Search results for " ring"
showing 10 items of 478 documents
Towards Vorst's conjecture in positive characteristic
2018
Vorst's conjecture relates the regularity of a ring with the $\mathbb{A}^1$-homotopy invariance of its $K$-theory. We show a variant of this conjecture in positive characteristic.
Der Satz von Tits für PGL2(R), R ein kommutativer Ring vom stabilen Rang 2
1996
Certain permutation groups on sets with distance relation are characterized as groups of projectivities PGL2(R) on the projective line over a commutative ring R of stable rank 2, thus generalizing a classical result of Tits where R is a field.
The Detector Control of the PANDA Experiment
2014
The PANDA experiment will be built at the antiproton storage ring HESR, a part of the new accelerator facility FAIR in Darmstadt, Germany. PANDA aims amongst other topics for high precision measurements in hadron spectroscopy and search for exotic matter. To guarantee the high resolution of the different components a detector control system (DCS) monitoring temperatures, humidity, pressure, and controlling chillers and power supplies is needed. The DCS of PANDA is built using the open-source software package EPICS (Experimental Physics and Industrial Control System) with a PANDA specific version of Control-System Studio. In this document the general concepts of the PANDA DCS will be discuss…
Cooling and slowing of trapped antiprotons below 100 meV
1989
Electron cooling of trapped antiprotons allows their storage at energies 10 million times lower than is available in any antiproton storage ring. More than 60 000 antiprotons with energies from 0 to 3000 eV are stored in an ion trap from a single pulse of 5.9-MeV antiprotons from LEAR. Trapped antiprotons maintain their initial energy distribution over a storage lifetime exceeding 50 h unless allowed to collide with a cold buffer gas of trapped electrons, where- upon they cool dramatically to 1 eV in tens of seconds. The cooled antiprotons can be stacked into a harmonic potential well suited for long-term storage and precision measurements.
Vortex rings in two-dimensional harmonic traps
2006
We use the configuration interaction technique to study vortex formation in rotating systems of interacting spinless fermions and bosons trapped in a two-dimensional harmonic potential. In the fermionic case, the vortices appear as holes in the Fermi sea and localize in rings. The yrast spectrum is dominated by rigid rotation of the vortex ring, showing periodic oscillations. The Bose system shows a similar yrast spectrum and vortex formation. This can be explained by a one-to-one correspondence of the fermion and boson many-particle configurations. A simple mean-field model can reproduce the oscillations in the yrast spectrum, but fails to explain the localization of vortices.
Valence band photoemission from thin iron films - A comparison of experimental and theoretical results
1998
Abstract In this contribution, we report on photoemission data from thin iron films on W(110) that have been carried out by means of spin-resolved photoelectron spectroscopy as well as Magnetic Circular Dichroism in valence band photoemission at the storage ring BESSY. These techniques give complementary information on the electronic and magnetic properties, such as exchange and spin–orbit splitting. We compare our experimental data to new photoemission calculations, which have been obtained in the framework of a fully relativistic one-step theory for ferromagnetic materials.
TOPOLOGICAL PARTIAL *-ALGEBRAS: BASIC PROPERTIES AND EXAMPLES
1999
Let [Formula: see text] be a partial *-algebra endowed with a topology τ that makes it into a locally convex topological vector space [Formula: see text]. Then [Formula: see text] is called a topological partial *-algebra if it satisfies a number of conditions, which all amount to require that the topology τ fits with the multiplier structure of [Formula: see text]. Besides the obvious cases of topological quasi *-algebras and CQ*-algebras, we examine several classes of potential topological partial *-algebras, either function spaces (lattices of Lp spaces on [0, 1] or on ℝ, amalgam spaces), or partial *-algebras of operators (operators on a partial inner product space, O*-algebras).
Thermally Induced Structural Modification of Silica Nanoparticles Investigated by Raman and Infrared Absorption Spectroscopies
2010
We report an experimental investigation by Raman and infrared (IR) absorption spectroscopies on the structural modifications induced by isochronal thermal treatments on amorphous SiO2 nanoparticles (fumed silica). In particular, three different commercial types of this material, characterized by particle mean diameters of 7, 14, and 40 nm, were subjected to thermal treatments from 100 up to 1000 °C. We found that some properties of fumed silica, such as the SiOSi mean bond angle, ring size distribution, and surface adsorbed water content, are drastically different from those of common bulk silica materials and intimately related to the particles' dimension. The SiOSi mean bond angle, probed…
Vergleich der DNS-Analyse mit histomorphologischen parametern beim Magenkarzinom
1992
After curative resection of stomach carcinomas (adenocarcinomas: n=58, signet ring cell carcinomas: n = 24, undifferentiated carcinomas: n = 21) the DNA content of the tumor cells was compared with the histomorphological parameters. There was a correlation between the DNA content and the histomorphological parameters. The DNA analysis had no additionally prognostic influence. In the multivariate regression analysis the prognosis depended on lymph node status (p=0.0009), pT-stage (p = 0.02), tumor localization (p = 0.03) and the histological type (p=0.05). The prognosis was independent of the DNA content. Furthermore, neither did the degree of differentiation, the operative procedure, the sa…
Safety and efficacy of a fixed-dose combination regimen of grazoprevir, ruzasvir, and uprifosbuvir with or without ribavirin in participants with and…
2017
Background There is a need for hepatitis C virus (HCV) therapies with excellent efficacy across genotypes and in diverse populations. Part A of the C-CREST-1 and C-CREST-2 trials led to the selection of a three-drug regimen of grazoprevir (MK-5172; an HCV NS3/4A protease inhibitor; 100 mg/day) plus ruzasvir (MK-8408; an NS5A inhibitor; 60 mg/day) plus uprifosbuvir (MK-3682; an HCV NS5B polymerase inhibitor; 450 mg/day). Part B of the studies tested this combination as a single formulation in different treatment durations in a broader population. Methods Part B of these randomised, phase 2, open-label clinical trials enrolled individuals from 15 countries who were chronically infected with H…