Optical Module Front-End for a Neutrino Underwater Telescope: PMT interface

A proposal for a new system to capture signals in the Optical Module (OM) of an Underwater Neutrino Telescope is described. It concentrates on the problem of power consumption in relation to precision. In particular, a solution for the interface between the photomultiplier (PMT) and the front-end electronics is presented

Smart Analogue Sampler for the Optical Module of a Cherenkov Neutrino Detector

A transient waveform sampler/recorder IC has been developed and realized in AMS C35B4 technology. This chip has been designed to fit the needs of a proposal for a front-end architecture for the readout of the anode signal of the photomultipliers in an underwater neutrino telescope. The design is based around a 3 channels x 32 cells switched capacitor array unit sampling its voltage inputs at 200MHz external clock rate and transferring the stored analogue voltage samples to its single analogue output at 1/10th of the sampling rate. This unit is replicated inside the ASIC providing 4 independent analogue sampling queues for signal transients up to 32 x 5 ns and a fifth unit storing transients up to 128 x 5 ns. A micro-pipelined unit, based on Muller C-gates, controls the 5 independent samplers. This paper briefly summarizes the complete front-end architecture and discusses in more detail the internal structure of the ASIC and its first functional tests

Low Power Front End for the Optical Module of a Neutrino Underwater Telescope

A proposal for a new system to capture signals in the Optical Module (OM) of an underwater neutrino telescope is described. It concentrates on the problem of power consumption and time precision. In particular, a solution for the interface between the photomultiplier (PMT) and the front-end electronics is presented

Phenols content and 2-D electrophoresis protein pattern: a promising tool to monitor Posidonia meadows health state

<p>Abstract</p> <p>Background</p> <p>The endemic seagrass <it>Posidonia oceanica </it>(L.) Delile colonizes soft bottoms producing highly productive meadows that play a crucial role in coastal ecosystems dynamics. Human activities and natural events are responsible for a widespread meadows regression; to date the identification of "diagnostic" tools to monitor conservation status is a critical issue. In this study the feasibility of a novel tool to evaluate ecological impacts on <it>Posidonia </it>meadows has been tested. Quantification of a putative stress indicator, <it>i.e</it>. phenols content, has been coupled to 2-D electrophoretic protein analysis of rhizome samples.</p> <p>Results</p> <p>The overall expression pattern from <it>Posidonia </it>rhizome was determined using a preliminary proteomic approach, 437 protein spots were characterized by p<it>I </it>and molecular weight. We found that protein expression differs in samples belonging to sites with high or low phenols: 22 unique protein spots are peculiar of "low phenols" and 27 other spots characterize "high phenols" samples.</p> <p>Conclusion</p> <p><it>Posidonia </it>showed phenols variations within the meadow, that probably reflect the heterogeneity of environmental pressures. In addition, comparison of the 2-D electrophoresis patterns allowed to highlight qualitative protein expression differences in response to these pressures. These differences may account for changes in metabolic/physiological pathways as adaptation to stress. A combined approach, based on phenols content determination and 2-D electrophoresis protein pattern, seems a promising tool to monitor <it>Posidonia </it>meadows health state.</p

Proposal, development and test of an analog front-end electronic board for Nemo telescope

The NEMO collaboration is involved in the R&D of the main technologies for the project of a km3 scale underwater neutrino telescope. The proposed detector is made up of thousands of Optical Modules (hereafter OM), spread over the entire volume for Cˇ erenkov light detection. Each OMis equipped with a photo multiplier tube (PMT) and an electronic circuit for data acquisition and transmission (DAQ-Board). This work points out the possible benefits of a hybrid solution based on an analog ASIC (Application Specific Integrated Circuit) employed for the analog signal acquisition and an FPGA (Field Programmable Gate Array), a digital programmable IC (Integrated Circuit) which performs the data acquisition and the data transmission

FoodOmics as a new frontier to reveal microbial community and metabolic processes occurring on table olives fermentation

Table olives are considered the most widespread fermented food in the Mediterranean area and their consumption is expanding all over the world. This fermented vegetable can be considered as a natural functional food thanks to their high nutritional value and high content of bioactive compounds that contribute to the health and well-being of consumers. The presence of bioactive compounds is strongly influenced by a complex microbial consortium, traditionally exploited through culture-dependent approaches. Recently, the rapid spread of omics technologies has represented an important challenge to better understand the function, the adaptation and the exploitation of microbial diversity in different complex ecosystems, such as table olives. This review provides an overview of the potentiality of omics technologies to in depth investigate the microbial composition and the metabolic processes that drive the table olives fermentation, affecting both sensorial profile and safety properties of the final product. Finally, the review points out the role of omics approaches to raise at higher sophisticated level the investigations on microbial, gene, protein, and metabolite, with huge potential for the integration of table olives composition with functional assessments

Three-years of SO2 flux measurements of Mt. Etna using an automated UV scanner array: comparison with conventional traverses and uncertainties in flux retrieval

Routine measurements of SO2 flux using the traverse method on Mt. Etna (Italy) were augmented in late 2004 when an array of automatic scanning ultraviolet spectrometers was installed. Each instrument allows one SO2 scan to be recorded every ~6 min. Here we report the methods that we developed to automatically and robustly transform SO2 profiles into SO2 flux data. Radian geometry and Fast Fourier Transform algorithm were used for reducing plume cross sections and for discriminating between volcanic plumes from those produced by water vapour clouds. Uncertainty in flux measurements depends on the accuracy of plume-height estimation, on assumptions concerning plume-geometry, and on the quality of the retrieved SO2 amounts. We compare 3 years of flux measurements made using both the automated network and “conventional” traverse methods beneath the plume. We found a good agreement between the datasets, both in terms of magnitude and in temporal variations. These results validate the Etna SO2 flux monitoring system. Emission rates are available to the 24-hour manned operations room via intranet, providing real-time information on degassing rates and plume location

Study of the effects of salt crystallisation on degradation of limestone rocks

Salt crystallization is widely recognized as a cause of deterioration of porous building materials. In particular, the crystallization pressure of salt crystals growing in confined pores is found to be the main cause for damage. The aim of this study is to better understand the degradation of porous rocks induced by salt crystallisation and correlate such processes with the intrinsic characteristics of materials. With this intend, an experimental salt weathering simulation has been carried out on two limestones widely used in the Baroque architecture of eastern Sicily. A systematic approach including petrographic, porosimetric and colorimetric analyses, was used to evaluate the correlation among salt crystallisation, microstructural and chromatic variations of limestone. Results showed a quite different resistance of the two limestones to salt damage, and this was found to be strongly dependent on their pore structure and textural characteristics