WorldWideScience

Sample records for gas generators prepared

  1. Composition, preparation, and gas generation results from simulated wastes of Tank 241-SY-101

    International Nuclear Information System (INIS)

    Bryan, S.A.; Pederson, L.R.

    1994-08-01

    This document reviews the preparation and composition of simulants that have been developed to mimic the wastes temporarily stored in Tank 241-SY-101 at Hanford. The kinetics and stoichiometry of gases that are generated using these simulants are also compared, considering the roles of hydroxide, chloride, and transition metal ions; the identities of organic constituents; and the effects of dilution, radiation, and temperature. Work described in this report was conducted for the Flammable Gas Safety Program at Pacific Northwest Laboratory, (a) whose purpose is to develop information that is necessary to mitigate potential safety hazards associated with waste tanks at the Hanford Site. The goal of this research and of related efforts at the Georgia Institute of Technology (GIT), Argonne National Laboratory (ANL), and Westinghouse Hanford Company (WHC) is to determine the thermal and thermal/radiolytic mechanisms by which flammable and other gases are produced in Hanford wastes, emphasizing those stored in Tank 241-SY-101. A variety of Tank 241-SY-101 simulants have been developed to date. The use of simulants in laboratory testing activities provides a number of advantages, including elimination of radiological risks to researchers, lower costs associated with experimentation, and the ability to systematically alter simulant compositions to study the chemical mechanisms of reactions responsible for gas generation. The earliest simulants contained the principal inorganic components of the actual waste and generally a single complexant such as N-(2-hydroxyethyl) ethylenediaminetriacetic acid (HEDTA) or ethylenediaminetriacetic acid (EDTA). Both homogeneous and heterogeneous compositional forms were developed. Aggressive core sampling and analysis activities conducted during Windows C and E provided information that was used to design new simulants that more accurately reflected major and minor inorganic components

  2. Cracked gas generator

    Energy Technology Data Exchange (ETDEWEB)

    Abthoff, J; Schuster, H D; Gabler, R

    1976-11-17

    A small cracked-gas generator in a vehicle driven, in particular, by an air combustion engine has been proposed for the economic production of the gases necessary for low toxicity combustion from diesel fuel. This proceeds via catalytic crack-gasification and exploitation of residual heat from exhaust gases. This patent application foresees the insertion of one of the catalysts supporting the cracked-gas reaction in a container through which the reacting mixture for cracked-gas production flows in longitudinal direction. Further, air ducts are embedded in the catalyst through which exhaust gases and fresh air flow in counter direction to the cracked gas flow in the catalyst. The air vents are connected through heat conduction to the catalyst. A cracked gas constituting H/sub 2//CO/CO/sub 2//CH/sub 4/ and H/sub 2/O can be produced from the air-fuel mixture using appropriate catalysts. By the addition of 5 to 25% of cracked gas to the volume of air drawn in by the combustion engine, a more favourable combustion can be achieved compared to that obtained under normal combustion conditions.

  3. Gas turbine electric generator

    International Nuclear Information System (INIS)

    Nemoto, Masaaki; Yuhara, Tetsuo.

    1993-01-01

    When troubles are caused to a boundary of a gas turbine electric generator, there is a danger that water as an operation medium for secondary circuits leaks to primary circuits, to stop a plant and the plant itself can not resume. Then in the present invention, helium gases are used as the operation medium not only for the primary circuits but also for the secondary circuits, to provide so-called a direct cycle gas turbine system. Further, the operation media of the primary and secondary circuits are recycled by a compressor driven by a primary circuit gas turbine, and the turbine/compressor is supported by helium gas bearings. Then, problems of leakage of oil and water from the bearings or the secondary circuits can be solved, further, the cooling device in the secondary circuit is constituted as a triple-walled tube structure by way of helium gas, to prevent direct leakage of coolants into the reactor core even if cracks are formed to pipes. (N.H.)

  4. Natural gas for utility generation

    International Nuclear Information System (INIS)

    Moore, T.

    1992-01-01

    Forecasters predict that natural gas will be the dominant fuel choice for utility capacity additions in the coming decade and that power generation will be by far the largest growth market for gas sales. While gas's low emissions, high efficiency potential, and present low cost argue persuasively for a surge in gas-fired generation, many utilities have been slow to commit to a gas future, citing reasoned concern about long-term price trends and the ability of gas suppliers to deliver the fuel where and when it will be needed. Meanwhile, the relatively low cost of gas-fired units is providing an opportunity for independent power producers to compete strongly with utilities for generation contracts. EPRI studies suggest that a sound, competitive strategy will be based not on how much gas a utility burns, but rather on how this capacity fits into its overall generating mix at various fuel price levels. Gas suppliers will need to pay special attention to the operating needs of power generators if they are to solidify this important market

  5. Dry radon gas generator

    International Nuclear Information System (INIS)

    Vandrish, G.

    1979-10-01

    A radon gas standard with a source strength of 120037 pCi capable of delivering 121 pCi of radon gas successively to a large number of cells has been developed. The absolute source strength has been calibrated against two radium solution standards and is accurate to 4 percent. A large number of cells (approxiiately 50) may be calibrated conveniently on a daily basis with appropriate corrections for sequential changes in the amount of gas delivered, and a correction for the growth of radon in the standard on successive days. Daily calibration of ten cells or less does not require these corrections. The standard is suitable for field use and the source emanation rate is stable over extreme temperatue and pressure ranges and over six months

  6. Gas compression infrared generator

    International Nuclear Information System (INIS)

    Hug, W.F.

    1980-01-01

    A molecular gas is compressed in a quasi-adiabatic manner to produce pulsed radiation during each compressor cycle when the pressure and temperature are sufficiently high, and part of the energy is recovered during the expansion phase, as defined in U.S. Pat. No. 3,751,666; characterized by use of a cylinder with a reciprocating piston as a compressor

  7. Gas generation in repositories

    International Nuclear Information System (INIS)

    Biddle, P.; Rees, J.H.; McGahan, D.; Rushbrook, P.E.

    1987-09-01

    The nature and quantities of gases likely to be produced by various processes in repositories for low level and intermediate level radioactive wastes are examined in this preliminary study. Many simplifying assumptions are made where published or experimental data is unavailable. The corrosion of the canisters and metallic components in wastes is likely to be the major gas production process in both types of repository. A significant contribution from microbiological activity is expected to occur in low level repositories, predominantly where no cement grouting of the cans has been carried out. A number of areas for further research, required before a more comprehensive study could be carried out, have been identified. (author)

  8. Signal generation in gas detectors

    International Nuclear Information System (INIS)

    Stillman, A.

    1993-01-01

    This tutorial describes the generation of electrical signals in gas detectors. Ionization of the gas by the passage of charged particles generates these signals. Starting with the Bethe-Bloch equation, the treatment is a general introduction to the production of ion-pairs in gas devices. I continue with the characterization of the ionization as an electrical signal, and calculate the signal current in a simple example. Another example demonstrates the effect of space charge on the design of a detector. The AGS Booster ionization profile monitor is a model for this calculation

  9. Progress of 90Y generator preparation

    International Nuclear Information System (INIS)

    Yin Bangshun; Li Mingqi; Deng Qimin; Cheng Zuoyong

    2009-01-01

    90 Y is an important radionuclide in radioimmunotherapy. The medical 90 Y is mainly obtained from 90 Y generator through methods of precipitation,coprecipitation, electrodeposition, solvent extraction, chromatography and so on. The progress of 90 Y generator, the advantages and disadvantages of different types of 90 Y generator, and the tendency of 90 Y generator preparation were described respectively. Comprehensive analysis showed that inorganic ion-exchange chromatography will be the main tendency of future 90 Y generator preparation. (authors)

  10. Gas Generation from Actinide Oxide Materials

    Energy Technology Data Exchange (ETDEWEB)

    George Bailey; Elizabeth Bluhm; John Lyman; Richard Mason; Mark Paffett; Gary Polansky; G. D. Roberson; Martin Sherman; Kirk Veirs; Laura Worl

    2000-12-01

    This document captures relevant work performed in support of stabilization, packaging, and long term storage of plutonium metals and oxides. It concentrates on the issue of gas generation with specific emphasis on gas pressure and composition. Even more specifically, it summarizes the basis for asserting that materials loaded into a 3013 container according to the requirements of the 3013 Standard (DOE-STD-3013-2000) cannot exceed the container design pressure within the time frames or environmental conditions of either storage or transportation. Presently, materials stabilized and packaged according to the 3013 Standard are to be transported in certified packages (the certification process for the 9975 and the SAFKEG has yet to be completed) that do not rely on the containment capabilities of the 3013 container. Even though no reliance is placed on that container, this document shows that it is highly likely that the containment function will be maintained not only in storage but also during transportation, including hypothetical accident conditions. Further, this document, by summarizing materials-related data on gas generation, can point those involved in preparing Safety Analysis Reports for Packages (SARPs) to additional information needed to assess the ability of the primary containment vessel to contain the contents and any reaction products that might reasonably be produced by the contents.

  11. Gas Generation from Actinide Oxide Materials

    International Nuclear Information System (INIS)

    Bailey, George; Bluhm, Elizabeth; Lyman, John; Mason, Richard; Paffett, Mark; Polansky, Gary; Roberson, G. D.; Sherman, Martin; Veirs, Kirk; Worl, Laura

    2000-01-01

    This document captures relevant work performed in support of stabilization, packaging, and long term storage of plutonium metals and oxides. It concentrates on the issue of gas generation with specific emphasis on gas pressure and composition. Even more specifically, it summarizes the basis for asserting that materials loaded into a 3013 container according to the requirements of the 3013 Standard (DOE-STD-3013-2000) cannot exceed the container design pressure within the time frames or environmental conditions of either storage or transportation. Presently, materials stabilized and packaged according to the 3013 Standard are to be transported in certified packages (the certification process for the 9975 and the SAFKEG has yet to be completed) that do not rely on the containment capabilities of the 3013 container. Even though no reliance is placed on that container, this document shows that it is highly likely that the containment function will be maintained not only in storage but also during transportation, including hypothetical accident conditions. Further, this document, by summarizing materials-related data on gas generation, can point those involved in preparing Safety Analysis Reports for Packages (SARPs) to additional information needed to assess the ability of the primary containment vessel to contain the contents and any reaction products that might reasonably be produced by the contents

  12. Centralized power generation: what share for gas?

    International Nuclear Information System (INIS)

    Honore, A.; Pharabod, E.; Lecointe, O.; Poyer, L.

    2007-01-01

    Up to a recent past, most energy scenarios were foreseeing a fast growth of natural gas consumption thanks to an assumed strong penetration of gas-fueled power plants. The share of natural gas in the centralized power generation has been the subject of a meeting of the French gas association (AFG) which aimed at answering the following questions: today's position of gas power generation in Europe in the present day context of gas prices (level, volatility), the share of natural gas in the French power mix in the coming years, the strategies of development of gas power plants by historical operators and newcomers, the gas arbitration between its sale to end-users and its use for power generation, and the integration of the CO 2 risk. (J.S.)

  13. Natural gas poised to penetrate deeper into electric generation

    International Nuclear Information System (INIS)

    Swanekamp, R.

    1995-01-01

    This article describes how advancements in gas supply, distribution and storage, coupled with new options in combustion equipment, continue to expand the use of natural gas for electric generation. The challenge is to meet the increasing demand while keeping prices competitive with other fuels--and keep a small band of skeptics at bay. To prepare for the projected growth in gas consumption, the natural-gas industry has invented in new infrastructure and technologies. Pipelines have been built; storage facilities have been expanded; and highly precise flow measurement stations have been installed. To mitigate supply and price risk, suppliers are offering short-, mid-, or long-term contracts which include service options and guarantees. In spite of these preparations, not all power producers are comfortable with the potential tidal wave of gas-fired capacity. Reason: It limits the electric-generation resource base to one fuel for future capacity

  14. Gas target neutron generator studies

    International Nuclear Information System (INIS)

    Chatoorgoon, V.

    1978-01-01

    The need for an intense neutron source for the study of radiation damage on materials has resulted in the proposal of various solid, liquid, and gas targets. Among the gas targets proposed have been the transonic gas target, two types of hypersonic gas target, and the subsonic gas target (SGT). It has been suggested that heat deposition in a subsonic channel might create a gas density step which would constitute an attractive gas target type. The first part of the present study examines this aspect of the SGT and shows that gas density gradients are indeed formed by heat deposition in subsonic flow. The variation of beam voltage, gas density, gas pressure, and gas temperature within the channel have been calculated as functions of the system parameters: beam voltage, beam current, channel diameter, stagnation tank temperature and pressure. The analysis is applicable to any beam particle and target gas. For the case of T + on D 2 , which is relevant to the fusion application, the 14 MeV neutron profiles are presented as a function of system parameters. It is found that the SGT is compatible with concentrated intense source operation. The possibility of instability was investigated in detail using a non-linear analysis which made it possible to follow the complete time development of the SGT. It was found that the SGT is stable against all small perturbations and certain types of large perturbations. It appears that the SGT is the most advantageous type of gas target, operating at a lower mass flow and less severe stagnation tank conditions than the other types. The second part of the thesis examines a problem associated with the straight hypersonic target, the deuterium spill into the tritium port. The regime of practical operation for this target is established. (auth)

  15. Preparation of zirconium molybdate gel generator

    International Nuclear Information System (INIS)

    Charoen, S.; Aungurarat, G.; Laohawilai, S.; Sukontpradit, W.; Jingjit, S.

    1994-01-01

    A procedure for preparation of 99mTc generator based on conversion to zirconium molybdate gel of 99Mo produced by neutron activation was reported. The gel was prepared from zirconium oxychloride solution pH 1.6, ammonium molybdate solution pH 3-5 and mole ratio of Zr:Mo 1:1 which had water content about 7-8%. Small generators containing 1-1.5 g of gel were eluted with average efficiencies of 77% and the activity peak in the first 3 ml of 10 ml of saline solution. The amount of Mo and Zr in eluates were below the acceptance limit. The gel generators of activity about 100 mCi were prepared and had the good performance in elutability and stability

  16. Gas in electricity generation [In New Zealand

    International Nuclear Information System (INIS)

    Devine, K.

    1995-01-01

    Gas is New Zealand's major thermal fuel for electricity generation. This paper describes what influences the volumes of gas burnt by ECNZ, and forecasts future gas demands for electricity generation. It also reviews the uncertainties associated with these forecasts and likely competition in building new electricity generating stations and outlines the strategy now being formulated to accommodate them. Because ECNZ's generation system is hydro-based, relatively small rapid changes in hydrological conditions can significantly affect the amount of gas used. This situation will change over time with major increases in thermal generation likely to be needed over the next 20 years. However, there are considerable uncertainties on gas supply and electricity demand levels in the long run, which will complicate investment and fuel decisions. (Author)

  17. The Chemistry of Flammable Gas Generation

    International Nuclear Information System (INIS)

    ZACH, J.J.

    2000-01-01

    The document collects information from field instrumentation, laboratory tests, and analytical models to provide a single source of information on the chemistry of flammable gas generation at the Hanford Site. It considers the 3 mechanisms of formation: radiolysis, chemical reactions, and thermal generation. An assessment of the current models for gas generation is then performed. The results are that the various phenomena are reasonably understood and modeled compared to field data

  18. The Chemistry of Flammable Gas Generation

    Energy Technology Data Exchange (ETDEWEB)

    ZACH, J.J.

    2000-10-30

    The document collects information from field instrumentation, laboratory tests, and analytical models to provide a single source of information on the chemistry of flammable gas generation at the Hanford Site. It considers the 3 mechanisms of formation: radiolysis, chemical reactions, and thermal generation. An assessment of the current models for gas generation is then performed. The results are that the various phenomena are reasonably understood and modeled compared to field data.

  19. Installation for gas purification and gas mixture preparation

    International Nuclear Information System (INIS)

    Ciortea, Constantin; Dumitrescu, Ioana; Armeanu, Adrian

    2002-01-01

    The Gas Production Division of ICSI at Rm. Valcea developed advanced facilities for purification of hydrogen, nitrogen, methane gases, etc, with concentrations up to 99.999 % vol. Pure and ultrapure gases are used for analytical purposes in food industry, biology, medicine, research laboratories, chemical and metallurgical industries. In the frame of ICSI the purified gases are used for preparation of usual and special mixtures of gases as for instance for production of Ar + CO 2 , Ar + CH 4 , Ar + H 2 , Ar + N 2 , N 2 + CO 2 , N 2 + O 2 etc. These mixtures are required in diverse sectors of chemical, electrical, machine and food industry, in nuclear power plants for monitoring, in laboratories of equipment calibrations, etc. (authors)

  20. Modelling gas generation in radioactive waste repositories

    International Nuclear Information System (INIS)

    Agg, P.J.

    1993-02-01

    In a repository containing low- and intermediate-level waste, gas generation will occur principally by the coupled processes of metal corrosion and microbial degradation of cellulosic waste. This Paper describes a mathematical model design to address gas generation by these mechanisms. The metal corrosion model incorporates a three-stage process encompassing both aerobic and anaerobic corrosion regimes; the microbial degradation model simulates the activities of eight different microbial populations, which are maintained as functions both of pH and of the concentrations of particular chemical species. Gas concentrations have been measured over a period of three years in large-scale drum experiments designed to simulate repository conditions. Model predictions are confirmed against the experimental measurements, and a prediction is then made of gas concentrations and generation rates over an assessment period of one million years in a radioactive waste repository. (author)

  1. Modelling gas generation in radioactive waste repositories

    International Nuclear Information System (INIS)

    Agg, P.J.

    1992-07-01

    In a repository containing low- and intermediate-level waste, gas generation will occur principally by the coupled processes of metal corrosion and microbial degradation of cellulosic waste. This paper describes a mathematical model designed to address gas generation by these mechanisms. The metal corrosion model incorporates a three-stage process encompassing both aerobic and anaerobic corrosion regimes; the microbial degradation model simulates the activities of eight different microbial populations, which are maintained as functions both of pH and of the concentrations of particular chemical species. Gas concentrations have been measured over a period of three years in large-scale drum experiments designed to simulate repository conditions. Model predictions are confirmed against the experimental measurements, and a prediction is then made of gas concentrations and generation rates over an assessment period of one million years in a radioactive waste repository. (Author)

  2. New generation of gas infrared point heaters

    Energy Technology Data Exchange (ETDEWEB)

    Schink, Damian [Pintsch Aben B.V., Dinslaken (Germany)

    2011-11-15

    It is more than thirty years since gas infrared heating for points was introduced on the railway network of what is now Deutsche Bahn. These installations have remained in service right through to the present, with virtually no modifications. More stringent requirements as regards availability, maintainability and remote monitoring have, however, led to the development of a new system of gas infrared heating for points - truly a new generation. (orig.)

  3. Natural gas and electricity generation in Queensland

    International Nuclear Information System (INIS)

    Webb, G.

    2001-01-01

    The focus of this article is on electricity generation in Queensland. Black coal accounted for 97 percent, while natural gas made up only 1 percent of the fuel used in thermal power generation in 1997-98. The share of natural gas in thermal electricity generation is expected to rise to 21 percent by 2014-2015, because of the emphasis on natural gas in Queensland's new energy policy. Since 1973-1974, Queensland has led the way in electricity consumption, with an average annual growth rate of 6.8 percent but the average thermal efficiency has fallen from 38.0 percent in 1991-1992, to 36.6 percent in 1997-1998

  4. Gas-fired electric power generating technologies

    International Nuclear Information System (INIS)

    1994-09-01

    The workshop that was held in Madrid 25-27 May 1994 included participation by experts from 16 countries. They represented such diverse fields and disciplines as technology, governmental regulation, economics, and environment. Thus, the participants provided an excellent cross section of key areas and a diversity of viewpoints. At the workshop, a broad range of topics regarding gas-fired electric power generation was discussed. These included political, regulatory and financial issues as well as more specific technical questions regarding the environment, energy efficiency, advanced generation technologies and the status of competitive developments. Important technological advances in gas-based power and CHP technologies have already been achieved including higher energy efficiency and lower emissions, with further improvements expected in the near future. Advanced technology trends include: (a) The use of gas technology to reduce emissions from existing coal-fired power plants. (b) The wide-spread application of combined-cycle gas turbines in new power plants and the growing use of aero-derivative gas turbines in CHP applications. (c) Phosphoric acid fuel cells that are being introduced commercially. Their market penetration will grow over the next 10 years. The next generation of fuel cells (solid oxide and molten carbonate) is expected to enter the market around the year 2000. (EG)

  5. ELECTRICITY GENERATION FROM LANDFILL GAS IN TURKEY.

    Science.gov (United States)

    Salihoglu, Nezih Kamil

    2018-05-08

    Landfill gas (LFG)-to-energy plants in Turkey were investigated, and the LFG-to-energy plant of a metropolitan municipal landfill was monitored for 3 years. Installed capacities and actual gas engine working hours were determined. An equation was developed to estimate the power capacity for LFG-to-energy plants for a given amount of landfilled waste. Monitoring the actual gas generation rates enabled determination of LFG generation factors for Turkish municipal waste. A significant relationship (R = 0.524, p kitchen waste generation behaviors influenced by the ambient temperature. However, no significant correlation was found between the ambient temperature and the generated LFG. A temperature buffering capacity was inferred to exist within the landfill, which enables the anaerobic reactions to continue functioning even during cold seasons. The average LFG and energy generation rates were 45 m 3 LFG/ton waste landfilled and 0.08 MWh/ton waste landfilled, respectively. The mean specific LFG consumption for electricity generation was 529 ± 28 m 3 /MWh.

  6. A Flue Gas Tube for Thermoelectric Generator

    DEFF Research Database (Denmark)

    2013-01-01

    The invention relates to a flue gas tube (FGT) (1) for generation of thermoelectric power having thermoelectric elements (8) that are integrated in the tube. The FTG may be used in combined heat and power (CHP) system (13) to produce directly electricity from waste heat from, e.g. a biomass boiler...

  7. DESIGN, FABRICATION, AND TESTING OF AN ADVANCED, NON-POLLUTING TURBINE DRIVE GAS GENERATOR

    International Nuclear Information System (INIS)

    Unknown

    2002-01-01

    The objectives of this report period were to complete the development of the Gas Generator design, which was done; fabricate and test of the non-polluting unique power turbine drive gas Gas Generator, which has been postponed. Focus during this report period has been to complete the brazing and bonding necessary to fabricate the Gas Generator hardware, continue making preparations for fabricating and testing the Gas Generator, and continuing the fabrication of the Gas Generator hardware and ancillary hardware in preparation for the test program. Fabrication is more than 95% complete and is expected to conclude in early May 2002. the test schedule was affected by relocation of the testing to another test supplier. The target test date for hot fire testing is now not earlier than June 15, 2002

  8. Certification of power generation from sewage gas

    International Nuclear Information System (INIS)

    Ronchetti, C.

    2004-01-01

    This article discusses the certification of power generated from sewage gas in packaged co-generation units in Switzerland. Since 2003, such electricity can be sold as 'green power' to consumers, who pay an additional charge for this ecologically generated power. Since the eco-balance of this electricity generated in wastewater treatment plant is considered as being excellent, the prestigious 'Naturemade Star' label has been awarded to it. This label sets most stringent requirements. The Canius wastewater treatment plant in the 'Lenzerheide' in eastern Switzerland is taken as an example to illustrate the procedure that has to be gone through to receive certification. This certification is carried out by independent auditors and guarantees that the 'green' electricity offered by the utility meets the high ecological criteria set by the label

  9. Interdependence of the Electricity Generation System and the Natural Gas System and Implications for Energy Security

    Science.gov (United States)

    2013-05-15

    installation of natural gas generation or cogeneration plants to increase their energy security from the typical three days using diesel supplies to weeks-to...better quantify the regional impact of natural gas for energy security. Modeling and simulation could identify those regions and DoD installations that...Interdependence of the Electricity Generation System and the Natural Gas System and Implications for Energy Security N. Judson 15 May 2013 Prepared for the

  10. Gas generation from the irradiation of mortar

    International Nuclear Information System (INIS)

    Lewis, M.A.; Warren, D.W.

    1989-01-01

    A mortar formulation capable of immobilizing chloride salts with high levels of radioactivity is being developed. As part of the developmental effort, radiation effects are being investigated. The radiolytic generation of gas(es) from irradiated mortar formulations was determined for several formulations with variable salt loadings at several test temperatures. The irradiation of a mortar formulation consisting of cement, slag, fly ash, water and 0 to 10 wt % salt led to the generation of hydrogen. The rate of generation was approximately constant, steady state pressures were not attained and final pressures were comparatively high. Higher salt concentrations were correlated with higher hydrogen generation rates for experiments at ambient temperature while lower rates were observed at 120/degree/C. The irradiation of a mortar consisting of cement, fly ash, water and salt led to the radiolytic generation of both oxygen and hydrogen. The addition of 2 wt % FeS or CaS inhibited oxygen generation and changed the hydrogen production rate. 10 refs., 4 figs., 3 tabs

  11. WIPP panel simulations with gas generation

    International Nuclear Information System (INIS)

    DeVries, K.L.; Callahan, G.D.; Munson, D.E.

    1996-01-01

    An important issue in nuclear waste repository performance is the potential for fracture development resulting in pathways for release of radionuclides beyond the confines of the repository. A series of demonstration calculations using structural finite element analyses are presented here to examine the effect of internal gas generation on the response of a sealed repository. From the calculated stress fields, the most probable location for a fracture to develop was determined to be within the pillars interior to the repository for the range of parameter values considered. If a fracture interconnects the rooms and panels of the repository, fracture opening produces significant additional void volume to limit the excess gas pressure to less than 1.0 MPa above the overburden pressure. Consequently, the potential for additional fracture development into the barrier pillar is greatly reduced, which provides further confidence that the waste will be contained within the repository

  12. Gas generation from Hanford grout samples

    International Nuclear Information System (INIS)

    Jonah, C.D.; Kapoor, S.; Matheson, M.S.; Mulac, W.A.; Meisel, D.

    1996-01-01

    In an extension of our work on the radiolytic processes that occur in the waste tanks at the Hanford site, we studied the gas generation from grout samples that contained nuclear waste simulants. Grout is one option for the long-term storage of low-level nuclear waste solutions but the radiolytic effects on grout have not been thoroughly defined. In particular, the generation of potentially flammable and hazardous gases required quantification. A research team at Argonne examined this issue and found that the total amount of gases generated radiolytically from the WHC samples was an order of magnitude higher than predicted. This implies that novel pathways fro charge migration from the solid grout to the associated water are responsible for gas evolution. The grout samples produced hydrogen, nitrous oxide, and carbon monoxide as well as nitrogen and oxygen. Yields of each of these substances were determined for doses that are equivalent to about 80 years storage of the grout. Carbon monoxide, which was produced in 2% yield, is of particular importance because even small amounts may adversely affect catalytic conversion instrumentation that has been planned for installation in the storage vaults

  13. Preparing Generation Z for the Teaching Profession

    Science.gov (United States)

    Carter, Tim

    2018-01-01

    Generation Z, also known as the Homeland Generation, is the most recent generational cohort to enter the university setting. As with other generational cohorts, various shaping factors have impacted this group contributing to its unique and defining characteristics. When carefully considered, these characteristics may provide insight into how to…

  14. 21 CFR 866.2580 - Gas-generating device.

    Science.gov (United States)

    2010-04-01

    ...) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Microbiology Devices § 866.2580 Gas-generating device. (a) Identification. A gas-generating device is a device intended for medical purposes that produces...

  15. Seeded inert gas driven disk generator

    International Nuclear Information System (INIS)

    Joshi, N.K.; Venkatramani, N.; Rohatgi, V.K.

    1987-01-01

    This report outlines the present status of work being carried out in closed cycle MHD and disk generators. It gives the basic principles and discusses a proposal for setting up an experimental facility to study nonequilibrium plasmas using an inert gas driven disk generator. Disk geometry is a near ideal geometry for plasma studies since it has single or few pair electrodes combined with near perfect insulating walls. The proposed outlay of facility with components and subsystem is given. The facility may also be used to study the concept of fully ionized seed and to develop advanced diagnostic techniques. The absic equation describing the working parameters of such a system is also given in the Appendix. (author). 57 refs

  16. Gas supply planning for new gas-fired electricity generation facilities

    International Nuclear Information System (INIS)

    Slocum, J.C.

    1990-01-01

    This paper explores several key issues in gas supply planning for new gas fired electric generation facilities. This paper will have two main sections, as follows: developing the gas supply plan for a gas-fired electricity generation facility and exploring key gas supply contract pricing issues

  17. Miniature Gas-Turbine Power Generator

    Science.gov (United States)

    Wiberg, Dean; Vargo, Stephen; White, Victor; Shcheglov, Kirill

    2003-01-01

    A proposed microelectromechanical system (MEMS) containing a closed- Brayton-cycle turbine would serve as a prototype of electric-power generators for special applications in which high energy densities are required and in which, heretofore, batteries have been used. The system would have a volume of about 6 cm3 and would operate with a thermal efficiency >30 percent, generating up to 50 W of electrical power. The energy density of the proposed system would be about 10 times that of the best battery-based systems now available, and, as such, would be comparable to that of a fuel cell. The working gas for the turbine would be Xe containing small quantities of CO2, O2, and H2O as gaseous lubricants. The gas would be contained in an enclosed circulation system, within which the pressure would typically range between 5 and 50 atm (between 0.5 and 5 MPa). The heat for the Brayton cycle could be supplied by any of a number of sources, including a solar concentrator or a combustor burning a hydrocarbon or other fuel. The system would include novel heat-transfer and heat-management components. The turbine would be connected to an electric power generator/starter motor. The system would include a main rotor shaft with gas bearings; the bearing surfaces would be made of a ceramic material coated with nanocrystalline diamond. The shaft could withstand speed of 400,000 rpm or perhaps more, with bearing-wear rates less than 10(exp -)4 those of silicon bearings and 0.05 to 0.1 those of SiC bearings, and with a coefficient of friction about 0.1 that of Si or SiC bearings. The components of the system would be fabricated by a combination of (1) three-dimensional xray lithography and (2) highly precise injection molding of diamond-compatible metals and ceramic materials. The materials and fabrication techniques would be suitable for mass production. The disadvantages of the proposed system are that unlike a battery-based system, it could generate a perceptible amount of sound, and

  18. Preparation of a pure molecular quantum gas.

    Science.gov (United States)

    Herbig, Jens; Kraemer, Tobias; Mark, Michael; Weber, Tino; Chin, Cheng; Nägerl, Hanns-Christoph; Grimm, Rudolf

    2003-09-12

    An ultracold molecular quantum gas is created by application of a magnetic field sweep across a Feshbach resonance to a Bose-Einstein condensate of cesium atoms. The ability to separate the molecules from the atoms permits direct imaging of the pure molecular sample. Magnetic levitation enables study of the dynamics of the ensemble on extended time scales. We measured ultralow expansion energies in the range of a few nanokelvin for a sample of 3000 molecules. Our observations are consistent with the presence of a macroscopic molecular matter wave.

  19. Process for preparing a normal lighting and heating gas etc

    Energy Technology Data Exchange (ETDEWEB)

    Becker, J

    1910-12-11

    A process for preparing a normal lighting and heating gas from Australian bituminous shale by distillation and decomposition in the presence of water vapor is characterized by the fact that the gasification is suitably undertaken with gradual filling of a retort and with simultaneous introduction of water vapor at a temperature not exceeding 1,000/sup 0/ C. The resulting amount of gas is heated in the same or a second heated retort with freshly supplied vapor.

  20. Gas generation from transuranic waste degradation: an interim assessment

    International Nuclear Information System (INIS)

    Molecke, M.A.

    1979-10-01

    A review of all available, applicable data pertaining to gas generation from the degradation of transuranic waste matrix material and packaging is presented. Waste forms are representative of existing defense-related TRU wastes and include cellulosics, plastics, rubbers, concrete, process sludges, and mild steel. Degradation mechanisms studied were radiolysis, thermal, bacterial, and chemical corrosion. Gas generation rates are presented in terms of moles of gas produced per year per drum, and in G(gas) values for radiolytic degradation. Comparison of generation rates is made, as is a discussion of potential short- and long-term concerns. Techniques for reducing gas generation rates are discussed. 6 figures, 10 tables

  1. Gas Generation from Solids in Aqueous Suspensions

    International Nuclear Information System (INIS)

    Meisel, D.; Schatz, T.

    1999-01-01

    The presence of solid particles suspended in solution may change the radiation-induced chemistry of a system in many ways. Catalytic surface effects may manifest themselves through the acceleration or inhibition of various reactions. As importantly, the yield of primary radiolysis products may be affected as the solids absorb a significant fraction of the radiation energy. The latter is the subject of this study. We explore the possibility that absorption of radiation by the solid particles may initiate chemistry in the water. This is a question of fundamental as well as practical significance. On the fundamental side we ask whether electron-hole pairs generated in the solid phase can escape and cross into the aqueous phase and initiate chemical reactions such as gas generation and how this possibility depends on the energy levels of the material and on particle size. From a practical angle, such questions are directly relevant to any heterogeneous system exposed to radiation. High-level waste temporarily stored in underground tanks, low-level waste permanently stored in humid grout, or soil particles migrating in geological formations are but a few examples

  2. Preparation of 90Sr-90Y generator

    International Nuclear Information System (INIS)

    Jin Xiaohai; Yu Haibin; Zhang Jinming; Zhang Peixin; Lin Qiongfang

    1990-01-01

    In recent years, 90 Y has been considered as one of the best radionuclides for tumor radioimmunotherapy when chelated to tumor-associated antibodies. This evaluation is based on the superior properties of this radionuclide (suitable half-life, pure β-ray emitter of intermediate energy, stable daughters, and suitable chemical properties) and because it is available as a radionuclide generator product by decay of its 28a parent 90 Sr. The experimental conditions of 90 Sr- 90 Y generator are described. The elution efficiency of 90 Sr- 90 Y generator reaches 98%. One of the most important problems is the 90 Sr contamination breakthrough from the generator. The level of 90 Sr contamination must be controlled to the clinical standard. The cation exchange resin 732 (100-150 mesh) was successfully used for the separation of 90 Y from 90 Sr. The method used by the authors provides a 90 Y-HAc solution which is very simple and safe for administration to the patients. 90 Y was separated from 90 Sr almost completely, the level of the 90 Sr contamination per 740 MBq 90 Y product was only 0.74 kBq. However the toxicity of 90 Sr is extremely high, the human life-time permissible dose is 74 kBq, then 740 MBq of 90 Y is allowed to be administrated to a patient for 50-100 times

  3. Preparation of hollow fiber membranes for gas separation

    NARCIS (Netherlands)

    Li, Shu-Guang

    1994-01-01

    Today, immersion precipitation is the most often used process for the preparation of gas separation membranes from polymeric materials. In this process a polymer solution in the form of a thin liquid film or hollow fiber is immersed in a nonsolvent bath where the polymer precipitates and forms a

  4. Development of biomass gasification systems for gas turbine power generation

    International Nuclear Information System (INIS)

    Larson, E.D.; Svenningsson, P.

    1991-01-01

    Gas turbines are of interest for biomass applications because, unlike steam turbines, they have relatively high efficiencies and low unit capital costs in the small sizes appropriate for biomass installations. Gasification is a simple and efficient way to make biomass usable in gas turbines. The authors evaluate here the technical requirements for gas turbine power generation with biomass gas and the status of pressurized biomass gasification and hot gas cleanup systems. They also discuss the economics of gasifier-gas turbine cycles and make some comparisons with competing technologies. Their analysis indicates that biomass gasifiers fueling advanced gas turbines are promising for cost-competitive cogeneration and central station power generation. Gasifier-gas turbine systems are not available commercially, but could probably be developed in 3 to 5 years. Extensive past work related to coal gasification and pressurized combustion of solid fuels for gas turbines would be relevant in this effort, as would work on pressurized biomass gasification for methanol synthesis

  5. Assessing the difference. Greenhouse gas emissions of electricity generation chains

    International Nuclear Information System (INIS)

    Spadaro, J.V.; Langlois, L.; Hamilton, B.

    2000-01-01

    Greenhouse gases have to the potential to influence global climate change by interfering with the natural process of heat exchange between the earth's atmosphere and outer space. Reducing atmospheric GHG concentrations have become an international priority as evidenced by the signing of the Kyoto Protocol, which would reduce emissions from industrialized countries (Annex 1) by about 5% below 1990 levels during the commitment period 2008-12. There are a number of technical options that could be implemented in order to achieve the proposed reduction target. As for emissions related to electricity generation, perhaps the most important factor over the near term is the improvement in efficiency of using energy at all the stages of the fuel cycle, including fuel preparation and transportation, fuel-to-electricity conversion at the power plant and at the point of end-use (which has not been considered here). Strategies for reducing methane releases during fuel mining and during gas transmission are very relevant. Switching to less carbon intensive or low carbon fuels, such as gas, nuclear power and renewables, will play a major role in reducing emissions. These changes are technically feasible using present day knowledge and experience, require minimal changes in consumer lifestyle, and represent reasonable capital turnover (gas and nuclear for baseload generation and renewables in niche markets or for peak load applications). This article has presented information on GHG emission factors for different fuels using a Full Energy Chain approach, which attempts to quantify the environmental emissions from all stages of electricity generation, i.e. 'cradle-to-grave'. Fossil-fueled technologies have the highest emission factors, with coal typically twice as high as natural gas. Considering the large variations in fuel- to-electricity conversion technology, it can be said that GHG emission factors can be an order of magnitude higher than current solar PV systems and up to two

  6. Survey of landfill gas generation potential

    International Nuclear Information System (INIS)

    Gauntlett, W.D.

    1992-09-01

    This project identifies all the landfill sites in each of the 50 states capable of producing 750,000 SCFD of mixed landfill gas for a period of at least 10 years. The study identified 749 landfill sites nationally, with an aggregate gas production rate sufficient to fuel approximately 6000 MW of fuel cell power plants

  7. Heat Recovery From Tail Gas Incineration To Generate Power

    Energy Technology Data Exchange (ETDEWEB)

    Tawfik, Tarek

    2010-09-15

    Many industrial processes result in tail gas wastes that must be flared or incinerated to abide with environmental guidelines. Tail gas incineration occurs in several chemical processes resulting in high-temperature exhaust gas that simply go to the stack, thus wasting all that valuable heat! This paper discusses useful heat recovery and electric power generation utilizing available heat in exhaust gas from tail gas incinerators. This heat will be recovered in a waste-heat recovery boiler that will produce superheated steam to expand in a steam turbine to generate power. A detailed cost estimate is presented.

  8. The potential for gas fired generation in Atlantic Canada

    International Nuclear Information System (INIS)

    MacDonald, T.

    2002-01-01

    The objective of this presentation was to stimulate discussion regarding the potential for Maritimes based gas fired power generation. It was noted that although the subject is complex, simplified assumptions are presented. The topics of discussion include the move to restructure the electric power industry in Nova Scotia and New Brunswick, the interest in gas fired generation in Atlantic Canada, the expected increase in natural gas consumption, and the issue of whether there is sufficient supply and adequate infrastructure to support demand. Other topics of discussion included the impact of regulations on the industry, and the future outlook of natural gas supply as it relates to power generation. The efforts of the natural gas industry to meet US natural gas generating requirements were also discussed. 3 tabs., 8 figs

  9. 46 CFR 154.908 - Inert gas generator: Location.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Inert gas generator: Location. 154.908 Section 154.908 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SAFETY... Atmospheric Control in Cargo Containment Systems § 154.908 Inert gas generator: Location. (a) Except as...

  10. NEXT GENERATION GAS TURBINE (NGGT) SYSTEMS STUDY

    Energy Technology Data Exchange (ETDEWEB)

    Unknown

    2001-12-05

    to how they could serve multiple applications, both in terms of incorporation of technology into current products, as well as to an NGGT product. In summary, potential program costs are shown for development of the candidate systems along with the importance of future DOE enabling participation. Three main conclusions have been established via this study: (1) Rapid recent changes within the power generation regulatory environment and the resulting ''bubble'' of gas turbine orders has altered the timing and relative significance associated with the conclusions of the ADL study upon which the original DOE NGGT solicitation was based. (2) Assuming that the relevant technologies were developed and available for an NGGT market opportunity circa 2010, the top candidate system that meets or exceeds the DOE PRDA requirements was determined to be a hybrid aero-derivative/heavy duty concept. (3) An investment by DOE of approximately $23MM/year to develop NGGT technologies near/mid term for validation and migration into a reasonable fraction of the installed base of GE F-class products could be leveraged into $1.2B Public Benefit, with greatest benefits resulting from RAM improvements. In addition to the monetary Public Benefit, there is also significant benefit in terms of reduced energy consumption, and reduced power plant land usage.

  11. Outlook for gas sales for electricity generation in the Northeast

    International Nuclear Information System (INIS)

    Linderman, C.W.

    1998-01-01

    Issues regarding future supply and demand of natural gas as opposed to coal in the electric power generation sector, generation performance standards of coal plants, new combined cycle applications, distributed generation, and the advantages of natural gas over coal are discussed. The electricity demand and supply situation in the Northeast, present and future, and the growing movement toward green power, green power certification programs, the need and demand for disclosure of emissions and fuel source of supply, price and other customer information were summarized. Nuclear power generation and the chances of it being replaced by natural gas-fuelled generation are assessed. Some pipeline siting issues and the need for careful coordination with the electric system to minimize new corridors, are also reviewed. The advantages of natural gas in terms of technology and reduced pollution, hence cleaner air, were cited as the reasons why natural gas has almost unlimited potential as the fuel of choice well into the 21. century

  12. Preparation of environmental analyses for synfuel and unconventional gas technologies

    Energy Technology Data Exchange (ETDEWEB)

    Reed, R.M. (ed.)

    1982-09-01

    Government agencies that offer financial incentives to stimulate the commercialization of synfuel and unconventional gas technologies usually require an analysis of environmental impacts resulting from proposed projects. This report reviews potentially significant environmental issues associated with a selection of these technologies and presents guidance for developing information and preparing analyses to address these issues. The technologies considered are western oil shale, tar sand, coal liquefaction and gasification, peat, unconventional gas (western tight gas sands, eastern Devonian gas shales, methane from coal seams, and methane from geopressured aquifers), and fuel ethanol. Potentially significant issues are discussed under the general categories of land use, air quality, water use, water quality, biota, solid waste disposal, socioeconomics, and health and safety. The guidance provided in this report can be applied to preparation and/or review of proposals, environmental reports, environmental assessments, environmental impact statements, and other types of environmental analyses. The amount of detail required for any issue discussed must, by necessity, be determined on a case-by-case basis.

  13. The greenhouse impact of unconventional gas for electricity generation

    Energy Technology Data Exchange (ETDEWEB)

    Hultman, Nathan; Ramig, Christopher [School of Public Policy, University of Maryland, 2101 Van Munching Hall, College Park, MD 20742 (United States); Rebois, Dylan [Department of Mechanical Engineering, University of Maryland, 2181 Glenn L Martin Hall, Building 088, College Park, MD 20742 (United States); Scholten, Michael [Joint Quantum Institute, University of Maryland, 2207 Computer and Space Sciences Building, College Park, MD 20742 (United States)

    2011-10-15

    New techniques to extract natural gas from unconventional resources have become economically competitive over the past several years, leading to a rapid and largely unanticipated expansion in natural gas production. The US Energy Information Administration projects that unconventional gas will supply nearly half of US gas production by 2035. In addition, by significantly expanding and diversifying the gas supply internationally, the exploitation of new unconventional gas resources has the potential to reshape energy policy at national and international levels-altering geopolitics and energy security, recasting the economics of energy technology investment decisions, and shifting trends in greenhouse gas (GHG) emissions. In anticipation of this expansion, one of the perceived core advantages of unconventional gas-its relatively moderate GHG impact compared to coal-has recently come under scrutiny. In this paper, we compare the GHG footprints of conventional natural gas, unconventional natural gas (i.e. shale gas that has been produced using the process of hydraulic fracturing, or 'fracking'), and coal in a transparent and consistent way, focusing primarily on the electricity generation sector. We show that for electricity generation the GHG impacts of shale gas are 11% higher than those of conventional gas, and only 56% that of coal for standard assumptions.

  14. Framing scenarios of electricity generation and gas use: EPRI report series on gas demands for power generation. Final report

    International Nuclear Information System (INIS)

    Thumb, S.; Glover, W.; Hughes, W.R.

    1996-07-01

    Results of three EPRI projects have been combined to analyze power industry consumption of gas and other generating fuels. The report's capstone is a scenario analysis of power industry generation and fuel consumption. The Utility Fuel Consumption Model (UFCM), developed for the project, predicts generating capacity and generation by region and fuel through 2015, based on load duration curves, generation dispatch, and expected capacity additions. Scenarios embody uncertain factors, such as electricity demand growth, fuel switching, coal-gas competition, the merit order of gas-coal dispatch, and retirement of nuclear units, that substantially affect gas consumption. Some factors, especially electricity demand have very large effects. The report includes a consistent database on NUG (non-utility generation) capacity and generation and assesses historical and prospective trends in NUG generation. The report shows that NUG capacity growth will soon decline substantially. The study assesses industry capability for price-induced fuel switching from gas to oil and coal, documenting conversions of coal units to dual coal-gas capability and determining that gas-to-oil switching remains a strong influence on fuel availability and gas prices, though regulation and taxation have increased trigger prices for switching. 61 tabs

  15. Separation of krypton from dissolver off-gas of a reprocessing plant using preparative gas chromatography

    International Nuclear Information System (INIS)

    Matoni, M.

    1984-02-01

    Kr-85 can be separated from the pre-purified purge air in the final processing step of the purification phase for dissolver off-gases of a reprocessing plant with the aid of preparative gas chromatography. Activated carbon adsorbers in combination with helium as carrier gas permits maximum gas mixture through-flow. A separation temperature of 30 0 C is considered optimal. An adsorbent volume of 40 dm 3 is necessary for processing the residual gas flow of 2.5 Nm 3 /h; the adsorbent is divided between 2 columns linked in series each of which are 2 m long with an internal diameter of 100 mm. The helium flow required is five times greater than the off-gas flow. The degree of purity for krypton is greater than 90% for a decontamination factor of greater than 1000. (orig./HP) [de

  16. The greenhouse impact of unconventional gas for electricity generation

    International Nuclear Information System (INIS)

    Hultman, Nathan; Ramig, Christopher; Rebois, Dylan; Scholten, Michael

    2011-01-01

    New techniques to extract natural gas from unconventional resources have become economically competitive over the past several years, leading to a rapid and largely unanticipated expansion in natural gas production. The US Energy Information Administration projects that unconventional gas will supply nearly half of US gas production by 2035. In addition, by significantly expanding and diversifying the gas supply internationally, the exploitation of new unconventional gas resources has the potential to reshape energy policy at national and international levels—altering geopolitics and energy security, recasting the economics of energy technology investment decisions, and shifting trends in greenhouse gas (GHG) emissions. In anticipation of this expansion, one of the perceived core advantages of unconventional gas—its relatively moderate GHG impact compared to coal—has recently come under scrutiny. In this paper, we compare the GHG footprints of conventional natural gas, unconventional natural gas (i.e. shale gas that has been produced using the process of hydraulic fracturing, or 'fracking'), and coal in a transparent and consistent way, focusing primarily on the electricity generation sector. We show that for electricity generation the GHG impacts of shale gas are 11% higher than those of conventional gas, and only 56% that of coal for standard assumptions.

  17. Natural gas as a public utilities' generator for market orientation

    International Nuclear Information System (INIS)

    Delnoij, J.

    1995-01-01

    The forthcoming free market for the energy sector in Europe is discussed. The author (retiring chairman of KVGN) advocates strengthening the collective market position of energy distribution companies and of the total gas sector, e.g. by continuing the combination of gas distribution and gas purchase and by increased tuning of research and market developments. Energy distribution companies have to strengthen the relation with their customers and set explicit quality objectives. The author also supported competition between the different forms of energy on the energy market and the strive of the gas sector to substitute polluting energy carriers, and electricity generated from these low-efficient energy carriers, by gas

  18. Gas-fired Power Generation in India: Challenges and opportunities

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-01

    India's fast growing economy needs to add 100,000 MW power generating capacity between 2002-2012. Given limitations to the use of coal in terms of environmental considerations, quality and supply constraints, gas is expected to play an increasingly important role in India's power sector. This report briefs NMC Delegates on the potential for gas-fired power generation in India and describes the challenges India faces to translate the potential for gas-fired power generation into reality.

  19. Lifecycle greenhouse gas emissions of coal, conventional and unconventional natural gas for electricity generation

    Science.gov (United States)

    An analysis of the lifecycle greenhouse gas (GHG) emissions associated with natural gas use recently published by Howarth et al. (2011) stated that use of natural gas produced from shale formations via hydraulic fracturing would generate greater lifecycle GHG emissions than petro...

  20. Preparing a highly degenerate Fermi gas in an optical lattice

    International Nuclear Information System (INIS)

    Williams, J. R.; Huckans, J. H.; Stites, R. W.; Hazlett, E. L.; O'Hara, K. M.

    2010-01-01

    We propose a method to prepare fermionic atoms in a three-dimensional optical lattice at unprecedentedly low temperatures and uniform filling factors. The process involves adiabatic loading of degenerate atoms into multiple energy bands of an optical lattice followed by a filtering stage whereby atoms from all but the lowest band are removed. Of critical importance is the use of a nonharmonic trapping potential to provide external confinement for the atoms. For realistic experimental parameters, this procedure will produce a Fermi gas in a lattice with a reduced temperature T/T F ∼0.003 and an entropy per particle of s∼0.02 k B .

  1. Process gas generator feeding internal combustion piston engines

    Energy Technology Data Exchange (ETDEWEB)

    Iwantscheff, G; Kostka, H; Henkel, H J

    1978-10-26

    The invention relates to a process gas generator feeding gaseous fuel to internal combustion piston engines. The cylinder linings of the internal combustion engine are enclosed by the catalytic reaction chamber of the process gas generator which contains perforated sintered nozzle bricks as carriers of the catalysts needed for the conversion. The reaction chamber is surrounded by the exhaust gas chamber around which a tube coil is ound which feeds the fuel charge to the reaction chamber after evaporation and mixing with exhaust gas and air. The fuel which may be used for this purpose, e.g., is low-octane gasoline or diesel fuel. In the reaction chamber the fuel is catalytically converted at temperatures above 200/sup 0/C, e.g., into low-molecular paraffins, carbon monoxide and hydrogen. Operation of the internal combustion engine with a process gas generator greatly reduces the pollutant content of the exhaust gases.

  2. Preparing the Next Generation of Educators for Democracy

    Science.gov (United States)

    Embry-Jenlink, Karen

    2018-01-01

    In the keynote address of the 42nd annual meeting of the Southeastern Regional Educators Association (SRATE), ATE President Karen Embry-Jenlink examines the critical role of teacher educators in preparing the next generation of citizens and leaders to sustain democracy. Drawing from historic and current events and personal experience,…

  3. Gas Generation from K East Basin Sludges - Series II Testing

    International Nuclear Information System (INIS)

    Bryan, Samuel A.; Delegard, Calvin H.; Schmidt, Andrew J.; Sell, Rachel L.; Silvers, Kurt L.; Gano, Susan R.; Thornton, Brenda M.

    2001-01-01

    This report describes work to examine the gas generation behavior of actual K East (KE) Basin floor, pit and canister sludge. Mixed and unmixed and fractionated KE canister sludge were tested, along with floor and pit sludges from areas in the KE Basin not previously sampled. The first report in this series focused on gas generation from KE floor and canister sludge collected using a consolidated sampling technique. The third report will present results of gas generation testing of irradiated uranium fuel fragments with and without sludge addition. The path forward for management of the K Basin Sludge is to retrieve, ship, and store the sludge at T Plant until final processing at some future date. Gas generation will impact the designs and costs of systems associated with retrieval, transportation and storage of sludge

  4. RAETRAD MODEL OF RADON GAS GENERATION, TRANSPORT, AND INDOOR ENTRY

    Science.gov (United States)

    The report describes the theoretical basis, implementation, and validation of the Radon Emanation and Transport into Dwellings (RAETRAD) model, a conceptual and mathematical approach for simulating radon (222Rn) gas generation and transport from soils and building foundations to ...

  5. Advanced On Board Inert Gas Generation System (OBBIGS), Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Valcor Engineering Corporation proposes to develop an advanced On Board Inert Gas Generation System, OBIGGS, for aircraft fuel tank inerting to prevent hazardous...

  6. Power generation from landfill gas workshop discussion of Session 1

    International Nuclear Information System (INIS)

    Loning, A.; Bevan, G.; Moss, H.

    1992-01-01

    The discussion following presentations on the UK Dept. of Energy's involvement with power generation form landfill gas and the UK Government's attitude to pollution prevention from landfill gas power production is presented. The discussion focusses particularly on the Non-Fossil Fuel Obligation. (UK)

  7. Gas generation and migration analysis for TRU waste disposal system

    International Nuclear Information System (INIS)

    Ando, Kenichi; Noda, Masaru; Yamamoto, Mikihiko; Mihara, Morihiro

    2005-09-01

    In TRU waste disposal system, significant quantities of gases may be generated due to metal corrosion, radiolysis effect and microorganism activities. It is therefore recommended that the potential impact of gas generation and migration on TRU waste repository should be evaluated. In this study, gas generation rates were calculated in the repository and gas migration analysis in the disposal system were carried out using two phase flow model with results of gas generation rates. First, the time dependencies of gas generation rate in each TRU waste repositories were evaluated based on amounts of metal, organic matter and radioactivity. Next, the accumulation pressure of gases and expelled pore water volume nuclides in the repository were calculated by TOUGH2 code. After that, the results showed that the increase of gas pressure was the range of 1.3 to 1.4 MPa. In the repository with and without buffer, the rate of expelled pore water was 0.006 - 0.009 m 3 /y and 0.018 - 0.24m 3 /y, respectively. In addition, the radioactive gas migration through the repository and geosphere are evaluated. And re-saturation analysis is also performed to evaluate the initial condition of the system. (author)

  8. Preparation of an sup(113m) indium generator

    International Nuclear Information System (INIS)

    Ling, H.W.

    1979-01-01

    This paper describes the features related to the preparation of sup(113m) In from a generator for nuclear medicine application. 113 Sn radioisotope is adsorbed on a hidrated zirconium oxide column and sup(113m) In generated from the decay of 113 Sn is eluted with diluted hydrochloric acid. This procedure is simple and appropriate for the separation of the desired radionuclide. Parameters which may affect the adsorption of 113 Sn like tin and hydrochloric acid concentration and temperature are studied. The influence of eluent concentration and temperature and flow rate of elution on sup(113m) In separation yields are observed. The purity of eluted sup(113m) In is analysed and variation of elution yield in a generator prepared with enriched tin is studied. (Author) [pt

  9. Gas Generation of Heated PBX 9502

    Energy Technology Data Exchange (ETDEWEB)

    Holmes, Matthew David [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Parker, Gary Robert [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-10-07

    Uniaxially pressed samples of PBX 9502 were heated until self-ignition (cookoff) in order to collect pressure and temperature data relevant for model development. Samples were sealed inside a small gas-tight vessel, but were mechanically unconfined. Long-duration static pressure rise, as well as dynamic pressure rise during the cookoff event, were recorded. Time-lapse photography of the sample was used to measure the thermal expansion of the sample as a function of time and temperature. High-speed videography qualitatively characterized the mechanical behavior and failure mechanisms at the time of cookoff. These results provide valuable input to modeling efforts, in order to improve the ability to predict pressure output during cookoff as well as the effect of pressure on time-toignition.

  10. Carbon nanotubes for gas detection: materials preparation and device assembly

    International Nuclear Information System (INIS)

    Terranova, M L; Lucci, M; Orlanducci, S; Tamburri, E; Sessa, V; Reale, A; Carlo, A Di

    2007-01-01

    An efficient sensing device for NH 3 and NO x detection has been realized using ordered arrays of single-walled C nanotubes deposited onto an interdigitated electrode platform operating at room temperature. The sensing material has been prepared using several chemical-physical techniques for purification and positioning of the nanotubes inside the electrode gaps. In particular, both DC and AC fields have been applied in order to move and to align the nanostructures by electrophoresis and dielectrophoresis processes. We investigated the effects of different voltages applied to a gate contact on the back side of the substrate on the performances of the device and found that for different gas species (NH 3 , NO x ) a constant gate bias increases the sensitivity for gas detection. Moreover, in this paper we demonstrate that a pulsed bias applied to the gate contact facilitates the gas interaction with the nanotubes, either reducing the absorption times or accelerating the desorption times, thus providing a fast acceleration and a dramatic improvement of the time dependent behaviour of the device

  11. Gas-Generator Augmented Expander Cycle Rocket Engine

    Science.gov (United States)

    Greene, William D. (Inventor)

    2011-01-01

    An augmented expander cycle rocket engine includes first and second turbopumps for respectively pumping fuel and oxidizer. A gas-generator receives a first portion of fuel output from the first turbopump and a first portion of oxidizer output from the second turbopump to ignite and discharge heated gas. A heat exchanger close-coupled to the gas-generator receives in a first conduit the discharged heated gas, and transfers heat to an adjacent second conduit carrying fuel exiting the cooling passages of a primary combustion chamber. Heat is transferred to the fuel passing through the cooling passages. The heated fuel enters the second conduit of the heat exchanger to absorb more heat from the first conduit, and then flows to drive a turbine of one or both of the turbopumps. The arrangement prevents the turbopumps exposure to combusted gas that could freeze in the turbomachinery and cause catastrophic failure upon attempted engine restart.

  12. Power-generation method using combined gas and steam turbines

    Energy Technology Data Exchange (ETDEWEB)

    Liu, C; Radtke, K; Keller, H J

    1997-03-20

    The invention concerns a method of power generation using a so-called COGAS (combined gas and steam) turbine installation, the aim being to improve the method with regard to the initial costs and energy consumption so that power can be generated as cheaply as possible. This is achieved by virtue of the fact that air taken from the surrounding atmosphere is splint into an essentially oxygen-containing stream and an essentially nitrogen-containing stream and the two streams fed further at approximately atmospheric pressure. The essentially nitrogen-containing stream is mixed with an air stream to form a mixed nitrogen/air stream and the mixed-gas stream thus produced is brought to combustion chamber pressure in the compressor of the gas turbine, the combustion of the combustion gases in the combustion chamber of the gas turbine being carried out with the greater part of this compressed mixed-gas stream. (author) figs.

  13. Chemical looping reforming of generator gas

    Energy Technology Data Exchange (ETDEWEB)

    Mendiara, T.; Jensen, Anker; Glarborg, P.

    2010-02-15

    The main objective of this work is to investigate the carbon deposition during reforming of hydrocarbons in a Chemical Looping Reformer (CLR). This knowledge is needed to asses the viability of the CLR technology in reforming tar from biomass gasification preserving lighter hydrocarbons and minimizing the carbon formation during the process. Two different setups were used to test the reactivity of the different samples in the conditions of interest for the tar reforming process: 1) Fixed bed flow reactor (FR), and 2) Thermogravimetric analyzer (TGA). In the experiments, the gas atmosphere was switched from reducing to oxidizing atmosphere in every cycle. During the oxidizing cycle, the carrier was regenerated using a mixture of oxygen and nitrogen. Four different oxygen carriers based on nickel (Ni40 and Ni60), manganese (Mn) and ilmenite (Fe) were tested. In the tests, toluene was used to simulate the tars. The Fe and the Mn carrier reacted to a small extent with methane at the highest temperature studied, 800 degrees C. The Ni-carriers did not react at 600 degrees C at first, but they showed some reactivity after having been activated at the higher temperature. Carbon formation occurred with the Ni-carriers, more so with the Ni60 than the Ni40. Ni40, Mn and Fe were activated at the higher temperature. However, Fe showed only low capacity. Ni60 showed no capability of tar reforming. Ni40 showed a high tendency to carbon formation at 800 degrees C, but the formation could be lowered by changing some parameters. Mn formed almost no carbon. Ni40 and Mn were chosen for further studies. Carbon deposition occurred for both Ni40 and Mn, but the amount deposited for Ni40 was about 10 times bigger. Ni40 reacted with the methane and toluene only at 800 degrees C. The conversion over Mn was not as big as for toluene alone. Carbon was formed from carbon monoxide on the Ni40 carrier and on the Mn, but to a much less extent on the latter one. The presence of hydrogen decreased

  14. Generator gas as a fuel to power a diesel engine

    Directory of Open Access Journals (Sweden)

    Tutak Wojciech

    2014-01-01

    Full Text Available The results of gasification process of dried sewage sludge and use of generator gas as a fuel for dual fuel turbocharged compression ignition engine are presented. The results of gasifying showed that during gasification of sewage sludge is possible to obtain generator gas of a calorific value in the range of 2.15  2.59 MJ/m3. It turned out that the generator gas can be effectively used as a fuel to the compression ignition engine. Because of gas composition, it was possible to run engine with partload conditions. In dual fuel operation the high value of indicated efficiency was achieved equal to 35%, so better than the efficiency of 30% attainable when being fed with 100% liquid fuel. The dual fuel engine version developed within the project can be recommended to be used in practice in a dried sewage sludge gasification plant as a dual fuel engine driving the electric generator loaded with the active electric power limited to 40 kW (which accounts for approx. 50% of its rated power, because it is at this power that the optimal conditions of operation of an engine dual fuel powered by liquid fuel and generator gas are achieved. An additional advantage is the utilization of waste generated in the wastewater treatment plant.

  15. Gas generation in incinerator ash; Gasbildning i aska

    Energy Technology Data Exchange (ETDEWEB)

    Arm, Maria; Lindeberg, Johanna; Rodin, Aasa; Oehrstroem, Anna; Backman, Rainer; Oehman, Marcus; Bostroem, Dan

    2006-02-15

    In recent years, explosions have occurred in certain phases of ash handling in Sweden. Investigations have revealed that hydrogen may have been present in all cases. The hydrogen is believed to be generated by chemical reactions of aluminium and other metals within the ash in the presence of water. The purpose with this study is to increase the knowledge of gas generation of incinerator ash. Thereby, guides for appropriate ash management can be introduced and the risk for further explosions prevented. The study has comprised analyses of the ash properties, such as chemical and physical composition and the pH, of ash from 14 incineration plants (mostly waste incineration plants). Different fractions of ash materials representing different parts of the process in each plant have been analysed. Furthermore, the fuel and the technical differences between the plants have been analysed. A tool for measuring the gas generation in the laboratory has been developed and the gas generation of the different ash materials at natural and increased pH was measured. Gas analyses and thermodynamic calculations have also been performed. The results showed that: bottom ash from fluidised bed boilers generated small amounts of gas at increased pH, much smaller amounts than the idle pass, cyclone and filter ash did, bottom ash from grate fired boilers generated more gas at increased pH than their cyclone ash and filter ash, with exception of the Linkoeping plant, all bio waste incineration plants generated ash with low gas generation potential, all fly ash materials with a gas generation potential of more than 10 l/kg originated from municipal waste incineration plants, filter ash that had been stored in oxygen rich environment generated significant less gas than fresh filter ash of the same origin, hardly any other gases were generated apart from hydrogen (very small amounts of acetone, furane, benzene and most likely methane were detected in some of the ash materials), there were no

  16. Reactive intermediates in the gas phase generation and monitoring

    CERN Document Server

    Setser, D W

    2013-01-01

    Reactive Intermediates in the Gas Phase: Generation and Monitoring covers methods for reactive intermediates in the gas phase. The book discusses the generation and measurement of atom and radical concentrations in flow systems; the high temperature flow tubes, generation and measurement of refractory species; and the electronically excited long-lived states of atoms and diatomic molecules in flow systems. The text also describes the production and detection of reactive species with lasers in static systems; the production of small positive ions in a mass spectrometer; and the discharge-excite

  17. Preparation of a generator of technetium-99m

    International Nuclear Information System (INIS)

    Jimeno de Osso, F.

