Thermoluminescence of a mixed rare earth phosphate powder La1−x−yCexTbyPO4

International audienceThe properties of thermoluminescence (TL) observed from various mixed rare earth (RE) phosphate powders La1−x−yCexTbyPO4 are reported. TL peaks appear around −175°C, −135°C, −80°C, −35°C and +25°C and the TL emission spectra of La1−x−yCexTbyPO4 are mainly composed of characteristic line transitions of Tb3+ ions. The results show that the co-doping with Ce3+ is not required to observe the TL emission of Tb3+. A model for the recombination mechanisms of the various TL peaks is discussed

Low temperature synthesis of ZnGa2O4 : Mn

International audienceThe dependence of the firing conditions on the crystal structure formation of ZnGa2O4 has been investigated. The effects of temperature and atmosphere were examined and gave evidence of the instability of the zinc gallate under a reducing atmosphere at temperatures above 600 degrees C. A new preparation route has allowed to synthesize ZnGa2O4 at low temperature, right from 300 degrees C, avoiding the decomposition of the matrix during the annealing. Moreover, a different behavior under excitation has been observed for the phosphor prepared via this new route compared with the compound obtained by solid state reaction. A model, based on the optical behavior observed, is presented

Synthesis of europium and disprosium activated strontium monoaluminate

International audienceThe formation of SrAl2O4 by solid state reaction between SrCO3 and Al2O3 has been studied. The firing conditions, namely the time, the atmosphere and the temperature, have been optimized so as to obtain pure well crystallized SrAl2O4, allowing the further study of the influence of the atmosphere on the optoelectronic properties of the phosphor. To this end, fluorescent and thermoluminescent experiments have been carried out in order to characterize the defects responsible for the phosphorescent mechanism

mF2C: Towards a coordinated management of the IoT-fof-cloud continuum

Fog computing enables location dependent resource allocation and low latency services, while fostering novel market and business opportunities in the cloud sector. Aligned to this trend, we refer to Fog-tocloud (F2C) computing system as a new pool of resources, set into a layered and hierarchical model, intended to ease the entire fog and cloud resources management and coordination. The H2020 project mF2C aims at designing, developing and testing a first attempt for a real F2C architecture. This document outlines the architecture and main functionalities of the management framework designed in the mF2C project to coordinate the execution of services in the envisioned set of heterogeneous anddistributed resources.Postprint (author's final draft

Prognostic value of increase in transcript levels of Tp73 ΔEx2-3 isoforms in low-grade glioma patients

Glial tumours are a devastating, poorly understood condition carrying a gloomy prognosis for which clinicians sorely lack reliable predictive parameters facilitating a sound treatment strategy. Tp73, a p53 family member, expresses two main classes of isoforms – transactivatory activity (TA)p73 and ΔTAp73 – exhibiting tumour suppressor gene and oncogene properties, respectively. The authors examined their expression status in high- and low-grade adult gliomas. Isoform-specific real-time reverse transcription-polymerase chain reaction was used for the analysis of Tp73 isoform transcript expression in a series of 51 adult patients harbouring glial tumours, in order to compare tumour grades with each other, and with non-tumoural samples obtained from epileptic patients as well. Our data demonstrate increase of TAp73 and ΔTAp73 transcript levels at onset and early stage of the disease. We also show that ΔEx2–3 isoform expression in low-grade tumours anticipates clinical and imaging progression to higher grades, and correlates to the patients' survival. Expression levels of P1 promoter generated Tp73 isoforms – and particularly ΔEx2–3 – indeed allow for prediction of the clinical progression of low-grade gliomas in adults. Our data are the first such molecular biology report regarding low-grade tumours and as such should be of help for sound decision-making

University of Southampton takes science into the schools

This paper describes the educational outreach work in local schools by the Optical Society of America Student Chapter based in Southampton at the Optoelectronics Research Centre

Patricia Era Bath: a community Ophthalmologist

Dr. Patricia Era Bath was not only a medical doctor but also an ophthalmologist, a laser scientist, a surgeon, a researcher, an inventor, an activist, and a humanitarian. She is best known as the inventor of laser cataract removal but also proposed a new discipline in medicine to promote technical, medical, and social aspects of eye care and blindness prevention. As such, she passively and actively allowed millions of people across the world to recover their sight

UV-written devices in rare-earth doped silica-on-silicon grown by FHD

This thesis is concerned with the fabrication of all-UV-written devices in rare-earth doped silica-on-silicon to demonstrate the viability of this versatile single step channel definition process for the production of light sources. The requirements for the glass substrate and the fabrication of waveguiding structures through use of the Flame Hydrolysis Deposition technique are discussed. The development of a process for rare-earth doping of the core layer through the immersion of a partially consolidated soot into a solution containing rare-earth ions is presented. The pre-requisites for direct-UV-writing of channels in a three-layer buried waveguide structure are then considered and results on the physical behaviour of the channels and spectroscopic properties of the rare-earth ions are reported. This study has resulted in the first demonstration of an all-UV-written waveguide laser in silica-on-silicon. Low-loss operation (0.11-0.3 dBcm-1) of a 10mm long channel waveguide laser doped with 1.26wt% of neodymium was demonstrated with efficient lasing action (~ 33% slope efficiency). Erbium, ytterbium and thulium doping have been investigated to allow the production of light sources at other wavelengths. Further optimisation is still required to allow lasing to be achieved. Nevertheless, demonstration of y-splitters and Bragg grating fabrication in the doped material shows the potential of the combined fabrication techniques for the production of DFB laser-arrays for WDM technology. The additional developments required for the production of such devices are also discussed

Functionalized Transparent Surfaces with Enhanced Self-Cleaning against Ink Aerosol Contamination

During operation of a standard commercial inkjet printer, suspended ink particles form an ink aerosol inside the printing chamber that can cause serious malfunctions, including contamination of the transparent window of the printhead position calibration optical sensors. In this work, transparent conducting film (TCF) and surface functionalization through self-assembled monolayer (SAM) are proposed and investigated to repel ink aerosol deposition on a transparent surface and to reduce its adverse effects. The results show that the combination of the Joule heating effect induced by applying an electrical current to the TCF and hydrophobic property of the SAM reduces transmittance loss from an average of 10% to less than 1.5%. Correspondingly, the area of the surface covered by ink decreases from 45.62% ± 6.15% to 1.71% ± 0.25%. The preliminary results are obtained with glass substrates and subsequently extended to the plastic window of a commercial inkjet printer calibration sensor, thus demonstrating the potential of the proposed approach to reduce aerosol contamination in real applications.Peer Reviewe

Synthèse basse température du gallate de zinc

st Brazilian Congress on Thermal Analysis and Calorimetry (I CBRATEC); Minas Gerais, Braz; 29 March 1998 through 2 April 1998International audienceThe dependence of the firing conditions on the crystal structure formation of ZnGa2 O4 has been investigated. The effects of temperature and atmosphere were examined and gave evidence of the instability of the zinc gallate under a reducing atmosphere at temperatures above 600°C. A new preparation route has allowed to synthesize ZnGa2 O4 at low-temperature, right from 300°C, avoiding the decomposition of the matrix during the annealing