134,195 research outputs found
All-solid-state radiometers for environmental studies to 700 GHz
We report results with an all-solid-state radiometer for measurements of the ClO molecule at 649 GHz. The project is part of a program to provide low-noise, low-weight, low-power radiometers for space operation, and special effort has been expended on the development of high-efficiency solid-state frequency multipliers and Schottky-barrier mixers with low local oscillator power requirements. The best measured system noise temperature was 1750 K with the mixer and preamplifier cooled to 77 K. The mixer diode was easily pumped into saturation, indicating that the design has excellent prospects of operating at higher frequencies - our present design goal being 1 THz. We comment on the principal design features of such systems and will report on stratospheric measurements performed with this system
Production of strange particles in charged jets in p--Pb and Pb--Pb collisions measured with ALICE at the LHC
Studies of jet production can provide information about the properties of the
hot and dense strongly interacting matter created in ultra-relativistic
heavy-ion collisions. Specifically, measurement of strange particles in jets
may clarify the role of fragmentation processes in the anomalous baryon to
meson ratio at intermediate particle pT that was observed in PbPb and, to a
lesser extent, in pPb collisions. In this contribution, measurements of the pT
spectra of Lambda and Antilambda baryons and K0s mesons produced in association
with charged jets in PbPb collisions at sqrt(sNN)=2.76 TeV and pPb collisions
at sqrt(sNN)=5.02 TeV are presented. The analysis is based on data which was
recorded by ALICE at the LHC, exploiting its excellent particle identification
capabilities. The baryon meson ratios of the spectra of strange particles
associated with jets are studied for different event activities in p-Pb and are
restricted to central events in PbPb. A comparison to the ratios obtained for
inclusive particles and for particles stemming from the underlying event as
well as to PYTHIA simulations is shown.Comment: 4 pages, 3 figures, HPT2014 proceeding
Electron-Cloud Effects in past and future machines - walk through 50 years of Electron-Cloud studies
Past electron-cloud (e-cloud) observations, studies and mitigation techniques
are quickly reviewed along with some ongoing code developments, the preceding
ECLOUD workshops, recent contacts with the spacecraft community, the important
role of Francesco Ruggiero, and a few current electron-cloud topics discussed
at ECLOUD12 in La Biodola.Comment: 9 pages, contribution to the Joint INFN-CERN-EuCARD-AccNet Workshop
on Electron-Cloud Effects: ECLOUD'12; 5-9 Jun 2012, La Biodola, Isola d'Elba,
Ital
Process nominalizations in russian
Within a minimalist framework of sound-meaning correlation, the present study concentrates on process nominalizations of Russian. It is shown how these constructions are built up syntactically and semantically and in which respects they differ from other types of nominalizations. The analysis follows a lexicalist conception of word formation and the differentiation of Semantic Form and Conceptual Structure
A Noether-Deuring theorem for derived categories
We prove a Noether-Deuring theorem for the derived category of bounded
complexes of modules over a Noetherian algebra
The real plane Cremona group is a non-trivial amalgam
We show that the real Cremona group of the plane is a non-trivial amalgam of
two groups amalgamated along their intersection and give an alternative proof
of its abelianisation
A matrix-algebraic algorithm for the Riemannian logarithm on the Stiefel manifold under the canonical metric
We derive a numerical algorithm for evaluating the Riemannian logarithm on
the Stiefel manifold with respect to the canonical metric. In contrast to the
existing optimization-based approach, we work from a purely matrix-algebraic
perspective. Moreover, we prove that the algorithm converges locally and
exhibits a linear rate of convergence.Comment: 30 pages, 5 figures, Matlab cod
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