Prime note su esplorazioni speleosubacquee nel complesso carsico La Val-Noglar-Battei-Mainarda – Località Pradis – Comune di Clauzetto (Pordenone – Friuli Venezia Giulia – Italia)

Si descrive una recente esplorazione speleosubacquea compiuta nel sifone terminale del complesso carsico “La Val-Noglar- Battei-Mainarda” in Comune di Clauzetto, Provincia di Pordenone – Regione Friuli Venezia Giulia. Tale complesso si sviluppa per quasi 7 chilometri all’interno degli affioramenti carbonatici, denominati “Calcari del Cellina”, di età Giurassico sup.-Cretacico inf. Il pozzo-sifone si incontra a circa 340 metri di profondità (dislivello massimo), ed è costantemente alimentato da un arrivo d’acqua perenne e dalle acque drenate in occasione di precipitazioni piovose, quando buona parte delle condotte più profonde della cavità vengono temporaneamente allagate. Il percorso, attrezzato in modo fisso, per giungere al pozzo-sifone ha richiesto circa due anni di lavoro, in quanto la grotta è attiva e soggetta a frequenti piene ed è stato necessario garantire che tutta la linea di discesa potesse rimanere fuori cascata e in quota rispetto ai laghi. L’immersione si è arrestata a 44 metri di profondità. Strettoie non percorribili con attrezzatura precludono la prosecuzione. L’immersione è stata fatta seguendo le linee guida speleosub internazionali e con uso di una miscela respiratoria trimix per garantire un ottimale rapporto sicurezza-operatività. Viene dato un inquadramento geologico dell’area con i dettagli dell’immersione e un rilievo speditivo. L’U.S. Pordenonese CAI, in collaborazione con G.G. Pradis, G.S. Sacile, G.S. Urbinate, G.G. Treviso e CSIF di Udine, ha coordinato le attività.The relation describes a recent spelosubaqueous exploration done in the terminal flooded well of the Karst system called “Complex La Val-Noglar-Battei-Mainarda” in the municipal district of Clauzetto, Province of Pordenone - Friuli Venezia giulia. The total lenght of this Karst complex is almost 7 kilometers through carbonate outcrops, informally denominated “Calcari del Cellina”, of the superior Jurassic - inferior Cretaceus. The well-siphon is situated in the lowest point of the Karst system, in a depth of about 230 meters, and it is costantly supplied by an arrival of perennial water and from waters drained by the system on the occasion of rainy precipitations. In these occasions most of the deepest ducts are temporarily flooded. The way to reach the well-syphon, equipped in fixed, required about 2 years of work because it is an active cave and it is subject to frequent flood. It has been necessary to take care of the arms in punctual way to keep all the line of descent far from the falls and high respect the lakes. The immersion stopped to 44 meters deep. Bottlenecks not practicable with the equipment preclude the prosecution. A trimix respiratory mixture of helium, oxygen and nitrogen”best mix” was used to guarantee an optimal connection of security and operativity. The immersion was done following the technical standard of speleosubaqueous security that are shared in the sector. In this relation there is a geological explanation of the area and the details of the immersion with the speedy survey of the explored places. The coordination’s activity was followed by the Unione Speleologica Pordenonese CAI, in collaboration with Gruppo Grotte Pradis, Gruppo Speleologico Sacile, Gruppo Speleologico Urbinate, Centro Speleoloico Idrologico Friulano and Gruppo Grotte Treviso. Last year two speedy immersions to perform an on-the spot investigation preceded this immersion

Flux through a time-periodic gate: Monte Carlo test of a homogenization result

We investigate via Monte Carlo numerical simulations and theoretical considerations the outflux of random walkers moving in an interval bounded by an interface exhibiting channels (pores, doors) which undergo an open/close cycle according to a periodic schedule. We examine the onset of a limiting boundary behavior characterized by a constant ratio between the outflux and the local density, in the thermodynamic limit. We compare such a limit with the predictions of a theoretical model already obtained in the literature as the homogenization limit of a suitable diffusion problem

