Search results for "Monitoring"
showing 10 items of 3614 documents
The role of evanescent modes in Global-Local analysis of UGW in plates with varying local zone-scatterer relations
2023
In order to provide a reliable and robust SHM performance, Ultrasonic Guided Waves (UGWs) need to be analyzed and understood. Numerical modeling of UGW propagation and scattering by hybrid methods offers the possibility of simulating UGW interaction with waveguides of arbitrary cross-sections and discontinuities. Maximizing the accuracy of such methods is important to perform quantitative SHM, while maintaining minimum computational cost. This work investigates the role of evanescent modes in the numerical analysis of UGWs in aluminum and composite plates with defects, by the hybrid Global-Local method. The complex solutions to the UGW eigenvalue problem are found and the scattering spectra…
Escalating CO2 degassing at the Pisciarelli fumarolic system, and implications for the ongoing Campi Flegrei unrest
2019
Abstract This short communication aims at providing an updated report on degassing activity and ground deformation variations observed during the ongoing (2012–2019) Campi Flegrei caldera unrest, with a particular focus on Pisciarelli, currently its most active fumarolic field. We show that the CO2 flux from the main Pisciarelli fumarolic vent (referred as “Soffione”) has increased by a factor > 3 since 2012, reaching in 2018–2019 levels (>600 tons/day) that are comparable to those typical of a medium-sized erupting arc volcano. A substantial widening of the degassing vents and bubbling pools, and a further increase in CO2 concentrations in ambient air (up to 6000 ppm), have also been detec…
Recent advances in ground-based ultraviolet remote sensing of volcanic SO2 fluxes
2011
Measurements of volcanic SO2 emission rates have been the mainstay of remote-sensing volcanic gas geochemistry for almost four decades, and they have contributed significantly to our understanding of volcanic systems and their impact upon the atmosphere. The last ten years have brought step-change improvements in the instrumentation applied to these observations, which began with the application of miniature ultraviolet spectrometers that were deployed in scanning and traverse configurations, with differential optical absorption spectroscopy evaluation routines. This study catalogs the more recent empirical developments, including: ultraviolet cameras; wide-angle field-of-view differential …
Unmanned aerial vehicle measurements of volcanic carbon dioxide fluxes
2008
[i] We report the first measurements of volcanic gases with an unmanned aerial vehicle (UAV). The data were collected at La Fossa crater, Vulcano, Italy, during April 2007, with a helicopter UAV of 3 kg payload, carrying an ultraviolet spectrometer for remotely sensing the SO 2 flux (8.5 Mg d- 1 ), and an infrared spectrometer, and electrochemical sensor assembly for measuring the plume CO 2 /SO 2 ratio; by multiplying these data we compute a CO 2 flux of 170 Mg d -1 . Given the deeper exsolution of carbon dioxide from magma, and its lower solubility in hydro-thermal systems, relative to SO 2 , the ability to remotely measure CO 2 fluxes is significant, with promise to provide more profound…
First multi-GAS based characterisation of the Boiling Lake volcanic gas (Dominica, Lesser Antilles)
2013
We used a Multi-component Gas Analyser System (Multi-GAS) to measure, for the very first time, the composition (H2O, CO2, H2S, SO2) of the volcanic gas plume issuing from the Boiling Lake, a vigorously degassing, hot (T ~ 80-90°C) volcanic lake in Dominica, West Indies. The Multi-GAS captured in-plume concentrations of H2O, CO2 and H2S were well above those typical of ambient atmosphere, while no volcanic SO2 was detected (<0.05 ppm). These were used to derive the Boiling Lake plume characteristic ratios of CO2/H2S (5.2±0.4) and H2O/CO2 (31.4±6). Assuming that other volcanic gas species (e.g., HCl, CO, H2, N2, etc.) are absent in the plume, we recalculated a (air-free) composition fo…
Experimental Analysis of the Thermal Performance of Wood Fiber Insulating Panels
2023
During the last decades, attention to energy and environmental problems has significantly grown, along with the development of international and national policies addressing sustainability issues. In the construction sector, one of the most widespread energy efficiency strategies consists of thermal insulation of buildings thanks to external insulating panels. Among these, wood fiber is an insulating material characterized by a natural, eco-sustainable and biodegradable structure, coming from the recycling of waste wood from sawmills. The present study aimed to characterize small test building insulated with wood fiber panels from the thermal point of view, comparing the results with those …
Iz opyta raboty nad učebnym kompleksom "Vsë prosto!"
2016
The article presents the comments of the authors of the textbook series "Vsye Prosto!" ("Everything Is Easy!") on ways of meeting the challenges related to teaching the Russian language at the initial stage. In particular, it involves the introduction of the Russian alphabet, ways of explaining assignments, monitoring achievements and evaluation, as well as the presentation of cross-cultural materials.
Exposure assessment of mycotoxins in food and biological samples through high resolution mass spectrometry-based strategies
2022
Las micotoxinas son metabolitos secundarios tóxicos producidos por varios géneros de hongos y que se encuentran frecuentemente en productos alimenticios. La ingestión de micotoxinas puede provocar la aparición de un amplio abanico de efectos perjudiciales para la salud. Con el objetivo de reducir el impacto sanitario debido a la ingesta de productos contaminados por micotoxinas, la Comisión Europea estableció la Regulación No 1881/2006, donde se fijan límites máximos para ciertas micotoxinas en varias tipologías de productos alimenticios. Como herramienta complementaria, el Panel de Contaminantes en la Cadena Alimentaria (CONTAM Panel) han propuesto valores de ingesta diaria tolerable, que …
Modeling the influence of potassium content and heating rate on biomass pyrolysis
2017
This study presents a combined kinetic and particle model that describes the effect of potassium and heating rate during the fast pyrolysis of woody and herbaceous biomass. The model calculates the mass loss rate, over a wide range of operating conditions relevant to suspension firing. The shrinking particle model considers internal and external heat transfer limitations and incorporates catalytic effects of potassium on the product yields. Modeling parameters were tuned with experimentally determined char yields at high heating rates (>200 K s−1) using a wire mesh reactor, a single particle burner, and a drop tube reactor. The experimental data demonstrated that heating rate and potassium …
Gender-Typed Sport Practice, Physical Self-Perceptions, and Performance-Related Emotions in Adolescent Girls
2020
Youth sport experience provides opportunities for physical, personal, and social development in youngsters. Sport is a social system in which socially constructed gender differences and stereotypes are incorporated, and specific sport activities are often perceived as gender characterized. The objective of this study was to examine the relationship between some salient physical and emotional self-perceptions and the type of sport practiced. A sample of 261 female athletes, aged 14–21 years (Mage = 15.59, SD = 2.00), practicing different sports, categorized as feminine (e.g., artistic and rhythmic gymnastics), masculine (e.g., soccer and rugby), or neutral (e.g., track and field and tennis),…