    1981-01-01

    Practical description is given of equipment and operations necessary in the preparation of an isotopic generator of technetium-99m. The preparation and application of the active solution and throughly washed of the chromatographic column have been studied in order to allow molibdenum-99 to be adsorbed on a small band, and the solution of tectium-99m to be eluted with high efficiency and purity. The equipment and accesories used are easy and safety to manage, simplifying operations to be carried out with the active product, eliminating the sterile environment in the shielded cell, and facilitating the preparation of the solution of technetium-99m in sterile and pyrogen-free conditions.(author) [es

  18. High pressure gas driven liquid metal MHD homopolar generator

    International Nuclear Information System (INIS)

    Itoh, Yasuyuki

    1988-01-01

    A liquid metal MHD homopolar generator is proposed to be used as a high repetition rate pulsed power supply. In the generator, the thermal energy stored in a high pressure gas (He) reservoir is rapidly converted into kinetic energy of a rotating liquid metal (NaK) cylinder which is contracted by a gas driven annular free piston. The rotational kinetic energy is converted into electrical energy by making use of the homopolar generator principle. The conversion efficiency is calculated to be 47% in generating electrical energy of 20 kJ/pulse (1.7 MW peak power) at a repetition rate of 7 Hz. From the viewpoint of energy storage, the high pressure gas reservoir with a charging pressure of 15 MPa is considered to ''electrically'' store the energy at a density of 10 MJ/m 3 . (author)

  19. Radiolytic gas generation in plutonium contaminated waste materials

    International Nuclear Information System (INIS)

    Kazanjian, A.R.

    1976-01-01

    Many plutonium contaminated waste materials decompose into gaseous products because of exposure to alpha radiation. The gases generated (usually hydrogen) over long-storage periods may create hazardous conditions. To determine the extent of such hazards, knowing the gas generation yields is necessary. These yields were measured by contacting some common Rocky Flats Plant waste materials with plutonium and monitoring the enclosed atmospheres for extensive periods of time. The materials were Plexiglas, polyvinyl chloride, glove-box gloves, machining oil, carbon tetrachloride, chlorothene VG solvent, Kimwipes (dry and wet), polyethylene, Dowex-1 resin, and surgeon's gloves. Both 239 Pu oxide and 238 Pu oxide were used as radiation sources. The gas analyses were made by mass spectrometry and the results obtained were the total gas generation, the hydrogen generation, the oxygen consumption rate, and the gas composition over the entire storage period. Hydrogen was the major gas produced in most of the materials. The total gas yields varied from 0.71 to 16 cm 3 (standard temperature pressure) per day per curie of plutonium. The oxygen consumption rates varied from 0.0088 to 0.070 millimoles per day per gram of plutonium oxide-239 and from 0.0014 to 0.0051 millimoles per day per milligram 238 Pu

  20. Preparation of alveolate hydrophobic catalyst for tritium waste gas treatment

    International Nuclear Information System (INIS)

    Yang, Yong; Peng, Shuming; Wang, Heyi; Du, Yang; Li, Jiamao

    2016-01-01

    Highlights: • The catalyst is hydrophobic, it will not be poisoned by steam in room air at room temperature which is better than Pt-Al 2 O 3 . • At room temperature, the conversion of low concentration of H2 and tritium gas in room air over the catalyst is high. • The air resistance of catalyst is much lower than graininess Pt-Al 2 O 3 . • It is inorganic and will not burn. - Abstract: To prepare a catalyst for the detritiation of waste gases at high flow rates, a heat-resistant hydrophobic zeolitic molecular sieve coating was synthesized on the surface of alveolate cordierite by hydrothermal processing. The alveolate hydrophobic catalyst prepared from the support was essentially waterproof and not easily poisoned by moisture. At room temperature, the conversion of low concentrations of H 2 in humid air over the catalyst was higher than 95% at different space velocities (0–16,000 h −1 ) and different relative humidities. The reaction rate constant of the oxidation of tritium over alveolate hydrophobic catalyst is 0.182 s −1 at 293.3 K–293.7 K and 59%–60% RH, it is much higher than the catalyst of reference honeycomb catalyst.

  1. Preparation of next generation set of group cross sections. 3

    International Nuclear Information System (INIS)

    Kaneko, Kunio

    2002-03-01

    This fiscal year, based on the examination result about the evaluation energy range of heavy element unresolved resonance cross sections, the upper energy limit of the energy range, where ultra-fine group cross sections are produced, was raised to 50 keV, and an improvement of the group cross section processing system was promoted. At the same time, reflecting the result of studies carried out till now, a function producing delayed neutron data was added to the general-purpose group cross section processing system , thus the preparation of general purpose group cross section processing system has been completed. On the other hand, the energy structure, data constitution and data contents of next generation group cross section set were determined, and the specification of a 151 groups next generation group cross section set was defined. Based on the above specification, a concrete library format of the next generation cross section set has been determined. After having carried out the above-described work, using the general-purpose group cross section processing system , which was complete in this study, with use of the JENDL-3. 2 evaluated nuclear data, the 151 groups next generation group cross section of 92 nuclides and the ultra fine group resonance cross section library for 29 nuclides have been prepared. Utilizing the 151 groups next generation group cross section set and the ultra-fine group resonance cross-section library, a bench mark test calculation of fast reactors has been performed by using an advanced lattice calculation code. It was confirmed, by comparing the calculation result with a calculation result of continuous energy Monte Carlo code, that the 151 groups next generation cross section set has sufficient accuracy. (author)

  2. Gas generation matrix depletion quality assurance project plan

    International Nuclear Information System (INIS)

    1998-01-01

    The Los Alamos National Laboratory (LANL) is to provide the necessary expertise, experience, equipment and instrumentation, and management structure to: Conduct the matrix depletion experiments using simulated waste for quantifying matrix depletion effects; and Conduct experiments on 60 cylinders containing simulated TRU waste to determine the effects of matrix depletion on gas generation for transportation. All work for the Gas Generation Matrix Depletion (GGMD) experiment is performed according to the quality objectives established in the test plan and under this Quality Assurance Project Plan (QAPjP)

  3. Gas generation from low-level radioactive waste: Concerns for disposal

    International Nuclear Information System (INIS)

    Siskind, B.

    1992-01-01

    The Advisory Committee on Nuclear Waste (ACNW) has urged the Nuclear Regulatory Commission (NRC) to reexamine the topic of hydrogen gas generation from low-level radioactive waste (LLW) in closed spaces to ensure that the slow buildup of hydrogen from water-bearing wastes in sealed containers does not become a problem for long-term safe disposal. Brookhaven National Laboratory (BNL) has prepared a report, summarized in this paper, for the NRC to respond to these concerns. The paper discusses the range of values for G(H 2 ) reported for materials of relevance to LLW disposal; most of these values are in the range of 0.1 to 0.6. Most studies of radiolytic hydrogen generation indicate a leveling off of pressurization, probably because of chemical kinetics involving, in many cases, the radiolysis of water within the waste. Even if no leveling off occurs, realistic gas leakage rates (indicating poor closure by gaskets on drums and liners) will result in adequate relief of pressure for radiolytic gas generation from the majority of commercial sector LLW packages. Biodegradative gas generation, however, could pose a pressurization hazard even at realistic gas leakage rates. Recommendations include passive vents on LLW containers (as already specified for high integrity containers) and upper limits to the G values and/or the specific activity of the LLW

  4. Utilization of hydrogen gas production for electricity generation in ...

    African Journals Online (AJOL)

    Utilization of hydrogen gas production for electricity generation in fuel cell by Enterobacter aerogenes ADH 43 with many kinds of carbon sources in batch stirred tank reactor. MA Rachman, LD Eniya, Y Liasari, MM Nasef, A Ahmad, H Saidi ...

  5. Gas Generation from K East Basin Sludges - Series I Testing

    International Nuclear Information System (INIS)

    Delegard, Calvin H.; Bryan, Samuel A.; Schmidt, Andrew J.; Bredt, Paul R.; King, Christopher M.; Sell, Rachel L.; Burger, Leland L.; Silvers, Kurt L.

    2000-01-01

    This report describes work to examine the gas generation behavior of actual K East (KE) Basin floor and canister sludge. The path forward for management of the K Basin Sludge is to retrieve, ship, and store the sludge at T Plant until final processing at some future date. Gas generation will impact the designs and costs of systems associated with retrieval, transportation and storage of sludge. The overall goals for this testing were to collect detailed gas generation rate and composition data to ascertain the quantity and reactivity of the metallic uranium (and other reactive species) present in the K Basin sludge. The gas generation evaluation included four large-scale vessels (850 ml) and eight small-scale vessels (30 ml) in an all-metal, leak tight system. The tests were conducted for several thousand hours at ambient and elevated temperatures (32 C, 40 C, 60 C, 80 C, and 95 C) to accelerated the reactions and provide conclusive gas generation data within a reasonable testing period. The sludge used for these tests was collected from the KE Basin floor and canister barrels (containing damaged spent fuel elements) using a consolidated sampling technique (i.e., material from several locations was combined to form ''consolidated samples''). Portions of these samples were sieved to separate particles greater than 250 m (P250) from particle less than 250 m (M250). This separation was performed to mimic the separation operations that are planned during the retrieval of certain K Basin sludge types and to gain a better understanding of how uranium metal is distributed in the sludge. The corrosion rate of the uranium metal particles in the sludge was found to agree reasonably well with corrosion rates reported in the literature

  6. Modelling of gas generation in deep geological repositories after closure

    International Nuclear Information System (INIS)

    Poller, A.; Mayer, G.; Darcis M; Smith, P.

    2016-12-01

    In deep geological repositories for radioactive waste, significant quantities of gases will be generated in the long term as a result of various processes, notably the anaerobic corrosion of metals and the degradation of organic materials. Therefore, the impact of gas production on post-closure safety of the repositories needs to be assessed as part of a safety case. The present report provides a comprehensive description of the quantitative modelling of gas generation and associated water consumption during the post-closure phase of deep geological repositories in Opalinus Clay based on current scientific knowledge and on current preliminary repository designs. This includes a presentation of the modelling basis, namely the conceptual and mathematical models, the input data used, the computer tools developed, the relevant uncertainties and principal programme / design options, as well as the derivation, analysis and discussion of specific assessment cases. The modelling is carried out separately for the two main sources of gas, which are the emplaced waste including the disposal containers; and the construction materials. The contribution of construction materials to gas generation rates in emplacement tunnels for spent fuel (SF) and vitrified high-level waste (HLW) is significant during several thousand years after closure. In the long term, however, the corrosion of the disposal canisters, which are in the reference case assumed to be fabricated of carbon steel, accounts for the vast majority of the total gas produced in these tunnels. The contribution of construction materials in emplacement caverns for long lived intermediate-level waste (ILW) and low- and intermediate-level waste (L/ILW) to gas generation is generally small. In ILW emplacement caverns, gas generation is generally dominated by hydrogen generation from the corrosion of cast iron Mosaik-II waste containers for PWR internals and from the corrosion of aluminium in operational waste from the

  7. Modelling of gas generation in deep geological repositories after closure

    Energy Technology Data Exchange (ETDEWEB)

    Poller, A. [National Cooperative for the Disposal of Radioactive Waste (NAGRA), Wettingen (Switzerland); Mayer, G.; Darcis M [AF-Consult Switzerland Ltd, Baden-Dättwil, (Switzerland); Smith, P. [Safety Assessment Management Ltd, Henley-On-Thames, Oxfordshire (United Kingdom)

    2016-12-15

    In deep geological repositories for radioactive waste, significant quantities of gases will be generated in the long term as a result of various processes, notably the anaerobic corrosion of metals and the degradation of organic materials. Therefore, the impact of gas production on post-closure safety of the repositories needs to be assessed as part of a safety case. The present report provides a comprehensive description of the quantitative modelling of gas generation and associated water consumption during the post-closure phase of deep geological repositories in Opalinus Clay based on current scientific knowledge and on current preliminary repository designs. This includes a presentation of the modelling basis, namely the conceptual and mathematical models, the input data used, the computer tools developed, the relevant uncertainties and principal programme / design options, as well as the derivation, analysis and discussion of specific assessment cases. The modelling is carried out separately for the two main sources of gas, which are the emplaced waste including the disposal containers; and the construction materials. The contribution of construction materials to gas generation rates in emplacement tunnels for spent fuel (SF) and vitrified high-level waste (HLW) is significant during several thousand years after closure. In the long term, however, the corrosion of the disposal canisters, which are in the reference case assumed to be fabricated of carbon steel, accounts for the vast majority of the total gas produced in these tunnels. The contribution of construction materials in emplacement caverns for long lived intermediate-level waste (ILW) and low- and intermediate-level waste (L/ILW) to gas generation is generally small. In ILW emplacement caverns, gas generation is generally dominated by hydrogen generation from the corrosion of cast iron Mosaik-II waste containers for PWR internals and from the corrosion of aluminium in operational waste from the

  8. Microporous Organic Polymers Based on Hyper-Crosslinked Coal Tar: Preparation and Application for Gas Adsorption.

    Science.gov (United States)

    Gao, Hui; Ding, Lei; Bai, Hua; Li, Lei

    2017-02-08

    Hyper-crosslinked polymers (HCPs) are promising materials for gas capture and storage, but high cost and complicated preparation limit their practical application. In this paper, a new type of HCPs (CTHPs) was synthesized through a one-step mild Friedel-Crafts reaction with low-cost coal tar as the starting material. Chloroform was utilized as both solvent and crosslinker to generate a three-dimensional crosslinked network with abundant micropores. The maximum BET surface area of the prepared CTHPs could reach up to 929 m 2  g -1 . Owing to the high affinity between the heteroatoms on the coal-tar building blocks and the CO 2 molecules, the adsorption capacity of CTHPs towards CO 2 reached up to 14.2 wt % (1.0 bar, 273 K) with a high selectivity (CO 2 /N 2 =32.3). Furthermore, the obtained CTHPs could adsorb 1.27 wt % H 2 at 1.0 bar and 77.3 K, and also showed capacity for the capture of high organic vapors at room temperature. In comparison with other reported porous organic polymers, CTHPs have the advantages of low-cost, easy preparation, and high gas-adsorption performance, making them suitable for mass production and practical use in the future. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Natural gas and electricity generation in New South Wales

    International Nuclear Information System (INIS)

    Webb, G.

    2001-01-01

    In its Profile of the Australian Electricity Industry, ABARE noted that NSW was the first State in Australia to unbundle the operations of its State owned electricity industry. The process commenced in 1991, when the Electricity Commission of NSW was renamed Pacific Power and reorganised into six generation and transmission sectors. The power generation fuel mix for NSW in 1999-2000 was as follows: black coal, 97 percent and natural gas, 3 percent. NSW has also imported some brown coal generated electricity from Victoria in recent years. The import of cheap brown coal power from this State due to a marked increase in the availability of brown coal base-load generators in the Latrobe Valley forced some surplus black coal generating capacity in NSW to be withdrawn from the marketplace. Four generating units were closed down in 1998 two 500 MW units at Liddell and two 300 MW units at Munmorah. Further prospects for natural gas are reported to be good; its share in the thermal electricity generation market is forecasted to rise from 3 percent in 1999-2000 to 12 percent in 2014-1015

  10. Agricultural residues as fuel for producer gas generation

    Energy Technology Data Exchange (ETDEWEB)

    Hoeglund, C

    1981-01-01

    This paper reports on results from a series of tests with four different types of agricultural residues as fuel for producer gas generation. The fuels are coconut shells, coconut husks, pelletized wheat-straw and pressed sugar cane. The tests were made with a 73 Hp (50 kW) agricultural tractor diesel engine equipped with a standard gasifier developed for wood chips in Sweden, and run on a testbed at the Swedish National Machinery Testing Institute. The engine was operated on approximately 10% diesel oil and 90% producer gas. The gas composition, its calorific value and temperature, the pressure drop and the engine power were monitored. Detailed elementary analysis of the fuel and gas were carried out. Observations were also made regarding the important aspects of bridging and slagging in the gasifier. The tests confirmed that coconut shells make an excellent fuel for producer gas generation. After 8 hours of running no problems with slags and bridging were experienced. Coconut husks showed no bridging but some slag formation. The gasifier operated satisfactorily for this fuel. Pelletized wheat straw and pressed sugar cane appeared unsuitable as fuel in the unmodified test gasifier (Type F 300) due to slag formation. It is important to note, however, that the present test results are not optimal for any of the fuels used, the gasifier being designed for wood-chips and not for the test-fuels used. Tests using approximately modified gasifiers are planned for the future.

  11. Process for water-gas generation from degassed combustibles

    Energy Technology Data Exchange (ETDEWEB)

    1906-05-23

    A process for water-gas generation in a continuous operation from degassed combustibles in the lower part of a vertical exterior-heated retort, whose middle part can serve to degas the combustibles, is described. It is characterized in that the water vapor employed is obtained by vaporizing water in the upper part of the retort by means of the waste heat from the heating gases, which had effected the coking of the combustibles before the water-gas recovery or after the latter.

  12. Investigation of Productivity of Brown’s (HHO Gas Generator

    Directory of Open Access Journals (Sweden)

    Andrius Brazdžiūnas

    2017-01-01

    Full Text Available There were made tests of productivity of Brown’s gas generator using different potassium hydroxide (KOH concentration changing voltage and amperage. It is described experimental stand that is used to do researches and methodology of experiments performance. Brown’s gas production in electrolyser (electrolyser – the device that is going electrolysis to use stainless steel (AISI 316 electrodes. It was determined after researches that increasing the potassium hydroxide (KOH concentration in the solution and using the same amperage and voltage of the all concentration results are similar. The highest productivity 1.429 l/min was obtained by using a 120 A amperage and 15 V voltage.

  13. Use of gas for new generating capacity - The customer's view

    International Nuclear Information System (INIS)

    Linderman, C.W.

    1992-01-01

    This paper reviews the future gas demand for electric power generation in the US. It shows substantial growth along the eastern seaboard which will require pipeline capacity additions in order to serve the load. Many of the existing gas-fired plants fuel will switch to a commodity which will probably not comply with many of the new emissions requirements and that the alternate fuel for new units will be distillate oil. The demand for gas appears to be at the upper end of some of the gas supply scenarios. In serving the industry, there are a number of considerations that the gas transportation sector of the gas industry must identify. Pipelines will be dealing with a new group of organizations which they may or may not be familiar. Some of the real time operational differences that are seen at this point, especially dealing with load response and reliability, are crucial to a successful interface. This paper concludes that the previous levels of interaction must be replaced by a greater level of coordination than both industries have had previously

  14. Generation of synthesis gas by partial oxidation of natural gas in a gas turbine

    NARCIS (Netherlands)

    Cornelissen, R.; Tober, E.; Kok, Jacobus B.W.; van der Meer, Theodorus H.

    2006-01-01

    The application of partial oxidation in a gas turbine (PO-GT) in the production of synthesis gas for methanol production is explored. In PO-GT, methane is compressed, preheated, partial oxidized and expanded. For the methanol synthesis a 12% gain in thermal efficiency has been calculated for the

  15. Continuous organic waste digester and methane gas generator

    Energy Technology Data Exchange (ETDEWEB)

    Araneta, V.A.

    1979-01-01

    A patent on the construction of a utility model of an industrial product of a continuous organic-waste digester and methane-gas generator is described. It comprises an airtight chamber to receive slurry of organic waste; a gas-water scrubber to purge carbon dioxide, odor-omitting gases and froth or scrum from newly formed methane gas evolving from said slurry of organic wastes; and two dually functioning slurry-feed and -discharge pipes connected to a reversible pump. It has one pipe with an opening at the base of an airtight chamber and the other pipe with up-ended openings below the fluid level of the slurry to be accumulated in the airtight chamber.

  16. Power import or domestic power generation using gas?

    International Nuclear Information System (INIS)

    Saettler, M.; Bohnenschaefer, W.; Schlesinger, M.

    2001-01-01

    This report for the Swiss Federal Office of Energy (SFOE) presents expert opinion on the question of how Switzerland could meet its demands for power in the future. The results of the analysis of two options - the import of electrical power or its generation using natural-gas-fired power stations - made in the light of gas market liberalisation are presented. These include the assessment of the use of 'GuD' (combined gas and steam-turbine) power stations in the 100 MW e l to 400 MW e l class regarding their cost, their emissions and primary energy consumption. The authors discuss the assessments from the political and economic points of view. An appendix supplies characteristic data for 'GuD' power stations and an example of a model calculation for a 400 MW e l 'GuD' power station

  17. Physicists and Economic Growth: Preparing the Next Generation

    Science.gov (United States)

    Arion, Douglas

    2012-02-01

    For many years it has been recognized that many physicists are ``hidden'' -- deep in the industrial world or holding positions not named ``physicist.'' In parallel with this phenomenon is the recognition that many new and innovative product ideas are, in fact, generated by physicists. There are many more ideas that could be brought to market to the benefit of both society and the inventor, but physicists don't often see themselves as the innovators and inventors that they actually are. A number of education programs have arisen to try to address this issue and to engender a greater entrepreneurial spirit in the scientific community. The ScienceWorks program at Carthage College was one of the first to do so, and has for nearly twenty years prepared undergraduate science majors to understand and practice innovation and value creation. Other programs, such as professional masters degrees, also serve to bridge the technical and business universes. As it is no doubt easier to teach a scientist the world of business than it is to teach a businessperson the world of physics, providing educational experiences in innovation and commercialization to physics students can have tremendous economic impact, and will also better prepare them for whatever career direction they may ultimately pursue, even if it is the traditional tenure-track university position. This talk will discuss education programs that have been effective at preparing physics students for the professional work environment, and some of the positive outcomes that have resulted. Also discussed will be the variety of opportunities and resources that exist for faculty and students to develop the skills, knowledge and abilities to recognize and successfully commercialize innovations.

  18. Competition between coal and gas for large scale power generation

    International Nuclear Information System (INIS)

    Howieson, B.

    1997-01-01

    The relative competitiveness of coal- and gas-fired generation will be affected by distinctive country and market factors as well as site specific considerations, regarding such factors as environment, market structure and economics (such as fuel and plant costs). National and international politics have an impact on all three factors and any decision on the development of generation plant must take into account both current and future political climates. An analysis suggests that, at the present time, upgrading existing coal stations is attractive compared with new combined cycle gas turbines (CCGTs). However, this conclusion is highly dependent on the site specific nature of existing plant and the anticipated future environmental regime. Increased environmental pressure, particularly in the area of CO 2 emissions, would result in CCGTs being the first choice plant option. (R.P.)

  19. Natural gas power generation in Brazil: New window of opportunity?

    International Nuclear Information System (INIS)

    Gorini de Oliveira, Ricardo; Moraes Marreco, Juliana de

    2006-01-01

    This survey analyses the need as well as the attractiveness of private investment in natural gas thermal power generation under the Brazilian new power sector reform. Providing a scenario analysis from 2004 to 2014, this paper focuses on the investor perspective, and concludes that investments in natural gas thermal power plants in Brazil are not feasible, without financial subsidies stimulating investors. The more wary of risk both government and society are, and the more averse to risk the investor is, the higher the probability of higher capacity payment to provide incentives to investors. The alternative would be a lower capacity payment combined with higher thermal power tariffs; meaning that generators would receive much more payment when operating, despite assuming higher risks. Additionally, the improvement in safety supply cost is estimated and a sensibility analysis on the actual variables is performed

  20. Electricity generation from landfill gas: a commercial view revisited

    International Nuclear Information System (INIS)

    Limbrick, A.J.

    1992-01-01

    Wapsey's Wood power station has been generating electricity from landfill gas since 1987. Despite a good technical track record, the project did not secure a fair price for the electricity it sold until it was included in the 1991 Non-Fossil Fuel Obligation (NFFO). The NFFO has served to bring forward approximately 560 MW of renewable energy generating capacity, of which 15 per cent is fuelled by landfill gas. However, case histories such as that of Wapsey's Wood highlight the weaknesses of the current arrangements. To secure the continued steady growth of commercially robust renewable energy projects, there is a need to boost the business confidence of potential developers. The paper proposes two ways to remove the present uncertainty: simplify the application procedures, and remove the December 1998 expiry date that currently applies to power purchase agreements under the NFFO. (author)

  1. Greenhouse gas emissions from shale gas and coal for electricity generation in South Africa

    Directory of Open Access Journals (Sweden)

    Brett Cohen

    2014-03-01

    Full Text Available There is increased interest, both in South Africa and globally, in the use of shale gas for electricity and energy supply. The exploitation of shale gas is, however, not without controversy, because of the reported environmental impacts associated with its extraction. The focus of this article is on the greenhouse gas footprint of shale gas, which some literature suggests may be higher than what would have been expected as a consequence of the contribution of fugitive emissions during extraction, processing and transport. Based on some studies, it has been suggested that life-cycle emissions may be higher than those from coal-fired power. Here we review a number of studies and analyse the data to provide a view of the likely greenhouse gas emissions from producing electricity from shale gas, and compare these emissions to those of coal-fired power in South Africa. Consideration was given to critical assumptions that determine the relative performance of the two sources of feedstock for generating electricity � that is the global warming potential of methane and the extent of fugitive emissions. The present analysis suggests that a 100-year time horizon is appropriate in analysis related to climate change, over which period the relative contribution is lower than for shorter periods. The purpose is to limit temperature increase in the long term and the choice of metric should be appropriate. The analysis indicates that, regardless of the assumptions about fugitive emissions and the period over which global warming potential is assessed, shale gas has lower greenhouse gas emissions per MWh of electricity generated than coal. Depending on various factors, electricity from shale gas would have a specific emissions intensity between 0.3 tCO2/MWh and 0.6 tCO2/MWh, compared with about 1 tCO2/MWh for coal-fired electricity in South Africa.

  2. Gas jet structure influence on high harmonic generation

    OpenAIRE

    Grant-Jacob, James; Mills, Benjamin; Butcher, Thomas J.; Chapman, Richard T.; Brocklesby, William S.; Frey, Jeremy G.

    2011-01-01

    Gas jets used as sources for high harmonic generation (HHG) have a complex three-dimensional density and velocity profile. This paper describes how the profile influences the generation of extreme-UV light. As the position of the laser focus is varied along the jet flow axis, we show that the intensity of the output radiation varies by approximately three times, with the highest flux being observed when the laser is focused into the Mach disc. The work demonstrated here will aid in the optimi...

  3. Automation of steam generator services at public service electric & gas

    Energy Technology Data Exchange (ETDEWEB)

    Cruickshank, H.; Wray, J.; Scull, D. [Public Service Electric & Gas, Hancock`s Bridge, NJ (United States)

    1995-03-01

    Public Service Electric & Gas takes an aggressive approach to pursuing new exposure reduction techniques. Evaluation of historic outage exposure shows that over the last eight refueling outages, primary steam generator work has averaged sixty-six (66) person-rem, or, approximately tewenty-five percent (25%) of the general outage exposure at Salem Station. This maintenance evolution represents the largest percentage of exposure for any single activity. Because of this, primary steam generator work represents an excellent opportunity for the development of significant exposure reduction techniques. A study of primary steam generator maintenance activities demonstrated that seventy-five percent (75%) of radiation exposure was due to work activities of the primary steam generator platform, and that development of automated methods for performing these activities was worth pursuing. Existing robotics systems were examined and it was found that a new approach would have to be developed. This resulted in a joint research and development project between Westinghouse and Public Service Electric & Gas to develop an automated system of accomplishing the Health Physics functions on the primary steam generator platform. R.O.M.M.R.S. (Remotely Operated Managed Maintenance Robotics System) was the result of this venture.

  4. Electricity generation with natural gas or with uranium?

    International Nuclear Information System (INIS)

    Villanueva M, C.

    2009-10-01

    The program of works and investments of electric sector that actualize each year the Federal Commission of Electricity, include to the projects of electric power generating stations that will begin its commercial operation inside the horizon of the next ten years, in order to satisfy opportunely with appropriate reservation margins the demand of power and energy in the national interconnected system that grows year to year. In spite of its inherent advantages, in the electric sector prospective 2008-2017 are not considered explicitly to the nuclear power plants, except for the small amplification of capacity of nuclear power plant of Laguna Verde, that already is executing. In this context, the objective of this work is to present and to discuss arguments to favor and against the combined cycle and nuclear technologies, to indicate the risks and disadvantages in that it incurs the electric sector when leaning on so disproportionately on the fossil fuels for the electricity generation, in particular the natural gas, deferring to an indefinite future the installation of nuclear plants whose proven technology is economic, sure, clean and reliable and it contributes decisively to the national energy security. To mitigate the harmful effects of excessive dependence on natural gas to generate electric power, was propose alternatives to the expansion program of electric sector to year 2017, which would have as benefits the decrease of the annual total cost of electric power supply for public service, the significant reduction of natural gas imports and emissions reduction of CO 2 to the atmosphere. (Author)

  5. FEBEX. Investigations on gas generation, release and migration

    International Nuclear Information System (INIS)

    Jockwer, Norbert; Wieczorek, Klaus

    2008-06-01

    The FEBEX project is based on the Spanish reference concept for the disposal of radioactive waste in crystalline rock, which considers the emplacement of the canisters enclosing the conditioned waste surrounded by clay barriers constructed of high-compacted bentonite blocks in horizontal drifts /ENR 957. The whole project consisted of an experimental and a modelling part. The experimental part itself was divided into the in-situ test, a mock-up test performed at the CIEMAT laboratory, and various small-scale laboratory tests. In the modelling part it was expected to develop and validate the thermo-hydro-mechanical (THM) and the thermo-hydro-chemical (THC) processes for the performance assessment of the near-field behaviour. GRS was only involved in the in-situ test and some additional laboratory work with regard to gas generation, gas migration, and pore pressure build-up in the buffer constructed of high-compacted bentonite blocks around the electrical heaters simulating the waste containers. The following topics are covered: installation and dismantling of the heater pipes; methods of gas generation and release measurement, summary of results and discussion

  6. Generation and characterization of gas bubbles in liquid metals

    International Nuclear Information System (INIS)

    Eckert, S.; Gerbeth, G.; Witke, W.

    1996-01-01

    There is an ongoing research performed in the RCR on local transport phenomena in turbulent liquid metal (LM) duct flows exposed to external magnetic fields. In this context so-called MHD flow phenomena can be observed, which are unknown in usual hydraulic engineering. The field of interest covers also the influence of magnetic fields on the behaviour of liquid metal - gas mixtures. Profound knowledge on these LMMHD two-phase flow plays an important role in a variety of technological applications, in particular, in the design of Liquid-Metal MHD generators or for several metallurgical processes employing gas-stirred reactors. However, the highly empirical nature of two-phase flow analysis gives little hope for the prediction of MHD two-phase flows without extensive experimental data. A summary is given about the authors research activities focussing on two directions: (a) Momentum transfer between gas and liquid metal in a bubbly flow regime to investigate the influence of the external magnetic field on the velocity slip ration S (b) Peculiarities of the MHD turbulence to use small gas bubbles as local tracers in order to study the turbulent mass transfer

  7. The natural gas industry getting prepared for the competitive market

    International Nuclear Information System (INIS)

    Karbenn, F.; Schenk, S.

    1999-01-01

    The European Internal Market for natural gas is drawing near, and although the European Directive passed on 11 May 1998 provides for step-wise deregulation, it is expected that in Germany the phase of transition for the gas industry will be as comparatively short as it was for the electric power industry. The contribution here is intended to outline the expected consequences for the gas industry in EC member states and particularly in Germany, and to indicate strategies for managing upcoming risks. The instruments discussed in the article will gain in importance with increasing liberalisation of the markets. (orig./CB) [de

  8. Gas dynamic virtual nozzle for generation of microscopic droplet streams

    Energy Technology Data Exchange (ETDEWEB)

    DePonte, D P; Weierstall, U; Schmidt, K; Warner, J; Starodub, D; Spence, J C H; Doak, R B [Department of Physics, Arizona State University, Tempe, AZ 85287-1504 (United States)], E-mail: dandeponte@gmail.com

    2008-10-07

    As shown by Ganan-Calvo (1998 Phys. Rev. Lett. 80 285-8), a free liquid jet can be compressed in diameter through gas dynamic forces exerted by a coaxially co-flowing gas, obviating the need for a solid nozzle to form a microscopic liquid jet and thereby alleviating the clogging problems that plague conventional droplet sources of small diameter. We describe in this paper a novel form of droplet beam source based on this principle. The source is miniature, robust, dependable, easily fabricated, essentially immune to clogging and eminently suitable for delivery of microscopic liquid droplets, including hydrated biological samples, into vacuum for analysis using vacuum instrumentation. Monodisperse, single-file droplet streams are generated by triggering the device with a piezoelectric actuator.

  9. PBX 9502 Gas Generation Progress Report FY17

    Energy Technology Data Exchange (ETDEWEB)

    Holmes, Matthew David [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Erickson, Michael Andrew Englert [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-10-03

    The self-ignition (“cookoff”) behavior of PBX 9502 depends on the dynamic evolution of gas permeability and physical damage in the material. The time-resolved measurement of product gas generation yields insight regarding the crucial properties that dominate cookoff behavior. We report on small-scale laboratory testing performed in FY17, in which small unconfined samples of PBX 9502 were heated in a small custom-built sealed pressure vessel to self-ignition. We recorded time-lapse video of the evolving physical changes in the sample, quasi-static long-duration pressure rise, then high-speed video and dynamic pressure rise of the cookoff event. We report the full pressure attained during the cookoff of a 1.02g sample in a free volume of 62.5 cm3.

  10. Gas generation and release from the VLJ repository

    International Nuclear Information System (INIS)

    Vieno, T.; Valkiainen, M.

    1992-01-01

    The VLJ repository is an underground disposal facility located at the Olkiluoto nuclear power plant site on the west coast of Finland. The repository will house low (LLW) and intermediate level radioactive wastes (MLW) from the TVO I and TVO II BWR's and the spent fuel interim store at Olkiluoto. The disposal rooms have been excavated at a depth of 60... 100 meters in the crystalline bedrock. They consist of two rock silos - one for the LLW and the other for MLW. Low level waste is usually packed in steel drums and steel boxes. Medium level wastes consists of bituminized resins in steel drums. Wastes packages are emplaced in concrete boxes before transportation into the repository. Low level wastes are emplaced in the shotcreted rock silo where no backfilling will used. For medium level wastes, a separate silo of reinforced concrete has been constructed inside the rock silo. No backfilling will be used inside the concrete silo and an opening will be made in the lid of the concrete silo for gas release. The microbial degradation of low level wastes is the principle gas generation process in the repository. The gas transport though the bedrock covering the repository is evaluated with the help of ground water flow study. It is recommended that the shotcrete lining on the ceiling of the repository cavern is partly removed before the final sealing of the repository. Provided that dissipation of gases from the disposal cavern into the rock can been assured, the overall effects of gas generation on the long-term safety of the repository are insignificant. 10 refs., 6 figs

  11. Utilization of stable isotopes for characterizing an underground gas generator

    International Nuclear Information System (INIS)

    Pirard, J.P.; Antenucci, D.; Renard, X.; Letolle, R.

    1994-01-01

    The principles of isotopic exchange and isotope ratio result interpretation are first reviewed; then, in the framework of an underground coal gasification project in Belgium, experiments and modelling of the underground gas generator have been carried out: isotopic abundances of carbon, hydrogen and oxygen have been measured in the gasifying agent (O 2 , H 2 O) and in the effluent (CO 2 , CO, H 2 , H 2 O, CH 4 , O 2 , heavy oils and various organic and mineral substances). Gasification kinetics and temperatures have been evaluated and isotope application to thermometry is discussed. 1 fig., 9 refs

  12. Study of compressor systems for a gas-generator engine

    Science.gov (United States)

    Sather, Bernard I; Tauschek, Max J

    1950-01-01

    Various methods of providing compressor-capacity and pressure-ratio control in the gas-generator type of compound engine over a range of altitudes from sea level to 50,000 feet are presented. The analytical results indicate that the best method of control is that in which the first stage of compression is carried out in a variable-speed supercharger driven by a hydraulic slip coupling. The constant-speed second stage could be either a mixed-flow rotary compressor or a piston-type compressor. A variable-area turbine nozzle is shown to be unnecessary for cruising operation of the engine.

  13. Gas generation in pure and impure plutonium-bearing materials

    International Nuclear Information System (INIS)

    Mason, R.; Allen, T.; Eller, P.G.; Hagan, R.; Horrell, D.; Rink, N.

    1999-01-01

    The Los Alamos National Laboratory's (LANL's) materials identification and surveillance (MIS) project identifies materials to be stored in DOE-STD-3013-96 containers, determines the chemical and physical character of stored materials, and evaluates processing to be used to stabilize materials to meet the standard. The project has completed processing and analysis of 9 Hanford items and 24 Rocky Flats items, representing a substantial portion of the oxides to be packaged for long-term storage. The resultant data provide insight into the physical and chemical characteristics of the materials at the sites. A component of the study was to investigate gas generation for representative materials. These studies included headspace gas measurements over the 9 Hanford items, measurement of gas generation in 10-g surveillance samples of MIS powders, and pressure monitoring. Before examining the Hanford cans, sampling and analysis methods were demonstrated on HRA-905191, an item from the LANL vault. This item was not typical of materials designated to be stored in 3013 cans, as it contained plastic vials, emery cloths, paper towels, and a large percentage of thorium. However, it was one of the items that contained significant hydrogen in the headspace. A mass spectrometer was used to determine the composition of headspace gases. Oxygen was substantially depleted in all cases, and the percent of nitrogen in many items was greater than that found in air. In both cans with a high hydrogen content, the corresponding oxygen content was near zero (HRA905191 and ARF-102-85-365). In some cases, carbon dioxide was generated in the cans. Carbon monoxide was found in item BLO-39-11-85-295. This item has a high americium content, thus higher temperature than other materials examined. The only notable impurities in item BLO-39-11-85-295 were carbon at ≅0.1 wt% and chlorides at 0.2 wt%. Seven long-term surveillance vessels each holding approximately10 g of MIS powders have been monitored

  14. Advanced Combustion Systems for Next Generation Gas Turbines

    Energy Technology Data Exchange (ETDEWEB)

    Joel Haynes; Jonathan Janssen; Craig Russell; Marcus Huffman

    2006-01-01

    Next generation turbine power plants will require high efficiency gas turbines with higher pressure ratios and turbine inlet temperatures than currently available. These increases in gas turbine cycle conditions will tend to increase NOx emissions. As the desire for higher efficiency drives pressure ratios and turbine inlet temperatures ever higher, gas turbines equipped with both lean premixed combustors and selective catalytic reduction after treatment eventually will be unable to meet the new emission goals of sub-3 ppm NOx. New gas turbine combustors are needed with lower emissions than the current state-of-the-art lean premixed combustors. In this program an advanced combustion system for the next generation of gas turbines is being developed with the goal of reducing combustor NOx emissions by 50% below the state-of-the-art. Dry Low NOx (DLN) technology is the current leader in NOx emission technology, guaranteeing 9 ppm NOx emissions for heavy duty F class gas turbines. This development program is directed at exploring advanced concepts which hold promise for meeting the low emissions targets. The trapped vortex combustor is an advanced concept in combustor design. It has been studied widely for aircraft engine applications because it has demonstrated the ability to maintain a stable flame over a wide range of fuel flow rates. Additionally, it has shown significantly lower NOx emission than a typical aircraft engine combustor and with low CO at the same time. The rapid CO burnout and low NOx production of this combustor made it a strong candidate for investigation. Incremental improvements to the DLN technology have not brought the dramatic improvements that are targeted in this program. A revolutionary combustor design is being explored because it captures many of the critical features needed to significantly reduce emissions. Experimental measurements of the combustor performance at atmospheric conditions were completed in the first phase of the program

  15. Sonatrach prepares for greater exports of natural gas

    International Nuclear Information System (INIS)

    Taleb, M.

    1993-01-01

    Algeria is increasing its capacity to export natural gas in order to reinforce its strong position in the growing international market. The country's reserves are estimated at more than 3.6 trillion cu m. Algerian energy and development policy is based on a rational exploitation of this resource. A liquefield natural gas (LNG) pioneer, Algeria has one of the world's most important LNG production capacities. With a location encouraging export to nearby countries, Algeria has an important place in the world natural gas market and an exclusive role within its trading region. The effort will especially focus on southern Europe. The paper discusses Algeria's growing role in international markets, as well as local markets

  16. Counter-Rotatable Fan Gas Turbine Engine with Axial Flow Positive Displacement Worm Gas Generator

    Science.gov (United States)

    Giffin, Rollin George (Inventor); Murrow, Kurt David (Inventor); Fakunle, Oladapo (Inventor)

    2014-01-01

    A counter-rotatable fan turbine engine includes a counter-rotatable fan section, a worm gas generator, and a low pressure turbine to power the counter-rotatable fan section. The low pressure turbine maybe counter-rotatable or have a single direction of rotation in which case it powers the counter-rotatable fan section through a gearbox. The gas generator has inner and outer bodies having offset inner and outer axes extending through first, second, and third sections of a core assembly. At least one of the bodies is rotatable about its axis. The inner and outer bodies have intermeshed inner and outer helical blades wound about the inner and outer axes and extending radially outwardly and inwardly respectively. The helical blades have first, second, and third twist slopes in the first, second, and third sections respectively. A combustor section extends through at least a portion of the second section.

  17. Study of physical properties, gas generation and gas retention in simulated Hanford waste

    International Nuclear Information System (INIS)

    Bryan, S.A.; Pederson, L.R.; Scheele, R.D.

    1993-04-01

    The purpose of this study was to establish the chemical and physical processes responsible for the generation and retention of gases within high-level waste from Tank 101-SY on the Hanford Site. This research, conducted using simulated waste on a laboratory scale, supports the development of mitigation/remediation strategies for Tank 101-SY. Simulated waste formulations are based on actual waste compositions. Selected physical properties of the simulated waste are compared to properties of actual Tank 101-SY waste samples. Laboratory studies using aged simulated waste show that significant gas generation occurs thermally at current tank temperatures (∼60 degrees C). Gas compositions include the same gases produced in actual tank waste, primarily N 2 , N 2 O, and H 2 . Gas stoichiometries have been shown to be greatly influenced by several organic and inorganic constituents within the simulated waste. Retention of gases in the simulated waste is in the form of bubble attachment to solid particles. This attachment phenomenon is related to the presence of organic constituents (HEDTA, EDTA, and citrate) of the simulated waste. A mechanism is discussed that relates the gas bubble/particle interactions to the partially hydrophobic surface produced on the solids by the organic constituents

  18. Safe Management of Waste Generated during Shale Gas Operations

    Science.gov (United States)

    Kukulska-Zając, Ewa; Król, Anna; Holewa-Rataj, Jadwiga

    2017-04-01

    Exploration and exploitation of hydrocarbon deposits, regardless of their type, are connected with the generation of waste, which may have various environmental effects. Such wastes may pose a serious risk to the surrounding environment and public health because they usually contain numerous potentially toxic chemicals. Waste associated with exploration and exploitation of unconventional hydrocarbon deposits is composed of a mixture of organic and inorganic materials, the qualitative and quantitative composition of which changes widely over time, depending on numerous factors. As a result the proper characteristic of this type of waste is very important. Information gained from detailed chemical analyses of drilling chemicals, drilling wastes, and flowback water can be used to manage shale gas-related wastes more appropriately, to develop treatment methods, to store the waste, and assess the potential environmental and health risk. The following paper will focus mainly on the results of research carried out on waste samples coming from the unconventional hydrogen exploration sites. Additionally, regulatory frameworks applicable to the management of wastes produced during this type of works will be discussed. The scope of research concerning physicochemical parameters for this type of wastes will also be presented. The presented results were obtained during M4ShaleGas project realization. The M4ShaleGas project has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement no. 640715.

  19. Entropy Generation Minimization for Reverse Water Gas Shift (RWGS Reactors

    Directory of Open Access Journals (Sweden)

    Lei Zhang

    2018-05-01

    Full Text Available Thermal design and optimization for reverse water gas shift (RWGS reactors is particularly important to fuel synthesis in naval or commercial scenarios. The RWGS reactor with irreversibilities of heat transfer, chemical reaction and viscous flow is studied based on finite time thermodynamics or entropy generation minimization theory in this paper. The total entropy generation rate (EGR in the RWGS reactor with different boundary conditions is minimized subject to specific feed compositions and chemical conversion using optimal control theory, and the optimal configurations obtained are compared with three reference reactors with linear, constant reservoir temperature and constant heat flux operations, which are commonly used in engineering. The results show that a drastic EGR reduction of up to 23% can be achieved by optimizing the reservoir temperature profile, the inlet temperature of feed gas and the reactor length simultaneously, compared to that of the reference reactor with the linear reservoir temperature. These optimization efforts are mainly achieved by reducing the irreversibility of heat transfer. Optimal paths have subsections of relatively constant thermal force, chemical force and local EGR. A conceptual optimal design of sandwich structure for the compact modular reactor is proposed, without elaborate control tools or excessive interstage equipment. The results can provide guidelines for designing industrial RWGS reactors in naval or commercial scenarios.

  20. Preparation of copper and silicon/copper powders by a gas ...

    Indian Academy of Sciences (India)

    Pure and silicon-coated metal copper nano to submicron-sized powders were prepared by gas evaporation and condensation. This powder was synthesized by using an industrial electron accelerator, ELV-6, with Ar as the carrier gas. Vapour from the liquefied metal surface was transferred to the cold zone by the carrier ...

  1. Gas Generation in Radioactive Wastes - MAGGAS Predictive Life Cycle Model

    International Nuclear Information System (INIS)

    Streatfield, R.E.; Hebditch, D.J.; Swift, B.T.; Hoch, A.R.; Constable, M.

    2006-01-01

    Gases may form from radioactive waste in quantities posing different potential hazards throughout the waste package life cycle. The latter includes surface storage, transport, placing in an operating repository, storage in the repository prior to backfill, closure and the post-closure stage. Potentially hazardous situations involving gas include fire, flood, dropped packages, blocked package vents and disruption to a sealed repository. The MAGGAS (Magnox Gas generation) model was developed to assess gas formation for safety assessments during all stages of the waste package life cycle. This is a requirement of the U.K. regulatory authorities and Nirex and progress in this context is discussed. The processes represented in the model include: Corrosion, microbial degradation, radiolysis, solid-state diffusion, chemico-physical degradation and pressurisation. The calculation was split into three time periods. First the 'aerobic phase' is used to model the periods of surface storage, transport and repository operations including storage in the repository prior to backfill. The second and third periods were designated 'anaerobic phase 1' and 'anaerobic phase 2' and used to model the waste packages in the post-closure phase of the repository. The various significant gas production processes are modeled in each phase. MAGGAS (currently Version 8) is mounted on an Excel spreadsheet for ease of use and speed, has 22 worksheets and is operated routinely for assessing waste packages (e.g. for ventilation of stores and pressurisation of containers). Ten operational and decommissioning generic nuclear power station waste streams were defined as initial inputs, which included ion exchange materials, sludges and concentrates, fuel element debris, graphite debris, activated components, contaminated items, desiccants and catalysts. (authors)

  2. On-line Automated Sample Preparation-Capillary Gas Chromatography for the Analysis of Plasma Samples.

    NARCIS (Netherlands)

    Louter, A.J.H.; van der Wagt, R.A.C.A.; Brinkman, U.A.T.

    1995-01-01

    An automated sample preparation module, (the automated sample preparation with extraction columns, ASPEC), was interfaced with a capillary gas chromatograph (GC) by means of an on-column interface. The system was optimised for the determination of the antidepressant trazodone in plasma. The clean-up

  3. Recent study of nanomaterials prepared by inert gas condensation ...

    Indian Academy of Sciences (India)

    ITO), ZnO, Al2O3, Ag2O, CdO, CuO, ZnSe:ZnO etc., were prepared by this technique and characterized. Results of some of these materials will be presented in this paper. In solid-state 207Pb NMR on PbF2 a separate signal due to the presence ...

  4. Environmental baselines: preparing for shale gas in the UK

    Science.gov (United States)

    Bloomfield, John; Manamsa, Katya; Bell, Rachel; Darling, George; Dochartaigh, Brighid O.; Stuart, Marianne; Ward, Rob

    2014-05-01

    Groundwater is a vital source of freshwater in the UK. It provides almost 30% of public water supply on average, but locally, for example in south-east England, it is constitutes nearly 90% of public supply. In addition to public supply, groundwater has a number of other uses including agriculture, industry, and food and drink production. It is also vital for maintaining river flows especially during dry periods and so is essential for maintaining ecosystem health. Recently, there have been concerns expressed about the potential impacts of shale gas development on groundwater. The UK has abundant shales and clays which are currently the focus of considerable interest and there is active research into their characterisation, resource evaluation and exploitation risks. The British Geological Survey (BGS) is undertaking research to provide information to address some of the environmental concerns related to the potential impacts of shale gas development on groundwater resources and quality. The aim of much of this initial work is to establish environmental baselines, such as a baseline survey of methane occurrence in groundwater (National methane baseline study) and the spatial relationships between potential sources and groundwater receptors (iHydrogeology project), prior to any shale gas exploration and development. The poster describes these two baseline studies and presents preliminary findings. BGS are currently undertaking a national survey of baseline methane concentrations in groundwater across the UK. This work will enable any potential future changes in methane in groundwater associated with shale gas development to be assessed. Measurements of methane in potable water from the Cretaceous, Jurassic and Triassic carbonate and sandstone aquifers are variable and reveal methane concentrations of up to 500 micrograms per litre, but the mean value is relatively low at documented in the range 2km. The geological modelling process will be presented and discussed

  5. Tuning of Preparational Factors Affecting the Morphological Structure and Gas Separation Property of Asymmetric Polysulfone Membranes

    Science.gov (United States)

    Yuenyao, C.; Ruangdit, S.; Chittrakarn, T.

    2017-09-01

    The aim of this work was to study the effect of preparational factors such as solvent type, evaporation time (ET) and non-solvent additive, on the morphological structure, physical and gas separation properties of the prepared membrane samples by tuning of these parameters. Flat sheet asymmetric polysulfone (PSF) membranes were prepared by the dry/wet phase inversion process combined with the double coagulation bath method. The alteration of the prepared membranes were analyzed through scientific techniques such as Scanning Electron Microscope (SEM) and Dynamic Mechanical Thermal Analysis (DMTA). Furthermore, gas separation performance of membrane samples was measured in term of gas permeation and ideal selectivity of CO2/CH4. Experimental results showed that the change of preparational factors affected to the gas permeation of asymmetric PSF membranes. For example, the selective layer thickness increased with increasing of ET. This lead to increase significantly of ideal selectivity of CO2/CH4. The CO2/CH4 ideal selectivity was also increased with increase of ethanol (non-solvent additive) concentration in casting solution. In summary, the tuning of preparational factors affected to morphological structure, physical and gas separation properties of PSF membranes.

  6. Preparing US community greenhouse gas inventories for climate action plans

    International Nuclear Information System (INIS)

    Blackhurst, Michael; Scott Matthews, H; Hendrickson, Chris T; Sharrard, Aurora L; Azevedo, Ines Lima

    2011-01-01

    This study illustrates how alternative and supplemental community-level greenhouse gas (GHG) inventory techniques could improve climate action planning. Eighteen US community GHG inventories are reviewed for current practice. Inventory techniques could be improved by disaggregating the sectors reported, reporting inventory uncertainty and variability, and aligning inventories with local organizations that could facilitate emissions reductions. The potential advantages and challenges of supplementing inventories with comparative benchmarks are also discussed. While GHG inventorying and climate action planning are nascent fields, these techniques can improve CAP design, help communities set more meaningful emission reduction targets, and facilitate CAP implementation and progress monitoring.

  7. Preparing US community greenhouse gas inventories for climate action plans

    Energy Technology Data Exchange (ETDEWEB)

    Blackhurst, Michael [Department of Civil, Architectural and Environmental Engineering, The University of Texas at Austin, 1 University Station C1752, Austin, TX 78712-0276 (United States); Scott Matthews, H; Hendrickson, Chris T [Department of Civil and Environmental Engineering, Carnegie Mellon University, 119 Porter Hall, Pittsburgh, PA 15213 (United States); Sharrard, Aurora L [Green Building Alliance, 333 East Carson Street, Suite 331, Pittsburgh, PA 15219 (United States); Azevedo, Ines Lima, E-mail: mblackhurst@gmail.com, E-mail: hsm@cmu.edu, E-mail: auroras@gbapgh.org, E-mail: cth@andrew.cmu.edu, E-mail: iazevedo@cmu.edu [Department of Engineering and Public Policy, Carnegie Mellon University, 119 Porter Hall, Pittsburgh, PA 15213 (United States)

    2011-07-15

    This study illustrates how alternative and supplemental community-level greenhouse gas (GHG) inventory techniques could improve climate action planning. Eighteen US community GHG inventories are reviewed for current practice. Inventory techniques could be improved by disaggregating the sectors reported, reporting inventory uncertainty and variability, and aligning inventories with local organizations that could facilitate emissions reductions. The potential advantages and challenges of supplementing inventories with comparative benchmarks are also discussed. While GHG inventorying and climate action planning are nascent fields, these techniques can improve CAP design, help communities set more meaningful emission reduction targets, and facilitate CAP implementation and progress monitoring.

  8. Accounting for fuel price risk when comparing renewable to gas-fired generation: the role of forward natural gas prices

    International Nuclear Information System (INIS)

    Bolinger, Mark; Wiser, Ryan; Golove, William

    2006-01-01

    Unlike natural gas-fired generation, renewable generation (e.g., from wind, solar, and geothermal power) is largely immune to fuel price risk. If ratepayers are rational and value long-term price stability, then-contrary to common practice-any comparison of the levelized cost of renewable to gas-fired generation should be based on a hedged gas price input, rather than an uncertain gas price forecast. This paper compares natural gas prices that can be locked in through futures, swaps, and physical supply contracts to contemporaneous long-term forecasts of spot gas prices. We find that from 2000 to 2003, forward gas prices for terms of 2-10 years have been considerably higher than most contemporaneous long-term gas price forecasts. This difference is striking, and implies that comparisons between renewable and gas-fired generation based on these forecasts over this period have arguably yielded results that are biased in favor of gas-fired generation

  9. Natural gas power generation: interruptible gas distribution network regulation; Geracao termoeletrica a gas natural: regulacao do segmento interruptivel de distribuicao de gas canalizado

    Energy Technology Data Exchange (ETDEWEB)

    Paula, Claudio Paiva de; Kann, Zevi [Agencia Reguladora de Saneamento e Energia do Estado de Sao Paulo (ARSESP), SP (Brazil)

    2008-07-01

    The paper relates studies regarding the natural gas distribution network interruptible branch. This new service can be appropriate for thermal power generation on flexible dispatch mode, as 'take or pay' contracts surplus jobs. The paper indicates no regulatory restraints in an interruptible network implantation. The final conclusion is that interruptible contracts can be an improvement on the distribution business and certainly can accommodate a suitable demand and supply volumes in the long-term gas market balance. (author)

  10. BIOMASS GASIFICATION AND POWER GENERATION USING ADVANCED GAS TURBINE SYSTEMS

    Energy Technology Data Exchange (ETDEWEB)

    David Liscinsky

    2002-10-20

    A multidisciplined team led by the United Technologies Research Center (UTRC) and consisting of Pratt & Whitney Power Systems (PWPS), the University of North Dakota Energy & Environmental Research Center (EERC), KraftWork Systems, Inc. (kWS), and the Connecticut Resource Recovery Authority (CRRA) has evaluated a variety of gasified biomass fuels, integrated into advanced gas turbine-based power systems. The team has concluded that a biomass integrated gasification combined-cycle (BIGCC) plant with an overall integrated system efficiency of 45% (HHV) at emission levels of less than half of New Source Performance Standards (NSPS) is technically and economically feasible. The higher process efficiency in itself reduces consumption of premium fuels currently used for power generation including those from foreign sources. In addition, the advanced gasification process can be used to generate fuels and chemicals, such as low-cost hydrogen and syngas for chemical synthesis, as well as baseload power. The conceptual design of the plant consists of an air-blown circulating fluidized-bed Advanced Transport Gasifier and a PWPS FT8 TwinPac{trademark} aeroderivative gas turbine operated in combined cycle to produce {approx}80 MWe. This system uses advanced technology commercial products in combination with components in advanced development or demonstration stages, thereby maximizing the opportunity for early implementation. The biofueled power system was found to have a levelized cost of electricity competitive with other new power system alternatives including larger scale natural gas combined cycles. The key elements are: (1) An Advanced Transport Gasifier (ATG) circulating fluid-bed gasifier having wide fuel flexibility and high gasification efficiency; (2) An FT8 TwinPac{trademark}-based combined cycle of approximately 80 MWe; (3) Sustainable biomass primary fuel source at low cost and potentially widespread availability-refuse-derived fuel (RDF); (4) An overall integrated

  11. Radiolytic gas generation in salt cake technical task plan

    International Nuclear Information System (INIS)

    Walker, D.D.; Crawford, C.L.; Bibler, N.E.

    1993-01-01

    High-level radioactive wastes are stored in large, steel tanks in the Savannah River Site Tank Farms. The liquid levels in these tanks are monitored to detect leakage of waste out of tanks or leakage of liquids into the tanks. Recent unexplained level fluctuations in high-level waste (HLW) tanks have caused High Level Waste Engineering (HLWE) to develop a program to better understand tank level behavior. Interim Waste Technology (IWT) has been requested by HLWE to obtain data which will lead to a better understanding of the radiolytic generations of gases in salt cake. The task described below will provide data from laboratory experiments with simulated wastes which can be used in tank level fluctuation modeling. The following experimental programs have been formulated to meet the task requirements of the customer: (A) determine whether radiolytically generated gas bubbles can be trapped in salt cake; (B) determine the composition of gases produced by radiolysis; (C) determine the yield of radiolysis gases as a function of radiation dose; (D) determine bubble distribution

  12. Preparation and Gas Adsorption of Porous Materials from Molecular Precursors

    DEFF Research Database (Denmark)

    Hu, Xinming

    with bimodal porosity are produced via cyclotrimerization of two aromatic tetranitriles and in situ carbonization in molten ZnCl2. The carbonization occurs by decomposition of triazine rings, which results in complete loss of nitrogen and formation of substantial mesopores. The resulting materials possess...... surface areas above 1200 m2 g−1 and exhibit exceptionally high H2 uptake (up to 2.34 wt% at 77 K and 1 bar) but low CO2 uptake capacity. In Chapter 4, a nitrogen-rich porous carbon is prepared via cyclotrimerization of a perfluorinated aromatic nitrile and in situ carbonization in molten ZnCl2......), and H2 (2.0 wt%, 77 K and 1.0 bar). Chapters 5, 6, and 7 deal with the construction of triazatriangulenium (TATA)-based ionic porous frameworks. A variety of polycondensation reactions have been applied, but only FeCl3-promoted oxidative polymerization of thiophene-/carbazolefunctionalized TATAs...

  13. The selective generation of acetic acid directly from synthesis gas

    International Nuclear Information System (INIS)

    Knifton, J.F.

    1986-01-01

    The authors conclude that each of the ruthenium, cobalt and iodide-containing catalyst components have very specific roles to play in the ''melt'' catalyzed conversion of synthesis gas to acetic acid. C 1 -Oxygenate formation is only observed in the presence of ruthenium carbonyls - [Ru(CO) 3 I 3 ] - is here the dominant species - and there is a direct relationship between liquid yield, ΣOAc - productivity and [Ru(CO) 3 I 3 ] - content. Controlled quantities of iodide ensure that initially formed MeOH is rapidly converted to the more reactive methyl iodide. Subsequent cobalt-catalyzed carbonylation to acetic acid may be preparatively attractive (>80% selectivity, good yields) relative to competing syntheses, where the [Co(CO) 4 ] - concentration is maximized that is, where the Co/Ru ratio is >1, the syngas feedstock is rich in CO, and the initial iodide/cobalt ratios are ca. unity. Formation of cobalt-iodide species appears to be a competing, inhibitory step in this catalysis

  14. Characterization and calibration of gas sensor systems at ppb level—a versatile test gas generation system

    Science.gov (United States)

    Leidinger, Martin; Schultealbert, Caroline; Neu, Julian; Schütze, Andreas; Sauerwald, Tilman

    2018-01-01

    This article presents a test gas generation system designed to generate ppb level gas concentrations from gas cylinders. The focus is on permanent gases and volatile organic compounds (VOCs) for applications like indoor and outdoor air quality monitoring or breath analysis. In the design and the setup of the system, several issues regarding handling of trace gas concentrations have been considered, addressed and tested. This concerns not only the active fluidic components (flow controllers, valves), which have been chosen specifically for the task, but also the design of the fluidic tubing regarding dead volumes and delay times, which have been simulated for the chosen setup. Different tubing materials have been tested for their adsorption/desorption characteristics regarding naphthalene, a highly relevant gas for indoor air quality monitoring, which has generated high gas exchange times in a previous gas mixing system due to long time adsorption/desorption effects. Residual gas contaminations of the system and the selected carrier air supply have been detected and quantified using both an analytical method (GC-MS analysis according to ISO 16000-6) and a metal oxide semiconductor gas sensor, which detected a maximum contamination equivalent to 28 ppb of carbon monoxide. A measurement strategy for suppressing even this contamination has been devised, which allows the system to be used for gas sensor and gas sensor system characterization and calibration in the low ppb concentration range.

  15. Experimental substantiation of combined methods for designing processes for the commercial preparation of gas at gas condensate fields

    Energy Technology Data Exchange (ETDEWEB)

    Gurevich, G R; Karlinskii, E D; Posypkina, T V

    1977-04-01

    An analysis is made of the possibility of using two analytical methods for studying vapor--liquid equilibrium of hydrocarbon mixtures that are used in designing the separation of natural gas and the stabilization of condensate--the Chao and Sider method, which uses computations by equilibrium constants. A combined computational method is proposed for describing a unified process of natural gas separation and condensate stabilization. The method of preparing the original data for the computation of the separation and stabilization processes can be significantly simplified. 10 references, 1 table.

  16. Moving on From Millennials: Preparing for Generation Z.

    Science.gov (United States)

    Shatto, Bobbi; Erwin, Kelly

    2016-06-01

    Much has been written about teaching Millennials; however, little has been discussed about Generation Z-those just entering college. Nursing instructors must adapt to the upcoming generation's mobile tech-savviness and self-directed learning, which often is accompanied by a lack of critical thinking skills. Teaching strategies and incorporating technology are highlighted. J Contin Educ Nurs. 2016;47(6):253-254. Copyright 2016, SLACK Incorporated.

  17. In-house Preparation of 188W/188Re Generators

    International Nuclear Information System (INIS)

    Sriwiang, Wiranee; Minsakorn, Napharat; Wardwilai, Charudej; Yindirum, Chareon; Sangsuriyan, Jatupol

    2007-08-01

    Full text: Low activity 188W/188Re generators were developed for the purpose of routinely supplying rhenium-188 for laboratory experiments and research works. Chromatography technology was applied in the construction of the generators. The chromatography columns containing 1.74 g alumina (Al2O3) were housed in plastic (PE) shielding inside the 30mm thick lead shield. Three generators were loaded with three different 188W activities; 25mCi (RG1), 25 mCi (RG2) and 50 mCi (RG3). Generator performances were determined in terms of elution yields, radiochemical purity, Al-breakthrough, 188W-breakthrough, and radionuclidic purity of the eluted products. These generators can be used for more than 6 months with average elution yields greater than 90 %. Radiochemical purity of 188ReO4- was high (> 99.7 % by ITLC), low level of 188W -breakthrough and low contamination of 192Ir and 191Os. There were only less than 1 ppm of 186W carrier and less than 3 ppm of Al-breakthrough. Key words: 188W/188Re, Generator, 188Re, Radionuclide

  18. Preparing a Nation for the Eclipse of a Generation -

    Science.gov (United States)

    Speck, Angela; Habbal, Shadia; Tresch Fienberg, Richard; Kentrianakis, Michael; Fraknoi, Andrew; Nordgren, Tyler; Penn, Matthew; Pasachoff, Jay M.; Bakich, Michael; Winter, Henry; Gay, Pamela; Motta, Mario

    2018-01-01

    On August 21st 2017, there was a total solar eclipse visible from a vast swath of the US.In preparation for that event, the American Astronomical society created a taskforce charged with planning for the eclipse for the entire nation. The preparations included interfacing with the public, the media, non-profit organizations and governmental organizations. Preliminary data suggests that nearly 90% of American adults watched the eclipse either directly or via live streams. Moreover, there were no major problems associated with the event, in spite of valiant attempts from, e.g. imprope solar viewing materials. The eclipse offered opportunities for many scientific experiments within and ebyond astronomy. Here we present on the work of the taskforce, and the lessons learned as well as lesser known science experiments undertaken during the eclipse.

