Science.gov

Sample records for plant cycling operations

  1. Cycling operation of fossil plants

    SciTech Connect

    Bhatnagar, U.S.; Weiss, M.D.; White, W.H. ); Buchanan, T.L.; Harvey, L.E.; Shewchuk, P.K.; Weinstein, R.E. )

    1991-05-01

    This report presents a methodology for examining the economic feasibility of converting fossil power plants from baseload to cycling service. It employs this approach to examine a proposed change of Pepco's Potomac River units 3, 4, and 5 from baseload operation of two-shift cycling. The project team first reviewed all components and listed potential cycling effects involved in the conversion of Potomac River units 3, 4, and 5. They developed general cycling plant screening criteria including the number of hot, warm, or cold restart per year and desired load ramp rates. In addition, they evaluated specific limitations on the boiler, turbine, and the balance of plant. They estimated the remaining life of the facility through component evaluation and boiler testing and also identified and prioritized potential component deficiencies by their impact on key operational factors: safety, heat rate, turn down, startup/shutdown time, and plant availability. They developed solutions to these problems; and, since many solutions mitigate more than one problem, they combined and reprioritized these synergistic solutions. Economic assessments were performed on all solutions. 13 figs., 20 tabs.

  2. Operational strategies for dispatchable combined cycle plants, Part II

    SciTech Connect

    Nolan, J.P.; Landis, F.P.

    1996-11-01

    The Brush Cogeneration Facility is a dual-unit, combined cycle, cogeneration plant, operating in a dual cycling, automatically-dispatchable mode. Part I of this report described the contract, including automatic generation control (AGC) by Public Service Company of Colorado (PSCO), and the operation of Unit One. This part of the report covers the operation of Unit Two. Unit two is still in its operating infancy, but is showing that fuel efficiency and low emissions levels are not incompatible with cycling, load-following service. 1 fig.

  3. Investment and operating costs of binary cycle geothermal power plants

    NASA Technical Reports Server (NTRS)

    Holt, B.; Brugman, J.

    1974-01-01

    Typical investment and operating costs for geothermal power plants employing binary cycle technology and utilizing the heat energy in liquid-dominated reservoirs are discussed. These costs are developed as a function of reservoir temperature. The factors involved in optimizing plant design are discussed. A relationship between the value of electrical energy and the value of the heat energy in the reservoir is suggested.

  4. Integrated operation and management system for a 700MW combined cycle power plant

    SciTech Connect

    Shiroumaru, I. ); Iwamiya, T. ); Fukai, M. )

    1992-03-01

    Yanai Power Plant of the Chugoku Electric Power Co., Inc. (Yamaguchi Pref., Japan) is in the process of constructing a 1400MW state-of-the-art combined cycle power plant. The first phase, a 350MW power plant, started operation on a commercial basis in November, 1990. This power plant has achieved high efficiency and high operability, major features of a combined cycle power plant. The integrated operation and management system of the power plant takes care of operation, maintenance, control of general business, etc., and was built using the latest computer and digital control and communication technologies. This paper reports that it is expected that this system will enhance efficient operation and management for the power plant.

  5. Design and operation of a geopressurized-geothermal hybrid cycle power plant

    SciTech Connect

    Campbell, R.G.; Hattar, M.M.

    1991-02-01

    Geopressured-geothermal resources can contribute significantly to the national electricity supply once technical and economic obstacles are overcome. Power plant performance under the harsh conditions of a geopressured resource was unproven, so a demonstration power plant was built and operated on the Pleasant Bayou geopressured resource in Texas. This one megawatt facility provided valuable data over a range of operating conditions. This power plant was a first-of-a-kind demonstration of the hybrid cycle concept. A hybrid cycle was used to take advantage of the fact that geopressured resources contain energy in more than one form -- hot water and natural gas. Studies have shown that hybrid cycles can yield thirty percent more power than stand-alone geothermal and fossil fuel power plants operating on the same resource. In the hybrid cycle at Pleasant Bayou, gas was burned in engines to generate electricity directly. Exhaust heat from the engines was then combined with heat from the brine to generate additional electricity in a binary cycle. Heat from the gas engine was available at high temperature, thus improving the efficiency of the binary portion of the hybrid cycle. Design power output was achieved, and 3445 MWh of power were sold to the local utility over the course of the test. Plant availability was 97.5% and the capacity factor was over 80% for the extended run at maximum power production. The hybrid cycle power plant demonstrated that there are no technical obstacles to electricity generation at Pleasant Bayou. 14 refs., 38 figs., 16 tabs.

  6. Influence of the type of working fluid in the lower cycle and superheated steam parameters in the upper cycle on effectiveness of operation of binary power plant

    NASA Astrophysics Data System (ADS)

    Stachel, Aleksander A.; Wiśniewski, Sławomir

    2015-03-01

    In the paper presented have been the results of the analysis of effectiveness of operation of binary power plant consisting of combined two Clausius-Rankine cycles, namely the binary cycle with water as a working fluid in the upper cycle and organic substance as a working fluid in the lower cycle, as well as a single fluid component power plant operating also in line with the C-R cycle for superheated steam, with water as a working fluid. The influence of the parameters of superheated steam in the upper cycle has been assessed as well as the type of working fluid in the lower cycle. The results of calculations have been referred to the single-cycle classical steam power plant operating at the same parameters of superheated steam and the same mass flow rate of water circulating in both cycles. On the basis of accomplished analysis it has been shown that the binary power plant shows a greater power with respect to the reference power plant.

  7. Development of a protocol to optimize electric power consumption and life cycle environmental impacts for operation of wastewater treatment plant.

    PubMed

    Piao, Wenhua; Kim, Changwon; Cho, Sunja; Kim, Hyosoo; Kim, Minsoo; Kim, Yejin

    2016-12-01

    In wastewater treatment plants (WWTPs), the portion of operating costs related to electric power consumption is increasing. If the electric power consumption decreased, however, it would be difficult to comply with the effluent water quality requirements. A protocol was proposed to minimize the environmental impacts as well as to optimize the electric power consumption under the conditions needed to meet the effluent water quality standards in this study. This protocol was comprised of six phases of procedure and was tested using operating data from S-WWTP to prove its applicability. The 11 major operating variables were categorized into three groups using principal component analysis and K-mean cluster analysis. Life cycle assessment (LCA) was conducted for each group to deduce the optimal operating conditions for each operating state. Then, employing mathematical modeling, six improvement plans to reduce electric power consumption were deduced. The electric power consumptions for suggested plans were estimated using an artificial neural network. This was followed by a second round of LCA conducted on the plans. As a result, a set of optimized improvement plans were derived for each group that were able to optimize the electric power consumption and life cycle environmental impact, at the same time. Based on these test results, the WWTP operating management protocol presented in this study is deemed able to suggest optimal operating conditions under which power consumption can be optimized with minimal life cycle environmental impact, while allowing the plant to meet water quality requirements.

  8. Power Plant Cycling Costs

    SciTech Connect

    Kumar, N.; Besuner, P.; Lefton, S.; Agan, D.; Hilleman, D.

    2012-07-01

    This report provides a detailed review of the most up to date data available on power plant cycling costs. The primary objective of this report is to increase awareness of power plant cycling cost, the use of these costs in renewable integration studies and to stimulate debate between policymakers, system dispatchers, plant personnel and power utilities.

  9. Effectiveness of Operation of Organic Rankine Cycle Installation Applied in the Liquid Natural Gas Regasification Plant

    NASA Astrophysics Data System (ADS)

    Kaczmarek, R.; Stachel, A. A.

    2017-05-01

    An analysis of the operation of an Organic Rankine Cycle (ORC) installation heated by a low-temperature heat source is presented for the case where a condenser of a working fluid is cooled by a liquid of ultralow temperature. For this purpose, the process of regasification of liquid natural gas (LNG) is considered. In the process, the condensation heat of the working fluid in ORC is taken by the LNG evaporating subsequently (i.e., undergoing regasification). The paper presents the schematic of this installation and its application, as well as the results of calculations on the basis of the analysis in terms of the power and efficiency. In the analysis, organic fluids used in the ORC as working ones have been selected.

  10. Design and operation of a geopressured-geothermal hybrid cycle power plant

    SciTech Connect

    Campbell, R.G.; Hattar, M.M.

    1991-02-01

    The following appendices are included: process flow diagram, piping and instrumentation diagram, new equipment specifications, main single line diagram, shutdown and start-up procedures, data sheets for tests, plant outages, detailed process equations, computer program and sample output, chemical analysis and scanning electron microscopy results, and management report data sheets for January 5, 1990 to May 29, 1990. (MHR)

  11. Design and operation of a geopressurized-geothermal hybrid cycle power plant

    SciTech Connect

    Campbell, R.G.; Hattar, M.M.

    1991-02-01

    This is an appendix to Volume 1 of the report by the same name. Items included are: process flow diagram; piping and instrumentation diagram; new equipment specifications; main single line diagram; shutdown start-up procedures; data sheets for tests; plant outages; detailed process equations; computer program and sample output; chemical analysis and scanning electron microscopy results; and management report data sheets January 5, 1990 -- May 29, 1990.

  12. Thermal and environmental characteristics of the primary equipment of the 480-MW Razdan-5 power-generating plant operating as a combined-cycle plant

    NASA Astrophysics Data System (ADS)

    Sargsyan, K. B.; Eritsyan, S. Kh.; Petrosyan, G. S.; Avtandilyan, A. V.; Gevorkyan, A. R.; Klub, M. V.

    2015-01-01

    Results of thermal tests of 480-MW power-generating Unit 5 of Razdan Thermal Power Plant (hereinafter, Razdan-5 power unit) are presented. The tests were carried out by LvivORGRES after an integration trial of the power unit. The aim of the tests was thermal characterization of the steam boiler and the steam turbine when the power unit operates as a combined-cycle plant. The economic efficiency of the boiler and the turbine and the environmental characteristics of the power unit are determined and the calculated and the actual values are compared. The specific heat gross and net rates required for the power unit to generate the electric power are established.

  13. Design possibilities and peformance of combined cycle operation of converted steam power plants

    SciTech Connect

    Linnemeijer, M.J.J.; Van Buijtenen, J.P. )

    1988-01-01

    An interesting method for boosting thermal efficiency and/or power output of an existing steam power plant is repowering through the addition of gas turbines. The forced draught fan is replaced by a gas turbine and the air heater by low-temperature economisers. This conversion will change the performance of the installation significantly. Therefore the design of the existing installation has to be reviewed based on new unit performance calculations. Since the conversion has to be economical, it is important to find a good compromise between investment and improvement of performance. This paper describes the change in performance of the installation created by the conversion in general and a number of design possibilities based on the experience gained with the realization of a number of conversion projects.

  14. Deoxygenation in cycling fossil plants

    SciTech Connect

    Pearl, W.L.; Hobart, R.L.; Hook, T.A.; McNea, D.A. )

    1992-04-01

    In a previous EPRI study (Phase 1 of RP1184-9) at the Port Everglades plant of Florida Power and Light, it was demonstrated that minimizing shutdown oxygen levels at a cycling plant could reduce corrosion product transport to the boilers. A continuation of the program was performed to demonstrate the use of two forms of activated carbon to catalyze the hydrazine/oxygen reaction as a method to minimize the oxygen levels of cycling fossil plants. An activated carbon impregnated fiber overlay on a powdered resin precoat was tested at TU Electric's Tradinghouse Creek Unit 1 and a carbon bed followed by a deep bed demineralizer was tested at Duquesne's Elrama Unit 4. The improvement in attainable oxygen control was demonstrated and the effect on corrosion product transport during cyclic operation was evaluated. The study also demonstrated the application of a data acquisition system for prompt data assessment, control of chemical additions, identification of problems, and development of responsive corrective actions.

  15. Proceedings: 1990 fossil plant cycling conference

    SciTech Connect

    Not Available

    1991-12-01

    Fossil plant cycling continues to be a key issue for many electric utilities. EPRI's previous cycling workshops, held in 1983, 1985, and 1987, allowed utilities to benefit from collective industry experience in the conversion of baseload fossil units to cyclic operation. Continued improvements in equipment, retrofits, diagnostics, and controls were highlighted at the 1990 conference. The objective is to provide a forum for utility discussions of the cycling operation of fossil fuel power plants. Potomac Electric Power Company (PEPCO) hosted the 1990 EPRI Fossil Fuel Cycling Conference in Washington, DC, on December 4--6, 1990. More than 130 representatives from utilities, vendors, government agencies, universities, and industry associations attended the conference. Following the general session, technical sessions covered such topics as plant modifications, utility retrofit experience, cycling economics, life assessment, controls, environmental controls, and energy storage. Attendees also toured PEPCO's Potomac River generating station, the site of an earlier EPRI cycling conversion study.

  16. Cycling Through Plants

    ERIC Educational Resources Information Center

    Cavallo, Ann

    2005-01-01

    Children notice seeds and plants every day. But do they really understand what seeds are and how they are related to plants? Have they ever observed what is inside the seed? What happens to the "things" inside a seed when it grows? What do plants need to grow, and what do they need to stay healthy? Through a sequence of three related learning…

  17. Cycling Through Plants

    ERIC Educational Resources Information Center

    Cavallo, Ann

    2005-01-01

    Children notice seeds and plants every day. But do they really understand what seeds are and how they are related to plants? Have they ever observed what is inside the seed? What happens to the "things" inside a seed when it grows? What do plants need to grow, and what do they need to stay healthy? Through a sequence of three related learning…

  18. Thermodynamics of combined cycle plant

    NASA Astrophysics Data System (ADS)

    Crane, R. I.

    The fundamental thermodynamics of power plants including definitions of performance criteria and an introduction to exergy are reviewed, and treatments of simplified performance calculations for the components which form the major building blocks and a gas/steam combined cycle plant are given: the gas turbine, the heat recovery steam generator, and the remainder of the steam plant. Efficiency relationships and energy and exergy analyses of combined cycle plant are presented, with examples. Among the aspects considered are gas turbine performance characteristics and fuels, temperature differences for heat recovery, multiple steam pressures and reheat, supplementary firing and feed water heating. Attention is drawn to points of thermodynamic interest arising from applications of combined cycle plant to repowering of existing steam plant and to combined heat and power (cogeneration); some advances, including coal firing, are also introduced.

  19. Operational, control and protective system transient analyses of the closed-cycle GT-HTGR power plant

    SciTech Connect

    Openshaw, F.L.; Chan, T.W.

    1980-07-01

    This paper presents a description of the analyses of the control/protective system preliminary designs for the gas turbine high-temperature gas-cooled reactor (GT-HTGR) power plant. The control system is designed to regulate reactor power, control electric load and turbine speed, control the temperature of the helium delivered to the turbines, and control thermal transients experienced by the system components. In addition, it provides the required control programming for startup, shutdown, load ramp, and other expected operations. The control system also handles conditions imposed on the system during upset and emergency conditions such as loop trip, reactor trip, or electrical load rejection.

  20. Parabolic Trough Organic Rankine Cycle Power Plant

    SciTech Connect

    Canada, S.; Cohen, G.; Cable, R.; Brosseau, D.; Price, H.

    2005-01-01

    Arizona Public Service (APS) is required to generate a portion of its electricity from solar resources in order to satisfy its obligation under the Arizona Environmental Portfolio Standard (EPS). In recent years, APS has installed and operates over 4.5 MWe of fixed, tracking, and concentrating photovoltaic systems to help meet the solar portion of this obligation and to develop an understanding of which solar technologies provide the best cost and performance to meet utility needs. During FY04, APS began construction of a 1-MWe parabolic trough concentrating solar power plant. This plant represents the first parabolic trough plant to begin construction since 1991. The plant will also be the first commercial deployment of the Solargenix parabolic trough collector technology developed under contract to the National Renewable Energy Laboratory (NREL). The plant will use an organic Rankine cycle (ORC) power plant, provided by Ormat. The ORC power plant is much simpler than a conventional steam Rankine cycle power plant and allows unattended operation of the facility.

  1. Operational analysis of open-cycle MHD

    NASA Astrophysics Data System (ADS)

    Lippert, T. E.; McCutchan, D. A.

    1980-07-01

    Open cycle magnetohydrodynamic (OCMHD) conceptual power plant designs are studied in the context of a utility system to form a better basis for understanding their design, design requirements, and market possibilities. Based on assumed or projected plant costs and performance characteristics, assumed economics and escalation factors, and one coal supply and delivery scenario, overall and regional OCMHD utility market possibilities are reviewed. Additionally, for one hypothetical utility system a generation expansion plan is developed that includes OCMHD as a baseload power generating station. The impact on generation system economics and operation of alternating selected MHD plant cost and performance characteristics is reviewed. Baseload plant availability is shown as an important plant design consideration, and a general methodology and data base is developed to assess the impact on design and cost of various reliability decisions. An overall plant availability goal is set and the required availabilities of various MHD high technology components are derived to meet the plant goal. The approach is then extended to projecting channel life goals for various plant design configurations and assumptions.

  2. Rigorous Kinetic Modeling, Optimization, and Operability Studies of a Modified Claus Unit for an Integrated Gasification Combined Cycle (IGCC) Power Plant with CO{sub 2} Capture

    SciTech Connect

    Jones, Dustin; Bhattacharyya, Debangsu; Turton, Richard; Zitney, Stephen E

    2011-12-15

    The modified Claus process is one of the most common technologies for sulfur recovery from acid gas streams. Important design criteria for the Claus unit, when part of an Integrated Gasification Combined Cycle (IGCC) power plant, are the ability to destroy ammonia completely and the ability to recover sulfur thoroughly from a relatively low purity acid gas stream without sacrificing flame stability. Because of these criteria, modifications to the conventional process are often required, resulting in a modified Claus process. For the studies discussed here, these modifications include the use of a 95% pure oxygen stream as the oxidant, a split flow configuration, and the preheating of the feeds with the intermediate pressure steam generated in the waste heat boiler (WHB). In the future, for IGCC plants with CO{sub 2} capture, the Claus unit must satisfy emission standards without sacrificing the plant efficiency in the face of typical disturbances of an IGCC plant, such as rapid change in the feed flow rates due to load-following and wide changes in the feed composition because of changes in the coal feed to the gasifier. The Claus unit should be adequately designed and efficiently operated to satisfy these objectives. Even though the Claus process has been commercialized for decades, most papers concerned with the modeling of the Claus process treat the key reactions as equilibrium reactions. Such models are validated by manipulating the temperature approach to equilibrium for a set of steady-state operating data, but they are of limited use for dynamic studies. One of the objectives of this study is to develop a model that can be used for dynamic studies. In a Claus process, especially in the furnace and the WHB, many reactions may take place. In this work, a set of linearly independent reactions has been identified, and kinetic models of the furnace flame and anoxic zones, WHB, and catalytic reactors have been developed. To facilitate the modeling of the Claus

  3. Waste Water Plant Operators Manual.

    ERIC Educational Resources Information Center

    Washington State Coordinating Council for Occupational Education, Olympia.

    This manual for sewage treatment plant operators was prepared by a committee of operators, educators, and engineers for use as a reference text and handbook and to serve as a training manual for short course and certification programs. Sewage treatment plant operators have a responsibility in water quality control; they are the principal actors in…

  4. Deoxygenation in cycling fossil plants. Final report

    SciTech Connect

    Pearl, W.L.; Hobart, R.L.; Hook, T.A.; McNea, D.A.

    1992-04-01

    In a previous EPRI study (Phase 1 of RP1184-9) at the Port Everglades plant of Florida Power and Light, it was demonstrated that minimizing shutdown oxygen levels at a cycling plant could reduce corrosion product transport to the boilers. A continuation of the program was performed to demonstrate the use of two forms of activated carbon to catalyze the hydrazine/oxygen reaction as a method to minimize the oxygen levels of cycling fossil plants. An activated carbon impregnated fiber overlay on a powdered resin precoat was tested at TU Electric`s Tradinghouse Creek Unit 1 and a carbon bed followed by a deep bed demineralizer was tested at Duquesne`s Elrama Unit 4. The improvement in attainable oxygen control was demonstrated and the effect on corrosion product transport during cyclic operation was evaluated. The study also demonstrated the application of a data acquisition system for prompt data assessment, control of chemical additions, identification of problems, and development of responsive corrective actions.

  5. Integrating hospital and physician revenue cycle operations.

    PubMed

    Lockett, Kevin M

    2014-03-01

    Standardized revenue cycle processes should be a key component of the coordinated care delivery strategy organizations will require to complete the transition to population health management. Integrating hospital and physician revenue cycle operations can help organizations better navigate new payment models, reduce costs, and improve value. The most comprehensive approach involves integrating patient access and registration, coding operations, and receivables management across different settings.

  6. Diagnosing Physical Plant Operation

    ERIC Educational Resources Information Center

    McKay, B. P.; Smith, H. W.

    1972-01-01

    Describes a survey designed to help administrators evaluate functional aspects, adequacy of employee work areas, quality of housekeeping methods, maintenance response, interior and exterior appearances, alteration and renovation satisfaction, employee feelings about parking adequacy, plant security, and attraction and function of roads and…

  7. Operate a Nuclear Power Plant.

    ERIC Educational Resources Information Center

    Frimpter, Bonnie J.; And Others

    1983-01-01

    Describes classroom use of a computer program originally published in Creative Computing magazine. "The Nuclear Power Plant" (runs on Apple II with 48K memory) simulates the operating of a nuclear generating station, requiring students to make decisions as they assume the task of managing the plant. (JN)

  8. Operate a Nuclear Power Plant.

    ERIC Educational Resources Information Center

    Frimpter, Bonnie J.; And Others

    1983-01-01

    Describes classroom use of a computer program originally published in Creative Computing magazine. "The Nuclear Power Plant" (runs on Apple II with 48K memory) simulates the operating of a nuclear generating station, requiring students to make decisions as they assume the task of managing the plant. (JN)

  9. A Learning Cycle Inquiry into Plant Nutrition.

    ERIC Educational Resources Information Center

    Lee, Cherin A.

    2003-01-01

    Describes an investigation on plant nutrition that was developed in the form of a guided inquiry learning cycle and can be implemented in a wide range of grade levels from middle school through college. Investigates the needs of plants to live. (Contains 17 references.) (YDS)

  10. Use and recovery of ammonia in power plant cycles

    SciTech Connect

    Pflug, H.D.; Bettenworth, H.J.; Syring, H.A.

    1995-01-01

    The paper presents some practical and theoretical aspects of the use of ammonia in power plant water/steam cycles. The plants considered are fully automated units with once-through boilers, which operate under complex conditions and are subject to frequent starts and load changes. The boilers are chemically conditioned with combined oxygen ammonia treatment and the condensate polishing plant is only operated during start-up, in the event of a condenser leak or to remove excess ammonia. The paper also covers the recovery of ammonia from the condensate polishing plant waste regenerants and reuse for conditioning the feedwater. In particular, the paper deals with the following points: theoretical analysis of the chemical equilibrium of ammonia and carbon dioxide in water, including calculation of the concentrations from the parameters normally measured, such as conductivities and pH; equipment for monitoring and controlling the amount of ammonia fed to the water/steam cycle, including the optimum positioning of the sampling and feed-points, the parameters suitable for feed control and their temperature dependence; the partial pressure and distribution coefficient of ammonia; the consumption and losses of ammonia through the water/steam cycle during operation; the recovery of ammonia from condensate polishing plant waste regenerants by steam stripping. The paper should be of interest to both planning engineers and plant operators.

  11. Modern geothermal power: Binary cycle geothermal power plants

    NASA Astrophysics Data System (ADS)

    Tomarov, G. V.; Shipkov, A. A.

    2017-04-01

    In the second part of the review of modern geothermal power plant technologies and equipment, a role, a usage scale, and features of application of binary cycle plants in the geothermal economy are considered. Data on the use of low-boiling fluids, their impact on thermal parameters and performance of geothermal binary power units are presented. A retrospective of the use of various low-boiling fluids in industrial binary power units in the world since 1965 is shown. It is noted that the current generating capacity of binary power units running on hydrocarbons is equal to approximately 82.7% of the total installed capacity of all the binary power units in the world. At the same time over the past 5 years, the total installed capacity of geothermal binary power units in 25 countries increased by more than 50%, reaching nearly 1800 MW (hereinafter electric power is indicated), by 2015. A vast majority of the existing binary power plants recovers heat of geothermal fluid in the range of 100-200°C. Binary cycle power plants have an average unit capacity of 6.3 MW, 30.4 MW at single-flash power plants, 37.4 MW at double-flash plants, and 45.4 MW at power plants working on superheated steam. The largest binary cycle geothermal power plants (GeoPP) with an installed capacity of over 60 MW are in operation in the United States and the Philippines. In most cases, binary plants are involved in the production process together with a steam cycle. Requirements to the fluid ensuring safety, reliability, and efficiency of binary power plants using heat of geothermal fluid are determined, and differences and features of their technological processes are shown. Application of binary cycle plants in the technological process of combined GeoPPs makes it possible to recover geothermal fluid more efficiently. Features and advantages of binary cycle plants using multiple fluids, including a Kalina Cycle, are analyzed. Technical characteristics of binary cycle plants produced by various

  12. English for Petrochemical Plant Operators.

    ERIC Educational Resources Information Center

    Bynum, Henri Sue

    The development of a program and curriculum for instruction in technical English for Saudi Arabian petrochemical plant operator trainees studying in the United States for two years was undertaken by the University of South Alabama's English Language Center. The program was designed to accommodate (1) the degree of skills and prior learning of the…

  13. Method of optimizing performance of Rankine cycle power plants

    DOEpatents

    Pope, William L.; Pines, Howard S.; Doyle, Padraic A.; Silvester, Lenard F.

    1982-01-01

    A method for efficiently operating a Rankine cycle power plant (10) to maximize fuel utilization efficiency or energy conversion efficiency or minimize costs by selecting a turbine (22) fluid inlet state which is substantially in the area adjacent and including the transposed critical temperature line (46).

  14. Interplay between cell growth and cell cycle in plants.

    PubMed

    Sablowski, Robert; Carnier Dornelas, Marcelo

    2014-06-01

    The growth of organs and whole plants depends on both cell growth and cell-cycle progression, but the interaction between both processes is poorly understood. In plants, the balance between growth and cell-cycle progression requires coordinated regulation of four different processes: macromolecular synthesis (cytoplasmic growth), turgor-driven cell-wall extension, mitotic cycle, and endocycle. Potential feedbacks between these processes include a cell-size checkpoint operating before DNA synthesis and a link between DNA contents and maximum cell size. In addition, key intercellular signals and growth regulatory genes appear to target at the same time cell-cycle and cell-growth functions. For example, auxin, gibberellin, and brassinosteroid all have parallel links to cell-cycle progression (through S-phase Cyclin D-CDK and the anaphase-promoting complex) and cell-wall functions (through cell-wall extensibility or microtubule dynamics). Another intercellular signal mediated by microtubule dynamics is the mechanical stress caused by growth of interconnected cells. Superimposed on developmental controls, sugar signalling through the TOR pathway has recently emerged as a central control point linking cytoplasmic growth, cell-cycle and cell-wall functions. Recent progress in quantitative imaging and computational modelling will facilitate analysis of the multiple interconnections between plant cell growth and cell cycle and ultimately will be required for the predictive manipulation of plant growth.

