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GAS HYDRATES IN THREE INDIAN OCEAN REGIONS, A COMPARATIVE STUDY OF OCCURRENCE AND SUBSURFACE HYDROLOGYKastner, Miriam, Spivack, Arthur J., Torres, Marta, Solomon, Evan A., Borole, D.V., Robertson, Gretchen, Das, Hamendra C. 07 1900 (has links)
To establish the structural and lithological controls on gas hydrate distribution and to assess the potential energy resource and environmental hazards in the Indian Ocean, non-pressurized and pressurized cores were recovered from the Krishna-Godavari (K-G) and Mahanadi Basins offshore east India, and from an Andaman Sea site. The pore fluids were analyzed for: salinity, Cl-, sulfate, sulfide, carbonate alkalinity, Ca2+, Mg2+, Sr2+, K+, Na+, Ba2+, and Li+ concentrations, δ13C-DIC, δ18O, D/H, and 87Sr/86Sr ratios; together with infra-red imaging they provided important constraints on the presence and distribution of gas hydrates, thus on the subsurface hydrology. Evidence for methane hydrate was obtained at each of the sites. Only in the K-G Basin, between the sulfate-methane transition zone (SMT) depth and ~80 mbsf, higher than seawater chloride concentrations are observed; below this zone to the depth of the base of the gas hydrate zone (BGHSZ), chloride concentrations and salinity are lower than seawater value. In the Andaman Sea and Mahanadi Basin, only lower than seawater chloride concentrations are observed, and the shallowest gas hydrates occur at 100-200 m below the sulfate-methane transition zone (SMT) and extend to the depth of the BGHSZ. In the K-G Basin, the highest methane hydrate concentrations are associated with fracture zones in clay-rich sediments and/or in some coarser grained horizons. In the Andaman Sea, however, they are primarily associated with volcanic ash horizons. Assuming dilution by water released from dissociated methane hydrate, chloride and salinity anomalies suggest pore volume occupancies on the order of <1% to a maximum of ~61% at two sites (10, 21) in the K-G Basin and <1% to a maximum of ~76% at the Andaman Sea site. Overall, the percent pore volume occupancies based on pressure core methane concentrations and the chloride concentrations in conventional cores are similar.
Variations in sulfate gradients were observed with the steepest gradient having the SMT at 8 mbsf in the K-G Basin and the deepest SMT at ~25 mbsf at the Andaman Sea site. The extreme negative δ13C values of the dissolved inorganic carbon (DIC), ranging from -38‰ to -47‰ at the SMT at some of the sites, indicate that anaerobic oxidation of methane (AOM) is an important reaction responsible for sulfate reduction at these sites. At several sites in the K-G Basin, however, the δ13C-DIC values indicate that organic matter oxidation is the dominant reaction.
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2nd International Conference of Sustainable Sports Tourism: Book of AbstractsHodeck, Alexander, Tuchel, Jacqueline, Hente, Luisa, Abdelkarim, Osama, Belal, Mayada, El Beih, Sarah 19 May 2021 (has links)
Abstracts of the proceedings of the Second International Conference on Sustainable Sport Tourism
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Über das Expressionsverhalten von Reparatur- und ABC- Transporter-Genen sowie inflammatorischen Signalwegen im Kolon- und Pankreaskarzinom / Expression of heatshock proteins, ABC-transporters and toll-like transporters under nutrient deprivation in a colorectal and pancreatic tumor modelSchmitt, Johannes Christian January 2021 (has links) (PDF)
Das Mikromilieu solider Tumor (tumor mircoenvironment, TME) weist verschiedene Besonderheiten auf, von denen bekannt ist, dass sie zu Chemotherapieresistenz und Tumorprogression beitragen können. Neben der Extrazellulären Matrix (ECM), den cancer associated cells (CAC) und diversen Entzündungszellen tragen auch chemische und physikalische Besonderheiten (Hypoxie, Azidose, erhöhter Gewebedruck, oxidativer Stress und Nährstoffmangel) zu Tumorprogression und Chemotherapieresistenz bei. Zudem wissen wir, dass Hitzeschock-Proteine (HSPs), Toll-like Rezeptoren (TLRs) und ABC-Transporter mit erhöhter Chemotherapieresistenz und Tumorprogression im Pankreas- und Kolonkarzinom einhergehen.
