Further progress in ion back-flow reduction with patterned gaseous hole-multipliers

A new idea on electrostatic deviation and capture of back-drifting avalanche-ions in cascaded gaseous hole-multipliers is presented. It involves a flipped reversed-bias Micro-Hole & Strip Plate (F-R-MHSP) element, the strips of which are facing the drift region of the multiplier. The ions, originating from successive multiplication stages, are efficiently deviated and captured by such electrode. Experimental results are provided comparing the ion-blocking capability of the F-R-MHSP to that of the reversed-bias Micro-Hole & Strip Plate (R-MHSP) and the Gas Electron Multiplier (GEM). Best ion-blocking results in cascaded hole-multipliers were reached with a detector having the F-R-MHSP as the first multiplication element. A three-element F-R-MHSP/GEM/MHSP cascaded multiplier operated in atmospheric-pressure Ar/CH4 (95/5), at total gain of ~10^{5}, yielded ion back-flow fractions of 3*10^{-4} and 1.5*10^{-4}, at drift fields of 0.5 and 0.2 kV/cm, respectively. We describe the F-R-MHSP concept and the relevance of the obtained ion back-flow fractions to various applications; further ideas are also discussed.Comment: 17 pages, 11 figures, published in JINS

THE DYNAMIC SUPPORT STRUCTURE AND THE FOOT STABILITY RELATED TO RUNNING SPEED

Introduction - The alterations of the dynamic support structure in running, related to the horizontal speed increase, has been studied by several authors; Cavanagh (1989)studies the displacement of the support center and the pressure distributions; Nigg et all (1981) analyses the active and passive loader Bates (1983) study the critical variables defining the support dynamic. Simultaneously, the study of the rearfoot mobility around the horizontal axes of the subtalar joint during ground contact has been gaining in importance (Nigg et all, 1978). The above mentioned subjects are integrated in the present study for a more complete knowledge of the foot contact. Relations between the increase of running speed and respectively the variables defining the rearfoot mobility and the critical variable6 of the ground reaction forces are establish. Methods - Six sprinter of Portuguese national level carried out each of them 6 performances, barefoot, at three different speeds (Vl=3.3 7 me-I+/-0.56 ; V2=4. 37me"+/-0.37 e V,55 -44 me-I+/-0.31). The kinetic data were obtained on a force platform (Kistler 9281B, sampling frequency 1000 Hz) connected t6 the computer via A/D card (DT 2801A Data Translation). The runners speed was controlled by means of photoelectric censors that synchronized the collection of the kinetic and video images. The kinematic data was processed according to the methodology proposed by Nigg et all (1978). Results and Discussion - The obtained kinetic results are similar to those contained in the corresponding bibliographic references , in form patterns as well as in quantitative results (Cavanagh,1989 ; Nigg et a11,1981; Batee et all, 1983). Regarding the rearfoot mobility the displacement/time curves are similar to the ones presented by Nigg et all (1978) as far as barefoot runners are concerned. Significant statistical correlations (correlation coefficient, Bravais-Pearson) were ascertained showing that the running speed increase ie related to : (1) decrease of ground contact time (r=-0.96, P-ZO.01) , (2) increase of anteriorposterior speed variation (aVy) (r50.77,

Human Chronic Necrotizing Granulomatous Meningoencephalitis: A Novel Case Report

Necrotizing and granulomatous meningoencephalitis are common central nervous system diseases known to affect canines. To date, necrotizing granulomatous meningoencephalitis has yet to be described in humans. Current studies of presumed pathogenesis and possible treatment options have only been described in canines. This is a case report of a 55-year-old female patient who was diagnosed with necrotizing granulomatous meningoencephalitis in the setting of new-onset neurological symptoms without any infectious or malignant source

T-Tube Endoscopic Removal by ERCP in a Liver-Transplanted Patient After Failed Percutaneous Removal

info:eu-repo/semantics/publishedVersio

Free mobility, locked rights: the posting of construction workers from Portugal

Mobility has become a cornerstone of the contemporary social world. In the European Union, the removal of barriers aimed at promoting the free movement of the labour force is a major goal of the integration process. This article investigates the political economy of posting, analysing the working and living conditions of Portuguese construction workers posted to other EU Member States. It highlights a set of abusive and exploitative practices involved in posting and the role those practices play in the (de)regulation of labour within the construction sector. In spite of the access to a pan-European labour market and the general principle of equal treatment, posted workers have restricted social rights in the host country. The study presented is based on research developed within the ‘EU Post Lab’ project, aimed at promoting activities of cooperation and awareness raising in the field of posting. The methodology adopted includes document analysis and interviews.info:eu-repo/semantics/acceptedVersio

Nanomaterials with high solar reflectance as an emerging path towards energy-efficient envelope systems: a review

The application of nanomaterials in the construction field is allowing the development of smart, green, durable and more efficient buildings. Among the most widely researched nanomaterials are nanosized cool pigments, which are being enforced to achieve thermal and energy-efficient facades, with the development of high reflectance and retro-reflectance coatings. Their peculiar optical and catalytic activity turns nanomaterials into suitable candidates to be used as dark coloured high solar reflectance without affecting aesthetic characteristics, thus improving the durability of coatings. The objective of this paper is to review the state-of-the-art on the benefits of using high reflectance nanopigments as coatings in building facades and their production and synthesis processes. It is thus divided into three main topics: (i) the benefits of using nanopigments on facades, (ii) the most important nanomaterials used as cool pigments and (iii) the main methods of synthesizing nanopigments. One expects that the study of near-infrared nanopigmentation synthesis processes will be able to promote and disseminate the use of nanotechnology in construction, assessing the production problems and limitation and thus helping to disseminate new products by reducing production costs and increase availability. [GRAPHICS]