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Sample records for gay hydrate production

  1. Comparative Assessment of Advanced Gay Hydrate Production Methods

    Energy Technology Data Exchange (ETDEWEB)

    M. D. White; B. P. McGrail; S. K. Wurstner

    2009-06-30

    Displacing natural gas and petroleum with carbon dioxide is a proven technology for producing conventional geologic hydrocarbon reservoirs, and producing additional yields from abandoned or partially produced petroleum reservoirs. Extending this concept to natural gas hydrate production offers the potential to enhance gas hydrate recovery with concomitant permanent geologic sequestration. Numerical simulation was used to assess a suite of carbon dioxide injection techniques for producing gas hydrates from a variety of geologic deposit types. Secondary hydrate formation was found to inhibit contact of the injected CO{sub 2} regardless of injectate phase state, thus diminishing the exchange rate due to pore clogging and hydrate zone bypass of the injected fluids. Additional work is needed to develop methods of artificially introducing high-permeability pathways in gas hydrate zones if injection of CO{sub 2} in either gas, liquid, or micro-emulsion form is to be more effective in enhancing gas hydrate production rates.

  2. [Skin hydration and hydrating products].

    Science.gov (United States)

    Duplan, H; Nocera, T

    2018-05-01

    One of the skin's principal functions is to protect the body against its environment by maintaining an effective epidermal barrier, not only against external factors, but also to prevent water loss from the body. Indeed, water homeostasis is vital for the normal physiological functioning of skin. Hydration levels affect not only visible microscopic parameters such as the suppleness and softness of skin, but also molecular parameters, enzyme activities and cellular signalling within the epidermis. The body is continually losing some of its water, but this phenomenon is limited and the optimal hydration gradient in skin is ensured via a set of sophisticated regulatory processes that rely on the functional and dynamic properties of the uppermost level of the skin consisting of the stratum corneum. The present article brings together data recently acquired in the fields of skin hydration and the characterisation of dehydrated or dry skin, whether through study of the regulatory processes involved or as a result of changes in the techniques used for in situ measurement, and thus in optimisation of management. Copyright © 2018. Published by Elsevier Masson SAS.

  3. ConocoPhillips Gas Hydrate Production Test

    Energy Technology Data Exchange (ETDEWEB)

    Schoderbek, David [ConocoPhillips Co., Houston, TX (United States); Farrell, Helen [ConocoPhillips Co., Houston, TX (United States); Howard, James [ConocoPhillips Co., Houston, TX (United States); Raterman, Kevin [ConocoPhillips Co., Houston, TX (United States); Silpngarmlert, Suntichai [ConocoPhillips Co., Houston, TX (United States); Martin, Kenneth [ConocoPhillips Co., Houston, TX (United States); Smith, Bruce [ConocoPhillips Co., Houston, TX (United States); Klein, Perry [ConocoPhillips Co., Houston, TX (United States)

    2013-06-30

    Work began on the ConocoPhillips Gas Hydrates Production Test (DOE award number DE-NT0006553) on October 1, 2008. This final report summarizes the entire project from January 1, 2011 to June 30, 2013.

  4. METHANE HYDRATE PRODUCTION FROM ALASKAN PERMAFROST

    Energy Technology Data Exchange (ETDEWEB)

    Thomas E. Williams; Keith Millheim; Bill Liddell

    2005-03-01

    Natural-gas hydrates have been encountered beneath the permafrost and considered a nuisance by the oil and gas industry for years. Oil-field engineers working in Russia, Canada and the USA have documented numerous drilling problems, including kicks and uncontrolled gas releases, in Arctic regions. Information has been generated in laboratory studies pertaining to the extent, volume, chemistry and phase behavior of gas hydrates. Scientists studying hydrates agree that the potential is great--on the North Slope of Alaska alone, it has been estimated at 590 TCF. However, little information has been obtained on physical samples taken from actual rock containing hydrates. This gas-hydrate project is a cost-shared partnership between Maurer Technology, Anadarko Petroleum, Noble Corporation, and the U.S. Department of Energy's Methane Hydrate R&D program. The purpose of the project is to build on previous and ongoing R&D in the area of onshore hydrate deposition to help identify, quantify and predict production potential for hydrates located on the North Slope of Alaska. As part of the project work scope, team members drilled and cored the HOT ICE No. 1 on Anadarko leases beginning in January 2003 and completed in March 2004. Due to scheduling constraints imposed by the Arctic drilling season, operations at the site were suspended between April 21, 2003 and January 30, 2004. An on-site core analysis laboratory was designed, constructed and used for determining physical characteristics of frozen core immediately after it was retrieved from the well. The well was drilled from a new and innovative Anadarko Arctic Platform that has a greatly reduced footprint and environmental impact. Final efforts of the project were to correlate geology, geophysics, logs, and drilling and production data and provide this information to scientists for future hydrate operations. Unfortunately, no gas hydrates were encountered in this well; however, a wealth of information was generated

  5. Detection and Production of Methane Hydrate

    Energy Technology Data Exchange (ETDEWEB)

    George Hirasaki; Walter Chapman; Gerald Dickens; Colin Zelt; Brandon Dugan; Kishore Mohanty; Priyank Jaiswal

    2011-12-31

    This project seeks to understand regional differences in gas hydrate systems from the perspective of as an energy resource, geohazard, and long-term climate influence. Specifically, the effort will: (1) collect data and conceptual models that targets causes of gas hydrate variance, (2) construct numerical models that explain and predict regional-scale gas hydrate differences in 2-dimensions with minimal 'free parameters', (3) simulate hydrocarbon production from various gas hydrate systems to establish promising resource characteristics, (4) perturb different gas hydrate systems to assess potential impacts of hot fluids on seafloor stability and well stability, and (5) develop geophysical approaches that enable remote quantification of gas hydrate heterogeneities so that they can be characterized with minimal costly drilling. Our integrated program takes advantage of the fact that we have a close working team comprised of experts in distinct disciplines. The expected outcomes of this project are improved exploration and production technology for production of natural gas from methane hydrates and improved safety through understanding of seafloor and well bore stability in the presence of hydrates. The scope of this project was to more fully characterize, understand, and appreciate fundamental differences in the amount and distribution of gas hydrate and how this would affect the production potential of a hydrate accumulation in the marine environment. The effort combines existing information from locations in the ocean that are dominated by low permeability sediments with small amounts of high permeability sediments, one permafrost location where extensive hydrates exist in reservoir quality rocks and other locations deemed by mutual agreement of DOE and Rice to be appropriate. The initial ocean locations were Blake Ridge, Hydrate Ridge, Peru Margin and GOM. The permafrost location was Mallik. Although the ultimate goal of the project was to understand

  6. METHANE HYDRATE PRODUCTION FROM ALASKAN PERMAFROST

    Energy Technology Data Exchange (ETDEWEB)

    Donn McGuire; Steve Runyon; Richard Sigal; Bill Liddell; Thomas Williams; George Moridis

    2005-02-01

    Natural-gas hydrates have been encountered beneath the permafrost and considered a nuisance by the oil and gas industry for years. Engineers working in Russia, Canada and the USA have documented numerous drilling problems, including kicks and uncontrolled gas releases, in arctic regions. Information has been generated in laboratory studies pertaining to the extent, volume, chemistry and phase behavior of gas hydrates. Scientists studying hydrate potential agree that the potential is great--on the North Slope of Alaska alone, it has been estimated at 590 TCF. However, little information has been obtained on physical samples taken from actual rock containing hydrates. This gas-hydrate project is in the final stages of a cost-shared partnership between Maurer Technology, Noble Corporation, Anadarko Petroleum, and the U.S. Department of Energy's Methane Hydrate R&D program. The purpose of the project is to build on previous and ongoing R&D in the area of onshore hydrate deposition to identify, quantify and predict production potential for hydrates located on the North Slope of Alaska. Hot Ice No. 1 was planned to test the Ugnu and West Sak sequences for gas hydrates and a concomitant free gas accumulation on Anadarko's 100% working interest acreage in section 30 of Township 9N, Range 8E of the Harrison Bay quadrangle of the North Slope of Alaska. The Ugnu and West Sak intervals are favorably positioned in the hydrate-stability zone over an area extending from Anadarko's acreage westward to the vicinity of the aforementioned gas-hydrate occurrences. This suggests that a large, north-to-south trending gas-hydrate accumulation may exist in that area. The presence of gas shows in the Ugnu and West Sak reservoirs in wells situated eastward and down dip of the Hot Ice location indicate that a free-gas accumulation may be trapped by gas hydrates. The Hot Ice No. 1 well was designed to core from the surface to the base of the West Sak interval using the

  7. METHANE HYDRATE PRODUCTION FROM ALASKAN PERMAFROST

    Energy Technology Data Exchange (ETDEWEB)

    Ali Kadaster; Bill Liddell; Tommy Thompson; Thomas Williams; Michael Niedermayr

    2005-02-01

    Natural-gas hydrates have been encountered beneath the permafrost and considered a nuisance by the oil and gas industry for years. Engineers working in Russia, Canada and the USA have documented numerous drilling problems, including kicks and uncontrolled gas releases, in arctic regions. Information has been generated in laboratory studies pertaining to the extent, volume, chemistry and phase behavior of gas hydrates. Scientists studying hydrate potential agree that the potential is great--on the North Slope of Alaska alone, it has been estimated at 590 TCF. However, little information has been obtained on physical samples taken from actual rock containing hydrates. This gas-hydrate project was a cost-shared partnership between Maurer Technology, Noble Corporation, Anadarko Petroleum, and the U.S. Department of Energy's Methane Hydrate R&D program. The purpose of the project is to build on previous and ongoing R&D in the area of onshore hydrate deposition to identify, quantify and predict production potential for hydrates located on the North Slope of Alaska. The work scope included drilling and coring a well (Hot Ice No. 1) on Anadarko leases beginning in FY 2003 and completed in 2004. During the first drilling season, operations were conducted at the site between January 28, 2003 to April 30, 2003. The well was spudded and drilled to a depth of 1403 ft. Due to the onset of warmer weather, work was then suspended for the season. Operations at the site were continued after the tundra was re-opened the following season. Between January 12, 2004 and March 19, 2004, the well was drilled and cored to a final depth of 2300 ft. An on-site core analysis laboratory was built and implemented for determining physical characteristics of the hydrates and surrounding rock. The well was drilled from a new Anadarko Arctic Platform that has a minimal footprint and environmental impact. Final efforts of the project are to correlate geology, geophysics, logs, and drilling and

  8. Ground movements associated with gas hydrate production

    International Nuclear Information System (INIS)

    Siriwardane, H.J.; Kutuk, B.

    1992-03-01

    This report deals with a study directed towards a modeling effort on production related ground movements and subsidence resulting from hydrate dissociation. The goal of this research study was to evaluate whether there could be subsidence related problems that could be an impediment to hydrate production. During the production of gas from a hydrate reservoir, it is expected that porous reservoir matrix becomes more compressible which may cause reservoir compression (compaction) under the influence of overburden weight. The overburden deformations can propagate its influence upwards causing subsidence near the surface where production equipment will be located. In the present study, the reservoir compaction is modeled by using the conventional ''stress equilibrium'' approach. In this approach, the overburden strata move under the influence of body force (i.e. self weight) in response to the ''cavity'' generated by reservoir depletion. The present study is expected to provide a ''lower bound'' solution to the subsidence caused by hydrate reservoir depletion. The reservoir compaction anticipated during hydrate production was modeled by using the finite element method, which is a powerful computer modeling technique. The ground movements at the reservoir roof (i.e. reservoir compression) cause additional stresses and disturbance in the overburden strata. In this study, the reservoir compaction was modeled by using the conventional ''stress equilibrium'' approach. In this approach, the overburden strata move under the influence of body force (i.e. self weight) in response to the ''cavity'' generated by reservoir depletion. The resulting stresses and ground movements were computed by using the finite element method. Based on the parameters used in this investigation, the maximum ground subsidence could vary anywhere from 0.50 to 6.50 inches depending on the overburden depth and the size of the depleted hydrate reservoir

  9. METHANE HYDRATE PRODUCTION FROM ALASKAN PERMAFROST

    Energy Technology Data Exchange (ETDEWEB)

    Richard Sigal; Kent Newsham; Thomas Williams; Barry Freifeld; Timothy Kneafsey; Carl Sondergeld; Shandra Rai; Jonathan Kwan; Stephen Kirby; Robert Kleinberg; Doug Griffin

    2005-02-01

    Natural-gas hydrates have been encountered beneath the permafrost and considered a nuisance by the oil and gas industry for years. Engineers working in Russia, Canada and the USA have documented numerous drilling problems, including kicks and uncontrolled gas releases, in arctic regions. Information has been generated in laboratory studies pertaining to the extent, volume, chemistry and phase behavior of gas hydrates. Scientists studying hydrate potential agree that the potential is great--on the North Slope of Alaska alone, it has been estimated at 590 TCF. However, little information has been obtained on physical samples taken from actual rock containing hydrates. The work scope drilled and cored a well The Hot Ice No. 1 on Anadarko leases beginning in FY 2003 and completed in 2004. An on-site core analysis laboratory was built and utilized for determining the physical characteristics of the hydrates and surrounding rock. The well was drilled from a new Anadarko Arctic Platform that has a minimal footprint and environmental impact. The final efforts of the project are to correlate geology, geophysics, logs, and drilling and production data and provide this information to scientists developing reservoir models. No gas hydrates were encountered in this well; however, a wealth of information was generated and is contained in this report. The Hot Ice No. 1 well was drilled from the surface to a measured depth of 2300 ft. There was almost 100% core recovery from the bottom of surface casing at 107 ft to total depth. Based on the best estimate of the bottom of the methane hydrate stability zone (which used new data obtained from Hot Ice No. 1 and new analysis of data from adjacent wells), core was recovered over its complete range. Approximately 580 ft of porous, mostly frozen, sandstone and 155 of conglomerate were recovered in the Ugnu Formation and approximately 215 ft of porous sandstone were recovered in the West Sak Formation. There were gas shows in the bottom

  10. Development of hydrate risk quantification in oil and gas production

    Science.gov (United States)

    Chaudhari, Piyush N.

    Subsea flowlines that transport hydrocarbons from wellhead to the processing facility face issues from solid deposits such as hydrates, waxes, asphaltenes, etc. The solid deposits not only affect the production but also pose a safety concern; thus, flow assurance is significantly important in designing and operating subsea oil and gas production. In most subsea oil and gas operations, gas hydrates form at high pressure and low temperature conditions, causing the risk of plugging flowlines, with a undesirable impact on production. Over the years, the oil and gas industry has shifted their perspective from hydrate avoidance to hydrate management given several parameters such as production facility, production chemistry, economic and environmental concerns. Thus, understanding the level of hydrate risk associated with subsea flowlines is an important in developing efficient hydrate management techniques. In the past, hydrate formation models were developed for various flow-systems (e.g., oil dominated, water dominated, and gas dominated) present in the oil and gas production. The objective of this research is to extend the application of the present hydrate prediction models for assessing the hydrate risk associated with subsea flowlines that are prone to hydrate formation. It involves a novel approach for developing quantitative hydrate risk models based on the conceptual models built from the qualitative knowledge obtained from experimental studies. A comprehensive hydrate risk model, that ranks the hydrate risk associated with the subsea production system as a function of time, hydrates, and several other parameters, which account for inertial, viscous, interfacial forces acting on the flow-system, is developed for oil dominated and condensate systems. The hydrate plugging risk for water dominated systems is successfully modeled using The Colorado School of Mines Hydrate Flow Assurance Tool (CSMHyFAST). It is found that CSMHyFAST can be used as a screening tool in

  11. Hydrate bearing clayey sediments: Formation and gas production concepts

    KAUST Repository

    Jang, Jaewon; Santamarina, Carlos

    2016-01-01

    Hydro-thermo-chemo and mechanically coupled processes determine hydrate morphology and control gas production from hydrate-bearing sediments. Force balance, together with mass and energy conservation analyses anchored in published data provide robust asymptotic solutions that reflect governing processes in hydrate systems. Results demonstrate that hydrate segregation in clayey sediments results in a two-material system whereby hydrate lenses are surrounded by hydrate-free water-saturated clay. Hydrate saturation can reach ≈2% by concentrating the excess dissolved gas in the pore water and ≈20% from metabolizable carbon. Higher hydrate saturations are often found in natural sediments and imply methane transport by advection or diffusion processes. Hydrate dissociation is a strongly endothermic event; the available latent heat in a reservoir can sustain significant hydrate dissociation without triggering ice formation during depressurization. The volume of hydrate expands 2-to-4 times upon dissociation or CO2single bondCH4 replacement. Volume expansion can be controlled to maintain lenses open and to create new open mode discontinuities that favor gas recovery. Pore size is the most critical sediment parameter for hydrate formation and gas recovery and is controlled by the smallest grains in a sediment. Therefore any characterization must carefully consider the amount of fines and their associated mineralogy.

  12. Hydrate bearing clayey sediments: Formation and gas production concepts

    KAUST Repository

    Jang, Jaewon

    2016-06-20

    Hydro-thermo-chemo and mechanically coupled processes determine hydrate morphology and control gas production from hydrate-bearing sediments. Force balance, together with mass and energy conservation analyses anchored in published data provide robust asymptotic solutions that reflect governing processes in hydrate systems. Results demonstrate that hydrate segregation in clayey sediments results in a two-material system whereby hydrate lenses are surrounded by hydrate-free water-saturated clay. Hydrate saturation can reach ≈2% by concentrating the excess dissolved gas in the pore water and ≈20% from metabolizable carbon. Higher hydrate saturations are often found in natural sediments and imply methane transport by advection or diffusion processes. Hydrate dissociation is a strongly endothermic event; the available latent heat in a reservoir can sustain significant hydrate dissociation without triggering ice formation during depressurization. The volume of hydrate expands 2-to-4 times upon dissociation or CO2single bondCH4 replacement. Volume expansion can be controlled to maintain lenses open and to create new open mode discontinuities that favor gas recovery. Pore size is the most critical sediment parameter for hydrate formation and gas recovery and is controlled by the smallest grains in a sediment. Therefore any characterization must carefully consider the amount of fines and their associated mineralogy.

  13. Behaviour of gas production from type 3 hydrate reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Pooladi-Darvish, M. [Calgary Univ., AB (Canada). Dept. of Chemical and Petroleum Engineering]|[Fekete Associates Inc., Calgary, AB (Canada); Zatsepina, O. [Calgary Univ., AB (Canada). Dept. of Chemical and Petroleum Engineering; Hong, H. [Fekete Associates Inc., Calgary, AB (Canada)

    2008-07-01

    The possible role of gas hydrates as a potential energy resource was discussed with particular reference to methods for estimating the rate of gas production from hydrate reservoirs under different operating conditions. This paper presented several numerical simulations studies of gas production from type 3 hydrate reservoirs in 1-D and 2-D geometries. Type 3 reservoirs include gas production from hydrate-reservoirs that lie totally within the hydrate stability zone and are sandwiched by impermeable layers on top and bottom. The purpose of this study was to better understand hydrate decomposition by depressurization. The study questioned whether 1-D modeling of type 3 hydrate reservoirs is a reasonable approximation. It also determined whether gas rate increases or decreases with time. The important reservoir characteristics for determining the rate of gas production were identified. Last, the study determined how competition between fluid and heat flow affects hydrate decomposition. This paper also described the relation and interaction between the heat and fluid flow mechanisms in depressurization of type 3 hydrate reservoirs. All results of 1-D and 2-D numerical simulation and analyses were generated using the STARS simulator. It was shown that the rate of gas production depends on the initial pressure/temperature conditions and permeability of the hydrate bearing formation. A high peak rate may be achieved under favourable conditions, but this peak rate is obtained after an initial period where the rate of gas production increases with time. The heat transfer in the direction perpendicular to the direction of fluid flow is significant, requiring 2D modeling. The hydraulic diffusivity is low because of the low permeability of hydrate-bearing formations. This could result in competition between heat and fluid flow, thereby influencing the behaviour of decomposition. 6 refs., 3 tabs., 12 figs.

  14. Methane Production and Carbon Capture by Hydrate Swapping

    DEFF Research Database (Denmark)

    Mu, Liang; von Solms, Nicolas

    2017-01-01

    There are essentially two different approaches to producing methane from natural gas hydrate reservoirs, either bring the hydrate out of its thermodynamic stability region or expose the hydrate to a substance that will form a more stable hydrate structure, forcing an in situ swapping of the trapped...... experimental runs were performed to examine the influence of operating conditions on methane production by CO2/(CO2 + N2) injection in the temperature range of 274.15–277.15 K and 7.039–10.107 MPa pressure. Our results show that the use of the (CO2 + N2) binary gas mixture is advantageous compared to the use...

  15. Spatial resolution of gas hydrate and permeability changes from ERT data in LARS simulating the Mallik gas hydrate production test

    Science.gov (United States)

    Priegnitz, Mike; Thaler, Jan; Spangenberg, Erik; Schicks, Judith M.; Abendroth, Sven

    2014-05-01

    The German gas hydrate project SUGAR studies innovative methods and approaches to be applied in the production of methane from hydrate-bearing reservoirs. To enable laboratory studies in pilot scale, a large reservoir simulator (LARS) was realized allowing for the formation and dissociation of gas hydrates under simulated in-situ conditions. LARS is equipped with a series of sensors. This includes a cylindrical electrical resistance tomography (ERT) array composed of 25 electrode rings featuring 15 electrodes each. The high-resolution ERT array is used to monitor the spatial distribution of the electrical resistivity during hydrate formation and dissociation experiments over time. As the present phases of poorly conducting sediment, well conducting pore fluid, non-conducting hydrates, and isolating free gas cover a wide range of electrical properties, ERT measurements enable us to monitor the spatial distribution of these phases during the experiments. In order to investigate the hydrate dissociation and the resulting fluid flow, we simulated a hydrate production test in LARS that was based on the Mallik gas hydrate production test (see abstract Heeschen et al., this volume). At first, a hydrate phase was produced from methane saturated saline water. During the two months of gas hydrate production we measured the electrical properties within the sediment sample every four hours. These data were used to establish a routine estimating both the local degrees of hydrate saturation and the resulting local permeabilities in the sediment's pore space from the measured resistivity data. The final gas hydrate saturation filled 89.5% of the total pore space. During hydrate dissociation, ERT data do not allow for a quantitative determination of free gas and remaining gas hydrates since both phases are electrically isolating. However, changes are resolved in the spatial distribution of the conducting liquid and the isolating phase with gas being the only mobile isolating phase

  16. Hydrate prevention in petroleum production sub sea system

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, Paula L.F.; Rocha, Humberto A.R. [Universidade Estacio de Sa (UNESA), Rio de Janeiro, RJ (Brazil); Rodrigues, Antonio P. [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil)

    2012-07-01

    In spite of the merits of the several hydrate prevention techniques used nowadays, such as: chemical product injection for inhibition and use of thick thermal insulate lines; hydrates per times happen and they are responsible for considerable production losses. Depressurization techniques can be used so much for prevention as in the remediation. Some hydrate removal techniques need a rig or vessel, resources not readily available and with high cost, reason that limits such techniques just for remediation and not for prevention. In the present work it is proposed and described an innovative depressurization system, remote and resident, for hydrate prevention and removal, applicable as for individual sub sea wells as for grouped wells by manifold. Based on low cost jet pumps, without movable parts and with a high reliability, this technique allows hydrate prevention or remediation in a fast and remote way, operated from the production unit. The power fluid line and fluid return line can be integrated in the same umbilical or annulus line structure, without significant increase in the construction costs and installation. It is not necessary to wait for expensive resource mobilization, sometimes not available quickly, such as: vessels or rigs. It still reduces the chemical product consumption and permits to depressurized stopped lines. Other additional advantage, depressurization procedure can be used in the well starting, removing fluid until riser emptying. (author)

  17. Hydrate-Bearing Clayey Sediments: Morphology, Physical Properties, Production and Engineering/Geological Implications

    Energy Technology Data Exchange (ETDEWEB)

    Dai, Sheng [Georgia Tech Research Corporation, Atlanta, GA (United States); Santamarina, J. Carlos [King Abdulaziz Univ., Jeddah (Saudi Arabia)

    2017-12-30

    Fine-grained sediments host more than 90 percent of global gas hydrate accumulation. However, hydrate formation in clay-dominated sediments is less understood and characterized than other types of hydrate occurrence. There is an inadequate understanding of hydrate formation mechanisms, segregation structures, hydrate lens topology, system connectivity, and physical macro-scale properties of clay-dominated hydrate-bearing sediments. This situation hinders further analyses of the global carbon budget as well as engineering challenges/solutions related to hydrate instability and production. This project studies hydrate-bearing clay-dominated sediments with emphasis on the enhanced fundamental understanding of hydrate formation and resulting morphology, the development laboratory techniques to emulate natural hydrate formations, the assessment of analytical tools to predict physical properties, the evaluation of engineering and geological implications, and the advanced understanding of gas production potential from finegrained sediments.

  18. Experimental hydrate formation and gas production scenarios based on CO{sub 2} sequestration

    Energy Technology Data Exchange (ETDEWEB)

    Stevens, J.C.; Howard, J.J. [ConocoPhillips, Bartlesville, OK (United States). Reservoir Laboratories; Baldwin, B.A. [Green Country Petrophysics LLC, Dewey, OK (United States); Ersland, G.; Husebo, J.; Graue, A. [Bergen Univ., Bergen (Norway). Dept. of Physics and Technology

    2008-07-01

    Gas hydrate production strategies have focused on depressurization or thermal stimulation of the reservoir, which in turn leads to hydrate dissociation. In order to evaluate potential production scenarios, the recovery efficiency of the natural gas from hydrate must be known along with the corresponding amounts of produced water. This study focused on the exchange of carbon dioxide (CO{sub 2}) with the natural gas hydrate and the subsequent release of free methane (CH{sub 4}). Laboratory experiments that investigated the rates and mechanisms of hydrate formation in coarse-grained porous media have shown the significance of initial water saturation and salinity on forming methane hydrates. Many of the experiments were performed in a sample holder fitted with an MRI instrument for monitoring hydrate formation. Hydrate-saturated samples were subjected to different procedures to release methane. The rates and efficiency of the exchange process were reproducible over a series of initial conditions. The exchange process was rapid and efficient in that no free water was observed in the core with MRI measurements. Injection of CO{sub 2} into the whole-core hydrate-saturated pore system resulted in methane production at the outlet end. Permeability measurements on these hydrate saturated cores during hydrate formation decreased to low values, but enough for gas transport. The lower permeability values remained constant during the methane-carbon dioxide exchange process in the hydrate structure. 12 refs., 9 figs.

  19. Challenges, uncertainties and issues facing gas production from gas hydrate deposits

    Energy Technology Data Exchange (ETDEWEB)

    Moridis, G.J.; Collett, T.S.; Pooladi-Darvish, M.; Hancock, S.; Santamarina, C.; Boswell, R.; Kneafsey, T.; Rutqvist, J.; Kowalsky, M.; Reagan, M.T.; Sloan, E.D.; Sum, A.K.; Koh, C.

    2010-11-01

    The current paper complements the Moridis et al. (2009) review of the status of the effort toward commercial gas production from hydrates. We aim to describe the concept of the gas hydrate petroleum system, to discuss advances, requirement and suggested practices in gas hydrate (GH) prospecting and GH deposit characterization, and to review the associated technical, economic and environmental challenges and uncertainties, including: the accurate assessment of producible fractions of the GH resource, the development of methodologies for identifying suitable production targets, the sampling of hydrate-bearing sediments and sample analysis, the analysis and interpretation of geophysical surveys of GH reservoirs, well testing methods and interpretation of the results, geomechanical and reservoir/well stability concerns, well design, operation and installation, field operations and extending production beyond sand-dominated GH reservoirs, monitoring production and geomechanical stability, laboratory investigations, fundamental knowledge of hydrate behavior, the economics of commercial gas production from hydrates, and the associated environmental concerns.

  20. Lightweight Approaches to Natural Gas Hydrate Exploration & Production

    Science.gov (United States)

    Max, M. D.; Johnson, A. H.

    2017-12-01

    Lower-cost approaches to drilling and reservoir utilization are made possible by adapting both emerging and new technology to the unique, low risk NGH natural gas resource. We have focused on drilling, wellbore lining technology, and reservoir management with an emphasis on long-term sand control and adaptive mechanical stability during NGH conversion to its constituent gas and water. In addition, we suggest that there are opportunities for management of both the gas and water with respect to maintaining desired thermal conditions. Some of the unique aspects of NGH deposits allow for new, more efficient technology to be applied to development, particularly in drilling. While NGH-bearing sands are in deepwater, they are confined to depths beneath the seafloor of 1.2 kilometers or less. As a result, they will not be significantly above hydrostatic pressure, and temperatures will be less than 30 oC. Drilling will be through semi-consolidated sediment without liquid hydrocarbons. These characteristics mean that high capability drillships are not needed. What is needed is a new perspective about drilling and producing NGH. Drilling from the seafloor will resolve the high-pressure differential between a wellhead on the sea surface in a vessel and reservoir to about the hydrostatic pressure difference between the seafloor and, at most, the base of the GHSZ. Although NGH production will begin using "off-the-shelf" technology, innovation will lead to new technology that will bring down costs and increase efficiency in the same way that led to the shale breakthrough. Commercial success is possible if consideration is given to what is actually needed to produce NGH in a safe and environmentally manner. Max, M.D. 2017. Wellbore Lining for Natural Gas Hydrate. U.S. Patent Application US15644947 Max, M.D. & Johnson, A.H. 2017. E&P Cost Reduction Opportunities for Natural Gas Hydrate. OilPro. . Max, M.D. & Johnson, A.H. 2016. Exploration and Production of Oceanic Natural Gas

  1. Preliminary report on the economics of gas production from natural gas hydrates

    International Nuclear Information System (INIS)

    Walsh, M.; Wilson, S.; Patil, S.; Moridis, G.; Boswell, R.; Koh, C.; Sloan, D.

    2008-01-01

    Gas hydrates are solid crystalline compounds in which gas molecules reside inside cages that are formed by hydrogen-bonded water molecules in a crystal lattice. At particularly low temperatures and high pressures, a guest molecule will combine with water to form gas hydrates. Gas hydrates are found in two different settings in which the temperature and pressure conditions are suitable for their existence, notably in Arctic permafrost regions and below the seafloor. Because of the size of this possible future resource, if any of the gas in hydrates can be proven to be economically recoverable, then production from gas hydrates could become an important portion of the world's energy portfolio as demand for natural gas increases along with the technology to compress and distribute natural gas to distant markets. This paper presented a compilation of economic research that was conducted on the resource potential of gas hydrates. The paper reported a preliminary estimate of the price of natural gas that may lead to economically-viable production from North American Arctic region hydrates. The paper also discussed the implications of a recent study on the production of class 3 marine hydrate deposits from the Gulf of Mexico. The state of the art technologies and methods in hydrate reservoir modeling and hydrate reservoir production and petrophysical testing were also discussed. It was concluded that the somewhat optimistic results presented in this report should be interpreted with caution, however, the economically-viable gas production from hydrates was not an unreasonable scenario. 23 refs., 2 tabs., 10 figs

  2. Petrophysical Characterization and Reservoir Simulator for Methane Gas Production from Gulf of Mexico Hydrates

    Energy Technology Data Exchange (ETDEWEB)

    Kishore Mohanty; Bill Cook; Mustafa Hakimuddin; Ramanan Pitchumani; Damiola Ogunlana; Jon Burger; John Shillinglaw

    2006-06-30

    Gas hydrates are crystalline, ice-like compounds of gas and water molecules that are formed under certain thermodynamic conditions. Hydrate deposits occur naturally within ocean sediments just below the sea floor at temperatures and pressures existing below about 500 meters water depth. Gas hydrate is also stable in conjunction with the permafrost in the Arctic. Most marine gas hydrate is formed of microbially generated gas. It binds huge amounts of methane into the sediments. Estimates of the amounts of methane sequestered in gas hydrates worldwide are speculative and range from about 100,000 to 270,000,000 trillion cubic feet (modified from Kvenvolden, 1993). Gas hydrate is one of the fossil fuel resources that is yet untapped, but may play a major role in meeting the energy challenge of this century. In this project novel techniques were developed to form and dissociate methane hydrates in porous media, to measure acoustic properties and CT properties during hydrate dissociation in the presence of a porous medium. Hydrate depressurization experiments in cores were simulated with the use of TOUGHFx/HYDRATE simulator. Input/output software was developed to simulate variable pressure boundary condition and improve the ease of use of the simulator. A series of simulations needed to be run to mimic the variable pressure condition at the production well. The experiments can be matched qualitatively by the hydrate simulator. The temperature of the core falls during hydrate dissociation; the temperature drop is higher if the fluid withdrawal rate is higher. The pressure and temperature gradients are small within the core. The sodium iodide concentration affects the dissociation pressure and rate. This procedure and data will be useful in designing future hydrate studies.

  3. Towards understanding the role of amines in the SO2 hydration and the contribution of the hydrated product to new particle formation in the Earth's atmosphere.

    Science.gov (United States)

    Lv, Guochun; Nadykto, Alexey B; Sun, Xiaomin; Zhang, Chenxi; Xu, Yisheng

    2018-08-01

    By theoretical calculations, the gas-phase SO 2 hydration reaction assisted by methylamine (MA) and dimethylamine (DMA) was investigated, and the potential contribution of the hydrated product to new particle formation (NPF) also was evaluated. The results show that the energy barrier for aliphatic amines (MA and DMA) assisted SO 2 hydration reaction is lower than the corresponding that of water and ammonia assisted SO 2 hydration. In these hydration reactions, nearly barrierless reaction (only a barrier of 0.1 kcal mol -1 ) can be found in the case of SO 2  + 2H 2 O + DMA. These lead us to conclude that the SO 2 hydration reaction assisted by MA and DMA is energetically facile. The temporal evolution for hydrated products (CH 3 NH 3 + -HSO 3 - -H 2 O or (CH 3 ) 2 NH 2 + -HSO 3 - -H 2 O) in molecular dynamics simulations indicates that these complexes can self-aggregate into bigger clusters and can absorb water and amine molecules, which means that these hydrated products formed by the hydration reaction may serve as a condensation nucleus to initiate the NPF. Copyright © 2018 Elsevier Ltd. All rights reserved.

  4. Simulation of microwave stimulation for the production of gas from methane hydrate sediment

    International Nuclear Information System (INIS)

    Zhao, Jiafei; Fan, Zhen; Wang, Bin; Dong, Hongsheng; Liu, Yu; Song, Yongchen

    2016-01-01

    Graphical abstract: Schematic diagram illustrating the process of gas production in hydrate-bearing sediment induced by microwave stimulation. Temperature gradients caused by the drop of microwave penetration depth appear in the sediment, leading to a rapid dissociation rate at the upper part of reservoir. - Highlights: • Hydrate dissociation behavior was analyzed in porous media by microwave stimulation. • Microwave stimulation provides sufficient energy conversion for hydrate dissociation. • Hydrate saturation and specific heat capacity of sediment mainly affect efficiency. • Heat conduction decreases temperature gradients promoting homogeneous dissociation. - Abstract: Natural gas hydrates dissociate via an endothermic process. One of the key requirements for any production technique is to supply the heat necessary for this dissociation. In this study, first, a microwave stimulation model for the production of gas from methane hydrate sediment is developed, which includes mass transport, energy conversion and conservation, and intrinsic kinetic reactions as the governing equations. In addition, the theoretical mixing rule of Lichtenecker and Rother is introduced for calculating the average dielectric data of the sediment containing methane hydrates, which affects the penetration of microwaves into the sediment. Next, simulations are performed for investigating gas production, as well as effects of initial water saturation, initial hydrate saturation, and sediment thermal properties induced by microwave stimulation. Moreover, the energy efficiency ratio is employed in the simulation. The simulation results show that microwave stimulation provides timely energy conversion sufficient for promoting the dissociation of hydrates, with rapid, continuous gas production. Temperature gradients caused by the decrease of the microwave penetration depth appear in the reservoir, leading to a rapid dissociation rate in the upper part of the sediment. The energy

  5. Effect of Graphene Oxide (GO on the Morphology and Microstructure of Cement Hydration Products

    Directory of Open Access Journals (Sweden)

    Liguo Wang

    2017-12-01

    Full Text Available In this study, the effects of graphene oxide (GO on the microstructure of cement mortars were studied using scanning electron microscopy (SEM, thermogravimetric (TG, and X-ray diffraction (XRD techniques. Cement mortar samples with different proportions of GO (0.02, 0.04, 0.06, and 0.08 wt % based on the weight of cement were prepared. The test results showed that GO affected the crystallization of cement hydration products, C–S–H (calcium silicate hydrate is the main hydrate product and CH (calcium hydroxide. The morphology of hydration products changed with the increase of GO content. Furthermore, the results of XRD analyses showed that the diffraction peak intensity and the crystal grain size of CH (001, (100, (101, and (102 for GO samples increased considerably compared with the control sample. Based on the results, it can be understood that GO can modify the crystal surface of CH, leading to the formation of larger crystals.

  6. Sensitivity Analysis of Methane Hydrate Reservoirs: Effects of Reservoir Parameters on Gas Productivity and Economics

    Science.gov (United States)

    Anderson, B. J.; Gaddipati, M.; Nyayapathi, L.

    2008-12-01

    This paper presents a parametric study on production rates of natural gas from gas hydrates by the method of depressurization, using CMG STARS. Seven factors/parameters were considered as perturbations from a base-case hydrate reservoir description based on Problem 7 of the International Methane Hydrate Reservoir Simulator Code Comparison Study led by the Department of Energy and the USGS. This reservoir is modeled after the inferred properties of the hydrate deposit at the Prudhoe Bay L-106 site. The included sensitivity variables were hydrate saturation, pressure (depth), temperature, bottom-hole pressure of the production well, free water saturation, intrinsic rock permeability, and porosity. A two-level (L=2) Plackett-Burman experimental design was used to study the relative effects of these factors. The measured variable was the discounted cumulative gas production. The discount rate chosen was 15%, resulting in the gas contribution to the net present value of a reservoir. Eight different designs were developed for conducting sensitivity analysis and the effects of the parameters on the real and discounted production rates will be discussed. The breakeven price in various cases and the dependence of the breakeven price on the production parameters is given in the paper. As expected, initial reservoir temperature has the strongest positive effect on the productivity of a hydrate deposit and the bottom-hole pressure in the production well has the strongest negative dependence. Also resulting in a positive correlation is the intrinsic permeability and the initial free water of the formation. Negative effects were found for initial hydrate saturation (at saturations greater than 50% of the pore space) and the reservoir porosity. These negative effects are related to the available sensible heat of the reservoir, with decreasing productivity due to decreasing available sensible heat. Finally, we conclude that for the base case reservoir, the break-even price (BEP

  7. Preliminary report on the commercial viability of gas production from natural gas hydrates

    Science.gov (United States)

    Walsh, M.R.; Hancock, S.H.; Wilson, S.J.; Patil, S.L.; Moridis, G.J.; Boswell, R.; Collett, T.S.; Koh, C.A.; Sloan, E.D.

    2009-01-01

    Economic studies on simulated gas hydrate reservoirs have been compiled to estimate the price of natural gas that may lead to economically viable production from the most promising gas hydrate accumulations. As a first estimate, $CDN2005 12/Mscf is the lowest gas price that would allow economically viable production from gas hydrates in the absence of associated free gas, while an underlying gas deposit will reduce the viability price estimate to $CDN2005 7.50/Mscf. Results from a recent analysis of the simulated production of natural gas from marine hydrate deposits are also considered in this report; on an IROR basis, it is $US2008 3.50-4.00/Mscf more expensive to produce marine hydrates than conventional marine gas assuming the existence of sufficiently large marine hydrate accumulations. While these prices represent the best available estimates, the economic evaluation of a specific project is highly dependent on the producibility of the target zone, the amount of gas in place, the associated geologic and depositional environment, existing pipeline infrastructure, and local tariffs and taxes. ?? 2009 Elsevier B.V.

  8. Productivity in Lesbian, Gay, Bisexual, and Transgender Scholarship in Counseling Psychology: Institutional and Individual Ratings for 1990 through 2008

    Science.gov (United States)

    Smith, Nathan Grant

    2010-01-01

    This study examined individual and institutional productivity in lesbian, gay, bisexual, and transgender (LGBT) scholarship published in counseling psychology--oriented journals for the years 1990 through 2008. Eight journals were included in the analyses. An author-weighted score was calculated for each scholar, using a formula developed by…

  9. Constant rate natural gas production from a well in a hydrate reservoir

    International Nuclear Information System (INIS)

    Ji Chuang; Ahmadi, Goodarz; Smith, Duane H.

    2003-01-01

    Using a computational model, production of natural gas at a constant rate from a well that is drilled into a confined methane hydrate reservoir is studied. It is assumed that the pores in the reservoir are partially saturated with hydrate. A linearized model for an axisymmetric condition with a fixed well output is used in the analysis. For different reservoir temperatures and various well outputs, time evolutions of temperature and pressure profiles, as well as the gas flow rate in the hydrate zone and the gas region, are evaluated. The distance of the decomposition front from the well as a function of time is also computed. It is shown that to maintain a constant natural gas production rate, the well pressure must be decreased with time. A constant low production rate can be sustained for a long duration of time, but a high production rate demands unrealistically low pressure at the well after a relatively short production time. The simulation results show that the process of natural gas production in a hydrate reservoir is a sensitive function of reservoir temperature and hydrate zone permeability

  10. Challenges, uncertainties, and issues facing gas production from gas-hydrate deposits

    Science.gov (United States)

    Moridis, G.J.; Collett, T.S.; Pooladi-Darvish, M.; Hancock, S.; Santamarina, C.; Boswel, R.; Kneafsey, T.; Rutqvist, J.; Kowalsky, M.B.; Reagan, M.T.; Sloan, E.D.; Sum, A.K.; Koh, C.A.

    2011-01-01

    The current paper complements the Moridis et al. (2009) review of the status of the effort toward commercial gas production from hydrates. We aim to describe the concept of the gas-hydrate (GH) petroleum system; to discuss advances, requirements, and suggested practices in GH prospecting and GH deposit characterization; and to review the associated technical, economic, and environmental challenges and uncertainties, which include the following: accurate assessment of producible fractions of the GH resource; development of methods for identifying suitable production targets; sampling of hydrate-bearing sediments (HBS) and sample analysis; analysis and interpretation of geophysical surveys of GH reservoirs; well-testing methods; interpretation of well-testing results; geomechanical and reservoir/well stability concerns; well design, operation, and installation; field operations and extending production beyond sand-dominated GH reservoirs; monitoring production and geomechanical stability; laboratory investigations; fundamental knowledge of hydrate behavior; the economics of commercial gas production from hydrates; and associated environmental concerns. ?? 2011 Society of Petroleum Engineers.

  11. Numerical simulation studies of gas production scenarios from hydrate accumulations at the Mallik Site, McKenzie Delta, Canada

    International Nuclear Information System (INIS)

    Moridis, George J.; Collett, Timothy S.; Dallimore, Scott R.; Satoh, Tohru; Hancock, Stephen; Weatherill, Brian

    2002-01-01

    The Mallik site represents an onshore permafrost-associated gas hydrate accumulation in the Mackenzie Delta, Northwest Territories, Canada. An 1150 m deep gas hydrate research well was drilled at the site in 1998. The objective of this study is the analysis of various gas production scenarios from several gas-hydrate-bearing zones at the Mallik site. The TOUGH2 general-purpose simulator with the EOSHYDR2 module were used for the analysis. EOSHYDR2 is designed to model the non-isothermal CH(sub 4) (methane) release, phase behavior and flow under conditions typical of methane-hydrate deposits by solving the coupled equations of mass and heat balance, and can describe any combination of gas hydrate dissociation mechanisms. Numerical simulations indicated that significant gas hydrate production at the Mallik site was possible by drawing down the pressure on a thin free-gas zone at the base of the hydrate stability field. Gas hydrate zones with underlying aquifers yielded significant gas production entirely from dissociated gas hydrate, but large amounts of produced water. Lithologically isolated gas-hydrate-bearing reservoirs with no underlying free gas or water zones, and gas-hydrate saturations of at least 50% were also studied. In these cases, it was assumed that thermal stimulation by circulating hot water in the well was the method used to induce dissociation. Sensitivity studies indicated that the methane release from the hydrate accumulations increases with gas-hydrate saturation, the initial formation temperature, the temperature of the circulating water in the well, and the formation thermal conductivity. Methane production appears to be less sensitive to the rock and hydrate specific heat and permeability of the formation

  12. Impact of pore-water freshening on clays and the compressibility of hydrate-bearing reservoirs during production

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Junbong [U.S. Geological Survey, Woods Hole, MA; Cao, Shuang [Louisiana State University, Baton Rouge, LA; Waite, William [U.S. Geological Survey, Woods Hole, MA; Jung, Jongwon [Chungbuk National University, Cheongju-si, Chungbuk, South Korea

    2017-06-25

    Gas production efficiency from natural hydrate-bearing sediments depends in part on geotechnical properties of fine-grained materials, which are ubiquitous even in sandy hydrate-bearing sediments. The responses of fine-grained material to pore fluid chemistry changes due to freshening during hydrate dissociation could alter critical sediment characteristics during gas production activities. We investigate the electrical sensitivity of fine grains to pore fluid freshening and the implications of freshening on sediment compression and recompression parameters.

  13. Gas production potential of disperse low-saturation hydrate accumulations in oceanic sediments

    International Nuclear Information System (INIS)

    Moridis, George J.; Sloan, E. Dendy

    2007-01-01

    In this paper, we evaluate the gas production potential of disperse, low-saturation (S H H hydrate-bearing sediments subject to depressurization-induced dissociation over a 10-year production period. We investigate the sensitivity of items (a)-(c) to the following hydraulic properties, reservoir conditions, and operational parameters: intrinsic permeability, porosity, pressure, temperature, hydrate saturation, and constant pressure at which the production well is kept. The results of this study indicate that, despite wide variations in the aforementioned parameters (covering the entire spectrum of such deposits), gas production is very limited, never exceeding a few thousand cubic meters of gas during the 10-year production period. Such low production volumes are orders of magnitude below commonly accepted standards of economic viability, and are further burdened with very unfavorable gas-to-water ratios. The unequivocal conclusion from this study is that disperse, low-S H hydrate accumulations in oceanic sediments are not promising targets for gas production by means of depressurization-induced dissociation, and resources for early hydrate exploitation should be focused elsewhere

  14. Simulating the gas hydrate production test at Mallik using the pilot scale pressure reservoir LARS

    Science.gov (United States)

    Heeschen, Katja; Spangenberg, Erik; Schicks, Judith M.; Priegnitz, Mike; Giese, Ronny; Luzi-Helbing, Manja

    2014-05-01

    LARS, the LArge Reservoir Simulator, allows for one of the few pilot scale simulations of gas hydrate formation and dissociation under controlled conditions with a high resolution sensor network to enable the detection of spatial variations. It was designed and built within the German project SUGAR (submarine gas hydrate reservoirs) for sediment samples with a diameter of 0.45 m and a length of 1.3 m. During the project, LARS already served for a number of experiments simulating the production of gas from hydrate-bearing sediments using thermal stimulation and/or depressurization. The latest test simulated the methane production test from gas hydrate-bearing sediments at the Mallik test site, Canada, in 2008 (Uddin et al., 2011). Thus, the starting conditions of 11.5 MPa and 11°C and environmental parameters were set to fit the Mallik test site. The experimental gas hydrate saturation of 90% of the total pore volume (70 l) was slightly higher than volumes found in gas hydrate-bearing formations in the field (70 - 80%). However, the resulting permeability of a few millidarcy was comparable. The depressurization driven gas production at Mallik was conducted in three steps at 7.0 MPa - 5.0 MPa - 4.2 MPa all of which were used in the laboratory experiments. In the lab the pressure was controlled using a back pressure regulator while the confining pressure was stable. All but one of the 12 temperature sensors showed a rapid decrease in temperature throughout the sediment sample, which accompanied the pressure changes as a result of gas hydrate dissociation. During step 1 and 2 they continued up to the point where gas hydrate stability was regained. The pressure decreases and gas hydrate dissociation led to highly variable two phase fluid flow throughout the duration of the simulated production test. The flow rates were measured continuously (gas) and discontinuously (liquid), respectively. Next to being discussed here, both rates were used to verify a model of gas

  15. Methane Production from Gas Hydrate Deposits through Injection of Supercritical CO2

    Directory of Open Access Journals (Sweden)

    Matthias Haeckel

    2012-06-01

    Full Text Available The recovery of natural gas from CH4-hydrate deposits in sub-marine and sub-permafrost environments through injection of CO2 is considered a suitable strategy towards emission-neutral energy production. This study shows that the injection of hot, supercritical CO2 is particularly promising. The addition of heat triggers the dissociation of CH4-hydrate while the CO2, once thermally equilibrated, reacts with the pore water and is retained in the reservoir as immobile CO2-hydrate. Furthermore, optimal reservoir conditions of pressure and temperature are constrained. Experiments were conducted in a high-pressure flow-through reactor at different sediment temperatures (2 °C, 8 °C, 10 °C and hydrostatic pressures (8 MPa, 13 MPa. The efficiency of both, CH4 production and CO2 retention is best at 8 °C, 13 MPa. Here, both CO2- and CH4-hydrate as well as mixed hydrates can form. At 2 °C, the production process was less effective due to congestion of transport pathways through the sediment by rapidly forming CO2-hydrate. In contrast, at 10 °C CH4 production suffered from local increases in permeability and fast breakthrough of the injection fluid, thereby confining the accessibility to the CH4 pool to only the most prominent fluid channels. Mass and volume balancing of the collected gas and fluid stream identified gas mobilization as equally important process parameter in addition to the rates of methane hydrate dissociation and hydrate conversion. Thus, the combination of heat supply and CO2 injection in one supercritical phase helps to overcome the mass transfer limitations usually observed in experiments with cold liquid or gaseous CO2.

  16. Geomechanical response of permafrost-associated hydrate deposits to depressurization-induced gas production

    Science.gov (United States)

    Rutqvist, J.; Moridis, G.J.; Grover, T.; Collett, T.

    2009-01-01

    In this simulation study, we analyzed the geomechanical response during depressurization production from two known hydrate-bearing permafrost deposits: the Mallik (Northwest Territories, Canada) deposit and Mount Elbert (Alaska, USA) deposit. Gas was produced from these deposits at constant pressure using horizontal wells placed at the top of a hydrate layer (HL), located at a depth of about 900??m at the Mallik site and 600??m at the Mount Elbert site. The simulation results show that general thermodynamic and geomechanical responses are similar for the two sites, but with substantially higher production and more intensive geomechanical responses at the deeper Mallik deposit. The depressurization-induced dissociation begins at the well bore and then spreads laterally, mainly along the top of the HL. The depressurization results in an increased shear stress within the body of the receding hydrate and causes a vertical compaction of the reservoir. However, its effects are partially mitigated by the relatively stiff permafrost overburden, and compaction of the HL is limited to less than 0.4%. The increased shear stress may lead to shear failure in the hydrate-free zone bounded by the HL overburden and the downward-receding upper dissociation interface. This zone undergoes complete hydrate dissociation, and the cohesive strength of the sediment is low. We determined that the likelihood of shear failure depends on the initial stress state as well as on the geomechanical properties of the reservoir. The Poisson's ratio of the hydrate-bearing formation is a particularly important parameter that determines whether the evolution of the reservoir stresses will increase or decrease the likelihood of shear failure.

  17. Hydration products of lime-metakaolin pastes at ambient temperature with ageing

    Energy Technology Data Exchange (ETDEWEB)

    Gameiro, A., E-mail: agameiro@lnec.pt [National Laboratory of Civil Engineering, Materials Department, Av. do Brasil, 101, 1700 Lisbon (Portugal); Santos Silva, A., E-mail: ssilva@lnec.pt [National Laboratory of Civil Engineering, Materials Department, Av. do Brasil, 101, 1700 Lisbon (Portugal); Veiga, R., E-mail: rveiga@lnec.pt [National Laboratory of Civil Engineering, Buildings Department, Av. do Brasil, 101, 1700 Lisbon (Portugal); Velosa, A., E-mail: avelosa@ua.pt [Department of Civil Engineering, Geobiotec, University of Aveiro, Campus Universitario de Santiago, 3810-193 Aveiro (Portugal)

    2012-05-10

    Highlights: Black-Right-Pointing-Pointer We study the compounds formed in lime/MK blended pastes and their stability over time. Black-Right-Pointing-Pointer Different mixes of lime/MK pastes show different reaction kinetics during curing time, being the pozzolanic compounds formed directly proportional to the lime by MK replacement. Black-Right-Pointing-Pointer Some pozzolanic products are found to be unstable during the hydration reaction employed in our study. - Abstract: Mortars constituted of lime mixtures with pozzolanic additions have been extensively used in the past for the construction of historic and traditional buildings. This paper presents the results of blended pastes of lime and metakaolin (MK), namely compounds formed and their stability over time. This research is part of an extensive study aiming at the formulation of lime based mortars for restoration purposes. It has been shown for several years that MK has been applied in inorganic binders due to its capacity to react vigorously with calcium hydroxide (CH). In the presence of water originating a series of major hydrated phases, namely tetra calcium aluminate hydrate (C{sub 4}AH{sub 13}), calcium silicates hydrates (CSH) and calcium aluminium silicate hydrates (stratlingite - C{sub 2}ASH{sub 8}). Several blended pastes of lime and MK, with different substitution rates of lime by MK (wt%) were prepared and cured at a temperature of 20 Degree-Sign C and relative humidity RH > 95%. The phase composition of the formed hydrated phases was determined by X-ray diffraction (XRD) and simultaneous thermal analysis (TG-DTA). The obtained results showed that lime/MK pastes compositions displayed different reaction kinetics during curing time, being the pozzolanic products content directly proportional to the substitution rate of lime by MK. Also, a relationship between the increase stratlingite content and the MK substitution rate of lime by MK was found.

  18. Experimental investigation into methane hydrate production during three-dimensional thermal stimulation with five-spot well system

    International Nuclear Information System (INIS)

    Wang, Yi; Li, Xiao-Sen; Li, Gang; Zhang, Yu; Li, Bo; Chen, Zhao-Yang

    2013-01-01

    Highlights: • The production behaviors of methane hydrate are obtained in the 3-D simulator. • The thermal stimulation method with a five-spot well is used for hydrate production. • The water and gas production, efficiency, recovery, production rate are analyzed. • The effect of injection rate change on the production behavior is investigated. - Abstract: The cubic hydrate simulator (CHS) is used to study the methane hydrate production behaviors in porous media by the thermal stimulation with a five-spot well system. The hot water injection rates range from 10.0 to 40.0 ml/min. The thermal stimulation process is analyzed, and the conclusions are that the hydrate decomposition boundary moves from the central point to the surroundings gradually and finally covers almost the entire hydrate field in the CHS during the thermal stimulation process. The heat conduction plays a more significant role than the convection for the heat diffusion in the thermal stimulation process. The increasing injection rate of the hot water enhances the rate of hydrate decomposition, shortens the production time, and decreases the water production volumes, while it has little influence on the final gas production volumes. Furthermore, the change of the hot water injection rate (R inj ) has little influence on the final gas recovery, however, the higher R inj leads to the higher average production rate and the lower energy efficiency

  19. Decomposition of methane hydrate for hydrogen production using microwave and radio frequency in-liquid plasma methods

    International Nuclear Information System (INIS)

    Rahim, Ismail; Nomura, Shinfuku; Mukasa, Shinobu; Toyota, Hiromichi

    2015-01-01

    This research involves two in-liquid plasma methods of methane hydrate decomposition, one using radio frequency wave (RF) irradiation and the other microwave radiation (MW). The ultimate goal of this research is to develop a practical process for decomposition of methane hydrate directly at the subsea site for fuel gas production. The mechanism for methane hydrate decomposition begins with the dissociation process of methane hydrate formed by CH_4 and water. The process continues with the simultaneously occurring steam methane reforming process and methane cracking reaction, during which the methane hydrate is decomposed releasing CH_4 into H_2, CO and other by-products. It was found that methane hydrate can be decomposed with a faster rate of CH_4 release using microwave irradiation over that using radio frequency irradiation. However, the radio frequency plasma method produces hydrogen with a purity of 63.1% and a CH conversion ratio of 99.1%, which is higher than using microwave plasma method which produces hydrogen with a purity of 42.1% and CH_4 conversion ratio of 85.5%. - Highlights: • The decomposition of methane hydrate is proposed using plasma in-liquid method. • Synthetic methane hydrate is used as the sample for decomposition in plasma. • Hydrogen can be produced from decomposition of methane hydrate. • Hydrogen purity is higher when using radio frequency stimulation.

  20. Toward Production From Gas Hydrates: Current Status, Assessment of Resources, and Simulation-Based Evaluationof Technology and Potential

    Energy Technology Data Exchange (ETDEWEB)

    Reagan, Matthew; Moridis, George J.; Collett, Timothy; Boswell, Ray; Kurihara, M.; Reagan, Matthew T.; Koh, Carolyn; Sloan, E. Dendy

    2008-02-12

    Gas hydrates are a vast energy resource with global distribution in the permafrost and in the oceans. Even if conservative estimates are considered and only a small fraction is recoverable, the sheer size of the resource is so large that it demands evaluation as a potential energy source. In this review paper, we discuss the distribution of natural gas hydrate accumulations, the status of the primary international R&D programs, and the remaining science and technological challenges facing commercialization of production. After a brief examination of gas hydrate accumulations that are well characterized and appear to be models for future development and gas production, we analyze the role of numerical simulation in the assessment of the hydrate production potential, identify the data needs for reliable predictions, evaluate the status of knowledge with regard to these needs, discuss knowledge gaps and their impact, and reach the conclusion that the numerical simulation capabilities are quite advanced and that the related gaps are either not significant or are being addressed. We review the current body of literature relevant to potential productivity from different types of gas hydrate deposits, and determine that there are consistent indications of a large production potential at high rates over long periods from a wide variety of hydrate deposits. Finally, we identify (a) features, conditions, geology and techniques that are desirable in potential production targets, (b) methods to maximize production, and (c) some of the conditions and characteristics that render certain gas hydrate deposits undesirable for production.

  1. Numerical studies of gas production from several CH4 hydrate zones at the Mallik site, Mackenzie Delta, Canada

    Science.gov (United States)

    Moridis, G.J.; Collett, T.S.; Dallimore, S.R.; Satoh, T.; Hancock, S.; Weatherill, B.

    2004-01-01

    The Mallik site represents an onshore permafrost-associated gas hydrate accumulation in the Mackenzie Delta, Northwest Territories, Canada. A gas hydrate research well was drilled at the site in 1998. The objective of this study is the analysis of various gas production scenarios from five methane hydrate-bearing zones at the Mallik site. In Zone #1, numerical simulations using the EOSHYDR2 model indicated that gas production from hydrates at the Mallik site was possible by depressurizing a thin free gas zone at the base of the hydrate stability field. Horizontal wells appeared to have a slight advantage over vertical wells, while multiwell systems involving a combination of depressurization and thermal stimulation offered superior performance, especially when a hot noncondensible gas was injected. Zone #2, which involved a gas hydrate layer with an underlying aquifer, could yield significant amounts of gas originating entirely from gas hydrates, the volumes of which increased with the production rate. However, large amounts of water were also produced. Zones #3, #4 and #5 were lithologically isolated gas hydrate-bearing deposits with no underlying zones of mobile gas or water. In these zones, thermal stimulation by circulating hot water in the well was used to induce dissociation. Sensitivity studies indicated that the methane release from the hydrate accumulations increased with the gas hydrate saturation, the initial formation temperature, the temperature of the circulating water in the well, and the formation thermal conductivity. Methane production appears to be less sensitive to the specific heat of the rock and of the hydrate, and to the permeability of the formation. ?? 2004 Published by Elsevier B.V.

  2. Halogen systematics in the Mallik 5L-38 gas hydrate production research well, Northwest Territories, Canada: Implications for the origin of gas hydrates under terrestrial permafrost conditions

    International Nuclear Information System (INIS)

    Tomaru, Hitoshi; Fehn, Udo; Lu, Zunli; Matsumoto, Ryo

    2007-01-01

    The authors report here halogen concentrations in pore waters and sediments collected from the Mallik 5L-38 gas hydrate production research well, a permafrost location in the Mackenzie Delta, Northwest Territories, Canada. Iodine and Br are commonly enriched in waters associated with CH 4 , reflecting the close association between these halogens and source organic materials. Pore waters collected from the Mallik well show I enrichment, by one order of magnitude above that of seawater, particularly in sandy layers below the gas hydrate stability zone (GHSZ). Although Cl and Br concentrations increase with depth similar to the I profile, they remain below seawater values. The increase in I concentrations observed below the GHSZ suggests that I-rich fluids responsible for the accumulation of CH 4 in gas hydrates are preferentially transported through the sandy permeable layers below the GHSZ. The Br and I concentrations and I/Br ratios in Mallik are considerably lower than those in marine gas hydrate locations, demonstrating a terrestrial nature for the organic materials responsible for the CH 4 at the Mallik site. Halogen systematics in Mallik suggest that they are the result of mixing between seawater, freshwater and an I-rich source fluid. The comparison between I/Br ratios in pore waters and sediments speaks against the origin of the source fluids within the host formations of gas hydrates, a finding compatible with the results from a limited set of 129 I/I ratios determined in pore waters, which gives a minimum age of 29 Ma for the source material, i.e. at the lower end of the age range of the host formations. The likely scenario for the gas hydrate formation in Mallik is the derivation of CH 4 together with I from the terrestrial source materials in formations other than the host layers through sandy permeable layers into the present gas hydrate zones

  3. Hydration interactions and stability of soluble microbial products in aqueous solutions.

    Science.gov (United States)

    Wang, Ling-Ling; Wang, Long-Fei; Ye, Xiao-Dong; Yu, Han-Qing

    2013-10-01

    Soluble microbial products (SMP) are organic compounds excreted by microorganisms in their metabolism and decay and the main constituents in effluent from biological wastewater treatment systems. They also have an important contribution to the dissolved organic matters in natural aqueous systems. So far the interactions between SMP colloids have not been well explored. In this work, the interactions between SMP colloids in water and salt solutions were studied by using a combination of static and dynamic light scattering, Fourier transform infrared spectra, Zeta potential and acid-base titration techniques. The second osmotic virial coefficient had a larger value in a 750-mM salt solution than that in a 50-mM solution, indicating that repulsion between SMP colloids increased with an increase in salt concentration, which is contrary with the classic Derjaguin, Landau, Verwey, and Overbeek (DLVO) theory. Such a repulsion was attributed to water structuring and enhanced by the accumulation of hydrophilic counter ions around SMP colloids and the formed hydration force. The repulsion and hydration effect led to the dispersing and deeper draining structure, accompanied by a decreased hydrodynamic radius and increased diffusion coefficient. This hydration force was related to so-called ion specific effect, and electrolyte sodium chloride had a more substantial effect on hydration force than KCl, CsCl, NaBr and NaI. Our results provide an experimental approach to explore the SMP structures, inter-colloid interactions and confirm the non-DLVO forces. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. In vitro methods for evaluating skin hydration under diapers and incontinence products.

    Science.gov (United States)

    Tate, M L; Wright, A S

    2017-11-01

    Excessive skin hydration from wearing wet undergarments, such as infant diapers and adult incontinence products, has been historically problematic. Skin damage occurs from wetness (urine) and limited product breathability. Evaporative water loss has been measured on adult arms (armband method) or infant torsos (on-baby method), after wearing a saline-insulted diaper product. The current study developed a reliable in vitro method of evaluating diaper and incontinence products for improvements in skin dryness. A simulated skin substrate was applied to a heated mechanical arm or baby torso. A disposable diaper or incontinence product was wrapped around the arm or baby torso, and loaded with saline. Hydration of the simulated skin was measured by evaporimetry and compared with clinical data from adult armband evaluations. The heated mechanical arm and baby torso accurately distinguished products for skin dryness. Eight diaper products were evaluated and compared to human test results. The torso in vitro and mechanical arm evaluations demonstrated strong correlations to human epidermal water loss evaluations, with repeatable results. Additionally, the bench test has been used for adult incontinence products, and it proved to differentiate those products as well as infant products. A rapid and reliable means of evaluation has been developed, and it is predictive of human subject testing. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  5. Drilling and Production Testing the Methane Hydrate Resource Potential Associated with the Barrow Gas Fields

    Energy Technology Data Exchange (ETDEWEB)

    Steve McRae; Thomas Walsh; Michael Dunn; Michael Cook

    2010-02-22

    In November of 2008, the Department of Energy (DOE) and the North Slope Borough (NSB) committed funding to develop a drilling plan to test the presence of hydrates in the producing formation of at least one of the Barrow Gas Fields, and to develop a production surveillance plan to monitor the behavior of hydrates as dissociation occurs. This drilling and surveillance plan was supported by earlier studies in Phase 1 of the project, including hydrate stability zone modeling, material balance modeling, and full-field history-matched reservoir simulation, all of which support the presence of methane hydrate in association with the Barrow Gas Fields. This Phase 2 of the project, conducted over the past twelve months focused on selecting an optimal location for a hydrate test well; design of a logistics, drilling, completion and testing plan; and estimating costs for the activities. As originally proposed, the project was anticipated to benefit from industry activity in northwest Alaska, with opportunities to share equipment, personnel, services and mobilization and demobilization costs with one of the then-active exploration operators. The activity level dropped off, and this benefit evaporated, although plans for drilling of development wells in the BGF's matured, offering significant synergies and cost savings over a remote stand-alone drilling project. An optimal well location was chosen at the East Barrow No.18 well pad, and a vertical pilot/monitoring well and horizontal production test/surveillance well were engineered for drilling from this location. Both wells were designed with Distributed Temperature Survey (DTS) apparatus for monitoring of the hydrate-free gas interface. Once project scope was developed, a procurement process was implemented to engage the necessary service and equipment providers, and finalize project cost estimates. Based on cost proposals from vendors, total project estimated cost is $17.88 million dollars, inclusive of design work

  6. Preparation and efficacy assessment of malva nut polysaccharide for skin hydrating products.

    Science.gov (United States)

    Kanlayavattanakul, M; Fungpaisalpong, K; Pumcharoen, M; Lourith, N

    2017-11-01

    Scaphium scaphigerum or malva nut has long been served in Chinese medicine. However, the use of this herb in modern health care applications has, to date, been rarely reported. Maceration of the herb in water afforded malva nut polysaccharide which was standardized. Safety and skin hydrating efficacy of the polysaccharide and products were evaluated in human volunteers. Malva nut polysaccharide (41.71±0.64%) having 36.58±0.51% total sugar content was isolated, with further analysis quantifying ash, carbohydrate, reducing sugar and moisture contents to be 6.05±0.00, 40.06±1.00, 12.20±0.05 and 12.64±0.31%, respectively. The polysaccharide exhibited swelling and hydrating capacities of 0.46±0.01% and 54.46±0.02g/g, with L*, a* and b* of 52.56±0.04, 9.02±0.06 and 18.42±0.03, respectively, and a viscosity of 1263.00±2.00 cps. Accelerated testing indicated the biopolysaccharide to be stable, resulting in no skin irritation in 15 human volunteers. The skin hydrating efficacy as assessed via a randomized single-blind, placebo-controlled study in 24 volunteers highlighted the superior performance of malva nut over the vehicle (moisture retainment for 70min as examined by Corneometer ® CM 825). A stable skin moisturizing gel containing malva nut was developed and was shown to exhibit improved performance over benchmark tamarind and algae polysaccharide gels (after 180min observation). Malva nut polysaccharide has potential as a key ingredient in skin hydrating products, which should encourage its further development. Copyright © 2017 Académie Nationale de Pharmacie. Published by Elsevier Masson SAS. All rights reserved.