Hier wurde untersucht, ob ein in vitro induzierter Nährstoffmangel im HT29 Kolonkarzinom, im Panc-1 Pankreaskarzinom und im MIA PaCa-2 Pankreaskarzinom zu einer gesteigerten Expression von HSP70, HSP90, MDR1, ABCB5 und TLR1 bis TLR10 auf mRNA und Proteinebene führt. Zudem wurde unter allen Versuchsbedingungen die Stoffwechselaktivität über einen MTS-Test gemessen. Der Nährstoffmangel wurde über die Kultivierung in einem Hybridomamedium, welches als proteinfreies Medium gilt und über die Kultivierung in einem serumfreien Medium induziert.
Es zeigte sich, dass insbesondere die entdifferenzierte Panc-1 Pankreaskarzinomzelllinie eine erhöhte Resistenz gegenüber dem induzierten Nährstoffmangel aufwies. Auf mRNA-Ebene zeigten sich bei allen drei Tumorzelllinien deutliche Expressionssteigerungen. Diese waren insbesondere im Hybridomamedium nachweisbar und traten beim HT29-Kolonkarzinom nach 48h und im Panc-1 Pankreaskarzinom bereits nach 24h auf. Besonders intensive Expressionssteigerungen konnten im HT29 Kolonkarzinom bei ABCB5, TLR7 und TLR9 nachgewiesen werden. Die Expression von MDR1 war insbesondere im MIA PaCa-2 Pankreaskarzinom gesteigert. Auf Proteinebene konnte im HT29 Kolonkarzinom eine Expressionssteigerung bei HSP90 und TLR6 nachgewiesen werden.
Die Ergebnisse lassen zwei Interpretationen zu. Zum einen könnte über den Nährstoffmangel eine aggressivere Subpopulation selektioniert worden sein. In diesem Zusammenhang konnten die Expressionsdaten des Tumorstammzellmarkers CD133 leider nicht ausgewertet werden. Alternativ kann angenommen werden, dass die untersuchten Tumorzelllinien ihren aggressiven Phänotyp erst unter Nährstoffmangelbedingungen, wie wir sie regelmäßig in soliden Tumoren finden, zur Expression bringen. / The tumor microenvironment (TME) in solid tumors is low on nutrients and favors tumor progression and resistance to chemotherapies in different ways.
In this study we cultured HT29 colorectal carcinoma cells, Panc-1 pancreatic carcinoma cells and MIA PaCa-2 pancreatic carcinoma cells in nutrient deprived conditions (NDC) and performed rtPCR expression analysis, SDS-PAGE and immunohistochemical staining after 24, 48 and 72 hours. Gene expression of ABC transporters (ABCB5, MDR1), heat-shock proteins (HSP70, HSP90) and Toll-like receptors (TLR1 – TLR10) in the NDC compared to normal condition was analyzed. We performed MTS tetrazolium assays to monitor the activity of the respiratory chain in any condition.
We showed that the examined cell lines, and in particular Panc-1 pancreatic carcinoma, are very resistant to the NDC. The gens of interest showed increase expression after 48 hours (HT29) and 24 hours (Panc-1).
The results suggest that culturing in NDC either selects a very aggressive and resistant subpopulation or NDC induces gene expression changes and shows us how cancer cells really perform in the nutrient deprived tumor environment. Unfortunately, we were not able to use the gene expression analysis of the stem cell marker CD133.