  15. Combined cycle power plant incorporating coal gasification

    DOEpatents

    Liljedahl, Gregory N.; Moffat, Bruce K.

    1981-01-01

    A combined cycle power plant incorporating a coal gasifier as the energy source. The gases leaving the coal gasifier pass through a liquid couplant heat exchanger before being used to drive a gas turbine. The exhaust gases of the gas turbine are used to generate both high pressure and low pressure steam for driving a steam turbine, before being exhausted to the atmosphere.

  16. Vuilleumier cycle cryocooler operating below 8 K

    NASA Technical Reports Server (NTRS)

    Matsubara, Y.; Kaneko, M.

    1985-01-01

    This paper describes the design and development of a Vuilleumier cycle cryocooler (VM cooler) operating below 8 K, for the application of small superconducting devices. Liquid nitrogen has been used as a heat sink of the hot displacer. The annular gap between the phenolic displacer and SUS 304 stainless cylinder has been used as a gap regenerator. In order to obtain the cooling temperature below 3 K, we designed a single stage VM cooler which is precooled to 10 K by another two stage VM cooler. The effect of the mean operating pressure, cycle speed and phase difference between the hot and cold displacer of each VM cooler will be also discussed, including the experimental results.

  17. Model Predictive Control of Integrated Gasification Combined Cycle Power Plants

    SciTech Connect

    B. Wayne Bequette; Priyadarshi Mahapatra

    2010-08-31

    The primary project objectives were to understand how the process design of an integrated gasification combined cycle (IGCC) power plant affects the dynamic operability and controllability of the process. Steady-state and dynamic simulation models were developed to predict the process behavior during typical transients that occur in plant operation. Advanced control strategies were developed to improve the ability of the process to follow changes in the power load demand, and to improve performance during transitions between power levels. Another objective of the proposed work was to educate graduate and undergraduate students in the application of process systems and control to coal technology. Educational materials were developed for use in engineering courses to further broaden this exposure to many students. ASPENTECH software was used to perform steady-state and dynamic simulations of an IGCC power plant. Linear systems analysis techniques were used to assess the steady-state and dynamic operability of the power plant under various plant operating conditions. Model predictive control (MPC) strategies were developed to improve the dynamic operation of the power plants. MATLAB and SIMULINK software were used for systems analysis and control system design, and the SIMULINK functionality in ASPEN DYNAMICS was used to test the control strategies on the simulated process. Project funds were used to support a Ph.D. student to receive education and training in coal technology and the application of modeling and simulation techniques.

  18. Single stage rankine and cycle power plant

    SciTech Connect

    Closs, J.J.

    1981-10-13

    The specification describes a Rankine cycle power plant of the single stage type energized by gasified freon, the latter being derived from freon in the liquid state in a boiler provided in the form of a radio frequency heating cell adapted at low energy input to effect a rapid change of state from liquid freon at a given temperature and pressure to gaseous freon of relatively large volume, thereby to drive a Rankine cycle type of engine recognized in the prior art as a steam engine type of engine of the piston or turbine type.

  19. Modeling Tritium Life cycle in Nuclear Plants

    SciTech Connect

    Hussey, D.; Saunders, P.; Morey, D.; Pitt, N.; Wilson, J.; Claes, B.

    2006-07-01

    The mathematical development of a tritium model for nuclear power plants is presented. The model requires that the water and tritium material balance be satisfied throughout normal operations and shutdown. The model results obtained at the time of publishing include the system definitions and comparison of the model predictions of tritium generations compared to the observed plant data of the Braidwood station. A scenario that models using ion exchange resin to remove coolant boron demonstrates the tritium concentration levels are manageable. (authors)

  20. Simultaneous production of desalinated water and power using a hybrid-cycle OTEC plant

    SciTech Connect

    Panchal, C.B.; Bell, K.J.

    1987-05-01

    A systems study for simultaneous production of desalinated water and electric power using the hybrid-cycle OTEC system was carried out. The hybrid cycle is a combination of open and closed-cycle OTEC systems. A 10 MWe shore-based hybrid-cycle OTEC plant is discussed and corresponding operating parameters are presented. Design and plant operating criteria for adjusting the ratio of water production to power generation are described and their effects on the total system were evaluated. The systems study showed technical advantages of the hybrid-cycle power system as compared to other leading OTEC systems for simultaneous production of desalinated water and electric power generation.

  1. 14 CFR 121.434 - Operating experience, operating cycles, and consolidation of knowledge and skills.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Operating experience, operating cycles, and... Qualifications § 121.434 Operating experience, operating cycles, and consolidation of knowledge and skills. Link... completed, on that type airplane and in that crewmember position, the operating experience, operating cycles...

  2. Plant operation report and daily operation summary

    SciTech Connect

    Not Available

    1985-01-01

    The operational, maintenance and evaluation activities and highlights that were required during the month of February 1985 are summarized for the Central Receiver System and the Distributed Collector System. (BCS)

  3. Plant operation report and daily operation summary

    SciTech Connect

    Not Available

    1985-03-01

    The operational, maintenance and evaluation activities and highlights that were required during the month of March 1985 for the Central Receiver System (CRS) and the Distributed Collector System (DCS) are summarized. Both the CRS and the DCS suffered serious reductions in their operational ability; the CRS due to a pending trace heating repair. The DCS was out of service due to a failure in the Power Conversion System feedwater pump. (BCS)

  4. Taxonomy of the nuclear plant operator's role

    SciTech Connect

    Kisner, R.A.; Fullerton, A.M.; Frey, P.R.; Dougherty, E.M.

    1981-01-01

    A program is presently under way at the Oak Ridge National Laboratory (ORNL) to define the functional design requirements of operational aids for nuclear power plant operators. A first and important step in defining these requirements is to develop an understanding of the operator's role or function. This paper describes a taxonomy of operator functions that applies during all operational modes and conditions of the plant. Other topics such as the influence of automation, role acceptance, and the operator's role during emergencies are also discussed. This systematic approach has revealed several areas which have potential for improving the operator's ability to perform his role.

  5. Combined cycle plants: Yesterday, today, and tomorrow (review)

    NASA Astrophysics Data System (ADS)

    Ol'khovskii, G. G.

    2016-07-01

    Gas turbine plants (GTP) for a long time have been developed by means of increasing the initial gas temperature and improvement of the turbo-machines aerodynamics and the efficiency of the critical components air cooling within the framework of a simple thermodynamic cycle. The application of watercooling systems that were used in experimental turbines and studied approximately 50 years ago revealed the fundamental difficulties that prevented the practical implementation of such systems in the industrial GTPs. The steam cooling researches have developed more substantially. The 300 MW power GTPs with a closedloop steam cooling, connected in parallel with the intermediate steam heating line in the steam cycle of the combined cycle plant (CCP) have been built, tested, and put into operation. The designs and cycle arrangements of such GTPs and entire combined cycle steam plants have become substantially more complicated without significant economic benefits. As a result, the steam cooling of gas turbines has not become widespread. The cycles—complicated by the intermediate air cooling under compression and reheat of the combustion products under expansion and their heat recovery to raise the combustion chamber entry temperature of the air—were used, in particular, in the domestic power GTPs with a moderate (700-800°C) initial gas turbine entry temperature. At the temperatures being reached to date (1300-1450°C), only one company, Alstom, applies in their 240-300 MW GTPs the recycled fuel cycle under expansion of gases in the turbine. Although these GTPs are reliable, there are no significant advantages in terms of their economy. To make a forecast of the further improvement of power GTPs, a brief review and assessment of the water cooling and steam cooling of hot components and complication of the GTP cycle by the recycling of fuel under expansion of gases in the turbine has been made. It is quite likely in the long term to reach the efficiency for the

  6. The trigeneration cycle as a way to create multipurpose stationary power plants based on conversion of aeroderivative turbofan engines

    NASA Astrophysics Data System (ADS)

    Varaksin, A. Yu.; Arbekov, A. N.; Inozemtsev, A. A.

    2014-10-01

    A schematic cycle is considered, and thermodynamic analysis is performed to substantiate the possibility of creating multipurpose industrial power plants, operating on a trigeneration cycle, based on production-type turbofan engines.

  7. Peer groups and operational cycle enhancements to the performance indicator report

    SciTech Connect

    Stromberg, H.M.; DeHaan, M.S.; Gentillon, C.D.; Wilson, G.E.; Vanden Heuvel, L.N.

    1992-12-01

    Accurate performance evaluation and plant trending by the performance indicator program are integral parts of monitoring the operation of commercial nuclear power plants. The presentations of the NRC/AEOD performance indicator program have undergone a number of enhancements. The diversity of the commercial nuclear plants, coupled with continued improvements in the performance indicator program, has resulted in the evaluation of plants in logical peer groups and highlighted the need to evaluate the impact of plant operational conditions on the performance indicators. These enhancements allow a more-meaningful evaluation of operating commercial nuclear power plant performance. This report proposes methods to enhance the presentation of the performance indicator data by analyzing the data in logical peer groups and displaying the performance indicator data based on the operational status of the plants. Previously, preliminary development of the operational cycle displays of the performance indicator data was documented. This report extends the earlier findings and presents the continued development of the peer groups and operational cycle trend and deviation data and displays. This report describes the peer groups and enhanced PI data presentations by considering the operational cycle phase breakdowns, calculation methods, and presentation methods.

  8. Extension of the supercritical carbon dioxide brayton cycle to low reactor power operation: investigations using the coupled anl plant dynamics code-SAS4A/SASSYS-1 liquid metal reactor code system.

    SciTech Connect

    Moisseytsev, A.; Sienicki, J. J.

    2012-05-10

    Significant progress has been made on the development of a control strategy for the supercritical carbon dioxide (S-CO{sub 2}) Brayton cycle enabling removal of power from an autonomous load following Sodium-Cooled Fast Reactor (SFR) down to decay heat levels such that the S-CO{sub 2} cycle can be used to cool the reactor until decay heat can be removed by the normal shutdown heat removal system or a passive decay heat removal system such as Direct Reactor Auxiliary Cooling System (DRACS) loops with DRACS in-vessel heat exchangers. This capability of the new control strategy eliminates the need for use of a separate shutdown heat removal system which might also use supercritical CO{sub 2}. It has been found that this capability can be achieved by introducing a new control mechanism involving shaft speed control for the common shaft joining the turbine and two compressors following reduction of the load demand from the electrical grid to zero. Following disconnection of the generator from the electrical grid, heat is removed from the intermediate sodium circuit through the sodium-to-CO{sub 2} heat exchanger, the turbine solely drives the two compressors, and heat is rejected from the cycle through the CO{sub 2}-to-water cooler. To investigate the effectiveness of shaft speed control, calculations are carried out using the coupled Plant Dynamics Code-SAS4A/SASSYS-1 code for a linear load reduction transient for a 1000 MWt metallic-fueled SFR with autonomous load following. No deliberate motion of control rods or adjustment of sodium pump speeds is assumed to take place. It is assumed that the S-CO{sub 2} turbomachinery shaft speed linearly decreases from 100 to 20% nominal following reduction of grid load to zero. The reactor power is calculated to autonomously decrease down to 3% nominal providing a lengthy window in time for the switchover to the normal shutdown heat removal system or for a passive decay heat removal system to become effective. However, the

  9. University of Minnesota Physical Plant Operations.

    ERIC Educational Resources Information Center

    Minnesota State Office of the Legislative Auditor, St. Paul. Program Evaluation Div.

    In March 1988, the Office of the Legislative Auditor for the State of Minnesota conducted a program evaluation and financial audit of physical plant operations at the University of Minnesota's Twin Cities campus. The auditors examined the physical plant's management, financial, and personnel controls and the effectiveness and efficiency of…

  10. University of Minnesota Physical Plant Operations.

    ERIC Educational Resources Information Center

    Minnesota State Office of the Legislative Auditor, St. Paul. Program Evaluation Div.

    In March 1988, the Office of the Legislative Auditor for the State of Minnesota conducted a program evaluation and financial audit of physical plant operations at the University of Minnesota's Twin Cities campus. The auditors examined the physical plant's management, financial, and personnel controls and the effectiveness and efficiency of…

  11. Experience with organic Rankine cycles in heat recovery power plants

    SciTech Connect

    Bronicki, L.Y.; Elovic, A.; Rettger, P.

    1996-11-01

    Over the last 30 years, organic Rankine cycles (ORC) have been increasingly employed to produce power from various heat sources when other alternatives were either technically not feasible or economical. These power plants have logged a total of over 100 million turbine hours of experience demonstrating the maturity and field proven technology of the ORC cycle. The cycle is well adapted to low to moderate temperature heat sources such as waste heat from industrial plants and is widely used to recover energy from geothermal resources. The above cycle technology is well established and applicable to heat recovery of medium size gas turbines and offers significant advantages over conventional steam bottoming cycles.

  12. Electric power generating plant having direct-coupled steam and compressed-air cycles

    DOEpatents

    Drost, M.K.

    1981-01-07

    An electric power generating plant is provided with a Compressed Air Energy Storage (CAES) system which is directly coupled to the steam cycle of the generating plant. The CAES system is charged by the steam boiler during off peak hours, and drives a separate generator during peak load hours. The steam boiler load is thereby levelized throughout an operating day.

  13. Electric power generating plant having direct coupled steam and compressed air cycles

    DOEpatents

    Drost, Monte K.

    1982-01-01

    An electric power generating plant is provided with a Compressed Air Energy Storage (CAES) system which is directly coupled to the steam cycle of the generating plant. The CAES system is charged by the steam boiler during off peak hours, and drives a separate generator during peak load hours. The steam boiler load is thereby levelized throughout an operating day.

  14. Hybrid solar central receiver for combined cycle power plant

    DOEpatents

    Bharathan, Desikan; Bohn, Mark S.; Williams, Thomas A.

    1995-01-01

    A hybrid combined cycle power plant including a solar central receiver for receiving solar radiation and converting it to thermal energy. The power plant includes a molten salt heat transfer medium for transferring the thermal energy to an air heater. The air heater uses the thermal energy to preheat the air from the compressor of the gas cycle. The exhaust gases from the gas cycle are directed to a steam turbine for additional energy production.

  15. Hybrid solar central receiver for combined cycle power plant

    DOEpatents

    Bharathan, D.; Bohn, M.S.; Williams, T.A.

    1995-05-23

    A hybrid combined cycle power plant is described including a solar central receiver for receiving solar radiation and converting it to thermal energy. The power plant includes a molten salt heat transfer medium for transferring the thermal energy to an air heater. The air heater uses the thermal energy to preheat the air from the compressor of the gas cycle. The exhaust gases from the gas cycle are directed to a steam turbine for additional energy production. 1 figure.

  16. Inertial Fusion Power Plant Concept of Operations and Maintenance

    SciTech Connect

    Anklam, T.; Knutson, B.; Dunne, A. M.; Kasper, J.; Sheehan, T.; Lang, D.; Roberts, V.; Mau, D.

    2015-01-15

    Parsons and LLNL scientists and engineers performed design and engineering work for power plant pre-conceptual designs based on the anticipated laser fusion demonstrations at the National Ignition Facility (NIF). Work included identifying concepts of operations and maintenance (O&M) and associated requirements relevant to fusion power plant systems analysis. A laser fusion power plant would incorporate a large process and power conversion facility with a laser system and fusion engine serving as the heat source, based in part on some of the systems and technologies advanced at NIF. Process operations would be similar in scope to those used in chemical, oil refinery, and nuclear waste processing facilities, while power conversion operations would be similar to those used in commercial thermal power plants. While some aspects of the tritium fuel cycle can be based on existing technologies, many aspects of a laser fusion power plant presents several important and unique O&M requirements that demand new solutions. For example, onsite recovery of tritium; unique remote material handling systems for use in areas with high radiation, radioactive materials, or high temperatures; a five-year fusion engine target chamber replacement cycle with other annual and multi-year cycles anticipated for major maintenance of other systems, structures, and components (SSC); and unique SSC for fusion target waste recycling streams. This paper describes fusion power plant O&M concepts and requirements, how O&M requirements could be met in design, and how basic organizational and planning issues can be addressed for a safe, reliable, economic, and feasible fusion power plant.

  17. Inertial fusion power plant concept of operations and maintenance

    NASA Astrophysics Data System (ADS)

    Knutson, Brad; Dunne, Mike; Kasper, Jack; Sheehan, Timothy; Lang, Dwight; Anklam, Tom; Roberts, Valerie; Mau, Derek

    2015-02-01

    Parsons and LLNL scientists and engineers performed design and engineering work for power plant pre-conceptual designs based on the anticipated laser fusion demonstrations at the National Ignition Facility (NIF). Work included identifying concepts of operations and maintenance (O&M) and associated requirements relevant to fusion power plant systems analysis. A laser fusion power plant would incorporate a large process and power conversion facility with a laser system and fusion engine serving as the heat source, based in part on some of the systems and technologies advanced at NIF. Process operations would be similar in scope to those used in chemical, oil refinery, and nuclear waste processing facilities, while power conversion operations would be similar to those used in commercial thermal power plants. While some aspects of the tritium fuel cycle can be based on existing technologies, many aspects of a laser fusion power plant presents several important and unique O&M requirements that demand new solutions. For example, onsite recovery of tritium; unique remote material handling systems for use in areas with high radiation, radioactive materials, or high temperatures; a five-year fusion engine target chamber replacement cycle with other annual and multi-year cycles anticipated for major maintenance of other systems, structures, and components (SSC); and unique SSC for fusion target waste recycling streams. This paper describes fusion power plant O&M concepts and requirements, how O&M requirements could be met in design, and how basic organizational and planning issues can be addressed for a safe, reliable, economic, and feasible fusion power plant.

  18. 300 MW combined-cycle plant with integrated coal gasification

    SciTech Connect

    Kehlhofer, R.H.

    1984-09-01

    The main obstacle to further expansion of the combined cycle principle is its lack of fuel flexibility. To this day, gas turbines are still limited to gaseous or liquid fuels. This paper shows a viable way to add a cheap solid fuel, coal, to the list. The plant system in question is a 2 X 150 MW combined-cycle plant of BBC Brown Boveri with integrated coal gasification plant of British Gas/Lurgi. The main point of interest is that All the individual components of the power plant described in this paper have proven their worth commercially. It is therefore not a pilot plant but a viable commercial proposition.

  19. Water Treatment Technology - General Plant Operation.

    ERIC Educational Resources Information Center

    Ross-Harrington, Melinda; Kincaid, G. David

    One of twelve water treatment technology units, this student manual on general plant operations provides instructional materials for seven competencies. (The twelve units are designed for a continuing education training course for public water supply operators.) The competencies focus on the following areas: water supply regulations, water plant…

  20. Water Treatment Technology - General Plant Operation.

    ERIC Educational Resources Information Center

    Ross-Harrington, Melinda; Kincaid, G. David

    One of twelve water treatment technology units, this student manual on general plant operations provides instructional materials for seven competencies. (The twelve units are designed for a continuing education training course for public water supply operators.) The competencies focus on the following areas: water supply regulations, water plant…

  1. The effect of ultradian and orbital cycles on plant growth

    NASA Technical Reports Server (NTRS)

    Berry, W.; Hoshizaki, T.; Ulrich, A.

    1986-01-01

    In a series of experiments using sugar beets, researchers investigated the effects of varying cycles lengths on growth (0.37 hr to 48 hr). Each cycle was equally divided into a light and dark period so that each treatment regardless of cycle length received the same amount of light over the 17 weeks of the experiment. Two growth parameters were used to evaluate the effects of cycle length, total fresh weight and sucrose content of the storage root. Both parameters showed very similar responses in that under long cycles (12 hr or greater) growth was normal, whereas plants growing under shorter cycle periods were progressively inhibited. Minimum growth occurred at a cycle period of 0.75 hr. The yield at the 0.75 hr cycle, where was at a minimum, for total fresh weight was only 51 percent compared to the 24 hr cycle. The yield of sucrose was even more reduced at 41 percent of the 24 hr cycle.

  2. Raft River binary-cycle geothermal pilot power plant final report

    SciTech Connect

    Bliem, C.J.; Walrath, L.F.

    1983-04-01

    The design and performance of a 5-MW(e) binary-cycle pilot power plant that used a moderate-temperature hydrothermal resource, with isobutane as a working fluid, are examined. Operating problems experienced and solutions found are discussed and recommendations are made for improvements to future power plant designs. The plant and individual systems are analyzed for design specification versus actual performance figures.

  3. HLW flowsheet material balance for DWPF rad operation with Tank 51 sludge and ITP Cycle 1 precipitate

    SciTech Connect

    Choi, A.S.

    1995-04-19

    This document presents the details of the Savannah River Plant Flowsheet for the Rad Operation with Tank Sludge and ITP Cycle 1 Precipitate. Topics discussed include: material balance; radiolysis chemistry of tank precipitates; algorithm for ESP washing; chemistry of hydrogen and ammonia generation in CPC; batch sizes for processing feed; and total throughput of a streams during one cycle of operation.

  4. All-regime combined-cycle plant: Engineering solutions

    NASA Astrophysics Data System (ADS)

    Berezinets, P. A.; Tumanovskii, G. G.; Tereshina, G. E.; Krylova, I. N.; Markina, V. N.; Migun, E. N.

    2016-12-01

    The development of distributed power generation systems as a supplement to the centralized unified power grid increases the operational stability and efficiency of the entire power generation industry and improves the power supply to consumers. An all-regime cogeneration combined-cycle plant with a power of 20-25 mW (PGU-20/25T) and an electrical efficiency above 50% has been developed at the All-Russia Thermal Engineering Institute (ATEI) as a distributed power generation object. The PGU-20/25T two-circuit cogeneration plant provides a wide electrical and thermal power adjustment range and the absence of the mutual effect of electrical and thermal power output regimes at controlled frequency and power in a unified or isolated grid. The PGU-20/25T combined-cycle plant incorporates a gas-turbine unit (GTU) with a power of 16 MW, a heat recovery boiler (HRB) with two burners (before the boiler and the last heating stage), and a cogeneration steam turbine with a power of 6/9 MW. The PGU-20/25T plant has a maximum electrical power of 22 MW and an efficiency of 50.8% in the heat recovery regime and a maximum thermal power output of 16.3 MW (14 Gcal/h) in the cogeneration regime. The use of burners can increase the electrical power to 25 MW in the steam condensation regime at an efficiency of 49% and the maximum thermal power output to 29.5 MW (25.4 Gcal/h). When the steam turbine is shut down, the thermal power output can grow to 32.6 MW (28 Gcal/h). The innovative equipment, which was specially developed for PGU-20/25T, improves the reliability of this plant and simplifies its operation. Among this equipment are microflame burners in the heat recovery boiler, a vacuum system based on liquid-ring pumps, and a vacuum deaerator. To enable the application of PGU-20/25T in water-stressed regions, an air condenser preventing the heat-transfer tubes from the risk of covering with ice during operation in frost air has been developed. The vacuum system eliminates the need for

  5. Life Cycle Costs in Education: Operations & Maintenance Considered.

    ERIC Educational Resources Information Center

    Moussatche, Helena; Languell-Urquhart, Jennifer; Woodson, Carol

    2000-01-01

    Discusses life cycle cost analysis when deciding on flooring finishes and examines operations and maintenance cost effectiveness relative to hard, resilient, and soft flooring. A chart of evaluated flooring materials' characteristics, appropriate maintenance procedures, and recommended frequency is included. (GR)

  6. Maintenance Cycle Extension in the IRIS Advanced Light Water Reactor Plant Design

    SciTech Connect

    Galvin, Mark R.; Todreas, Neil E.; Conway, Larry E.

    2003-09-15

    New nuclear power generation in the United States will be realized only if the economic performance can be made competitive with other methods of electrical power generation. The economic performance of a nuclear power plant can be significantly improved by increasing the time spent on-line generating electricity relative to the time spent off-line conducting maintenance and refueling. Maintenance includes planned actions (surveillances) and unplanned actions (corrective maintenance) to respond to component degradation or failure. A methodology is described that can be used to resolve, in the design phase, maintenance-related operating cycle length barriers. A primary goal was to demonstrate the applicability and utility of the methodology in the context of the International Reactor, Innovative and Secure (IRIS) design. IRIS is an advanced light water nuclear power plant that is being designed to maximize this on-line generating time by increasing the operating cycle length. This is consequently a maintenance strategy paper using the IRIS plant as the example.Potential IRIS operating cycle length maintenance-related barriers, determined by modification of an earlier operating pressurized water reactor (PWR) plant cycle length analysis to account for differences between the design of IRIS and this operating PWR, are presented. The proposed methodology to resolve these maintenance-related barriers by the design process is described. The results of applying the methodology to two potential IRIS cycle length barriers, relief valve testing and emergency heat removal system testing, are presented.

  7. HTGR-GT closed-cycle gas turbine: a plant concept with inherent cogeneration (power plus heat production) capability

    SciTech Connect

    McDonald, C.F.

    1980-04-01

    The high-grade sensible heat rejection characteristic of the high-temperature gas-cooled reactor-gas turbine (HTGR-GT) plant is ideally suited to cogeneration. Cogeneration in this nuclear closed-cycle plant could include (1) bottoming Rankine cycle, (2) hot water or process steam production, (3) desalination, and (4) urban and industrial district heating. This paper discusses the HTGR-GT plant thermodynamic cycles, design features, and potential applications for the cogeneration operation modes. This paper concludes that the HTGR-GT plant, which can potentially approach a 50% overall efficiency in a combined cycle mode, can significantly aid national energy goals, particularly resource conservation.

  8. Performance analysis of an OTEC plant and a desalination plant using an integrated hybrid cycle

    SciTech Connect

    Uehara, Haruo; Miyara, Akio; Ikegami, Yasuyuki; Nakaoka, Tsutomu

    1996-05-01

    A performance analysis of an OTEC plant using an integrated hybrid cycle (I-H OTEC Cycle) has been conducted. The I-H OTEC cycle is a combination of a closed-cycle OTEC plant and a spray flash desalination plant. In an I-H OTEC cycle, warm sea water evaporates the liquid ammonia in the OTEC evaporator, then enters the flash chamber and evaporates itself. The evaporated steam enters the desalination condenser and is condensed by the cold sea water passed through the OTEC condenser. The optimization of the I-H OTEC cycle is analyzed by the method of steepest descent. The total heat transfer area of heat exchangers per net power is used as an objective function. Numerical results are reported for a 10 MW I-H OTEC cycle with plate-type heat exchangers and ammonia as working fluid. The results are compared with those of a joint hybrid OTEC cycle (J-H OTEC Cycle).