NO2 Dispersion Model Of Emissions Of A 20 kWe Biomass Gasifier

Biomass valorization represents a simple way to reduce Green House Gases emissions. However, the biomass-to-energy field is limited by high gaseous emission concentrations. Innovative abatement technologies can make gaseous emissions close to zero. In this work, three different NO2 abatement technologies were assessed and compared. A deterministic approach was used to estimate NO2 concentrations using experimental concentrations at the chimney for a 20 kWe biomass gasifier. The gasifier chimney was described as an equivalent stack. The pollutant propagation was simulated with a Gaussian plume dispersion model. On this purpose, the unknown equivalent stack flow rate in the model was adjusted using the available data of NO2 on the ground, considering the changing of the air stability between nighttime and daytime and the variable wind direction. Thanks to pollutants dispersion modeling, the evaluation of the optimal abatement technology was possible, investigating the potential effect produced on people and the environment. Results show a bioscrubber technology as the best one to reduce NO2 concentrations at 100, 1000, 3000 m from the emission point of 74, 75, 70 %, respectively

Environmental Impact Analysis of Flue Gases Emissions for a 20 Kwe Biomass Gasifier

Due to the potential ability to support local development, create local employment, and contribute to climate change mitigation decentralized bioenergy CHP systems are receiving increasing attention. With bioenergy CHP systems are possible to achieve energy efficiency by converting primary energy to heat and electricity, replacing fossil fuels and reducing carbon dioxide emissions in the atmosphere. In particular, biomass cogeneration is considered a reliable efficient energy production technology and an effective alternative to reduce greenhouse gas emissions due to their low CO2 emission, using near biomass production sites (e.g., agricultural activities, forestes), avoiding long supply chains. In this paper, a techno-environmental assessment for a biomass powered micro-scale CHP system based on gasifier combined with an internal combustion engine sized for a maximum electrical and thermal output of 20 kWe and 40 kWth, is analyzed. CO2 direct emissions and CO2 equivalent emissions for NO2, CO, HC were assessed in order to obtain the final environmental impact of the plant. Several cases were considered changing biomass kind and flue gas treatment systems. Results show that biomass kind has not an impact on the toxic gas emissions, while the bioscrubber is the best flue gas treatment technology to reduce concentrations of all pollutants

Monte Carlo study of gating and selection in potassium channels

The study of selection and gating in potassium channels is a very important issue in modern biology. Indeed such structures are known in all types of cells in all organisms where they play many important functional roles. The mechanism of gating and selection of ionic species is not clearly understood. In this paper we study a model in which gating is obtained via an affinity-switching selectivity filter. We discuss the dependence of selectivity and efficiency on the cytosolic ionic concentration and on the typical pore open state duration. We demonstrate that a simple modification of the way in which the selectivity filter is modeled yields larger channel efficiency

Fick and Fokker--Planck diffusion law in inhomogeneous media

We discuss diffusion of particles in a spatially inhomogeneous medium. From the microscopic viewpoint we consider independent particles randomly evolving on a lattice. We show that the reversibility condition has a discrete geometric interpretation in terms of weights associated to un--oriented edges and vertices. We consider the hydrodynamic diffusive scaling that gives, as a macroscopic evolution equation, the Fokker--Planck equation corresponding to the evolution of the probability distribution of a reversible spatially inhomogeneous diffusion process. The geometric macroscopic counterpart of reversibility is encoded into a tensor metrics and a positive function. The Fick's law with inhomogeneous diffusion matrix is obtained in the case when the spatial inhomogeneity is associated exclusively with the edge weights. We discuss also some related properties of the systems like a non-homogeneous Einstein relation and the possibility of uphill diffusion

Ophiolitic sequences from the central sector of the Catena Costiera (Calabria): stratigraphy, petrology and structural analyses