  19. Greenhouse Gas Abatement with Distributed Generation in California's Commercial Buildings

    International Nuclear Information System (INIS)

    Stadler, Michael; Marnay, Chris; Cardoso, Goncalo; Megel, Olivier; Siddiqui, Afzal; Lai, Judy

    2009-01-01

    Lawrence Berkeley National Laboratory (LBL) is working with the California Energy Commission (CEC) to determine the role of distributed generation (DG) in greenhouse gas reductions. The impact of DG on large industrial sites is well known, and mostly, the potentials are already harvested. In contrast, little is known about the impact of DG on commercial buildings with peak electric loads ranging from 100 kW to 5 MW. We examine how DG with combined heat and power (CHP) may be implemented within the context of a cost minimizing microgrid that is able to adopt and operate various smart energy technologies, such as thermal and photovoltaic (PV) on-site generation, heat exchangers, solar thermal collectors, absorption chillers, and storage systems. We use a mixed-integer linear program (MILP) that has the minimization of a site's annual energy costs as objective. Using 138 representative commercial sites in California (CA) with existing tariff rates and technology data, we find the greenhouse gas reduction potential for California's commercial sector. This paper shows results from the ongoing research project and finished work from a two year U.S. Department of Energy research project. To show the impact of the different technologies on CO2 emissions, several sensitivity runs for different climate zones within CA with different technology performance expectations for 2020 were performed. The considered sites can contribute between 1 Mt/a and 1.8 Mt/a to the California Air Resources Board (CARB) goal of 6.7Mt/a CO2 abatement potential in 2020. Also, with lower PV and storage costs as well as consideration of a CO2 pricing scheme, our results indicate that PV and electric storage adoption can compete rather than supplement each other when the tariff structure and costs of electricity supply have been taken into consideration. To satisfy the site's objective of minimizing energy costs, the batteries will be charged also by CHP systems during off-peak and mid-peak hours and

  20. Quality control of residual solvents in [18F]FDG preparations by gas chromatography

    International Nuclear Information System (INIS)

    Lee, Hak Jeong; Jeong, Jae Min; Lee, Yun Sang; Kim, Hyung Woo; Chang, Young Soo; Lee, Dong Soo; Chung, June Key; Lee, Myung Chul

    2007-01-01

    Analysis of volatile organic solvents in 2-deoxy-2[ 18 F] fluoro-D-glucose ([ 18 F]FDG) preparations was performed by gas chromatography (GC), in accordance with USP. Analyses were carried out on a Hewlett-Packard 6890 gas chromatography equipped with an FID. We determined the amounts of ethanol and acetonitrile on every batch of our routine [ 18 F]FDG preparations, ranging between 5000 ppm and 100 ppm. In our routine preparation of [ 18 F]FDG, the amount of acetonitrile and ethanol in the final product were well below the maximum allowable limit described in the USP. Our [ 18 F]FDG preparations were in accordance with the suggested USP maximum allowable levels of the quality control analysis of volatile organic compounds

  1. Survey for preparing the database for R and D of new engines. Waste power generation, solar heat system, geothermal power generation, clean energy vehicle, coal liquefaction/gasification, and combined systems; Shin energy gijutsu kaihatsu kankei data shu sakusei chosa. Haikibutsu hatsuden, taiyonetsu riyo, chinetsu hatsuden, clean energy jidosha, sekitan ekika gas ka oyobi odanteki tema

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    The present developmental conditions and issues of new energies are systematically arranged for effective promotion of their diffusion. One hundred and forty six general waste power generation facilities of 558,000kW are in operation in 1995, and among them 89 facilities supplies 1,080 GWh to power companies. 50 industrial waste power facilities of 247,000kW are in operation. 20,000 solar systems and 180,000 hot water heaters are in operation in 1995. Commercial geothermal power generation facilities of 490,000kW and private ones of 36,000kW are in operation. Introduction of expensive clean energy vehicles is making very slow progress. The pilot study on bituminous coal liquefaction is in promotion mainly by NEDO. The experiment of entrained bed coal gasification in Nakoso was successfully completed, and development of a commercial plant is to be expected. Power rates of 10 power companies were reduced in 1996, and unit purchase prices of surplus power of photovoltaic and wind power generation were also revised. The new menu and unit purchase price were announced in 1996 for surplus power of waste power generation and fuel cell. 67 figs., 284 tabs.

  2. Dutch gas amendment throws open market to generators

    International Nuclear Information System (INIS)

    Anon.

    1997-01-01

    An analysis of the text of an amendment to European Union legislation on gas power production rules from the Dutch government is set out. Its pro-liberalisation stance has profound implications for the French, Belgian and Austrian gas power producers. Reactions to the Dutch proposals are noted and data on gas markets in various Member States is presented in table form. (UK)

  3. Gas Generation from K East Basin Sludges and Irradiated Metallic Uranium Fuel Particles Series III Testing

    International Nuclear Information System (INIS)

    Schmidt, Andrew J.; Delegard, Calvin H.; Bryan, Samuel A.; Elmore, Monte R.; Sell, Rachel L.; Silvers, Kurt L.; Gano, Susan R.; Thornton, Brenda M.

    2003-01-01

    The path forward for managing of Hanford K Basin sludge calls for it to be packaged, shipped, and stored at T Plant until final processing at a future date. An important consideration for the design and cost of retrieval, transportation, and storage systems is the potential for heat and gas generation through oxidation reactions between uranium metal and water. This report, the third in a series (Series III), describes work performed at the Pacific Northwest National Laboratory (PNNL) to assess corrosion and gas generation from irradiated metallic uranium particles (fuel particles) with and without K Basin sludge addition. The testing described in this report consisted of 12 tests. In 10 of the tests, 4.3 to 26.4 g of fuel particles of selected size distribution were placed into 60- or 800-ml reaction vessels with 0 to 100 g settled sludge. In another test, a single 3.72-g fuel fragment (i.e., 7150-mm particle) was placed in a 60 ml reaction vessel with no added sludge. The twelfth test contained only sludge. The fuel particles were prepared by crushing archived coupons (samples) from an irradiated metallic uranium fuel element. After loading the sludge materials (whether fuel particles, mixtures of fuel particles and sludge, or sludge-only) into reaction vessels, the solids were covered with an excess of K Basin water, the vessels closed and connected to a gas measurement manifold, and the vessels back-flushed with inert neon cover gas. The vessels were then heated to a constant temperature. The gas pressures and temperatures were monitored continuously from the times the vessels were purged. Gas samples were collected at various times during the tests, and the samples analyzed by mass spectrometry. Data on the reaction rates of uranium metal fuel particles with water as a function of temperature and particle size were generated. The data were compared with published studies on metallic uranium corrosion kinetics. The effects of an intimate overlying sludge layer

  4. A small capacity co generative gas-turbine plant in factory AD 'Komuna' - Skopje (Macedonia)

    International Nuclear Information System (INIS)

    Dimitrov, Konstantin; Armenski, Slave; Tashevski, Done

    2000-01-01

    The factory AD 'Komuna' -Skopje (Macedonia), has two steam block boilers, type ST 800 for steam production for process and space heating. The factory satisfies the electricity needs from the national grid. By the use of natural gas like fuel it is possible to produce electrical energy in its own co generative gas turbine plant. In this article, a co generative plant with small-scale gas turbine for electricity production is analyzed . The gas from gas turbine have been introduce in the steam block boiler. Also, a natural gas consumption, the electricity production, total investment and payback period of investment are determined. (Authors)

  5. Technology of steam generators for gas-cooled reactors. Proceedings of a specialists' meeting

    International Nuclear Information System (INIS)

    1988-01-01

    The activity of the IAEA in the field of the technology of gas-cooled reactors was formalized by formation of an International Working Group on Gas-Cooled Reactors (IWGCR). The gas cooled reactor program considered by the IWGCR includes carbon-dioxide-cooled thermal reactors, helium cooled thermal high temperature reactors for power generation and for process heat applications and gas-cooled fast breeder reactors. This report covers the papers dealing with operating experience, steam generators for next generation of gas-cooled reactors, material development and corrosion problems, and thermohydraulics

  6. Technology of steam generators for gas-cooled reactors. Proceedings of a specialists' meeting

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1988-07-01

    The activity of the IAEA in the field of the technology of gas-cooled reactors was formalized by formation of an International Working Group on Gas-Cooled Reactors (IWGCR). The gas cooled reactor program considered by the IWGCR includes carbon-dioxide-cooled thermal reactors, helium cooled thermal high temperature reactors for power generation and for process heat applications and gas-cooled fast breeder reactors. This report covers the papers dealing with operating experience, steam generators for next generation of gas-cooled reactors, material development and corrosion problems, and thermohydraulics.

  7. TRU waste transportation -- The flammable gas generation problem

    International Nuclear Information System (INIS)

    Connolly, M.J.; Kosiewicz, S.T.

    1997-01-01

    The Nuclear Regulatory Commission (NRC) has imposed a flammable gas (i.e., hydrogen) concentration limit of 5% by volume on transuranic (TRU) waste containers to be shipped using the TRUPACT-II transporter. This concentration is the lower explosive limit (LEL) in air. This was done to minimize the potential for loss of containment during a hypothetical 60 day period. The amount of transuranic radionuclide that is permissible for shipment in TRU waste containers has been tabulated in the TRUPACT-II Safety Analysis Report for Packaging (SARP, 1) to conservatively prevent accumulation of hydrogen above this 5% limit. Based on the SARP limitations, approximately 35% of the TRU waste stored at the Idaho National Engineering and Environmental Lab (INEEL), Los Alamos National Lab (LANL), and Rocky Flats Environmental Technology Site (RFETS) cannot be shipped in the TRUPACT-II. An even larger percentage of the TRU waste drums at the Savannah River Site (SRS) cannot be shipped because of the much higher wattage loadings of TRU waste drums in that site's inventory. This paper presents an overview of an integrated, experimental program that has been initiated to increase the shippable portion of the Department of Energy (DOE) TRU waste inventory. In addition, the authors will estimate the anticipated expansion of the shippable portion of the inventory and associated cost savings. Such projection should provide the TRU waste generating sites a basis for developing their TRU waste workoff strategies within their Ten Year Plan budget horizons

  8. RANDOMNUMBERS, Random Number Sequence Generated from Gas Ionisation Chamber Data

    International Nuclear Information System (INIS)

    Frigerio, N.A.; Sanathanan, L.P.; Morley, M.; Tyler, S.A.; Clark, N.A.; Wang, J.

    1989-01-01

    1 - Description of problem or function: RANDOM NUMBERS is a data collection of almost 2.7 million 31-bit random numbers generated by using a high resolution gas ionization detector chamber in conjunction with a 4096-channel multichannel analyzer to record the radioactive decay of alpha particles from a U-235 source. The signals from the decaying alpha particles were fed to the 4096-channel analyzer, and for each channel the frequency of signals registered in a 20,000-microsecond interval was recorded. The parity bits of these frequency counts, 0 for an even count and 1 for and odd count, were then assembled in sequence to form 31-bit random numbers and transcribed onto magnetic tape. This cycle was repeated to obtain the random numbers. 2 - Method of solution: The frequency distribution of counts from the device conforms to the Brockwell-Moyal distribution which takes into account the dead time of the counter. The count data were analyzed and tests for randomness on a sample indicate that the device is a highly reliable source of truly random numbers. 3 - Restrictions on the complexity of the problem: The RANDOM NUMBERS tape contains 2,669,568 31-bit numbers

  9. Microstructural and magnetic behavior of nanostructured soft alloys prepared by mechanical grinding and gas atomization

    International Nuclear Information System (INIS)

    Marin, P.; Lopez, M.; Garcia-Escorial, A.; Lieblich, M.

    2007-01-01

    Nanocrystalline powder of Fe-Si-B-Cu-Nb has been obtained by means of mechanical milling of the corresponding nanocrystalline ribbons. Gas atomization technique has been used to minimize the magnetic hardening due to stress effects observed in ball-milled samples. Fe-Si-B-Cu-Nb and Fe-Si nanocrystalline samples have been prepared by gas atomization. The aim of our work is to analyse the particle size dependence of coercivity in this nanostructured alloys and to show the analogies and differences between ball-milled and gas atomized samples

  10. Comparative funding consequences of large versus small gas-fired power generation units

    International Nuclear Information System (INIS)

    Johnson, N.G.

    1995-01-01

    Gas producers are increasingly looking to privately-owned gas-fired power generation as a major growth market to support the development of new fields being discovered across Australia. Gas-fired generating technology is more environmentally friendly than coal-fired power stations, has lower unit capital costs and has higher efficiency levels. With the recent downward trends in gas prices for power generation (especially in Western Australia) it is likely that gas will indeed be the consistently preferred fuel for generation in Australia. Gas producers should be sensitive to the different financial and risk characteristics of the potential market represented by large versus small gas-fired private power stations. These differences are exaggerated by the much sharper focus given by the private sector to quantify risk and to its allocation to the parties best able to manage it. The significant commercial differences between classes of generation projects result in gas producers themselves being exposed to diverging risk profiles through their gas supply contracts with generating companies. Selling gas to larger generation units results in gas suppliers accepting proportionately (i.e. not just prorata to the larger installed capacity) higher levels of financial risk. Risk arises from the higher probability of a project not being completed, from the increased size of penalty payments associated with non-delivery of gas and from the rising level of competition between gas suppliers. Gas producers must fully understand the economics and risks of their potential electricity customers and full financial analysis will materially help the gas supplier in subsequent commercial gas contract negotiations. (author). 1 photo

  11. Preparation for Future Defuelling and Decommissioning Works on EDF Energy's UK Fleet of Advanced Gas Cooled Reactors

    International Nuclear Information System (INIS)

    Bryers, John; Ashmead, Simon

    2016-01-01

    EDF Energy/Nuclear Generation is the owner and operator of 14 Advanced Gas cooled Reactors (AGR) and one Pressurised Water Reactor (PWR), on 8 nuclear stations in the UK. EDF Energy/Nuclear Generation is responsible for all the activities associated with the end of life of its nuclear installations: de-fuelling, decommissioning and waste management. As the first AGR is forecast to cease generation within 10 years, EDF Energy has started planning for the decommissioning. This paper covers: - broad outline of the technical strategy and arrangements for future de-fuelling and decommissioning works on the UK AGR fleet, - high level strategic drivers and alignment with wider UK nuclear policy, - overall programme of preparation and initial works, - technical approaches to be adopted during decommissioning. (authors)

  12. Gas-turbine industry prepares to become base-load supplier

    International Nuclear Information System (INIS)

    Hansen, T.

    1996-01-01

    Gas-turbine technology has entered a new era; the simple-cycle units of yesterday are making room for new, highly sophisticated combined-cycle units. In July 1949, the first U.S. commercial power generation gas turbine was installed at Oklahoma Gas and Electric Co.'s Belle Isle Station. This unit was a General Electric (GE) MS3000 heavy-duty gas turbine rated at 3,5000 kW. In 1994, more than 900 gas turbines totaling over 33,000 MW were ordered worldwide, according to Power-Data Group, LaJolla, Calif. These figures show just how far gas turbines have come in less than 50 years. Today, simple-cycle units rated at up to 150 MW (with efficiencies around 35 percent) and combined-cycle units rated at over 200 MW (approaching 60-percent efficiency) are up and running

  13. Quality Assurance Program Plan for TRUPACT-II Gas Generation Test Program

    International Nuclear Information System (INIS)

    2002-01-01

    The Gas Generation Test Program (GGTP), referred to as the Program, is designed to establish the concentration of flammable gases and/or gas generation rates in a test category waste container intended for shipment in the Transuranic Package Transporter-II (TRUPACT-II). The phrase 'gas generationtesting' shall refer to any activity that establishes the flammable gas concentration or the flammable gas generation rate. This includes, but is not limited to, measurements performed directly on waste containers or during tests performed on waste containers. This Quality Assurance Program Plan (QAPP) documents the quality assurance (QA) and quality control (QC) requirements that apply to the Program. The TRUPACT-II requirements and technical bases for allowable flammable gas concentration and gas generation rates are described in the TRUPACT-II Authorized Methods for Payload Control (TRAMPAC).

  14. 78 FR 57626 - Algonquin Gas Transmission, LLC; Notice of Intent To Prepare An Environmental Impact Statement...

    Science.gov (United States)

    2013-09-19

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. PF13-16-000] Algonquin Gas Transmission, LLC; Notice of Intent To Prepare An Environmental Impact Statement for the Planned Algonquin Incremental Market Project, Request for Comments on Environmental Issues, and Notice of Public Scoping Meetings The staff of the Federal Energy...

  15. 78 FR 33403 - Transcontinental Gas Pipe Line Company, LLC; Notice of Intent To Prepare an Environmental...

    Science.gov (United States)

    2013-06-04

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. PF13-5-000] Transcontinental Gas Pipe Line Company, LLC; Notice of Intent To Prepare an Environmental Assessment for the Planned Leidy Southeast Expansion Project, Request for Comments on Environmental Issues, and Notice of Public Scoping Meetings The staff of the Federal...

  16. 77 FR 59391 - Transcontinental Gas Pipe Line Company, LLC; Notice of Intent To Prepare an Environmental...

    Science.gov (United States)

    2012-09-27

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. CP12-497-000] Transcontinental Gas Pipe Line Company, LLC; Notice of Intent To Prepare an Environmental Assesment for the Proposed Brandywine Creek Replacement Project; Request for Comments on Environmental Issues; and Notice of Public Scoping Meeting The staff of the Federal...

  17. 76 FR 40717 - Transcontinental Gas Pipe Line Company, LLC; Notice of Intent To Prepare an Environmental...

    Science.gov (United States)

    2011-07-11

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. PF11-4-000] Transcontinental Gas Pipe Line Company, LLC; Notice of Intent To Prepare an Environmental Assessment for the Planned Northeast Supply Link Project, Request for Comments on Environmental Issues, and Notice of Public Scoping Meetings The staff of the Federal Energy...

  18. 75 FR 42738 - Transcontinental Gas Pipe Line Company, LLC; Notice of Intent To Prepare an Environmental...

    Science.gov (United States)

    2010-07-22

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. PF10-16-000] Transcontinental Gas Pipe Line Company, LLC; Notice of Intent To Prepare an Environmental Assessment for the Planned Mid-Atlantic Connector Expansion Project, Request for Comments on Environmental Issues, and Notice of Public Scoping Meeting July 15, 2010. The...

  19. Examination of background contamination levels for gas counting and AMS target preparation in Trondheim

    DEFF Research Database (Denmark)

    Gulliksen, S.; Thomsen, M.S.

    1992-01-01

    conventional gas proportional counting (GPC) system. We have also studied contamination levels of our target preparation for C-14 accelerator mass spectrometry (AMS) dating in Uppsala. A significant lower background is obtained for Icelandic double spar than for marbles, probably due to a crystal structure...

  20. ObsPack: a framework for the preparation, delivery, and attribution of atmospheric greenhouse gas data

    NARCIS (Netherlands)

    Masarie, K. A.; Peters, W.; Jacobson, A. R.; Tans, P. P.

    2014-01-01

    Observation Package (ObsPack) is a framework designed to bring together atmospheric greenhouse gas observations from a variety of sampling platforms, prepare them with specific applications in mind, and package and distribute them in a self-consistent and well-documented product. Data products

  1. ObsPack: a framework for the preparation, delivery, and attribution of atmospheric greenhouse gas measurements

    NARCIS (Netherlands)

    Masarie, K. A.; Peters, W.; Jacobson, A. R.; Tans, P. P.

    2014-01-01

    Observation Package (ObsPack) is a framework designed to bring together atmospheric greenhouse gas observations from a variety of sampling platforms, prepare them with specific applications in mind, and package and distribute them in a self-consistent and well-documented product. Data products

  2. Gas generation in deep radioactive waste repositories: a review of processes, controls and models

    International Nuclear Information System (INIS)

    Jones, M.A.

    1990-10-01

    Gas generation within radioactive waste repositories may produce two general problems: 1) breaching of engineered and natural barriers due to high gas pressures; 2) enhanced radiological risk due to reduced groundwater travel times and/or greater aqueous or gaseous activities reaching the biosphere. As a result of these concerns, HMIP must be aware of the current status of relevant research, together with any associated deficiencies. This report addresses the current status of published research on near-field gas generation from worldwide sources and documents the important gas generating processes, the factors controlling them and models available to simulate them. In the absence of suitable models, outline technical specifications for corrosion and microbial degradation gas generation models are defined and the deficiencies in the current understanding of gas generation are highlighted; a conceptual research programme to correct these deficiencies is presented. (author)

  3. Power generation from landfill gas, Middleton Broom, UK

    International Nuclear Information System (INIS)

    Anon.

    1994-01-01

    A power station is fuelled by gas from a landfill site at Middleton Broom, West Yorkshire in the North of England. The plant was commissioned in January 1993 and has a Declared Net Capacity of about 1.2 MW (enough power for about 700 homes). The electricity produced is exported to the National Grid. After various possible uses of the landfill gas were explored, it was decided that a power station fuelled by the gas was the most commercially viable prospect. Because of the proximity of housing to the landfill site, gas is pumped to the power station, located about 1,500 m from the landfill. (UK)

  4. Biomass gasification hot gas cleanup for power generation

    Energy Technology Data Exchange (ETDEWEB)

    Wiant, B.C.; Bachovchin, D.M. [Westinghouse Electric Corp., Orlando, FL (United States); Carty, R.H.; Onischak, M. [Institute of Gas Technology, Chicago, IL (United States); Horazak, D.A. [Gilbert/Commonwealth, Reading, PA (United States); Ruel, R.H. [The Pacific International Center for High Technology Research, Honolulu, HI (United States)

    1993-12-31

    In support of the US Department of Energy`s Biomass Power Program, a Westinghouse Electric led team consisting of the Institute of Gas Technology (IGT), Gilbert/Commonwealth (G/C), and the Pacific International Center for High Technology Research (PICHTR), is conducting a 30 month research and development program. The program will provide validation of hot gas cleanup technology with a pressurized fluidized bed, air-blown, biomass gasifier for operation of a gas turbine. This paper discusses the gasification and hot gas cleanup processes, scope of work and approach, and the program`s status.

  5. Country-Level Life Cycle Assessment of Greenhouse Gas Emissions from Liquefied Natural Gas Trade for Electricity Generation.

    Science.gov (United States)

    Kasumu, Adebola S; Li, Vivian; Coleman, James W; Liendo, Jeanne; Jordaan, Sarah M

    2018-02-20

    In the determination of the net impact of liquefied natural gas (LNG) on greenhouse gas emissions, life cycle assessments (LCA) of electricity generation have yet to combine the effects of transport distances between exporting and importing countries, country-level infrastructure in importing countries, and the fuel sources displaced in importing countries. To address this, we conduct a LCA of electricity generated from LNG export from British Columbia, Canada with a three-step approach: (1) a review of viable electricity generation markets for LNG, (2) the development of results for greenhouse gas emissions that account for transport to importing nations as well as the infrastructure required for power generation and delivery, and (3) emissions displacement scenarios to test assumptions about what electricity is being displaced in the importing nation. Results show that while the ultimate magnitude of the greenhouse gas emissions associated with natural gas production systems is still unknown, life cycle greenhouse gas emissions depend on country-level infrastructure (specifically, the efficiency of the generation fleet, transmission and distribution losses and LNG ocean transport distances) as well as the assumptions on what is displaced in the domestic electricity generation mix. Exogenous events such as the Fukushima nuclear disaster have unanticipated effects on the emissions displacement results. We highlight national regulations, environmental policies, and multilateral agreements that could play a role in mitigating emissions.

  6. Progress Toward a Microfabricated Gas Turbine Generator for Soldier Portable Power Applications

    National Research Council Canada - National Science Library

    Jacobson, S. A; Das, S; Savoulides, N; Steyn, J. L; Lang, J; Li, H. Q; Livermore, C; Schmidt, M. A; Teo, C. J; Umans, S. D; Epstein, A. H; Arnold, D. P; Park, J-W; Zana, I; Allen, M. G

    2004-01-01

    Microelectromechanical systems (MEMS) turbocharger and electric generator devices have been fabricated and tested as part of a program at MIT to develop a microfabricated gas turbine generator for portable power applications...

  7. Using natural gas generation to improve power system efficiency in China

    International Nuclear Information System (INIS)

    Hu, Junfeng; Kwok, Gabe; Xuan, Wang; Williams, James H.; Kahrl, Fredrich

    2013-01-01

    China's electricity sector faces the challenge of managing cost increases, improving reliability, and reducing its environmental footprint even as operating conditions become more complex due to increasing renewable penetration, growing peak demand, and falling system load factors. Addressing these challenges will require changes in how power generation is planned, priced, and dispatched in China. This is especially true for natural gas generation, which is likely to play an important role in power systems worldwide as a flexible generation resource. Although natural gas is commonly perceived to be economically uncompetitive with coal in China, these perceptions are based on analysis that fails to account for the different roles that natural gas generation plays in power systems—baseload, load following, and peaking generation. Our analysis shows that natural gas generation is already cost-effective for meeting peak demand in China, resulting in improved capacity factors and heat rates for coal-fired generators and lower system costs. We find that the largest barrier to using natural gas for peaking generation in China is generation pricing, which could be addressed through modest reforms to support low capacity factor generation. - Highlights: • Using gas generation as a “capacity resource” in China could have multiple benefits. • Benefits include lower total costs, improved efficiency for coal generators. • Price reforms needed to support low capacity factor generation in China

  8. Adsorption of mercury by activated carbon prepared from dried sewage sludge in simulated flue gas.

    Science.gov (United States)

    Park, Jeongmin; Lee, Sang-Sup

    2018-04-25

    Conversion of sewage sludge to activated carbon is attractive as an alternative method to ocean dumping for the disposal of sewage sludge. Injection of activated carbon upstream of particulate matter control devices has been suggested as a method to remove elemental mercury from flue gas. Activated carbon was prepared using various activation temperatures and times and was tested for their mercury adsorption efficiency using lab-scale systems. To understand the effect of the physical property of the activated carbon, its mercury adsorption efficiency was investigated as a function of their Brunauer-Emmett-Teller (BET) surface area. Two simulated flue gas conditions: (1) without hydrogen chloride (HCl) and (2) with 20 ppm HCl, were used to investigate the effect of flue gas composition on the mercury adsorption capacity of activated carbon. Despite very low BET surface area of the prepared sewage sludge activated carbons, their mercury adsorption efficiencies were comparable under both simulated flue gas conditions to those of pinewood and coal activated carbons. After injecting HCl into the simulated flue gas, all sewage sludge activated carbons demonstrated high adsorption efficiencies, i.e., more than 87%, regardless of their BET surface area. IMPLICATIONS We tested activated carbons prepared from dried sewage sludge to investigate the effect of their physical properties on their mercury adsorption efficiency. Using two simulated flue gas conditions, we conducted mercury speciation for the outlet gas. We found that the sewage sludge activated carbon had comparable mercury adsorption efficiency to pinewood and coal activated carbons, and the presence of HCl minimized the effect of physical property of the activated carbon on its mercury adsorption efficiency.

  9. A model of gas generation and transport within TRU [transuranic] waste drums

    International Nuclear Information System (INIS)

    Smith, F.G. III.

    1987-01-01

    Gas generation from the radiolytic decomposition of organic material contaminated with plutonium is modeled. Concentrations of gas throughout the waste drum are determined using a diffusional transport model. The model accurately reproduces experimentally measured gas concentrations. With polyethylene waste in unvented drums, the model predicts that hydrogen gas can accumulate to concentrations greater than 4 mole percent (lower flammable limit) with about 5 Ci of plutonium. Polyethylene provides a worst case for combustible waste material. If the drum liner is punctured and a carbon composite filter vent is installed in the drum lid, the plutonium loading can be increased to 240 Ci without generating flammable gas mixtures. 5 refs., 7 figs., 4 tabs

  10. Hanford site guide for preparing and maintaining generator group pollution prevention program documentation

    International Nuclear Information System (INIS)

    1995-12-01

    This manual provides the necessary guidance to contractor generator groups for developing and maintaining documentation of their pollution prevention (P2) program activities. Preparation of program documentation will demonstrate compliance with contractor and U.S. Department of Energy (DOE) requirements, as well as state and federal regulations. Contractor waste generator groups are no longer required to prepare and update facility waste minimization plans. Developing and maintaining program documentation replace this requirement

  11. Preparing for the Next Generation of Direct Broadcast

    Science.gov (United States)

    Shin, H.; Friedman Dubey, K.; Baptiste, E.; Prasad, K.; Lawrence, D.

    2010-12-01

    With the anticipated launch of NPP, JPSS-1 and GOES-R in the next five years, the flow of weather data to users will rise ten times (Berchoff, 2009). This volume of data will put a strain on the government infrastructure tasked for data distribution, which could limit real-time data distribution to government users only, forcing others to retrieve their data days to weeks later. In order to receive real-time data, direct reception will become a necessity. SeaSpace Corporation has created a complete solution in anticipation of the forthcoming needs of data users. This solution is made up of four parts: 1) ground reception stations, 2) software to process the data into products, 3) data storage hardware, and 4) data cataloging software and server. The ground station component consists of two systems, an X/L/S-band tracking system and an L-band geostationary system. The combined X-, L-, and S-band reception capabilities are included to ensure the user can receive the maximum amount of data. The X-band receiver in this system can receive data from Terra, Aqua, NPP, JPSS, Oceansat-2, and FY-3. The L-band receiver can currently receive NOAA and MetOp. The follow-on to MetOp will be assigned the mid-morning orbit in the next generation constellation, ensuring L-band reception will continue to be a necessity. The S-band is used for DMSP reception, which may, in the near-future, become more widely available to non-defense clients. The L-band stationary antenna in the proposed solution is used for reception of geostationary satellites, such as GOES, COMS, and MTSAT. Upon launch, GOES-R data can be received with hardware/software upgrade. Once the data is received by the ground stations, TeraScan’s Rapid Environmental Processing System (REPS) automatically processes the data through level 3 products using the official NOAA and NASA algorithms. REPS can process large amounts of satellite data incredibly quickly: for instance, all MODIS products are produced in less than

  12. NEXT GENERATION GAS TURBINE (NGGT) SYSTEMS STUDY; FINAL

    International Nuclear Information System (INIS)

    Unknown

    2001-01-01

    , both in terms of incorporation of technology into current products, as well as to an NGGT product. In summary, potential program costs are shown for development of the candidate systems along with the importance of future DOE enabling participation. Three main conclusions have been established via this study: (1) Rapid recent changes within the power generation regulatory environment and the resulting ''bubble'' of gas turbine orders has altered the timing and relative significance associated with the conclusions of the ADL study upon which the original DOE NGGT solicitation was based. (2) Assuming that the relevant technologies were developed and available for an NGGT market opportunity circa 2010, the top candidate system that meets or exceeds the DOE PRDA requirements was determined to be a hybrid aero-derivative/heavy duty concept. (3) An investment by DOE of approximately$23MM/year to develop NGGT technologies near/mid term for validation and migration into a reasonable fraction of the installed base of GE F-class products could be leveraged into$1.2B Public Benefit, with greatest benefits resulting from RAM improvements. In addition to the monetary Public Benefit, there is also significant benefit in terms of reduced energy consumption, and reduced power plant land usage

  13. Gas generation by self-radiolysis of tritiated waste materials

    International Nuclear Information System (INIS)

    Tadlock, W.E.; Abell, G.C.; Steinmeyer, R.H.

    1980-01-01

    Studies simulating the effect of self-radiolysis in disposal packages containing tritiated waste materials show hydrogen to be the dominant gas-phase product. Pressure buildup and gas composition over various tritiated octane and tritiated water samples are designed to give worst case results. One effect of tritium fixation agents is to reduce pressure buildup. The results show that development of explosive gas mixtures is unlikely and that maximum pressure buildup in typical Mound Facility waste packages can be expected to be <0.25 MPa

  14. High gas dependence for power generation in Thailand: The vulnerability analysis

    International Nuclear Information System (INIS)

    Nakawiro, Thanawat; Bhattacharyya, Subhes C.

    2007-01-01

    Thailand uses 74% of its natural gas supply for power generation and 70% of its power comes from gas-based technology. High dependence on natural gas in power generation raises concerns about security of electricity supply that could affect competitiveness of Thai manufacturing and other industries at the global level. The effect of fuel dependence on security of electricity supply has received less emphasis in the literature. Given this gap, this research examines the economic impact of high dependence on natural gas for power generation in Thailand by analyzing the effect of changes in fuel prices (including fuel oil and natural gas) on electricity tariff in Thailand. At the same time, the research quantifies the vulnerability of the Thai economy due to high gas dependence in power generation. Our research shows that for every 10% change in natural gas price, electricity tariff in Thailand would change by 3.5%. In addition, we found that the gas bill for power generation consumed between 1.94% and 3.05% of gross domestic product (GDP) between 2000 and 2004 and in terms of GDP share per unit of energy, gas dependence in power generation is almost similar to that of crude oil import dependence. We also found that the basic metal industry, being an electricity intensive industry, is the most affected industry. Additionally, we find that volatility of gas price is the main factor behind the vulnerability concern. The research accordingly simulates two mitigation options of the problem, namely reducing gas dependence and increasing efficiency of gas-fired power plants, where the results show that these methods can reduce the vulnerability of the country from high gas dependence in power generation

  15. Preparation of activated carbon from waste plastics polyethylene terephthalate as adsorbent in natural gas storage

    Science.gov (United States)

    Yuliusman; Nasruddin; Sanal, A.; Bernama, A.; Haris, F.; Ramadhan, I. T.

    2017-02-01

    The main problem is the process of natural gas storage and distribution, because in normal conditions of natural gas in the gas phase causes the storage capacity be small and efficient to use. The technology is commonly used Compressed Natural Gas (CNG) and Liquefied Natural Gas (LNG). The weakness of this technology safety level is low because the requirement for high-pressure CNG (250 bar) and LNG requires a low temperature (-161°C). It takes innovation in the storage of natural gas using the technology ANG (Adsorbed Natural Gas) with activated carbon as an adsorbent, causing natural gas can be stored in a low pressure of about 34.5. In this research, preparation of activated carbon using waste plastic polyethylene terephthalate (PET). PET plastic waste is a good raw material for making activated carbon because of its availability and the price is a lot cheaper. Besides plastic PET has the appropriate characteristics as activated carbon raw material required for the storage of natural gas because the material is hard and has a high carbon content of about 62.5% wt. The process of making activated carbon done is carbonized at a temperature of 400 ° C and physical activation using CO2 gas at a temperature of 975 ° C. The parameters varied in the activation process is the flow rate of carbon dioxide and activation time. The results obtained in the carbonization process yield of 21.47%, while the yield on the activation process by 62%. At the optimum process conditions, the CO2 flow rate of 200 ml/min and the activation time of 240 minutes, the value % burn off amounted to 86.69% and a surface area of 1591.72 m2/g.

  16. Natural gas for power generation : issues and implications : an energy market assessment

    International Nuclear Information System (INIS)

    2006-06-01

    This report presented a historical examination of trends in natural gas-fired generation as well as a perspective on the issues and potential implications of increasing reliance on natural gas. Potential changes to Canadian energy consumers were reviewed in addition to natural gas infrastructure and services. Electricity prices relating to natural gas generation were examined. A broad regional and continental perspective was employed to account for energy market integration and the fact that gas trends reflect developments outside of Canada. The report was divided into 2 sections: (1) an examination of the trend toward natural-gas fired generation of electricity in North America; and (2) an examination of issues in closer detail from a regional perspective followed by a discussion of the changes in generation and natural gas markets in western, eastern, and central North America. Questions arising from the analysis of specific regional supply, demand and infrastructure situations were also examined. Recommendations were presented for issues concerning the current gas market and the appropriate role of the government in ensuring adequate generation. Uncertainties in future natural gas supply were also considered. It was concluded that rapid industrial growth will continue to increase demand for natural gas and electricity supply. 5 figs

  17. Fuel Flexibility: Landfill Gas Contaminant Mitigation for Power Generation

    Energy Technology Data Exchange (ETDEWEB)

    Storey, John Morse [ORNL; Theiss, Timothy J [ORNL; Kass, Michael D [ORNL; FINNEY, Charles E A [ORNL; Lewis, Samuel [Oak Ridge National Laboratory (ORNL); Kaul, Brian C [ORNL; Besmann, Theodore M [ORNL; Thomas, John F [ORNL; Rogers, Hiram [ORNL; Sepaniak, Michael [University of Tennessee, Knoxville (UTK)

    2014-04-01

    This research project focused on the mitigation of silica damage to engine-based renewable landfill gas energy systems. Characterization of the landfill gas siloxane contamination, combined with characterization of the silica deposits in engines, led to development of two new mitigation strategies. The first involved a novel method for removing the siloxanes and other heavy contaminants from the landfill gas prior to use by the engines. The second strategy sought to interrupt the formation of hard silica deposits in the engine itself, based on inspection of failed landfill gas engine parts. In addition to mitigation, the project had a third task to develop a robust sensor for siloxanes that could be used to control existing and/or future removal processes.

  18. Natural gas for electric power generation: Strategic issues, risks and opportunities

    International Nuclear Information System (INIS)

    Linderman, C.

    1992-01-01

    Natural gas is again being regarded as a significant fuel for electric power generation. It was once a predominant fuel for utilities in gas-producing areas, but natural gas consumption declined greatly after the 1973 oil shock because of reduced electricity demand and increased coal and nuclear generation. Moreover, wellhead price and other forms of regulation produced gas shortages in the 1970s. The resurgence of natural gas in future resource plans stems from its inherent ideal fuel characteristics: short lead time; low capital costs; small increments of modular capacity; delivered close to load centers; environmentally benign, preferable to oil and coal; and potential for high thermal efficiency in gas turbines. Natural gas, if available and attractively priced, is an ideal fuel for electric power generation. No other fuel shares these attractive characteristics, and utilities, facing higher than expected load growth, are relying on an increasing proportion of gas-fired combustion turbines, combined cycle plants, and cogeneration to meet a growing, yet uncertain, future demand for electricity. Despite these desirable operating characteristics, the varied past and uncertain future of natural gas markets raise legitimate concerns about the riskiness of current utility natural gas strategies. This report, which summarizes the major findings from research efforts, is intended to help utility decision-makers understand the full range of risks they face with natural gas electric power generation and to identify actions they can take to mitigate those risks

  19. Study on gas turbines. Leading role of high efficiency power generation; Gas turbine kenkyu. Kokoritsu hatsuden no shuyaku wo nerau

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-01-31

    This review summarizes research works of Central Research Institute of Electric Power Industry on gas turbines playing a leading role of high efficiency power generation. This article describes historical changes of gas turbine technology, changes and current status from the viewpoint of electric power industry, and development trend in various makers. Increase in the flow-in gas temperature, low NOx combustion technology, use of various fuels, and durability evaluation and improvement technology for high temperature parts are described as technological problems and development trends. The increase in temperature is indispensable for the improvement of efficiency. Materials having heat resistance, anticorrosion and strength are required. Accordingly, Ni-based single crystal super alloy has been developed. Developments of ceramic gas turbine and catalytic combustor are also described. The coal gasification combined power generation is expected as a new power generation technology having availability of various coals, high efficiency, and excellent environmental protection. Development of 1500 {degree}C class combustor for turbines has been promoted. Evaluation and improvement of durability of high temperature parts are also described. For the new utilization technology of gas turbines, repowering and compressed air storage gas turbine power generation technology are introduced. 92 figs., 14 tabs.

  20. Micro generation of electricity with gasification gas in a engine generator in dual mode; Microgeracao de eletricidade com gas de gaseificacao num motor gerador dual

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Marcelo Jose da; Souza, Samuel Nelson Melegari de; Souza, Abel Alves de; Ricieri, Reinaldo P. [Universidade Estadual do Oeste do Parana (UNIOESTE), Cascavel, PE (Brazil)], E-mail: marcelo_js07@hotmail.com

    2010-07-01

    Among the alternatives to the increase of world energy demand the use of biomass as energy source is one of the most promising as it contributes to reducing emissions of carbon dioxide in the atmosphere. Gasification is a process technology of biomass energy in a gaseous biofuel. The fuel gas got a low calorific value that can be used in diesel engine in dual mode for power generation in isolated communities. This study aimed to evaluate the reduction in the consumption of oil diesel an engine generator, using gas from gasification of wood. The engine generator brand used, it was a BRANCO, with direct injection power of 10 hp and mated to an electric generator 5,5 kW. The fuel gas was produced in a gasifier type co-current. The engine generator was put on load system from 0.5 kW to 3.5 kW through electric bank of heaters. For the oil diesel savings, the gas was injected mixed with intake air, as the oil diesel was normally injected by the injector of the engine (motor dual). The consumption od diesel was measured diesel by means of a precision scale. It was concluded that the engine converted to dual mode when using the gas for the gasification of wood showed a decrease in diesel consumption by up to 57%. (author)

  1. New generation enrichment monitoring technology for gas centrifuge enrichment plants

    International Nuclear Information System (INIS)

    Ianakiev, Kiril D.; Alexandrov, Boian S.; Boyer, Brian D.; Hill, Thomas R.; Macarthur, Duncan W.; Marks, Thomas; Moss, Calvin E.; Sheppard, Gregory A.; Swinhoe, Martyn T.

    2008-01-01

    The continuous enrichment monitor, developed and fielded in the 1990s by the International Atomic Energy Agency, provided a go-no-go capability to distinguish between UF 6 containing low enriched (approximately 4% 235 U) and highly enriched (above 20% 235 U) uranium. This instrument used the 22-keV line from a 109 Cd source as a transmission source to achieve a high sensitivity to the UF 6 gas absorption. The 1.27-yr half-life required that the source be periodically replaced and the instrument recalibrated. The instrument's functionality and accuracy were limited by the fact that measured gas density and gas pressure were treated as confidential facility information. The modern safeguarding of a gas centrifuge enrichment plant producing low-enriched UF 6 product aims toward a more quantitative flow and enrichment monitoring concept that sets new standards for accuracy stability, and confidence. An instrument must be accurate enough to detect the diversion of a significant quantity of material, have virtually zero false alarms, and protect the operator's proprietary process information. We discuss a new concept for advanced gas enrichment assay measurement technology. This design concept eliminates the need for the periodic replacement of a radioactive source as well as the need for maintenance by experts. Some initial experimental results will be presented.

  2. Fuel prices, emission standards, and generation costs for coal vs natural gas power plants.

    Science.gov (United States)

    Pratson, Lincoln F; Haerer, Drew; Patiño-Echeverri, Dalia

    2013-05-07

    Low natural gas prices and stricter, federal emission regulations are promoting a shift away from coal power plants and toward natural gas plants as the lowest-cost means of generating electricity in the United States. By estimating the cost of electricity generation (COE) for 304 coal and 358 natural gas plants, we show that the economic viability of 9% of current coal capacity is challenged by low natural gas prices, while another 56% would be challenged by the stricter emission regulations. Under the current regulations, coal plants would again become the dominant least-cost generation option should the ratio of average natural gas to coal prices (NG2CP) rise to 1.8 (it was 1.42 in February 2012). If the more stringent emission standards are enforced, however, natural gas plants would remain cost competitive with a majority of coal plants for NG2CPs up to 4.3.

  3. Power generation potential using landfill gas from Ontario municipal solid waste landfills. Appendix B2

    International Nuclear Information System (INIS)

    Anon.

    1993-01-01

    Twenty-six landfill sites have been identified in Ontario with potential gas production rates suitable for recovery and use in power plant applications. If 70% of the gas naturally generated from these sites was collected and utilized, ca 88 MW could be produced in 1991 (declining to 74 MW by 2001) from the gas generated. Assuming the current average generation rate of one tonne per capita, an estimated nine million tonnes of municipal refuse is produced annually in Ontario, and landfilling is expected to continue to play a major role. It is suggested that the level of gas generation identified for the year 1991 will be sustainable given that as old landfills are spent, new ones are built. The accuracy of the prediction depends largely on future government policies regarding incineration, the effects of present waste reduction programs, and approval of new landfill sites. Due to the combined costs of the gas collection system, auxiliary equipment, and gas processing system, installed cost of a landfill-gas fired power plant is high relative to that of conventional natural gas-fired plants. For landfills presently without a gas collection system, the high initial capital investment for gas field test programs and for the installation of a collection system is a barrier that deters municipalities from tapping this energy potential. 2 figs., 3 tabs

  4. Gas generation and migration in the shallow land disposal and preliminary impact analysis

    International Nuclear Information System (INIS)

    Nakai, Kunihiro

    1996-01-01

    As the latent effect in the case of gas generation in waste repositories, the damage of barriers by gas pressure, the pushing-out of contaminated water by pressure gas in waste repositories, the movement of radioactive gases containing H-3, C-14 and others, the explosion accompanying the release of combustible gas like hydrogen onto ground, and the effect to ground-water flow by gas movement or pressure are conceivable. The mechanism and the rate of gas generation, and the amount of the substances that generate gases in low level radioactive waste are explained. The models for evaluating the generation, accumulation and movement of gases are described. As to the evaluation of gas movement, the conditions for the evaluation, the results of evaluating gas permeation, the sensitivity of various parameters and so on are reported. Also the effects of radioactive gases, the pushing-out of pore water, the explosion of pressure-accumulating gases and the effect to ground-water flow were evaluated. Supposing the gas generation in shallow underground waste repositories, the model for evaluating the behaviors of gases and water in a whole system was made, and the preliminary evaluation was carried out. (K.I.)

  5. Power-generating process of obtaining gas-energy carrier and reducer from coal

    International Nuclear Information System (INIS)

    Tleugabulov, S.; Duncheva, E.; Zubkevich, M.

    1999-01-01

    The manufacture of power-generating gas has the important economic value for Kazakhstan having large territory, raw and fuel resources especially power coal and clean coal wastes. The technology of reception of gas-energy carrier and reducer from power coal is developed. The basic product of technological process is heated reducing gas. Reducing potential of the gas is characterized by a volumetric share of components (CO+H 2 )-RC in relation to volume of whole mix of gases received with gasification of coal. The value of parameter RC is regulated by a degree of enrichment of air by oxygen r 0 , and the temperature - by the charge of a parity of endothermic reaction in the chamber of gas regeneration. The dependence of the gas structure and temperature on the degree of enrichment of air by oxygen is shown and the circuit of the gas generator is given. (author)

  6. Study related to the generation of the conditional intensities of ideal Bose-gas

    International Nuclear Information System (INIS)

    Al-Oklah, H.

    2007-01-01

    In this paper, we will answer on the following question: Are there any conditions on the chemical potential and temperature of an ideal BOSE gas when generating the conditional intensities of ideal Bose-gas, and will the position distribution of the ideal Bose-gas be a Gibbs-process. The study shows that there should be no conditions on the chemical potential and thermodynamical temperature of an ideal BOSE gas when we generate the conditional intensities of ideal Bose-gas except that the fundamental conditions, the chemical potential is negative and the inverse temperature is positive. Thus the position distribution of the ideal Bose-gas may only be a Gibbs-process, in the special case when the thermodynamical temperature of the ideal BOSE gas tends to the absolute zero. (author)

  7. Sample collection and preparation of biofluids and extracts for gas chromatography-mass spectrometry.

    Science.gov (United States)

    Emwas, Abdul-Hamid M; Al-Talla, Zeyad A; Kharbatia, Najeh M

    2015-01-01

    To maximize the utility of gas chromatography-mass spectrometry (GC-MS) in metabonomics research, all stages of the experimental design should be standardized, including sample collection, storage, preparation, and sample separation. Moreover, the prerequisite for any GC-MS analysis is that a compound must be volatile and thermally stable if it is to be analyzed using this technique. Since many metabolites are nonvolatile and polar in nature, they are not readily amenable to analysis by GC-MS and require initial chemical derivatization of the polar functional groups in order to reduce the polarity and to increase the thermal stability and volatility of the analytes. In this chapter, an overview is presented of the optimum approach to sample collection, storage, and preparation for gas chromatography-mass spectrometry-based metabonomics with particular focus on urine samples as example of biofluids.

  8. Closed-cycle gas turbine power generating system

    International Nuclear Information System (INIS)

    Jubb, A.; Ward, R.G.; Hurst, J.N.; Holliday, J.B.; Ashley, J.W.

    1975-01-01

    The invention deals with a gas-cooled reactor with at least one condenser, one turbin and one off-gas heat exchanger for preheating the coolant arranged in the pressure vessel inside a common supporting structure in the from of a pipe cylinder. This supporting structure can be removed from the pressure vessel independently of the core. The pipe cylinder is connected with the core feeding and recirculation lines. It has axial coolant channels in the cylindrical wall. The heat exchanger consists of a large number of coolant channels in axial direction. The feeding line is surrounded by several interpenetrating elastic ring elements. (HP) [de

  9. Effects of stepwise gas combustion on NOx generation

    International Nuclear Information System (INIS)

    Woperane Seredi, A.; Szepesi, E.

    1999-01-01

    To decrease NO x emission from gas boilers, the combustion process of gas has been modified from continuous combustion to step-wise combustion. In this process the combustion temperature, the temperature peaks in the flame, the residence time of combustion products in the high-temperature zone and the oxygen partial pressure are changed advantageously. Experiments were performed using multistage burners, and the NO x emission was recorded. It was found that the air factor of the primary combustion space has a determining effect on the NO x reduction. (R.P.)

  10. Obstacles to the penetration of electric generation markets by natural gas

    International Nuclear Information System (INIS)

    Schleede, G.R.

    1992-01-01

    This paper reviews and compares the advantages and disadvantages that electric power generators have in generating electricity from a variety of fuel sources. It then goes on to emphasize the use of natural gas and how it can become more competitive in the electric generation field. The paper is based primarily on experiences by the author during his employment with the New England Electric System (NEES). The author reviews the source of electricity for this utility and describes the percentages of each fuel source. It then goes on to specifically discuss the planned natural gas-fired projects in the utility system. The paper outlines the NEES strategy of diversification with respect to gas suppliers and describes the important considerations it used when planning for electric generation with gas. These include determining pressure requirements needed by the gas distribution system when the gas-generators come on-line; determining the placement of the generators within the overall system (i.e. peak load facilities, base load facilities, etc.); contracting flexibility because of the need to vary the amount of gas taken; and the ability to manage pipeline capacity and gas supplies when they are not needed

  11. Organic richness and gas generation potential of Permian Barren

    Indian Academy of Sciences (India)

    The organic geochemistry of shales in terms of its organic richness, hydrocarbon source potential, thermal maturity, depositional environment, etc., are essential stipulations for shale gas resources assessment. In this study, a total of 32 core samples of Permian Barren Measures from four boreholes in Raniganj field of ...

  12. Preparation of Active Absorbent for Flue Gas Desulfurization From Coal Bottom Ash: Effect of Absorbent Preparation Variables

    Directory of Open Access Journals (Sweden)

    Chang Chin Li, Lee Keat Teong, Subhash Bhatia and Abdul Rahman Mohamed

    2012-08-01

    Full Text Available An active absorbent for flue gas desulfurization was prepared from coal bottom ash, calcium oxide (CaO and calcium sulfate by hydro-thermal process. The absorbent was examined for its micro-structural properties. The experiments conducted were based on Design Of Experiments (DOE according to 23 factorial design. The effect of various absorbent preparation variables such as ratio of CaO to bottom ash (A, hydration temperature (B and hydration period (C towards the BET (Brunauer-Emmett-Teller specific surface area of the absorbent were studied. At a CaO to bottom ash ratio = 2, hydration temperature = 200 ?C and hydration period = 10 hrs, absorbent with a surface area of 90.1 m2/g was obtained. Based on the analysis of the factorial design, it was concluded that factor A and C as well as the interaction of factors ABC and BC are the significant factors that effect the BET surface area of the absorbent. A linear mathematical model that describes the relation between the independent variables and interaction between variables towards the BET specific surface area of the absorbent was also developed. Analysis of variance (ANOVA showed that the model was significant at 1% level.Key Words: Absorbent, Bottom Ash, Design Of Experiments, Desulfurization, Surface Area.

  13. An optimization model for natural gas supply portfolios of a power generation company

    International Nuclear Information System (INIS)

    Jirutitijaroen, Panida; Kim, Sujin; Kittithreerapronchai, Oran; Prina, José

    2013-01-01

    Highlights: ► An optimization model for daily operation of a natural gas-fired generation company is proposed. ► The model considers uncertainties in electricity price and natural gas price. ► The model is formulated to capture the hedging decisions by the company. ► The solution yields quantities of natural gas, generating schedule and purchasing quantities of electricity. ► Higher profit can be achieved by adapting inventory and production to the actual spot prices of natural gas and electricity. - Abstract: This paper considers a deregulated electricity market environment where a natural gas-fired generation company can engage in different types of contracts to manage its natural gas supply as well as trade on the electricity market. If the contracts are properly designed, they can protect the company from fluctuations in electricity price and demand, at some cost to the company’s expected profit. This reduction in profit can be mitigated by trading on the natural gas and electricity spot markets, but this trading activity may also sometimes result in losses. A stochastic programming model is formulated to capture the hedging decisions made by the company, as well as the interactions between the natural gas and electricity markets. The benefits offered by this approach for profit maximization in a variety of business scenarios, such as the case where the company can hold some amount of gas in storage are studied and presented. It is found that the stochastic model enables the company to optimize the electricity generation schedule and the natural gas consumption, including spot price transactions and gas storage management. Several managerial insights into the natural gas market, natural gas storage, and distribution profit are given

  14. Influence of gas-generation on melt/concrete interaction

    International Nuclear Information System (INIS)

    Powers, D.A.

    1979-01-01

    Gases formed during the interaction of a high-temperature melt with concrete are shown to stem from the thermal dehydration and decarboxylation of the concrete. The kinetics of these decomposition reactions are described. Gases within the melt cause an apparent swelling of the melt. The observed swelling is not easily correlated to the rate of gas evolution. Metallic melts cause CO 2 /CO and H 2 O liberated from the melt to be reduced to CO and hydrogen. When these gases escape from the melt they assist in aerosol formation. As the gases cool they react along a pathway whose oxygen fugacity is apparently buffered by the iron-Wuestite equilibrium. Methane is a product of the gas-phase reaction. (orig./HP) [de

  15. Gas Supply, Pricing Mechanism and the Economics of Power Generation in China

    Directory of Open Access Journals (Sweden)

    Yuanxin Liu

    2018-04-01

    Full Text Available During the “13th Five-Year Plan” period, green energy is the top priority for China. China has realized that natural gas, as a low-carbon energy source, fits with the nation’s energy demand and will play a critical role in the energy transition, but the actual industry development is slower than expected. By analyzing the major gas corporations around the world, the paper finds that the key factors of the sector are supply and price of the energy resource. A comprehensive analysis on domestic and foreign imported gas reveals a trend of oversupply in China in the future. Given the critical import dependence, China has introduced a series of gas price reforms since 2013, which have led to negative impacts on important gas consumption sectors including power generation. With the levelized cost of electricity (LCOE model, we find that under the prevailing gas supply structure and price level, the economy of utility gas power generation will remain unprofitable, while combined cooling heating and power (CCHP is only commercially feasible in coastal developed regions. If continuing, such a trend will not only bring forth disastrous consequences to gas power industry, but also damage the upstream gas industry, more importantly, impede the energy transition. We conclude the paper with policy implications on pricing mechanism reform, developing domestic unconventional gas and the R&D of gas turbine.

  16. Accounting for fuel price risk: Using forward natural gas prices instead of gas price forecasts to compare renewable to natural gas-fired generation

    Energy Technology Data Exchange (ETDEWEB)

    Bolinger, Mark; Wiser, Ryan; Golove, William

    2003-08-13

    Against the backdrop of increasingly volatile natural gas prices, renewable energy resources, which by their nature are immune to natural gas fuel price risk, provide a real economic benefit. Unlike many contracts for natural gas-fired generation, renewable generation is typically sold under fixed-price contracts. Assuming that electricity consumers value long-term price stability, a utility or other retail electricity supplier that is looking to expand its resource portfolio (or a policymaker interested in evaluating different resource options) should therefore compare the cost of fixed-price renewable generation to the hedged or guaranteed cost of new natural gas-fired generation, rather than to projected costs based on uncertain gas price forecasts. To do otherwise would be to compare apples to oranges: by their nature, renewable resources carry no natural gas fuel price risk, and if the market values that attribute, then the most appropriate comparison is to the hedged cost of natural gas-fired generation. Nonetheless, utilities and others often compare the costs of renewable to gas-fired generation using as their fuel price input long-term gas price forecasts that are inherently uncertain, rather than long-term natural gas forward prices that can actually be locked in. This practice raises the critical question of how these two price streams compare. If they are similar, then one might conclude that forecast-based modeling and planning exercises are in fact approximating an apples-to-apples comparison, and no further consideration is necessary. If, however, natural gas forward prices systematically differ from price forecasts, then the use of such forecasts in planning and modeling exercises will yield results that are biased in favor of either renewable (if forwards < forecasts) or natural gas-fired generation (if forwards > forecasts). In this report we compare the cost of hedging natural gas price risk through traditional gas-based hedging instruments (e

  17. Effects of microbial processes on gas generation under expected WIPP repository conditions: Annual report through 1992

    International Nuclear Information System (INIS)

    Francis, A.J.; Gillow, J.B.

    1993-09-01

    Microbial processes involved in gas generation from degradation of the organic constituents of transuranic waste under conditions expected at the Waste Isolation Pilot Plant (WIPP) repository are being investigated at Brookhaven National Laboratory. These laboratory studies are part of the Sandia National Laboratories -- WIPP Gas Generation Program. Gas generation due to microbial degradation of representative cellulosic waste was investigated in short-term ( 6 months) experiments by incubating representative paper (filter paper, paper towels, and tissue) in WIPP brine under initially aerobic (air) and anaerobic (nitrogen) conditions. Samples from the WIPP surficial environment and underground workings harbor gas-producing halophilic microorganisms, the activities of which were studied in short-term experiments. The microorganisms metabolized a variety of organic compounds including cellulose under aerobic, anaerobic, and denitrifying conditions. In long-term experiments, the effects of added nutrients (trace amounts of ammonium nitrate, phosphate, and yeast extract), no nutrients, and nutrients plus excess nitrate on gas production from cellulose degradation

  18. Recent developments on field gas extraction and sample preparation methods for radiokrypton dating of groundwater

    Science.gov (United States)

    Yokochi, Reika

    2016-09-01

    Current and foreseen population growths will lead to an increased demand in freshwater, large quantities of which is stored as groundwater. The ventilation age is crucial to the assessment of groundwater resources, complementing the hydrological model approach based on hydrogeological parameters. Ultra-trace radioactive isotopes of Kr (81 Kr and 85 Kr) possess the ideal physical and chemical properties for groundwater dating. The recent advent of atom trap trace analyses (ATTA) has enabled determination of ultra-trace noble gas radioisotope abundances using 5-10 μ L of pure Kr. Anticipated developments will enable ATTA to analyze radiokrypton isotope abundances at high sample throughput, which necessitates simple and efficient sample preparation techniques that are adaptable to various sample chemistries. Recent developments of field gas extraction devices and simple and rapid Kr separation method at the University of Chicago are presented herein. Two field gas extraction devices optimized for different sampling conditions were recently designed and constructed, aiming at operational simplicity and portability. A newly developed Kr purification system enriches Kr by flowing a sample gas through a moderately cooled (138 K) activated charcoal column, followed by a gentle fractionating desorption. This simple process uses a single adsorbent and separates 99% of the bulk atmospheric gases from Kr without significant loss. The subsequent two stages of gas chromatographic separation and a hot Ti sponge getter further purify the Kr-enriched gas. Abundant CH4 necessitates multiple passages through one of the gas chromatographic separation columns. The presented Kr separation system has a demonstrated capability of extracting Kr with > 90% yield and 99% purity within 75 min from 1.2 to 26.8 L STP of atmospheric air with various concentrations of CH4. The apparatuses have successfully been deployed for sampling in the field and purification of groundwater samples.

  19. ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT: BIOQUELL, INC. CLARIS C HYDROGEN PEROXIDE GAS GENERATOR

    Science.gov (United States)

    The Environmental Technology Verification report discusses the technology and performance of the Clarus C Hydrogen Peroxide Gas Generator, a biological decontamination device manufactured by BIOQUELL, Inc. The unit was tested by evaluating its ability to decontaminate seven types...

  20. Relative Role of Gas Generation and Displacement Rates in Cavity Nucleation and Growth

    DEFF Research Database (Denmark)

    Singh, Bachu Narain; Foreman, A. J E.

    1984-01-01

    Problems of helium diffusion and clustering during irradiation are analysed. Using the “homogeneous” nucleation theory , the effect of damage rate on cavity density is calculated for different gas generation to damage rate ratios. The influence of gas mobility on cavity nucleation has been...

  1. Hourly weather forecasts for gas turbine power generation

    Directory of Open Access Journals (Sweden)

    G. Giunta

    2017-06-01

    Full Text Available An hourly short-term weather forecast can optimize processes in Combined Cycle Gas Turbine (CCGT plants by helping to reduce imbalance charges on the national power grid. Consequently, a reliable meteorological prediction for a given power plant is crucial for obtaining competitive prices for the electric market, better planning and stock management, sales and supplies of energy sources. The paper discusses the short-term hourly temperature forecasts, at lead time day+1 and day+2, over a period of thirteen months in 2012 and 2013 for six Italian CCGT power plants of 390 MW each (260 MW from the gas turbine and 130 MW from the steam turbine. These CCGT plants are placed in three different Italian climate areas: the Po Valley, the Adriatic coast, and the North Tyrrhenian coast. The meteorological model applied in this study is the eni-Kassandra Meteo Forecast (e‑kmf™, a multi-model approach system to provide probabilistic forecasts with a Kalman filter used to improve accuracy of local temperature predictions. Performance skill scores, computed by the output data of the meteorological model, are compared with local observations, and used to evaluate forecast reliability. In the study, the approach has shown good overall scores encompassing more than 50,000 hourly temperature values. Some differences from one site to another, due to local meteorological phenomena, can affect the short-term forecast performance, with consequent impacts on gas-to-power production and related negative imbalances. For operational application of the methodology in CCGT power plant, the benefits and limits have been successfully identified.

  2. Conical flow near singular rays. [shock generation in ideal gas

    Science.gov (United States)

    Zahalak, G. I.; Myers, M. K.

    1974-01-01

    The steady flow of an ideal gas past a conical body is investigated by the method of matched asymptotic expansions, with particular emphasis on the flow near the singular ray occurring in linearized theory. The first-order problem governing the flow in this region is formulated, leading to the equation of Kuo, and an approximate solution is obtained in the case of compressive flow behind the main front. This solution is compared with the results of previous investigations with a view to assessing the applicability of the Lighthill-Whitham theories.

  3. Integration of gas chromatography mass spectrometry methods for differentiating ricin preparation methods.

    Science.gov (United States)

    Wunschel, David S; Melville, Angela M; Ehrhardt, Christopher J; Colburn, Heather A; Victry, Kristin D; Antolick, Kathryn C; Wahl, Jon H; Wahl, Karen L

    2012-05-07

    The investigation of crimes involving chemical or biological agents is infrequent, but presents unique analytical challenges. The protein toxin ricin is encountered more frequently than other agents and is found in the seeds of Ricinus communis, commonly known as the castor plant. Typically, the toxin is extracted from castor seeds utilizing a variety of different recipes that result in varying purity of the toxin. Moreover, these various purification steps can also leave or differentially remove a variety of exogenous and endogenous residual components with the toxin that may indicate the type and number of purification steps involved. We have applied three gas chromatography-mass spectrometry (GC-MS) based analytical methods to measure the variation in seed carbohydrates and castor oil ricinoleic acid, as well as the presence of solvents used for purification. These methods were applied to the same samples prepared using four previously identified toxin preparation methods, starting from four varieties of castor seeds. The individual data sets for seed carbohydrate profiles, ricinoleic acid, or acetone amount each provided information capable of differentiating different types of toxin preparations across seed types. However, the integration of the data sets using multivariate factor analysis provided a clear distinction of all samples based on the preparation method, independent of the seed source. In particular, the abundance of mannose, arabinose, fucose, ricinoleic acid, and acetone were shown to be important differentiating factors. These complementary tools provide a more confident determination of the method of toxin preparation than would be possible using a single analytical method.

