Search results for "O2"
showing 10 items of 1115 documents
Volcanic CO2 mapping and flux measurements 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 potentiality of a commercial infrared laser unit (GasFinder 2.0 from Boreal Laser Ltd) to measurement of volcanic CO2 flux emissions. 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 concentrations of CO2 along cross-sections of the atmospheric plumes of the two main fumarolic fields in t…
CO2 degassing at La Solfatara volcano (Phlegrean Fields): Processes affecting d13C and d18O of soil CO2
2010
Abstract The soil CO2 degassing is a ected by processes of isotope exchange and fractionation during transport across the soil, which can deeply modify the pristine isotope composition. This has been observed in 10 the Solfatara volcano, upon a eld survey of 110 points, where the CO2 ux was measured, together with temperature, CO2 concentra- tion and oxygen and carbon isotopes within the soil. Furthermore, in some selected sites, the measurements were made at di erent depths, in order to analyze vertical gradients. Oxygen isotope composition 15 appears controlled by exchange with soil water (either meteoric or fumarolic condensate), due to the fast kinetic of the isotopic equilib- rium betw…
Production of dibutyl carbonate by insertion of CO2 in titanium(IV) tetrabutoxide
2015
The species resulting from insertion of 12CO2 and 13CO2 into titanium(IV) butoxide is for the first time fully characterized by means of infrared and nuclear magnetic resonance spectroscopy. Results show formation of Ti-monobutylcarbonate, that easily undergoes nucleophilic attack by an aliphatic amine. The hydrolysis of the resulting species produces butylcarbamate and dibutylcarbonate as the only main products. Characterization results of the carbonate-like adduct, along with its reactivity with amine molecules open the route to new ways of CO2 utilization as building block for valuable organic compounds.
Is vaginal fractional CO2 laser treatment effective in improving overactive bladder symptoms in post-menopausal patients? Preliminary results
2016
To evaluate the role of vaginal fractional CO2 laser treatment in the relief of Overactive Bladder (OAB) symptoms in post-menopausal women.Post-menopausal women who complained of one or more symptoms related to vulvo-vaginal atrophy (VVA), who experienced symptoms of OAB and who underwent vaginal treatment with fractional CO2 laser were enrolled in the study. At baseline (T0) and 30 days post-treatment T1), vaginal status (using Vaginal Health Index - VHI), subjective intensity of VVA symptoms (using a visual analog scale - VAS) and micturition diary were evaluated. OAB symptoms were also assessed using a validated questionnaire.Thirty patients were enrolled. A statistically significant imp…
Sejas, žokļa rajona bazālo šūnu karcinomu ārstēšana ar CO2 lāzeri
2021
KOPSAVILKUMS Ievads: Bazālo šūnu karcinoma ir ļaundabīgs ādas audzējs, kura attīstībā galvenais riska faktors ir ultravioletā B gaisma, bet tā attīstību ietekmē arī ģenētiskās saslimšanas. Kaut tā ir gados vecāku cilvēku saslimšana, tiek novērtos, ka ik gadu saslimst aizvien jaunāki cilvēki. Visbiežākā audzēja lokalizācija ir uz sejas. Visvairāk pielietotā ārstēšanas metode ir ķirurģiska ekscīzija, tomēr bazālo šūnu karcinomu var ārstēt arī ar medikamentiem un izmantojot CO2 lāzera terapiju. Mērķis: Izpētīt bazālo šūnu karcinomu biežākos satopamos subtipus un to lokācijas. Noskaidrot vai CO2 lāzera terapija ir vienlīdz efektīva ķirurģiskai ekscīzijai. Uzzināt audzēja recidivēšanās laiku. Ma…
Total CO2 output from Vulcano island (Aeolian Islands, Italy)
2012
Total CO2 output from fumaroles, soil gas, bubbling gas discharges and water dissolved gases discharged from the island, was estimated for Vulcano island, Italy. The CO2 emission from fumaroles from the La Fossa summit crater was estimated from the SO2 crater output, while CO2 discharged through diffuse soil emission was quantified on the basis of 730 measurements of CO2 fluxes from the soil of the island, performed by using the accumulation chamber method. The results indicate an overall output of ≅500 t day 1 of CO2 from the island. The main contribution to the total CO2 output comes from the summit area of the La Fossa cone (453 t day 1), with 362 t day 1 from crater fumaroles and 91 t d…
Degassing at the Volcanic/Geothermal System of Kos (Greece): Geochemical Characterization of the Released Gases and CO2 Output Estimation
2019
Forty-five gas samples have been collected from natural gas manifestations at the island of Kos—the majority of which are found underwater along the southern coast of the island. On land, two anomalous degassing areas have been recognized. These areas are mainly characterized by the lack of vegetation and after long dry periods by the presence of sulfate salt efflorescence. Carbon dioxide is the prevailing gas species (ranging from 88 to 99%), while minor amounts of N2 (up to 7.5%) and CH4 (up to 2.1%) are also present. Significant contents of H2 (up to 0.2%) and H2S (up to 0.3%) are found in the on-land manifestations. Only one of the underwater manifestations is generally rich in N2 (up t…
Photocatalytic CO 2 Valorization by Using Ti O2 , ZrO2 and Graphitic Based Semiconductors
2018
In this century, a broad scientific interest has been devoted to fulfill sustainable industrial processes and climatic change remediation. In this prospective, various green technologies have been studied to valorize CO 2• The aim of this research is the CO 2 reduction in presence of water by using the photocatalytic technology with nanomaterials as the photocatalysts. The present work overviews the main outcomes obtained by using graphitic and oxide based photocatalysts both in gas/solid and liquid/solid batch reactors under simulated solar light. In all gas/solid regime tests the major products detected were methane, carbon monoxide, and acetaldehyde.
Photocatalytic membrane reactor for CO2 conversion
2017
Photocatalytic membrane reactor for CO2 conversion
CO2 conversion in continuous photocatalytic membrane reactor
2017
CO2 conversion in continuous photocatalytic membrane reactor