  9. Parametric analysis of closed cycle magnetohydrodynamic (MHD) power plants

    NASA Technical Reports Server (NTRS)

    Owens, W.; Berg, R.; Murthy, R.; Patten, J.

    1981-01-01

    A parametric analysis of closed cycle MHD power plants was performed which studied the technical feasibility, associated capital cost, and cost of electricity for the direct combustion of coal or coal derived fuel. Three reference plants, differing primarily in the method of coal conversion utilized, were defined. Reference Plant 1 used direct coal fired combustion while Reference Plants 2 and 3 employed on site integrated gasifiers. Reference Plant 2 used a pressurized gasifier while Reference Plant 3 used a ""state of the art' atmospheric gasifier. Thirty plant configurations were considered by using parametric variations from the Reference Plants. Parametric variations include the type of coal (Montana Rosebud or Illinois No. 6), clean up systems (hot or cold gas clean up), on or two stage atmospheric or pressurized direct fired coal combustors, and six different gasifier systems. Plant sizes ranged from 100 to 1000 MWe. Overall plant performance was calculated using two methodologies. In one task, the channel performance was assumed and the MHD topping cycle efficiencies were based on the assumed values. A second task involved rigorous calculations of channel performance (enthalpy extraction, isentropic efficiency and generator output) that verified the original (task one) assumptions. Closed cycle MHD capital costs were estimated for the task one plants; task two cost estimates were made for the channel and magnet only.

  10. Why should we study the plant cell cycle?

    PubMed

    Inzé, Dirk

    2003-04-01

    Description of the molecular biology of plant and animal cell cycles highlights similarities and critical differences. The cell cycle is a point of control in both growth and development and deepening understanding of underlying processes and mechanisms may have many practical applications.

  11. Plant operation report. Daily evaluation summary

    SciTech Connect

    Not Available

    1983-07-01

    The operation and maintenance of the IEA Small Solar Power Systems Project are reported, giving plant highlights, statistics, and cost data. The system includes both a distributed collector system and a central receiver system, for which monthly status data are given. (LEW)

  12. Operational development of small plant growth systems

    NASA Technical Reports Server (NTRS)

    Scheld, H. W.; Magnuson, J. W.; Sauer, R. L.

    1986-01-01

    The results of a study undertaken on the first phase of an empricial effort in the development of small plant growth chambers for production of salad type vegetables on space shuttle or space station are discussed. The overall effort is visualized as providing the underpinning of practical experience in handling of plant systems in space which will provide major support for future efforts in planning, design, and construction of plant-based (phytomechanical) systems for support of human habitation in space. The assumptions underlying the effort hold that large scale phytomechanical habitability support systems for future space stations must evolve from the simple to the complex. The highly complex final systems will be developed from the accumulated experience and data gathered from repetitive tests and trials of fragments or subsystems of the whole in an operational mode. These developing system components will, meanwhile, serve a useful operational function in providing psychological support and diversion for the crews.

  13. Operating data on a novel absorption refrigeration cycle. Progress report

    SciTech Connect

    McCluskey, R.J.

    1993-12-23

    This report describes the modifications and repairs made to the 200 ton absorption refrigeration pilot plant since April 1992, when Clarkson University assumed responsibility for it. Current operating problems and the performance of the plant, achieved to date, are detailed. Performance has been limited by small air leaks into the absorption section of the plant and by plugging in a heat exchanger which has limited the flow of purified glycol to the absorber. Nonetheless, the plant has been operated for periods of over eight hours with sustained cooling loads of 40 tons. Chilled water has been produced at a temperature as low as 38 degrees Fahrenheit. The principal leak sources have been pinpointed. Plans are described for achieving plant operation at designed levels.

  14. 47 CFR 32.6534 - Plant operations administration expense.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 2 2014-10-01 2014-10-01 false Plant operations administration expense. 32....6534 Plant operations administration expense. (a) This account shall include costs incurred in the general administration of plant operations. This includes supervising plant operations (except...

  15. 47 CFR 32.6534 - Plant operations administration expense.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 2 2012-10-01 2012-10-01 false Plant operations administration expense. 32....6534 Plant operations administration expense. (a) This account shall include costs incurred in the general administration of plant operations. This includes supervising plant operations (except...

  16. 47 CFR 32.6534 - Plant operations administration expense.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 2 2011-10-01 2011-10-01 false Plant operations administration expense. 32....6534 Plant operations administration expense. (a) This account shall include costs incurred in the general administration of plant operations. This includes supervising plant operations (except as...

  17. 47 CFR 32.6534 - Plant operations administration expense.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Plant operations administration expense. 32....6534 Plant operations administration expense. (a) This account shall include costs incurred in the general administration of plant operations. This includes supervising plant operations (except as...

  18. Carbon corrosion in PEM fuel cells during drive cycle operation

    DOE PAGES

    Borup, Rodney L.; Papadias, D. D.; Mukundan, Rangachary; ...

    2015-09-14

    One of the major contributors to degradation involves the electrocatalyst, including the corrosion of the carbons used as catalyst supports, which leads to changes in the catalyst layer structure. We have measured and quantified carbon corrosion during drive cycle operation and as a variation of the upper and lower potential limits used during drive cycle operation. The amount of carbon corrosion is exacerbated by the voltage cycling inherent in the drive cycle compared with constant potential operation. The potential gap between upper and lower potentials appears to be more important than the absolute operating potentials in the normal operating potentialmore » regime (0.40V to 0.95V) as changes in the measured carbon corrosion are similar when the upper potential was lower compared to raising the lower potential. Catalyst layer thinning was observed during the simulated drive cycle operation which had an associated decrease in catalyst layer porosity. This catalyst layer thinning is not due solely to carbon corrosion, although carbon corrosion likely plays a role; much of this thinning must be from compaction of the material in the catalyst layer. As a result, the decrease in catalyst layer porosity leads to additional performance losses due to mass transport losses.« less

  19. Carbon corrosion in PEM fuel cells during drive cycle operation

    SciTech Connect

    Borup, Rodney L.; Papadias, D. D.; Mukundan, Rangachary; Spernjak, Dusan; Langlois, David Alan; Ahluwalia, Rajesh; More, Karen L.; Grot, Steve

    2015-09-14

    One of the major contributors to degradation involves the electrocatalyst, including the corrosion of the carbons used as catalyst supports, which leads to changes in the catalyst layer structure. We have measured and quantified carbon corrosion during drive cycle operation and as a variation of the upper and lower potential limits used during drive cycle operation. The amount of carbon corrosion is exacerbated by the voltage cycling inherent in the drive cycle compared with constant potential operation. The potential gap between upper and lower potentials appears to be more important than the absolute operating potentials in the normal operating potential regime (0.40V to 0.95V) as changes in the measured carbon corrosion are similar when the upper potential was lower compared to raising the lower potential. Catalyst layer thinning was observed during the simulated drive cycle operation which had an associated decrease in catalyst layer porosity. This catalyst layer thinning is not due solely to carbon corrosion, although carbon corrosion likely plays a role; much of this thinning must be from compaction of the material in the catalyst layer. As a result, the decrease in catalyst layer porosity leads to additional performance losses due to mass transport losses.

  20. OPTIMAL DESIGN AND OPERATION OF HELIUM REFRIGERATION SYSTEMS USING THE GANNI CYCLE

    SciTech Connect

    Venkatarao Ganni, Peter Knudsen

    2010-04-01

    The constant pressure ratio process, as implemented in the floating pressure - Ganni cycle, is a new variation to prior cryogenic refrigeration and liquefaction cycle designs that allows for optimal operation and design of helium refrigeration systems. This cycle is based upon the traditional equipment used for helium refrigeration system designs, i.e., constant volume displacement compression and critical flow expansion devices. It takes advantage of the fact that for a given load, the expander sets the compressor discharge pressure and the compressor sets its own suction pressure. This cycle not only provides an essentially constant system Carnot efficiency over a wide load range, but invalidates the traditional philosophy that the (‘TS’) design condition is the optimal operating condition for a given load using the as-built hardware. As such, the Floating Pressure- Ganni Cycle is a solution to reduce the energy consumption while increasing the reliability, flexibility and stability of these systems over a wide operating range and different operating modes and is applicable to most of the existing plants. This paper explains the basic theory behind this cycle operation and contrasts it to the traditional operational philosophies presently used.

  1. Optimal Design and Operation of Helium Refrigeration Systems Using the Ganni Cycle

    NASA Astrophysics Data System (ADS)

    Ganni, V.; Knudsen, P.

    2010-04-01

    The constant pressure ratio process, as implemented in the floating pressure—Ganni cycle, is a new variation to prior cryogenic refrigeration and liquefaction cycle designs that allows for optimal operation and design of helium refrigeration systems. This cycle is based upon the traditional equipment used for helium refrigeration system designs, i.e., constant volume displacement compression and critical flow expansion devices. It takes advantage of the fact that for a given load, the expander sets the compressor discharge pressure and the compressor sets its own suction pressure. This cycle not only provides an essentially constant system Carnot efficiency over a wide load range, but invalidates the traditional philosophy that the (`TS') design condition is the optimal operating condition for a given load using the as-built hardware. As such, the Floating Pressure-Ganni Cycle is a solution to reduce the energy consumption while increasing the reliability, flexibility and stability of these systems over a wide operating range and different operating modes and is applicable to most of the existing plants. This paper explains the basic theory behind this cycle operation and contrasts it to the traditional operational philosophies presently used.

  2. Differential temperature operation of plant immune responses

    PubMed Central

    Cheng, Cheng; Gao, Xiquan; Feng, Baomin; Sheen, Jen; Shan, Libo; He, Ping

    2014-01-01

    Temperature fluctuation is a key determinant for microbial invasion and host evasion. In contrast to mammalians that maintain constant body temperature, plant temperature oscillates on a daily basis. It remains elusive how plants operate inducible defenses in response to temperature fluctuation. Here we report that ambient temperature changes lead to pronounced shifts of two distinct plant immune responses: pattern-triggered immunity (PTI) and effector-triggered immunity (ETI). Plants preferentially activate ETI signaling at relatively low temperatures (10~23°C), whereas they switch to PTI signaling at moderately elevated temperatures (23~32°C). The Arabidopsis arp6 and hta9hta11 mutants, phenocopying plants grown at the elevated temperatures, exhibit enhanced PTI and yet reduced ETI responses. As the secretion of bacterial effectors favors low temperatures whereas bacteria multiply vigorously at elevated temperatures accompanied with increased microbe-associated molecular pattern production, our findings suggest that temperature oscillation might have driven dynamic co-evolution of distinct plant immune signaling responding to pathogen physiological changes. PMID:24067909

  3. Plutonium purification cycle in centrifugal extractors: from flowsheet design to industrial operation

    SciTech Connect

    Baron, P.; Dinh, B.; Duhamet, J.; Drain, F.; Meze, F.; Lavenu, A.

    2008-07-01

    The extension of the UP2 plant at La Hague includes a new plutonium purification cycle using multistage centrifugal extractors to replace the previous cycle that used mixer/settler banks. This type of extractor is suitable for the treatment of fuel containing a high proportion of plutonium-238, as its short residence time limits solvent degradation. This paper deals with the research done to devise its flowsheet, the centrifugal extractors in which it is operated, as well as the feedback of six years of industrial operation.

  4. Safeguards operations in the integral fast reactor fuel cycle

    SciTech Connect

    Goff, K.M.; Benedict, R.W.; Brumbach, S.B.; Dickerman, C.E.; Tompot, R.W.

    1994-08-01

    Argonne National Laboratory is currently demonstrating the fuel cycle for the Integral Fast Reactor (IFR), an advanced reactor concept that takes advantage of the properties of metallic fuel and liquid metal cooling to offer significant improvements in reactor safety, operation, fuel-cycle economics, environmental protection, and safeguards. The IFR fuel cycle employs a pyrometallurgical process using molten salts and liquid metals to recover actinides from spent fuel. The safeguards aspects of the fuel cycle demonstration must be approved by the United States Department of Energy, but a further goal of the program is to develop a safeguards system that could gain acceptance from the Nuclear Regulatory Commission and International Atomic Energy Agency. This fuel cycle is described with emphasis on aspects that differ from aqueous reprocessing and on its improved safeguardability due to decreased attractiveness and diversion potential of all process streams, including the fuel product.

  5. Effect of fuel cycle length on plant performance and cost

    SciTech Connect

    O`Donnell, E.P.

    1996-08-01

    As competitive pressures increase in the utility industry, many nuclear units are moving to longer fuel cycles in order to increase capacity factors and lower cost. This paper reviews recent experience with longer cycle operation for both GPU Nuclear and the industry as a whole.

  6. Mammoth geothermal power plant: operation update

    SciTech Connect

    Campbell, R.G.; Holt, B.; Asper, W.

    1987-06-01

    The Mammoth Geothermal Power Plant, the world's first modular, air-cooled binary plant, was designed to produce a year-round average of 7 megawatts of electrical power, net. Firm power was first produced in February 1985. Reservoir performance has been excellent. There is no evidence of a decline in productivity, and injection well pressures have been lower than anticipated. Downhole pumps have been in operation over one year, without servicing. Early problems due to resonant frequencies in the turbine have been solved. Heat exchanger fouling has been as expected. The isobutane pumps and the air coolers have performed in accordance with expectations. Plans are underway to expand the geothermal development at Mammoth, employing the Magmamax process and the same environmentally benign design concepts. Design specification and operation are discussed.

  7. Method of optimizing performance of Rankine cycle power plants. [US DOE Patent

    DOEpatents

    Pope, W.L.; Pines, H.S.; Doyle, P.A.; Silvester, L.F.

    1980-06-23

    A method is described for efficiently operating a Rankine cycle power plant to maximize fuel utilization efficiency or energy conversion efficiency or minimize costs by selecting a turbine fluid inlet state which is substantially on the area adjacent and including the transposed critical temperature line.

  8. Innovative open air brayton combined cycle systems for the next generation nuclear power plants

    NASA Astrophysics Data System (ADS)

    Zohuri, Bahman

    The purpose of this research was to model and analyze a nuclear heated multi-turbine power conversion system operating with atmospheric air as the working fluid. The air is heated by a molten salt, or liquid metal, to gas heat exchanger reaching a peak temperature of 660 0C. The effects of adding a recuperator or a bottoming steam cycle have been addressed. The calculated results are intended to identify paths for future work on the next generation nuclear power plant (GEN-IV). This document describes the proposed system in sufficient detail to communicate a good understanding of the overall system, its components, and intended uses. The architecture is described at the conceptual level, and does not replace a detailed design document. The main part of the study focused on a Brayton --- Rankine Combined Cycle system and a Recuperated Brayton Cycle since they offer the highest overall efficiencies. Open Air Brayton power cycles also require low cooling water flows relative to other power cycles. Although the Recuperated Brayton Cycle achieves an overall efficiency slightly less that the Brayton --- Rankine Combined Cycle, it is completely free of a circulating water system and can be used in a desert climate. Detailed results of modeling a combined cycle Brayton-Rankine power conversion system are presented. The Rankine bottoming cycle appears to offer a slight efficiency advantage over the recuperated Brayton cycle. Both offer very significant advantages over current generation Light Water Reactor steam cycles. The combined cycle was optimized as a unit and lower pressure Rankine systems seem to be more efficient. The combined cycle requires a lot less circulating water than current power plants. The open-air Brayton systems appear to be worth investigating, if the higher temperatures predicted for the Next Generation Nuclear Plant do materialize.

  9. Ramjet-Mode Operation in a Combined Cycle Engine Combustor

    NASA Astrophysics Data System (ADS)

    Kato, Kanenori; Kudo, Kenji; Murakami, Atsuo; Tani, Kouichiro; Kanda, Takeshi

    A rocket-ramjet combined-cycle engine was tested in ramjet-mode. The combustor model had two rockets in the combustor section. They were used as an igniter in this operation mode. In the preliminary tests, the downstream combustion ramjet-mode was demonstrated with a 1.4-degree of divergent duct condition. In this study, the upstream and downstream combustion ramjet-mode operations were applied to the combined cycle engine model with large angle of divergent duct condition. In the case of upstream combustion ramjet-mode, the combustion condition at the exit of the combustor showed high combustion efficiency.

  10. The Conceptual Design of an Integrated Nuclearhydrogen Production Plant Using the Sulfur Cycle Water Decomposition System

    NASA Technical Reports Server (NTRS)

    Farbman, G. H.

    1976-01-01

    A hydrogen production plant was designed based on a hybrid electrolytic-thermochemical process for decomposing water. The sulfur cycle water decomposition system is driven by a very high temperature nuclear reactor that provides 1,283 K helium working gas. The plant is sized to approximately ten million standard cubic meters per day of electrolytically pure hydrogen and has an overall thermal efficiently of 45.2 percent. The economics of the plant were evaluated using ground rules which include a 1974 cost basis without escalation, financing structure and other economic factors. Taking into account capital, operation, maintenance and nuclear fuel cycle costs, the cost of product hydrogen was calculated at $5.96/std cu m for utility financing. These values are significantly lower than hydrogen costs from conventional water electrolysis plants and competitive with hydrogen from coal gasification plants.

  11. Thermal cycling can extend tool life in orthopaedic operating rooms.

    PubMed

    Katchky, Ryan N; McLachlin, Stewart D; Wong, Edwin K Y; Finkelstein, Joel; Kreder, Hans J; Whyne, Cari M

    2016-03-01

    Thermal cycling is a temperature modulation process developed to improve the performance, durability and longevity of materials. This process has been successfully utilized in the automotive, aeronautic and manufacturing industries. Surgical cutting tools undergo cyclical loading and generally fail by dulling, suggesting that thermal cycling may improve their performance and longevity. Ten 2.5 mm orthopaedic drill bits were randomized, with five undergoing thermal cycling within their sterile packaging and five serving as untreated controls. Using a servohydraulic testing machine, 100 drilling cycles were performed with each drill bit into the diaphyseal region of bovine femurs. After every 25 cycles, data was collected by performing identical drilling cycles into simulated human cortical bone material. Maximum force, maximum normalized torque and drilling work were measured, and a scanning electron microscope was used to measure outer corner wear. After 100 drilling cycles, the maximum drilling force, maximum normalized torque, drilling work and microscopic outer corner wear were all significantly lower for the treated drill bits (p < 0.05). Thermal cycling has the potential to decrease operating room costs and thermal necrosis associated with dull cutting tools. Application of this technology may also be relevant to surgical cutting tools such as saw blades, burrs and reamers. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  12. EXAMINING CONCEPT OF OPERATIONS IN FUTURE PLANTS.

    SciTech Connect

    O'HARA,J.M.HIGGINS,J.BROWN,W.KRAMER,J.PERSENSKY,J.

    2004-09-19

    This paper will examine the results of this research that focus on future concepts of operations. Our approach was to look at current technological developments in the areas of reactor technology, I&C technology, and human-system integration technology and to make projections into the near and longer-term future concerning their potential impact on human performance. The results were discussed in terms of three aspects of concepts of operations: functional staffing models, plant automation, and training and qualifications. Significant changes to each are anticipated and discussed. Research will be needed to address these changes in order to provide for confidence that changes to concepts of operations are accomplished in ways that maintain public safety.

  13. Modular Trough Power Plant Cycle and Systems Analysis

    SciTech Connect

    Price, H.; Hassani, V.

    2002-01-01

    This report summarizes an analysis to reduce the cost of power production from modular concentrating solar power plants through a relatively new and exciting concept that merges two mature technologies to produce distributed modular electric power in the range of 500 to 1,500 kWe. These are the organic Rankine cycle (ORC) power plant and the concentrating solar parabolic (CSP) trough technologies that have been developed independent of each other over many years.

  14. Life Cycle Assessment of the MBT plant in Ano Liossia, Athens, Greece

    SciTech Connect

    Abeliotis, Konstadinos; Kalogeropoulos, Alexandros; Lasaridi, Katia

    2012-01-15

    Highlights: Black-Right-Pointing-Pointer We model the operation of an MBT plant in Greece based on LCA. Black-Right-Pointing-Pointer We compare four different MBT operating scenarios (among them and with landfilling). Black-Right-Pointing-Pointer Even the current operation of the MBT plant is preferable to landfilling. Black-Right-Pointing-Pointer Utilization of the MBT compost and metals generates the most environmental gains. Black-Right-Pointing-Pointer Thermal exploitation of RDF improves further the environmental performance of the plant. - Abstract: The aim of this paper is the application of Life Cycle Assessment to the operation of the MBT facility of Ano Liossia in the region of Attica in Greece. The region of Attica is home to almost half the population of Greece and the management of its waste is a major issue. In order to explicitly analyze the operation of the MBT plant, five scenarios were generated. Actual operation data of the MBT plant for the year 2008 were provided by the region of Attica and the LCA modeling was performed via the SimaPro 5.1 software while impact assessment was performed utilizing the Eco-indicator'99 method. The results of our analysis indicate that even the current operation of the MBT plant is preferable to landfilling. Among the scenarios of MBT operation, the one with complete utilization of the MBT outputs, i.e. compost, RDF, ferrous and non-ferrous metals, is the one that generates the most environmental gains. Our analysis indicates that the exploitation of RDF via incineration is the key factor towards improving the environmental performance of the MBT plant. Our findings provide a quantitative understanding of the MBT plant. Interpretation of results showed that proper operation of the modern waste management systems can lead to substantial reduction of environmental impacts and savings of resources.

  15. Loading concepts for Hoover Powerplant to optimize plant operating efficiency

    SciTech Connect

    Stitt, S.C.

    1983-08-01

    Plant efficiency gains that could be realized at Hoover Powerplant by the use of an algorithm to optimize plant efficiency are given. Comparisons are shown between the present plant operating conditions modeled on a digital computer, and the plant with the proposed unified bus operating under control of a GELA (Generator Efficiency Loading Algorithm) system. The basic concepts of that algorithm are given.

  16. AVESTAR Center for Operational Excellence of Electricity Generation Plants

    SciTech Connect

    Zitney, Stephen

    2012-08-29

    To address industry challenges in attaining operational excellence for electricity generation plants, the U.S. Department of Energy’s (DOE) National Energy Technology Laboratory (NETL) has launched a world-class facility for Advanced Virtual Energy Simulation Training and Research (AVESTARTM). This presentation will highlight the AVESTARTM Center simulators, facilities, and comprehensive training, education, and research programs focused on the operation and control of high-efficiency, near-zero-emission electricity generation plants. The AVESTAR Center brings together state-of-the-art, real-time, high-fidelity dynamic simulators with full-scope operator training systems (OTSs) and 3D virtual immersive training systems (ITSs) into an integrated energy plant and control room environment. AVESTAR’s initial offering combines--for the first time--a “gasification with CO2 capture” process simulator with a “combined-cycle” power simulator together in a single OTS/ITS solution for an integrated gasification combined cycle (IGCC) power plant with carbon dioxide (CO2) capture. IGCC systems are an attractive technology option for power generation, especially when capturing and storing CO2 is necessary to satisfy emission targets. The AVESTAR training program offers a variety of courses that merge classroom learning, simulator-based OTS learning in a control-room operations environment, and immersive learning in the interactive 3D virtual plant environment or ITS. All of the courses introduce trainees to base-load plant operation, control, startups, and shutdowns. Advanced courses require participants to become familiar with coordinated control, fuel switching, power-demand load shedding, and load following, as well as to problem solve equipment and process malfunctions. Designed to ensure work force development, training is offered for control room and plant field operators, as well as engineers and managers. Such comprehensive simulator-based instruction allows

  17. Computing and cognition in future power-plant operations

    SciTech Connect

    Kisner, R.A.; Sheridan, T.B.

    1983-01-01

    The intent of this paper is to speculate on the nature of future interactions between people and computers in the operation of power plants. In particular, the authors offer a taxonomy for examining the differing functions of operators in interacting with the plant and its computers, and the differing functions of the computers in interacting with the plant and its operators.

  18. Tidd PFBC Demonstration Plant operation and testing

    SciTech Connect

    Marrocco, M.; Hafer, D.R.

    1993-05-01

    The Tidd PFBC Demonstration Plant, located in Brilliant, Ohio, is in its third year of operation and testing. The plant has achieved many of its original performance goals and test objectives; however, current emissions standards and the projected performance of competing technologies have caused a reassessment of the program goals. This paper provides a review of PFBC technology and discusses project goals and milestones achieved. Emphasis is placed on environmental performance and on projected modifications to be undertaken to improve sulfur capture and reduce calcium/sulfur molar ratio. A large-scale hot gas clean up demonstration is also in progress at Tidd. The demonstration has been providing information on ceramic barrier filter technology since its commissioning in October 1992. The Tidd Plant has met both its performance guarantees for emissions and its environmental permit limits. However, the tightening of government environmental standards and the projected performance of competing technologies have required a reassessment of the goals of AEP`s PFBC program. Efforts are focusing on achieving better environmental performance, particularly with respect to sulfur capture and sorbent utilization.

  19. Tidd PFBC Demonstration Plant operation and testing

    SciTech Connect

    Marrocco, M.; Hafer, D.R.

    1993-01-01

    The Tidd PFBC Demonstration Plant, located in Brilliant, Ohio, is in its third year of operation and testing. The plant has achieved many of its original performance goals and test objectives; however, current emissions standards and the projected performance of competing technologies have caused a reassessment of the program goals. This paper provides a review of PFBC technology and discusses project goals and milestones achieved. Emphasis is placed on environmental performance and on projected modifications to be undertaken to improve sulfur capture and reduce calcium/sulfur molar ratio. A large-scale hot gas clean up demonstration is also in progress at Tidd. The demonstration has been providing information on ceramic barrier filter technology since its commissioning in October 1992. The Tidd Plant has met both its performance guarantees for emissions and its environmental permit limits. However, the tightening of government environmental standards and the projected performance of competing technologies have required a reassessment of the goals of AEP's PFBC program. Efforts are focusing on achieving better environmental performance, particularly with respect to sulfur capture and sorbent utilization.

  20. Comparative analysis of CCMHD power plants. [Closed Cycle MHD

    NASA Technical Reports Server (NTRS)

    Alyea, F. N.; Marston, C. H.; Mantri, V. B.; Geisendorfer, B. G.; Doss, H.

    1981-01-01

    A study of Closed Cycle MHD (CCMHD) power generation systems has been conducted which emphasizes both advances in component conceptual design and overall system performance. New design data are presented for the high temperature, regenerative argon heaters (HTRH) and the heat recovery/seed recovery (HRSR) subsystem. Contamination of the argon by flue gas adsorbed in the HTRH is examined and a model for estimation of contamination effects in operating systems is developed. System performance and cost data have been developed for the standard CCMHD/steam cycle as powered by both direct fired cyclone combustors and selected coal gasifiers. In addition, a new CCMHD thermodynamic cycle has been identified.