  7. Hydration products and mechanical properties of hydroceramics solidified waste for simulated Non-alpha low and intermediate level radioactive wastes

    International Nuclear Information System (INIS)

    Wang Jin; Hong Ming; Wang Junxia; Li Yuxiang; Teng Yuancheng; Wu Xiuling

    2011-01-01

    In this paper, simulated non-alpha low and intermediate level radioactive wastes was handled as curing object and that of 'alkali-slag-coal fly ash-metakaolin' hydroceramics waste forms were prepared by hydrothermal synthesis method. The hydration products were analyzed by X ray diffraction. The composition of hydrates and the compressive strength of waste forms were determined and measured. The results indicate that the main crystalline phase of hydration products were analcite when the temperature was 150 to 180 degree C and the salt content ratio was 0.10 to 0.30. Analcite diffraction peaks in hydration products is increasing when the temperature was raised and the reaction time prolonged. Strength test results show that the solidified waste forms have superior compressive strength. The compressive strength gradually decreased with the increase in salt content ratio in waste forms. (authors)

  8. Overview of the 2006-2008 JOGMEC/NRCan/Aurora Mallik Gas Hydrate Production Test Program

    Science.gov (United States)

    Yamamoto, K.; Dallimore, S. R.

    2008-12-01

    During the winters of 2007 and 2008 the Japan Oil, Gas and Metals National Corporation (JOGMEC) and Natural Resources Canada (NRCan), with Aurora Research Institute as the operator, carried out an on-shore gas hydrate production test program at the Mallik site, Mackenzie Delta, Northwest Territories, Canada. The prime objective of the program was to verify the feasibility of depressurization technique by drawing down the formation pressure across a 12m perforated gas hydrate bearing section. This project was the second full scale production test at this site following the 2002 Japex/JNOC/GSC et al Mallik research program in which seven participants organizatinos from five countries undertook a thermal test using hot water circulation Field work in 2007 was devoted to establishing a production test well, installing monitoring devices outside of casing, conducting base line geophysical studies and undertaking a short test to gain practical experience prior to longer term testing planned for 2008 . Hydrate-dissociated gas was produced to surface by depressurization achieved by lowering the fluid level with a dowhole pump. However, the operation was terminated 60 hours after the start of the pumping mainly due to sand production problems. In spite of the short period (12.5 hours of ellapsed pumping time), at least 830m3 of the gas was produced and accumulated in the borehole. Sand screens were installed across the perforated interval at the bottom hole for the 2008 program to overcome operational problems encountered in 2007 and achieve sustainable gas production. Stable bottom hole flowing pressures were successfully achieved during a 6 day test with continuous pump operation. Sustained gas production was achieved with rates between 2000- 4000m3/day and cummulative gas volume in the surface of approximately 13,000m3. Temperature and pressure data measured at the bottom hole and gas and water production rates gave positive evidence for the high efficiency of gas

  9. Production of natural gas from methane hydrate by a constant downhole pressure well

    International Nuclear Information System (INIS)

    Ahmadi, Goodarz; Ji, Chuang; Smith, Duane H.

    2007-01-01

    Natural gas production from the dissociation of methane hydrate in a confined reservoir by a depressurizing downhole well was studied. The case that the well pressure was kept constant was treated, and two different linearization schemes in an axisymmetric configuration were used in the analysis. For different fixed well pressures and reservoir temperatures, approximate self similar solutions were obtained. Distributions of temperature, pressure and gas velocity field across the reservoir were evaluated. The distance of the decomposition front from the well and the natural gas production rate as functions of time were also computed. Time evolutions of the resulting profiles were presented in graphical forms, and their differences with the constant well output results were studied. It was shown that the gas production rate was a sensitive function of well pressure and reservoir temperature. The sensitivity of the results to the linearization scheme used was also studied

  10. Vowel production, speech-motor control, and phonological encoding in people who are lesbian, bisexual, or gay, and people who are not

    Science.gov (United States)

    Munson, Benjamin; Deboe, Nancy

    2003-10-01

    A recent study (Pierrehumbert, Bent, Munson, and Bailey, submitted) found differences in vowel production between people who are lesbian, bisexual, or gay (LBG) and people who are not. The specific differences (more fronted /u/ and /a/ in the non-LB women; an overall more-contracted vowel space in the non-gay men) were not amenable to an interpretation based on simple group differences in vocal-tract geometry. Rather, they suggested that differences were either due to group differences in some other skill, such as motor control or phonological encoding, or learned. This paper expands on this research by examining vowel production, speech-motor control (measured by diadochokinetic rates), and phonological encoding (measured by error rates in a tongue-twister task) in people who are LBG and people who are not. Analyses focus on whether the findings of Pierrehumbert et al. (submitted) are replicable, and whether group differences in vowel production are related to group differences in speech-motor control or phonological encoding. To date, 20 LB women, 20 non-LB women, 7 gay men, and 7 non-gay men have participated. Preliminary analyses suggest that there are no group differences in speech motor control or phonological encoding, suggesting that the earlier findings of Pierrehumbert et al. reflected learned behaviors.

  11. Development of an offshore gas field: Hydrate and paraffin tests for ensuring continuous production; Entwicklung eines offshore Gasfelds - Hydrat- und Paraffinuntersuchungen zur Sicherstellung der kontinuierlichen Produktion

    Energy Technology Data Exchange (ETDEWEB)

    Zettlitzer, M.; Busch, M. [RWE Dea AG, Wietze (Germany)

    2005-07-01

    Production in offshore gas fields often requires transporting of undried raw gas through pipelines laid on, or in, the sea floor. This will cool the gas down - at worst to sea floor temperature, which may be as low as 4 C. This will cause condensation of the water and higher hydrocarbons. Two of the related problems are gone into here, i.e. potential formation of gas hydrates and potential paraffin deposits. The paraffin problem is relevant not only for crude gas transport but also - even more so - for gas conditioning in a freeze-dryer. (orig.)

  12. Geologic and porous media factors affecting the 2007 production response characteristics of the JOGMEC/NRCan/AURORA Mallik gas hydrate production research well

    Energy Technology Data Exchange (ETDEWEB)

    Dallimore, S. R.; Wright, J. F.; Nixon, F. M. [Natural Resources Canada, Sidney, BC (Canada). Geological Survey of Canada; Kurihara, M. [Japan Oil Engineering, Tokyo (Japan); Yamamoto, K.; Fujii, T.; Fujii, K.; Numasawa, M.; Yasuda, M. [Japan Oil, Gas, Metals National Corp., Chiba (Japan). Technical Research Centre; Imasato, Y. [Schlumberger K.K., Fuchinombe (Japan)

    2008-07-01

    The joint research project between Japan Oil, Gas and Metals National Corporation (JOGMEC), Natural Resources Canada (NRCan) and the Aurora Research Institute was conducted in an effort to measure and monitor the response of a terrestrial gas hydrate reservoir to pressure draw down. This paper reviewed the geologic setting and porous media conditions of a concentrated gas hydrate production interval between 1093 and 1105 m. The short-duration production test was conducted at the Mallik site in Canada's Mackenzie Delta in April 2007. The production interval consists of a sand-dominated succession with occasional silty sand interbeds. Gas hydrate occurs primarily within the sediment pore spaces, with concentrations ranging between 50-90 per cent. Experiments on pore water salinity and porous media conditions on pressure-temperature stability suggest that the partition between gas hydrate stability and instability should be considered as a phase boundary zone rather than a discrete threshold. The experiment revealed that there are significant changes to the physical properties following gas hydrate dissociation, with sediments containing no hydrate behaving as unconsolidated sands. A strong reservoir response to pressure draw down was observed with increasing gas flow during the testing period. Sand inflow to the well during the test may be attributed to loss of sediment strength during gas hydrate dissociation, with the sediment behaving as a gasified slurry. It was concluded that the gas flow response observed during the 2007 production test at Mallik was highly influenced by porous media properties and by the geological heterogeneities which may initiate high permeability conduits in sediments within the production interval of the Mallik gas hydrate reservoir. 18 refs., 6 figs.

  13. Assessment of Gas Production Potential from Hydrate Reservoir in Qilian Mountain Permafrost Using Five-Spot Horizontal Well System

    Directory of Open Access Journals (Sweden)

    Yun-Pei Liang

    2015-09-01

    Full Text Available The main purpose of this study is to investigate the production behaviors of gas hydrate at site DK-2 in the Qilian Mountain permafrost using the novel five-spot well (5S system by means of numerical simulation. The whole system is composed of several identical units, and each single unit consists of one injection well and four production wells. All the wells are placed horizontally in the hydrate deposit. The combination method of depressurization and thermal stimulation is employed for hydrate dissociation in the system. Simulation results show that favorable gas production and hydrate dissociation rates, gas-to-water ratio, and energy ratio can be acquired using this kind of multi-well system under suitable heat injection and depressurization driving forces, and the water production rate is manageable in the entire production process under current technology. In addition, another two kinds of two-spot well (2S systems have also been employed for comparison. It is found that the 5S system will be more commercially profitable than the 2S configurations for gas production under the same operation conditions. Sensitivity analysis indicates that the gas production performance is dependent on the heat injection rate and the well spacing of the 5S system.

  14. Hydro-geomechanical behaviour of gas-hydrate bearing soils during gas production through depressurization and CO2 injection

    Science.gov (United States)

    Deusner, C.; Gupta, S.; Kossel, E.; Bigalke, N.; Haeckel, M.

    2015-12-01

    Results from recent field trials suggest that natural gas could be produced from marine gas hydrate reservoirs at compatible yields and rates. It appears, from a current perspective, that gas production would essentially be based on depressurization and, when facing suitable conditions, be assisted by local thermal stimulation or gas hydrate conversion after injection of CO2-rich fluids. Both field trials, onshore in the Alaska permafrost and in the Nankai Trough offshore Japan, were accompanied by different technical issues, the most striking problems resulting from un-predicted geomechanical behaviour, sediment destabilization and catastrophic sand production. So far, there is a lack of experimental data which could help to understand relevant mechanisms and triggers for potential soil failure in gas hydrate production, to guide model development for simulation of soil behaviour in large-scale production, and to identify processes which drive or, further, mitigate sand production. We use high-pressure flow-through systems in combination with different online and in situ monitoring tools (e.g. Raman microscopy, MRI) to simulate relevant gas hydrate production scenarios. Key components for soil mechanical studies are triaxial systems with ERT (Electric resistivity tomography) and high-resolution local strain analysis. Sand production control and management is studied in a novel hollow-cylinder-type triaxial setup with a miniaturized borehole which allows fluid and particle transport at different fluid injection and flow conditions. Further, the development of a large-scale high-pressure flow-through triaxial test system equipped with μ-CT is ongoing. We will present results from high-pressure flow-through experiments on gas production through depressurization and injection of CO2-rich fluids. Experimental data are used to develop and parametrize numerical models which can simulate coupled process dynamics during gas-hydrate formation and gas production.

  15. Introduction of the 2007-2008 JOGMEC/NRCan/Aurora Mallik Gas Hydrate Production Research Program, NWT, Canada

    Science.gov (United States)

    Yamamoto, K.; Dallimore, S. R.; Numasawa, M.; Yasuda, M.; Fujii, T.; Fujii, K.; Wright, J.; Nixon, F.

    2007-12-01

    Japan Oil, Gas and Metals National Corporation (JOGMEC) and Natural Resource Canada (NRCan) have embarked on a new research program to study the production potential of gas hydrates. The program is being carried out at the Mallik gas hydrate field in the Mackenzie Delta, a location where two previous scientific investigations have been carried in 1998 and 2002. In the 2002 program that was undertaken by seven partners from five countries, 468m3 of gas flow was measured during 124 hours of thermal stimulation using hot warm fluid. Small-scale pressure drawdown tests were also carried out using Schlumberger's Modular Dynamics Tester (MDT) wireline tool, gas flow was observed and the inferred formation permeabilities suggested the possible effectiveness of the simple depressurization method. While the testing undertaken in 2002 can be cited as the first well constrained gas production from a gas hydrate deposit, the results fell short of that required to fully calibrate reservoir simulation models or indeed establish the technical viability of long term production from gas hydrates. The objectives of the current JOGMEC/NRCan/Aurora Mallik production research program are to undertake longer term production testing to further constrain the scientific unknowns and to demonstrate the technical feasibility of sustained gas hydrate production using the depressurization method. A key priority is to accurately measure water and gas production using state-of-art production technologies. The primary production test well was established during the 2007 field season with the re-entry and deepening of JAPEX/JNOC/GSC Mallik 2L-38 well, originally drilled in 1998. Production testing was carried out in April of 2007 under a relatively low drawdown pressure condition. Flow of methane gas was measured from a 12m perforated interval of gas-hydrate-saturated sands from 1093 to 1105m. The results establish the potential of the depressurization method and provide a basis for future

  16. A gas production system from methane hydrate layers by hot water injection and BHP control with radial horizontal wells

    Energy Technology Data Exchange (ETDEWEB)

    Yamakawa, T.; Ono, S.; Iwamoto, A.; Sugai, Y.; Sasaki, K. [Kyushu Univ., Fukuoka, Fukuoka (Japan)

    2010-07-01

    Reservoir characterization of methane hydrate (MH) bearing turbidite channel in the eastern Nankai Trough, in Japan has been performed to develop a gas production strategy. This paper proposed a gas production system from methane hydrate (MH) sediment layers by combining the hot water injection method and bottom hole pressure control at the production well using radial horizontal wells. Numerical simulations of the cylindrical homogeneous MH layer model were performed in order to evaluate gas production characteristics by the depressurization method with bottom hole pressure control. In addition, the effects of numerical block modeling and averaging physical properties of MH layers were presented. According to numerical simulations, combining the existing production system with hot water injection and bottom hole pressure control results in an outward expansion of the hot water chamber from the center of the MH layer with continuous gas production. 10 refs., 15 figs.

  17. Thermodynamic stability and guest distribution of CH4/N2/CO2 mixed hydrates for methane hydrate production using N2/CO2 injection

    International Nuclear Information System (INIS)

    Lim, Dongwook; Ro, Hyeyoon; Seo, Yongwon; Seo, Young-ju; Lee, Joo Yong; Kim, Se-Joon; Lee, Jaehyoung; Lee, Huen

    2017-01-01

    Highlights: • We examine the thermodynamic stability and guest distribution of CH 4 /N 2 /CO 2 mixed hydrates. • Phase equilibria of the CH 4 /N 2 /CO 2 mixed hydrates were measured to determine the thermodynamic stability. • The N 2 /CO 2 ratio of the hydrate phase is almost constant despite the enrichment of CO 2 in the hydrate phase. • 13 C NMR results indicate the preferential occupation of N 2 and CO 2 in the small and large cages of sI hydrates, respectively. - Abstract: In this study, thermodynamic stability and cage occupation behavior in the CH 4 – CO 2 replacement, which occurs in natural gas hydrate reservoirs by injecting flue gas, were investigated with a primary focus on phase equilibria and composition analysis. The phase equilibria of CH 4 /N 2 /CO 2 mixed hydrates with various compositions were measured to determine the thermodynamic stability of gas hydrate deposits replaced by N 2 /CO 2 gas mixtures. The fractional experimental pressure differences (Δp/p) with respect to the CSMGem predictions were found to range from −0.11 to −0.02. The composition analysis for various feed gas mixtures with a fixed N 2 /CO 2 ratio (4.0) shows that CO 2 is enriched in the hydrate phase, and the N 2 /CO 2 ratio in the hydrate phase is independent of the feed CH 4 fractions. Moreover, 13 C NMR measurements indicate that N 2 molecules preferentially occupy the small 5 12 cages of sI hydrates while the CO 2 molecules preferentially occupy the large 5 12 6 2 cages, resulting in an almost constant area ratio of CH 4 molecules in the large to small cages of the CH 4 /N 2 /CO 2 mixed hydrates. The overall experimental results provide a better understanding of stability conditions and guest distributions in natural gas hydrate deposits during CH 4 – flue gas replacement.

  18. Evaluation of the Gas Production Potential of Marine HydrateDeposits in the Ulleung Basin of the Korean East Sea

    Energy Technology Data Exchange (ETDEWEB)

    Moridis, George J.; Reagan, Matthew T.; Kim, Se-Joon; Seol,Yongkoo; Zhang, Keni

    2007-11-16

    Although significant hydrate deposits are known to exist in the Ulleung Basin of the Korean East Sea, their survey and evaluation as a possible energy resource has not yet been completed. However, it is possible to develop preliminary estimates of their production potential based on the limited data that are currently available. These include the elevation and thickness of the Hydrate-Bearing Layer (HBL), the water depth, and the water temperature at the sea floor. Based on this information, we developed estimates of the local geothermal gradient that bracket its true value. Reasonable estimates of the initial pressure distribution in the HBL can be obtained because it follows closely the hydrostatic. Other critical information needs include the hydrate saturation, and the intrinsic permeabilities of the system formations. These are treated as variables, and sensitivity analysis provides an estimate of their effect on production. Based on the geology of similar deposits, it is unlikely that Ulleung Basin accumulations belong to Class 1 (involving a HBL underlain by a mobile gas zone). If Class 4 (disperse, low saturation accumulations) deposits are involved, they are not likely to have production potential. The most likely scenarios include Class 2 (HBL underlain by a zone of mobile water) or Class 3 (involving only an HBL) accumulations. Assuming nearly impermeable confining boundaries, this numerical study indicates that large production rates (several MMSCFD) are attainable from both Class 2 and Class 3 deposits using conventional technology. The sensitivity analysis demonstrates the dependence of production on the well design, the production rate, the intrinsic permeability of the HBL, the initial pressure, temperature and hydrate saturation, as well as on the thickness of the water zone (Class 2). The study also demonstrates that the presence of confining boundaries is indispensable for the commercially viable production of gas from these deposits.

  19. Fluid Flow Patterns During Production from Gas Hydrates in the Laboratory compared to Field Settings: LARS vs. Mallik

    Science.gov (United States)

    Strauch, B.; Heeschen, K. U.; Priegnitz, M.; Abendroth, S.; Spangenberg, E.; Thaler, J.; Schicks, J. M.

    2015-12-01

    The GFZ's LArge Reservoir Simulator LARS allows for the simulation of the 2008 Mallik gas hydrate production test and the comparison of fluid flow patterns and their driving forces. Do we see the gas flow pattern described for Mallik [Uddin, M. et al., J. Can. Petrol Tech, 50, 70-89, 2011] in a pilot scale test? If so, what are the driving forces? LARS has a network of temperature sensors and an electric resistivity tomography (ERT) enabling a good spatial resolution of gas hydrate occurrences, water and gas distribution, and changes in temperature in the sample. A gas flow meter and a water trap record fluid flow patterns and a backpressure valve has controlled the depressurization equivalent to the three pressure stages (7.0 - 5.0 - 4.2 MPa) applied in the Mallik field test. The environmental temperature (284 K) and confining pressure (13 MPa) have been constant. The depressurization induced immediate endothermic gas hydrate dissociation until re-establishment of the stability conditions by a consequent temperature decrease. Slight gas hydrate dissociation continued at the top and upper lateral border due to the constant heat input from the environment. Here transport pathways were short and permeability higher due to lower gas hydrate saturation. At pressures of 7.0 and 5.0 MPa the LARS tests showed high water flow rates and short irregular spikes of gas production. The gas flow patterns at 4.2 MPa and 3.0MPa resembled those of the Mallik test. In LARS the initial gas surges overlap with times of hydrate instability while water content and lengths of pathways had increased. Water production was at a minimum. A rapidly formed continuous gas phase caused the initial gas surges and only after gas hydrate dissociation decreased to a minimum the single gas bubbles get trapped before slowly coalescing again. In LARS, where pathways were short and no additional water was added, a transport of microbubbles is unlikely to cause a gas surge as suggested for Mallik.

  20. Instrumented Pressure Testing Chamber (IPTC) Characterization of Methane Gas Hydrate-Bearing Pressure Cores Collected from the Methane Production Test Site in the Eastern Nankai Trough, Offshore Japan

    Science.gov (United States)

    Waite, W. F.; Santamarina, J. C.; Dai, S.; Winters, W. J.; Yoneda, J.; Konno, Y.; Nagao, J.; Suzuki, K.; Fujii, T.; Mason, D. H.; Bergeron, E.

    2014-12-01

    Pressure cores obtained at the Daini-Atsumi Knoll in the eastern Nankai Trough, the site of the methane hydrate production test completed by the Methane Hydrate Resources in Japan (MH21) project in March 2013, were recovered from ~300 meters beneath the sea floor at close to in situ pressure. Cores were subsequently stored at ~20 MPa and ~5°C, which maintained hydrate in the cores within stability conditions. Pressure core physical properties were measured at 10 MPa and ~6°C, also within the methane hydrate stability field, using the IPTC and other Pressure Core Characterization Tools (PCCTs). Discrete IPTC measurements were carried out in strata ranging from silty sands to clayey silts within the turbidite sequences recovered in the cores. As expected, hydrate saturations were greatest in more permeable coarser-grained layers. Key results include: 1) Where hydrate saturation exceeded 40% in sandy sediments, the gas hydrate binds sediment grains within the matrix. The pressure core analyses yielded nearly in situ mechanical properties despite the absence of effective stress in the IPTC. 2) In adjacent fine-grained sediment (hydrate saturation < 15%), hydrate did not significantly bind the sediment. IPTC results in these locations were consistent with the zero effective-stress limit of comparable measurements made in PCCT devices that are designed to restore the specimen's in situ effective stress. In sand-rich intervals with high gas hydrate saturations, the measured compressional and shear wave velocities suggest that hydrate acts as a homogeneously-distributed, load-bearing member of the bulk sediment. The sands with high gas hydrate saturations were prone to fracturing (brittle failure) during insertion of the cone penetrometer and electrical conductivity probes. Authors would like to express their sincere appreciation to MH21 and the Ministry of Economy, Trade and Industry for permitting this work to be disclosed at the 2014 Fall AGU meeting.

  1. Problems of ecological and technical safety by exploration and production of natural gas hydrates

    Directory of Open Access Journals (Sweden)

    Chen-Chen

    2006-10-01

    Full Text Available Gas hydrates - the firm crystal connections form water (liquid water, ice, water vapor and low-molecular waterproof natural gases (mainly methane whose crystal structure effectively compresses gas e.s.: each cubic meter of hydrate can yield over 160 m3 of methane.In present time, the exploitation of the Messoyahsk (Russia and Mallik (Canada deposits of gas hydrates is conducted actively. The further perfection of prospecting methods in the field of studying gas hydrates containing sediments depends on the improvement of geophysical and the well test research, among which native-state core drilling is one of the major. Sampling a native-state core from gas hydrates sediments keeps not only the original composition but structural - textural features of their construction.Despite of the appeal to use gas hydrates as a perspective and ecologically pure fuel possessing huge resources, the investigation and development of their deposits can lead to a number of negative consequences connected with hazards arising from the maintenance of their technical and ecological safety of carrying out. Scales of the arising problems can change from local to regional and even global.

  2. Natural Gas Hydrate as a Storage Mechanism for Safe, Sustainable and Economical Production from Offshore Petroleum Reserves

    Directory of Open Access Journals (Sweden)

    Michael T. Kezirian

    2017-06-01

    Full Text Available Century Fathom presents an innovative process to utilize clathrate hydrates for the production, storage and transportation of natural gas from off-shore energy reserves in deep ocean environments. The production scheme was developed by considering the preferred state of natural gas in the deep ocean and addressing the hazards associated with conventional techniques to transport natural gas. It also is designed to mitigate the significant shipping cost inherent with all methods. The resulting proposed scheme restrains transport in the hydrate form to the ocean and does not attempt to supply energy to the residential consumer. Instead; the target recipients are industrial operations. The resulting operational concept is intrinsically safer by design; environmentally sustainable and significantly cost-effective compared with currently proposed schemes for the use of natural gas hydrates and has the potential to be the optimal solution for new production of reserves; depending on the distance to shore and capacity of the petroleum reserve. A potential additional benefit is the byproduct of desalinated water.

  3. Toward production from gas hydrates: Current status, assessment of resources, and simulation-based evaluation of technology and potential

    Science.gov (United States)

    Moridis, G.J.; Collett, T.S.; Boswell, R.; Kurihara, M.; Reagan, M.T.; Koh, C.; Sloan, E.D.

    2009-01-01

    Gas hydrates (GHs) are a vast energy resource with global distribution in the permafrost and in the oceans. Even if conservative estimates are considered and only a small fraction is recoverable, the sheer size of the resource is so large that it demands evaluation as a potential energy source. In this review paper, we discuss the distribution of natural GH accumulations, the status of the primary international research and development (R&D) programs, and the remaining science and technological challenges facing the commercialization of production. After a brief examination of GH accumulations that are well characterized and appear to be models for future development and gas production, we analyze the role of numerical simulation in the assessment of the hydrate-production potential, identify the data needs for reliable predictions, evaluate the status of knowledge with regard to these needs, discuss knowledge gaps and their impact, and reach the conclusion that the numerical-simulation capabilities are quite advanced and that the related gaps either are not significant or are being addressed. We review the current body of literature relevant to potential productivity from different types of GH deposits and determine that there are consistent indications of a large production potential at high rates across long periods from a wide variety of hydrate deposits. Finally, we identify (a) features, conditions, geology and techniques that are desirable in potential production targets; (b) methods to maximize production; and (c) some of the conditions and characteristics that render certain GH deposits undesirable for production. Copyright ?? 2009 Society of Petroleum Engineers.

  4. Time lapse survey plan on the first offshore methane hydrate production test in 2013 around the eastern Nankai Trough area by multi-component OBC seismic tool

    Science.gov (United States)

    Inamori, T.; Hayashi, T.; Asakawa, E.; Takahashi, H.; Saeki, T.

    2011-12-01

    We are planning to conduct the multi-component ocean bottom cable (hereafter OBC) seismic survey to monitor the methane hydrate dissociation zone at the 1st offshore methane hydrate production test site in the eastern Nankai Trough, Japan, in 2013. We conducted the first OBC survey in the methane hydrate concentrated zone around the eastern Nankai Trough area in 2006 by RSCS which we developed. We obtained to the good image of methane hydrate bearing layer by P-P section as similar as the conventional surface seismic survey. However, we could not obtain the good image from P-S section compared with P-P section. On the other hand, we studied the sonic velocity distribution at the Mallik 2nd production test before and after in 2007, by the sonic tool data. We could clearly delineate the decrease of S-wave velocity, however, we could not detect the decrease of P-wave velocity because of the presence of the dissociated methane gas from methane hydrate. From these reason we guess the S-wave data is more proper to delineate the condition of the methane hydrate zone at the methane hydrate production tests than P-wave data. We are now developing the new OBC system, which we call Deep-sea Seismic System (hereafter DSS). The sensor of the DSS will install three accelerometers and one hydrophone. A feasibility study to detect the methane hydrate dissociation with the DSS was carried out and we found that the methane hydrate dissociation could be detected with the DSS depending on the zone of the dissociation. And the baseline survey will be held at the 1st offshore methane hydrate production test site in summer 2012. Two monitoring surveys are planned after the methane hydrate production test in 2013. We believe that we will get the good images to delineate the methane hydrate dissociated zone from this time lapse survey. The Authors would like to thank METI, MH21 consortium and JOGMEC for permissions to publish this paper.

  5. PRODUCTION OF HYDRATED ELECTRONS FROM PHOTOIONIZATION OF DISSOLVED ORGANIC MATTER IN NATURAL WATERS

    Science.gov (United States)

    Under UV irradiation, an important primary photochemical reaction of colored dissolved organic matter (CDOM) is electron ejection, producing hydrated electrons (e-aq). The efficiency of this process has been studied in both fresh and seawater samples with both steady-state scave...

  6. Novel nanotechnology for efficient production of binary clathrate hydrates of hydrogen and other compounds

    Energy Technology Data Exchange (ETDEWEB)

    Di Profio, P.; Arca, S.; Germani, R.; Savelli, G. [Perugia Univ., Perugia (Italy). Dept. of Chemistry, Center of Excellence on Innovative Nanostructured Materials

    2008-07-01

    The development of a hydrogen-based economy depends on finding ways to store hydrogen, but current hydrogen storage methods have significant disadvantages. One main challenge in storing sufficient amounts of hydrogen (up to 4 weight per cent) into a clathrate matrix is that of a kinetic origin, in that the mass transfer of hydrogen gas into clathrate structures is significantly limited by the macroscopic scale of the gas-liquid or gas-ice interfaces involved. This paper discussed the possibility of storing hydrogen in clathrate hydrates. It presented a newly developed method for preparing binary hydrogen hydrates that is based on the formation of amphiphile-aided nanoemulsions. Nanotechnology is used to reduce the size of hydrate particles to a few nanometers, thereby minimizing the kinetic hindrance to hydrate formation. This process has potential for increasing the amount of hydrogen stored, as it has provided ca. 1 weight per cent of hydrogen. Two new co-formers were also successfully tested, namely cyclopentane and tetrahydrothiophene. 23 refs., 10 figs.

  7. Gay and Lesbian Parents

    Science.gov (United States)

    ... Life Listen Español Text Size Email Print Share Gay and Lesbian Parents Page Content Article Body I am gay. Should I worry how this will affect my children? Millions of children have one or more gay and/or lesbian parents. For some children, having ...

  8. Overview of the science activities for the 2002 Mallik gas hydrate production research well program, Mackenzie Delta, N.W.T., Canada

    Science.gov (United States)

    Dallimore, S. R.; Collett, T. S.; Uchida, T.; Weber, M.

    2003-04-01

    With the completion of scientific studies undertaken as part of the 1998 Mallik 2L-38 gas hydrate research well, an international research site was established for the study of Arctic natural gas hydrates in the Mackenzie Delta of northwestern Canada. Quantitative well log analysis and core studies reveal multiple gas hydrate layers from 890 m to 1106 m depth, exceeding 110 m in total thickness. High gas hydrate saturation values, which in some cases exceed 80% of the pore volume, establish the Mallik gas hydrate field as one of the most concentrated gas hydrate reservoirs in the world. Beginning in December 2001 and continuing to the middle of March 2002, two 1188 m deep science observation wells were drilled and instrumented and a 1166 m deep production research well program was carried out. The program participants include 8 partners; The Geological Survey of Canada (GSC), The Japan National Oil Corporation (JNOC), GeoForschungsZentrum Potsdam (GFZ), United States Geological Survey (USGS), United States Department of the Energy (USDOE), India Ministry of Petroleum and Natural Gas (MOPNG)/Gas Authority of India (GAIL) and the Chevron-BP-Burlington joint venture group. In addition the project has been accepted as part of the International Scientific Continental Drilling Program. The Geological Survey of Canada is coordinating the science program for the project and JAPEX Canada Ltd. acted as the designated operator for the fieldwork. Primary objectives of the research program are to advance fundamental geological, geophysical and geochemical studies of the Mallik gas hydrate field and to undertake advanced production testing of a concentrated gas hydrate reservoir. Full-scale field experiments in the production well monitored the physical behavior of the hydrate deposits in response to depressurization and thermal stimulation. The observation wells facilitated cross-hole tomography and vertical seismic profile experiments (before and after production) as well as

  9. Methane Hydrates: Chapter 8

    Science.gov (United States)

    Boswell, Ray; Yamamoto, Koji; Lee, Sung-Rock; Collett, Timothy S.; Kumar, Pushpendra; Dallimore, Scott

    2008-01-01

    Gas hydrate is a solid, naturally occurring substance consisting predominantly of methane gas and water. Recent scientific drilling programs in Japan, Canada, the United States, Korea and India have demonstrated that gas hydrate occurs broadly and in a variety of forms in shallow sediments of the outer continental shelves and in Arctic regions. Field, laboratory and numerical modelling studies conducted to date indicate that gas can be extracted from gas hydrates with existing production technologies, particularly for those deposits in which the gas hydrate exists as pore-filling grains at high saturation in sand-rich reservoirs. A series of regional resource assessments indicate that substantial volumes of gas hydrate likely exist in sand-rich deposits. Recent field programs in Japan, Canada and in the United States have demonstrated the technical viability of methane extraction from gas-hydrate-bearing sand reservoirs and have investigated a range of potential production scenarios. At present, basic reservoir depressurisation shows the greatest promise and can be conducted using primarily standard industry equipment and procedures. Depressurisation is expected to be the foundation of future production systems; additional processes, such as thermal stimulation, mechanical stimulation and chemical injection, will likely also be integrated as dictated by local geological and other conditions. An innovative carbon dioxide and methane swapping technology is also being studied as a method to produce gas from select gas hydrate deposits. In addition, substantial additional volumes of gas hydrate have been found in dense arrays of grain-displacing veins and nodules in fine-grained, clay-dominated sediments; however, to date, no field tests, and very limited numerical modelling, have been conducted with regard to the production potential of such accumulations. Work remains to further refine: (1) the marine resource volumes within potential accumulations that can be

  10. Effects of Geomechanical Mechanism on the Gas Production Behavior: A Simulation Study of Class-3 Type Four-Way-Closure Ridge Hydrate Deposit Offshore Southwestern Taiwan

    Science.gov (United States)

    Wu, Cheng-Yueh; Chiu, Yung-Cheng; Huang, Yi-Jyun; Hsieh, Bieng-Zih

    2017-04-01

    The future energy police of Taiwan will heavily rely on the clean energy, including renewable energy and low-carbon energy, to meet the target of mitigating CO2 emission. In addition to developing the renewable energies like solar and wind resources, Taiwan will increase the natural gas consumption to obtain enough electrical power with low-carbon emission. The vast resources of gas hydrates recognized in southwestern offshore Taiwan makes a great opportunity for Taiwan to have own energy resources in the future. Therefore, Taiwan put significant efforts on the evaluation of gas hydrate reserves recently. Production behavior of natural gas dissociated from gas hydrate deposits is an important issue to the hydrate reserves evaluation. The depressurization method is a useful engineering recovery method for gas production from a class-3 type hydrate deposit. The dissociation efficiency will be affected by the pressure drawdown disturbance. However, when the pore pressure of hydrate deposits is depressurized for gas production, the rock matrix will surfer more stresses and the formation deformation might be occurred. The purpose of this study was to investigate the effects of geomechanical mechanism on the gas production from a class-3 hydrate deposit using depressurization method. The case of a class-3 type hydrate deposit of Four-Way-Closure Ridge was studied. In this study a reservoir simulator, STARS, was used. STARS is a multiphase flow, heat transfer, geo-chemical and geo-mechanical mechanisms coupling simulator which is capable to simulate the dissociation/reformation of gas hydrate and the deformation of hydrate reservoirs and overburdens. The simulating ability of STARTS simulator was validated by duplicating the hydrate comparison projects of National Energy Technology Lab. The study target, Four-Way-Closure (FWC) Ridge hydrate deposit, was discovered by the bottom simulating reflectors (BSRs). The geological parameters were collected from the geological and

  11. Quantification of synthesized hydration products using synchrotron microtomography and spectral analysis

    Energy Technology Data Exchange (ETDEWEB)

    Deboodt, Tyler; Ideker, Jason H.; Isgor, O. Burkan; Wildenschild, Dorthe

    2017-12-01

    The use of x-ray computed tomography (CT) as a standalone method has primarily been used to characterize pore structure, cracking and mechanical damage in cementitious systems due to low contrast in the hydrated phases. These limitations have resulted in the inability to extract quantifiable information on such phases. The goal of this research was to address the limitations caused by low contrast and improving the ability to distinguish the four primary hydrated phases in portland cement; C-S-H, calcium hydroxide, monosulfate, and ettringite. X-ray CT on individual layers, binary mixtures of phases, and quaternary mixtures of phases to represent a hydrated portland cement paste were imaged with synchrotron radiation. Known masses of each phase were converted to a volume and compared to the segmented image volumes. It was observed that adequate contrast in binary mixing of phases allowed for segmentation, and subsequent image analysis indicated quantifiable volumes could be extracted from the tomographic volume. However, low contrast was observed when C-S-H and monosulfate were paired together leading to difficulties segmenting in an unbiased manner. Quantification of phases in quaternary mixtures included larger errors than binary mixes due to histogram overlaps of monosulfate, C-S-H, and calcium hydroxide.

  12. Characterisation of products of tricalcium silicate hydration in the presence of heavy metals

    International Nuclear Information System (INIS)

    Chen, Q.Y.; Hills, C.D.; Tyrer, M.; Slipper, I.; Shen, H.G.; Brough, A.

    2007-01-01

    The hydration of tricalcium silicate (C 3 S) in the presence of heavy metal is very important to cement-based solidification/stabilisation (s/s) of waste. In this work, tricalcium silicate pastes and aqueous suspensions doped with nitrate salts of Zn 2+ , Pb 2+ , Cu 2+ and Cr 3+ were examined at different ages by X-ray powder diffraction (XRD), thermal analysis (DTA/TG) and 29 Si solid-state magic angle spinning/nuclear magnetic resonance (MAS/NMR). It was found that heavy metal doping accelerated C 3 S hydration, even though Zn 2+ doping exhibited a severe retardation effect at an early period of time of C 3 S hydration. Heavy metals retarded the precipitation of portlandite due to the reduction of pH resulted from the hydrolysis of heavy metal ions during C 3 S hydration. The contents of portlandite in the control, Cr 3+ -doped, Cu 2+ -doped, Pb 2+ -doped and Zn 2+ -doped C 3 S pastes aged 28 days were 16.7, 5.5, 5.5, 5.5, and 2 Cr(OH) 7 .3H 2 O, Ca 2 (OH) 4 4Cu(OH) 2 .2H 2 O and CaZn 2 (OH) 6 .2H 2 O). These compounds were identified as crystalline phases in heavy metal doping C 3 S suspensions and amorphous phases in heavy metal doping C 3 S pastes. 29 Si NMR data confirmed that heavy metals promoted the polymerisation of C-S-H gel in 1-year-old of C 3 S pastes. The average numbers of Si in C-S-H gel for the Zn 2+ -doped, Cu 2+ -doped, Cr 3+ -doped, control, and Pb 2+ -doped C 3 S pastes were 5.86, 5.11, 3.66, 3.62, and 3.52. And the corresponding Ca/Si ratios were 1.36, 1.41, 1.56, 1.57 and 1.56, respectively. This study also revealed that the presence of heavy metal facilitated the formation of calcium carbonate during C 3 S hydration process in the presence of carbon dioxide

  13. Micro-structural characterization of the hydration products of bauxite-calcination-method red mud-coal gangue based cementitious materials

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xiaoming [State Key Laboratory of Advanced Metallurgy, School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing 100083 (China); Zhang, Na [Green Construction Materials and Circulation Economy Center, Architectural Design and Research Institute of Tsinghua University Co., Ltd., Beijing 100084 (China); Yao, Yuan, E-mail: yuanyaocas@163.com [School of Engineering and Computer Science, University of the Pacific, Stockton, CA 95211 (United States); Sun, Henghu; Feng, Huan [School of Engineering and Computer Science, University of the Pacific, Stockton, CA 95211 (United States)

    2013-11-15

    Highlights: • Al{sup IV} and Al{sup VI} both exist in the hydration products. • Increase of Ca/Si ratio promotes the conversion from [AlO{sub 4}] to [AlO{sub 6}]. • Polymerization degree of [SiO{sub 4}] in the hydration products declines. -- Abstract: In this research, the micro-structural characterization of the hydration products of red mud-coal gangue based cementitious materials has been investigated through SEM-EDS, {sup 27}Al MAS NMR and {sup 29}Si MAS NMR techniques, in which the used red mud was derived from the bauxite calcination method. The results show that the red mud-coal gangue based cementitious materials mainly form fibrous C-A-S-H gel, needle-shaped/rod-like AFt in the early hydration period. With increasing of the hydration period, densification of the pastes were promoted resulting in the development of strength. EDS analysis shows that with the Ca/Si of red mud-coal gangue based cementitious materials increases, the average Ca/Si and Ca/(Si + Al) atomic ratio of C-A-S-H gel increases, while the average Al/Si atomic ratio of C-A-S-H gel decreases. MAS NMR analysis reveals that Al in the hydration products of red mud-coal gangue based cementitious materials exists in the forms of Al{sup IV} and Al{sup VI}, but mainly in the form of Al{sup VI}. Increasing the Ca/Si ratio of raw material promotes the conversion of [AlO{sub 4}] to [AlO{sub 6}] and inhibits the combination between [AlO{sub 4}] and [SiO{sub 4}] to form C-A-S-H gel. Meanwhile, the polymerization degree of [SiO{sub 4}] in the hydration products declines.

  14. Micro-structural characterization of the hydration products of bauxite-calcination-method red mud-coal gangue based cementitious materials

    International Nuclear Information System (INIS)

    Liu, Xiaoming; Zhang, Na; Yao, Yuan; Sun, Henghu; Feng, Huan

    2013-01-01

    Highlights: • Al IV and Al VI both exist in the hydration products. • Increase of Ca/Si ratio promotes the conversion from [AlO 4 ] to [AlO 6 ]. • Polymerization degree of [SiO 4 ] in the hydration products declines. -- Abstract: In this research, the micro-structural characterization of the hydration products of red mud-coal gangue based cementitious materials has been investigated through SEM-EDS, 27 Al MAS NMR and 29 Si MAS NMR techniques, in which the used red mud was derived from the bauxite calcination method. The results show that the red mud-coal gangue based cementitious materials mainly form fibrous C-A-S-H gel, needle-shaped/rod-like AFt in the early hydration period. With increasing of the hydration period, densification of the pastes were promoted resulting in the development of strength. EDS analysis shows that with the Ca/Si of red mud-coal gangue based cementitious materials increases, the average Ca/Si and Ca/(Si + Al) atomic ratio of C-A-S-H gel increases, while the average Al/Si atomic ratio of C-A-S-H gel decreases. MAS NMR analysis reveals that Al in the hydration products of red mud-coal gangue based cementitious materials exists in the forms of Al IV and Al VI , but mainly in the form of Al VI . Increasing the Ca/Si ratio of raw material promotes the conversion of [AlO 4 ] to [AlO 6 ] and inhibits the combination between [AlO 4 ] and [SiO 4 ] to form C-A-S-H gel. Meanwhile, the polymerization degree of [SiO 4 ] in the hydration products declines

  15. Gas hydrates

    Digital Repository Service at National Institute of Oceanography (India)

    Ramprasad, T.

    , not all of them are white like snow. Some hydrates from the deep Gulf of Mexico are richly colored in shades of yellow, orange, or even red. The ice-like masses are beautiful, and contrast with the dull gray of deep sea muds. Hydrates from the Blake... volcanoes and associated gas hydrates: Marine Geology, v. 167, p. 29-42. Milkov, A.V. and R. Sassen, 2001a, Estimate of gas hydrate resource, northwestern Gulf of Mexico continental slope: Marine Geology, v. 179, pp. 71-83. Milkov, A.V., Sassen, R...

  16. KIGAM Seafloor Observation System (KISOS) for the baseline study in monitoring of gas hydrate test production in the Ulleung Basin, Korea

    Science.gov (United States)

    Lee, Sung-rock; Chun, Jong-hwa

    2013-04-01

    For the baseline study in the monitoring gas hydrate test production in the Ulleung Basin, Korea Institute of Geoscience and Mineral Resources (KIGAM) has developed the KIGAM Seafloor Observation System (KISOS) for seafloor exploration using unmanned remotely operated vehicle connected with a ship by a cable. The KISOS consists of a transponder of an acoustic positioning system (USBL), a bottom finding pinger, still camera, video camera, water sampler, and measuring devices (methane, oxygen, CTD, and turbidity sensors) mounted on the unmanned ROV, and a sediment collecting device collecting sediment on the seafloor. It is very important to monitoring the environmental risks (gas leakage and production water/drilling mud discharge) which may be occurred during the gas hydrate test production drilling. The KISOS will be applied to solely conduct baseline study with the KIGAM seafloor monitoring system (KIMOS) of the Korean gas hydrate program in the future. The large scale of environmental monitoring program includes the environmental impact assessment such as seafloor disturbance and subsidence, detection of methane gas leakage around well and cold seep, methane bubbles and dissolved methane, change of marine environments, chemical factor variation of water column and seabed, diffusion of drilling mud and production water, and biological factors of biodiversity and marine habitats before and after drilling test well and nearby areas. The design of the baseline survey will be determined based on the result of SIMAP simulation in 2013. The baseline survey will be performed to provide the gas leakage and production water/drilling mud discharge before and after gas hydrate test production. The field data of the baseline study will be evaluated by the simulation and verification of SIMAP simulator in 2014. In the presentation, the authors would like introduce the configuration of KISOS and applicability to the seafloor observation for the gas hydrate test production in

  17. Evaluation of mechanical strength and hydrate products evolution of calcium aluminate cement, for endodontic applications

    International Nuclear Information System (INIS)

    Luz, A.P.; Borba, N.Z.; Pandolfelli, V.C.

    2011-01-01

    Mineral trioxide aggregate (MTA) is the most used retrograde filling cement in the endodontic area. Nevertheless, although its composition is similar to the conventional Portland cement, its high cost, long setting time and low mechanical strength have led to a continuous search for new alternative materials. Considering these aspects, the mechanical strength and crystalline phase evolution of a calcium aluminate cement (CAC), during its hydration process, have been evaluated in this work aiming to apply such material for endodontic treatments. Secar 71 cement samples were prepared and kept in contact with water or SBF (simulated body fluid) during 15 days at 37 deg C. Compressive strength, apparent porosity, X ray diffraction and thermogravimetric tests were carried out for the samples evaluation after 1, 3, 7 and 15 days. The main identified phases were CAH_1_0, C_2AH_8, C_3AH_6 and AH_3. Moreover, when in the presence of SBF, some changes in the amount of the hydrates in the CAC samples were observed, which affected the mechanical behavior of the cement. (author)

  18. Thermodynamic inhibitor performance extender that, effectively and economically prevent hydrate formation in the oil field production systems

    Energy Technology Data Exchange (ETDEWEB)

    Allenson, Stephen; Johnston, Angela [Nalco Energy Services, Sugar Land, TX (United States)

    2008-07-01

    This paper presents the development of a new additive that was developed to improve the effectiveness of the treatment two to four fold when added to the thermodynamic hydrate inhibitor (THI). Consequently, the THI/additive treatment can now enable the system to handle two to four times the amount of water production or can allow treatment of the same amount of water at half to quarter the dosage of THI. This new additive extends the performance of the THI and allows for a significant increase in production or a significant drop in the amount of THI usage with a corresponding drop in cost. This paper will further discuss the overall process of THI enhancement and will present several case studies where the enhanced THI has been successfully applied. (author)

  19. Historical methane hydrate project review

    Science.gov (United States)

    Collett, Timothy; Bahk, Jang-Jun; Frye, Matt; Goldberg, Dave; Husebo, Jarle; Koh, Carolyn; Malone, Mitch; Shipp, Craig; Torres, Marta

    2013-01-01

    In 1995, U.S. Geological Survey made the first systematic assessment of the volume of natural gas stored in the hydrate accumulations of the United States. That study, along with numerous other studies, has shown that the amount of gas stored as methane hydrates in the world greatly exceeds the volume of known conventional gas resources. However, gas hydrates represent both a scientific and technical challenge and much remains to be learned about their characteristics and occurrence in nature. Methane hydrate research in recent years has mostly focused on: (1) documenting the geologic parameters that control the occurrence and stability of gas hydrates in nature, (2) assessing the volume of natural gas stored within various gas hydrate accumulations, (3) analyzing the production response and characteristics of methane hydrates, (4) identifying and predicting natural and induced environmental and climate impacts of natural gas hydrates, and (5) analyzing the effects of methane hydrate on drilling safety.Methane hydrates are naturally occurring crystalline substances composed of water and gas, in which a solid water-­‐lattice holds gas molecules in a cage-­‐like structure. The gas and water becomes a solid under specific temperature and pressure conditions within the Earth, called the hydrate stability zone. Other factors that control the presence of methane hydrate in nature include the source of the gas included within the hydrates, the physical and chemical controls on the migration of gas with a sedimentary basin containing methane hydrates, the availability of the water also included in the hydrate structure, and the presence of a suitable host sediment or “reservoir”. The geologic controls on the occurrence of gas hydrates have become collectively known as the “methane hydrate petroleum system”, which has become the focus of numerous hydrate research programs.Recognizing the importance of methane hydrate research and the need for a coordinated

  20. Gas Hydrates | Alaska Division of Geological & Geophysical Surveys

    Science.gov (United States)

    Preliminary Report - Cascadia Margin Gas Hydrates, Volume 204 Initial Report Mallik 2002 GSC Bulletin 585 : Scientific results from the Mallik 2002 gas hydrate production well program Offshore gas hydrate sample

  1. A Scanning Transmission X-ray Microscopy Study of Cubic and Orthorhombic C3A and Their Hydration Products in the Presence of Gypsum

    Directory of Open Access Journals (Sweden)

    Vanessa Rheinheimer

    2016-08-01

    Full Text Available This paper shows the microstructural differences and phase characterization of pure phases and hydrated products of the cubic and orthorhombic (Na-doped polymorphs of tricalcium aluminate (C3A, which are commonly found in traditional Portland cements. Pure, anhydrous samples were characterized using scanning transmission X-ray microscopy (STXM, X-ray photoelectron spectroscopy (XPS and X-ray diffraction (XRD and demonstrated differences in the chemical and mineralogical composition as well as the morphology on a micro/nano-scale. C3A/gypsum blends with mass ratios of 0.2 and 1.9 were hydrated using a water/C3A ratio of 1.2, and the products obtained after three days were assessed using STXM. The hydration process and subsequent formation of calcium sulfate in the C3A/gypsum systems were identified through the changes in the LIII edge fine structure for Calcium. The results also show greater Ca LII binding energies between hydrated samples with different gypsum contents. Conversely, the hydrated samples from the cubic and orthorhombic C3A at the same amount of gypsum exhibited strong morphological differences but similar chemical environments.

  2. Numerical modeling of the simulated gas hydrate production test at Mallik 2L-38 in the pilot scale pressure reservoir LARS - Applying the "foamy oil" model

    Science.gov (United States)

    Abendroth, Sven; Thaler, Jan; Klump, Jens; Schicks, Judith; Uddin, Mafiz

    2014-05-01

    In the context of the German joint project SUGAR (Submarine Gas Hydrate Reservoirs: exploration, extraction and transport) we conducted a series of experiments in the LArge Reservoir Simulator (LARS) at the German Research Centre of Geosciences Potsdam. These experiments allow us to investigate the formation and dissociation of hydrates at large scale laboratory conditions. We performed an experiment similar to the field-test conditions of the production test in the Mallik gas hydrate field (Mallik 2L-38) in the Beaufort Mackenzie Delta of the Canadian Arctic. The aim of this experiment was to study the transport behavior of fluids in gas hydrate reservoirs during depressurization (see also Heeschen et al. and Priegnitz et al., this volume). The experimental results from LARS are used to provide details about processes inside the pressure vessel, to validate the models through history matching, and to feed back into the design of future experiments. In experiments in LARS the amount of methane produced from gas hydrates was much lower than expected. Previously published models predict a methane production rate higher than the one observed in experiments and field studies (Uddin et al. 2010; Wright et al. 2011). The authors of the aforementioned studies point out that the current modeling approach overestimates the gas production rate when modeling gas production by depressurization. They suggest that trapping of gas bubbles inside the porous medium is responsible for the reduced gas production rate. They point out that this behavior of multi-phase flow is not well explained by a "residual oil" model, but rather resembles a "foamy oil" model. Our study applies Uddin's (2010) "foamy oil" model and combines it with history matches of our experiments in LARS. Our results indicate a better agreement between experimental and model results when using the "foamy oil" model instead of conventional models of gas flow in water. References Uddin M., Wright J.F. and Coombe D

  3. Characterization and Prediction of the Gas Hydrate Reservoir at the Second Offshore Gas Production Test Site in the Eastern Nankai Trough, Japan

    Directory of Open Access Journals (Sweden)

    Machiko Tamaki

    2017-10-01

    Full Text Available Following the world’s first offshore production test that was conducted from a gas hydrate reservoir by a depressurization technique in 2013, the second offshore production test has been planned in the eastern Nankai Trough. In 2016, the drilling survey was performed ahead of the production test, and logging data that covers the reservoir interval were newly obtained from three wells around the test site: one well for geological survey, and two wells for monitoring surveys, during the production test. The formation evaluation using the well log data suggested that our target reservoir has a more significant heterogeneity in the gas hydrate saturation distribution than we expected, although lateral continuity of sand layers is relatively good. To evaluate the spatial distribution of gas hydrate, the integration analysis using well and seismic data was performed. The seismic amplitude analysis supports the lateral reservoir heterogeneity that has a significant positive correlation with the resistivity log data at the well locations. The spatial distribution of the apparent low-resistivity interval within the reservoir observed from log data was investigated by the P-velocity volume derived from seismic inversion. The integrated results were utilized for the pre-drill prediction of the reservoir quality at the producing wells. These approaches will reduce the risk of future commercial production from the gas hydrate reservoir.

  4. A Double-Blind, Randomised Study Comparing the Skin Hydration and Acceptability of Two Emollient Products in Atopic Eczema Patients with Dry Skin.

    Science.gov (United States)

    Djokic-Gallagher, Jasmina; Rosher, Phil; Oliveira, Gabriela; Walker, Jennine

    2017-09-01

    Healthcare professionals tend to recommend emollients based primarily on patient/consumer preference and cost, with cheaper options assumed to be therapeutically equivalent. The aim of this study was therefore to compare the effects on skin hydration of two emollients prescribed in the UK, Doublebase Dayleve™ gel (DELP) and a cheaper alternative, Zerobase Emollient™ cream (ZBC). This was a single-centre, randomised, double-blind, concurrent bi-lateral (within-patient) comparison in 18 females with atopic eczema and dry skin on their lower legs. DELP gel and ZBC cream were each applied to one lower leg twice daily for 4 days and on the morning only on day 5. The efficacy of both products was assessed by hydration measurements using a Corneometer CM825 probe (Courage-Khazaka Electronic). The measurements were made three times daily on days 1 to 5. The primary efficacy variable was the area under the curve (AUC) of the change from baseline corneometer readings over the 5 days. Skin hydration using DELP gel was significantly higher than using ZBC cream (p skin hydration observed for DELP gel was substantial and long lasting. In contrast, for ZBC cream, there was no significant improvement of the cumulative skin hydration as measured by the AUC (p = 0.22). DELP gel achieved substantial, long-lasting and cumulative skin hydration, whilst ZBC cream achieved no measurable improvement in skin hydration compared to before treatment. Healthcare professionals should be aware that different emollients can perform differently. Dermal Laboratories Ltd. EudraCT number:2014-001026-16.

  5. Le problème des hydrates dans le contexte de la production et du transport polyphasiques des pétroles bruts et des gaz naturels. Deuxième partie : les solutions possibles aux difficultés d'exploitation générées par les hydrates Hydrates Problem Within the Framework of Multiphase Production and Transport of Crude Oils and Natural Gases. Part Two: Possible Solutions to Exploitation Difficulties Generated by Hydrates

    Directory of Open Access Journals (Sweden)

    Behar E.

    2006-11-01

    Full Text Available L'exploitation en mer des gisements de combustibles fossiles fluides a amplifié le besoin d'accroître nos connaissances sur les hydrates qui sont susceptibles de boucher les installations de production, de traitement et de transport. La première partie rappelait la structure moléculaire des hydrates I, Il et H et décrivait ensuite succinctement l'analyse physico-chimique de leur formation, tant sur les plans thermodynamique que cinétique. Dans cette deuxième partie, les remèdes possibles aux problèmes rencontrés par les compagnies opératrices sont indiqués, essentiellement les inhibiteurs thermodynamiques classiques tels que les alcools ou les sels qui diminuent la température de formation des hydrates, et les additifs dispersants qui évitent la croissance et/ou l'agglomération des cristaux. Pour terminer, une boucle pilote de circulation originale est présentée, ses caractéristiques qui permettent la validation des additifs dispersants dans des conditions hydrodynamiques et physico-chimiques représentatives étant soulignées. Offshore exploitation of fossil fluid fuels has emphasized the need of improving our knowledge on hydrates which can plug production, treatment and transport facilities. The first part recalled the molecular structure of I, II and H hydrates, then the physical-chemistry of their formation was briefly reviewed from both the thermodynamic and the kinetic points of view. In this second part, the possible remedies to the problems met by operating companies are described, mainly classical thermodynamic inhibitors such as alcohols or salts which decrease the hydrates formation temperature, and dispersant additives which avoid crystals growth and/or agglomeration. At last an original circulation loop at pilot scale is presented, its characteristics which allow the testing of dispersant additives under representative hydrodynamic and physico-chemical conditions being outlined.

  6. Le problème des hydrates dans le contexte de la production et du transport polyphasiques des pétroles bruts et des gaz naturels. Première partie : physico-chimie de la formation et de la dissociation des hydrates Hydrates Problem Within the Framework of Multiphase Production and Transport of Crude Oils and Natural Gases. Part One: Physical-Chemistry of Hydrates Formation and Dissociation

    Directory of Open Access Journals (Sweden)

    Behar E.

    2006-11-01

    Full Text Available L'exploitation en mer des gisements de combustibles fossiles fluides a amplifié le besoin d'accroître nos connaissances sur les hydrates qui sont susceptibles de boucher les installations de production, de traitement et de transport. Dans cette publication, la structure moléculaire des hydrates I, II et H est rappelée, ensuite l'analyse physico-chimique de leur formation est succinctement décrite tant sur les plans thermodynamique que cinétique. Enfin, les remèdes possibles aux problèmes rencontrés par les compagnies opératrices sont indiqués, essentiellement les inhibiteurs thermodynamiques classiques tels que les alcools ou les sels qui diminuent la température de formation des hydrates, et les additifs dispersants qui évitent la croissance et/ou l'agglomération des cristaux. Pour terminer, une boucle pilote de circulation originale est présentée, ses caractéristiques qui permettent la validation des additifs dispersants dans des conditions hydrodynamiques et physico-chimiques représentatives étant soulignées. Offshore exploitation of fossil fluid fuels has emphasized the need of improving our knowledge on hydrates which can plug production, treatment and transport facilities. In this paper, the molecular structure of I, II and H hydrates is recalled, then the physical-chemistry of their formation is briefly reviewed from both the thermodynamic and the kinetic points of view. Finally, the possible remedies to the problems met by operating companies are described, mainly classical thermodynamic inhibitors such as alcohols or salts which decrease the hydrates formation temperature, and dispersant additives which avoid crystals growth and/or agglomeration. At last an original circulation loop at pilot scale is presented, its characteristics which allow the testing of dispersant additives under representative hydrodynamic and physico-chemical conditions being outlined.

  7. Preliminary assessment of the waveform inversion method for interpretation of cross-well seismic data from the thermal production test, JAPEX/JNOC/GSC et al. Mallik 5L-38 gas hydrate production research well

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, T. [Nagoya Univ., Nagoya (Japan). Research Center for Seismology and Volcanology; Shimizu, S. [Japan National Oil Co., Chiba (Japan); Asakawa, E. [JGI Inc., Tokyo (Japan); Kamei, R.; Matsuoka, T. [Kyoto Univ., Kyoto (Japan). Dept. of Civil and Earth Resources Engineering

    2005-07-01

    The JAPEX/JNOC/GSC et al. Mallik 3L-38 and 4L-38 test wells were subjected to repeated cross-well seismic surveys before and during the gas production test from the gas-hydrate-bearing layer at a depth of about 905 to 920 m. High-resolution velocity images in the gas-hydrate-bearing layer were obtained using the frequency-domain nonlinear waveform inversion method. An acoustic waveform inversion method was used along with the frequency-domain approach in order to detect the change in acoustic properties of the gas-hydrate-bearing layer resulting from gas production. The layered structures with small lateral heterogeneities were reconstructed by tomography analysis of preprocessed waveform data using a smaller number of source-receiver pairs. Preliminary results reveal high velocity and very high attenuation in the gas-hydrate-bearing layers. No obvious velocity decreases were noted. Information for further detailed processing was also gathered.

  8. Operating without a Safety Net: Gay Male Adolescents and Emerging Adults' Experiences of Marginalization and Migration, and Implications for Theory of Syndemic Production of Health Disparities

    Science.gov (United States)

    Bruce, Douglas; Harper, Gary W.

    2011-01-01

    Health disparities among gay men (HIV, substance use, depression) have been described as a mutually occurring "syndemic" that is socially produced through two overarching dynamics: marginalization and migration. Although the syndemic theory proposes a developmental trajectory, it has been largely based on epidemiological studies of adult gay men…

  9. Chloral Hydrate

    Science.gov (United States)

    ... if you are allergic to chloral hydrate, aspirin, tartrazine (a yellow dye in some processed foods and ... in, tightly closed, and out of reach of children. Store it at room temperature, away from excess ...

  10. The application of DTA and TG methods to investigate the non-crystalline hydration products of CaAl2O4 and Ca7ZrAl6O18 compounds

    International Nuclear Information System (INIS)

    Szczerba, Jacek; Madej, Dominika; Śnieżek, Edyta; Prorok, Ryszard

    2013-01-01

    Highlights: ► Hydrates, i.e. CAH 10 , C 2 AH 8 , C 3 AH 6 and C 4 AH 19 are formed during hydration of CaAl 2 O 4 and Ca 7 ZrAl 6 O 18 . ► Hydrated CaAl 2 O 4 and Ca 7 ZrAl 6 O 18 compounds were investigated by X-ray diffraction, SEM/EDS and thermal analysis. ► The hydration reaction proceeds as consumes the unreacted core of the CaAl 2 O 4 and Ca 7 ZrAl 6 O 18 grain. - Abstract: The hydration products and thermal decomposition mechanism of hydrated CaAl 2 O 4 and Ca 7 ZrAl 6 O 18 compounds were investigated by X-ray diffraction, SEM/EDS and thermal analysis. The processes of crystal hydrate nucleation and precipitation were preceded by the evolution of the X-ray amorphous phase during the first 24 h of hydration. DTA–TGA–EGA techniques allowed the study of the detailed decomposition and identification of intermediate and stable to be performed. The differential thermal analysis (DTA) curves of hydrated CaAl 2 O 4 and Ca 7 ZrAl 6 O 18 compounds show five similar endothermic peaks due to crystal water desorption. According to the quantitative TGA–EGA analyses performed on hydrated CaAl 2 O 4 and Ca 7 ZrAl 6 O 18 compounds, it was found that C 2 AH 8 , C 3 AH 6 and Al(OH) 3 phases are the main hydration products of CaAl 2 O 4 . Under the same laboratory conditions, the hydration of Ca 7 ZrAl 6 O 18 proceeds with the formation of mainly CAH 10 and AH 3 -gel phases. We provide the original illustrations of the hydrate crystals formation via amorphous phases

  11. Isostructural and cage-specific replacement occurring in sII hydrate with external CO2/N2 gas and its implications for natural gas production and CO2 storage

    International Nuclear Information System (INIS)

    Seo, Young-ju; Park, Seongmin; Kang, Hyery; Ahn, Yun-Ho; Lim, Dongwook; Kim, Se-Joon; Lee, Jaehyoung; Lee, Joo Yong; Ahn, Taewoong; Seo, Yongwon; Lee, Huen

    2016-01-01

    structural sustainability and cage-specific replacement observed in the C 3 H 8 + CH 4 hydrate with external CO 2 /N 2 gas will have significant implications for suggesting target gas hydrate reservoirs and understanding the precise nature of guest exchange in gas hydrates for both safe natural gas production and long-term CO 2 sequestration.

  12. Amino Acids Generated from Hydrated Titan Tholins: Comparison with Miller-Urey Electric Discharge Products

    Science.gov (United States)

    Cleaves, H. James, II; Neish, Catherine; Callahan, Michael P.; Parker, Eric; Fernandez, Facundo M.; Dworkin, Jason P.

    2014-01-01

    Various analogues of Titan haze particles (termed tholins) have been made in the laboratory. In certain geologic environments on Titan, these haze particles may come into contact with aqueous ammonia (NH3) solutions, hydrolyzing them into molecules of astrobiological interest. A Titan tholin analogue hydrolyzed in aqueous NH3 at room temperature for 2.5 years was analyzed for amino acids using highly sensitive ultra-high performance liquid chromatography coupled with fluorescence detection and time-of-flight mass spectrometry (UHPLC-FDToF-MS) analysis after derivatization with a fluorescent tag. We compare here the amino acids produced from this reaction sequence with those generated from room temperature Miller-Urey (MU) type electric discharge reactions. We find that most of the amino acids detected in low temperature MU CH4N2H2O electric discharge reactions are generated in Titan simulation reactions, as well as in previous simulations of Triton chemistry. This argues that many processes provide very similar mixtures of amino acids, and possibly other types of organic compounds, in disparate environments, regardless of the order of hydration. Although it is unknown how life began, it is likely that given reducing conditions, similar materials were available throughout the early Solar System and throughout the universe to facilitate chemical evolution.

  13. Religiusitas pada Gay (Studi Fenomenologis pada Gay yang Beragama Islam)

    OpenAIRE

    Ariansyah

    2015-01-01

    Gay still be controversial and viewed negatively in Indonesian society. Most assume that it is impossible for gay to have religiosity. But in the reality, gays also have religiosity. This study aims to determine how the religiosity that is owned by a gay. In addition to knowing religiosity, this study also aims to determine the factors that led to participants being gay. This study used a qualitative phenomenological method. Participants in this study consists of 3 people. M...

  14. Clinker mineral hydration at reduced relative humidities

    DEFF Research Database (Denmark)

    Jensen, Ole Mejlhede; Hansen, Per Freiesleben; Lachowski, Eric E.

    1999-01-01

    and experimental data are presented showing that C(3)A can hydrate at lower humidities than either C3S or C2S. It is suggested that the initiation of hydration during exposure to water vapour is nucleation controlled. When C(3)A hydrates at low humidity, the characteristic hydration product is C(3)AH(6......Vapour phase hydration of purl cement clinker minerals at reduced relative humidities is described. This is relevant to modern high performance concrete that may self-desiccate during hydration and is also relevant to the quality of the cement during storage. Both the oretical considerations...

