Jahn-Teller Spectral Fingerprint in Molecular Photoemission: C60

The h_u hole spectral intensity for C60 -> C60+ molecular photoemission is calculated at finite temperature by a parameter-free Lanczos diagonalization of the electron-vibration Hamiltonian, including the full 8 H_g, 6 G_g, and 2 A_g mode couplings. The computed spectrum at 800 K is in striking agreement with gas-phase data. The energy separation of the first main shoulder from the main photoemission peak, 230 meV in C60, is shown to measure directly and rather generally the strength of the final-state Jahn-Teller coupling.Comment: 5 pages, 3 figure

Precipitation products from the hydrology SAF

Abstract. The EUMETSAT Satellite Application Facility on Support to Operational Hydrology and Water Management (H-SAF) was established by the EUMETSAT Council on 3 July 2005, starting activity on 1 September 2005. The Italian Meteorological Service serves as Leading Entity on behalf of twelve European member countries. H-SAF products include precipitation, soil moisture and snow parameters. Some products are based only on satellite observations, while other products are based on the assimilation of satellite measurements/products into numerical models. In addition to product development and generation, H-SAF includes a product validation program and a hydrological validation program that are coordinated, respectively, by the Italian Department of Civil Protection and by the Polish Institute of Meteorology and Water Management. The National Center of Aeronautical Meteorology and Climatology (CNMCA) of the Italian Air Force is responsible for operational product generation and dissemination. In this paper we describe the H-SAF precipitation algorithms and products, which have been developed by the Italian Institute of Atmospheric Sciences and Climate (in collaboration with the international community) and by CNMCA during the Development Phase (DP, 2005–2010) and the first Continuous Development and Operations Phase (CDOP-1, 2010–2012). The precipitation products are based on passive microwave measurements obtained from radiometers onboard different sun-synchronous low-Earth-orbiting satellites (especially, the SSM/I and SSMIS radiometers onboard DMSP satellites and the AMSU-A + AMSU-B/MHS radiometer suites onboard EPS-MetOp and NOAA-POES satellites), as well as on combined infrared/passive microwave measurements in which the passive microwave precipitation estimates are used in conjunction with SEVIRI images from the geostationary MSG satellite. Moreover, the H-SAF product generation and dissemination chain and independent product validation activities are described. Also, the H-SAF program and its associated activities that currently are being carried out or are planned to be performed within the second CDOP phase (CDOP-2, 2012–2017) are presented in some detail. Insofar as CDOP-2 is concerned, it is emphasized that all algorithms and processing schemes will be improved and enhanced so as to extend them to satellites that will be operational within this decade – particularly the geostationary Meteosat Third Generation satellites and the low-Earth-orbiting Core Observatory of the international Global Precipitation Measurement mission. Finally, the role of H-SAF within the international science and operations community is explained.</p

The validation service of the hydrological SAF geostationary and polar satellite precipitation products

Abstract. The development phase (DP) of the EUMETSAT Satellite Application Facility for Support to Operational Hydrology and Water Management (H-SAF) led to the design and implementation of several precipitation products, after 5 yr (2005–2010) of activity. Presently, five precipitation estimation algorithms based on data from passive microwave and infrared sensors, on board geostationary and sun-synchronous platforms, function in operational mode at the H-SAF hosting institute to provide near real-time precipitation products at different spatial and temporal resolutions. In order to evaluate the precipitation product accuracy, a validation activity has been established since the beginning of the project. A Precipitation Product Validation Group (PPVG) works in parallel with the development of the estimation algorithms with two aims: to provide the algorithm developers with indications to refine algorithms and products, and to evaluate the error structure to be associated with the operational products. In this paper, the framework of the PPVG is presented: (a) the characteristics of the ground reference data available to H-SAF (i.e. radar and rain gauge networks), (b) the agreed upon validation strategy settled among the eight European countries participating in the PPVG, and (c) the steps of the validation procedures. The quality of the reference data is discussed, and the efforts for its improvement are outlined, with special emphasis on the definition of a ground radar quality map and on the implementation of a suitable rain gauge interpolation algorithm. The work done during the H-SAF development phase has led the PPVG to converge into a common validation procedure among the members, taking advantage of the experience acquired by each one of them in the validation of H-SAF products. The methodology is presented here, indicating the main steps of the validation procedure (ground data quality control, spatial interpolation, up-scaling of radar data vs. satellite grid, statistical score evaluation, case study analysis). Finally, an overview of the results is presented, focusing on the monthly statistical indicators, referred to the satellite product performances over different seasons and areas