  4. Nanocomposite metal/plasma polymer films prepared by means of gas aggregation cluster source

    Energy Technology Data Exchange (ETDEWEB)

    Polonskyi, O.; Solar, P.; Kylian, O.; Drabik, M.; Artemenko, A.; Kousal, J.; Hanus, J.; Pesicka, J.; Matolinova, I. [Charles University in Prague, Faculty of Mathematics and Physics, V Holesovickach 2, 18000 Prague 8 (Czech Republic); Kolibalova, E. [Tescan, Libusina trida 21, 632 00 Brno (Czech Republic); Slavinska, D. [Charles University in Prague, Faculty of Mathematics and Physics, V Holesovickach 2, 18000 Prague 8 (Czech Republic); Biederman, H., E-mail: bieder@kmf.troja.mff.cuni.cz [Charles University in Prague, Faculty of Mathematics and Physics, V Holesovickach 2, 18000 Prague 8 (Czech Republic)

    2012-04-02

    Nanocomposite metal/plasma polymer films have been prepared by simultaneous plasma polymerization using a mixture of Ar/n-hexane and metal cluster beams. A simple compact cluster gas aggregation source is described and characterized with emphasis on the determination of the amount of charged clusters and their size distribution. It is shown that the fraction of neutral, positively and negatively charged nanoclusters leaving the gas aggregation source is largely influenced by used operational conditions. In addition, it is demonstrated that a large portion of Ag clusters is positively charged, especially when higher currents are used for their production. Deposition of nanocomposite Ag/C:H plasma polymer films is described in detail by means of cluster gas aggregation source. Basic characterization of the films is performed using transmission electron microscopy, ultraviolet-visible and Fourier-transform infrared spectroscopies. It is shown that the morphology, structure and optical properties of such prepared nanocomposites differ significantly from the ones fabricated by means of magnetron sputtering of Ag target in Ar/n-hexane mixture.

  5. Utilization of hydrogen gas production for electricity generation in ...

    African Journals Online (AJOL)

    Lecturer

    2012-05-03

    % total sugar concentration of sugar ... 107 cfu/ml, pH was nearly constant at 6.0, and finally the H2 was drifted to fuel cell to generate electrical power until 4 V ..... hybrid system, reverse micelles and by metabolic engi- neering.

  6. Modeling of microbial gas generation: application to the eastern Mediterranean “Biogenic Play”

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, M.; Dubille, M.; Montadert, L.

    2016-07-01

    Biogenic gas is becoming increasingly important as an exploration target in the petroleum industry because it occurs in geologically predictable circumstances and in large quantities at shallow depths as free gas or gas hydrates. As accumulations of biogenic gas result in a subtle synchronization between early generation and early trapping, we integrated a macroscopic model of microbial gas generation within a 3D basin and petroleum system forward simulator. The macroscopic model is based on a microscopic model, which consists in a 1D sedimentary column that accounts for sedimentation, compaction, Darcy flow and Diffusion flow. The organic carbon is the only non-soluble element considered in this version of the model. The dissolved elements are O2, SO4 2-, H2, CH3COOH, and CH4. Methane is dissolved in water or present as a free phase if its concentration exceeds its solubility at given pressure and temperature. In this microscopic model, the transformation of substrate into biomass is described through a set of logistic equations coupled with the transport equations (advection and diffusion). Based on the microscopic considerations we developed the macroscopic model of low maturity/biogenic gas generation in which hydrocarbons are generated through first order kinetic reactions at low maturity. This macroscopic model is adapted to petroleum system modeling at basin scale with TemisFlow®, which aims to understand and predict hydrocarbon generation, migration, and accumulation. It is composed of: i) A source rock criteria which allow defining the biogenic gas source rocks potential and ii) A kinetic model of methane generation. The previous model has been successfully applied on different basins such as the Carupano Basin from the offshore Venezuela, the Magdalena Delta (offshore Colombia) and the offshore Vietnam where direct observations of low-maturity gas were available. Furthermore, it has been applied in the offshore Lebanon in order to check the viability of

  7. Preparation of standard mixtures of gas hydrocarbons in air by the diffusion dilution method

    International Nuclear Information System (INIS)

    Garcia, M. R.; Perez, M. M.

    1979-01-01

    An original diffusion system able to produce continuously gaseous samples is described. This system can generate samples with concentrations of benzene in air from 0.1 to 1 ppm a reproducible way. The diffusion dilution method used Is also studied. The use of this diffusion system has been extended to the preparation of binary mixtures (benzene-toluene). Whit a secondary dilution device is possible preparing these mixtures over a wide range of concentrations (0.11 to 0.04 ppm for benzene and 0.06 to 0.02 for toluene). (Author) 7 refs

  8. Engineering design and exergy analyses for combustion gas turbine based power generation system

    International Nuclear Information System (INIS)

    Sue, D.-C.; Chuang, C.-C.

    2004-01-01

    This paper presents the engineering design and theoretical exergetic analyses of the plant for combustion gas turbine based power generation systems. Exergy analysis is performed based on the first and second laws of thermodynamics for power generation systems. The results show the exergy analyses for a steam cycle system predict the plant efficiency more precisely. The plant efficiency for partial load operation is lower than full load operation. Increasing the pinch points will decrease the combined cycle plant efficiency. The engineering design is based on inlet air-cooling and natural gas preheating for increasing the net power output and efficiency. To evaluate the energy utilization, one combined cycle unit and one cogeneration system, consisting of gas turbine generators, heat recovery steam generators, one steam turbine generator with steam extracted for process have been analyzed. The analytical results are used for engineering design and component selection

  9. Design considerations: gas turbines for electric power generation

    International Nuclear Information System (INIS)

    Moon, D.M.

    1979-01-01

    The gas turbine represents one of the most sophisticated designs from the standpoint of time dependent deformation behavior. The large size of the equipment, which limits the amount of full scale testing, together with the demanding performance requirements and high level of reliability desired places a high degree of emphasis on the high temperature deformation design process. As an example of the various design considerations used in this equipment, a brief overview of the turbine will be given, highlighting the materials, stress, temperatures, and load history experienced by the major components. Particular attention will then be focused on the vane segment design considerations. This component is not only structurally complicated, but experiences steep temperature gradients imposed by internal cooling and large temperature transients during cyclic duty operation which have to be addressed in the design procedure. Based on this discussion the limitations of the current design procedures will be highlighted and the areas requiring additional research inputs will be discussed

  10. Study on economic potential of nuclear-gas combined cycle power generation in Chinese market

    International Nuclear Information System (INIS)

    Zhou Zhiwei; Bian Zhiqiang; Yang Mengjia

    2004-01-01

    Facing the challenges of separation of electric power plant and grid, and the deregulation of Chinese electricity supplying market in near future, nuclear power plants mainly operated as based load at the present regulated market should look for new operation mode. The economics of electric generation with nuclear-natural gas combined cycle is studied based on current conditions of natural gas and nuclear power plants in China. The results indicate that the technology development of nuclear-natural gas combined cycle for power generation is of potential prospects in Chinese electric market. (authors)

  11. Cr(VI) generation during sample preparation of solid samples – A ...

    African Journals Online (AJOL)

    Cr(VI) generation during sample preparation of solid samples – A chromite ore case study. R.I Glastonbury, W van der Merwe, J.P Beukes, P.G van Zyl, G Lachmann, C.J.H Steenkamp, N.F Dawson, M.H Stewart ...

  12. Performance of PZC-Mo generator and labeling results prepared with its eluate and MDP kit

    International Nuclear Information System (INIS)

    Yishu Liu

    2006-01-01

    This paper described the performance of Tc-99m generator prepared with Mo adsorbent PZC and irradiated nature MoO 3 , and the labeling results of MDP kit prepared with Tc-99m eluted from PZC-Mo generator and MDP was report as well. ThreeTc-99m generators was prepared with different batches of PZC and reactor irradiated nature Mo. The adsorption efficiency of two batches of the PZC is good (96.4% and 93.4%) and that of one batch of PZC is not satisfy (77.8%). The elution efficiency is not so high, and it increases along with the elution date. The elution file is very broad till to 30 ml and the Mo breakthrough is high to unacceptable. The labelling efficiency of MDP kit, prepared with Tc-99m eluate eluted with saline containing 0.05% NaClO from Mo-PZC generator, is approximately 77∼84% and it can reach to >98% labelling with eluate without containing 0.05%HClO in eluate. (author)

  13. Preparation of imaging kits locally using indium-113 as a suitable short-lived generator product

    International Nuclear Information System (INIS)

    Hamid, Hamid Seidna

    1999-05-01

    In this study forty patients are selected to do brain , lung , bone , liver and spleen imaging. Patients were selected carefully in the bases of the imaging history disorders. Kits prepared and kept frozen in (- 20 degree C) eluent the generator and indium 113 products were added to each kit and imaging sorted out using gamma camera and analysed statistically

  14. Heat-pipe assisted thermoelectric generators for exhaust gas applications

    OpenAIRE

    Gonçalves, L. M.; Martins, Jorge; Antunes, Joaquim; Rocha, Romeu; Brito, F. P.

    2012-01-01

    Millions of hybrid cars are already running on our roads with the purpose of reducing fossil fuel dependence. One of their main advantages is the recovery of wasted energy, namely by brake recovery. However, there are other sources of wasted energy in a car powered by an internal combustion engine, such as the heat lost through the cooling system, lubrication system (oil coolers) and in the exhaust system. These energies can be recuperated by the use of thermoelectric generators (TEG) based o...

  15. Generation of oxy-hydrogen gas and its effect on performance of spark ignition engine

    Science.gov (United States)

    Patil, N. N.; Chavan, C. B.; More, A. S.; Baskar, P.

    2017-11-01

    Considering the current scenario of petroleum fuels, it has been observed that, they will last for few years from now. On the other hand, the ever increasing cost of a gasoline fuels and their related adverse effects on environment caught the attention of researchers to find a supplementary source. For commercial fuels, supplementary source is not about replacing the entire fuel, instead enhancing efficiency by simply making use of it in lesser amount. From the recent research that has been carried out, focus on the use of Hydrogen rich gas as a supplementary source of fuel has increased. But the problem related to the storage of hydrogen gas confines the application of pure hydrogen in petrol engine. Using oxy-hydrogen gas (HHO) generator the difficulties of storing the hydrogen have overcome up to a certain limit. The present study highlights on performance evaluation of conventional petrol engine by using HHO gas as a supplementary fuel. HHO gas was generated from the electrolysis of water. KOH solution of 3 Molar concentration was used which act as a catalyst and accelerates the rate of generation of HHO gas. Quantity of gas to be supplied to the engine was controlled by varying amount of current. It was observed that, engine performance was improved on the introduction of HHO gas.

  16. Status and integration of studies of gas generation in Hanford wastes

    International Nuclear Information System (INIS)

    Pederson, L.R.; Bryan, S.A.

    1996-10-01

    The purpose of this report is to review recent progress in determining the mechanism, kinetics, and stoichiometry of gas generation in Hanford waste tanks. Information has been gathered from the results of (1) laboratory studies with simulated wastes; (2) laboratory studies with actual waste core samples (Tanks SY-101 and SY-103); (3) studies of thermal and radiolytic reactions in the gas phase; (4) gas solubility evaluations; and (5) in-tank gas composition data. The results of laboratory studies using simulated wastes, which were aimed at determining chemical mechanisms responsible for gas generation, are summarized in Section 2. Emphasized are findings from work performed at the Georgia Institute of Technology (GIT), which was conducted under subcontract to Pacific Northwest National Laboratory (PNNL) and completed in FY 1996. Thermally activated pathways for the decomposition of hydroxyethylethylene-diaminetriacetic acid (HEDTA, trisodium salt) in simulated wastes were established by this work, among other accomplishments

  17. Status and integration of studies of gas generation in Hanford wastes

    Energy Technology Data Exchange (ETDEWEB)

    Pederson, L.R.; Bryan, S.A.

    1996-10-01

    The purpose of this report is to review recent progress in determining the mechanism, kinetics, and stoichiometry of gas generation in Hanford waste tanks. Information has been gathered from the results of (1) laboratory studies with simulated wastes; (2) laboratory studies with actual waste core samples (Tanks SY-101 and SY-103); (3) studies of thermal and radiolytic reactions in the gas phase; (4) gas solubility evaluations; and (5) in-tank gas composition data. The results of laboratory studies using simulated wastes, which were aimed at determining chemical mechanisms responsible for gas generation, are summarized in Section 2. Emphasized are findings from work performed at the Georgia Institute of Technology (GIT), which was conducted under subcontract to Pacific Northwest National Laboratory (PNNL) and completed in FY 1996. Thermally activated pathways for the decomposition of hydroxyethylethylene-diaminetriacetic acid (HEDTA, trisodium salt) in simulated wastes were established by this work, among other accomplishments.

  18. Performance and Economics of Catalytic Glow Plugs and Shields in Direct Injection Natural Gas Engines for the Next Generation Natural Gas Vehicle Program: Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Mello, J. P.; Bezaire, D.; Sriramulu, S.; Weber, R.

    2003-08-01

    Subcontractor report details work done by TIAX and Westport to test and perform cost analysis for catalytic glow plugs and shields for direct-injection natural gas engines for the Next Generation Natural Gas Vehicle Program.

  19. Numerical study of the generation of runaway electrons in a gas diode with a hot channel

    Energy Technology Data Exchange (ETDEWEB)

    Lisenkov, V. V., E-mail: lisenkov@iep.uran.ru [Institute of Electrophysics UrB RAS, 106 Amundsena St., Ekaterinburg 620012 (Russian Federation); Ural Federal University, 19 Mira St., Ekaterinburg 620002 (Russian Federation); Shklyaev, V. A., E-mail: shklyaev@to.hcei.tsc.ru [Institute of High Current Electronics SD RAS, 2/3 Akademichesky Avenue, 634055 Tomsk (Russian Federation); National Research Tomsk Polytechnic University, 30 Lenin Avenue, 634050 Tomsk (Russian Federation)

    2015-11-15

    A new method for increasing the efficiency of runaway electron beam generation in atmospheric pressure gas media has been suggested and theoretically proved. The method consists of creating a hot region (e.g., a spark channel or a laser plume) with a decreased numerical density of gas molecules (N) near the cathode. In this method, the ratio E/N (E—electric field strength) is increased by decreasing N instead of increasing E, as has been done in the past. The numerical model that is used allows the simultaneous calculation of the formation of a subnanosecond gas discharge and the generation of runaway electrons in gas media. The calculations have demonstrated the possibility of obtaining current pulses of runaway electrons with amplitudes of hundred of amperes and durations of more than 100 ps. The influence of the hot channel geometry on the parameters of the generated beam has been investigated.

  20. 76 FR 62055 - Wabash Gas Storage, LLC; Notice of Intent To Prepare an Environmental Assessment for the Planned...

    Science.gov (United States)

    2011-10-06

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. PF11-6-000] Wabash Gas Storage, LLC; Notice of Intent To Prepare an Environmental Assessment for the Planned Wabash Gas Storage Project, Request for Comments on Environmental Issues, and Notice of Public Scoping Meeting The staff of the Federal Energy Regulatory Commission ...

  1. 78 FR 38024 - Magnolia LNG, LLC; Liquefied Natural Gas Limited; Notice of Intent To Prepare an Environmental...

    Science.gov (United States)

    2013-06-25

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. PF13-9-000] Magnolia LNG, LLC; Liquefied Natural Gas Limited; Notice of Intent To Prepare an Environmental Impact Statement for the Planned Magnolia Liquefied Natural Gas Project, Request for Comments on Environmental Issues, and Notice of Public Scoping Meeting The staff of...

  2. 75 FR 65475 - Tallulah Gas Storage, LLC; Notice of Intent To Prepare an Environmental Assessment for the...

    Science.gov (United States)

    2010-10-25

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. CP10-494-000] Tallulah Gas Storage, LLC; Notice of Intent To Prepare an Environmental Assessment for the Proposed Tallulah Gas Storage Project, Request for Comments on Environmental Issues, and Notice of Onsite Environmental Review October 18, 2010. The staff of the Federal...

  3. Reduction of impurity contamination in a working gas for closed-cycle MHD power generation

    International Nuclear Information System (INIS)

    Endo, N.; Yoshikawa, K.; Shioda, S.

    1989-01-01

    The reduction of impurity contamination in a working inert gas for closed-cycle MHD power generation is examined. A conceptual operation system of regenerative heat exchangers is proposed for minimizing the amount of combustion gas which mixes in the working inert gas. Experiments have shown that this mixing can be reduced significantly by evacuating and flushing the heat exchangers after being heated by combustion gas. Calculations have shown that, among the main molecular contaminants in the working inert gas, CO 2 , H 2 O and O 2 can be removed as compounds with the seed material, while N 2 and H 2 can be reduced by a partial purification of the circulating working inert gas. (author)

  4. Megawatt low-temperature DC plasma generator with divergent channels of gas-discharge tract

    Science.gov (United States)

    Gadzhiev, M. Kh.; Isakaev, E. Kh.; Tyuftyaev, A. S.; Yusupov, D. I.; Sargsyan, M. A.

    2017-04-01

    We have developed and studied a new effective megawatt double-unit generator of low-temperature argon plasma, which belongs to the class of dc plasmatrons and comprises the cathode and anode units with divergent gas-discharge channels. The generator has an efficiency of about 80-85% and ensures a long working life at operating currents up to 4000 A.

  5. Full-energy-chain analysis of greenhouse gas emissions for solar thermal electric power generation systems

    International Nuclear Information System (INIS)

    Norton, B.; Lawson, W.R.

    1997-01-01

    Technical attributes and environmental impacts of solar thermal options for centralized electricity generation are discussed. In particular, the full-energy-chain, including embodied energy and energy production, is considered in relation to greenhouse gas emission arising from solar thermal electricity generation. Central receiver, parabolic dish, parabolic trough and solar pond systems are considered. (author)

  6. Natural Gas, Wind and Nuclear Options for Generating Electricity in a Carbon Constrained World

    NARCIS (Netherlands)

    Kooten, van G.C.

    2012-01-01

    A linear programming model is used to examine the impact of carbon taxes on the optimal generation mix in the Alberta electrical system. The model permits decommissioning of generating assets with high carbon dioxide emissions and investment in new gas-fired, wind and, in some scenarios, nuclear

  7. Drought Resilience of Water Supplies for Shale Gas Extraction and Related Power Generation in Texas

    Science.gov (United States)

    Reedy, R. C.; Scanlon, B. R.; Nicot, J. P.; Uhlman, K.

    2014-12-01

    There is considerable concern about water availability to support energy production in Texas, particularly considering that many of the shale plays are in semiarid areas of Texas and the state experienced the most extreme drought on record in 2011. The Eagle Ford shale play provides an excellent case study. Hydraulic fracturing water use for shale gas extraction in the play totaled ~ 12 billion gallons (bgal) in 2012, representing ~7 - 10% of total water use in the 16 county play area. The dominant source of water is groundwater which is not highly vulnerable to drought from a recharge perspective because water is primarily stored in the confined portion of aquifers that were recharged thousands of years ago. Water supply drought vulnerability results primarily from increased water use for irrigation. Irrigation water use in the Eagle Ford play was 30 billion gallons higher in the 2011 drought year relative to 2010. Recent trends toward increased use of brackish groundwater for shale gas extraction in the Eagle Ford also reduce pressure on fresh water resources. Evaluating the impacts of natural gas development on water resources should consider the use of natural gas in power generation, which now represents 50% of power generation in Texas. Water consumed in extracting the natural gas required for power generation is equivalent to ~7% of the water consumed in cooling these power plants in the state. However, natural gas production from shale plays can be overall beneficial in terms of water resources in the state because natural gas combined cycle power generation decreases water consumption by ~60% relative to traditional coal, nuclear, and natural gas plants that use steam turbine generation. This reduced water consumption enhances drought resilience of power generation in the state. In addition, natural gas combined cycle plants provide peaking capacity that complements increasing renewable wind generation which has no cooling water requirement. However, water

  8. 75 FR 67996 - Environmental Documents Prepared for Proposed Oil, Gas, and Mineral Operations by the Gulf of...

    Science.gov (United States)

    2010-11-04

    ... Environmental Documents Prepared for Proposed Oil, Gas, and Mineral Operations by the Gulf of Mexico Outer... regarding whether those effects have significant impacts. Environmental Assessments are used to evaluate.... ACTION: Notice of the Availability of Environmental Documents Prepared for OCS Mineral Proposals by the...

  9. Price elasticity of natural gas demand in the power generation sector

    International Nuclear Information System (INIS)

    McArdle, P.F.

    1990-01-01

    Today, the demand for energy by the electric generation sector is highly competitive and price-responsive. Previous estimates of the price elasticity of natural gas demand in this sector have focused primarily on data from the 1960s and 1970s. Such estimates fail to take full account of economic, regulatory, and legislative developments that have altered the structure of the electric generation market during the 1980s. Structural changes include an increased ability of utilities to choose among generating options, the increase in non-utility generators, the amending of the Fuel Use Act, and a more competitive market for electricity. An accurate estimate of price elasticity requires a refocusing on data from the post-1983 period. The purpose of this paper is to answer two questions: how price responsive (elastic) is natural gas demand in this market; and what changes in natural gas demand elasticity have occurred over time

  10. The Efficiency Improvement by Combining HHO Gas, Coal and Oil in Boiler for Electricity Generation

    Directory of Open Access Journals (Sweden)

    Chia-Nan Wang

    2017-02-01

    Full Text Available Electricity is an essential energy that can benefit our daily lives. There are many sources available for electricity generation, such as coal, natural gas and nuclear. Among these sources, coal has been widely used in thermal power plants that account for about 41% of the worldwide electricity supply. However, these thermal power plants are also found to be a big pollution source to our environment. There is a need to explore alternative electricity sources and improve the efficiency of electricity generation. This research focuses on improving the efficiency of electricity generation through the use of hydrogen and oxygen mixture (HHO gas. In this research, experiments have been conducted to investigate the combined effects of HHO gas with other fuels, including coal and oil. The results show that the combinations of HHO with coal and oil can improve the efficiency of electricity generation while reducing the pollution to our environment.

  11. Heat Generation on Implant Surface During Abutment Preparation at Different Elapsed Time Intervals.

    Science.gov (United States)

    Al-Keraidis, Abdullah; Aleisa, Khalil; Al-Dwairi, Ziad Nawaf; Al-Tahawi, Hamdi; Hsu, Ming-Lun; Lynch, Edward; Özcan, Mutlu

    2017-10-01

    The purpose of this study was to evaluate heat generation at the implant surface caused by abutment preparation using a diamond bur in a high-speed dental turbine in vitro at 2 different water-coolant temperatures. Thirty-two titanium-alloy abutments were connected to a titanium-alloy implant embedded in an acrylic resin placed within a water bath at a controlled temperature of 37°C. The specimens were equally distributed into 2 groups (16 each). Group 1: the temperature was maintained at 20 ± 1°C; and group 2: the temperature was maintained at 32 ± 1°C. Each abutment was prepared in the axial plane for 1 minute and in the occlusal plane for 1 minute. The temperature of the heat generated from abutment preparation was recorded and measured at 3 distinct time intervals. Water-coolant temperature (20°C vs 32°C) had a statistically significant effect on the implant's temperature change during preparation of the abutment (P water-coolant temperature of 20 ± 1°C during preparation of the implant abutment decreased the temperature recorded at the implant surface to 34.46°C, whereas the coolant temperature of 32 ± 1°C increased the implant surface temperature to 40.94°C.

  12. Gas generation phenomena in radioactive waste transportation packaging

    International Nuclear Information System (INIS)

    Nigrey, P.J.

    1998-01-01

    The interaction of radiation from radioactive materials with the waste matrix can lead to the deterioration of the waste form resulting in the possible of gaseous species. Depending on the type and characteristics of the radiation source, the generation of hydrogen may predominate. Since the interaction of alpha particles with the waste form results in significant energy transfer, other gases such as carbon oxides, methane, nitrogen oxides, oxygen, water, and helium are possible. The type of gases produced from the waste forms is determined by the mechanisms involved in the waste degradation. For transuranic wastes, the identified degradation mechanisms are reported to be caused by radiolysis, thermal decomposition or dewatering, chemical corrosion, and bacterial action. While all these mechanisms may be responsible for the building of gases during the storage of wastes, radiolysis and thermal decomposition appear to be main contributors during waste transport operations. (authors)

  13. Radiolytic gas generation in Salt Cake Quality Assurance Plan

    International Nuclear Information System (INIS)

    Walker, D.D.

    1993-01-01

    High-level radioactive wastes are stored in large, steel tanks in the Savannah River Site's Tank Farms. The liquid levels in these tanks are monitored to detect leakage of waste out of tanks or leakage of liquids into the tanks. Recent unexplained level fluctuations in high-level waste (HLW) tanks have caused High Level Waste Engineering (HLWE) to develop a program to better understand tank level behavioral Interim Waste Technology (IWT) has been requested by HLWE to obtain data which will lead to a better understanding of the radiolytic generation of gases in salt cake. A task plan has been written in response to this request. This document details the controls necessary to ensure the quality of the results of the activities described in the task plan

  14. Next Generation Thermal Barrier Coatings for the Gas Turbine Industry

    Science.gov (United States)

    Curry, Nicholas; Markocsan, Nicolaie; Li, Xin-Hai; Tricoire, Aurélien; Dorfman, Mitch

    2011-01-01

    The aim of this study is to develop the next generation of production ready air plasma sprayed thermal barrier coating with a low conductivity and long lifetime. A number of coating architectures were produced using commercially available plasma spray guns. Modifications were made to powder chemistry, including high purity powders, dysprosia stabilized zirconia powders, and powders containing porosity formers. Agglomerated & sintered and homogenized oven spheroidized powder morphologies were used to attain beneficial microstructures. Dual layer coatings were produced using the two powders. Laser flash technique was used to evaluate the thermal conductivity of the coating systems from room temperature to 1200 °C. Tests were performed on as-sprayed samples and samples were heat treated for 100 h at 1150 °C. Thermal conductivity results were correlated to the coating microstructure using image analysis of porosity and cracks. The results show the influence of beneficial porosity on reducing the thermal conductivity of the produced coatings.

  15. Regulation and Measurement of the Heat Generated by Automatic Tooth Preparation in a Confined Space.

    Science.gov (United States)

    Yuan, Fusong; Zheng, Jianqiao; Sun, Yuchun; Wang, Yong; Lyu, Peijun

    2017-06-01

    The aim of this study was to assess and regulate heat generation in the dental pulp cavity and circumambient temperature around a tooth during laser ablation with a femtosecond laser in a confined space. The automatic tooth preparing technique is one of the traditional oral clinical technology innovations. In this technique, a robot controlled an ultrashort pulse laser to automatically complete the three-dimensional teeth preparing in a confined space. The temperature control is the main measure for protecting the tooth nerve. Ten tooth specimens were irradiated with a femtosecond laser controlled by a robot in a confined space to generate 10 teeth preparation. During the process, four thermocouple sensors were used to record the pulp cavity and circumambient environment temperatures with or without air cooling. A statistical analysis of the temperatures was performed between the conditions with and without air cooling (p heat generated in the pulp cavity was lower than the threshold for dental pulp damage. These results indicate that femtosecond laser ablation with air cooling might be an appropriate method for automatic tooth preparing.

  16. The PZC-based Tc-99m generator preparation and its performance test

    International Nuclear Information System (INIS)

    Liu Yishu

    2007-01-01

    This paper described the preparation of Tc-99m generator prepared with Japan distributing Mo adsorbent PZC and irradiated nature MoO 3 and its performance test. Four Tc-99m generators were prepared with different batches of PZC and reactor irradiated nature MoO 3 . The adsorption capacity of PZC to Mo is approximately 200mgMo/gPZC. The adsorption efficiency of three batches PZC is good (>90%) and that of one batch of PZC is not good enough (∼83%). The loss of fine powder (The PZC is fragile) is quite different with the different preparation process of PZC. The elution efficiency is 80-90% and has the up trend with the elution date. The Mo breakthrough can be controlled to acceptable level by connecting HZO safe column containing 1.0g HZO. All the specifications of eluted from PZC-based Tc-99m generator can meet the requirements under Sodium Pertechnetate injection in China Pharmacopoeia. (author)

  17. Preparation and characterization of polyaniline-cadmium sulfide nanocomposite for gas sensor application

    Science.gov (United States)

    Al-Jawad, Selma M. H.; Rafic, Sewench N.; Muhsen, Mustafa M.

    2017-09-01

    Polyaniline (PANI) was prepared by chemical oxidative polymerization of aniline monomers as emeraldine salt form. By the same method, polyaniline-cadmium sulfide nanocomposites were synthesized in the presence of different percentages (10-50 wt.%) of cadmium sulfide (CdS) which was prepared by using sol-gel method. The optical band gap was decrease with increasing of CdS concentration, that is obtained from UV-VIS measurements. From SEM and AFM, there is uniform distribution for cadmium sulfide nanoparticles in the PANI matrix. The electrical measurements of nanocomposites exhibit the effect of crystallite size and the high resistivity of CdS on the resistivity of nanocomposites. Emeraldine salt PANI, CdS and PANI-CdS nanocomposites were investigated as gas sensors. From this investigation, the sensitivity of PANI-CdS for NO2 gas increase with the increasing of operation temperature and the optimum sensitivity was obtained at 200∘C. The sensitivity of nanocomposites at best temperature (200∘C) was increased and faster response time with the increasing of CdS contents.

  18. Gas sensing properties of graphene–WO3 composites prepared by hydrothermal method

    International Nuclear Information System (INIS)

    Chu, Xiangfeng; Hu, Tao; Gao, Feng; Dong, Yongping; Sun, Wenqi; Bai, Linshan

    2015-01-01

    Graphical abstract: - Highlights: • The amount of graphene had an effect on the morphology of graphene–WO 3 composites. • The optimum temperature of 0.1 wt% graphene–WO 3 sensor to acetaldehyde was 100 °C. • 0.1 wt% graphene–WO 3 sensor exhibited good selectivity to acetaldehyde at 100 °C. - Abstract: Graphene–WO 3 composites mixed with different amounts of graphene (0, 0.1, 0.5, 1 and 3 wt%) were prepared by hydrothermal method at 180 °C for 24 h. The as-prepared graphite oxide, graphene and graphene–WO 3 composites were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectra (FT-IR) and Raman spectroscopy, respectively. The effect of the amount of graphene in the composites on the gas-sensing responses and the gas-sensing selectivity of the materials was investigated. The experimental results revealed that the sensor based on 0.1 wt% graphene–WO 3 composite exhibited high response and good selectivity to acetaldehyde vapor at 100 °C, the optimum operating temperature of this sensor to 1000 ppm acetaldehyde vapor decreased from 180 °C to 100 °C comparing with that of pure WO 3 . The response time and the recovery time for 100 ppm acetaldehyde vapor were 250 s and 225 s, respectively

  19. Two generators to produce SI-traceable reference gas mixtures for reactive compounds at atmospheric levels

    Science.gov (United States)

    Pascale, C.; Guillevic, M.; Ackermann, A.; Leuenberger, D.; Niederhauser, B.

    2017-12-01

    To answer the needs of air quality and climate monitoring networks, two new gas generators were developed and manufactured at METAS in order to dynamically generate SI-traceable reference gas mixtures for reactive compounds at atmospheric concentrations. The technical features of the transportable generators allow for the realization of such gas standards for reactive compounds (e.g. NO2, volatile organic compounds) in the nmol · mol-1 range (ReGaS2), and fluorinated gases in the pmol ṡ mol-1 range (ReGaS3). The generation method is based on permeation and dynamic dilution. The transportable generators have multiple individual permeation chambers allowing for the generation of mixtures containing up to five different compounds. This mixture is then diluted using mass flow controllers, thus making the production process adaptable to generate the required amount of substance fraction. All parts of ReGaS2 in contact with the gas mixture are coated to reduce adsorption/desorption processes. Each input parameter required to calculate the generated amount of substance fraction is calibrated with SI-primary standards. The stability and reproducibility of the generated amount of substance fractions were tested with NO2 for ReGaS2 and HFC-125 for ReGaS3. They demonstrate stability over 1-4 d better than 0.4% and 0.8%, respectively, and reproducibility better than 0.7% and 1%, respectively. Finally, the relative expanded uncertainty of the generated amount of substance fraction is smaller than 3% with the major contributions coming from the uncertainty of the permeation rate and/or of the purity of the matrix gas. These relative expanded uncertainties meet then the needs of the data quality objectives fixed by the World Meteorological Organization.

  20. Preparation, characterization and gas permeation study of PSf/MgO nanocomposite membrane

    Directory of Open Access Journals (Sweden)

    S. M. Momeni

    2013-09-01

    Full Text Available Nanocomposite membranes composed of polymer and inorganic nanoparticles are a novel method to enhance gas separation performance. In this study, membranes were fabricated from polysulfone (PSf containing magnesium oxide (MgO nanoparticles and gas permeation properties of the resulting membranes were investigated. Membranes were prepared by solution blending and phase inversion methods. Morphology of the membranes, void formations, MgO distribution and aggregates were observed by SEM analysis. Furthermore, thermal stability, residual solvent in the membrane film and structural ruination of membranes were analyzed by thermal gravimetric analysis (TGA. The effects of MgO nanoparticles on the glass transition temperature (Tg of the prepared nanocomposites were studied by differential scanning calorimetry (DSC. The Tg of nanocomposite membranes increased with MgO loading. Fourier transform infrared (FTIR spectra of nanocomposite membranes were analyzed to identify the variations of the bonds. The results obtained from gas permeation experiments with a constant pressure setup showed that adding MgO nanoparticles to the polymeric membrane structure increased the permeability of the membranes. At 30 wt% MgO loading, the CO2 permeability was enhanced from 25.75×10-16 to 47.12×10-16 mol.m/(m².s.Pa and the CO2/CH4 selectivity decreased from 30.84 to 25.65 when compared with pure PSf. For H2, the permeability was enhanced from 44.05×10-16 to 67.3×10-16 mol.m/(m².s.Pa, whereas the H2/N2 selectivity decreased from 47.11 to 33.58.

  1. Ecological balance of power generation from sewage gas; Oekobilanz Klaergasverstromung

    Energy Technology Data Exchange (ETDEWEB)

    Ronchetti, C.; Bienz, P.; Pridal, R.

    2002-07-01

    This report for the Swiss Federal Office of Energy (SFOE) presents the ecological balance made for the production of electrical power from biogas that is produced in waste water treatment plants. The study was needed as the basis for deciding if power thus generated could be certified to the strict 'Naturemade Star' standards. This label is used to designate 'green' power. The report briefly describes the processes usually used in the treatment of sewage sludge, the energy-intensive aerobic and anaerobic digestion, which produces biogas. The ecological factors of the two processes were assessed using the Eco-Indicator 99 tool. The results are discussed, which showed that a typical modern waste water treatment plant is significantly better as far as energy is concerned than older examples of plant (e.g. those built in 1995) as far as ecological impact is concerned. Also, the study addresses other forms of biogas use, like, for example, its use as a fuel for vehicles.

  2. Calculating the flue gas dew point for raw brown coal fired steam generators

    Energy Technology Data Exchange (ETDEWEB)

    Schinkel, W.

    1977-01-01

    The paper analyzes parameters influencing the sulfuric acid dew point in flue gas of steam generators. Sulfur content and alkaline earths content in the fuel air ratio during combustion, fly ash content in the flue gas (which absorbs sulfur dioxide and sulfur trioxide) and combustion conditions in steam generators are relevant parameters in the combustion process. A thermodynamic and reaction kinetic calculation of the sulfuric acid dew point is, however, not yet possible. A statistical evaluation of dew point measurements in steam generators is, therefore, employed. Various diagrams show results of dew point measurements carried out at generators with steam capacities ranging from 40 to 660 t/h, which demonstrate relations of these parameters to flue gas dew points, in particular the relative sulfur content (sulfur content in the raw brown coal compared to coal ash content and alkaline earths content). A function is derived for the conversion of fuel sulfur to sulfur trioxide. A diagram presents the relation of the flue gas dew point to partial pressures of sulfuric acid and steam. Direct calculation of the flue gas dew point was achieved by the proposed method. It is applied in steam generator design. (17 refs.)

  3. First Study of Helium Gas Purification System as Primary Coolant of Co-Generation Reactor

    International Nuclear Information System (INIS)

    Piping Supriatna

    2009-01-01

    The technological progress of NPP Generation-I on 1950’s, Generation-II, Generation-III recently on going, and Generation-IV which will be implemented on next year 2025, concept of nuclear power technology implementation not only for generate electrical energy, but also for other application which called cogeneration reactor. Commonly the type of this reactor is High Temperature Reactor (HTR), which have other capabilities like Hydrogen production, desalination, Enhanced Oil Recovery (EOR), etc. The cogeneration reactor (HTR) produce thermal output higher than commonly Nuclear Power Plant, and need special Heat Exchanger with helium gas as coolant. In order to preserve heat transfer with high efficiency, constant purity of the gas must be maintained as well as possible, especially contamination from its impurities. In this report has been done study for design concept of HTR primary coolant gas purification system, including methodology by sampling He gas from Primary Coolant and purification by using Physical Helium Splitting Membrane. The examination has been designed in physical simulator by using heater as reactor core. The result of study show that the of Primary Coolant Gas Purification System is enable to be implemented on cogeneration reactor. (author)

  4. Microbial Gas Generation Under Expected Waste Isolation Pilot Plant Repository Conditions: Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Gillow, J.B.; Francis, A.

    2011-07-01

    Gas generation from the microbial degradation of the organic constituents of transuranic (TRU) waste under conditions expected in the Waste Isolation Pilot Plant (WIPP) was investigated. The biodegradation of mixed cellulosic materials and electron-beam irradiated plastic and rubber materials (polyethylene, polyvinylchloride, hypalon, leaded hypalon, and neoprene) was examined. We evaluated the effects of environmental variables such as initial atmosphere (air or nitrogen), water content (humid ({approx}70% relative humidity, RH) and brine inundated), and nutrient amendments (nitogen phosphate, yeast extract, and excess nitrate) on microbial gas generation. Total gas production was determined by pressure measurement and carbon dioxide (CO{sub 2}) and methane (CH{sub 4}) were analyzed by gas chromatography; cellulose degradation products in solution were analyzed by high-performance liquid chromatography. Microbial populations in the samples were determined by direct microscopy and molecular analysis. The results of this work are summarized.

  5. Microbial Gas Generation Under Expected Waste Isolation Pilot Plant Repository Conditions: Final Report

    International Nuclear Information System (INIS)

    Gillow, J.B.; Francis, A.

    2011-01-01

    Gas generation from the microbial degradation of the organic constituents of transuranic (TRU) waste under conditions expected in the Waste Isolation Pilot Plant (WIPP) was investigated. The biodegradation of mixed cellulosic materials and electron-beam irradiated plastic and rubber materials (polyethylene, polyvinylchloride, hypalon, leaded hypalon, and neoprene) was examined. We evaluated the effects of environmental variables such as initial atmosphere (air or nitrogen), water content (humid (∼70% relative humidity, RH) and brine inundated), and nutrient amendments (nitogen phosphate, yeast extract, and excess nitrate) on microbial gas generation. Total gas production was determined by pressure measurement and carbon dioxide (CO 2 ) and methane (CH 4 ) were analyzed by gas chromatography; cellulose degradation products in solution were analyzed by high-performance liquid chromatography. Microbial populations in the samples were determined by direct microscopy and molecular analysis. The results of this work are summarized.

  6. Gas Generators and Their Potential to Support Human-Scale HIADS (Hypersonic Inflatable Aerodynamic Decelerators)

    Science.gov (United States)

    Bodkin, Richard J.; Cheatwood, F. M.; Dillman, Robert A; Dinonno, John M.; Hughes, Stephen J.; Lucy, Melvin H.

    2016-01-01

    As HIAD technology progresses from 3-m diameter experimental scale to as large as 20-m diameter for human Mars entry, the mass penalties of carrying compressed gas has led the HIAD team to research current state-of-the-art gas generator approaches. Summarized below are several technologies identified in this survey, along with some of the pros and cons with respect to supporting large-scale HIAD applications.

  7. Investigation on the performance of polymer zirconium compound (PZC) for chromatographic Tc-99m generator preparation

    International Nuclear Information System (INIS)

    Le Van So

    2004-01-01

    The performance of PZC was investigated for chromatographic Tc-99m generator preparation. Mo-adsorption of PZC in different Mo-solutions and Tc-99m elution of 99 Mo-PZC column were studied. Mo- adsorption capacity of higher than 250mgMo/gPZC and Tc-99m elution yield of higher than 80% were achieved with PZC adsorbent. Mo-99 breakthrough of 0.02% and Molybdenum element breakthrough of around 5μg Mo/ml were found in Tc-99m eluate. A good relationship between the Mo-content of adsorption solution and the Mo-adsorption capacity, adsorption percentage, Mo-breakthrough and Tc-99m elution yield was found. The preparation of PZC based Tc-99m chromatographic generator with 4 gram weight of PZC was successfully conducted. (author)

  8. Layout of an internally heated gas generator for the steam gasification of coal

    International Nuclear Information System (INIS)

    Feistel, P.P.; Duerrfeld, R.; Heck, K.H. van; Juentgen, H.

    1975-01-01

    Industrial-scale steam gasification of coal using heat from high temperature reactors requires research and development on allothermal gas generators. Bergbau-Forschung GmbH, Essen, does theoretical and experimental work in this field. The experiments deal with reaction kinetics, heat transfer and material tests. Their significance for the layout of a full-scale gas generator is shown. Including material specifications, the feasibility of a gasifier, characterized by a fluid bed volume of 318 m 3 and a heat transferring area of 4000 m 2 , results. The data, now available, are used to determine the gasification throughput from the heat balance, i.e. the equality of heat consumed and heat transferred. Throughputs of about 50 t/hr of coal are possible for a single gas generator, the helium outlet temperature of the HTR being 950 0 C/ Bergbau-Forschung has commissioned a medium-scale pilot plant (200 kg/hr). (Auth.)

  9. The effects of introducing natural gas in the Canary Islands for electricity generation

    International Nuclear Information System (INIS)

    Ramos-Real, Francisco Javier; Moreno-Piquero, Juan Carlos; Ramos-Henriquez, Jose Manuel

    2007-01-01

    This study analyses the economic effects of introducing natural gas in the Canary Islands to generate electricity in combined cycle gas turbine (CCGT) plants. To this end we will evaluate how this measure contributes to achieving the objectives of the islands' energy policy and we calculate the cost of generating a kWh from this technology. For this calculation we obtain the net present value (NPV) of the total production costs during the economic lifetime of the plant so as to subsequently find the unitary cost per kWh generated. The result obtained indicates that the kWh cost is some 25% lower than the cost of using petroleum derivatives. Additionally, if we consider the positive effect of CO 2 emissions reductions, the cost is 41% lower. The introduction of natural gas will also be a decisive factor in complying with Kyoto requirements and in diversifying supply sources in the Canaries

  10. Dynamics of Dispersive Wave Generation in Gas-Filled Photonic Crystal Fiber with the Normal Dispersion

    Directory of Open Access Journals (Sweden)

    Zhixiang Deng

    2017-01-01

    Full Text Available The absence of Raman and unique pressure-tunable dispersion is the characteristic feature of gas-filled photonic crystal fiber (PCF, and its zero dispersion points can be extended to the near-infrared by increasing gas pressure. The generation of dispersive wave (DW in the normal group velocity dispersion (GVD region of PCF is investigated. It is demonstrated that considering the self-steepening (SS and introducing the chirp of the initial input pulse are two suitable means to control the DW generation. The SS enhances the relative average intensity of blue-shift DW while weakening that of red-shift DW. The required propagation distance of DW emission is markedly varied by introducing the frequency chirp. Manipulating DW generation in gas-filled PCF by the combined effects of either SS or chirp and three-order dispersion (TOD provides a method for a concentrated transfer of energy into the targeted wavelengths.

  11. Nondestructive Evaluation of the J-2X Direct Metal Laser Sintered Gas Generator Discharge Duct

    Science.gov (United States)

    Esther, Elizabeth A.; Beshears, Ronald D.; Lash, Rhonda K.

    2012-01-01

    The J-2X program at NASA's Marshall Space Flight Center (MSFC) procured a direct metal laser sintered (DMLS) gas generator discharge duct from Pratt & Whitney Rocketdyne and Morris Technologies for a test program that would evaluate the material properties and durability of the duct in an engine-like environment. DMLS technology was pursued as a manufacturing alternative to traditional techniques, which used off nominal practices to manufacture the gas generator duct's 180 degree turn geometry. MSFC's Nondestructive Evaluation (NDE) Team performed radiographic, ultrasonic, computed tomographic, and fluorescent penetrant examinations of the duct. Results from the NDE examinations reveal some shallow porosity but no major defects in the as-manufactured material. NDE examinations were also performed after hot-fire testing the gas generator duct and yielded similar results pre and post-test and showed no flaw growth or development.

  12. Quality Assurance Project Plan for the Gas Generation Testing Program at the INEL

    International Nuclear Information System (INIS)

    1994-10-01

    The data quality objectives (DQOs) for the Program are to evaluate compliance with the limits on total gas generation rates, establish the concentrations of hydrogen and methane in the total gas flow, determine the headspace concentration of VOCs in each drum prior to the start of the test, and obtain estimates of the concentrations of several compounds for mass balance purposes. Criteria for the selection of waste containers at the INEL and the parameters that must be characterized prior to and during the tests are described. Collection of gaseous samples from 55-gallon drums of contact-handled transuranic waste for the gas generation testing is discussed. Analytical methods and calibrations are summarized. Administrative quality control measures described in this QAPjP include the generation, review, and approval of project documentation; control and retention of records; measures to ensure that personnel, subcontractors or vendors, and equipment meet the specifications necessary to achieve the required data quality for the project

  13. Spin Start Line Effects on the J2X Gas Generator Chamber Acoustics

    Science.gov (United States)

    Kenny, R. Jeremy

    2011-01-01

    The J2X Gas Generator engine design has a spin start line connected near to the turbine inlet vanes. This line provides helium during engine startup to begin turbomachinery operation. The spin start line also acts as an acoustic side branch which alters the chamber's acoustic modes. The side branch effectively creates 'split modes' in the chamber longitudinal modes, in particular below the first longitudinal mode and within the frequency range associated with the injection-coupled response of the Gas Generator. Interaction between the spin start-modified chamber acoustics and the injection-driven response can create a higher system response than without the spin start attached to the chamber. This work reviews the acoustic effects of the spin start line as seen throughout the workhorse gas generator test program. A simple impedance model of the spin start line is reviewed. Tests were run with no initial spin start gas existing in the line, as well as being initially filled with nitrogen gas. Tests were also run with varying spin start line lengths from 0" to 40". Acoustic impedance changes due to different spin start gas constituents and line lengths are shown. Collected thermocouple and static pressure data in the spin start line was used to help estimate the fluid properties along the line length. The side branch impedance model was coupled to a chamber impedance model to show the effects on the overall chamber response. Predictions of the spin start acoustic behavior for helium operation are shown and compared against available data.

  14. Purification of cyclotron-produced 81Rb for the preparation of small krypton-81m generators

    International Nuclear Information System (INIS)

    Andersen, P.; Haasbroek, F.J.; Venter, S.S.J.; Strelow, F.W.E.

    1981-01-01

    A method is described for the separation of 81 Rb from sodium bromide targets. Ammonium molybdophosphate columns are used and the separation takes only about 20 minutes. More than 90% of the 81 Rb is recovered. The purified 81 Rb enables small Rubidium-81/Krypton-81m generators to be prepared with Bio-Rad 50W-X8 ion-exchange resin (200-400 mesh) [af

  15. Development of the Next Generation Gas Trap for the Space Station Internal Thermal Control System

    Science.gov (United States)

    Leimkuehler, Thomas O.; Spelbring, Chris; Reeves, Daniel R.; Holt, James M.

    2003-01-01

    The current dual-membrane gas trap is designed to remove non-condensed gases (NCG) from the Internal Thermal Control System (ITCS) coolant on board the International Space Station (ISS). To date it has successfully served its purpose of preventing depriming, overspeed, and shutdown of the ITCS pump. However, contamination in the ITCS coolant has adversely affected the gas venting rate and lifetime of the gas trap, warranting a development effort for a next-generation gas trap. Design goals are to meet or exceed the current requirements to (1) include greater operating ranges and conditions, (2) eliminate reliance on the current hydrophilic tube fabrication process, and (3) increase operational life and tolerance to particulate and microbial growth fouling. In addition, the next generation gas trap will essentially be a 'dropin" design such that no modifications to the ITCS pump package assembly (PPA) will be required, and the implementation of the new design will not affect changes to the ITCS operational conditions, interfaces, or software. This paper will present the initial membrane module design and development work which has included (1) a trade study among several conceptual designs, (2) performance modeling of a hydrophobic-only design, and (3) small-scale development test data for the hydrophobic-only design. Testing has shown that the hydrophobic-only design is capable of performing even better than the current dual-membrane design for both steady-state gas removal and gas slug removal.

  16. Status and integration of the gas generation studies performed for the Hydrogen Safety Program

    International Nuclear Information System (INIS)

    Pederson, L.R.; Strachan, D.M.

    1993-02-01

    Waste in Tank 241-SY-101 on the Hanford Site generates and periodically releases hydrogen, nitrous oxide, and nitrogen gases. Studies have been conducted at several laboratories to determine the chemical mechanisms for the gas generation and release. Results from these studies are presented and integrated in an attempt to describe current understanding of the physical properties of the waste and the mechanisms of gas generation and retention. Existing tank data are consistent with the interpretation that gases are uniformly generated in the tank, released continuously from the convecting layer, and stored in the nonconvecting layer. Tank temperature measurements suggest that the waste consists of ''gobs'' of material that reach neutral buoyancy at different times. The activation energy of the rate limiting step of the gas generating process was calculated to be about 7 kJ/mol but measured in the laboratory at 80 to 100 kJ/mol. Based on observed temperature changes in the tank the activation energy is probably not higher than about 20 kJ/mol. Several simulated waste compositions have been devised for use in laboratory studies in the place of actual waste from Tank 241-SY-101. Data from these studies can be used to predict how the actual waste might behave when heated or diluted. Density evaluations do not confirm that heating waste at the bottom of the tank would induce circulation within the waste; however, heating may release gas bubbles by dissolving the solids to which the bubbles adhere. Gas generation studies on simulated wastes indicated that nitrous oxide and hydrogen yields are not particularly coupled. Solubility studies of nitrous oxide, the most soluble of the principal gaseous products, indicate it is unlikely that dissolved gases contribute substantially to the quantity of gas released during periodic events

  17. Genetic algorithm to optimize the design of main combustor and gas generator in liquid rocket engines

    Science.gov (United States)

    Son, Min; Ko, Sangho; Koo, Jaye

    2014-06-01

    A genetic algorithm was used to develop optimal design methods for the regenerative cooled combustor and fuel-rich gas generator of a liquid rocket engine. For the combustor design, a chemical equilibrium analysis was applied, and the profile was calculated using Rao's method. One-dimensional heat transfer was assumed along the profile, and cooling channels were designed. For the gas-generator design, non-equilibrium properties were derived from a counterflow analysis, and a vaporization model for the fuel droplet was adopted to calculate residence time. Finally, a genetic algorithm was adopted to optimize the designs. The combustor and gas generator were optimally designed for 30-tonf, 75-tonf, and 150-tonf engines. The optimized combustors demonstrated superior design characteristics when compared with previous non-optimized results. Wall temperatures at the nozzle throat were optimized to satisfy the requirement of 800 K, and specific impulses were maximized. In addition, the target turbine power and a burned-gas temperature of 1000 K were obtained from the optimized gas-generator design.

  18. Using Probability of Exceedance to Compare the Resource Risk of Renewable and Gas-Fired Generation

    Energy Technology Data Exchange (ETDEWEB)

    Bolinger, Mark [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2017-08-01

    Of the myriad risks surrounding long-term investments in power plants, resource risk is one of the most difficult to mitigate, and is also perhaps the risk that most-clearly distinguishes renewable generation from natural gas-fired generation. For renewable generators like wind and solar projects, resource risk manifests as a quantity risk—i.e., the risk that the quantity of wind and insolation will be less than expected.i For gas-fired generators (i.e., a combined-cycle gas turbine or “CCGT”), resource risk manifests primarily as a price risk—i.e., the risk that natural gas will cost more than expected. Most often, resource risk—and natural gas price risk in particular—falls disproportionately on utility ratepayers, who are typically not well-equipped to manage this risk. As such, it is incumbent upon utilities, regulators, and policymakers to ensure that resource risk is taken into consideration when making or approving resource decisions, or enacting policies that influence the development of the electricity sector more broadly.

  19. Preparation and properties of carbonaceous products prepared by the cracking of natural gas; Fabrication et proprietes de corps carbones prepares par craquage de gaz naturel

    Energy Technology Data Exchange (ETDEWEB)

    Blum, P L; Bochirol, L; Rappeneau, J; Cornuault, P; Blanchard, R; Moreau, C [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1964-07-01

    Complete results are presented of tests recently carried out at the Grenoble Nuclear Research Centre in an attempt to transform natural gas (gas from Lacq), used as a source of pyrolytic carbon, into carbonaceous products with improved properties. Several methods have been studied: 1 - By using normal grade industrial graphite as support (density of about 1.50) products having densities of about 1.80 are obtained. Their open porosity (6 to 7 per cent) is lower than that of conventional graphites, and several of their characteristics are more or less equal to, or better than those obtained from a double impregnation witch pitch. 2 - The use as supporting material of the semi-products ('cooked') usually used for graphite production does not lead to satisfactory results. The main reasons for this are given. 3 - A new process, called 'BB5', has been developed. The starting materials here are powdered products (petrol coke or graphite) which are put into shape with the use of a binder which can be dispersed in water. The supports thus produced make it possible, because of their porous structure, to make the most of the densification produced by cracking natural gas below 1000 deg. C. The products obtained, which are made up of equal amounts approximately of the supporting material and of pyrocarbon can attain densities of over 1.90. Their very low open porosity can be reduced almost to zero and their impermeability is then excellent (k=10{sup -8} cm{sup 2}sec{sup -1}). They have also a remarkably high resistance to compression, values of 15 to 20 kg/mm{sup 2} being obtained for those carbons which have not undergone a final graphitization treatment. Some examples are given of possible nuclear applications of the materials produced in this manner. (authors) [French] On expose l'ensemble des essais effectues recemment au CEN-G pour preparer, a partir de gaz naturel (gaz de Lacq) comme source de carbone pyrolytique, des corps carbones de caracteristiques ameliorees

  20. A microfluidic DNA library preparation platform for next-generation sequencing.

    Directory of Open Access Journals (Sweden)

    Hanyoup Kim

    Full Text Available Next-generation sequencing (NGS is emerging as a powerful tool for elucidating genetic information for a wide range of applications. Unfortunately, the surging popularity of NGS has not yet been accompanied by an improvement in automated techniques for preparing formatted sequencing libraries. To address this challenge, we have developed a prototype microfluidic system for preparing sequencer-ready DNA libraries for analysis by Illumina sequencing. Our system combines droplet-based digital microfluidic (DMF sample handling with peripheral modules to create a fully-integrated, sample-in library-out platform. In this report, we use our automated system to prepare NGS libraries from samples of human and bacterial genomic DNA. E. coli libraries prepared on-device from 5 ng of total DNA yielded excellent sequence coverage over the entire bacterial genome, with >99% alignment to the reference genome, even genome coverage, and good quality scores. Furthermore, we produced a de novo assembly on a previously unsequenced multi-drug resistant Klebsiella pneumoniae strain BAA-2146 (KpnNDM. The new method described here is fast, robust, scalable, and automated. Our device for library preparation will assist in the integration of NGS technology into a wide variety of laboratories, including small research laboratories and clinical laboratories.

  1. A microfluidic DNA library preparation platform for next-generation sequencing.

    Science.gov (United States)

    Kim, Hanyoup; Jebrail, Mais J; Sinha, Anupama; Bent, Zachary W; Solberg, Owen D; Williams, Kelly P; Langevin, Stanley A; Renzi, Ronald F; Van De Vreugde, James L; Meagher, Robert J; Schoeniger, Joseph S; Lane, Todd W; Branda, Steven S; Bartsch, Michael S; Patel, Kamlesh D

    2013-01-01

    Next-generation sequencing (NGS) is emerging as a powerful tool for elucidating genetic information for a wide range of applications. Unfortunately, the surging popularity of NGS has not yet been accompanied by an improvement in automated techniques for preparing formatted sequencing libraries. To address this challenge, we have developed a prototype microfluidic system for preparing sequencer-ready DNA libraries for analysis by Illumina sequencing. Our system combines droplet-based digital microfluidic (DMF) sample handling with peripheral modules to create a fully-integrated, sample-in library-out platform. In this report, we use our automated system to prepare NGS libraries from samples of human and bacterial genomic DNA. E. coli libraries prepared on-device from 5 ng of total DNA yielded excellent sequence coverage over the entire bacterial genome, with >99% alignment to the reference genome, even genome coverage, and good quality scores. Furthermore, we produced a de novo assembly on a previously unsequenced multi-drug resistant Klebsiella pneumoniae strain BAA-2146 (KpnNDM). The new method described here is fast, robust, scalable, and automated. Our device for library preparation will assist in the integration of NGS technology into a wide variety of laboratories, including small research laboratories and clinical laboratories.

  2. Aeroderivative Pratt & Whitney FT8-3 gas turbine – an interesting solution for power generation

    Directory of Open Access Journals (Sweden)

    Sorinel-Gicu TALIF

    2011-03-01

    Full Text Available The intermediate load electric power stations become more and more interesting for theelectric power market in Romania. In this context, the Combined Cycle Power Plants came as a veryattractive solution. This paper presents the results of a study regarding the use of the aeroderivativePratt & Whitney FT8-3 gas turbine, available in Romania, for the electric power generation in aCombined Cycle Power Plant. It is also analyzed the Combined Heat in Power generation with FT8-3gas turbine when saturated steam or hot water are required.

  3. Power Generation and Transportation Systems Research Department: 1992 annual status report (Gas Research Institute)

    International Nuclear Information System (INIS)

    Benedict, A.

    1992-09-01

    Activities of Gas Research Institute's Power Generation and Transportation Systems subprogram for the period between October 1, 1991 and September 30, 1992 are summarized. The particular project areas covered in the report are Cogeneration and Power Systems, Engine Technology and Component Development, Natural Gas Vehicles Research, and Electric Power Generation. For each project area a separate chapter is provided. Each chapter includes a rationale for funding the research effort, the goals and objectives to be achieved, a general statement on research accomplishments, and the strategy employed in the project area. Each chapter also contains a series of summary reports on the status of each contract

  4. Variation in excess oxidant factor in combustion products of MHD generator. [Natural gas fuel

    Energy Technology Data Exchange (ETDEWEB)

    Pinkhasik, M S; Mironov, V D; Zakharko, Yu A; Plavinskii, A I

    1977-12-01

    Methods and difficulties associated with determining the excess oxidant factor for natural gas-fired MHD generators are discussed. The measurement of this factor is noted to be essential for the optimization of the combustion chamber and operation of MHD generators. A gas analyzer of electrochemical type is considered as a quick - response sensor capable of analyzing the composition of the combustion products and thus determining accurately the excess oxidant factor. The principle of operation of this sensor is discussed and the dependence of the electrochemical sensor emf on excess oxidant factor is shown. Three types of sensors are illustrated and tables of test results are provided.

  5. High-brightness high-order harmonic generation at 13 nm with a long gas jet

    International Nuclear Information System (INIS)

    Kim, Hyung Taek; Kim, I Jong; Lee, Dong Gun; Park, Jong Ju; Hong, Kyung Han; Nam, Chang Hee

    2002-01-01

    The generation of high-order harmonics is well-known method producing coherent extreme-ultraviolet radiation with pulse duration in the femtosecond regime. High-order harmonics have attracted much attention due to their unique features such as coherence, ultrashort pulse duration, and table-top scale system. Due to these unique properties, high-order harmonics have many applications of atomic and molecular spectroscopy, plasma diagnostics and solid-state physics. Bright generation of high-order harmonics is important for actual applications. Especially, the generation of strong well-collimated harmonics at 13 nm can be useful for the metrology of EUV lithography optics because of the high reflectivity of Mo-Si mirrors at this wavelength. The generation of bright high-order harmonics is rather difficult in the wavelength region below 15nm. Though argon and xenon gases have large conversion efficiency, harmonic generation from these gases is restricted to wavelengths over 20 nm due to low ionization potential. Hence, we choose neon for the harmonic generation around 13 nm; it has larger conversion efficiency than helium and higher ionization potential than argon. In this experiment, we have observed enhanced harmonic generation efficiency and low beam divergence of high-order harmonics from a elongated neon gas jet by the enhancement of laser propagation in an elongated gas jet. A uniform plasma column was produced when the gas jet was exposed to converging laser pulses.

  6. Gas Diffusion Barriers Prepared by Spatial Atmospheric Pressure Plasma Enhanced ALD.

    Science.gov (United States)

    Hoffmann, Lukas; Theirich, Detlef; Pack, Sven; Kocak, Firat; Schlamm, Daniel; Hasselmann, Tim; Fahl, Henry; Räupke, André; Gargouri, Hassan; Riedl, Thomas

    2017-02-01

    In this work, we report on aluminum oxide (Al 2 O 3 ) gas permeation barriers prepared by spatial ALD (SALD) at atmospheric pressure. We compare the growth characteristics and layer properties using trimethylaluminum (TMA) in combination with an Ar/O 2 remote atmospheric pressure plasma for different substrate velocities and different temperatures. The resulting Al 2 O 3 films show ultralow water vapor transmission rates (WVTR) on the order of 10 -6 gm -2 d -1 . In notable contrast, plasma based layers already show good barrier properties at low deposition temperatures (75 °C), while water based processes require a growth temperature above 100 °C to achieve equally low WVTRs. The activation energy for the water permeation mechanism was determined to be 62 kJ/mol.

  7. Gas Sensing of Fluorine Doped Tin Oxide Thin Films Prepared by Spray Pyrolysis

    Directory of Open Access Journals (Sweden)

    A. A. YADAV

    2008-05-01

    Full Text Available Fluorine doped tin oxide (F: SnO2 films have been prepared onto the amorphous glass substrates by a spray pyrolysis. XRD studies reveal that the material deposited is polycrystalline SnO2 and have tetragonal structure. It is observed that films are highly orientated along (200 direction. The direct optical band gap energy for the F: SnO2 films are found to be 4.15 eV. Gas sensing properties of the sensor were checked against combustible gases like H2, CO2 CO, C3H8, CH4.The H2 sensitivity of the F-doped SnO2 sensor was found to be increased. The increase in the sensitivity is discussed in terms of increased resistivity and reduced permeation of gaseous oxygen into the underlying sensing layer due to the surface modification of the sensor.

