545 research outputs found

    A match coefficient approach for damage imaging in structural components by ultrasonic synthetic aperture focus

    Get PDF
    Ultrasonic Synthetic Aperture Focus (SAF) techniques are commonly used to image structural defects. In this paper, a variation of SAF based on ideas borrowed from Matched Field Processing (MFP) is evaluated to reduce artifacts and sidelobes of the resulting images. In particular, instead of considering the full RF ultrasonic waveforms for the SAF time backpropagation, only selected features from the waveforms are utilized to form a “data vector” and a “replica” (expected) vector of MFP. These vectors are adaptive for the pair of transmitter-receiver and the focus point. The image is created as a matched filter between these two vectors. Experimental results are shown for an isotropic and homogenous metallic plate with simulated defects, probed by six piezoelectric patches used as receivers or transmitters

    Development of groundwater radon continuous monitors: Comparison between α scintillation and γ spectrometry systems

    Get PDF
    Two temporised continuous monitoring systems, designed to measure the radon concentration in natural environments, mainly groundwater, were assembled, tested and cross-check compared, evaluating the background noise, sensitivity, calibration values and soundest application in the Earth Science framework. The two systems have been customised by DINCE Laboratory, based on best-fitting criteria selected according to the ING laboratory, partially in the frame of two EC funded, Geochemical Seismic Zonation (GSZ) and Automatic Geochemical Monitoring of Volcanoes, addressed to earthquake prediction research and prototype developing, aimed to seismic and volcanic risks surveillance. Following best-fitting criteria of the radon monitoring aimed to natural risk research, both systems are operative by discrete temporised sampling of an aliquot of groundwater, with a minimal interval of six hours. During their functioning at the ENEA Centre of Frascati (Rome), the test-site chosen, both systems provided a continuous and reliable response

    Development, Validation and Preliminary Experiments of a Measuring Technique for Eggs Aging Estimation Based on Pulse Phase Thermography

    Get PDF
    Assessment of the freshness of hen eggs destinated to human consumption is an extremely important goal for the modern food industry and sale chains, as eggs show a rapid natural aging which also depends on the storage conditions. Traditional techniques, such as candling and visual observation, have some practical limitations related to the subjective and qualitative nature of the analysis. The main objective of this paper is to propose a robust and automated approach, based on the use of pulsed phase thermography (PPT) and image processing, that can be used as an effective quality control tool to evaluate the freshness of eggs. As many studies show that the air chamber size is proportional to the egg freshness, the technique relies on the monitoring of the air chamber parameters to infer egg aging over time. The raw and phase infrared images are acquired and then post-processed by a dedicated algorithm which has been designed to automatically measure the size of the air chamber, in terms of normalized area and volume. The robustness of the method is firstly assessed through repeatability and reproducibility tests, which demonstrate that the uncertainty in the measure of the air chamber size never exceeds 5%. Then, an experimental campaign on a larger sample of 30 eggs, equally divided into three size categories (M, L, XL), is conducted. For each egg, the main sizes of the air chamber are measured with the proposed method and their evolution over time is investigated. Results have revealed, for all the egg categories, the existence of an analytic relationship and a high degree of correlation (R-2 > 0.95) between the geometric data of the air chamber and the weight loss, which is a well-known marker of egg aging

    Densely populated settings: the challenge of siting geological facilities for deep geothermics, CO2 and natural gas storage, and radioactive waste disposal Underground Coexistence and Synergies for a Sound Energy Mix in the Post-Kyoto Era

    Get PDF
    The abstracts herein – collected for the 34th Course of the International School of Geophysics, held in Erice, Italy (“Ettore Majorana” Foundation and Centre for Scientific Culture, 25-30 September, 2010) – focus on geophysical, geological and geochemical methods applied to the planning of the soundest energy mix in densely populated countries, where the coexistence of different technologies requires unique underground facilities and resources. In the framework of IEA and EU programmes, where the concepts of “smart grids” and “smart cities” are prevailing, we rather propose the concept of “smart region” planning the use of both underground and surface areas in a new social-energetic paradigm of “zero kilometer” life. The coexistence of geological storage of CO2 and natural gas, geothermics and, possibly, nuclear waste temporary storage (near surface or geological) is today necessary owing to the progressive decrease of space and resources. In this context, the following technologies turn out to be very important: renewables (geothermal energy), nuclear power, clean coal technologies via CO2 Capture and Storage (CCS), Enhanced Oil Recovery (EOR), Enhanced Coal Bed Methane (ECBM), non-conventional gas exploitation, and seasonal storage of natural gas (also for strategic reserves). These technologies have been recently emphasized in Italy by the Ministry of Economic Development and by the Ministry of the Environment and Territory, as well as by research institutions such as INGV and CNR. Key topics addressed during the Course were: • Geological storage and disposal: assessment of available volume and structures. • Subsurface geological resources: management of potential conflicts among various technologies. • Geological site characterization and risk assessment for policy makers and regulators: the role of the energy industry. • New high tech frontiers for geothermal power production. • New concepts in nuclear waste disposal. • Numerical simulation software for geothermal exploration, geological storage and nuclear waste disposal. • Sharing subsurface data coming from oil & gas and geothermal exploration. • High resolution characterization of shallow aquifers and reservoirs: multi-strata exploitation by different energy technologies. • Case histories and natural analogues: “learning by doing” and “acceptable risk” concepts. The 34th Course of the International School of Geophysics is dedicated to students and young contract researchers starting their carreers in a period of energetic-environmental global crisis. Although their scientific contribution is of high quality, they are usually underpaid in public research institutions with respect to volatile staff of some international organizations who, making use of the results of governmentfunded research, make final decisions on low-carbon energy technologies

    Experimental study of CO2 sequestration by ECBM recovery: the case of Sulcis coal.

