Search results for " Stable"
showing 10 items of 202 documents
Mineralogy of the soils altered by fumarolic activity at Nisyros volcano, Greece
2017
Nisyros is the easternmost island of the South Aegean Active Volcanic arc in Greece. It is an active stratovolcano known for its intense hydrothermal activity. In this study we present the results of the mineralogical analyses of 20 soil samples collected in the caldera area. Samples were analysed through X-ray diffraction and the results allow us to divide them in two groups: Lakki Plain and Stefanos Crater. In their majority the soils of Lakki Plain have a main mineralogical assemblage that consists of quartz, feldspar and gismondine (Ca2Al4Si4O16·9H2O). Gismondine as well as stellerite (CaAl2Si7O18·7H2O), which is appearing in some samples, derive from hydrothermal alteration, whilst wol…
Characterisation and origin of hydrothermal waters at São Miguel (Azores) inferred by chemical and isotopic composition
2017
Abstract This study focuses on the characterisation and origin of hydrothermal waters discharging from three main active volcanoes (Furnas, Fogo and Sete Cidades) at Sao Miguel, where 33 water with temperatures ranging between 13 and 97 °C, and 5 precipitate samples were collected. The developed conceptual model for this active hydrothermal system reveals that all waters can be classified by Na-HCO 3 , Na-Cl and Na-SO 4 types and are of meteoric origin. This is confirmed by the stable hydrogen and oxygen isotope data that are positioned close to the local meteoric water line (− 4.1‰ ≤ δ 18 O H2O ≤ 5.2‰; − 17.6‰ ≤ δD H2O ≤ 20.4‰), except for the Na-Cl type water at Ferraria (Sete Cidades a…
Gas geochemistry and CO2 output estimation at the island of Milos, Greece
2018
Abstract Twenty gas samples have been collected from the natural gas manifestations of Milos Island, the majority of which is found underwater along its coast. Furthermore, three anomalous degassing fumarolic areas (Kalamos, Paleochori and Adamas) have been recognized on-land. Almost all the gases are CO2-dominated with CO2 ranging from 88 to 99% vol for the samples taken underwater, while the on-land manifestations show a wider range (15–98%) due to air contamination. Methane reaches up to 1.0% vol, H2 up to 3.2% vol and H2S up to 3.5% vol indicating a hydrothermal origin of the gases. The isotope composition of He points out to mantle contributions up to 45%, while the C-isotope compositi…
Geochemical characterisation of the alkaline and hyperalkaline groundwater in the Othrys Ophiolite Massif, central Greece
2021
The complex geology of Greece includes two important parallel running ophiolitic belts. The Othrys Massif in central Greece belongs to the westernmost of them. In the current study, 33 water samples from cold hyperalkaline and hypothermal (T < 40°C) alkaline springs and 30 gas samples (either dissolved or free) were collected at 17 different sites in and around this wide ophiolite outcrop, aiming to determine the origin of fluids and evidence gas-water-rock interaction processes taking place in the area. Water samples were analysed for their chemical (major ions and trace elements) and isotope (d18O-H2O, d2H-H2O) composition. They can be subdivided into alkaline (pH <11) of both Mg-Ca…
Microbial methane oxidation leading to extreme isotopic fractionation in thermal springs of central Greece
2017
The Greek territory belongs to the geodynamically active Alpine-Himalayan orogenic belt. As such, it shows intense seismic activity, active volcanic systems and areas of enhanced geothermal fluxes. One of these areas is the Sperchios basin and the northern part of Evia island in central Greece, which present widespread thermal manifestations (D’Alessandro et al., 2014). Five of them with temperatures from 33 to 80°C present bubbling gases whose dominating species are either CO2 or N2. All gases contain from 27 to 4000 ppm of CH4. The isotopic composition of CH4 in these gases covers a wide range with δ13C values ranging from -21.7 to +16.9 ‰ and δ2H values ranging from -124 to +301 ‰. The h…
The trophic structure of a fish assemblage in a non-tidal Mediterranean Lagoon: integrating data from the Fishbase information system with results fr…
2010
La resistenza di interfaccia calcestruzzo poroso-terreni a grana fina per il consolidamento di pendii mediante trincee drenanti profonde
2022
Le trincee drenanti profonde rappresentano uno dei metodi più efficaci per la mitigazione del rischio da frana, in pendii con falda idrica. Esse sono realizzate mediante pannelli o pali secanti. Il riempimento è costituito di calcestruzzo poroso o materiale granulare. Se le trincee sono adeguatamente “innestate” nel terreno stabile e il materiale di riempimento ha sufficiente resistenza e rigidezza come il calcestruzzo poroso, si ha ulteriore in-cremento di resistenza a taglio per effetto shear keys, oltre a quello derivante dalla riduzione delle pressioni in-terstiziali. L’incremento di resistenza è dovuto sia alla resistenza all’interfaccia calcestruzzo–terreni sia a quella intrinseca del…
EXPERIMENTAL INVESTIGATION OF DILUTE SOLID-LIQUID SUSPENSION IN AN UNBAFFLED STIRRED VESSELS BY A NOVEL PULSED LASER BASED IMAGE ANALYSIS TECHNIQUE
2009
The availability of experimental information on solid distribution inside stirred tanks is a topic of great importance in several industrial applications. The measurement of solid particle distribution in turbulent multiphase flow is not simple and the development of suitable measurement techniques is still in progress. In this work a novel non-intrusive technique for measuring particle concentration fields in solid-liquid systems is employed. The technique makes use of a laser sheet, a high sensitivity digital camera for image acquisition and a Matlab procedure for post-processing the acquired images. Experimental data are here obtained for the case of an unbaffled stirred tank. Stable tor…
A Dose-Dependent Improvement in Exercise Tolerance in Patients With Stable Angina Treated With Mildronate: A Clinical Trial “MILSS I”
2011
Objective. To assess the efficacy of various doses of Mildronate in combination with standard therapy for the exercise tolerance of patients with stable angina pectoris. The primary efficacy variable was the change in exercise time in bicycle ergometry from the baseline to 12 weeks of treatment. The secondary endpoints were the changes in maximum achieved load and time to the onset of angina from the baseline to week 12. Material and Methods. A total of 512 patients with chronic coronary heart disease who had ischemia as the limiting factor in the exercise test from 72 study centers in 4 countries were enrolled in this prospective, randomized, double-blind, placebo controlled phase 2 study.…
Tertiary lymphoid structures in pulmonary metastases of microsatellite stable colorectal cancer
2023
Tertiary lymphoid structures (TLSs) are ectopic lymphoid aggregates located at sites of chronic inflammation and recognized as prognosticators in several cancers. We aimed to analyse the prognostic effect of TLSs in colorectal cancer (CRC) pulmonary metastases and primary tumours, with a comparison to the CD3+ and CD8+ cell density-based immune cell score (ICS). For TLS density and TLS maximum diameter analysis, 67 pulmonary metastases and 63 primary tumours were stained with haematoxylin and eosin. For ICS scoring and analysis, CD3 and CD8 immunohistochemistry was performed. Excellent interobserver agreement was achieved in all TLS measurements. Of all patients, 36 patients had low TLS den…