  8. Outlook of natural gas thermal generation; A geracao termeletrica a gas natural e o PPT (Programa Prioritario de Termoeletricidade)

    Energy Technology Data Exchange (ETDEWEB)

    Felix, Makyo A.; Correia Junior, Clovis [Bahiagas - Companhia de Gas da Bahia, Salvador, BA (Brazil); Garcia, Celestino B. [Agencia Nacional do Petroleo, Gas Natural e Biocombustiveis (ANP), Rio de Janeiro, RJ (Brazil)

    2004-07-01

    The national integrated system has always had hydroelectricity as its main source of energy supply. However, a long period of lack of investment in sector put the country in a complacent position in which there was an overabundance of energy supply. The subsequent power shortage of 2001, led to a long term strategy of assuring supply with perspective of attending demand quickly and guaranteeing the security of the system by exploiting a source of energy rarely used in the country: thermal energy using natural gas. For this reason, the federal government launched the PPT Program (Priority Program of Thermoelectricity) with the aim of stimulating investment in thermo electrical plants, utilizing natural gas which is cheaper and less polluting. However, investment by the private sector did not fulfill expectations even with regular production, financial incentives of the government and favourable points through thermal generation using natural gas. Therefore, PETROBRAS decided to assume the risk and form partnerships to assure investments in thermo electrical plants. In the strategy of implanting thermal plants, who would be responsible to carry out this process along with guarantees of supply, was not properly defined. The establishment of thermal plants without a regulatory framework and undefined investment plan, compromises the essence of its creation. It is from this angle, that evaluates the recent collapse of energy of the Northeast region and the effective implantation of thermoelectricity utilizing natural gas. (author)

  9. Recovery Act: Brea California Combined Cycle Electric Generating Plant Fueled by Waste Landfill Gas

    Energy Technology Data Exchange (ETDEWEB)

    Galowitz, Stephen

    2012-12-31

    The primary objective of the Project was to maximize the productive use of the substantial quantities of waste landfill gas generated and collected at the Olinda Landfill near Brea, California. An extensive analysis was conducted and it was determined that utilization of the waste gas for power generation in a combustion turbine combined cycle facility was the highest and best use. The resulting Project reflected a cost effective balance of the following specific sub-objectives: • Meeting the environmental and regulatory requirements, particularly the compliance obligations imposed on the landfill to collect, process and destroy landfill gas • Utilizing proven and reliable technology and equipment • Maximizing electrical efficiency • Maximizing electric generating capacity, consistent with the anticipated quantities of landfill gas generated and collected at the Olinda Landfill • Maximizing equipment uptime • Minimizing water consumption • Minimizing post-combustion emissions • The Project produced and will produce a myriad of beneficial impacts. o The Project created 360 FTE construction and manufacturing jobs and 15 FTE permanent jobs associated with the operation and maintenance of the plant and equipment. o By combining state-of-the-art gas clean up systems with post combustion emissions control systems, the Project established new national standards for best available control technology (BACT). o The Project will annually produce 280,320 MWh’s of clean energy o By destroying the methane in the landfill gas, the Project will generate CO2 equivalent reductions of 164,938 tons annually. The completed facility produces 27.4 MWnet and operates 24 hours a day, seven days a week.

  10. Various bio-mechanical factors affecting heat generation during osteotomy preparation: A systematic review.

    Science.gov (United States)

    Chauhan, Chirag J; Shah, Darshana N; Sutaria, Foram B

    2018-01-01

    As implant site preparation and bone are critical precursors to primary healing, thermal and mechanical damage to the bone must be minimized during the preparation of the implant site. Moreover, excessively traumatic surgery can adversely affect the maturation of bone tissue at the bone/implant interface and consequently diminish the predictability of osseointegration. So, this study was carried out to evaluate the various biological and mechanical factors responsible for heat generation during osteotomy site preparation to reduce the same for successful osseointegration of dental implants. A broad search of the dental literature in PubMed added by manual search was performed for articles published between 1992 and December 2015. Various bio-mechanical factors related to dental implant osteotomy preparation such as dental implant drill designs/material/wear, drilling methods, type of irrigation, and bone quality were reviewed. Titles and abstracts were screened and articles which fulfilled the inclusion criteria were selected for a full-text reading. The initial database search yielded 123 titles, of which 59 titles were discarded after reading the titles and abstracts, 30 articles were again excluded based on inclusion and exclusion criteria, and finally 34 articles were selected for data extraction. Many biological and mechanical factors responsible for heat generation were found. Literatures of this review study have indicated that there are various bio-mechanical reasons, which affect the temperature rise during osteotomy and suggest that the amount of heat generation is a multifactorial in nature and it should be minimized for better primary healing of the implant site.

  11. Separation of cis- and trans-Asarone from Acorus tatarinowii by Preparative Gas Chromatography

    Directory of Open Access Journals (Sweden)

    H. L. Zuo

    2012-01-01

    Full Text Available A preparative gas chromatography (pGC method was developed for the separation of isomers (cis- and trans-asarone from essential oil of Acorus tatarinowii. The oil was primarily fractionated by silica gel chromatography using different ratios of petroleum ether and ethyl acetate as gradient elution solvents. And then the fraction that contains mixture of the isomers was further separated by pGC. The compounds were separated on a stainless steel column packed with 10% OV-101 (3 m × 6 mm, i.d., and then the effluent was split into two gas flows. One percent of the effluent passed to the flame ionization detector (FID for detection and the remaining 99% was directed to the fraction collector. Two isomers were collected after 90 single injections (5 uL with the yield of 178 mg and 82 mg, respectively. Furthermore, the structures of the obtained compounds were identified as cis- and trans-asarone by 1H- and 13C-NMR spectra, respectively.

  12. Gas sensing properties of magnesium ferrite prepared by co-precipitation method

    International Nuclear Information System (INIS)

    Hankare, P.P.; Jadhav, S.D.; Sankpal, U.B.; Patil, R.P.; Sasikala, R.; Mulla, I.S.

    2009-01-01

    Polycrystalline magnesium ferrite (MgFe 2 O 4 ) was prepared by the co-precipitation method. The synthesized compound was characterized for their phase and morphology by X-ray diffraction and scanning electron microscopy, respectively. Conductance responses of the (MgFe 2 O 4 ) were measured towards gases like hydrogen sulfide (H 2 S), liquefied petroleum gas (LPG), ethanol vapors (C 2 H 5 OH), SO x , H 2 , NO x , NH 3, methanol, acetone and petrol. The gas sensing characterstics were obtained by measuring the sensitivity as a function of various controlling factors like operating temperatures and concentrations of gases. It was found that the sensor exhibited various responses towards these gases at different operating temperatures. Furthermore; the MgFe 2 O 4 based sensor exhibited a fast response and a good recovery towards petrol at temperature 250 deg. C. The results of the response towards petrol reveal that (MgFe 2 O 4 ) synthesized by a simple co-precipitation method, would be a suitable material for the fabrication of the petrol sensor.

  13. Integration of steam injection and inlet air cooling for a gas turbine generation system

    International Nuclear Information System (INIS)

    Wang, F.J.; Chiou, J.S.

    2004-01-01

    The temperature of exhaust gases from simple cycle gas turbine generation sets (GENSETs) is usually very high (around 500 deg. C), and a heat recovery steam generator (HRSG) is often used to recover the energy from the exhaust gases and generate steam. The generated steams can be either used for many useful processes (heating, drying, separation etc.) or used back in the power generation system for enhancing power generation capacity and efficiency. Two well-proven techniques, namely steam injection gas turbine (STIG) and inlet air cooling (IAC) are very effective features that can use the generated steam to improve the power generation capacity and efficiency. Since the energy level of the generated steam needed for steam injection is different from that needed by an absorption chiller to cool the inlet air, a proper arrangement is required to implement both the STIG and the IAC features into the simple cycle GENSET. In this study, a computer code was developed to simulate a Tai power's Frame 7B simple cycle GENSET. Under the condition of local summer weather, the benefits obtained from the system implementing both STIG and IAC features are more than a 70% boost in power and 20.4% improvement in heat rate

  14. Study of gas generation in drum L/ILW packages using hermetic containers

    International Nuclear Information System (INIS)

    Molnar, M.; Palcsu, L.; Svingor, E.; Futo, I.; Major, Z.; Veres, M.

    2005-01-01

    Complete text of publication follows. During the storage of low and intermediate level radioactive waste (L/ILW) significant quantities of gas may be produced. It is likely that a small proportion of the generated gas will be radioactive as a result of the incorporation of the isotopes 3 H and 14 C that are present within the waste. To obtain reliable estimates of the quantities and rates of the gas production in L/ILWa series of measurements was carried out of waste packages produced and temporarily stored at the site of Paks Nuclear Power Plant (NPP). Ten drums filled with selected original L/ILW were placed into hermetic containers equipped with sampling valves for repeated sampling. These hermetic containers were stored at the same site where the L/ILW is stored primarily in the Paks NPP. The pressure and the temperature of the headspace gas in the containers were monitored continuously. Qualitative gas component analyses of headspace gases of drums and their containers were executed by quadrupole mass spectrometer. The gas generation rate in the stored L/ILW was calculated by the measured state parameters and the composition variation of the gas in the closed containers. Stable isotope measurements were executed from the CO 2 , CH 4 and N 2 fractions by stable isotope ratio mass spectrometer. Helium measurements were done by noble gas mass spectrometer. The tritium content of the vapour, H 2 and CH 4 fractions was measured by a low background liquid scintillation counter. 14 C content of the CO 2 and CH 4 fractions was measured by a low background gas proportional counter system (ATOMKI). Our results showed that the main generated gases in L/ILW are carbon dioxide, methane, hydrogen and nitrogen. The typical rates were 0.05-0.2 normal litre gas/day for CO 2 and CH 4 generation, and less than 0.02 normal litre gas/day for H 2 . Because of the typical vanishing of the O 2 from the headspace gases no explosive gas mixture was indicated in the L/ILW drums during

  15. Testing various types of agricultural wastes for the production of generator gas

    Energy Technology Data Exchange (ETDEWEB)

    Kjellstroem, B

    1982-05-08

    The aim of the project was to get an improved basis for the assessment of aretes which was required for use in a Swedish gas generator. It was found that waste which possessed high contents of ashes with a low melting point were unsuitable as a fuel. Four types of waste were tested. The shells of coconuts were applicable as fuel. The design of the generator had to be modified in order to use pellets of straw or compressed sugar-canes.

  16. Gas to Power in North America. Issues surrounding the use of natural gas in the next generation of North American power plants

    International Nuclear Information System (INIS)

    Thorn, T.

    2006-01-01

    In January 2006 a study was concluded on Gas to Power in North America. This study has been prepared for EDI and IGU and is part of the Gas to Power Project, which has been set up in view of the pivotal role power is likely to play in the development of new gas markets and the realization that it will take enormous efforts to achieve the projected growth. In this report the focus is on North America

  17. Hydrogen generation from natural gas for the fuel cell systems of tomorrow

    Science.gov (United States)

    Dicks, Andrew L.

    In most cases hydrogen is the preferred fuel for use in the present generation of fuel cells being developed for commercial applications. Of all the potential sources of hydrogen, natural gas offers many advantages. It is widely available, clean, and can be converted to hydrogen relatively easily. When catalytic steam reforming is used to generate hydrogen from natural gas, it is essential that sulfur compounds in the natural gas are removed upstream of the reformer and various types of desulfurisation processes are available. In addition, the quality of fuel required for each type of fuel cell varies according to the anode material used, and the cell temperature. Low temperature cells will not tolerate high concentrations of carbon monoxide, whereas the molten fuel cell (MCFC) and solid oxide fuel cell (SOFC) anodes contain nickel on which it is possible to electrochemically oxidise carbon monoxide directly. The ability to internally reform fuel gas is a feature of the MCFC and SOFC. Internal reforming can give benefits in terms of increased electrical efficiency owing to the reduction in the required cell cooling and therefore parasitic system losses. Direct electrocatalysis of hydrocarbon oxidation has been the elusive goal of fuel cell developers over many years and recent laboratory results are encouraging. This paper reviews the principal methods of converting natural gas into hydrogen, namely catalytic steam reforming, autothermic reforming, pyrolysis and partial oxidation; it reviews currently available purification techniques and discusses some recent advances in internal reforming and the direct use of natural gas in fuel cells.

  18. Study on incineration technology of oil gas generated during the recovery process of oil spill

    Energy Technology Data Exchange (ETDEWEB)

    Hou, Shuhn-Shyurng [Department of Mechanical Engineering, Kun Shan University, Tainan 71003 (China); Ko, Yung-Chang [China Steel Corporation, Kaohsiung 81233 (China); Lin, Ta-Hui [Department of Mechanical Engineering, National Cheng Kung University, Tainan 70101 (China)

    2011-03-15

    The objective of this study is to design, set up and operate an incinerator system capable of providing clean exhaust and safety control for burning oil gas generated during the recovery process of oil spill in Taiwan. In this study, we successfully develop a vertical-type incinerator, which consists of five oil gas burners with entrained primary air, a pilot burner, and an auxiliary burner. The incinerator system is equipped with necessary control units in order to achieve safe, easy, fast, and efficient operation. Flame appearance, flue gas temperature and CO emission of the incinerator system for burning oil gas are reported and discussed. Under the long-term operation, it is found that the new designed incinerator is satisfactory for burning oil gas with low supply pressure at various compositions and supply rates during the recovery process of oil spill. It is noteworthy that the results obtained herein are of great significance to provide a good guidance for those who need to design, set up and operate an incinerator system providing clean exhaust and safety control for burning oil gas generated during the recovery process of oil spill in a polluted site with a large area. (author)

  19. Study on incineration technology of oil gas generated during the recovery process of oil spill

    International Nuclear Information System (INIS)

    Hou, Shuhn-Shyurng; Ko, Yung-Chang; Lin, Ta-Hui

    2011-01-01

    The objective of this study is to design, set up and operate an incinerator system capable of providing clean exhaust and safety control for burning oil gas generated during the recovery process of oil spill in Taiwan. In this study, we successfully develop a vertical-type incinerator, which consists of five oil gas burners with entrained primary air, a pilot burner, and an auxiliary burner. The incinerator system is equipped with necessary control units in order to achieve safe, easy, fast, and efficient operation. Flame appearance, flue gas temperature and CO emission of the incinerator system for burning oil gas are reported and discussed. Under the long-term operation, it is found that the new designed incinerator is satisfactory for burning oil gas with low supply pressure at various compositions and supply rates during the recovery process of oil spill. It is noteworthy that the results obtained herein are of great significance to provide a good guidance for those who need to design, set up and operate an incinerator system providing clean exhaust and safety control for burning oil gas generated during the recovery process of oil spill in a polluted site with a large area.

  20. Modification of inkjet printer for polymer sensitive layer preparation on silicon-based gas sensors

    Directory of Open Access Journals (Sweden)

    Tianjian Li

    2015-04-01

    Full Text Available Inkjet printing is a versatile, low cost deposition technology with the capabilities for the localized deposition of high precision, patterned deposition in a programmable way, and the parallel deposition of a variety of materials. This paper demonstrates a new method of modifying the consumer inkjet printer to prepare polymer-sensitive layers on silicon wafer for gas sensor applications. A special printing tray for the modified inkjet printer to support a 4-inch silicon wafer is designed. The positioning accuracy of the deposition system is tested, based on the newly modified printer. The experimental data show that the positioning errors in the horizontal direction are negligibly small, while the positioning errors in the vertical direction rise with the increase of the printing distance of the wafer. The method for making suitable ink to be deposited to form the polymer-sensitive layer is also discussed. In the testing, a solution of 0.1 wt% polyvinyl alcohol (PVA was used as ink to prepare a sensitive layer with certain dimensions at a specific location on the surface of the silicon wafer, and the results prove the feasibility of the methods presented in this article.

  1. Considerations for reduction of gas generation in a low-level radioactive waste repository

    International Nuclear Information System (INIS)

    Cho, Chan Hee; Son, Jung Kwon; Lee, Myung Chan; Song, Myung Jae

    1997-01-01

    In a low-level radioactive waste repository, H 2 , CO 2 , and CH 4 will be generated principally by the coupled processes of metal corrosion and microbial degradation of cellulosic waste. The metal corrosion model incorporates a three-stage process encompassing aerobic and anaerobic corrosion regimes; the microbial degradation model simulates the activities of eight different microbial populations, which are maintained as functions both of pH and of the concentrations of particular chemical species. A prediction is made for gas concentrations and generation rates over an assessment period of ten thousand years in a radioactive waste repository. The results suggest that H 2 is the principal gas generated within the radioactive waste cavern. The generation rates of CO 2 and CH 4 are likely to be insignificant by comparison with H 2 . Therefore, an effective way to decrease gas generation in a radioactive waste repository seems to be to reduce metal content since the generation rate of H 2 is most sensitive to the concentration of steel

  2. A summary of volatile impurity measurements and gas generation studies on MISSTD-1, a high-purity plutonium oxide produced by low-temperature calcination of plutonium oxalate

    Energy Technology Data Exchange (ETDEWEB)

    Berg, John M. [Los Alamos National Laboratory; Narlesky, Joshua E. [Los Alamos National Laboratory; Veirs, Douglas K. [Los Alamos National Laboratory

    2012-06-08

    Plutonium dioxide of high specific surface area was subjected to long-term tests of gas generation in sealed containers. The material preparation and the storage conditions were outside the bounds of acceptable parameters defined by DOE-STD-3013-2012 in that the material was stabilized to a lower temperature than required and had higher moisture content than allowed. The data provide useful information for better defining the bounding conditions for safe storage. Net increases in internal pressure and transient increases in H{sub 2} and O{sub 2} were observed, but were well within the bounds of gas compositions previously shown to not threaten integrity of 3013 containers.

  3. A summary of volatile impurity measurements and gas generation studies on MISSTD-1, a high-purity plutonium oxide produced by low-temperature calcination of plutonium oxalate

    International Nuclear Information System (INIS)

    Berg, John M.; Narlesky, Joshua E.; Veirs, Douglas K.

    2012-01-01

    Plutonium dioxide of high specific surface area was subjected to long-term tests of gas generation in sealed containers. The material preparation and the storage conditions were outside the bounds of acceptable parameters defined by DOE-STD-3013-2012 in that the material was stabilized to a lower temperature than required and had higher moisture content than allowed. The data provide useful information for better defining the bounding conditions for safe storage. Net increases in internal pressure and transient increases in H 2 and O 2 were observed, but were well within the bounds of gas compositions previously shown to not threaten integrity of 3013 containers.

  4. Preparation of zirconium molybdate gel for 99mTc gel generator

    International Nuclear Information System (INIS)

    Aliludin, Z.; Ohkubo, Masatake; Kushita, Kouhei

    1988-09-01

    Zirconium molybdate gel has excellent characteristics for use as column matrix material of 99m Tc generators. In this work, zirconium molybdate gels were prepared under different conditions; pH's of molybdate solutions from 2.5 to 7.0, Mo:Zr molar ratios from 0.7:1.0 to 1.3:1.0, drying temperatures from an ambient temperature to 200 deg C, and drying times from 1 h to 25 h. Contents of water, nitrate, molybdenum and zirconium were measured to examine the fundamental conditions in gel preparation. The Mo:Zr molar ratio was 1.0:1.0 for the most of gels obtained. A 99m Tc generator was prepared with an amorphous zirconium molybdate containing a tracer level of 99 Mo as column matrix material. Elution of 99m Tc was rapid and the average elution efficiency was 90 % for 6 ml elutions. Contents of radionuclidic impurities, Zr and Mo in the eluates, were low enough to meet the pharmacopoeia requirements for human use. (author)

  5. Technology on In-Situ Gas Generation to Recover Residual Oil Reserves

    Energy Technology Data Exchange (ETDEWEB)

    Sayavur Bakhtiyarov

    2008-02-29

    This final technical report covers the period October 1, 1995 to February 29, 2008. This chapter begins with an overview of the history of Enhanced Oil Recovery techniques and specifically, CO2 flood. Subsequent chapters conform to the manner consistent with the Activities, Tasks, and Sub-tasks of the project as originally provided in Exhibit C1 in the Project Management Plan dated September 20, 1995. These chapters summarize the objectives, status and conclusions of the major project activities performed during the project period. The report concludes by describing technology transfer activities stemming from the project and providing a reference list of all publications of original research work generated by the project team or by others regarding this project. The overall objective of this project was a final research and development in the United States a technology that was developed at the Institute for Geology and Development of Fossil Fuels in Moscow, Russia. Before the technology can be convincingly adopted by United States oil and gas producers, the laboratory research was conducted at Mew Mexico Institute of Mining and Technology. The experimental studies were conducted to measure the volume and the pressure of the CO{sub 2} gas generated according to the new Russian technology. Two experimental devices were designed, built and used at New Mexico Tech facilities for these purposes. The designed setup allowed initiating and controlling the reaction between the 'gas-yielding' (GY) and 'gas-forming' (GF) agents proposed by Russian technology. The temperature was controlled, and the generated gas pressure and volume were recorded during the reaction process. Additionally, the effect of surfactant addition on the effectiveness of the process was studied. An alternative GY reactant was tested in order to increase the efficiency of the CO2 gas generation process. The slim tube and the core flood experimental studies were conducted to define

  6. Gas generation in SFL 3-5 and effects on radionuclide release

    Energy Technology Data Exchange (ETDEWEB)

    Skagius, K.; Lindgren, M.; Pers, K. [Kemakta Konsult AB, Stockholm (Sweden)

    1999-12-01

    A deep repository, SFL 3-5, is presently planned for disposing of long-lived low- and intermediate-level waste. In this study the amounts of gas that can be generated in the waste packages and in the vaults are estimated. The potential gas pressure build-up, the displacement of contaminated water and the consequences on radionuclide release from the engineered barriers in the repository are also addressed. The study is focussed on the repository design and waste inventory that was defined for the prestudy of SFL 3-5. Since the reporting of the prestudy the design of the repository has been modified and the waste inventory has been updated and a preliminary safety assessment of the repository has been carried outbased on the new design and updated waste inventory. The implications on gas generation and release of these modifications in design and waste inventory are briefly addressed in this study.

  7. Gas generation in SFL 3-5 and effects on radionuclide release

    International Nuclear Information System (INIS)

    Skagius, K.; Lindgren, M.; Pers, K.

    1999-12-01

    A deep repository, SFL 3-5, is presently planned for disposing of long-lived low- and intermediate-level waste. In this study the amounts of gas that can be generated in the waste packages and in the vaults are estimated. The potential gas pressure build-up, the displacement of contaminated water and the consequences on radionuclide release from the engineered barriers in the repository are also addressed. The study is focussed on the repository design and waste inventory that was defined for the prestudy of SFL 3-5. Since the reporting of the prestudy the design of the repository has been modified and the waste inventory has been updated and a preliminary safety assessment of the repository has been carried out based on the new design and updated waste inventory. The implications on gas generation and release of these modifications in design and waste inventory are briefly addressed in this study

  8. 77 FR 441 - Measurement and Control of Combustible Gas Generation and Dispersal

    Science.gov (United States)

    2012-01-05

    ... hydrogen that could be generated in different severe accident scenarios.'' The petitioner states that the... different severe accident scenarios.'' The petitioner states that the total quantity of hydrogen could... onset of a severe accident, combustible gas monitoring systems be functional within a timeframe that...

  9. Control strategies for gas turbine generators for grid connected and islanding operations

    DEFF Research Database (Denmark)

    Mahat, Pukar; Chen, Zhe; Bak-Jensen, Birgitte

    2010-01-01

    fine while a DG is connected to a grid, might not work as desired while it is islanded and vise versa. This paper presents a strategy to operate distribution systems with a small gas turbine generator (GTG), which is capable of supplying local loads, in both islanding and grid connected conditions...

  10. Modeling and experiments on differential pumping in linear plasma generators operating at high gas flows

    NARCIS (Netherlands)

    Eck, van H.J.N.; Koppers, W.R.; Rooij, van G.J.; Goedheer, W.J.; Engeln, R.A.H.; Schram, D.C.; Lopes Cardozo, N.J.; Kleyn, A.W.

    2009-01-01

    The direct simulation Monte Carlo (DSMC) method was used to investigate the efficiency of differential pumping in linear plasma generators operating at high gas flows. Skimmers are used to separate the neutrals from the plasma beam, which is guided from the source to the target by a strong axial

  11. Semi-continuous high speed gas analysis of generated vapors of chemical warfare agents

    NARCIS (Netherlands)

    Trap, H.C.; Langenberg, J.P.

    1999-01-01

    A method is presented for the continuous analysis of generated vapors of the nerve agents soman and satin and the blistering agent sulfur mustard. By using a gas sampling valve and a very short (15 cm) column connected to an on-column injector with a 'standard length' column, the system can either

  12. Contribution of N2O to the greenhouse gas balance of first-generation biofuels

    NARCIS (Netherlands)

    Smeets, E.W.M.; Bouwman, A.F.; Stehfest, E.; Vuuren, van P.; Posthuma, A.

    2009-01-01

    n this study, we analyze the impact of fertilizer- and manure-induced N2O emissions due to energy crop production on the reduction of greenhouse gas (GHG) emissions when conventional transportation fuels are replaced by first-generation biofuels (also taking account of other GHG emissions during the

  13. Methods and systems for detecting gas flow by photoacoustic signal generation

    Science.gov (United States)

    Choudhury, Niloy; Challener, William Albert

    2018-03-06

    A method for the detection of a gas flowing from a location in a structure is described. A hollow-core optical fiber is placed in a position adjacent the structure. The fiber includes a sound-conductive cladding layer; and further includes at least one aperture extending into its cross-sectional diameter. A beam of pulsed, optical is transmitted into the fiber with a tunable laser. The optical energy is characterized by a wavelength that can be absorbed by the gas that flows into the fiber through the aperture. This causes a temperature fluctuation in the region of gas absorption, which in turn generates an acoustic wave in the absorption region. The acoustic wave travels through the cladding layer, and can be detected with a microphone, so as to provide the location of gas flow, based on the recorded position and movement of the acoustic wave. A related system is also described.

  14. Metathesis in the generation of low-temperature gas in marine shales

    Directory of Open Access Journals (Sweden)

    Jarvie Daniel M

    2010-01-01

    Full Text Available Abstract The recent report of low-temperature catalytic gas from marine shales took on additional significance with the subsequent disclosure of natural gas and low-temperature gas at or near thermodynamic equilibrium in methane, ethane, and propane. It is important because thermal cracking, the presumed source of natural gas, cannot generate these hydrocarbons at equilibrium nor can it bring them to equilibrium over geologic time. The source of equilibrium and the source of natural gas are either the same (generation under equilibrium control or closely associated. Here we report the catalytic interconversion of hydrocarbons (metathesis as the source of equilibrium in experiments with Cretaceous Mowry shale at 100°C. Focus was on two metathetic equilibria: methane, ethane, and propane, reported earlier, Q (K = [(C1*(C3]/[(C22], and between these hydrocarbons and n-butane, Q* (K = [(C1*(n-C4]/[(C2*(C3], reported here for the first time. Two observations stand out. Initial hydrocarbon products are near equilibrium and have maximum average molecular weights (AMW. Over time, products fall from equilibrium and AMW in concert. It is consistent with metathesis splitting olefin intermediates [Cn] to smaller intermediates (fission as gas generation creates open catalytic sites ([ ]: [Cn] + [ ] → [Cn-m] + [Cm]. Fission rates increasing exponentially with olefin molecular weight could contribute to these effects. AMW would fall over time, and selective fission of [C3] and [n-C4] would draw Q and Q* from equilibrium. The results support metathesis as the source of thermodynamic equilibrium in natural gas.

  15. Integrated biomass gasification combined cycle distributed generation plant with reciprocating gas engine and ORC

    International Nuclear Information System (INIS)

    Kalina, Jacek

    2011-01-01

    The paper theoretically investigates the performance of a distributed generation plant made up of gasifier, Internal Combustion Engine (ICE) and Organic Rankine Cycle (ORC) machine as a bottoming unit. The system can be used for maximization of electricity production from biomass in the case where there is no heat demand for cogeneration plant. To analyze the performance of the gasifier a model based on the thermodynamic equilibrium approach is used. Performance of the gas engine is estimated on the basis of the analysis of its theoretical thermodynamic cycle. Three different setups of the plant are being examined. In the first one the ORC module is driven only by the heat recovered from engine exhaust gas and cooling water. Waste heat from a gasifier is used for gasification air preheating. In the second configuration a thermal oil circuit is applied. The oil transfers heat from engine and raw gas cooler into the ORC. In the third configuration it is proposed to apply a double cascade arrangement of the ORC unit with a two-stage low temperature evaporation of working fluid. This novel approach allows utilization of the total waste heat from the low temperature engine cooling circuit. Two gas engines of different characteristics are taken into account. The results obtained were compared in terms of electric energy generation efficiency of the system. The lowest obtained value of the efficiency was 23.6% while the highest one was 28.3%. These are very favorable values in comparison with other existing small and medium scale biomass-fuelled power generation plants. - Highlights: →The study presents performance analysis of a biomass-fuelled local power plant. →Downdraft wood gasifier, gas engine and ORC module are modelled theoretically. →Method for estimation of the producer gas fired engine performance is proposed. →Two gas engines of different characteristics are taken into account. →Different arrangements of the bottoming ORC cycle ere examined.

  16. Gas generation over plutonium oxides in the 94-1 shelf-life surveillance program

    International Nuclear Information System (INIS)

    Berg, J.M.; Harradine, D.M.; Hill, D.D.; McFarlan, James T.; Padilla, D.D.; Prenger, F. Coyne; Veirs, D.K.; Worl, L.A.

    2002-01-01

    The Department of Energy (DOE) is embarking upon a program to store large quantities of plutonium-bearing materials for up to fifty years. The Los Alamos National Laboratory Shelf Life Project was established to bound the behavior of plutonium-bearing material meeting the DOE 3013 Standard. The shelf life study monitors temperature, pressure and gas composition over oxide materials in a limited number of large-scale 3013 inner containers and in many small-scale containers. For the large-scale study, baseline plutonium oxides, oxides exposed to high-humidity atmospheres, and oxides containing chloride salt impurities are planned. The first large-scale container represents a baseline and contains dry plutonium oxide prepared according to the 3013 Standard. This container has been observed for pressure, temperature and gas compositional changes for less than a year. Results indicate that no detectable changes in pressure and gas composition are observed.

  17. Greenhouse gas emission reduction by means of fuel switching in electricity generation: Addressing the potentials

    International Nuclear Information System (INIS)

    Delarue, Erik; D'haeseleer, William

    2008-01-01

    Many countries committed themselves in the Kyoto protocol to reduce greenhouse gas (GHG) emissions. Some of these targeted emission reductions could result from a switch from coal-fired to gas-fired electricity generation. The focus in this work lies on Western Europe, with the presence of the European Union Emission Trading Scheme (EU ETS). For the switching to occur, several conditions have to be fulfilled. First, an economical incentive must be present, i.e. a sufficiently high European Union Allowance (EUA) price together with a sufficiently low natural gas price. Second, the physical potential for switching must exist, i.e. at a given load, there must remain enough power plants not running to make switching possible. This paper investigates what possibilities exist for switching coal-fired plants for gas-fired plants, dependent on the load level (the latter condition above). A fixed allowance cost and a variable natural gas price are assumed. The method to address GHG emission reduction potentials is first illustrated in a methodological case. Next, the GHG emission reduction potentials are addressed for several Western European countries together with a relative positioning of their electricity generation. GHG emission reduction potentials are also compared with simulation results. GHG emission reduction potentials tend to be significant. The Netherlands have a very widespread switching zone, so GHG emission reduction is practically independent of electricity generation. Other counties, like Germany, Spain and Italy could reduce GHG emissions significantly by switching. With an allowance cost following the switch level of a 50% efficient gas-fired plant and a 40% efficient coal-fired plant in the summer season (like in 2005), the global GHG emission reduction (in the electricity generating sector) for the eight modeled zones could amount to 19%

  18. Environmental and economic assessment of landfill gas electricity generation in Korea using LEAP model

    International Nuclear Information System (INIS)

    Shin, Ho-Chul; Park, Jin-Won; Kim, Ho-Seok; Shin, Eui-Soon

    2005-01-01

    As a measure to establish a climate-friendly energy system, Korean government has proposed to expand landfill gas (LFG) electricity generation capacity. The purpose of this paper is to analyze the impacts of LFG electricity generation on the energy market, the cost of generating electricity and greenhouse gases emissions in Korea using a computer-based software tool called 'Long-range Energy Alternative Planning system' (LEAP) and the associated 'Technology and Environmental Database'. In order to compare LFG electricity generation with existing other generating facilities, business as usual scenario of existing power plants was surveyed, and then alternative scenario investigations were performed using LEAP model. Different alternative scenarios were considered, namely the base case with existing electricity facilities, technological improvement of gas engine and LFG maximum utilization potential with different options of gas engine (GE), gas turbine (GT), and steam turbine (ST). In the technological improvement scenario, there will be 2.86 GWh or more increase in electricity output, decrease of 45 million won (Exchange rate (1$=1200 won)). in costs, and increase of 10.3 thousand ton of CO 2 in global warming potentials due to same period (5 year) of technological improvement. In the maximum utilization potential scenario, LFG electricity generation technology is substituted for coal steam, nuclear, and combined cycle process. Annual cost per electricity product of LFG electricity facilities (GE 58MW, GT 53.5MW, and ST 54.5MW) are 45.1, 34.3, and 24.4 won/kWh, and steam turbine process is cost-saving. LFG-utilization with other forms of energy utilization reduces global warming potential by maximum 75% with compared to spontaneous emission of CH 4 . LFG electricity generation would be the good solution for CO 2 displacement over the medium term and additional energy profits

  19. Economic and environmental aspects of coal preparation and the impact on coal use for power generation

    International Nuclear Information System (INIS)

    Lockhart, N.C.

    1995-01-01

    Australia is the world's largest coal exporter, and coal is the nation's largest export and dominant revenue earner. The future competitiveness of coal will be maintained through improved preparation of coal for traditional markets, by upgrading for new markets, and via coal utilization processes that are more efficient and environmentally acceptable. Australia is also a niche supplier of technologies and services with the potential to expand. This potential extends to the increasing vertical integration of coal supplies (whether Australian, indigenous or blended) with downstream utilization such as power generation. Technological advancement is a key element of industry strategy and coal preparation research and development, and clean coal technologies are critical aspects. This paper summarizes these issues, linking the economic and environmental aspects across the coal production and utilization chain. (author). 2 tabs., 1 fig., 6 refs

  20. Studies of adsorber materials for preparing 68Ge/68Ga generators

    International Nuclear Information System (INIS)

    Brambilla, Tania de Paula

    2013-01-01

    The 68 Ga is a promising radionuclide for nuclear medicine, decaying by positron emission with an abundance of 89%, with physical half-life of 68 minutes, which is compatible with the pharmacokinetics of many biomolecules and low molecular weight substrates. Another important feature is its availability through a generator system, where the parent radionuclide, 68 Ge (t 1/2 = 270.95 days) is adsorbed on a column and the daughter, 68 Ga, is eluted in an ionic form 68Ga 3+ . The development of 68 Ge/ 68 Ga generators began in the 60s, but its clinical use began to be acceptable and relevant only recently. The method of separation of 68 Ge and 68 Ga most used is the ion-exchange chromatographic system, due to its practical operation, but other generator systems have been proposed, such as solvent extraction and evaporation technique. Currently, 68 Ge/ 68 Ga generators are commercially available using inorganic matrices columns prepared with TiO 2 or SnO 2 as well using organic resin. The efficiency of 68 Ga elution ranges from 70% to 80%, decreasing over time. The 68 Ge breakthrough varies from 10 -2 to10 -3 % or lower in a fresh generator, but there is an increase in the levels of contamination after long periods of use. Even with all the technological advances in the development of 68 Ge/ 68 Ga generators in the past decades, the 68 Ga eluted from commercial generators is not suitable for direct use in humans and some improvements in the systems need to be made to reduce the 68 Ge breakthrough and chemical impurities levels. The main objective of this work was to develop a 68 Ge/ 68 Ga generator system is which 68 Ga could be eluted with quality required for clinical use. The chemical behavior of Ge and Ga was evaluated on various inorganic adsorbents materials. Two types of 68 Ge/ 68 Ga generator systems were developed using TiO 2 as adsorbent material: elution system with manual pressure and vacuum controlled. The efficiencies of the generators were similar to

  1. Determination of leveled costs of electric generation for gas plants, coal and nuclear

    International Nuclear Information System (INIS)

    Alonso V, G.; Palacios H, J.C.; Ramirez S, J.R.; Gomez, A.

    2005-01-01

    The present work analyzes the leveled costs of electric generation for different types of nuclear reactors known as Generation III, these costs are compared with the leveled costs of electric generation of plants with the help of natural gas and coal. In the study several discount rates were used to determine their impact in the initial investment. The obtained results are comparable with similar studies and they show that it has more than enough the base of the leveled cost the nuclear option it is quite competitive in Mexico. Also in this study it is also thinks about the economic viability of a new nuclear power station in Mexico. (Author)

  2. Optimization of the steam generator project of a gas cooled nuclear reactor

    International Nuclear Information System (INIS)

    Sakai, Massao

    1978-01-01

    The present work is concerned with the modeling of the primary and secondary circuits of a gas cooled nuclear reactor in order to obtain the relation between the parameters of the two cycles and the steam generator performance. The procedure allows the optimization of the steam generator, through the maximization of the plant net power, and the application of the optimal control theory of dynamic systems. The heat balances for the primary and secondary circuits are carried out simultaneously with the optimized - design parameters of the steam generator, obtained using an iterative technique. (author)

  3. Preparation of {sup 183,184}Re samples for modelling a rapid gas phase chemistry of Nielsbohrium (Ns), element 107

    Energy Technology Data Exchange (ETDEWEB)

    Eichler, R.; Gaeggeler, H.W.; Eichler, B.; Tuerler, A. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-09-01

    Chemical gas phase reactions of the heavier group 7 elements in the system O{sub 2}/H{sub 2}O are presumably best suited for a separation of Nielsbohrium from the lighter transactinides. We expect a higher reaction velocity using the more reactive gas system O{sub 3}/H{sub 2}O{sub 2}. For the experimental verification of this idea we prepared {sup 183}Re/{sup 184}Re samples for thermochromatography experiments with both gas systems. (author) 8 refs.

  4. Robust Sub-nanomolar Library Preparation for High Throughput Next Generation Sequencing.

    Science.gov (United States)

    Wu, Wells W; Phue, Je-Nie; Lee, Chun-Ting; Lin, Changyi; Xu, Lai; Wang, Rong; Zhang, Yaqin; Shen, Rong-Fong

    2018-05-04

    Current library preparation protocols for Illumina HiSeq and MiSeq DNA sequencers require ≥2 nM initial library for subsequent loading of denatured cDNA onto flow cells. Such amounts are not always attainable from samples having a relatively low DNA or RNA input; or those for which a limited number of PCR amplification cycles is preferred (less PCR bias and/or more even coverage). A well-tested sub-nanomolar library preparation protocol for Illumina sequencers has however not been reported. The aim of this study is to provide a much needed working protocol for sub-nanomolar libraries to achieve outcomes as informative as those obtained with the higher library input (≥ 2 nM) recommended by Illumina's protocols. Extensive studies were conducted to validate a robust sub-nanomolar (initial library of 100 pM) protocol using PhiX DNA (as a control), genomic DNA (Bordetella bronchiseptica and microbial mock community B for 16S rRNA gene sequencing), messenger RNA, microRNA, and other small noncoding RNA samples. The utility of our protocol was further explored for PhiX library concentrations as low as 25 pM, which generated only slightly fewer than 50% of the reads achieved under the standard Illumina protocol starting with > 2 nM. A sub-nanomolar library preparation protocol (100 pM) could generate next generation sequencing (NGS) results as robust as the standard Illumina protocol. Following the sub-nanomolar protocol, libraries with initial concentrations as low as 25 pM could also be sequenced to yield satisfactory and reproducible sequencing results.

  5. Comparative evaluation of different nanostructured metal oxides for preparation of clinically useful 99Mo/99mTc generators

    International Nuclear Information System (INIS)

    Ram, Ramu; Chakravarty, Rubel; Dash, Ashutosh

    2015-01-01

    The potential of nanostructured metal oxides such as nanotitania, nanozirconia, nanoalumina and mesoporous alumina, as new generation sorbent materials for preparation of 99 Mo/ 99m Tc generator has recently been demonstrated. A comparative assessment of such materials is essential for determination of their suitability for preparation of clinically useful generators using (n,γ) 99 Mo. Characteristics which were compared included the sorption capacity, shelf-life of the generator, radioactive concentration and purity of 99m Tc for radiopharmaceutical applications. Mesoporous alumina was identified as the most suitable sorbent for ensuring sustainable production of clinical grade 99 Mo/ 99m Tc generators using low specific activity 99 Mo. (author)

  6. Hanford Site guide for preparing and maintaining generator group pollution prevention program documentation

    International Nuclear Information System (INIS)

    Place, B.G.

    1998-01-01

    This document provides guidance to generator groups for preparing and maintaining documentation of Pollution Prevention Waste Minimization (P2/WMin) Program activities. The guidance is one of a hierarchical series that includes the Hanford Site Waste Minimization and Pollution Prevention Awareness Program Plan (DOE-RL, 1998a) and Prime contractor implementation plans describing programs required by Resource Conservation and Recovery Act of 1976 (RCRA) 3002(b) and 3005(h) (RCRA and EPA, 1994). Documentation guidance for the following five P2/WMin elements are discussed: Fiscal Year (FY) Goals; Budget and Staffing; Waste Minimization (WMin) Assessments (WMAs); Quarterly Pollution Prevention (P2) Reporting WMin Certification

  7. Simulation and Parametric Analysis of a Hybrid SOFC-Gas Turbine Power Generation System

    International Nuclear Information System (INIS)

    Hassan, A.M.; Fahmy

    2004-01-01

    Combined SOFC-Gas Turbine Power Generation Systems are aimed to increase the power and efficiency obtained from the technology of using high temperature fuel cells by integrating them with gas turbines. Hybrid systems are considered in the last few years as one of the most promising technologies to obtain electric energy from the natural gas at very high efficiency with a serious potential for commercial use. The use of high temperature allows internal reforming for natural gas and thus disparity of fuel composition is allowed. Also air preheating is performed thanks to the high operating cell temperature as a task of energy integration. In this paper a modeling approach is presented for the fuel cell-gas turbine hybrid power generation systems, to obtain the sofc output voltage, power, and the overall hybrid system efficiency. The system has been simulated using HYSYS, the process simulation software to help improving the process understanding and provide a quick system solution. Parametric analysis is also presented in this paper to discuss the effect of some important SOFC operating parameters on the system performance and efficiency

  8. The velocity of missiles generated by the disintegration of gas-pressurized vessels and pipes

    International Nuclear Information System (INIS)

    Baum, M.R.

    1984-01-01

    A theoretical model is developed to describe the velocity of fragments generated when a gas-pressurized vessel disintegrates. The predictions are compared with new and existing experimental data for spherical and cylindrical vessels and are shown to be an improvement over the widely used empirical correlation developed by Moore. It is also shown that, by an appropriate definition of the energy available for doing work on the fragments, the velocity of the fragments from the disintegration of a section of gas pipeline may be predicted by the same model

  9. Electricity generation from synthesis gas by microbial processes: CO fermentation and microbial fuel cell technology.

    Science.gov (United States)

    Kim, Daehee; Chang, In Seop

    2009-10-01

    A microbiological process was established to harvest electricity from the carbon monoxide (CO). A CO fermenter was enriched with CO as the sole carbon source. The DGGE/DNA sequencing results showed that Acetobacterium spp. were enriched from the anaerobic digester fluid. After the fermenter was operated under continuous mode, the products were then continuously fed to the microbial fuel cell (MFC) to generate electricity. Even though the conversion yield was quite low, this study proved that synthesis gas (syn-gas) can be converted to electricity with the aid of microbes that do not possess the drawbacks of metal catalysts of conventional methods.

  10. The velocity of missiles generated by the disintegration of gas-pressurised vessels and pipes

    International Nuclear Information System (INIS)

    Baum, M.R.

    1983-03-01

    A theoretical model is developed to describe the velocity of fragments generated when a gas-pressurised vessel disintegrates. The predictions are compared with new and existing experimental data for spherical and cylindrical vessels and are shown to be an improvement over the widely used empirical correlation developed by Moore. It is also shown that, by an appropriate definition of the energy available for doing work on the fragments, the velocity of the fragments from the disintegration of a section of gas pipeline may be predicted by the same model. (author)

  11. Ultrafine particles and nitrogen oxides generated by gas and electric cooking

    OpenAIRE

    Dennekamp, M; Howarth, S; Dick, C; Cherrie, J; Donaldson, K; Seaton, A

    2001-01-01

    OBJECTIVES—To measure the concentrations of particles less than 100 nm diameter and of oxides of nitrogen generated by cooking with gas and electricity, to comment on possible hazards to health in poorly ventilated kitchens.
METHODS—Experiments with gas and electric rings, grills, and ovens were used to compare different cooking procedures. Nitrogen oxides (NOx) were measured by a chemiluminescent ML9841A NOx analyser. A TSI 3934 scanning mobility particle sizer was used to measure average nu...

  12. Radiolytic gas generation from cement-based waste hosts for DOE low-level radioactive wastes

    International Nuclear Information System (INIS)

    Dole, L.R.; Friedman, H.A.

    1986-01-01

    Using cement-based immobilization binders with simulated radioactive waste containing sulfate, nitrate, nitrite, phosphate, and fluoride anions, the gamma- and alpha-radiolytic gas generation factors (G/sub t/, molecules/100 eV) and gas compositions were measured on specimens of cured grouts. These tests studied the effects of; (1) waste composition; (2) the sample surface-to-volume ratio; (3) the waste slurry particle size; and (4) the water content of the waste host formula. The radiolysis test vessels were designed to minimize the ''dead'' volume and to simulate the configuration of waste packages

  13. Techno-economic assessment and policy of gas power generation considering the role of multiple stakeholders in China

    International Nuclear Information System (INIS)

    Dong Jun; Zhang Xu; Xu Xiaolin

    2012-01-01

    In accordance with the energy planning in China, within the “Twelfth Five-Year” period (2011–2015), the proportion of natural gas among primary energy consumption is expected to increase from the current 4% to 8%. In 2015, about 17 natural gas pipelines will be completed. This paper reviews the current situation of gas power generation, analyzes the main opportunities and obstacles of gas power generation development in China, and conducts a techno-economic assessment of the natural gas power generation, taking into account the role and the interaction of the multiple stakeholders in the natural gas industry chain. Taking a power plant fueled with the natural gas transported by the second West-to-East Pipeline as an example, it is found that the on-grid power price fluctuates upward with the rise of gas price and downward with the increase of annual utilization hours, and the influences of tax policies on the on-grid power price prove to be highly significant. As the analysis and calculation indicate, the environmental benefits of natural gas power generation ought to be strongly emphasized, compared with coal-fired power generation. Finally, this paper puts forward specific policy recommendations, from the perspectives of electricity price, gas price, tax, power grid dispatching, etc. - Highlights: ► Presents the opportunities and obstacles of gas power generation development in China. ► Analyzes the interactions of multiple stakeholders in the natural gas industry chain. ► Conducts a techno-economic assessment on the natural gas power generation. ► Discusses the responsibilities and risks of multiple stakeholders. ► Puts forward policy recommendations, from electricity price, gas price, tax, etc.

  14. 76 FR 35884 - Gas Transmission Northwest LLC; Notice of Intent To Prepare an Environmental Assessment for the...

    Science.gov (United States)

    2011-06-20

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. PF11-5-000] Gas Transmission Northwest LLC; Notice of Intent To Prepare an Environmental Assessment for the Planned Carty Lateral Project, Request for Comments on Environmental Issues, and Notice of Public Scoping Meeting The staff of the Federal Energy Regulatory Commission ...

  15. 77 FR 11527 - Bluewater Gas Storage, LLC; Notice of Intent To Prepare an Environmental Assessment for the...

    Science.gov (United States)

    2012-02-27

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. CP12-51-000] Bluewater Gas Storage, LLC; Notice of Intent To Prepare an Environmental Assessment for the Proposed St. Clair River Crossing Replacement Project, Request for Comments on Environmental Issues, and Notice of Onsite Environmental Review The staff of the Federal...

  16. 78 FR 35627 - Columbia Gas Transmission, LLC; Notice of Intent To Prepare an Environmental Assessment for the...

    Science.gov (United States)

    2013-06-13

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. PF13-7-000] Columbia Gas Transmission, LLC; Notice of Intent To Prepare an Environmental Assessment for the Planned East Side Expansion Project, Request for Comments on Environmental Issues, and Notice of Public Scoping Meeting The staff of the Federal Energy Regulatory...

  17. 76 FR 12955 - CenterPoint Energy Gas Transmission Company, LLC; Notice of Intent To Prepare an Environmental...

    Science.gov (United States)

    2011-03-09

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. CP11-78-000] CenterPoint Energy Gas Transmission Company, LLC; Notice of Intent To Prepare an Environmental Assessment for the Proposed Line AM- 46 Replacement Project, Request for Comments on Environmental Issues, and Notice of Onsite Environmental Review The staff of the...

  18. 78 FR 26350 - Columbia Gas Transmission, LLC; Notice of Intent To Prepare an Environmental Assessment for the...

    Science.gov (United States)

    2013-05-06

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. CP13-125-000] Columbia Gas Transmission, LLC; Notice of Intent To Prepare an Environmental Assessment for the Proposed Giles County Project, Request for Comments on Environmental Issues, and Notice of Environmental Site Review The staff of the Federal Energy Regulatory...

  19. 77 FR 32626 - Transcontinental Gas Pipe Line Company, LLC; Notice of Intent To Prepare an Environmental Impact...

    Science.gov (United States)

    2012-06-01

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. PF09-8-000] Transcontinental Gas Pipe Line Company, LLC; Notice of Intent To Prepare an Environmental Impact Statement for the Planned Rockaway Delivery Lateral Project, Request for Comments on Environmental Issues, and Notice of Public Scoping Meetings The staff of the Federa...

  20. 76 FR 10350 - Kern River Gas Transmission Company; Notice of Intent To Prepare an Environmental Assessment for...

    Science.gov (United States)

    2011-02-24

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. CP11-46-000] Kern River Gas Transmission Company; Notice of Intent To Prepare an Environmental Assessment for the Proposed Mountain Pass Lateral Project, Request for Comments on Environmental Issues and Notice of Onsite Environmental Review The staff of the Federal Energy...

  1. 78 FR 5794 - Northern Natural Gas Company; Notice of Intent To Prepare an Environmental Assessment for the...

    Science.gov (United States)

    2013-01-28

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. PF13-2-000] Northern Natural Gas Company; Notice of Intent To Prepare an Environmental Assessment for the Planned West Leg 2014 Expansion Project, Request for Comments on Environmental Issues, and Notice of Onsite Environmental Review The staff of the Federal Energy Regulatory...

  2. 75 FR 8323 - National Fuel Gas Supply Corporation; Notice of Intent To Prepare an Environmental Assessment for...

    Science.gov (United States)

    2010-02-24

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. PF10-1-000] National Fuel Gas Supply Corporation; Notice of Intent To Prepare an Environmental Assessment for the Planned Line N Projects, Notice of Public Scoping Meeting, and Request for Comments on Environmental Issues February 18, 2010. The staff of the Federal Energy...

  3. 77 FR 24193 - Columbia Gas Transmission, LLC; Notice of Intent to Prepare an Environmental Assessment for the...

    Science.gov (United States)

    2012-04-23

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. PF12-6-000] Columbia Gas Transmission, LLC; Notice of Intent to Prepare an Environmental Assessment for the Planned Line MB Loop Extension Project, Request for Comments on Environmental Issues, and Notice of Public Scoping Meeting The staff of the Federal Energy Regulatory...

  4. 75 FR 38805 - Central New York Oil and Gas Company, LLC; Notice of Intent To Prepare an Environmental...

    Science.gov (United States)

    2010-07-06

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. CP10-194-000] Central New York Oil and Gas Company, LLC; Notice of Intent To Prepare an Environmental Assessment for the Proposed North-South Project, Request for Comments on Environmental Issues, and Notice of Public Scoping Meeting and Onsite Environmental Reviews June 24,...

  5. 75 FR 64303 - Tennessee Gas Pipeline Company; Notice of Intent To Prepare an Environmental Assessment for the...

    Science.gov (United States)

    2010-10-19

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. PF10-23-000] Tennessee Gas Pipeline Company; Notice of Intent To Prepare an Environmental Assessment for the Planned Northeast Upgrade Project, Request for Comments on Environmental Issues, and Notice of Public Scoping Meetings October 8, 2010. The staff of the Federal Energy...

  6. 78 FR 41393 - Columbia Gas Transmission, LLC: Notice of Intent To Prepare an Environmental Assessment for the...

    Science.gov (United States)

    2013-07-10

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. CP13-478-000] Columbia Gas Transmission, LLC: Notice of Intent To Prepare an Environmental Assessment for the Proposed Line 1570 Project Request for Comments on Environmental Issues, and Notice of Public Scoping Meeting The staff of the Federal Energy Regulatory Commission ...

  7. 75 FR 63462 - Central New York Oil and Gas Company, LLC; Notice of Intent To Prepare an Environmental...

    Science.gov (United States)

    2010-10-15

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. CP10-480-000] Central New York Oil and Gas Company, LLC; Notice of Intent To Prepare an Environmental Assessment for the Proposed MARC I Hub Line Project and Request for Comments on Environmental Issues, and Notice of Public Scoping Meeting and Onsite Review September 22, 2010...

  8. 75 FR 26220 - Notice of Intent to Prepare an Environmental Assessment for the Planned Leader One Gas Storage...

    Science.gov (United States)

    2010-05-11

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Leader One Energy, LLC] Notice of Intent to Prepare an Environmental Assessment for the Planned Leader One Gas Storage Project, Request for Comments on Environmental Issues, and Notice of a Site Visit April 30, 2010. The staff of the Federal Energy Regulatory Commission (FERC or...

  9. 75 FR 6175 - Notice of Intent to Prepare an Environmental Impact Statement on the Effects of Oil and Gas...

    Science.gov (United States)

    2010-02-08

    ... effects over a longer time frame, consider a more reasonable range of alternatives consistent with our... traditional knowledge in the decision- making process Effectiveness and feasibility of marine mammal... Intent to Prepare an Environmental Impact Statement on the Effects of Oil and Gas Activities in the...

  10. 77 FR 34405 - Environmental Documents Prepared for Oil, Gas, and Mineral Operations by the Gulf of Mexico Outer...

    Science.gov (United States)

    2012-06-11

    ... Geophysical Survey, SEA M09- Planning Area of the 013. Gulf of Mexico. Energy Resource Technology GOM, South... Oil, Gas, and Mineral Operations by the Gulf of Mexico Outer Continental Shelf (OCS) Region AGENCY... documents prepared for OCS mineral proposals by the Gulf of Mexico OCS Region SUMMARY: BOEM, in accordance...

  11. 76 FR 38673 - Environmental Documents Prepared for Proposed Oil, Gas, and Mineral Operations by the Gulf of...

    Science.gov (United States)

    2011-07-01

    ... the Survey, SEA M10-008. Gulf of Mexico. Coastal Technology Corporation, Located on the Atlantic 2/1.... Planning Areas of the Gulf of Mexico. Energy Resource Technology GOM, Matagorda Island, Block 2/3/2011 Inc... Environmental Documents Prepared for Proposed Oil, Gas, and Mineral Operations by the Gulf of Mexico Outer...

  12. 77 FR 43586 - Southern Star Central Gas Pipeline, Inc.; Notice of Intent To Prepare an Environmental Assessment...

    Science.gov (United States)

    2012-07-25

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. CP12-479-000] Southern Star... abandonment of facilities by Southern Star Central Gas Pipeline, Inc. (Southern Star) in Logan and Oklahoma... concern. Southern Star provided landowners with a fact sheet prepared by the FERC entitled ``An Interstate...

  13. Moisture effects on greenhouse gases generation in nitrifying gas-phase compost biofilters.

    Science.gov (United States)

    Maia, Guilherme D N; Day, George B; Gates, Richard S; Taraba, Joseph L; Coyne, Mark S

    2012-06-01

    Gas-phase compost biofilters are extensively used in concentrated animal feeding operations to remove odors and, in some cases, ammonia from air sources. The expected biochemical pathway for these predominantly aerobic systems is nitrification. However, non-uniform media with low oxygen levels can shift biofilter microbial pathways to denitrification, a source of greenhouse gases. Several factors contribute to the formation of anoxic/anaerobic zones: media aging, media and particle structure, air velocity distribution, compaction, biofilm thickness, and moisture content (MC) distribution. The present work studies the effects of media moisture conditions on ammonia (NH(3)) removal and greenhouse gas generation (nitrous oxide, N(2)O and methane, CH(4)) for gas-phase compost biofilters subject to a 100-day controlled drying process. Continuous recordings were made for the three gases and water vapor (2.21-h sampling cycle, each cycle consisted of three gas species, and water vapor, for a total of 10,050 data points). Media moisture conditions were classified into three corresponding media drying rate (DR) stages: Constant DR (wetter media), falling DR, and stable-dry system. The first-half of the constant DR period (0-750 h; MC=65-52%, w.b.) facilitated high NH(3) removal rates, but higher N(2)O generation and no CH(4) generation. At the drier stages of the constant DR (750-950 h; MC=52-48%, w.b.) NH(3) removal remained high but N(2)O net generation decreased to near zero. In the falling DR stage (1200-1480 h; MC=44-13%) N(2)O generation decreased, CH(4) increased, and NH(3) was no longer removed. No ammonia removal or greenhouse gas generation was observed in the stable-dry system (1500-2500 h; MC=13%). These results indicate that media should remain toward the drier region of the constant DR (in close proximity to the falling DR stage; MC=50%, approx.), to maintain high levels of NH(3) removal, reduced levels of N(2)O generation, and nullify levels of CH(4

  14. Life Cycle Greenhouse Gas Emissions from Electricity Generation: A Comparative Analysis of Australian Energy Sources

    Directory of Open Access Journals (Sweden)

    Robert G. Hynes

    2012-03-01

    Full Text Available Electricity generation is one of the major contributors to global greenhouse gas emissions. Transitioning the World’s energy economy to a lower carbon future will require significant investment in a variety of cleaner technologies, including renewables and nuclear power. In the short term, improving the efficiency of fossil fuel combustion in energy generation can provide an important contribution. Availability of life cycle GHG intensity data will allow decision-makers to move away from overly simplistic assertions about the relative merits of certain fuels, and focus on the complete picture, especially the critical roles of technology selection and application of best practice. This analysis compares the life-cycle greenhouse gas (GHG intensities per megawatt-hour (MWh of electricity produced for a range of Australian and other energy sources, including coal, conventional liquefied natural gas (LNG, coal seam gas LNG, nuclear and renewables, for the Australian export market. When Australian fossil fuels are exported to China, life cycle greenhouse gas emission intensity in electricity production depends to a significant degree on the technology used in combustion. LNG in general is less GHG intensive than black coal, but the gap is smaller for gas combusted in open cycle gas turbine plant (OCGT and for LNG derived from coal seam gas (CSG. On average, conventional LNG burned in a conventional OCGT plant is approximately 38% less GHG intensive over its life cycle than black coal burned in a sub-critical plant, per MWh of electricity produced. However, if OCGT LNG combustion is compared to the most efficient new ultra-supercritical coal power, the GHG intensity gap narrows considerably. Coal seam gas LNG is approximately 13–20% more GHG intensive across its life cycle, on a like-for like basis, than conventional LNG. Upstream fugitive emissions from CSG (assuming best practice gas extraction techniques do not materially alter the life cycle

  15. Variance Analysis of Wind and Natural Gas Generation under Different Market Structures: Some Observations

    Energy Technology Data Exchange (ETDEWEB)

    Bush, B.; Jenkin, T.; Lipowicz, D.; Arent, D. J.; Cooke, R.

    2012-01-01

    Does large scale penetration of renewable generation such as wind and solar power pose economic and operational burdens on the electricity system? A number of studies have pointed to the potential benefits of renewable generation as a hedge against the volatility and potential escalation of fossil fuel prices. Research also suggests that the lack of correlation of renewable energy costs with fossil fuel prices means that adding large amounts of wind or solar generation may also reduce the volatility of system-wide electricity costs. Such variance reduction of system costs may be of significant value to consumers due to risk aversion. The analysis in this report recognizes that the potential value of risk mitigation associated with wind generation and natural gas generation may depend on whether one considers the consumer's perspective or the investor's perspective and whether the market is regulated or deregulated. We analyze the risk and return trade-offs for wind and natural gas generation for deregulated markets based on hourly prices and load over a 10-year period using historical data in the PJM Interconnection (PJM) from 1999 to 2008. Similar analysis is then simulated and evaluated for regulated markets under certain assumptions.

  16. Analysis of Precooling Injection Transient of Steam Generator for High Temperature Gas Cooled Reactor

    Directory of Open Access Journals (Sweden)

    Yan Wang

    2017-01-01

    Full Text Available After a postulated design basis accident leads high temperature gas cooled reactor to emergency shutdown, steam generator still remains with high temperature level and needs to be cooled down by a precooling before reactor restarts with clearing of fault. For the large difference of coolant temperature between inlet and outlet of steam generator in normal operation, the temperature distribution on the components of steam generator is very complicated. Therefore, the temperature descending rate of the components in steam generator needs to be limited to avoid the potential damage during the precooling stage. In this paper, a pebble-bed high temperature gas cooled reactor is modeled by thermal-hydraulic system analysis code and several postulated precooling injection transients are simulated and compared to evaluate their effects, which will provide support for the precooling design. The analysis results show that enough precooling injection is necessary to satisfy the precooling requirements, and larger mass flow rate of precooling water injection will accelerate the precooling process. The temperature decrease of steam generator is related to the precooling injection scenarios, and the maximal mass flow rate of the precooling injection should be limited to avoid the excessively quick temperature change of the structures in steam generator.

  17. Development of a technology for the preparation of 188W-188Re generators

    International Nuclear Information System (INIS)

    Oliveira, Alexandre de

    2004-01-01

    A big interest has recently arisen concerning the use of Rhenium-188 (188Re) for various medical applications. Tumor therapy with antibodies labeled with 188Re is the main application, but it is being studied its application in carcinomas of medullar thyroid, bone pain palliation and radionuclide synovectomy, among others. Rhenium-188 decays 79% to the ground state of stable 188Os (Eβ1max - 2,11 MeV) and 20% to the first excited state (Eβ2max = 1,97 MeV). The deexcitation of this state gives a 155 keV gamma ray (15r%) which can be detected by imaging. Another great advantage is the viability of carrier-free 188Re from the decay of 188W (t 1/2 = 69.4 days) in a generator system. The objective of this work is the development of the technology for the preparation of 188W- 188Re generators. To accomplish this, the steps of the work are: preparation of the targets of W; irradiation of W targets in order to measure the activation and radionuclidic impurities; development of 188W-188Re generators; development of a method for the quality control of 188Re: chemical, radiochemical and radionuclidic purities. The study of alumina-based generators was performed with the irradiation of targets of natural metallic W and W03 and showed that this kind of generator will only be viable with the importation of 188W, due to the low neutron flux of the Reactor IEA-R1 Reactor for the commercial routine production of this radioisotope, but the technology of production and quality control were successful. The gel type chromatographic generators of WZr were produced with natural WO3 targets and showed that, if enriched targets are to be used and with the power upgrade of the IEA-R1 Reactor, they can be produced by the Radiopharmacy Center at IPEN-SP. The quality control methodology were determined and the results were inside the limits given by the Pharmacopoeia. (author)

  18. 76 FR 36910 - Astoria Generating Company, L.P., NRG Power Marketing LLC, Arthur Kill Power LLC, Astoria Gas...

    Science.gov (United States)

    2011-06-23

    ... Generating Company, L.P., NRG Power Marketing LLC, Arthur Kill Power LLC, Astoria Gas Turbine Power LLC... Generating Company, L.P., NRG Power Marketing LLC, Arthur Kill Power LLC, Astoria Gas Turbine Power [[Page... subscribed docket(s). For assistance with any FERC Online service, please e-mail [email protected

  19. 76 FR 34692 - Astoria Generating Company, L.P., NRG Power Marketing LLC, Arthur Kill Power LLC, Astoria Gas...