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Contributions to the 11th International Conference on Formal Concept Analysis28 May 2013 (has links) (PDF)
Formal concept analysis (FCA) is a mathematical formalism based on order and lattice theory for data analysis. It has found applications in a broad range of neighboring fields including Semantic Web, data mining, knowledge representation, data visualization and software engineering.
ICFCA is a series of annual international conferences that started in 2003 in Darmstadt and has been held in several continents: Europe, Australia, America and Africa. ICFCA has evolved to be the main forum for researchers working on theoretical or applied aspects of formal concept analysis worldwide.
In 2013 the conference returned to Dresden where it was previously held in 2006. This year the selection of contributions was especially competitive. This volume is one of two volumes containing the papers presented at ICFCA 2013. The other volume is published by Springer Verlag as LNAI 7880 in its LNCS series.
In addition to the regular contributions, we have included an extended abstract: Jean-Paul Doignon reviews recent results connecting formal concept analysis and knowledge space theory in his contribution “Identifiability in Knowledge Space Theory: a Survey of Recent Results”.
The high-quality of the program of the conference was ensured by the much-appreciated work of the authors, the Program Committee members, and the Editorial Board members. Finally, we wish to thank the local organization team. They provided support to make ICFCA 2013 proceed smoothly in a pleasant atmosphere.
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THE GAS HYDRATE PROCESS FOR SEPARATION OF CO2 FROM FUEL GAS MIXTURE: MACRO AND MOLECULAR LEVEL STUDIESRipmeester, John A., Englezos, Peter, Kumar, Rajnish 07 1900 (has links)
The “Integrated Coal Gasification Combined Cycle” (IGCC) represents an advanced approach for green field projects for power generation. This process requires separation of carbon dioxide from the shifted-synthesis gas mixture (fuel gas). Treated fuel gas consists of approximately 40% CO2 and rest H2. Gas hydrate based separation technology for hydrate forming gas mixtures is one of the novel approaches for gas separation. The present study illustrates the gas hydrate-based separation process for the recovery of CO2 and H2 from the fuel gas mixture and discusses relevant issues from macro and molecular level perspectives. Propane (C3H8) is used as an additive to reduce the operating pressure for hydrate formation and hence the compression costs. Based on gas uptake measurement during hydrate formation, a hybrid conceptual process for pre-combustion capture of CO2 is presented. The result shows that it is possible to separate CO2 from hydrogen and obtain a hydrate phase with 98% CO2 in two stages starting from a mixture of 39.2% CO2. Molecular level work has also been performed on CO2/H2 and CO2/H2/C3H8 systems to understand the mechanism by which propane reduces the operating pressure without compromising the separation efficiency.
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INDIAN CONTINENTAL MARGIN GAS HYDRATE PROSPECTS: RESULTS OF THE INDIAN NATIONAL GAS HYDRATE PROGRAM (NGHP) EXPEDITION 01Collett, Timothy S., Riedel, Michael, Cochran, J.R., Boswell, Ray, Kumar, Pushpendra, Sathe, A.V. 07 1900 (has links)
Studies of geologic and geophysical data from the offshore of India have revealed two
geologically distinct areas with inferred gas hydrate occurrences: the passive continental margins
of the Indian Peninsula and along the Andaman convergent margin. The Indian National Gas
Hydrate Program (NGHP) Expedition 01 was designed to study the occurrence of gas hydrate off
the Indian Peninsula and along the Andaman convergent margin with special emphasis on
understanding the geologic and geochemical controls on the occurrence of gas hydrate in these
two diverse settings. NGHP Expedition 01 established the presence of gas hydrates in Krishna-
Godavari, Mahanadi and Andaman basins. The expedition discovered one of the richest gas
hydrate accumulations yet documented (Site 10 in the Krishna-Godavari Basin), documented the
thickest and deepest gas hydrate stability zone yet known (Site 17 in Andaman Sea), and
established the existence of a fully-developed gas hydrate system in the Mahanadi Basin (Site 19).