  15. Predicting the Impact of Multiwalled Carbon Nanotubes on the Cement Hydration Products and Durability of Cementitious Matrix Using Artificial Neural Network Modeling Technique

    Directory of Open Access Journals (Sweden)

    Babak Fakhim

    2013-01-01

    Full Text Available In this study the feasibility of using the artificial neural networks modeling in predicting the effect of MWCNT on amount of cement hydration products and improving the quality of cement hydration products microstructures of cement paste was investigated. To determine the amount of cement hydration products thermogravimetric analysis was used. Two critical parameters of TGA test are PHPloss and CHloss. In order to model the TGA test results, the ANN modeling was performed on these parameters separately. In this study, 60% of data are used for model calibration and the remaining 40% are used for model verification. Based on the highest efficiency coefficient and the lowest root mean square error, the best ANN model was chosen. The results of TGA test implied that the cement hydration is enhanced in the presence of the optimum percentage (0.3 wt% of MWCNT. Moreover, since the efficiency coefficient of the modeling results of CH and PHP loss in both the calibration and verification stages was more than 0.96, it was concluded that the ANN could be used as an accurate tool for modeling the TGA results. Another finding of this study was that the ANN prediction in higher ages was more precise.

  16. Impacts of Hydrate Distribution on the Hydro-Thermo-Mechanical Properties of Hydrate-Bearing Sediments

    Science.gov (United States)

    Dai, S.; Seol, Y.

    2015-12-01

    In general, hydrate makes the sediments hydraulically less conductive, thermally more conductive, and mechanically stronger; yet the dependency of these physical properties on hydrate saturation varies with hydrate distribution and morphology. Hydrate distribution in sediments may cause the bulk physical properties of their host sediments varying several orders of magnitude even with the same amount of hydrate. In natural sediments, hydrate morphology is inherently governed by the burial depth and the grain size of the host sediments. Compare with patchy hydrate, uniformly distributed hydrate is more destructive to fluid flow, yet leads to higher gas and water permeability during hydrate dissociation due to the easiness of forming percolation paths. Water and hydrate have similar thermal conductivity values; the bulk thermal conductivity of hydrate-bearing sediments depends critically on gas-phase saturation. 60% of gas saturation may result in evident thermal conductivity drop and hinder further gas production. Sediments with patchy hydrate yield lower stiffness than that with cementing hydrate but higher stiffness than that with pore filling and loading bearing hydrate. Besides hydrate distribution, the stress state and loading history also play an important role in the mechanical behavior of hydrate-bearing sediments.

  17. A high yield process for hydrate formation

    Energy Technology Data Exchange (ETDEWEB)

    Giavarini, C.; Maccioni, F. [Univ. of Roma La Sapienza, Roma (Italy). Dept. of Chemical Engineering

    2008-07-01

    Due to the large quantities of natural gas stored in deep ocean hydrates, hydrate reservoirs are a substantial energy resource. Hydrates concentrate methane by as much as a factor of 164. As such, several natural gas transportation and storage systems using gas hydrates have been studied, and many of them are nearing practical use. In these systems, the hydrate is produced as a slurry by a spray process at approximately 7 megapascal (MPa), and then shaped into pellets. The use of a spray process, instead of a conventional stirred vessel is necessary in order to reach high hydrate concentrations in the hydrate-ice system. This paper presented a new procedure to produce a bulk of concentrated methane hydrate in a static traditional reactor at moderate pressure, controlling pressure and temperature in the interval between ice melting and the hydrate equilibrium curve. This paper discussed the experimental procedure which included formation of methane hydrate at approximately 5 MPa and 2 degrees Celsius in a reaction calorimeter at a volume of two liters. Results were also discussed. It was concluded that the procedure seemed suitable for the development of a gas hydrate storage and transport technology. It was found that the spray procedure took more time, but could be sped up and made continuous by using two vessels, one for hydrate formation and the other for hydrate concentration. The advantage was the production of a concentrated hydrate, using a simpler equipment and working at lower pressures respect to the spray process. 9 refs., 5 figs.

  18. Lesbians, gays and religion.

    Science.gov (United States)

    Newmanxy, Bernie Sue

    2002-10-01

    SUMMARY This study measured the effects of religious affiliation and gender on attitudes about lesbians and gay men among 2,846 college graduates who were beginning graduate study in social work or counseling. Males were more negative than females in their attitudes toward both lesbians and gay men. Conservative Protestants were the most negative in their attitudes toward lesbians and gay men, while those who were Atheist, Agnostic, Jewish or claimed no religion were most positive. Beliefs that the Bible forbids homosexuality are discussed and readings and arguments challenging this belief that can be used as class content are presented.

  19. Micro-structural characterization of the hydration products of bauxite-calcination-method red mud-coal gangue based cementitious materials.

    Science.gov (United States)

    Liu, Xiaoming; Zhang, Na; Yao, Yuan; Sun, Henghu; Feng, Huan

    2013-11-15

    In this research, the micro-structural characterization of the hydration products of red mud-coal gangue based cementitious materials has been investigated through SEM-EDS, (27)Al MAS NMR and (29)Si MAS NMR techniques, in which the used red mud was derived from the bauxite calcination method. The results show that the red mud-coal gangue based cementitious materials mainly form fibrous C-A-S-H gel, needle-shaped/rod-like AFt in the early hydration period. With increasing of the hydration period, densification of the pastes were promoted resulting in the development of strength. EDS analysis shows that with the Ca/Si of red mud-coal gangue based cementitious materials increases, the average Ca/Si and Ca/(Si+Al) atomic ratio of C-A-S-H gel increases, while the average Al/Si atomic ratio of C-A-S-H gel decreases. MAS NMR analysis reveals that Al in the hydration products of red mud-coal gangue based cementitious materials exists in the forms of Al(IV) and Al(VI), but mainly in the form of Al(VI). Increasing the Ca/Si ratio of raw material promotes the conversion of [AlO4] to [AlO6] and inhibits the combination between [AlO4] and [SiO4] to form C-A-S-H gel. Meanwhile, the polymerization degree of [SiO4] in the hydration products declines. Published by Elsevier B.V.

  20. Biodiesel production from palm oil using hydrated lime-derived CaO as a low-cost basic heterogeneous catalyst

    International Nuclear Information System (INIS)

    Roschat, Wuttichai; Siritanon, Theeranun; Yoosuk, Boonyawan; Promarak, Vinich

    2016-01-01

    Graphical abstract: Hydrated lime-derived CaO can be utilized as high efficient heterogeneous solid catalyst for transesterification of palm oil to biodiesel product. - Highlights: • CaO with high surface area and pore volume was successfully prepared from hydrated lime using a simple method. • Hydrated lime-derived CaO were used as a catalyst in transesterification of palm oil to biodiesel. • Over 97% FAME yield was achieved from transesterification of palm oil in 2 h. • This CaO has high potential for applications as green and low-cost catalyst. - Abstract: In this study, hydrated lime-derived calcium oxide (CaO) was used as a catalyst for the transesterification of palm oil. The catalysts were characterized by TG-DTA, XRD, XRF, FT-IR, SEM, Hammett indicator method, TPD-CO_2 and BET by N_2 adsorption. Under the optimal conditions at catalyst loading of 6 wt.%, methanol/oil molar ratio of 15:1, reaction temperature 65 °C, and stirring rate of 200 rpm; 97% yield of biodiesel could be achieved in 2 h. Effects of water amount were investigated and the catalyst could tolerate high water content of 5 wt.%. The kinetic of the reaction followed pseudo-first order with the activation energy (Ea) of 121.12 kJ/mol and frequency factor (A) of 1.203 × 10"1"7 min"−"1. After treatments, high quality biodiesel was obtained which indicated that the very cheap hydrated lime-derived CaO showed excellent catalytic activity and high potential for applications in biodiesel production.

  1. Gas hydrates forming and decomposition conditions analysis

    Directory of Open Access Journals (Sweden)

    А. М. Павленко

    2017-07-01

    Full Text Available The concept of gas hydrates has been defined; their brief description has been given; factors that affect the formation and decomposition of the hydrates have been reported; their distribution, structure and thermodynamic conditions determining the gas hydrates formation disposition in gas pipelines have been considered. Advantages and disadvantages of the known methods for removing gas hydrate plugs in the pipeline have been analyzed, the necessity of their further studies has been proved. In addition to the negative impact on the process of gas extraction, the hydrates properties make it possible to outline the following possible fields of their industrial use: obtaining ultrahigh pressures in confined spaces at the hydrate decomposition; separating hydrocarbon mixtures by successive transfer of individual components through the hydrate given the mode; obtaining cold due to heat absorption at the hydrate decomposition; elimination of the open gas fountain by means of hydrate plugs in the bore hole of the gushing gasser; seawater desalination, based on the hydrate ability to only bind water molecules into the solid state; wastewater purification; gas storage in the hydrate state; dispersion of high temperature fog and clouds by means of hydrates; water-hydrates emulsion injection into the productive strata to raise the oil recovery factor; obtaining cold in the gas processing to cool the gas, etc.

  2. Characterizing Natural Gas Hydrates in the Deep Water Gulf of Mexico: Applications for Safe Exploration and Production Activities

    Energy Technology Data Exchange (ETDEWEB)

    Bent, Jimmy

    2014-05-31

    In 2000 Chevron began a project to learn how to characterize the natural gas hydrate deposits in the deep water portion of the Gulf of Mexico (GOM). Chevron is an active explorer and operator in the Gulf of Mexico and is aware that natural gas hydrates need to be understood to operate safely in deep water. In August 2000 Chevron worked closely with the National Energy Technology Laboratory (NETL) of the United States Department of Energy (DOE) and held a workshop in Houston, Texas to define issues concerning the characterization of natural gas hydrate deposits. Specifically, the workshop was meant to clearly show where research, the development of new technologies, and new information sources would be of benefit to the DOE and to the oil and gas industry in defining issues and solving gas hydrate problems in deep water.

  3. Studying the effectiveness of re-hydration on productivity in a sugar beet workers among farmers in West Azarbaijan city

    Directory of Open Access Journals (Sweden)

    F. Golbabaei

    2014-09-01

    Full Text Available Introduction: Heat-related illnesses are major causes of morbidity in the world. Workers who are exposed to extreme heat are not be able to activate their compensatory mechanisms and their health will consequently be at risk. Heat stress due to its impact on work performance increases the likelihood of worker disease and injuries and it also affect productivity. During sugar beet harvest, farmers from about 8 am to 4 pm, are exposed to sunlight and excessive heat. Therefore, preventive measures are essential in order to protect the health of farmers and improve productivity. The aim of this project as to study the effectiveness of the rehydration to reduce heat stress and increasing productivity during sugar beet harvest, conducted in 2012.   .Material and Method: in this project, 20 farmers from sugar beet farmers were studied during summer season, from 8 am to 4 pm in West Azarbaijan- Boukan city where the average temperature and relative humidity were 29.85 0C and 41%, respectively during sugar beet harvest. Selection criteria were defined as working more than 50% of the day’s working schedule and to have worked for at least 10 days of the follow-up period. Individual characteristics and water consumption rate during the work shift and also Production output data by farmers were recorded at the end of the working day. Environmental parameters using a portable monitoring device was measured and recorded and finally, the collected data was used for analysis using spss software version 20.   .Results: WBGT-TWA index for four the period of the time from morning to afternoon obtained 27.39 0C, as it was greater than the allowable thresholds. Ten workers receive 6-7 L of liquid and harvest production was significantly increased among those who are better hydrated (P=0.005, from 5 to 7 tons of harvest sugar beet per any worker per day, against lower 5 tons for farmers without drinking enough water.  . Conclusion: Farmers productivity can be

  4. Gay and Lesbian Medical Association

    Science.gov (United States)

    ... men who have sex with men (MSM), including gay and bisexual men. GLMA President Jesse Joad, MD, ... to establish clear and comprehensive regulations ensuring lesbian, gay, bisexual and transgender people do not face discrimination ...

  5. HYDRATE CORE DRILLING TESTS

    Energy Technology Data Exchange (ETDEWEB)

    John H. Cohen; Thomas E. Williams; Ali G. Kadaster; Bill V. Liddell

    2002-11-01

    The ''Methane Hydrate Production from Alaskan Permafrost'' project is a three-year endeavor being conducted by Maurer Technology Inc. (MTI), Noble, and Anadarko Petroleum, in partnership with the U.S. DOE National Energy Technology Laboratory (NETL). The project's goal is to build on previous and ongoing R&D in the area of onshore hydrate deposition. The project team plans to design and implement a program to safely and economically drill, core and produce gas from arctic hydrates. The current work scope includes drilling and coring one well on Anadarko leases in FY 2003 during the winter drilling season. A specially built on-site core analysis laboratory will be used to determine some of the physical characteristics of the hydrates and surrounding rock. Prior to going to the field, the project team designed and conducted a controlled series of coring tests for simulating coring of hydrate formations. A variety of equipment and procedures were tested and modified to develop a practical solution for this special application. This Topical Report summarizes these coring tests. A special facility was designed and installed at MTI's Drilling Research Center (DRC) in Houston and used to conduct coring tests. Equipment and procedures were tested by cutting cores from frozen mixtures of sand and water supported by casing and designed to simulate hydrate formations. Tests were conducted with chilled drilling fluids. Tests showed that frozen core can be washed out and reduced in size by the action of the drilling fluid. Washing of the core by the drilling fluid caused a reduction in core diameter, making core recovery very difficult (if not impossible). One successful solution was to drill the last 6 inches of core dry (without fluid circulation). These tests demonstrated that it will be difficult to capture core when drilling in permafrost or hydrates without implementing certain safeguards. Among the coring tests was a simulated hydrate

  6. Trichloroethylene decomposition and in-situ dry sorption of Cl-products by calcium oxides prepared from hydrated limes.

    Science.gov (United States)

    Gotoh, Yoshimi; Iwata, Goichi; Choh, Kyaw; Kubota, Mitsuhiro; Matsuda, Hitoki

    2011-10-01

    A comparison of CaOs produced by calcining two types of hydrated lime and calcium carbonate was made for decomposition of trichloroethylene and in-situ dry sorption of the decomposed Cl-products using a lab-scale gas flow type tubular packed bed reactor. About 20 mg of CaO sample was mixed with about 2 g of Al2O3 particles and packed in the reactor and allowed to react with a flowing standard gas containing 500 ppm of C2HCl3 (N2 balance) at 673 and 873 K, under the condition that the reaction of CaO with C2HCl3 might be completed within a few hours. It was found that no thermal decomposition of C2HCl3 at or below 673 K was observed in a reactor packed only with Al2O3 particles. However, a considerable amount of decomposition of C2HCl3 was obtained in a reactor packed with CaO and Al2O3, even at 673 K. For 1 mol of CaO prepared by calcining highly reactive Ca(OH)2 at 673 K, decomposition of 0.42 mol of C2HCl3 and in-situ absorption product of 0.53 mol of CaCl2 were obtained. At 873 K, about 46% of C2HCl3 was thermally decomposed. The total amount of C2HCl3 decomposed in CaO-Al2O3 particle bed at 873 K became nearly twice larger than that at 673 K. For 1 mol of CaO prepared by calcining highly reactive Ca(OH)2 at 873 K, decomposition of 0.59 mol of C2HCl3 and in-situ absorption product of 0.67 mol of CaCl2 were obtained. Small amounts of C2Cl2, C2Cl4, CCl4, etc. were detected during decomposition of C2HCl3 at 673 and 873 K. It was recognized that the data on decomposition of C2HCl3 as well as in-situ dry sorption of Cl-products in CaO particle bed were correlated with specific surface area of the CaO employed. Copyright © 2011 Elsevier Ltd. All rights reserved.

  7. Flow assurance intervention, hydrates remediation

    Energy Technology Data Exchange (ETDEWEB)

    Mancini, Christopher S. [Oceaneering International Inc., Houston, TX (United States)

    2012-07-01

    This paper addresses the issues of removing hydrates in sub sea flow lines and associated equipment with an Remotely Operated Vehicle (ROV) of opportunity and a multi-service-vessel (MSV). The paper is split into three topics: the equipment used with the ROV, assessing the interface points and handling fluids produced from drawing down the pressure. Each section is explained thoroughly and backed up with real world experience. The equipment section details information from actual jobs performed and why the particular components were utilized. The system is generally contained in an ROV mounted skid. Pumps are utilized to draw down the pressure inside the hydrated section of equipment, removing one of the three necessary components for hydrates formation. Once the section is pumped down, several options exist for handling the fluids pumped out of the system: pumping to surface, re-injection into the well, or injection into an operating flow line. This method of hydrates remediation is both economical and timely. Hydrate blockages form in low temperatures and high pressures. Reducing the pressure or increasing the temperature so the conditions lie to the right of the hydrate dissociation curve will slowly decompose the blockage. Depressurization and the use of MEG or methanol will give favorable conditions to remove the hydrate plug. Oceaneering has the capabilities to remove hydrates using the FRS in conjunction with an installation vessel to dispose of the gas and fluid removed from the flow line. Hydrate remediation techniques should be implemented into the initial design to reduce costs later. The cost of stopped production combined with the day rate for equipment needed for hydrate removal outweighs the costs if no technique is utilized. (author)

  8. Baseline seismic survey for the 2nd offshore methane hydrate production test in the Eastern Nankai Trough

    Science.gov (United States)

    Teranishi, Y.; Inamori, T.; Kobayashi, T.; Fujii, T.; Saeki, T.; Takahashi, H.; Kobayashi, F.

    2017-12-01

    JOGMEC carries out seismic monitoring surveys before and after the 2nd offshore methane hydrate (MH) production test in the Eastern Nankai Trough and evaluates MH dissociation behavior from the time-lapse seismic response. In 2016, JOGMEC deployed Ocean Bottom Cable (OBC) system provided by OCC in the Daini Atsumi Knoll with water depths of 900-1100 m. The main challenge of the seismic survey was to optimize the cable layout for ensuring an effective time-lapse seismic detectability while overcoming the following two issues: 1. OBC receiver lines were limited to only two lines. It was predicted that the imaging of shallow reflectors would suffer from lack of continuity and resolution due to this limitation of receiver lines. 2. The seafloor and shallow sedimentary layers including monitoring target are dipping to the Northwest direction. It was predicted that the refection points would laterally shift to up-dip direction (Southeast direction). In order to understand the impact of the issues above, the seismic survey was designed with elastic wave field simulation. The reflection seismic survey for baseline data was conducted in August 2016. A total of 70 receiver stations distributed along one cable were deployed successfully and a total of 9952 shots were fired. After the baseline seismic survey, the hydrophone and geophone vertical component datasets were processed as outlined below: designaturing, denoising, surface consistent deconvolution and surface consistent amplitude correction. High-frequency imaging with Reverse Time Migration (RTM) was introduced to these data sets. Improvements in imaging from the RTM are remarkable compared to the Kirchhoff migration and the existing Pre-stack time migration with 3D marine surface seismic data obtained and processed in 2002, especially in the following parts. The MH concentrated zone which has complex structures. Below the Bottom Simulating Reflector (BSR) which is present as a impedance-contrast boundary

  9. Experimental Investigation of Effect on Hydrate Formation in Spray Reactor

    Directory of Open Access Journals (Sweden)

    Jianzhong Zhao

    2015-01-01

    Full Text Available The effects of reaction condition on hydrate formation were conducted in spray reactor. The temperature, pressure, and gas volume of reaction on hydrate formation were measured in pure water and SDS solutions at different temperature and pressure with a high-pressure experimental rig for hydrate formation. The experimental data and result reveal that additives could improve the hydrate formation rate and gas storage capacity. Temperature and pressure can restrict the hydrate formation. Lower temperature and higher pressure can promote hydrate formation, but they can increase production cost. So these factors should be considered synthetically. The investigation will promote the advance of gas storage technology in hydrates.

  10. Calcium Aluminate Cement Hydration Model

    Directory of Open Access Journals (Sweden)

    Matusinović, T.

    2011-01-01

    Full Text Available Calcium aluminate cement (AC is a very versatile special cement used for specific applications. As the hydration of AC is highly temperature dependent, yielding structurally different hydration products that continuously alter material properties, a good knowledge of thermal properties at early stages of hydration is essential. The kinetics of AC hydration is a complex process and the use of single mechanisms models cannot describe the rate of hydration during the whole stage.This paper examines the influence of temperature (ϑ=5–20 °C and water-to-cement mass ratio (mH /mAC = 0.4; 0.5 and 1.0 on hydration of commercial iron-rich AC ISTRA 40 (producer: Istra Cement, Pula, Croatia, which is a part of CALUCEM group, Figs 1–3. The flow rate of heat generation of cement pastes as a result of the hydration reactions was measured with differential microcalorimeter. Chemically bonded water in the hydrated cement samples was determined by thermo-gravimetry.Far less heat is liberated when cement and water come in contact for the first time, Fig. 1, than in the case for portland cement (PC. Higher water-to-cement ratio increases the heat evolved at later ages (Fig. 3 due to higher quantity of water available for hydration. A significant effect of the water-to-cement ratio on the hydration rate and hydration degree showed the importance of water as being the limiting reactant that slows down the reaction early. A simplified stoichiometric model of early age AC hydration (eq. (8 based on reaction schemes of principal minerals, nominally CA, C12A7 and C4AF (Table 1, was employed. Hydration kinetics after the induction period (ϑ < 20 °C had been successfully described (Fig. 4 and Table 2 by a proposed model (eq. (23 which simultaneously comprised three main mechanisms: nucleation and growth, interaction at phase boundary, and mass transfer. In the proposed kinetic model the nucleation and growth is proportional to the amount of reacted minerals (eq

  11. Comradeship of Cock? Gay porn and the entrepreneurial voyeur

    OpenAIRE

    Maddison, Stephen

    2017-01-01

    Thirty years of academic and critical scholarship on the subject of gay porn have born witness to significant changes not only in the kinds of porn produced for, and watched by, gay men, but in the modes of production and distribution of that porn, and the legal, economic and social contexts in which it has been made, sold/shared, and watched. Those thirty years have also seen a huge shift in the cultural and political position of gay men, especially in the US and UK, and other apparently ‘ad...

  12. Observed gas hydrate morphologies in marine sediment

    Energy Technology Data Exchange (ETDEWEB)

    Holland, M.; Schultheiss, P.; Roberts, J.; Druce, M. [Geotek Ltd., Daventry, Northamptonshire (United Kingdom)

    2008-07-01

    The morphology of gas hydrate in marine sediments determines the basic physical properties of the sediment-hydrate matrix and provides information regarding the formation of gas hydrate deposits, and the nature of the disruption that will occur on dissociation. Small-scale morphology is useful in estimating the concentrations of gas hydrate from geophysical data. It is also important for predicting their response to climate change or commercial production. Many remote techniques for gas hydrate detection and quantification depend on hydrate morphology. In this study, morphology of gas hydrate was examined in HYACINTH pressure cores from recent seagoing expeditions. Visual and infrared observations from non-pressurized cores were also used. The expeditions and pressure core analysis were described in detail. This paper described the difference between two types of gas hydrate morphologies, notably pore-filling and grain-displacing. Last, the paper addressed the impact of hydrate morphology. It was concluded that a detailed morphology of gas hydrate is an essential component for a full understanding of the past, present, and future of any gas hydrate environment. 14 refs., 4 figs.

  13. Gay-Lussac Experiment

    Science.gov (United States)

    Ladino, L. A.; Rondón, S. H.

    2015-01-01

    In this paper, we present a low-cost method to study the Gay-Lussac's law. We use a heating wire wrapped around the test tube to heat the air inside and make use of a solid state pressure sensor which requires a previous calibration to measure the pressure in the test tube.

  14. Gay Immigrants and Grindr

    DEFF Research Database (Denmark)

    Shield, Andrew DJ

    2018-01-01

    In this (open-access) essay, I assess the idea that Grindr and related apps render urban gay spaces obsolete, and offer three counter-arguments based on my research with immigrants and tourists who use Grindr. In short: newcomers who use Grindr might actually bring new life to queer urban spaces...

  15. Alcohol cosurfactants in hydrate antiagglomeration.

    Science.gov (United States)

    York, J Dalton; Firoozabadi, Abbas

    2008-08-28

    Because of availability, as well as economical and environmental considerations, natural gas is projected to be the premium fuel of the 21st century. Natural gas production involves risk of the shut down of onshore and offshore operations because of blockage from hydrates formed from coproduced water and hydrate-forming species in natural gas. Industry practice has been usage of thermodynamic inhibitors such as alcohols often in significant amounts, which have undesirable environmental and safety impacts. Thermodynamic inhibitors affect bulk-phase properties and inhibit hydrate formation. An alternative is changing surface properties through usage of polymers and surfactants, effective at 0.5 to 3 weight % of coproduced water. One group of low dosage hydrate inhibitors (LDHI) are kinetic inhibitors, which affect nucleation rate and growth. A second group of LDHI are antiagglomerants, which prevent agglomeration of small hydrate crystallites. Despite great potential, work on hydrate antiagglomeration is very limited. This work centers on the effect of small amounts of alcohol cosurfactant in mixtures of two vastly different antiagglomerants. We use a model oil, water, and tetrahydrofuran as a hydrate-forming species. Results show that alcohol cosurfactants may help with antiagglomeration when traditional antiagglomerants alone are ineffective. Specifically, as low as 0.5 wt. % methanol cosurfactant used in this study is shown to be effective in antiagglomeration. Without the cosurfactant there will be agglomeration independent of the AA concentration. To our knowledge, this is the first report of alcohol cosurfactants in hydrate antiagglomerants. It is also shown that a rhamnolipid biosurfactant is effective down to only 0.5 wt. % in such mixtures, yet a quaternary ammonium chloride salt, i. e., quat, results in hydrate slurries down to 0.01 wt. %. However, biochemical surfactants are less toxic and biodegradable, and thus their use may prove beneficial even if at

  16. Paradoxes of an assimilation politics: media production of gay male belonging in the Canadian 'vital public' from the tainted blood scandal to the present.

    Science.gov (United States)

    Crath, Rory; Rangel, Cristian

    2017-07-01

    Canadian media discourses on gay men's sexuality and political inclusion serve as a rich site for understanding current tensions in debates on sexual citizenship under biopolitical regimes. This paper addresses how public health reporting in one health news media source, Canada's leading newspaper The Globe and Mail, discursively produced contiguous understandings of the moral, social and biological dimensions of gay male subjectivity and sexuality within the context of HIV risk discourses. Specifically, we critically examine the newspaper's coverage of what constitutes the public good when national blood supplies are at stake. Our analysis reveals a profound dichotomy in which gay men - as sexual subjects and subjects of rights - are recalibrated following the political and economic investments of bourgeoisie communities of interest. However encompassing the securing of legal social rights might be, gay men's sexuality is resistant to a reformatting under a heteronormative regulatory regime, as the social traumas caused by HIV continue to cast a shadow on sexual behaviours that purportedly risk leakage of contamination into the body politic.

  17. Lesbian, Gay, Bisexual, and Transgender Health

    Science.gov (United States)

    ... Objectives » Lesbian, Gay, Bisexual, and Transgender Health Lesbian, Gay, Bisexual, and Transgender Health Overview (active tab) Objectives National Snapshots Lesbian, Gay, Bisexual, and Transgender Health View HP2020 Data for: ...

  18. PERSEPSI GAY TERHADAP STIGMATISASI GAY OLEH PETUGAS KESEHATAN

    Directory of Open Access Journals (Sweden)

    Yafi Sabila Rosyad

    2015-04-01

    Full Text Available Background: The presence of gays in the community still makes heterosexual as normal sex orientation.Thereareunfair perceptionsof heterosexual group that develop into real behaviorswhicharevery detrimental for homosexuals group in the form of stigmatization against homosexuals.Stigmatization for gay in society also comes fromhealthprofessionals when they think homosexualsconduct violationto theruleof law,social andreligiousvalues.Therefore gays tend to visit certain healthcare providers who are familiar with them or to hide the identity that they are homosexuals.Objective:Todeterminetheperceptionsof gaysregarding gaystigmatizationofhealthcare providers.Methods:A qualitativeby using snowball samplingwith the total of 10participants was applied.TheConceptual Content CognitiveMap(3CMmethods followedby interviewwere utilized to gather data.Results:Six themesregarding gaystigmatizationofhealthcare as perceived by gays as follows: (1 gay isa divergence and contagious; (2 being gay is normal; (3 flamboyant and hedonist personality; (4 exclusiveand bad personality; (5 at high risk of sexually transmitted diseases, lack of self-control, and diseased; and(6 having good personality.Conclusion:Six themes with predominantly negative perceptions regarding stigmatization on gays byhealth careproviders as perceived by gays describe the need of transformation of health care service toincrease the quality of health of minor population like gay.

  19. Consuming My Way Gay

    Directory of Open Access Journals (Sweden)

    Matthew Eichler

    2012-07-01

    Full Text Available As members of consumerist societies, we are socialized into what it means to be good citizens and participate in society through our consumption. For many, this is taught in the home, yet for lesbian, gay, bisexual, transgender, and queer (LGBTQ individuals, home is often not a source of reliable information about our identities. As such, LGBTQ individuals turn to the marketplace to seek information about their sexual and gender identities. This autoethnographic account shares, through three vignettes, how coming out as a queer man is shaped by consumptive pedagogy—that is, learning through consumption. First, material goods are explored as the signifier of sexual orientation. Then, the gay bar as marketplace and the online marketplace for relationships are explored.

  20. Dehydration behaviour of hydrates

    Energy Technology Data Exchange (ETDEWEB)

    Dette, S.S.; Stelzer, T.; Jones, M.J.; Ulrich, J. [Martin-Luther-Universitaet Halle-Wittenberg, Zentrum fuer Ingenieurwissenschaften, Verfahrenstechnik/TVT, 06099 Halle (Germany)

    2010-07-15

    Immersing a crystalline solvate in a suitable anti-solvent can induce phase transformation to solvent-free solid phase. In certain cases the solvent-mediated phase transition results in the generation of hollow, tubular structures. Both the tube dimensions of sodium-2-keto-L-gulonate anhydrate (skga) and the dehydration kinetics of sodium-2-keto-L-gulonate monohydrate (skgm) can be modified by the antisolvent employed. An explanation for the variable dehydration behaviour of skgm in the antisolvents is presented here. Furthermore, other crystalline hydrates were dehydrated in dry methanol. Providing an operational window can be found, any hydrate material could possibly find use in the production of tubes (micro- or nanotubes for different applications). The experimental conditions selected (dry methanol as antisolvent, dehydration temperature at 25 C) for the dehydration did not lead to the anhydrate tube growth for all hydrates investigated. Based upon the results presented here a first hypothesis is presented to explain this effect. (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  1. Hydration Properties of Ground Granulated Blast-Furnace Slag (GGBS Under Different Hydration Environments

    Directory of Open Access Journals (Sweden)

    Shuhua LIU

    2017-02-01

    Full Text Available The hydration properties of various cementitious materials containing Ground Granulated Blast-furnace Slag (GGBS, two alkali-activated slag cements (AAS-1 and AAS-2 in which sodium silicate and sodium hydroxide act as alkaline activators respectively, supersulfated cement (SSC and slag Portland cement(PSC, are compared with ordinary Portland cement (OPC to investigate the effect of activating environment on the hydration properties in this study by determining the compressive strength of the pastes, the hydration heat of binders within 96 hours, and the hydration products at age of 28 days. The results show that C-S-H gels are the main hydrated products for all cementitious systems containing GGBS. Ca(OH2 is the hydration products of OPC and PSC paste. However, ettringite and gypsum crystals instead of Ca(OH2 are detected in SSC paste. Additionally, tobermorite, a crystalline C-S-H, and calcite are hydrated products in AAS-1. Tobermorite, cowlesite and calcite are hydrated products of AAS-2 as well. Based on strength results, AAS-1 paste exhibits the highest compressive strength followed by POC, PSC, SSC in order at all testing ages and AAS-2 give the lowest compressive strength except for the early age at 3 days, which is higher than SSC but still lower than PSC. From hydration heat analysis, alkalinity in the reaction solution is a vital factor influencing the initial hydration rate and the initial hydration rate from higher to lower is AAS-2, AAS-1, OPC, PSC and SSC. Although AAS possesses a faster reaction rate in the initial hours, cumulative hydration heat of AAS is comparably lower than that of OPC, but higher than those of PSC and SSC in turn, which indicates that the hydration heat of clinkers is much higher than that of slag.DOI: http://dx.doi.org/10.5755/j01.ms.23.1.14934

  2. Experimental investigation of methane release from hydrate formation in sandstone through both hydrate dissociation and CO{sub 2} sequestration

    Energy Technology Data Exchange (ETDEWEB)

    Husebo, J.; Graue, A.; Kvamme, B. [Bergen Univ., Bergen (Norway). Dept. of Physics and Technology; Stevens, J.; Howard, J.J. [ConocoPhillips, Ponca City, OK (United States); Baldwin, B.A. [Green Country Petrophysics LLC, Dewey, OK (United States)

    2008-07-01

    Large amounts of natural gas trapped in hydrate reservoirs are found in Arctic regions and in deep offshore locations around the world. Natural gas production from hydrate deposits offer significant potential for future energy needs. However, research is needed in order to propose potential production schemes for natural gas hydrates. Natural gas molecules can be freed from hydrate structured cages by depressurization, by heating and by exposing the hydrate to a substance that will form a thermodynamically more stable hydrate structure. This paper provided a comparison of two approaches for releasing methane from methane hydrate in porous sandstone. The study scope covered the dissociation rate of methane hydrate in porous media through depressurization, and also referred to previous work done on producing methane from hydrates in sandstone while sequestering carbon dioxide (CO{sub 2}). The study was conducted in a laboratory setting. The paper discussed the experimental design which included the placing of a pressure- and temperature-controlled sample holder inside the bore of a magnetic resonance imager. The experimental procedures were then outlined, with reference to hydrate formation; carbon dioxide sequestration; hydrate dissociation experiments with constant volume; and hydrate dissociation experiments at constant pressure. The constant volume experiments demonstrated that in order to dissociate a large amount of hydrate, the initial depressurization had to be significantly lower than the hydrate stability pressure. 9 refs., 9 figs.

  3. Gay, Mostly Gay, or Bisexual Leaning Gay? An Exploratory Study Distinguishing Gay Sexual Orientations Among Young Men.

    Science.gov (United States)

    Savin-Williams, Ritch C; Cash, Brian M; McCormack, Mark; Rieger, Gerulf

    2017-01-01

    This exploratory study assessed physiological, behavioral, and self-report measures of sexual and romantic indicators of sexual orientation identities among young men (mean age = 21.9 years) with predominant same-sex sexual and romantic interests: those who described themselves as bisexual leaning gay (n = 11), mostly gay (n = 17), and gay (n = 47). Although they were not significantly distinguishable based on physiological (pupil dilation) responses to nude stimuli, on behavioral and self-report measures a descending linear trend toward the less preferred sex (female) was significant regarding sexual attraction, fantasy, genital contact, infatuation, romantic relationship, sex appeal, and gazing time to the porn stimuli. Results supported a continuum of sexuality with distinct subgroups only for the self-report measure of sexual attraction. The other behavioral and self-report measures followed the same trend but did not significantly differ between the bisexual leaning gay and mostly gay groups, likely the result of small sample size. Results suggest that romantic indicators are as good as sexual measures in assessing sexual orientation and that a succession of logically following groups from bisexual leaning gay, mostly gay, to gay. Whether these three groups are discrete or overlapping needs further research.

  4. Know about Gays and Lesbians.

    Science.gov (United States)

    Hyde, Margaret O.; Forsyth, Elizabeth H.

    Homosexuality has emerged as a major issue making headlines across the country, including initiatives, which have been put on state and local ballots, that limit or guarantee the civil rights of gays and lesbians. This book, designed as a guide for juveniles, separates fact from fiction about gays and lesbians and explains homosexuality in clear,…

  5. Formation rate of natural gas hydrate

    Energy Technology Data Exchange (ETDEWEB)

    Mork, Marit

    2002-07-01

    The rate of methane hydrate and natural gas hydrate formation was measured in a 9.5 litre stirred tank reactor of standard design. The experiments were performed to better understand the performance and scale-up of a reactor for continuous production of natural gas hydrates. The hydrate formation rate was measured at steady-state conditions at pressures between 70 and 90 bar and temperatures between 7 and 15 deg C. Between 44 and 56 % of the gas continuously supplied to the reactor was converted to hydrate. The experimental results show that the rate of hydrate formation is strongly influenced by gas injection rate and pressure. The effect of stirring rate is less significant and subcooling has no observable effect on the formation rate. Hydrate crystal concentration and gas composition do not influence the hydrate formation rate. Observations of produced hydrate crystals indicate that the crystals are elongated, about 5 micron in diameter and 10 micron long. Analysis of the results shows that the rate of hydrate formation is dominated by gas-liquid mass transfer. A mass transfer model, the bubble-to-crystal model, was developed for the hydrate formation rate in a continuous stirred tank reactor, given in terms of concentration driving force and an overall mass transfer coefficient. The driving force is the difference between the gas concentration at the gas-liquid interface and at the hydrate crystal surface. These concentrations correspond to the solubility of gas in water at experimental temperature and pressure and the solubility of gas at hydrate equilibrium temperature and experimental pressure, respectively. The overall mass transfer coefficient is expressed in terms of superficial gas velocity and impeller power consumption, parameters commonly used in study of stirred tank reactors. Experiments and modeling show that the stirred tank reactor has a considerable potential for increased production capacity. However, at higher hydrate production rates the

  6. Diverse artikelen in Gay Amsterdam News

    NARCIS (Netherlands)

    Hekma, G.

    2002-01-01

    Vernedering, in: Gay Amsterdam News 125 (jan 2002), pp. 20-21; Webseks, zaad, zweetseks, in: Gay Amsterdam News 126 (feb 2002), pp. 30-31; Wurgseks, in: Gay Amsterdam News 127 (mrt 2002), pp. 30-31; Wijnandus Johannes Sengers (1927-2002), in: Gay Amsterdam News 133 (sept 2002), pp. 49.

  7. Gay bashing - a rite of passage?

    NARCIS (Netherlands)

    van der Meer, T.A.M.

    2003-01-01

    Most of what is known about the perpetrators of anti-gay violence is reported by victims of such violence. None the less, it is obvious from such reports that 'gay bashers' are overwhelmingly young men who operate in groups, sometimes at gay cruising sites or near gay bars. Drawing on finding from

  8. Thermal conductivity of hydrate-bearing sediments

    Science.gov (United States)

    Cortes, Douglas D.; Martin, Ana I.; Yun, Tae Sup; Francisca, Franco M.; Santamarina, J. Carlos; Ruppel, Carolyn D.

    2009-01-01

    A thorough understanding of the thermal conductivity of hydrate-bearing sediments is necessary for evaluating phase transformation processes that would accompany energy production from gas hydrate deposits and for estimating regional heat flow based on the observed depth to the base of the gas hydrate stability zone. The coexistence of multiple phases (gas hydrate, liquid and gas pore fill, and solid sediment grains) and their complex spatial arrangement hinder the a priori prediction of the thermal conductivity of hydrate-bearing sediments. Previous studies have been unable to capture the full parameter space covered by variations in grain size, specific surface, degree of saturation, nature of pore filling material, and effective stress for hydrate-bearing samples. Here we report on systematic measurements of the thermal conductivity of air dry, water- and tetrohydrofuran (THF)-saturated, and THF hydrate–saturated sand and clay samples at vertical effective stress of 0.05 to 1 MPa (corresponding to depths as great as 100 m below seafloor). Results reveal that the bulk thermal conductivity of the samples in every case reflects a complex interplay among particle size, effective stress, porosity, and fluid-versus-hydrate filled pore spaces. The thermal conductivity of THF hydrate–bearing soils increases upon hydrate formation although the thermal conductivities of THF solution and THF hydrate are almost the same. Several mechanisms can contribute to this effect including cryogenic suction during hydrate crystal growth and the ensuing porosity reduction in the surrounding sediment, increased mean effective stress due to hydrate formation under zero lateral strain conditions, and decreased interface thermal impedance as grain-liquid interfaces are transformed into grain-hydrate interfaces.

  9. Physical Properties of Gas Hydrates: A Review

    Energy Technology Data Exchange (ETDEWEB)

    Gabitto, Jorge [Prairie View A& M University; Tsouris, Costas [ORNL

    2010-01-01

    Methane gas hydrates in sediments have been studied by several investigators as a possible future energy resource. Recent hydrate reserves have been estimated at approximately 1016?m3 of methane gas worldwide at standard temperature and pressure conditions. In situ dissociation of natural gas hydrate is necessary in order to commercially exploit the resource from the natural-gas-hydrate-bearing sediment. The presence of gas hydrates in sediments dramatically alters some of the normal physical properties of the sediment. These changes can be detected by field measurements and by down-hole logs. An understanding of the physical properties of hydrate-bearing sediments is necessary for interpretation of geophysical data collected in field settings, borehole, and slope stability analyses; reservoir simulation; and production models. This work reviews information available in literature related to the physical properties of sediments containing gas hydrates. A brief review of the physical properties of bulk gas hydrates is included. Detection methods, morphology, and relevant physical properties of gas-hydrate-bearing sediments are also discussed.

  10. Strength Estimation for Hydrate-Bearing Sediments From Direct Shear Tests of Hydrate-Bearing Sand and Silt

    Science.gov (United States)

    Liu, Zhichao; Dai, Sheng; Ning, Fulong; Peng, Li; Wei, Houzhen; Wei, Changfu

    2018-01-01

    Safe and economic methane gas production, as well as the replacement of methane while sequestering carbon in natural hydrate deposits, requires enhanced geomechanical understanding of the strength and volume responses of hydrate-bearing sediments during shear. This study employs a custom-made apparatus to investigate the mechanical and volumetric behaviors of carbon dioxide hydrate-bearing sediments subjected to direct shear. The results show that both peak and residual strengths increase with increased hydrate saturation and vertical stress. Hydrate contributes mainly the cohesion and dilatancy constraint to the peak strength of hydrate-bearing sediments. The postpeak strength reduction is more evident and brittle in specimens with higher hydrate saturation and under lower stress. Significant strength reduction after shear failure is expected in silty sediments with high hydrate saturation Sh ≥ 0.65. Hydrate contribution to the residual strength is mainly by increasing cohesion at low hydrate saturation and friction at high hydrate saturation. Stress state and hydrate saturation are dominating both the stiffness and the strength of hydrate-bearing sediments; thus, a wave velocity-based peak strength prediction model is proposed and validated, which allows for precise estimation of the shear strength of hydrate-bearing sediments through acoustic logging data. This method is advantageous to geomechanical simulators, particularly when the experimental strength data of natural samples are not available.

  11. Artificial Hydration and Nutrition

    Science.gov (United States)

    ... Crisis Situations Pets and Animals myhealthfinder Food and Nutrition Healthy Food Choices Weight Loss and Diet Plans ... Your Health Resources Healthcare Management Artificial Hydration and Nutrition Artificial Hydration and Nutrition Share Print Patients who ...

  12. Hydraulic and Mechanical Effects from Gas Hydrate Conversion and Secondary Gas Hydrate Formation during Injection of CO2 into CH4-Hydrate-Bearing Sediments

    Science.gov (United States)

    Bigalke, N.; Deusner, C.; Kossel, E.; Schicks, J. M.; Spangenberg, E.; Priegnitz, M.; Heeschen, K. U.; Abendroth, S.; Thaler, J.; Haeckel, M.

    2014-12-01

    The injection of CO2 into CH4-hydrate-bearing sediments has the potential to drive natural gas production and simultaneously sequester CO2 by hydrate conversion. The process aims at maintaining the in situ hydrate saturation and structure and causing limited impact on soil hydraulic properties and geomechanical stability. However, to increase hydrate conversion yields and rates it must potentially be assisted by thermal stimulation or depressurization. Further, secondary formation of CO2-rich hydrates from pore water and injected CO2 enhances hydrate conversion and CH4 production yields [1]. Technical stimulation and secondary hydrate formation add significant complexity to the bulk conversion process resulting in spatial and temporal effects on hydraulic and geomechanical properties that cannot be predicted by current reservoir simulation codes. In a combined experimental and numerical approach, it is our objective to elucidate both hydraulic and mechanical effects of CO2 injection and CH4-CO2-hydrate conversion in CH4-hydrate bearing soils. For the experimental approach we used various high-pressure flow-through systems equipped with different online and in situ monitoring tools (e.g. Raman microscopy, MRI and ERT). One particular focus was the design of triaxial cell experimental systems, which enable us to study sample behavior even during large deformations and particle flow. We present results from various flow-through high-pressure experimental studies on different scales, which indicate that hydraulic and geomechanical properties of hydrate-bearing sediments are drastically altered during and after injection of CO2. We discuss the results in light of the competing processes of hydrate dissociation, hydrate conversion and secondary hydrate formation. Our results will also contribute to the understanding of effects of temperature and pressure changes leading to dissociation of gas hydrates in ocean and permafrost systems. [1] Deusner C, Bigalke N, Kossel E

  13. Methane hydrates in nature - Current knowledge and challenges

    Science.gov (United States)

    Collett, Timothy S.

    2014-01-01

    Recognizing the importance of methane hydrate research and the need for a coordinated effort, the United States Congress enacted the Methane Hydrate Research and Development Act of 2000. At the same time, the Ministry of International Trade and Industry in Japan launched a research program to develop plans for a methane hydrate exploratory drilling project in the Nankai Trough. India, China, the Republic of Korea, and other nations also have established large methane hydrate research and development programs. Government-funded scientific research drilling expeditions and production test studies have provided a wealth of information on the occurrence of methane hydrates in nature. Numerous studies have shown that the amount of gas stored as methane hydrates in the world may exceed the volume of known organic carbon sources. However, methane hydrates represent both a scientific and technical challenge, and much remains to be learned about their characteristics and occurrence in nature. Methane hydrate research in recent years has mostly focused on: (1) documenting the geologic parameters that control the occurrence and stability of methane hydrates in nature, (2) assessing the volume of natural gas stored within various methane hydrate accumulations, (3) analyzing the production response and characteristics of methane hydrates, (4) identifying and predicting natural and induced environmental and climate impacts of natural methane hydrates, (5) analyzing the methane hydrate role as a geohazard, (6) establishing the means to detect and characterize methane hydrate accumulations using geologic and geophysical data, and (7) establishing the thermodynamic phase equilibrium properties of methane hydrates as a function of temperature, pressure, and gas composition. The U.S. Department of Energy (DOE) and the Consortium for Ocean Leadership (COL) combined their efforts in 2012 to assess the contributions that scientific drilling has made and could continue to make to advance

  14. Effects of gay identity, gender and explicitness of advertising imagery on gay responses to advertising.

    Science.gov (United States)

    Oakenfull, Gillian

    2007-01-01

    The present research draws from literature relating to gay identity in psychology and sociology and feminist theory to consider the effect of gay identity and gender on gays' and lesbians' attitudes toward various types of advertising content that are most commonly used to target gay consumers. As such, this study empirically tests whether gay males' and lesbians' responses to gay-oriented advertising content are moderated by individual characteristics: (1) the degree to which they identify as gay, and (2) their gender, and by the explicitness and gender of the gay-oriented advertising imagery.

  15. Methane hydrate dissociation using inverted five-spot water flooding method in cubic hydrate simulator

    International Nuclear Information System (INIS)

    Li, Gang; Li, Xiao-Sen; Li, Bo; Wang, Yi

    2014-01-01

    The combination forms of the hydrate dissociation methods in different well systems are divided into 6 main patterns. Dissociation processes of methane hydrate in porous media using the inverted five-spot water flooding method (Pattern 4) are investigated by the experimental observation and numerical simulation. In situ methane hydrate is synthesized in the Cubic Hydrate Simulator (CHS), a 5.832-L cubic reactor. A center vertical well is used as the hot water injection well, while the four vertical wells at the corner are the gas and water production wells. The gas production begins simultaneously with the hot water injection, while after approximately 20 min of compression, the water begins to be produced. One of the common characteristics of the inverted five-spot water flooding method is that both the gas and water production rates decrease with the reduction of the hydrate dissociation rate. The evaluation of the energy efficiency ratio might indicate the inverted five-spot water flooding as a promising gas producing method from the hydrate reservoir. - Highlights: • A three-dimensional 5.8-L cubic pressure vessel is developed. • Gas production of hydrate using inverted five-spot flooding method is studied. • Water/gas production rate and energy efficiency ratio are evaluated. • Temperature distributions of numerical simulation and experiment agree well. • Hydrate dissociation process is a moving boundary problem in this study

  16. Tapping methane hydrates for unconventional natural gas

    Science.gov (United States)

    Ruppel, Carolyn

    2007-01-01

    Methane hydrate is an icelike form of concentrated methane and water found in the sediments of permafrost regions and marine continental margins at depths far shallower than conventional oil and gas. Despite their relative accessibility and widespread occurrence, methane hydrates have never been tapped to meet increasing global energy demands. With rising natural gas prices, production from these unconventional gas deposits is becoming economically viable, particularly in permafrost areas already being exploited for conventional oil and gas. This article provides an overview of gas hydrate occurrence, resource assessment, exploration, production technologies, renewability, and future challenges.

  17. Production of Hydrated Metal Ions by Fast Ion or Atom Beam Sputtering. Collision-Induced Dissociation and Successive Hydration Energies of Gaseous Cu+ with 1-4 Water Molecules

    NARCIS (Netherlands)

    Magnera, Thomas F.; David, Donald E.; Stulik, Dusan; Orth, Robert G.; Jonkman, Harry T.; Michl, Josef

    1989-01-01

    Low-temperature sputtering of frozen aqueous solutions of metal salts, of hydrated crystalline transition-metal salts, of frosted metal surfaces, and of frosted metal salts with kiloelectronvolt energy rare gas atoms or ions produces copious amounts of cluster ions, among which M+(H2O)n and/or

  18. Analyses of production tests and MDT tests conducted in Mallik and Alaska methane hydrate reservoirs : what can we learn from these well tests?

    Energy Technology Data Exchange (ETDEWEB)

    Kurihara, M.; Funatsu, K.; Ouchi, H. [Japan Oil Engineering Co., Tokyo (Japan); Masuda, Y. [Tokyo Univ., Tokyo (Japan). School of Engineering; Yamamoto, K. [Japan Oil, Gas and Metals National Corp., Tokyo (Japan); Narita, H. [National Inst. of Advanced Industrial Science and Technology, Tokyo (Japan); Dallimore, S.R. [Natural Resources Canada, Ottawa, ON (Canada). Geological Survey of Canada; Collett, T.S. [United States Geological Survey, Reston, VA (United States); Hancock, S.H. [APA Petroleum Engineering Ltd., Calgary, AB (Canada)

    2008-07-01

    This paper described a series of pressure drawdown tests conducted to evaluate a modular formation dynamics tester (MDT) wireline tool. The tests were conducted at the Mallik methane hydrate (MH) reservoir as well as in MH reservoirs in Alaska over a period of several years. Production tests were also conducted to evaluate depressurization methods, and measure production and bottomhole pressure (BHP) below known MH stability pressures in order to estimate permeability and MH dissociation radius properties. The results of the tests were then history-matched using a numerical simulator. An analysis of the simulation study showed that the MDT tests were useful in estimating initial effective permeability levels in the presence of MH. However, wellbore storage erased important data used to indicate the radius of MH dissociation and effective permeability after partial MH dissociation. The study also showed that steady flow conditions must be established before obtaining solutions from history-matched production tests. Parameters accurately estimated using the MDT and production tests were outlined, and suggestions for future designs and analyses for MH reservoirs were presented. 14 refs., 7 tabs., 17 figs.

  19. Separation of water through gas hydrate formation

    DEFF Research Database (Denmark)

    Boch Andersen, Torben; Thomsen, Kaj

    2009-01-01

    Gas hydrate is normally recognized as a troublemaker in the oil and gas industry. However, gas hydrate has some interesting possibilities when used in connection with separation of water. Nordic Sugar has investigated the possibility of using gas hydrates for concentration of sugar juice. The goal...... of the project was to formulate an alternative separation concept, which can replace the traditional water evaporation process in the sugar production. Work with the separation concept showed that gas hydrates can be used for water separation. The process is not suitable for sugar production because of large...... volumes and the needs for high pressure. The process could be interesting for concentration of heat sensitive, high value products...

  20. Novel understanding of calcium silicate hydrate from dilute hydration

    KAUST Repository

    Zhang, Lina

    2017-05-13

    The perspective of calcium silicate hydrate (C-S-H) is still confronting various debates due to its intrinsic complicated structure and properties after decades of studies. In this study, hydration at dilute suspension of w/s equaling to 10 was conducted for tricalcium silicate (C3S) to interpret long-term hydration process and investigate the formation, structure and properties of C-S-H. Based on results from XRD, IR, SEM, NMR and so forth, loose and dense clusters of C-S-H with analogous C/S ratio were obtained along with the corresponding chemical formulae proposed as Ca5Si4O13∙6.2H2O. Crystalline structure inside C-S-H was observed by TEM, which was allocated at the foil-like proportion as well as the edge of wrinkles of the product. The long-term hydration process of C3S in dilute suspension could be sketchily described as migration of calcium hydroxide and in-situ growth of C-S-H with equilibrium silicon in aqueous solution relatively constant and calcium varied.

  1. Gas hydrate in nature

    Science.gov (United States)

    Ruppel, Carolyn D.

    2018-01-17

    Gas hydrate is a naturally occurring, ice-like substance that forms when water and gas combine under high pressure and at moderate temperatures. Methane is the most common gas present in gas hydrate, although other gases may also be included in hydrate structures, particularly in areas close to conventional oil and gas reservoirs. Gas hydrate is widespread in ocean-bottom sediments at water depths greater than 300–500 meters (m; 984–1,640 feet [ft]) and is also present in areas with permanently frozen ground (permafrost). Several countries are evaluating gas hydrate as a possible energy resource in deepwater or permafrost settings. Gas hydrate is also under investigation to determine how environmental change may affect these deposits.

  2. Health Issues for Gay Men: Prevention First

    Science.gov (United States)

    ... Lifestyle Adult health Understand important health issues for gay men and men who have sex with men — ... Staff All men face certain health risks. However, gay men and men who have sex with men ...

  3. Health Concerns for Gay and Lesbian Teens

    Science.gov (United States)

    ... Text Size Email Print Share Health Concerns for Gay and Lesbian Teens Page Content Article Body Sexual activity Most teens, whether they are gay, lesbian, bisexual , or straight, are not sexually active. ...

  4. Association of Gay and Lesbian Psychiatrists

    Science.gov (United States)

    ... Awards AGLP News Newsletter Archives Education Journal of Gay and Lesbian Mental Health GAP LGBT Online Curriculum ... an End to Harmful ‘Religious Freedom’ Laws...> WPA: Gay “Cures” Are Harmful And Don’t Work See ...

  5. Hydrates on tap: scientists say natural gas hydrates may be tough nut to crack

    Energy Technology Data Exchange (ETDEWEB)

    Mahoney, J.

    2001-12-01

    Gas hydrates are methane molecules trapped in cages of water molecules, yielding a substance with a slushy, sherbet-like consistency. Drilling for hydrates is similar to conventional oil and gas drilling, however, the secret to economic production still remains hidden. Hydrates exist in abundance in such places as deep ocean floor and below ground in some polar regions. The real challenge lies in producing gas from this resource, inasmuch as there is no existing technology for production of gas specifically from methane hydrates. This paper describes an international research program, involving a five-country partnership to spud the first of three wells into the permafrost of the Mackenzie River Delta in the Northwest Territories. The project, worth about $15 million, has brought together public funding and expertise from Japan, Germany, India as well as the Canadian and US Geological Surveys and the US Dept. of Energy in an effort to gain information on the production response of gas hydrates. The operator of the project is Japan Petroleum Exploration Company of Canada, a subsidiary of Japan National Oil Corporation. Since Japan is poor in domestic hydrocarbon resources, but is surrounded by deep water that contains potential for gas hydrates, Japan has a great deal riding on the success of this project. Germany and the United States are also very much interested. Current thinking is that gas is in contact with the hydrates and that it should be possible to develop a free gas reservoir as if it were a conventional deposit. As the free gas is drawn off, the pressure is reduced on the hydrates in contact with it , the hydrates dissociate from the gas and replenish the conventional reservoir. So far this is still only a theory, but it appears to be a sensible approach to hydrate production. 1 photo.

  6. Gas hydrate nucleation

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-12-31

    The overall aim of the project was to gain more knowledge about the kinetics of gas hydrate formation especially the early growth phase. Knowledge of kinetics of gas hydrate formation is important and measurements of gas hydrate particle size and concentration can contribute to improve this knowledge. An experimental setup for carrying out experimental studies of the nucleation and growth of gas hydrates has been constructed and tested. Multi wavelength extinction (MWE) was the experimental technique selected for obtaining particle diameter and concentration. The principle behind MWE is described as well as turbidity spectrum analysis that in an initial stage of the project was considered as an alternative experimental technique. Details of the experimental setup and its operation are outlined. The measuring cell consists of a 1 litre horizontal tube sustaining pressures up to 200 bar. Laser light for particle size determination can be applied through sapphire windows. A description of the various auxiliary equipment and of another gas hydrate cell used in the study are given. A computer program for simulation and analysis of gas hydrate experiments is based on the gas hydrate kinetics model proposed by Skovborg and Rasmussen (1993). Initial measurements showed that knowledge of the refractive index of gas hydrates was important in order to use MWE. An experimental determination of the refractive index of methane and natural gas hydrate is described. The test experiments performed with MWE on collectives of gas hydrate particles and experiments with ethane, methane and natural gas hydrate are discussed. Gas hydrate particles initially seem to grow mainly in size and at latter stages in number. (EG) EFP-94; 41 refs.

  7. Gas hydrate nucleation

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-12-31

    The overall aim of the project was to gain more knowledge about the kinetics of gas hydrate formation especially the early growth phase. Knowledge of kinetics of gas hydrate formation is important and measurements of gas hydrate particle size and concentration can contribute to improve this knowledge. An experimental setup for carrying out experimental studies of the nucleation and growth of gas hydrates has been constructed and tested. Multi wavelength extinction (MWE) was the experimental technique selected for obtaining particle diameter and concentration. The principle behind MWE is described as well as turbidity spectrum analysis that in an initial stage of the project was considered as an alternative experimental technique. Details of the experimental setup and its operation are outlined. The measuring cell consists of a 1 litre horizontal tube sustaining pressures up to 200 bar. Laser light for particle size determination can be applied through sapphire windows. A description of the various auxiliary equipment and of another gas hydrate cell used in the study are given. A computer program for simulation and analysis of gas hydrate experiments is based on the gas hydrate kinetics model proposed by Skovborg and Rasmussen (1993). Initial measurements showed that knowledge of the refractive index of gas hydrates was important in order to use MWE. An experimental determination of the refractive index of methane and natural gas hydrate is described. The test experiments performed with MWE on collectives of gas hydrate particles and experiments with ethane, methane and natural gas hydrate are discussed. Gas hydrate particles initially seem to grow mainly in size and at latter stages in number. (EG) EFP-94; 41 refs.

  8. Supramolecular Organization of Nonstoichiometric Drug Hydrates: Dapsone

    Science.gov (United States)

    Braun, Doris E.; Griesser, Ulrich J.

    2018-01-01

    The observed moisture- and temperature dependent transformations of the dapsone (4,4′-diaminodiphenyl sulfone, DDS) 0. 33-hydrate were correlated to its structure and the number and strength of the water-DDS intermolecular interactions. A combination of characterization techniques was used, including thermal analysis (hot-stage microscopy, differential scanning calorimetry and thermogravimetric analysis), gravimetric moisture sorption/desorption studies and variable humidity powder X-ray diffraction, along with computational modeling (crystal structure prediction and pair-wise intermolecular energy calculations). Depending on the relative humidity the hydrate contains between 0 and 0.33 molecules of water per molecule DDS. The crystal structure is retained upon dehydration indicating that DDS hydrate shows a non-stoichiometric (de)hydration behavior. Unexpectedly, the water molecules are not located in structural channels but at isolated-sites of the host framework, which is counterintuitively for a hydrate with non-stoichiometric behavior. The water-DDS interactions were estimated to be weaker than water-host interactions that are commonly observed in stoichiometric hydrates and the lattice energies of the isomorphic dehydration product (hydrate structure without water molecules) and (form III) differ only by ~1 kJ mol−1. The computational generation of hypothetical monohydrates confirms that the hydrate with the unusual DDS:water ratio of 3:1 is more stable than a feasible monohydrate structure. Overall, this study highlights that a deeper understanding of the formation of hydrates with non-stoichiometric behavior requires a multidisciplinary approach including suitable experimental and computational methods providing a firm basis for the development and manufacturing of high quality drug products. PMID:29520359

  9. The Prevalence of Lisping in Gay Men

    Science.gov (United States)

    Van Borsel, John; De Bruyn, Els; Lefebvre, Evelien; Sokoloff, Anouschka; De Ley, Sophia; Baudonck, Nele

    2009-01-01

    This study evaluated the stereotype that gay men lisp. Two clinicians who were unaware of the specific purpose of the study and the populations involved judged randomized audio-recordings of 175 gay males, 100 heterosexual males and 100 heterosexual females for the presence of lisping during reading of a standardized text. In the gay males a…

  10. Basics of development of gas hydrate deposits

    Energy Technology Data Exchange (ETDEWEB)

    Makogon, Yuri F.; Holditch, Stephen A.; Makogon, Taras Y.

    2005-07-01

    Natural gas hydrate deposits could possibly be an important energy resource during this century. However, many problems associated with producing these deposits must first be solved. The industry must develop new technologies to produce the gas, to forecast possible tectonic cataclysms in regions of gas hydrate accumulations, and to prevent damage to the environment. These global issues must be addressed by every company or country who wants to produce gas hydrate deposits. Cooperative research between industry and universities can lead to technology breakthroughs in coming years. This paper reviews the Messoyakha field and the Blake Ridge and Nankai areas to explain a methodology for estimating how much gas might be producible from gas hydrate deposits (GHDs) under various conditions. The Messoyakha field is located on land, while the Blake Ridge and Nankai areas are offshore. Messoyakha is the first and the only GHD where gas production from hydrates has reached commercial flow rates. The Blake Ridge GHD has been studied for 20 years and 11 wells have been drilled to collect gas-hydrate samples. The potential resources of gas (gas in place) from Blake Ridge is estimated at 37.7Oe10{sup 12} m{sup 3} (1.330 Tcf) in hydrate form and 19.3Oe10{sup 12}m{sup 3} (681 Bcf) [5] in free gas. To estimate how much of the potential resource can be produced we need a thorough understanding of both the geologic and the thermodynamic characteristics of the formations. (Author)

  11. Gas hydrate exploration activities in Korea

    Energy Technology Data Exchange (ETDEWEB)

    Keun-Pil Park, K.P. [Korea Inst. of Geoscience and Mineral Resources, Gas Hydrate R and D Organization, Ministry of Knowledge Economy, Yuseong-gu, Daejeon (Korea, Republic of)

    2008-07-01

    Korea's first gas hydrate research project was launched in 1996 to study the gas hydrate potential in the Ulleung Basin of the East Sea. It involved a series of laboratory experiments followed by a preliminary offshore seismic survey and regional reconnaissance geophysical and marine geological surveys. The bottom simulating reflector (BSR) was interpreted to show wide area distribution in the southern part of the Ulleung Basin, and its average burial depth was 187 m below the sea floor in the East Sea. A three-phase 10-year National Gas Hydrate Development Program was launched in 2004 to estimate the potential reserves in the East Sea. It will involve drilling to identify natural gas hydrates and to determine the most optimized production methods. Drilling sites were proposed based on five indicators that imply gas hydrate occurrence, notably BSR, gas vent, enhanced seismic reflection, acoustic blanking and gas seeping structure. The UBGH-X-01 gas hydrate expedition in the East Sea Ulleung Basin involved 5 logging while drilling (LWD) surveys at three high priority sites. One wire line logging was implemented at the site of the UBGH09. A total 334 m of non-pressurized conventional cores and 16 pressure cores were obtained in late 2007. The UBGH-X-01 was successfully completed, recovering many natural samples of gas hydrate from 3 coring sites in the East Sea. 7 refs., 12 figs.

  12. The hydration of slag, part 1: reaction models for blended cement

    NARCIS (Netherlands)

    Chen, Wei; Brouwers, Jos

    2007-01-01

    Reaction models are proposed to quantify the hydration products and to determine the composition of C–S–H from alkali-activated slags (AAS). Products of the slag hydration are first summarized from observations in literature. The main hydration products include C–S–H, hydrotalcite, hydrogarnet, AFm

  13. The hydration of slag, part 1: reaction models for alkali-activated slag

    NARCIS (Netherlands)

    Chen, Wei; Brouwers, H.J.H.

    2007-01-01

    Reaction models are proposed to quantify the hydration products and to determine the composition of C–S–H from alkali-activated slags (AAS). Products of the slag hydration are first summarized from observations in literature. The main hydration products include C–S–H, hydrotalcite, hydrogarnet, AFm

  14. Effects of obesity on body temperature in otherwise-healthy females when controlling hydration and heat production during exercise in the heat.

    Science.gov (United States)

    Adams, J D; Ganio, Matthew S; Burchfield, Jenna M; Matthews, Andy C; Werner, Rachel N; Chokbengboun, Amanda J; Dougherty, Erin K; LaChance, Alex A

    2015-01-01

    Previous studies investigating body temperature responses in obese individuals during exercise in the heat fail to control metabolic heat production or hydration status during exercise. To determine if there are differences in body temperature responses between obese and non-obese females when controlling metabolic heat production during exercise. Twenty healthy females, ten obese (43.5 ± 4.5 % fat, 77.5 ± 14.4 kg) and ten non-obese (26.3 ± 6.2 % fat, 53.7 ± 6.4 kg), cycled for 60 min in a warm environment (40 °C, 30 % humidity) at a work load that elicited either 300 W of metabolic heat production (fixed heat production; FHP) or 175 W/m(2) of skin surface area (body surface area, BSA). Before and during exercise, rectal temperature (T re), mean skin temperature (T sk), oxygen uptake (VO2), and sweat rate were measured. Fluid was provided throughout exercise so that euhydration was maintained throughout. In the FHP trial, when absolute heat production was similar between obese (287 ± 15 W) and non-obese (295 ± 18 W) individuals (P > 0.05), there were no differences at the end of exercise in T re (38.26 ± 0.40 vs. 38.30 ± 0.30 °C, respectively) or T sk (36.94 ± 1.65 vs. 35.85 ± 0.67 °C) (all P > 0.05). In the BSA trials, relative heat production was similar between obese and non-obese individuals (168 ± 8 vs. 176 ± 5 W/m(2), respectively; P > 0.05). Similar to the FHP trials, there were no differences between obese and non-obese T re (38.45 ± 0.33 vs. 38.08 ± 0.29 °C, respectively) or T sk (36.82 ± 1.04 vs. 36.11 ± 0.64 °C) at the end of exercise (all P > 0.05). When obese and non-obese females exercised at a fixed metabolic heat production and euhydration was maintained, there were no differences in body temperature between groups.

  15. General and gay-related racism experienced by Latino gay men.

    Science.gov (United States)

    Ibañez, Gladys E; Van Oss Marin, Barbara; Flores, Stephen A; Millett, Gregorio; Diaz, Rafael M

    2009-07-01

    Latino gay men report experiences of racial discrimination within and outside the gay community. This study focused on correlates of racism within general and gay contexts. Racism was assessed in a probability sample of 911 Latino gay men recruited from 3 U.S. cities. Factor analysis of the 10-item scale produced 2 factors: (a) General Racism Experiences, and (b) Racism Experiences in Gay Contexts. The scale and each factor showed adequate reliability and validity. Latino gay men with darker skin, more Indian features, more time in the United States, and low self-esteem reported more racism in both general and gay contexts. The authors examine the psychometric properties of a measure that assesses interpersonal racism among Latinos, report correlates of racism within a gay context, and provide an assessment tool for understanding the role of racism in the lives of Latino gay men.