Mesozoic ophiolites crop out in the Catena Costiera (Northern Calabrian Arc). The Northern Calabrian Arc is characterized by the superposition of three structural elements (OGNIBEN, 1973): the uppermost Hercynian continental section intruded by late- Variscan granitoids (Calabrian Nappe), the intermediate ophiolitic Nappe and the lowermost Mesozoic passive margin carbonate sequences (Apenninic Units). The studied area is located in the central Catena Costiera (fig. 1) where the ophiolitic sequences are characterized by both aphyric and porphyritic metabasalts with a T-MORB affinity (LIBERI et alii, 2006). They represent the basement of a peliticarenaceous metasedimentary sequence, previously interpreted as a pre-Mesozoic continental basement (Bagni Unit of AMODIO MORELLI et alii, 1976). In the metasedimentary cover, a remarkable increase in the carbonatic supply is noticed moving from south to north of the study area. According to this evidence two stratigraphic sequences have been defined for the southernmost Cozzo Cervello area and the northernmost San Martino di Finita area. The Cozzo Cervello area ophiolitic sequence is characterized by: metabasites, thin levels of volcanoclastic metasediments, rare metacarbonates, metapelites and metarenites. The San Martino di Finita area ophiolitic sequence is instead characterized by: metabasites, volcanoclastic metasediments and calcschists. The studied rocks underwent a polyphase deformation history and the meso- and microstructural analyses allowed distinguishing three main (D1-D3) deformation phases: – D1, this phase is characterized by a S1 foliation locally developed and preserved as microlithons inside the S2 main foliation; – D2, a N-S trending isoclinal folding event (F2; fig. 2 a,b) is responsible for the formation of the S2 foliation (fig. 2 d), that represent the main surface recognizable in the field; – D3, this phase is characterized by asymmetric folds (F3) developed at different scales and showing a WNW-ESE trending axes. An incipient foliation (S3) is locally developed in the phyllosilicate-rich levels (fig. 2 c,d). *Dipartimento di Scienze della Terra, Università della Calabria. ([email protected]) **Dipartimento di Scienze della Terra, Università di Pisa The petrographic analysis allows to define the mineralogical assemblage of the different lithotypes and to determine the relationships between deformation and blastesis. The metabasites are characterized by the mineralogical assemblage: Epidote + Na-amphibole + Lawsonite + Phengite + Chlorite + Albite Calcite Quartz + Magnetite. Metapelites and metarenites are characterized by: Epidote + Phengite + Stilpnomelane + Na-Amphibole + Pumpellyite + Chlorite + Albite + Quartz + Magnetite. The calcschist are constituted by: Calcite + Phengite + Chlorite + Albite + Quartz + Magnetite. The described mineralogical assemblages suggest that the studied rocks underwent P-T conditions typical of the blueschist facies as suggested by the blastesis of Na-amphiboles, lawsonite, stilpnomelane and phengite along the S2 foliation. The blastesis of white mica can be observed along the S3 foliation also. The following metamorphic retrogression developed within the prehnitepumpellyite facies and is characterized by a static recrystalization. Fig. 1 – Tectonic sketch map of central sector of the Catena Costiera, after LIBERI et alii (2006). 64 OPHIOLITIC SEQUENCES FROM THE CATENA COSTIERA 65 Fig. 2 – a) isoclinal folds (F2) in the metapelites of Cozzo Cervello area; b) isoclinal folds (F2) in the calcschists of San Martino di Finita area; c) crenulation F3 in the metabasites; d) microscopic view of the main foliation S2 deformed by the later D3 phase in the metapelites. The white line indicates white mica flakes along S3. The field study and the tectonometamorphic evolution reconstructed for the ophiolitic sequences cropping out in the central sector of the Catena Costiera of Calabria show that a subduction and exhumation history inside an accretionary wedge can be proposed. In particular, the characterization and the definition of the complex relationships existing within the ophiolitic metasedimentary cover allow us to propose: 1. the source area was composite, with both carbonatic and siliciclastic contributions; 2. the presence of terrigenous deposit, even in the lowermost part of the sedimentary sequence, seem to indicate that this part of oceanic crust was located close to the continental margin; 3. the San Martino di Finita type sedimentary cover can be correlated with that of the Malvito ophiolitic unit (sensu AMODIO MORELLI et alii, 1976), cropping out in the northernmost sector of the Catena Costiera; 4. the subdivision between the Bagni and Gimigliano-Monte Reventino Units, as proposed by DIETRICH & SCANDONE (1972) and AMODIO MORELLI et alii (1976) for the study area, is not supported by the data collected in this work. REFERENCES AMODIO MORELLI L., BONARDI G., COLONNA V., DIETRICH D., GIUNTA G., IPPOLITO F., LIGUORI V., LORENZONI S., PAGLIONICO A., PERRONE V., PICCARRETA G., RUSSO M., SCANDONE P., ZANETTIN-LORENZONI E. & ZUPPETTA A. (1976) - L’arco Calabro-peloritano nell’orogene appenninicomagrebide. Mem. Soc. Geol. It, 17, 1–60. DIETRICH D. & SCANDONE P. (1972) - The position of the basic and ultrabasic rocks in the tectonic units of the southern Apennines. Atti Acc. Pont., 21, 61–75. LIBERI F., MORTEN L. & PILUSO E. (2006) - Geodynamic significance of the ophiolites within the Calabrian Arc. Island Arc, 15, 26–43. OGNIBEN L. (1973) - Schema geologico della Calabria in base ai dati odierni. Geologia Romana, 12, 243

Newly identified active faults in the Pollino seismic gap, southern Italy, and their seismotectonic significance

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