    Get PDF
    An ECBM (Enhanced Coal Bed Methane) feasibility study started for the Sulcis Coal Province (SW Sardinia, Italy) in December 2004: geochemical, structural-geology, stratigraphic and reservoir engineering considerations are discussed. The first newly gathered experimental data are discussed, including: fluid geochemistry (major and minor elements, dissolved gases, C and He isotopic ratios) of the reservoir, coal composition and experimental data on CO2/CH4 adsorption on coal. A MapInfo GIS structure was built up including stratigraphical, geo-structural, hydrogeochemical, coal-compositional and environmental impact information as well as the CO2 sources location and typology. Even if these data could be preliminary with respect to the coal characteritics effectively located at the future injection depth, they highlighted both the challenging positive and negative aspects of the Sulcis Coal Province versus the exploitation of the ECBM technique. The most important objective of this phase I of the project is the selection of the best Sulcis ECBM test-pilot site, which will be followed (Phase II) by the choice of a scaled up site and possibly by a future network (Phase III). These phases are foreseen to be accompanied by the selection of progressively added CO2 industrial sources, to be used within the project economic spreadsheet model, actually in evolution. CO2 geological storage and CH4 production potentials in Sulcis have been grossly evaluated as a whole, in the frame of the Sardinia region CO2 sources, including the coal-fired power plants, both existent and foreseen (hundreds of millions of tonns of CO2 are possible to be stored underground in the next decades). The reservoir estimates, both for the CO2 injection and for the CH4 production are clearly involving to start the test-site phase exploitation, in the frame of an auspicabile international operative project

    Radon and helium as pathfinders of fault systems and groundwater evolution in different Italian areas

    Get PDF
    Groundwater surveys in some Italian areas with different geological and geodynamical features were performed in order to evaluate dissolved rare gases (222Rn, He and Ar) as potential tracers of fault systems and groundwater evolution (fluid origin, water-rock-gas interaction, fluid migration and mixing phenomena). The obtained results showed that the highest values of Rn and He were found along important fault systems cutting the investigated areas, where the fault-related permeability increases deep-seated fluid circulation. However, dissolved-radon anomalies may be due to: a) a rapid ascent of Rn-bearing fluids, equilibrated with lithologies richer in U than outcropping formation; b) a local enrichment of U due to the action of low enthalpy groundwater or strong carrier gas (CO2) discharges usually occurring along the fault systems

    Response to letter to the editor regarding physical restraint in psychiatric setting

    Get PDF
    The following letter addresses the issues of the applicability of physical restriction, with particular attention to the therapeutic regime and its meaning as a therapeutic or restrictive provision, while considering possible alternative measures in the context of Italian jurisprudence. The letter, in response to the questions posed by Cioffi and Tomassini, examines the possible legal implications for doctors and suggests that the integration of jurisprudence and psychiatry seems to be mandatory to define the operational protocols for the management of physical restraint. Introduzione. La seguente lettera affronta il problema relativo all’applicabilità della contenzione fisica, con particolare riferimento al regime terapeutico, nonché la sua valenza giuridica quale misura terapeutica o restrittiva, considerando eventuali approcci alternativi. La lettera, in risposta alle domande poste da Cioffi e Tomassini, esamina le possibili implicazioni legali cui possono incorrere i medici nell’applica-re la contenzione fisica, suggerendo la necessità di un’integrazione tra le norme giurisprudenziale e la scienza psichiatrica, al fine di definire i protocolli operativi di gestione della contenzione fisica

    Thermal anomalies and fluid geochemistry framework in occurrence of the 2000-2001 Nizza Monferrate seismic sequence (northern Italy): Episodic changes in the fault zone heat flow or chemical mixing phenomena?

    Get PDF
    International audienceThe paper discusses the correlation between the heating of shallow groundwater over a 10 × 20 km wide area close to the town of Nizza Monferrato (Piemonte Region, Northern Italy) and the concomitant local seismic sequences during the period August 2000 ? July 2001. The first seismic sequence started on 21 August 2000 with a Ml = 5.2 earthquake. Within few hours, the local authorities received calls alerting that the groundwater temperature rose from 10 to 30°C in many shallow wells. Our geochemical experimental data and the geological-seismotectonic framework do not allow the hypothesis of simple fluid mixing between the thermal reservoir of Acqui Terme and the Nizza-Monferrato shallow groundwater to explain the observed thermal anomalies. On the other hand, we invoke more complex processes such as frictional heating, mechano-chemistry, fault-valve mechanism, adiabatic decompression and hydrogeologically driven heat flow i.e., thermal effects due to variations of basin-scale permeability field. All these processes are able to transmit heat to the surface and to generate a transient incremental heat flow better than the mass transfer occurring typically when fluids from different reservoirs mix
    • …
    corecore