80 research outputs found
Physical characteristics of concentration fields of tropospheric bioaerosols in the South of Western Siberia
The State Research Center of Virology and Biotechnology "Vector" and the Institute of Optics SB RAS are performing systematic study of tropospheric bioaerosols in the South of Western Siberia. The work summarizes the results of analysis of some physical characteristics of the data array on bioaerosol concentration obtained with an airplane laboratory at the altitudes of 0.5, 1, 1.5, 2, 3, 4, 5.5 and 7 km. The flights were performed during the last 10 days of each month in 1999-2003. It was shown that the concentration of total protein aerosols obeyed the laws of continual statistics, and the concentration of culturable microorganism aerosols obeyed the laws of discrete statistics. The analysis of correlation coefficients and cross correlation of bioaerosol concentration fields was performed. Wavelet analysis of the data showed that variations of tropospheric bioaerosol concentration were mainly determined by typical seasonal processes with periods of 12, 6, 4 and 8-9 months. Seasonal variations cause approximately 80% of the total dispersion of variations of total protein concentration, and the amplitudes of variations of culturable microorganism concentration are small as compared with the constant component. Harmonic analysis of bioaerosol concentration fields was performed. Harmonics that are significant in wavelet spectra for all time series were taken for the approximation of the series. It was revealed that four-month periodicity was internal and was caused by a wave spreading from above with a vertical rate of about 4 km/month. © 2005 Elsevier Ltd. All rights reserved
Physical characteristics of concentration fields of tropospheric bioaerosols in the South of Western Siberia
The State Research Center of Virology and Biotechnology "Vector" and the Institute of Optics SB RAS are performing systematic study of tropospheric bioaerosols in the South of Western Siberia. The work summarizes the results of analysis of some physical characteristics of the data array on bioaerosol concentration obtained with an airplane laboratory at the altitudes of 0.5, 1, 1.5, 2, 3, 4, 5.5 and 7 km. The flights were performed during the last 10 days of each month in 1999-2003. It was shown that the concentration of total protein aerosols obeyed the laws of continual statistics, and the concentration of culturable microorganism aerosols obeyed the laws of discrete statistics. The analysis of correlation coefficients and cross correlation of bioaerosol concentration fields was performed. Wavelet analysis of the data showed that variations of tropospheric bioaerosol concentration were mainly determined by typical seasonal processes with periods of 12, 6, 4 and 8-9 months. Seasonal variations cause approximately 80% of the total dispersion of variations of total protein concentration, and the amplitudes of variations of culturable microorganism concentration are small as compared with the constant component. Harmonic analysis of bioaerosol concentration fields was performed. Harmonics that are significant in wavelet spectra for all time series were taken for the approximation of the series. It was revealed that four-month periodicity was internal and was caused by a wave spreading from above with a vertical rate of about 4 km/month. © 2005 Elsevier Ltd. All rights reserved
Nuclear Polarization of Molecular Hydrogen Recombined on a Non-metallic Surface
The nuclear polarization of molecules formed by recombination
of nuclear polarized H atoms on the surface of a storage cell initially coated
with a silicon-based polymer has been measured by using the longitudinal
double-spin asymmetry in deep-inelastic positron-proton scattering. The
molecules are found to have a substantial nuclear polarization, which is
evidence that initially polarized atoms retain their nuclear polarization when
absorbed on this type of surfac
Evaluation of Fermi Read-out of the ATLAS Tilecal Prototype
Prototypes of the \fermi{} system have been used to read out a prototype of the \atlas{} hadron calorimeter in a beam test at the CERN SPS. The \fermi{} read-out system, using a compressor and a 40 MHz sampling ADC, is compared to a standard charge integrating read-out by measuring the energy resolution of the calorimeter separately with the two systems on the same events. Signal processing techniques have been designed to optimize the treatment of \fermi{} data. The resulting energy resolution is better than the one obtained with the standard read-out
Response of the ATLAS tile calorimeter prototype to muons
A study of high energy muons traversing the ATLAS hadron Tile calorimeter in the barrel region in the energy range between 10 and 300~GeV is presented. Both test beam experimental data and Monte Carlo simulations are given and show good agreement. The Tile calorimeter capability of detecting isolated muons over the above energy range is demonstrated. A signal to background ratio of about 10 is expected for the nominal LHC luminosity (). The photoelectron statistics effect in the muon shape response is shown. The e/mip ratio is found to be ; the e/ ratio is in the range 0.91 - 0.97. The energy loss of a muon in the calorimeter, dominated by the energy lost in the absorber, can be correlated to the energy loss in the active material. This correlation allows one to correct on an event by event basis the muon energy loss in the calorimeter and therefore reduce the low energy tails in the muon momentum distribution
A measurement of the energy loss spectrum of 150 GeV muons in iron
The energy loss spectrum of 150 GeV muons has been measured with a prototype of the ATLAS hadron calorimeter in the H8 beam of the CERN SPS.\\ The differential probability per radiation length of a fractional energy loss has been measured in the range ; it is then compared with the theoretical predictions for energy losses due to bremsstrahlung and production of electron-positron pairs or of energetic knock-on electrons.\\ The integrated probability is in agreement with the theoretical predictions of and . %7.8.96 - start Agreement with theory is also found in two intervals of where production of electron-positron pairs and knock-on electrons dominates. In the region of bremsstrahlung dominance () the measured integrated probability is in agreement with the theoretical value of , obtained using Petrukhin and Shestakov's \cite{PS} description of the bremsstrahlung process. The same result is about 3.6 standard deviations (defined as the quadratic sum of statistical and systematic errors) lower than the theoretical prediction of , obtained using Tsai's \cite{TS} description of bremsstrahlung
Results from a combined test of an electromagnetic liquid argon calorimeter with a hadronic scintillating-tile calorimeter
The first combined test of an electromagnetic liquid argon accordion calorimeter and a hadronic scintillating-tile calorimeter was carried out at the CERN SPS. These devices are prototypes of the barrel calorimeter of the future ATLAS experiment at the LHC. The energy resolution of pions in the energy range from 20 to 300~GeV at an incident angle of about 11 is well-described by the expression \sigma/E = ((46.5 \pm 6.0)\%/\sqrt{E} +(1.2 \pm 0.3)\%) \oplus (3.2 \pm 0.4)~\mbox{GeV}/E. Shower profiles, shower leakage, and the angular resolution of hadronic showers were also studied
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