  1. Direct coal-fired gas turbines for combined cycle plants

    SciTech Connect

    Rothrock, J.; Wenglarz, R.; Hart, P.; Mongia, H.

    1993-11-01

    The combustion/emissions control island of the CFTCC plant produces cleaned coal combustion gases for expansion in the gas turbine. The gases are cleaned to protect the turbine from flow-path degeneration due to coal contaminants and to reduce environmental emissions to comparable or lower levels than alternate clean coal power plant tedmologies. An advantage of the CFTCC system over other clean coal technologies using gas turbines results from the CFTCC system having been designed as an adaptation to coal of a natural gas-fired combined cycle plant. Gas turbines are built for compactness and simplicity. The RQL combustor is designed using gas turbine combustion technology rather than process plant reactor technology used in other pressurized coal systems. The result is simpler and more compact combustion equipment than for alternate technologies. The natural effect is lower cost and improved reliability. In addition to new power generation plants, CFTCC technology will provide relatively compact and gas turbine compatible coal combustion/emissions control islands that can adapt existing natural gas-fired combined cycle plants to coal when gas prices rise to the point where conversion is economically attractive. Because of the simplicity, compactness, and compatibility of the RQL combustion/emission control island compared to other coal technologies, it could be a primary candidate for such conversions.

  2. EDF Nuclear Power Plants Operating Experience with MOX fuel

    SciTech Connect

    Thibault, Xavier

    2006-07-01

    EDF started Plutonium recycling in PWR in 1987 and progressively all the 20 reactors, licensed in using MOX fuel, have been loaded with MOX assemblies. At the origin of MOX introduction, these plants operated at full power in base load and the core management limited the irradiation time of MOX fuel assemblies to 3 annual cycles. Since 1995 all these reactors can operate in load follow mode. Since that time, a large amount of experience has been accumulated. This experience is very positive considering: - Receipt, handling, in core behaviour, pool storage and shipment of MOX fuel; - Operation of the various systems of the plant; - Environment impact; - Radioprotection; - Safety file requirements; - Availability for the grid. In order to reduce the fuel cost and to reach a better adequacy between UO{sub 2} fuel reprocessing flow and plutonium consumption, EDF had decided to improve the core management of MOX plants. This new core management call 'MOX Parity' achieves parity for MOX and UO{sub 2} assemblies in term of discharge burn-up. Compared to the current MOX assembly the Plutonium content is increased from 7,08% to 8,65% (equivalent to natural uranium enriched to respectively 3,25% and 3,7%) and the maximum MOX assembly burn-up moves from 42 to 52 GWd/t. This amount of burn-up is obtained from loading MOX assemblies for one additional annual cycle. Some, but limited, adaptations of the plant are necessary. In addition a new MOX fuel assembly has been designed to comply with the safety criteria taking into account the core management performances. These design improvements are based on the results of an important R and D program including numerous experimental tests and post-irradiated fuel examinations. In particular, envelope conditions compared to MOX Parity neutronic solicitations has been extensively investigated in order to get a full knowledge of the in reactor fuel behavior. Moreover, the operating conditions of the plant have been evaluated in many

  3. 14 CFR 121.434 - Operating experience, operating cycles, and consolidation of knowledge and skills.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... consolidation of knowledge and skills. 121.434 Section 121.434 Aeronautics and Space FEDERAL AVIATION... Qualifications § 121.434 Operating experience, operating cycles, and consolidation of knowledge and skills. (a... of knowledge and skills, required by this section, except as follows: (1) Crewmembers other...

  4. 14 CFR 121.434 - Operating experience, operating cycles, and consolidation of knowledge and skills.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... consolidation of knowledge and skills. 121.434 Section 121.434 Aeronautics and Space FEDERAL AVIATION... Qualifications § 121.434 Operating experience, operating cycles, and consolidation of knowledge and skills. (a... of knowledge and skills, required by this section, except as follows: (1) Crewmembers other...

  5. 14 CFR 121.434 - Operating experience, operating cycles, and consolidation of knowledge and skills.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... consolidation of knowledge and skills. 121.434 Section 121.434 Aeronautics and Space FEDERAL AVIATION... Qualifications § 121.434 Operating experience, operating cycles, and consolidation of knowledge and skills. (a... of knowledge and skills, required by this section, except as follows: (1) Crewmembers other...

  6. 14 CFR 121.434 - Operating experience, operating cycles, and consolidation of knowledge and skills.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... consolidation of knowledge and skills. 121.434 Section 121.434 Aeronautics and Space FEDERAL AVIATION... Qualifications § 121.434 Operating experience, operating cycles, and consolidation of knowledge and skills. (a... of knowledge and skills, required by this section, except as follows: (1) Crewmembers other...

  7. The optimization air separation plants for combined cycle MHD-power plant applications

    NASA Technical Reports Server (NTRS)

    Juhasz, A. J.; Springmann, H.; Greenberg, R.

    1980-01-01

    Some of the design approaches being employed during a current supported study directed at developing an improved air separation process for the production of oxygen enriched air for magnetohydrodynamics (MHD) combustion are outlined. The ultimate objective is to arrive at conceptual designs of air separation plants, optimized for minimum specific power consumption and capital investment costs, for integration with MHD combined cycle power plants.

  8. Carnot's cycle for small systems: irreversibility and cost of operations

    PubMed

    Sekimoto; Takagi; Hondou

    2000-12-01

    In the thermodynamic limit, the existence of a maximal efficiency of energy conversion attainable by a Carnot cycle consisting of quasistatic isothermal and adiabatic processes precludes the existence of a perpetual machine of the second kind, whose cycles yield positive work in an isothermal environment. We employ the recently developed framework of the energetics of stochastic processes (called "stochastic energetics") to reanalyze the Carnot cycle in detail, taking account of fluctuations, without taking the thermodynamic limit. We find that in this nonmacroscopic situation both processes of connection to and disconnection from heat baths and adiabatic processes that cause distortion of the energy distribution are sources of inevitable irreversibility within the cycle. Also, the so-called null-recurrence property of the cumulative efficiency of energy conversion over many cycles and the irreversible property of isolated, purely mechanical processes under external "macroscopic" operations are discussed in relation to the impossibility of a perpetual machine, or Maxwell's demon. This analysis may serve as the basis for the design and analysis of mesoscopic energy converters in the near future.

  9. Carnot's cycle for small systems: Irreversibility and cost of operations

    NASA Astrophysics Data System (ADS)

    Sekimoto, Ken; Takagi, Fumiko; Hondou, Tsuyoshi

    2000-12-01

    In the thermodynamic limit, the existence of a maximal efficiency of energy conversion attainable by a Carnot cycle consisting of quasistatic isothermal and adiabatic processes precludes the existence of a perpetual machine of the second kind, whose cycles yield positive work in an isothermal environment. We employ the recently developed framework of the energetics of stochastic processes (called ``stochastic energetics'') to reanalyze the Carnot cycle in detail, taking account of fluctuations, without taking the thermodynamic limit. We find that in this nonmacroscopic situation both processes of connection to and disconnection from heat baths and adiabatic processes that cause distortion of the energy distribution are sources of inevitable irreversibility within the cycle. Also, the so-called null-recurrence property of the cumulative efficiency of energy conversion over many cycles and the irreversible property of isolated, purely mechanical processes under external ``macroscopic'' operations are discussed in relation to the impossibility of a perpetual machine, or Maxwell's demon. This analysis may serve as the basis for the design and analysis of mesoscopic energy converters in the near future.

  10. Working fluid selection for the Organic Rankine Cycle (ORC) exhaust heat recovery of an internal combustion engine power plant

    NASA Astrophysics Data System (ADS)

    Douvartzides, S.; Karmalis, I.

    2016-11-01

    Organic Rankine cycle technology is capable to efficiently convert low-grade heat into useful mechanical power. In the present investigation such a cycle is used for the recovery of heat from the exhaust gases of a four stroke V18 MAN 51/60DF internal combustion engine power plant operating with natural gas. Design is focused on the selection of the appropriate working fluid of the Rankine cycle in terms of thermodynamic, environmental and safety criteria. 37 candidate fluids have been considered and all Rankine cycles examined were subcritical. The thermodynamic analysis of all fluids has been comparatively undertaken and the effect of key operation conditions such as the evaporation pressure and the superheating temperature was taken into account. By appropriately selecting the working fluid and the Rankine cycle operation conditions the overall plant efficiency was improved by 5.52% and fuel consumption was reduced by 12.69%.

  11. Interrelationships of food safety and plant pathology: the life cycle of human pathogens on plants.

    PubMed

    Barak, Jeri D; Schroeder, Brenda K

    2012-01-01

    Bacterial food-borne pathogens use plants as vectors between animal hosts, all the while following the life cycle script of plant-associated bacteria. Similar to phytobacteria, Salmonella, pathogenic Escherichia coli, and cross-domain pathogens have a foothold in agricultural production areas. The commonality of environmental contamination translates to contact with plants. Because of the chronic absence of kill steps against human pathogens for fresh produce, arrival on plants leads to persistence and the risk of human illness. Significant research progress is revealing mechanisms used by human pathogens to colonize plants and important biological interactions between and among bacteria in planta. These findings articulate the difficulty of eliminating or reducing the pathogen from plants. The plant itself may be an untapped key to clean produce. This review highlights the life of human pathogens outside an animal host, focusing on the role of plants, and illustrates areas that are ripe for future investigation.

  12. Construction of Simulation Model for OTEC Plant Using Uehara Cycle

    NASA Astrophysics Data System (ADS)

    Goto, Satoru; Motoshima, Yoshiki; Sugi, Takenao; Yasunaga, Takeshi; Ikegami, Yasuyuki; Nakamura, Masatoshi

    Ocean Thermal Energy Conversion (OTEC) converts heat energy into electricity using 20-27[°C] temperature difference between warm seawater at surface and cold seawater in depth. In this paper, a simulation model for an OTEC plant, which uses the Uehara cycle with an ammonia-water mixture as working fluid, is constructed based on the mass balance and the heat balance. Moreover, a method of the initial value determination for numerical simulation is developed. Accuracy of the simulation model was evaluated by comparing with the experimental results of a pilot OTEC plant.

  13. Functions and operations of nuclear power plant crews

    SciTech Connect

    Kisner, R.A.; Frey, P.R.

    1982-04-01

    This report summarizes the results of work performed at Oak Ridge National Laboratory and its subcontractors to define the functions, operations, and organization of nuclear power plant operating crews. The primary information sources used were ANS and IEEE standards, normal and emergency operating procedures from nuclear power plants, interviews, and literature reviews. The function and organization of operating crews for several plants are discussed genericly. The report covers a wide spectrum of topics including review of standards affecting human factors in the control room, influence of automation on operator functions, classification of operator functions, function of operator at onset of emergency, crew organization, work-induced stress, and operator acceptance of his role.

  14. Accelerating progress toward operational excellence of fossil energy plants with CO2 capture

    SciTech Connect

    Zitney, S.; Liese, E.; Mahapatra, P.; Turton, R. Bhattacharyya, D.

    2012-01-01

    To address challenges in attaining operational excellence for clean energy plants, the National Energy Technology Laboratory has launched a world-class facility for Advanced Virtual Energy Simulation Training And Research (AVESTARTM). The AVESTAR Center brings together state-of-the-art, real-time, high-fidelity dynamic simulators with operator training systems and 3D virtual immersive training systems into an integrated energy plant and control room environment. This paper will highlight the AVESTAR Center simulators, facilities, and comprehensive training, education, and research programs focused on the operation and control of an integrated gasification combined cycle power plant (IGCC) with carbon dioxide capture.

  15. Thermodynamic analysis and optimization of fuel cell based Combined Cycle Cogeneration plant

    NASA Astrophysics Data System (ADS)

    Odukoya, Adedoyin

    Power plants operating in combined cycle cogeneration configuration are becoming increasingly popular because of high energy conversion efficiency and reduced pollutant and green-house gas emissions. On the other hand, fuel cell technology continues to be of global interest because it can operate with very low to 0% green-house gas emission depending on the fuel. The aim of the present work is to investigate the effect of co-firing of natural gas with synthetic gas generated from coal gasification on the thermodynamic performance of an air blown coal gasification Combined Cycle Cogeneration unit with a solid oxide fuel cell (SOFC) arrangement. The effects of the operating temperature of the SOFC and the pressure ratio and turbine inlet temperature of the gas turbine on the net work output and efficiency of the power cycles on the cogeneration unit are simulated. Simulations are also conducted on the thermal and cogeneration efficiencies of the individual power cycle as well as the overall plants respectively. The optimal pressure ratio, temperature of operation of the SOFC and, gas turbine inlet temperature was determined using a sequential quadratic program solver base on the Quasi-Newton algorithm.

  16. Development of a plant-wide dynamic model of an integrated gasification combined cycle (IGCC) plant

    SciTech Connect

    Bhattacharyya, D.; Turton, R.; Zitney, S.

    2009-01-01

    In this presentation, development of a plant-wide dynamic model of an advanced Integrated Gasification Combined Cycle (IGCC) plant with CO2 capture will be discussed. The IGCC reference plant generates 640 MWe of net power using Illinois No.6 coal as the feed. The plant includes an entrained, downflow, General Electric Energy (GEE) gasifier with a radiant syngas cooler (RSC), a two-stage water gas shift (WGS) conversion process, and two advanced 'F' class combustion turbines partially integrated with an elevated-pressure air separation unit (ASU). A subcritical steam cycle is considered for heat recovery steam generation. Syngas is selectively cleaned by a SELEXOL acid gas removal (AGR) process. Sulfur is recovered using a two-train Claus unit with tail gas recycle to the AGR. A multistage intercooled compressor is used for compressing CO2 to the pressure required for sequestration. Using Illinois No.6 coal, the reference plant generates 640 MWe of net power. The plant-wide steady-state and dynamic IGCC simulations have been generated using the Aspen Plus{reg_sign} and Aspen Plus Dynamics{reg_sign} process simulators, respectively. The model is generated based on the Case 2 IGCC configuration detailed in the study available in the NETL website1. The GEE gasifier is represented with a restricted equilibrium reactor model where the temperature approach to equilibrium for individual reactions can be modified based on the experimental data. In this radiant-only configuration, the syngas from the Radiant Syngas Cooler (RSC) is quenched in a scrubber. The blackwater from the scrubber bottom is further cleaned in the blackwater treatment plant. The cleaned water is returned back to the scrubber and also used for slurry preparation. The acid gas from the sour water stripper (SWS) is sent to the Claus plant. The syngas from the scrubber passes through a sour shift process. The WGS reactors are modeled as adiabatic plug flow reactors with rigorous kinetics based on the mid

  17. Exergy analysis of internal regeneration in supercritical cycles of ORC power plant

    NASA Astrophysics Data System (ADS)

    Borsukiewicz-Gozdur, Aleksandra

    2012-09-01

    In the paper presented is an idea of organic Rankine cycle (ORC) operating with supercritical parameters and so called dry fluids. Discussed is one of the methods of improving the effectiveness of operation of supercritical cycle by application of internal regeneration of heat through the use of additional heat exchanger. The main objective of internal regenerator is to recover heat from the vapour leaving the turbine and its transfer to the liquid phase of working fluid after the circulation pump. In effect of application of the regenerative heat exchanger it is possible to obtain improved effectiveness of operation of the power plant, however, only in the case when the ORC plant is supplied from the so called sealed heat source. In the present paper presented is the discussion of heat sources and on the base of the case study of two heat sources, namely the rate of heat of thermal oil from the boiler and the rate of heat of hot air from the cooler of the clinkier from the cement production line having the same initial temperature of 260 oC, presented is the influence of the heat source on the justification of application of internal regeneration. In the paper presented are the calculations for the supercritical ORC power plant with R365mfc as a working fluid, accomplished has been exergy changes and exergy efficiency analysis with the view to select the most appropriate parameters of operation of the power plant for given parameters of the heat source.

  18. DREAMs make plant cells to cycle or to become quiescent.

    PubMed

    Magyar, Zoltán; Bögre, László; Ito, Masaki

    2016-12-01

    Cell cycle phase specific oscillation of gene transcription has long been recognized as an underlying principle for ordered processes during cell proliferation. The G1/S-specific and G2/M-specific cohorts of genes in plants are regulated by the E2F and the MYB3R transcription factors. Mutant analysis suggests that activator E2F functions might not be fully required for cell cycle entry. In contrast, the two activator-type MYB3Rs are part of positive feedback loops to drive the burst of mitotic gene expression, which is necessary at least to accomplish cytokinesis. Repressor MYB3Rs act outside the mitotic time window during cell cycle progression, and are important for the shutdown of mitotic genes to impose quiescence in mature organs. The two distinct classes of E2Fs and MYB3Rs together with the RETINOBLATOMA RELATED are part of multiprotein complexes that may be evolutionary related to what is known as DREAM complex in animals. In plants, there are multiple such complexes with distinct compositions and functions that may be involved in the coordinated cell cycle and developmental regulation of E2F targets and mitotic genes. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Preparation of Effective Operating Manuals to Support Waste Management Plant Operator Training

    SciTech Connect

    Brown, S. R.

    2003-02-25

    Effective plant operating manuals used in a formal training program can make the difference between a successful operation and a failure. Once the plant process design and control strategies have been fixed, equipment has been ordered, and the plant is constructed, the only major variable affecting success is the capability of plant operating personnel. It is essential that the myriad details concerning plant operation are documented in comprehensive operating manuals suitable for training the non-technical personnel that will operate the plant. These manuals must cover the fundamental principles of each unit operation including how each operates, what process variables are important, and the impact of each variable on the overall process. In addition, operators must know the process control strategies, process interlocks, how to respond to alarms, each of the detailed procedures required to start up and optimize the plant, and every control loop-including when it is appropriate to take manual control. More than anything else, operating mistakes during the start-up phase can lead to substantial delays in achieving design processing rates as well as to problems with government authorities if environmental permit limits are exceeded. The only way to assure return on plant investment is to ensure plant operators have the knowledge to properly run the plant from the outset. A comprehensive set of operating manuals specifically targeted toward plant operators and supervisors written by experienced operating personnel is the only effective way to provide the necessary information for formal start-up training.

  20. Life Cycle Cost Analysis of Ready Mix Concrete Plant

    NASA Astrophysics Data System (ADS)

    Topkar, V. M.; Duggar, A. R.; Kumar, A.; Bonde, P. P.; Girwalkar, R. S.; Gade, S. B.

    2013-11-01

    India, being a developing nation is experiencing major growth in its infrastructural sector. Concrete is the major component in construction. The requirement of good quality of concrete in large quantities can be fulfilled by ready mix concrete batching and mixing plants. The paper presents a technique of applying the value engineering tool life cycle cost analysis to a ready mix concrete plant. This will help an investor or an organization to take investment decisions regarding a ready mix concrete facility. No economic alternatives are compared in this study. A cost breakdown structure is prepared for the ready mix concrete plant. A market survey has been conducted to collect realistic costs for the ready mix concrete facility. The study establishes the cash flow for the ready mix concrete facility helpful in investment and capital generation related decisions. Transit mixers form an important component of the facility and are included in the calculations. A fleet size for transit mixers has been assumed for this purpose. The life cycle cost has been calculated for the system of the ready mix concrete plant and transit mixers.

  1. Importance of the specific heat anomaly in the design of binary Rankine cycle power plants

    SciTech Connect

    Pope, W.L.; Doyle, P.A.; Fulton, R.L.; Silvester, L.F.

    1980-05-01

    The transposed critical temperature (TPCT) is shown to be an extremely important thermodynamic property in the selection of working fluids and turbine states for geothermal power plants operating on a closed organic (binary) Rankine cycle. When the optimum working fluid composition and process states are determined for specified source and sink conditions, turbine inlet states consistently lie adjacent to the working fluids' TPCT line for all resource temperatures, constraints, and cost and efficiency factors investigated.

  2. Technical data for concentrated solar power plants in operation, under construction and in project.

    PubMed

    Pelay, Ugo; Luo, Lingai; Fan, Yilin; Stitou, Driss; Rood, Mark

    2017-08-01

    This article presents technical data for concentrated solar power (CSP) plants in operation, under construction and in project all over the world in the form of tables. These tables provide information about plants (e.g., name of the CSP plant, country of construction, owner of the plant, aim of the plant) and their technical characteristics (e.g., CSP technology, solar power, area of the plant, presence and type of hybridization system, electricity cost, presence and type of TES, power cycle fluid, heat transfer fluid, operating temperature, operating pressure, type of turbine, type and duration of storage, etc.). Further interpretation of the data and discussions on the current state-of-the-art and future trends of CSP can be found in the associated research article (Pelay et al., 2017) [1].

  3. Special function instruments for binary cycle geothermal power plants

    SciTech Connect

    Robertus, R.J.; Shannon, D.W.; Sullivan, R.G.

    1984-04-01

    Three special instruments have been designed to support plant operations at the Heber geothermal power plant in Heber, California. All are aids to give operating information which no commercial instruments can provide. The first is a package for determining CO/sub 2/ breakout conditions for a particular brine. Brine is sampled continuously at either the wellhead or the plant inlet. A temperature-pressure curve is generated which will span all possible operating combinations. That information tells designers or operators what pump pressures must be used to keep the CO/sub 2/ in solution. A second package unit will detect the presence of ppM levels of isobutane in either brine or water streams. It samples actual flowing brine streams continuously. The function is to alert operators when leaks are occurring in heat exchangers. A final unit senses water in flowing hydrocarbon streams. The sampled streams can be either liquid or vapor. Sensitivity is close to actual solubility limit for water in isobutane. This device warns operators when their hydrocarbon has been contaminated with brine (or cooling water).

  4. Improving geothermal power plants with a binary cycle

    NASA Astrophysics Data System (ADS)

    Tomarov, G. V.; Shipkov, A. A.; Sorokina, E. V.

    2015-12-01

    The recent development of binary geothermal technology is analyzed. General trends in the introduction of low-temperature geothermal sources are summarized. The use of single-phase low-temperature geothermal fluids in binary power plants proves possible and expedient. The benefits of power plants with a binary cycle in comparison with traditional systems are shown. The selection of the working fluid is considered, and the influence of the fluid's physicochemical properties on the design of the binary power plant is discussed. The design of binary power plants is based on the chemical composition and energy potential of the geothermal fluids and on the landscape and climatic conditions at the intended location. Experience in developing a prototype 2.5 MW Russian binary power unit at Pauzhetka geothermal power plant (Kamchatka) is outlined. Most binary systems are designed individually for a specific location. Means of improving the technology and equipment at binary geothermal power plants are identified. One option is the development of modular systems based on several binary systems that employ the heat from the working fluid at different temperatures.

  5. 6. INTERIOR VIEW OF CROSSCUT HYDRO PLANT, SHOWING 25 CYCLE60 ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. INTERIOR VIEW OF CROSSCUT HYDRO PLANT, SHOWING 25 CYCLE-60 CYCLE FREQUENCY CHANGER Photographer unknown, December 14, 1940 - Cross Cut Hydro Plant, North Side of Salt River, Tempe, Maricopa County, AZ

  6. Regulation of the xanthophyll cycle pool size in duckweed (Lemna minor) plants.

    PubMed

    García-Plazaola, José Ignacio; Hernández, Antonio; Artetxe, Unai; Becerril, José María

    2002-09-01

    Duckweed (Lemna minor L.) plants grown under high light are characterized, when compared to low light acclimated plants, by a higher xanthophyll cycle (VAZ) pool content, but also by a higher proportion of photoconvertible violaxanthin and a superior ability to synthesize VAZ pigments. When duckweed plants were transferred to a high light environment a general response was the quick adjustment of the carotenoid composition, mainly xanthophyll cycle pigments. These changes resulted from a balance between a process of continuous light-independent carotenoid degradation and a light-induced accumulation. The use of norflurazon, an inhibitor of carotenogenesis, allowed us to demonstrate that the observed light induced increase of the VAZ pool was mainly caused by de novo synthesis through carotenogenesis. The extent of light-induced carotenogenesis was proportional to the light treatment and also to the operation of the VAZ cycle since it was partly abolished by treatments leading to a low activity of the VAZ cycle, such as low light, DTT or DCMU. These results suggest that not only the light itself, but also a mechanism triggered by a factor associated with the de-epoxidation state of the VAZ cycle controls carotenogenesis at some point before phytoene formation in the terpenoid biosynthesis pathway.

  7. Model of environmental life cycle assessment for coal mining operations.

    PubMed

    Burchart-Korol, Dorota; Fugiel, Agata; Czaplicka-Kolarz, Krystyna; Turek, Marian

    2016-08-15

    This paper presents a novel approach to environmental assessment of coal mining operations, which enables assessment of the factors that are both directly and indirectly affecting the environment and are associated with the production of raw materials and energy used in processes. The primary novelty of the paper is the development of a computational environmental life cycle assessment (LCA) model for coal mining operations and the application of the model for coal mining operations in Poland. The LCA model enables the assessment of environmental indicators for all identified unit processes in hard coal mines with the life cycle approach. The proposed model enables the assessment of greenhouse gas emissions (GHGs) based on the IPCC method and the assessment of damage categories, such as human health, ecosystems and resources based on the ReCiPe method. The model enables the assessment of GHGs for hard coal mining operations in three time frames: 20, 100 and 500years. The model was used to evaluate the coal mines in Poland. It was demonstrated that the largest environmental impacts in damage categories were associated with the use of fossil fuels, methane emissions and the use of electricity, processing of wastes, heat, and steel supports. It was concluded that an environmental assessment of coal mining operations, apart from direct influence from processing waste, methane emissions and drainage water, should include the use of electricity, heat and steel, particularly for steel supports. Because the model allows the comparison of environmental impact assessment for various unit processes, it can be used for all hard coal mines, not only in Poland but also in the world. This development is an important step forward in the study of the impacts of fossil fuels on the environment with the potential to mitigate the impact of the coal industry on the environment. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Scenarios for Low Carbon and Low Water Electric Power Plant Operations: Implications for Upstream Water Use.

