99 research outputs found
Possible probe of the QCD odderon singularity through the quasidiffractive eta_c production in gamma-gamma collisions
The reactions gamma-gamma to eta_c eta_c and gamma gamma to eta_c + X are
discussed within the three gluon exchange model. We give predictions for the
differential cross-sections and discuss feasibility of measuring these
processes at LEP2 and TESLA. The total cross-sections were estimated to be
approximately equal to 40 fb and 120 fb for gamma-gamma to eta_c eta_c and
gamma-gamma to eta_c + X respectively assuming exchange of elementary gluons
that corresponds to the odderon with intercept equal to unity. These values can
be enhanced by a factor equal to 1.9 and 2.1 for LEP2 and TESLA energies if the
odderon intercept is equal to 1.07. The estimate of cross-sections sigma(e^+
e^- to e^+ e^- eta_c eta_c) and sigma (e^+ e^- to e^+ e^- eta_c + X) for
untagged e^+ and e^- is also given.Comment: 11 pages, Latex, epsf, 5 eps figures include
Incidence, course, and outcome of Clostridium difficile infection in children with hematological malignancies or undergoing hematopoietic stem cell transplantation
Large Self-affine fractality in \p^+p and Kp collisions at 250 GeV/
Taking into account the anisotropy of phase space in multiparticle
production, a self-affine analysis of factorial moments was carried out on the
NA22 data for \p^+\Pp and \PK^+\Pp collisions at 250 GeV/. Within the
transverse plane, the Hurst exponents measuring the anisotropy are consistent
with unit value (i.e. no anisotropy). They are, however, only half that value
when the longitudinal direction is compared to the transverse ones. Fractality,
indeed, turns out to be self-affine rather than self-similar in multiparticle
production. In three-dimensional phase space, power-law scaling is observed to
be better realized in self-affine than in self-similar analysis.Comment: 10 pages and 4 figure
PCF-Based Cavity Enhanced Spectroscopic Sensors for Simultaneous Multicomponent Trace Gas Analysis
A multiwavelength, multicomponent CRDS gas sensor operating on the basis of a compact photonic crystal fibre supercontinuum light source has been constructed. It features a simple design encompassing one radiation source, one cavity and one detection unit (a spectrograph with a fitted ICCD camera) that are common for all wavelengths. Multicomponent detection capability of the device is demonstrated by simultaneous measurements of the absorption spectra of molecular oxygen (spin-forbidden b-X branch) and water vapor (polyads 4v, 4v + δ) in ambient atmospheric air. Issues related to multimodal cavity excitation, as well as to obtaining the best signal-to-noise ratio are discussed together with methods for their practical resolution based on operating the cavity in a “quasi continuum” mode and setting long camera gate widths, respectively. A comprehensive review of multiwavelength CRDS techniques is also given
Diversity of muskox Ovibos moschatus (Zimmerman, 1780) (Bovidae, Mammalia) in time and space based on cranial morphometry
Muskox Ovibos moschatus is a Pleistocene relic, which has survived only in North America and Greenland. During the Pleistocene, it was widely distributed in Eurasia and North America. To evaluate its morphological variability through time and space, we conducted an extensive morphometric study of 217 Praeovibos and Ovibos skull remains. The analyses showed that the skulls grew progressively wider from Praeovibos sp. to the Pleistocene O. moschatus, while from the Pleistocene to the recent O. moschatus, the facial regions of the skull turned narrower and shorter. We also noticed significant geographic differences between the various Pleistocene Ovibos crania. Siberian skulls were usually larger than those from Western and Central Europe. Eastern Europeanmuskoxen also exceeded in size those from the other regions of Europe. The large size of Late Pleistocene muskoxen from regions located in more continental climatic regimes was probably associated with the presence of more suitable food resources in steppe-tundra settings. Consistently, radiocarbon-dated records of this species are more numerous in colder periods, when the steppe-tundra was widely spread, and less abundant in warmer periods
Software for calculation of noise maps implemented on supercomputer
Investigation results relevant to the implementation of algorithms for calculation of noise maps are presented in this paper. The aim of implementing the algorithms on a computer cluster is explained. Selected implementation details of the software called Noise Propagation Model are described. The software interaction with the data acquisition system is presented. Noise maps obtained using the described software are presented. A comparison between the outcomes of the implemented models and the simulation results of a commercial program is presented. An analysis of the computation efficiency is described. A discussion concerning dynamic presentation of noise maps is also presented
Characterization of research methods dealing with selected protective functions of polymer packages
Opisano metodykę badań pojemników polimerowych (na przykładzie butelek i kanistrów) przeznaczonych głównie do ochrony i transportu substancji w stanie płynnym. Podano charakterystykę zastosowanej aparatury badawczo-pomiarowej, w której wykorzystywane są techniki video-rejestracji i analizy obrazu (videoXtens firmy Zwick/Roell), metody bezkontaktowe (skaner 3D firmy GOM), metody elementów skończonych (Ansys). Wykazano wpływ obecności płynów chemii motoryzacyjnej w połączeniu gwintowym na moment dokręcający (para polimer/polimer) oraz kąt dokręcenia nakrętki na szyjce pojemnika. Porównano pojemniki polimerowe (podobna masa, cechy geometryczne i przeznaczenie) pod kątem wytrzymałości na obciążenie ściskające.Polymer containers (i.e. bottles and canisters) designed for the protection and transportation of substances being in the liquid state are presented in the paper. The equipment of research and measurement with video recording and image analysis (videoXtens of Zwick/Roell), non-contact methods (3D scanner of GOM company) and finite element method (Ansys) were used in the study quoted here. An influence of motorization fluids in the screwed connection on torque (polymer/polymer couple) and the angle tight of screw cap on container neck were demonstrated. Polymer containers (similar in mass, geometry and application) were compared paying attention to their compression strength
Structural and technological defects of closures in plastic packages
W pracy opisano podstawowe wady konstrukcyjne i technologiczne zamknięć w opakowaniach polimerowych, a także przedstawiono możliwości zmniejszania wybranych wad na etapie projektowania poprzez zastosowanie wspomagania komputerowego przetwórstwa tworzyw.Basic structural and technological defects of closures in plastic packages are described in the paper. Possibilities of reducing the selected defects during design with the use of computer aided engineering in plastic processing are also discussed
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