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NEPTUNE-CANADA BASED GEOPHYSICAL IMAGING OF GAS HYDRATE IN THE BULLSEYE VENTWilloughby, E.C., Mir, R, Scholl, Carsten, Edwards, R.N. 07 1900 (has links)
Using the NEPTUNE-Canada cable-linked ocean-floor observatory we plan continuous, real-time monitoring of the gas hydrate-associated, “Bullseye” cold vent offshore Vancouver Island. Our group inferred the presence of a massive gas hydrate deposit there, based on the significant resistivity anomaly in our controlled-source electromagnetic (CSEM) dataset, as well as anomalously heightened shear moduli, from seafloor compliance data. This interpretation was confirmed by drilling by IODP expedition 311 (site U1328), which indicated a 40 m thick gas hydrate layer near the surface. Sporadic venting and variations in blanking in yearly single-channel seismic surveys suggest the system is evolving in time. We are preparing two stationary semi-permanent imaging experiments: a CSEM and a seafloor compliance installation. These are designed not only to assess the extent of the gas hydrate deposit, but also for long-term monitoring of the gas hydrate/free gas system. The principle of the CSEM experiment is to input a particular electromagnetic signal at a transmitter (TX) dipole on the seafloor, and to record the phase and amplitude of the response at several seafloor receiver (RX) dipoles, at various TX-RX separations. The data are sensitive to the underlying resistivity, which is increased when conductive pore water is displaced by electrically-insulating gas hydrate. The experiment is controlled onshore, and can be expanded to include a downhole TX. Repeated soundings at this site, over several years, will allow measurement of minute changes in resistivity as a function of depth, and by inference, changes in gas hydrate or underlying free gas distribution. Similarly, the displacement of pore fluids by solid gas hydrate will affect elastic parameters. Thus, seafloor compliance data, the transfer function between pressure and seafloor displacement time series, most sensitive to shear modulus as a function of depth, will be gathered continuously to monitor the evolution of the gas hydrate distribution.
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SITE SELECTION FOR DOE/JIP GAS HYDRATE DRILLING IN THE NORTHERN GULF OF MEXICOHutchinson, Deborah R., Shelander, Dianna, Dai, Jianchun, McConnel, Dan, Shedd, William, Frye, Matthew, Ruppel, Carolyn, Boswell, Ray, Jones, Emrys, Collett, Timothy S., Rose, Kelly, Dugan, Brandon, Wood, Warren, Latham, Tom 07 1900 (has links)
In the late spring of 2008, the Chevron-led Gulf of Mexico Gas Hydrate Joint Industry Project (JIP) expects
to conduct an exploratory drilling and logging campaign to better understand gas hydrate-bearing sands in
the deepwater Gulf of Mexico. The JIP Site Selection team selected three areas to test alternative
geological models and geophysical interpretations supporting the existence of potential high gas hydrate
saturations in reservoir-quality sands. The three sites are near existing drill holes which provide geological
and geophysical constraints in Alaminos Canyon (AC) lease block 818, Green Canyon (GC) 955, and
Walker Ridge (WR) 313. At the AC818 site, gas hydrate is interpreted to occur within the Oligocene Frio
volcaniclastic sand at the crest of a fold that is shallow enough to be in the hydrate stability zone. Drilling
at GC955 will sample a faulted, buried Pleistocene channel-levee system in an area characterized by
seafloor fluid expulsion features, structural closure associated with uplifted salt, and abundant seismic
evidence for upward migration of fluids and gas into the sand-rich parts of the sedimentary section.