    PubMed

    Dodder, Rebecca S; Barnwell, Jessica T; Yelverton, William H

    2016-11-01

    Electric sector water use, in particular for thermoelectric operations, is a critical component of the water-energy nexus. On a life cycle basis per unit of electricity generated, operational (e.g., cooling system) water use is substantially higher than water demands for the fuel cycle (e.g., natural gas and coal) and power plant manufacturing (e.g., equipment and construction). However, could shifting toward low carbon and low water electric power operations create trade-offs across the electricity life cycle? We compare business-as-usual with scenarios of carbon reductions and water constraints using the MARKet ALlocation (MARKAL) energy system model. Our scenarios show that, for water withdrawals, the trade-offs are minimal: operational water use accounts for over 95% of life cycle withdrawals. For water consumption, however, this analysis identifies potential trade-offs under some scenarios. Nationally, water use for the fuel cycle and power plant manufacturing can reach up to 26% of the total life cycle consumption. In the western United States, nonoperational consumption can even exceed operational demands. In particular, water use for biomass feedstock irrigation and manufacturing/construction of solar power facilities could increase with high deployment. As the United States moves toward lower carbon electric power operations, consideration of shifting water demands can help avoid unintended consequences.

  9. RETRAN analyses for improving plant procedures and operator training

    SciTech Connect

    Broughton, T.G.; Trikouros, N.G.

    1983-05-01

    The technical quality of procedures governing integrated nuclear power plant operation is influenced by knowledge of system, component, and operator interactions. This knowledge includes, in part, operating plant data and realistic simulations of plant operation. This same information can be used to develop training materials for teaching plant dynamic response to plant operators and engineering staffs. Realistic simulations of plant performance have been used to supplement existing plant data or to provide data where none existed. The simulations may cover events with durations in hours and may be required to consider unique plant conditions including actual core physics conditions, valve leakage, and auxiliary steam loads. In addition, it should be possible for the simulation to account for operator interaction and to provide the information operators would have available through plant instrumentation. Simulations using the RETRAN computer code have been used in the development of procedures and training materials. Procedure applications have included development and validation of general control philosophy and establishment of specific test conditions and setpoints. Training applications include development of materials for teaching general plant response, specific plant response during tests, and analysis of plant performance.

  10. eWaterCycle: A global operational hydrological forecasting model

    NASA Astrophysics Data System (ADS)

    van de Giesen, Nick; Bierkens, Marc; Donchyts, Gennadii; Drost, Niels; Hut, Rolf; Sutanudjaja, Edwin

    2015-04-01

    Development of an operational hyper-resolution hydrological global model is a central goal of the eWaterCycle project (www.ewatercycle.org). This operational model includes ensemble forecasts (14 days) to predict water related stress around the globe. Assimilation of near-real time satellite data is part of the intended product that will be launched at EGU 2015. The challenges come from several directions. First, there are challenges that are mainly computer science oriented but have direct practical hydrological implications. For example, we aim to make use as much as possible of existing standards and open-source software. For example, different parts of our system are coupled through the Basic Model Interface (BMI) developed in the framework of the Community Surface Dynamics Modeling System (CSDMS). The PCR-GLOBWB model, built by Utrecht University, is the basic hydrological model that is the engine of the eWaterCycle project. Re-engineering of parts of the software was needed for it to run efficiently in a High Performance Computing (HPC) environment, and to be able to interface using BMI, and run on multiple compute nodes in parallel. The final aim is to have a spatial resolution of 1km x 1km, which is currently 10 x 10km. This high resolution is computationally not too demanding but very memory intensive. The memory bottleneck becomes especially apparent for data assimilation, for which we use OpenDA. OpenDa allows for different data assimilation techniques without the need to build these from scratch. We have developed a BMI adaptor for OpenDA, allowing OpenDA to use any BMI compatible model. To circumvent memory shortages which would result from standard applications of the Ensemble Kalman Filter, we have developed a variant that does not need to keep all ensemble members in working memory. At EGU, we will present this variant and how it fits well in HPC environments. An important step in the eWaterCycle project was the coupling between the hydrological and

  11. Research on Chinese Life Cycle-Based Wind Power Plant Environmental Influence Prevention Measures

    PubMed Central

    Wang, Hanxi; Xu, Jianling; Liu, Yuanyuan; Zhang, Tian

    2014-01-01

    The environmental impact of wind power plants over their life cycle is divided into three stages: construction period, operation period and retired period. The impact is mainly reflected in ecological destruction, noise pollution, water pollution and the effect on bird migration. In response to these environmental effects, suggesting reasonable locations, reducing plant footprint, optimizing construction programs, shielding noise, preventing pollution of terrestrial ecosystems, implementing combined optical and acoustical early warning signals, making synthesized use of power generation equipment in the post-retired period and using other specific measures, including methods involving governance and protection efforts to reduce environmental pollution, can be performed to achieve sustainable development. PMID:25153474

  12. South Bangkok combined cycle plant technical feasibility study. Export trade information

    SciTech Connect

    Not Available

    1990-07-01

    The report, written by Black and Veatch International, was funded by the U.S. Trade and Development Agency on behalf of the Electricity Generating Authority of Thailand. It establishes the conceptual design for the installation of a 300 MW combined cycle unit at the South Bangkok Plant. It is divided into the following sections: Gas/Oil Resource Assessment; Water Resources Assessment; Bases of Design; Site Arrangement; Generation Plant Arrangement; Conceptual Design; Transmission System Integration; Capital and Operating Cost Estimate; and Project Implementation.

  13. Research on Chinese life cycle-based wind power plant environmental influence prevention measures.

    PubMed

    Wang, Hanxi; Xu, Jianling; Liu, Yuanyuan; Zhang, Tian

    2014-08-19

    The environmental impact of wind power plants over their life cycle is divided into three stages: construction period, operation period and retired period. The impact is mainly reflected in ecological destruction, noise pollution, water pollution and the effect on bird migration. In response to these environmental effects, suggesting reasonable locations, reducing plant footprint, optimizing construction programs, shielding noise, preventing pollution of terrestrial ecosystems, implementing combined optical and acoustical early warning signals, making synthesized use of power generation equipment in the post-retired period and using other specific measures, including methods involving governance and protection efforts to reduce environmental pollution, can be performed to achieve sustainable development.

  14. Life Cycle Cost Analyses of U.S. Air Force Heating Plants

    DTIC Science & Technology

    1989-08-01

    1989. 31 ORNL/TM- 11146 internal Distribution 1. D. W. Burton 17. V. K. Wilkinson 2. E. C. Fox 18-20. J. M. Young 3 -7. F. P. Griffin 21. Central Research...required for the heating plant operation are assumed to follow the standard "bathtub" reliability curve as shown in Fig. 3 . The first three years of...ORNL/TM- 11146 NOAK RIDGE ~NATIONAL N LABORATORY Life-Cycle Cost Analyses of U.S.Air Force Heating Plants V. K. Wilkinson DTI * ~DI LECT A’roreve-3f

  15. Operator Serves as Integral Member of Plant Design Team

    ERIC Educational Resources Information Center

    Norris, Dan P.; Collins, Floyd W.

    1978-01-01

    It is suggested that plant operators can be useful in designing sewage treatment plants. The advantages of this cooperative arrangement to the consulting engineers and the city, and the pitfalls, are discussed. (BB)

  16. Operator Serves as Integral Member of Plant Design Team

    ERIC Educational Resources Information Center

    Norris, Dan P.; Collins, Floyd W.

    1978-01-01

    It is suggested that plant operators can be useful in designing sewage treatment plants. The advantages of this cooperative arrangement to the consulting engineers and the city, and the pitfalls, are discussed. (BB)

  17. 16. SOUTH SIDE OF STEAM PLANT COOLING TOWER IN OPERABLE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    16. SOUTH SIDE OF STEAM PLANT COOLING TOWER IN OPERABLE CONDITION, WITH STACKS OF ORIGINAL BOILERS IN BACKGROUND. June 10, 1941 - Crosscut Steam Plant, North side Salt River near Mill Avenue & Washington Street, Tempe, Maricopa County, AZ

  18. Selection of a closed Brayton cycle gas turbine for an intermediate-duty solar-electric power plant

    NASA Astrophysics Data System (ADS)

    Vieth, G. L.; Plummer, D. F.

    1980-03-01

    Subsystem and system analyses were performed to select the preferred working gas, performance characteristics and size of a closed cycle gas turbine for an intermediate-duty solar-electric power plant. Capital costs for all major subsystems were evaluated, but the principal selection criterion was the projected cost of electricity produced by the plant. Detailed analyses of the power conversion loop were conducted for both air and helium systems. Since the plant was intended for use on an intermediate-duty cycle, thermal storage was required. The coupling of the storage and power conversion loops in combination with the daily operating cycle influenced plant performance and energy costs in addition to the selection of the power conversion cycle.

  19. Maintenance Carbon Cycle in Crassulacean Acid Metabolism Plant Leaves 1

    PubMed Central

    Kenyon, William H.; Severson, Ray F.; Black, Clanton C.

    1985-01-01

    The reciprocal relationship between diurnal changes in organic acid and storage carbohydrate was examined in the leaves of three Crassulacean acid metabolism plants. It was found that depletion of leaf hexoses at night was sufficient to account quantitatively for increase in malate in Ananas comosus but not in Sedum telephium or Kalanchoë daigremontiana. Fructose and to a lesser extent glucose underwent the largest changes. Glucose levels in S. telephium leaves oscillated diurnally but were not reciprocally related to malate fluctuations. Analysis of isolated protoplasts and vacuoles from leaves of A. comosus and S. telephium revealed that vacuoles contain a large percentage (>50%) of the protoplast glucose, fructose and malate, citrate, isocitrate, ascorbate and succinate. Sucrose, a major constituent of intact leaves, was not detectable or was at extremely low levels in protoplasts and vacuoles from both plants. In isolated vacuoles from both A. comosus and S. telephium, hexose levels decreased at night at the same time malate increased. Only in A. comosus, however, could hexose metabolism account for a significant amount of the nocturnal increase in malate. We conclude that, in A. comosus, soluble sugars are part of the daily maintenance carbon cycle and that the vacuole plays a dynamic role in the diurnal carbon assimilation cycle of this Crassulacean acid metabolism plant. PMID:16664005

  20. Dimensional approach on hot air turbine power plant in opened cycle for straw recycling

    NASA Astrophysics Data System (ADS)

    Bălănescu, D. T.; Homutescu, V. M.; Atanasiu, M. V.

    2016-08-01

    Currently, disposal of straw is one of the biggest problems that crop plant producers are facing. The ideal case implies not only to get rid of straw but also to recover its energetic potential. In this context, the performance of a hot air turbine power plant operating in open cycle, with straw as fuel, was analyzed in a previous study and proved to be a very interesting solution for straw disposal. As consequence, dimensional analysis of the hot air turbine power plant is required into the next step and this makes the subject of the present study. The dimensional analysis is focused on the compressed air heater - the largest component of the Power Plant, with crucial role in what concerns its entire size and mass. Once both performance and dimensional analysis performed, the final conclusions are drawn in an overall approach, by taking also into consideration the economic aspects.

  1. Modifying Operating Cycles to Increase Stability in a LITS

    NASA Technical Reports Server (NTRS)

    Burt, Eric; Tjoelker, Robert

    2009-01-01

    The short-term instability in the frequency of a linear-ion-trap frequency standard (LITS) can be reduced by modifying two cycles involved in its operation: (1) the bimodal (bright/dim) cycle of a plasma discharge lamp used for state preparation and detection and (2) a microwave-interrogation cycle. The purpose and effect of the modifications is to enable an increase in the microwave- interrogation cycle time, motivated by the general principle that the short-term uncertainty or instability decreases with increasing microwave-interrogation time. Stated from a slightly different perspective, the effect of modifications is to enable the averaged LITS readings to settle to their longterm stability over a shorter total observation time. The basic principles of a LITS were discussed in several NASA Tech Briefs articles. Here are recapitulated only those items of background information necessary to place the present modifications in context. A LITS includes a microwave local oscillator, the frequency of which is stabilized by comparison with the frequency of a ground-state hyperfine transition of Hg-199(+) ions. In a LITS of the type to which the modifications apply, the comparison involves a combination of optical and micro wave excitation and interrogation of the ions in two collinear ion traps: a quadrupole trap wherein the optical excitation used for state preparation and detection takes place, and a multipole (e.g., 12-pole) trap wherein the microwave interrogation of the clock transition takes place. The ions are initially loaded into the quadrupole trap and are thereafter shuttled between the two traps. This concludes the background information.

  2. Steam turbine development for advanced combined cycle power plants

    SciTech Connect

    Oeynhausen, H.; Bergmann, D.; Balling, L.; Termuehlen, H.

    1996-12-31

    For advanced combined cycle power plants, the proper selection of steam turbine models is required to achieve optimal performance. The advancements in gas turbine technology must be followed by advances in the combined cycle steam turbine design. On the other hand, building low-cost gas turbines and steam turbines is desired which, however, can only be justified if no compromise is made in regard to their performance. The standard design concept of two-casing single-flow turbines seems to be the right choice for most of the present and future applications worldwide. Only for very specific applications it might be justified to select another design concept as a more suitable option.

  3. Aerodynamic Heat-Power Engine Operating on a Closed Cycle

    NASA Technical Reports Server (NTRS)

    Ackeret, J.; Keller, D. C.

    1942-01-01

    Hot-air engines with dynamic compressors and turbines offer new prospects of success through utilization of units of high efficiencies and through the employment of modern materials of great strength at high temperature. Particular consideration is given to an aerodynamic prime mover operating on a closed circuit and heated externally. Increase of the pressure level of the circulating air permits a great increase of limit load of the unit. This also affords a possibility of regulation for which the internal efficiency of the unit changes but slightly. The effect of pressure and temperature losses is investigated. A general discussion is given of the experimental installation operating at the Escher Wyss plant in Zurich for a considerable time at high temperatures.

  4. Life Cycle Assesment of Daugavgriva Waste Water Treatment Plant

    NASA Astrophysics Data System (ADS)

    Romagnoli, F.; Sampaio, F.; Blumberga, D.

    2009-01-01

    This paper presents the assessment of the environmental impacts caused by the treatment of Riga's waste water in the Daugavgriva plant with biogas energy cogeneration through the life cycle assessment (LCA). The LCA seems to be a good tool to assess and evaluate the most serious environmental impacts of a facility The results showed clearly that the impact category contributing the most to the total impact -eutrophicationcomes from the wastewater treatment stage. Climate change also seems to be a relevant impact coming from the wastewater treatment stage and the main contributor to the Climate change is N2O. The main environmental benefits, in terms of the percentages of the total impact, associated to the use of biogas instead of any other fossil fuel in the cogeneration plant are equal to: 3,11% for abiotic depletation, 1,48% for climate change, 0,51% for acidification and 0,12% for eutrophication.

  5. Closed cycle osmotic power plants for electric power production

    NASA Astrophysics Data System (ADS)

    Reali, M.

    1980-04-01

    The paper deals with closed-cycle osmotic power plants (CCOPPs), which are not meant for the exploitation of natural salinity gradients but, rather, for the exploitation of those abundant heat sources having temperatures slightly higher than ambient temperature, e.g., geothermal fields, ocean temperature gradients, waste heat from power plants, and solar energy. The paper gives a general description of the CCOPP, along with some indications of its potential for energy generation. The concept of the CCOPP lies in producing electric power by means of the osmotic flows of suitable solvents and subsequently in separating them again from their solutes by means of thermal energy obtained from any available heat source. The discussion covers osmotic phenomena and the CCOPP, as well as important features of the CCOPP.

  6. Operational results of a Closed Brayton Cycle test-loop.

    SciTech Connect

    Fuller, Robert; Wright, Steven Alan; Nichols, Kenneth Graham.; Brown, Nicholas; Lipinski, Ronald J.

    2004-11-01

    A number of space and terrestrial power system designs plan to use nuclear reactors that are coupled to Closed-loop Brayton Cycle (CBC) systems to generate electrical power. Because very little experience exists regarding the operational behavior of these systems, Sandia National Laboratories (through its Laboratory Directed Research and Development program) is developing a closed-loop test bed that can be used to determine the operational behavior of these systems and to validate models for these systems. Sandia has contracted Barber-Nichols Corporation to design, fabricate, and assemble a Closed-loop Brayton Cycle (CBC) system. This system was developed by modifying commercially available hardware. It uses a 30 kWe Capstone C-30 gas-turbine unit (www.capstoneturbine.com) with a modified housing that permits the attachment of an electrical heater and a water cooled chiller that are connected to the turbo-machinery in a closed loop. The test-loop reuses the Capstone turbine, compressor, and alternator. The Capstone system's nominal operating point is 1150 K turbine inlet temperature at 96,000 rpm. The annular recuperator and portions of the Capstone control system (inverter) and starter system are also reused. The rotational speed of the turbo-machinery is controlled either by adjusting the alternator load by either using the electrical grid or a separate load bank. This report describes the test-loop hardware SBL-30 (Sandia Brayton Loop-30kWe). Also presented are results of early testing and modeling of the unit. The SBL-30 hardware is currently configured with a heater that is limited to 80 kW{sub th} with a maximum outlet temperature of {approx}1000 K.

  7. Operational Results of a Closed Brayton Cycle Test-Loop

    NASA Astrophysics Data System (ADS)

    Wright, Steven A.; Fuller, Robert; Lipinski, Ronald J.; Nichols, Kenneth; Brown, Nicholas

    2005-02-01

    A number of space and terrestrial power system designs plan to use nuclear reactors that are coupled to Closed-loop Brayton Cycle (CBC) systems to generate electrical power. Because very little experience exists regarding the operational behavior of these systems, Sandia National Laboratories (through its Laboratory Directed Research and Development program) is developing a closed-loop test bed that can be used to determine the operational behavior of these systems and to validate models for these systems. Sandia has contracted Barber-Nichols Corporation to design, fabricate, and assemble a Closed-loop Brayton Cycle (CBC) system. This system was developed by modifying commercially available hardware. It uses a 30 kWe Capstone C-30 gas-turbine unit (www.capstoneturbine.com) with a modified housing that permits the attachment of an electrical heater and a water cooled chiller that are connected to the turbo-machinery in a closed loop. The test-loop reuses the Capstone turbine, compressor, and alternator. The Capstone system's nominal operating point is 1150 K turbine inlet temperature at 96,000 rpm. The annular recuperator and portions of the Capstone control system (inverter) and starter system are also reused. The rotational speed of the turbo-machinery is controlled either by adjusting the alternator load by either using the electrical grid or a separate load bank. This report describes the test-loop hardware SBL-30 (Sandia Brayton Loop-30kWe). Also presented are results of early testing and modeling of the unit. The SBL-30 hardware is currently configured with a heater that is limited to 80 kWth with a maximum outlet temperature of ˜1000 K.

  8. Computer, Video, and Rapid-Cycling Plant Projects in an Undergraduate Plant Breeding Course.

    ERIC Educational Resources Information Center

    Michaels, T. E.

    1993-01-01

    Studies the perceived effectiveness of four student projects involving videotape production, computer conferencing, microcomputer simulation, and rapid-cycling Brassica breeding for undergraduate plant breeding students in two course offerings in consecutive years. Linking of the computer conferencing and video projects improved the rating of the…

  9. Computer, Video, and Rapid-Cycling Plant Projects in an Undergraduate Plant Breeding Course.

    ERIC Educational Resources Information Center

    Michaels, T. E.

    1993-01-01

    Studies the perceived effectiveness of four student projects involving videotape production, computer conferencing, microcomputer simulation, and rapid-cycling Brassica breeding for undergraduate plant breeding students in two course offerings in consecutive years. Linking of the computer conferencing and video projects improved the rating of the…

  10. Technical and economic feasibility of a Thermal Gradient Utilization Cycle (TGUC) power plant. Final report

    SciTech Connect

    Raiji, A.M.; Renfroe, D.A.; Lalk, T.R.

    1980-01-01

    The technical and economic feasibility of a Thermal Gradient Utilization Cycle (TGUC), a new concept in power generation, was investigated. Power is generated by exploiting the natural atmosheric temperature gradient. A low grade energy source is used to vaporize a fluid which rises in a pipe to a higher elevation where it is condensed. The cycle is completed by passing the condensed liquid through a turbine as it returns to the lower elevation. A digital computer model was developed and used to simulate the operation of the cycle and to conduct a parameteric study. Life cycle cost analysis and energy analyses were conducted for the specific case of a TGUC using the ambient air at the lower elevation as an energy source. Although the cycle has a low thermal efficiency and is site specific, it is technically feasible. Variations in mass flow rate of the working fluid and elevation were found to affect the cycle power output to a large extent. The investment cost of a hypothetical 10 megawatt TGUC power plant was determined to be $3,080 per kilowatt, with life cycle busbar costs of electricity ranging from 47 to 55 Mills per kilowatt-hour depending on the method of financing. Results of the energy analyses showed that a TGUC system would have a positive net energy and a second law efficiency of 23% for the case of a TGUC system using the atmosphere as an energy source.

  11. Skill Development of Plant Operators in the Chemical Industry

    NASA Astrophysics Data System (ADS)

    Sakata, Kouichi

    In the chemical industry, most of the chemical products are manufactured by operating equipment and changing raw materials chemically and physically. Knowledge and skills regarding the raw materials and the products are required to manufacture the products of good quality safely. Furthermore the knowledge and skills concerning the chemical process, the equipment and other treated materials are needed to operate plant appropriately. The way of plant operation partially depends on the type of process such as continuous process and batch process. As a plant operator is promoted to an upper position, required to improve one's skills. To operate plant safely, the base action to prevent an error of judgment, and the adaptive action based on the rule and principle i.e. KNOW-WHY are also required. In this paper, it reports on some cases of the skill development of plant operators in Omuta Works.

  12. Specific features of combined generation of electric power, heat, and cold by combined-cycle plants

    NASA Astrophysics Data System (ADS)

    Klimenko, A. V.; Agababov, V. S.; Rogova, A. A.; Tideman, P. A.

    2015-03-01

    Trigeneration systems based on the combined-cycle plants of condensation type and the combined-cycle plants of cogeneration type of several possible structures for the simultaneous generation of heat and cold are developed. Two types of their operational modes are considered: trigeneration complexes with separate and simultaneous generation of heat and cold. In the first case, two assemblies (thermotransformers) of different types are used for generation of heat and cold, one of which is designed to generate heat and the second to generate cold. In the second case, the heat and cold are generated simultaneously in one thermotransformer. In the article, the results of thermodynamic analysis and calculations of technical and economic efficiency of the developed trigeneration systems are presented.

  13. Combined-cycle plant built in record time

    SciTech Connect

    1995-04-01

    This article reports that this low-cost cogeneration plant meets residential community`s environmental concerns with noise minimization, emissions control, and zero wastewater discharge. Supplying electricity to the local utility and steam to two hosts, the Auburndale cogeneration facility embodies the ``reference plant`` design approach developed by Westinghouse Power Generation (WPG), Orlando, Fla. With this approach customers meet their particular needs by choosing from a standard package of plant equipment and design options. Main goals of the concept are reduced construction time efficient and reliable power generation, minimal operating staff, and low cost. WPG built the plant on a turnkey basis for Auburndale Power Partners Limited Partnership (APP). APP is a partially owned subsidiary of Mission Energy, a California-based international developer and operator of independent-power facilities. The cogeneration facility supplies 150 MW of electric power to Florida Power Corp and exports 120,000 lb/hr of steam to Florida Distillers Co and Coca-Cola Foods.

  14. Global operational hydrological forecasts through eWaterCycle

    NASA Astrophysics Data System (ADS)

    van de Giesen, Nick; Bierkens, Marc; Donchyts, Gennadii; Drost, Niels; Hut, Rolf; Sutanudjaja, Edwin

    2015-04-01

    Central goal of the eWaterCycle project (www.ewatercycle.org) is the development of an operational hyper-resolution hydrological global model. This model is able to produce 14 day ensemble forecasts based on a hydrological model and operational weather data (presently NOAA's Global Ensemble Forecast System). Special attention is paid to prediction of situations in which water related issues are relevant, such as floods, droughts, navigation, hydropower generation, and irrigation stress. Near-real time satellite data will be assimilated in the hydrological simulations, which is a feature that will be presented for the first time at EGU 2015. First, we address challenges that are mainly computer science oriented but have direct practical hydrological implications. An important feature in this is the use of existing standards and open-source software to the maximum extent possible. For example, we use the Community Surface Dynamics Modeling System (CSDMS) approach to coupling models (Basic Model Interface (BMI)). The hydrological model underlying the project is PCR-GLOBWB, built by Utrecht University. This is the motor behind the predictions and state estimations. Parts of PCR-GLOBWB have been re-engineered to facilitate running it in a High Performance Computing (HPC) environment, run parallel on multiple nodes, as well as to use BMI. Hydrological models are not very CPU intensive compared to, say, atmospheric models. They are, however, memory hungry due to the localized processes and associated effective parameters. To accommodate this memory need, especially in an ensemble setting, a variation on the traditional Ensemble Kalman Filter was developed that needs much less on-chip memory. Due to the operational nature, the coupling of the hydrological model with hydraulic models is very important. The idea is not to run detailed hydraulic routing schemes over the complete globe but to have on-demand simulation prepared off-line with respect to topography and

  15. Plant operation report and daily evaluation summary

    SciTech Connect

    Not Available

    1984-01-02

    This report summarizes the operational and maintenance activities and highlights of the Small Solar Power System (SSPS) that were required during the month. The operation, maintenance, and cost data are attached to this report.

  16. Water/Wastewater Treatment Plant Operator Qualifications.

    ERIC Educational Resources Information Center

    Water and Sewage Works, 1979

    1979-01-01

    This article summarizes in tabular form the U.S. and Canadian programs for classification of water and wastewater treatment plant personnel. Included are main characteristics of the programs, educational and experience requirements, and indications of requirement substitutions. (CS)

  17. Water/Wastewater Treatment Plant Operator Qualifications.

    ERIC Educational Resources Information Center

    Water and Sewage Works, 1979

    1979-01-01

    This article summarizes in tabular form the U.S. and Canadian programs for classification of water and wastewater treatment plant personnel. Included are main characteristics of the programs, educational and experience requirements, and indications of requirement substitutions. (CS)

  18. Fuel cell power plant economic and operational considerations

    NASA Technical Reports Server (NTRS)

    Lance, J. R.

    1984-01-01

    Fuel cell power plants intended for electric utility and cogeneration applications are now in the design and construction stage. This paper describes economic and operational considerations being used in the development and design of plants utilizing air cooled phosphoric acid fuel cells. Fuel cell power plants have some unique characteristics relative to other types of power plants. As a result it was necessary to develop specific definitions of the fuel cell power plant characteristics in order to perform cost of electricity calculations. This paper describes these characteristics and describes the economic analyses used in the Westinghouse fuel cell power plant program.

  19. SSPS monthly data: plant operation report and daily operation summary

    SciTech Connect

    Not Available

    1984-01-01

    Daily operation data are given for both the central receiver and distributed collector systems for the month of June 1984. Data include meteorological data, heliostat field performance, power conversion, and electric energy production. (LEW)

  20. SSPS monthly data: plant operation report and daily operation summary

    SciTech Connect

    Not Available

    1984-01-01

    Daily operation data are given for both the central receiver and the distributed collector systems for the month of May 1984. Data include meteorological data, heliostat field performance, power conversion, and electric energy production. (LEW)

  1. Solid oxide fuel cell/gas turbine power plant cycles and performance estimates

    SciTech Connect

    Lundberg, W.L.