  16. Hydration states of AFm cement phases

    Energy Technology Data Exchange (ETDEWEB)

    Baquerizo, Luis G., E-mail: luis.baquerizoibarra@holcim.com [Innovation, Holcim Technology Ltd., CH-5113 Holderbank (Switzerland); Matschei, Thomas [Innovation, Holcim Technology Ltd., CH-5113 Holderbank (Switzerland); Scrivener, Karen L. [Laboratory of Construction Materials, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne (Switzerland); Saeidpour, Mahsa; Wadsö, Lars [Building Materials, Lund University, Box 124, 221 000 Lund (Sweden)

    2015-07-15

    The AFm phase, one of the main products formed during the hydration of Portland and calcium aluminate cement based systems, belongs to the layered double hydrate (LDH) family having positively charged layers and water plus charge-balancing anions in the interlayer. It is known that these phases present different hydration states (i.e. varying water content) depending on the relative humidity (RH), temperature and anion type, which might be linked to volume changes (swelling and shrinkage). Unfortunately the stability conditions of these phases are insufficiently reported. This paper presents novel experimental results on the different hydration states of the most important AFm phases: monocarboaluminate, hemicarboaluminate, strätlingite, hydroxy-AFm and monosulfoaluminate, and the thermodynamic properties associated with changes in their water content during absorption/desorption. This data opens the possibility to model the response of cementitious systems during drying and wetting and to engineer systems more resistant to harsh external conditions.

  17. Thermal conductivity measurements in unsaturated hydrate-bearing sediments

    Science.gov (United States)

    Dai, Sheng; Cha, Jong-Ho; Rosenbaum, Eilis J.; Zhang, Wu; Seol, Yongkoo

    2015-08-01

    Current database on the thermal properties of hydrate-bearing sediments remains limited and has not been able to capture their consequential changes during gas production where vigorous phase changes occur in this unsaturated system. This study uses the transient plane source (TPS) technique to measure the thermal conductivity of methane hydrate-bearing sediments with various hydrate/water/gas saturations. We propose a simplified method to obtain thermal properties from single-sided TPS signatures. Results reveal that both volume fraction and distribution of the pore constituents govern the thermal conductivity of unsaturated specimens. Thermal conductivity hysteresis is observed due to water redistribution and fabric change caused by hydrate formation and dissociation. Measured thermal conductivity increases evidently when hydrate saturation Sh > 30-40%, shifting upward from the geometric mean model prediction to a Pythagorean mixing model. These observations envisage a significant drop in sediment thermal conductivity when residual hydrate/water saturation falls below ~40%, hindering further gas production.

  18. Supramolecular Organization of Nonstoichiometric Drug Hydrates: Dapsone

    Directory of Open Access Journals (Sweden)

    Doris E. Braun

    2018-02-01

    Full Text Available The observed moisture- and temperature dependent transformations of the dapsone (4,4′-diaminodiphenyl sulfone, DDS 0. 33-hydrate were correlated to its structure and the number and strength of the water-DDS intermolecular interactions. A combination of characterization techniques was used, including thermal analysis (hot-stage microscopy, differential scanning calorimetry and thermogravimetric analysis, gravimetric moisture sorption/desorption studies and variable humidity powder X-ray diffraction, along with computational modeling (crystal structure prediction and pair-wise intermolecular energy calculations. Depending on the relative humidity the hydrate contains between 0 and 0.33 molecules of water per molecule DDS. The crystal structure is retained upon dehydration indicating that DDS hydrate shows a non-stoichiometric (dehydration behavior. Unexpectedly, the water molecules are not located in structural channels but at isolated-sites of the host framework, which is counterintuitively for a hydrate with non-stoichiometric behavior. The water-DDS interactions were estimated to be weaker than water-host interactions that are commonly observed in stoichiometric hydrates and the lattice energies of the isomorphic dehydration product (hydrate structure without water molecules and (form III differ only by ~1 kJ mol−1. The computational generation of hypothetical monohydrates confirms that the hydrate with the unusual DDS:water ratio of 3:1 is more stable than a feasible monohydrate structure. Overall, this study highlights that a deeper understanding of the formation of hydrates with non-stoichiometric behavior requires a multidisciplinary approach including suitable experimental and computational methods providing a firm basis for the development and manufacturing of high quality drug products.

  19. Hydration study of ordinary portland cement in the presence of zinc ions

    Directory of Open Access Journals (Sweden)

    Monica Adriana Trezza

    2007-12-01

    Full Text Available Hydration products of Portland cement pastes, hydrated in water and in the presence of zinc ions were studied comparatively at different ages. Hydration products were studied by X ray diffractions (XRD and infrared spectroscopy (IR. Although IR is not frequently used in cement chemistry, it evidenced a new phase Ca(Zn(OH32. 2H2O formed during cement hydration in the presence of zinc. The significant retardation of early cement hydration in the presence of zinc is assessed in detail by differential calorimetry as a complement to the study carried out by IR and XRD, providing evidence that permits to evaluate the kinetic of the early hydration.

  20. Gayspeak: Gay Male & Lesbian Communication.

    Science.gov (United States)

    Chesebro, James W., Ed.

    In a departure from previous statistical studies, this book focuses on the social responses to homosexuality rather than on homosexual behavior itself. The essays in the book maintain that communication--how gay men and lesbians relate to one another as well as to heterosexuals--is the major factor that determines public opinion about…

  1. Beyond Gay-Straight Alliances

    Science.gov (United States)

    Sadowski, Michael

    2010-01-01

    Decades' worth of studies point to the importance of parental involvement in K-12 schooling. Yet when it comes to policies related to lesbian, gay, bisexual, and transgender (LGBT) students, families are often deliberately left out of the conversation, according to several leading experts in LGBT youth development. Even in schools where…

  2. Hydration rate of obsidian.

    Science.gov (United States)

    Friedman, I; Long, W

    1976-01-30

    The hydration rates of 12 obsidian samples of different chemical compositions were measured at temperatures from 95 degrees to 245 degrees C. An expression relating hydration rate to temperature was derived for each sample. The SiO(2) content and refractive index are related to the hydration rate, as are the CaO, MgO, and original water contents. With this information it is possible to calculate the hydration rate of a sample from its silica content, refractive index, or chemical index and a knowledge of the effective temperature at which the hydration occurred. The effective hydration temperature can be either measured or approximated from weather records. Rates have been calculated by both methods, and the results show that weather records can give a good approximation to the true EHT, particularly in tropical and subtropical climates. If one determines the EHT by any of the methods suggested, and also measures or knows the rate of hydration of the particular obsidian used, it should be possible to carry out absolute dating to +/- 10 percent of the true age over periods as short as several years and as long as millions of years.

  3. Deconstructing Concealed Gayness Text in The Film Negeri van Oranje: Critical Discourse Analysis

    Directory of Open Access Journals (Sweden)

    Heri Setiawan

    2018-02-01

    Full Text Available As one of the most popular creative cultural products, film sometimes speaks beyond what it presents. It is not always produced merely for entertainment purposes, but also to spread a certain ideology and represent a particular culture. Anchored in queer theory, this research looks at the Indonesian film, Negeri Van Oranje, which was chosen purposely to be analyzed using Fairclough’s critical discourse analysis model with an aim to deconstruct the concealed gayness text in the film. From the analysis, it was found that the gay scenes in the film try to tell its audience about the positions, feelings, challenges, and rejections that Indonesian gay people experience living amongst heteronormative surroundings. Some new notions about gay people’s life in Indonesia are extracted based on the analysis of the gay scenes in the film. The strategy of inserting gay content into a film nationally released in Indonesia is also revealed. The results of the analysis could be used to create a picture of what gay life looks like in Indonesia, a multicultural country that is well-known as the place in which the world’s largest Muslim population dwells.

  4. In-situ gas hydrate hydrate saturation estimated from various well logs at the Mount Elbert Gas Hydrate Stratigraphic Test Well, Alaska North Slope

    Science.gov (United States)

    Lee, M.W.; Collett, T.S.

    2011-01-01

    In 2006, the U.S. Geological Survey (USGS) completed detailed analysis and interpretation of available 2-D and 3-D seismic data and proposed a viable method for identifying sub-permafrost gas hydrate prospects within the gas hydrate stability zone in the Milne Point area of northern Alaska. To validate the predictions of the USGS and to acquire critical reservoir data needed to develop a long-term production testing program, a well was drilled at the Mount Elbert prospect in February, 2007. Numerous well log data and cores were acquired to estimate in-situ gas hydrate saturations and reservoir properties.Gas hydrate saturations were estimated from various well logs such as nuclear magnetic resonance (NMR), P- and S-wave velocity, and electrical resistivity logs along with pore-water salinity. Gas hydrate saturations from the NMR log agree well with those estimated from P- and S-wave velocity data. Because of the low salinity of the connate water and the low formation temperature, the resistivity of connate water is comparable to that of shale. Therefore, the effect of clay should be accounted for to accurately estimate gas hydrate saturations from the resistivity data. Two highly gas hydrate-saturated intervals are identified - an upper ???43 ft zone with an average gas hydrate saturation of 54% and a lower ???53 ft zone with an average gas hydrate saturation of 50%; both zones reach a maximum of about 75% saturation. ?? 2009.

  5. Conflict Management of Gay Couples' Relationship in Semarang

    OpenAIRE

    Putri Aprilina, Noni; Naryoso, Agus

    2017-01-01

    Gay people in Indonesia are still a minority. The low population of gays causes jealousy and possessiveness to be the gay nature feeling of gay with each other. They will be very angry if their partner see theyre dating someone else (Aditya, 2009). Based on the above phenomenon can be concluded that gays also experience conflict in the relationship they live. Conflict experienced by gay is different from one another. Some show conflict-related issues of jealousy, usually higher sexual jealous...

  6. Medical students’ attitudes toward gay men

    OpenAIRE

    Matharu, Kabir; Kravitz, Richard L; McMahon, Graham T; Wilson, Machelle D; Fitzgerald, Faith T

    2012-01-01

    Abstract Background Healthcare providers’ attitudes toward sexual minorities influence patient comfort and outcomes. This study characterized medical student attitudes toward gay men, focusing on behavior, personhood, gay civil rights, and male toughness. Methods A cross-sectional web-based anonymous survey was sent to medical students enrolled at the University of California, Davis (N = 371) with a response rate of 68%. Results Few respondents expressed negative attitudes toward gay men or w...

  7. First-principles elasticity of monocarboaluminate hydrates

    KAUST Repository

    Moon, J.

    2014-07-01

    The elasticity of monocarboaluminate hydrates, 3CaO·Al2O3·CaCO3·xH2O (x = 11 or 8), has been investigated by first-principles calculations. Previous experimental study revealed that the fully hydrated monocarboaluminate (x = 11) exhibits exceptionally low compressibility compared to other reported calcium aluminate hydrates. This stiff hydration product can contribute to the strength of concrete made with Portland cements containing calcium carbonates. In this study, full elastic tensors and mechanical properties of the crystal structures with different water contents (x = 11 or 8) are computed by first-principles methods based on density functional theory. The results indicate that the compressibility of monocarboaluminate is highly dependent on the water content in the interlayer region. The structure also becomes more isotropic with the addition of water molecules in this region. Since the monocarboaluminate is a key hydration product of limestone added cement, elasticity of the crystal is important to understand its mechanical impact on concrete. Besides, it is put forth that this theoretical calculation will be useful in predicting the elastic properties of other complex cementitous materials and the influence of ion exchange on compressibility.

  8. First-principles elasticity of monocarboaluminate hydrates

    KAUST Repository

    Moon, J.; Yoon, S.; Wentzcovitch, R. M.; Monteiro, P. J. M.

    2014-01-01

    The elasticity of monocarboaluminate hydrates, 3CaO·Al2O3·CaCO3·xH2O (x = 11 or 8), has been investigated by first-principles calculations. Previous experimental study revealed that the fully hydrated monocarboaluminate (x = 11) exhibits exceptionally low compressibility compared to other reported calcium aluminate hydrates. This stiff hydration product can contribute to the strength of concrete made with Portland cements containing calcium carbonates. In this study, full elastic tensors and mechanical properties of the crystal structures with different water contents (x = 11 or 8) are computed by first-principles methods based on density functional theory. The results indicate that the compressibility of monocarboaluminate is highly dependent on the water content in the interlayer region. The structure also becomes more isotropic with the addition of water molecules in this region. Since the monocarboaluminate is a key hydration product of limestone added cement, elasticity of the crystal is important to understand its mechanical impact on concrete. Besides, it is put forth that this theoretical calculation will be useful in predicting the elastic properties of other complex cementitous materials and the influence of ion exchange on compressibility.

  9. Ultrasonic sound speed of hydrating calcium sulphate hemihydrate; part 2, the correlation of sound velocity to hydration degree

    NARCIS (Netherlands)

    de Korte, A.C.J.; Brouwers, Jos; Fischer, H.B; Matthes, C.; Beuthan, C.

    2011-01-01

    In this article the sound velocity through a mix is correlated to the hydration degree of the mix. Models are presented predicting the sound velocity through fresh slurries and hardened products. These two states correspond to the starting and finishing point of the hydration process. The present

  10. Ultrasonic sound speed of hydrating calcium sulphate hemihydrate; Part 2, The correlation of sound velocity to hydration degree

    NARCIS (Netherlands)

    Korte, de A.C.J.; Brouwers, H.J.H.; Fischer, H.B.; Mattes, Chr.; Beutha, C.

    2011-01-01

    In this article the sound velocity through a mix is correlated to the hydration degree of the mix. Models are presented predicting the sound velocity through fresh slurries and hardened products. These two states correspond to the starting and finishing point of the hydration process. The present

  11. Geomechanical Performance of Hydrate-Bearing Sediment in Offshore Environments

    Energy Technology Data Exchange (ETDEWEB)

    Stephen Holditch; Tad Patzek; Jonny Rutqvist; George Moridis; Richard Plumb

    2008-03-31

    The objective of this multi-year, multi-institutional research project was to develop the knowledge base and quantitative predictive capability for the description of geomechanical performance of hydrate-bearing sediments (hereafter referred to as HBS) in oceanic environments. The focus was on the determination of the envelope of hydrate stability under conditions typical of those related to the construction and operation of offshore platforms. We have developed a robust numerical simulator of hydrate behavior in geologic media by coupling a reservoir model with a commercial geomechanical code. We also investigated the geomechanical behavior of oceanic HBS using pore-scale models (conceptual and mathematical) of fluid flow, stress analysis, and damage propagation. The objective of the UC Berkeley work was to develop a grain-scale model of hydrate-bearing sediments. Hydrate dissociation alters the strength of HBS. In particular, transformation of hydrate clusters into gas and liquid water weakens the skeleton and, simultaneously, reduces the effective stress by increasing the pore pressure. The large-scale objective of the study is evaluation of geomechanical stability of offshore oil and gas production infrastructure. At Lawrence Berkeley National Laboratory (LBNL), we have developed the numerical model TOUGH + Hydrate + FLAC3D to evaluate how the formation and disassociation of hydrates in seafloor sediments affects seafloor stability. Several technical papers were published using results from this model. LBNL also developed laboratory equipment and methods to produce realistic laboratory samples of sediments containing gas hydrates so that mechanical properties could be measured in the laboratory. These properties are required to run TOUGH + Hydrate + FLAC3D to evaluate seafloor stability issues. At Texas A&M University we performed a detailed literature review to determine what gas hydrate formation properties had been measured and reported in the literature. We

  12. Impact of welan gum on tricalcium aluminate–gypsum hydration

    International Nuclear Information System (INIS)

    Ma Lei; Zhao Qinglin; Yao Chukang; Zhou Mingkai

    2012-01-01

    The retarding effect of welan gum on tricalcium aluminate–gypsum hydration, as a partial system of ordinary Portland cement (OPC) hydration, was investigated with several methods. The tricalcium aluminate–gypsum hydration behavior in the presence or absence of welan gum was researched by field emission gun scanning electron microscopy, X-ray diffraction and zeta potential analysis. Meanwhile, we studied the surface electrochemical properties and adsorption characteristics of welan gum by utilizing a zeta potential analyzer and UV–VIS absorption spectrophotometer. By adding welan gum, the morphology change of ettringite and retardation of hydration stages in tricalcium aluminate–gypsum system was observed. Moreover, we detected the adsorption behavior and zeta potential inversion of tricalcium aluminate and ettringite, as well as a rapid decrease in the zeta potential of tricalcium aluminate–gypsum system. The reduction on nucleation rate of ettringite and hydration activity of C 3 A was also demonstrated. Thus, through the adsorption effect, welan gum induces a retarding behavior in tricalcium aluminate–gypsum hydration. Highlights: ► Adsorption characteristics of welan gum on C 3 A and ettringite have been studied. ► C 3 A–gypsum hydration behavior and the hydration products are examined in L/S = 3. ► Welan gum retards the process of C 3 A–gypsum hydration. ► The addition of welan gum changes the nucleation growth of ettringite.

  13. "Straight-acting gays": the relationship between masculine consciousness, anti-effeminacy, and negative gay identity.

    Science.gov (United States)

    Sánchez, Francisco J; Vilain, Eric

    2012-02-01

    Some gay men are preoccupied with traditional notions of masculinity and express negative feelings towards effeminate behavior in gay men. Various scholars have speculated that such attitudes by gay men reflect internalized negative feelings about being gay. Thus, we sought to assess the importance of masculinity among gay men, to compare their ideal versus perceived masculinity-femininity, to ask how gay men assess masculinity, and to test whether masculine consciousness and anti-effeminacy could predict negative feelings about being gay. Results from an online survey of 751 gay men in the United States (MAge=32.64 years, SD=11.94) showed that the majority rated masculinity for themselves and in a same-sex partner as important, and they ideally wished that their behavior was more masculine (Cohen's d=.42) and less feminine (d=.42) than they perceived it to be. Furthermore, one's behavior was more important than how one looks when assessing masculinity. A multiple regression analysis showed that the degree to which they were preoccupied with masculinity and expressed anti-effeminacy accounted for 30% of the variance in negative feelings about being gay. These finding further support the idea that masculinity is an important construct for gay men and that masculine consciousness and anti-effeminacy are related to negative feelings about being gay.

  14. Older Single Gay Men's Body Talk: Resisting and Rigidifying the Aging Discourse in the Gay Community.

    Science.gov (United States)

    Suen, Yiu Tung

    2017-01-01

    Previous research saw older gay men as subject to structural marginalization of ageism but yet possessing agency to interpret aging in diverse ways. I move beyond this duality, drawing on the theory of defensive othering to understand how older gay men live with the aging discourse in the gay community. Informed by grounded theory, I analyzed interviews with 25 self-identified single gay men aged 50 or above in England inductively. It emerged that many older gay men found it difficult to escape the discourse that marginalizes the aging body. Even when they argued they were the exception and "looked good," they were discursively producing a two-tier system: they themselves as the "good older gay men," as opposed to the other "bad older gay men," who "had given up." Such a defensive othering tactic seemingly allowed them to resist age norms from applying to them personally, but unintentionally reinforced an ageist discourse.

  15. Recycle of fired phosphogypsum waste product as a cement replacement and its role on the hydration and strength development of pastes

    International Nuclear Information System (INIS)

    Tantawi, S.H.

    2005-01-01

    The effect of Partially up to fully substituted of treated phosphogypsum x(PG) for natural gypsum on the physico- mechanical as well as kinetic of hydration of ordinary Portland cement has been discussed . The results show that by increasing PG % the water to cement ratio decreased while the initial and final setting times increased So PG acts as a retarder and water reducer . The retardation effect may be attributed to formation of ettringite layer which formed on the surface of C3A of cement pastes . The chemically combined water, free lime content and bulk density increased with curing time and with PG content for all cement pastes up to 90 days due to increasing of the rate of hydration. The compressive strength increased by increasing of PG % due to formation of anhydrite , changes in major oxides content and reduction of impurities . X-Ray Diffraction, SEM and DTA of some samples have been studied

  16. A Double-Blind, Randomised Study Comparing the Skin Hydration and Acceptability of Two Emollient Products in Atopic Eczema Patients with Dry Skin

    OpenAIRE

    Djokic-Gallagher, Jasmina; Rosher, Phil; Oliveira, Gabriela; Walker, Jennine

    2017-01-01

    Introduction Healthcare professionals tend to recommend emollients based primarily on patient/consumer preference and cost, with cheaper options assumed to be therapeutically equivalent. The aim of this study was therefore to compare the effects on skin hydration of two emollients prescribed in the UK, Doublebase Dayleve? gel (DELP) and a cheaper alternative, Zerobase Emollient? cream (ZBC). Methods This was a single-centre, randomised, double-blind, concurrent bi-lateral (within-patient) com...

  17. The "Marital" Liaisons of Gay Men.

    Science.gov (United States)

    Harry, Joseph

    1979-01-01

    Reports research on the nature of enduring sexual liaisons among homosexual men. Such relationships vary widely and may be subinstitutional adaptions to lack of community support. Gay men committed to the heterosexual world were less likely to enter enduring relationships. Open marriage is the more enduring form of gay male liaisons. (Author)

  18. Stereotypes of Older Lesbians and Gay Men

    Science.gov (United States)

    Wright, Sara L.; Canetto, Silvia Sara

    2009-01-01

    This study examined stereotypes of older lesbians and gay men. Key findings are that older lesbians and gay men were perceived as similar to older heterosexual women and men with regard to aging stereotypes, such as being judicious. At the same time, sexual minorities were targets of unique stereotypes. Consistent with the implicit inversion…

  19. Personality of Polish gay men and women

    Directory of Open Access Journals (Sweden)

    Marcin Kwiatkowski

    2015-12-01

    Full Text Available Background Sexuality is a part of one’s identity and personality that is shaped under the influence of biological and environmental factors and interactions with society. The results of research conducted so far and concerning the personality traits of gay men and women are not consistent, and only a small number of them concern the Polish population. Hence the objective of the present research was to provide personality profiles of men and women with different sexual orientations. Participants and procedure The participants (N = 346 included 84 gay women, 82 gay men, 95 heterosexual women and 85 heterosexual men. The following measures were used: a survey developed by the author, the Kinsey Scale, the EPQ-R (Eysenck Personality Questionnaire Revised adapted by Brzozowski and Drwal (1995, and the Sixteen-factor Personality Questionnaire of Cattell adapted by Nowakowska (1970. Results The results support the hypothesis that gay women and heterosexual men share similar personality traits, while gay men have more diverse traits, similar to the traits typical for heterosexual women and men. In particular, personalities of gay men are described by such traits as progressive attitude, independence, or willingness to take risks, which means traits linked to factor Q1. The highest values of that factor are observable in the case of gay men, as compared to gay women, and also in comparison with heterosexual men and women. Conclusions Sexual orientation is responsible for differences in personality traits of the studied group to a greater extent than their biological sex.

  20. Gay and Lesbian Scene in Metelkova

    Directory of Open Access Journals (Sweden)

    Nataša Velikonja

    2013-09-01

    Full Text Available The article deals with the development of the gay and lesbian scene in ACC Metelkova, while specifying the preliminary aspects of establishing and building gay and lesbian activism associated with spatial issues. The struggle for space or occupying public space is vital for the gay and lesbian scene, as it provides not only the necessary socializing opportunities for gays and lesbians, but also does away with the historical hiding of homosexuality in the closet, in seclusion and silence. Because of their autonomy and long-term, continuous existence, homo-clubs at Metelkova contributed to the consolidation of the gay and lesbian scene in Slovenia and significantly improved the opportunities for cultural, social and political expression of gays and lesbians. Such a synthesis of the cultural, social and political, further intensified in Metelkova, and characterizes the gay and lesbian community in Slovenia from the very outset of gay and lesbian activism in 1984. It is this long-term synthesis that keeps this community in Slovenia so vital and politically resilient.

  1. Planned gay father families in kinship arrangements

    NARCIS (Netherlands)

    Bos, H.H.M.W.

    2010-01-01

    The current study examined whether there are differences between gay father families (n = 36) and heterosexual families (n = 36) on father-child relationship, fathers' experiences of parental stress and children's wellbeing. The gay fathers in this study all became parents while in same-sex

  2. A Gay Bibliography: Fifth Edition, Summer 1975.

    Science.gov (United States)

    American Library Association Social Responsibilities Round Table.

    This selective nonfiction bibliography features materials that present or support positive views of the gay experience, that help in understanding a gay-related issue, or that have special historical value. Listed are 200 nonfiction items: books, pamphlets, articles, periodicals, audiovisuals, directories,and other bibliographies. Complete…

  3. The bimolecular reaction of radiolysis product of hydrated electron at temperature up to 473K; Reaksi bimolekular antar produk radiolisis elektron terhidrasi pada temperatur hingga 473K

    Energy Technology Data Exchange (ETDEWEB)

    Sunaryo, G R [Reactor Safety Technology Research Centre, National Atomic Energy Agency, Serpong (Indonesia)

    1996-06-01

    Rate constant from the bimolecular reaction of hydrated electron was determined by using radiolysis method. The methanol solution with concentration of 5 x 10{sup -2} dm{sup 3} mol{sup -1} was used as a scavenger of H and OH radicals. The pH was kept by adding the buffer solution of 1.0 x 10{sup -3} dm{sup 3} mol{sup -1} Na{sub 2}HPO{sub 4} + 1.0 x 10{sup 4} dm{sup 3} mol{sup -1} NaH{sub 2}PO{sub 4}. The irradiation was done by using the electron beam which come from linear accelerator 28 MeV with pulse width 10ns and dose of 80 Gy per pulse. The absorbance of hydrated electron was observed at wavelength of 824 nm. By using the kinetic equation the rate reaction constants were obtained. The bimolecular reaction of hydrated electron increase with temperature up to 423K. The activation energy was 19.3 kJ mol{sup -1} and the 2 k (298K) was 1.1 x 10{sup 10} dm{sup 3} mol{sup -1}. Then this bimolecular reaction decrease at temperature higher than 423K and the rate reaction constant at 473K almost similar with that at 298K. (author)

  4. Well log characterization of natural gas-hydrates

    Science.gov (United States)

    Collett, Timothy S.; Lee, Myung W.

    2012-01-01

    controlling the formation and occurrence of gas hydrate in nature along with data on gas-hydrate reservoir properties (i.e., porosities and permeabilities) needed to accurately predict gas production rates for various gas-hydrate production schemes.

  5. Portland cement hydration in the presence of admixtures: black gram pulse and superplasticizer

    Directory of Open Access Journals (Sweden)

    Viveka Nand Dwivedi

    2008-12-01

    Full Text Available Effect of admixtures such as black gram pulse (BGP and sulfonated naphthalene based superplasticizer (SP on the hydration of Portland cement has been studied. The hydration characteristics of OPC in the presence of BGP and SP were studied with the help of non evaporable water content determinations, calorimetric method, Mössbauer spectroscopic and atomic force microscopic techniques. Results have shown that both BGP and SP get adsorbed at the surface of cement and its hydration products. The hydration of Portland cement is retarded in the presence of both the admixtures and nanosize hydration products are formed.

  6. A textual analysis of male gayness in Nakanjani Sibiya's novel ...

    African Journals Online (AJOL)

    ... represents gay images that are in agreement with the 1996 Constitution of South Africa, which protects the rights of gay people. The analysis of male gayness is situated within the theoretical framework of intercultural communication. Intercultural communication theory regards gay identities as microcultures or subcultures ...

  7. "Nothing Has Stopped Me. I Keep Going:" Black Gay Narratives

    Science.gov (United States)

    Bartone, Michael D.

    2017-01-01

    Are being Black and gay problematic in the United States? Are Black gay youth "suffering" with these two intersecting identities? Traditional Eurocentric epistemologies would have one believe that Black males, Black gay males, and gay males (liminal groups) are suffering, rarely acknowledging those successfully navigating through…

  8. Hydrate Phase Assemblages in Blends of Ye'elimite and Gypsum with Alite and Belite

    DEFF Research Database (Denmark)

    Pedersen, Malene Thostrup; Skibsted, Jørgen

    2016-01-01

    Calcium sulpho-aluminate (CSA) cements all contain ye’elimite, either as the main phase or in intermediate amounts, while they differ in their content of accessory phases. Belite is the main phase in most CSA cements, however, alite - CSA cements have been produced. The hydrate phases formed during...... and hydration kinetics. The improved understanding of the hydrate phase assemblages as well as the hydration kinetics for the model systems will form the fundamental basis for further optimizations of blended systems including ye’elimite with the aim of maximizing the reaction degree of the main clinker phases...... hydration of CSA cements depend on the type of CSA cement and the amount of gypsum added. The hydration reactions of the main phases are by themselves well documented, whereas the simultaneous hydration of CSA cement components is not fully understood in terms of hydration products and kinetics. To further...

  9. Pedophilia and the gay movement.

    Science.gov (United States)

    Sandfort, T

    A history of literature and views existing within the COC (Cultural and Recreational Center), the major Dutch organization of homosexual men and women, regarding pedophilia and its relationship to homosexuality are discussed, beginning with definite separation between the pedophile and homosexual identities and ending with an abolishment of oppression towards pedophilia, for which the COC is in part responsible. The article argues that the homosexual identify is by no means a "constant" but a fluid identity, based on societal views and conditions. By accepting pedophilia, the COC hopefully will broaden the idea of the gay identity.

  10. Tswanarising global gayness: the 'unAfrican' argument, Western gay media imagery, local responses and gay culture in Botswana.

    Science.gov (United States)

    McAllister, John

    2013-01-01

    This paper is a strategic intervention in the debate over the value of globalised gay identity for emerging sexual minority communities in the South. Focusing on self-identifying gay men in Botswana using semi-structured interviews, it explores their views of what characterises 'modern gay culture' and relates these to international media clichés of a glamorous, stylish, hedonistic gayness. I argue that identifying with what is so visibly a Western image of gayness exposes sexual minority communities to the most dangerous of the justifications for homophobia in Africa, the argument that sexual dissidence is a neo-colonial conspiracy to subvert 'African values'. The 'unAfrican' argument has to be taken very seriously, not only because it taps into the intense, conflicted emotions at the heart of the post-colonial condition, but also because it contains an undeniable germ of truth. This poses a dilemma, since global gay discourses, including the media clichés, are an important source of inspiration for African sexual minorities. A communication activism strategy is proposed to undermine the unAfrican argument by cultivating and asserting the 'tswanarisation' of gay culture in Botswana that is already taking place. A similar strategy may also be effective in other African societies.

  11. Maximum Recoverable Gas from Hydrate Bearing Sediments by Depressurization

    KAUST Repository

    Terzariol, Marco; Goldsztein, G.; Santamarina, Carlos

    2017-01-01

    financial analyses; results highlight the need for innovative production strategies in order to make hydrate accumulations an economically-viable energy resource. Horizontal directional drilling and multi-wellpoint seafloor dewatering installations may lead

  12. Gay men seeking surrogacy to achieve parenthood.

    Science.gov (United States)

    Norton, Wendy; Hudson, Nicky; Culley, Lorraine

    2013-09-01

    Assisted reproduction technologies have developed at an extraordinary rate in recent years. This, combined with the changing landscape of legal, technical and social possibilities, enables gay men to consider their options for fatherhood as new opportunities emerge for them to create families. Media coverage of gay celebrities embracing surrogacy as a way of having a family and high-profile legal cases have raised awareness of surrogacy across the world. However, gay fatherhood achieved through assisted reproduction is a highly under-researched area, both in the UK and internationally. The research that currently exists on gay fatherhood is largely related to gay men who become parents through processes such as adoption and fostering and children conceived through previous heterosexual relationships. Much of this evidence has centred on parenting experiences, the outcomes for children or the legal perspectives. This paper outlines the different types of surrogacy and the legal issues facing gay men who choose this route to parenthood, summarizes the limited research on gay men and surrogacy and discusses gaps in the current knowledge base. Copyright © 2013 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.

  13. India National Gas Hydrate Program Expedition 02 Technical Contributions

    Science.gov (United States)

    Collett, T. S.; Kumar, P.; Shukla, K. M.; Nagalingam, J.; Lall, M. V.; Yamada, Y.; Schultheiss, P. J.; Holland, M.; Waite, W. F.

    2017-12-01

    The National Gas Hydrate Program Expedition 02 (NGHP-02) was conducted from 3-March-2015 to 28-July-2015 off the eastern coast of India. The primary objective of this expedition was the exploration and discovery of highly saturated gas hydrate occurrences in sand reservoirs that would be targets of future production testing. The first 2 months of the expedition were dedicated to logging while drilling (LWD) operations with a total of 25 holes being drilled and logged. The next 3 months were dedicated to coring operations at 10 of the most promising sites. NGHP-02 downhole logging, coring and formation pressure testing have confirmed the presence of large, highly saturated, gas hydrate accumulations in coarse-grained sand-rich depositional systems throughout the Krishna-Godavari Basin within the regions defined during NGHP-02 as Area-B, Area-C, and Area-E. The nature of the discovered gas hydrate occurrences closely matched pre-drill predictions, confirming the project developed depositional models for the sand-rich depositional facies in the Krishna-Godavari and Mahanadi Basins. The existence of a fully developed gas hydrate petroleum system was established in Area-C of the Krishna-Godavari Basin with the discovery of a large slope-basin interconnected depositional system, including a sand-rich, gas-hydrate-bearing channel-levee prospect at Sites NGHP-02-08 and -09. The acquisition of closely spaced LWD and core holes in the Area-B L1 Block gas hydrate accumulation have provided one of the most complete three-dimensional petrophysical-based views of any known gas hydrate reservoir system in the world. It was concluded that Area-B and Area-C in the area of the greater Krishna-Godavari Basin contain important world-class gas hydrate accumulations and represent ideal sites for consideration of future gas hydrate production testing.

  14. Sport fans' impressions of gay male athletes.

    Science.gov (United States)

    Campbell, Jamonn; Cothren, Denise; Rogers, Ross; Kistler, Lindsay; Osowski, Anne; Greenauer, Nathan; End, Christian

    2011-01-01

    The purpose of this study was to examine sport fans' impressions of gay male athletes. Participants formed impressions of a fictional athlete from their favorite team after reading a short scenario about the player. The scenarios described the athlete as being gay or straight, and either becoming a distraction or not causing a distraction to the team. While males' ratings of the athlete did not significantly differ, female fans formed significantly more positive impressions of the gay male player than the straight athlete. These results are discussed in terms of the ingroup bias and the shifting culture of homophobia in sport.

  15. A new aluminium-hydrate species in hydrated Portland cements characterized by 27Al and 29Si MAS NMR spectroscopy

    International Nuclear Information System (INIS)

    Andersen, Morten Daugaard; Jakobsen, Hans J.; Skibsted, Jorgen

    2006-01-01

    Recent 27 Al MAS NMR studies of hydrated Portland cements and calcium-silicate-hydrate (C-S-H) phases have shown a resonance from Al in octahedral coordination, which cannot be assigned to the well-known aluminate species in hydrated Portland cements. This resonance, which exhibits the isotropic chemical shift δ iso = 5.0 ppm and the quadrupole product parameter P Q = 1.2 MHz, has been characterized in detail by 27 Al MAS and 27 Al{ 1 H} CP/MAS NMR for different hydrated white Portland cements and C-S-H phases. These experiments demonstrate that the resonance originates from an amorphous or disordered aluminate hydrate which contains Al(OH) 6 3- or O x Al(OH) 6-x (3+x)- units. The formation of the new aluminate hydrate is related to the formation of C-S-H at ambient temperatures, however, it decomposes by thermal treatment at temperatures of 70-90 o C. From the experiments in this work it is proposed that the new aluminate hydrate is either an amorphous/disordered aluminate hydroxide or a calcium aluminate hydrate, produced as a separate phase or as a nanostructured surface precipitate on the C-S-H phase. Finally, the possibilities of Al 3+ for Ca 2+ substitution in the principal layers and interlayers of the C-S-H structure are discussed

  16. A prediction method of natural gas hydrate formation in deepwater gas well and its application

    Directory of Open Access Journals (Sweden)

    Yanli Guo

    2016-09-01

    Full Text Available To prevent the deposition of natural gas hydrate in deepwater gas well, the hydrate formation area in wellbore must be predicted. Herein, by comparing four prediction methods of temperature in pipe with field data and comparing five prediction methods of hydrate formation with experiment data, a method based on OLGA & PVTsim for predicting the hydrate formation area in wellbore was proposed. Meanwhile, The hydrate formation under the conditions of steady production, throttling and shut-in was predicted by using this method based on a well data in the South China Sea. The results indicate that the hydrate formation area decreases with the increase of gas production, inhibitor concentrations and the thickness of insulation materials and increases with the increase of thermal conductivity of insulation materials and shutdown time. Throttling effect causes a plunge in temperature and pressure in wellbore, thus leading to an increase of hydrate formation area.

  17. Characterization of un-hydrated and hydrated BioAggregate™ and MTA Angelus™.

    Science.gov (United States)

    Camilleri, J; Sorrentino, F; Damidot, D

    2015-04-01

    high calcium ion release early, which was maintained over the 28-day period as opposed to MTA Angelus, which demonstrated low early calcium ion release which increased as the material aged. The mineralogical composition of BioAggregate was different to MTA Angelus. As opposed to MTA Angelus, BioAggregate did not contain aluminium and contained additives such as calcium phosphate and silicon dioxide. As a consequence, BioAggregate reacted more slowly and formation of calcium hydroxide and leaching of calcium ions in solution were not evident as the material aged. The additives in BioAggregate modify the kinetics and the end products of hydration. Although newer generation tricalcium silicate-based materials contain similar constituents to MTA, they do not undergo the same setting reactions, and thus, their clinical performance will not be comparable to that of MTA.

  18. Maximum Recoverable Gas from Hydrate Bearing Sediments by Depressurization

    KAUST Repository

    Terzariol, Marco

    2017-11-13

    The estimation of gas production rates from hydrate bearing sediments requires complex numerical simulations. This manuscript presents a set of simple and robust analytical solutions to estimate the maximum depressurization-driven recoverable gas. These limiting-equilibrium solutions are established when the dissociation front reaches steady state conditions and ceases to expand further. Analytical solutions show the relevance of (1) relative permeabilities between the hydrate free sediment, the hydrate bearing sediment, and the aquitard layers, and (2) the extent of depressurization in terms of the fluid pressures at the well, at the phase boundary, and in the far field. Close form solutions for the size of the produced zone allow for expeditious financial analyses; results highlight the need for innovative production strategies in order to make hydrate accumulations an economically-viable energy resource. Horizontal directional drilling and multi-wellpoint seafloor dewatering installations may lead to advantageous production strategies in shallow seafloor reservoirs.

  19. Overview: Nucleation of clathrate hydrates.

    Science.gov (United States)

    Warrier, Pramod; Khan, M Naveed; Srivastava, Vishal; Maupin, C Mark; Koh, Carolyn A

    2016-12-07

    Molecular level knowledge of nucleation and growth of clathrate hydrates is of importance for advancing fundamental understanding on the nature of water and hydrophobic hydrate formers, and their interactions that result in the formation of ice-like solids at temperatures higher than the ice-point. The stochastic nature and the inability to probe the small length and time scales associated with the nucleation process make it very difficult to experimentally determine the molecular level changes that lead to the nucleation event. Conversely, for this reason, there have been increasing efforts to obtain this information using molecular simulations. Accurate knowledge of how and when hydrate structures nucleate will be tremendously beneficial for the development of sustainable hydrate management strategies in oil and gas flowlines, as well as for their application in energy storage and recovery, gas separation, carbon sequestration, seawater desalination, and refrigeration. This article reviews various aspects of hydrate nucleation. First, properties of supercooled water and ice nucleation are reviewed briefly due to their apparent similarity to hydrates. Hydrate nucleation is then reviewed starting from macroscopic observations as obtained from experiments in laboratories and operations in industries, followed by various hydrate nucleation hypotheses and hydrate nucleation driving force calculations based on the classical nucleation theory. Finally, molecular simulations on hydrate nucleation are discussed in detail followed by potential future research directions.

  20. Formation of submarine gas hydrates

    Energy Technology Data Exchange (ETDEWEB)

    Soloviev, V.; Ginsburg, G.D. (Reserch Institute of Geology and Mineral Resources of the Ocean ' ' VNII Okeangeologia' ' , St. Petersburg (Russian Federation))

    1994-03-01

    Submarine gas hydrates have been discoverd in the course of deep-sea drilling (DSDP and ODP) and bottom sampling in many offshore regions. This paper reports on expeditions carried out in the Black, Caspian and Okhotsk Seas. Gas hydrate accumulations were discovered and investigated in all these areas. The data and an analysis of the results of the deep-sea drilling programme suggest that the infiltration of gas-bearing fluids is a necessary condition for gas hydrate accumulation. This is confirmed by geological observations at three scale levels. Firstly, hydrates in cores are usually associated with comparatively coarse-grained, permeable sediments as well as voids and fractures. Secondly, hydrate accumulations are controlled by permeable geological structures, i.e. faults, diapirs, mud volcanos as well as layered sequences. Thirdly, in the worldwide scale, hydrate accumulations are characteristic of continental slopes and rises and intra-continental seas where submarine seepages also are widespread. Both biogenic and catagenic gas may occur, and the gas sources may be located at various distances from the accumulation. Gas hydrates presumably originate from water-dissolved gas. The possibility of a transition from dissolved gas into hydrate is confirmed by experimental data. Shallow gas hydrate accumulations associated with gas-bearing fluid plumes are the most convenient features for the study of submarine hydrate formation in general. These accumulations are known from the Black, Caspian and Okhotsk Seas, the Gulf of Mexico and off northern California. (au) (24 refs.)

  1. Overview: Nucleation of clathrate hydrates

    Science.gov (United States)

    Warrier, Pramod; Khan, M. Naveed; Srivastava, Vishal; Maupin, C. Mark; Koh, Carolyn A.

    2016-12-01

    Molecular level knowledge of nucleation and growth of clathrate hydrates is of importance for advancing fundamental understanding on the nature of water and hydrophobic hydrate formers, and their interactions that result in the formation of ice-like solids at temperatures higher than the ice-point. The stochastic nature and the inability to probe the small length and time scales associated with the nucleation process make it very difficult to experimentally determine the molecular level changes that lead to the nucleation event. Conversely, for this reason, there have been increasing efforts to obtain this information using molecular simulations. Accurate knowledge of how and when hydrate structures nucleate will be tremendously beneficial for the development of sustainable hydrate management strategies in oil and gas flowlines, as well as for their application in energy storage and recovery, gas separation, carbon sequestration, seawater desalination, and refrigeration. This article reviews various aspects of hydrate nucleation. First, properties of supercooled water and ice nucleation are reviewed briefly due to their apparent similarity to hydrates. Hydrate nucleation is then reviewed starting from macroscopic observations as obtained from experiments in laboratories and operations in industries, followed by various hydrate nucleation hypotheses and hydrate nucleation driving force calculations based on the classical nucleation theory. Finally, molecular simulations on hydrate nucleation are discussed in detail followed by potential future research directions.

  2. Molecular analysis of petroleum derived compounds that adsorb onto gas hydrate surfaces

    International Nuclear Information System (INIS)

    Borgund, Anna E.; Hoiland, Sylvi; Barth, Tanja; Fotland, Per; Askvik, Kjell M.

    2009-01-01

    Field observations have shown that some streams of water, gas and crude oil do not form gas hydrate plugs during petroleum production even when operating within thermodynamic conditions for hydrate formation. Also, when studied under controlled laboratory conditions, some oils are found to form hydrate dispersed systems whereas others form plugs. Oils with low tendency to form hydrate plugs are believed to contain natural hydrate plug inhibiting components (NICs) that adsorb onto the hydrate surface, making them less water-wet and preventing the particles from agglomerating into large hydrate clusters. The molecular structure of the NICs is currently unknown. In this work, hydrate adsorbing components were extracted from crude oils using freon hydrates as an extraction phase. The fractions were found to be enriched in polar material, and more polar material is associated with hydrates generated in biodegraded crude oils than in non-biodegraded oils. Various fractionation schemes and analytical techniques have been applied in the search for molecular characterisation. The average molecular weights were found to be approximately 500 g/mole. GC-MS chromatograms show a large UCM (Unresolved Complex Mixture). Thus, GC-MS has a limited potential for identification of compounds. A commercial biosurfactant was used as a model compound in the search for similar structures in the extracts. The results from analysis of the hydrate adsorbing components suggest that the type and structure are more important for hydrate morphology than the amount of material adsorbed.

  3. Advanced Gas Hydrate Reservoir Modeling Using Rock Physics

    Energy Technology Data Exchange (ETDEWEB)

    McConnell, Daniel

    2017-12-30

    Prospecting for high saturation gas hydrate deposits can be greatly aided with improved approaches to seismic interpretation and especially if sets of seismic attributes can be shown as diagnostic or direct hydrocarbon indicators for high saturation gas hydrates in sands that would be of most interest for gas hydrate production.

    A large 3D seismic data set in the deep water Eastern Gulf of Mexico was screened for gas hydrates using a set of techniques and seismic signatures that were developed and proven in the Central deepwater Gulf of Mexico in the DOE Gulf of Mexico Joint Industry Project JIP Leg II in 2009 and recently confirmed with coring in 2017.

    A large gas hydrate deposit is interpreted in the data where gas has migrated from one of the few deep seated faults plumbing the Jurassic hydrocarbon source into the gas hydrate stability zone. The gas hydrate deposit lies within a flat-lying within Pliocene Mississippi Fan channel that was deposited outboard in a deep abyssal environment. The uniform architecture of the channel aided the evaluation of a set of seismic attributes that relate to attenuation and thin-bed energy that could be diagnostic of gas hydrates. Frequency attributes derived from spectral decomposition also proved to be direct hydrocarbon indicators by pseudo-thickness that could be only be reconciled by substituting gas hydrate in the pore space. The study emphasizes that gas hydrate exploration and reservoir characterization benefits from a seismic thin bed approach.

  4. Becoming Gay Fathers through Transnational Commercial Surrogacy

    DEFF Research Database (Denmark)

    Petersen, Michael Nebeling

    2018-01-01

    Based on eight interviews with Danish gay male couples and one gayman, who had or were planning to become fathers through transnationalcommercial surrogacy, I examine the ways the men form familysubjectivities between traditional kinship patterns and fundamentally newforms of kinship and family....... Arguing that class, mobility, and privilegeshould also be understood as relational and negotiated positions, I showthat gay men engaged in surrogacy must be understood as more flexibleand differentiated. Second, I show how kinship as synonymous withbiogenetic relatedness is supplemented by notions...

  5. Gas hydrate cool storage system

    Science.gov (United States)

    Ternes, M.P.; Kedl, R.J.

    1984-09-12

    The invention presented relates to the development of a process utilizing a gas hydrate as a cool storage medium for alleviating electric load demands during peak usage periods. Several objectives of the invention are mentioned concerning the formation of the gas hydrate as storage material in a thermal energy storage system within a heat pump cycle system. The gas hydrate was formed using a refrigerant in water and an example with R-12 refrigerant is included. (BCS)

  6. THERMODYNAMIC MODEL OF GAS HYDRATES

    OpenAIRE

    Недоступ, В. И.; Недоступ, О. В.

    2015-01-01

    The interest to gas hydrates grows last years. Therefore working out of reliable settlement-theoretical methods of definition of their properties is necessary. The thermodynamic model of gas hydrates in which the central place occupies a behaviour of guest molecule in cell is described. The equations of interaction of molecule hydrate formative gas with cell are received, and also an enthalpy and energy of output of molecule from a cell are determined. The equation for calculation of thermody...

  7. Wedding Imagery and Public Support for Gay Marriage.

    Science.gov (United States)

    Brewer, Paul R; Wilson, David C; Habegger, Michael

    2016-08-01

    This study uses an experiment embedded in a large, nationally representative survey to test whether exposure to imagery of a gay or lesbian couple's wedding influences support for gay marriage. It also tests whether any such effects depend on the nature of the image (gay or lesbian couple, kissing or not) and viewer characteristics (sex, age, race, education, religion, and ideology). Results show that exposure to imagery of a gay couple kissing reduced support for gay marriage relative to the baseline. Other image treatments (gay couple not kissing, lesbian couple kissing, lesbian couple not kissing) did not significantly influence opinion.

  8. Balancing Accuracy and Computational Efficiency for Ternary Gas Hydrate Systems

    Science.gov (United States)

    White, M. D.

    2011-12-01

    Geologic accumulations of natural gas hydrates hold vast organic carbon reserves, which have the potential of meeting global energy needs for decades. Estimates of vast amounts of global natural gas hydrate deposits make them an attractive unconventional energy resource. As with other unconventional energy resources, the challenge is to economically produce the natural gas fuel. The gas hydrate challenge is principally technical. Meeting that challenge will require innovation, but more importantly, scientific research to understand the resource and its characteristics in porous media. Producing natural gas from gas hydrate deposits requires releasing CH4 from solid gas hydrate. The conventional way to release CH4 is to dissociate the hydrate by changing the pressure and temperature conditions to those where the hydrate is unstable. The guest-molecule exchange technology releases CH4 by replacing it with a more thermodynamically stable molecule (e.g., CO2, N2). This technology has three advantageous: 1) it sequesters greenhouse gas, 2) it releases energy via an exothermic reaction, and 3) it retains the hydraulic and mechanical stability of the hydrate reservoir. Numerical simulation of the production of gas hydrates from geologic deposits requires accounting for coupled processes: multifluid flow, mobile and immobile phase appearances and disappearances, heat transfer, and multicomponent thermodynamics. The ternary gas hydrate system comprises five components (i.e., H2O, CH4, CO2, N2, and salt) and the potential for six phases (i.e., aqueous, liquid CO2, gas, hydrate, ice, and precipitated salt). The equation of state for ternary hydrate systems has three requirements: 1) phase occurrence, 2) phase composition, and 3) phase properties. Numerical simulation of the production of geologic accumulations of gas hydrates have historically suffered from relatively slow execution times, compared with other multifluid, porous media systems, due to strong nonlinearities and

  9. Offsetting Risks: High School Gay-Straight Alliances and Lesbian, Gay, Bisexual, and Transgender (LGBT) Youth

    Science.gov (United States)

    Heck, Nicholas C.; Flentje, Annesa; Cochran, Bryan N.

    2011-01-01

    Lesbian, gay, bisexual, and transgender (LGBT) youth are at risk for engaging in negative health behaviors and for experiencing at-school victimization. Specific benefits of attending a high school with a gay-straight alliance (GSA), including lower levels of suicidality, have been published; however, it is unclear whether GSAs are related to…

  10. Transport of hydrate slurry at high water cut

    OpenAIRE

    Melchuna , Aline; Cameirão , Ana; Herri , Jean-Michel; Ouabbas , Yamina; Glenat , Philippe

    2014-01-01

    Poster; International audience; Oil transportation in pipelines at the end of field production life implies to flow high quantities of water which represents the dominant phase. The process of crystallization of gas hydrates in this system needs to be studied and compared to the opposite one widely studied in the literature where water is the dispersed phase. The laboratory is equipped with the Archimede flow loop where the hydrate crystallization and transport are monitored. The flow loop is...

  11. "Kids not rights, is their craving": sex education, gay rights, and the threat of gay teachers.

    Science.gov (United States)

    Graydon, Michael

    2011-08-01

    In July 1977, the Ontario Humans Rights Commission recommended adding sexual orientation to the Code. This move was generally supported but Toronto newspapers and evangelists sought assurances that school boards could still dismiss homosexual teachers. They demanded children be shielded from gay teachers, who they accused of sexual predation. I historically link this to a reenergized fear of homosexuals which emerged during Toronto sex education debates in the 1970s. Later, influenced by Anita Bryant's Save the Children crusade, Toronto newspapers and evangelists argued gay teachers were the dangerous effect of gay rights. After the 1977 murder of Emanuel Jaques and the publication of Gerald Hannon's "Men Loving Boys, Loving Men" article, anti-gay sentiment in Toronto exploded, temporarily halting the progress of gay rights.

  12. Experimental setting for assessing mechanical strength of gas hydrate pellet

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, S.J.; Choi, J.H.; Koh, B.H. [Dongguk Univ., Phil-dong, Chung-gu, Seoul (Korea, Republic of). Dept. of Mechanical Engineering

    2008-07-01

    Due to the constant increase in global demand for clean energy, natural gas production from stranded medium and small size gas wells has drawn significant interest. Because the ocean transport of natural gas in the form of solid hydrate pellets (NGHP) has been estimated to be economically feasible, several efforts have been made to develop a total NGHP ocean transport chain. The investigation of mechanical strength of solid-form hydrate pellet has been an important task in fully exploiting the benefit of gas hydrate in the perspective of mass transportation and storage. This paper provided the results of a preliminary study regarding the assessment of mechanical properties of the gas hydrate pellet. The preliminary study suggested some of the key issues regarding formation and strength of gas hydrate pellets. Instead of utilizing the gas hydrate pellet, the study focused on a preliminary test setup for developing the ice pellet which was readily applied to the gas hydrate pellet in the future. The paper described the pelletization of ice powder as well as the experimental setup. Several photographs were illustrated, including samples of ice pellets; compression test for ice pellet using air press and load cell; and the initiation of crack in the cross section of an ice pellet. It was found that mechanical strength, especially, compression strength was not significantly affected by different level of press-forming force up to a certain level. 4 refs., 1 tab., 4 figs.

  13. Structural and hydration properties of amorphous tricalcium silicate

    International Nuclear Information System (INIS)

    Mori, K.; Fukunaga, T.; Shiraishi, Y.; Iwase, K.; Xu, Q.; Oishi, K.; Yatsuyanagi, K.; Yonemura, M.; Itoh, K.; Sugiyama, M.; Ishigaki, T.; Kamiyama, T.; Kawai, M.

    2006-01-01

    Mechanical milling was carried out to synthesize amorphous tricalcium silicate (Ca 3 SiO 5 ) sample, where Ca 3 SiO 5 is the most principal component of Portland cement. The partial phase transformation from the crystalline to the amorphous state was observed by X-ray and neutron diffractions. Moreover, it was found that the structural distortion on the Ca-O correlation exists in the milled Ca 3 SiO 5 . The hydration of the milled Ca 3 SiO 5 with D 2 O proceeds as follows: the formation of hydration products such as Ca(OD) 2 rapidly occurs in the early hydration stage, and then proceeds slowly after about 15 h. The induction time for the hydration of the milled Ca 3 SiO 5 is approximately one half shorter than that for the hydration of the unmilled one. This result means that the mechanical milling brings about the chemical activity of Ca 3 SiO 5 for hydration, and may be particularly useful for increasing the reactivity in the early hydration stage

  14. Ab initio modelling of methane hydrate thermophysical properties.

    Science.gov (United States)

    Jendi, Z M; Servio, P; Rey, A D

    2016-04-21

    The key thermophysical properties of methane hydrate were determined using ab initio modelling. Using density functional theory, the second-order elastic constants, heat capacity, compressibility, and thermal expansion coefficient were calculated. A wide and relevant range of pressure-temperature conditions were considered, and the structures were assessed for stability using the mean square displacement and radial distribution functions. Methane hydrate was found to be elastically isotropic with a linear dependence of the bulk modulus on pressure. Equally significant, multi-body interactions were found to be important in hydrates, and water-water interactions appear to strongly influence compressibility like in ice Ih. While the heat capacity of hydrate was found to be higher than that of ice, the thermal expansion coefficient was significantly lower, most likely due to the lower rigidity of hydrates. The mean square displacement gave important insight into stability, heat capacity, and elastic moduli, and the radial distribution functions further confirmed stability. The presented results provide a much needed atomistic thermoelastic characterization of methane hydrates and are essential input for the large-scale applications of hydrate detection and production.

  15. Influence of Lithium Carbonate on C3A Hydration

    Directory of Open Access Journals (Sweden)

    Weiwei Han

    2018-01-01

    Full Text Available Lithium salts, known to ameliorate the effects of alkali-silica reaction, can make significant effects on cement setting. However, the mechanism of effects on cement hydration, especially the hydration of C3A which is critical for initial setting time of cement, is rarely reported. In this study, the development of pH value of pore solution, conductivity, thermodynamics, and mineralogical composition during hydration of C3A with or without Li2CO3 are investigated. The results demonstrate that Li2CO3 promotes C3A hydration through high alkalinity, due to higher activity of lithium ion than that of calcium ion in the solution and carbonation of C3A hydration products resulted from Li2CO3. Li2CO3 favors the C3A hydration in C3A-CaSO4·2H2O-Ca(OH2-H2O hydration system and affects the mineralogical variation of the ettringite phase(s.

  16. Hormones and silk. Gay men in the Spanish film comedies of the transition to democracy (1976-1981).

    Science.gov (United States)

    Melero, Alejandro

    2013-01-01

    This article studies the representation of gay men in Spanish comedies of the 1970s. It analyzes how cinema used the stereotypical image of gay men projected by the dictatorship and how, once it ended, this image endured in the comedy genre. It introduces film theories on the construction of humor taken from relevant authors, such as Jordan, Charney, Voitylla, and Petri. Afterward, it focuses on the works of Ozores as a filmmaker who encapsulates the main characteristics of the so-called comedia de mariquitas (sissy comedy). It analyzes how the construction of humor was based on the Francoist conception of gay men, and questions why the figure of the gay man was so effective in the production of comedy. Finally, this article refers to Dyer's theories around stereotyping, and develops them to study the Spanish context.

  17. Manufacture of Methane Hydrate using Carbon Nano Tubes

    International Nuclear Information System (INIS)

    Park, Sung Seek

    2010-02-01

    Methane hydrate is formed by physical binding between water molecule and gas such as methane, ethane, propane, or carbon dioxide, etc., which is captured in the cavities of water molecule under the specific temperature and pressure. More than 99% of naturally produced methane hydrate consists of methane, and is widely dispersed in the continental slope and continental Shelf of the Pacific and the Atlantic, the Antarctica etc. The reserve of fossil fuel is 500 billion carbon ton and the reserve of methane is 360 million carbon ton. The reserve of gas hydrate is more than 1 trillion carbon ton, which is twice the fossil fuel. Therefore, natural gas hydrate as a kind of gas hydrate is expected to replace fossil fuel as new energy source of 21st century. Also 1 m 3 hydrate of pure methane can be decomposed to the maximum of 216 m 3 methane at standard condition. If these characteristics of hydrate are reversely utilized, natural gas is fixed into water in the form of hydrate solid. Therefore, the hydrate is considered to be a great way to transport and store natural gas in large quantity. Especially the transportation cost is known to be 18∼25% less than the liquefied transportation. However, when natural gas hydrate is artificially formed, its reaction time may be too long and the gas consumption in water becomes relatively low, because the reaction rate between water and gas is low. Therefore, for the practical purpose in the application, the present investigation focuses on the rapid production of hydrates and increases gas consumption by adding MWCNT and NaCl into pure water. The results show that the equilibrium pressure in seawater is more higher than that in pure water, and methane hydrate could be formed rapidly during pressurization if the subcooling is maintained at 9K or above in seawater and 8K or above in pure water, respectively. Also, amount of consumed gas volume in pure water is more higher that in seawater at the same experimental conditions

  18. Novel understanding of calcium silicate hydrate from dilute hydration

    KAUST Repository

    Zhang, Lina; Yamauchi, Kazuo; Li, Zongjin; Zhang, Xixiang; Ma, Hongyan; Ge, Shenguang

    2017-01-01

    The perspective of calcium silicate hydrate (C-S-H) is still confronting various debates due to its intrinsic complicated structure and properties after decades of studies. In this study, hydration at dilute suspension of w/s equaling to 10

  19. Hydrate-CASM for modeling Methane Hydrate-Bearing Sediments

    Science.gov (United States)

    De La Fuente Ruiz, M.; Vaunat, J.; Marin Moreno, H.

    2017-12-01

    A clear understanding of the geomechanical behavior of methane hydrate-bearing sediments (MHBS) is crucial to assess the stability of the seafloor and submarine infrastructures to human and natural loading changes. Here we present the Hydrate-CASM, a new elastoplastic constitutive model to predict the geomechanical behavior of MHBS. Our model employs the critical state model CASM (Clay and Sand Model) because of its flexibility in describing the shape of the yield surface and its proven ability to predict the mechanical behavior of sands, the most commercially viable hydrate reservoirs. The model considers MHBS as a deformable elastoplastic continuum, and hydrate-related changes in the stress-strain behavior are predicted by a densification mechanism. The densification attributes the mechanical contribution of hydrate to; a reduction of the available void ratio; a decrease of the swelling line slope; and an increase of the volumetric yield stress. It is described by experimentally derived physical parameters except from the swelling slope coefficient that requires empirical calibration. The Hydrate-CASM is validated against published triaxial laboratory tests performed at different confinement stresses, hydrate saturations, and hydrate morphologies. During the validation, we focused on capturing the mechanical behavior of the host sediment and consider perturbations of the sediment's mechanical properties that could result from the sample preparation. Our model successfully captures the experimentally observed influence of hydrate saturation in the magnitude and trend of the stiffness, shear strength, and dilatancy of MHBS. Hence, we propose that hydrate-related densification changes might be a major factor controlling the geomechanical response of MHBS.

  20. An international effort to compare gas hydrate reservoir simulators

    Energy Technology Data Exchange (ETDEWEB)

    Wilder, J.W. [Akron Univ., Akron, OH (United States). Dept. of Theoretical and Applied Math; Moridis, G.J. [California Univ., Berkely, CA (United States). Earth Sciences Div., Lawrence Berkely National Lab.; Wilson, S.J. [Ryder Scott Co., Denver, CO (United States); Kurihara, M. [Japan Oil Engineering Co. Ltd., Tokyo (Japan); White, M.D. [Pacific Northwest National Laboratory Hydrology Group, Richland, WA (United States); Masuda, Y. [Tokyo Univ., Tokyo (Japan). Dept. of Geosystem Engineering; Anderson, B.J. [National Energy Technology Lab., Morgantown, WV (United States)]|[West Virginia Univ., Morgantown, WV (United States). Dept. of Chemical Engineering; Collett, T.S. [United States Geological Survey, Denver, CO (United States); Hunter, R.B. [ASRC Energy Services, Anchorage, AK (United States); Narita, H. [National Inst. of Advanced Industrial Science and Technology, MEthane hydrate Research Lab., Sapporo (Japan); Pooladi-Darvish, M. [Fekete Associates Inc., Calgary, AB (Canada); Rose, K.; Boswell, R. [National Energy Technology Lab., Morgantown, WV (United States)

    2008-07-01

    In this study, 5 different gas hydrate production scenarios were modeled by the CMG STARS, HydateResSim, MH-21 HYDRES, STOMP-HYD and the TOUGH+HYDRATE reservoir simulators for comparative purposes. The 5 problems ranged in complexity from 1 to 3 dimensional with radial symmetry, and in horizontal dimensions of 20 meters to 1 kilometer. The scenarios included (1) a base case with non-isothermal multi-fluid transition to equilibrium, (2) a base case with gas hydrate (closed-domain hydrate dissociation), (3) dissociation in a 1-D open domain, (4) gas hydrate dissociation in a one-dimensional radial domain, similarity solutions, (5) gas hydrate dissociation in a two-dimensional radial domain. The purpose of the study was to compare the world's leading gas hydrate reservoir simulators in an effort to improve the simulation capability of experimental and naturally occurring gas hydrate accumulations. The problem description and simulation results were presented for each scenario. The results of the first scenario indicated very close agreement among the simulators, suggesting that all address the basics of mass and heat transfer, as well as overall process of gas hydrate dissociation. The third scenario produced the initial divergence among the simulators. Other differences were noted in both scenario 4 and 5, resulting in significant corrections to algorithms within several of the simulators. The authors noted that it is unlikely that these improvements would have been identified without this comparative study due to a lack of real world data for validation purposes. It was concluded that the solution for gas hydrate production involves a combination of highly coupled fluid, heat and mass transport equations combined with the potential for formation or disappearance of multiple solid phases in the system. The physical and chemical properties of the rocks containing the gas hydrate depend on the amount of gas hydrate present in the system. Each modeling and

  1. Legislators' positions on gay and lesbian rights: the personal and political.

    Science.gov (United States)

    Herrick, Rebekah

    2010-01-01

    This article examines state legislators' public position on gay and lesbian rights by using responses to survey data on their positions toward civil unions and inclusion of sexual orientation in anti-job discrimination laws. The research finds that although state legislators are mixed on their positions, they are less supportive of gay and lesbian rights than is the general public. It also finds that their public positions are a product of both their personal beliefs and values as well as their political calculations. The implications of these findings are explored.

  2. Are gay communities dying or just in transition? Results from an international consultation examining possible structural change in gay communities.

    Science.gov (United States)

    Simon Rosser, B R; West, William; Weinmeyer, Richard

    2008-05-01

    This study sought to identify how urban gay communities are undergoing structural change, reasons for that change, and implications for HIV prevention planning. Key informants (N=29) at the AIDS Impact Conference from 17 cities in 14 countries completed surveys and participated in a facilitated structured dialog about if gay communities are changing, and if so, how they are changing. In all cities, the virtual gay community was identified as currently larger than the offline physical community. Most cities identified that while the gay population in their cities appeared stable or growing, the gay community appeared in decline. Measures included greater integration of heterosexuals into historically gay-identified neighborhoods and movement of gay persons into suburbs, decreased number of gay bars/clubs, less attendance at gay events, less volunteerism in gay or HIV/AIDS organizations, and the overall declining visibility of gay communities. Participants attributed structural change to multiple factors including gay neighborhood gentrification, achievement of civil rights, less discrimination, a vibrant virtual community, and changes in drug use. Consistent with social assimilation, gay infrastructure, visibility, and community identification appears to be decreasing across cities. HIV prevention planning, interventions, treatment services, and policies need to be re-conceptualized for MSM in the future. Four recommendations for future HIV prevention and research are detailed.

  3. HIV among African American Gay and Bisexual Men

    Science.gov (United States)

    ... Syndicated Content Website Feedback HIV Among African American Gay and Bisexual Men Recommend on Facebook Tweet Share Compartir Black/African American a gay, bisexual, and other men who have sex with ...

  4. Lesbian, Gay, Bisexual, and Transgender Persons and Tobacco Use

    Science.gov (United States)

    ... Division of Reproductive Health More CDC Sites Lesbian, Gay, Bisexual, and Transgender Persons and Tobacco Use Recommend ... and Influence Resources References People who are lesbian, gay, bisexual, or transgender (LGBT) include all races and ...

  5. Gay, Lesbian, Bisexual and Transgender Health: Stigma and Discrimination

    Science.gov (United States)

    ... their lives. The Effects of Negative Attitudes on Gay, Bisexual, and Other Men Who Have Sex with Men Some people may have negative attitudes toward gay, bisexual, and other men who have sex with ...

