Daytime lidar measurements of tidal winds in the mesospheric sodium layer at Urbana, Illinois

For more than 15 years lidar systems have been used to study the chemistry and dynamics of the mesospheric sodium layer. Because the layer is an excellent tracer of atmospheric wave motions, sodium lidar has proven to be particularly useful for studying the influence of gravity waves and tides on mesospheric dynamics. These waves, which originate in the troposphere and stratosphere, propagate through the mesosphere and dissipate their energy near the mesopause making important contributions to the momentum and turbulence budget in this region of the atmosphere. Recently, the sodium lidar was modified for daytime operation so that wave phenomena and chemical effects could be monitored throughout the complete diurnal cycle. The results of continuous 24 hour lidar observations of the sodium layer structure are presented alond with measurement of the semidiurnal tidal winds

Herd-level risk factors influencing serological Yersinia prevalence in fattening pig herds

Yersiniosis is the third most frequent zoonosis reported in the European Union with pork as an important source. Identifying risk factors in swine production which may decrease the risk of pork production contamination during pre-harvest is an important step prior to controlling Yersinia spp.. Therefore, management strategies and production processes which might be associated with fattening pigs testing seropositive for pathogenic Yersinia spp. were investigated on 80 fattening pig farms. Although more than 70 farm characteristics were included in the risk assessment, there were only a few which seemed to be connected with serological prevalence: housing on a fully slatted floor and the use of municipal water were observed in herds with low serological Yersinia prevalence, whereas recurring health problems and a low daily weight gain compared to the mean of the herds included in the study were identified more often in herds with a high prevalence

The Contribution of Renewable Energy to a Sustainable Energy System

This report provides an overview of the main results from the scenarios analysed in the CASCADE MINTS project to assess the role of renewables in solving global and European en-ergy and environmental issues. The main conclusion is that renewable energy can make a sub-stantial contribution to reducing greenhouse gas emissions and improving diversification of the European energy production portfolio, although other technologies will also be needed in order to achieve post Kyoto targets. The report outlines the impacts, costs and benefits of ambitious renewables targets for Europe in the medium term. It also presents lessons learned from taking the global perspective

Characterisation of ionisation chambers for a mixed radiation field and investigation of their suitability as radiation monitors for the LHC

Monitoring of the radiation environment is one of the key tasks in operating a high-energy accelerator such as the Large Hadron Collider (LHC). The radiation fields consist of neutrons, charged hadrons as well as photons and electrons with energy spectra extending from those of thermal neutrons up to several hundreds of GeV. The requirements for measuring the dose equivalent in such a field are different from standard uses and it is thus necessary to investigate the response of monitoring devices thoroughly before the implementation of a monitoring system can be conducted. For the LHC, it is currently foreseen to install argon- and hydrogen-filled high-pressure ionisation chambers as radiation monitors of mixed fields. So far their response to these fields was poorly understood and, therefore, further investigation was necessary to prove that they can serve their function well enough. In this study, ionisation chambers of type IG5 (Centronic Ltd) were characterised by simulating their response functions by means of detailed FLUKA calculations as well as by calibration measurements for photons and neutrons at fixed energies. The latter results were used to obtain a better understanding and validation of the FLUKA simulations. Tests were also conducted at the CERF facility at CERN in order to compare the results with simulations of the response in a mixed radiation field. It is demonstrated that these detectors can be characterised sufficiently enough to serve their function as radiation monitors for the LH

FORCE ANALYSIS OF THE UNDERWATER STATIONARY RUNNIG

It aimed to analyze the vertical component of the ground reaction force in the underwater stationary running. The sample was composed by 6 subjects divided in two groups (Male Group and Female Group). The underwater stationary running was performed in two immersion levels: in the hip level and in the xiphoid process level. An underwater force plate was used. For data analysis descriptive statistics was used. The mean values of vertical GRF were 2,08BW for the MG and 1,69BW for the FG in the hip level; 1,15BW for the MG and 1,12BW for the FG in the xiphoid process level. The results showed the vertical component of the GRF is affected by the immersion level and by the frequency of the activity. Both factors should be considered by professionals who work with therapeutic or physical conditioning programs using the underwater stationary running

A model for in vitro evaluation of overlapping connections between devices used in the endovascular repair of popliteal aneurysms