    1996-12-31

    SOFC pressurization enhances SOFC efficiency and power performance. It enables the direct integration of the SOFC and gas turbine technologies which can form the basis for very efficient combined- cycle power plants. PSOFC/GT cogeneration systems, producing steam and/or hot water in addition to electric power, can be designed to achieve high fuel effectiveness values. A wide range of steam pressures and temperatures are possible owing to system component arrangement flexibility. It is anticipated that Westinghouse will offer small PSOFC/GT power plants for sale early in the next decade. These plants will have capacities less than 10 MW net ac, and they will operate with efficiencies in the 60-65% (net ac/LHV) range.

  2. Closed-cycle helium gas turbine for solar tower power plant

    NASA Astrophysics Data System (ADS)

    Duran, P.

    1980-07-01

    Closed-cycle helium gas turbines with an atmospheric cold heat source, currently under development for very high temperature nuclear power plants, are discussed for use in solar energy conversion systems not requiring long term thermal storage. In the 10 MW-el range, and with a turbine inlet temperature of 900 C, the thermal efficiency of a complex gas turbine, including cooling between low pressure and high pressure compressors as well as reheating between high pressure and low pressure turbine and regenerative heat exhangers, lies between 41 and 43%. The efficiency is constant in time and is sustained even at off-design operation; it is equivalent to the efficiency achieved by a thermal power plant, which allows running the solar plant with an auxiliary fossil fuel combustor.

  3. The cogeneration steam turbine of the T-40/50-8.8 type for the combined cycle power plant PGU-115

    NASA Astrophysics Data System (ADS)

    Valamin, A. Ye.; Kultyshev, A. Yu.; Bilan, V. N.; Goldberg, A. A.; Sakhnin, Yu. A.; Shekhter, M. V.; Paneque Aguilera, H. C.; Stepanov, M. Yu.; Shibaev, T. L.; Polyaeva, Ye. N.

    2012-12-01

    This paper describes the design of the steam turbine intended for a single-unit two-shaft combined-cycle plant and its main systems, the heat flow diagram, and turbine plant arrangement. The turbine should operate as part of the combined-cycle power plant that will be constructed on the basis of the modern PG6111FA gas turbine manufactured in the USA.

  4. Optimization of CCGT power plant and performance analysis using MATLAB/Simulink with actual operational data.

    PubMed

    Hasan, Naimul; Rai, Jitendra Nath; Arora, Bharat Bhushan

    2014-01-01

    In the Modern scenario, the naturally available resources for power generation are being depleted at an alarming rate; firstly due to wastage of power at consumer end, secondly due to inefficiency of various power system components. A Combined Cycle Gas Turbine (CCGT) integrates two cycles- Brayton cycle (Gas Turbine) and Rankine cycle (Steam Turbine) with the objective of increasing overall plant efficiency. This is accomplished by utilising the exhaust of Gas Turbine through a waste-heat recovery boiler to run a Steam Turbine. The efficiency of a gas turbine which ranges from 28% to 33% can hence be raised to about 60% by recovering some of the low grade thermal energy from the exhaust gas for steam turbine process. This paper is a study for the modelling of CCGT and comparing it with actual operational data. The performance model for CCGT plant was developed in MATLAB/Simulink.

  5. Thermal energy storage for integrated gasification combined-cycle power plants

    SciTech Connect

    Drost, M.K.; Antoniak, Z.I.; Brown, D.R.; Somasundaram, S.

    1990-07-01

    There are increasingly strong indications that the United States will face widespread electrical power generating capacity constraints in the 1990s; most regions of the country could experience capacity shortages by the year 2000. The demand for new generating capacity occurs at a time when there is increasing emphasis on environmental concerns. The integrated gasification combined-cycle (IGCC) power plant is an example of an advanced coal-fired technology that will soon be commercially available. The IGCC concept has proved to be efficient and cost-effective while meeting all current environmental regulations on emissions; however, the operating characteristics of the IGCC system have limited it to base load applications. The integration of thermal energy storage (TES) into an IGCC plant would allow it to meet cyclic loads while avoiding undesirable operating characteristics such as poor turn-down capability, impaired part-load performance, and long startup times. In an IGCC plant with TES, a continuously operated gasifier supplies medium-Btu fuel gas to a continuously operated gas turbine. The thermal energy from the fuel gas coolers and the gas turbine exhaust is stored as sensible heat in molten nitrate salt; heat is extracted during peak demand periods to produce electric power in a Rankine steam power cycle. The study documented in this report was conducted by Pacific Northwest Laboratory (PNL) and consists of a review of the technical and economic feasibility of using TES in an IGCC power plant to produce intermediate and peak load power. The study was done for the US Department of Energy's (DOE) Office of Energy Storage and Distribution. 11 refs., 5 figs., 18 tabs.

  6. Binary Cycle Geothermal Demonstration Power Plant New Developments

    SciTech Connect

    Lacy, Robert G.; Jacobson, William O.

    1980-12-01

    San Diego Gas and Electric Company (SDG and E) has been associated with geothermal exploration and development in the Imperial Valley since 1971. SDG and E currently has interests in the four geothermal reservoirs shown. Major SDG and E activities have included drilling and flow testing geothermal exploration wells, feasibility and process flow studies, small-scale field testing of power processes and equipment, and pilot plant scale test facility design, construction and operation. Supporting activities have included geothermal leasing, acquisition of land and water rights, pursual of a major new transmission line to carry Imperial Valley geothermal and other sources of power to San Diego, and support of Magma Electric's 10 MW East Mesa Geothermal Power Plant.

  7. Yannawa wastewater treatment plant (Bangkok, Thailand): design, construction and operation.

    PubMed

    Kirkwood, S

    2004-01-01

    Yannawa Wastewater Treatment plant (Phase 1) serves a population equivalent of 500,000 and is located on a restricted site within the city of Bangkok, Thailand. Secondary treatment is based on the CASS sequencing batch reactor (SBR) process and the plant is one of the largest multi-storey SBRs in the world. The limitation of available site area, the ground conditions and the characteristics of the wastewater to be treated set a series of challenges for the designers, contractors and commissioning and operational staff. This paper briefly describes the collection system, the process selection and the treatment streams of the wastewater treatment plant. The SBR secondary treatment plant is described in more detail. The problems that arose during commissioning and operation and the solutions made possible by the use of an SBR type of process are discussed. Details of plant performance during performance testing and during the first three years of plant operation are provided.

  8. Parametric study of a two-shaft gas turbine cycle model of power plant

    NASA Astrophysics Data System (ADS)

    Ibrahim, Thamir K.; Rahman, M. M.

    2012-09-01

    In this paper, the parametric study of a two shafts gas turbine cycle model of the power plant was proposed. The power output, compression work, specific fuel consumption and thermal efficiency are evaluated with respect to the cycle temperature and compression ratio for a typical set of operating conditions. Two shafts gas turbine cycle with realistic parameters is modeled. The computational model was developed utilizing the MATLAB codes. Turbine work found to be decreases as ambient temperature increases as well as the thermal efficiency decreases. It can be seen that the thermal efficiency and power output increases linearly with increases of compression ratio while decreases of ambient temperature. The power of the simulated two shafts gas turbine reach to 135MW, which is higher than the simple gas-turbine cycle (Baiji gas turbine power plant, power < 131MW). The specific fuel consumption increases with increases of ambient temperature as well as the lower turbine inlet temperature. Even though at the lower turbine inlet temperature is decrement the thermal efficiency dramatically and the power output increases linearly with increases of compression ratio and decreases the ambient temperature.

  9. High-Level Functional and Operational Requirements for the Advanced Fuel Cycle Facilty

    SciTech Connect

    Charles Park

    2006-12-01

    High-Level Functional & Operational Requirements for the AFCF -This document describes the principal functional and operational requirements for the proposed Advanced Fuel Cycle Facility (AFCF). The AFCF is intended to be the world's foremost facility for nuclear fuel cycle research, technology development, and demonstration. The facility will also support the near-term mission to develop and demonstrate technology in support of fuel cycle needs identified by industry, and the long-term mission to retain and retain U.S. leadership in fuel cycle operations. The AFCF is essential to demonstrate a more proliferation-resistant fuel cycle and make long-term improvements in fuel cycle effectiveness, performance and economy.

  10. Correlation and reassessment of the OTEC plant power cycle

    NASA Astrophysics Data System (ADS)

    Heydt, G. T.; Leidenfrost, W.; McDonald, A. T.; Ogborn, L. L.

    1984-07-01

    The purpose of this effort is to investigate alternative system concepts and component configurations to improve performance of the OTEC power system. Reliability, Availability, and Maintainability (RAM) characteristics were examined along with various methods of converting energy into utility-grade energy. A research program consisting of five tasks was developed: development of engineering guidelines for OTEC systems; thermal and mechanical evaluation of components; evaluation of electrical system requirements; evaluation of operating strategies for OTEC plants; and application of modern technology to OTEC design choices. These studies are discussed in detail along with recommendations and conclusions.

  11. Design and initial operation of Dofasco's CPCM wastewater treatment plant

    SciTech Connect

    Harschnitz, P.; Kowalchuk, W.; Ray, E.L.; Rynn, K.A. )

    1994-04-01

    A new coupled picking/cold mill (CPCM) was recently commissioned at Dofasco. The complex produces oily, particulate bearing and acidic wastewaters which must be managed in an environmentally sound manner. Segregation of these streams within the mill and a new wastewater treatment plant satisfy this requirement. The design of the wastewater treatment plant was based on meeting current and anticipated government regulations, incorporating Best Available Technology, maximize reuse/recycle and minimizing operating cost. The treatment plant was commissioned during 1992. Extensive training was provided for operations and maintenance personnel. While start-up took longer than expected and required a number of minor modifications, the plant has consistently met discharge criteria.

  12. AVESTAR Center for Operational Excellence of Clean Energy Plants

    SciTech Connect

    Zitney, Stephen

    2012-01-01

    To address challenges in attaining operational excellence for clean energy plants, the U.S. Department of Energy's National Energy Technology Laboratory has launched a world-class facility for Advanced Virtual Energy Simulation Training and Research (AVESTAR{trademark}). The AVESTAR Center brings together state-of-the-art, real time,high-fidelity dynamic simulators with operator training systems and 3D virtual immersive training systems into an integrated energy plant and control room environment. This presentation will highlight the AVESTAR Center simulators, facilities, and comprehensive training, education, and research programs focused on the operation and control of high-efficiency, near-zero-emission energy plants.

  13. AVESTAR Center for Operational Excellence of Clean Energy Plants

    SciTech Connect

    Zitney, Stephen

    2012-05-01

    To address challenges in attaining operational excellence for clean energy plants, the U.S.Department of Energy’s National Energy Technology Laboratory has launched a world-class facility for Advanced Virtual Energy Simulation Training and Research (AVESTAR™). The AVESTAR Center brings together state-of-the-art, real time,high-fidelity dynamic simulators with operator training systems and 3D virtual immersive training systems into an integrated energy plant and control room environment. This presentation will highlight the AVESTAR Center simulators, facilities, and comprehensive training, education, and research programs focused on the operation and control of high-efficiency, near-zero-emission energy plants.

  14. SSPS monthly data, October 1984. Plant operation report and daily operation summary

    SciTech Connect

    Not Available

    1984-01-01

    Operation and maintenance highlights and test and evaluation highlights are presented for the Small Solar Power Systems (SSPS) Central Receiver System (CRS) and Distributed Collector System (DCS). The major portion of this report consists of the following plant statistics for October, 1984: monthly operation summary; CRS daily operation summary; and DCS daily operation summary.

  15. SSPS monthly data, (December 1984). Plant operation report and daily operation summary

    SciTech Connect

    Not Available

    1984-01-01

    Operation and maintenance highlights and test and evaluation highlights are presented for the Small Solar Power Systems (SSPS) Central Receiver System (CRS) and Distributed Collector System (DCS). The major portion of this report consists of the following plant statistics for December 1984: monthly operation summary; CRS daily operation summary; and DCS daily operation summary.

  16. Plant operation report and daily operation summary. SSPS monthly data, March 1984. [Small Solar Power System

    SciTech Connect

    Not Available

    1984-01-01

    Operation and maintenance highlights and test and evaluation highlights are presented for the Small Solar Power Systems (SSPS) Central Receiver System (CRS) and Distributed Collector System (DCS). The major portion of this report consists of the following plant statistics: monthly operation summary for March 1984; CRS daily operation summary; and DCS daily operation summary.

  17. SSPS monthly data, August 1984: plant operation report and daily operation summary

    SciTech Connect

    Not Available

    1984-08-01

    Operation and maintenance highlights and test and evaluation highlights are presented for the Small Solar Power Systems (SSPS) Central Receiver System (CRS) and Distributed Collector System (DCS). The major portion of this report consists of the following plant statistics: monthly operation summary for August 1984; CRS daily operation summary; and DCS daily operation summary.

  18. SSPS monthly data, September 1984: plant operation report and daily operation summary

    SciTech Connect

    Not Available

    1984-09-01

    Operation and maintenance highlights and test and evaluation highlights are presented for Small Solar Power Systems (SSPS) Central Receiver System (CRS) and Distributed Collector System (DCS). The major portion of this report consists of the following plant statistics: monthly operation and summary for September 1984; CRS daily operation summary; and DCS daily operation summary. (LEW).

  19. SSPS monthly data, November 1984. Plant operation report and daily operation summary

    SciTech Connect

    Not Available

    1984-01-01

    Operation and maintenance highlights and test and evaluation highlights are presented for the Small Solar Power Systems (SSPS) Central Receiver System (CRS) and Distributed Collector System (DCS). The major portion of this report consists of the following plant statistics for November 1984: monthly operation summary, CRS daily operation summary, and DCS daily operation summary.

  20. STS-1 operational flight profile. Volume 5: Descent, cycle 3

    NASA Technical Reports Server (NTRS)

    Moore, R.; Baker, A.; Hite, R.; Hochstein, A.; Lyons, J.; Strong, K.

    1980-01-01

    The trajectory data presented are to be used for orbiter systems and subsystems evalation, flight and mission control center software verification, flight techniques and timeline development, crew training, and evaluation of operational mission suitability. The entry profile is very similar to cycle 2, however, elevon and body flap temperature margins have increased and the elevon schedule was changed. The terminal area energy management (TAEM) profile was completely reshaped to conform with new angle of attack constraints and left hand turn around the heading alignment cylinder. Also, the entry/TAEM interface was adjusted to minimize guidance induced angle of attack transients across the interface. The approach and landing phase was reshaped for a 20 deg glideslope and reduced velocity at touchdown. The definition of the runway threshold was standardized for all landing sites. This results in a shift at Edwards Air Force Base in aim points and touchdown relative to the threshold of 1000 feet. The rollout remains essentially unchanged with the exception of the speedbrake, which is now deployed to 50 percent at touchdown.

  1. Thioredoxin, a master regulator of the tricarboxylic acid cycle in plant mitochondria.

    PubMed

    Daloso, Danilo M; Müller, Karolin; Obata, Toshihiro; Florian, Alexandra; Tohge, Takayuki; Bottcher, Alexandra; Riondet, Christophe; Bariat, Laetitia; Carrari, Fernando; Nunes-Nesi, Adriano; Buchanan, Bob B; Reichheld, Jean-Philippe; Araújo, Wagner L; Fernie, Alisdair R

    2015-03-17

    Plant mitochondria have a fully operational tricarboxylic acid (TCA) cycle that plays a central role in generating ATP and providing carbon skeletons for a range of biosynthetic processes in both heterotrophic and photosynthetic tissues. The cycle enzyme-encoding genes have been well characterized in terms of transcriptional and effector-mediated regulation and have also been subjected to reverse genetic analysis. However, despite this wealth of attention, a central question remains unanswered: "What regulates flux through this pathway in vivo?" Previous proteomic experiments with Arabidopsis discussed below have revealed that a number of mitochondrial enzymes, including members of the TCA cycle and affiliated pathways, harbor thioredoxin (TRX)-binding sites and are potentially redox-regulated. We have followed up on this possibility and found TRX to be a redox-sensitive mediator of TCA cycle flux. In this investigation, we first characterized, at the enzyme and metabolite levels, mutants of the mitochondrial TRX pathway in Arabidopsis: the NADP-TRX reductase a and b double mutant (ntra ntrb) and the mitochondrially located thioredoxin o1 (trxo1) mutant. These studies were followed by a comparative evaluation of the redistribution of isotopes when (13)C-glucose, (13)C-malate, or (13)C-pyruvate was provided as a substrate to leaves of mutant or WT plants. In a complementary approach, we evaluated the in vitro activities of a range of TCA cycle and associated enzymes under varying redox states. The combined dataset suggests that TRX may deactivate both mitochondrial succinate dehydrogenase and fumarase and activate the cytosolic ATP-citrate lyase in vivo, acting as a direct regulator of carbon flow through the TCA cycle and providing a mechanism for the coordination of cellular function.

  2. Plant Growth and Development: An Outline for a Unit Structured Around the Life Cycle of Rapid-Cycling Brassica Rapa.

    ERIC Educational Resources Information Center

    Becker, Wayne M.

    This outline is intended for use in a unit of 10-12 lectures on plant growth and development at the introductory undergraduate level as part of a course on organismal biology. The series of lecture outlines is structured around the life cycle of rapid-cycling Brassica rapa (RCBr). The unit begins with three introductory lectures on general plant…

  3. Greenhouse gas emissions from forestry operations: a life cycle assessment.

    PubMed

    Sonne, Edie

    2006-01-01

    Most forest carbon assessments focus only on biomass carbon and assume that greenhouse gas (GHG) emissions from forestry activities are minimal. This study took an in-depth look at the direct and indirect emissions from Pacific Northwest (PNW) Douglas-fir [Pseudotsuga menziesii (Mirbel) Franco] forestry activities to support or deny this claim. Greenhouse gas budgets for 408 "management regimes" were calculated using Life Cycle Assessment (LCA) methodology. These management regimes were comprised of different combinations of three types of seedlings (P + 1, 1 + 1, and large plug), two types of site preparation (pile and burn, and chemical), 17 combinations of management intensity including fertilization, herbicide treatment, pre-commercial thinning (PCT), commercial thinning (CT), and nothing, and four different rotation ages (30, 40, 50, and 60 yr). Normalized to 50 yr, average direct GHG emissions were 8.6 megagrams (Mg) carbon dioxide equivalents (CO2e) ha(-1), which accounted for 84% of total GHG emissions from the average of 408 management regimes. Harvesting (PCT, CT, and clear cutting) contributed the most to total GHG emissions (5.9 Mg CO2e per 700 m3 harvested timber), followed by pile and burn site preparation (4.0 Mg CO2e ha(-1) or 32% of total GHG emissions) and then fertilization (1.9 Mg CO2e ha(-1) or 15% of total GHG emissions). Seedling production, seedling transportation, chemical site preparation, and herbicide treatment each contributed less than 1% of total GHG emissions when assessed per hectare of planted timberland. Total emissions per 100 m3 averaged 1.6 Mg CO2e ha(-1) over all 408 management regimes. An uncertainty analysis using Monte Carlo simulations revealed that there are significant differences between most alternative management regimes.

  4. Computer control improves ethylene plant operation

    SciTech Connect

    Whitehead, B.D.; Parnis, M.

    1987-11-01

    ICIA Australia ordered a turnkey 250,000-tpy ethylene plant to be built at the Botany site, Sydney, Australia. Following a feasibility study, an additional order was placed for a process computer system for advanced process control and optimization. This article gives a broad outline of the process computer tasks, how the tasks were implemented, what problems were met, what lessons were learned and what results were achieved.

  5. Influence of Plants on Chlorine Cycling in Terrestrial Environments

    NASA Astrophysics Data System (ADS)

    Montelius, Malin; Thiry, Yves; Marang, Laura; Ranger, Jacques; Cornelis, Jean-Thomas; Svensson, Teresia; Bastviken, David

    2016-04-01

    Chlorine (Cl), one of the 20 most abundant elements on Earth, is crucial for life as a regulator of cellular ionic strength and an essential co-factor in photosynthesis. Chlorinated organic compounds (Clorg) molecules are surprisingly abundant in soils, in fact many studies during the last decades show that Clorg typically account for more than 60% of the total soil Cl pool in boreal and temperate forest soils and frequently exceed chloride (Cl-) levels. The natural and primarily biotic formation of this Clorg pool has been confirmed experimentally but the detailed content of the Clorg pool and the reasons for its high abundance remains puzzling and there is a lack of Cl budgets for different ecosystems. Recently, the radioisotope 36Cl has caused concerns because of presence in radioactive waste, a long half-life (301 000 years), potential high mobility, and limited knowledge about Cl residence times, speciation and uptake by organisms in terrestrial environments. The chlorination of organic molecules may influence the pool of available Cl- to organisms and thereby the Cl cycling dynamics. This will prolong residence times of total Cl in the soil-vegetation system, which affects exposure times in radioactive 36Cl isotope risk assessments. We tested to what extent the dominating tree species influences the overall terrestrial Cl cycling and the balance between Cl- and Clorg. Total Cl and Clorg were measured in different tree compartments and soil horizons in the Breuil experimental forest, Bourgogne, established in 1976 and located at Breuil-Chenue in Eastern France. The results from this field experiment show how the dominating tree species affected Cl cycling and accumulation over a time period of 30 years. Cl uptake by trees as well as content of both total Cl and Clorg in soil humus was much higher in experimental plots with coniferous forests compared to deciduous forests. The amounts of Clorg found in plant tissue indicate significant Clorg production inside

  6. Industrial bottoming-cycle targeting of opportunities at the plant site. Volume I. Executive summary

    SciTech Connect

    Moore, N.L.; Brown, H.L.; Hamel, B.B.; Toy, M.P.; Hedman, B.A.

    1982-09-01

    Bottoming cycle potential in the US industrial marketplace is identified using the General Energy Associates Industrial Plant Energy Profile Data Base. From the data base technology evaluations and economic estimates can be made directly at the plant site level. The top 10,000 plants in the country were individually analyzed for these bottoming cycle applications. Results are summarized as follows: potential number of plant sites and megawatts, potential energy savings, electric production, regional and state profiles, bottoming cycle/working fluid systems, and projection of future bottoming cycle applications.

  7. Operating experience with a flexible cogeneration plant in Colorado

    SciTech Connect

    Wadman, B.

    1997-01-01

    Much has been written about the interesting gas turbine cogeneration Project in Fort Lupton, Colorado, U.S.A., as created and developed by the Thermo Cogeneration Partnership under the leadership of Paul Steinway, project general manager. The plant is based on five 40 MW-class gas turbine generator modules supplied by Stewart & Stevenson, who is also responsible for operation and maintenance of the plant through its operating arm, Stewart & Stevenson Operations, Inc. The plant, first placed into service in mid-1994 after only 18 months of construction, is of particular interest because it has to function with a wide degree of flexibility in load management, and it also uses one of the latest-design aeroderivative gas turbines, namely the GE LM6000. This article describes the plant design, equipment and operating experience thus far. 6 figs.

  8. How-to-Do-It. Fast Plants--Rapid-Cycling Brassicas.

    ERIC Educational Resources Information Center

    Hafner, Robert

    1990-01-01

    Described is an activity in which the life cycle of a plant is investigated over a 20-day period. Included are background information, a list of materials, procedures, diagrams of the plant, apparatus, and pollination. An outline is suggested. (CW)

  9. How-to-Do-It. Fast Plants--Rapid-Cycling Brassicas.

    ERIC Educational Resources Information Center

    Hafner, Robert

    1990-01-01

    Described is an activity in which the life cycle of a plant is investigated over a 20-day period. Included are background information, a list of materials, procedures, diagrams of the plant, apparatus, and pollination. An outline is suggested. (CW)

  10. Analyzing the possibility of constructing the air heating system for an integrated solid fuel gasification combined-cycle power plant

    NASA Astrophysics Data System (ADS)

    Mikula, V. A.; Ryzhkov, A. F.; Val'tsev, N. V.

    2015-11-01

    Combined-cycle power plants operating on solid fuel have presently been implemented only in demonstration projects. One of possible ways for improving such plants consists in making a shift to hybrid process circuits of integrated gasification combined-cycle plants with external firing of solid fuel. A high-temperature air heater serving to heat compressed air is a key element of the hybrid process circuit. The article describes application of a high-temperature recuperative metal air heater in the process circuit of an integrated gasification combined-cycle power plant (IGCC). The available experience with high-temperature air heating is considered, and possible air heater layout arrangements are analyzed along with domestically produced heat-resistant grades of steel suitable for manufacturing such air heater. An alternative (with respect to the traditional one) design is proposed, according to which solid fuel is fired in a noncooled furnace extension, followed by mixing the combustion products with recirculation gases, after which the mixture is fed to a convective air heater. The use of this design makes it possible to achieve considerably smaller capital outlays and operating costs. The data obtained from thermal and aerodynamic calculations of the high-temperature air heater with a thermal capacity of 258 MW for heating air to a temperature of up to 800°C for being used in the hybrid process circuit of a combined-cycle power plant are presented.

  11. Davis PV plant operation and maintenance manual

    SciTech Connect

    1994-09-01

    This operation and maintenance manual contains the information necessary to run the Photovoltaics for Utility Scale Applications (PVUSA) test facility in Davis, California. References to more specific information available in drawings, data sheets, files, or vendor manuals are included. The PVUSA is a national cooperative research and demonstration program formed in 1987 to assess the potential of utility scale photovoltaic systems.

  12. Streamlined Plant Operations Save $300,000

    ERIC Educational Resources Information Center

    Nikkel, W. H.

    1974-01-01

    Describes results of turning to management consulting by Oakland Community College in Bloomfield Hills, Illinois. From an expensive, overstaffed custodial/maintenance department and inadequate work scheduling and supervision, Oakland went to a streamlined operation with procedures and manpower requirements optimized through use of a sophisticated…

  13. Prediction of Technological Failures in Nuclear Power Plant Operation

    SciTech Connect

    Salnykov, A. A.

    2015-01-15

    A method for predicting operating technological failures in nuclear power plants which makes it possible to reduce the unloading of the generator unit during the onset and development of an anomalous engineering state of the equipment by detecting a change in state earlier and taking suitable measures. With the circulating water supply loop of a nuclear power plant as an example, scenarios and algorithms for predicting technological failures in the operation of equipment long before their actual occurrence are discussed.

  14. Transient studies of an Integrated Gasification Combined Cycle (IGCC) plant with CO2 capture

    SciTech Connect

    Bhattacharyya, D.; Turton, R.; Zitney, S.