Changes in regular condom use among immigrant transsexuals attending a counselling and testing reference site in central Rome: a 12 year study

Objective: To analyse data from male to female transsexuals attending between 1992 and 2003 an outpatient clinic considered the main HIV counselling and testing site in Rome for foreign people. Methods: Data collected between 1992 and 2003, from a routine anti-HIV testing and counselling activity, were analysed. A brief standard interview was performed at each test. A cross sectional analysis to assess the association of regular condom use with demographic and behavioural variables using multiple logistic regression was performed. A follow up analysis to define the effect of single factors on the occurrence of new anti-HIV seroconversions was also performed. The incidence of anti-HIV seroconversion was calculated in person years of observation. Results: Overall, 473 transsexuals sex workers were tested. Most of them (99%) were from South America (mainly Columbia and Brazil). Anti-HIV prevalence was 32%, but a progressive decrease over time was observed (from 57% in 1993 to12% in 2003). The proportion of patients reporting regular condom use at enrolment was 75%. A progressive increase in regular condom use was reported over time (from 43% in 1992–3 to 79% in 2002–3). 15 new HIV infections were observed during follow up (incidence 2.1 per 100 person years). Though the proportion of patients reporting regular condom use increased over time, 10 out of the 15 new infections occurred in patients reporting unprotected sex during follow up (rate 8.4 per 100 person years). Conclusions: Our data suggest that counselling may lead to an increase in safe sex practices among immigrant transsexuals. However, the incidence of new HIV infections is still high and mainly related to non-regular condom use, which still remains the primary objective of prevention

0.16 μm BCD single-photon avalanche diode with 30 ps timing jitter, high detection efficiency and low noise

CMOS SPADs are nowadays an established imaging technology for applications requiring single-photon sensitivity in a compact form-factor (e.g. three-dimensional LIDAR imaging and fluorescence lifetime FLIM microscopy). However, we aimed at further enhance overall SPAD performances, by exploiting smart power technologies, such as the BCD (Bipolar-CMOS-DMOS) one. We achieved the present state-of-the-art SPADs fabricated in the 0.16 mu m BCD technology by STMicroelectronics, attaining &gt;60% photon detection efficiency at 500 nm, dark count rate density &lt;0.2 cps/mu m(2), and less than 30 ps FWHM timing jitter

An Efficient Method for LED Light Sources Characterization

Digital LED drivers capable of blending the spectrum of two LED fixtures with different Correlated Color Temperatures through the LEDs' power supply control are widespread. However, the digital control of lighting systems is possible only after a careful study of the LED's response, in terms of illuminance and Correlated Color Temperature. The proposed work takes advantage of the Tunable White technology for the realization of an efficient method for LED light source characterization. In order to evaluate how the light changes as a function of the electric power supplied by the LED drivers, an experimental setup to characterize LED light sources has been designed. Starting from the data acquired from the experimental setup, a model for dimming the LED driver and obtaining the desired values of quality of light has been developed. The proposed model is based on the least squares method and its accuracy is evaluated by comparing the obtained values of illuminance and Correlated Color Temperature with those measured by an illuminance spectrophotometer. Results achieved an error of 0.3% for Correlated Color Temperature and 1.5% for illuminance using the proposed approximation functions

Investigation of the hot carrier degradation in power LDMOS transistors with customized thick oxide

In this paper, we report a combined experimental/simulation analysis of the degradation induced by hot carrier mechanisms, under ON-state stress, in silicon-based LDMOS transistors. In this regime, electrons can gain sufficient kinetic energy necessary to create interface states, hence inducing device degradation. In particular, the ON-resistance degradation in linear regime has been experimentally characterized by means of different stress conditions and temperatures. The hot-carrier stress regime has been fully reproduced in the frame of TCAD simulations by using physics-based models able to provide the degradation kinetics. A thorough investigation of the spatial interface trap distribution and its gate-bias and temperature dependences has been carried out achieving a quantitative understanding of the degradation effects in the device