This work proposes a new methodology to investigate the potential for disconnection (Type III endoleak) of pairs of overlapped endoprostheses in a popliteal model vessel after a cyclic physiologic load, for three different overlap lengths. A multiaxial fatigue accelerated testing was designed to mimic the physiological loads and movements to which the peripheral arteries are submitted during gait. The experiment design was based on principles from technical standards ASTM F2477-07 and ASTM F2942-13. Migration and disconnection were monitored by DIC (Digital Image Correlation) for three different overlap lengths (20, 30 and 40mm). The testing method proposed in this work was efficient to provide a simulated environment to evaluate the influence of gait biomechanics on overlapped endoprosthesis disconnection. Obtained results demonstrated minimal or absence of relevant migration between the endoprosthesis, range -0.06 to 0,34 millimeters. The proposed methodology was verified as a valuable tool to investigate the influence of the biomechanical environment which the devices are subjected to on the migration of overlapped endoprosthesis. It may become a new alternative to study the pre-clinical in vitro performance of single endoprosthesis or multiple connected devices with different overlapped regions

The influence of the type of filling gas on the response of ionisation chambers to a mixed high-energy radiation field

Radiation protection dosimetry in radiation fields behind the shielding of high-energy accelerators such as CERN is a challenging task and the quantitative understanding of the detector response used for dosimetry is essential. Measurements with ionisation chambers are a standard method to determine absorbed dose (in the detector material). For applications in mixed radiation fields, ionisation chambers are often also calibrated in terms of ambient dose equivalent at conventional reference radiation fields. The response of a given ionisation chamber to the various particle types of a complex high-energy radiation field in terms of ambient dose equivalent depends of course on the materials used for the construction and the chamber gas used. This paper will present results of computational studies simulating the exposure of high-pressure ionisation chambers filled with different types of gases to the radiation field at CERN's CERN-EU high-energy reference field facility. At this facility complex high-energy radiation fields, similar to those produced by cosmic rays at flight altitudes, are produced. The particle fluence and spectra calculated with FLUKA Monte Carlo simulations have been benchmarked in several measurements. The results can be used to optimise the response of ionisation chambers for the measurement of ambient dose equivalent in high-energy mixed radiation field

Epitaxial and layer-by-layer growth of EuO thin films on yttria-stabilized cubic zirconia (001) using MBE distillation

We have succeeded in growing epitaxial and highly stoichiometric films of EuO on yttria-stabilized cubic zirconia (YSZ) (001). The use of the Eu-distillation process during the molecular beam epitaxy assisted growth enables the consistent achievement of stoichiometry. We have also succeeded in growing the films in a layer-by-layer fashion by fine tuning the Eu vs. oxygen deposition rates. The initial stages of growth involve the limited supply of oxygen from the YSZ substrate, but the EuO stoichiometry can still be well maintained. The films grown were sufficiently smooth so that the capping with a thin layer of aluminum was leak tight and enabled ex situ experiments free from trivalent Eu species. The findings were used to obtain recipes for better epitaxial growth of EuO on MgO (001).Comment: 10 pages, 15 figure

Field calibration studies for ionisation chambers in mixed high-energy radiation fields

The monitoring of ambient doses at work places around high-energy accelerators is a challenging task due the complexity of the mixed stray radiation fields encountered. At CERN, mainly Centronics IG5 high-pressure ionisation chambers are used to monitor radiation exposure in mixed fields. The monitors are calibrated in the operational quantity ambient dose equivalent H*(10) using standard, source-generated photon- and neutron fields. However, the relationship between ionisation chamber reading and ambient dose equivalent in a mixed high-energy radiation field can only be assessed if the spectral response to every component and the field composition is known. Therefore, comprehensive studies were performed at the CERN-EU high-energy reference field facility where the spectral fluence for each particle type has been assessed with Monte Carlo simulations. Moreover, studies have been performed in an accessible controlled radiation area in the vicinity of a beam loss point of CERN's proton synchrotron. The comparison of measurements and calculations has shown reasonable agreement for most exposure conditions. The results indicate that conventionally calibrated ionisation chambers can give satisfactory response in terms of ambient dose equivalent in stray radiation fields at high-energy accelerators in many cases. These studies are one step towards establishing a method of ‘field calibration' of radiation protection instruments in which Monte Carlo simulations will be used to establish a correct correlation between the response of specific detectors to a given high-energy radiation fiel

Initial State: Theory Status

I present a brief discussion of the different approaches to the study initial state effects in heavy ion collisions in view of the recent results from Pb+Pb and p+p collisions at the LHC.Comment: 8 pages, 6 figures. Contribution to the proceedings of the XXII International Conference on Ultrarelativistic Nucleus-Nucleus Collisions, QM2011. Annecy, France, 22-28 May 201