    2010-01-01

    Next-generation coal-fired power plants need to consider the option for CO2 capture as stringent governmental mandates are expected to be issued in near future. Integrated gasification combined cycle (IGCC) plants are more efficient than the conventional coal combustion processes when the option for CO2 capture is considered. However, no IGCC plant with CO2 capture currently exists in the world. Therefore, it is important to consider the operability and controllability issues of such a plant before it is commercially built. To facilitate this objective, a detailed plant-wide dynamic simulation of an IGCC plant with 90% CO2 capture has been developed in Aspen Plus Dynamics{reg_sign}. The plant considers a General Electric Energy (GEE)-type downflow radiant-only gasifier followed by a quench section. A two-stage water gas shift (WGS) reaction is considered for conversion of CO to CO2. A two-stage acid gas removal (AGR) process based on a physical solvent is simulated for selective capture of H2S and CO2. Compression of the captured CO2 for sequestration, an oxy-Claus process for removal of H2S and NH3, black water treatment, and the sour water treatment are also modeled. The tail gas from the Claus unit is recycled to the SELEXOL unit. The clean syngas from the AGR process is sent to a gas turbine followed by a heat recovery steam generator. This turbine is modeled as per published data in the literature. Diluent N2 is used from the elevated-pressure ASU for reducing the NOx formation. The heat recovery steam generator (HRSG) is modeled by considering generation of high-pressure, intermediate-pressure, and low-pressure steam. All of the vessels, reactors, heat exchangers, and the columns have been sized. The basic IGCC process control structure has been synthesized by standard guidelines and existing practices. The steady state results are validated with data from a commercial gasifier. In the future grid-connected system, the plant should satisfy the environmental

  15. 40 CFR 86.884-7 - Dynamometer operation cycle for smoke emission tests.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 19 2011-07-01 2011-07-01 false Dynamometer operation cycle for smoke... (CONTINUED) Emission Regulations for New Diesel Heavy-Duty Engines; Smoke Exhaust Test Procedure § 86.884-7 Dynamometer operation cycle for smoke emission tests. (a) The following sequence of operations shall be...

  16. 40 CFR 86.884-7 - Dynamometer operation cycle for smoke emission tests.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 19 2010-07-01 2010-07-01 false Dynamometer operation cycle for smoke... (CONTINUED) Emission Regulations for New Diesel Heavy-Duty Engines; Smoke Exhaust Test Procedure § 86.884-7 Dynamometer operation cycle for smoke emission tests. (a) The following sequence of operations shall be...

  17. Relationship between xanthophyll cycle and non-photochemical quenching in rice (Oryza sativa L.) plants in response to light stress.

    PubMed

    Vaz, Janet; Sharma, Prabhat K

    2011-01-01

    Thirty days old rice plants grown under low and moderate light conditions were transferred to full sunlight to observe the extent of photoinhibitory damage and protective mechanism, and the relationship between xanthophyll cycle and nonphotochemical quenching (qN) under changing light environment. Control plants (low, moderate and sun grown) exhibited similar Fv/Fm ratio, indicating similar photosynthetic efficiency prior to light stress. On exposure to the high light treatment, low light grown plants exhibited faster and higher degree of photoinhibition compared to moderate and high light grown plants. Moderate and high light grown plants showed relatively less photoinhibition and also showed higher qN, indicating better capacity of energy dissipation. Increase in qN in moderate light and sun grown plants was accompanied by conversion of violaxanthin (V) to antheraxanthin (A) and zeaxanthin (Z) indicating operation of Z-dependent thermal dissipation. Rice plants fed with ascorbate (AsA), a stimulator of the de-epoxidation state of V to Z, showed higher Fv/Fm ratio and qN than the plants fed with dithiothreitol (DTT) an inhibitor of xanthophyll cycle. This indicated that an increased amount of energy reached PS II reaction centre, due to absence of A and Z formation, thereby causing greater damage to photosynthesis in DTT fed rice plants. The present data confirmed the relationship between qN and Z in dissipating the excess light energy, thereby protecting plants against photodamage.

  18. US nuclear power plant operating cost and experience summaries

    SciTech Connect

    Kohn, W.E.; Reid, R.L.; White, V.S.

    1998-02-01

    NUREG/CR-6577, U.S. Nuclear Power Plant Operating Cost and Experience Summaries, has been prepared to provide historical operating cost and experience information on U.S. commercial nuclear power plants. Cost incurred after initial construction are characterized as annual production costs, representing fuel and plant operating and maintenance expenses, and capital expenditures related to facility additions/modifications which are included in the plant capital asset base. As discussed in the report, annual data for these two cost categories were obtained from publicly available reports and must be accepted as having different degrees of accuracy and completeness. Treatment of inconclusive and incomplete data is discussed. As an aid to understanding the fluctuations in the cost histories, operating summaries for each nuclear unit are provided. The intent of these summaries is to identify important operating events; refueling, major maintenance, and other significant outages; operating milestones; and significant licensing or enforcement actions. Information used in the summaries is condensed from annual operating reports submitted by the licensees, plant histories contained in Nuclear Power Experience, trade press articles, and the Nuclear Regulatory Commission (NRC) web site (www.nrc.gov).

  19. Surveillance dosimetry of operating power plants

    SciTech Connect

    McElroy, W.N.; Davis, A.I.; Gold, R.

    1981-10-16

    The main focus of the research efforts presently underway is the LWR power reactor surveillance program in which metallurgical test specimens of the reactor PV and dosimetry sensors are placed in three or more surveillance capsules at or near the reactor PV inner wall. They are then irradiated in a temperature and neutron flux-spectrum environment as similar as possible to the PV itself for periods of about 1.5 to 15 effective full-power years (EFPY), with removal of the last capsule at a fluence corresponding to the 30- to 40-year plant end-of-life (EOL) fluence. Because the neutron flux level at the surveillance position is greater than at the vessel, the test is accelerated wit respect to the vessel exposure, allowing early assessment of EOL conditions.

  20. Startup optimization of a combined cycle power plant based on cooperative fuzzy reasoning and a neural network

    SciTech Connect

    Matsumoto, H.; Ohsawa, Y.; Takahashi, S.; Akiyama, T.; Hanaoka, H.; Ishiguro, O.

    1997-03-01

    A startup optimization control system for a gas and steam turbine combined cycle power plant is developed. The system can minimize startup time of the plant through cooperative fuzzy reasoning and a neural network autonomously adapting to varying process dynamics due to varying operational conditions, i.e. the ambient temperature and humidity. The operational conditions are taken into consideration by the neural network with a learning mechanism to optimize the schedule. The system is applied to a simulation for a plant with a three pressure staged reheat type 235.7 MW rated capacity, and the following points are seen: (1) the system can harmonize machines operations making good use of the operational margins, i.e. machine thermal stress and NOx emission; (2) startup time and energy loss are reduced by 35.6% and 26.3%, respectively, compared with the conventional off-line startup scheduling method.

  1. Operation of Wastewater Treatment Plants, Manual of Practice No. 11.

    ERIC Educational Resources Information Center

    Albertson, Orrie E.; And Others

    This book is intended to be a reference or textbook on the operation of wastewater treatment plants. The book contains thirty-one chapters and three appendices and includes the description, requirements, and latest techniques of conventional unit process operation, as well as the symptoms and corrective measures regarding process problems. Process…

  2. Operation of Wastewater Treatment Plants, Manual of Practice No. 11.

    ERIC Educational Resources Information Center

    Albertson, Orrie E.; And Others

    This book is intended to be a reference or textbook on the operation of wastewater treatment plants. The book contains thirty-one chapters and three appendices and includes the description, requirements, and latest techniques of conventional unit process operation, as well as the symptoms and corrective measures regarding process problems. Process…

  3. Operation of Wastewater Treatment Plants: A Home Study Training Program.

    ERIC Educational Resources Information Center

    California State Univ., Sacramento. Dept. of Civil Engineering.

    This manual was prepared by experienced wastewater treatment plant operators to provide a home study course to develop new qualified workers and expand the abilities of existing workers. The objective of this manual is to provide the knowledge and skills necessary for certification. Participants learn the basic operational aspects of treatment…

  4. Operation of Wastewater Treatment Plants: A Home Study Training Program.

    ERIC Educational Resources Information Center

    California State Univ., Sacramento. Dept. of Civil Engineering.

    This manual was prepared by experienced wastewater treatment plant operators to provide a home study course to develop new qualified workers and expand the abilities of existing workers. The objective of this manual is to provide the knowledge and skills necessary for certification. Participants learn the basic operational aspects of treatment…

  5. Annual radiological environmental operating report: Browns Ferry Nuclear Plant, 1992. Operations Services/Technical Programs

    SciTech Connect

    Not Available

    1993-04-01

    This report describes the environmental radiological monitoring program conducted by TVA in the vicinity of Browns Ferry Nuclear Plant (BFN) in 1992. The program includes the collection of samples from the environment and the determination of the concentrations of radioactive materials in the samples. Samples are taken from stations in the general area of the plant and from areas not influenced by plant operations. Station locations are selected after careful consideration of the weather patterns and projected radiation doses to the various areas around the plant. Material sampled includes air, water, milk, foods, vegetation, soil, fish, sediment, and direct radiation levels. Results from stations near the plant are compared with concentrations from control stations and with preoperational measurements to determine potential impacts of plant operations. Small amounts of Co-60 and Cs-134 were found in sediment samples downstream from the plant. This activity in stream sediment would result in no measurable increase over background in the dose to the general public.

  6. Operational and design strategies to improve PFBC power plant efficiency

    SciTech Connect

    Romeo, L.M.; Cortes, C.; Martinez, D.

    1998-07-01

    Nowadays the state of the art of PFBC technology lies halfway between the demonstration stage in units of intermediate size (72--79 MWe) and the commercial availability of larger scale plants. The operation of existing power stations has demonstrated that several points remain widely open to improvements. Due to fuel quality effects and the use of retrofitted plants, the PFBC power plant efficiency presently demands significant improvements. Likewise, the high energy efficiencies offered by the PFBC concept had not been completely demonstrated. To overcome these difficulties and further develop the technology a semiempirical model of a pressurized fluidized bed power plant has been developed. The model has been validated with actual plant data, being able to predict the Escatron (Spain) PFBC power plant behavior under different operating conditions. It has been widely tested to study not only the fluidized bed behavior, but also the influence of fluidized bed variables in the rest of the power plant. Good agreement has been found between the computed results and actual plant data at different operational regimes for the most important variables of the power plant. The main aim of this model is to study different strategies to improve the efficiency in the power plant. These strategies include: the improvement of soot blowing schedules of external heat exchangers; air preheating system optimization; selection of operational set-points that bring the highest efficiency; evaluation of the efficiency improvements due to design changes (changes in retrofitted steam turbines and heat exchangers, natural gas reburning, selection of different types of coal). This paper describes the model developed, the strategies to improve efficiency, as well as its results, and as conclusions, point out the improvements and perspectives for future work.

  7. The effectiveness of combined-cycle power plants hot startups simulating

    NASA Astrophysics Data System (ADS)

    Radin, Yu. A.; Kontorovich, T. S.; Molchanov, K. A.

    2015-09-01

    Activities aimed at substantiating the maneuverability characteristics of power-generating equipment installed at district heating power plants (DHPP) and especially at combined-cycle power plants (CCPPs) are quite topical for the modern conditions and involve calculations of thermally stressed state and analysis of the cyclic strength of steam path critical elements at different loading rates. Until recently, such problems have been solved in two possible ways: based on the results of tests carried out on operating equipment and using the mathematical models of heavily stressed parts of CCPP equipment. In this article, preference is given to the second way. The results of mathematical modeling represented as time dependences of the temperature state of equipment critical parts were taken as initial data for calculating their thermally stressed state and for analyzing their damageability according to the criterion of the equivalent operating hours. This criterion is an integral indicator characterizing the extent of damage accumulated in equipment parts and can be used for elaborating equipment maintenance programs. A dependence of the equivalent operating hours on the initial temperature of the metal of the high-pressure steam superheater's outlet header, the component imposing the strongest limitations on the power unit loading rate, is obtained. It is shown that the number of equivalent operating hours of the CCPP steam circuit part equipment accumulated during hot startups does not have any essential effect on the equipment service life (heat-recovery steam generators, steam turbine, and steam lines).

  8. New Mexico gas plant operator automates field control

    SciTech Connect

    Trosper, R.L. ); Stubbs, R.G. ); Carver, D. )

    1994-03-07

    GPM Gas Corp., Houston, a subsidiary of Phillips Petroleum Co., has implemented a field automation control system (FACS) that allows company operators remotely to monitor natural-gas operations in GPM's New Mexico region. The system has helped improve operating efficiencies and reduce staffing. Operators can now accurately monitor and control gas gathering, booster, and plant operations. The systems allows remote monitoring and measuring of gas flow rates, temperatures, and pressures from the wellhead through processing. Producers who sell gas into GPM's systems now have access to real-time production information through telephone or facsimile for each individual meter station connected to their well sites.

  9. Operation and analysis of a supercritical CO2 Brayton cycle.

    SciTech Connect

    Wright, Steven Alan; Radel, Ross F.; Vernon, Milton E.; Pickard, Paul S.; Rochau, Gary Eugene

    2010-09-01

    Sandia National Laboratories is investigating advanced Brayton cycles using supercritical working fluids for use with solar, nuclear or fossil heat sources. The focus of this work has been on the supercritical CO{sub 2} cycle (S-CO2) which has the potential for high efficiency in the temperature range of interest for these heat sources, and is also very compact, with the potential for lower capital costs. The first step in the development of these advanced cycles was the construction of a small scale Brayton cycle loop, funded by the Laboratory Directed Research & Development program, to study the key issue of compression near the critical point of CO{sub 2}. This document outlines the design of the small scale loop, describes the major components, presents models of system performance, including losses, leakage, windage, compressor performance, and flow map predictions, and finally describes the experimental results that have been generated.

  10. An Examination of Operational Availability in Life Cycle Cost Models

    DTIC Science & Technology

    1983-09-01

    necessary and identify by block number) Life Cycle Cost Management Reliability Life Cycle Cost Model Maintainability Availability Supportability...availability and the relative cost for those levels. 2 The analytical models must go beyond individual parameters of reliability and maintainability (R&M...availability is a function of reliability and maintainability (R&M) (3:20). The two terms that comprise the function are defined here. Reliability : The

  11. Design and operation of small biogas plants

    SciTech Connect

    Abdel-Dayem, A.M.; Hamad, M.A.

    1980-12-01

    This paper concentrates on the experience gained from the adaptation of the Chinese biogas technology to rural areas of Egypt. Three different prototype digesters have been constructed. The first is a 10 M/sup 3/ rectangular digester of the water pressure type, the second is a 6 M/sup 3/ circular and shallow digester with domed roof and dished bottom. The third prototype unit with a capacity of 7 M/sup 3/ has been recently constructed. It combines the features of both plug flow and the Indian movable cap types. Provisions for solar heating of feed water, composting of effluent and attachments to both latrine and animal shed were incorporated in the unit. The structural theory, design criteria, construction technique and cost estimation of the circular digester are described. Some operation and performance data of the circular digester are presented. This covers the effects of variation of ambient temperature on internal temperature, effects of temperature and pressure on the gas production rate and composition.

  12. Evaluation of the ECAS open cycle MHD power plant design

    NASA Technical Reports Server (NTRS)

    Seikel, G. R.; Staiger, P. J.; Pian, C. C. P.

    1978-01-01

    The Energy Conversion Alternatives Study (ECAS) MHD/steam power plant is described. The NASA critical evaluation of the design is summarized. Performance of the MHD plant is compared to that of the other type ECAS plant designs on the basis of efficiency and the 30-year levelized cost of electricity. Techniques to improve the plant design and the potential performance of lower technology plants requiring shorter development time and lower development cost are then discussed.

  13. Numerical Research of Steam and Gas Plant Efficiency of Triple Cycle for Extreme North Regions

    NASA Astrophysics Data System (ADS)

    Galashov, Nikolay; Tsibulskii, Svjatoslav; Matveev, Aleksandr; Masjuk, Vladimir

    2016-02-01

    The present work shows that temperature decrease of heat rejection in a cycle is necessary for energy efficiency of steam turbine plants. Minimum temperature of heat rejection at steam turbine plant work on water steam is 15°C. Steam turbine plant of triple cycle where lower cycle of steam turbine plant is organic Rankine cycle on low-boiling substance with heat rejection in air condenser, which safely allows rejecting heat at condensation temperatures below 0°C, has been offered. Mathematical model of steam and gas plant of triple cycle, which allows conducting complex researches with change of working body appearance and parameters defining thermodynamic efficiency of cycles, has been developed. On the basis of the model a program of parameters and index cycles design of steam and gas plants has been developed in a package of electron tables Excel. Numerical studies of models showed that energy efficiency of steam turbine plants of triple cycle strongly depend on low-boiling substance type in a lower cycle. Energy efficiency of steam and gas plants net 60% higher can be received for steam and gas plants on the basis of gas turbine plant NK-36ST on pentane and its condensation temperature below 0°C. It was stated that energy efficiency of steam and gas plants net linearly depends on condensation temperature of low-boiling substance type and temperature of gases leaving reco very boiler. Energy efficiency increases by 1% at 10% decrease of condensation temperature of pentane, and it increases by 0.88% at 15°C temperature decrease of gases leaving recovery boiler.

  14. Beyond the conventional life cycle inventory in wastewater treatment plants.

    PubMed

    Lorenzo-Toja, Yago; Alfonsín, Carolina; Amores, María José; Aldea, Xavier; Marin, Desirée; Moreira, María Teresa; Feijoo, Gumersindo

    2016-05-15

    The conventional approach for the environmental assessment of wastewater treatment plants (WWTPs) is typically based on the removal efficiency of organic load and nutrients as well as the quantification of energy and chemicals consumption. Current wastewater treatment research entails the monitoring of direct emissions of greenhouse gases (GHG) and emerging pollutants such as pharmaceutical and personal care products (PPCPs), which have been rarely considered in the environmental assessment of a wastewater treatment facility by life cycle assessment (LCA) methodology. As a result of that, the real environmental impacts of a WWTP may be underestimated. In this study, two WWTPs located in different climatic regions (Atlantic and Mediterranean) of Spain were evaluated in extensive sampling campaigns that included not only conventional water quality parameters but also direct GHG emissions and PPCPs in water and sludge lines. Regarding the GHG monitoring campaign, on-site measurements of methane (CH4) and nitrous oxide (N2O) were performed and emission factors were calculated for both WWTPs. GHG direct emissions accounted for 62% of the total global warming potential (GWP), much more relevant than indirect CO2 emissions associated with electricity use. Regarding PPCPs, 19 compounds were measured in the main streams: influent, effluent and sludge, to perform the evaluation of the toxicity impact categories. Although the presence of heavy metals in the effluent and the sludge as well as the toxicity linked to the electricity production may shade the toxicity impacts linked to PPCPs in some impact categories, the latter showed a notable influence on freshwater ecotoxicity potential (FETP). For this impact category, the removal of PPCPs within the wastewater treatment was remarkably important and arose as an environmental benefit in comparison with the non-treatment scenario.

  15. Physics-Based Prognostics for Optimizing Plant Operation

    SciTech Connect

    Leonard J. Bond; Don B. Jarrell

    2005-03-01

    Scientists at the Pacific Northwest National Laboratory (PNNL) have examined the necessity for optimization of energy plant operation using 'DSOM{reg_sign}'--Decision Support Operation and Maintenance and this has been deployed at several sites. This approach has been expanded to include a prognostics components and tested on a pilot scale service water system, modeled on the design employed in a nuclear power plant. A key element in plant optimization is understanding and controlling the aging process of safety-specific nuclear plant components. This paper reports the development and demonstration of a physics-based approach to prognostic analysis that combines distributed computing, RF data links, the measurement of aging precursor metrics and their correlation with degradation rate and projected machine failure.

  16. Physics-Based Prognostics for Optimizing Plant Operation

    SciTech Connect

    Jarrell, Donald B.; Bond, Leonard J.

    2006-02-28

    Scientists at the Pacific Northwest National Laboratory (PNNL) have examined the necessity for optimization of energy plant operation using “DSOM® ” – Decision Support Operation and Maintenance and this has been deployed at several sites. This approach has been expanded to include a prognostics component and tested on a pilot scale service water system, modeled on the design employed in a nuclear power plant. A key element in plant optimization is understanding and controlling the aging process of safety-specific nuclear plant components. This paper reports the development and demonstration of a physics-based approach to prognostic analysis that combines distributed computing, RF data links, the measurement of aging precursor metrics and their correlation with degradation rate and projected machine failure.

  17. Sustainable operation of a biological wastewater treatment plant

    NASA Astrophysics Data System (ADS)

    Trikoilidou, E.; Samiotis, G.; Bellos, D.; Amanatidou, E.

    2016-11-01

    The sustainable operation of a biological wastewater treatment plant is significantly linked to its removal efficiency, cost of sludge management, energy consumption and monitoring cost. The biological treatment offers high organic removal efficiency, it also entails significant sludge production, which contains active (live) and inactive (dead) microorganisms and must be treated prior to final disposal, in order to prevent adverse impact on public health and environment. The efficiency of the activated sludge treatment process is correlated to an efficient solid-liquid separation, which is strongly depended on the biomass settling properties. The most commonly encountered settling problems in a wastewater treatment plant, which are usually associated with operating conditions and specific microorganisms growth, are sludge bulking, floating sludge, pin point flocs and straggler flocs. Sustainable management of sludge and less energy consumption are the two principal aspects that determine the operational cost of wastewater treatment plants. Sludge treatment and management accumulate more than 50% of the operating cost. Aerobic wastewater treatment plants have high energy requirements for covering the needs of aeration and recirculations. In order to ensure wastewater treatment plants’ effective operation, a large number of physicochemical parameters have to be monitored, thus further increasing the operational cost. As the operational parameters are linked to microbial population, a practical way of wastewater treatment plants’ controlling is the microscopic examination of sludge, which is proved to be an important tool for evaluating plants’ performance and assessing possible problems and symptoms. This study presents a biological wastewater treatment plant with almost zero biomass production, less energy consumption and a practical way for operation control through microbial manipulation and microscopic examination.

  18. Closed-cycle helium gas turbine for solar tower power plant

    NASA Astrophysics Data System (ADS)

    Duban, P.

    1980-04-01

    Thermodynamic conversion of solar energy through a process avoiding any long-term thermal storage can be considered a realistic objective for nations able to use other permanent energy sources. Even so, the building and maintenance of a solar tower power plant with its heliostat field require very large investments of primary energy. High thermal efficiency must be achieved to yield acceptable energetic returns, which in turn require an extensive input of advanced technical know-how. Closed-cycle helium gas turbines with an atmospheric cold heat source, currently under development for VHT nuclear power plants, meet the required criteria. In the 10 MW-el range, and a turbine inlet temperature of 900 C, the thermal efficiency of a complex gas turbine, including cooling between low-pressure and high pressure compressors and reheating between low-pressure and high pressure turbine and regenerative heat exchanger, lies between .41 and .43. This efficiency is constant in time and is sustained even at off-design operation; it is equivalent to the efficiency achieved by a thermal power plant, which allows running the solar plant with an auxiliary fossil fuel combustor.

  19. Extending Depot Length and Intervals for DDG 51 Class Ships: Examining the 72 Month Operational Cycle

    DTIC Science & Technology

    2016-01-01

    Extending Depot Length and Intervals for DDG-51-Class Ships Examining the 72- Month Operational Cycle Roland J. Yardley, Daniel Tremblay, Brian...to a 36- month Optimized Fleet Response Plan operational cycle. However, with the constrained budget environment, the Navy is evaluating how best to...Class Ships: The 72- Month Cycle removal of the crew during the execution of maintenance to mitigate costs in this employment approach. This research

  20. ECONOMICS AND FEASIBILITY OF RANKINE CYCLE IMPROVEMENTS FOR COAL FIRED POWER PLANTS

    SciTech Connect

    Richard E. Waryasz; Gregory N. Liljedahl

    2004-09-08

    therefore determines the steam cycle parameters and combustion technology that would yield the lowest cost of electricity (COE) for the next generation of coal-fired steam power plants. The second part of the study (Repowering) explores the means of upgrading the efficiency and output of an older existing coal fired steam power plant. There are currently more than 1,400 coal-fired units in operation in the United States generating about 54 percent of the electricity consumed. Many of these are modern units are clean and efficient. Additionally, there are many older units in excellent condition and still in service that could benefit from this repowering technology. The study evaluates the technical feasibility, thermal performance, and economic viability of this repowering concept.

  1. Environmental impact efficiency of natural gas combined cycle power plants: A combined life cycle assessment and dynamic data envelopment analysis approach.

    PubMed

    Martín-Gamboa, Mario; Iribarren, Diego; Dufour, Javier

    2017-09-26

    The energy sector is still dominated by the use of fossil resources. In particular, natural gas represents the third most consumed resource, being a significant source of electricity in many countries. Since electricity production in natural gas combined cycle (NGCC) plants provides some benefits with respect to other non-renewable technologies, it is often seen as a transitional solution towards a future low‑carbon power generation system. However, given the environmental profile and operational variability of NGCC power plants, their eco-efficiency assessment is required. In this respect, this article uses a novel combined Life Cycle Assessment (LCA) and dynamic Data Envelopment Analysis (DEA) approach in order to estimate -over the period 2010-2015- the environmental impact efficiencies of 20 NGCC power plants located in Spain. A three-step LCA+DEA method is applied, which involves data acquisition, calculation of environmental impacts through LCA, and the novel estimation of environmental impact efficiency (overall- and term-efficiency scores) through dynamic DEA. Although only 1 out of 20 NGCC power plants is found to be environmentally efficient, all plants show a relatively good environmental performance with overall eco-efficiency scores above 60%. Regarding individual periods, 2011 was -on average- the year with the highest environmental impact efficiency (95%), accounting for 5 efficient NGCC plants. In this respect, a link between high number of operating hours and high environmental impact efficiency is observed. Finally, preliminary environmental benchmarks are presented as an additional outcome in order to further support decision-makers in the path towards eco-efficiency in NGCC power plants. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Dynamic Operations Wayfinding System (DOWS) for Nuclear Power Plants

    SciTech Connect

    Boring, Ronald Laurids; Ulrich, Thomas Anthony; Lew, Roger Thomas

    2015-08-01

    A novel software tool is proposed to aid reactor operators in respond- ing to upset plant conditions. The purpose of the Dynamic Operations Wayfind- ing System (DOWS) is to diagnose faults, prioritize those faults, identify paths to resolve those faults, and deconflict the optimal path for the operator to fol- low. The objective of DOWS is to take the guesswork out of the best way to combine procedures to resolve compound faults, mitigate low threshold events, or respond to severe accidents. DOWS represents a uniquely flexible and dy- namic computer-based procedure system for operators.