    Science.gov (United States)

    2011-06-14

    ... Generating Company, L.P., NRG Power Marketing LLC, Arthur Kill Power LLC, Astoria Gas Turbine Power LLC... Generating Company, L.P., NRG Power Marketing LLC, Arthur Kill Power LLC, Astoria Gas Turbine Power LLC... notification when a document is added to a subscribed docket(s). For assistance with any FERC Online service...

  20. Controllable preparation of copper phthalocyanine single crystal nano column and its chlorine gas sensing properties

    Directory of Open Access Journals (Sweden)

    Jianhong Zhao

    2016-09-01

    Full Text Available The unsubstituted copper phthalocyanine (CuPc single crystal nano columns were fabricated for the first time as chlorine (Cl2 gas sensors in this paper. The nano columns of CuPc have been prepared on different substrates via template-free physical vapor deposition (PVD approach. The growth mechanism of CuPc nano column on quartz was explored and the same condition used on other substrates including glass, sapphire (C-plane, M-plane, R-plane, Si and SiO2/Si came to a same conclusion, which confirmed that the aligned growth of CuPc nano column is not substrate-dependent. And then the CuPc nano column with special morphology was integrated as in-situ sensor device which exhibits high sensitivity and selectivity towards Cl2 at room temperature with a minimum detection limit as low as 0.08 ppm. The response of sensor was found to increase linearly (26∼659% with the increase for Cl2 within concentration range (0.08∼4.0ppm. These results clearly demonstrate the great potential of the nano column growth and device integration approach for sensor device.

  1. Gas permeability of thin polyimide foils prepared by in-situ polymerisation

    International Nuclear Information System (INIS)

    Stolarz, Anna; Varlam, Mihai; Wellum, Roger

    2008-01-01

    The entrance windows to the gas detector chambers as well as to the target containers used in high-energy and high-intensity accelerators must be as thin as possible to minimise energy losses of the particles used in astrophysics and nuclear physics studies. Because of their good physical properties, polyimide foils are often considered as suitable material for such windows, but commercially available foils, having a thickness greater than 7-8 μm (>1 mg/cm 2 ), would cause energy losses of particles significant for some nuclear reactions studied. Foils prepared by in-situ polymerisation can, however, be as thin as 0.07 μm (∼10 μg/cm 2 ). The permeability of 4 μm foils produced by in-situ polymerisation has been measured at room temperature for He and Ar. For He measurements were performed in the pressure range of 4-70 mbar and for Ar in the range of 20-140 mbar and the permeability was found to be in good agreement with the values published for the thicker commercial foils

  2. Thermal-maturity limit for primary thermogenic-gas generation from humic coals as determined by hydrous pyrolysis

    Science.gov (United States)

    Lewan, Michael; Kotarba, M.J.

    2014-01-01

    Hydrous-pyrolysis experiments at 360°C (680°F) for 72 h were conducted on 53 humic coals representing ranks from lignite through anthracite to determine the upper maturity limit for hydrocarbon-gas generation from their kerogen and associated bitumen (i.e., primary gas generation). These experimental conditions are below those needed for oil cracking to ensure that generated gas was not derived from the decomposition of expelled oil generated from some of the coals (i.e., secondary gas generation). Experimental results showed that generation of hydrocarbon gas ends before a vitrinite reflectance of 2.0%. This reflectance is equivalent to Rock-Eval maximum-yield temperature and hydrogen indices (HIs) of 555°C (1031°F) and 35 mg/g total organic carbon (TOC), respectively. At these maturity levels, essentially no soluble bitumen is present in the coals before or after hydrous pyrolysis. The equivalent kerogen atomic H/C ratio is 0.50 at the primary gas-generation limit and indicates that no alkyl moieties are remaining to source hydrocarbon gases. The convergence of atomic H/C ratios of type-II and -I kerogen to this same value at a reflectance of indicates that the primary gas-generation limits for humic coal and type-III kerogen also apply to oil-prone kerogen. Although gas generation from source rocks does not exceed vitrinite reflectance values greater than , trapped hydrocarbon gases can remain stable at higher reflectance values. Distinguishing trapped gas from generated gas in hydrous-pyrolysis experiments is readily determined by of the hydrocarbon gases when a -depleted water is used in the experiments. Water serves as a source of hydrogen in hydrous pyrolysis and, as a result, the use of -depleted water is reflected in the generated gases but not pre-existing trapped gases.

  3. The DOE/NREL Next Generation Natural Gas Vehicle Program - An Overview

    International Nuclear Information System (INIS)

    Kevin Walkowicz; Denny Stephens; Kevin Stork

    2001-01-01

    This paper summarizes the Next Generation Natural Gas Vehicle (NG-NGV) Program that is led by the U.S. Department Of Energy's (DOE's) Office of Heavy Vehicle Technologies (OHVT) through the National Renewable Energy Laboratory (NREL). The goal of this program is to develop and implement one Class 3-6 compressed natural gas (CNG) prototype vehicle and one Class 7-8 liquefied natural gas (LNG) prototype vehicle in the 2004 to 2007 timeframe. OHVT intends for these vehicles to have 0.5 g/bhp-hr or lower emissions of oxides of nitrogen (NOx) by 2004 and 0.2 g/bhp-hr or lower NOx by 2007. These vehicles will also have particulate matter (PM) emissions of 0.01 g/bhp-hr or lower by 2004. In addition to ambitious emissions goals, these vehicles will target life-cycle economics that are compatible with their conventionally fueled counterparts

  4. Conceptual design study of closed Brayton cycle gas turbines for fusion power generation

    International Nuclear Information System (INIS)

    Kuo, S.C.

    1976-01-01

    A conceptual design study is presented of closed Brayton cycle gas turbine power conversion systems suitable for integration with advanced-concept Tokamak fusion reactors (such as UWMAK-III) for efficient power generation without requiring cooling water supply for waste heat rejection. A baseline cycle configuration was selected and parametric performance analyses were made. Based on the results of the parametric analysis and trade-off and interface considerations, the reference design conditions for the baseline cycle were selected. Conceptual designs were made of the major helium gas turbine power system components including a 585-MWe single-shaft turbomachine, (three needed), regenerator, precooler, intercooler, and the piping system connecting them. Structural configuration and significant physical dimensions for major components are illustrated, and a brief discussion on major advantages, power control and crucial technologies for the helium gas turbine power system are presented

  5. Generation and confinement of microwave gas-plasma in photonic dielectric microstructure.

    Science.gov (United States)

    Debord, B; Jamier, R; Gérôme, F; Leroy, O; Boisse-Laporte, C; Leprince, P; Alves, L L; Benabid, F

    2013-10-21

    We report on a self-guided microwave surface-wave induced generation of ~60 μm diameter and 6 cm-long column of argon-plasma confined in the core of a hollow-core photonic crystal fiber. At gas pressure of 1 mbar, the micro-confined plasma exhibits a stable transverse profile with a maximum gas-temperature as high as 1300 ± 200 K, and a wall-temperature as low as 500 K, and an electron density level of 10¹⁴ cm⁻³. The fiber guided fluorescence emission presents strong Ar⁺ spectral lines in the visible and near UV. Theory shows that the observed combination of relatively low wall-temperature and high ionisation rate in this strongly confined configuration is due to an unprecedentedly wide electrostatic space-charge field and the subsequent ion acceleration dominance in the plasma-to-gas power transfer.

  6. Aspects on the gas generation and migration in repositories for high level waste in salt formations

    International Nuclear Information System (INIS)

    Ruebel, Andre; Buhmann, Dieter; Meleshyn, Artur; Moenig, Joerg; Spiessl, Sabine

    2013-07-01

    In a deep geological repository for high-level waste, gases may be produced during the post-closure phase by several processes. The generated gases can potentially affect safety relevant features and processes of the repository, like the barrier integrity, the transport of liquids and gases in the repository and the release of gaseous radionuclides from the repository into the biosphere. German long-term safety assessments for repositories for high-level waste in salt which were performed prior 2010 did not explicitly consider gas transport and the consequences from release of volatile radionuclides. Selected aspects of the generation and migration of gases in repositories for high-level waste in a salt formation are studied in this report from the viewpoint of the performance assessment. The knowledge on the availability of water in the repository, in particular the migration of salt rock internal fluids in the temperature field of the radioactive waste repository towards the emplacement drifts, was compiled and the amount of water was roughly estimated. Two other processes studied in this report are on the one hand the release of gaseous radionuclides from the repository and their potential impact in the biosphere and on the other hand the transport of gases along the drifts and shafts of the repository and their interaction with the fluid flow. The results presented show that there is some gas production expected to occur in the repository due to corrosion of container material from water disposed of with the backfill and inflowing from the host rock during the thermal phase. If not dedicated gas storage areas are foreseen in the repository concept, these gases might exceed the storage capacity for gases in the repository. Consequently, an outflow of gases from the repository could occur. If there are failed containers for spent fuel, radioactive gases might be released from the containers into the gas space of the backfill and subsequently transported together

  7. Preparation of 99Mo for 99mTc generators and the issue of further development. A survey report

    International Nuclear Information System (INIS)

    Malek, Z.

    1998-01-01

    The following topics are dealt with: World production of Mo-99 for technetium generators; Typical procedures for the preparation of Mo-99; Current and expected decline in the production of Mo-99; and Directions of further development (Water reactors-irradiation systems for the preparation of Mo-99; Homogeneous reactor systems for the preparation of Mo-99 based on molten salts; Systems with accelerators; Thermal processes for the reprocessing of irradiated target material). (P.A.)

  8. Life-cycle comparison of greenhouse gas emissions and water consumption for coal and shale gas fired power generation in China

    International Nuclear Information System (INIS)

    Chang, Yuan; Huang, Runze; Ries, Robert J.; Masanet, Eric

    2015-01-01

    China has the world's largest shale gas reserves, which might enable it to pursue a new pathway for electricity generation. This study employed hybrid LCI (life cycle inventory) models to quantify the ETW (extraction-to-wire) GHG (greenhouse gas) emissions and water consumption per kWh of coal- and shale gas-fired electricity in China. Results suggest that a coal-to-shale gas shift and upgrading coal-fired power generation technologies could provide pathways to less GHG and water intensive power in China. Compared to different coal-fired generation technologies, the ETW GHG emissions intensity of gas-fired CC (combined cycle) technology is 530 g CO 2 e/kWh, which is 38–45% less than China's present coal-fired electricity. Gas-fired CT (combustion turbine) technology has the lowest ETW water consumption intensity at 960 g/kWh, which is 34–60% lower than China's present coal-fired electricity. The GHG-water tradeoff of the two gas-fired power generation technologies suggests that gas-fired power generation technologies should be selected based on regional-specific water resource availabilities and electricity demand fluctuations in China. However, the low price of coal-fired electricity, high cost of shale gas production, insufficient pipeline infrastructures, and multiple consumers of shale gas resources may serve as barriers to a coal-to-shale gas shift in China's power sector in the near term. - Highlights: • The GHG and water footprints of coal- and shale gas-fired electricity are estimated. • A coal-to-shale gas shift can enable less GHG and water intensive power in China. • The GHG emissions of shale gas-fired combined cycle technology is 530 g CO 2 e/kWh. • The water consumption of shale gas-fired combustion turbine technology is 960 g/kWh. • Shale gas-fired power generation technologies selection should be regional-specific

  9. Looked after or Left Behind: The Effectiveness of Principal Preparation Programs as Perceived by Generation Y Principals

    Science.gov (United States)

    Sledge, Chandra

    2013-01-01

    This research study intended to discover the perceptions of 10 Illinois Generation Y novice high school principals pertaining to the effectiveness of their principal preparation programs in terms of how well it prepared them to lead in the first three years of their principalship, and what subsequent professional development they deemed necessary…

  10. Accounting for fuel price risk when comparing renewable togas-fired generation: the role of forward natural gas prices

    Energy Technology Data Exchange (ETDEWEB)

    Bolinger, Mark; Wiser, Ryan; Golove, William

    2004-07-17

    Unlike natural gas-fired generation, renewable generation (e.g., from wind, solar, and geothermal power) is largely immune to fuel price risk. If ratepayers are rational and value long-term price stability, then--contrary to common practice--any comparison of the levelized cost of renewable to gas-fired generation should be based on a hedged gas price input, rather than an uncertain gas price forecast. This paper compares natural gas prices that can be locked in through futures, swaps, and physical supply contracts to contemporaneous long-term forecasts of spot gas prices. We find that from 2000-2003, forward gas prices for terms of 2-10 years have been considerably higher than most contemporaneous long-term gas price forecasts. This difference is striking, and implies that comparisons between renewable and gas-fired generation based on these forecasts over this period have arguably yielded results that are biased in favor of gas-fired generation.

  11. Characterization of the gas-puff imploding plasma on the NRL Gamble II generator

    International Nuclear Information System (INIS)

    Stephanakis, S.J.; Boller, J.R.; Cooperstein, G.

    1984-01-01

    Recently, an experimental and theoretical effort has been undertaken at NRL aimed at contributing to understanding the physics of the implosion dynamics and of the resulting highly localized plasma pinch in such experiments. Supersonic nozzles producing a cylindrical gas flow provide the load for the Gamble II generator operating at the 1.5 TW level. The gas jet is preionized and then imploded to the axis by the machine electrical pulse in a very short time scale. During the implosion process, the attained kinetic energy is efficiently converted to plasma thermal energy and produces the desired radiation. Preliminary experimental results are presented from the study of the conditions necessary in order to efficiently couple such loads to the Gamble II generator. These results are correlated to existing scaling laws and are compared with theoretical models

  12. Dynamic performance of power generation systems for off-shore oil and gas platforms

    DEFF Research Database (Denmark)

    Pierobon, Leonardo; Breuhaus, Peter; Haglind, Fredrik

    2014-01-01

    %) arises on the prediction of the rotational speed of the high pressure shaft, while the largest deviation (average relative error ~20%) occurs in the evaluation of the pressure at the outlet of the low pressure turbine. As waste heat recovery units (e.g. organic Rankine cycles) are likely...... to be implemented in future off-shore platforms, the proposed model may serve in the design phase for a preliminary assessment of the dynamic response of the power generation system and to evaluate if requirements such as minimum and maximum frequency during transient operation and the recovery time are satisfied......On off-shore oil and gas platforms two or more gas turbines typically support the electrical demand on site by operating as a stand-alone (island) power system. As reliability and availability are major concerns during operation, the dynamic performance of the power generation system becomes...

  13. [Chronic CO poisoning. Use of generator gas during the second world war and recent research].

    Science.gov (United States)

    Tvedt, B; Kjuus, H

    1997-06-30

    The consequences of long-lasting and low-grade exposure to carbon monoxide are a matter of debate. During the second world war, lack of petrol led to widespread use of wood as fuel (generator gas vehicles), especially in the Nordic countries. This caused many cases of "acute" or "chronic" carbon monoxide poisoning. Typical symptoms of "chronic poisoning" were headache, dizziness and tiredness. Usually the symptoms disappeared after some weeks or month, but in some patients probably became permanent. The experiences from the generator gas era are now almost forgotten, and chronic carbon monoxide poisoning is easily overlooked. The authors describe two cases of such poisoning. A crane driver at a smelting works developed permanent symptoms after twenty years of exposure. A faulty oil-fired central heating system caused long-lasting symptoms in four members of a family.

  14. Energy and exergy analysis of electricity generation from natural gas pressure reducing stations

    International Nuclear Information System (INIS)

    Neseli, Mehmet Alparslan; Ozgener, Onder; Ozgener, Leyla

    2015-01-01

    Highlights: • Forecasting the recoverable energy from natural gas pressure reduction stations. • Electricity generation through pressure reduction stations via turboexpanders. • A thermodynamics analysis of PRS. - Abstract: Electricity generation or power recovery through pressure reduction stations (PRS) for general use has not been realized in Izmir. The main objective of the present study was to do a case study for calculating electricity to be recovered in one natural gas pressure reduction stations in Izmir. It is the first forecasting study to obtain energy from natural gas pressure-reducing stations in Izmir. Energy can be obtained from natural gas PRS with turbo-expanders instead of using throttle valves or regulators from the PRS. The exergy performance of PRS with TE is evaluated in this study. Exergetic efficiencies of the system and components are determined to assess their individual performances. Based upon pressure change and volumetric flow rate, it can be obtained by recovering average estimated installed capacity and annual energy 494.24 kW, 4113.03 MW h, respectively. In terms of estimated installed capacity power and annual energy, the highest level is 764.88 kW, approximately 6365.34 MW h, in Aliaga PRS. Also it can be seen that CO 2 emission factor average value is 295.45 kg/MW h

  15. Rapid hydrogen gas generation using reactive thermal decomposition of uranium hydride.

    Energy Technology Data Exchange (ETDEWEB)

    Kanouff, Michael P.; Van Blarigan, Peter; Robinson, David B.; Shugard, Andrew D.; Gharagozloo, Patricia E.; Buffleben, George M.; James, Scott Carlton; Mills, Bernice E.

    2011-09-01

    Oxygen gas injection has been studied as one method for rapidly generating hydrogen gas from a uranium hydride storage system. Small scale reactors, 2.9 g UH{sub 3}, were used to study the process experimentally. Complimentary numerical simulations were used to better characterize and understand the strongly coupled chemical and thermal transport processes controlling hydrogen gas liberation. The results indicate that UH{sub 3} and O{sub 2} are sufficiently reactive to enable a well designed system to release gram quantities of hydrogen in {approx} 2 seconds over a broad temperature range. The major system-design challenge appears to be heat management. In addition to the oxidation tests, H/D isotope exchange experiments were performed. The rate limiting step in the overall gas-to-particle exchange process was found to be hydrogen diffusion in the {approx}0.5 {mu}m hydride particles. The experiments generated a set of high quality experimental data; from which effective intra-particle diffusion coefficients can be inferred.

  16. Generator of a dense atomic gas curtain (for use in Intersecting Storage Rings)

    CERN Document Server

    Zankel, K

    1975-01-01

    A supersonic beam source is described which continuously generates a gas curtain for the proton beam profile observation in the Intersecting Storage Rings at CERN. Its maximum intensity is 10/sup 20 / atoms/sr s. A commonly used theoretical model for the determination of the intensity downstream of the source is discussed. Some results about the condensation behaviour of sodium vapour on metallic substrate surfaces are reported. (8 refs).

  17. Numerical analysis for thermal waves in gas generated by impulsive heating of a boundary surface

    International Nuclear Information System (INIS)

    Utsumi, Takayuki; Kunugi, Tomoaki

    1996-01-01

    Thermal wave in gas generated by an impulsive heating of a solid boundary was analyzed numerically by the Differential Algebraic CIP (Cubic Interpolated Propagation) scheme. Numerical results for the ordinary heat conduction equation were obtained with a high accuracy. As for the hyperbolic thermal fluid dynamics equation, the fundamental feature of the experimental results by Brown and Churchill with regard to thermoacoustic convection was qualitatively reproduced by the DA-CIP scheme. (author)

  18. The smoke ion source: A device for the generation of cluster ions via inert gas condensation

    International Nuclear Information System (INIS)

    McHugh, K.M.; Sarkas, H.W.; Eaton, J.G.; Bowen, K.H.; Westgate, C.R.

    1989-01-01

    We report the development of an ion source for generating intense, continuous beams of both positive and negative cluster ions. This device is the result of the marriage of the inert gas condensation method with techniques for injecting electrons directly into expanding jets. In the preliminary studies described here, we have observed cluster ion size distributions ranging from n=1-400 for Pb n + and Pb n - and from n=12-5700 for Li n - . (orig.)

  19. Thermal hydrodynamic modeling and simulation of hot-gas duct for next-generation nuclear reactor

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Injun [School of Mechanical Engineering, Yeungnam University, Gyeongsan 712-749 (Korea, Republic of); Hong, Sungdeok; Kim, Chansoo [Korea Atomic Energy Research Institute, Daejeon 305-353 (Korea, Republic of); Bai, Cheolho; Hong, Sungyull [School of Mechanical Engineering, Yeungnam University, Gyeongsan 712-749 (Korea, Republic of); Shim, Jaesool, E-mail: jshim@ynu.ac.kr [School of Mechanical Engineering, Yeungnam University, Gyeongsan 712-749 (Korea, Republic of)

    2016-12-15

    Highlights: • Thermal hydrodynamic nonlinear model is presented to examine a hot gas duct (HGD) used in a fourth-generation nuclear power reactor. • Experiments and simulation were compared to validate the nonlinear porous model. • Natural convection and radiation are considered to study the effect on the surface temperature of the HGD. • Local Nusselt number is obtained for the optimum design of a possible next-generation HGD. - Abstract: A very high-temperature gas-cooled reactor (VHTR) is a fourth-generation nuclear power reactor that requires an intermediate loop that consists of a hot-gas duct (HGD), an intermediate heat exchanger (IHX), and a process heat exchanger for massive hydrogen production. In this study, a mathematical model and simulation were developed for the HGD in a small-scale nitrogen gas loop that was designed and manufactured by the Korea Atomic Energy Research Institute. These were used to investigate the effect of various important factors on the surface of the HGD. In the modeling, a porous model was considered for a Kaowool insulator inside the HGD. The natural convection and radiation are included in the model. For validation, the modeled external surface temperatures are compared with experimental results obtained while changing the inlet temperatures of the nitrogen working fluid. The simulation results show very good agreement with the experiments. The external surface temperatures of the HGD are obtained with respect to the porosity of insulator, emissivity of radiation, and pressure of the working fluid. The local Nusselt number is also obtained for the optimum design of a possible next-generation HGD.

  20. High Temperature Gas-Cooled Reactors Lessons Learned Applicable to the Next Generation Nuclear Plant

    International Nuclear Information System (INIS)

    Beck, J.M.; Collins, J.W.; Garcia, C.B.; Pincock, L.F.

    2010-01-01

    High Temperature Gas Reactors (HTGR) have been designed and operated throughout the world over the past five decades. These seven HTGRs are varied in size, outlet temperature, primary fluid, and purpose. However, there is much the Next Generation Nuclear Plant (NGNP) has learned and can learn from these experiences. This report captures these various experiences and documents the lessons learned according to the physical NGNP hardware (i.e., systems, subsystems, and components) affected thereby.

  1. The Efficiency Improvement by Combining HHO Gas, Coal and Oil in Boiler for Electricity Generation

    OpenAIRE

    Chia-Nan Wang; Min-Tsong Chou; Hsien-Pin Hsu; Jing-Wein Wang; Sridhar Selvaraj

    2017-01-01

    Electricity is an essential energy that can benefit our daily lives. There are many sources available for electricity generation, such as coal, natural gas and nuclear. Among these sources, coal has been widely used in thermal power plants that account for about 41% of the worldwide electricity supply. However, these thermal power plants are also found to be a big pollution source to our environment. There is a need to explore alternative electricity sources and improve the efficiency of elec...

  2. Frequency and distribution of leakages in steam generators of gas-cooled reactors

    International Nuclear Information System (INIS)

    Bongratz, R.; Breitbach, G.; Wolters, J.

    1988-01-01

    In gas cooled reactors with graphitic primary circuit structures - such as HTR, AGR or Magnox - the water ingress is an event of great safety concern. Water or steam entering the primary circuit react with the hot graphite and carbon-oxide and hydrogen are produced. As the most important initiating event a leak in a steam generator must be taken into account. From the safety point of view as well as for availability reasons it is necessary to construct reliable boilers. Thus the occurrence of a boiler leak should be a rare event. In the context of a probabilistic safety study for an HTR-Project much effort was invested to get information about the frequency and the size distribution of tube failures in steam generators of gas cooled reactors. The main data base was the boiler tube failure statistics of United Kingdom gas cooled reactors. The data were selected and applied to a modern HTR steam generator design. A review of the data showed that the failure frequency is not connected with the load level (pressures, temperatures) or with the geometric size of the heating surface of the boiler. Design, construction, fabrication, examination and operation conditions have the greatest influence an the failure frequency but they are practically not to be quantified. The typical leak develops from smallest size. By erosion effects of the entering water or steam it is enlarged to perhaps some mm 2 , then usually it is detected by moisture monitors. Sudden tube breaks were not reported in the investigated period. As a rule boiler leaks in gas cooled reactors are much more, rare then leaks in steam generators of light water reactors and fossil fired boilers. (author)

  3. Greenhouse gas emission for co-generation installation - reduction and selling

    International Nuclear Information System (INIS)

    Manev, S.; Stankov, N.; Asenov, A.

    2005-01-01

    According to Kyoto protocol countries which have the availability to buy green house gas emissions from other countries could be made by means of realization of investment project. In this article the authors review the necessary scope of work which have to be done in order particular project for co-generation installation to be realized, according the requirement and their own experience in this field

  4. Improvement to the gas cycle energy generating installations with heat recuperation

    International Nuclear Information System (INIS)

    Tilliette, Zephyr.

    1977-01-01

    Improvement to the gas cycle energy generating installations with heat recuperation, comprising a heat source, supplying a fluid at high temperature and pressure, an expansion turbine, at least one recuperator fitted to the turbine outlet, a cooler and compressor in series, the compressor returning the high pressure fluid to the source after heat exchange in the recuperator with the low pressure fluid from the turbine. It is characterised in that at least one steam generator is connected to the low pressure end of the recuperator [fr

  5. Developments in, and environmental impacts of, electricity generation from municipal solid waste and landfill gas combustion

    International Nuclear Information System (INIS)

    Porteous, A.

    1993-01-01

    The 1991 NFFO allocations for renewable energy generation are reviewed with emphasis on electricity from municipal solid waste (MSW) and landfill gas (LFG) combustion tranches. The implications of materials recovery on the calorific value of MSW are considered, as are the environmental impacts of both MSW and LFG combustion with special reference to air pollutant emissions. The performance and economics of state of the art incineration and LFG power generating plants are examined. It is shown that energy recovery from these wastes can be both cost effective and environmentally desirable. (Author)

  6. Generation risk assessment in volatile conditions with wind, hydro, and natural gas units

    International Nuclear Information System (INIS)

    Sahin, Cem; Shahidehpour, Mohammad; Erkmen, Ismet

    2012-01-01

    Highlights: ► Stochastic price-based unit commitment (PBUC) for a generation company (GENCO). ► Water inflow, wind, and NG interruption uncertainties are considered. ► Diversification of assets and bilateral contracts enhance payoff and decrease financial risk. ► The utilization of NG in the risk-neutral GENCO case increases as the wind uncertainty increases. ► NG utilization is lowered by the algorithm to decrease in risk-considered case. -- Abstract: This paper studies a generating company (GENCO)’s midterm (a few months to a year) scheduling payoffs and risks in volatile operating conditions. The proposed algorithm considers the integration of intermittent wind units into a GENCO’s generation assets and coordinates the GENCO’s hourly wind generation schedule with that of natural gas (NG) units (with volatile gas prices) and hydro units (with water inflow forecast) for maximizing the GENCO’s payoff. The proposed midterm GENCO model applies market price forecasts to the risk-constrained stochastic price-based unit commitment (PBUC) for calculating the GENCO’s risk in energy and ancillary services markets. The proposed PBUC minimizes the cost of (a) NG contracts, storage, startup and shutdown, (b) startup and shutdown of cascaded hydro units, and (c) penalty for defaulting on the scheduled power delivery. Simulation results show that the diversification of generating assets including bilateral contracts (BCs) could enhance the GENCO’s midterm planning by increasing the expected payoff and decreasing the financial risk.

  7. Slurry growth, gas retention, and flammable gas generation by Hanford radioactive waste tanks: Synthetic waste studies, FY 1991

    International Nuclear Information System (INIS)

    Bryan, S.A.; Pederson, L.R.; Ryan, J.L.; Scheele, R.D.; Tingey, J.M.

    1992-08-01

    Of 177 high-level waste storage tanks on the Hanford Site, 23 have been placed on a safety watch list because they are suspected of producing flammable gases in flammable or explosive concentrate. One tankin particular, Tank 241-SY-101 (Tank 101-SY), has exhibited slow increases in waste volume followed by a rapid decrease accompanied by venting of large quantities of gases. The purpose of this study is to help determine the processes by which flammable gases are produced, retained, and eventually released from Tank 101-SY. Waste composition data for single- and double-shell waste tanks on the flammable gas watch listare critically reviewed. The results of laboratory studies using synthetic double-shell wastes are summarized, including physical and chemical properties of crusts that are formed, the stoichiometry and rate ofgas generation, and mechanisms responsible for formation of a floating crust

  8. Life Cycle Energy Consumption and Greenhouse Gas Emissions Analysis of Natural Gas-Based Distributed Generation Projects in China

    Directory of Open Access Journals (Sweden)

    Hansi Liu

    2017-10-01

    Full Text Available In this paper, we used the life-cycle analysis (LCA method to evaluate the energy consumption and greenhouse gas (GHG emissions of natural gas (NG distributed generation (DG projects in China. We took the China Resources Snow Breweries (CRSB NG DG project in Sichuan province of China as a base scenario and compared its life cycle energy consumption and GHG emissions performance against five further scenarios. We found the CRSB DG project (all energy input is NG can reduce GHG emissions by 22%, but increase energy consumption by 12% relative to the scenario, using coal combined with grid electricity as an energy input. The LCA also indicated that the CRSB project can save 24% of energy and reduce GHG emissions by 48% relative to the all-coal scenario. The studied NG-based DG project presents major GHG emissions reduction advantages over the traditional centralized energy system. Moreover, this reduction of energy consumption and GHG emissions can be expanded if the extra electricity from the DG project can be supplied to the public grid. The action of combining renewable energy into the NG DG system can also strengthen the dual merit of energy conservation and GHG emissions reduction. The marginal CO2 abatement cost of the studied project is about 51 USD/ton CO2 equivalent, which is relatively low. Policymakers are recommended to support NG DG technology development and application in China and globally to boost NG utilization and control GHG emissions.

  9. Climate change impacts and greenhouse gas mitigation effects on U.S. hydropower generation

    International Nuclear Information System (INIS)

    Boehlert, Brent; Strzepek, Kenneth M.; Gebretsadik, Yohannes; Swanson, Richard; McCluskey, Alyssa; Neumann, James E.; McFarland, James; Martinich, Jeremy

    2016-01-01

    Highlights: • Analyze contiguous U.S. hydropower generation under various emissions scenarios. • Employ systems model that allocates water to competing uses in 2119 river basins. • Average U.S. generation increases under climate change, but falls under low flows. • Mitigation benefits are $2-$4 billion/year due to high values of carbon-free energy. - Abstract: Climate change will have potentially significant effects on hydropower generation due to changes in the magnitude and seasonality of river runoff and increases in reservoir evaporation. These physical impacts will in turn have economic consequences through both producer revenues and consumer expenditures. We analyze the physical and economic effects of changes in hydropower generation for the contiguous U.S. in futures with and without global-scale greenhouse gas (GHG) mitigation, and across patterns from 18 General Circulation Models. Using a monthly water resources systems model of 2119 river basins that routes simulated river runoff through reservoirs, and allocates water to potentially conflicting and climate dependent demands, we provide a first-order estimate of the impacts of various projected emissions outcomes on hydropower generation, and monetize these impacts using outputs from an electric sector planning model for over 500 of the largest U.S. hydropower facilities. We find that, due to generally increasing river runoff under higher emissions scenarios in the Pacific Northwest, climate change tends to increase overall hydropower generation in the contiguous U.S. During low flow months, generation tends to fall with increasing emissions, potentially threatening the estimated low flow, firm energy from hydropower. Although global GHG mitigation slows the growth in hydropower generation, the higher value placed on carbon-free hydropower leads to annual economic benefits ranging from $1.8 billion to $4.3 billion. The present value of these benefits to the U.S. from global greenhouse gas

  10. Mass flow discharge and total temperature characterisation of a pyrotechnic gas generator formulation for airbag systems

    Energy Technology Data Exchange (ETDEWEB)

    Neutz, Jochen; Koenig, Andreas [Fraunhofer Institut fuer Chemische Technologie ICT, Pfinztal (Germany); Knauss, Helmut; Jordan, Sebastian; Roediger, Tim; Smorodsky, Boris [Universitaet Stuttgart (Germany). Institut fuer Aerodynamik und Gasdynamik; Bluemcke, Erich Walter [AUDI AG, Department I/EK-523, Ingolstadt (Germany)

    2009-06-15

    The mass flow characteristics of gas generators for airbag applications have to comply with a number of requirements for an optimal deployment of the airbag itself. Up to now, the mass flow was determined from pressure time histories of so-called can tests. This procedure suffers from the missing knowledge on the temperature of the generated gas entering the can. A new test setup described in this paper could overcome this problem by providing highly time resolved information on the gas's total temperature and the mass flow of the generator. The test setup consisted of a combustion chamber with a specially designed Laval nozzle in combination with a temperature sensor of high time resolution. The results showed a high time resolved temperature signal, which was disturbed by the formation of a slag layer on the sensor. Plausibility considerations with experimentally and thermodynamically determined combustion temperatures led to satisfying results for the overall temperature as characteristic parameter of airbag inflating gases flows from pyrotechnics. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

  11. A three-dimensional algebraic grid generation scheme for gas turbine combustors with inclined slots

    Science.gov (United States)

    Yang, S. L.; Cline, M. C.; Chen, R.; Chang, Y. L.

    1993-01-01

    A 3D algebraic grid generation scheme is presented for generating the grid points inside gas turbine combustors with inclined slots. The scheme is based on the 2D transfinite interpolation method. Since the scheme is a 2D approach, it is very efficient and can easily be extended to gas turbine combustors with either dilution hole or slot configurations. To demonstrate the feasibility and the usefulness of the technique, a numerical study of the quick-quench/lean-combustion (QQ/LC) zones of a staged turbine combustor is given. Preliminary results illustrate some of the major features of the flow and temperature fields in the QQ/LC zones. Formation of co- and counter-rotating bulk flow and shape temperature fields can be observed clearly, and the resulting patterns are consistent with experimental observations typical of the confined slanted jet-in-cross flow. Numerical solutions show the method to be an efficient and reliable tool for generating computational grids for analyzing gas turbine combustors with slanted slots.

  12. Numerical Study of the Working Process in the Reducing Gas Generator of the Upper Stage Oxygen - Methane Engine

    Directory of Open Access Journals (Sweden)

    D. M. Yagodnikov

    2015-01-01

    Full Text Available This article deals with the problems of creating a reducing gas generator of the liquid rocket engine (LRE of upper stage using advanced fuel components, namely oxygen + liquid natural gas. Relevance of the work is justified by the need to create and develop of environmentally friendly missile systems for space applications using methane-based fuel (liquid natural gas. As compared to the currently used unsymmetrical dimethyl-hydrazine and kerosene, this fuel is environmentally safe, passive to corrosion, has better cooling properties and high energy characteristics in the re-generatively cooled chambers, as well as is advantageous for LRE of multiple start and use.The purpose of this work is a mathematical modeling, calculation of the working process efficiency, as well as study of gas-dynamic structure of the flow in the gas generator flow path. The object of study is the upper stage LRE gas generator, which uses the reducing scheme on the liquid propellants: oxygen + liquid methane. Research methods are based on numerical simulation.Computational studies allowed us to receive the velocity, temperatures, and concentrations of reactants and combustion products in the longitudinal section of gas generator. Analysis of the gas-dynamic structure of flow shows a complete equalization of the velocity field by 2/3 of the gas generator length. Thus, the same distance is not enough to equalize the temperature distribution of the gasification products and their concentrations in radius. Increasing the total excess oxidant ratio from 0.15 to 0.25 leads to a greater spread of the parameters at the exit of the gas generator by ~ 13 ÷ 17%. As a recommendation to reduce the size of the working area, is proposed a dual-zone gas generator-mixing scheme with fuel separately supplied to the first and second zones.

  13. Monitoring of gas generation during the charge/discharge regime of miners' headlamps

    International Nuclear Information System (INIS)

    Szanto, Zs.; Molnar, M.; Palcsu, L.; Futo, I.; Rinyu, L.; Svingor, E.

    2004-01-01

    Complete text of publication follows. The miners' headlamp combines a battery pack for waistbelt mounting with a detachable headlamp/cable unit. The battery that incorporates the Ni/Cd 'gel-cells' and the KOH electrolyte (which acts only as an ion conductor and does not contribute significantly to the cell's reaction) is the most important piece of the lamp. The total reaction of the NiCd cell is: 2NiOOH + 2H 2 O + Cd ↔ 2Ni(OH) 2 + Cd(OH) 2 The preferred charging regime for caplamps is top-up charging with an occasional full discharge cycle. Nickel-cadmium cells are charged by applying direct current with the proper polarity to the cell. That means the charger will deliver a constant amount of current to the battery regardless of its voltage. During the first 70% of the charge cycle, a NiCd battery absorbs almost all of the energy and the battery remains cool. After the 70% charge threshold is reached, less and less energy is absorbed. The cells start to generate excess gases the pressure rises and the temperature increases. The charge acceptance drops further and once full charge is reached, the battery goes into overcharge. The higher the overcharge rate the higher the rate of gas generation. The battery made up of three NiCd cells has the potential for cell reversal problems when the discharge is deep enough to bring one or more of the cells in a battery to zero voltage. If discharge continues beyond this point, the voltage on the depleted cell will reverse polarity. The problem that occurs is the generation of hydrogen gas. As the electrodes change polarity they will generate hydrogen. Since the hydrogen will not recombine, the internal cell pressure will build up to a level that causes the cell to vent if the reverse charge current is maintained for a significant period of time. Due to the potential hazard during underground working gas emission generated into the cells and the amount of vented gas is strictly regulated 1. The three characteristics of cell

  14. Hanford Site Guide for Preparing and Maintaining Generator Group Pollution Prevention Documentation

    International Nuclear Information System (INIS)

    PLACE, B.G.

    2000-01-01

    This document provides guidance to generator groups for preparing and maintaining documentation of Pollution Prevention/Waste Minimization (P2/WMin) Program activities. The guidance is one of a hierarchical series that includes the Hanford Site Waste Minimization and Pollution Prevention Awareness Program Plan (DOE-RL, 2000) and Prime Contractor implementation plans describing programs required by Resource Conservation and Recovery Act of 1976 (RCRA) 3002(b) and 3005(h) (RCRA and EPA, 1994) and Department of Energy Acquisition Regulations (DEAR) (48 CFR 970.5204-2 and 48 CFR 970.5204-78). Documentation guidance for the following five P2/WMin elements is discussed: Fiscal Year (FY) Goals; Budget and Staffing; Pollution Prevention (P2) Reporting; WMin Certification; and Waste Minimization (WMin) Assessments (WMAs)

  15. Preparation of nanostructured PbS thin films as sensing element for NO{sub 2} gas

    Energy Technology Data Exchange (ETDEWEB)

    Kaci, S., E-mail: k_samira05@yahoo.fr [Centre de Recherche en Technologie des Semi-conducteurs pour l’Energétique (CRTSE) Division Couches Minces et Interfaces, 02 Bd Frantz Fanon, B.P. 140, 7 Merveilles, 16038 Algiers (Algeria); Keffous, A.; Hakoum, S. [Centre de Recherche en Technologie des Semi-conducteurs pour l’Energétique (CRTSE) Division Couches Minces et Interfaces, 02 Bd Frantz Fanon, B.P. 140, 7 Merveilles, 16038 Algiers (Algeria); Trari, M. [Université des Sciences et Technologies Houari Boumediene (USTHB), Laboratoire de Stockage et de Valorisation des Eneriges Renouvelables, Faculté de Chimie, BP 32, EL Alia, 16111 Bab Ezzouar, Algiers (Algeria); Mansri, O.; Menari, H. [Centre de Recherche en Technologie des Semi-conducteurs pour l’Energétique (CRTSE) Division Couches Minces et Interfaces, 02 Bd Frantz Fanon, B.P. 140, 7 Merveilles, 16038 Algiers (Algeria)

    2014-06-01

    In this work, we demonstrate that semiconducting films of A{sub IV}B{sub VI} compounds, in particular, of nanostructured lead sulfide (PbS) which prepared by chemical bath deposition (CBD), can be used as a sensing element for nitrogen dioxide (NO{sub 2}) gas. The CBD method is versatile, simple in implementation and gives homogeneous semiconductor structures. We have prepared PbS nanocrystalline thin film at different reaction baths and temperatures. In the course of deposition, variable amounts of additives, such as organic substances among them, were introduced into the baths. The energy dispersive analysis (EDX) confirms the chemical composition of PbS films. A current–voltage (I–V) characterization of Pd/nc-PbS/a-SiC:H pSi(100)/Al Schottky diode structures were studied in the presence of NO{sub 2} gas. The gas sensing behavior showed that the synthesized PbS nanocrystalline thin films were influenced by NO{sub 2} gas at room temperature. The results can be used for developing an experimental sensing element based on chemically deposited nanostructured PbS films which can be applicable in gas sensors.

  16. Preparation of 99Mo/99mTc generators based on 99Mo zirconium molybdates in the Gel Synthesis Device for Generators

    International Nuclear Information System (INIS)

    Lopez M, I. Z.; Monroy G, F.; Rivero G, T.; Rojas N, P.

    2008-01-01

    The 99m Tc is used for diagnosis and therapy. It is produced commercially from 99 Mo obtained from the fission of 235 U, which is retained in chromatographic columns filled with alumina whose maximum capacity is 0.2%. Given these constraints new methods of preparation 99 Mo/ 99m Tc generators have been developed using zirconium molybdates gels containing up to 30% of Mo, which is part of the generator matrix, and retaining quality and purity similar characteristics to those commercial generators. The present study aims to determine the flow of agitation, temperature and drying time optimal to prepare 99 Mo/ 99m Tc generators based on 99 Mo zirconium molybdates in the Gel Synthesis Device 99 Mo/ 99m Tc Generators designed and built by groups of the Radioactive Materials Research Laboratory and Automation and Instrumentation Department of the National Institute of Nuclear Research. (Author)

  17. Steam generator materials performance in high temperature gas-cooled reactors

    International Nuclear Information System (INIS)

    Chafey, J.E.; Roberts, D.I.

    1980-11-01

    This paper reviews the materials technology aspects of steam generators for HTGRs which feature a graphite-moderated, uranium-thorium, all-ceramic core and utilizes high-pressure helium as the primary coolant. The steam generators are exposed to gas-side temperatures approaching 760 0 C and produce superheated steam at 538 0 C and 16.5 MPa (2400 psi). The prototype Peach Bottom I 40-MW(e) HTGR was operated for 1349 EFPD over 7 years. Examination after decommissioning of the U-tube steam generators and other components showed the steam generators to be in very satisfactory condition. The 330-MW(e) Fort St. Vrain HTGR, now in the final stages of startup, has achieved 70% power and generated more than 1.5 x 10 6 MWh of electricity. The steam generators in this reactor are once-through units of helical configuration, requiring a number of new materials factors including creep-fatigue and water chemistry control. Current designs of larger HTGRs also feature steam generators of helical once-through design. Materials issues that are important in these designs include detailed consideration of time-dependent behavior of both base metals and welds, as required by current American Society of Mechanical Engineers (ASME) Code rules, evaluation of bimetallic weld behavior, evaluation of the properties of large forgings, etc

  18. Evaluation of Start Transient Oscillations with the J-2X Engine Gas Generator Assembly

    Science.gov (United States)

    Hulka, J. R.; Morgan, C. J.; Casiano, M. J.

    2015-01-01

    During development of the gas generator for the liquid oxygen/liquid hydrogen propellant J-2X rocket engine, distinctive and oftentimes high-amplitude pressure oscillations and hardware vibrations occurred during the start transient of nearly every workhorse gas generator assembly test, as well as during many tests of engine system hardware. These oscillations appeared whether the steady-state conditions exhibited stable behavior or not. They occurred similarly with three different injector types, and with every combustion chamber configuration tested, including chamber lengths ranging over a 5:1 range, several different nozzle types, and with or without a side branch line simulating a turbine spin start gas supply line. Generally, two sets of oscillations occurred, one earlier in the start transient and at higher frequencies, and the other almost immediately following and at lower frequencies. Multiple dynamic pressure measurements in the workhorse combustion chambers indicated that the oscillations were associated with longitudinal acoustic modes of the combustion chambers, with the earlier and higher frequency oscillation usually related to the second longitudinal acoustic mode and the later and lower frequency oscillation usually related to the first longitudinal acoustic mode. Given that several early development gas generator assemblies exhibited unstable behavior at frequencies near the first longitudinal acoustic modes of longer combustion chambers, the start transient oscillations are presumed to provide additional insight into the nature of the combustion instability mechanisms. Aspects of the steadystate oscillations and combustion instabilities from development and engine system test programs have been reported extensively in the three previous JANNAF Liquid Propulsion Subcommittee meetings (see references below). This paper describes the hardware configurations, start transient sequence operations, and transient and dynamic test data during the start

  19. Software and Hardware System for Fast Processes Study When Preparing Foundation Beds of Oil and Gas Facilities

    Science.gov (United States)

    Gruzin, A. V.; Gruzin, V. V.; Shalay, V. V.

    2018-04-01

    Analysis of existing technologies for preparing foundation beds of oil and gas buildings and structures has revealed the lack of reasoned recommendations on the selection of rational technical and technological parameters of compaction. To study the nature of the dynamics of fast processes during compaction of foundation beds of oil and gas facilities, a specialized software and hardware system was developed. The method of calculating the basic technical parameters of the equipment for recording fast processes is presented, as well as the algorithm for processing the experimental data. The performed preliminary studies confirmed the accuracy of the decisions made and the calculations performed.

  20. Influence of Carrier Gas Composition on the Stress of Al₂O₃ Coatings Prepared by the Aerosol Deposition Method.

    Science.gov (United States)

    Schubert, Michael; Exner, Jörg; Moos, Ralf

    2014-08-05

    Al₂O₃ films were prepared by the aerosol deposition method at room temperature using different carrier gas compositions. The layers were deposited on alumina substrates and the film stress of the layer was calculated by measuring the deformation of the substrate. It was shown that the film stress can be halved by using oxygen instead of nitrogen or helium as the carrier gas. The substrates were annealed at different temperature steps to gain information about the temperature dependence of the reduction of the implemented stress. Total relaxation of the stress can already be achieved at 300 °C. The XRD pattern shows crystallite growth and reduction of microstrain while annealing.

  1. Preparation of nanostructured ZrO2 thin films by using spray pyrolysis technique for gas sensing application

    International Nuclear Information System (INIS)

    Deshmukh, S.B.; Bari, R.H.; Jain, G.H.

    2013-01-01

    In present work the nano-structured pure ZrO 2 thin films were prepared using spray pyrolysis techniques. The aqueous solution of ZrCl 4 , was used as a precursor with flow rate controlled 5 mI/min. The films were synthesized on glass substrate between temperature 250-400℃ and subjected to different analytical characterization like SEM, XRD, TEM, FTIR, UV, TGA-DTA/DSC. The gas sensing performances of various gases were tested in different operating temperature range. The sensitivity, selectivity, response and recovery time for H 2 S gas was discussed. Also nano structured grain size discussed. (author)

  2. The new 6 MW gas turbine for the power generation; Die neue 6 MW Gasturbine fuer die Stromerzeugung

    Energy Technology Data Exchange (ETDEWEB)

    Blaswich, Michael; Theis, Sascha [MAN Diesel and Turbo SE, Oberhausen (Germany)

    2012-07-01

    MAN Diesel and Turbo SE (Oberhausen, Federal Republic of Germany) had developed a new gas turbine in the 6 MW class. This device is the founding stone for a family of gas turbines which at first cover the power range from 6 to 8 MW for the propulsion of pumps, compressors and electric devices. The two-shaft industrial gas turbine consists of a gas generator with an axial compressor with eleven levels, six external single combustion chambers, one two-step high-pressure turbine and a two-step power turbine. Beside the two-shaft industrial gas turbine, there exists a single-shaft industrial gas turbine for the power generation. The single-shaft industrial gas turbine consists of three turbine stages, a gas turbine compressor and combustion chamber being identical in construction to the two-shaft industrial gas turbine. The gas turbine package contains the gas turbine module as well as a filter module. The gas turbine was successfully tested. Further tests and the commissioning of the first customer's plant are planned for this year.

  3. Evaluation of potential opportunities for electric power generation from landfill gas at “Tsalapitsa”

    Directory of Open Access Journals (Sweden)

    Ganev Ivaylo

    2014-01-01

    Full Text Available Potential opportunities for electric power generation from landfill gas (LFG utilization were estimated for the second largest landfill site in Bulgaria, situated near the city of Plovdiv. The work performed was based on detailed analysis of experimentally obtained and model-predicted features of the “Tsalapitsa” landfill site. The study presents a short description of the site, the global characteristics of the disposed municipal solid waste, and the experimentally obtained methane composition of the LFG. Based on the above described observations, the potential for LFG recovery at “Tsalapitsa” was determined, together with that for electric power generation for the next 25 years. A set of recommendations was then developed regarding the parameters required for the installation of electric power generation from LFG in Plovdiv.

  4. FY 1998 survey report. Survey to prepare a data book related to new energy technology development (Trends on the waste power generation, solar heat utilization, geothermal power generation, clean energy cars, coal liquefaction/coal gasification and new energy); 1998 nendo chosa hokokusho. Shin energy gijutsu kaihatsu kankei data shu sakusei chosa (haikibutsu hatsuden, taiyonetsu riyo, chinetsu hatsuden, clean energy, jidosha, sekitan ekika gas ka oyobi shin energy kanren doko)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-03-01

    Together with the progress of technology development, policies for the introduction/promotion of new energy technology are being developed such as promotion of the commercialization development, revision of the law system, and expansion of the subsidy system for promotion. To push the introduction/promotion forward more effectively, it is necessary to arrange various kinds of data comprehensively/systematically and to make them the basic data for contribution to the spread/education. As to the six fields of the waste power generation, solar heat utilization, geothermal power generation, clean energy cars, coal liquefaction, and coal gasification of the technology fields of new energy, this report collected/arranged the data made public recently in terms mainly of the following: trends of the introduction in Japan and abroad, policy/law/subsidy system in Japan and abroad, cost, system outline, basic terms, a list of the main affiliated companies and groups, and the nation's outlook for energy introduction and policies of each new energy technology in Japan and abroad, and the trends. Moreover, characteristics by field were described of the state of the commercialization/introduction of new energy technology. (NEDO)

  5. Air quality impacts of projections of natural gas-fired distributed generation

    Science.gov (United States)

    Horne, Jeremy R.; Carreras-Sospedra, Marc; Dabdub, Donald; Lemar, Paul; Nopmongcol, Uarporn; Shah, Tejas; Yarwood, Greg; Young, David; Shaw, Stephanie L.; Knipping, Eladio M.

    2017-11-01

    This study assesses the potential impacts on emissions and air quality from the increased adoption of natural gas-fired distributed generation of electricity (DG), including displacement of power from central power generation, in the contiguous United States. The study includes four major tasks: (1) modeling of distributed generation market penetration; (2) modeling of central power generation systems; (3) modeling of spatially and temporally resolved emissions; and (4) photochemical grid modeling to evaluate the potential air quality impacts of increased DG penetration, which includes both power-only DG and combined heat and power (CHP) units, for 2030. Low and high DG penetration scenarios estimate the largest penetration of future DG units in three regions - New England, New York, and California. Projections of DG penetration in the contiguous United States estimate 6.3 GW and 24 GW of market adoption in 2030 for the low DG penetration and high DG penetration scenarios, respectively. High DG penetration (all of which is natural gas-fired) serves to offset 8 GW of new natural gas combined cycle (NGCC) units, and 19 GW of solar photovoltaic (PV) installations by 2030. In all scenarios, air quality in the central United States and the northwest remains unaffected as there is little to no DG penetration in those states. California and several states in the northeast are the most impacted by emissions from DG units. Peak increases in maximum daily 8-h average ozone concentrations exceed 5 ppb, which may impede attainment of ambient air quality standards. Overall, air quality impacts from DG vary greatly based on meteorological conditions, proximity to emissions sources, the number and type of DG installations, and the emissions factors used for DG units.

  6. Regional impacts of expanding gas-fired electric generation in the northeast US and eastern Canada

    International Nuclear Information System (INIS)

    Mitchell, G.

    2002-01-01

    New York, New England, Ontario, Quebec and Canada's Maritime provinces come under the jurisdiction of the Northeast Power Coordinating Committee (NPCC) of the North American Electric Reliability Council (NERC). The objective of this Council is to assist with the coordination of electric supply, as well as transmission planning and reliability for the utilities. The annual ten year forecast of electric supply, demand and fuel sources produced by the NERC formed the basis for the data presented. The deregulation of the electricity market in a few jurisdictions in the region resulted in the break-up of several electric utilities into their core components, namely, generation, distribution and transmission. The generation sector is where the fastest break-up activity is taking place, and merchant energy companies are emerging. Each of these merchant energy companies is competing against the other to effect sales into the wholesale power market through the building of at risk generation plants. The deregulation process is subjected to different processes and time tables depending on each state or province regulations. The construction of new power plants in the region is being driven by the merchant energy companies. They are building low capital cost and highly efficient natural gas combined-cycle base load plants as well as lower cost and moderately efficient natural gas/oil-fired simple-cycle peaking plants. This activity is mainly restricted to the United States, since hydroelectric power, coal and nuclear power are the main presence in Canada. New England experiences summer peaks while Canada has winter peak electric demand. To optimize intra-regional peak generation capacity sharing, there is an opportunity for the electric industry to move gas by wire, and a number of projects are being developed. It is expected that pipeline expansion will be lower in Quebec and Ontario and result in more capacity expansions from the Maritimes combined with intra

  7. Study of defect generated visible photoluminescence in zinc oxide nano-particles prepared using PVA templates

    Energy Technology Data Exchange (ETDEWEB)

    Oudhia, A. [Department of Physics, Government V.Y.T. PG. Autonomous College, Durg, 491001 C.G. (India); Choudhary, A., E-mail: aarti.bhilai@gmail.com [Department of Physics, Government V.Y.T. PG. Autonomous College, Durg, 491001 C.G. (India); Sharma, S.; Aggrawal, S. [Department of Physics, Government V.Y.T. PG. Autonomous College, Durg, 491001 C.G. (India); Dhoble, S.J. [RTM University Nagpur, Maharashtra (India)

    2014-10-15

    Intrinsic defect generated photoluminescence (PL) in zinc oxide nanoparticles (NPs) obtained by a PVA template based wet-chemical process has been studied. A good controllability was achieved on the surface defects, structure and the morphology of ZnO NPs through the variation of solvents used in synthesis. The PL emission strongly depended on the defect structure and morphology. SEM, XRD, annealing and PL excitation studies were used to analyze the types of defects involved in the visible emission as well as the defect concentration. The mechanism for the blue, green and yellow emissions was proposed. The spectral content of the visible emission was controlled through generation/removal of defects through the shape transformation or annealing by focusing on defect origins and broad controls. - Highlights: • ZnO nanoparticles were synthesized using poly-vinyl alcohol template in various solvents. • The structure and morphology of ZnO nanoparticles were depended on dielectric constant and boiling point of solvents. • Photoluminescence properties of ZnO nanoparticles were studied. • Maximum optical absorbance and Photoluminescence intensity were found in ethanolic preparation. • ZnO nanoparticles were annealed at different temperatures for detection of defect emission.

  8. Power and energy saving in buildings by distributed generation based on gas-engine systems

    Energy Technology Data Exchange (ETDEWEB)

    Arghandeh, R.; Amidpour, M.; Ghaffari, A. [Khaje Nasir Toosi Univ. of Technology, Tehran (Iran, Islamic Republic of). Joint Program of Energy Systems Engineering; Manchester Univ., Manchester (United Kingdom)

    2008-07-01

    Buildings consume high amounts of energy and produce high amounts of greenhouse gas (GHG) emissions. This paper discussed the use of gas cogeneration distributed generation (DG) technologies as a means of reducing energy consumption from buildings as well as energy losses from transmission lines in Iran. Energy sources and power generation systems were reviewed, and the economical benefits and energy savings resulting from the use of cogeneration systems were outlined. Actual rates of electricity consumption for Iran were estimated. Building power consumption was divided into the following 6 major sections: (1) lighting, (2) home appliances, (3) restaurant and cooking devices, (4) sports facilities, (5) utilities, and (6) electronics. Energy consumption criteria (ECC) and daily consumption charts (DCC) were used to plan and design the cogeneration systems. Energy balances, capital costs, and investment rates of return (IRR) were then calculated for 2 scenarios for a sample building. Results of the study showed that gas engine combined heat and power (CHP) DG systems are a reliable and economic technology for reducing energy consumption in buildings. The IRR of the CHP DG system for the sample building was achieved in 1 year. 13 refs., 10 tabs., 11 figs.

  9. Linear and nonlinear instability theory of a noble gas MHD generator

    International Nuclear Information System (INIS)

    Mesland, A.J.

    1982-01-01

    This thesis deals with the stability of the working medium of a seeded noble gas magnetohydrodynamic generator. The aim of the study is to determine the instability mechanism which is most likely to occur in experimental MHD generators and to describe its behaviour with linear and nonlinear theories. In chapter I a general introduction is given. The pertinent macroscopic basic equations are derived in chapter II, viz. the continuity, the momentum and the energy equation for the electrons and the heavy gas particles, consisting of the seed particles and the noble gas atoms. Chapter III deals with the linear plane wave analysis of small disturbances of a homogeneous steady state. The steady state is discussed in chapter IV. The values for the steady state parameters used for the calculations both for the linear analysis as for the nonlinear analysis are made plausible with the experimental values. Based on the results of the linear plane wave theory a nonlinear plane wave model of the electrothermal instability is introduced in chapter V. (Auth.)

  10. Methane gas generation from waste water extraction process of crude palm oil in experimental digesters

    Science.gov (United States)

    Dillon, A.; Penafiel, R.; Garzón, P. V.; Ochoa, V.

    2015-12-01

    Industrial processes to extract crude palm oil, generates large amounts of waste water. High concentrations of COD, ST, SV, NH4 + and low solubility of O2, make the treatment of these effluents starts with anaerobic processes. The anaerobic digestion process has several advantages over aerobic degradation: lower operating costs (not aeration), low sludge production, methane gas generation. The 4 stages of anaerobic digestion are: hydrolysis, acidogenic, acetogenesis and methanogenesis. Through the action of enzymes synthesized by microbial consortia are met. The products of each step to serve as reagents is conducted as follows. The organic load times and cell hydraulic retention, solids content, nutrient availability, pH and temperature are factors that influence directly in biodigesters. The objectives of this presentation is to; characterize the microbial inoculum and water (from palm oil wasted water) to be used in biodigestores, make specific methanogenic activity in bioassays, acclimatize the microorganisms to produce methane gas using basal mineral medium with acetate for the input power, and to determine the production of methane gas digesters high organic load.

  11. Effects of Surfactant Contamination on the Next Generation Gas Trap for the ISS Internal Thermal Control System

    Science.gov (United States)

    Leimkuehler, Thomas O.; Lukens, Clark; Reeves, Daniel R.; Holt, James M.

    2004-01-01

    The current dual-membrane gas trap is designed to remove non-condensed gas bubbles from the Internal Thermal Control System (ITCS) coolant on board the International Space Station (ISS). To date it has successfully served its purpose of preventing gas bubbles from causing depriming, overspeed, and shutdown of the ITCS pump. However, contamination in the ITCS coolant has adversely affected the gas venting rate and lifetime of the gas trap, warranting a development effort for a next-generation gas trap. Previous testing has shown that a hydrophobic-only design is capable of performing even better than the current dual-membrane design for both steady-state gas removal and gas slug removal in clean deionized water. This paper presents results of testing to evaluate the effects of surfactant contamination on the steady-state performance of the hydrophobic-only design.

  12. Greenhouse gas mitigation potential of short-rotation-coppice based generation of electricity in Germany

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, A.; Meyer-Aurich, A.; Kern, J.; Balasus, A.; Prochnow, A. [Leibniz Inst. of Agricultural Engineering, Potsdam (Germany)

    2010-07-01

    The generation of energy from wood biomass may help secure local energy supplies and reduce the greenhouse effect by substituting fossil resources with bio-based ones. In the case of short rotation coppice (SRC), bio-based resources can be generated by extensive agricultural production systems. They produce less carbon dioxide equivalent (CO{sub 2eq}) emissions than fossil resources. This paper reported on a study in which a model system was developed for a regional supply chain producing second generation bioenergy generated from SRC in eastern Germany. The study focuses on the generation of electricity and was compared to a business-as-usual reference system, based on the latest CO{sub 2} mitigation factors for renewable energies in the German power-generation mix. A life cycle assessment based on greenhouse gas (GHG) inventories was also conducted in which other factors were also considered, such as options for nutrient cycling. The key determinants for GHG mitigation with SRC were also discussed with regards to indirect land-use effects resulting from increased demand for land.

  13. Piezoelectric transformers for low-voltage generation of gas discharges and ionic winds in atmospheric air

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Michael J. [Department of Aerospace and Mechanical Engineering, University of Notre Dame, Notre Dame, Indianapolis 46556 (United States); Go, David B., E-mail: dgo@nd.edu [Department of Aerospace and Mechanical Engineering, University of Notre Dame, Notre Dame, Indianapolis 46556 (United States); Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indianapolis 46556 (United States)

    2015-12-28

    To generate a gas discharge (plasma) in atmospheric air requires an electric field that exceeds the breakdown threshold of ∼30 kV/cm. Because of safety, size, or cost constraints, the large applied voltages required to generate such fields are often prohibitive for portable applications. In this work, piezoelectric transformers are used to amplify a low input applied voltage (<30 V) to generate breakdown in air without the need for conventional high-voltage electrical equipment. Piezoelectric transformers (PTs) use their inherent electromechanical resonance to produce a voltage amplification, such that the surface of the piezoelectric exhibits a large surface voltage that can generate corona-like discharges on its corners or on adjacent electrodes. In the proper configuration, these discharges can be used to generate a bulk air flow called an ionic wind. In this work, PT-driven discharges are characterized by measuring the discharge current and the velocity of the induced ionic wind with ionic winds generated using input voltages as low as 7 V. The characteristics of the discharge change as the input voltage increases; this modifies the resonance of the system and subsequent required operating parameters.

  14. Valuing natural gas power generation assets in the new competitive marketplace

    Science.gov (United States)

    Hsu, Michael Chun-Wei

    1999-10-01

    The profitability of natural gas fired power plants depends critically on the spread between electricity and natural gas prices. The price levels of these two energy commodities are the key uncertain variables in determining the operating margin and therefore the value of a power plant. The owner of a generation unit has the decision of dispatching the plant only when profit margins are positive. This operating flexibility is a real option with real value. In this dissertation I introduce the spark spread call options and illustrate how such paper contracts replicate the uncertain payoff space facing power asset owners and, therefore, how the financial options framework can be applied in estimating the value of natural gas generation plants. The intrinsic value of gas power plants is approximated as the sum of a series of spark spread call options with succeeding maturity dates. The Black-Scholes spread option pricing model, with volatility and correlation term structure adjustments, is utilized to price the spark spread options. Sensitivity analysis is also performed on the BS spread option formulation to compare different asset types. In addition I explore the potential of using compound and compound-exchange option concepts to evaluate, respectively, the benefits of delaying investment in new generation and in repowering existing antiquated units. The compound option designates an option on top of another option. In this case the series of spark spread call options is the 'underlying' option while the option to delay new investments is the 'overlying.' The compound-exchange option characterizes the opportunity to 'exchange' the old power plant, with its series of spark spread call options, for a set of new spark spread call options that comes with the new generation unit. The strike price of the compound-exchange option is the repowering capital investment and typically includes the purchase of new steam generators and combustion turbines, as well as other

  15. THE CHEMICAL COMPOSITION AND VARIOUS SAMPLES PREPARATION METHODS FOR In Vitro GAS TEST OF TWO TROPICAL FEEDS

    Directory of Open Access Journals (Sweden)

    J. Daryatmo

    2015-04-01

    Full Text Available A 3x2 factorial experimental design was conducted to evaluate the chemical composition ofSesbania grandiflora (SG and Manihot esculenta Crantz (MEC leaves and to measure the effects ofpreparation and drying methods on the in vitro gas production in the presence and absence of PEG. Thecollected samples were divided into three groups: One group was fresh samples (F. The second groupwas oven-dried at 55°C for 48h (OD and the last group was freeze-dried at –40°C for 72h (FD. Resultsshowed that the mean value of gas production from fresh SG and MEC samples were not significantlyhigher (P<0.05 than from FD and OD samples. In SG and MEC, the mean value of gas production ofFD was not significant compared to OD samples (P>0.05. Gas production from samples added withPEG were higher (P<0.05 than without PEG. In conclusion, the preparation and drying methods of feedsamples could affect the volume of gas production. The addition of PEG in SG and MEC resulted inhigher gas production volumes.

