound generation efficiency and protect the film. To avoid the oxidation of carbon nanotubes at elevated temperatures and reduce the thermal inertia of surrounding medium the enclosure is filled with inert gas (preferably with high heat capacity ratio, γ=Cp/Cv, and low heat capacity, Cp). To generate sound directly as the first harmonic of applied audio signal without use of an energy consuming dc biasing, an audio signal modulated carrier frequency at much higher frequency is used to provide power input. Various other inventive means are described to provide enhanced projected sound intensity, increased projector efficiency, and lengthened projector life, like the use of infrared reflecting coatings and particles on the projector plates, non-parallel sheet alignment in sheet stacks, and cooling means on one projector side.Board of Regents, University of Texas Syste
Parton Distributions in Impact Parameter Space
Fourier transform of the generalized parton distributions (GPDs) at zero
skewness with respect to the transverse momentum transfer gives the
distribution of partons in the impact parameter space. We investigate the GPDs
as well as the impact parameter dependent parton distributions (ipdpdfs) by
expressing them in terms of overlaps of light front wave functions (LFWFs) and
present a comparative study using three different model LFWFs.Comment: 13 pages, 6 figure
Evolution of Structure Functions And Their Moments In Chiral Field Theory
Evolution of structure functions and their moments at low and moderate
is studied in the chiral field theory. Evolution equations based on
perturbation expansion in the coupling constant of the effective theory are
derived and solved for the moments. The kernels of evolution arising from
different processes have been calculated with contributions from direct and
cross channels, the interference terms being non-negligible in the kinematic
regions under consideration. This is shown to lead to flavor-dependence of the
kernels which manifests in observable effects. The invalidity of the
probabilistic approach to the evolution process is also pointed out.Comment: 18 pages, LaTex, 5 figure
'The Voracity Effect' and Climate Change: The Impact of Clean Technologies
In the absence of a successful international cooperative agreement over the control of emissions there is a growing interest in the role that clean technologies may play to alleviate the climate change problem. Within a non-cooperative transboundary pollution game, we investigate, analytically and within a numerical example based on empirical evidence, the impact of the adoption of a cleaner technology (i.e., a decrease in the emission to output ratio). We show that countries may respond by increasing their emissions resulting in an increase in the stock of pollution that may be detrimental to welfare. This possibility is shown to arise for a signi cant and empirically relevant range of parameters. It is when the damage and/or the initial stock of pollution are relatively large and when the natural rate of decay of pollution is relatively small that the perverse e¤ect of clean technologies is strongest. Cooperation over the control of emissions is necessary to ensure that the development of cleaner technologies does not exacerbate the free riding behavior that is at the origin of the climate change problem.transboundary pollution;renewable resource;climate change;clean technolo- gies;differential games
Double Soft Graviton Theorems and BMS Symmetries
It is now well understood that Ward identities associated to the (extended)
BMS algebra are equivalent to single soft graviton theorems. In this work, we
show that if we consider nested Ward identities constructed out of two BMS
charges, a class of double soft factorization theorems can be recovered. By
making connections with earlier works in the literature, we argue that at the
sub-leading order, these double soft graviton theorems are the so-called
consecutive double soft graviton theorems. We also show how these nested Ward
identities can be understood as Ward identities associated to BMS symmetries in
scattering states defined around (non-Fock) vacua parametrized by
supertranslations or superrotations.Comment: 29 pages, minor changes added, footnote 3 removed, consistency check
with Ref:22 settle
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