  6. Phase behavior of methane hydrate in silica sand

    International Nuclear Information System (INIS)

    Sun, Shi-Cai; Liu, Chang-Ling; Ye, Yu-Guang; Liu, Yu-Feng

    2014-01-01

    Highlights: • Hydrate p-T trace in coarse-grained sediment is consistent with that in bulk water. • Fine-grained sediment affects hydrate equilibrium for the depressed water activity. • Hydrate equilibrium in sediment is related to the pore size distribution. • The application of hydrate equilibrium in sediment depends on the actual condition. -- Abstract: Two kinds of silica sand powder with different particle size were used to investigate the phase behavior of methane hydrate bearing sediment. In coarse-grained silica sand, the measured temperature and pressure range was (281.1 to 284.2) K and (5.9 to 7.8) MPa, respectively. In fine-grained silica sand, the measured temperature and pressure range was (281.5 to 289.5) K and (7.3 to 16.0) MPa, respectively. The results show that the effect of coarse-grained silica sand on methane hydrate phase equilibrium can be ignored; however, the effect of fine-grained silica sand on methane hydrate phase equilibrium is significant, which is attributed to the depression of water activity caused by the hydrophilicity and negatively charged characteristic of silica particle as well as the pore capillary pressure. Besides, the analysis of experimental results using the Gibbs–Thomson equation shows that methane hydrate phase equilibrium is related to the pore size distribution of silica sand. Consequently, for the correct application of phase equilibrium data of hydrate bearing sediment, the geological condition and engineering requirement should be taken into consideration in gas production, resource evaluation, etc

  7. Ductile flow of methane hydrate

    Science.gov (United States)

    Durham, W.B.; Stern, L.A.; Kirby, S.H.

    2003-01-01

    Compressional creep tests (i.e., constant applied stress) conducted on pure, polycrystalline methane hydrate over the temperature range 260-287 K and confining pressures of 50-100 MPa show this material to be extraordinarily strong compared to other icy compounds. The contrast with hexagonal water ice, sometimes used as a proxy for gas hydrate properties, is impressive: over the thermal range where both are solid, methane hydrate is as much as 40 times stronger than ice at a given strain rate. The specific mechanical response of naturally occurring methane hydrate in sediments to environmental changes is expected to be dependent on the distribution of the hydrate phase within the formation - whether arranged structurally between and (or) cementing sediments grains versus passively in pore space within a sediment framework. If hydrate is in the former mode, the very high strength of methane hydrate implies a significantly greater strain-energy release upon decomposition and subsequent failure of hydrate-cemented formations than previously expected.

  8. Identity and Sex: Concurent Aspects of Gay Tourism

    OpenAIRE

    Monterrubio, J. Carlos

    2008-01-01

    The present article aims to contribute to the recognition of two relevant aspects in gay travel; identity and sex. The paper explores the existing published work related to the relationships between tourism, gay men and identity. It concludes that the issue of identity commonly plays a crucial role as a travel reason in gay tourism. Also, it analyses the research evidence to suggest that sex is a frequently-present phenomenon in gay travel. By critically analysing the available research, the ...

  9. Energy from gas hydrates - assessing the opportunities and challenges for Canada: report of the expert panel on gas hydrates

    International Nuclear Information System (INIS)

    2008-09-01

    significant safety issues, unique to the production of gas from gas hydrate, that were not already encountered and addressed in the course of more conventional natural gas production, both onshore and offshore. refs., tabs., figs

  10. Methane hydrates and the future of natural gas

    Science.gov (United States)

    Ruppel, Carolyn

    2011-01-01

    For decades, gas hydrates have been discussed as a potential resource, particularly for countries with limited access to conventional hydrocarbons or a strategic interest in establishing alternative, unconventional gas reserves. Methane has never been produced from gas hydrates at a commercial scale and, barring major changes in the economics of natural gas supply and demand, commercial production at a large scale is considered unlikely to commence within the next 15 years. Given the overall uncertainty still associated with gas hydrates as a potential resource, they have not been included in the EPPA model in MITEI’s Future of Natural Gas report. Still, gas hydrates remain a potentially large methane resource and must necessarily be included in any consideration of the natural gas supply beyond two decades from now.

  11. Gay Youth in American Public High Schools: Invisible Diversity.

    Science.gov (United States)

    Reed, Donald B.

    Gay youth enter high school with the knowledge that they are different and with the belief that heterosexuality is normal and that homosexuality is not normal. Also, gay youth enter high school with the belief that honesty and integrity are important personal values. Additionally, the gay youth enter high school without family knowledge of their…

  12. Sexual and Intimacy Issues for Aging Gay Men

    Science.gov (United States)

    Pope, Mark; Wierzalis, Edward A.; Barret, Bob; Rankins, Michael

    2007-01-01

    The authors focus on the special issues involved in providing counseling to aging gay men regarding sex and intimacy. Although the stresses of aging experienced by gay men are similar to those of heterosexual men, older gay men face issues of a stigmatized sexual orientation, invisibility, negative stereotypes, and discrimination regarding aging.

  13. Coping with Perceived Ethnic Prejudice on the Gay Scene

    Science.gov (United States)

    Jaspal, Rusi

    2017-01-01

    There has been only cursory research into the sociological and psychological aspects of ethnic/racial discrimination among ethnic minority gay and bisexual men, and none that focuses specifically upon British ethnic minority gay men. This article focuses on perceptions of intergroup relations on the gay scene among young British South Asian gay…

  14. Explaining Couple Cohesion in Different Types of Gay Families

    Science.gov (United States)

    van Eeden-Moorefield, Brad; Pasley, Kay; Crosbie-Burnett, Margaret; King, Erin

    2012-01-01

    This Internet-based study used data from a convenience sample of 176 gay men in current partnerships to examine differences in outness, cohesion, and relationship quality between three types of gay male couples: first cohabiting partnerships, repartnerships, and gay stepfamilies. Also, we tested whether relationship quality mediated the link…

  15. Correlates of Gay-Related Name-Calling in Schools

    Science.gov (United States)

    Slaatten, Hilde; Hetland, Jørn; Anderssen, Norman

    2015-01-01

    The aim of this study was to examine whether attitudes about gay-related name-calling, social norms concerning gay-related name-calling among co-students, teacher intervention, and school-related support would predict whether secondary school pupils had called another pupil a gay-related name during the last month. A total of 921 ninth-grade…

  16. Addiction and recovery in gay and lesbian persons

    National Research Council Canada - National Science Library

    Kus, Robert J

    1995-01-01

    .... Addiction and Recovery is a vital resourcefor anyone providing servicesfor gay, lesbian, and bisexualclients. Rik Isensee,LCSW Author, LOVE BEIWEEN MEN, and GROWING UP GAY IN A DYSFUNCTIONAL FAMILYMore pre-publication REVIEWS,COMMENTARIES, EVALUATIONS . .. "A ddiction and Recovery in Gay and Lesbian Persons" is an excellentcollection of multifa...

  17. Introduction to the Gas Hydrate Master Project of Energy National Science and Technology Program of Taiwan

    Science.gov (United States)

    Yang, T. F.; Research Team of Gas Hydrate Project of CGS of Taiwan

    2011-12-01

    Bottom Simulating Reflectors (BSRs), which have been considered as one of major indicators of the gas hydrate in sub-seafloor, have been detected and widely distributed in offshore SW Taiwan. The Central Geological Survey of Taiwan launched a 4-year multidisciplinary gas hydrate investigation program in 2004 to explore the potential of gas hydrate resources in the area. The results indicate that enormous amounts of gas hydrate should occur beneath the seafloor, although none of solid gas hydrate samples have been found. Therefore, a second stage of another 4-year program started in 2008 to extend the studies/investigation. In the ongoing projects, some specific areas will be studied in detail to assess the components of gas hydrate petroleum system and provide a better assessment of the energy resource potential of gas hydrate in the target area. In addition to the field investigations, phase equilibrium of gas hydrate via experiment, theoretical modeling, and molecular simulations has also been studied. The results can provide insights into gas hydrate production technology. Considering the high potential energy resources, the committee of the energy national science and technology program suggests initiating a master project to plan the strategy and timeline for the gas hydrate exploration, exploitation and production in Taiwan. The plan will be introduced in this presentation.

  18. Global identification predicts gay-male identity integration and well-being among Turkish gay men.

    Science.gov (United States)

    Koc, Yasin; Vignoles, Vivian L

    2016-12-01

    In most parts of the world, hegemonic masculinity requires men to endorse traditional masculine ideals, one of which is rejection of homosexuality. Wherever hegemonic masculinity favours heterosexuality over homosexuality, gay males may feel under pressure to negotiate their conflicting male gender and gay sexual identities to maintain positive self-perceptions. However, globalization, as a source of intercultural interaction, might provide a beneficial context for people wishing to create alternative masculinities in the face of hegemonic masculinity. Hence, we tested if global identification would predict higher levels of gay-male identity integration, and indirectly subjective well-being, via alternative masculinity representations for gay and male identities. A community sample of 219 gay and bisexual men from Turkey completed the study. Structural equation modelling revealed that global identification positively predicted gay-male identity integration, and indirectly subjective well-being; however, alternative masculinity representations did not mediate this relationship. Our findings illustrate how identity categories in different domains can intersect and affect each other in complex ways. Moreover, we discuss mental health and well-being implications for gay men living in cultures where they experience high levels of prejudice and stigma. © 2016 The British Psychological Society.

  19. Gas hydrates in the Ulleung Basin, East Sea of Korea

    Directory of Open Access Journals (Sweden)

    Byong-Jae Ryu Michael Riedel

    2017-01-01

    Full Text Available To develop gas hydrates as a potential energy source, geophysical surveys and geological studies of gas hydrates in the Ulleung Basin, East Sea off the east coast of Korea have been carried out since 1997. Bottom-simulating reflector (BSR, initially used indicator for the potential presence of gas hydrates was first identified on seismic data acquired in 1998. Based on the early results of preliminary R&D project, 12367 km of 2D multichannel reflection seismic lines, 38 piston cores, and multi-beam echo-sounder data were collected from 2000 to 2004. The cores showed high amounts of total organic carbon and high residual hydrocarbon gas levels. Gas composition and isotope ratios define it as of primarily biogenic origin. In addition to the BSRs that are widespread across the basin, numerous chimney structures were found in seismic data. These features indicate a high potential of the Ulleung Basin to host significant amounts of gas hydrate. Dedicated geophysical surveys, geological and experimental studies were carried out culminating in two deep drilling expeditions, completed in 2007 and 2010. Sediment coring (including pressure coring, and a comprehensive well log program complements the regional studies and were used for a resource assessment. Two targets for a future test-production are currently proposed: pore-filling gas hydrate in sand-dominated sediments and massive occurrences of gas hydrate within chimney-like structures. An environmental impact study has been launched to evaluate any potential risks to production.

  20. Measurements of gas permeability and non-Darcy flow in gas-water-hydrate systems

    Energy Technology Data Exchange (ETDEWEB)

    Ersland, G.; Husebo, J.; Graue, A.; Kvamme, B. [Bergen Univ., Bergen (Norway). Dept. of Physics and Technology; Baldwin, B. [Green Country Petrophysics LLC, Dewey, OK (United States); Stevens, J.; Howard, J. [ConocoPhillips, OK (United States)

    2008-07-01

    Storage of carbon dioxide (CO{sub 2}) in natural gas hydrate reservoirs may offer stable long-term storage of a greenhouse gas while benefiting from methane production, without requiring heat. By exposing hydrate to a thermodynamically preferred hydrate former, CO{sub 2}, the hydrate may be maintained macroscopically in the solid state and retain the stability of the formation. However, there is concern over the flow capacity in such reservoirs. This depends on several factors, notably thermodynamic destabilization of hydrate in small pores due to capillary effects; the presence of liquid channels separating the hydrate from the mineral surfaces; and, the connectivity of gas or liquid filled pores and channels. This paper described a technique for measuring gas permeability in gas-water-hydrate systems. It reported on several experiments that measured gas permeability during stages of hydrate growth in sandstone core plugs. Interactions between minerals and surrounding molecules were also discussed. The formation of methane hydrate in porous media was monitored and quantified with magnetic resonance imaging (MRI). MRI images of hydrate growth within the porous rock were provided along with measurements of gas permeability and non-Darcy flow effects at various hydrate saturations. Gas permeability was measured at steady state flow of methane through the hydrate-bearing core sample. Significant gas permeability was recorded for porous sandstone even when hydrates occupied up to 60 per cent of the pore space. It was concluded that MRI imaging can be used effectively to map and quantify hydrate saturation in sandstone core plugs. 27 refs., 2 tabs., 10 figs.

  1. Shifting Focus: From Hydration for Performance to Hydration for Health.

    Science.gov (United States)

    Perrier, Erica T

    2017-01-01

    Over the past 10 years, literature on hydration biomarkers has evolved considerably - from (de)hydration assessment towards a more global definition of biomarkers of hydration in daily life. This shift in thinking about hydration markers was largely driven by investigating the differences that existed between otherwise healthy individuals whose habitual, ad-libitum drinking habits differ, and by identifying physiological changes in low-volume drinkers who subsequently increase their water intake. Aside from obvious differences in urinary volume and concentration, a growing body of evidence is emerging that links differences in fluid intake with small, but biologically significant, differences in vasopressin (copeptin), glomerular filtration rate, and markers of metabolic dysfunction or disease. Taken together, these pieces of the puzzle begin to form a picture of how much water intake should be considered adequate for health, and represent a shifting focus from hydration for performance, toward hydration for health outcomes. This narrative review outlines the key areas of research in which the global hydration process - including water intake, urinary hydration markers, and vasopressin - has been associated with health outcomes, focusing on kidney and metabolic endpoints. It will also provide a commentary on how various hydration biomarkers may be used in hydration for health assessment. Finally, if adequate water intake can play a role in maintaining health, how might we tell if we are drinking enough? Urine output is easily measured, and can take into account differences in daily physical activity, climate, dietary solute load, and other factors that influence daily water needs. Today, targets have been proposed for urine osmolality, specific gravity, and color that may be used by researchers, clinicians, and individuals as simple indicators of optimal hydration. However, there remain a large number of incomplete or unanswered research questions regarding the

  2. The temperature hydration kinetics

    Directory of Open Access Journals (Sweden)

    Mircea Oroian

    2017-07-01

    Full Text Available The aim of this study is to evaluate the hydration kinetics of lentil seeds (Lens culinaris in water at different temperatures (25, 32.5, 40, 55, 70 and 80 °C for assessing the adequacy of models for describing the absorption phenomena during soaking. The diffusion coefficient values were calculated using Fick’s model for spherical and hemispherical geometries and the values were in the range of 10−6 m2/s. The experimental data were fitted to Peleg, Sigmoidal, Weibull and Exponential models. The models adequacy was determined using regression coefficients (R2, root mean square error (RMSE and reduced chi-square (χ2. The Peleg model is the suitable one for predicting the experimental data. Temperature had a positive and significant effect on the water absorption capacities and absorption was an endothermic process.

  3. Major factors influencing the generation of natural gas hydrate in porous media

    Directory of Open Access Journals (Sweden)

    V.N. Khlebnikov

    2017-11-01

    Full Text Available Current researches related to natural gas hydrate mainly focus on its physical and chemical properties, as well as the approaches to the production (decomposition of hydrate. Physical modeling of the flow process in hydrate deposits is critical to the study on the exploitation or decomposition of hydrate. However, investigation of the dynamic hydrate process by virtue of porous media like sand-packed tubes which are widely used in petroleum production research is rarely reported in literature. In this paper, physical simulation of methane hydrate generation process was conducted using river sand-packed tubes in the core displacement apparatus. During the simulation, the influences of parameters such as reservoir temperature, methane pressure and reservoir model properties on the process of hydrate generation were investigated. The following results are revealed. First, the use of ice-melted water as the immobile water in the reservoir model can significantly enhance the rate of methane hydrate generation. Second, the process driving force in porous media (i.e., extents to which the experimental pressure or temperature deviating those corresponding to the hydrate phase equilibrium plays a key role in the generation of methane hydrate. Third, the induction period of methane hydrate generation almost does not change with temperature or pressure when the methane pressure is above 1.4 folds of the hydrate phase equilibrium pressure or the laboratory temperature is lower than the phase equilibrium temperature by 3 °C or more. Fourth, the parameters such as permeability, water saturation and wettability don't have much influence on the generation of methane hydrate.

  4. Numerical Simulations for Enhanced Methane Recovery from Gas Hydrate Accumulations by Utilizing CO2 Sequestration

    Science.gov (United States)

    Sridhara, Prathyusha

    In 2013, the International Energy Outlook (EIA, 2013) projected that global energy demand will grow by 56% between 2010 and 2040. Despite strong growth in renewable energy supplies, much of this growth is expected to be met by fossil fuels. Concerns ranging from greenhouse gas emissions and energy security are spawning new interests for other sources of energy including renewable and unconventional fossil fuel such as shale gas and oil as well as gas hydrates. The production methods as well as long-term reservoir behavior of gas hydrate deposits have been under extensive investigation. Reservoir simulators can be used to predict the production potentials of hydrate formations and to determine which technique results in enhanced gas recovery. In this work, a new simulation tool, Mix3HydrateResSim (Mix3HRS), which accounts for complex thermodynamics of multi-component hydrate phase comprised of varying hydrate solid crystal structure, is used to perform the CO2-assisted production technique simulations from CH4 hydrate accumulations. The simulator is one among very few reservoir simulators which can simulate the process of CH4 substitution by CO2 (and N2 ) in the hydrate lattice. Natural gas hydrate deposits around the globe are categorized into three different classes based on the characteristics of the geological sediments present in contact with the hydrate bearing deposits. Amongst these, the Class 2 hydrate accumulations predominantly confirmed in the permafrost and along seashore, are characterized by a mobile aqueous phase underneath a hydrate bearing sediment. The exploitation of such gas hydrate deposits results in release of large amounts of water due to the presence of permeable water-saturated sediments encompassing the hydrate deposits, thus lowering the produced gas rates. In this study, a suite of numerical simulation scenarios with varied complexity are considered which aimed at understanding the underlying changes in physical, thermodynamic and

  5. CO2 injection into submarine, CH4-hydrate bearing sediments: Parameter studies towards the development of a hydrate conversion technology

    Science.gov (United States)

    Deusner, Christian; Bigalke, Nikolaus; Kossel, Elke; Haeckel, Matthias

    2013-04-01

    In the recent past, international research efforts towards exploitation of submarine and permafrost hydrate reservoirs have increased substantially. Until now, findings indicate that a combination of different technical means such as depressurization, thermal stimulation and chemical activation is the most promising approach for producing gas from natural hydrates. Moreover, emission neutral exploitation of CH4-hydrates could potentially be achieved in a combined process with CO2 injection and storage as CO2-hydrate. In the German gas hydrate initiative SUGAR, a combination of experimental and numerical studies is used to elucidate the process mechanisms and technical parameters on different scales. Experiments were carried out in the novel high-pressure flow-through system NESSI (Natural Environment Simulator for sub-Seafloor Interactions). Recent findings suggest that the injection of heated, supercritical CO2 is beneficial for both CH4 production and CO2 retention. Among the parameters tested so far are the CO2 injection regime (alternating vs. continuous injection) and the reservoir pressure / temperature conditions. Currently, the influence of CO2 injection temperature is investigated. It was shown that CH4 production is optimal at intermediate reservoir temperatures (8 ° C) compared to lower (2 ° C) and higher temperatures (10 ° C). The reservoir pressure, however, was of minor importance for the production efficiency. At 8 ° C, where CH4- and CO2-hydrates are thermodynamically stable, CO2-hydrate formation appears to be slow. Eventual clogging of fluid conduits due to CO2-rich hydrate formation force open new conduits, thereby tapping different regions inside the CH4-hydrate sample volume for CH4gas. In contrast, at 2 ° C immediate formation of CO2-hydrate results in rapid and irreversible obstruction of the entire pore space. At 10 ° C pure CO2-hydrates can no longer be formed. Consequently the injected CO2 flows through quickly and interaction with

  6. Effect of polymers on the nanostructure and on the carbonation of calcium silicate hydrates: a scanning transmission X-ray microscopy study

    KAUST Repository

    Ha, J.; Chae, S.; Chou, K. W.; Tyliszczak, T.; Monteiro, P. J. M.

    2011-01-01

    This study investigated the effects of organic polymers (polyethylene glycol and hexadecyltrimethylammonium) on structures of calcium silicate hydrates (C-S-H) which is the major product of Portland cement hydration. Increased surface areas

  7. Thermal properties of methane hydrate by experiment and modeling and impacts upon technology

    Energy Technology Data Exchange (ETDEWEB)

    Warzinski, R.P.; Gamwo, I.K.; Rosenbaum, E.J. [United States Dept. of Energy, Pittsburgh, PA (United States). National Energy Technology Laboratory; Myshakin, E.M. [NETL Support Contractor, South Park, PA (United States); Jiang, H.; Jordan, K.D. [Pittsburgh Univ., Pittsburgh, PA (United States). Dept. of Chemistry; English, N.J. [Dublin University College, Dublin (Ireland). Conway Inst. of Biomolecular and Biomedical Research, Centre for Synthesis and Chemical Biology; Shaw, D.W. [Geneva College, Beaver Falls, PA (United States). Dept. of Engineering

    2008-07-01

    The current hydrate research at the National Energy Technology Laboratory (NETL) involves both experimental and theoretical work on developing models and methods for predicting the behaviour of gas hydrates in their natural environment under production of climate change scenarios. The modeling efforts include both fundamental and reservoir scale simulations and economic modeling. The thermal properties of methane hydrate are important for hydrate production, seafloor stability and climate change scenarios. A new experimental technique and advanced molecular dynamics simulation (MDS) have determined the thermal properties of pure methane hydrate under conditions similar to naturally occurring hydrate-bearing sediments. The thermal conductivity and thermal diffusivity values of low-porosity methane hydrate formed in the laboratory were measured using an innovative single-sided, Transient Plane Source (TPS) technique. The results were in good agreement with results from an equilibrium MDS method using in-plane polarization of the water molecules. MDS was also performed using a non-equilibrium model with a fully polarizable force field for water. The Tough+Hydrate reservoir simulator was also used to evaluate the impact of thermal conductivity on gas production from a hydrate-bearing reservoir. 42 refs., 1 tab., 5 figs.

  8. Obsidian hydration dates glacial loading?

    Science.gov (United States)

    Friedman, I; Pierce, K L; Obradovich, J D; Long, W D

    1973-05-18

    Three different groups of hydration rinds have been measured on thin sections of obsidian from Obsidian Cliff, Yellowstone National Park, Wyoming. The average thickness of the thickest (oldest) group of hydration rinds is 16.3 micrometers and can be related to the original emplacement of the flow 176,000 years ago (potassium-argon age). In addition to these original surfaces, most thin sections show cracks and surfaces which have average hydration rind thicknesses of 14.5 and 7.9 micrometers. These later two hydration rinds compare closely in thickness with those on obsidian pebbles in the Bull Lake and Pinedale terminal moraines in the West Yellowstone Basin, which are 14 to 15 and 7 to 8 micrometers thick, respectively. The later cracks are thought to have been formed by glacial loading during the Bull Lake and Pinedale glaciations, when an estimated 800 meters of ice covered the Obsidian Cliff flow.

  9. Hysteresis of methane hydrate formation/decomposition at subsea geological conditions

    International Nuclear Information System (INIS)

    Klapproth, Alice; Piltz, Ross; Peterson, Vanessa K.; Kennedy, Shane J.; Kozielski, Karen A.; Hartley, Patrick G.

    2009-01-01

    Full text: Gas hydrates are a major risk when transporting oil and gas in offshore subsea pipelines. Under typical conditions in these pipelines (at high pressure and low temperature) the formation of gas hydrates is favourable. The hydrates form large solid plugs that can block pipelines and can even cause them to burst. This represents a major problem for the gas mining industry, which currently goes to extreme measures to reduce the risk of hydrate formation because there is no reliable experimental data on hydrate processes. The mechanisms of gas hydrate formation, growth and inhibition are poorly understood. A clear understanding of the fundamental processes will allow development of cost effective technologies to avoid production losses in gas pipelines. We are studying the nucleation of the methane hydrates by measuring the hysteresis of hydrate formation/decomposition by neutron diffraction. When a gas hydrate is decomposed (melted) the resulting water has a 'supposed memory effect' raising the probability of rapid hydrate reformation. This rapid reformation does not occur for pure water where nucleation can be delayed by several hours (induction time) due to metastability [1]. The memory effect can only be destroyed by extreme heating of the effected area. Possible causes of this effect include residual water structure, persistent hydrate crystal lites remaining in solution and remaining dissolved gas. We will compare the kinetics of formation and the stability region of hydrate formation of 'memory' water for comparison with pure water. This information has important implications for the oil and gas industry because it should provide a better understanding of the role of multiple dissociation and reformation of gas hydrates in plug formation.

  10. Hydration water and microstructure in calcium silicate and aluminate hydrates

    International Nuclear Information System (INIS)

    Fratini, Emiliano; Ridi, Francesca; Chen, Sow-Hsin; Baglioni, Piero

    2006-01-01

    Understanding the state of the hydration water and the microstructure development in a cement paste is likely to be the key for the improvement of its ultimate strength and durability. In order to distinguish and characterize the reacted and unreacted water, the single-particle dynamics of water molecules in hydrated calcium silicates (C 3 S, C 2 S) and aluminates (C 3 A, C 4 AF) were studied by quasi-elastic neutron scattering, QENS. The time evolution of the immobile fraction represents the hydration kinetics and the mobile fraction follows a non-Debye relaxation. Less sophisticated, but more accessible and cheaper techniques, like differential scanning calorimetry, DSC, and near-infrared spectroscopy, NIR, were validated through QENS results and they allow one to easily and quantitatively follow the cement hydration kinetics and can be widely applied on a laboratory scale to understand the effect of additives (i.e., superplasticizers, cellulosic derivatives, etc) on the thermodynamics of the hydration process. DSC provides information on the free water index and on the activation energy involved in the hydration process while the NIR band at 7000 cm -1 monitors, at a molecular level, the increase of the surface-interacting water. We report as an example the effect of two classes of additives widely used in the cement industry: superplasticizers, SPs, and cellulose derivatives. SPs interact at the solid surface, leading to a consistent increment of the activation energy for the processes of nucleation and growth of the hydrated phases. In contrast, the cellulosic additives do not affect the nucleation and growth activation energy, but cause a significant increment in the water availability: in other words the hydration process is more efficient without any modification of the solid/liquid interaction, as also evidenced by the 1 H-NMR. Additional information is obtained by scanning electron microscopy (SEM), ultra small angle neutron scattering (USANS) and wide

  11. Hydration dependent dynamics in RNA

    International Nuclear Information System (INIS)

    Olsen, Greg L.; Bardaro, Michael F.; Echodu, Dorothy C.; Drobny, Gary P.; Varani, Gabriele

    2009-01-01

    The essential role played by local and collective motions in RNA function has led to a growing interest in the characterization of RNA dynamics. Recent investigations have revealed that even relatively simple RNAs experience complex motions over multiple time scales covering the entire ms-ps motional range. In this work, we use deuterium solid-state NMR to systematically investigate motions in HIV-1 TAR RNA as a function of hydration. We probe dynamics at three uridine residues in different structural environments ranging from helical to completely unrestrained. We observe distinct and substantial changes in 2 H solid-state relaxation times and lineshapes at each site as hydration levels increase. By comparing solid-state and solution state 13 C relaxation measurements, we establish that ns-μs motions that may be indicative of collective dynamics suddenly arise in the RNA as hydration reaches a critical point coincident with the onset of bulk hydration. Beyond that point, we observe smaller changes in relaxation rates and lineshapes in these highly hydrated solid samples, compared to the dramatic activation of motion occurring at moderate hydration

  12. Policy Issues in Gay and Lesbian Adoption.

    Science.gov (United States)

    Sullivan, Ann

    1995-01-01

    Notes that adoption agencies have developed few specific policies on the issue of lesbian and gay adoption. Provides an overview of key considerations about homosexual adopters, including beliefs and values of agency professionals, the legal and social ramifications of adoption into a relationship not based on marriage, and possible consequences…

  13. Parental Influence, Gay Youths, and Safer Sex

    Science.gov (United States)

    LaSala, Michael C.

    2007-01-01

    To begin to understand the role that family relationships and interactions play in young gay men's decisions to avoid unsafe sexual practices, parents and sons (ages 16 to 25) in 30 families were qualitatively interviewed about issues and concerns related to HIV risk. Most of the youths reported feeling obliged to their parents to stay healthy,…

  14. Medical students' attitudes toward gay men.

    Science.gov (United States)

    Matharu, Kabir; Kravitz, Richard L; McMahon, Graham T; Wilson, Machelle D; Fitzgerald, Faith T

    2012-08-08

    Healthcare providers' attitudes toward sexual minorities influence patient comfort and outcomes. This study characterized medical student attitudes toward gay men, focusing on behavior, personhood, gay civil rights, and male toughness. A cross-sectional web-based anonymous survey was sent to medical students enrolled at the University of California, Davis (N = 371) with a response rate of 68%. Few respondents expressed negative attitudes toward gay men or would deny them civil rights. More negative responses were seen with respect to aspects of intimate behavior and homosexuality as a natural form of sexual expression. Men and students younger than 25 years old were more likely to endorse negative attitudes toward behavior as well as more traditional views on male toughness. We show that an important minority of students express discomfort with the behavior of gay men and hold to a narrow construction of male identity. These findings suggest that competency training must move beyond conceptual discussions and address attitudes toward behaviors through new pedagogical approaches.

  15. California Considers Adding Gays' Contributions to Textbooks

    Science.gov (United States)

    Manzo, Kathleen Kennedy

    2006-01-01

    A bill that has been sent to the floor of the California Senate would require textbooks used in public schools to include information on the roles and contributions of gay people throughout history, a move that could affect the content of instructional materials throughout much of the country. The measure would help build tolerance of diverse…

  16. Medical students’ attitudes toward gay men

    Science.gov (United States)

    2012-01-01

    Background Healthcare providers’ attitudes toward sexual minorities influence patient comfort and outcomes. This study characterized medical student attitudes toward gay men, focusing on behavior, personhood, gay civil rights, and male toughness. Methods A cross-sectional web-based anonymous survey was sent to medical students enrolled at the University of California, Davis (N = 371) with a response rate of 68%. Results Few respondents expressed negative attitudes toward gay men or would deny them civil rights. More negative responses were seen with respect to aspects of intimate behavior and homosexuality as a natural form of sexual expression. Men and students younger than 25 years old were more likely to endorse negative attitudes toward behavior as well as more traditional views on male toughness. Conclusions We show that an important minority of students express discomfort with the behavior of gay men and hold to a narrow construction of male identity. These findings suggest that competency training must move beyond conceptual discussions and address attitudes toward behaviors through new pedagogical approaches. PMID:22873668

  17. Medical students’ attitudes toward gay men

    Directory of Open Access Journals (Sweden)

    Matharu Kabir

    2012-08-01

    Full Text Available Abstract Background Healthcare providers’ attitudes toward sexual minorities influence patient comfort and outcomes. This study characterized medical student attitudes toward gay men, focusing on behavior, personhood, gay civil rights, and male toughness. Methods A cross-sectional web-based anonymous survey was sent to medical students enrolled at the University of California, Davis (N = 371 with a response rate of 68%. Results Few respondents expressed negative attitudes toward gay men or would deny them civil rights. More negative responses were seen with respect to aspects of intimate behavior and homosexuality as a natural form of sexual expression. Men and students younger than 25 years old were more likely to endorse negative attitudes toward behavior as well as more traditional views on male toughness. Conclusions We show that an important minority of students express discomfort with the behavior of gay men and hold to a narrow construction of male identity. These findings suggest that competency training must move beyond conceptual discussions and address attitudes toward behaviors through new pedagogical approaches.

  18. Gay Rights on Campus, circa 2011

    Science.gov (United States)

    Cramer, Elizabeth P.; Ford, Charles H.

    2011-01-01

    The environment for lesbian, gay, bisexual, and transgender (LGBT) students, staff, and faculty on college campuses has certainly improved over the last generation, but recent dramatic episodes confirm the continuing need for vigilance and reform. Students remain the constituency most vulnerable to the effects of entrenched bigotry: the harassment…

  19. Sampling Lesbian, Gay, and Bisexual Populations

    Science.gov (United States)

    Meyer, Ilan H.; Wilson, Patrick A.

    2009-01-01

    Sampling has been the single most influential component of conducting research with lesbian, gay, and bisexual (LGB) populations. Poor sampling designs can result in biased results that will mislead other researchers, policymakers, and practitioners. Investigators wishing to study LGB populations must therefore devote significant energy and…

  20. College Students' Attitudes toward Gays and Lesbians

    Science.gov (United States)

    Chonody, Jill M.; Siebert, Darcy Clay; Rutledge, Scott Edward

    2009-01-01

    A variety of pedagogical techniques have shown promising results in promoting acceptance and affirmation of gays and lesbians among students in social work, allied health, and education professions. In this article we examine whether 211 students enrolled in a human sexuality course in a southeastern university changed their attitudes toward gays…

  1. Method of purifying uranium tetrafluoride hydrate and preparing uranium (VI) peroxide hydrate using a fluoride complexing agent

    International Nuclear Information System (INIS)

    Barreiro, A.J.; Lowe, C.M.T.; Lefever, J.A.; Pyman, R.L.

    1983-01-01

    The annual production of phosphate rock, on the order of about 30-40 million tons yearly, represents several million pounds of uranium. The present invention provides a process of purifying uranium tetrafluoride hydrate to produce a uranium (VI) peroxide product meeting 'yellow cake' standards using a double precipitation procedure. A fluoride complexing agent is used in the precipitation

  2. Mechanism of gypsum hydration

    Directory of Open Access Journals (Sweden)

    Pacheco, G.

    1991-06-01

    Full Text Available There is an hypothesis that the mechanism o f gypsum hydration and dehydration is performed through two simultaneous phenomena. In this study we try to clear up this phenomenon using chlorides as accelerators or a mixture of ethanol-methanol as retarders to carry out the gypsum setting. Natural Mexican gypsum samples and a hemihydrate prepared in the laboratory are used. The following analytical techniques are used: MO, DRX, DTA, TG and DTG. In agreement with the obtained results, it can be concluded: that colloid formation depends on the action of accelerators or retarders and the crystals are a consequence of the quantity of hemihydrate formed.

    En el mecanismo de hidratación y deshidratación del yeso existe la hipótesis de que éste se efectúa por dos fenómenos simultáneos. Este estudio intenta esclarecer estos fenómenos, empleando: cloruros como aceleradores o mezcla etanol-metanol como retardadores para efectuar el fraguado del yeso. Se emplean muestras de yeso de origen natural mexicano y hemihydrate preparado en laboratorio; se utilizan técnicas analíticas: MO, DRX, DTA, TG y DTG. De acuerdo a los resultados obtenidos se puede deducir: que la formación del coloide depende de la acción de los agentes aceleradores o retardadores y que los cristales son consecuencia de la cantidad de hemihidrato formado.

  3. Permafrost-associated natural gas hydrate occurrences on the Alaska North Slope

    Science.gov (United States)

    Collett, T.S.; Lee, M.W.; Agena, W.F.; Miller, J.J.; Lewis, K.A.; Zyrianova, M.V.; Boswell, R.; Inks, T.L.

    2011-01-01

    In the 1960s Russian scientists made what was then a bold assertion that gas hydrates should occur in abundance in nature. Since this early start, the scientific foundation has been built for the realization that gas hydrates are a global phenomenon, occurring in permafrost regions of the arctic and in deep water portions of most continental margins worldwide. In 1995, the U.S. Geological Survey made the first systematic assessment of the in-place natural gas hydrate resources of the United States. That study suggested that the amount of gas in the gas hydrate accumulations of northern Alaska probably exceeds the volume of known conventional gas resources on the North Slope. Researchers have long speculated that gas hydrates could eventually become a producible energy resource, yet technical and economic hurdles have historically made gas hydrate development a distant goal. This view began to change in recent years with the realization that this unconventional resource could be developed with existing conventional oil and gas production technology. One of the most significant developments was the completion of the BPXA-DOE-USGS Mount Elbert Gas Hydrate Stratigraphic Test Well on the Alaska North Slope, which along with the Mallik project in Canada, have for the first time allowed the rational assessment of gas hydrate production technology and concepts. Almost 40 years of gas hydrate research in northern Alaska has confirmed the occurrence of at least two large gas hydrate accumulations on the North Slope. We have also seen in Alaska the first ever assessment of how much gas could be technically recovered from gas hydrates. However, significant technical concerns need to be further resolved in order to assess the ultimate impact of gas hydrate energy resource development in northern Alaska. ?? 2009 Elsevier Ltd.

  4. Moessbauer and calorimetric studies of portland cement hydration in the presence of black gram pulse

    International Nuclear Information System (INIS)

    Rai, Sarita; Kurian, Sajith; Dwivedi, V. N.; Das, S. S.; Singh, N. B.; Gajbhiye, N. S.

    2009-01-01

    Effect of different concentrations of naturally occurring admixture in the form of fine powder of black gram pulse (BGP) on the hydration of Portland cement was studied by isothermal calorimetry and 57 Fe Moessbauer spectroscopy. The spectra were recorded for anhydrous cement and the hydration products at room temperature and 77 K. In the presence of BGP, the spectra showed superparamagnetic doublets at room temperature and the sextet at 77 K, due to the presence of fine particles of iron containing component. Moessbauer studies of hydration products confirmed the formation of nanosize hydration products containing Fe 3+ . The isomer shift (δ) and the quadrupole splitting (ΔE Q ) values of C 4 AF in the cement confirmed iron in an octahedral and tetrahedral environment with +3 oxidation state. The high value of quadrupole splitting showed the high asymmetry of the electron environment around the iron atom. The overall mechanism of the hydration of cement in presence of BGP is discussed.

  5. Reconsideration on Hydration of Sodium Ion: From Micro-Hydration to Bulk Hydration

    Science.gov (United States)

    Yongquan, Zhou; Chunhui, Fang; Yan, Fang; Fayan, Zhu; Haiwen, Ge; Hongyan, Liu

    2017-12-01

    Micro hydration structures of the sodium ion, [Na(H2O) n ]+, n = 1-12, were probed by density functional theory (DFT) at B3LYP/aug-cc-pVDZ level in both gaseous and aqueous phase. The predicted equilibrium sodium-oxygen distance of 0.240 nm at the present level of theory. The four-, five- and six-coordinated cluster can transform from each other at the ambient condition. The analysis of the successive water binding energy and natural charge population (NBO) on Na+ clearly shows that the influence of Na+ on the surrounding water molecules goes beyond the first hydration shell with the hydration number of 6. The Car-Parrinello molecular dynamic simulation shows that only the first hydration sphere can be found, and the hydration number of Na+ is 5.2 and the hydration distance ( r Na-O) is 0.235 nm. All our simulations mentioned in the present paper show an excellent agreement with the diffraction result from X-ray scattering study.

  6. Race Fucker: representações raciais na pornografia gay Race Fucker: racial representations in gay pornography

    Directory of Open Access Journals (Sweden)

    Osmundo Pinho

    2012-06-01

    Full Text Available Neste estudo, procuro explorar determinada perspectiva crítica relacionada à articulação entre raça, sexualidade e gênero, entendendo que a pornografia gay se prestaria exemplarmente a flagrar a produção de um sistema ordenado de classificações e categorias, estereótipos e representações, instituídos como um discurso capaz de ser lido como o inventário da fetichização socialmente produzida para o desejo sexual racializado. Para desenvolver essa perspectiva apresento uma breve discussão teórica sobre a pornografia, interrogada pela articulação prazer/poder e a leitura de três conjuntos êmicos de representação racial associados ao desejo homossexual: a negritude, a branquidade e a brasilidade.In this study the author seeks to explore a specific critical perspective related to the race, sexuality and gender articulation, understanding that gay pornography will be exemplary to show the production of a coordinated system of classifications and categories, stereotypes and representations built as a discourse that may be read as a socially produced inventory of fetichization for racialized sexual desire. In order to develop this view the author presents a short theoretical discussion on pornography, interrogated by the power/pleasure articulation and the reading of three hemic corpora of racial representation related to homosexual desire: blackness, whiteness and brazilianness.

  7. Different Mechanism Effect between Gas-Solid and Liquid-Solid Interface on the Three-Phase Coexistence Hydrate System Dissociation in Seawater: A Molecular Dynamics Simulation Study

    Directory of Open Access Journals (Sweden)

    Zhixue Sun

    2017-12-01

    Full Text Available Almost 98% of methane hydrate is stored in the seawater environment, the study of microscopic mechanism for methane hydrate dissociation on the sea floor is of great significance to the development of hydrate production, involving a three-phase coexistence system of seawater (3.5% NaCl + hydrate + methane gas. The molecular dynamics method is used to simulate the hydrate dissociation process. The dissociation of hydrate system depends on diffusion of methane molecules from partially open cages and a layer by layer breakdown of the closed cages. The presence of liquid or gas phases adjacent to the hydrate has an effect on the rate of hydrate dissociation. At the beginning of dissociation process, hydrate layers that are in contact with liquid phase dissociated faster than layers adjacent to the gas phase. As the dissociation continues, the thickness of water film near the hydrate-liquid interface became larger than the hydrate-gas interface giving more resistance to the hydrate dissociation. Dissociation rate of hydrate layers adjacent to gas phase gradually exceeds the dissociation rate of layers adjacent to the liquid phase. The difficulty of methane diffusion in the hydrate-liquid side also brings about change in dissociation rate.

  8. #GoAllOut: A Physician's Reflection on Gay Games 9.

    Science.gov (United States)

    Ng, Henry H

    2015-03-01

    The article addresses the author's perspectives on the Gay Games on individual, community and public health. Using the Gay Games motto of "Participation, Inclusion, Personal Best," the author will explore the many benefits and effects of the Gay Games.

  9. Formation and dissociation of CO{sub 2} and CO{sub 2}-THF hydrates compared to CH{sub 4} and CH{sub 4}-THF hydrates

    Energy Technology Data Exchange (ETDEWEB)

    Giavarini, C.; Maccioni, F.; Broggi, A. [Roma Univ. La Sapienza, Roma (Italy). Dept. of Chemical Engineering; Politi, M. [ENEL-RICERCHE, Brindisi (Italy)

    2008-07-01

    Carbon sequestration involves the removal of greenhouse gases from industrial or utility plant streams and their long term storage so that they cannot interact with the climate system. Different methods for selective carbon dioxide (CO{sub 2}) removal are in commercial use and are based on, gas absorption, membrane process, and cryogenic fractionation. In addition, disposal of captured CO{sub 2} in the ocean and in geological reservoirs has been proposed by researchers. Another challenge is to take advantage of the properties of CO{sub 2} hydrates for carbon sequestration since it could have a number of uses such as chemical production. As such, it is important to understand the hydrate decomposition kinetics during storage, transportation, and disposal. This paper presented a project that involved the separation of carbon dioxide from the flue gases of powers plants, in the form of hydrate. The project also involved the storage, use, and disposal of the hydrate. The purpose of the study was to evaluate the decomposition kinetics of CO{sub 2} hydrate containing different quantities of ice, at low pressures and temperatures between -3 and 0 degrees Celsius. In addition, in order to evaluate the tetrahydrofuran (THF) stabilization effect, the study examined the influence of THF on the formation and decomposition kinetics of mixed THF-methane (CH{sub 4}) and THF-CO{sub 2} hydrates. Preservation tests were conducted to determine the best pressure and temperature conditions for the mixed-hydrates conservation, with reference to the simple hydrates. The paper described the apparatus for the formation and dissociation tests which consisted of a jacketed stainless steel reactor, equipped with stirrer. The paper also described the hydrate formation procedure as well as hydrate characterization. Last, the paper discussed the hydrate dissociation tests that were conducted immediately after hydrate formation in the reactor. It was concluded that the hydrophilic and hydrophobic

  10. Storage capacity of hydrogen in gas hydrates

    International Nuclear Information System (INIS)

    Tsuda, Takaaki; Ogata, Kyohei; Hashimoto, Shunsuke; Sugahara, Takeshi; Sato, Hiroshi; Ohgaki, Kazunari

    2010-01-01

    The storage capacity of H 2 in the THF, THT, and furan hydrates was studied by p-V-T measurements. We confirmed that the storage and release processes of H 2 in all hydrates could be performed reversibly by pressure swing without destroying of hydrate cages. H 2 absorption in both THT and furan hydrates is much faster than THF hydrate in spite of same unit-cell structure. On the other hand, the storage amounts of H 2 are coincident in the all additive hydrates and would reach at about 1.0 mass% asymptotically.

  11. Permeability of sediment cores from methane hydrate deposit in the Eastern Nankai Trough, Japan

    Science.gov (United States)

    Konno, Y.; Yoneda, J.; Egawa, K.; Ito, T.; Jin, Y.; Kida, M.; Suzuki, K.; Nakatsuka, Y.; Nagao, J.

    2013-12-01

    Effective and absolute permeability are key parameters for gas production from methane-hydrate-bearing sandy sediments. Effective and/or absolute permeability have been measured using methane-hydrate-bearing sandy cores and clayey and silty cores recovered from Daini Atsumi Knoll in the Eastern Nankai Trough during the 2012 JOGMEC/JAPEX Pressure coring operation. Liquid-nitrogen-immersed cores were prepared by rapid depressurization of pressure cores recovered by a pressure coring system referred to as the Hybrid PCS. Cores were shaped cylindrically on a lathe with spraying of liquid nitrogen to prevent hydrate dissociation. Permeability was measured by a flooding test or a pressure relaxation method under near in-situ pressure and temperature conditions. Measured effective permeability of hydrate-bearing sediments is less than tens of md, which are order of magnitude less than absolute permeability. Absolute permeability of clayey cores is approximately tens of μd, which would perform a sealing function as cap rocks. Permeability reduction due to a swelling effect was observed for a silty core during flooding test of pure water mimicking hydrate-dissociation-water. Swelling effect may cause production formation damage especially at a later stage of gas production from methane hydrate deposits. This study was financially supported by the Research Consortium for Methane Hydrate Resources in Japan (MH21 Research Consortium) that carries out Japan's Methane Hydrate R&D Program conducted by the Ministry of Economy, Trade and Industry (METI).

  12. The analysis of magnesium oxide hydration in three-phase reaction system

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Xiaojia; Guo, Lin; Chen, Chen; Liu, Quan; Li, Tie; Zhu, Yimin, E-mail: ntp@dlmu.edu.cn

    2014-05-01

    In order to investigate the magnesium oxide hydration process in gas–liquid–solid (three-phase) reaction system, magnesium hydroxide was prepared by magnesium oxide hydration in liquid–solid (two-phase) and three-phase reaction systems. A semi-empirical model and the classical shrinking core model were used to fit the experimental data. The fitting result shows that both models describe well the hydration process of three-phase system, while only the semi-empirical model right for the hydration process of two-phase system. The characterization of the hydration product using X-Ray diffraction (XRD) and scanning electron microscope (SEM) was performed. The XRD and SEM show hydration process in the two-phase system follows common dissolution/precipitation mechanism. While in the three-phase system, the hydration process undergo MgO dissolution, Mg(OH){sub 2} precipitation, Mg(OH){sub 2} peeling off from MgO particle and leaving behind fresh MgO surface. - Graphical abstract: There was existence of a peeling-off process in the gas–liquid–solid (three-phase) MgO hydration system. - Highlights: • Magnesium oxide hydration in gas–liquid–solid system was investigated. • The experimental data in three-phase system could be fitted well by two models. • The morphology analysis suggested that there was existence of a peel-off process.

  13. International Society of Nephrology-Hydration and Kidney Health Initiative - Expanding Research and Knowledge.

    Science.gov (United States)

    Moist, Louise M; Clark, William F; Segantini, Luca; Damster, Sandrine; Le Bellego, Laurent; Wong, Germaine; Tonelli, Marcello

    2016-01-01

    The purpose of this manuscript is to describe a collaborative research initiative to explore the role of hydration in kidney health. Our understanding of the effects of hydration in health and disease is surprisingly limited, particularly when we consider the vital role of hydration in basic human physiology. Recent initiatives and research outcomes have challenged the global medical community to expand our knowledge about hydration, including the differences between water, sugared beverages and other consumables. Identification of the potential mechanisms contributing to the benefits of hydration has stimulated the global nephrology community to advance research regarding hydration for kidney health. Hydration and kidney health has been a focus of research for several research centers with a rapidly expanding world literature and knowledge. The International Society of Nephrology has collaborated with Danone Nutricia Research to promote development of kidney research initiatives, which focus on the role of hydration in kidney health and the global translation of this new information. This initiative supports the use of existing data in different regions and countries to expand dialogue among experts in the field of hydration and health, and to increase scientific interaction and productivity with the ultimate goal of improving kidney health. © 2016 The Author(s) Published by S. Karger AG, Basel.

  14. Origins of saccharide-dependent hydration at aluminate, silicate, and aluminosilicate surfaces.

    Science.gov (United States)

    Smith, Benjamin J; Rawal, Aditya; Funkhouser, Gary P; Roberts, Lawrence R; Gupta, Vijay; Israelachvili, Jacob N; Chmelka, Bradley F

    2011-05-31

    Sugar molecules adsorbed at hydrated inorganic oxide surfaces occur ubiquitously in nature and in technologically important materials and processes, including marine biomineralization, cement hydration, corrosion inhibition, bioadhesion, and bone resorption. Among these examples, surprisingly diverse hydration behaviors are observed for oxides in the presence of saccharides with closely related compositions and structures. Glucose, sucrose, and maltodextrin, for example, exhibit significant differences in their adsorption selectivities and alkaline reaction properties on hydrating aluminate, silicate, and aluminosilicate surfaces that are shown to be due to the molecular architectures of the saccharides. Solid-state (1)H, (13)C, (29)Si, and (27)Al nuclear magnetic resonance (NMR) spectroscopy measurements, including at very high magnetic fields (19 T), distinguish and quantify the different molecular species, their chemical transformations, and their site-specific adsorption on different aluminate and silicate moieties. Two-dimensional NMR results establish nonselective adsorption of glucose degradation products containing carboxylic acids on both hydrated silicates and aluminates. In contrast, sucrose adsorbs intact at hydrated silicate sites and selectively at anhydrous, but not hydrated, aluminate moieties. Quantitative surface force measurements establish that sucrose adsorbs strongly as multilayers on hydrated aluminosilicate surfaces. The molecular structures and physicochemical properties of the saccharides and their degradation species correlate well with their adsorption behaviors. The results explain the dramatically different effects that small amounts of different types of sugars have on the rates at which aluminate, silicate, and aluminosilicate species hydrate, with important implications for diverse materials and applications.

  15. Reported Effects of Masculine Ideals on Gay Men.

    Science.gov (United States)

    Sánchez, Francisco J; Greenberg, Stefanie T; Liu, William Ming; Vilain, Eric

    2009-01-01

    This exploratory study used consensual qualitative research methodology (Hill et al., 2005) to analyze what gay men associate with masculinity and femininity, how they feel masculine ideals affect their self-image, and how masculine ideals affect their same-sex relationships. Written responses were collected from 547 self-identified gay men in the U.S. via an Internet-based survey. Findings supported previous reports that perceptions of gender roles among gay men appear based on masculine and feminine stereotypes. Additionally, more adverse versus positive effects on self-image and same-sex romantic relationships were reported including difficulty being emotional and affectionate, pressure to be physically attractive, and pressure to appear masculine in order to be accepted by society and to be seen as desirable by other gay men. While research on gay men's experience with masculinity continues, psychologists should consider the possible influence of traditional masculine ideals when conceptualizing their gay male clients.

  16. How Like Perceives Like: Gay People on "Gaydar".

    Science.gov (United States)

    Barton, Bernadette

    2015-01-01

    When lacking explicit knowledge of someone's sexual orientation, gay people commonly assess the likelihood that another is gay using their "gaydar." The term gaydar is a playful mix of the word gay with radar, suggesting that one can sense, intuit, or perceive some set of characteristics in another that signal a shared minority status. While commonly mentioned, the exact criteria a gay person uses when employing their gaydar are little discussed. Drawing methodologically on a series of five focus groups of self-identified lesbians and gay men, this study explores the physical, visual, energetic, and conversational cues gay people consider when they employ the trope of gaydar. Specifically, interview subjects most often described their gaydar as triggered by the following elements: physical presentation, including mannerisms, dress, and voice; interactions, especially eye contact; a presence or absence of certain conversational social norms; and, intangibly, as a kind of energetic exchange.

  17. Hydration mechanism and leaching behavior of bauxite-calcination-method red mud-coal gangue based cementitious materials

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Na; Li, Hongxu [School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing 100083 (China); Beijing Key Laboratory of Rare and Precious Metals Green Recycling and Extraction, University of Science and Technology Beijing, Beijing 100083 (China); Liu, Xiaoming, E-mail: liuxm@ustb.edu.cn [School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing 100083 (China); Beijing Key Laboratory of Rare and Precious Metals Green Recycling and Extraction, University of Science and Technology Beijing, Beijing 100083 (China)

    2016-08-15

    Highlights: • Nanocrystalline regions in size of ∼5 nm were found in the amorphous C-A-S-H gel. • A hydration model was proposed to clarify the hydration mechanism. • The developed cementitious materials are environmentally acceptable. - Abstract: A deep investigation on the hydration mechanism of bauxite-calcination-method red mud-coal gangue based cementitious materials was conducted from viewpoints of hydration products and hydration heat analysis. As a main hydration product, the microstructure of C-A-S-H gel was observed using high resolution transmission electron microscopy. It was found that the C-A-S-H gel is composed of amorphous regions and nanocrystalline regions. Most of regions in the C-A-S-H gel are amorphous with continuous distribution, and the nanocrystalline regions on scale of ∼5 nm are dispersed irregularly within the amorphous regions. The hydration heat of red mud-coal gangue based cementitious materials is much lower than that of the ordinary Portland cement. A hydration model was proposed for this kind of cementitious materials, and the hydration process mainly consists of four stages which are dissolution of materials, formation of C-A-S-H gels and ettringite, cementation of hydration products, and polycondensation of C-A-S-H gels. There are no strict boundaries among these four basic stages, and they proceed crossing each other. Moreover, the leaching toxicity tests were also performed to prove that the developed red mud-coal gangue based cementitious materials are environmentally acceptable.

  18. Hydration mechanism and leaching behavior of bauxite-calcination-method red mud-coal gangue based cementitious materials

    International Nuclear Information System (INIS)

    Zhang, Na; Li, Hongxu; Liu, Xiaoming

    2016-01-01

    Highlights: • Nanocrystalline regions in size of ∼5 nm were found in the amorphous C-A-S-H gel. • A hydration model was proposed to clarify the hydration mechanism. • The developed cementitious materials are environmentally acceptable. - Abstract: A deep investigation on the hydration mechanism of bauxite-calcination-method red mud-coal gangue based cementitious materials was conducted from viewpoints of hydration products and hydration heat analysis. As a main hydration product, the microstructure of C-A-S-H gel was observed using high resolution transmission electron microscopy. It was found that the C-A-S-H gel is composed of amorphous regions and nanocrystalline regions. Most of regions in the C-A-S-H gel are amorphous with continuous distribution, and the nanocrystalline regions on scale of ∼5 nm are dispersed irregularly within the amorphous regions. The hydration heat of red mud-coal gangue based cementitious materials is much lower than that of the ordinary Portland cement. A hydration model was proposed for this kind of cementitious materials, and the hydration process mainly consists of four stages which are dissolution of materials, formation of C-A-S-H gels and ettringite, cementation of hydration products, and polycondensation of C-A-S-H gels. There are no strict boundaries among these four basic stages, and they proceed crossing each other. Moreover, the leaching toxicity tests were also performed to prove that the developed red mud-coal gangue based cementitious materials are environmentally acceptable.

  19. Differential thermal, Thermogravimetric and X-ray diffraction investigation of hydration phases in cementitious waste form

    International Nuclear Information System (INIS)

    Khalil, M.Y.; Nagy, M.E.; El-Sourougy, M.R.; Zaki, A.A.

    1996-01-01

    Hydration phases of cement determine the final properties of the product. Adding other components to the cement paste may alter the final phases formed and affect properties of the hardened products. In this work ordinary portland cement and/or blast furnace slag cement were hardened with low-or intermediate-level radioactive liquid wastes and different additives. Hydration phases were investigated using differential thermal, thermogravimetric, and X-ray diffraction techniques. Low-and intermediate-level liquid wastes were found not to affect the hydration phases of cement. The addition of inorganic exchangers and latex were found to affect the hydration properties of the cement waste system. This resulted in a reduction of compressive strength. On the contrary, addition of epoxy also affected the hydration causing increase in compressive strength. 10 figs., 2 tabs

  20. Reported Effects of Masculine Ideals on Gay Men

    OpenAIRE

    Sánchez, Francisco J.; Greenberg, Stefanie T.; Liu, William Ming; Vilain, Eric

    2009-01-01

    This exploratory study used consensual qualitative research methodology (Hill et al., 2005) to analyze what gay men associate with masculinity and femininity, how they feel masculine ideals affect their self-image, and how masculine ideals affect their same-sex relationships. Written responses were collected from 547 self-identified gay men in the U.S. via an Internet-based survey. Findings supported previous reports that perceptions of gender roles among gay men appear based on masculine and...

  1. [Sputum viscosity and pulmonary function measurements during a one-week parenteral treatment with a standardized oxidation product of oil of turpentine and terpin hydrate].

    Science.gov (United States)

    Löllgen-Horres, I; Löllgen, H

    1976-01-01

    In 23 patients with chronic obstructive lung diseases, viscosity, airway resistance, arterial blood gases and acid-base balance, and sputum aspect were measured before and after one-week treatment with Ozothin, a substance from oxidation products of ol. terebinth. and terpinum hydratum. Within this time, viscosity of the sputum was reduced, airway resistance decreased, and arterial oxygen pressure slightly increased, whereas arterial carbon dioxide tension obvious change of sputum aspect could be observed. Correlation calculations revealed no significant relations between viscosity and the above cited lung function values. The results indicate that administration of Ozothin may liquefy viscous secretion and reduce sputum viscosity.

  2. Counseling Issues for Gay Men and Lesbians Seeking Assisted Reproductive Technologies (ART)

    Science.gov (United States)

    ... for Reproductive Medicine Counseling issues to discuss with gay men and lesbians seeking assisted reproductive technology (ART) More lesbian, gay, bisexual, and transgender (LGBT) individuals and couples are ...

  3. Gay and lesbian mental health: a sourcebook for practitioners

    National Research Council Canada - National Science Library

    Alexander, Christopher J

    1996-01-01

    ...: parenting, coming out processes of lesbians, gay men's self-image, adolescence as a homosexual, parental guidance of homosexual children, eating disorders, aging, dual needs of ethnic homosexuals...

  4. Sorbitol dehydration into isosorbide in a molten salt hydrate medium

    NARCIS (Netherlands)

    Li, J.; Spina, A.; Moulijn, J.A.; Makkee, M.

    2013-01-01

    The sorbitol conversion in a molten salt hydrate medium (ZnCl2; 70 wt% in water) was studied. Dehydration is the main reaction, initially 1,4- and 3,6-anhydrosorbitol are the main products that are subsequently converted into isosorbide; two other anhydrohexitols, (1,5- and 2,5-), formed are in less

  5. Modeling the influence of limestone addition on cement hydration

    Directory of Open Access Journals (Sweden)

    Ashraf Ragab Mohamed

    2015-03-01

    Full Text Available This paper addresses the influence of using Portland limestone cement “PLC” on cement hydration by characterization of its microstructure development. The European Standard EN 197-1:2011 and Egyptian specification ESS 4756-1/2009 permit the cement to contain up to 20% ground limestone. The computational tools assist in better understanding the influence of limestone additions on cement hydration and microstructure development to facilitate the acceptance of these more economical and ecological materials. μic model has been developed to enable the modeling of microstructural evolution of cementitious materials. In this research μic model is used to simulate both the influence of limestone as fine filler, providing additional surfaces for the nucleation and growth of hydration products. Limestone powder also reacts relatively slow with hydrating cement to form monocarboaluminate (AFmc phase, similar to the mono-sulfoaluminate (AFm phase formed in ordinary Portland cement. The model results reveal that limestone cement has accelerated cement hydration rate, previous experimental results and computer model “cemhyd3d” are used to validate this model.

  6. Gas Hydrate Research Database and Web Dissemination Channel

    Energy Technology Data Exchange (ETDEWEB)

    Micheal Frenkel; Kenneth Kroenlein; V Diky; R.D. Chirico; A. Kazakow; C.D. Muzny; M. Frenkel

    2009-09-30

    To facilitate advances in application of technologies pertaining to gas hydrates, a United States database containing experimentally-derived information about those materials was developed. The Clathrate Hydrate Physical Property Database (NIST Standard Reference Database {number_sign} 156) was developed by the TRC Group at NIST in Boulder, Colorado paralleling a highly-successful database of thermodynamic properties of molecular pure compounds and their mixtures and in association with an international effort on the part of CODATA to aid in international data sharing. Development and population of this database relied on the development of three components of information-processing infrastructure: (1) guided data capture (GDC) software designed to convert data and metadata into a well-organized, electronic format, (2) a relational data storage facility to accommodate all types of numerical and metadata within the scope of the project, and (3) a gas hydrate markup language (GHML) developed to standardize data communications between 'data producers' and 'data users'. Having developed the appropriate data storage and communication technologies, a web-based interface for both the new Clathrate Hydrate Physical Property Database, as well as Scientific Results from the Mallik 2002 Gas Hydrate Production Research Well Program was developed and deployed at http://gashydrates.nist.gov.

  7. Heat Transfer Analysis of Methane Hydrate Sediment Dissociation in a Closed Reactor by a Thermal Method

    Directory of Open Access Journals (Sweden)

    Mingjun Yang

    2012-05-01

    Full Text Available The heat transfer analysis of hydrate-bearing sediment involved phase changes is one of the key requirements of gas hydrate exploitation techniques. In this paper, experiments were conducted to examine the heat transfer performance during hydrate formation and dissociation by a thermal method using a 5L volume reactor. This study simulated porous media by using glass beads of uniform size. Sixteen platinum resistance thermometers were placed in different position in the reactor to monitor the temperature differences of the hydrate in porous media. The influence of production temperature on the production time was also investigated. Experimental results show that there is a delay when hydrate decomposed in the radial direction and there are three stages in the dissociation period which is influenced by the rate of hydrate dissociation and the heat flow of the reactor. A significant temperature difference along the radial direction of the reactor was obtained when the hydrate dissociates and this phenomenon could be enhanced by raising the production temperature. In addition, hydrate dissociates homogeneously and the temperature difference is much smaller than the other conditions when the production temperature is around the 10 °C. With the increase of the production temperature, the maximum of ΔToi grows until the temperature reaches 40 °C. The period of ΔToi have a close relation with the total time of hydrate dissociation. Especially, the period of ΔToi with production temperature of 10 °C is twice as much as that at other temperatures. Under these experimental conditions, the heat is mainly transferred by conduction from the dissociated zone to the dissociating zone and the production temperature has little effect on the convection of the water in the porous media.

  8. Methods to determine hydration states of minerals and cement hydrates

    Energy Technology Data Exchange (ETDEWEB)

    Baquerizo, Luis G., E-mail: luis.baquerizoibarra@holcim.com [Innovation, Holcim Technology Ltd., CH-5113 Holderbank (Switzerland); Matschei, Thomas [Innovation, Holcim Technology Ltd., CH-5113 Holderbank (Switzerland); Scrivener, Karen L. [Laboratory of Construction Materials, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne (Switzerland); Saeidpour, Mahsa; Thorell, Alva; Wadsö, Lars [Building Materials, Lund University, Box 124, 221 000 Lund (Sweden)

    2014-11-15

    This paper describes a novel approach to the quantitative investigation of the impact of varying relative humidity (RH) and temperature on the structure and thermodynamic properties of salts and crystalline cement hydrates in different hydration states (i.e. varying molar water contents). The multi-method approach developed here is capable of deriving physico-chemical boundary conditions and the thermodynamic properties of hydrated phases, many of which are currently missing from or insufficiently reported in the literature. As an example the approach was applied to monosulfoaluminate, a phase typically found in hydrated cement pastes. New data on the dehydration and rehydration of monosulfoaluminate are presented. Some of the methods used were validated with the system Na{sub 2}SO{sub 4}–H{sub 2}O and new data related to the absorption of water by anhydrous sodium sulfate are presented. The methodology and data reported here should permit better modeling of the volume stability of cementitious systems exposed to various different climatic conditions.

  9. Methods to determine hydration states of minerals and cement hydrates

    International Nuclear Information System (INIS)

    Baquerizo, Luis G.; Matschei, Thomas; Scrivener, Karen L.; Saeidpour, Mahsa; Thorell, Alva; Wadsö, Lars

    2014-01-01

    This paper describes a novel approach to the quantitative investigation of the impact of varying relative humidity (RH) and temperature on the structure and thermodynamic properties of salts and crystalline cement hydrates in different hydration states (i.e. varying molar water contents). The multi-method approach developed here is capable of deriving physico-chemical boundary conditions and the thermodynamic properties of hydrated phases, many of which are currently missing from or insufficiently reported in the literature. As an example the approach was applied to monosulfoaluminate, a phase typically found in hydrated cement pastes. New data on the dehydration and rehydration of monosulfoaluminate are presented. Some of the methods used were validated with the system Na 2 SO 4 –H 2 O and new data related to the absorption of water by anhydrous sodium sulfate are presented. The methodology and data reported here should permit better modeling of the volume stability of cementitious systems exposed to various different climatic conditions

  10. On the conditions of preparation of hydrated rare earth orthovanadates

    Energy Technology Data Exchange (ETDEWEB)

    Nakhodnova, A P; Belousova, E E; Shuba, Yu I; Zaslavskij, L V

    1988-10-01

    The properties of Ln(NO/sub 3/)/sub 3/-Na/sub 3/VO/sub 4/-H/sub 2/O solution series, where Ln is Er, Ho, Eu are investigated by the methods of residual concentrations, conductometry and potentiometry. It is found that at equivalent ratios of the initial components LnVO/sub 4/xmH/sub 2/O hydrated orthovanadates are formed. Deviations towards excess of rare earths or vanadium result in contamination of the compounds by products of side reactions. According to the data on X-ray phase analysis, hydrated erbium, holmium, europium orthovanadates have the zirconium crystal structure typical for anhydrous compounds. It is shown that hydrate water, being a component of orthovanadates, can be referred to adsorbed and interlayer water.

  11. On the conditions of preparation of hydrated rare earth orthovanadates

    International Nuclear Information System (INIS)

    Nakhodnova, A.P.; Belousova, E.E.; Shuba, Yu.I.; Zaslavskij, L.V.

    1988-01-01

    The properties of Ln(NO 3 ) 3 -Na 3 VO 4 -H 2 O solution series, where Ln is Er, Ho, Eu are investigated by the methods of residual concentrations, conductometry and potentiometry. It is found that at equivalent ratios of the initial components LnVO 4 xmH 2 O hydrated orthovanadates are formed. Deviations towards excess of rare earths or vanadium result in contamination of the compounds by products of side reactions. According to the data on X-ray phase analysis, hydrated erbium, holmium, europium orthovanadates have the zirconium crystal structure typical for anhydrous compounds. It is shown that hydrate water, being a component of orthovanadates, can be referred to adsorbed and interlayer water

  12. Coupled numerical modeling of gas hydrates bearing sediments from laboratory to field-scale conditions

    Science.gov (United States)

    Sanchez, M. J.; Santamarina, C.; Gai, X., Sr.; Teymouri, M., Sr.

