Modelling of an IR scintillation counter

A systematic study of the excitation and de-excitation mechanisms in ternary gas mixtures Ar+CO2+N2 is presented regarding the possibility of developing a proportional scintillation counter based on the detection of the infrared molecular emissions associated with the lowest vibrational states of molecules. The use of visible or near-infrared photons ([lambda]<1 [mu]m) for applications like imaging and quality control of microstructure detectors has been reported. In view of these applications we analyse the processes leading to near-infrared emissions in pure argon and give an estimation of the number of photons emitted per electron, at several pressures, as a function of the charge gain.http://www.sciencedirect.com/science/article/B6TJM-3YXB101-2M/1/b5bfeb3739389bb6dbe4d84c8746dbf

Gait maturation in children with cerebral palsy: A pilot study

This study aimed at observing children with cerebral palsy's (CP) gait maturation and to correlate gait maturation's motor skill parameters. Podogram and video shooting of eight children's gait were used. Children up to seven years of age participated in the study. Cluster analysis was applied, dividing the sample into two groups, using the relation between pelvis’ width and the spreading of the ankles (REL) as parameters. Data were analyzed using t-test, analysis of Deltas, and Pearson’s correlation. Deviance from normality for all the parameters was demonstrated with greater failure in speed and cadence and a significant correlation among these parameters, and yet between them and the REL parameter. Although children with CP had acquired gait, they still do it immaturely

Quality control of GEM detectors using scintillation techniques

Non destructive quality control of microstructures at the manufacturing stage is an important issue in the foreseen use of huge numbers of such gaseous detectors in the future high luminosity colliders. In this work we report on the use of the scintillation light emitted by the avalanches in GEM channels for checking defects in the foils. The test system is described and data on the relative efficiency of several gaseous mixtures are presented. The foil images obtained with a low-noise CCD system are analysed and compared with the optical images obtained with an industrial inspection system of high magnification. The validity of this test method is established and possible extensions of its use are discussed.Comment: 11 pages, 9 figure

The Energy Resolution and Window Area Capabilities of the Gas Proportional Scintillation Counter

The behaviour of xenon and argon-xenon gas proportional scintillation counters is con sidered. For X-rays, ranges of window area are defined showing competition with semiconductor detectors. Data for primary scintillation of X-rays and alpha particles are included. Relative efficiencies of tetraphenylbutadiene, p-terphenyl, diphenyl-stilbene, sodium salicylate and p-quaterphenyl were measure

Kinematical changes in swimming front crawl and breaststroke with the AquaTrainer® snorkel

The aim of the present study was to assess the kinematical changes when swimming maximal bouts in Front Crawl and Breaststroke with the AquaTrainer® snorkel. Thirteen male swimmers (7 at Breaststroke and 6 at Front Crawl) of national level performed randomly two maximal bouts of 100-m swims: one bout using the Aqua- Trainer® snorkel (snorkel swim) and another one without the snorkel (free swim). The swims were videotaped in sagital plane with a pair of cameras providing 2D kinematics evaluation. The following measures were assessed: swimming performance (T100), stroke cycle period (P), stroke rate (SR), stroke length (SL), swimming velocity (v), swimming eYciency as estimated by the stroke index (SI), speed Xuctuation (dv) and the mathematical characterisation of dv. T100 was signiWcantly higher when swimming with the snorkel than in free swimming at Breaststroke (= 6.26%) and at Front Crawl (= 4.75%). P, SR and SL, as well as SI and dv did not present signiWcant diVerences. The main Wnding of the study was that changes in the swimming velocity imposed by the use of the Aquatrainer® do not seem due to changes in general kinematics or swimming eYcienc

Quality control of GEM detectors using scintillation techniques

Non-destructive quality control of microstructures at the manufacturing stage is an important issue in the foreseen use of huge numbers of such gaseous detectors in the future high luminosity colliders. In this work we report on the use of the scintillation light emitted by the avalanches in GEM channels for checking defects in the foils. The test system is described and data on the relative efficiency of several gaseous mixtures are presented. The foil images obtained with a low-noise CCD system are analysed and compared with the optical images obtained with an industrial inspection system of high magnification. The validity of this test method is established and possible extensions of its use are discussed.http://www.sciencedirect.com/science/article/B6TJM-3YXB101-2K/1/86489e830e1d4ba436e110adeb1da95

The Photon-Assisted Cascaded Electron Multiplier: a Concept for Potential Avalanche-Ion Blocking

We present a Photon-Assisted Cascaded Electron Multipliers (PACEM) which has a potential for ion back-flow blocking in gaseous radiation detectors: the avalanche from a first multiplication stage propagates to the successive one via its photons, which in turn induce photoelectron emission from a photocathode deposited on the second multiplier stage; the multiplication process may further continue via electron-avalanche propagation. The photon-mediated stage allows, by a proper choice of geometry and fields, complete blocking of the ion back-flow into the first element; thus, only ions from the latter will flow back to the drift region. The PACEM concept was validated in a double-MHSP (Micro-Hole & Strip Plate) cascaded multiplier operated in xenon, where the intermediate scintillation stage provided optical gain of ~60. The double-MHSP detector had a total gain above 10^4 and energy resolution of 18% FWHM for 5.9 keV x-rays.Comment: 13 pages, 5 figures. Submitted to JINST - electronic Journal of Instrumentation, June 25, 200

Estabilidade da cor de doces em massa de polpa de umbu (Spondias Tuberosa Arr. Cam.) no estádio de maturação verde.

Os frutos de umbu (Spondias tuberosa Arr. Cam.) maduros são altamente perecíveis, e o aproveitamento deles no estádio de maturação verde, sob a forma de doce é uma interessante alternativa econômica, para o semi-árido nordestino. A conservação da cor, durante o armazenamento, constitui um fator de qualidade dos mais importantes para o consumo, e o presente trabalho objetivou avaliar sua alteração em função de diferentes formulações, embalagens (polipropileno e celofane) e temperaturas (33 e 43°C), por 90 dias de armazenamento. A adição de pectina e/ou xarope de glicose não alterou a luminosidade (L*), mas diminuiu os valores de a* (intensidade do vermelho ) e b*. (intensidade do amarelo). Verificou-se diminuição dos valores de L* a* e b*, notadamente para os doces armazenados à temperatura de 43°C e para a formulação sem adição de pectina. A embalagem não exerceu efeito significativo sobre L*( luminosidade), mas afetou a* e b* aos 90 dias de estocagem, em ambas as temperaturas. Os resultados globais indicaram o uso de pectina e xarope de glicose, embalagens de polipropileno e estocagem à temperaturas mais baixas como sendo as condições mais adequadas para preservação da cor