Drilling at WR313 targets ponded sheet sands and associated channel/levee deposits within a minibasin,
making this a non-structural play. The potential for gas hydrate occurrence at WR313 is supported by
shingled phase reversals consistent with the transition from gas-charged sand to overlying gas-hydrate
saturated sand. Drilling locations have been selected at each site to 1) test geological methods and models
used to infer the occurrence of gas hydrate in sand reservoirs in different settings in the northern Gulf of
Mexico; 2) calibrate geophysical models used to detect gas hydrate sands, map reservoir thicknesses, and
estimate the degree of gas hydrate saturation; and 3) delineate potential locations for subsequent JIP drilling and coring operations that will collect samples for comprehensive physical property, geochemical and other
analyses
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PRESSURE CORE ANALYSIS: THE KEYSTONE OF A GAS HYDRATE INVESTIGATIONSchultheiss, Peter, Holland, Melanie, Roberts, John, Humphrey, Gary 07 1900 (has links)
Gas hydrate investigations are converging on a suite of common techniques for hydrate
observation and quantification. Samples retrieved and analyzed at full in situ pressures are the
”gold standard” with which the physical and chemical analysis of conventional cores, as well as
the interpretation of geophysical data, are calibrated and groundtruthed. Methane mass balance
calculations from depressurization of pressure cores provide the benchmark for gas hydrate
concentration assessment. Nondestructive measurements of pressure cores have removed errors in
the estimation of pore volume, making this methane mass balance technique accurate and robust.
Data from methane mass balance used to confirm chlorinity baselines makes porewater
freshening analysis more accurate. High-resolution nondestructive analysis of gas-hydratebearing
cores at in situ pressures and temperatures also provides detailed information on the in
situ nature and morphology of gas hydrate in sediments, allowing better interpretation of
conventional core thermal images as well as downhole electrical resistivity logs. The detailed
profiles of density and Vp, together with spot measurements of Vs, electrical resistivity, and
hardness, provide background data essential for modeling the behavior of the formation on a
larger scale. X-ray images show the detailed hydrate morphology, which provides clues to the
mechanism of deposit formation and data for modeling the kinetics of deposit dissociation. Gashydrate-
bearing pressure cores subjected to X-ray tomographic reconstruction provide evidence
that gas hydrate morphology in many natural sedimentary environments is particularly complex
and impossible to replicate in the laboratory. Even when only a small percentage of the sediment
column is sampled with pressure cores, these detailed measurements greatly enhance the
understanding and interpretation of the more continuous data sets collected by conventional
coring and downhole logging. Pressure core analysis has become the keystone that links these
data sets together and is an essential component of modern gas hydrate investigations.
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EFFECT OF CLATHRATE STRUCTURE AND PROMOTER ON THE PHASE BEHAVIOUR OF HYDROGEN CLATHRATESChapoy, Antonin, Anderson, Ross, Tohidi, Bahman 07 1900 (has links)
Hydrogen is currently considered by many as the “fuel of the future”. It is particularly favoured as a replacement for fossil fuels due to its clean-burning properties; the waste product of combustion being water. While hydrogen is relatively easy to produce, there is currently a lack of practical storage methods for molecular H2, and this is greatly hindering the use of hydrogen as a fuel. Gases are normally stored in vessels under only moderate pressures and in liquid form where possible, which yields the highest energy density. However, to store reasonable quantities of hydrogen in similar volume containers, cryogenic temperatures or extreme pressure are required. Many potential hydrogen storage technologies are currently under investigation, including adsorption on metal hydrides, nanotubes and glass microspheres, and the chemical breakdown of compounds containing hydrogen to release H2. Recent studies have sparked interest in hydrates as a potential hydrogen storage material. The molecular storage of hydrogen in clathrate hydrates could offer significant benefits with regard to ease of formation/regeneration, cost and safety, as compared to other storage materials currently under investigation. Here, we present new experimental hydrate stability data for sII forming hydrogen–water (up to pressures of 180 MPa) and hydrogen–water–tetrahydrofuran systems, the structure-H forming hydrogen–water–methyclycohexane system, and semi-clathrate forming hydrogen–water–tetra-n-butyl ammonium bromide/tetra–n-butyl ammonium fluoride systems.
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