225 research outputs found
High-voltage pulse discharge as factor of the methanogenesis initiation
Results of scientific research on influence of the high-voltage pulse discharge on process of bioorganic waste methane sludge fermentation in agricultural production are given in the article. Powerful infra- and ultrasonic fluctuations leading to emergence of shock waves exert strong impact on processes: disinfecting, cleanings and deflocculation of bioorganic mix, as well as on activity of various physical and chemical changes of synthesis products. Selecting the modes of high-voltage pulse processing, it is possible to provide highly productive anaerobic bacteria. At the same time "artificial selection" as a result of which weak microorganisms perish is observed, and the strong group remains. Viable species of microorganisms, having received at the order nutrient medium, as a result of destruction and death of weak microorganisms, begin to breed quickly, increasing growth of a biofilm responsible for a biogas exit. For the analysis of experimental data on development of technological process for anaerobic sludge fermentation the method of trans-resonant functional topography which provided informational content of the active environment concerning ions and free radicals arising in the course of modifying the organic substratum was used.Keywords: biogas unit, anaerobic sludge fermentation, electro technology, methanogenesis,pulse discharge, bioorganic waste, water substratum, organic fertilizers, processing, ecology
Pressure-Induced Interlinking of Carbon Nanotubes
We predict new forms of carbon consisting of one and two dimensional networks
of interlinked single wall carbon nanotubes, some of which are energetically
more stable than van der Waals packing of the nanotubes on a hexagonal lattice.
These interlinked nanotubes are further transformed with higher applied
external pressures to more dense and complicated stable structures, in which
curvature-induced carbon sp re-hybridizations are formed. We also discuss
the energetics of the bond formation between nanotubes and the electronic
properties of these predicted novel structures.Comment: 4 pages, 4 postscript figures; To be appear in PR
Crystal Undulator As A Novel Compact Source Of Radiation
A crystalline undulator (CU) with periodically deformed crystallographic
planes is capable of deflecting charged particles with the same strength as an
equivalent magnetic field of 1000 T and could provide quite a short period L in
the sub-millimeter range. We present an idea for creation of a CU and report
its first realization. One face of a silicon crystal was given periodic
micro-scratches (grooves), with a period of 1 mm, by means of a diamond blade.
The X-ray tests of the crystal deformation have shown that a sinusoidal-like
shape of crystalline planes goes through the bulk of the crystal. This opens up
the possibility for experiments with high-energy particles channeled in CU, a
novel compact source of radiation. The first experiment on photon emission in
CU has been started at LNF with 800 MeV positrons aiming to produce 50 keV
undulator photons.Comment: Presented at PAC 2003 (Portland, May 12-16
Experimental study of the radiation emitted by 180-GeV/c electrons and positrons volume-reflected in a bent crystal
The radiation emitted by 180-GeV/c volume-reflected electrons and positrons impinging on a bent crystal has been measured by the H8RD22 Collaboration on the H8 beamline at the CERN SPS. A dedicated spectrometer has been developed to measure high-energy photon spectra (up to similar to 100 GeV) under volume reflection: photon and charged particle beams have been separated by a bending magnet and leptons were detected and tagged by microstrip silicon detectors and a Pb-scintillator sampling calorimeter. A comparison between the experimental and analytical data for the amorphous and volume-reflection cases is presented and the differences are discussed
Double volume reflection of a proton beam by a sequence of two bent crystals
The doubling of the angle of beam deflection due to volume reflection of protons by a sequence of two bent silicon crystals was experimentally observed at the 400 GeV proton beam of the CERN SPS. A similar sequence of short bent crystals can be used as an efficient primary collimator for the Large Hadron Collider
Experimental study of the radiation emitted by 180-GeV/c electrons and positrons volume-reflected in a bent crystal
The radiation emitted by 180-GeV/c volume-reflected electrons and positrons impinging on a bent crystal has been measured by the H8RD22 Collaboration on the H8 beamline at the CERN SPS. A dedicated spectrometer has been developed to measure high-energy photon spectra (up to similar to 100 GeV) under volume reflection: photon and charged particle beams have been separated by a bending magnet and leptons were detected and tagged by microstrip silicon detectors and a Pb-scintillator sampling calorimeter. A comparison between the experimental and analytical data for the amorphous and volume-reflection cases is presented and the differences are discussed
Strong reduction of the off-momentum halo in crystal assisted collimation of the SPS beam
A study of crystal assisted collimation has been continued at the CERN SPS for different energies of stored beams using 120 GeV/. c and 270 GeV/. c protons and Pb ions with 270 GeV/. c per charge. A bent silicon crystal used as a primary collimator deflected halo particles using channeling and directing them into the tungsten absorber. A strong correlation of the beam losses in the crystal and off-momentum halo intensity measured in the first high dispersion (HD) area downstream was observed. In channeling conditions, the beam loss rate induced by inelastic interactions of particles with nuclei is significantly reduced in comparison with the non-oriented crystal. A maximal reduction of beam losses in the crystal larger than 20 was observed with 270 GeV/. c protons. The off-momentum halo intensity measured in the HD area was also strongly reduced in channeling conditions. The reduction coefficient was larger than 7 for the case of Pb ions. A strong loss reduction was also detected in regions of the SPS ring far from the collimation area. It was shown by simulations that the miscut angle between the crystal surface and its crystallographic planes doubled the beam losses in the aligned crystal.peer-reviewe
First Measurement of Electroproduction off Nuclei in the Current and Target Fragmentation Regions
We report results of hyperon production in semi-inclusive
deep-inelastic scattering off deuterium, carbon, iron, and lead targets
obtained with the CLAS detector and the Continuous Electron Beam Accelerator
Facility 5.014~GeV electron beam. These results represent the first
measurements of the multiplicity ratio and transverse momentum
broadening as a function of the energy fraction~() in the current and target
fragmentation regions. The multiplicity ratio exhibits a strong suppression at
high~~and~an enhancement at~low~. The measured transverse momentum
broadening is an order of magnitude greater than that seen for light mesons.
This indicates that the propagating entity interacts very strongly with the
nuclear medium, which suggests that propagation of diquark configurations in
the nuclear medium takes place at least part of the time, even at high~. The
trends of these results are qualitatively described by the Giessen
Boltzmann-Uehling-Uhlenbeck transport model, particularly for the multiplicity
ratios. These observations will potentially open a new era of studies of the
structure of the nucleon as well as of strange baryons.Comment: 14 pages, 6 figure
First Measurement of Hard Exclusive π- Δ++ Electroproduction Beam-Spin Asymmetries off the Proton
The polarized cross-section ratio σLT′/σ0 from hard exclusive π-Δ++ electroproduction off an unpolarized hydrogen target has been extracted based on beam-spin asymmetry measurements using a 10.2 GeV/10.6 GeV incident electron beam and the CLAS12 spectrometer at Jefferson Lab. The study, which provides the first observation of this channel in the deep-inelastic regime, focuses on very forward-pion kinematics in the valence regime, and photon virtualities ranging from 1.5 GeV2 up to 7 GeV2. The reaction provides a novel access to the d-quark content of the nucleon and to p→Δ++ transition generalized parton distributions. A comparison to existing results for hard exclusive π+n and π0p electroproduction is provided, which shows a clear impact of the excitation mechanism, encoded in transition generalized parton distributions, on the asymmetry
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