    2017-12-01

    Stability and behavior of Hydrate Bearing Sediments (HBS) are characterized by the metastable character of the gas hydrate structure which strongly depends on thermo-hydro-chemo-mechanical (THCM) actions. Hydrate formation, dissociation and methane production from hydrate bearing sediments are coupled THCM processes that involve, amongst other, exothermic formation and endothermic dissociation of hydrate and ice phases, mixed fluid flow and large changes in fluid pressure. The analysis of available data from past field and laboratory experiments, and the optimization of future field production studies require a formal and robust numerical framework able to capture the very complex behavior of this type of soil. A comprehensive fully coupled THCM formulation has been developed and implemented into a finite element code to tackle problems involving gas hydrates sediments. Special attention is paid to the geomechanical behavior of HBS, and particularly to their response upon hydrate dissociation under loading. The numerical framework has been validated against recent experiments conducted under controlled conditions in the laboratory that challenge the proposed approach and highlight the complex interaction among THCM processes in HBS. The performance of the models in these case studies is highly satisfactory. Finally, the numerical code is applied to analyze the behavior of gas hydrate soils under field-scale conditions exploring different features of material behavior under possible reservoir conditions.

  13. Broadband Seismic Studies at the Mallik Gas Hydrate Research Well

    Science.gov (United States)

    Sun, L. F.; Huang, J.; Lyons-Thomas, P.; Qian, W.; Milkereit, B.; Schmitt, D. R.

    2005-12-01

    The JAPEX/JNOC/GSC et al. Mallik 3L-38, 4L-38 and 5L-38 scientific wells were drilled in the MacKenzie Delta, NWT, Canada in early 2002 primarily for carrying out initial tests of the feasibility of producing methane gas from the large gas hydrate deposits there [1]. As part of this study, high resolution seismic profiles, a pseudo-3D single fold seismic volume and broadband (8~180Hz) multi-offset vertical seismic profiles (VSP) were acquired at the Mallik site. Here, we provide details on the acquisition program, present the results of the 2D field profile, and discuss the potential implications of these observations for the structure of the permafrost and gas hydrate zones. These zones have long been problematic in seismic imaging due to the lateral heterogeneities. Conventional seismic data processing usually assume a stratified, weak-contrast elastic earth model. However, in permafrost and gas hydrate zones this approximation often becomes invalid. This leads to seismic wave scattering caused by multi-scale perturbation of elastic properties. A 3D viscoelastic finite difference modeling algorithm was employed to simulate wave propagation in a medium with strong contrast. Parameters in this modeling analysis are based on the borehole geophysical log data. In addition, an uncorrelated Vibroseis VSP data set was studied to investigate frequency-dependent absorption and velocity dispersion. Our results indicate that scattering and velocity dispersion are important for a better understanding of attenuation mechanisms in heterogeneous permafrost and gas hydrate zones. [1] Dallimore, S.R., Collett, T.S., Uchida, T., and Weber, M., 2005, Overview of the science program for the Mallik 2002 Gas Hydrate Production Research Well Program; in Scientific Results from Mallik 2002 Gas Hydrate production Research Well Program, MacKenzie Delta, Northwest Territories, Canada, (ed.) S.R. Dallimore and T.S. Collett; Geological Survey of Canada, Bulletin 585, in press.

  14. Marginalization among the marginalized: gay men's anti-effeminacy attitudes.

    Science.gov (United States)

    Taywaditep, K J

    2001-01-01

    Contemporary research has shown that a significant portion of gay men have traits, interests, occupations, and behaviors that are consistent with the stereotype of gay men as effeminate, androgynous, or unmasculine. A great number of gay men exhibit gender nonconformity during childhood; most, however, "defeminize" during adolescence, possibly in response to stigmatization and society's gender-role prescription. Only a relatively small percentage of gay men continue to be gender-nonconforming in their adulthood, often at a price, as they also tend to have lower psychological well-being. Although gay culture historically appreciated camp and drag, which subvert the gender-based power hierarchy and celebrate gender nonconformity, anti-effeminacy prejudice is widespread among gay men. Ironically, gender-nonconforming gay men may suffer from discrimination not only from society at large, but from other gay men, who are most likely to have experienced stigmatization and may have been effeminate earlier in their lives. Drawing from anecdotes and findings from various sources, this article suggests that beyond many gay men's erotic preference for masculinity lies contempt and hostility toward effeminacy and effeminate men on sociopolitical and personal levels. Two correlates of gay men's anti-effeminacy attitudes are proposed: (a) hegemonic masculinity ideology, or the degree to which one subscribes to the value system in which masculinity is an asset, and men and masculinity are considered superior to women and femininity; and (b) masculinity consciousness, or the saliency of masculinity in one's self-monitoring, public self-consciousness, and self-concept. These two variables are hypothesized to interact with gay men's self-perceived masculinity-femininity and their history of defeminization in predicting attitudes toward effeminacy. Research is underway to measure levels of anti-effeminacy attitudes and explore hypothesized correlates.

  15. Is Br2 hydration hydrophobic?

    Science.gov (United States)

    Alcaraz-Torres, A; Gamboa-Suárez, A; Bernal-Uruchurtu, M I

    2017-02-28

    The spectroscopic properties of bromine in aqueous systems suggest it can behave as either hydrophilic or hydrophobic solute. In small water clusters, the halogen bond and the hydrogen-halogen interaction are responsible for its specific way of binding. In water hydrates, it is efficiently hosted by two different cages forming the crystal structure and it has been frequently assumed that there is little or no interaction between the guest and the host. Bromine in liquid solution poses a challenging question due to its non-negligible solubility and the large blue shift measured in its absorption spectra. Using a refined semi-empirical force field, PM3-PIF, we performed a Born-Oppenheimer molecular dynamics study of bromine in liquid water. Here we present a detailed study in which we retrieved the most representative hydration structures in terms of the most frequent positions around bromine and the most common water orientations. Albeit being an approximate description of the total hydration phenomenon, it captures the contribution of the leading molecular interactions in form of the recurrent structures. Our findings confirm that the spectroscopic signature is mainly caused by the closest neighbors. The dynamics of the whole first hydration shell strongly suggests that the external molecules in that structure effectively isolate the bulk from the presence of bromine. The solvation structure fluctuates from a hydrophilic to a hydrophobic-like environment along the studied trajectory.

  16. Hydration modeling of calcium sulphates

    NARCIS (Netherlands)

    de Korte, A.C.J.; Brouwers, H.J.H.; Al-Mattarneh, Hashem; Mustapha, Kamal N.; Nuruddin, Muhd Fadhil

    2008-01-01

    The CEMHYD3D model has been extended at the University of Twente in the last ten years [1,2]. At present the cement hydration model is extended for the use of gypsum. Although gypsum was present in the model already, the model was not suitable for high contents of gypsum and did not include the

  17. The Dependence of Water Permeability in Quartz Sand on Gas Hydrate Saturation in the Pore Space

    Science.gov (United States)

    Kossel, E.; Deusner, C.; Bigalke, N.; Haeckel, M.

    2018-02-01

    Transport of fluids in gas hydrate bearing sediments is largely defined by the reduction of the permeability due to gas hydrate crystals in the pore space. Although the exact knowledge of the permeability behavior as a function of gas hydrate saturation is of crucial importance, state-of-the-art simulation codes for gas production scenarios use theoretically derived permeability equations that are hardly backed by experimental data. The reason for the insufficient validation of the model equations is the difficulty to create gas hydrate bearing sediments that have undergone formation mechanisms equivalent to the natural process and that have well-defined gas hydrate saturations. We formed methane hydrates in quartz sand from a methane-saturated aqueous solution and used magnetic resonance imaging to obtain time-resolved, three-dimensional maps of the gas hydrate saturation distribution. These maps were fed into 3-D finite element method simulations of the water flow. In our simulations, we tested the five most well-known permeability equations. All of the suitable permeability equations include the term (1-SH)n, where SH is the gas hydrate saturation and n is a parameter that needs to be constrained. The most basic equation describing the permeability behavior of water flow through gas hydrate bearing sand is k = k0 (1-SH)n. In our experiments, n was determined to be 11.4 (±0.3). Results from this study can be directly applied to bulk flow analysis under the assumption of homogeneous gas hydrate saturation and can be further used to derive effective permeability models for heterogeneous gas hydrate distributions at different scales.

  18. Experimental Study on Methane Hydrate Formation and Transport from Emulsions in a “Gas Lift” Riser in a Flowloop

    OpenAIRE

    Pham , Trung-Kien; Cameirao , Ana ,; Herri , Jean-Michel; Glenat , Philippe

    2017-01-01

    Session : Flow Assurance: Transportability Strategies - GasHyDyn : Logiciel de simulation de la composition et de la stabilité des hydrates de gaz; International audience; Production of crude oil with natural gas and water at low temperature and high pressure favours conditions for gas hydrate formation which can cause many troubles, up to blockage of pipelines. This work deals with hydrate kinetics of crystallization and agglomeration together with slurry transport and deposition under flowi...

  19. In-situ study of the thermal properties of hydrate slurry by high pressure DSC

    Energy Technology Data Exchange (ETDEWEB)

    Sari, O.; Hu, J.; Brun, F.; Erbeau, N. [Institute of Thermal Engineering, University of Applied Sciences of Western Switzerland, Yverdon-les-Bains (Switzerland); Homsy, P. [Nestec, Vevey (Switzerland); Logel, J.-C. [Axima Refrigeration, Bischheim (France)

    2008-07-01

    Knowing the enthalpy of hydrate slurry is very essential for energy balance and industrial applications. No direct measurement processes had been developed in this field in the past time. A new experimental method with special device has been developed to carry out on-line measurement of the thermal properties for hydrate slurry under dynamic conditions. With this special device, it is possible to deliver the hydrate slurry to the high pressure DSC (Differential Scanning Calorimetry) directly from the production tank or pipes. Thermal data acquisition will be performed afterwards by DSC. The investigated conditions were at pressure of 30 bar and temperature of {approx}+7 {sup o}C. The dissociation enthalpy of CO{sub 2} hydrate slurry was about 54 kJ/kg, corresponding 10.8% of solid fraction. The on-line measurement results for CO{sub 2} hydrate slurry give a good tendency to apply this phase change slurry to the industrial refrigeration process. (author)

  20. Observation of microstructure of hydrated Ca3SiO5

    International Nuclear Information System (INIS)

    Mori, Kazuhiro; Sato, Takashi; Fukunaga, Toshiharu; Oishi, Koji; Kimura, Katsuhiko; Iwase, Kenji; Sugiyama, Masaaki; Itoh, Keiji; Shikanai, Fumihito; Wuernisha, Tuerxun; Yonemura, Masao; Sulistyanintyas, Dyah; Tsukushi, Itaru; Takata, Shinich; Otomo, Toshiya; Kamiyma, Takashi; Kawai, Masayoshi

    2006-01-01

    Quasi-elastic neutron scattering experiments were carried out to evaluate the hydration rate of tricalcium silicate (Ca 3 SiO 5 ). Furthermore, in the early hydration period, a variation in surface roughness of Ca 3 SiO 5 was observed in nano-scale by the small-angle neutron scattering. From these results, it was found that the hydration rate of Ca 3 SiO 5 is suppressed when the surface of Ca 3 SiO 5 becomes rough through the creation of hydration products C-S-H gel and Ca(OH) 2 , and this roughness is associated with changes in the Ca 3 SiO 5 hydration rate

  1. Study on gas hydrate as a new energy resource in the 21th century

    Energy Technology Data Exchange (ETDEWEB)

    Ryu, Byeong-Jae; Kwak Young-Hoon; Kim, Won-Sik [Korea Institute of Geology Mining and Materials, Taejon (KR)] (and others)

    1999-12-01

    Natural gas hydrate, a special type of clathrate hydrates, is a metastable solid compound which mainly consists of methane and water, and generally called as gas hydrate. It is stable in the specific low-temperature/high-pressure conditions. Gas hydrates play an important role as major reservoir of methane on the earth. On the other hand, the formation and dissociation of gas hydrates could cause the plugging in pipeline, gas kick during production, atmospheric pollution and geohazard. To understand the formation and dissociation of the gas hydrate, the experimental equilibrium conditions of methane hydrate were measured in pure water, 3 wt.% NaCl and MgCl{sub 2} solutions. The equilibrium conditions of propane hydrates were also measured in pure water. The relationship between methane hydrate formation time and overpressure was also analyzed through the laboratory work. The geophysical surveys using air-gun system and multibeam echo sounder were implemented to develop exploration techniques and to evaluate the gas hydrate potential in the East Sea, Korea. General indicators of submarine gas hydrates on seismic data is commonly inferred from the BSR developed parallel to the see floor, amplitude blanking at the upper part of the BSR, and phase reversal and decrease of the interval velocity at BSR. The field data were processed using Geobit 2.9.5 developed by KIGAM to detect the gas hydrate indicators. The accurate velocity analysis was performed by XVA (X-window based Velocity Analysis). Processing results show that the strong reflector occurred parallel to the sea floor were shown at about 1800 ms two way travel time. The interval velocity decrease at this strong reflector and at the reflection phase reversal corresponding to the reflection at the sea floor. Gas hydrate stability field in the study area was determined using the data of measured hydrate equilibrium condition, hydrothermal gradient and geothermal gradient. The depth of BSR detected in the seismic

  2. Homecoming: the relevance of radical feminism for gay men.

    Science.gov (United States)

    Jensen, Robert

    2004-01-01

    Sexual politics in the gay male world would be enhanced by a serious engagement with radical feminist politics, particularly critiques of pornography and the sex industry. As the domination/subordination dynamic at the heart of patriarchy damages homosexual men, such engagement is crucial to the future of a gay movement.

  3. Masculine Gender Role Conflict and Negative Feelings about Being Gay.

    Science.gov (United States)

    Sánchez, Francisco J; Westefeld, John S; Liu, William Ming; Vilain, Eric

    2010-04-01

    Professional psychologists who work with gay men have noted that traditional masculine ideals play a prominent role in the gay community whereby some endorse these traditional ideals and stigmatize effeminate behavior by other gay men. One hypothesis is that this behavior reflects negative feelings about being gay. This article examined this hypothesis by reporting the results of an online survey of 622 self-identified gay men. Participants completed the Gender Role Conflict Scale, Lesbian and Gay Identity Scale, the Social Desirability Scale, and questions related to the importance of masculinity. Results showed that most participants valued the public appearance of masculinity; and they ideally wished to be more masculine than they felt they were (Cohen's d = 0.42). A multiple regression analysis showed that the degree to which they valued masculinity and were concerned with violating masculine ideals was positively related with negative feelings about being gay (Cohen's f(2) = .67). These findings highlight the importance of exploring the role that masculine ideals play in gay client's lives given that negative feelings about oneself can adversely affect psychological well-being.

  4. Masculine Gender Role Conflict and Negative Feelings about Being Gay

    Science.gov (United States)

    Sánchez, Francisco J.; Westefeld, John S.; Liu, William Ming; Vilain, Eric

    2009-01-01

    Professional psychologists who work with gay men have noted that traditional masculine ideals play a prominent role in the gay community whereby some endorse these traditional ideals and stigmatize effeminate behavior by other gay men. One hypothesis is that this behavior reflects negative feelings about being gay. This article examined this hypothesis by reporting the results of an online survey of 622 self-identified gay men. Participants completed the Gender Role Conflict Scale, Lesbian and Gay Identity Scale, the Social Desirability Scale, and questions related to the importance of masculinity. Results showed that most participants valued the public appearance of masculinity; and they ideally wished to be more masculine than they felt they were (Cohen’s d = 0.42). A multiple regression analysis showed that the degree to which they valued masculinity and were concerned with violating masculine ideals was positively related with negative feelings about being gay (Cohen’s f2 = .67). These findings highlight the importance of exploring the role that masculine ideals play in gay client’s lives given that negative feelings about oneself can adversely affect psychological well-being. PMID:20428323

  5. Unsettled Relations: Schools, Gay Marriage, and Educating for Sexuality

    Science.gov (United States)

    Mayo, Cris

    2013-01-01

    In this article, Cris Mayo examines the relationship among anti-LGBTQ policies, gay marriage, and sexuality education. Her concern is that because gay marriage is insufficiently different from heterosexual marriage, adding it as an issue to curriculum or broader culture debate elides rather than addresses sexual difference. In other words,…

  6. Sexual Orientation of Adult Sons of Gay Fathers.

    Science.gov (United States)

    Bailey, J. Michael; And Others

    1995-01-01

    Examined the sexual orientation of 82 adult sons of 55 gay men. Found that more than 90% of the sons whose sexual orientation could be rated were heterosexual. Gay and heterosexual sons did not differ on potentially relevant variables such as length of time they had lived with their fathers. (MDM)

  7. Guidelines for Counseling Gay Males With Low Self-Esteem.

    Science.gov (United States)

    Nagorski, Alec P.

    The purpose of this study was to gain an understanding of the relationship between a gay male's low self-esteem and environmental oppression, thereby establishing guidelines for the counselor in directing the client toward a more positive gay identity. This document is divided into the following sections: (1) Initial Interview; (2) Theory of…

  8. Viral Hepatitis: Information for Gay and Bisexual Men

    Science.gov (United States)

    VIRAL HEPATITIS Information for Gay and Bisexual Men What is viral hepatitis? Viral hepatitis is an infection of the liver caused by one of several ... each virus is spread in different ways. Are gay and bisexual men at risk for viral hepatitis? ...

  9. Preservice Teacher Attitudes toward Gay and Lesbian Parents

    Science.gov (United States)

    Herbstrith, Julie C.; Tobin, Renée M.; Hesson-McInnis, Matthew S.; Schneider, W. Joel

    2013-01-01

    Gay and lesbian parents are raising an increasing number of children, but little is known about how these parents are viewed by school personnel. In this study, preservice teacher attitudes toward gay and lesbian parents were assessed using implicit, explicit, behavioral, and behavioroid measures. Implicit measures indicate that participants rated…

  10. What's Good about Being Gay? Perspectives from Youth

    Science.gov (United States)

    Harper, Gary W.; Brodsky, Asya; Bruce, Douglas

    2012-01-01

    This article explores gay and bisexual male adolescents' positive perceptions of their sexual orientation identity. In-depth qualitative interviews were conducted with an ethnically diverse sample of 63 gay/bisexual male adolescents in Chicago (N = 42) and Miami (N = 21). Data revealed two major conceptual categories: (1) positive personal…

  11. Cognitive-Behavioral Erectile Dysfunction Treatment for Gay Men

    Science.gov (United States)

    Hart, Trevor A.; Schwartz, Danielle R.

    2010-01-01

    The purpose of the present paper is to assist cognitive-behavioral therapists who are treating erectile dysfunction among gay men. Little information is available to cognitive-behavioral therapists about the psychological and social effects of erectile dysfunction in this population, or how to incorporate the concerns of gay men with erectile…

  12. Faith and Sexual Orientation Identity Development in Gay College Men

    Science.gov (United States)

    Dunn, Merrily; Glassmann, Danny; Garrett, J. Matthew; Badaszewski, Philip; Jones, Ginny; Pierre, Darren; Fresk, Kara; Young, Dallin; Correll-Hughes, Larry

    2015-01-01

    This study examines the experiences of gay-identified college men related to their faith and sexual orientation identity development. The findings suggest that for gay-identified college men, faith and sexual orientation identity development includes examination of one's faith and sexual orientation identity, important relationships, and a desire…

  13. Guidelines for Psychological Practice With Lesbian, Gay, and Bisexual Clients

    Science.gov (United States)

    American Psychologist, 2012

    2012-01-01

    The "Guidelines for Psychological Practice With Lesbian, Gay, and Bisexual Clients" provide psychologists with (a) a frame of reference for the treatment of lesbian, gay, and bisexual clients and (b) basic information and further references in the areas of assessment, intervention, identity, relationships, diversity, education, training, and…

  14. Missing!: Picture Books Reflecting Gay and Lesbian Families

    Science.gov (United States)

    Rowell, Elizabeth H.

    2007-01-01

    Early childhood educators carefully reflect on the messages conveyed about family diversity in the materials they select to use. Picture books depicting gay and lesbian families can enhance the curriculum and make an important contribution to young children's development. Families comprised of same-sex parents or those who have gay and lesbian…

  15. Seismic reflections associated with submarine gas hydrates

    Energy Technology Data Exchange (ETDEWEB)

    Andreassen, K

    1996-12-31

    Gas hydrates are often suggested as a future energy resource. This doctoral thesis improves the understanding of the concentration and distribution of natural submarine gas hydrates. The presence of these hydrates are commonly inferred from strong bottom simulating reflection (BSR). To investigate the nature of BSR, this work uses seismic studies of hydrate-related BSRs at two different locations, one where gas hydrates are accepted to exist and interpreted to be very extensive (in the Beaufort Sea), the other with good velocity data and downhole logs available (offshore Oregon). To ascertain the presence of free gas under the BSR, prestack offset data must supplement near-vertical incidence seismic data. A tentative model for physical properties of sediments partially saturated with gas hydrate and free gas is presented. This model, together with drilling information and seismic data containing the BSR beneath the Oregon margin and the Beaufort Sea, made it possible to better understand when to apply the amplitude-versus-offset (AVO) method to constrain BSR gas hydrate and gas models. Distribution of natural gas hydrates offshore Norway and Svalbard is discussed and interpreted as reflections from the base of gas hydrate-bearing sediments, overlying sediments containing free gas. Gas hydrates inferred to exist at the Norwegian-Svalbard continental margin correlate well with Cenozoic depocenters, and the associated gas is assumed to be mainly biogenic. Parts of that margin have a high potential for natural gas hydrates of both biogenic and thermogenic origin. 235 refs., 86 figs., 4 tabs.

  16. Seismic reflections associated with submarine gas hydrates

    Energy Technology Data Exchange (ETDEWEB)

    Andreassen, K.

    1995-12-31

    Gas hydrates are often suggested as a future energy resource. This doctoral thesis improves the understanding of the concentration and distribution of natural submarine gas hydrates. The presence of these hydrates are commonly inferred from strong bottom simulating reflection (BSR). To investigate the nature of BSR, this work uses seismic studies of hydrate-related BSRs at two different locations, one where gas hydrates are accepted to exist and interpreted to be very extensive (in the Beaufort Sea), the other with good velocity data and downhole logs available (offshore Oregon). To ascertain the presence of free gas under the BSR, prestack offset data must supplement near-vertical incidence seismic data. A tentative model for physical properties of sediments partially saturated with gas hydrate and free gas is presented. This model, together with drilling information and seismic data containing the BSR beneath the Oregon margin and the Beaufort Sea, made it possible to better understand when to apply the amplitude-versus-offset (AVO) method to constrain BSR gas hydrate and gas models. Distribution of natural gas hydrates offshore Norway and Svalbard is discussed and interpreted as reflections from the base of gas hydrate-bearing sediments, overlying sediments containing free gas. Gas hydrates inferred to exist at the Norwegian-Svalbard continental margin correlate well with Cenozoic depocenters, and the associated gas is assumed to be mainly biogenic. Parts of that margin have a high potential for natural gas hydrates of both biogenic and thermogenic origin. 235 refs., 86 figs., 4 tabs.

  17. Influence of fluorosurfactants on hydrate formation rates

    Energy Technology Data Exchange (ETDEWEB)

    Kim, C.U.; Jeong, K.E.; Chae, H.J.; Jeong, S.Y. [Korea Reasearch Inst. of Chemical Technology, Alternative Chemicals/Fuel Research Center, Yuseong-Gu, Daejon (Korea, Republic of)

    2008-07-01

    Gas hydrates, or clathrates, are ice-like solids that forms when natural gas is in contact with liquid water or ice under high pressure and low temperature. There is significant interest in studying the storage and transportation of gas in the form of hydrates. However, a critical problem impacting the industrial application of gas hydrates for storage and transportation of natural gas is the slow formation rate of natural gas hydrate. Researchers have previously reported on the promotion effect of some additives on gas hydrate formation and hydrate gas content. Fluorosurfactants are significantly superior to nonfluorinated surfactants in wetting action, as well as stability in harsh environments, both thermal and chemical. This paper discussed an experimental investigation into the effects of fluorosurfactants with different ionic types on the formation of methane hydrate. The surfactants used were FSN-100 of DuPont Zonyl as non-ionic surfactant and FC-143 of DuPont as anionic surfactant. The paper discussed the experimental apparatus for methane hydrate formation. It also discussed hydrate formation kinetics and the series of hydrate formation experiments that were conducted in the presence of fluorosurfactants. Last, the paper explored the results of the study. It was concluded that anionic fluorosurfactant of FC-143 had a better promoting effect on methane hydrate formation compared with nonionic surfactant of FSN-100. 8 refs., 2 tabs., 2 figs.

  18. The mediation of gay men's lives: A review on gay dating app studies

    NARCIS (Netherlands)

    Wu, S. (Shangwei); J.R. Ward (Janelle)

    2018-01-01

    textabstractA growing body of literature focuses on gay men's use of mobile dating applications or “dating apps.” Running on smartphones and working with GPS, dating apps connect users to others in close geographic proximity and often in real time. These apps allow users to create profiles to

  19. Destabilizing Anti-Gay Environments through Gay-Straight Alliances: Possibilities and Limitations through Shifting Discourses

    Science.gov (United States)

    Currie, Sean; Mayberry, Maralee; Chenneville, Tiffany

    2012-01-01

    Drawing upon research with Gay-Straight Alliance (GSA) advisors, high-school principals, and two district-level administrators, we examine the potential and limits of the safe-space discourse that encompasses the aims of GSAs. We argue that this discourse conceals heteronormative school environments, which supplies the groundwork for hostility…

  20. That’s Gay! Gay as a Slur Among College Students

    Directory of Open Access Journals (Sweden)

    Robert Postic

    2014-11-01

    Full Text Available In recent years, the use of the word “gay” as a synonym for dumb or lame or stupid has become prevalent in our culture. Because of this, it is clear that many individuals do not consider the word to be a slur and are not offended by its use. Using an original data set (N = 790 collected from four Midwestern universities in the winter of 2011-2012, this article examines the characteristics of those college students who perceive the word gay to be a slur or who are offended. We find that those individuals who report having more gay friends are more likely to take offense at the use of the word gay as a slur even after controls are instituted. We also find that, contrary to expectations, attendance at religious services appears to have a direct relationship, with more frequent attenders more likely to express offense at the use of gay as a slur. Egalitarianism also emerged as a significant predictor. We offer suggestions as to why some college students perceive the word to be a slur while a majority of college students do not.

  1. The mediation of gay men’s lives: A review on gay dating app studies

    NARCIS (Netherlands)

    Wu, S.; Ward, J.

    2018-01-01

    textabstractA growing body of literature focuses on gay men's use of mobile dating applications or “dating apps.” Running on smartphones and working with GPS, dating apps connect users to others in close geographic proximity and often in real time. These apps allow users to create profiles to

  2. The only gay in the village? Everyday life of gays and lesbians in rural Slovenia.

    Science.gov (United States)

    Kuhar, Roman; Svab, Alenka

    2014-01-01

    The article deals with the comparison of the characteristics, experiences, and perceptions of everyday life of gays and lesbians living in rural and urban areas of Slovenia. We focus on the following thematic aspects: (1) coming out; (2) intimate partnerships; (3) the access and the use of gay infrastructure; and (4) violence against gays and lesbians. The article also addresses and discusses the urban/rural divide as a Western construct that might not be completely applicable to other social and cultural contexts. Taking Slovenia as an example, this article questions the self-evidence of rural/urban divide as an analytical concept. On the basis of our research, we conclude that this concept requires continuous revisions and reinterpretations in a concrete social and cultural context(s). The characteristics of gay and lesbian everyday life either in rural or in urban context in Slovenia lead to the conclusion that even within a specific social and cultural context, the concept of urban/rural divide should be used carefully, taking into account complexities of everyday lives and various factors that influence them.

  3. Occurrence of gas hydrate in Oligocene Frio sand: Alaminos Canyon Block 818: Northern Gulf of Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Boswell, R.D.; Shelander, D.; Lee, M.; Latham, T.; Collett, T.; Guerin, G.; Moridis, G.; Reagan, M.; Goldberg, D.

    2009-07-15

    A unique set of high-quality downhole shallow subsurface well log data combined with industry standard 3D seismic data from the Alaminos Canyon area has enabled the first detailed description of a concentrated gas hydrate accumulation within sand in the Gulf of Mexico. The gas hydrate occurs within very fine grained, immature volcaniclastic sands of the Oligocene Frio sand. Analysis of well data acquired from the Alaminos Canyon Block 818 No.1 ('Tigershark') well shows a total gas hydrate occurrence 13 m thick, with inferred gas hydrate saturation as high as 80% of sediment pore space. Average porosity in the reservoir is estimated from log data at approximately 42%. Permeability in the absence of gas hydrates, as revealed from the analysis of core samples retrieved from the well, ranges from 600 to 1500 millidarcies. The 3-D seismic data reveals a strong reflector consistent with significant increase in acoustic velocities that correlates with the top of the gas-hydrate-bearing sand. This reflector extends across an area of approximately 0.8 km{sup 2} and delineates the minimal probable extent of the gas hydrate accumulation. The base of the inferred gas-hydrate zone also correlates well with a very strong seismic reflector that indicates transition into units of significantly reduced acoustic velocity. Seismic inversion analyses indicate uniformly high gas-hydrate saturations throughout the region where the Frio sand exists within the gas hydrate stability zone. Numerical modeling of the potential production of natural gas from the interpreted accumulation indicates serious challenges for depressurization-based production in settings with strong potential pressure support from extensive underlying aquifers.

  4. Some like it mellow: on gay men complicating pornography discourses.

    Science.gov (United States)

    Corneau, Simon; van der Meulen, Emily

    2014-01-01

    Despite the proliferation of writing on pornography generally, much of the literature that focuses on gay pornography specifically conforms to either a pro- or anti-porn framework. This overly simplistic dichotomy positions pornography as a homogeneous construct, albeit one that is either "good" or "bad." Even theorists who situate pornography on a continuum, with erotica at one end and hardcore at the other, tend to reify these discourses. Further, it is not uncommon for researchers to draw conclusions about the effects of pornography consumption without defining exactly what pornography is. This ethnographic research draws on qualitative interviews with 20 consumers' of gay pornography in Toronto, Canada. By using a thematic analysis to document the ways in which gay men define, distinguish, and conceptualize gay pornography, five definitional categories were developed: Mellow; Commercial; Raunch; Amateur; and Bareback. These broad conceptualizations are discussed in reference to writing on gay pornography. Our research results emphasize the importance of clear definitions of pornography within pornography research.

  5. Emo Gay Boys and Subculture: Postpunk Queer Youth and (Re)thinking Images of Masculinity

    Science.gov (United States)

    Peters, Brian M.

    2010-01-01

    This is an exploration of gay youth subculture and emo boys. The study is a mesh of findings and related theoretical understandings about gay emo subculture, masculinities, style, and alternative gay youth. This study looks at gay male teenagers who identify with emo, a movement that stems from music and aesthetics creating a particular visual for…

  6. "Gay Boy Talk" Meets "Girl Talk": HIV Risk Assessment Assumptions in Young Gay Men's Sexual Health Communication with Best Friends

    Science.gov (United States)

    Mutchler, Matt G.; McDavitt, Bryce

    2011-01-01

    Young adults, particularly young gay men (YGM), are vulnerable to human immunodeficiency virus (HIV). Yet, little is known about how YGM discuss sexual health issues with their friends ("gay boy talk"). We conducted semi-structured interviews with YGM and their best friends (11 YGM/YGM dyads and 13 YGM/heterosexual female dyads). In this paper, we…

  7. Improving the Lives of Students, Gay and Straight Alike: Gay-Straight Alliances and the Role of School Psychologists

    Science.gov (United States)

    Murphy, Heather Elise

    2012-01-01

    Lesbian, gay, bisexual, and transgender (LGBT) students face many risk factors every day when they enter their school's door. These students often fear for their safety at school, are victimized, have academic difficulties, suffer from issues with their identity development, and are at risk for suicide. School-based Gay-Straight Alliances (GSAs)…

  8. Identification of the hydrate gel phases present in phosphate-modified calcium aluminate binders

    Energy Technology Data Exchange (ETDEWEB)

    Chavda, Mehul A.; Bernal, Susan A. [Department of Materials Science and Engineering, The University of Sheffield, Sheffield S1 3JD (United Kingdom); Apperley, David C. [Solid-State NMR Group, Department of Chemistry, Durham University, Durham DH1 3LE (United Kingdom); Kinoshita, Hajime [Department of Materials Science and Engineering, The University of Sheffield, Sheffield S1 3JD (United Kingdom); Provis, John L., E-mail: j.provis@sheffield.ac.uk [Department of Materials Science and Engineering, The University of Sheffield, Sheffield S1 3JD (United Kingdom)

    2015-04-15

    The conversion of hexagonal calcium aluminate hydrates to cubic phases in hydrated calcium aluminate cements (CAC) can involve undesirable porosity changes and loss of strength. Modification of CAC by phosphate addition avoids conversion, by altering the nature of the reaction products, yielding a stable amorphous gel instead of the usual crystalline hydrate products. Here, details of the environments of aluminium and phosphorus in this gel were elucidated using solid-state NMR and complementary techniques. Aluminium is identified in both octahedral and tetrahedral coordination states, and phosphorus is present in hydrous environments with varying, but mostly low, degrees of crosslinking. A {sup 31}P/{sup 27}Al rotational echo adiabatic passage double resonance (REAPDOR) experiment showed the existence of aluminium–phosphorus interactions, confirming the formation of a hydrated calcium aluminophosphate gel as a key component of the binding phase. This resolves previous disagreements in the literature regarding the nature of the disordered products forming in this system.

  9. Capillary pressure controlled methane hydrate and ice growth-melting patterns in porous media : synthetic silica versus natural sandstone

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, R.; Tohidi, B.; Webber, B. [Heriot-Watt Univ., Centre for Gas Research, Edinburgh (United Kingdom). Inst. of Petroleum Engineering

    2008-07-01

    Although naturally-occurring gas hydrates (or clathrate hydrates) in marine sediments can pose a hazard to deepwater hydrocarbon production operations, they represent a potential strategic energy reserve. Gas hydrates can also provide a means for deep ocean carbon dioxide disposal through sequestration/storage. They have long-term importance with respect to ocean margin stability, methane release, and global climate change. However, fundamental knowledge is still lacking regarding the mechanisms of hydrate growth, accumulation and distribution within the subsurface. Marine sediments which host gas hydrates are commonly fine-grained silts, muds, and clays with narrow mean pore diameters, leading to speculation that capillary phenomena could play a significant role in controlling hydrate distribution in the seafloor, and may be partly responsible for discrepancies between observed and predicted hydrate stability zone thicknesses. A close relationship between hydrate inhibition and pore size has been confirmed through previous laboratory studies. Clathrate stability has been significantly reduced in narrow pores. However, the focus of investigations has generally been hydrate dissociation conditions in porous media, with capillary controls on the equally important process of hydrate growth being largely overlooked. This paper presented the results of an experimental investigation into methane hydrate growth and dissociation equilibria in natural medium grained sandstone. The study also compared data with that previously measured for mesoporous silica glasses. The paper discussed solid-liquid phase behaviour in confined geometries including hysteresis in porous media. It also discussed the experimental equipment and method. It was concluded that, as for synthetic silicas, hydrate growth and dissociation in the sandstone were characterised by a measurable hysteresis between opposing transitions, notably hydrate (or ice) formation occurring at temperatures lower than

  10. Fire extinction utilizing carbon dioxide hydrate

    Energy Technology Data Exchange (ETDEWEB)

    Hatakeyama, T.; Aida, E.; Yokomori, T.; Ohmura, R.; Ueda, T. [Keio Univ., Hiyoshi, Kohoku-ku, Yokohama (Japan)

    2008-07-01

    Clathrate hydrates formed with nonflammable gases may be suitable for use as fire extinguishing agents because dissociation of the hydrates results in the temperature decrease in the combustion field and the nonflammable gases released from the dissociated hydrates prevent the supply of the oxygen to the combustion field. This paper discussed experiments in which ordinary ice and dry ice were used to evaluate the performance of CO{sub 2} hydrate as a fire extinguishing agent. The paper described the apparatus and procedure for the preparation of CO{sub 2} hydrate crystals. A schematic of the reactor to form CO{sub 2} hydrate and a photograph of CO{sub 2} hydrate crystal formed in the study were also presented. Other illustrations, photographs, and tables that were presented included a schematic diagram of the experimental apparatus used for the flame extinction experiments; a photograph of CO{sub 2} hydrate powder; sequential video graphs of the flame extinction by the supply of CO{sub 2} hydrate crystals to the methanol pool flame and the relevant illustration; and heat of CO{sub 2} hydrate dissociation, water vaporization and sublimation of dry ice. It was concluded that the critical mass of the CO{sub 2} hydrate required to extinguish a flame was much less than that of ordinary ice, indicating the superiority of CO{sub 2} hydrate to the ice. In addition, the experiments also revealed that the size of the CO{sub 2} hydrate particles had a significant effect on the performance of flame extinction. 5 refs., 2 tabs., 7 figs.

  11. Canaries in the mine? Gay community, consumption and aspiration in neoliberal Washington, DC

    OpenAIRE

    Lewis, Nathaniel

    2016-01-01

    Gay men have been implicated in neoliberal urban development strategies (e.g. the creative city) as a ‘canary’ population that forecasts growth. Paradoxically, both neoliberal re-development of North American inner-cities and the ways in which gay men become neoliberalised as individuals contribute to the dissolution of urban gay communities. In contrast to discourses of homonormativity, which suggest that gay men’s declining attachments to gay communities stem from new equalities and consequ...

  12. Delineation, Characterization and Assessment of Gas-hydrates: Examples from Indian Offshore

    Science.gov (United States)

    Sain, K.

    2017-12-01

    Successful test productions in McKenzie delta, Alaska, Nankai Trough and more recently in South China Sea have provided great hopes for production of gas-hydrates in near future, and boosted national programs of many countries including India. It has been imperative to map the prospective zones of gas-hydrates and evaluate their resource potential. Hence, we have adopted a systematic strategy for the delineation, characterization and quantification of gas-hydrates based on seismic traveltime tomography, full-waveform inversion, impedance inversion, attributes computation and rock-physical modeling. The bathymetry, seafloor temperature, total organic carbon content, sediment-thickness, rate of sedimentation, geothermal gradient imply that shallow sediments of Indian deep water are good hosts for occurrences of gas-hydrates. From the analysis of multi-channel seismic (MCS) data, we have identified the Krishna-Godavari (KG), Mahanadi and Andaman basins as prospective for gas-hydrates, and their presence has been validated by drilling and coring of Indian Expeditions-01 and -02. The MCS data also shows BSR-like features in the Cauvery, Kerala-Konkan and Saurashtra basins indicating that gas-hydrates cannot be ruled out from these basins also. We shall present several approaches that have been applied to field seismic and well-log data for the detection, characterization and quantification of gas-hydrates along the Indian margin.

  13. A thermodynamic approach to the hydration of sulphate-resisting Portland cement

    International Nuclear Information System (INIS)

    Lothenbach, Barbara; Wieland, Erich

    2006-01-01

    A thermodynamic approach is used to model changes in the hydrate assemblage and the composition of the pore solution during the hydration of calcite-free and calcite-containing sulphate-resisting Portland cement CEM I 52.5 N HTS. Modelling is based on thermodynamic data for the hydration products and calculated hydration rates for the individual clinker phases, which are used as time-dependent input parameters. Model predictions compare well with the composition of the hydrate assemblage as observed by TGA and semi-quantitative XRD and with the experimentally determined compositions of the pore solutions. The calculations show that in the presence of small amounts of calcite typically associated with Portland cement, C-S-H, portlandite, ettringite and calcium monocarbonate are the main hydration products. In the absence of calcite in the cement, however, siliceous hydrogarnet instead of calcium monocarbonate is observed to precipitate. The use of a higher water-to-cement ratio for the preparation of a calcite-containing cement paste has a minor effect on the composition of the hydrate assemblage, while it significantly changes the composition of the pore solution. In particular, lower pH value and higher Ca concentrations appear that could potentially influence the solubility and uptake of heavy metals and anions by cementitious materials

  14. Tetrafluoroethane (R134a) hydrate formation within variable volume reactor accompanied by evaporation and condensation

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, K.; Choo, Y. S.; Hong, H. J.; Yoon, Y. S.; Song, M. H., E-mail: songm@dgu.edu [Department of Mechanical, Robotics, and Energy Engineering, Dongguk University, Seoul 100-715 (Korea, Republic of)

    2015-03-15

    Vast size hydrate formation reactors with fast conversion rate are required for the economic implementation of seawater desalination utilizing gas hydrate technology. The commercial target production rate is order of thousand tons of potable water per day per train. Various heat and mass transfer enhancement schemes including agitation, spraying, and bubbling have been examined to maximize the production capacities in scaled up design of hydrate formation reactors. The present experimental study focused on acquiring basic knowledge needed to design variable volume reactors to produce tetrafluoroethane hydrate slurry. Test vessel was composed of main cavity with fixed volume of 140 ml and auxiliary cavity with variable volume of 0 ∼ 64 ml. Temperatures at multiple locations within vessel and pressure were monitored while visual access was made through front window. Alternating evaporation and condensation induced by cyclic volume change provided agitation due to density differences among water and vapor, liquid and hydrate R134a as well as extended interface area, which improved hydrate formation kinetics coupled with latent heat release and absorption. Influences of coolant temperature, piston stroke/speed, and volume change period on hydrate formation kinetics were investigated. Suggestions of reactor design improvement for future experimental study are also made.

  15. An innovative approach to enhance methane hydrate formation kinetics with leucine for energy storage application

    International Nuclear Information System (INIS)

    Veluswamy, Hari Prakash; Kumar, Asheesh; Kumar, Rajnish; Linga, Praveen

    2017-01-01

    Highlights: • Innovative combinatorial hybrid approach to reduce nucleation stochasticity and enhance hydrate growth. • Methane hydrate growth curves are similar in UTR and STR configurations in presence of leucine. • Amalgamation of stirred (STR) and unstirred (UTR) configuration is demonstrated. • Reliable method for scale up and commercial production of Solidified Natural Gas (SNG). - Abstract: Natural gas storage in clathrate hydrates or solidified natural gas (SNG) offers the safest, cleanest and the most compact mode of storage aided by the relative ease in natural gas (NG) recovery with minimal cost compared to known conventional methods of NG storage. The stochastic nature of hydrate nucleation and the slow kinetics of hydrate growth are major challenges that needs to be addressed on the SNG production side. A deterministic and fast nucleation coupled with rapid crystallization kinetics would empower this beneficial technology for commercial application. We propose a hybrid combinatorial approach of methane hydrate formation utilizing the beneficial aspect of environmentally benign amino acid (leucine) as a kinetic promoter by combining stirred and unstirred reactor operation. This hybrid approach is simple, can easily be implemented and scaled-up to develop an economical SNG technology for efficient storage of natural gas on a large scale. Added benefits include the minimal energy requirement during hydrate growth resulting in overall cost reduction for SNG technology.

  16. Tetrafluoroethane (R134a) hydrate formation within variable volume reactor accompanied by evaporation and condensation

    International Nuclear Information System (INIS)

    Jeong, K.; Choo, Y. S.; Hong, H. J.; Yoon, Y. S.; Song, M. H.

    2015-01-01

    Vast size hydrate formation reactors with fast conversion rate are required for the economic implementation of seawater desalination utilizing gas hydrate technology. The commercial target production rate is order of thousand tons of potable water per day per train. Various heat and mass transfer enhancement schemes including agitation, spraying, and bubbling have been examined to maximize the production capacities in scaled up design of hydrate formation reactors. The present experimental study focused on acquiring basic knowledge needed to design variable volume reactors to produce tetrafluoroethane hydrate slurry. Test vessel was composed of main cavity with fixed volume of 140 ml and auxiliary cavity with variable volume of 0 ∼ 64 ml. Temperatures at multiple locations within vessel and pressure were monitored while visual access was made through front window. Alternating evaporation and condensation induced by cyclic volume change provided agitation due to density differences among water and vapor, liquid and hydrate R134a as well as extended interface area, which improved hydrate formation kinetics coupled with latent heat release and absorption. Influences of coolant temperature, piston stroke/speed, and volume change period on hydrate formation kinetics were investigated. Suggestions of reactor design improvement for future experimental study are also made

  17. Electrical Conductive Mechanism of Gas Hydrate-Bearing Reservoirs in the Permafrost Region of Qilian Mountain

    Science.gov (United States)

    Peng, C.; Zou, C.; Tang, Y.; Liu, A.; Hu, X.

    2017-12-01

    In the Qilian Mountain, gas hydrates not only occur in pore spaces of sandstones, but also fill in fractures of mudstones. This leads to the difficulty in identification and evaluation of gas hydrate reservoir from resistivity and velocity logs. Understanding electrical conductive mechanism is the basis for log interpretation. However, the research is insufficient in this area. We have collected well logs from 30 wells in this area. Well logs and rock samples from DK-9, DK-11 and DK-12 wells were used in this study. The experiments including SEM, thin section, NMR, XRD, synthesis of gas hydrate in consolidated rock cores under low temperature and measurement of their resistivity and others were performed for understanding the effects of pore structure, rock composition, temperature and gas hydrate on conductivity. The results show that the porosity of reservoir of pore filling type is less than 10% and its clay mineral content is high. As good conductive passages, fractures can reduce resistivity of water-saturated rock. If fractures in the mudstone are filled by calcite, resistivity increases significantly. The resistivity of water-saturated rock at 2°C is twice of that at 18°C. The gas hydrate formation process in the sandstone was studied by resistivity recorded in real time. In the early stage of gas hydrate formation, the increase of residual water salinity may lead to the decrease of resistivity. In the late stage of gas hydrate formation, the continuity decrease of water leads to continuity increase of resistivity. In summary, fractures, rock composition, temperature and gas hydrate are important factors influencing resistivity of formation. This study is helpful for more accurate evaluation of gas hydrate from resistivity log. Acknowledgment: We acknowledge the financial support of the National Special Program for Gas Hydrate Exploration and Test-production (GZH201400302).

  18. Investigation of the Methane Hydrate Formation by Cavitation Jet

    Science.gov (United States)

    Morita, H.; Nagao, J.

    2015-12-01

    Methane hydrate (hereafter called "MH") is crystalline solid compound consisting of hydrogen-bonded water molecules forming cages and methane gas molecules enclosed in the cage. When using MH as an energy resource, MH is dissociated to methane gas and water and collect only the methane gas. The optimum MH production method was the "depressurization method". Here, the production of MH means dissociating MH in the geologic layers and collecting the resultant methane gas by production systems. In the production of MH by depressurization method, MH regeneration was consider to important problem for the flow assurance of MH production system. Therefore, it is necessary to clarify the effect of flow phenomena in the pipeline on hydrate regeneration. Cavitation is one of the flow phenomena which was considered a cause of MH regeneration. Large quantity of microbubbles are produced by cavitation in a moment, therefore, it is considered to promote MH formation. In order to verify the possible of MH regeneration by cavitation, it is necessary to detailed understanding the condition of MH formation by cavitation. As a part of a Japanese National hydrate research program (MH21, funded by METI), we performed a study on MH formation using by cavitation. The primary objective of this study is to demonstrate the formation MH by using cavitation in the various temperature and pressure condition, and to clarify the condition of MH formation by using observation results.

  19. Language, gay pornography, and audience reception.

    Science.gov (United States)

    Leap, William L

    2011-01-01

    Erotic imagery is an important component of gay pornographic cinema, particularly, where work of audience reception is concerned. However, to assume the audience engagement with the films is limited solely to the erotic realm is to underestimate the workings of ideological power in the context and aftermath of reception. For example, the director of the film under discussion here (Men of Israel; Lucas, 2009b) intended to present an erotic celebration of the nation-state. Yet, most viewers ignore the particulars of context in their comments about audience reception, placing the "Israeli" narrative within a broader framework, using transnational rather than film-specific criteria to guide their "reading" of the Israeli-centered narrative. This article uses as its entry point the language that viewers employ when describing their reactions to Men of Israel on a gay video club's Web site; this article shows how the work of audience reception may draw attention to a film's erotic details while invoking social and political messages that completely reframe the film's erotic narrative.

  20. The history of gay bathhouses. 1984.

    Science.gov (United States)

    Bérubé, Allan

    2003-01-01

    Public policy regarding bathhouses has been criticized as being based on political expediency rather than on medical or social science. To affect that shortcoming, we include here a brief history of gay bathhouses. The history of the baths is rarely told, but whenever it is told it necessarily reflects the times in which it was written. For that reason, we include a history written in 1984, at the time that much of what was known about AIDS, routes of transmission and the role of the bathhouses was very much in flux. This history not only gives a context for the current discussion, but also allows the reader to see the history from that distant point in time. This paper was first published in December 1984 as an article in Coming Up!, a lesbian and gay community newspaper published monthly in San Francisco (California). It was later edited and reprinted in a book titled Policing Public Sex (1996). The version of the paper presented here is from the original 1984 article (pp. 15-19); several images appeared with the article that are not reproduced here. As with all the reprinted papers in this volume, no editorial changes were made to the paper and only minor typographical errors were corrected.

  1. Sitges (Catalunya y el carnaval gay: el turismo

    Directory of Open Access Journals (Sweden)

    Lacaba Gutiérrez, José Juan

    2004-01-01

    Full Text Available In this paper, I explain the development of a tourist village in the Catalonian coast (northeast of Spain as a gay destination during carnival times during the month February. My intention is to include my reflections in this paper in the symbolic - cognitive studies about tourism and I want also to reflect about the idea of the constructions in gay culture of different places all around the world of leisure or/and pilgrimage. Sitges is a scale gay destination really knowledge in Western Europe during the hole year, but during carnival times, it's convert in a gay pilgrimage in different ways and there is have been crated during those last years gays places of leisure in the village that make me create the idea of the existence of a gay Carnival in Sitges Carnival. Because we cannot consider the gay carnival independent of what I call Sitges Carnival, I explain also the development and the historical conflicts between those two carnivals, and how those separate spaces have been created

  2. Age cohort differences in the developmental milestones of gay men.

    Science.gov (United States)

    Drasin, Harry; Beals, Kristin P; Elliott, Marc N; Lever, Janet; Klein, David J; Schuster, Mark A

    2008-01-01

    As the social context in which gay men live changes due to greater visibility, greater acceptance, and easier access to gay subculture, gay males may self-identify and take part in gay social activities at earlier ages than in the past. This study examined whether developmental milestones associated with sexual orientation for gay men have changed over the past several decades. A large and diverse sample of 2,402 gay men who responded to a 1994 survey published in a national magazine provided retrospective information on the age at which they reached individual psychological, social, and sexual behavior developmental milestones. We found evidence that individual psychological and sexual behavior milestones (e.g., awareness of attraction to males, having an orgasm with other male) are slowly moving toward earlier chronological ages (by 1 year of age every 8-25 years, p coming out) are moving more rapidly in a similar direction (by 1 year of age every 2-5 years, p < 0.001). The authors perform an innovative sensitivity test to demonstrate the persistence of the finding after correcting for the bias attributable to underrepresentation of those who have not yet self-identified as gay in such samples.

  3. Hydrates plugs dissociation in pipelines; Dissociation des bouchons d'hydrates de gaz dans les conduites petrolieres sous-marines

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen Hong, D.

    2005-03-15

    Natural gas hydrates plugs cause problems during drilling, well operations, production, transportation and processing of oil and gas. Especially, it is a very serious problem in off-shore oil transportation where low temperature and high pressure become more and more favourable to gas hydrate formation as the new production wells are more and more deeper. Up to now, although many studies have been developed concerning the possibility of preventing pipe plugging, there is limited information in open literature on hydrate plugs dissociation and all models in literature are numerically complicated. In this study, hydrate plugs are formed from water in n-dodecane mixture with addition of a dispersant E102B in two different experimental apparatus in order to obtain hydrates plugs with different sizes (diameter of 7, 10.75 and 12 cm). Then, the plugs are dissociated by the method of two-sided depressurization. In this paper, we propose a numerical model which describes the dissociation of gas hydrate plugs in pipelines. The numerical model, which is constructed for cylindrical coordinates and for two-sided pressurization, is based on enthalpy method. We present also an approximate analytical model which has an average error 2.7 % in comparison with the numerical model. The excellent agreement between our experimental results, literature data and the two models shows that the models give a good prediction independently of the pipeline diameter, plug porosity and gas. The simplicity of the analytical model will make it easier in industrial applications. (author)

  4. A Numerical Model for the Thermomechanical Conditions During Hydration of Early-age Concrete

    DEFF Research Database (Denmark)

    Hattel, Jesper; Thorborg, Jesper

    2003-01-01

    In the present study, a macroscopic numerical model for the thermomechanical conditions during hydration of early-age concrete is presented. The formulation is based on a semi-coupled, incremental thermomechanical model where the heat production from the hydration process is expressed in terms...... of the maturity and the thermal activation is expressed by the Arrhenius principle. The material properties are assumed to depend on the hydration process via the maturity. The discretization of the governing equations is accomplished by a control volume formulation involving a time-splitting scheme for the heat...

  5. Clinker mineral hydration at reduced relative humidities

    DEFF Research Database (Denmark)

    Jensen, Ole Mejlhede

    1998-01-01

    This report deals with gas phase hydration of pure cement clinker minerals at reduced relative humidities. This is an important subject in relation to modern high performance concrete which may self-desiccate during hydration. In addition the subject has relevance to storage stability where...... prehydration may occur. In the report both theoretical considerations and experimental data are presented. It is suggested that the initiation of hydration during water vapour exposure is nucleation controlled....

  6. (Re)locating the gay Filipino: resistance, postcolonialism, and identity.

    Science.gov (United States)

    Manalansan, M F

    1993-01-01

    This paper attempts to critically analyze issues of postcolonial displacement, immigration, and homosexuality by examining the works of two Filipino gay immigrant writers, John Silva and Ralph Peña. Using postcolonial and critical theories, anthropological studies, and ethnographic fieldwork in New York City, this paper focuses on the role of language, memory, the body, race/ethnicity, and social class in the narrative strategies of the two writers. This paper argues that gay postcolonial writers such as these two relocate and reconfigure homosexual/gay identity in the face of new and oppressive hierarchies, identities, and practices.

  7. Designing a reservoir flow rate experiment for the GOM hydrate JIP leg 2 LWD drilling

    Energy Technology Data Exchange (ETDEWEB)

    Gullapalli, I.; Silpngarmlert, S.; Reik, B.; Kamal, M.; Jones, E. [Chevron Energy Technology Co., San Ramon, CA (United States); Moridis, G. [Lawrence Berkeley National Laboratories, CA (United States); Collett, T. [United States Geological Survey, Reston, VA (United States)

    2008-07-01

    Studies have indicated that the Gulf of Mexico may contain large deep sea hydrate deposits. This paper provided details of short-term production profiles obtained from a geological model of hydrate deposits located in the Gulf area. A well test analysis tool was used to obtain the production parameters. Pressure transients from numerical simulations of various well test designs were used to provide estimates of important flow parameters. The aim of the study was to determine the type and duration of a well test capable of providing data to support the accurate modeling of gas hydrate deposits. Parameters studied in the test included the effects of permeability and hydrate saturation as a function of the duration of the flow test. Results indicated that production using a constant bottom hole pressure is an appropriate method of impacting hydrate dissociation by depressurization. However, changes in transient pressure plots could not be characterized in order to identify regions of varying saturation levels. Results suggested that the rate of effective water to effective gas was higher than rates obtained from relative permeability relations due to low gas saturation levels. Fluid saturation regions were in areas of low confidence in relative permeability curves. However, it was not possible to calculate absolute permeability of the reservoir for systems with short production periods. Further studies are needed to determine effective permeability using history matching and a hydrate simulator. 8 refs., 4 tabs., 27 figs.

  8. Gay guys using gay language: friendship, shared values and the intent-context-effect matrix.

    Science.gov (United States)

    McCormack, Mark; Wignall, Liam; Morris, Max

    2016-12-01

    This article draws on in-depth interviews with 35 openly gay male undergraduates from four universities in England to develop an understanding of the changing nature of language related to homosexuality. In addition to finding a diminution in the prevalence of homophobic language, we demonstrate that participants maintain complex and nuanced understandings of phrases that do not use homophobic pejoratives, such as 'that's so gay'. The majority of participants rejected the notion that these phrases are inherently homophobic, instead arguing that the intent with which they are said and the context in which they are used are vital in understanding their meaning and effect. We conceptualize an intent-context-effect matrix to understand the interdependency of these variables. Highlighting the situated nature of this matrix, we also demonstrate the importance of the existence of shared norms between those saying and hearing the phrase when interpreting such language. © London School of Economics and Political Science 2016.

  9. Accelerated hydration of high silica cements

    International Nuclear Information System (INIS)

    Walker, Colin; Yui, Mikazu

    2012-01-01

    Current Japanese designs for high level radioactive waste (HLW) repositories anticipate the use of both bentonite (buffer and backfill material) and cement based materials. Using hydrated Ordinary Portland Cement (OPC) as a grouting material is undesirable because the associated high pH buffer will have an undisputed detrimental effect on the performance of the bentonite buffer and backfill and of the host rock by changing its porosity. Instead, hydrated low pH cement (LopHC) grouting materials are being developed to provide a pH inferior or equal to 11 to reduce these detrimental effects. LopHC grouting materials use mixtures of superfine OPC (SOPC) clinker and silica fume (SF), and are referred as high silica cements (HSC). The focus of the present study was to identify the development of the unhydrated and hydrated mineral assemblage and the solution chemistry during the hydration of HSC. Since hydration experiments of cementitious materials are notably slow, a ball mill was used to accelerate hydration. This was done for two reasons. Firstly, to develop a method to rapidly hydrate cement based materials without the need for higher temperatures (which can alter the mineral assemblage), and secondly, to ensure that the end point of hydration was reached in a reasonable time frame and so to realize the final mineralogy and solution chemistry of hydrated HSC

  10. Microstructure of natural hydrate host sediments

    International Nuclear Information System (INIS)

    Jones, K.W.; Kerkar, P.B.; Mahajan, D.; Lindquist, W.B.; Feng, H.

    2007-01-01

    There is worldwide interest in the study of natural gas hydrate because of its potential impact on world energy resources, control on seafloor stability, significance as a drilling hazard and probable impact on climate as a reservoir of a major greenhouse gas. Gas hydrates can (a) be free floating in the sediment matrix (b) contact, but do not cement, existing sediment grains, or (c) actually cement and stiffen the bulk sediment. Seismic surveys, often used to prospect for hydrates over a large area, can provide knowledge of the location of large hydrate concentrations because the hydrates within the sediment pores modify seismic properties. The ability to image a sample at the grain scale and to determine the porosity, permeability and seismic profile is of great interest since these parameters can help in determining the location of hydrates with certainty. We report here on an investigation of the structure of methane hydrate sediments at the grain-size scale using the synchrotron radiation-based computed microtomography (CMT) technique. Work has started on the measurements of the changes occurring as tetrahydrofuran hydrate, a surrogate for methane hydrate, is formed in the sediment

  11. "You Can't Just Walk Down the Street and Meet Someone": The Intersection of Social-Sexual Networking Technology, Stigma, and Health Among Gay and Bisexual Men in the Small City.

    Science.gov (United States)

    White Hughto, Jaclyn M; Pachankis, John E; Eldahan, Adam I; Keene, Danya E

    2017-05-01

    Social-sexual networking technologies have been reported to yield both psychosocial benefits and sexual risks for gay and bisexual men, yet little research has explored how technology interacts with the social-geographical environment to shape the health of gay and bisexual men in the relatively understudied environment of small cities. This article draws on 29 semistructured interviews examining the use of social-sexual networking technologies among racially diverse gay and bisexual men in two small cities. Questions probed participants' use of technology to meet sexual partners, engagement in the gay community, and the role of virtual and nonvirtual spaces in relation to health. Findings suggest that social networking technologies can help men navigate the challenges of small cities, including small and insular gay communities, lack of dedicated gay spaces, and sexual minority stigma. However, participants also describe declines in gay community visibility and cohesion, which they attribute to technology use. The article concludes by discussing the intersections of virtual and physical space in small cities as sites for the production of health and illness.

  12. “You Can’t Just Walk Down the Street and Meet Someone”: The Intersection of Social–Sexual Networking Technology, Stigma, and Health Among Gay and Bisexual Men in the Small City

    Science.gov (United States)

    White Hughto, Jaclyn M.; Pachankis, John E.; Eldahan, Adam I.; Keene, Danya E.

    2016-01-01

    Social–sexual networking technologies have been reported to yield both psychosocial benefits and sexual risks for gay and bisexual men, yet little research has explored how technology interacts with the social–geographical environment to shape the health of gay and bisexual men in the relatively understudied environment of small cities. This article draws on 29 semistructured interviews examining the use of social–sexual networking technologies among racially diverse gay and bisexual men in two small cities. Questions probed participants’ use of technology to meet sexual partners, engagement in the gay community, and the role of virtual and nonvirtual spaces in relation to health. Findings suggest that social networking technologies can help men navigate the challenges of small cities, including small and insular gay communities, lack of dedicated gay spaces, and sexual minority stigma. However, participants also describe declines in gay community visibility and cohesion, which they attribute to technology use. The article concludes by discussing the intersections of virtual and physical space in small cities as sites for the production of health and illness. PMID:27885147

  13. Application of empirical hydration distribution functions around polar atoms for assessing hydration structures of proteins

    International Nuclear Information System (INIS)

    Matsuoka, Daisuke; Nakasako, Masayoshi

    2013-01-01

    Highlights: ► Empirical distribution functions of water molecules in protein hydration are made. ► The functions measure how hydrogen-bond geometry in hydration deviate from ideal. ► The functions assess experimentally identified hydration structures of protein. - Abstract: To quantitatively characterize hydrogen-bond geometry in local hydration structures of proteins, we constructed a set of empirical hydration distribution functions (EHDFs) around polar protein atoms in the main and side chains of 11 types of hydrophilic amino acids (D. Matsuoka, M. Nakasako, Journal of Physical Chemistry B 113 (2009) 11274). The functions are the ensemble average of possible hydration patterns around the polar atoms, and describe the anisotropic deviations from ideal hydrogen bond geometry. In addition, we defined probability distribution function of hydration water molecules (PDFH) over the hydrophilic surface of a protein as the sum of EHDFs of solvent accessible polar protein atoms. The functions envelop most of hydration sites identified in crystal structures of proteins (D. Matsuoka, M. Nakasako, Journal of Physical Chemistry B 114 (2010) 4652). Here we propose the application of EHDFs and PDFHs for assessing crystallographically identified hydration structures of proteins. First, hydration water molecules are classified with respect to the geometry in hydrogen bonds in referring EHDFs. Difference Fourier electron density map weighted by PDFH of protein is proposed to identify easily density peaks as candidates of hydration water molecules. A computer program implementing those ideas was developed and used for assessing hydration structures of proteins

  14. Waters of Hydration of Cupric Hydrates: A Comparison between Heating and Absorbance Methods

    Science.gov (United States)

    Barlag, Rebecca; Nyasulu, Frazier

    2011-01-01

    The empirical formulas of four cupric hydrates are determined by measuring the absorbance in aqueous solution. The Beer-Lambert Law is verified by constructing a calibration curve of absorbance versus known Cu[superscript 2+](aq) concentration. A solution of the unknown hydrate is prepared by using 0.2-0.3 g of hydrate, and water is added such…

  15. Effect of a new moisturizing lotion on immediate and cumulative skin hydration: Two randomized, intra-individual, vehicle- and comparator-controlled studies.

    Science.gov (United States)

    Nogueira, Alessandra; Sidou, Farzaneh; Brocard, Sylvie

    2011-08-01

    Moisturizers increase skin hydration and can serve as adjunctive care in dermatologic conditions such as xerosis, psoriasis vulgaris, atopic dermatitis and ichthyosis, in which dry skin is implicated. A non-irritating hydrating lotion (CDA lotion) was recently developed. We assessed the effect of CDA lotion on skin hydration in two randomized, evaluator-blind and intra-individual comparison studies. After a single application, CDA lotion induced significantly greater hydration than the non-treated control for at least 24 hours (p skin hydration up to 3 days after treatment cessation (p skin dryness score up to 7 days after treatment cessation (p hydration effects of CDA lotion were also compared to those of several currently available moisturizing products. In summary, application of CDA lotion increases skin hydration and alleviates the condition of skin dryness.

  16. The Potential Socio-economic Impacts of Gas Hydrate Exploitation

    Science.gov (United States)

    Riley, David; Schaafsma, Marije; Marin-Moreno, Héctor; Minshull, Tim A.

    2017-04-01

    Gas hydrate has garnered significant interest as a possible clean fossil fuel resource, especially in countries with limited energy supplies. Whilst the sector is still in its infancy, there has been escalating development towards commercial production. To the best of our knowledge it appears that, despite its potential, existing analyses of the social and economic impacts of hydrate exploitation have been very limited. Before any viable commercial production commences, the potential impacts across society must be considered. It is likely that such impact assessments will become a legislative requirement for hydrate exploitation, similar to their requirement in conventional oil and gas projects. Social impact analysis should guide hydrate development to have the highest possible net benefits to the human and natural environment. Without active commercial hydrate operations, potential socio-economic impacts can only be inferred from other fossil fuel resource focused communities, including those directly or indirectly affected by the oil and gas industry either in the vicinity of the well or further afield. This review attempts to highlight potential impacts by synthesising current literature, focusing on social impacts at the extraction stage of operation, over time. Using a DPSIR (Driving forces; Pressures; States; Impacts; Responses) framework, we focus on impacts upon: health and wellbeing, land use and access, services and infrastructure, population, employment opportunities, income and lifestyles. Human populations directly or indirectly related with fossil fuel extraction activities often show boom and bust dynamics, and so any impacts may be finite or change temporally. Therefore potential impacts have to be reassessed throughout the lifetime of the exploitation. Our review shows there are a wide range of possible positive and negative socio-economic impacts from hydrate development. Exploitation can bring jobs and infrastructure to remote areas, although

  17. Submarine methane hydrates - Potential fuel resource of the 21st century

    Digital Repository Service at National Institute of Oceanography (India)

    Desa, E.

    of these countries to initiate harvesting methane hydrates as soon as scientists and technologists come forward with dependable, safe and cost effective mechanisms to explore and exploit this resource. Technological factors : Lack of suitable production technology... reduction in deep-water development costs. All these are positive factors for hydrate exploration and development. Much of the engineering required to exploit these deposits can be achieved by suitably adopting proven technology currently used...

  18. Go home, gay boy! Or, why do Singaporean gay men prefer to "go home" and not "come out"?

    Science.gov (United States)

    Tan, Chris K K

    2011-01-01

    Anglo-American ontologies posit that gay men should come out to match their outer selves with their inner ones. In Confucianized Singapore, however, gay men refrain from coming out to their parents to avoid shaming their families. Instead, they couch their homosexuality in kinship terms and "go home" with their boyfriends (Chou, 2000). "Going home" gains familial acceptance, but it does not challenge mainstream discourses of homosexuality. By examining how Singaporean gay men negotiate their sexuality with their families, I question the validity of coming out and going home as both ontological discourses and strategies.