  16. Exhaust circulation into dry gas desulfurization process to prevent carbon deposition in an Oxy-fuel IGCC power generation

    International Nuclear Information System (INIS)

    Kobayashi, Makoto; Nakao, Yoshinobu; Oki, Yuso

    2014-01-01

    Highlights: • Power plant with semi-closed gas turbine and O 2 –CO 2 coal gasifier was studied. • We adopt dry gas sulfur removal process to establish the system. • The exhaust gas circulation remarkably prevented carbon deposition. • Efficiency loss for exhaust gas circulation is quite small. • Appropriate operating condition of sulfur removal process is revealed. - Abstract: Semi-closed cycle operation of gas turbine fueled by oxygen–CO 2 blown coal gasification provides efficient power generation with CO 2 separation feature by excluding pre-combustion type CO 2 capture that usually brings large efficiency loss. The plant efficiency at transmission end is estimated as 44% at lower heating value (LHV) providing compressed CO 2 with concentration of 93 vol%. This power generation system will solve the contradiction between economical resource utilization and reduction of CO 2 emission from coal-fired power plant. The system requires appropriate sulfur reduction process to protect gas turbine from corrosion and environment from sulfur emission. We adopt dry gas sulfur removal process to establish the system where apprehension about the detrimental carbon deposition from coal gas. The effect of circulation of a portion of exhaust gas to the process on the retardation of carbon deposition was examined at various gas compositions. The circulation remarkably prevented carbon deposition in the sulfur removal sorbent. The impact of the circulation on the thermal efficiency is smaller than the other auxiliary power consumption. Thus, the circulation is appropriate operation for the power generation

  17. Gas-generated thermal oxidation of a coordination cluster for an anion-doped mesoporous metal oxide.

    Science.gov (United States)

    Hirai, Kenji; Isobe, Shigehito; Sada, Kazuki

    2015-12-18

    Central in material design of metal oxides is the increase of surface area and control of intrinsic electronic and optical properties, because of potential applications for energy storage, photocatalysis and photovoltaics. Here, we disclose a facile method, inspired by geochemical process, which gives rise to mesoporous anion-doped metal oxides. As a model system, we demonstrate that simple calcination of a multinuclear coordination cluster results in synchronic chemical reactions: thermal oxidation of Ti8O10(4-aminobenzoate)12 and generation of gases including amino-group fragments. The gas generation during the thermal oxidation of Ti8O10(4-aminobenzoate)12 creates mesoporosity in TiO2. Concurrently, nitrogen atoms contained in the gases are doped into TiO2, thus leading to the formation of mesoporous N-doped TiO2. The mesoporous N-doped TiO2 can be easily synthesized by calcination of the multinuclear coordination cluster, but shows better photocatalytic activity than the one prepared by a conventional sol-gel method. Owing to an intrinsic designability of coordination compounds, this facile synthetic will be applicable to a wide range of metal oxides and anion dopants.

  18. Gas spark switches with increased operating life for Marx generator of lightning test complex

    Energy Technology Data Exchange (ETDEWEB)

    Bykov, Yu. A.; Krastelev, E. G., E-mail: ekrastelev@yandex.ru [Russian Academy of Sciences, Joint Institute for High Temperature (Russian Federation)

    2016-12-15

    A new design of gas spark switches with an increased operating life and stable dynamic characteristics for the Marx generator of the lightning test complex has been developed. The switches are characterized by the following parameters in the mode of operation: voltage up to 80 kV, discharge current up to 50 kA, flowing charge up to 3.5 C/pulse. An increased operating life is achieved by using torus-shaped electrodes with increased working surface area and a trigger electrode in the form of a thick disk with a hole located between them. Low breakdown delay time and high stability of breakdown voltage under dynamic conditions are provided by gas preionization in the spark gap using UV radiation of an additional corona discharge in the axial region.

  19. Gas generation from radiolytic attack of TRU-contaminated hydrogenous waste

    International Nuclear Information System (INIS)

    Zerwekh, A.

    1979-06-01

    In 1970, the Waste Management and Transportation Division of the Atomic Energy Commission ordered a segregation of transuranic (TRU)-contaminated solid wastes. Those below a contamination level of 10 nCi/g could still be buried; those above had to be stored retrievably for 20 y. The possibility that alpha-radiolysis of hydrogenous materials might produce toxic, corrosive, and flammable gases in retrievably stored waste prompted an investigation of gas identities and generation rates in the laboratory and field. Typical waste mixtures were synthesized and contaminated for laboratory experiments, and drums of actual TRU-contaminated waste were instrumented for field testing. Several levels of contamination were studied, as well as pressure, temperature, and moisture effects. G (gas) values were determined for various waste matrices, and degradation products were examined

  20. Software and Dataware for Energy Generation and Consumption Analysis System of Gas Processing Enterprises

    Science.gov (United States)

    Dolotovskii, I. V.; Dolotovskaya, N. V.; Larin, E. A.

    2018-05-01

    The article presents the architecture and content of a specialized analytical system for monitoring operational conditions, planning of consumption and generation of energy resources, long-term planning of production activities and development of a strategy for the development of the energy complex of gas processing enterprises. A compositional model of structured data on the equipment of the main systems of the power complex is proposed. The correctness of the use of software modules and the database of the analytical system is confirmed by comparing the results of measurements on the equipment of the electric power system and simulation at the operating gas processing plant. A high accuracy in the planning of consumption of fuel and energy resources has been achieved (the error does not exceed 1%). Information and program modules of the analytical system allow us to develop a strategy for improving the energy complex in the face of changing technological topology and partial uncertainty of economic factors.

  1. Corrosive gas generation potential from chloride salt radiolysis in plutonium environments

    International Nuclear Information System (INIS)

    Tandon, L.; Allen, T.H.; Mason, R.E.; Penneman, R.A.

    1999-01-01

    The specific goal of this project was to evaluate the magnitude and practical significance of radiation effects involving mixtures of chloride salts and plutonium dioxide (PuO 2 ) sealed in stainless steel containers and stored for up to 50 yr, after stabilization at 950 C and packaging according to US Department of Energy (DOE) standards. The potential for generating chemically aggressive molecular chlorine (and hydrogen chloride by interaction with adsorbed water or hydrogen gas) by radiolysis of chloride ions was studied. To evaluate the risks, an annotated bibliography on chloride salt radiolysis was created with emphasis on effects of plutonium alpha radiation. The authors present data from the material identification and surveillance (MIS) project obtained from examination and analysis of representative PuO 2 items from various DOE sites, including the headspace gas analysis data of sealed mixtures of PuO 2 and chloride salts following long-term storage

  2. High-harmonic generation in a quantum electron gas trapped in a nonparabolic and anisotropic well

    Science.gov (United States)

    Hurst, Jérôme; Lévêque-Simon, Kévin; Hervieux, Paul-Antoine; Manfredi, Giovanni; Haas, Fernando

    2016-05-01

    An effective self-consistent model is derived and used to study the dynamics of an electron gas confined in a nonparabolic and anisotropic quantum well. This approach is based on the equations of quantum hydrodynamics, which incorporate quantum and nonlinear effects in an approximate fashion. The effective model consists of a set of six coupled differential equations (dynamical system) for the electric dipole and the size of the electron gas. Using this model we show that: (i) high harmonic generation is related to the appearance of chaos in the phase space, as attested to by related Poincaré sections; (ii) higher order harmonics can be excited efficiently and with relatively weak driving fields by making use of chirped electromagnetic waves.

  3. NH4HCO3 gas-generating liposomal nanoparticle for photoacoustic imaging in breast cancer

    Directory of Open Access Journals (Sweden)

    Xia J

    2017-03-01

    Full Text Available Jizhu Xia, Gang Feng, Xiaorong Xia, Lan Hao, Zhigang Wang Chongqing Key Laboratory of Ultrasound Molecular Imaging, Department of Ultrasound, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, People’s Republic of China Abstract: In this study, we have developed a biodegradable nanomaterial for photoacoustic imaging (PAI. Its biodegradation products can be fully eliminated from a living organism. It is a gas-generating nanoparticle of liposome-encapsulating ammonium bicarbonate (NH4HCO3 solution, which is safe, effective, inexpensive, and free of side effects. When lasers irradiate these nanoparticles, NH4HCO3 decomposes to produce CO2, which can absorb much of the light energy under laser irradiation with a specific wavelength, and then expand under heat to generate a thermal acoustic wave. An acoustic detector can detect this wave and show it as a photoacoustic signal on a display screen. The intensity of the photoacoustic signal is enhanced corresponding to an increase in time, concentration, and temperature. During in vivo testing, nanoparticles were injected into tumor-bearing nude mice through the caudal vein, and photoacoustic signals were detected from the tumor, reaching a peak in 4 h, and then gradually disappearing. There was no damage to the skin or subcutaneous tissue from laser radiation. Our developed gas-generating nanomaterial, NH4HCO3 nanomaterial, is feasible, effective, safe, and inexpensive. Therefore, it is a promising material to be used in clinical PAI. Keywords: Photoacoustic tomography, CO2, NH4HCO3, contrast agent, cancer

  4. Lifetime and shelf life of sealed tritium-filled plasma focus chambers with gas generator

    Directory of Open Access Journals (Sweden)

    B.D. Lemeshko

    2017-11-01

    Full Text Available The paper describes the operation features of plasma focus chambers using deuterium–tritium mixture. Handling tritium requires the use of sealed, vacuum-tight plasma focus chambers. In these chambers, there is an accumulation of the impurity gases released from the inside surfaces of the electrodes and the insulator while moving plasma current sheath inside chambers interacting with β-electrons generated due to the decay of tritium. Decay of tritium is also accompanied by the accumulation of helium. Impurities lead to a decreased yield of neutron emission from plasma focus chambers, especially for long term operation. The paper presents an option of absorption type gas generator in the chamber based on porous titanium, which allows to significantly increase the lifetime and shelf life of tritium chambers. It also shows the results of experiments on the comparison of the operation of sealed plasma focus chambers with and without the gas generator. Keywords: Plasma focus, Neutron yield, Tritium-filled plasma focus chambers, PACS Codes: 29.25.-v, 52.58.Lq

  5. Discharges in the inlet region of a noble gas MHD generator

    International Nuclear Information System (INIS)

    Borghi, C.A.

    1982-01-01

    In this work the onset of the development of the non-equilibrium conductivity in the entrance region of a noble gas MHD generator is investigated both theoretically and experimentally. At low electron densities the discharge seems to be affected by a non-Maxwellian electron distribution. In Chapter II a self-consistent model of a stationary discharge in an Ar-Cs mixture at atmospheric pressure, is set up. It includes the possibility of deviations from a Maxwellian electron energy distribution. The model allows to calculate at what discharge parameters deviations from the Maxwellian electron distribution will become important. In Chapter III the relaxation of the plasma to a new equilibrium situation following a sudden change in the electron thermal energy is calculated by a model which can take radiation and a non-Maxwellian distribution into account. In Chapter IV an Ar-Cs discharge experiment is described with plasma parameters similar to those present in the entrance region of the generator. The ionization relaxation process in a noble gas MHD generator is experimentally studied and described in Chapter V. In this chapter the relaxation ionization region with and without pre-ionization is investigated. Current voltage characteristics are obtained by varying the applied voltage or the external load. The results are confronted with the theoretical results of the non-Maxwellian model developed in Chapter II. Conclusions of this work are drawn in Chapter VI. (Auth.)

  6. Partial catalytic oxidation of CH{sub 4} to synthesis gas for power generation - Final report

    Energy Technology Data Exchange (ETDEWEB)

    Mantzaras, I.; Schneider, A.

    2006-03-15

    The partial oxidation of methane to synthesis gas over rhodium catalysts has been investigated experimentally and numerically in the pressure range of 4 to 10 bar. The methane/oxidizer feed has been diluted with large amounts of H{sub 2}O and CO{sub 2} (up to 70% vol.) in order to simulate new power generation cycles with large exhaust gas recycle. Experiments were carried out in an optically accessible channel-flow reactor that facilitated laser-based in situ measurements, and also in a subscale gas-turbine catalytic reactor. Full-elliptic steady and transient two-dimensional numerical codes were used, which included elementary hetero-/homogeneous chemical reaction schemes. The following are the key conclusions: a) Heterogeneous (catalytic) and homogeneous (gas-phase) schemes have been validated for the partial catalytic oxidation of methane with large exhaust gas recycle. b) The impact of added H{sub 2}O and CO{sub 2} has been elucidated. The added H{sub 2}O increased the methane conversion and hydrogen selectivity, while it decreased the CO selectivity. The chemical impact of CO{sub 2} (dry reforming) was minimal. c) The numerical model reproduced the measured catalytic ignition times. It was further shown that the chemical impact of H{sub 2}O and CO{sub 2} on the catalytic ignition delay times was minimal. d) The noble metal dispersion increased with different support materials, in the order Rh/{alpha}-Al{sub 2}O{sub 3}, Rh/ZrO{sub 2}, and Rh/Ce-ZrO{sub 2}. An evident relationship was established between the noble metal dispersion and the catalytic behavior. (authors)

  7. Steam generator materials constraints in UK design gas-cooled reactors

    International Nuclear Information System (INIS)

    James, D.W.

    1988-01-01

    A widely reported problem with Magnox-type reactors was the oxidation of carbon steel components in gas circuits and steam generators. The effects of temperature, pressure, gas composition and steel composition on oxidation kinetics have been determined, thus allowing the probabilities of failure of critical components to be predicted for a given set of operating conditions. This risk analysis, coupled with regular inspection of reactor and boiler internals, has allowed continued operation of all U.K. Magnox plant. The Advanced Gas Cooled Reactor (AGR) is a direct development of the Magnox design. The first four AGRs commenced operation in 1976, at Hinkley Point 'B' and at Hunterston 'B'. All known materials problems with the steam generators have been diagnosed and solved by the development of appropriate operational strategies, together with minor plant modifications. Materials constraints no longer impose any restrictions to full load performance from the steam generators throughout the predicted life of the plant. Problems discussed in detail are: 1. oxidation of the 9 Cr - 1 Mo superheater. 2. Stress corrosion of the austenitic superheater. 3. Creep of the transition joints between the 9 Cr - 1 Mo and austenitic sections. With the 9 Cr - 1 Mo oxidation maximum temperature restriction virtually removed and creep constraints properly quantified, boiler operation in now favourably placed. Stress corrosion research has allowed the risk of tube failure to be related to time, temperature, stress and chemistry. As a result, the rigorous 'no wetting' policy has been relaxed for the normally high quality AGR feedwater, and the superheat margin has been reduced to 23 deg. C. This has increased the size of the operating window and reduced the number of expensive, and potentially harmful, plant trips. (author)

  8. PW-6ES gas turbine generator for Maglev linear motor car. Yamanashi rinia jikkensen daiichi hensei sharyo tosaiyo PW-6ES gas tabin hatsuden sochi

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, T [JR Railway Technical Research Inst., Tokyo (Japan); Nakamura, S [Ebara Corp., Tokyo (Japan)

    1994-06-10

    A power generator is developed to be used as the auxiliary power source for the first carriage at the levitation type railway Yamanashi linear experimental line. The gas turbine generator is installed to supply power to the electric equipment on the carriage, and the power generating conditions are transmitted to the ground commanding room via on-board central control system for centralized controlling. An aircraft diversion type ST6 gas turbine and a high frequency light weight generator are combined for the gas turbine generator developed this time. Single reduction planetary gear is employed for the reduction gear which connects the two units directly, the gas turbine being connected to one side and the generator to the other side with no coupling. The output of the generator is 350kW, AC 455V, and 400Hz, and power is supplied to the electric devices on the carriage after having been converted to DC 600V. Aluminium is used to reduce the weights of the soundproof enclosure and exhaust dust shell plate. 1 fig., 1 tab.

  9. The preparation of ZnO based gas-sensing thin films by ink-jet printing method

    International Nuclear Information System (INIS)

    Shen Wenfeng; Zhao Yan; Zhang Caibei

    2005-01-01

    An ink-jet printing technique was applied to prepare ZnO based gas-sensing thin films. ZnO inks with appropriate viscosity and surface tension were prepared by sol-gel techniques, and printed onto substrates using a commercial printer. After the drying and heating treatment processes, continuous ZnO films were formed and studied by scanning electron microscopy, X-ray diffraction and by a home-made gas sensitivity measuring system. It was found that the morphology and electrical properties of the films changed significantly with the thickness of the films, which can be adjusted simply by printing on the film with increasing frequency. Highest resistance and sensitivity to acetone vapor were obtained when the film was prepared by printing only once on it. Different dopants with certain concentrations could be added into the films by printing with different dopant inks and printing frequency. All Pd, Ag, and ZrO 2 dopants increased both the resistivity and the sensitivity of the films (180 ppm acetone). This work showed that the ink-jet printing technique was a convenient and low cost method to prepare films with controlled film thickness and dopant concentration

  10. The generation of electricity by gas turbines using the catalytic combustion of low-Btu gases

    DEFF Research Database (Denmark)

    Frederiksen, O.P.; Qvale, Einar Bjørn

    1989-01-01

    Various systems for the generation of electricity by gas turbines using catalytic combustion of low-Btu gases have been investigated. Parametric studies of three configurations that are deemed to be practically feasible have been completed. It is shown that thermodynamic efficiency of these systems...... may be quite high. The system design has been made to comply with generally accepted limitations on the operation of the compressors, turbines and heat exchangers. The heat catalyst has been investigated experimentally in order to establish design information. The system design has been carried out...... on the basis of these experiments and of commonly accepted limits on the operation of the compressors, turbines, and heat exchangers...

  11. Gas Generation during Sodium Permanganate Addition to HB-Line Phase II Filtrate Tank

    International Nuclear Information System (INIS)

    Hill, B.C.

    2002-01-01

    HB-Line Phase II process requires the addition of sodium permanganate followed by a sodium nitrite addition to prevent the precipitation of plutonium solids in a non-geometrically safe vessel. Previous experimental work has shown this method effective. Current concerns are related to the gas generated by the reaction. Potential difficulties include tank over-pressurization and tank overflow due to foaming or eructation. It is also necessary to verify that the quantity of permanganate specified by the facility is sufficient to reach the desired endpoint in a single addition

  12. Economic comparison of clean coal generating technologies with natural gas-combined cycle systems

    International Nuclear Information System (INIS)

    Sebesta, J.J.; Hoskins, W.W.

    1990-01-01

    This paper reports that there are four combustion technologies upon which U.S. electric utilities are expected to rely for the majority of their future power generating needs. These technologies are pulverized coal- fired combustion (PC); coal-fired fluidized bed combustion (AFBC); coal gasification, combined cycle systems (CGCC); and natural gas-fired combined cycle systems (NGCC). The engineering and economic parameters which affect the choice of a technology include capital costs, operating and maintenance costs, fuel costs, construction schedule, process risk, environmental and site impacts, fuel efficiency and flexibility, plant availability, capacity factors, timing of startup, and the importance of utility economic and financial factors

  13. Pressure pulses generated by gas released from a breached fuel element

    International Nuclear Information System (INIS)

    Wu, T.S.

    1979-01-01

    In experimental measurements of liquid pressure pulses generated by rapid release of gas from breached fuel elements in a nuclear reactor, different peak pressures were observed at locations equidistant from the origin of the release. Using the model of a submerged spherical bubble with a nonstationary center, this analysis predicts not only that the peak pressure would be higher at a point in front of the advancing bubble than that at a point the same distance behind the bubble origin, but also that the pressure pulse in front of the bubble reaches its peak later than the pulse behind the origin

  14. Life cycle water consumption and wastewater generation impacts of a Marcellus shale gas well.

    Science.gov (United States)

    Jiang, Mohan; Hendrickson, Chris T; VanBriesen, Jeanne M

    2014-01-01

    This study estimates the life cycle water consumption and wastewater generation impacts of a Marcellus shale gas well from its construction to end of life. Direct water consumption at the well site was assessed by analysis of data from approximately 500 individual well completion reports collected in 2010 by the Pennsylvania Department of Conservation and Natural Resources. Indirect water consumption for supply chain production at each life cycle stage of the well was estimated using the economic input-output life cycle assessment (EIO-LCA) method. Life cycle direct and indirect water quality pollution impacts were assessed and compared using the tool for the reduction and assessment of chemical and other environmental impacts (TRACI). Wastewater treatment cost was proposed as an additional indicator for water quality pollution impacts from shale gas well wastewater. Four water management scenarios for Marcellus shale well wastewater were assessed: current conditions in Pennsylvania; complete discharge; direct reuse and desalination; and complete desalination. The results show that under the current conditions, an average Marcellus shale gas well consumes 20,000 m(3) (with a range from 6700 to 33,000 m(3)) of freshwater per well over its life cycle excluding final gas utilization, with 65% direct water consumption at the well site and 35% indirect water consumption across the supply chain production. If all flowback and produced water is released into the environment without treatment, direct wastewater from a Marcellus shale gas well is estimated to have 300-3000 kg N-eq eutrophication potential, 900-23,000 kg 2,4D-eq freshwater ecotoxicity potential, 0-370 kg benzene-eq carcinogenic potential, and 2800-71,000 MT toluene-eq noncarcinogenic potential. The potential toxicity of the chemicals in the wastewater from the well site exceeds those associated with supply chain production, except for carcinogenic effects. If all the Marcellus shale well wastewater is

  15. 76 FR 36914 - Astoria Generating Company, L.P., NRG Power Marketing LLC, Arthur Kill Power LLC, Astoria Gas...

    Science.gov (United States)

    2011-06-23

    ... Generating Company, L.P., NRG Power Marketing LLC, Arthur Kill Power LLC, Astoria Gas Turbine Power LLC... Power Marketing LLC, Arthur Kill Power LLC, Astoria Gas Turbine Power LLC, Dunkirk Power LLC, Huntley... when a document is added to a subscribed docket(s). For assistance with any FERC Online service, please...

  16. Gas-to-power market and investment incentive for enhancing generation capacity: An analysis of Ghana's electricity sector

    International Nuclear Information System (INIS)

    Fritsch, Jorik; Poudineh, Rahmatallah

    2016-01-01

    Ghana's electricity generation capacity is currently insufficient to meet demand, making power outages and load shedding common. The resulting impact is potentially devastating for the country's growth prospects. Traditionally, lack of an affordable and reliable fuel supply for power generation, coupled with ineffective institutions and an unfavourable investment climate, have resulted in Ghana's electricity sector performing poorly. In light of the 2007 discovery of natural gas reserves in Ghanaian waters, this paper examines whether domestic gas could advance the performance of the electricity sector, and if so, how. The results of our analysis show that utilization of gas reserves in Ghana's gas-to-power market is an economically superior strategy compared to an export-oriented utilization scheme. The lack of an effective regulatory framework for investment, skill shortages, and an inefficient electricity pricing structure continue to be the main constraining factors. Our analysis also considers possible approaches to modification of the electricity tariff in order to send the right signal to potential investors in generation capacity, without compromising the affordability of power supply. - Highlights: •We examine if domestic gas can improve the Ghanaian electricity sector performance. •We compare domestic gas-to-power market utilisation versus gas export. •It shows that gas-to-power market is more economical compared to gas export. •Ineffective investment regime, skill shortage and inefficient tariffs are barriers.

  17. Impact of distributed and independent power generation on greenhouse gas emissions: Sri Lanka

    International Nuclear Information System (INIS)

    Wijayatunga, P.D.C.; Shrestha, R.M.

    2004-01-01

    Sri Lanka has a hydropower dominated power system with approximately two thirds of its generation capacity based on large hydro plants. The remaining one third are based on oil fired thermal generation with varying technologies, such as oil steam, Diesel, gas turbines and combined cycle plants. A significant portion of this capacity is in operation as independent power plants (IPPs). In addition to these, Sri Lanka presently has about 40 MWs of mini-hydro plants, which are distributed in the highlands and their surrounding districts, mainly connected to the primary distribution system. Further, there are a few attempts to build fuel wood fired power plants of small capacities and connect them to the grid in various parts of the country. The study presented in this paper investigates the impact of these new developments in the power sector on the overall emissions and the greenhouse gas (GHG) emissions in particular. It examines the resulting changes to the emissions and costs in the event of developing the proposed coal power plant as an IPP under different investment and operational conditions. The paper also examines the impact on emissions with 80 MWs of distributed power in different capacities of wind, mini-hydro and wood fired power plants. It is concluded that grid connected, distributed power generation (DPG) reduces emissions, with only a marginal increase in overall costs, due to the reduction in transmission and distribution network losses that result from the distributed nature of generation. These reductions can be enhanced by opting for renewable energy based DPGS, as the case presented in the paper, and coupling them with demand side management measures. It is also concluded that there is no impact on overall emissions by the base load IPPs unless they are allowed to change over to different fuel types and technologies. (author)

  18. Gas Production Generated from Crude Oil Biodegradation: Preliminary Study on its Aplication in Microbial Enhanced Oil Recovery (MEOR

    Directory of Open Access Journals (Sweden)

    Astri Nugroho

    2009-11-01

    Full Text Available Gas Production Generated from Crude Oil Biodegradation: Preliminary Study on its Aplication in MicrobialEnhanced Oil Recovery (MEOR. The objective of this study is to observe the capacity of gas production generatedfrom crude oil degradation by the isolated bacteria. The gas in the MEOR could increase pressure in the reservoir,decrease oil viscosity, increase oil permeability-due to the increase of the porosity and viscosity, and also increase oilvolume due to the amount of dissolved gas. A research on gas analysis of oil degradation by 6 isolated bacteria has beenconducted. The bacteria isolates including Bacillus badius (A, Bacillus circulans (B, Bacillus coagulans (C, Bacillusfirmus (D, Pasteurella avium (E and Streptobacillus moniliformis (F. The trial on gas production, gas analysis and oildegradation analysis, was carried out by using SMSS medium. The test of gas production was done by usingmicrorespirometer at 40°C. The result shows that B, C, D, E produce more gas than A and F. Gas of CO2, O2, CO, N2,CH4, and H2 were analyzed by using GC. The results show that only three gases were detected by GC i.e. CO2, N2, andO2. The concentration of CO2 and N2 gas increased while the concentration of O2 decreased over an 8th day ofobservation. CO2 gas producted by mix culture was higher than by the pure culture. On the 8th day of incubation, theproduction of CO2 gas by mix culture was 4,0452% while pure culture C and D only produced 2,4543% and 2,8729%.The mix culture increase simple hydrocarbon by 12.03% and the formation of a complex hydrocarbon by 3.07%. Themix culture (C-D generated the highest concentration of CO2 gas as well as a synergistic concortium that has ability todegrade crude oil.

  19. Potential for preparation of hot gas cleanup sorbents from spent hydroprocessing catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Furimsky, E.; Biagini, M. [Canada Centre for Mineral and Energy Technology, Ottawa, ON (Canada). Energy Research Labs.

    1996-01-01

    Three spent-decoked hydroprocessing catalysts and two corresponding fresh catalysts were tested as hot gas clean-up sorbents and compared with the zinc ferrite using a simulated coal gasification gas mixture. The catalysts deposited only by coke exhibited relatively good cleaning efficiency. The catalyst deposited by coke and metals such as vanadium and nickel was less efficient. The useful life of the spent hydroprocessing catalysts may be extended if utilized as hot gas clean-up sorbents. 12 refs., 3 figs., 4 tabs.

  20. Ensuring Reliable Natural Gas-Fired Generation with Fuel Contracts and Storage - DOE/NETL-2017/1816

    Energy Technology Data Exchange (ETDEWEB)

    Myles, Paul T. [National Energy Technology Lab. (NETL), Albany, OR (United States); Labarbara, Kirk A. [National Energy Technology Lab. (NETL), Albany, OR (United States); Logan, Cecilia Elise [National Energy Technology Lab. (NETL), Albany, OR (United States)

    2017-11-17

    This report finds that natural gas-fired power plants purchase fuel both on the spot market and through firm supply contracts; there do not appear to be clear drivers propelling power plants toward one or the other type. Most natural gas-fired power generators are located near major natural gas transmission pipelines, and most natural gas contracts are currently procured on the spot market. Although there is some regional variation in the type of contract used, a strong regional pattern does not emerge. Whether gas prices are higher with spot or firm contracts varies by both region and year. Natural gas prices that push the generators higher in the supply curve would make them less likely to dispatch. Most of the natural gas generators discussed in this report would be unlikely to enter firm contracts if the agreed price would decrease their dispatch frequency. The price points at which these generators would be unlikely to enter a firm contract depends upon the region that the generator is in, and how dependent that region is on natural gas. The Electric Reliability Council of Texas (ERCOT) is more dependent on natural gas than either Eastern Interconnection or Western Interconnection. This report shows that above-ground storage is prohibitively expensive with respect to providing storage for an extended operational fuel reserve comparable to the amount of on-site fuel storage used for coal-fired plants. Further, both pressurized and atmospheric tanks require a significant amount of land for storage, even to support one day’s operation at full output. Underground storage offers the only viable option for 30-day operational storage of natural gas, and that is limited by the location of suitable geologic formations and depleted fields.

  1. Development of a gas-generation model for the Waste Isolation Pilot Plant

    International Nuclear Information System (INIS)

    Brush, L.H.; Storz, L.J.; Garner, J.W.

    1993-01-01

    Design-basis transuranic (TRU) waste to be emplaced in the Waste Isolation Pilot Plant (WIPP) in southeastern New Mexico may generate significant quantities of gas, which may affect the performance of the WIPP with respect to regulations for radioactive and/or chemically hazardous waste constituents. We are developing a model to predict gas generation in WIPP disposal rooms during and after filling and sealing. Currently, the model includes: (1) oxic and anoxic corrosion of steels and other Fe-base alloys, including passivation and depassivation; (2) microbial degradation of cellulosics with O 2 , NO 3 - , FeO(OH), SO 4 2- , or CO 2 as the electron acceptor; (3) α radiolysis of brine; (4) consumption of CO 2 and, perhaps, H 2 S by Ca(OH) 2 (in cementitious materials) and CaO (a potential backfill additive). The code simulates these processes and interactions among them by converting reactants (steels, cellulosics, etc.) to gases and other products at experimentally observed or estimated rates and plotting temporal reaction paths in three-dimensional phase diagrams for solids in the Fe-H 2 O-CO 2 -H 2 -H 2 S system

  2. Evaluating the biogas yield and design of a biodigester to generate cooking gas from human faeces

    Directory of Open Access Journals (Sweden)

    Olawale Saheed ISMAIL

    2014-11-01

    Full Text Available Erratic power supply in the halls of residence in the University of Ibadan has been the major source of series of protest and students’ provocation on campus. Electric power is the only cheap source of energy that students use to heat and cook their food. The University claims to incur huge cost on electricity supply. An alternative energy is sought from the biogas generated from the digestion of faeces of members of the halls. The large population of the halls could be taken advantage of, as more quantity of faeces is expected daily. The first batch of the experiment, after a few days has stopped producing gas. This, as was later discovered, was as a result of low moisture content of the systems. Digester II of the batch II experiment yielded 0.00227m3 of biogas, out of which 0.0013 m3 is expected to be methane gas. A 540m3 yearly production of biogas is projected, which gave a payback period of 15 years for the cost of construction of the digester. This could be considered a free renewable energy as human faeces is a waste and readily available. Environmental impact of the methane generated and vented into the atmosphere has higher Global Warming Potential (GWP x21 than Carbon (IV oxide.

  3. [Efficiency of oxidant gas generator cells powered by electric or solar energy].

    Science.gov (United States)

    Brust Carmona, H; Benitez, A; Zarco, J; Sánchez, E; Mascher, I

    1998-02-01

    Diseases caused by microbial contaminants in drinking water continue to be a serious problem in countries like Mexico. Chlorination, using chlorine gas or chlorine compounds, is one of the best ways to treat drinking water. However, difficulties in handling chlorine gas and the inefficiency of hypochlorite solution dosing systems--due to sociopolitical, economic, and cultural factors--have reduced the utility of these chlorination procedures, especially in far-flung and inaccessible rural communities. These problems led to the development of appropriate technologies for the disinfection of water by means of the on-site generation of mixed oxidant gases (chlorine and ozone). This system, called MOGGOD, operates through the electrolysis of a common salt solution. Simulated system evaluation using a hydraulic model allowed partial and total costs to be calculated. When powered by electrical energy from the community power grid, the system had an efficiency of 90%, and in 10 hours it was able to generate enough gases to disinfect about 200 m3 of water at a cost of approximately N$8 (US $1.30). When the electrolytic cell was run on energy supplied through a photoelectric cell, the investment costs were higher. A system fed by photovoltaic cells could be justified in isolated communities that lack electricity but have a gravity-fed water distribution system.

  4. Theranostic gas-generating nanoparticles for targeted ultrasound imaging and treatment of neuroblastoma.

    Science.gov (United States)

    Lee, Jangwook; Min, Hyun-Su; You, Dong Gil; Kim, Kwangmeyung; Kwon, Ick Chan; Rhim, Taiyoun; Lee, Kuen Yong

    2016-02-10

    The development of safe and efficient diagnostic/therapeutic agents for treating cancer in clinics remains challenging due to the potential toxicity of conventional agents. Although the annual incidence of neuroblastoma is not that high, the disease mainly occurs in children, a population vulnerable to toxic contrast agents and therapeutics. We demonstrate here that cancer-targeting, gas-generating polymeric nanoparticles are useful as a theranostic tool for ultrasound (US) imaging and treating neuroblastoma. We encapsulated calcium carbonate using poly(d,l-lactide-co-glycolide) and created gas-generating polymer nanoparticles (GNPs). These nanoparticles release carbon dioxide bubbles under acidic conditions and enhance US signals. When GNPs are modified using rabies virus glycoprotein (RVG) peptide, a targeting moiety to neuroblastoma, RVG-GNPs effectively accumulate at the tumor site and substantially enhance US signals in a tumor-bearing mouse model. Intravenous administration of RVG-GNPs also reduces tumor growth in the mouse model without the use of conventional therapeutic agents. This approach to developing theranostic agents with disease-targeting ability may provide useful strategy for the detection and treatment of cancers, allowing safe and efficient clinical applications with fewer side effects than may occur with conventional agents. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Design/build/mockup of the Waste Isolation Pilot Plant gas generation experiment glovebox

    International Nuclear Information System (INIS)

    Rosenberg, K.E.; Benjamin, W.W.; Knight, C.J.; Michelbacher, J.A.

    1996-01-01

    A glovebox was designed, fabricated, and mocked-up for the WIPP Gas Generation Experiments (GGE) being conducted at ANL-W. GGE will determine the gas generation rates from materials in contact handled transuranic waste at likely long term repository temperature and pressure conditions. Since the customer's schedule did not permit time for performing R ampersand D of the support systems, designing the glovebox, and fabricating the glovebox in a serial fashion, a parallel approach was undertaken. As R ampersand D of the sampling system and other support systems was initiated, a specification was written concurrently for contracting a manufacturer to design and build the glovebox and support equipment. The contractor understood that the R ampersand D being performed at ANL-W would add additional functional requirements to the glovebox design. Initially, the contractor had sufficient information to design the glovebox shell. Once the shell design was approved, ANL-W built a full scale mockup of the shell out of plywood and metal framing; support systems were mocked up and resultant information was forwarded to the glovebox contractor to incorporate into the design. This approach resulted in a glovebox being delivered to ANL-W on schedule and within budget

  6. Thermoelectric Power Generation System for Future Hybrid Vehicles Using Hot Exhaust Gas

    Science.gov (United States)

    Kim, Sun-Kook; Won, Byeong-Cheol; Rhi, Seok-Ho; Kim, Shi-Ho; Yoo, Jeong-Ho; Jang, Ju-Chan

    2011-05-01

    The present experimental and computational study investigates a new exhaust gas waste heat recovery system for hybrid vehicles, using a thermoelectric module (TEM) and heat pipes to produce electric power. It proposes a new thermoelectric generation (TEG) system, working with heat pipes to produce electricity from a limited hot surface area. The current TEG system is directly connected to the exhaust pipe, and the amount of electricity generated by the TEMs is directly proportional to their heated area. Current exhaust pipes fail to offer a sufficiently large hot surface area for the high-efficiency waste heat recovery required. To overcome this, a new TEG system has been designed to have an enlarged hot surface area by the addition of ten heat pipes, which act as highly efficient heat transfer devices and can transmit the heat to many TEMs. As designed, this new waste heat recovery system produces a maximum 350 W when the hot exhaust gas heats the evaporator surface of the heat pipe to 170°C; this promises great possibilities for application of this technology in future energy-efficient hybrid vehicles.

  7. Theoretical and experimental results of a mesoscale electric power generation system from pressurized gas flow

    International Nuclear Information System (INIS)

    Krähenbühl, D; Kolar, J W; Zwyssig, C; Weser, H

    2009-01-01

    In many process applications where throttling is used to reduce pressure, the potential to obtain net work output is sacrificed to the throttling process. Examples are throttling valves of gas pipelines and conventional throttles in automotive applications or turbo expanders as used in cryogenic plants. With a new pressure reduction system that produces electricity while expanding the gas, the lost potential to obtain work output can be recovered. To achieve a high power density, this energy generation system requires an increased operating speed of the electrical machine and the turbomachinery. This paper presents a miniature compressed-air-to-electric-power system, based on a radial turbine with a rated rotational speed of 490 000 rpm and a rated electric power output of 150 W. A comprehensive description including turbine, diffuser and permanent magnet (PM) generator is given. Finally, measurements of the compressed-air-to-electric-power system with a maximum rotational speed of over 600 000 rpm, a maximum electric output power of 170 W, a maximum torque of 5.2 mN m and a turbine efficiency of 52% are presented

  8. The second generation model of greenhouse gas emissions: background and initial development

    International Nuclear Information System (INIS)

    Baron, R.; Wise, M.A.; Edmonds, J.A.; Pitcher, H.M.; Barns, D.

    1992-01-01

    The analysis of greenhouse gas emissions has made enormous progress during the course of the past decade. We have progressed from the use of simple time-trend extrapolations to the analysis of emissions of several greenhouse gases with parallel but independent behavioral and optimization models of energy, manufacturing, agriculture, and land-use systems. But our ability to examine potential future scenarios of greenhouse gas emissions is limited because modeling tools adequate to the task of integrating analyses of technologies and human activities on a global scale with regional detail, including energy production and consumption, agriculture, manufacture, capital formation, and land-use, along with the interdependencies between these categories, do not yet exist. The first generation of models were specialty models which focused on a particular aspect of the emissions problem without regard to how that activity interacted with other human and natural activities. The natural science pertaining to greenhouse warming now emphasizes the variety of gases associated with potential changes in the radiative composition of the atmosphere: CO 2 , CH 4 , CO, N 2 O, NO x , SO 2 , VOC's, chlorofluorocarbons, (CFC's) and CFC substitutes. Human activities generating the emissions of these gases are interdependent; actions taken to limit emissions from one segment of the economy will affect other segments of the economy. Policy issues such as the recycling of revenues from a carbon tax, land-use changes due to to tree-planting to sequestrate carbon dioxide or extensive development of biomass energy resources, require a more comprehensive modeling approach in which the relationship between technology, institutions, land use, economics and human activity is explicitly represented. The purpose of this paper is to describe briefly the design of a model which is capable of addressing greenhouse gas emissions and the consequences of alternative policy options. 7 refs

  9. Economics of herbaceous bioenergy crops for electricity generation: Implications for greenhouse gas mitigation

    Energy Technology Data Exchange (ETDEWEB)

    Khanna, M.; Onal, H.; Dhungana, B.; Wander, M. [University of Illinois Urbana Champaign, Urbana, IL (United States)

    2011-04-15

    This paper examines the optimal land allocation for two perennial crops, switchgrass and miscanthus that can be co-fired with coal for electricity generation. Detailed spatial data at county level is used to determine the costs of producing and transporting biomass to power plants in Illinois over a 15-year period. A supply curve for bioenergy is generated at various levels of bioenergy subsidies and the implications of production for farm income and greenhouse gas (GHG) emissions are analyzed. GHG emissions are estimated using lifecycle analysis and include the soil carbon sequestered by perennial grasses and the carbon emissions displaced by these grasses due to both conversion of land from row crops and co-firing the grasses with coal. We find that the conversion of less than 2% of the cropland to bioenergy crops could produce 5.5% of the electricity generated by coal-fired power plants in Illinois and reduce carbon emissions by 11% over the 15-year period. However, the cost of energy from biomass in Illinois is more than twice as high as that of coal. Costly government subsidies for bioenergy or mandates in the form of Renewable Portfolio Standards would be needed to induce the production and use of bioenergy for electricity generation. Alternatively, a modest price for GHG emissions under a cap-and-trade policy could make bioenergy competitive with coal without imposing a fiscal burden on the government.

  10. Modeled occupational exposures to gas-phase medical laser-generated air contaminants.

    Science.gov (United States)

    Lippert, Julia F; Lacey, Steven E; Jones, Rachael M

    2014-01-01

    Exposure monitoring data indicate the potential for substantive exposure to laser-generated air contaminants (LGAC); however the diversity of medical lasers and their applications limit generalization from direct workplace monitoring. Emission rates of seven previously reported gas-phase constituents of medical laser-generated air contaminants (LGAC) were determined experimentally and used in a semi-empirical two-zone model to estimate a range of plausible occupational exposures to health care staff. Single-source emission rates were generated in an emission chamber as a one-compartment mass balance model at steady-state. Clinical facility parameters such as room size and ventilation rate were based on standard ventilation and environmental conditions required for a laser surgical facility in compliance with regulatory agencies. All input variables in the model including point source emission rates were varied over an appropriate distribution in a Monte Carlo simulation to generate a range of time-weighted average (TWA) concentrations in the near and far field zones of the room in a conservative approach inclusive of all contributing factors to inform future predictive models. The concentrations were assessed for risk and the highest values were shown to be at least three orders of magnitude lower than the relevant occupational exposure limits (OELs). Estimated values do not appear to present a significant exposure hazard within the conditions of our emission rate estimates.

  11. Evaluation of the Life Cycle Greenhouse Gas Emissions from Hydroelectricity Generation Systems

    Directory of Open Access Journals (Sweden)

    Akhil Kadiyala

    2016-06-01

    Full Text Available This study evaluated the life cycle greenhouse gas (GHG emissions from different hydroelectricity generation systems by first performing a comprehensive review of the hydroelectricity generation system life cycle assessment (LCA studies and then subsequent computation of statistical metrics to quantify the life cycle GHG emissions (expressed in grams of carbon dioxide equivalent per kilowatt hour, gCO2e/kWh. A categorization index (with unique category codes, formatted as “facility type-electric power generation capacity” was developed and used in this study to evaluate the life cycle GHG emissions from the reviewed hydroelectricity generation systems. The unique category codes were labeled by integrating the names of the two hydro power sub-classifications, i.e., the facility type (impoundment (I, diversion (D, pumped storage (PS, miscellaneous hydropower works (MHPW and the electric power generation capacity (micro (µ, small (S, large (L. The characterized hydroelectricity generation systems were statistically evaluated to determine the reduction in corresponding life cycle GHG emissions. A total of eight unique categorization codes (I-S, I-L, D-µ, D-S, D-L, PS-L, MHPW-µ, MHPW-S were designated to the 19 hydroelectricity generation LCA studies (representing 178 hydropower cases using the proposed categorization index. The mean life cycle GHG emissions resulting from the use of I-S (N = 24, I-L (N = 8, D-µ (N = 3, D-S (N = 133, D-L (N = 3, PS-L (N = 3, MHPW-µ (N = 3, and MHPW-S (N = 1 hydroelectricity generation systems are 21.05 gCO2e/kWh, 40.63 gCO2e/kWh, 47.82 gCO2e/kWh, 27.18 gCO2e/kWh, 3.45 gCO2e/kWh, 256.63 gCO2e/kWh, 19.73 gCO2e/kWh, and 2.78 gCO2e/kWh, respectively. D-L hydroelectricity generation systems produced the minimum life cycle GHGs (considering the hydroelectricity generation system categories with a representation of at least two cases.

  12. Preparation of copper and silicon/copper powders by a gas ...

    Indian Academy of Sciences (India)

    Administrator

    aCentre for Materials Research, Department of Imaging and Applied Physics, ... Copper powder; Si/Cu composite particle; gas evaporation–condensation method; characteriza- tion. .... from the liquid metal surface, the mixed vapour of copper.

  13. Apples with apples: accounting for fuel price risk in comparisons of gas-fired and renewable generation

    Energy Technology Data Exchange (ETDEWEB)

    Bolinger, Mark; Wiser, Ryan

    2003-12-18

    For better or worse, natural gas has become the fuel of choice for new power plants being built across the United States. According to the US Energy Information Administration (EIA), natural gas combined-cycle and combustion turbine power plants accounted for 96% of the total generating capacity added in the US between 1999 and 2002--138 GW out of a total of 144 GW. Looking ahead, the EIA expects that gas-fired technology will account for 61% of the 355 GW new generating capacity projected to come on-line in the US up to 2025, increasing the nationwide market share of gas-fired generation from 18% in 2002 to 22% in 2025. While the data are specific to the US, natural gas-fired generation is making similar advances in other countries as well. Regardless of the explanation for (or interpretation of) the empirical findings, however, the basic implications remain the same: one should not blindly rely on gas price forecasts when comparing fixed-price renewable with variable-price gas-fired generation contracts. If there is a cost to hedging, gas price forecasts do not capture and account for it. Alternatively, if the forecasts are at risk of being biased or out of tune with the market, then one certainly would not want to use them as the basis for resource comparisons or investment decisions if a more certain source of data (forwards) existed. Accordingly, assuming that long-term price stability is valued, the most appropriate way to compare the levelized cost of these resources in both cases would be to use forward natural gas price data--i.e. prices that can be locked in to create price certainty--as opposed to uncertain natural gas price forecasts. This article suggests that had utilities and analysts in the US done so over the sample period from November 2000 to November 2003, they would have found gas-fired generation to be at least 0.3-0.6 cents/kWh more expensive (on a levelized cost basis) than otherwise thought. With some renewable resources, in particular wind

  14. 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.

  15. Effect of Gas Pressure on Polarization of SOFC Cathode Prepared by Plasma Spray

    Science.gov (United States)

    Li, Cheng-Xin; Wang, Zhun-Zhun; Liu, Shuai; Li, Chang-Jiu

    2013-06-01

    A cermet-supported tubular SOFC was fabricated using thermal spray. The cell performance was investigated at temperatures from 750 to 900 °C and pressures from 0.1 to 0.5 MPa to examine the effect of operating gas pressure on the cell performance. The influence of gas pressure on the cathodic polarization was studied through the electrochemical impedance approach to examine the controlling electrochemical processes during cell operation. Results show that increasing the operating gas pressure improves the power output performance significantly. When the gas pressure is increased from 0.1 to 0.3 MPa, the maximum power density is increased by a factor of 32% at a temperature of 800 °C. The cathode polarization decreases significantly with the increase of the gas pressure. The electrochemical analysis shows that the main control processes of the cathode reaction are the oxygen species transfer at the three-phase boundary and oxygen diffusion on the surface or in the bulk of the cathode, which are enhanced with increasing gas pressure.

  16. Capacity payment impact on gas-fired generation investments under rising renewable feed-in — A real options analysis

    International Nuclear Information System (INIS)

    Hach, Daniel; Spinler, Stefan

    2016-01-01

    We assess the effect of capacity payments on investments in gas-fired power plants in the presence of different degrees of renewable energy technology (RET) penetration. Low variable cost renewables increasingly make investments in gas-fired generation unprofitable. At the same time, growing feed-in from intermittent RETs amplifies fluctuations in power generation, thus entailing the need for flexible buffer capacity—currently mostly gas-fired power plants. A real options approach is applied to evaluate investment decisions and timing of a single investor in gas-fired power generation. We investigate the necessity and effectiveness of capacity payments. Our model incorporates multiple uncertainties and assesses the effect of capacity payments under different degrees of RET penetration. In a numerical study, we implement stochastic processes for peak-load electricity prices and natural gas prices. We find that capacity payments are an effective measure to promote new gas-fired generation projects. Especially in times of high renewable feed-in, capacity payments are required to incentivize peak-load investments. - Highlights: • We assess capacity payments under the specific focus of the influence of different degrees of renewable feed-in. • We use a real options approach to analyze investment decision and timing. • Our model reflects stochastic gas prices and stochastic electricity prices. • The case study shows the value of capacity payments to investors especially under high renewable feed-in.

  17. Gas Sensing Properties of Metal Doped WO3 Thin Film Sensors Prepared by Pulsed Laser Deposition and DC Sputtering Process

    Science.gov (United States)

    Bhuiyan, Md. Mosharraf Hossain; Ueda, Tsuyoshi; Ikegami, Tomoaki; Ebihara, Kenji

    2006-10-01

    Tungsten trioxide (WO3) thin films gas sensors were prepared by the KrF excimer pulsed laser deposition (PLD) method. The films were prepared on the quartz glass, silicon and also on the Al2O3 sensor substrates with platinum interdigitated electrodes. The effect of doping of the platinum (Pt), palladium (Pd) or gold (Au) on the WO3 thin film was also investigated. These metals were doped to the WO3 thin film by the DC sputtering process during the PLD. The substrate temperature and the oxygen pressure were 400 °C and 100 mTorr, respectively, during the deposition. The films were characterized by atomic force microscopy (AFM) and X-ray diffraction (XRD). The sensitivity of the prepared sensors to 60 ppm NO gas was examined using the two terminal resistance method in a chamber at atmospheric pressure and operating temperatures of 25-350 °C. The sensitivity of the WO3 thin films doped with Pt, Pd, or Au was found to be higher than that of the undoped WO3 thin film.

  18. Numerical Simulation and Experimental Study on Formation of High Concentration of H2 Generated by Gas Explosion

    Directory of Open Access Journals (Sweden)

    Lei Baiwei

    2016-10-01

    Full Text Available In coal mine fire rescues, if the abnormal increase of gas concentration occurs, it is the primary thing to analyze the reasons and identify sources of the abnormal forming, which is also the basis of judge the combustion state of fire area and formulate proper fire reliefs. Nowadays, related researches have recognized the methane explosion as the source of high concentration of H2 formation, but there are few studies about the conditions and reaction mechanism of gas explosion generating high concentration of H2.Therefore, this paper uses the chemical kinetic calculation software, ChemKin, and the 20L spherical explosion experimental device to simulate the generating process and formation conditions of H2 in gas explosion. The experimental results show that: the decomposition of water vapor is the main base element reaction (R84 which leads to the generation of H2.The free radical H is the key factor to influence the formation of H2 generated from gas explosion. With the gradual increase of gas explosion concentration, the explosive reaction becomes more incomplete, and then the generating quantity of H2 increases gradually. Experimental results of 20L spherical explosion are consistent with the change trend about simulation results, which verifies the accuracy of simulation analysis. The results of explosion experiments show that when gas concentration is higher than 9%, the incomplete reaction of methane explosion increases which leads to the gradual increase of H2 formation.

  19. Creation of technological bases of struggle with generation of natural gas hydrates

    International Nuclear Information System (INIS)

    Asadov, M.M.; Alieva, S.A.

    2005-01-01

    Chemical technological access, permitting directed of intensify processes prevention of gas hydrates during motion of the gas-liquid current of natural gas in the borehole cavity of natural gas-borehole cavity have been engineered. Determined technological regimes of gas current conditioning, permitting create nonequilibrium state providing condition for reversible process

  20. Generation of high-titer viral preparations by concentration using successive rounds of ultracentrifugation

    Directory of Open Access Journals (Sweden)

    Ichim Christine V

    2011-08-01

    Full Text Available Abstract Background Viral vectors provide a method of stably introducing exogenous DNA into cells that are not easily transfectable allowing for the ectopic expression or silencing of genes for therapeutic or experimental purposes. However, some cell types, in particular bone marrow cells, dendritic cells and neurons are difficult to transduce with viral vectors. Successful transduction of such cells requires preparation of highly concentrated viral stocks, which permit a high virus concentration and multiplicity of infection (MOI during transduction. Pseudotyping with the vesicular stomatitis virus G (VSV-G envelope protein is common practice for both lentiviral and retroviral vectors. The VSV-G glycoprotein adds physical stability to retroviral particles, allowing concentration of virus by high-speed ultracentrifugation. Here we describe a method report for concentration of virus from large volumes of culture supernatant by means of successive rounds of ultracentrifugation into the same ultracentrifuge tube. Method Stable retrovirus producer cell lines were generated and large volumes of virus-containing supernatant were produced. We then tested the transduction ability of virus following varying rounds of concentration by ultra-centrifugation. In a second series of experiments lentivirus-containing supernatant was produced by transient transfection of 297T/17 cells and again we tested the transduction ability of virus following multiple rounds of ultra-centrifugation. Results We report being able to centrifuge VSV-G coated retrovirus for as many as four rounds of ultracentrifugation while observing an additive increase in viral titer. Even after four rounds of ultracentrifugation we did not reach a plateau in viral titer relative to viral supernatant concentrated to indicate that we had reached the maximum tolerated centrifugation time, implying that it may be possible to centrifuge VSV-G coated retrovirus even further should it be necessary

  1. Preparation and characteristics of a Hg-195m/Au-195m generator for first-pass angiography

    International Nuclear Information System (INIS)

    Bett, R.; Cuninghame, J.G.; Dymond, D.S.; Elliott, A.T.; Flatman, W.; Sims, H.E.; Stone, D.L.; Wills, H.H.

    1984-01-01

    A Hg-195m/Au-195m generator has been developed for medical use in first pass heart angiography. The mercury parent is bound to a thiol-containing column material from which Au-195m is eluted in dilute sodium cyanide solution. Such generators may have large quantities of activity adsorbed on the column and this can result in radiolytic reactions which cause a decrease of elution efficiency with time. Careful timing of the various operations involved in preparing these generators can help to stop this deterioration. Gold-195m decays to Au-195 which has a half-life of 183 days and it is important to operate the generator in such way as to keep the amount of Au-195 injected into the patient to a minimum. The method of production of these generators is presented. Effects of radiolytic reactions on generator use, and implications of the mass 195 decay chain to ultimate purity of the product are discussed

  2. Second generation laser-heated microfurnace for the preparation of microgram-sized graphite samples

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Bin; Smith, A.M.; Long, S.

    2015-10-15

    We present construction details and test results for two second-generation laser-heated microfurnaces (LHF-II) used to prepare graphite samples for Accelerator Mass Spectrometry (AMS) at ANSTO. Based on systematic studies aimed at optimising the performance of our prototype laser-heated microfurnace (LHF-I) (Smith et al., 2007 [1]; Smith et al., 2010 [2,3]; Yang et al., 2014 [4]), we have designed the LHF-II to have the following features: (i) it has a small reactor volume of 0.25 mL allowing us to completely graphitise carbon dioxide samples containing as little as 2 μg of C, (ii) it can operate over a large pressure range (0–3 bar) and so has the capacity to graphitise CO{sub 2} samples containing up to 100 μg of C; (iii) it is compact, with three valves integrated into the microfurnace body, (iv) it is compatible with our new miniaturised conventional graphitisation furnaces (MCF), also designed for small samples, and shares a common vacuum system. Early tests have shown that the extraneous carbon added during graphitisation in each LHF-II is of the order of 0.05 μg, assuming 100 pMC activity, similar to that of the prototype unit. We use a ‘budget’ fibre packaged array for the diode laser with custom built focusing optics. The use of a new infrared (IR) thermometer with a short focal length has allowed us to decrease the height of the light-proof safety enclosure. These innovations have produced a cheaper and more compact device. As with the LHF-I, feedback control of the catalyst temperature and logging of the reaction parameters is managed by a LabVIEW interface.

  3. Nanoparticle Thin Films for Gas Sensors Prepared by Matrix Assisted Pulsed Laser Evaporation

    Directory of Open Access Journals (Sweden)

    Roberto Rella

    2009-04-01

    Full Text Available The matrix assisted pulsed laser evaporation (MAPLE technique has been used for the deposition of metal dioxide (TiO2, SnO2 nanoparticle thin films for gas sensor applications. For this purpose, colloidal metal dioxide nanoparticles were diluted in volatile solvents, the solution was frozen at the liquid nitrogen temperature and irradiated with a pulsed excimer laser. The dioxide nanoparticles were deposited on Si and Al2O3 substrates. A rather uniform distribution of TiO2 nanoparticles with an average size of about 10 nm and of SnO2 nanoparticles with an average size of about 3 nm was obtained, as demonstrated by high resolution scanning electron microscopy (SEM-FEG inspections. Gas-sensing devices based on the resistive transduction mechanism were fabricated by depositing the nanoparticle thin films onto suitable rough alumina substrates equipped with interdigitated electrical contacts and heating elements. Electrical characterization measurements were carried out in controlled environment. The results of the gas-sensing tests towards low concentrations of ethanol and acetone vapors are reported. Typical gas sensor parameters (gas responses, response/recovery time, sensitivity, and low detection limit towards ethanol and acetone are presented.

  4. Nanoparticle thin films for gas sensors prepared by matrix assisted pulsed laser evaporation.

    Science.gov (United States)

    Caricato, Anna Paola; Luches, Armando; Rella, Roberto

    2009-01-01

    The matrix assisted pulsed laser evaporation (MAPLE) technique has been used for the deposition of metal dioxide (TiO(2), SnO(2)) nanoparticle thin films for gas sensor applications. For this purpose, colloidal metal dioxide nanoparticles were diluted in volatile solvents, the solution was frozen at the liquid nitrogen temperature and irradiated with a pulsed excimer laser. The dioxide nanoparticles were deposited on Si and Al(2)O(3) substrates. A rather uniform distribution of TiO(2) nanoparticles with an average size of about 10 nm and of SnO(2) nanoparticles with an average size of about 3 nm was obtained, as demonstrated by high resolution scanning electron microscopy (SEM-FEG) inspections. Gas-sensing devices based on the resistive transduction mechanism were fabricated by depositing the nanoparticle thin films onto suitable rough alumina substrates equipped with interdigitated electrical contacts and heating elements. Electrical characterization measurements were carried out in controlled environment. The results of the gas-sensing tests towards low concentrations of ethanol and acetone vapors are reported. Typical gas sensor parameters (gas responses, response/recovery time, sensitivity, and low detection limit) towards ethanol and acetone are presented.

  5. Chloride ion-catalyzed generation of difluorocarbene for efficient preparation of gem-difluorinated cyclopropenes and cyclopropanes

    KAUST Repository

    Wang, Fei; Zhang, Wei; Zhu, Jieming; Li, Huaifeng; Huang, Kuo-Wei; Hu, Jinbo

    2011-01-01

    A chloride ion-catalyzed generation of difluorocarbene from a relatively non-toxic and inexpensive precursor, Me3SiCF2Cl (1), under mild and neutral conditions leads to an efficient preparation of gem-difluorocyclopropenes and difluorocyclopropanes through [2 + 1] cycloaddition reactions with alkynes and alkenes, respectively. © 2011 The Royal Society of Chemistry.

  6. Performance study of molybdenum gels with titanium for preparation of 99Mo-99mTc generators

    International Nuclear Information System (INIS)

    Moraes, Vanessa; Osso Junior, Joao Alberto

    2005-01-01

    99m Tc is the most used radioisotope in Nuclear Medicine, due to nuclear characteristics. It is obtained by the radioactive decay of 99 Mo, generator of radioisotope system. When 99 Mo is produced by the activation in reactor, the most used technique for the preparation of the generators is the gel type generator, which incorporates 99 Mo to the gel that is insoluble, chemically inert to the solutions and with properties of ion exchange. Several countries had already studied this methodology, as is the case of Vietnam, India, China, Australian. This work has the objective of studying the performance and characterization of molybdenum gels with titanium. Four variables in the preparation of the gel were studied: mass ratio between Mo and Ti (1.80 and 2.25), concentration of NaOH (2 and 4 mol/L), final temperature (25 and 50 deg C) and pH (3.5 and 4.5). The prepared gels were analyzed with relation to the size of its particles, identification of its structure, amount of molybdenum, amount of titanium, profile of elution, pH of the elution, determination of the radioisotopes in the eluate and final radiochemical purity. The final result is a formularization of the gel with the best characteristics for posterior preparation of the generator of 99m Tc- 99 Mo. (author)

  7. Influence of Carrier Gas Composition on the Stress of Al2O3 Coatings Prepared by the Aerosol Deposition Method

    Directory of Open Access Journals (Sweden)

    Michael Schubert

    2014-08-01

    Full Text Available Al2O3 films were prepared by the aerosol deposition method at room temperature using different carrier gas compositions. The layers were deposited on alumina substrates and the film stress of the layer was calculated by measuring the deformation of the substrate. It was shown that the film stress can be halved by using oxygen instead of nitrogen or helium as the carrier gas. The substrates were annealed at different temperature steps to gain information about the temperature dependence of the reduction of the implemented stress. Total relaxation of the stress can already be achieved at 300 °C. The XRD pattern shows crystallite growth and reduction of microstrain while annealing.

  8. Preparation and electrical properties of boron and boron phosphide films obtained by gas source molecular beam deposition

    Energy Technology Data Exchange (ETDEWEB)

    Kumashiro, Y.; Yokoyama, T.; Sakamoto, T.; Fujita, T. [Yokohama National Univ. (Japan)

    1997-10-01

    Boron and boron phosphide films were prepared by gas source molecular beam deposition on sapphire crystal at various substrate temperatures up to 800{degrees}C using cracked B{sub 2}H{sub 6} (2% in H{sub 2}) at 300{degrees}C and cracked PH{sub 3} (20% in H{sub 2}) at 900{degrees}C. The substrate temperatures and gas flow rates of the reactant gases determined the film growth. The boron films with amorphous structure are p type. Increasing growth times lead to increasing mobilities and decreasing carrier concentrations. Boron phosphide film with maximum P/B ratio is obtained at a substrate temperature of 600{degrees}C, below and above which they become phosphorous deficient due to insufficient supply of phosphorus and thermal desorption of the phosphorus as P{sub 2}, respectively, but they are all n type conductors due to phosphorus vacancies.

  9. Improvement of the decay heat removal characteristics of the generation IV gas-cooled fast reactor

    International Nuclear Information System (INIS)

    Epiney, A.S.

    2010-01-01

    Gas cooling in nuclear power plants (NPPs) has a long history, the corresponding reactor types developed in France, the UK and the US having been thermal neutron spectrum systems using graphite as the moderator. The majority of NPPs worldwide, however, are currently light water reactors, using ordinary water as both coolant and moderator. These NPPs - of the so-called second generation - will soon need replacement, and a third generation is now being made available, offering increased safety while still based on light water technology. For the longer-term future, viz. beyond the year 2030, R and D is currently ongoing on Generation IV NPPs, aimed at achieving closure of the nuclear fuel cycle, and hence both drastically improved utilization of fuel resources and minimization of long-lived radioactive wastes. Like the SFR, the GFR is an efficient breeder, also able to work as iso-breeder using simply natural uranium as feed and producing waste which is predominantly in the form of fission products. The main drawback of the GFR is the difficulty to evacuate decay heat following a loss-of-coolant accident (LOCA) due to the low thermal inertia of the core, as well as to the low coolant density. The present doctoral research focuses on the improvement of decay heat removal (DHR) for the Generation-IV GFR. The reference GFR system design considered in the thesis is the 2006 CEA concept, with a power of 2400 MWth. The CEA 2006 DHR strategy foresees, in all accidental cases (independent of the system pressure), that the reactor is shut down. For high pressure events, dedicated DHR loops with blowers and heat exchangers are designed to operate when the power conversion system cannot be used to provide acceptable core temperatures under natural convection conditions. For de-pressurized events, the strategy relies on a dedicated small containment (called the guard containment) providing an intermediate back-up pressure. The DHR blowers, designed to work under these pressure

  10. An automated multidimensional preparative gas chromatographic system for isolation and enrichment of trace amounts of xenon from ambient air.

