Search results for "gas [meson]"

2016

Recent gas flux measurements have shown that Strombolian explosions are often followed by periods of elevated flux, or “gas codas,” with durations of order a minute. Here we present UV camera data from 200 events recorded at Stromboli volcano to constrain the nature of these codas for the first time, providing estimates for combined explosion plus coda SO2 masses of ≈18–225 kg. Numerical simulations of gas slug ascent show that substantial proportions of the initial gas mass can be distributed into a train of “daughter bubbles” released from the base of the slug, which we suggest, generate the codas, on bursting at the surface. This process could also cause transitioning of slugs into cap b…

A New Web-Based Catalog of Earth Degassing Sites in Italy

2008

Italy is a region characterized by intense and widespread processes of Earth degassing. High-temperature gases are released by crater plumes and fumaroles in volcanic environments throughout Italy. Also prevalent are numerous low-temperature gas emissions rich in carbon dioxide (CO2). These low-temperature emissions are located in a large area, mainly in the western sector of central and southern Italy (Figure 1).

Intercomparison of SO2 camera systems for imaging volcanic gas plumes

2015

Abstract SO 2 camera systems are increasingly being used to image volcanic gas plumes. The ability to derive SO 2 emission rates directly from the acquired imagery at high time resolution allows volcanic process studies that incorporate other high time-resolution datasets. Though the general principles behind the SO 2 camera have remained the same for a number of years, recent advances in CCD technology and an improved understanding of the physics behind the measurements have driven a continuous evolution of the camera systems. Here we present an intercomparison of seven different SO 2 cameras. In the first part of the experiment, the various technical designs are compared and the advantage…

Volcanic CO2 flux measurement at Campi Flegrei by tunable diode laser absorption spectroscopy

2014

Near-infrared room-temperature Tunable Diode Lasers (TDL) have recently found increased usage in atmospheric chemistry and air monitoring research, but applications in volcanology are still limited to a few examples. Here, we explored the potential of a commercial infrared laser unit (GasFinder 2.0 from Boreal Laser Ltd) for measurement of volcanic CO2 mixing ratios, and ultimately for estimating the volcanic CO2 flux. Our field tests were conducted at Campi Flegrei near Pozzuoli, Southern Italy, where the GasFinder was used during three campaigns in October 2012, January 2013 and May 2013 to repeatedly measure the path-integrated mixing ratios of CO2 along cross-sections of the atmospheric…

Volcanic-gas monitoring

2015

The environmental impact of volcanoes is closely related to the rates, style and chemistry of their gas emissions (Delmelle, 2003). Monitoring the composition and mass flux of volcanic gases is therefore central to understanding how volcanism impacts our planet, on both global and local scales. There are two main modes of volcanic-gas release on Earth (Chapter 14): (i) the impulsive emission of large quantities of gases during episodic, large-scale volcanic eruptions, and (ii) the far more sluggish, but persistent, passive gas release from quiescent or mildly erupting volcanoes. Characterising the chemical composition of impulsive emissions has remained a challenge, and direct measurements …

The Application of the Life-Cycle Assessment in the Building Sector: An Italian Case Study

2017

The building sector is one of the most relevant in terms of generation of wealth and occupation, but it is also responsible for significant consumption of natural resources and the generation of environmental impacts, mainly greenhouse gas emissions. In order to improve the eco profile of buildings during their life-cycle, the reduction of the use of resources and the minimization of environmental impacts have become, in the last years, some of the main objectives to achieve in the design of sustainable buildings. The application of the life-cycle thinking approach, looking at the whole life cycle of buildings, is of paramount importance for a real decarbonization and reduction of the envir…

Volcanic CO2 measurements at Campi Flegrei by Infrared Tunable Diode Laser absorption Spectroscopy

2014

Gas studies add information for the interpretation of fluid circulation dynamics at dormant volcanoes and can contribute to eruption forecasting. Direct in-situ and remote-sensing techniques were used in order to improve volcanic gas monitoring, essential for hazard assessment. In the last decades, near-infrared diode lasers have increasingly been used in atmospheric research and, though in an experimental phase, are now finding applications in volcanic gas studies. The Tunable Diode Laser Spectroscopy technique (TDLS) relies on measuring the absorbance at specific wavelengths due to the absorption of IR radiation by a target gas. Here, we report on the application of the GasFinder 2.0, an …

Unraveling the prominent role of the Rh/ZrO2-interface in the water-gas shift reaction via a first principles microkinetic study

2018

The industrially important water–gas-shift (WGS) reaction is a complex network of competing elementary reactions in which the catalyst is a multicomponent system consisting of distinct domains. Herein, we have combined density functional theory calculations with microkinetic modeling to explore the active phase, kinetics, and reaction mechanism of the WGS over the Rh–ZrO2 interface. We have explicitly considered the support and metal and their interface and find that the Rh–ZrO2 interface is far more active toward WGS than Rh(111) facets, which are susceptible to CO poisoning. CO2 forming on the zirconia support rapidly transforms into formate. These findings demonstrate the central role of…

Alkylthio-tetrasubstituted μ-Nitrido Diiron Phthalocyanines: Spectroelectrochemistry, Electrical Properties, and Heterojunctions for Ammonia Sensing.

2020

Alkylthio-tetrasubstituted μ-nitrido diiron phthalocyanine complexes are synthesized with n-butyl, iso-butyl, tert-butyl, and n-hexadecyl alkyl moieties. For the first time, a spectroelectrochemical investigation of μ-nitrido diiron phthalocyanines is achieved at all the redox steps. The complexes are stable in all their redox states, unlike their unsubstituted analogues. The interest of the present complexes is to prepare sensing devices by a solution processing method. Films are characterized by electronic absorption and Raman spectroscopies. Electrical measurements on resistors show the highly resistive behavior of these complexes, whatever the chain length. However, when combined with t…

Iekšējās komunikācijas nozīme komandas veidošanā Kuldīgas novada pašvaldības iestādē “Kuldīgas novada muzejs”

2019

Kvalifikācijas darba saturs ir veltīts iekšējās komunikācijas lomai organizācijās, kā arī Kuldīgas novada pašvaldības iestādes “Kuldīgas novada muzejs” iekšējās komunikācijas nozīmei komandas veidošanā. Ikvienā organizācijā svarīgākais resurss ir cilvēki, kas tajā strādā. Šiem cilvēkiem un iekšējai komunikācijai starp darbiniekiem un organizāciju ir svarīga loma komandas darbā, līdz ar to organizācijas panākumu gūšanā. Kvalifikācijas darba pētījuma mērķis ir analizēt iekšējo komunikāciju Kuldīgas novada pašvaldības iestādē “Kuldīgas novada muzejs” un izprast tās nozīmi komandas veidošanā, izmantojot divas pētniecības metodes – aptauju un interviju. Pēc pētījumā gūtajiem rezultātiem var seci…