  19. Effect of MXene (Nano-Ti3C2 on Early-Age Hydration of Cement Paste

    Directory of Open Access Journals (Sweden)

    Haibin Yin

    2015-01-01

    Full Text Available As a new two-dimensional material, MXene (nano-Ti3C2 has been widely applied in many fields, especially for reinforced composite materials. In this paper, mechanical testing, X-ray diffraction (XRD, hydration heat, scanning electron microscope (SEM, and EDS analysis were used to analyze the impact of MXene on cement hydration properties. The obtained results revealed that (a MXene could greatly improve the early compressive strength of cement paste with 0.04 wt% concentration, (b the phase type of early-age hydration products has not been changed after the addition of MXene, (c hydration exothermic rate within 72 h has small difference at different amount of MXene, and (d morphologies of hydration products were varied with the dosage of MXene, a lot of tufted ettringites appeared in 3 d hydration products when the content of MXene was 0.04 wt%, which will have a positive effect on improving the early mechanical properties of cement paste. MXene has inhibited the Portland cement hydration process; the main role of MXene in the cement hydration process is to promote the messy ettringite becoming regular distribution at a node and form network connection structure in the crystals growth process, making the mechanics performance of cement paste significantly improved.

  20. Hydration in soccer: a review

    Directory of Open Access Journals (Sweden)

    Monteiro Cristiano Ralo

    2003-01-01

    Full Text Available Hydration should be considered before, during and after the exercise. This review intends to approach the main points of hydration process in soccer. The replacement of fluids during exercise is proportional to some factors, such as: exercise intensity; climatic conditions; the athlete's acclimatization; the athlete's physical conditioning; physiologic individual characteristics and the player's biomechanics. Performance is improved when players ingest not only water but also carbohydrate. The rates that carbohydrate and water are absorbed by the organism are limited by the rates of gastric emptying and intestinal absorption. The composition of drinks offered to the players should be influenced by the relative importance of the need of supplying carbohydrates or water; it should be remembered that the depletion of carbohydrate can result in fatigue and decrease of performance, but it is not usually a life-threatening condition. The addition of carbohydrate in these drinks increases the concentrations of blood glucose, increases the use of external fuel through the increase of the glucose oxidation in the muscles and it spares muscle glycogen. So, the ingestion of carbohydrate before and during the exercise can delay the emergence of fatigue and increase the players' performance. Several tactics can be used to avoid dehydration, like hyperhydration before exercise and player's acclimatization. The ideal situation to restore the player's fluid losses is between the sessions of exercises. Since soccer is a sport with quite peculiar characteristics related to hydration, the players should be concerned and educated about the importance of fluid ingestion before, during and after the exercise.

  1. Courtesy stigma: the social implications of associating with a gay person.

    Science.gov (United States)

    Sigelman, C K; Howell, J L; Cornell, D P; Cutright, J D; Dewey, J C

    1991-02-01

    We investigated the operation of courtesy stigma with American male college students who reacted to a fictitious male student described as gay, rooming by choice with a gay male student, involuntarily assigned to room with a gay, or rooming with a male heterosexual. Among respondents who expressed strong intolerance of gays, the voluntary associate of a gay was perceived as having homosexual tendencies and as possessing the same stereotyped personality traits attributed to a gay. No such courtesy stigma was attached to the involuntary associate of a gay by these respondents. Relatively tolerant respondents engaged in no courtesy stigmatization at all. Thus, courtesy stigmatization occurred only under circumscribed conditions and appeared to depend more on the tendency of highly intolerant individuals to infer that a male student who apparently liked a gay individual was himself gay than on a motivation to maintain cognitive consistency.

  2. Why alite stops hydrating below 80% relative humidity

    International Nuclear Information System (INIS)

    Flatt, Robert J.; Scherer, George W.; Bullard, Jeffrey W.

    2011-01-01

    It has been observed that the hydration of cement paste stops when the relative humidity drops below about 80%. A thermodynamic analysis shows that the capillary pressure exerted at that RH shifts the solubility of tricalcium silicate, so that it is in equilibrium with water. This is a reflection of the chemical shrinkage in this system: according to Le Chatelier's principle, since the volume of the products is less than that of the reactants, a negative (capillary) pressure opposes the reaction.

  3. A Computationally Efficient Equation of State for Ternary Gas Hydrate Systems

    Science.gov (United States)

    White, M. D.

    2012-12-01

    The potential energy resource of natural gas hydrates held in geologic accumulations, using lower volumetric estimates, is sufficient to meet the world demand for natural gas for nearly eight decades, at current rates of increase. As with other unconventional energy resources, the challenge is to economically produce the natural gas fuel. The gas hydrate challenge is principally technical. Meeting that challenge will require innovation, but more importantly, scientific research to understand the resource and its characteristics in porous media. The thermodynamic complexity of gas hydrate systems makes numerical simulation a particularly attractive research tool for understanding production strategies and experimental observations. Simply stated, producing natural gas from gas hydrate deposits requires releasing CH4 from solid gas hydrate. The conventional way to release CH4 is to dissociate the hydrate by changing the pressure and temperature conditions to those where the hydrate is unstable. Alternatively, the guest-molecule exchange technology releases CH4 by replacing it with more thermodynamically stable molecules (e.g., CO2, N2). This technology has three advantageous: 1) it sequesters greenhouse gas, 2) it potentially releases energy via an exothermic reaction, and 3) it retains the hydraulic and mechanical stability of the hydrate reservoir. Numerical simulation of the production of gas hydrates from geologic deposits requires accounting for coupled processes: multifluid flow, mobile and immobile phase appearances and disappearances, heat transfer, and multicomponent thermodynamics. The ternary gas hydrate system comprises five components (i.e., H2O, CH4, CO2, N2, and salt) and the potential for six phases (i.e., aqueous, nonaqueous liquid, gas, hydrate, ice, and precipitated salt). The equation of state for ternary hydrate systems has three requirements: 1) phase occurrence, 2) phase composition, and 3) phase properties. Numerical simulations that predict

  4. Mastery, Isolation, or Acceptance: Gay and Bisexual Men's Construction of Aging in the Context of Sexual Embodiment After Prostate Cancer.

    Science.gov (United States)

    Ussher, Jane M; Rose, Duncan; Perz, Janette

    2017-01-01

    Age is the predominant risk factor for developing prostate cancer, leading to its description as an "older man's disease." Changed sexual embodiment is a concern for men who develop prostate cancer, often compounding experiences of age-related sexual decline. Although research has examined heterosexual men's experiences of aging in the context of sexual embodiment after prostate cancer, gay and bisexual men have received little attention. This qualitative study used a material-discursive analysis, drawing on positioning theory and intersectionality, to explore constructions of aging following prostate cancer in 46 gay or bisexual men. Thematic decomposition of one-to-one interviews identified three subject positions: "mastering youth," involving maintaining an active sex life through biomedical interventions, accessing commercial sex venues, or having sex with younger men; "the lonely old recluse," involving self-positioning as prematurely aged and withdrawal from a gay sexual scene; and "accepting embodied aging," involving the incorporation of changed sexual function into intimate relationships and finding pleasure through nonsexual activities. These subject positions are conceptualized as the product of intersecting masculine and gay identities, interpreted in relation to broader cultural discourses of "new aging" and "sexual health," in which sexual activity is conceptualized as a lifelong goal.

  5. The future of drugs: recreational drug use and sexual health among gay and other men who have sex with men.

    Science.gov (United States)

    Race, Kane; Lea, Toby; Murphy, Dean; Pienaar, Kiran

    2017-02-01

    There are complex historical connections between sexual minoritisation and desires to chemically alter bodily experience. For gay men, drug and alcohol use can be a creative or experimental response to social marginalisation - and not necessarily a problematic one in every instance. Numerous studies have found that infection with HIV and other sexually transmissible infections (STIs) is more likely among gay and men who have sex with men (MSM) who use recreational drugs than those who do not, but the causal nature of these relations is uncertain. Sexualised drug use is associated with a range of other problems, including dependence, mental health issues, accident and overdose. A growing body of work in the Alcohol and Other Drugs (AOD) field demonstrates the action of drugs and their purported effects to be a product of their relations with various other actors, contexts and practices. Given these contingencies, it is impossible to predict the future of drugs or their effect on the sexual health of gay and MSM with any degree of certainty. This article outlines some of the conditions most likely to mediate such futures in the medium term. Public funding for lesbian, gay, bisexual, transgender and queer drug issues should not remain restricted to questions of HIV prevention and sexual health. It should be expanded to equip sexual health and AOD service providers with the cultural and sexual literacy to mitigate stigma and allow them to respond constructively to drug problems among sexual and gender minorities as a matter of priority.

  6. Simulation and Characterization of Methane Hydrate Formation

    Science.gov (United States)

    Dhakal, S.; Gupta, I.

    2017-12-01

    The ever rising global energy demand dictates human endeavor to explore and exploit new and innovative energy sources. As conventional oil and gas reserves deplete, we are constantly looking for newer sources for sustainable energy. Gas hydrates have long been discussed as the next big energy resource to the earth. Its global occurrence and vast quantity of natural gas stored is one of the main reasons for such interest in its study and exploration. Gas hydrates are solid crystalline substances with trapped molecules of gas inside cage-like crystals of water molecules. Gases such as methane, ethane, propane and carbon dioxide can form hydrates but in natural state, methane hydrates are the most common. Subsurface geological conditions with high pressure and low temperature favor the formation and stability of gas hydrates. While the occurrence and potential of gas hydrates as energy source has long been studied, there are still gaps in knowledge, especially in the quantitative research of gas hydrate formation and reservoir characterization. This study is focused on exploring and understanding the geological setting in which gas hydrates are formed and the subsequent changes in rock characteristics as they are deposited. It involves the numerical simulation of methane gas flow through fault to form hydrates. The models are representative of the subsurface geologic setting of Gulf of Mexico with a fault through layers of shale and sandstone. Hydrate formation simulated is of thermogenic origin. The simulations are conducted using TOUGH+HYDRATE, a numerical code developed at the Lawrence Berkley National Laboratory for modeling multiphase flow through porous medium. Simulation results predict that as the gas hydrates form in the pores of the model, the porosity, permeability and other rock properties are altered. Preliminary simulation results have shown that hydrates begin to form in the fault zone and gradually in the sandstone layers. The increase in hydrate

  7. Portuguese Older Gay Men: Pathways to Family Integrity

    Directory of Open Access Journals (Sweden)

    Filipa Daniela Marques

    2016-08-01

    Full Text Available Abstract Research in the field of older gay men remains scarce. This exploratory study examines older gay men's experiences in the construction of family integrity (versus disconnection and alienation. The family integrity approach is a developmental perspective that links ego integrity to a larger process of constructing meaning within the family system. The sample comprises ten participants (from 60 to 88 years old. A semi-structured interview was conducted and submitted to content analysis. The main findings suggest three experiences in older gay men's construction of family integrity: (i influence of homosexuality throughout life; (ii establishing a family of choice; (iii creating a legacy associated with homosexuality. Family integrity in older gay men seems to evolve from disclosure at a young age to making homosexuality a legacy in old age.

  8. Visibility that demystifies: gays, gender, and sex on television.

    Science.gov (United States)

    Netzley, Sara Baker

    2010-01-01

    A content analysis of 98 episodes of primetime entertainment programs on commercial broadcast and cable television stations from the 2005-2006 season showed that gay characters on television were more likely to be shown in sexual situations than straight characters, and women were more likely to be shown in same-sex sexual situations than men. In addition, gay characters were more likely to be depicted as sexually active on cable television than they were on commercial broadcast television, and they were more likely to be relegated to guest star status on commercial broadcast television than on cable television. The study also showed that gay characters made up 7.5% of all the characters studied. This study discusses the implications of these findings for gay and straight audiences.

  9. The discourse of liberation: Frames used in characterising the gay ...

    African Journals Online (AJOL)

    Kate H

    frames to express anti-gay sentiments, the Mail & Guardian primarily used these ... it is often silenced among traditional sources of knowledge such as friends, ... suggested by Van Dijk (1991) in considering issues of language and power, the ...

  10. Preservice elementary teacher's attitudes toward gay and lesbian parenting.

    Science.gov (United States)

    Maney, D W; Cain, R E

    1997-08-01

    This preliminary investigation assessed preservice elementary teacher's attitudes toward homosexual parents and their children. The study populations included 195 college students enrolled in an elementary school health methods course at a large northeastern university. A 51-item " and Lesbian Parenting Questionnaire" was used for data collection purposes. Reliability estimates for the scales were: attitudes toward lesbians and gay men (alpha = .90), comfort toward gay and lesbian families (alpha = .92), and knowledge about homosexuality (alpha = .52). Most respondents agreed gay men: were not disgusting, should be allowed to teach, were not perverted, and should not overcome their feelings of homosexuality. Most respondents disagreed lesbians cannot fit into society or were sick. Nearly all agreed female homosexuality should not be a basis for job discrimination. Females were significantly (p attitudes toward gay fathers than did male respondents. Respondents with stronger religious attitudes had significantly (p attitudes toward lesbian parents than respondents with weaker religious attitudes.

  11. Clubbing masculinities: gender shifts in gay men's dance floor choreographies.

    Science.gov (United States)

    Peterson, Grant Tyler

    2011-01-01

    This article adopts an interdisciplinary approach to understanding the intersections of gender, sexuality, and dance. It examines the expressions of sexuality among gay males through culturally popular forms of club dancing. Drawing on political and musical history, I outline an account of how gay men's gendered choreographies changed throughout the 1970s, 80s, and 90s. Through a notion of "technologies of the body," I situate these developments in relation to cultural levels of homophobia, exploring how masculine expressions are entangled with and regulated by musical structures. My driving hypothesis is that as perceptions of cultural homophobia decrease, popular choreographies of gay men's dance have become more feminine in expression. Exploring this idea in the context of the first decade of the new millennium, I present a case study of TigerHeat, one of the largest weekly gay dance club events in the United States.

  12. El personaje gay en la literatura colombiana

    Directory of Open Access Journals (Sweden)

    Luz María Rubio Rivas

    2012-01-01

    Full Text Available Este documento aborda desde el campo de los estudios culturales, las representaciones del personaje gay en la novela colombiana de los primeros siete años del presente siglo. Fue posible reconocer en las representaciones, una serie de normas positivas y negativas que rigen la sexualidad y el género de los personajes, los cuales se encuentran inscritos en estructuras de poder y de subordinación basadas en dichas normas, impuestas o administradas a través de diversas estrategias. También se encontró, en mayor o menor medida, la presencia de estereotipos, creencias y atribuciones de causalidad, de las que se presenta una breve mención.

  13. Dynamics of the Gay-Berne fluid

    International Nuclear Information System (INIS)

    de Miguel, E.; Rull, L.F.; Gubbins, K.E.

    1992-01-01

    Using molecular-dynamics computer simulation, we study the dynamical behavior of the isotropic and nematic phases of highly anisotropic molecular fluids. The interactions are modeled by means of the Gay-Berne potential with anisotropy parameters κ=3 and κ'=5. The linear-velocity autocorrelation function shows no evidence of a negative region in the isotropic phase, even at the higher densities considered. The self-diffusion coefficient parallel to the molecular axis shows an anomalous increase with density as the system enters the nematic region. This enhancement in parallel diffusion is also observed in the isotropic side of the transition as a precursor effect. The molecular reorientation is discussed in the light of different theoretical models. The Debye diffusion model appears to explain the reorientational mechanism in the nematic phase. None of the models gives a satisfactory account of the reorientation process in the isotropic phase

  14. Lesbian, Gay, Bisexual, and Transgender (LGBT) Survivorship.

    Science.gov (United States)

    Kamen, Charles

    2018-02-01

    To discuss lesbian, gay, bisexual, and transgender (LGBT)-specific survivorship issues including: integrating sexual and gender minority identities with cancer survivor identities; coordinating medical care and disclosing identities to health care providers; dealing with late effects of treatment; and addressing LGBT family and relationship issues. Published articles, quotes from an online survey of 311 LGBT survivors. The transition from active cancer treatment to survivorship presents challenges, and LGBT cancer survivors may face additional challenges as they enter the survivorship phase. Oncology nurses can improve the quality of survivorship care delivered to LGBT survivors and their caregivers by addressing the disparities and gaps in health care. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Moral elevation reduces prejudice against gay men.

    Science.gov (United States)

    Lai, Calvin K; Haidt, Jonathan; Nosek, Brian A

    2014-01-01

    Disgust is linked to social evaluation. People with higher disgust sensitivity exhibit more sexual prejudice, and inducing disgust increases sexual prejudice. We tested whether inducing moral elevation, the theoretical opposite of disgust, would reduce sexual prejudice. In four studies (N = 3622), we induced elevation with inspiring videos and then measured sexual prejudice with implicit and explicit measures. Compared to control videos that elicited no particular affective state, we found that elevation reduced implicit and explicit sexual prejudice, albeit very slightly. No effect was observed when the target of social evaluation was changed to race (Black-White). Inducing amusement, another positive emotion, did not significantly affect sexual prejudice. We conclude that elevation weakly but reliably reduces prejudice towards gay men.

  16. Properties and hydration of blended cements with steelmaking slag

    International Nuclear Information System (INIS)

    Kourounis, S.; Tsivilis, S.; Tsakiridis, P.E.; Papadimitriou, G.D.; Tsibouki, Z.

    2007-01-01

    The present research study investigates the properties and hydration of blended cements with steelmaking slag, a by-product of the conversion process of iron to steel. For this purpose, a reference sample and three cements containing up to 45% w/w steel slag were tested. The steel slag fraction used was the '0-5 mm', due to its high content in calcium silicate phases. Initial and final setting time, standard consistency, flow of normal mortar, autoclave expansion and compressive strength at 2, 7, 28 and 90 days were measured. The hydrated products were identified by X-ray diffraction while the non-evaporable water was determined by TGA. The microstructure of the hardened cement pastes and their morphological characteristics were examined by scanning electron microscopy. It is concluded that slag can be used in the production of composite cements of the strength classes 42.5 and 32.5 of EN 197-1. In addition, the slag cements present satisfactory physical properties. The steel slag slows down the hydration of the blended cements, due to the morphology of contained C 2 S and its low content in calcium silicates

  17. Attitudes toward straight, gay male, and transsexual parenting.

    Science.gov (United States)

    Weiner, Brittany A; Zinner, Leah

    2015-01-01

    This study examined American attitudes toward transsexual and gay male parenting, compared to straight parenting. After reporting levels of transphobia, participants read a vignette regarding a couple seeking child adoption. Individuals high in transphobia perceived nontraditional couples as more emotionally unstable than straight couples and were less willing to grant custody of a child to the nontraditional couples vs. the straight couples. In addition, the transsexual couple faced more prejudice and discrimination than the gay male couple. Implications of these findings are discussed.

  18. Military Gay Ban Revisited: Is our Military Ready for Change?

    Science.gov (United States)

    2009-02-20

    support from the lesbian, gay, bi-sexual, transgender ( LGBT ) community and in return made several campaign promises along the way. One of the campaign ...Lesbian, Gay, Bi-sexual, Transgender] ( LGBT ) rights is exploited by those seeking to divide us. But at its core, this issue is about who we are as...No. 85. July 2007. Donnelly, Elaine. Who Will Confront the “ LGBT Left?”. Center for Military Readiness. (5 February 2008). Frank

  19. Evaluation and analysis method for natural gas hydrate storage and transportation processes

    International Nuclear Information System (INIS)

    Hao Wenfeng; Wang Jinqu; Fan Shuanshi; Hao Wenbin

    2008-01-01

    An evaluation and analysis method is presented to investigate an approach to scale-up a hydration reactor and to solve some economic problems by looking at the natural gas hydrate storage and transportation process as a whole. Experiments with the methane hydration process are used to evaluate the whole natural gas hydrate storage and transportation process. The specific contents and conclusions are as follows: first, batch stirring effects and load coefficients are studied in a semi-continuous stirred-tank reactor. Results indicate that batch stirring and appropriate load coefficients are effective in improving hydrate storage capacity. In the experiments, appropriate values for stirring velocity, stirring time and load coefficient were found to be 320 rpm, 30 min and 0.289, respectively. Second, throughput and energy consumption of the reactor for producing methane hydrates are calculated by mass and energy balance. Results show that throughput of this is 1.06 kg/d, with a product containing 12.4% methane gas. Energy consumption is 0.19 kJ, while methane hydrates containing 1 kJ heat are produced. Third, an energy consumption evaluation parameter is introduced to provide a single energy consumption evaluation rule for different hydration reactors. Parameter analyses indicate that process simplicity or process integration can decrease energy consumption. If experimental gas comes from a small-scale natural gas field and the energy consumption is 0.02 kJ when methane hydrates containing 1 kJ heat are produced, then the decrease is 87.9%. Moreover, the energy consumption evaluation parameter used as an economic criterion is converted into a process evaluation parameter. Analyses indicate that the process evaluation parameter is relevant to technology level and resource consumption for a system, which can make it applicable to economic analysis and venture forecasting for optimal capital utilization

  20. Body image in gay and straight men: a qualitative study.

    Science.gov (United States)

    Morgan, John F; Arcelus, Jon

    2009-11-01

    Recent research has emphasized vulnerability to eating disorders in gay men, with calls for research on causality, cultural factors and focus on a younger age cohort. This study aimed to examine body image and related eating behaviours in younger gay and straight men. Qualitative study using a sample of gay and straight male university students, applying audiotaped and transcribed depth interview subjected to interpretative phenomenological analysis. Fifteen young men (18-24) with a spectrum of sexual orientation (gay, straight and bisexual) agreed to participate. Five dominant categories emerged: body image ideal, external influences, perception of body image, dieting, mechanisms for modification (diet, exercise, cosmetics) and sexual orientation. Health and aesthetic ideals appear less divorced for young men than women, offering some degree of protection from eating disorders. Nonetheless there is widespread body dissatisfaction. Media and social influences are powerful, particularly for single gay men, but the study suggests fewer differences than similarities between gay and straight men. Copyright (c) 2009 John Wiley & Sons, Ltd and Eating Disorders Association.

  1. Understanding Gay Community Subcultures: Implications for HIV Prevention.

    Science.gov (United States)

    Prestage, Garrett; Brown, Graham; De Wit, John; Bavinton, Benjamin; Fairley, Christopher; Maycock, Bruce; Batrouney, Colin; Keen, Phillip; Down, Ian; Hammoud, Mohamed; Zablotska, Iryna

    2015-12-01

    Gay and bisexual men (GBM) who participate in gay community subcultures have different profiles, including differing risk behaviors. We examined men's participation in gay community subcultures, and its association with risk behavior. In a cross-sectional survey, 849 GBM provided information about men in their personal networks. We devised measures of their participation in five subcultural groupings and explored their associations with sexual behavior. We identified five subcultural groupings: sexually adventurous; bear tribes; alternative queer; party scene; and sexually conservative. Higher scores on the sexually adventurous measure was associated with being older, having more gay friends, being HIV-positive, and being more sexually active. It was also independently associated with unprotected anal intercourse with casual partners (AOR 1.82; 95 % CI 1.20-2.76; p = 0.005). HIV prevention strategies need to account for the different subcultural groupings in which GBM participate. Measures of engagement with gay subcultures are useful indicators of differential rates of risk behavior and modes of participation in gay community life. Men in more sexually adventurous subcultures are more likely to engage in sexual risk behavior.

  2. Free energy of hydration of niobium oxide

    International Nuclear Information System (INIS)

    Plodinec, M.J.

    1996-01-01

    Some of the glasses being formulated by SRTC researchers contain niobium oxide. In this report, the free energy of hydration of the oxide is calculated from the free energies of formation of the oxide, the hydroxide, and water. This value can be used in calculations of the free energy of hydration of glasses containing niobium

  3. Investigations into surfactant/gas hydrate relationship

    Energy Technology Data Exchange (ETDEWEB)

    Rogers, Rudy; Zhang, Guochang; Dearman, Jennifer; Woods, Charles [Swalm School of Chemical Engineering, Mississippi State University, Mississippi State, MS 39762 (United States)

    2007-03-15

    Gas hydrates have unique physical properties portending useful industrial applications of gas storage, gas separation, or water desalination. When gas hydrates were found in the early 1990s to occur naturally and abundantly in seafloors, three other primary interests and concerns emerged: potential new energy source, climate threat from their greenhouse gases, and seafloor instabilities. This paper presents research showing how anionic synthetic surfactants helped develop an industrial gas hydrate storage process for natural gas and how naturally-occurring in-situ anionic biosurfactants influence the formation and placement of gas hydrates in ocean sediments. The catalytic effects, mechanisms, and surface specificities imparted by synthetic surfactants in the gas storage process and imparted by biosurfactants in porous media are discussed. The Bacillus subtilis bacterium that is indigenous to gas hydrate mounds in the Gulf of Mexico was cultured in the laboratory. Its biosurfactant was separated and found to catalyze gas hydrates in porous media. The experiments indicate that seafloor-biosurfactants can be produced rapidly in-situ to achieve threshold concentrations whereby hydrates are promoted. The biosurfactants accumulate and promote hydrate formation on specific mineral surfaces such as sodium montmorillonite. (author)

  4. 75 FR 9886 - Methane Hydrate Advisory Committee

    Science.gov (United States)

    2010-03-04

    ... DEPARTMENT OF ENERGY Methane Hydrate Advisory Committee AGENCY: Department of Energy, Office of Fossil Energy. ACTION: Notice of open meeting. SUMMARY: This notice announces a meeting of the Methane... the Committee: The purpose of the Methane Hydrate Advisory Committee is to provide advice on potential...

  5. Raman Spectroscopic Studies of Methane Gas Hydrates

    DEFF Research Database (Denmark)

    Hansen, Susanne Brunsgaard; Berg, Rolf W.

    2009-01-01

    A brief review of the Raman spectroscopic studies of methane gas hydrates is given, supported by some new measurements done in our laboratory.......A brief review of the Raman spectroscopic studies of methane gas hydrates is given, supported by some new measurements done in our laboratory....

  6. Multicomponent modelling of Portland cement hydration reactions

    NARCIS (Netherlands)

    Ukrainczyk, N.; Koenders, E.A.B.; Van Breugel, K.

    2012-01-01

    The prospect of cement and concrete technologies depends on more in depth understanding of cement hydration reactions. Hydration reaction models simulate the development of the microstructures that can finally be used to estimate the cement based material properties that influence performance and

  7. Experimental Setup to Characterize Bentonite Hydration Processes

    International Nuclear Information System (INIS)

    Bru, A.; Casero, D.; Pastor, J. M.

    2001-01-01

    We present an experimental setup to follow-up the hydration process of a bentonite. Clay samples, of 2 cm x 12 cm x 12 cm, were made and introduced in a Hele-Shaw cell with two PMM windows and two steel frames. In hydration experiments, a fluid enters by an orifice in the frame, located both at the top and the bottom of the cell, to perform hydration in both senses. To get a uniform hydration we place a diffuser near the orifice. Volume influxes in hydration cells are registered in time. The evolution of the developed interface was recorded on a videotape. The video cameras was fixed to a holder so that the vertical direction in the monitor was the same as the direction of the larger extension of the cell. (Author) 6 refs

  8. Volume of hydration in terminal cancer patients.

    Science.gov (United States)

    Bruera, E; Belzile, M; Watanabe, S; Fainsinger, R L

    1996-03-01

    In this retrospective study we reviewed the volume and modality of hydration of consecutive series of terminal cancer patients in two different settings. In a palliative care unit 203/290 admitted patients received subcutaneous hydration for 12 +/- 8 days at a daily volume of 1015 +/- 135 ml/day. At the cancer center, 30 consecutive similar patients received intravenous hydration for 11.5 +/- 5 days (P > 0.2) but at a daily volume of 2080 +/- 720 ml/day (P palliative care unit patients required discontinuation of hydration because of complications. Hypodermoclysis was administered mainly as a continuous infusion, an overnight infusion, or in one to three 1-h boluses in 62 (31%), 98 (48%) and 43 (21%) patients, respectively. Our findings suggest that, in some settings, patients may be receiving excessive volumes of hydration by less comfortable routes such as the intravenous route. Increased education and research in this area are badly needed.

  9. Hydration shells exchange charge with their protein

    DEFF Research Database (Denmark)

    Abitan, Haim; Lindgård, Per-Anker; Nielsen, Bjørn Gilbert

    2010-01-01

    . In our experiments, the amplitude of an ultrasonic pressure wave is gradually increased (0–20 atm) while we simultaneously measure the Raman spectra from the hydrated protein (β-lactoglobulin and lysozyme). We detected two types of spectral changes: first, up to 70% increase in the intensity......Investigation of the interaction between a protein and its hydration shells is an experimental and theoretical challenge. Here, we used ultrasonic pressure waves in aqueous solutions of a protein to explore the conformational states of the protein and its interaction with its hydration shells...... the presence of an ultrasonic pressure, a protein and its hydration shells are in thermodynamic and charge equilibrium, i.e. a protein and its hydration shells exchange charges. The ultrasonic wave disrupts these equilibria which are regained within 30–45 min after the ultrasonic pressure is shut off....

  10. Hydrate thermal dissociation behavior and dissociation enthalpies in methane-carbon dioxide swapping process

    DEFF Research Database (Denmark)

    Mu, Liang; von Solms, Nicolas

    2018-01-01

    The swapping of methane with carbon dioxide in hydrate has been proposed as a potential strategy for geologic sequestration of carbon dioxide and production of methane from natural hydrate deposits. However, this strategy requires a better understanding of the thermodynamic characteristics of CH4...... and CO2 hydrate as well as (CH4 + CO2) or (CH4 + CO2 + N2) mixed hydrates (since (CO2 + N2) gas mixture is often used as the swapping gas), along with the thermal physics property changes during gas exchange. In this study, a high pressure micro-differential scanning calorimetry (HP μ-DSC) was performed...

  11. Sexually Explicit Media Use by Sexual Identity: A Comparative Analysis of Gay, Bisexual, and Heterosexual Men in the United States.

    Science.gov (United States)

    Downing, Martin J; Schrimshaw, Eric W; Scheinmann, Roberta; Antebi-Gruszka, Nadav; Hirshfield, Sabina

    2017-08-01

    Advances in production and distribution of sexually explicit media (SEM) online have resulted in widespread use among men. Limited research has compared contexts of use and behaviors viewed in Internet SEM by sexual identity. The current study examined differences in recent SEM use (past 6 months) by sexual identity among an ethnically diverse sample of 821 men who completed an online survey in 2015. Both gay and bisexual men reported significantly more frequent use of Internet SEM compared to heterosexual men. Although most participants reported viewing SEM at home (on a computer, tablet, or smartphone), significantly more gay men reported SEM use at a sex party or commercial sex venue than either heterosexual or bisexual men. Sexual identity predicted viewing of high-risk and protective behaviors in separate logistic regression models. Specifically, compared to heterosexual men, gay and bisexual men had increased odds of viewing condomless anal sex (gay OR 5.20, 95 % CI 3.35-8.09; bisexual OR 3.99, 95 % CI 2.24-7.10) and anal sex with a condom (gay OR 3.93, 95 % CI 2.64-5.83; bisexual OR 4.59, 95 % CI 2.78-7.57). Compared to gay men, heterosexual and bisexual men had increased odds of viewing condomless vaginal sex (heterosexual OR 27.08, 95 % CI 15.25-48.07; bisexual OR 5.59, 95 % CI 3.81-8.21) and vaginal sex with a condom (heterosexual OR 7.90, 95 % CI 5.19-12.03; bisexual OR 4.97, 95 % CI 3.32-7.44). There was also evidence of identity discrepant SEM viewing as 20.7 % of heterosexual-identified men reported viewing male same-sex behavior and 55.0 % of gay-identified men reported viewing heterosexual behavior. Findings suggest the importance of assessing SEM use across media types and contexts and have implications for research to address the potential influence of SEM on sexual behavior (e.g., investigate associations between viewing condomless vaginal sex and engaging in high-risk encounters with female partners).

  12. An Examination of the Prediction of Hydrate Formation Conditions in the Presence of Thermodynamic Inhibitors

    Directory of Open Access Journals (Sweden)

    Carollina de M. Molinari O. Antunes

    Full Text Available Abstract Gas hydrates are crystalline compounds, solid structures where water traps small guest molecules, typically light gases, in cages formed by hydrogen bonds. They are notorious for causing problems in oil and gas production, transportation and processing. Gas hydrates may form at pressures and temperatures commonly found in natural gas and oil production pipelines, thus causing partial or complete pipe blockages. In order to inhibit hydrate formation, chemicals such as alcohols (e.g., ethanol, methanol, mono-ethylene glycol and salts (sodium, magnesium or potassium chloride are injected into the produced stream. The purpose of this work is to briefly review the literature on hydrate formation in mixtures containing light gases (hydrocarbons and carbon dioxide and water in the presence of thermodynamic inhibitors. Four calculation methods to predict hydrate formation in those systems were examined and compared. Three commercial packages (Multiflash®, PVTSim® and CSMGem and a hydrate prediction routine in Fortran90 using the van der Waals and Platteeuw theory and the Peng-Robinson equation of state were tested. Predictions given by the four methods were compared to independent experimental data from the literature. In general, the four methods were found to be reasonably accurate. CSMGem and Multiflash® showed the best results.

  13. [Study on the causes of sexual orientation of gay].

    Science.gov (United States)

    Zhang, Yan-hui; Bao, Yu-gang; Chen, Hao; Tan, Hong-zhuan

    2013-11-01

    To explore the relevant factors of the causes of sexual orientations of gay. From March to June 2013, 350 gays were recruited from one music bar and three bath centers where gays frequently visited in Changsha city, by proportional stratified sampling method. Meanwhile, another 332 males who identify themselves as non-homosexuality were also recruited considering the composition of ages, gender and educational background. Questionnaire survey was conducted to all the subjects, with 300 effective ones reclaimed. The questionnaire included the general demographic information, traits of character, the condition of foster in childhood and information of family members. The differences between the gays and non-homosexuality groups were analyzed to explore the causes of the sexual orientations of gays. There were statistical significant differences between gays and non- homosexuality group on following indexes (χ(2) was 59.63, 5.90, 16.01, 84.99, 161.57, 77.77, 112.32, 190.84, 30.10 respectively, all of P books or films about homosexual and experienced sexual pleasure from that before the age of 18. The rate of gays on these indexes was separately 62.3% (187/300), 57.7% (173/300) , 62.3% (187/300) , 63.0% (189/300), 67.3% (202/300) , 62.7% (189/300), 68.0% (204/300), 65.0% (195/300) and the rate on these indexes of non-homosexuality group was separately 21.3% (64/300), 28.0% (84/300) , 25.0% (75/300) , 12.7% (38/300), 31.3% (94/300), 17.7% (53/300) , 12.7% (38/300), 42.7% (128/300) . The rate of gays on these factors:the youngest boy in family, had the father or twin brothers who were homosexual or self identified as gay was 62.7% (188/300), 56.0% (168/300) and 62.0% (18/29) respectively; and the rate was 40.7% (122/300), 4.0% (12/300) and 20.0% (2/10), respectively among non-homosexuality group. The difference showed statistical significance (χ(2) was 34.52, 193.14, 5.27 respectively, all of P gays maybe was family relationship, tend and education since childhood

  14. HYDRATION AND PROPERTIES OF BLENDED CEMENT SYSTEMS INCORPORATING INDUSTRIAL WASTES

    Directory of Open Access Journals (Sweden)

    Heikal M.

    2013-06-01

    Full Text Available This paper aims to study the characteristics of ternary blended system, namely granulated blast-furnace slag (WCS, from iron steel company and Homra (GCB from Misr Brick (Helwan, Egypt and silica fume (SF at 30 mass % pozzolanas and 70 mass % OPC. The required water of standard consistency and setting times were measured as well as physico-chemical and mechanical characteristics of the hardened cement pastes were investigated. Some selected cement pastes were tested by TGA, DTA and FT-IR techniques to investigate the variation of hydrated products of blended cements. The pozzolanic activity of SF is higher than GCB and WCS. The higher activity of SF is mainly due to its higher surface area than the other two pozzolanic materials. On the other side, GCB is more pozzolanic than WCS due to GCB containing crystalline silica quartz in addition to an amorphous phase. The silica quartz acts as nucleating agents which accelerate the rate of hydration in addition to its amorphous phase, which can react with liberating Ca(OH2 forming additional hydration products.

  15. Gas Hydrate Storage of Natural Gas

    Energy Technology Data Exchange (ETDEWEB)

    Rudy Rogers; John Etheridge

    2006-03-31

    Environmental and economic benefits could accrue from a safe, above-ground, natural-gas storage process allowing electric power plants to utilize natural gas for peak load demands; numerous other applications of a gas storage process exist. A laboratory study conducted in 1999 to determine the feasibility of a gas-hydrates storage process looked promising. The subsequent scale-up of the process was designed to preserve important features of the laboratory apparatus: (1) symmetry of hydrate accumulation, (2) favorable surface area to volume ratio, (3) heat exchanger surfaces serving as hydrate adsorption surfaces, (4) refrigeration system to remove heat liberated from bulk hydrate formation, (5) rapid hydrate formation in a non-stirred system, (6) hydrate self-packing, and (7) heat-exchanger/adsorption plates serving dual purposes to add or extract energy for hydrate formation or decomposition. The hydrate formation/storage/decomposition Proof-of-Concept (POC) pressure vessel and supporting equipment were designed, constructed, and tested. This final report details the design of the scaled POC gas-hydrate storage process, some comments on its fabrication and installation, checkout of the equipment, procedures for conducting the experimental tests, and the test results. The design, construction, and installation of the equipment were on budget target, as was the tests that were subsequently conducted. The budget proposed was met. The primary goal of storing 5000-scf of natural gas in the gas hydrates was exceeded in the final test, as 5289-scf of gas storage was achieved in 54.33 hours. After this 54.33-hour period, as pressure in the formation vessel declined, additional gas went into the hydrates until equilibrium pressure/temperature was reached, so that ultimately more than the 5289-scf storage was achieved. The time required to store the 5000-scf (48.1 hours of operating time) was longer than designed. The lower gas hydrate formation rate is attributed to a

  16. Can hydrate dissolution experiments predict the fate of a natural hydrate system?

    Energy Technology Data Exchange (ETDEWEB)

    Hester, K.C.; Peltzer, E.T.; Dunk, R.M.; Walz, P.M.; Brewer, P.G. [Monterey Bay Aquarium Research Inst., Moss Landing, CA (United States); Dendy Sloan, E. [Colorado School of Mines, Golden, CO (United States). Center for Hydrate Research

    2008-07-01

    Gas hydrates are naturally occurring compounds found in permafrost regions and in oceans. In the natural environment, sufficient temperature and pressure conditions for hydrate formation exist over a significant portion of the ocean. However, in addition to pressure and temperature, the chemical potential of the gas in the hydrate must be equal to the surrounding waters. If the concentration of the gas in surrounding water is under-saturated with respect to the gas in the hydrate, the hydrate will dissolve to drive the system towards chemical equilibrium. This paper presented a dissolution study of exposed hydrate from outcrops at Barkley Canyon, located off Vancouver Island, British Columbia. A previous field experiment on synthetic methane hydrate samples had demonstrated that mass transfer controlled dissolution in under-saturated seawater. However, seafloor hydrate outcrops have been shown to have significant longevity compared to expected dissolution rates based upon convective boundary layer diffusion calculations. An in-situ dissolution experiment was performed on two distinct natural hydrate fabrics in order to help resolve this apparent disconnect between the dissolution rates of synthetic and natural hydrate. The paper presented a map of Barkley Canyon and discussed the field measurements and methods for the study. Exposed outcrops of gas hydrates were cored using a specially constructed stainless steel coring device and a hydraulic ram was located inside the corer. Hydrate samples were cored directly using the a manipulator arm and then injected into a sampling cell. The hydrate was then added to an open mesh exposure container, which allowed for exposure to ambient benthic currents with minimal disturbance. As well, in order to observe the slow dissolution of the hydrate in seawater at Barkley Canyon, time-lapse photography was employed. Last, the paper presented the results of the hydrate fabric porosities and hydrate dissolution rates. It was

  17. Calcium and magnesium silicate hydrates

    International Nuclear Information System (INIS)

    Lothenbach, B.; L'Hopital, E.; Nied, D.; Achiedo, G.; Dauzeres, A.

    2015-01-01

    Deep geological disposals are planed to discard long-lived intermediate-level and high-level radioactive wastes. Clay-based geological barriers are expected to limit the ingress of groundwater and to reduce the mobility of radioelements. In the interaction zone between the cement and the clay based material alteration can occur. Magnesium silicate hydrates (M-S-H) have been observed due to the reaction of magnesium sulfate containing groundwater with cements or in the interaction zone between low-pH type cement and clays. M-S-H samples synthesized in the laboratory showed that M-S-H has a variable composition within 0.7 ≤ Mg/Si ≤ 1.5. TEM/EDS analyses show an homogeneous gel with no defined structure. IR and 29 Si NMR data reveal a higher polymerization degree of the silica network in M-S-H compared to calcium silicate hydrates (C-S-H). The presence of mainly Q 3 silicate tetrahedrons in M-S-H indicates a sheet like or a triple-chain silica structure while C-S-H is characterised by single chain-structure. The clear difference in the silica structure and the larger ionic radius of Ca 2+ (1.1 Angstrom) compared to Mg 2+ (0.8 Angstrom) make the formation of an extended solid solution between M-S-H and C-S-H gel improbable. In fact, the analyses of synthetic samples containing both magnesium and calcium in various ratios indicate the formation of separate M-S-H and C-S-H gels with no or very little uptake of magnesium in CS-H or calcium in M-S-H

  18. Gas Hydrates Research Programs: An International Review

    Energy Technology Data Exchange (ETDEWEB)

    Jorge Gabitto; Maria Barrufet

    2009-12-09

    Gas hydrates sediments have the potential of providing a huge amount of natural gas for human use. Hydrate sediments have been found in many different regions where the required temperature and pressure conditions have been satisfied. Resource exploitation is related to the safe dissociation of the gas hydrate sediments. Basic depressurization techniques and thermal stimulation processes have been tried in pilot efforts to exploit the resource. There is a growing interest in gas hydrates all over the world due to the inevitable decline of oil and gas reserves. Many different countries are interested in this valuable resource. Unsurprisingly, developed countries with limited energy resources have taken the lead in worldwide gas hydrates research and exploration. The goal of this research project is to collect information in order to record and evaluate the relative strengths and goals of the different gas hydrates programs throughout the world. A thorough literature search about gas hydrates research activities has been conducted. The main participants in the research effort have been identified and summaries of their past and present activities reported. An evaluation section discussing present and future research activities has also been included.

  19. Coming out narratives of older gay men living in New Zealand.

    Science.gov (United States)

    Neville, Stephen; Kushner, Bernie; Adams, Jeffery

    2015-10-01

    Explore the coming out narratives in a group of older gay men. A narrative gerontological approach was employed to explore the coming out narratives of older gay men. Semi-structured digitally recorded individual interviews were undertaken with 12 gay men aged between 65 and 81 years who lived in the community. Data were analysed using a narrative data analytic process. Three collective narratives related to the coming out of older gay men were identified: 'early gay experiences', 'trying not to be gay' and 'acceptance'. Older gay men come from diverse socio-cultural backgrounds. However, they all grew up in an era where same-sex attraction was a criminal offence. The path to accepting being a gay man was individualised and stressful for these participants. Consequently health and social service providers need to support the ongoing development of resilience and provide a person-centred approach to care that promotes wellbeing. © 2015 AJA Inc.

  20. Religious affiliation and attitudes towards gay men: On the mediating role of masculinity threat

    NARCIS (Netherlands)

    Reese, G.; Steffens, M.C.; Jonas, K.J.

    2014-01-01

    Previous research suggests that people from some religious backgrounds hold more negative attitudes towards gay men than others do. The current research focuses on psychological variables as an alternative explanation to religious affiliation, testing whether masculinity beliefs regarding gay men

  1. Ten Things Gay Men Should Discuss with Their Health Care Provider

    Science.gov (United States)

    ... Conference Newsroom Support GLMA Site Search Ten Things Gay Men Should discuss with Their Healthcare Provider ( Download . ... have identified as most commonly of concern for gay men. While not all of these items apply ...

  2. Sexual orientation and education politics: gay and lesbian representation in American schools.

    Science.gov (United States)

    Wald, Kenneth D; Rienzo, Barbara A; Button, James W

    2002-01-01

    In what has sometimes provoked a "culture war" over America's schools, gays and lesbians have sought an expanded voice in the making of education policy. This paper explores the factors that promote gay representation on school boards, how this variable in turn influences gay representation in both administrative and teaching positions, and how all three forms of gay representation relate to school board policies regarding sexual orientation education. Three of the four models drawn from the social movement literature help to explain gay school board representation. In a manner similar to other minority groups, gay representation on school boards directly or indirectly promotes the appointment of gays to administrative and teaching positions and the adoption of policies that address the problems faced by gay and lesbian students in the public schools.

  3. Methane hydrate stability and anthropogenic climate change

    Directory of Open Access Journals (Sweden)

    D. Archer

    2007-07-01

    Full Text Available Methane frozen into hydrate makes up a large reservoir of potentially volatile carbon below the sea floor and associated with permafrost soils. This reservoir intuitively seems precarious, because hydrate ice floats in water, and melts at Earth surface conditions. The hydrate reservoir is so large that if 10% of the methane were released to the atmosphere within a few years, it would have an impact on the Earth's radiation budget equivalent to a factor of 10 increase in atmospheric CO2.

    Hydrates are releasing methane to the atmosphere today in response to anthropogenic warming, for example along the Arctic coastline of Siberia. However most of the hydrates are located at depths in soils and ocean sediments where anthropogenic warming and any possible methane release will take place over time scales of millennia. Individual catastrophic releases like landslides and pockmark explosions are too small to reach a sizable fraction of the hydrates. The carbon isotopic excursion at the end of the Paleocene has been interpreted as the release of thousands of Gton C, possibly from hydrates, but the time scale of the release appears to have been thousands of years, chronic rather than catastrophic.

    The potential climate impact in the coming century from hydrate methane release is speculative but could be comparable to climate feedbacks from the terrestrial biosphere and from peat, significant but not catastrophic. On geologic timescales, it is conceivable that hydrates could release as much carbon to the atmosphere/ocean system as we do by fossil fuel combustion.

  4. On the electrolytic generation of hydrated electron

    International Nuclear Information System (INIS)

    Ghosh Mazumdar, A.S.; Guha, S.N.

    1975-01-01

    Investigations on the electrolytic generation of hydrated electron in oxygenated as well as oxygen-free solutions at different pH were undertaken. Since sup(-e)aq is known to react rapidly with O 2 yielding the transient O 2 - ion, the latter was looked for through its interaction with phosphite ions resulting in their oxidation near the cathode. It appears from the results that in electrolytic processes, the primary electron (esup(-)sub(cathode)) probably reacts directly with reactive solutes like oxygen, bypassing the hydration step. Data obtained in oxygen-free solutions, however, support the possible formation of hydrated electron at least in alkaline solutions. (author)

  5. ‘Kids are just cruel anyway’: lesbian and gay parents talk about homophobic bullying

    OpenAIRE

    Clarke, V.; Kitzinger, C.; Potter, J.

    2004-01-01

    Psychologists recognise homophobic bullying as a serious problem for young lesbians and gay men; however, when it comes to children in lesbian and gay households the issue is not so clear cut. Whereas some psychologists sympathetic to lesbian and gay parenting regard it as a problem, most do not. Despite this, the inevitability and severe psychological consequences of homophobic bullying is a prevalent theme in discussions of lesbian and gay parenting in contexts ranging from custody cases to...

  6. Role Portrayal of Gay Men in Print Advertisements: A Study on US Market

    OpenAIRE

    satyaprakash, shilpa

    2010-01-01

    This dissertation research is aimed at analyzing the gay roles portrayal in print advertisements by the advertisers. In order to conduct this study, the researcher had selected sample of gay advertisements from the leading US gay magazine and the mainstream magazine. The researcher also developed a coding sheet for the purpose of this analysis. The coding sheet was developed on the basis of various aspects which would enable to find out the various roles that could be portrayed by the gay men...

  7. Protocol for Measuring the Thermal Properties of a Supercooled Synthetic Sand-water-gas-methane Hydrate Sample.

    Science.gov (United States)

    Muraoka, Michihiro; Susuki, Naoko; Yamaguchi, Hiroko; Tsuji, Tomoya; Yamamoto, Yoshitaka

    2016-03-21

    Methane hydrates (MHs) are present in large amounts in the ocean floor and permafrost regions. Methane and hydrogen hydrates are being studied as future energy resources and energy storage media. To develop a method for gas production from natural MH-bearing sediments and hydrate-based technologies, it is imperative to understand the thermal properties of gas hydrates. The thermal properties' measurements of samples comprising sand, water, methane, and MH are difficult because the melting heat of MH may affect the measurements. To solve this problem, we performed thermal properties' measurements at supercooled conditions during MH formation. The measurement protocol, calculation method of the saturation change, and tips for thermal constants' analysis of the sample using transient plane source techniques are described here. The effect of the formation heat of MH on measurement is very small because the gas hydrate formation rate is very slow. This measurement method can be applied to the thermal properties of the gas hydrate-water-guest gas system, which contains hydrogen, CO2, and ozone hydrates, because the characteristic low formation rate of gas hydrate is not unique to MH. The key point of this method is the low rate of phase transition of the target material. Hence, this method may be applied to other materials having low phase-transition rates.

  8. THCM Coupled Model for Hydrate-Bearing Sediments: Data Analysis and Design of New Field Experiments (Marine and Permafrost Settings)

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez, Marcelo J. [Texas A & M Univ., College Station, TX (United States); Santamarina, J. Carlos [King Abdullah Univ. of Science and Technology (Saudi Arabia)

    2017-02-14

    Gas hydrates are solid compounds made of water molecules clustered around low molecular weight gas molecules such as methane, hydrogen, and carbon dioxide. Methane hydrates form under pressure (P) and temperature (T) conditions that are common in sub-permafrost layers and in deep marine sediments. Stability conditions constrain the occurrence of gas hydrates to submarine sediments and permafrost regions. The amount of technically recoverable methane trapped in gas hydrate may exceed 104tcf. Gas hydrates are a potential energy resource, can contribute to climate change, and can cause large-scale seafloor instabilities. In addition, hydrate formation can be used for CO2 sequestration (also through CO2-CH4 replacement), and efficient geological storage seals. The experimental study of hydrate bearing sediments has been hindered by the very low solubility of methane in water (lab testing), and inherent sampling difficulties associated with depressurization and thermal changes during core extraction. This situation has prompted more decisive developments in numerical modeling in order to advance the current understanding of hydrate bearing sediments, and to investigate/optimize production strategies and implications. The goals of this research has been to addresses the complex thermo-hydro-chemo-mechanical THCM coupled phenomena in hydrate-bearing sediments, using a truly coupled numerical model that incorporates sound and proven constitutive relations, satisfies fundamental conservation principles. Analytical solutions aimed at verifying the proposed code have been proposed as well. These tools will allow to better analyze available data and to further enhance the current understanding of hydrate bearing sediments in view of future field experiments and the development of production technology.

  9. Attitudes toward Lesbians and Gays among American and Dutch Adolescents

    Science.gov (United States)

    Collier, Kate L.; Horn, Stacey S.; Bos, Henny M. W.; Sandfort, Theo G. M.

    2014-01-01

    Attitudes toward lesbians and gays vary across national populations, and previous research has found relatively more accepting attitudes in the Netherlands as compared to the U.S. In this study, we compared beliefs about and attitudes toward lesbians and gays in samples of Dutch and American heterosexual adolescents, utilizing survey data from 1,080 American adolescents (mean age = 15.86 years) attending two schools and from 1,391 Dutch adolescents (mean age = 16.27 years) attending eight schools. Findings indicated the Dutch participants were more tolerant of lesbians and gays, after adjusting for the gender, age, and racial/ethnic minority status of the participants. However, between-country differences were attenuated by accounting for the beliefs about lesbians and gays that participants used to justify their attitudes. American participants were more likely to justify their attitudes using beliefs related to social norms and religious opposition, while the Dutch participants were more likely to justify their attitudes using beliefs related to individual rights and the biological/genetic basis of homosexuality. The results suggest that the relative importance of particular beliefs about lesbians and gays to attitudes at the group level may be context-dependent but also that certain beliefs are salient to attitudes across national contexts. PMID:24512056

  10. Social and psychological creativity in gay male midlife identity management.

    Science.gov (United States)

    Hajek, Christopher

    2016-06-01

    This study utilizes a qualitative thematic analysis methodology and a social identity theory framework to explore ways in which early midlife gay men report enhancing their social identities through social and psychological creativity. Face-to-face, semi-structured interviews were conducted with forty early midlife gay men (aged 40-53) in four US cities. Men discussed the collective and individual essences of their age and gay identities, including attitudes, beliefs, and behaviours that they embraced to self-enhance at midlife. These discussions emphasized differences from the younger gay outgroup, often in the context of intergenerational interaction. Identified were three strategies (and seven substrategies) that summarized the ways that interviewees constructed their identities in the interest of self-enhancement, specifically in the context of intergenerational comparisons with younger gay men. These strategies may be considered as extensions to social creativity strategies presented in Tajfel and Turner's (Psychology of intergroup relations. Chicago, IL: Nelson, 1986: 7) social identity theory. © 2015 The British Psychological Society.

  11. Gay men's experiences of surrogacy clinics in India.

    Science.gov (United States)

    Riggs, Damien W; Due, Clemence; Power, Jennifer

    2015-01-01

    While growing numbers of Australian gay men are entering into 'offshore' surrogacy arrangements in order to become parents, little empirical research has been conducted with this population. This article reports on a qualitative analysis of interviews with 12 gay men who had entered into surrogacy arrangements in India. The findings outline both positive and negative experiences in terms of support pre-conception, during the birth and post-birth. Changes to legislation in India mean that gay men can no longer access surrogacy services there, but it is important to understand the experiences of men who had previously accessed those services. The article concludes by highlighting aspects of the data that demonstrate the particular experiences of gay men who undertake offshore surrogacy arrangements, especially with regard to their need for support and involvement in all aspects of the process. A more thoroughly developed network of care may help to facilitate such support and this may further increase the positive outcomes reported by gay men who form families through surrogacy arrangements. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  12. Men as victims: "victim" identities, gay identities, and masculinities.

    Science.gov (United States)

    Dunn, Peter

    2012-11-01

    The impact and meanings of homophobic violence on gay men's identities are explored with a particular focus on their identities as men and as gay men. Homosexuality can pose a challenge to conventional masculinities, and for some gay men, being victimized on account of sexual orientation reawakens conflicts about their masculinity that they thought they had resolved. Being victimized can reinvoke shame that is rooted in failure or unwillingness to uphold masculine norms. For some gay men, victimization therefore has connotations of nonmasculinity that make being a victim an undesirable status, yet that status must be claimed to obtain a response from criminal justice or victim services. Men who experience homophobic abuse are helped by accepting a victim identity, but only if they can quickly move on from it by reconstructing a masculine gay (nonvictim) identity. This process can be facilitated by agencies such as the police and victim services, provided they help men exercise agency in "fighting back," that is, resisting further victimization and recovering.

  13. Les commerces gays et le processus de gentrification

    Directory of Open Access Journals (Sweden)

    Colin Giraud

    2009-04-01

    Full Text Available Interrogeant le rôle des populations homosexuelles dans la gentrification d’un ancien quartier historique de Paris (celui du Marais, cet article aborde cette question dans sa dimension commerciale. Depuis le début des années 80, l’implantation de commerces gays dans ce secteur a accompagné les effets de la gentrification et les a même accélérés pour partie depuis les années 90. Aujourd’hui cependant, la relation entre cette présence commerciale spécifique et les transformations socio-économiques de ce quartier parisien apparaissent nettement plus ambigus.In this paper, we examinate the role of gay men towards gentrification and urban renaissance by focusing on gay business development in “Le Marais”. We demonstrate that, in this old neighbourhood of the city-center, the emergence of a gay commercial area has supported gentrification during the eighties and then contributed to the urban, economical and cultural renaissance. The historical link between gentrification and “gay spaces” has changed and became since a few years more and more diversified.

  14. Shame, gay men, and HIV disease.

    Science.gov (United States)

    Sabar, S

    1995-04-01

    Mental health professionals working with people with HIV disease are often confronted by the patients' feelings of shame and should be prepared to recognize and treat what can sabotage the openness crucial to the therapeutic process. Shame is unlike guilt in that instead of being a transgression against some moral code or value, it is the failure to live up to an internal ideal image of oneself; its sanction is rejection or abandonment as opposed to punishment. Shame can have many triggers, and when faced with these triggers, a strong sense of self can protect a person. However, most people with HIV find that shame does arise in some situations. In its wake, shame can cause withdrawal, substance abuse, depression, denial, rage, grandiosity, lack of entitlement, and perfectionism. Therapists can help gay men deal with shame and cope better with the indignities of HIV infection. Guidelines include building a strong patient/therapist relationship to build trust and improve self-esteem; and identifying the shame, and bringing it out for validation by the patient. Therapists must guide patients to an awareness of their true feelings, and help them trust their perceptions of these needs and feelings.

  15. Gas hydrate concentration and characteristics within Hydrate Ridge inferred from multicomponent seismic reflection data

    Science.gov (United States)

    Kumar, Dhananjay; Sen, Mrinal K.; Bangs, Nathan L.

    2007-12-01

    A seismic experiment composed of streamer and ocean bottom seismometer (OBS) surveys was conducted in the summer of 2002 at southern Hydrate Ridge, offshore Oregon, to map the gas hydrate distribution within the hydrate stability zone. Gas hydrate concentrations within the reservoir can be estimated with P wave velocity (Vp); however, we can further constrain gas hydrate concentrations using S wave velocity (Vs), and use Vs through its relationship to Vp (Vp/Vs) to reveal additional details such as gas hydrate form within the matrix (i.e., hydrate cements the grains, becomes part of the matrix frame or floats in pore space). Both Vp and Vs can be derived simultaneously by inverting multicomponent seismic data. In this study, we use OBS data to estimate seismic velocities where both gas hydrate and free gas are present in the shallow sediments. Once Vp and Vs are estimated, they are simultaneously matched with modeled velocities to estimate the gas hydrate concentration. We model Vp using an equation based on a modification of Wood's equation that incorporates an appropriate rock physics model and Vs using an empirical relation. The gas hydrate concentration is estimated to be up to 7% of the rock volume, or 12% of the pore space. However, Vp and Vs do not always fit the model simultaneously. Vp can vary substantially more than Vs. Thus we conclude that a model, in which higher concentrations of hydrate do not affect shear stiffness, is more appropriate. Results suggest gas hydrates form within the pore space of the sediments and become part of the rock framework in our survey area.

  16. Voices from the Glass Closet: Lesbian and Gay Teachers Talk about Their Lives.

    Science.gov (United States)

    Kissen, Rita M.

    This study explores issues of importance to gay and lesbian teachers. It seeks to answer questions and to dramatize the damaging effects of homophobia on the lives of gay teachers, as well as all teachers and students. The project was narrative and qualitative, consisting of informal and open ended interviews of 10 self-identifies gay or lesbian…

  17. Relationship Preferences Among Gay and Lesbian Online Daters : Individual and Contextual Influences

    NARCIS (Netherlands)

    Potarca, Gina; Mills, Melinda; Neberich, Wiebke

    There is currently little knowledge about what gay men and lesbians seek in a romantic relationship. This study extends the literature on gay men and lesbians' partnership preferences by engaging in the first large-scale empirical study of the long-term dating intentions and monogamy beliefs of gay

  18. 76 FR 44317 - Gay & Robinson, Inc.; Notice of Declaration of Intention and Soliciting Comments, Protests, and...

    Science.gov (United States)

    2011-07-25

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. DI11-12-000] Gay & Robinson... Filed: July 11, 2011. d. Applicant: Gay & Robinson, Inc. e. Name of Project: Olokele River Hydroelectric... Contact: Charles Okamoto, President, Gay & Robinson, Inc., P.O. Box 156, Kaumakani, Hawaii 96747...

  19. Sexualities on the Move: A Comparison of the Work Experiences of Gay Male Educators Teaching Overseas

    Science.gov (United States)

    Mizzi, Robert C.

    2015-01-01

    This paper expands on the extant research on gay male educators by comparing two research projects on such educators who taught in international settings. One study focused on five gay, male, adult educators who relocated to Canada from countries in the Global South and the second study focused on eight gay, male, adult educators who relocated to…

  20. 77 FR 33599 - Lesbian, Gay, Bisexual, and Transgender Pride Month, 2012

    Science.gov (United States)

    2012-06-07

    ..., Gay, Bisexual, and Transgender Pride Month, 2012 By the President of the United States of America A... live and love as we see fit. The lesbian, gay, bisexual, and transgender (LGBT) community has written a... coverage to someone just because they are lesbian, gay, bisexual, or transgender. Because we understand...

  1. 78 FR 33957 - Lesbian, Gay, Bisexual, and Transgender Pride Month, 2013

    Science.gov (United States)

    2013-06-06

    ..., Gay, Bisexual, and Transgender Pride Month, 2013 By the President of the United States of America A... equality from founding promise into lasting reality. Lesbian, gay, bisexual, and transgender (LGBT... Constitution and the laws of the United States, do hereby proclaim June 2013 as Lesbian, Gay, Bisexual, and...

  2. Why Parenthood, and Why Now? Gay Men's Motivations for Pursuing Parenthood

    Science.gov (United States)

    Goldberg, Abbie E.; Downing, Jordan B.; Moyer, April M.

    2012-01-01

    The current qualitative study of 35 preadoptive gay male couples (70 men) examined gay men's motivations to parent and their reasons for pursuing parenthood at the current time. Similar to heterosexual couples, gay men described a range of psychologically oriented reasons as shaping their decision to become parents. Some of these (e.g., desire to…

  3. Teenage Queerness: Negotiating Heteronormativity in the Representation of Gay Teenagers in "Glee"

    Science.gov (United States)

    Dhaenens, Frederik

    2013-01-01

    Despite a significant increase in gay representation in contemporary television fiction, many media scholars argue that the representation of gay men and women is governed by heteronormativity. They postulate that even rounded and heterogeneous representations of gay men and women are characters that desire to participate in institutions,…

  4. 76 FR 51024 - Gay & Robinson, Inc.; Notice of Preliminary Permit Application Accepted for Filing and Soliciting...

    Science.gov (United States)

    2011-08-17

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [ Project No. 14219-000] Gay & Robinson... Intervene, and Competing Applications On July 1, 2011, Gay & Robinson, Inc., filed an application for a.... Applicant Contact: Mr. Charles Okamoto, President, Gay & Robinson, Inc., P.O. Box 156, Kaumakani, Hawaii...

  5. 76 FR 32853 - Lesbian, Gay, Bisexual, And Transgender Pride Month, 2011

    Science.gov (United States)

    2011-06-07

    ..., Gay, Bisexual, And Transgender Pride Month, 2011 By the President of the United States of America A Proclamation The story of America's Lesbian, Gay, Bisexual, and Transgender (LGBT) community is the story of..., Don't Tell'' policy. With this repeal, gay and lesbian Americans will be able to serve openly in our...

  6. Coming out and Coming Back: Rural Gay Migration and the City

    Science.gov (United States)

    Annes, Alexis; Redlin, Meredith

    2012-01-01

    This research focuses on the complex meaning and role of the city in American and French rural gay men's imaginary and life experience. It explores how gay men who grew up in the country build their sense of self through back-and-forth movement from rural to urban spaces. Therefore, it questions traditional gay migration studies, which have often…

  7. 75 FR 32079 - Lesbian, Gay, Bisexual, and Transgender Pride Month, 2010

    Science.gov (United States)

    2010-06-07

    ..., Gay, Bisexual, and Transgender Pride Month, 2010 By the President of the United States of America A... equality on behalf of the lesbian, gay, bisexual, and transgender (LGBT) community. This month, as we.... That is why we must give committed gay couples the same rights and responsibilities afforded to any...

  8. How Organisational Culture Influences Teachers' Support of Openly Gay, Lesbian and Bisexual Students

    Science.gov (United States)

    Murphy, Meghan

    2015-01-01

    In this paper, I analyse the relationship between US high schools' organisational cultures and student perceptions of responses to anti-gay language in their school. Using data from 67 interviews with young people who identified as gay, lesbian or bisexual, I compare teachers' responses to anti-gay language in schools that do and schools that do…

  9. A Queer analysis of the discursive construction of gay identity in ...

    African Journals Online (AJOL)

    In 2003 the book Gayle: the language of kinks and queens: a history and dictionary of gay language in South Africa was published, documenting more than 1400 lexical items used by South African gays and lesbians. Given that the field of gay language is an established discipline within sociolinguistic research elsewhere ...

  10. GAS METHANE HYDRATES-RESEARCH STATUS, ANNOTATED BIBLIOGRAPHY, AND ENERGY IMPLICATIONS

    Energy Technology Data Exchange (ETDEWEB)

    James Sorensen; Jaroslav Solc; Bethany Bolles

    2000-07-01

    The objective of this task as originally conceived was to compile an assessment of methane hydrate deposits in Alaska from available sources and to make a very preliminary evaluation of the technical and economic feasibility of producing methane from these deposits for remote power generation. Gas hydrates have recently become a target of increased scientific investigation both from the standpoint of their resource potential to the natural gas and oil industries and of their positive and negative implications for the global environment After we performed an extensive literature review and consulted with representatives of the U.S. Geological Survey (USGS), Canadian Geological Survey, and several oil companies, it became evident that, at the current stage of gas hydrate research, the available information on methane hydrates in Alaska does not provide sufficient grounds for reaching conclusions concerning their use for energy production. Hence, the original goals of this task could not be met, and the focus was changed to the compilation and review of published documents to serve as a baseline for possible future research at the Energy & Environmental Research Center (EERC). An extensive annotated bibliography of gas hydrate publications has been completed. The EERC will reassess its future research opportunities on methane hydrates to determine where significant initial contributions could be made within the scope of limited available resources.

  11. Mapping the Fluid Pathways and Permeability Barriers of a Large Gas Hydrate Reservoir

    Science.gov (United States)

    Campbell, A.; Zhang, Y. L.; Sun, L. F.; Saleh, R.; Pun, W.; Bellefleur, G.; Milkereit, B.

