5,892 research outputs found
Contamination of the space station environment by vented chemicals
Gaseous materials vented from materials and life science experiments on the Space Station may have noticeable effects on the optical or plasma environment. The magnitude of the effects depends on: (1) rarefied gas dynamics; (2) photochemical reactions; and (3) airglow excitation mechanisms. In general, the effects from atomic species can be mitigated, but the disturbances resulting from venting of molecules like SF6, CO2 and C2H2 can be significant. The interaction of molecules with ambient plasma at orbital velocities should be studied with laboratory or space experiments
Adaptive dual-comb spectroscopy in the green region
Dual-comb spectroscopy is extended to the visible spectral range with a
set-up based on two frequency-doubled femtosecond ytterbium-doped fiber lasers.
The dense rovibronic spectrum of iodine around 19240 cm-1 is recorded within 12
ms at Doppler-limited resolution with a simple scheme that only uses
free-running femtosecond lasers
Canid Eschatologies in Irish and Norse Myth
While medieval Irish literature does not preserve any pre-Christian sources on eschatology, other Indo-European cultures do, notably that of the Norse cosmology and its end in Ragnarök. In the stories of Ragnarök, various canids (including the Fenris Wolf) are heavily involved. There may be traces of some eschatological canid-connected imagery in certain Celtic sources, but nothing seems definite. However, the Fenris wolf’s role in Norse cosmology is delayed by his binding by the other gods. The story of Fenris’ binding has similarities to the death-tale of CĂş Chulainn. The author suggests that not only might there be something eschatological in the similarities discernible in this comparison, but it also may be possible to understand the Irish hero’s death as his being taken into reserve, so to speak, for a final eschatological battle at some later date by either Lug or The MorrĂgan, in a similar fashion to how Odin and Freyja take great warriors to their halls in advance of Ragnarök
Marine Pollution and the Law of the Sea
This article reviews, Marine Pollution and the Law of the Sea, by John Warren Kindt, published by William S. Hem & Co., Inc. in 1986
Sneutrino as Lightest Supersymmetric Particle in B3 mSUGRA Models and Signals at the LHC
We consider B3 mSUGRA models where we have one lepton number violating LQD
operator at the GUT scale. This can alter the supersymmetric mass spectrum
leading to a sneutrino as the lightest supersymmetric particle in a large
region of parameter space. We take into account the restrictions from neutrino
masses, the muon anomalous magnetic moment, b -> s gamma and other precision
measurements. We furthermore investigate existing restrictions from direct
searches at LEP, the Tevatron and the CERN p\bar p collider. We then give
examples for characteristic signatures at the LHC.Comment: 22 pages, 11 figure
The response of the ionosphere to the injection of chemically reactive vapors
As a gas released in the ionosphere expands, it is rapidly cooled. When the vapor becomes sufficiently tenuous, it is reheated by collisions with the ambient atmosphere and its flow is then governed by diffusive expansion. As the injected gas becomes well mixed with the plasma, a hole is created by chemical processes. In the case of diatomic hydrogen release, depression of the electron concentrations is governed by the charge exchange reaction between oxygen ions and hydrogen, producing positive hydroxyl ions. Hydroxyl ions rapidly react with the electron gas to produce excited oxygen and hydrogen atoms. Enhanced airglow emissions result from the transition of the excited atoms to lower energy states. The electron temperature in the depleted region rises sharply causing a thermal expansion of the plasma and a further reduction in the local plasma concentration
Sneutrino LSPs in R-parity violating minimal supergravity models
We consider the minimal supergravity model (mSUGRA) with one additional
R-parity violating operator at the GUT scale. The superparticles mass spectra
at the weak scale are generally altered due to the presence of the R-parity
violating coupling in the renormalization group equations. We show that a
lepton number violating coupling at the GUT scale can lead to a sneutrino as
the lightest supersymmetric particle (LSP) in a large region of parameter space
consistent with the muon anomalous magnetic moment and other precision
measurements. We also give characteristic collider signatures at the LHC.Comment: 3 pages, 3 figures, to appear in the proceedings of SUSY08, Seoul,
Kore
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