    Science.gov (United States)

    Larson, Tuula; Östman, Conny; Colmsjö, Anders

    2011-04-01

    The monitoring of radioactive xenon isotopes is one of the principal methods for the detection of nuclear explosions in order to identify clandestine nuclear testing. In this work, a miniaturized, multiple-oven, six-column, preparative gas chromatograph was constructed in order to isolate trace quantities of radioactive xenon isotopes from ambient air, utilizing nitrogen as the carrier gas. The multidimensional chromatograph comprised preparative stainless steel columns packed with molecular sieves, activated carbon, and synthetic carbon adsorbents (e.g., Anasorb®-747 and Carbosphere®). A combination of purification techniques--ambient adsorption, thermal desorption, back-flushing, thermal focusing, and heart cutting--was selectively optimized to produce a well-defined xenon peak that facilitated reproducible heart cutting and accurate quantification. The chromatographic purification of a sample requires approximately 4 h and provides complete separation of xenon from potentially interfering components (such as water vapor, methane, carbon dioxide, and radon) with recovery and accuracy close to 100%. The preparative enrichment process isolates and concentrates a highly purified xenon gas fraction that is suitable for subsequent ultra-low-level γ-, ß/γ-spectroscopic or high-resolution mass spectrometric measurement (e.g., to monitor the gaseous fission products of nuclear explosions at remote locations). The Xenon Processing Unit is a free-standing, relatively lightweight, and transportable system that can be interfaced to a variety of sampling and detection systems. It has a relatively inexpensive, rugged, and compact modular (19-inch rack) design that provides easy access to all parts for maintenance and has a low power requirement.

  11. Life-cycle energy consumption and greenhouse gas emissions for electricity generation and supply in China

    International Nuclear Information System (INIS)

    Ou, Xunmin; Xiaoyu, Yan; Zhang, Xiliang

    2011-01-01

    The Well-to-Meter (WTM) analysis module in the Tsinghua-CA3EM model has been used to examine the primary fossil energy consumption (PFEC) and greenhouse gas (GHG) emissions for electricity generation and supply in China. The results show that (1) the WTM PFEC and GHG emission intensities for the 2007 Chinese electricity mix are 3.247 MJ/MJ and 297.688 g carbon dioxide of equivalent (gCO 2,e )/MJ, respectively; (2) power generation is the main contributing sub-stage; (3) the coal-power pathway is the only major contributor of PFEC (96.23%) and GHG emissions (97.08%) in the 2007 mix; and (4) GHG emissions intensity in 2020 will be reduced to 220.470 gCO 2,e /MJ with the development of nuclear and renewable energy and to 169.014 gCO 2,e /MJ if carbon dioxide capture and storage (CCS) technology is employed. It is concluded that (1) the current high levels of PFEC and GHG emission for electricity in China are largely due to the dominant role of coal in the power-generation sector and the relatively low efficiencies during all the sub-stages from resource extraction to final energy consumption and (2) the development of nuclear and renewable energy as well as low carbon technologies such as CCS can significantly reduce GHG emissions from electricity. (author)

  12. Modelling of steam condensation in the primary flow channel of a gas-heated steam generator

    International Nuclear Information System (INIS)

    Kawamura, H.; Meister, G.

    1982-10-01

    A new simulation code has been developed for the analysis of steam ingress accidents in high temperatures reactors which evaluates the heat transfer in a steam generator headed by a mixture of helium and water steam. Special emphasis is laid on the analysis of steam condensation in the primary circuit of the steam generator. The code takes wall and bulk condensation into account. A new method is proposed to describe the entrainment of water droplets in the primary gas flow. Some typical results are given. Steam condensation in the primary channel may have a significant effect on temperature distributions. The effect on the heat transferred by the steam generator, however, is found to be not so prominent as might be expected. The reason is discussed. A simplified code will also be described, which gives results with reasonable accuracy within much shorter execution times. This code may be used as a program module in a program simulating the total primary circuit of a high temperature reactor. (orig.) [de

  13. Role of metal ion impurities in generation of oxygen gas within anodic alumina

    Energy Technology Data Exchange (ETDEWEB)

    Shimizu, K. [Keio Univ., Yokohama (Japan). Chemical Lab.; Habazaki, H. [Hokkaido Univ., Sapporo (Japan). Graduate School of Engineering; Skeldon, P.; Thompson, G.E.; Wood, G.C. [University of Manchester Inst. of Science and Technology (United Kingdom). Corrosion and Protection Centre

    2002-07-01

    The generation of oxygen gas within an amorphous anodic alumina film is reported. The film was formed by anodizing aluminum, which was first electropolished and then chemically polished in CrO{sub 3}-H{sub 3}PO{sub 4} solution, in sodium tungstate electrolyte. The procedure results in incorporation of mobile Cr{sup 3+} species, from the chemical polishing film, and mobile W{sup 6+} species, from the electrolyte, into the amorphous structure. The tungsten species are present in the outer 27% of the film thickness, while Cr{sup 6+} species occupy a thin layer within the tungsten-containing region. Above the Cr{sup 3+} containing layer, a band develops that contains oxygen bubbles of a few nanometres size. The oxygen is generated by oxidation of O{sup 2-} ions of the alumina. A mechanism of oxygen generation within the alumina is proposed based on the electronic band structure of the oxide, modified by the Cr{sup 3+} and W{sup 6+} species, and on the ionic transport processes during oxide growth. (author)

  14. Life-cycle energy consumption and greenhouse gas emissions for electricity generation and supply in China

    Energy Technology Data Exchange (ETDEWEB)

    Ou, Xunmin [Institute of Energy, Environment and Economy (3E), Tsinghua University, Beijing 100084 (China); China Automotive Energy Research Center (CAERC), Beijing 100084 (China); School of Public Policy and Management (SPPM), Tsinghua University, Beijing 100084 (China); Xiaoyu, Yan [Smith School of Enterprise and the Environment, University of Oxford, Oxford OX1 2BQ (United Kingdom); Zhang, Xiliang [Institute of Energy, Environment and Economy (3E), Tsinghua University, Beijing 100084 (China); China Automotive Energy Research Center (CAERC), Beijing 100084 (China)

    2011-01-15

    The Well-to-Meter (WTM) analysis module in the Tsinghua-CA3EM model has been used to examine the primary fossil energy consumption (PFEC) and greenhouse gas (GHG) emissions for electricity generation and supply in China. The results show that (1) the WTM PFEC and GHG emission intensities for the 2007 Chinese electricity mix are 3.247 MJ/MJ and 297.688 g carbon dioxide of equivalent (gCO{sub 2,e})/MJ, respectively; (2) power generation is the main contributing sub-stage; (3) the coal-power pathway is the only major contributor of PFEC (96.23%) and GHG emissions (97.08%) in the 2007 mix; and (4) GHG emissions intensity in 2020 will be reduced to 220.470 gCO{sub 2,e}/MJ with the development of nuclear and renewable energy and to 169.014 gCO{sub 2,e}/MJ if carbon dioxide capture and storage (CCS) technology is employed. It is concluded that (1) the current high levels of PFEC and GHG emission for electricity in China are largely due to the dominant role of coal in the power-generation sector and the relatively low efficiencies during all the sub-stages from resource extraction to final energy consumption and (2) the development of nuclear and renewable energy as well as low carbon technologies such as CCS can significantly reduce GHG emissions from electricity. (author)

  15. Ultrasound-mediated drug delivery by gas bubbles generated from a chemical reaction.

    Science.gov (United States)

    Lee, Sungmun; Al-Kaabi, Leena; Mawart, Aurélie; Khandoker, Ahsan; Alsafar, Habiba; Jelinek, Herbert F; Khalaf, Kinda; Park, Ji-Ho; Kim, Yeu-Chun

    2018-02-01

    Highly echogenic and ultrasound-responsive microbubbles such as nitrogen and perfluorocarbons have been exploited as ultrasound-mediated drug carriers. Here, we propose an innovative method for drug delivery using microbubbles generated from a chemical reaction. In a novel drug delivery system, luminol encapsulated in folate-conjugated bovine serum albumin nanoparticles (Fol-BSAN) can generate nitrogen gas (N 2 ) by chemical reaction when it reacts with hydrogen peroxide (H 2 O 2 ), one of reactive oxygen species (ROS). ROS plays an important role in the initiation and progression of cancer and elevated ROS have been observed in cancer cells both in vitro and in vivo. High-intensity focussed ultrasound (HIFU) is used to burst the N 2 microbubbles, causing site-specific delivery of anticancer drugs such as methotrexate. In this research, the drug delivery system was optimised by using water-soluble luminol and Mobil Composition of Matter-41 (MCM-41), a mesoporous material, so that the delivery system was sensitive to micromolar concentrations of H 2 O 2 . HIFU increased the drug release from Fol-BSAN by 52.9 ± 2.9% in 10 minutes. The cytotoxicity of methotrexate was enhanced when methotrexate is delivered to MDA-MB-231, a metastatic human breast cancer cell line, using Fol-BSAN with HIFU. We anticipate numerous applications of chemically generated microbubbles for ultrasound-mediated drug delivery.

  16. Gas Generation Testing of Spherical Resorcinol-Formaldehyde (sRF) Resin

    Energy Technology Data Exchange (ETDEWEB)

    Colburn, Heather A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Bryan, Samuel A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Camaioni, Donald M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Mahoney, Lenna A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Adami, Susan R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2018-01-19

    This report describes gas generation testing of the spherical resorcinol-formaldehyde (sRF) resin that was conducted to support the technology maturation of the LAWPS facility. The current safety basis for the LAWPS facility is based primarily on two studies that had limited or inconclusive data sets. The two studies indicated a 40% increase in hydrogen generation rate of water (as predicted by the Hu model) with sRF resin over water alone. However, the previous studies did not test the range of conditions (process fluids and temperatures) that are expected in the LAWPS facility. Additionally, the previous studies did not obtain replicate test results or comparable liquid-only control samples. All of the testing described in this report, conducted with water, 0.45M nitric acid, and waste simulants with and without sRF resin, returned hydrogen generation rates that are within the current safety basis for the facility of 1.4 times the Hu model output for water.

  17. Preparation and characterization of ALD deposited ZnO thin films studied for gas sensors

    Energy Technology Data Exchange (ETDEWEB)

    Boyadjiev, S.I., E-mail: boiajiev@gmail.com [MTA-BME Technical Analytical Chemistry Research Group, Szent Gellért tér 4, Budapest, H-1111 (Hungary); Georgi Nadjakov Institute of Solid State Physics, Bulgarian Academy of Sciences, 72 Tzarigradsko Chaussee Blvd., 1784 Sofia (Bulgaria); Georgieva, V. [Georgi Nadjakov Institute of Solid State Physics, Bulgarian Academy of Sciences, 72 Tzarigradsko Chaussee Blvd., 1784 Sofia (Bulgaria); Yordanov, R. [Department of Microelectronics, Technical University of Sofia, 8 Kliment Ohridski Blvd., 1756 Sofia (Bulgaria); Raicheva, Z. [Georgi Nadjakov Institute of Solid State Physics, Bulgarian Academy of Sciences, 72 Tzarigradsko Chaussee Blvd., 1784 Sofia (Bulgaria); Szilágyi, I.M. [MTA-BME Technical Analytical Chemistry Research Group, Szent Gellért tér 4, Budapest, H-1111 (Hungary); Budapest University of Technology and Economics, Department of Inorganic and Analytical Chemistry, Szent Gellért tér 4, Budapest, H-1111 (Hungary)

    2016-11-30

    Highlights: • For the first time the gas sensing towards NO{sub 2} of very thin ALD ZnO films is studied. • The very thin ALD ZnO films showed excellent sensitivity to NO{sub 2} at room temperature. • These very thin film ZnO-based QCM sensors very well register even low concentrations. • The sensors have fully reversible sorption and are able to be recovered in short time. • Described fast and cost-effective ALD deposition of ZnO thin films for QCM gas sensor. - Abstract: Applying atomic layer deposition (ALD), very thin zinc oxide (ZnO) films were deposited on quartz resonators, and their gas sensing properties were studied using the quartz crystal microbalance (QCM) method. The gas sensing of the ZnO films to NO{sub 2} was tested in the concentration interval between 10 and 5000 ppm. On the basis of registered frequency change of the QCM, for each concentration the sorbed mass was calculated. Further characterization of the films was carried out by various techniques, i.e. by SEM-EDS, XRD, ellipsometry, and FTIR spectroscopy. Although being very thin, the films were gas sensitive to NO{sub 2} already at room temperature and could register very well as low concentrations as 100 ppm, while the sorption was fully reversible. Our results for very thin ALD ZnO films show that the described fast, simple and cost-effective technology could be implemented for producing gas sensors working at room temperature and being capable to detect in real time low concentrations of NO{sub 2}.

  18. A dual fired downdraft gasifier system to produce cleaner gas for power generation: Design, development and performance analysis

    International Nuclear Information System (INIS)

    Raman, P.; Ram, N.K.; Gupta, Ruchi

    2013-01-01

    The existing biomass gasifier systems have several technical challenges, which need to be addressed. They are reduction of impurities in the gas, increasing the reliability of the system, easy in operation and maintenance. It is also essential to have a simple design of gasifier system for power generation, which can work even in remote locations. A dual fired downdraft gasifier system was designed to produce clean gas from biomass fuel, used for electricity generation. This system is proposed to overcome a number of technical challenges. The system is equipped with dry gas cleaning and indirect gas cooling equipment. The dry gas cleaning system completely eliminates wet scrubbers that require large quantities of water. It also helps to do away with the disposal issues with the polluted water. With the improved gasifier system, the tar level in the raw gas is less than 100 mg Nm −3 .Cold gas efficiency has improved to 89% by complete gasification of biomass and recycling of waste heat into the reactor. Several parameters, which are considered in the design and development of the reactors, are presented in detail with their performance indicators. - Highlights: • Hot air injection in dual fired reactor reduces the tar content to less than 100 mg Nm −3 . • In clean gas the tar content is 35 mg Nm −3 and the dust content is nil. • The specific gasification rate is 2.8 Nm 3 kg −1 of fuel wood and cold gas efficiency is 89.7%. • CV of the gas: 5.3 MJ Nm −3 , SFC: 1.1 kg kWh −1 and wood to power efficiency: 21%. • Cold gas efficiency is improved by optimizing the reactor's design and recycling the waste heat from hot gas

  19. Using TOUGH2 to model the coupled effects of gas generation, repository consolidation, and multiphase brine and gas flow at the Waste Isolation Pilot Plant

    International Nuclear Information System (INIS)

    Freeze, G.A.; Larson, K.W.; Davies, P.B.; Webb, S.W.

    1995-01-01

    The Waste Isolation Pilot Plant (WIPP) is a US Department of Energy facility designed to demonstrate the safe underground disposal of transuranic waste. Following waste emplacement, each room will be backfilled with crushed salt. Due to deviatoric stress introduced by excavation, the walls of the waste disposal rooms in the repository will deform over time, consolidating waste containers and salt backfill, thereby decreasing the void volume of the repository. Long-term repository assessment must consider the processes of gas generation, room closure and expansion due to salt creep, and multiphase (brine and gas) fluid flow, as well as the complex coupling between these three processes. Stone (1992) used the mechanical creep closure code SANCHO to simulate the closure of a single, perfectly sealed disposal room filled with waste and backfill. The results of the SANCHO f-series simulations provide a relationship between gas generation, room closure, and room pressure. Several methods for coupling this relationship with multiphase fluid flow into and out of a room were examined by Freeze et al. TOUGH2 was employed to couple the processes of gas generation, room closure/consolidation, and multiphase brine and gas flow. Two empirically-based methods for approximating salt creep and room consolidation were implemented in TOUGH2: the pressure-time-porosity line interpolation approach and the fluid-phase-salt approach. Both approaches utilized links to the SANCHO f-series simulation results to calculate room-void-volume changes with time during a simulation

  20. Preparation and characterization of indium tin oxide thin films for their application as gas sensors

    International Nuclear Information System (INIS)

    Vaishnav, V.S.; Patel, P.D.; Patel, N.G.

    2005-01-01

    The structural and electrical properties of indium tin oxide (In 2 O 3 /SnO 2 ) thin films grown using direct evaporation technique on various substrates at different temperatures were studied. The effect of annealing, of films with different weight percent concentration of SnO 2 in In 2 O 3 and of different thickness on the structural and electrical properties were studied and optimized for use as gas sensor. The stability of the films against time and temperature variations was studied. The effect of the catalytic layers on the sensor microstructure and its performance towards the gas sensing application was observed

  1. Study on Gas Sensing Performance of In2O3 Thick Film Resistors Prepared by Screen Printing Technique

    Directory of Open Access Journals (Sweden)

    S. C. KULKARNI

    2011-02-01

    Full Text Available Indium Oxide (In2O3 thick films were prepared on alumina substrate by using standard screen printing technique. These films were dried and fired at temperatures between 750 0C to 950 0C for two hours in air atmosphere. The compositional, morphological and structural properties of In2O3 films were performed by Energy Dispersive Spectroscopy (EDX, XRD, and Scanning electron Microscopy respectively. We explore the various gases to study sensing performance of In2O3 thick films. The maximum response was reported to film fired at 750 0C for H2S gas at 150 0C operating temperature.

  2. Bonding and orientation of 1,4-benzenedimethanethiol on Au(111) prepared from solution and from gas phase

    International Nuclear Information System (INIS)

    Pasquali, L; Terzi, F; Zanardi, C; Seeber, R; Paolicelli, G; Mahne, N; Nannarone, S

    2007-01-01

    The orientation and bonding of 1,4-benzenedimethanethiol molecules on Au(111) is studied by means of x-ray and ultraviolet (UV) photoemission, x-ray absorption and metastable deexcitation spectroscopy. The organic films are prepared both from solution and by exposing the clean substrate to the vapours of the substance in an evacuated environment. This leads to two different growth modes: when self-assembled monolayers (SAMs) are prepared from solution, the molecules tend to form a bilayer film with the molecules standing upright and with the molecular axis forming an angle of about 30 0 with respect to the substrate normal; when growth is carried out from the gas phase, the molecules tend to assume at the earliest stages of exposure a flat-lying configuration, with both sulfur end-groups bonding to Au; at increasing exposure the surface coverage presents a saturation and the chemisorbed molecules tend to assume an upright arrangement

  3. Microbial gas generation under expected Waste Isolation Pilot Plant repository conditions

    International Nuclear Information System (INIS)

    Francis, A.J.; Gillow, J.B.; Giles, M.R.

    1997-03-01

    Gas generation from the microbial degradation of the organic constituents of transuranic waste under conditions expected at the Waste Isolation Pilot Plant (WIPP) repository was investigated at Brookhaven National Laboratory. The biodegradation of mixed cellulosics (various types of paper) and electron-beam irradiated plastic and rubber materials (polyethylene, polyvinylchloride, neoprene, hypalon, and leaded hypalon) was examined. The rate of gas production from cellulose biodegradation in inundated samples incubated for 1,228 days at 30 C was biphasic, with an initial rapid rate up to approximately 600 days incubation, followed by a slower rate. The rate of total gas production in anaerobic samples containing mixed inoculum was as follows: 0.002 mL/g cellulose/day without nutrients; 0.004 mL/g cellulose/day with nutrients; and 0.01 mL/g cellulose/day in the presence of excess nitrate. Carbon dioxide production proceeded at a rate of 0.009 micromol/g cellulose/day in anaerobic samples without nutrients, 0.05 micromol/g cellulose/day in the presence of nutrients, and 0.2 micromol/g cellulose/day with excess nitrate. Adding nutrients and excess nitrate stimulated denitrification, as evidenced by the accumulation of N 2 O in the headspace (200 micromol/g cellulose). The addition of the potential backfill bentonite increased the rate of CO 2 production to 0.3 micromol/g cellulose/day in anaerobic samples with excess nitrate. Analysis of the solution showed that lactic, acetic, propionic, butyric, and valeric acids were produced due to cellulose degradation. Samples incubated under anaerobic humid conditions for 415 days produced CO 2 at a rate of 0.2 micromol/g cellulose/day in the absence of nutrients, and 1 micromol/g cellulose/day in the presence of bentonite and nutrients. There was no evidence of biodegradation of electron-beam irradiated plastic and rubber

  4. An assessment of the possible fate of gas generated in a repository for low- and intermediate-level waste

    International Nuclear Information System (INIS)

    Leupin, O.X.; Cloet, V.; Marschall, P.; Schwyn, B.; Smith, P.; Zeyer, J.; Bernier-Latmani, R.; Papafotiou, A.; Stroes-Gascoyne, S.

    2016-12-01

    The present study provides an assessment of reactions that result in a gas pressure reduction - also called gas sinks - in a generic deep geological repository for low- and intermediate-level waste in Opalinus Clay. Both chemical reactions and microbial activity may contribute to or reduce gas pressure build-up. A complete synopsis is given, comprising the current state of chemical, microbial and geoscientific understanding of gas generation and consumption in a L/ILW repository. The degradation of organic materials (by both microbial and chemical reactions) and the anoxic corrosion of metals will generate various gaseous products such as hydrogen, carbon dioxide, methane, hydrogen sulphide and ammonia. Some of these gas species are expected to further react with materials present at the point of origin. More particularly, carbon dioxide and hydrogen sulphide are expected to react entirely with e.g. cement, water or iron. Thus, they do not contribute to a gas pressure build-up in the repository. The remaining gas species - mainly hydrogen, methane and small amounts of ammonia - are assumed not to react at the point of origin and can thus contribute to gas pressure build-up. Gas pressure build-up in the L/ILW emplacement caverns will result in gas migrating through the gas permeable seals and through the excavation-damaged zone to reach the operational and construction tunnels where microorganisms may utilise the gas and thus reduce gas pressure build-up. In order to allow bacteria to thrive over longer periods, the backfill material of the operational tunnel needs to have sufficient porosity and a pore water composition for favourable living conditions. Experimental findings at the Mont Terri underground rock laboratory show that bacteria found in borehole water are efficient at oxidising hydrogen as long as sulphate is present in the borehole water. Examples from nature and engineered underground structures provide supporting evidence that these assumptions are

  5. An assessment of the possible fate of gas generated in a repository for low- and intermediate-level waste

    Energy Technology Data Exchange (ETDEWEB)

    Leupin, O.X.; Cloet, V.; Marschall, P.; Schwyn, B. [National Cooperative for the Disposal of Radioactive Waste (NAGRA), Wettingen (Switzerland); Smith, P. [Safety Assessment Management Ltd, Henley-On-Thames, Oxfordshire (United Kingdom); Zeyer, J. [Swiss federal institute of technology (ETH), Zürich (Switzerland); Bernier-Latmani, R. [Swiss federal institute of technology (EPFL), Lausanne (Switzerland); Papafotiou, A. [Intera Inc., Ennetbaden (Switzerland); Stroes-Gascoyne, S. [University of Saskatchewan, Saskatoon, SK S7N 5C5 (Canada)

    2016-12-15

    The present study provides an assessment of reactions that result in a gas pressure reduction - also called gas sinks - in a generic deep geological repository for low- and intermediate-level waste in Opalinus Clay. Both chemical reactions and microbial activity may contribute to or reduce gas pressure build-up. A complete synopsis is given, comprising the current state of chemical, microbial and geoscientific understanding of gas generation and consumption in a L/ILW repository. The degradation of organic materials (by both microbial and chemical reactions) and the anoxic corrosion of metals will generate various gaseous products such as hydrogen, carbon dioxide, methane, hydrogen sulphide and ammonia. Some of these gas species are expected to further react with materials present at the point of origin. More particularly, carbon dioxide and hydrogen sulphide are expected to react entirely with e.g. cement, water or iron. Thus, they do not contribute to a gas pressure build-up in the repository. The remaining gas species - mainly hydrogen, methane and small amounts of ammonia - are assumed not to react at the point of origin and can thus contribute to gas pressure build-up. Gas pressure build-up in the L/ILW emplacement caverns will result in gas migrating through the gas permeable seals and through the excavation-damaged zone to reach the operational and construction tunnels where microorganisms may utilise the gas and thus reduce gas pressure build-up. In order to allow bacteria to thrive over longer periods, the backfill material of the operational tunnel needs to have sufficient porosity and a pore water composition for favourable living conditions. Experimental findings at the Mont Terri underground rock laboratory show that bacteria found in borehole water are efficient at oxidising hydrogen as long as sulphate is present in the borehole water. Examples from nature and engineered underground structures provide supporting evidence that these assumptions are

  6. Performance of Tc-99m generator prepared with Mo adsorbent PZC and irradiated nature MoO3

    International Nuclear Information System (INIS)

    Liu Yishu

    2006-01-01

    This paper describes the technical process of Tc-99m generator prepared with reactor actived Mo-99 and PZC and the performance of the generator was also reported. Two generators were prepared with different batch of PZC and by different technical process. The results show that the adsorption rate was ∼65% and the adsorption efficiency of 99 Mo can be seriously affected by the adsorption process (the temperature, intensity and frequency of shaking and the PZC volume in solution etc.). The elution efficiency was 43-73%. The Mo breakthrough 1.2 - 16% without safe column and its can be decreased to be very low by connecting a hydrate zirconia (HZO) safe column. (author)

  7. Predictive Model to determine the composition of the gas generated in a downdraft gasifier

    International Nuclear Information System (INIS)

    D'Espaux Shelton, Elbis; Copa Rey, José Ramón; Brito Sauvanel, Angel Luis

    2017-01-01

    There is currently a trend of using gasification modeling to describe the process without the need to develop experiments, which can be costly. This work presented the necessary tools to analyze the development of a mathematical model with the objective of predicting the chemical composition of the gas generated in a fixed bed downdraft gasifier, with parallel flows and air as a gasification agent as a function of kind of biomass used and the operating parameters of the equipment. This model allows the calculation of thermochemical processes that occur inside a downdraft gasifier and also the determination of temperature profiles. The model developed was based on the energy balance and species equations approach and the control volumes method was used. (author)

  8. Schlieren diagnostics of the Los Alamos hypersonic gas target neutron generator

    International Nuclear Information System (INIS)

    Haasz, A.A.; Lever, J.H.

    1981-01-01

    The gasdynamic behaviour of a planar model of the Los Alamos geometry hypersonic gas target neutron generator (GTNG) was investigated using Schlieren flow visualization photographs, static and total pressure and spill flow measurements. The model consisted of two symmetrical expansion nozzles with 220 μm throats producing a combined flow of about Mach 4 in the GTNG channel. Stagnation pressures of 100-800 kPa were used. Two basic flow configurations, spill line closed and spill line open, were studied in order to gain insight into the complex boundary layer development near the nozzle exit planes. Both flow configurations are discussed qualitatively, making use of the pressure measurements and theoretical analysis. (orig.)

  9. Numerical analysis of gas-liquid two-phase flow in secondary side of steam generator

    Energy Technology Data Exchange (ETDEWEB)

    Murase, Michio; Nakamura, Akira; Yagi, Yoshinori [Inst. of Nuclear Safety System Inc., Mihama, Fukui (Japan)

    2002-09-01

    The steam generator (SG) in a pressurized water reactor (PWR) is an important two-phase flow component as the boundary between the primary loop and the secondary loop. In this study, we performed gas-liquid two-phase flow analyses for SG reliability tests conduced by Nuclear Power Engineering Corporation (NUPEC) using the two-fluid model of a thermal-hydraulic computer code PHOENICS. In order to calculate the location of the boiling initiation accurately, detailed inputs were required for the friction coefficients affecting the velocity distribution and the heat transfer distribution. However, the velocity and heat transfer distributions did not greatly affect the void fractions in the upper region of the heat transfer tubes. The calculated void fractions agreed with the measured values within 4% as the local average and within 2% as an average in a cross-section, except the region of low void fractions. (author)

  10. 77 FR 6793 - D'Lo Gas Storage, LLC; Notice of Intent To Prepare an Environmental Assessment for the PROPOSED D...

    Science.gov (United States)

    2012-02-09

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. CP12-39-000] D'Lo Gas Storage, LLC; Notice of Intent To Prepare an Environmental Assessment for the PROPOSED D'LO Gas Storage Project, Request for Comments on Environmental Issues, and Notice of Onsite Environmental Review The staff of the Federal Energy Regulatory Commission ...

  11. Correlation of gas sensitivite properties with microstructure of Fe2O3-SnO2 ceramics prepared by high energy ball milling

    DEFF Research Database (Denmark)

    Jiang, Jianzhong; Lu, S.W.; Zhou, Y.X.

    1997-01-01

    A remarkable gas sensitivity to ethnaol gas has been observed in nanostructured Fe2O3-SnO2 materials with a composition of 6.4 mol% SnO2 prepared by high energy ball milling. The microstructure of the materials has been examined by x-ray diffraction (XRD) and Mossbauer spectroscopy. It was found...

  12. Thin film composite membranes of glossy polymers for gas separation : preparation and characterization

    NARCIS (Netherlands)

    Ebert, Katrin

    1995-01-01

    The application of polymeric composite membranes can be very interesting in the field of gas separation. The two main parameters which determine the applicability of membranes are the selectivity and the permeability. Good selectivities can be achieved by developing proper materials, high permeation

  13. Thermal preparation effects on the x-ray diffractograms of compounds produced during flue gas desulfurization

    International Nuclear Information System (INIS)

    Wertz, D.L.; Burns, K.H.; Keeton, R.W.

    1995-01-01

    The diffractograms of syn-gypsum and of flue gas desulfurization products indicate that CaSO 4 · 2H 2 O is converted to other phase(s) when heated to 100 degrees C. Syn-hannebachite CaSO 3 ·0.5H 2 O is unaffected by similar thermal treatment. 6 refs., 3 figs

  14. 78 FR 26354 - Transcontinental Gas Pipeline Company, LLC; Notice of Intent to Prepare an Environmental Impact...

    Science.gov (United States)

    2013-05-06

    ... proposes to: Add an incremental 6,540 horsepower (hp) of compression at its existing Compressor Station 195 in York County, Pennsylvania by: installing a new 35 kilovolt substation, variable frequency drive building, and associated coolers; replacing three existing natural gas- fired reciprocating engines and...

  15. Prediction of Non-Equilibrium Kinetics of Fuel-Rich Kerosene/LOX Combustion in Gas Generator

    International Nuclear Information System (INIS)

    Yu, Jung Min; Lee, Chang Jin

    2007-01-01

    Gas generator is the device to produce high enthalpy gases needed to drive turbo-pump system in liquid rocket engine. And, the combustion temperature in gas generator should be controlled below around 1,000K to avoid any possible thermal damages to turbine blade by using either fuel rich combustion or oxidizer rich combustion. Thus, nonequilibrium chemical reaction dominates in fuel-rich combustion of gas generator. Meanwhile, kerosene is a compounded fuel with various types of hydrocarbon elements and difficult to model the chemical kinetics. This study focuses on the prediction of the non-equilibrium reaction of fuel rich kerosene/LOX combustion with detailed kinetics developed by Dagaut using PSR (Perfectly Stirred Reactor) assumption. In Dagaut's surrogate model for kerosene, chemical kinetics of kerosene consists of 1,592 reaction steps with 207 chemical species. Also, droplet evaporation time is taken into account in the PSR calculation by changing the residence time of droplet in the gas generator. Frenklach's soot model was implemented along with detailed kinetics to calculate the gas properties of fuel rich combustion efflux. The results could provide very reliable and accurate numbers in the prediction of combustion gas temperature,species fraction and material properties

  16. Households' willingness to pay for safeguarding security of natural gas supply in electricity generation

    International Nuclear Information System (INIS)

    Damigos, D.; Tourkolias, C.; Diakoulaki, D.

    2009-01-01

    Security of energy supply is a major issue for all EU Member States due to Europe's increasing dependence on imported fossil-fuel sources and the continuous rise in energy demand. The latter is of particular importance in electricity sector given the continuously increasing use of gas for electricity generation. In order to properly tackle with the problem, concerted actions are required by the EU Member States in several levels, i.e. legislative, political, etc. Nevertheless, these actions will come at an additional cost paid by the society either through increased electricity bills or through public financing for energy security investments. Thus, such policies should be justified on the basis of cost-benefit analysis. Towards this direction, it may be necessary to take into account non-market costs and benefits, i.e. the value that consumers place on interruptions avoided. In order to explore households' perceptions and willingness to pay for securing gas supply for electricity production, an empirical study was conducted by means of the contingent valuation method. The results indicate that consumers are willing to pay a premium on their electricity bills in order to internalize the external costs of electricity production, in terms of energy security, which are caused from imported fuels. (author)

  17. Public health benefits of strategies to reduce greenhouse-gas emissions: low-carbon electricity generation.

    Science.gov (United States)

    Markandya, Anil; Armstrong, Ben G; Hales, Simon; Chiabai, Aline; Criqui, Patrick; Mima, Silvana; Tonne, Cathryn; Wilkinson, Paul

    2009-12-12

    In this report, the third in this Series on health and climate change, we assess the changes in particle air pollution emissions and consequent effects on health that are likely to result from greenhouse-gas mitigation measures in the electricity generation sector in the European Union (EU), China, and India. We model the effect in 2030 of policies that aim to reduce total carbon dioxide (CO(2)) emissions by 50% by 2050 globally compared with the effect of emissions in 1990. We use three models: the POLES model, which identifies the distribution of production modes that give the desired CO(2) reductions and associated costs; the GAINS model, which estimates fine particulate matter with aerodynamic diameter 2.5 microm or less (PM(2.5)) concentrations; and a model to estimate the effect of PM(2.5) on mortality on the basis of the WHO's Comparative Risk Assessment methods. Changes in modes of production of electricity to reduce CO(2) emissions would, in all regions, reduce PM(2.5) and deaths caused by it, with the greatest effect in India and the smallest in the EU. Health benefits greatly offset costs of greenhouse-gas mitigation, especially in India where pollution is high and costs of mitigation are low. Our estimates are approximations but suggest clear health gains (co-benefits) through decarbonising electricity production, and provide additional information about the extent of such gains.

  18. Fast discharging homopolar drum-type generator with gas bearing and flexible copper-fiber brushes

    International Nuclear Information System (INIS)

    Kibardin, A.S.; Komin, A.V.; Sojkin, V.F.; Frolkin, V.I.

    1984-01-01

    The description and results of testing schock-excited homopolar generator (SEHG) with a drum-type rotor, a gas bearing and flexible copper-fiber brushes are presented. SEHG has a magnetic core with two excitation coils with the designed field of 1.8-2 T in the gap. The drum-type titanium rotor has 80 kg, is 0.5 m in diameter, 0.25 m length and 0.05 m thick. SEHG power is 3.6 MJ, overall dimensions are 0.8x1 m. Single- and double-row bearings, representing an aluminium shell of 15 mm thick, established inside an external backward current lead and isolated from it, are used to control serviceability of a radial gas-static bearing, which is a support for an SEHG rotor. The bearing surface was covered with the colloidal graphite and had one or two rows by 24 openings for swelling. Brush units represent a bronze brush ring, containing 44 copper-fiber brushes. Tests results confirm serviceability of copper-fiber brushes with quite large dimensions and permit to count on producing the 2.4 MA electric discharge and 12 ms pulse rise time

  19. Power generation using coir-pith and wood derived producer gas in diesel engines

    Energy Technology Data Exchange (ETDEWEB)

    Ramadhas, A.S.; Jayaraj, S.; Muraleedharan, C. [Department of Mechanical Engineering, National Institute of Technology Calicut, Calicut-673 601, Kerala State (India)

    2006-10-15

    Partial combustion of biomass in the gasifier generates producer gas that can be used for heating purposes and as supplementary or sole fuel in internal combustion engines. In this study, the potential of coir-pith and wood chips as the feedstock for gasifier is analyzed. The performance of the gasifier-engine system is analyzed by running the engine for various producer gas-air flow ratios and at different load conditions. The system is experimentally optimized with respect to maximum diesel savings and lower emissions in the dual fuel mode operation while using coir-pith and wood chips separately. The performance and emission characteristics of the dual fuel engine are compared with that of diesel engine at different load conditions. Specific energy consumption in the dual fuel mode of operation is found to be in the higher side at all load conditions. The brake thermal efficiency of the engine while using wood chips in the dual mode operation is higher than that of coir-pith. The CO emission is higher in the case of dual fuel mode of operation as compared to that of diesel mode. In the dual fuel mode of operation, the higher diesel savings is achieved while using wood chips as compared to that of coir-pith. The comparison of the performance and emission characteristics of the dual fuel engine with diesel engine is also described. (author)

  20. Report on power generation potential using manure gas from Ontario farms. Appendix B3

    International Nuclear Information System (INIS)

    Anon.

    1993-01-01

    The potential for manure gas power generation in Ontario is assessed. Since biogas cannot be easily liquefied for reserve use applications, it must be consumed as it is produced, or stored as a gas under low or medium pressure. Simultaneous conversion of fuel into both thermal and electrical energy is known as cogeneration, and offers the potential of electrical power sales through utility interconnection. Typical electrical production results available on a per mature animal basis are: cow, 75 W; swine, 10 W; and poultry, 0.65 W. A supplementary benefit is that digestion greatly reduces manure odour. The potential number of manure biogas power plant units (MBU) by size can be determined from livestock data, farm size and animal type. There are ca 17,000 potential MBU (361 MW continuous power) related to cattle operations, 3,200 MBU (49 MW) associated with swine operations, and 14,000 MBU (42 MW) related to poultry, for a total technical potential of 452 MW. Based on available equipment packages and installation costs, it is estimated that 15 kW is the minimum capacity cogeneration unit worthy of consideration. Estimated cost of an on-farm biogas cogeneration plant ranges from $200,000 for a 15 kW installation to $500,000 for a 150 kW plant. Appendices present properties of manure gases, representative installations, involved groups, a literature search, selected equipment manufacturers, and case study data sheets. 27 refs., 4 figs., 10 tabs

  1. Tritium generation and neutron measurements in Pd-Si under high deuterium gas pressure

    International Nuclear Information System (INIS)

    Claytor, T.N.; Tuggle, D.G.; Menlove, H.O.

    1991-01-01

    This paper summarizes some of the methods applicable for low level tritium detection needed in the search for anomalous fusion in metal hydrides. It is also intended to further detail our tritium and neutron results that have been obtained with the Pd-Si-D system, originally presented at earlier workshops. A measure of reproducibility that was not evident in our previous work has been achieved partially due to the better detection sensitivity afforded by the use of low tritium deuterium and partially from the fact that the foil-wafer cells can be made with nearly identical electrical characteristics. This reproducibility has allowed us to narrow the optimum conditions for the experiment. While this experiment is rather different from the ''standard'' electrolytic cell or the Ti gas hydride experiment, similarities exist in that non equilibrium conditions are sought and the tritium generation levels are low and neutron emission is extremely weak. In contrast to many electrochemical cell experiments, the system used in these experiments is completely sealed during operation and uses no electrolyte. The major improvements to the experiment have been the use of vary low tritium deuterium for the hydriding and the replacement of the aluminum neutron counter tubes with ones of stainless steel. These changes have resulted in pronounced improvements to the detection systems since the background tritium level in the gas has been reduced by a factor of 300 and the neutron background has been decreased by a factor of 14. 16 refs., 8 figs., 1 tab

  2. Improvement of the decay heat removal characteristics of the generation IV gas-cooled fast reactor

    International Nuclear Information System (INIS)

    Epiney, A. S.

    2010-09-01

    The majority of NPPs worldwide are currently light water reactors, using ordinary water as both coolant and moderator. (...) For the longer-term future, viz. beyond the year 2030, Research and Development is currently ongoing on Generation IV NPPs, aimed at achieving closure of the nuclear fuel cycle, and hence both drastically improved utilization of fuel resources and minimization of long-lived radioactive wastes. Since the very beginning of the international cooperation on Generation IV, viz. the year 2000, the main research interest in Europe as regards the advanced fast-spectrum systems needed for achieving complete fuel cycle closure, has been for the Sodium-cooled Fast Reactor (SFR). However, the Gas-cooled Fast Reactor (GFR) is currently considered as the main back-up solution. Like the SFR, the GFR is an efficient breeder, also able to work as iso-breeder using simply natural uranium as feed and producing waste which is predominantly in the form of fission products. The main drawback of the GFR is the difficulty to evacuate decay heat following a loss-of-coolant accident (LOCA) due to the low thermal inertia of the core, as well as to the low coolant density. The present doctoral research focuses on the improvement of decay heat removal (DHR) for the Generation-IV GFR. The reference GFR system design considered in the thesis is the 2006 CEA concept, with a power of 2400 MWth. The CEA 2006 DHR strategy foresees, in all accidental cases (independent of the system pressure), that the reactor is shut down. For high pressure events, dedicated DHR loops with blowers and heat exchangers are designed to operate when the power conversion system cannot be used to provide acceptable core temperatures under natural convection conditions. For depressurized events, the strategy relies on a dedicated small containment (called the guard containment) providing an intermediate back-up pressure. The DHR blowers, designed to work under these pressure conditions, need to be

  3. Generation of low-Btu fuel gas from agricultural residues experiments with a laboratory scale gas producer

    Energy Technology Data Exchange (ETDEWEB)

    Williams, R O

    1977-01-01

    Two successive laboratory-scale, downdraft gas producers were fabricated and tested. Agricultural and food processing residues including walnut shells, corn cobs, tree prunings, and cotton gin waste, were converted to a low Btu producer gas. The performance of 2 spark ignition engines, when running on producer gas, was highly satisfactory. The ability of the producer to maintain a continuous supply of good quality gas was determined largely by firebox configuration. Fuel handling and fuel flow control problems tended to be specific to individual types of residues. During each test run, air input, firebox temperature, fuel consumption rate, and pressure differential across the producer were monitored. An overall conversion efficiency of 65% was achieved.

  4. Deposition of NORM generated by the oil and gas industries in Brazil

    International Nuclear Information System (INIS)

    Schenato, Flavia; Aguiar, Lais A.; Leal, Marco Aurelio; Ruperti Junior, Nerbe

    2013-01-01

    The natural occurring radioactive material (NORM) produced during E and P activities in the petroleum industry presents important implications for the management of solid wastes. The waste management strategy and final disposal policy regarding NORM should meet general radiation protection principles to ensure the long periods during which control may be necessary. The Brazilian Nuclear Energy Commission (CNEN) is responsible for the final destination of the radioactive waste produced in national territory. The Federal Law 10308/2001 establishes standards for the final destination of the radioactive waste providing information to the installation and operation of storage and disposal facilities. The licensee is responsible for the storage facilities, while CNEN is in charge of design, construction and installation of final disposal facilities, being possible to delegate such activities to a third parties, since preserved its full responsibility. The CNEN's Resolution on licensing of radioactive waste deposits, which is in the final approval stage, classifies the wastes generated by the E and P oil and gas industries and suggests two disposal methods to them, near surface and depth repositories, to be defined by safety analysis, but no formal criteria for disposal is really established. The guidelines for the safety analysis set for the licensing process of this class of waste is applied only to the implementation of interim storage facilities but not to repositories. Considering the large volume of NORM generated by the activities of E and P oil and gas industries and the growing demand of production with the exploration of pre-salt oil deposits in Brazil, this paper aims to discuss the development of national guidelines for the disposal of this class of waste to ensure long term safety and acceptability of disposal methods. (author)

  5. A flameless catalytic combustion-based thermoelectric generator for powering electronic instruments on gas pipelines

    International Nuclear Information System (INIS)

    Xiao, Heng; Qiu, Kuanrong; Gou, Xiaolong; Ou, Qiang

    2013-01-01

    Highlights: ► MPPT is used to improve the feature that TEG output is sensitive to load variation. ► The improved feature makes TEG suitable to power electronic device on gas pipeline. ► Test shows heat transfer uniformity plays an important role in improving TEG output. ► It can get an optimized TEG by uniformly filling a thermal insulation material. - Abstract: This paper presents a flameless catalytic combustion-based thermoelectric power generator that uses commercial thermoelectric modules. The structure of the thermoelectric generator (TEG) is introduced and the power performance is measured based on a designed circuit system. The open circuit voltage of the TEG is about 7.3 V. The maximum power output can reach up to 6.5 W when the load resistance matches the TEG internal resistance. However, the system output is sensitive to load variation. To improve this characteristic, maximum power point tracking technique is used and results in an open circuit voltage of 13.8 V. The improved characteristic makes the TEG system a good charger to keep the lead acid battery fully charged so as to meet the needs of electronic instruments on gas pipelines. In addition, the combustion features have been investigated based on the temperature measurement. Test results show that the uniformity of combustion heat transfer process and the combustion chamber structure play important roles in improving system power output. It can get an optimized TEG system (maximum power output: 8.3 W) by uniformly filling a thermal insulation material (asbestos) to avoid a non-uniform combustion heat transfer process

  6. Determination of residual acetone and acetone related impurities in drug product intermediates prepared as Spray Dried Dispersions (SDD) using gas chromatography with headspace autosampling (GCHS).

    Science.gov (United States)

    Quirk, Emma; Doggett, Adrian; Bretnall, Alison

    2014-08-05

    Spray Dried Dispersions (SDD) are uniform mixtures of a specific ratio of amorphous active pharmaceutical ingredient (API) and polymer prepared via a spray drying process. Volatile solvents are employed during spray drying to facilitate the formation of the SDD material. Following manufacture, analytical methodology is required to determine residual levels of the spray drying solvent and its associated impurities. Due to the high level of polymer in the SDD samples, direct liquid injection with Gas Chromatography (GC) is not a viable option for analysis. This work describes the development and validation of an analytical approach to determine residual levels of acetone and acetone related impurities, mesityl oxide (MO) and diacetone alcohol (DAA), in drug product intermediates prepared as SDDs using GC with headspace (HS) autosampling. The method development for these analytes presented a number of analytical challenges which had to be overcome before the levels of the volatiles of interest could be accurately quantified. GCHS could be used after two critical factors were implemented; (1) calculation and application of conversion factors to 'correct' for the reactions occurring between acetone, MO and DAA during generation of the headspace volume for analysis, and the addition of an equivalent amount of polymer into all reference solutions used for quantitation to ensure comparability between the headspace volumes generated for both samples and external standards. This work describes the method development and optimisation of the standard preparation, the headspace autosampler operating parameters and the chromatographic conditions, together with a summary of the validation of the methodology. The approach has been demonstrated to be robust and suitable to accurately determine levels of acetone, MO and DAA in SDD materials over the linear concentration range 0.008-0.4μL/mL, with minimum quantitation limits of 20ppm for acetone and MO, and 80ppm for DAA. Copyright

  7. Advanced exergoenvironmental assessment of a natural gas-fired electricity generating facility

    International Nuclear Information System (INIS)

    Açıkkalp, Emin; Aras, Haydar; Hepbasli, Arif

    2014-01-01

    Highlights: • Advanced exergoenvironmental analysis was conducted for an electricity generating facility. • Exergy destructions and environmental effects were divided into parts. • Environmental relations between the components were determined. • Environmental improvement strategies of the system were determined. - Abstract: This paper presents conventional and advanced exergoenvironmental analyses of an electricity generation facility located in the Eskisehir Industry Estate Zone, Turkey. This facility consists of gas turbine and steam cycles, which generate electrical power of approximately 37 MW and 18 MW, respectively. Exergy efficiency of the system is 0.402 and exergy destruction rate of the system is 78.242 MW. Unit exergy cost of electrical power generated by the system is 25.66 $/GJ and total exergoeconomic factor of the system is 0.279. Conventional exergy analysis method was applied to the system first. Next, exergy environmental impacts of exergy destruction rate within the facility’s components were divided into four parts generally, as endogenous, exogenous, avoidable and unavoidable environmental impact of exergy destruction rate. Through this analysis, improvement potential of the environmental impacts of the components and the overall system and the environmental relations between the components were then determined. Finally, exergoenvironmental factor was determined as 0.277 and environmental impact of the electricity was 8.472 (Pts/h). The system has 33% development potential for environmental impacts while its components have weak relations because of big endogenous parts of environmental impacts (80%). It may be concluded that advanced exergoenvironmental analysis indicated that priority should be given to the GT and CC, while defining the improvement strategies

  8. DC Linked Hybrid Generation System with an Energy Storage Device including a Photo-Voltaic Generation and a Gas Engine Cogeneration for Residential Houses

    Science.gov (United States)

    Lung, Chienru; Miyake, Shota; Kakigano, Hiroaki; Miura, Yushi; Ise, Toshifumi; Momose, Toshinari; Hayakawa, Hideki

    For the past few years, a hybrid generation system including solar panel and gas cogeneration is being used for residential houses. Solar panels can generate electronic power at daytime; meanwhile, it cannot generate electronic power at night time. But the power consumption of residential houses usually peaks in the evening. The gas engine cogeneration system can generate electronic power without such a restriction, and it also can generate heat power to warm up house or to produce hot water. In this paper, we propose the solar panel and gas engine co-generation hybrid system with an energy storage device that is combined by dc bus. If a black out occurs, the system still can supply electronic power for special house loads. We propose the control scheme for the system which are related with the charging level of the energy storage device, the voltage of the utility grid which can be applied both grid connected and stand alone operation. Finally, we carried out some experiments to demonstrate the system operation and calculation for loss estimation.

  9. Effect of Simplifying Drilling Technique on Heat Generation During Osteotomy Preparation for Dental Implant.

    Science.gov (United States)

    El-Kholey, Khalid E; Ramasamy, Saravanan; Kumar R, Sheetal; Elkomy, Aamna

    2017-12-01

    To test the hypothesis that there would be no difference in heat production by reducing the number of drills during the implant site preparation relative to conventional drilling sequence. A total of 120 implant site preparations with 3 different diameters (3.6, 4.3, and 4.6 mm) were performed on bovine ribs. Within the same diameter group, half of the preparations were performed by a simplified drilling procedure (pilot drill + final diameter drill) and other half using the conventional drilling protocol (pilot drill followed by graduated series of drills to widen the site). Heat production by different drilling techniques was evaluated by measuring the bone temperature using k-type thermocouple and a sensitive thermometer before and after each drill. Mean for maximum temperature increase during site preparation of the 3.6, 4.3, and 4.6-mm implants was 2.45, 2.60, and 2.95° when the site was prepared by the simplified procedure, whereas it was 2.85, 3.10, and 3.60° for the sites prepared by the conventional technique, respectively. No significant difference in temperature increase was found when implants of the 3 different diameters were prepared either by the conventional or simplified drilling procedure. The simplified drilling technique produced similar amount of heat comparable to the conventional technique that proved the initial hypothesis.

  10. Study of sensing properties of SnO2 prepared by spray-pyrolysis deposition towards ethanol gas

    Science.gov (United States)

    Saadaldin, Nasser M.; Hussain, Nabiha; AlZouabi, Abla

    2018-05-01

    Ethanol is widely used in all kinds of products with direct exposure to the human skin (e.g. medicinal products like hand disinfectants in occupational settings, cosmetics like hairsprays or mouthwashes, in this study, thin films of (SnO2) were deposited by using the thermal spray method (SPD) on quartz at 450°C substrate temperature using tin chloride SnCl2.2H2O, (1.0M). A gas sensor was constructed with the prepared SnO2, used to detect ethanol gas and some other gases. The films were characterized by X-ray diffraction (XRD), and scanning electron microscopy (SEM). The grain size was calculated the results showed nanostructure polycrystalline and crystallize in a tetragonal, S.G:P42/m nm, reaching grain Size approximately 27nm. The sensing properties of the films were studied towards ethanol at different concentrations ranging within (1-200 ppm,) the results showed that the sensitivity of the film increases with the concentration of ethanol, the best operating temperature reached about 300 °C, We studied the sensing properties of the films towards Ethanol alcohol gas, The first and foremost concerns of topical ethanol applications for public health are its carcinogenic effects, high selectivity and sensitivity of the film towards ethanol gas was found compared to other tested toxic gases such as methanol gas, acetone and methylbenzene. Yet an upto-date risk assessment of ethanol application on the skin and inside the oral cavity is currently lacking.

  11. Committing to coal and gas: Long-term contracts, regulation, and fuel switching in power generation

    Science.gov (United States)

    Rice, Michael

    Fuel switching in the electricity sector has important economic and environmental consequences. In the United States, the increased supply of gas during the last decade has led to substantial switching in the short term. Fuel switching is constrained, however, by the existing infrastructure. The power generation infrastructure, in turn, represents commitments to specific sources of energy over the long term. This dissertation explores fuel contracts as the link between short-term price response and long-term plant investments. Contracting choices enable power plant investments that are relationship-specific, often regulated, and face uncertainty. Many power plants are subject to both hold-up in investment and cost-of-service regulation. I find that capital bias is robust when considering either irreversibility or hold-up due to the uncertain arrival of an outside option. For sunk capital, the rental rate is inappropriate for determining capital bias. Instead, capital bias depends on the regulated rate of return, discount rate, and depreciation schedule. If policies such as emissions regulations increase fuel-switching flexibility, this can lead to capital bias. Cost-of-service regulation can shorten the duration of a long-term contract. From the firm's perspective, the existing literature provides limited guidance when bargaining and writing contracts for fuel procurement. I develop a stochastic programming framework to optimize long-term contracting decisions under both endogenous and exogenous sources of hold-up risk. These typically include policy changes, price shocks, availability of fuel, and volatility in derived demand. For price risks, the optimal contract duration is the moment when the expected benefits of the contract are just outweighed by the expected opportunity costs of remaining in the contract. I prove that imposing early renegotiation costs decreases contract duration. Finally, I provide an empirical approach to show how coal contracts can limit

  12. Quantitation of next generation sequencing library preparation protocol efficiencies using droplet digital PCR assays - a systematic comparison of DNA library preparation kits for Illumina sequencing.

    Science.gov (United States)

    Aigrain, Louise; Gu, Yong; Quail, Michael A

    2016-06-13

    The emergence of next-generation sequencing (NGS) technologies in the past decade has allowed the democratization of DNA sequencing both in terms of price per sequenced bases and ease to produce DNA libraries. When it comes to preparing DNA sequencing libraries for Illumina, the current market leader, a plethora of kits are available and it can be difficult for the users to determine which kit is the most appropriate and efficient for their applications; the main concerns being not only cost but also minimal bias, yield and time efficiency. We compared 9 commercially available library preparation kits in a systematic manner using the same DNA sample by probing the amount of DNA remaining after each protocol steps using a new droplet digital PCR (ddPCR) assay. This method allows the precise quantification of fragments bearing either adaptors or P5/P7 sequences on both ends just after ligation or PCR enrichment. We also investigated the potential influence of DNA input and DNA fragment size on the final library preparation efficiency. The overall library preparations efficiencies of the libraries show important variations between the different kits with the ones combining several steps into a single one exhibiting some final yields 4 to 7 times higher than the other kits. Detailed ddPCR data also reveal that the adaptor ligation yield itself varies by more than a factor of 10 between kits, certain ligation efficiencies being so low that it could impair the original library complexity and impoverish the sequencing results. When a PCR enrichment step is necessary, lower adaptor-ligated DNA inputs leads to greater amplification yields, hiding the latent disparity between kits. We describe a ddPCR assay that allows us to probe the efficiency of the most critical step in the library preparation, ligation, and to draw conclusion on which kits is more likely to preserve the sample heterogeneity and reduce the need of amplification.

  13. Determination of leveled costs of electric generation for gas plants, coal and nuclear; Determinacion de costos nivelados de generacion electrica para plantas de gas, carbon y nucleares

    Energy Technology Data Exchange (ETDEWEB)

    Alonso V, G.; Palacios H, J.C.; Ramirez S, J.R.; Gomez, A. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)]. e-mail: galonso@nuclear.inin.mx

    2005-07-01

    The present work analyzes the leveled costs of electric generation for different types of nuclear reactors known as Generation III, these costs are compared with the leveled costs of electric generation of plants with the help of natural gas and coal. In the study several discount rates were used to determine their impact in the initial investment. The obtained results are comparable with similar studies and they show that it has more than enough the base of the leveled cost the nuclear option it is quite competitive in Mexico. Also in this study it is also thinks about the economic viability of a new nuclear power station in Mexico. (Author)

  14. Cost and greenhouse gas emission tradeoffs of alternative uses of lignin for second generation ethanol

    Science.gov (United States)

    Pourhashem, Ghasideh; Adler, Paul R.; McAloon, Andrew J.; Spatari, Sabrina

    2013-06-01

    Second generation ethanol bioconversion technologies are under demonstration-scale development for the production of lignocellulosic fuels to meet the US federal Renewable Fuel Standards (RFS2). Bioconversion technology utilizes the fermentable sugars generated from the cellulosic fraction of the feedstock, and most commonly assumes that the lignin fraction may be used as a source of thermal and electrical energy. We examine the life cycle greenhouse gas (GHG) emission and techno-economic cost tradeoffs for alternative uses of the lignin fraction of agricultural residues (corn stover, and wheat and barley straw) produced within a 2000 dry metric ton per day ethanol biorefinery in three locations in the United States. We compare three scenarios in which the lignin is (1) used as a land amendment to replace soil organic carbon (SOC); (2) separated, dried and sold as a coal substitute to produce electricity; and (3) used to produce electricity onsite at the biorefinery. Results from this analysis indicate that for life cycle GHG intensity, amending the lignin to land is lowest among the three ethanol production options (-25 to -2 g CO2e MJ-1), substituting coal with lignin is second lowest (4-32 g CO2e MJ-1), and onsite power generation is highest (36-41 g CO2e MJ-1). Moreover, the onsite power generation case may not meet RFS2 cellulosic fuel requirements given the uncertainty in electricity substitution. Options that use lignin for energy do so at the expense of SOC loss. The lignin-land amendment option has the lowest capital cost among the three options due to lower equipment costs for the biorefinery’s thermal energy needs and use of biogas generated onsite. The need to purchase electricity and uncertain market value of the lignin-land amendment could raise its cost compared to onsite power generation and electricity co-production. However, assuming a market value (50-100/dry Mg) for nutrient and soil carbon replacement in agricultural soils, and potentially

  15. Cost and greenhouse gas emission tradeoffs of alternative uses of lignin for second generation ethanol

    International Nuclear Information System (INIS)

    Pourhashem, Ghasideh; Spatari, Sabrina; Adler, Paul R; McAloon, Andrew J

    2013-01-01

    Second generation ethanol bioconversion technologies are under demonstration-scale development for the production of lignocellulosic fuels to meet the US federal Renewable Fuel Standards (RFS2). Bioconversion technology utilizes the fermentable sugars generated from the cellulosic fraction of the feedstock, and most commonly assumes that the lignin fraction may be used as a source of thermal and electrical energy. We examine the life cycle greenhouse gas (GHG) emission and techno-economic cost tradeoffs for alternative uses of the lignin fraction of agricultural residues (corn stover, and wheat and barley straw) produced within a 2000 dry metric ton per day ethanol biorefinery in three locations in the United States. We compare three scenarios in which the lignin is (1) used as a land amendment to replace soil organic carbon (SOC); (2) separated, dried and sold as a coal substitute to produce electricity; and (3) used to produce electricity onsite at the biorefinery. Results from this analysis indicate that for life cycle GHG intensity, amending the lignin to land is lowest among the three ethanol production options (−25 to −2 g CO 2 e MJ −1 ), substituting coal with lignin is second lowest (4–32 g CO 2 e MJ −1 ), and onsite power generation is highest (36–41 g CO 2 e MJ −1 ). Moreover, the onsite power generation case may not meet RFS2 cellulosic fuel requirements given the uncertainty in electricity substitution. Options that use lignin for energy do so at the expense of SOC loss. The lignin–land amendment option has the lowest capital cost among the three options due to lower equipment costs for the biorefinery’s thermal energy needs and use of biogas generated onsite. The need to purchase electricity and uncertain market value of the lignin–land amendment could raise its cost compared to onsite power generation and electricity co-production. However, assuming a market value ($50–$100/dry Mg) for nutrient and soil carbon replacement in

  16. Observation of the bremsstrahlung generation in the process of the Rayleigh endash Taylor instability development at gas puff implosion

    International Nuclear Information System (INIS)

    Baksht, R.B.; Fedunin, A.V.; Labetsky, A.Y.; Rousskich, A.G.; Shishlov, A.V.

    1997-01-01

    The electron magnetohydrodynamic model predicts the appearance of anode endash cathode voltage in the process of Rayleigh endash Taylor instability development during gas puff implosions. The appearance of the anode endash cathode voltage should be accompanied by the accelerated electron flow and the generation of the bremsstrahlung radiation. Experiments with neon and krypton gas puffs were performed on the GIT-4 [S. P. Bugaev, et al., Plasma Sci. 18, 115 (1990)] generator (1.6 MA, 120 ns) to observe the bremsstrahlung radiation during the gas puff implosion. Two spikes of the bremsstrahlung radiation were observed in the experiments. The first spike is connected with the gas breakdown; the second one is connected with the final stage of the implosion. The development of the RT instabilities does not initiate the bremsstrahlung radiation, therefore, the absence of anode endash cathode voltage is demonstrated. copyright 1997 American Institute of Physics

  17. Next-generation sequencing library preparation method for identification of RNA viruses on the Ion Torrent Sequencing Platform.

    Science.gov (United States)

    Chen, Guiqian; Qiu, Yuan; Zhuang, Qingye; Wang, Suchun; Wang, Tong; Chen, Jiming; Wang, Kaicheng

    2018-05-09

    Next generation sequencing (NGS) is a powerful tool for the characterization, discovery, and molecular identification of RNA viruses. There were multiple NGS library preparation methods published for strand-specific RNA-seq, but some methods are not suitable for identifying and characterizing RNA viruses. In this study, we report a NGS library preparation method to identify RNA viruses using the Ion Torrent PGM platform. The NGS sequencing adapters were directly inserted into the sequencing library through reverse transcription and polymerase chain reaction, without fragmentation and ligation of nucleic acids. The results show that this method is simple to perform, able to identify multiple species of RNA viruses in clinical samples.

  18. Influence of the gas phase composition on nanocrystalline diamond films prepared by MWCVD

    Czech Academy of Sciences Publication Activity Database

    Popov, C.; Jelínek, Miroslav; Boycheva, S.; Vorlíček, Vladimír; Kulisch, W.

    2005-01-01

    Roč. 23, - (2005), s. 31-34 ISSN 1422-6375 R&D Projects: GA AV ČR(CZ) IAA1010110 Grant - others:European Community Marie Curie Fellowship(XE) HPMF-CT-2002-01713 Institutional research plan: CEZ:AV0Z1010914 Keywords : microwave plasma CVD * nanocrystalline diamond films * characterization Subject RIV: BL - Plasma and Gas Discharge Physics

  19. Preparation of gas diffusion electrodes for high temperature PEM-type fuel cells

    Czech Academy of Sciences Publication Activity Database

    Mazur, P.; Mališ, J.; Paidar, M.; Schauer, Jan; Bouzek, K.

    2010-01-01

    Roč. 14, 1-3 (2010), s. 101-105 ISSN 1944-3994. [PERMEA 2009. Prague, 07.06.2009-11.06.2009] R&D Projects: GA ČR GA203/08/0465 Institutional research plan: CEZ:AV0Z40500505 Keywords : gas diffusion electrode * polymer electrolyte * ionic liquid Subject RIV: CD - Macromolecular Chemistry Impact factor: 0.752, year: 2010

  20. Process for generating substitute natural gas. Verfahren zur Erzeugung von Erdgasersatzgas

    Energy Technology Data Exchange (ETDEWEB)

    Messerschmidt, D

    1984-09-13

    The invention deals with a process for the production of a substitute for natural gas from coal gas or other feed gases containing hydrogen and methane. For a simpler and economically more efficient process it is suggested to separate the feed gas, purified or unpurified, by selection of the molar sieve in a PSA plant so that the sweep gas of the PSA plant can reach the quality of a substitute gas. (orig.).