Study of ion feedback in multi-GEM structures

We study the feedback of positive ions in triple and quadruple Gas Electron Multiplier (GEM) detectors. The effects of GEM hole diameter, detector gain, applied voltages, number of GEMs and other parameters on ion feedback are investigated in detail. In particular, it was found that the ion feedback is independent of the gas mixture and the pressure. In the optimized multi-GEM structure, the ion feedback current can be suppressed down to 0.5% of the anode current, at a drift field of 0.1 kV/cm and gain of 10^4. A simple model of ion feedback in multi-GEM structures is suggested. The results obtained are relevant to the performance of time projection chambers and gas photomultipliers.Comment: 9 pages, 11 figures. Submitted to Nucl. Instr. and Meth.

Light multi-GEM detector for high-resolution tracking systems

Controlled etching of copper electrodes in Gas Electron Multiplier foils allows a reduction of the material budget by more than a factor of two for a triple-GEM detector. Detectors making use of thinned foils provide performances similar to those obtained with standard devices: a gain above 10^4 for a double-GEM, with energy resolution of 27 % fwhm for 5.9 keV X-rays.Comment: Submitted to Nucl.Instr.& Meth.

Mid-infrared sub-wavelength grating mirror design: tolerance and influence of technological constraints

High polarization selective Si/SiO2 mid-infrared sub-wavelength grating mirrors with large bandwidth adapted to VCSEL integration are compared. These mirrors have been automatically designed for operation at \lambda = 2.3 $\mu$m by an optimization algorithm which maximizes a specially defined quality factor. Several technological constraints in relation with the grating manufacturing process have been imposed within the optimization algorithm and their impact on the optical properties of the mirror have been evaluated. Furthermore, through the tolerance computation of the different dimensions of the structure, the robustness with respect to fabrication errors has been tested. Finally, it appears that the increase of the optical performances of the mirror imposes a less tolerant design with severer technological constraints resulting in a more stringent control of the manufacturing process.Comment: The final publication is available at http://iopscience.iop.org/2040-8986/13/12/125502

Development of a triple GEM UV-photon detector operated in pure CF4 for the PHENIX experiment

Results obtained with a triple GEM detector operated in pure CF4 with and without a reflective CsI photocathode are presented. The detector operates in a stable mode at gains up to 10^4. A deviation from exponential growth starts to develop when the total charge exceeds ~ 4 10^6 e leading to gain saturation when the total charge is ~ 2 10^7 e and making the structure relatively robust against discharges. No aging effects are observed in the GEM foils after a total accumulated charge of ~ 10 mC/cm^2 at the anode. The ion back-flow current to the reflective photocathode is comparable to the electron current to the anode. However, no significant degradation of the CsI photocathode is observed for a total ion back-flow charge of ~ 7 mC/cm^2.Comment: 14 pages, 11 figures, Submitted to NIM

Economic inequalities in burden of illness, diagnosis and treatment of five long-term conditions in England: panel study

We compared the distribution by wealth of self-reported illness burden (estimated from validated scales, biomarker and reported symptoms) for angina, cataract, depression, diabetes and osteoarthritis, with the distribution of self-reported medical diagnosis and treatment. We aimed to determine if the greater illness burden borne by poorer participants was matched by appropriately higher levels of diagnosis and treatment

Conformational Mechanics of Polymer Adsorption Transitions at Attractive Substrates

Conformational phases of a semiflexible off-lattice homopolymer model near an attractive substrate are investigated by means of multicanonical computer simulations. In our polymer-substrate model, nonbonded pairs of monomers as well as monomers and the substrate interact via attractive van der Waals forces. To characterize conformational phases of this hybrid system, we analyze thermal fluctuations of energetic and structural quantities, as well as adequate docking parameters. Introducing a solvent parameter related to the strength of the surface attraction, we construct and discuss the solubility-temperature phase diagram. Apart from the main phases of adsorbed and desorbed conformations, we identify several other phase transitions such as the freezing transition between energy-dominated crystalline low-temperature structures and globular entropy-dominated conformations.Comment: 13 pages, 15 figure

Orale Mukositis bei Patienten unter Tumortherapie

Zusammenfassung: Zu den unerwünschten Nebenwirkungen bestimmter Chemo- und Radiotherapien gehört die orale Mukositis, eine Entzündung der Mundschleimhaut. Da sie die Lebensqualität der Patienten in hohem Maße beeinträchtigen kann, sollten Pflegende der Mundhygiene einen besonders hohen Stellenwert beimessen. In der täglichen Praxis wird die orale Mukositis oft kontrovers diskutiert. In diesem Artikel werden aktuelle theoriebasierte und erfahrungsbasierte Grundlagen und Anleitungen für die Pflege und Behandlung vorgestell

SERVice Oriented Intelligent Value Adding nEtwork for Clothing-SMEs embarking in Mass-Customisation [as a result of the Automatic knitting Sites pilot, Task D6.2a]. CORDIS.

Executive Summary: This report describes the outcomes of research and development work done by IFTH (France) and Nottingham Trent University (UK) to develop and evaluate the procedures for a business model to produce commercially customised fully-fashioned knitwear. It builds on the initial work done by Unicatum, RWTH and Hohenstein Institute (Germany). The purpose was to demonstrate the commercial potential for on-demand, localised manufacturing of up-market fashion products using new technology. The target market was upper-middle market knitwear for ladies, typical products being a jumper, cardigan or dress. As with the rest of the SERVIVE project, customisation has been assumed to be linked to style advice. Thus part of the overall product and consumer experience is the initial process of co-design. This is partly illustrated in the video of the demonstration [see http://www.youtube.com/watch?v=WIodKyciJAM]. However as this could vary according to each retailer (e.g. web-based or personal style advisor, product category, etc.), this aspect is better covered in other SERVIVE project deliverables. The key technology assumed in the micro-factory is one or more whole-garment 3D knitting machines. It is recognised that this can be an option with circular knitting (e.g. Santoni), but in this instance the focus is on the multiple flat-bed technology such as is available from Stoll and Shima Seiki