    2012-12-01

    An understanding of the relationship between the physical properties of gas hydrate saturated sedimentary basins aids in the detection, exploration and monitoring one of the world's upcoming energy resources. A large gas hydrate reservoir is located in the MacKenzie Delta of the Canadian Arctic and geophysical logs from the Mallik test site are available for the gas hydrate stability zone (GHSZ) between depths of approximately 850 m to 1100 m. The geophysical data sets from two neighboring boreholes at the Mallik test site are analyzed. Commonly used porosity logs, as well as nuclear magnetic resonance, compressional and Stoneley wave velocity dispersion logs are used to map zones of elevated and severely reduced porosity and permeability respectively. The lateral continuity of horizontal permeability barriers can be further understood with the aid of surface seismic modeling studies. In this integrated study, the behavior of compressional and Stoneley wave velocity dispersion and surface seismic modeling studies are used to identify the fluid pathways and permeability barriers of the gas hydrate reservoir. The results are compared with known nuclear magnetic resonance-derived permeability values. The aim of investigating this heterogeneous medium is to map the fluid pathways and the associated permeability barriers throughout the gas hydrate stability zone. This provides a framework for an understanding of the long-term dissociation of gas hydrates along vertical and horizontal pathways, and will improve the knowledge pertaining to the production of such a promising energy source.

  12. A Hydrate Database: Vital to the Technical Community

    Directory of Open Access Journals (Sweden)

    D Sloan

    2007-06-01

    Full Text Available Natural gas hydrates may contain more energy than all the combined other fossil fuels, causing hydrates to be a potentially vital aspect of both energy and climate change. This article is an overview of the motivation, history, and future of hydrate data management using a CODATA vehicle to connect international hydrate databases. The basis is an introduction to the Gas Hydrate Markup Language (GHML to connect various hydrate databases. The accompanying four articles on laboratory hydrate data by Smith et al., on field hydrate data by L?wner et al., on hydrate modeling by Wang et al., and on construction of a Chinese gas hydrate system by Xiao et al. provide details of GHML in their respective areas.

  13. The rise and fall of gay: a cultural-historical approach to gay identity development.

    Science.gov (United States)

    Weststrate, Nic M; McLean, Kate C

    2010-02-01

    Research on identity development has paid relatively little attention to the development of marginalised identities such as those of gays and lesbians, whose isolation from the canonical narrative of sexuality may limit the available resources required for establishing a coherent identity. We examined these contested identities in relation to cultural-historical factors that may have played a role in shaping these identities over the past 50 years, and looked at how such factors have impacted the voicing and silencing of gay experiences. Participants (N=251) reported (1) a memory of a cultural event relevant to their sexuality, and (2) a self-defining memory about their sexuality. Those in older cohorts reported cultural memories centred on politics and other external events (e.g., Stonewall riots), and younger cohorts reported more personal memories (e.g., coming out), suggesting that homosexual identities have become less culturally defined, and instead more personally defined. Further, participants of older cohorts reported self-defining events that were predominantly from one private domain (e.g., sex). In contrast, younger participants reported a variety of self-defining events. These results suggest that cultural-historical factors play an important role in defining the developmental pathway of individuals, perhaps especially those who have marginalised identities.

  14. Methane sources in gas hydrate-bearing cold seeps: Evidence from radiocarbon and stable isotopes

    Science.gov (United States)

    Pohlman, J.W.; Bauer, J.E.; Canuel, E.A.; Grabowski, K.S.; Knies, D.L.; Mitchell, C.S.; Whiticar, Michael J.; Coffin, R.B.

    2009-01-01

    Fossil methane from the large and dynamic marine gas hydrate reservoir has the potential to influence oceanic and atmospheric carbon pools. However, natural radiocarbon (14C) measurements of gas hydrate methane have been extremely limited, and their use as a source and process indicator has not yet been systematically established. In this study, gas hydrate-bound and dissolved methane recovered from six geologically and geographically distinct high-gas-flux cold seeps was found to be 98 to 100% fossil based on its 14C content. Given this prevalence of fossil methane and the small contribution of gas hydrate (??? 1%) to the present-day atmospheric methane flux, non-fossil contributions of gas hydrate methane to the atmosphere are not likely to be quantitatively significant. This conclusion is consistent with contemporary atmospheric methane budget calculations. In combination with ??13C- and ??D-methane measurements, we also determine the extent to which the low, but detectable, amounts of 14C (~ 1-2% modern carbon, pMC) in methane from two cold seeps might reflect in situ production from near-seafloor sediment organic carbon (SOC). A 14C mass balance approach using fossil methane and 14C-enriched SOC suggests that as much as 8 to 29% of hydrate-associated methane carbon may originate from SOC contained within the upper 6??m of sediment. These findings validate the assumption of a predominantly fossil carbon source for marine gas hydrate, but also indicate that structural gas hydrate from at least certain cold seeps contains a component of methane produced during decomposition of non-fossil organic matter in near-surface sediment.

  15. Gas Hydrate Formation Probability Distributions: The Effect of Shear and Comparisons with Nucleation Theory.

    Science.gov (United States)

    May, Eric F; Lim, Vincent W; Metaxas, Peter J; Du, Jianwei; Stanwix, Paul L; Rowland, Darren; Johns, Michael L; Haandrikman, Gert; Crosby, Daniel; Aman, Zachary M

    2018-03-13

    Gas hydrate formation is a stochastic phenomenon of considerable significance for any risk-based approach to flow assurance in the oil and gas industry. In principle, well-established results from nucleation theory offer the prospect of predictive models for hydrate formation probability in industrial production systems. In practice, however, heuristics are relied on when estimating formation risk for a given flowline subcooling or when quantifying kinetic hydrate inhibitor (KHI) performance. Here, we present statistically significant measurements of formation probability distributions for natural gas hydrate systems under shear, which are quantitatively compared with theoretical predictions. Distributions with over 100 points were generated using low-mass, Peltier-cooled pressure cells, cycled in temperature between 40 and -5 °C at up to 2 K·min -1 and analyzed with robust algorithms that automatically identify hydrate formation and initial growth rates from dynamic pressure data. The application of shear had a significant influence on the measured distributions: at 700 rpm mass-transfer limitations were minimal, as demonstrated by the kinetic growth rates observed. The formation probability distributions measured at this shear rate had mean subcoolings consistent with theoretical predictions and steel-hydrate-water contact angles of 14-26°. However, the experimental distributions were substantially wider than predicted, suggesting that phenomena acting on macroscopic length scales are responsible for much of the observed stochastic formation. Performance tests of a KHI provided new insights into how such chemicals can reduce the risk of hydrate blockage in flowlines. Our data demonstrate that the KHI not only reduces the probability of formation (by both shifting and sharpening the distribution) but also reduces hydrate growth rates by a factor of 2.

  16. A fermented barley and soybean formula enhances skin hydration.

    Science.gov (United States)

    Lee, Sein; Kim, Jong-Eun; Suk, Sujin; Kwon, Oh Wook; Park, Gaeun; Lim, Tae-Gyu; Seo, Sang Gwon; Kim, Jong Rhan; Kim, Dae Eung; Lee, Miyeong; Chung, Dae Kyun; Jeon, Jong Eun; Cho, Dong Woon; Hurh, Byung Serk; Kim, Sun Yeou; Lee, Ki Won

    2015-09-01

    Skin hydration is one of the primary aims of beauty and anti-aging treatments. Barley (Hordeum vulgare) and soybean (Glycine max) are major food crops, but can also be used as ingredients for the maintenance of skin health. We developed a natural product-based skin treatment using a barley and soybean formula (BS) incorporating yeast fermentation, and evaluated its skin hydration effects as a dietary supplement in a clinical study. Participants ingested a placebo- (n = 33) or BS- (3 g/day) containing drink (n = 32) for 8 weeks. A significant increase in hydration in the BS group as compared to the placebo group was observed on the faces of subjects after 4 and 8 weeks, and on the forearm after 4 weeks. Decreases in stratum corneum (SC) thickness were also observed on the face and forearm. BS enhanced hyaluronan (HA) and skin barrier function in vitro and reduced Hyal2 expression in human dermal fibroblasts (HDF). BS also recovered ultraviolet (UV) B-induced downregulation of HA in HaCaT cells. These results suggest that BS has promising potential for development as a health functional food to enhance skin health.

  17. Hydration kinetics of cement composites with varying water-cement ratio using terahertz spectroscopy

    Science.gov (United States)

    Ray, Shaumik; Dash, Jyotirmayee; Devi, Nirmala; Sasmal, Saptarshi; Pesala, Bala

    2015-03-01

    Cement is mixed with water in an optimum ratio to form concrete with desirable mechanical strength and durability. The ability to track the consumption of major cement constituents, viz., Tri- and Dicalcium Silicates (C3S, C2S) reacting with water along with the formation of key hydration products, viz., Calcium-Silicate-Hydrate (C-S-H) which gives the overall strength to the concrete and Calcium Hydroxide (Ca(OH)2), a hydration product which reduces the strength and durability, using an efficient technique is highly desirable. Optimizing the amount of water to be mixed with cement is one of the main parameters which determine the strength of concrete. In this work, THz spectroscopy has been employed to track the variation in hydration kinetics for concrete samples with different water-cement ratios, viz., 0.3, 0.4, 0.5 and 0.6. Results show that for the sample with water-cement ratio of 0.3, significant amount of the C3S and C2S remain unreacted even after the initial hydration period of 28 days while for the cement with water-cement ratio of 0.6, most of the constituents get consumed during this stage. Analysis of the formation of Ca(OH)2 has been done which shows that the concrete sample with water-cement ratio of 0.6 produces the highest amount of Ca(OH)2 due to higher consumption of C3S/C2S in presence of excess water which is not desirable. Samples with water-cement ratio of 0.4 and 0.5 show more controlled reaction during the hydration which can imply formation of an optimized level of desired hydration products resulting in a more mechanically strong and durable concrete.

  18. Exogenous origin of hydration on asteroid (16) Psyche: the role of hydrated asteroid families

    Science.gov (United States)

    Avdellidou, C.; Delbo', M.; Fienga, A.

    2018-04-01

    Asteroid (16) Psyche, which for a long time was the largest M-type with no detection of hydration features in its spectrum, was recently discovered to have a weak 3-μm band and thus it was eventually added to the group of hydrated asteroids. Its relatively high density, in combination with the high radar albedo, led researchers to classify the asteroid as a metallic object. It is believed that it is possibly a core of a differentiated body, a remnant of `hit-and-run' collisions. The detection of hydration is, in principle, inconsistent with a pure metallic origin for this body. Here, we consider the scenario in which the hydration on its surface is exogenous and was delivered by hydrated impactors. We show that impacting asteroids that belong to families whose members have the 3-μm band can deliver hydrated material to Psyche. We developed a collisional model with which we test all dark carbonaceous asteroid families, which contain hydrated members. We find that the major source of hydrated impactors is the family of Themis, with a total implanted mass on Psyche of the order of ˜1014 kg. However, the hydrated fraction could be only a few per cent of the implanted mass, as the water content in carbonaceous chondrite meteorites, the best analogue for the Themis asteroid family, is typically a few per cent of their mass.

  19. Oceanic hydrates: more questions than answers

    International Nuclear Information System (INIS)

    Laherrere, Jean

    2000-01-01

    Methane hydrates create problems by blocking pipelines and casing; they are also accused of contributing to environmental problems (e.g. global warming). Methane hydrates are also found in permafrost areas and in oceanic sediments where the necessary temperature and pressure for stability occur. Claims for the widespread occurrence in thick oceanic deposits are unfounded: apparently indirect evidence from seismic reflectors, seismic hydrocarbon indicators, logs and free samples is unreliable. At one time, hydrate was seen as a static, biogenic, continuous, huge resource but that view is changing to one of a dynamic, overpressurised, discontinuous and unreliable resource. Only Japan and India are currently showing any serious interest in hydrates. Academic research has raised more questions than answers. It is suggested that more hard exploratory evidence rather than theoretical study is required

  20. Vibrational dynamics of hydration water in amylose

    CERN Document Server

    Cavatorta, F; Albanese, G; Angelini, N

    2002-01-01

    We present a study of the dynamical properties of hydration water associated with amylose helices, based on low-temperature vibrational spectra collected using the TOSCA inelastic spectrometer at ISIS. The structural constraints of the polysaccharidic chains favour the formation of a high-density structure for water, which has been suggested by Imberty and Perez on the basis of conformational analysis. According to this model, hydration water can only enter the pores formed by six adjacent helices and completely fills the pores at a hydration level of about 0.27-g water/g dry amylose. Our measurements show that the dynamical behaviour of hydration water is similar to that observed in high-density amorphous ice. (orig.)

  1. Hydrate Control for Gas Storage Operations

    Energy Technology Data Exchange (ETDEWEB)

    Jeffrey Savidge

    2008-10-31

    The overall objective of this project was to identify low cost hydrate control options to help mitigate and solve hydrate problems that occur in moderate and high pressure natural gas storage field operations. The study includes data on a number of flow configurations, fluids and control options that are common in natural gas storage field flow lines. The final phase of this work brings together data and experience from the hydrate flow test facility and multiple field and operator sources. It includes a compilation of basic information on operating conditions as well as candidate field separation options. Lastly the work is integrated with the work with the initial work to provide a comprehensive view of gas storage field hydrate control for field operations and storage field personnel.

  2. Risk factors of methane hydrate resource development in the concentrated zones distributed in the eastern Nankai Trough

    Science.gov (United States)

    Yamamoto, K.; Nagakubo, S.

    2009-04-01

    Some environmental and safety concerns on the offshore methane hydrate development have been raised, but the ground of such allegations are sometime not fully reasonable. The risks of methane hydrate resource development to environment and safety should be discussed upon methane hydrate occurrences condition, the production methods, and the designs of production system, under comprehensively scientific manners. In the Phase 1 of the Methane Hydrate Exploitation Program in Japan (FY2001-2008), the Research Consortium for Methane Hydrate Resources in Japan (MH21 Research Consortium) found methane hydrate concentrated zones in the eastern Nankai Trough that are potential prospects for resource development. The concentrated zones are consisted of turbidite-derived sandy sediments and hydrate crystals in pore spaces of sand grains (pore-filling type structure). The MH21 Research Consortium proposed the depressurization method as prime technique due to its efficiency of gas production in such concentrated zones, and has tried to develop conceptual designs of production systems based on the information of existing devices and facilities. Under the condition and circumstances described above, the authors tried to extract and evaluate some risk factors concerning methane hydrate development using depressurization in the area. Leakage of methane gas, that is less harmful substance to ecosystem than heavier hydrocarbons, from production system can be one possible risk. However, in the case of gas production through wellbore, even if catastrophic damages happen in the subsea production system during gas production, the leakages do not continue because the borehole could be filled by seawater and depressurization is stopped immediately. Another possible risk is a leakage of produced gas through seafloor. If methane hydrate production makes high pressure or temperature zones in sediments, the risk should be considered. However, depressurization method makes opposite condition

  3. Growth of a Hydrate Mound in the Sea of Japan over 300 ka as Revealed by U-Th Ages of MDAC and by H2S Concentrations of Massive Hydrates

    Science.gov (United States)

    Matsumoto, R.; Snyder, G. T.; Hiruta, A.; Kakizaki, Y.; Huang, C. Y.; Shen, C. C.

    2017-12-01

    The geological and geophysical exploration of gas hydrate in the Sea of Japan has revealed that hydrates occur as thick massive deposits within gas chimneys which often give rise to pingo-like hydrate mounds on the seafloor. We examine one case in which LWD has demonstrated anomalous profiles including both very low natural gamma ray (<10 API) and high acoustic velocities (2.5 to 3.5 km/s) extending down to 120mbsf, the base of gas hydrate stability (BGHS)[1]. Both conventional and pressure coring have confirmed thick, massive deposits of pure-gas hydrates. Hydrates in the shallow subsurface (< 20mbsf) are characterized by high H2S concentrations corresponding to AOM-induced production of HS-. The deeper hydrates generally have negligible amounts of H2S, with occasional exceptions in which H2S is moderately high. These observations lead us to conclude that both the re-equilibration and growth of hydrates in high CH4 and low to zero H2S conditions has continued during burial, and that this ongoing growth is an essential processes involved in the development of massive hydrates in the Sea of Japan.Regardless of depth, the Japan Sea gas hydrates are closely associated with 13-C depleted, methane-derived authigenic carbonates (MDACs). These MDACs are considered to have been formed at near-SMT depths as a response to increased alkalinity caused by AOM and, as such, MDACs are assumed to represent approximate paleo-seafloor at times of enhanced methane flux and intensive accumulation of gas hydrate in shallow subsurface. U-Th ages of MDACs collected from various depths in a mound-chimney system in central Joetsu Spur have revealed that the paleo-seafloor of 300 ka is presently situated at 30 to 55 mbsf within the gas chimney, in contrast to off-mound sites where it is situated at 100 mbsf. This suggests that at 300 ka the mound stood as a "hydrate-pingo" of 70 m high relative to the surrounding sea floor. At this time, the BGHS shoaled upwards 10m due to eustatic sea

  4. Preservation of methane hydrate at 1 atm

    Science.gov (United States)

    Stern, L.A.; Circone, S.; Kirby, S.H.; Durham, W.B.

    2001-01-01

    A "pressure-release" method that enables reproducible bulk preservation of pure, porous, methane hydrate at conditions 50 to 75 K above its equilibrium T (193 K) at 1 atm is refined. The amount of hydrate preserved by this method appears to be greatly in excess of that reported in the previous citations, and is likely the result of a mechanism different from ice shielding.

  5. Early hydration cement Effect of admixtures superplasticizers

    Directory of Open Access Journals (Sweden)

    Puertas, F.

    2001-06-01

    Full Text Available Early hydration of portland cement with superplasticizer admixtures of different nature has been studied. These admixtures were: one based on melamine synthetic, other based on vinyl copolymer and other based on polyacrylate copolymers. The dosage of the formers were constant (1% weigth of cement and for the third, the influence of admixture dosage was also evaluated, giving dosage values among 1-0.3%. The pastes obtained were studied by conduction calorimetry, XRD and FTIR. Also the apparent fluidity was determined by "Minislump" test. The main results obtained were: a superplasticizers admixtures used, regardless of their nature and for the polycarboxilate one the dosage, retard the silicate hydration (specially, alite phase, b The ettringite formation is affected by the nature of the admixture. cA relationship between the dosage of admixture based on polycarboxilates and the time at the acceleration has been established. A lineal relation (y = 11.03 + 16.05x was obtained. From these results is possible to know, in function of dosage admixture, the time when the masive hydration products and the setting times are produced. Also the total heat releases in these reactions is independent of the nature and dosage of admixture, saying that in all cases the reactions are the same.

    En el presente trabajo se ha estudiado la hidratación inicial de un cemento portland aditivado con superplastificantes de diferente naturaleza. Dichos aditivos fueron: uno basado en melaminas sintéticas, otro en copolímeros vinilicos y otro en policarboxilatos. La dosificación de los dos primeros se fijó constante en 1% en peso con relación al cemento, mientras que para el tercero se evaluó, también, la influencia de la dosificación, tomando proporciones desde el 1% hasta el 0,3%. Las pastas obtenidas se estudiaron por: calorimetría de conducción, DRX y FTIR. También se determinó la fluidez de la pasta a través del ensayo del "Minislump ". Los

  6. Cultural Development Strategies and Urban Gay Tourism Revitalization

    Directory of Open Access Journals (Sweden)

    Jose M Prat Forga

    2015-12-01

    Full Text Available Municipal governments increasingly turn to cultural and leisure activities to promote and revitalize their cities. This study analysed the development of gay tourism in Barcelona (Spain by means of music festivals. While a significant body of literature has examined revitalization strategies that focus primarily around entertainment and commerce, this paper focuses on strategies in the development of cultural and leisure activities around this specific tourism population. It presents findings from a local survey distributed to key stakeholders in the promotion and development of this tourism (local agents and gay tourists. The survey data indicate that although most agents are guided by a varied set of goals, marketing objectives (“image city” and “brand city” guide the development and support of urban gay tourism in Barcelona.

  7. A moral justification for gay and lesbian civil rights legislation.

    Science.gov (United States)

    Samar, V J

    1994-01-01

    This essay explores, in two parts, the problems of justifying civil rights legislation for gays, lesbians, and bisexuals. Part I shows that discrimination against gays and lesbians at least in respect to employment, housing, and public accommodations is an evil unsupported by ethical traditions in utilitarianism, rights theory, and communitarianism. It also shows that two theories, Kantian theory and natural law theory, which do support such discrimination on the claim that homoerotic behavior is universally or objectively immoral only do so because of a failure to make precise the concept of "natural" which underlies those theories. Part II argues that anti-discrimination legislation is both an appropriate and effective means to promote the idea that discrimination against lesbians and gays in respect to most employment, housing, and public accommodations is sufficiently injurious to both individuals and society that it should not be tolerated. The section also explains how such legislation might succeed practically in eliminating discrimination in these areas.

  8. Attributions for sexual orientation vs. stereotypes : How beliefs about value violations account for attribution effects on anti-gay discrimination

    NARCIS (Netherlands)

    Reyna, Christine; Wetherell, Geoffrey; Yantis, Caitlyn; Brandt, Mark J.

    Attributions for sexual orientation strongly predict opposition to gay rights policies; however, we propose that beliefs that gays and lesbians violate important values drive gay rights opposition and account for the relationship between attributions and anti-gay discrimination. In two studies, we

  9. Gas-hydrate-bearing sand reservoir systems in the offshore of India: Results of the India National Gas Hydrate Program Expedition 02

    Science.gov (United States)

    Kumar, P.; Collett, Timothy S.; Vishwanath, K.; Shukla, K.M.; Nagalingam, J.; Lall, M.V.; Yamada, Y; Schultheiss, P.; Holland, M.

    2016-01-01

    The India National Gas Hydrate Program Expedition 02 (NGHP-02) was conducted from 3-March-2015 to 28-July-2015 off the eastern coast of India using the deepwater drilling vessel Chikyu. The primary goal of this expedition was to explore for highly saturated gas hydrate occurrences in sand reservoirs that would become targets for future production tests. The first two months of the expedition were dedicated to logging-whiledrilling (LWD) operations, with a total of 25 holes drilled and logged. The next three months were dedicated to coring operations at 10 of the most promising sites. With a total of five months of continuous field operations, the expedition was the most comprehensive dedicated gas hydrate investigation ever undertaken.

  10. The Dubbing of Gay-themed TV Series in Italy: Corpus-based Evidence of Manipulation and Censorship

    Directory of Open Access Journals (Sweden)

    Annalisa Sandrelli

    2016-02-01

    Full Text Available The manipulation and censorship of taboo and sensitive references in AVT has attracted the interest of several scholars over the last few years, but systematic studies of the impact of such practices on different genres in different countries are still needed. The paper analyses the Italian dubbing of three gay-themed TV series, Queer as Folk, Queer as Folk (US remake, and The L Word. Gay-themed series are less mainstream on Italian TV channels than in the UK and the USA, and gayspeak as a linguistic phenomenon is not well-known to Italian audiences. Consequently, the Italian dubbed dialogues are the product of different degrees of manipulation and even censorship. The paper finds empirical evidence of such alterations in data from the DubTalk corpus and attempts a tentative evaluation of the impact of such practices on the Italian versions of the above-mentioned series.

  11. Structure changes in the sol-gel systems of hydrated oxides

    International Nuclear Information System (INIS)

    Gaponov, Y.A.; Karakchiev, L.G.; Lyakhov, N.Z.; Tolochko, B.P.; Ito, K.; Amemiya, Y.

    1998-01-01

    Sols of hydrated aluminium oxide, hydrated zirconium oxide and their mixtures were investigated during the xerogel-amorphous-product-crystalline-product transition by SAXS using synchrotron radiation. In the different temperature regions certain changes in structure and morphology were observed. Some correlation between the characteristics of the initial sols and their mixtures (the size and shape of the pores) was observed. In the temperature region 298-1173 K the characteristics of the mixed sol are defined by the characteristics of the initial sols

  12. In Situ Raman Analyses of Natural Gas and Gas Hydrates at Hydrate Ridge, Oregon

    Science.gov (United States)

    Peltzer, E. T.; White, S. N.; Dunk, R. M.; Brewer, P. G.; Sherman, A. D.; Schmidt, K.; Hester, K. C.; Sloan, E. D.

    2004-12-01

    During a July 2004 cruise to Hydrate Ridge, Oregon, MBARI's sea-going laser Raman spectrometer was used to obtain in situ Raman spectra of natural gas hydrates and natural gas venting from the seafloor. This was the first in situ analysis of gas hydrates on the seafloor. The hydrate spectra were compared to laboratory analyses performed at the Center for Hydrate Research, Colorado School of Mines. The natural gas spectra were compared to MBARI gas chromatography (GC) analyses of gas samples collected at the same site. DORISS (Deep Ocean Raman In Situ Spectrometer) is a laboratory model laser Raman spectrometer from Kaiser Optical Systems, Inc modified at MBARI for deployment in the deep ocean. It has been successfully deployed to depths as great as 3600 m. Different sampling optics provide flexibility in adapting the instrument to a particular target of interest. An immersion optic was used to analyze natural gas venting from the seafloor at South Hydrate Ridge ( ˜780 m depth). An open-bottomed cube was placed over the vent to collect the gas. The immersion optic penetrated the side of the cube as did a small heater used to dissociate any hydrate formed during sample collection. To analyze solid hydrates at both South and North Hydrate Ridge ( ˜590 m depth), chunks of hydrate were excavated from the seafloor and collected in a glass cylinder with a mesh top. A stand-off optic was used to analyze the hydrate inside the cylinder. Due to the partial opacity of the hydrate and the small focal volume of the sampling optic, a precision underwater positioner (PUP) was used to focus the laser spot onto the hydrate. PUP is a stand-alone system with three degrees-of-freedom, capable of moving the DORISS probe head with a precision of 0.1 mm. In situ Raman analyses of the gas indicate that it is primarily methane. This is verified by GC analyses of samples collected from the same site. Other minor constituents (such as CO2 and higher hydrocarbons) are present but may be in

  13. The relationships between sense of belonging to the gay community, body image dissatisfaction, and self-esteem among Australian gay men.

    Science.gov (United States)

    Kousari-Rad, Pantea; McLaren, Suzanne

    2013-01-01

    Body image dissatisfaction has been linked to belonging to the gay community and poor self-esteem among gay men. This study was designed to explore the applicability of a moderation model and a mediation model in explaining the relations between sense of belonging to the gay community, body image dissatisfaction and self-esteem among 90 self-identified Australian gay men. Participants completed the psychological subscale of the Sense of Belonging Instrument, the Body Satisfaction Scale, and the Rosenberg Self-Esteem Scale. Results supported the moderation model; the relation between body image dissatisfaction and self-esteem was found to be statistically significant only at average and high levels of belonging to the gay community. The mediation model was also supported; body image dissatisfaction partially mediated the sense of belonging-self-esteem relation. Educating gay men and health professionals about the possible negative outcomes of "belonging" to an appearance-oriented community is important.

  14. Characterization of gas hydrate distribution using conventional 3D seismic data in the Pearl River Mouth Basin, South China Sea

    Science.gov (United States)

    Wang, Xiujuan; Qiang, Jin; Collett, Timothy S.; Shi, Hesheng; Yang, Shengxiong; Yan, Chengzhi; Li, Yuanping; Wang, Zhenzhen; Chen, Duanxin

    2016-01-01

    A new 3D seismic reflection data volume acquired in 2012 has allowed for the detailed mapping and characterization of gas hydrate distribution in the Pearl River Mouth Basin in the South China Sea. Previous studies of core and logging data showed that gas hydrate occurrence at high concentrations is controlled by the presence of relatively coarse-grained sediment and the upward migration of thermogenic gas from the deeper sediment section into the overlying gas hydrate stability zone (BGHSZ); however, the spatial distribution of the gas hydrate remains poorly defined. We used a constrained sparse spike inversion technique to generate acoustic-impedance images of the hydrate-bearing sedimentary section from the newly acquired 3D seismic data volume. High-amplitude reflections just above the bottom-simulating reflectors (BSRs) were interpreted to be associated with the accumulation of gas hydrate with elevated saturations. Enhanced seismic reflections below the BSRs were interpreted to indicate the presence of free gas. The base of the BGHSZ was established using the occurrence of BSRs. In areas absent of well-developed BSRs, the BGHSZ was calculated from a model using the inverted P-wave velocity and subsurface temperature data. Seismic attributes were also extracted along the BGHSZ that indicate variations reservoir properties and inferred hydrocarbon accumulations at each site. Gas hydrate saturations estimated from the inversion of acoustic impedance of conventional 3D seismic data, along with well-log-derived rock-physics models were also used to estimate gas hydrate saturations. Our analysis determined that the gas hydrate petroleum system varies significantly across the Pearl River Mouth Basin and that variability in sedimentary properties as a product of depositional processes and the upward migration of gas from deeper thermogenic sources control the distribution of gas hydrates in this basin.

  15. Direct observation of characteristic dissociation behaviors of hydrate-bearing cores by rapid-scanning X-ray CT imaging

    Energy Technology Data Exchange (ETDEWEB)

    Ebinuma, T.; Oyama, H.; Utiumi, T.; Nagao, J.; Narita, H. [National Inst. of Advanced Industrial Science and Technology, Toyohiraku, Sapporo (Japan)

    2008-07-01

    Methane hydrate has significant potential as a new source of energy. Major considerations in developing production methods of methane from hydrates are the fundamental properties of hydrate-bearing sediments, and the dissociation behavior of methane hydrate and the gas and water flow generated by its dissociation in sediments. Marine methane hydrates occur several hundred meters below the sea floor, in a variety of forms. The pore-space filling-type is considered to be the most suited to exploitation, as it is contained within the pore spaces of sandy sediments, and has relatively larger gas permeability compared to other forms. However, shallow sandy sediments are not usually consolidated, and methane hydrate is unstable at normal pressure and temperature. Therefore, common methods are not suitable, and new experimental methods have been developed to study the properties of hydrate-bearing sediment and its dissociation process. This paper presented the results of an experimental study involving the dissociation of artificial methane-hydrate-bearing sediments. The experiment was performed using X-ray computed tomography in order to directly observe dissociation behavior in the sediments and the gas and water flows generated by dissociation. The paper described the depressurization process and presented a schematic diagram of rapid scanning X-ray computed tomography scanner and core holder with tri-axial structure. The experimental apparatus for dissociation of methane hydrate was also illustrated. The thermal stimulation process and hot water injection process were explained. It was concluded that dissociation by depressurization demonstrated that the temperature reduction induced by depressurization depended on the phase equilibrium state of methane hydrate, and that dissociation preferentially occurred at the periphery of the core. This behavior was due to the heat flux from the outside of the core, where the heat flux controlled the dissociation rate. 10 refs

  16. Sexual issues in special populations: lesbian and gay individuals.

    Science.gov (United States)

    Dibble, Suzanne; Eliason, Michele J; Dejoseph, Jeanne F; Chinn, Peggy

    2008-05-01

    To provide an overview of health care needs and related sexuality issues of lesbian and gay patients. Research articles, books, clinical experience. Attitudes of health professionals as well as patients impact care in relation to sexuality and sexual issues. Oncology nurses using a framework of awareness, sensitivity, and knowledge can obtain and apply the essential information needed to provide culturally appropriate nursing care to this population. Lesbian and gay patients need nurses as allies in their fight with cancer. This is particularly true in assessment and managing concerns about sexuality and sexual issues.

  17. El porno gay hecho en México

    OpenAIRE

    Salinas Hernández, Héctor Miguel

    2011-01-01

    El presente trabajo propone presentar un panorama sobre la pornografía hecha en México por y para varones gay, en el ámbito del video y del cine. Arranca con la hipótesis de que la posibilidad de creación en México de porno exclusivo para varones gay se inserta en la visibilidad adquirida por el Movimiento de Disidencia Sexual a nivel mundial, facilitado por el mercado como elemento preponderante en la globalización. El documento presenta algunas aproximaciones teóricas a la pornografía y sus...

  18. Identity processes, threat, and interpersonal relations: accounts from British Muslim gay men.

    Science.gov (United States)

    Jaspal, Rusi; Cinnirella, Marco

    2012-01-01

    This study explores identity processes, identity threat, and interpersonal relations with other gay men in a qualitative interview study with a sample of young British Muslim gay men of Pakistani background. Transcripts were subjected to qualitative thematic analysis. Data were analyzed through the interpretive lens of Identity Process Theory. Three superordinate themes are reported: (a) self-continuity and the transition from straight to gay space; (b) interpersonal relations with other gay men and self- and other categorization; and (c) interpersonal contact or identification with White gay men as an identity enhancer. Theoretical and practical implications of the results are discussed.

  19. Social Marginalization and Internal Exclusion: Gay Men's Understandings and Experiences of Community.

    Science.gov (United States)

    O'Byrne, Patrick; Bryan, Alyssa; Hendriks, Andrew; Horvath, Cynthia; Bouchard, Christiane; Etches, Vera

    2014-03-01

    A total of 27 gay and bisexual men were interviewed about how they perceived the criminal prosecution of persons living with HIV who do not disclose their HIV status. The stories that emerged from the interviews raise questions about the nature of the gay community. The findings centre on the participants' descriptions of (1) the heterosexual meta-culture, (2) the locales of gay life, and (3) unsupportive elements in the gay community. Analysis of the interview data situates the gay community as a place of both inclusion and exclusion and as a heterogeneous environment. Copyright© by Ingram School of Nursing, McGill University.

  20. The influence of Na2O on the hydration of C3A II. Suspension hydration

    NARCIS (Netherlands)

    Spierings, G.A.C.M.; Stein, H.N.

    1976-01-01

    The influence of Na2O on the hydration of C3A was studied in suspensions from the start of the reaction onwards. The heat evolution rate in very early stages of the hydration, measured at varying NaOH concentrations, and SEM, indicate that at NaOH concentrations larger then 0.1 M the reaction

  1. Distinguishing between hydrated, partially hydrated or unhydrated clinker in hardened concrete using microscopy

    NARCIS (Netherlands)

    Valcke, S.L.A.; Rooij, M.R. de; Visser, J.H.M.; Nijland, T.G.

    2010-01-01

    Hydration of clinker particles is since long a topic of interest in both designing and optimizing cement composition and its quantity used in concrete. The interest for carefully observing and also quantifying the type or stage of clinker hydration in hardened cement paste is twofold. Firstly, the

  2. Controls on Gas Hydrate Formation and Dissociation

    Energy Technology Data Exchange (ETDEWEB)

    Miriam Kastner; Ian MacDonald

    2006-03-03

    The main objectives of the project were to monitor, characterize, and quantify in situ the rates of formation and dissociation of methane hydrates at and near the seafloor in the northern Gulf of Mexico, with a focus on the Bush Hill seafloor hydrate mound; to record the linkages between physical and chemical parameters of the deposits over the course of one year, by emphasizing the response of the hydrate mound to temperature and chemical perturbations; and to document the seafloor and water column environmental impacts of hydrate formation and dissociation. For these, monitoring the dynamics of gas hydrate formation and dissociation was required. The objectives were achieved by an integrated field and laboratory scientific study, particularly by monitoring in situ formation and dissociation of the outcropping gas hydrate mound and of the associated gas-rich sediments. In addition to monitoring with the MOSQUITOs, fluid flow rates and temperature, continuously sampling in situ pore fluids for the chemistry, and imaging the hydrate mound, pore fluids from cores, peepers and gas hydrate samples from the mound were as well sampled and analyzed for chemical and isotopic compositions. In order to determine the impact of gas hydrate dissociation and/or methane venting across the seafloor on the ocean and atmosphere, the overlying seawater was sampled and thoroughly analyzed chemically and for methane C isotope ratios. At Bush hill the pore fluid chemistry varies significantly over short distances as well as within some of the specific sites monitored for 440 days, and gas venting is primarily focused. The pore fluid chemistry in the tub-warm and mussel shell fields clearly documented active gas hydrate and authigenic carbonate formation during the monitoring period. The advecting fluid is depleted in sulfate, Ca Mg, and Sr and is rich in methane; at the main vent sites the fluid is methane supersaturated, thus bubble plumes form. The subsurface hydrology exhibits both

  3. ‘The Ties that Bind Us’: The Hidden Knots of Gay Marriage

    Directory of Open Access Journals (Sweden)

    Bronwyn Winter

    2014-08-01

    Full Text Available Gay marriage has become a major transnational gay rights issue: a key marker of gay citizenship, to the extent that it is considered self-evident that its legalisation represents progress. Yet it is becoming apparent that this ‘progress’ is concurrent with other forms of exclusion. In this article, I argue that gay marriage is a convenient liberal smokescreen, leaving other exclusions unaddressed or even enabling their reinforcement. The discussion involves examination of three case studies: Argentina, the first Latin American country to legalise gay marriage in 2010; France, which legalised gay marriage in May, 2013; and Australia, which has not legalised gay marriage at the time of this writing.

  4. Menthol Cigarette Smoking among Lesbian, Gay, Bisexual, and Transgender Adults

    Science.gov (United States)

    Fallin, Amanda; Goodin, Amie J.; King, Brian A.

    2015-01-01

    Background Menthol can mask the harshness and taste of tobacco, making menthol cigarettes easier to use and increasing their appeal among vulnerable populations. The tobacco industry has targeted youth, women, and racial minorities with menthol cigarettes, and these groups smoke menthol cigarettes at higher rates. The tobacco industry has also targeted the lesbian, gay, bisexual, and transgender (LGBT) communities with tobacco product marketing. Purpose To assess current menthol cigarette smoking by sexual orientation among a nationally representative sample of U.S. adults. Methods Data were obtained from the 2009–2010 National Adult Tobacco Survey, a national landline and cellular telephone survey of non-institutionalized U.S. adults aged ≥18 years, to compare current menthol cigarette smoking between LGBT (n=2,431) and heterosexual/straight (n=110,841) adults. Data were analyzed during January–April 2014 using descriptive statistics and logistic regression adjusted for sex, age, race, and educational attainment. Results Among all current cigarette smokers, 29.6% reported usually smoking menthol cigarettes in the past 30 days. Menthol use was significantly higher among LGBT smokers, with 36.3% reporting that the cigarettes they usually smoked were menthol compared to 29.3% of heterosexual/straight smokers (p<0.05); this difference was particularly prominent among LGBT females (42.9%) compared to heterosexual/straight women (32.4%) (p<0.05). Following adjustment, LGBT smokers had greater odds of usually smoking menthol cigarettes than heterosexual/straight smokers (OR=1.31, 95% CI=1.09, 1.57). Conclusions These findings suggest that efforts to reduce menthol cigarette use may have the potential to reduce tobacco use and tobacco-related disease and death among LGBT adults. PMID:25245795

  5. Visibilidade gay na escola: estudantes queer / Gay visibility in school: queer students

    Directory of Open Access Journals (Sweden)

    Aline Ferraz da Silva

    2007-01-01

    Full Text Available Nesse artigo apresento as considerações e análises presentes na pesquisa em processo, que realizo numa escola pública. Sua constituição deve seu primeiro movimento àsmanifestações de desconforto e homofobia com relação a um grupo específico de três estudantes gays na comunidade escolar na qual atuo como professora. Percebo que a presença desse grupo desacomoda o cotidiano escolar e desenvolvo minha argumentação com base no potencial desestabilizador desses sujeitos, na intenção de pensar o impensável no currículo escolar. Esse trabalho parte da visibilidade de uma identidade sexual que foge à norma heterossexual e desafia a tendência normalizadora e homogeneizadora da educação. A maneira como esse grupo gay se posiciona e constrói seus corpos cruza as fronteiras do masculino/feminino, desnaturalizando as identidadessexuais e de gênero que se baseiam em características biológicas e se apresentando como diferença que escapa às classificações binárias. Na construção da pesquisa utilizo como referência o pensamento de Michel Foucault, especialmente com relação à construção histórica e discursiva de conceitos como sexualidade, identidade, diferença enormalidade que têm servido para criação e manutenção de padrões de conduta. Ao levar a problematização desses conceitos para o contexto escolar, considero produtiva a teorização queer para pensar a possibilidade de uma educação não heteronormativa, produtora de diferenças, que desconstrua identidades ao invés de tentar cristalizá-las.Abstract This article presents the considerations and analysis that make part of my research in process in a public school. The construction of this research dues its first move to viewsof discomfort and homofobia related to a specific group of three gay students in a school where I work as a teacher. I realize that the presence of that group disarrenges the school quotidian and I develop my argumentation on the

  6. Hydration of urea and alkylated urea derivatives

    Science.gov (United States)

    Kaatze, Udo

    2018-01-01

    Compressibility data and broadband dielectric spectra of aqueous solutions of urea and some of its alkylated derivatives have been evaluated to yield their numbers Nh of hydration water molecules per molecule of solute. Nh values in a broad range of solute concentrations are discussed and are compared to hydration numbers of other relevant molecules and organic ions. Consistent with previous results, it is found that urea differs from other solutes in its unusually small hydration number, corresponding to just one third of the estimated number of nearest neighbor molecules. This remarkable hydration behavior is explained by the large density φH of hydrogen bonding abilities offered by the urea molecule. In terms of currently discussed models of reorientational motions and allied dynamics in water and related associating liquids, the large density φH causes a relaxation time close to that of undisturbed water with most parts of water encircling the solute. Therefore only a small part of disturbed ("hydration") water is left around each urea molecule. Adding alkyl groups to the basic molecule leads to Nh values which, within the series of n-alkylurea derivatives, progressively increase with the number of methyl groups per solute. With n-butylurea, Nh from dielectric spectra, in conformity with many other organic solutes, slightly exceeds the number of nearest neighbors. Compared to such Nh values, hydration numbers from compressibility data are substantially smaller, disclosing incorrect assumptions in the formula commonly used to interpret the experimental compressibilities. Similar to other series of organic solutes, effects of isomerization have been found with alkylated urea derivatives, indicating that factors other than the predominating density φH of hydrogen bond abilities contribute also to the hydration properties.

  7. In situ monitoring of the hydration process of K-PS geopolymer cement with ESEM

    International Nuclear Information System (INIS)

    Sun Wei; Zhang Yunsheng; Lin Wei; Liu Zhiyong

    2004-01-01

    Environmental scanning electron microscope (ESEM) was used to in situ quantitatively study the hydration process of K-PS geopolymer cement under an 80% RH environment. An energy dispersion X-ray analysis (EDXA) was also employed to distinguish the chemical composition of hydration product. The ESEM micrographs showed that metakaolin particles pack loosely at 10 min after mixing, resulting in the existence of many large voids. As hydration proceeds, a lot of gels were seen and gradually precipitated on the surfaces of these particles. At later stage, these particles were wrapped by thick gel layers and their interspaces were almost completely filled. The corresponding EDXA results illustrated that the molar ratios of K/Al increase while Si/Al decrease with the development of hydration. As a result, the molar ratios of K/Al and Si/Al of hydration products at an age of 4 h amounted to 0.99 and 1.49, respectively, which were close to the theoretical values (K/Al=1.0, Si/Al=1.0 for K-PS geopolymer cement paste). In addition, well-developed crystals could not been found at any ages; instead, spongelike amorphous gels were always been observed

  8. Mount Elbert Gas Hydrate Stratigraphic Test Well, Alaska North Slope: Overview of scientific and technical program

    Science.gov (United States)

    Hunter, R.B.; Collett, T.S.; Boswell, R.; Anderson, B.J.; Digert, S.A.; Pospisil, G.; Baker, R.; Weeks, M.

    2011-01-01

    The Mount Elbert Gas Hydrate Stratigraphic Test Well was drilled within the Alaska North Slope (ANS) Milne Point Unit (MPU) from February 3 to 19, 2007. The well was conducted as part of a Cooperative Research Agreement (CRA) project co-sponsored since 2001 by BP Exploration (Alaska), Inc. (BPXA) and the U.S. Department of Energy (DOE) in collaboration with the U.S. Geological Survey (USGS) to help determine whether ANS gas hydrate can become a technically and commercially viable gas resource. Early in the effort, regional reservoir characterization and reservoir simulation modeling studies indicated that up to 0.34 trillion cubic meters (tcm; 12 trillion cubic feet, tcf) gas may be technically recoverable from 0.92 tcm (33 tcf) gas-in-place within the Eileen gas hydrate accumulation near industry infrastructure within ANS MPU, Prudhoe Bay Unit (PBU), and Kuparuk River Unit (KRU) areas. To further constrain these estimates and to enable the selection of a test site for further data acquisition, the USGS reprocessed and interpreted MPU 3D seismic data provided by BPXA to delineate 14 prospects containing significant highly-saturated gas hydrate-bearing sand reservoirs. The "Mount Elbert" site was selected to drill a stratigraphic test well to acquire a full suite of wireline log, core, and formation pressure test data. Drilling results and data interpretation confirmed pre-drill predictions and thus increased confidence in both the prospect interpretation methods and in the wider ANS gas hydrate resource estimates. The interpreted data from the Mount Elbert well provide insight into and reduce uncertainty of key gas hydrate-bearing reservoir properties, enable further refinement and validation of the numerical simulation of the production potential of both MPU and broader ANS gas hydrate resources, and help determine viability of potential field sites for future extended term production testing. Drilling and data acquisition operations demonstrated that gas hydrate

  9. Experimental Determination of Refractive Index of Gas Hydrates

    DEFF Research Database (Denmark)

    Bylov, Martin; Rasmussen, Peter

    1997-01-01

    . For methane hydrate (structure I) the refractive index was found to be 1.346 and for natural gas hydrate (structure II) it was found to be 1.350. The measurements further suggest that the gas hydrate growth rate increases if the water has formed hydrates before. The induction time, on the other hand, seems......The refractive indexes of methane hydrate and natural gas hydrate have been experimentally determined. The refractive indexes were determined in an indirect manner making use of the fact that two non-absorbing materials will have the same refractive index if they cannot be distinguished visually...

  10. Heterogenous Couples in Heterosexual Marriages: Gay Men and Straight Women.

    Science.gov (United States)

    Bozett, Frederick W.

    1982-01-01

    Focuses on the spousal relationship of gay men who had been married. Describes the man's disclosure of his homosexuality, the wife's response, and the interactional effects on the marriage relationship. Suggests the wife appeared to be an enabler of his transition to a homosexual life-style. (Author/JAC)

  11. GAY RELATIONSHIPS AS ALTERNATIVE FORMS OF FAMILY-MARRIAGE LIFE

    Directory of Open Access Journals (Sweden)

    Ewa Perlińska

    2006-01-01

    Full Text Available My research and deliberation made in this study show that homosexuality is only one of the signs of human diversity - one from innumerable number of personality features. Therefore, one cannot talk about "gay identity", "homosexual personality", because, as far as I am concerned, it doesn't exist. Artificially generted gay population is only a group of peple being much different from one another and having only one common feature - their sexual orientation. Besides they differ from one another as much as one man from another. Gay relationships take on countless forms, but all of them, as the results of my research indicate, fulfil the majority of family in traditional point of view functions. The deliberation points out at one more conclusion - one cannot examine gay relationships as a separate model of family-marriage life. It should be forgotten about their different psyhosexual orientation and treat their trlationships, together with other interpersonal relationships, equally. Only from such position one can discern in their specific alternative models of family-marriage life.

  12. Groups for the Wives of Gay and Bisexual Men.

    Science.gov (United States)

    Auerback, Sandra; Moser, Charles

    1987-01-01

    Found groups for wives of gay and bisexual men to be an effective therapeutic intervention for the problems that arise when a husband makes a disclosure to his wife that he is interested in pursuing homosexual relationships. The groups helped wives resolve the issues of the marriage and to make positive changes in their lives. (Author)

  13. Career Construction with a Gay Client: A Case Study

    Science.gov (United States)

    Maree, Jacobus Gideon

    2014-01-01

    This article reports on the value of career construction counselling (CCC) with a gay person. The participant was selected purposively, with the selection criteria calling for a mid-career woman who had sought career counselling. The intervention involved administration of the "Career Construction Interview" (CCI) and the creation of a…

  14. The construction of men who are nurses as gay.

    Science.gov (United States)

    Harding, Thomas

    2007-12-01

    This paper is a report of a study to examine the construction of the stereotype of male nurses as gay, and to describe how this discourse impacts on a group of New Zealand male nurses. A discourse stereotyping male nurses as gay is accompanied by one which privileges hegemonic masculinity and marginalizes homosexuality. This social constructionist study drew on data collected from existing texts on men, nursing and masculinity and interviews with 18 New Zealand men conducted in 2003-2004. Discourse analysis, informed by masculinity theory and queer theory, was used to analyse the data. Despite the participants' beliefs that the majority of male nurses are heterosexual, the stereotype persists. A paradox emerged between the 'homosexual' general nurse and the 'heterosexual' psychiatric nurse. The stigma associated with homosexuality exposes male nurses to homophobia in the workplace. The heterosexual men employed strategies to avoid the presumption of homosexuality; these included: avoiding contact with gay colleagues and overt expression of their heterosexuality. There is a paradox between widespread calls for men to participate more in caring and discourses which stereotype male nurses as gay and conflate homosexuality and sexual predation. These stigmatizing discourses create a barrier to caring and, aligned with the presence of homophobia in the workplace, deter men's entry into the profession and may be important issues with respect to their retention. Nurse educators must ensure that nurses are able to resist collusion with stigmatizing discourses that marginalize men (and women) in the profession through the perpetration of gender and sexual stereotypes.

  15. Teaching Literature Gay-Affirmatively: A Homosexual Individuation Story

    Science.gov (United States)

    Sadownick, Douglas G.

    2007-01-01

    This article explores the possibility of a "homosexual hermeneutic" by which the great literary works of the western canon can be taught. This "interpretative methodology" is based in the author's own individuation process as gay. The author details his personal journey from engulfment in heteronormativity to the first crisis of his homosexual…

  16. Security for women and the lesbian, gay, bisexual, transgender and ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Security for women and the lesbian, gay, bisexual, transgender and intersex people in the conflict-affected regions in Colombia. Colombia is currently in the process of concluding peace negotiations with the guerrilla group Colombian Revolutionary Armed Forces (FARC). One of the principal expectations generated by the ...

  17. Condomless Sex: Gay Men, Barebacking, and Harm Reduction

    Science.gov (United States)

    Shernoff, Michael

    2006-01-01

    Social science research as well as a rise in sexually transmitted diseases and new HIV infections among men who have sex with men point to increasing numbers of gay men engaging in unprotected anal intercourse without condoms, a practice called "barebacking." There is some evidence that barebacking is linked to the rise of crystal methamphetamine…

  18. Parents Awareness of Lesbian, Gay, and Bisexual Youths Sexual Orientation

    Science.gov (United States)

    Daugelli, Anthony R.; Grossman, Arnold H.; Starks, Michael T.

    2005-01-01

    This study used a sample of 293 lesbian, gay, and bisexual youth to examine factors that differentiated youth whose parents knew of their sexual orientation from youth whose parents did not know. Earlier awareness and disclosure of same-gender attractions, greater childhood gender atypicality, and less internalized homophobia were characteristic…

  19. Lessons about Gay and Lesbian Lives: A Spaceship Exercise

    Science.gov (United States)

    Hillman, Jennifer; Martin, Renee A.

    2002-01-01

    We designed an active learning activity to allow students to experience stereotyping and consider the social stigma often directed toward gays and lesbians. We used an unusual fictional scenario to alleviate students' concerns about impression management and permit them to experience the role of someone faced with discrimination without the…

  20. Victimization and Suicidality Among Dutch Lesbian, Gay, and Bisexual Youths

    NARCIS (Netherlands)

    van Bergen, Diana; Bos, Henny M.W.; van Lisdonk, jantine; Keuzenkamp, S; Sandfort, T.G.M

    2013-01-01

    We examined Netherlands Institute for Social Research data, collected between May and August 2009, on 274 Dutch lesbian, gay, and bisexual youths. The data showed that victimization at school was associated with suicidal ideation and actual suicide attempts. Homophobic rejection by parents was also

  1. Helping Gay and Lesbian Students Integrate Sexual and Religious Identities

    Science.gov (United States)

    Bayne, Hannah Barnhill

    2016-01-01

    This article explores the impact of sexual and religious identity on college student development, examining developmental models and discussing how counselors can assist gay and lesbian students with integrating these 2 personal identities. Treatment approaches are presented, and the article concludes with an examination of ethical and…

  2. On a problem of Berenstein-Gay and its generalizations

    International Nuclear Information System (INIS)

    Volchkov, Valerii V; Volchkov, Vitaly V

    2010-01-01

    We obtain a solution of the Berenstein-Gay problem on the local analogue of spectral analysis on Riemannian symmetric spaces X of rank 1. The proof is based on constructing transmutation maps connected with eigenfunction expansions of the Laplace-Beltrami operator on X.

  3. The Complexities of Workplace Experience for Lesbian and Gay Teachers

    Science.gov (United States)

    Ferfolja, Tania; Hopkins, Lucy

    2013-01-01

    Discrimination against lesbians and gay men has been endemic throughout Australia's history. However, in twenty-first century Australian society there are signs of growing sophistication and acceptance of sexual diversities. Despite this, schools continue to be organisations where sexual "difference" is marginalised and silenced, having…

  4. Integrating Gay, Lesbian, and Bisexual Issues into Mainstream Psychology.

    Science.gov (United States)

    Goldfried, Marvin R.

    2001-01-01

    Illustrates how clinical and research writings on gay, lesbian, and bisexual (GLB) issues remain invisible to mainstream psychology in such areas as life span development and aging, teen suicide, substance abuse, victimization, and family and couple relationships, examining determinants of wellbeing among GLBs and discussing what mainstream…

  5. Perceived Career Barriers for Gay, Lesbian, and Bisexual Individuals

    Science.gov (United States)

    Parnell, Martha Keeton; Lease, Suzanne H.; Green, Michael L.

    2012-01-01

    This study examined career-related barriers that gay, lesbian, and bisexual (GLB) individuals had encountered in the past and anticipated in the future and the degree of hindrance associated with future barriers. Two hundred forty-one GLB participants (126 women and 115 men) completed the Career Barriers Inventory-Revised and 11 additional items…

  6. Odd Couples : A History of Gay Marriage in Scandinavia

    NARCIS (Netherlands)

    Rydström, Jens

    2011-01-01

    Odd Couples. A History of Gay Marriage in Scandinavia is het eerste omvangrijke boek over de geschiedenis van het geregistreerd partnerschap en het homohuwelijk in Scandinavië. Dit boek presenteert een grondig onderzoek naar de wisselwerking tussen het homoactivisme en traditionele partijpolitiek.

  7. Victimization and suicidality among Dutch lesbian, gay, and bisexual youths

    NARCIS (Netherlands)

    van Bergen, D.D.; Bos, H.M.W.; van Lisdonk, J.; Keuzenkamp, S.; Sandfort, T.G.M.

    2013-01-01

    We examined Netherlands Institute for Social Research data, collected between May and August 2009, on 274 Dutch lesbian, gay, and bisexual youths. The data showed that victimization at school was associated with suicidal ideation and actual suicide attempts. Homophobic rejection by parents was also

  8. Victimization and suicidality among Dutch lesbian, gay and bisexual youths

    NARCIS (Netherlands)

    van Bergen, D.D.; Bos, H.M.W.; van Lisdonk, J.; Keuzenkamp, S.; Sandfort, T.G.M.

    2013-01-01

    We examined Netherlands Institute for Social Research data, collected between May and August 2009, on 274 Dutch lesbian, gay, and bisexual youths. The data showed that victimization at school was associated with suicidal ideation and actual suicide attempts. Homophobic rejection by parents was also

  9. Peer education, reduction of risk appeal to gay teens.

    Science.gov (United States)

    1995-10-01

    The Hetrick-Martin Institute and AIDS educators help gay and lesbian adolescents confront issues such as AIDS education and discrimination. Intolerance and religious convictions held by the community impede proper AIDS education. Peer education programs in schools or health care facilities, and use of near-peer educators, are effective vehicles for AIDS education.

  10. Dating violence experiences of lesbian, gay, bisexual, and transgender youth.

    Science.gov (United States)

    Dank, Meredith; Lachman, Pamela; Zweig, Janine M; Yahner, Jennifer

    2014-05-01

    Media attention and the literature on lesbian, gay, and bisexual youth overwhelmingly focus on violence involving hate crimes and bullying, while ignoring the fact that vulnerable youth also may be at increased risk of violence in their dating relationships. In this study, we examine physical, psychological, sexual, and cyber dating violence experiences among lesbian, gay, and bisexual youth--as compared to those of heterosexual youth, and we explore variations in the likelihood of help-seeking behavior and the presence of particular risk factors among both types of dating violence victims. A total of 5,647 youth (51 % female, 74 % White) from 10 schools participated in a cross-sectional anonymous survey, of which 3,745 reported currently being in a dating relationship or having been in one during the prior year. Results indicated that lesbian, gay, and bisexual youth are at higher risk for all types of dating violence victimization (and nearly all types of dating violence perpetration), compared to heterosexual youth. Further, when looking at gender identity, transgender and female youth are at highest risk of most types of victimization, and are the most likely perpetrators of all forms of dating violence but sexual coercion, which begs further exploration. The findings support the development of dating violence prevention programs that specifically target the needs and vulnerabilities of lesbian, gay, and bisexual youth, in addition to those of female and transgender youth.

  11. Informal Mentoring for Lesbian, Gay, Bisexual, and Transgender Students

    Science.gov (United States)

    Mulcahy, Molly; Dalton, Sarah; Kolbert, Jered; Crothers, Laura

    2016-01-01

    The authors identified the process that 10 lesbian, gay, bisexual, and transgender (LGBT) high school students used to establish an informal adult-mentor relationship with a school personnel member. Five major themes emerged: (a) how LGBT students determined whether this person would be a safe mentor, (b) a listing of the important qualities of…

  12. Dual Minority Stress and Asian American Gay Men's Psychological Distress

    Science.gov (United States)

    Chen, Yung-Chi; Tryon, Georgiana Shick

    2012-01-01

    The present study investigated the direct and additive effects of racial minority stress and sexual minority stress on the psychological well-being among a community sample of 139 Asian American gay men. Self-esteem was tested to see whether it moderated or mediated the effects of perceived dual minority stress on psychological distress. Results…

  13. Gender Differences in African American Attitudes toward Gay Males.

    Science.gov (United States)

    Battle, Juan; Lemelle, Anthony J., Jr.

    2002-01-01

    Used data from the 1993 National Black Politics Study to examine the way gender worked in explaining African American attitudes toward gay men. Results indicated that African American females expressed more positive attitudes toward homosexual men than did African American males, and of the variables examined (including age, church attendance,…

  14. Influences of Steelmaking Slags on Hydration and Hardening of Concretes

    Science.gov (United States)

    Kirsanova, A. A.; Dildin, A. N.; Maksimov, S. P.

    2017-11-01

    It is shown that the slag of metallurgical production can be used in the construction industry as an active mineral additive for concrete. This approach allows us to solve environmental problems and reduce costs for the production of binder and concrete simultaneously. Most often slag is used in the form of a filler, an active mineral additive or as a part of a binder for artificial conglomerates. The introduction of slag allows one to notice a part of the cement, to obtain concretes that are more resistant to the impact of aggressive sulfate media. The paper shows the possibility of using recycled steel-smelting slags in the construction industry for the production of cement. An assessment was made of their effect on the hydration of the cement stone and hardening of the concrete together with the plasticizer under normal conditions. In the process of work, we used the slag of the Zlatoust Electrometallurgical Factory. Possible limitations of the content of steel-slag slag in concrete because of the possible presence of harmful impurities are shown. It is necessary to enter slag in conjunction with superplasticizers to reduce the flow of water mixing. Slags can be used as a hardening accelerator for cement concrete as they allow one to increase the degree of cement hydration and concrete strength. It is shown that slags can be used to produce fast-hardening concretes and their comparative characteristics with other active mineral additives are given.

  15. Effect of overpressure on gas hydrate distribution

    Energy Technology Data Exchange (ETDEWEB)

    Bhatnagar, G.; Chapman, W.G.; Hirasaki, G.J. [Rice Univ., Houston, TX (United States). Dept. of Chemical and Biomolecular Engineering; Dickens, G.R.; Dugan, B. [Rice Univ., Houston, TX (United States). Dept. of Earth Sciences

    2008-07-01

    Natural gas hydrate systems can be characterized by high sedimentation rates and/or low permeability sediments, which can lead to pore pressure higher than hydrostatic. This paper discussed a study that examined this effect of overpressure on gas hydrate and free gas distribution in marine sediments. A one-dimensional numerical model that coupled sedimentation, fluid flow, and gas hydrate formation was utilized. In order to quantify the relative importance of sedimentation rates and low permeability sediments, a dimensionless sedimentation-compaction group (scN) was defined, that compared the absolute permeability of the sediments to the sedimentation rate. Higher values of scN mean higher permeability or low sedimentation rate which generally yield hydrostatic pore pressure while lower values of scN normally create pore pressure greater than hydrostatic. The paper discussed non-hydrostatic consolidation in gas hydrate systems, including mass balances; constitutive relationships; normalized variables; and dimensionless groups. A numerical solution to the problem was presented. It was concluded that simulation results demonstrated that decreasing scN not only increased pore pressure above hydrostatic values, but also lowered the lithostatic stress gradient and gas hydrate saturation. This occurred because overpressure resulted in lower effective stress, causing higher porosity and lower bulk density of the sediment. 16 refs., 5 figs., 1 appendix.

  16. Methane hydrates in quaternary climate change

    International Nuclear Information System (INIS)

    Kennett, J. P.; Hill, T. M.; Behl, R. J.

    2005-01-01

    The hydrate reservoir in marine sediments is known to contain a large volume of exchangeable carbon stored as solid methane hydrate and associated free gas. This reservoir has been shown to be potentially unstable in response to changing intermediate water temperature and sea level (pressure). Evidence continues to grow for past episodes of major methane release at times of climatic warming. Yet few studies of late Quaternary climate change include methane hydrates as an integral part of the global climate system, in spite of the largest known oscillations at this time in sea level and upper ocean temperature changes for the Cenozoic or earlier, conditions that favor instability of the methane hydrate reservoir. Abrupt increases in atmospheric methane recorded in polar ice cores are widely believed to have resulted, not from ocean-floor methane degassing, but instead from continental wetland activation, a hypothesis thus far unsupported by geological data. Furthermore, as part of this Wetland Methane Hypothesis, the abrupt methane increases have been seen as a response to climatic warming rather than contributing significantly to the change. An alternative view (formulated as the Clathrate Gun Hypothesis) is that the speed, magnitude and timing of abrupt climate change in the recent geologic past are consistent with the process of major degassing of methane hydrates. We summarize aspects of this hypothesis here and needs to test this hypothesis. (Author)

  17. Blue LED irradiation to hydration of skin

    Science.gov (United States)

    Menezes, Priscila F. C.; Requena, Michelle B.; Lizarelli, Rosane F., Z.; Bagnato, Vanderlei S.

    2015-06-01

    Blue LED system irradiation shows many important properties on skin as: bacterial decontamination, degradation of endogenous skin chromophores and biostimulation. In this clinical study we prove that the blue light improves the skin hydration. In the literature none authors reports this biological property on skin. Then this study aims to discuss the role of blue light in the skin hydration. Twenty patients were selected to this study with age between 25-35 years old and phototype I, II and III. A defined area from forearm was pre determined (A = 4.0 cm2). The study was randomized in two treatment groups using one blue light device (power of 5.3mW and irradiance of 10.8mW/cm2). The first treatment group was irradiated with 3J/cm2 (277seconds) and the second with 6J/cm2 (555 seconds). The skin hydration evaluations were done using a corneometer. The measurements were collected in 7, 14, 21 and 30 days, during the treatment. Statistical test of ANOVA, Tukey and T-Student were applied considering 5% of significance. In conclusion, both doses were able to improve the skin hydration; however, 6J/cm2 has kept this hydration for 30 days.

  18. Prestack Waveform Inversion and Well Log Examination at GC955 and WR313 in the Gulf of Mexico for Estimation of Methane Hydrate Concentrations

    Science.gov (United States)

    Fortin, W.; Goldberg, D.; Kucuk, H. M.

    2017-12-01

    Gas hydrates are naturally occurring compounds, which, at a molecular scale, are lattice structures of ice embedded with various gas molecules in the lattice voids. Volumetric estimates of associated hydrocarbons vary greatly due to the difficulty in remotely estimating hydrate concentrations in marine sediments but embedded hydrocarbon stores are thought to represent a significant portion of global deposits. Inherent hydrate instabilities obscure our understanding of and complicates processes related to resource extraction and hydrate response to disturbances in the local environment. Understanding the spatial extent and variability of hydrate deposits have important implications for potential economic production, climate change, and assessing natural hazards risks. Seismic reflection techniques are capable of determining the extent of gas hydrate deposits, often through the observation of bottom simulating reflectors (BSRs). However, BSRs are not present everywhere gas hydrates exist. Using high resolution prestack time migrated seismic data and prestack waveform inversion (PWI) we produce highly resolved velocity models and compare them to co-located well logs. Coupling our PWI results with velocity-porosity relationships and nearby well control, we map hydrate properties at GC955 and WR313. Integrating small scale heterogeneities and variations along the velocity model with in-situ measurements, we develop a workflow aimed to quantify hydrate concentrations observed in seismic data over large areas in great detail regardless of the existence of a BSR.

  19. Effects of Nanosilica on Early Age Stages of Cement Hydration

    Directory of Open Access Journals (Sweden)

    Forood Torabian Isfahani

    2017-01-01

    Full Text Available Effects of nanosilica on cement hydration have been broadly investigated in the literature and early age cement hydration, as a whole, has been mainly considered, disregarding the substages of the hydration. The hydration of cement is characterized by different substages and nanosilica effect on the hydration could be a result of diverse, even contradictory, behavior of nanosilica in individual stages of the hydration. In this study, effects of nanosilica on different substages of cement hydration are investigated. Isothermal calorimetry results show that at early ages (initial 72 hours the effects of nanosilica depend on the phenomenon by which the hydration is governed: when the hydration is chemically controlled, that is, during initial reaction, dormant period, and acceleratory period, the hydration rate is accelerated by adding nanosilica; when the hydration is governed by diffusion process, that is, during postacceleratory period, the hydration rate is decelerated by adding nanosilica. The Thermal Gravimetric Analysis on the samples at the hardened state (after 28 days of curing reveals that, after adding nanosilica, the hydration degree slightly increased compared to the plain paste.

  20. Morphology studies on gas hydrates interacting with silica gel

    Energy Technology Data Exchange (ETDEWEB)

    Beltran, J.; Servio, P. [McGill Univ., Montreal, PQ (Canada). Dept. of Chemical Engineering

    2008-07-01

    Clathrate hydrates or gas hydrates are non-stoichiometric, crystalline compounds that form when small molecules come in contact with water at certain temperatures and pressures. Natural gas hydrates are found in the ocean bottom and in permafrost regions. It is thought that the amount of energy stored in natural hydrates is at least twice that of all other fossil fuels combined. In addition, trapping carbon dioxide as a hydrate in the bottom of the ocean has been suggested as an alternative means of reducing atmospheric carbon dioxide levels. Naturally occurring clathrates are found in close interaction with fine grained particles of very small mean pore diameters. Even though an increasing amount of hydrate equilibrium data for small diameter porous media has become available, the morphological behavior of hydrates subject to such conditions is yet to be explored. This paper presented a study that visually examined hydrate formation and decomposition of gas hydrates while interacting with fine grains of silica gel. The study showed still frames from high-resolution video recordings for hydrate formation and decomposition. The paper discussed the experiment including the apparatus as well as the results of hydrate formation and hydrate dissociation. This study enabled for the first time to observe clathrate morphology while hydrates interacted closely with fine grain particles with small mean pore diameters. 9 refs., 8 figs.