  3. Application of AI technology to nuclear plant operations

    SciTech Connect

    Sackett, J.I.

    1988-01-01

    In this paper, applications of Artificial Intelligence (AI) Technology to nuclear-power plant operation are reviewed. AI Technology is advancing rapidly and in the next five years is expected to enjoy widespread application to operation, maintenance, management and safety. Near term emphasis on a sensor validation, scheduling, alarm handling, and expert systems for procedural assistance. Ultimate applications are envisioned to culminate in autonomous control such as would be necessary for a power system in space, where automatic control actions are taken based upon reasoned conclusions regarding plant conditions, capability and control objectives.

  4. Operational energy performance assessment system of municipal wastewater treatment plants.

    PubMed

    Yang, Lingbo; Zeng, Siyu; Chen, Jining; He, Miao; Yang, Wan

    2010-01-01

    Based on the statistical analysis of operational energy consumption and its influential factors from data of 599 Chinese WWTPs in 2006, it is noticed that the most influential factors include treatment technology adopted, treated sewage amount, removed pollutants amount, etc. Using the conclusion above, this paper sets up an integrated system of operational energy performance assessment for municipal wastewater treatment plants. Combining with result from on-spot research and model simulation, the calculating method of benchmark value and score of 7 energy efficiency indicators grouped into 3 levels is stated. Applying the assessment system to three plants, its applicability and objectivity are proved and suggestions to improve energy performance are provided.

  5. Raccoon Mountain pumped-storage plant: Ten years operating experience

    SciTech Connect

    Adkins, F.E.

    1987-09-01

    Operational experience at the 1 530 MW Raccoon Mountain underground pumped-storage plant can be relevant to other large hydro facilities. A number of unusual features were incorporated and individual unit size was only recently overtaken elsewhere. Direct water cooling of rotor and stator winding has been successfully applied to salient pole machines. A number of problems, including difficulties with oil-filled 161 kV current transformers, and some mechanical aspects, are reported. Designed for remote supervisory control, the plant has required closer attention. Operating statistics are included.

  6. Direct carbonate fuel cell power plant operating with logistic fuels

    SciTech Connect

    Abens, S.G.; Steinfeld, G.

    1997-12-31

    In response to the US Department of Defense need for power generators which operate with logistic fuels, Energy Research Corporation and its subcontractors, Haldor Topsoe and Fluor Daniel, have conducted design studies and subscale equipment tests toward the development of fuel cell power plants with multifuel capability. A principal objective of this work was the development of a fixed-base carbonate fuel cell power plant design which can utilize both natural gas and military logistic fuels DF-2 and JP-8. To verify ERC`s technical approach, a 32 kW brassboard logistic fuel preprocessing system was assembled and operated with a Direct Carbonate Fuel Cell (DFC) stack. The project was conducted as part of DARPA`s Fuel Cell Power Plant Initiative Program for the development of dual use fuel cell power plants. The logistic fuel preprocessor consisted of a hydrodesulfurization plant which supplied desulfurized feed to an adiabatic prereformer. The methane-rich product gas provides fuel cell performance similar to that with natural gas. A preliminary design of a 3MW multifuel power plant prepared with input from the 32kW brassboard test confirmed that the thermal efficiency of a DFC power plant is nearly as high with logistic fuel (57%) as it is with natural gas (58%).

  7. Water use in the development and operation of geothermal power plants.

    SciTech Connect

    Clark, C. E.; Harto, C. B.; Sullivan, J. L.; Wang, M. Q.

    2010-09-17

    Geothermal energy is increasingly recognized for its potential to reduce carbon emissions and U.S. dependence on foreign oil. Energy and environmental analyses are critical to developing a robust set of geothermal energy technologies. This report summarizes what is currently known about the life cycle water requirements of geothermal electric power-generating systems and the water quality of geothermal waters. It is part of a larger effort to compare the life cycle impacts of large-scale geothermal electricity generation with other power generation technologies. The results of the life cycle analysis are summarized in a companion report, Life Cycle Analysis Results of Geothermal Systems in Comparison to Other Power Systems. This report is divided into six chapters. Chapter 1 gives the background of the project and its purpose, which is to inform power plant design and operations. Chapter 2 summarizes the geothermal electricity generation technologies evaluated in this study, which include conventional hydrothermal flash and binary systems, as well as enhanced geothermal systems (EGS) that rely on engineering a productive reservoir where heat exists but water availability or permeability may be limited. Chapter 3 describes the methods and approach to this work and identifies the four power plant scenarios evaluated: a 20-MW EGS plant, a 50-MW EGS plant, a 10-MW binary plant, and a 50-MW flash plant. The two EGS scenarios include hydraulic stimulation activities within the construction stage of the life cycle and assume binary power generation during operations. The EGS and binary scenarios are assumed to be air-cooled power plants, whereas the flash plant is assumed to rely on evaporative cooling. The well field and power plant design for the scenario were based on simulations using DOE's Geothermal Economic Technology Evaluation Model (GETEM). Chapter 4 presents the water requirements for the power plant life cycle for the scenarios evaluated. Geology, reservoir

  8. The relative contribution of genes operating in the S-methylmethionine cycle to methionine metabolism in Arabidopsis seeds.

    PubMed

    Cohen, Hagai; Salmon, Asaf; Tietel, Zipora; Hacham, Yael; Amir, Rachel

    2017-05-01

    Enzymes operating in the S -methylmethionine cycle make a differential contribution to methionine synthesis in seeds. In addition, mutual effects exist between the S -methylmethionine cycle and the aspartate family pathway in seeds. Methionine, a sulfur-containing amino acid, is a key metabolite in plant cells. The previous lines of evidence proposed that the S-methylmethionine (SMM) cycle contributes to methionine synthesis in seeds where methionine that is produced in non-seed tissues is converted to SMM and then transported via the phloem into the seeds. However, the relative regulatory roles of the S-methyltransferases operating within this cycle in seeds are yet to be fully understood. In the current study, we generated transgenic Arabidopsis seeds with altered expression of three HOMOCYSTEINE S-METHYLTRANSFERASEs (HMTs) and METHIONINE S-METHYLTRANSFERASE (MMT), and profiled them for transcript and metabolic changes. The results revealed that AtHMT1 and AtHMT3, but not AtHMT2 and AtMMT, are the predominant enzymes operating in seeds as altered expression of these two genes affected the levels of methionine and SMM in transgenic seeds. Their manipulations resulted in adapted expression level of genes participating in methionine synthesis through the SMM and aspartate family pathways. Taken together, our findings provide new insights into the regulatory roles of the SMM cycle and the mutual effects existing between the two methionine biosynthesis pathways, highlighting the complexity of the metabolism of methionine and SMM in seeds.

  9. Evaluation of nickel-yttria stabilized zirconia anode degradation during discharge operation and redox cycles operation by electrochemical calculation

    NASA Astrophysics Data System (ADS)

    Shimura, Takaaki; Jiao, Zhenjun; Shikazono, Naoki

    2016-10-01

    Degradation of Solid Oxide Fuel Cell (SOFC) anode during discharge operation and redox cycles operation were evaluated by three-dimensional electrochemical calculations using a Lattice Boltzmann method (LBM). Three dimensional microstructures were obtained by Focused Ion Beam Scanning Electron Microscopy (FIB-SEM) reconstruction. In the electrochemical calculations, changes in exchange current density and ionic conductivity of Yttria stabilized Zirconia (YSZ) during the operations were assumed and their values were calculated by fitting the calculated overpotential values to the experimental ones. Changes in triple phase boundary density calculated from the reconstructed microstructures were inconsistent with the gradual degradation observed during repeated redox-discharge cycles. Changes of the fitted exchange current density and YSZ ionic conductivity values in both discharge operation and redox cycle operation showed same tendency as the experimental results. Change in exchange current density or YSZ ionic conductivity should be considered as an essential factor which governs the cell performance change regardless of the redox treatment.

  10. Imaging Nuclear Morphology and Organization in Cleared Plant Tissues Treated with Cell Cycle Inhibitors.

    PubMed

    de Souza Junior, José Dijair Antonino; de Sa, Maria Fatima Grossi; Engler, Gilbert; Engler, Janice de Almeida

    2016-01-01

    Synchronization of root cells through chemical treatment can generate a large number of cells blocked in specific cell cycle phases. In plants, this approach can be employed for cell suspension cultures and plant seedlings. To identify plant cells in the course of the cell cycle, especially during mitosis in meristematic tissues, chemical inhibitors can be used to block cell cycle progression. Herein, we present a simplified and easy-to-apply protocol to visualize mitotic figures, nuclei morphology, and organization in whole Arabidopsis root apexes. The procedure is based on tissue clearing, and fluorescent staining of nuclear DNA with DAPI. The protocol allows carrying out bulk analysis of nuclei and cell cycle phases in root cells and will be valuable to investigate mutants like overexpressing lines of genes disturbing the plant cell cycle.

  11. A life cycle cost economics model for projects with uniformly varying operating costs. [management planning

    NASA Technical Reports Server (NTRS)

    Remer, D. S.

    1977-01-01

    A mathematical model is developed for calculating the life cycle costs for a project where the operating costs increase or decrease in a linear manner with time. The life cycle cost is shown to be a function of the investment costs, initial operating costs, operating cost gradient, project life time, interest rate for capital and salvage value. The results show that the life cycle cost for a project can be grossly underestimated (or overestimated) if the operating costs increase (or decrease) uniformly over time rather than being constant as is often assumed in project economic evaluations. The following range of variables is examined: (1) project life from 2 to 30 years; (2) interest rate from 0 to 15 percent per year; and (3) operating cost gradient from 5 to 90 percent of the initial operating costs. A numerical example plus tables and graphs is given to help calculate project life cycle costs over a wide range of variables.

  12. A life cycle cost economics model for projects with uniformly varying operating costs. [management planning

    NASA Technical Reports Server (NTRS)

    Remer, D. S.

    1977-01-01

    A mathematical model is developed for calculating the life cycle costs for a project where the operating costs increase or decrease in a linear manner with time. The life cycle cost is shown to be a function of the investment costs, initial operating costs, operating cost gradient, project life time, interest rate for capital and salvage value. The results show that the life cycle cost for a project can be grossly underestimated (or overestimated) if the operating costs increase (or decrease) uniformly over time rather than being constant as is often assumed in project economic evaluations. The following range of variables is examined: (1) project life from 2 to 30 years; (2) interest rate from 0 to 15 percent per year; and (3) operating cost gradient from 5 to 90 percent of the initial operating costs. A numerical example plus tables and graphs is given to help calculate project life cycle costs over a wide range of variables.

  13. SSPS monthly data, January 1985: plant operation report and daily operation summary

    SciTech Connect

    Not Available

    1985-01-01

    The operational, maintenance and evaluation activities and highlights that were required during the month of January 1985 for the Central Receiver System and the Distributed Collector System are summarized. Daily operational reports for these small solar power system plants are provided. Definitions of terms relating to the power systems are included. (BCS)

  14. Total Life Cycle Management for the Special Operations Craft Riverine

    DTIC Science & Technology

    2012-12-04

    serial, there is a high correlation factor involved. For example, the starter , alternator , and water pump are all serial components; the pistons...by twin turbocharged/aftercooled, six-cylinder marine diesel engines mounted side by side, with two water jets located on either side of the center...Construction Aluminum hull w/ FRP accessories Engines Yanmar 6LY2M-STE diesel , 440 HP @ 3300 RPM Engine duty cycle 3300 RPM intermittent

  15. Maximum power for a power plant with two Carnot-like cycles

    NASA Astrophysics Data System (ADS)

    Aragón-González, G.; León-Galicia, A.

    2017-01-01

    A stationary power plant with two Carnot-like cycles is optimized. Each cycle has the following irreversibilities: finite rate heat transfer between the working fluid and the external heat sources, internal dissipation of the working fluid, and heat leak between reservoirs. The optimal allocation or effectiveness of the heat exchangers for this power plant is determined by applying, two alternating design rules: fixed internal thermal conductance or fixed areas. The optimal relations obtained are substituted in the power and the maximum power, according to the isentropic ratio of each one of the Carnot-like cycles of the power plant, is calculated. Additionally, the efficiency to maximum power is presented.

  16. Trickle water and feeding system in plant culture and light-dark cycle effects on plant growth.

    PubMed

    Takano, T; Inada, K; Takanashi, J

    1987-01-01

    Rockwool, as an inert medium covered or bagged with polyethylene film, can be effectively used for plant culture in space station. The most important machine is the pump adjusting the dripping rate in the feeding system. Hydro-aeroponics may be adaptable to a space laboratory. The shortening of the light-dark cycles inhibits plant growth and induces an abnormal morphogenesis. A photoperiod of 12-hr-dark may be needed for plant growth.

  17. Trickle water and feeding system in plant culture and light-dark cycle effects on plant growth

    NASA Astrophysics Data System (ADS)

    Takano, T.; Inada, K.; Takanashi, J.

    Rockwool, as an inert medium covered or bagged with polyethylene film, can be effectively used for plant culture in space station. The most important machine is the pump adjusting the dripping rate in the feeding system. Hydro-aeroponics may be adaptable to a space laboratory. The shortening of the light-dark cycles inhibits plant growth and induces an abnormal morphogenesis. A photoperiod of 12-hr-dark may be needed for plant growth.

  18. Trickle water and feeding system in plant culture and light-dark cycle effects on plant growth

    NASA Technical Reports Server (NTRS)

    Takano, T.; Inada, K.; Takanashi, J.

    1987-01-01

    Rockwool, as an inert medium covered or bagged with polyethylene film, can be effectively used for plant culture in space stations. The most important machine is the pump adjusting the dripping rate in the feeding system. Hydro-aeroponics may be adaptable to a space laboratory. The shortening of the light-dark cycles inhibits plant growth and induces an abnormal morphogenesis. A photoperiod of 12 hr dark may be needed for plant growth.

  19. One-year operation of single household membrane bioreactor plant.

    PubMed

    Matulova, Z; Hlavinek, P; Drtil, M

    2010-01-01

    This paper evaluates the results from a 12-month study of a single-household wastewater treatment plant with submerged membrane module (household MBR plant) that was monitored from winter to winter season. The samples were collected at least twice a week (an intensive research study at real conditions). The household MBR (membrane bioreactor) plant was linked to a family house with 4 residents. In this study the treatment plant was fed by real domestic wastewater. In contrast to most other experiments with small-scale WWTPs (wastewater treatment plants) carried out in laboratories and facilities of large municipal WWTPs (polygons) which guarantee stable and flexible operation but the characteristics of wastewater and activated sludge in these studies usually differ from those that occur in real small-scale/single-household WWTPs. One of the main goals of this research was to test the response of membrane and activated sludge to different conditions during real operation of the household MBR plant, such as a long period of zero influent/load, or vice versa the presence of a large amount of concentrated wastewater (e.g. during the weekend), very low winter temperatures (water temperature below 5-6 degrees C), high pH values, and the presence of domestic detergents.

  20. RAW COPPER SLABS USED IN CASTING OPERATIONS AT BUFFALO PLANT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    RAW COPPER SLABS USED IN CASTING OPERATIONS AT BUFFALO PLANT OF AMERICAN BRASS COMPANY. MATERIALS STORAGE FOR THE CAST SHOP NOW OCCUPIES A PORTION OF THE ORIGINAL BRASS MILL BUILT BY THE BUFFALO COPPER AND BRASS ROLLING MILL IN 1906-07 AND EXPANDED IN 1911. - American Brass Foundry, 70 Sayre Street, Buffalo, Erie County, NY

  1. A Competency-Based Instructional Program for Plant Process Operations.

    ERIC Educational Resources Information Center

    McDaniel, Joy; Mills, Steven

    This program guide provides materials to prepare learners for employment as Process Plant Operators through classroom instruction and practical shop experience. Contents include instructional goal and subgoals, an instructional analysis that describes development of the materials and instructional equipment and supplies and facilities…

  2. Understanding plant community responses to combinations of biotic and abiotic factors in different phases of the plant growth cycle.

    PubMed

    Wood, Kevin A; Stillman, Richard A; Clarke, Ralph T; Daunt, Francis; O'Hare, Matthew T

    2012-01-01

    Understanding plant community responses to combinations of biotic and abiotic factors is critical for predicting ecosystem response to environmental change. However, studies of plant community regulation have seldom considered how responses to such factors vary with the different phases of the plant growth cycle. To address this deficit we studied an aquatic plant community in an ecosystem subject to gradients in mute swan (Cygnus olor) herbivory, riparian shading, water temperature and distance downstream of the river source. We quantified abundance, species richness, evenness, flowering and dominance in relation to biotic and abiotic factors during the growth-, peak-, and recession-phases of the plant growth cycle. We show that the relative importance of biotic and abiotic factors varied between plant community properties and between different phases of the plant growth cycle. Herbivory became more important during the later phases of peak abundance and recession due to an influx of swans from adjacent pasture fields. Shading by riparian vegetation also had a greater depressing effect on biomass in later seasons, probably due to increased leaf abundance reducing light intensity reaching the aquatic plants. The effect of temperature on community diversity varied between upstream and downstream sites by altering the relative competitiveness of species at these sites. These results highlight the importance of seasonal patterns in the regulation of plant community structure and function by multiple factors.

  3. Understanding Plant Community Responses to Combinations of Biotic and Abiotic Factors in Different Phases of the Plant Growth Cycle

    PubMed Central

    Wood, Kevin A.; Stillman, Richard A.; Clarke, Ralph T.; Daunt, Francis; O’Hare, Matthew T.

    2012-01-01

    Understanding plant community responses to combinations of biotic and abiotic factors is critical for predicting ecosystem response to environmental change. However, studies of plant community regulation have seldom considered how responses to such factors vary with the different phases of the plant growth cycle. To address this deficit we studied an aquatic plant community in an ecosystem subject to gradients in mute swan (Cygnus olor) herbivory, riparian shading, water temperature and distance downstream of the river source. We quantified abundance, species richness, evenness, flowering and dominance in relation to biotic and abiotic factors during the growth-, peak-, and recession-phases of the plant growth cycle. We show that the relative importance of biotic and abiotic factors varied between plant community properties and between different phases of the plant growth cycle. Herbivory became more important during the later phases of peak abundance and recession due to an influx of swans from adjacent pasture fields. Shading by riparian vegetation also had a greater depressing effect on biomass in later seasons, probably due to increased leaf abundance reducing light intensity reaching the aquatic plants. The effect of temperature on community diversity varied between upstream and downstream sites by altering the relative competitiveness of species at these sites. These results highlight the importance of seasonal patterns in the regulation of plant community structure and function by multiple factors. PMID:23166777

  4. Nuclear power plant control room operator control and monitoring tasks

    SciTech Connect

    Bovell, C.R.; Beck, M.G.; Carter, R.J.

    1998-07-01

    Oak Ridge National Laboratory is conducting a research project the purpose of which is to develop the technical bases for regulatory review criteria for use in evaluating the safety implications of human factors associated with the use of artificial intelligence and expert systems, and with advanced instrumentation and control (I and C) systems in nuclear power plants (NPP). This report documents the results from Task 8 of that project. The primary objectives of the task was to identify the scope and type of control and monitoring tasks now performed by control-room operators. Another purpose was to address the types of controls and safety systems needed to operate the nuclear plant. The final objective of Task 8 was to identify and categorize the type of information and displays/indicators required to monitor the performance of the control and safety systems. This report also discusses state-of-the-art controls and advanced display devices which will be available for use in control-room retrofits and in control room of future plants. The fundamental types of control and monitoring tasks currently conducted by operators can be divided into four classifications: function monitoring tasks, control manipulation tasks, fault diagnostic tasks, and administrative tasks. There are three general types of controls used in today`s NPPs, switches, pushbuttons, and analog controllers. Plant I and C systems include components to achieve a number of safety-related functions: measuring critical plant parameters, controlling critical plant parameters within safety limits, and automatically actuating protective devices if safe limits are exceeded. The types of information monitored by the control-room operators consist of the following parameters: pressure, fluid flow and level, neutron flux, temperature, component status, water chemistry, electrical, and process and area radiation. The basic types of monitoring devices common to nearly all NPP control rooms include: analog meters

  5. 9 CFR 351.12 - Circuit supervisor to be informed when plant operates.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... plant operates. 351.12 Section 351.12 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE... Facilities and Operations § 351.12 Circuit supervisor to be informed when plant operates. The operator of each certified plant shall inform the circuit supervisor, in advance, when the plant's work schedule...

  6. 9 CFR 351.12 - Circuit supervisor to be informed when plant operates.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... plant operates. 351.12 Section 351.12 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE... Facilities and Operations § 351.12 Circuit supervisor to be informed when plant operates. The operator of each certified plant shall inform the circuit supervisor, in advance, when the plant's work schedule...

  7. 9 CFR 351.12 - Circuit supervisor to be informed when plant operates.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... plant operates. 351.12 Section 351.12 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE... Facilities and Operations § 351.12 Circuit supervisor to be informed when plant operates. The operator of each certified plant shall inform the circuit supervisor, in advance, when the plant's work schedule...

  8. 9 CFR 351.12 - Circuit supervisor to be informed when plant operates.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... plant operates. 351.12 Section 351.12 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE... Facilities and Operations § 351.12 Circuit supervisor to be informed when plant operates. The operator of each certified plant shall inform the circuit supervisor, in advance, when the plant's work schedule...

  9. Life cycle assessment of a printed circuit board manufacturing plant in Turkey.

    PubMed

    Ozkan, Elif; Elginoz, Nilay; Germirli Babuna, Fatos

    2017-09-29

    The objective of this study is to investigate the environmental impacts of a printed circuit board (PCB) manufacturing plant through streamlined life cycle assessment approach. As a result, the most effective recommendations on minimizing the environmental impacts for the mentioned sector are revealed and first steps towards establishing a country specific database are taken. The whole PCB production consists of two consecutive stages: namely board fabrication followed by the manufacturing of PCB. Manufacturing of PCB contributes the highest shares to freshwater aquatic ecotoxicity potential (FAETP) and ozone layer depletion potential (ODP). Eighty-nine percent of FAETP is found to be generated from the manufacturing of PCB. Almost all of this contribution can be attributed to the disposal of copper containing wastewater treatment sludge from etching operations to incineration. On the other hand, PCB manufacturing has 73% share in total ODP. Within the manufacturing of PCB, as etching operations are found to be of importance for all the impact categories except eutrophication potential (EP), it is recommended to focus further studies on in-plant control of etching.

  10. Farm-scale ethanol plant for New Zealand. Stage 3: plant operation

    SciTech Connect

    Not Available

    1986-05-01

    The report describes the operation of a farm ethanol plant, the project being Stage 3 of a wider study of the applicability of such a plant. The plant was sited at Sheffield in Canterbury and drew on the local crops of barley, potatoes, and wheat as feedstock. The report concentrates on the practical aspects of plant operation. The most significant factor affecting the viability of the project was the energy cost in opepating an electric boiler. To reduce the cost, a low-unit-rate night-time electricity tariff was essential. To meet this a large measure of automatic control was found necessary for the batch-distillation process. The best yields of ethanol obtained were: for barley, 265 litres/ton; for potatoes, 98 litres/ton; energy consumption was 11 kWh/litre. The overall conclusion is that the small scale of operation and the high energy and labour costs make the economics of such a venture unattractive.

  11. Operating limit evaluation for disposal of uranium enrichment plant wastes

    SciTech Connect

    Lee, D.W.; Kocher, D.C.; Wang, J.C.

    1996-02-01

    A proposed solid waste landfill at Paducah Gaseous Diffusion Plant (PGDP) will accept wastes generated during normal plant operations that are considered to be non-radioactive. However, nearly all solid waste from any source or facility contains small amounts of radioactive material, due to the presence in most materials of trace quantities of such naturally occurring radionuclides as uranium and thorium. This paper describes an evaluation of operating limits, which are protective of public health and the environment, that would allow waste materials containing small amounts of radioactive material to be sent to a new solid waste landfill at PGDP. The operating limits are expressed as limits on concentrations of radionuclides in waste materials that could be sent to the landfill based on a site-specific analysis of the performance of the facility. These limits are advantageous to PGDP and DOE for several reasons. Most importantly, substantial cost savings in the management of waste is achieved. In addition, certain liabilities that could result from shipment of wastes to a commercial off-site solid waste landfill are avoided. Finally, assurance that disposal operations at the PGDP landfill are protective of public health and the environment is provided by establishing verifiable operating limits for small amounts of radioactive material; rather than relying solely on administrative controls. The operating limit determined in this study has been presented to the Commonwealth of Kentucky and accepted as a condition to be attached to the operating permit for the solid waste landfill.

  12. From driving cycle analysis to understanding battery performance in real-life electric hybrid vehicle operation

    NASA Astrophysics Data System (ADS)

    Liaw, Bor Yann; Dubarry, Matthieu

    This paper proposes a methodology and approach to understand battery performance and life through driving cycle and duty cycle analyses from electric and hybrid vehicle (EHV) operation in real-world situations. Conducting driving cycle analysis with trip data collected from EHV operation in real life is very difficult and challenging. In fact, no comprehensive approach has been accepted to date, except those using standard driving cycles on a dynamometer or a track. Similarly, analyzing duty cycle performance of a battery under real-life operation faces the same challenge. A successful driving cycle analysis, however, can significantly enhance our understanding of EHV performance in real-life driving. Likewise, we also expect similar results through duty cycle analysis for batteries. Since 1995, we have been developing tools to analyze EHV and power source performance. In particular, we were able to collect data from a fleet of 15 Hyundai Santa Fe electric sports utility vehicles (e-SUVs) operated on Oahu, Hawaii; from July 2001 to June 2003 to allow driving and duty cycle analyses in order to understand battery pack performance from a variety of EHV operating conditions. We thus developed a comprehensive approach that comprises fuzzy logic pattern recognition (FL-PR) techniques to perform driving and duty cycle analyses. This approach has been successfully applied to EHV performance analysis via the creation of a compositional driving profile called "driving cycle profile" (DrCP) for each trip. The same approach was used to analyze battery performance via the construction of "duty cycle profile" (DuCP) to express battery usage under various operating conditions. The combination of the two analyses enables us to understand both the usage profile of EHV and battery performance in synergetic details and in a systematic manner using a pattern recognition technique.

  13. An engineering analysis of a closed cycle plant growth module

    NASA Technical Reports Server (NTRS)

    Stickford, G. H., Jr.; Jakob, F. E.; Landstrom, D. K.

    1986-01-01

    The SOLGEM model is a numerical engineering model which solves the flow and energy balance equations for the air flowing through a growing environment, assuming quasi-steady state conditions within the system. SOLGEM provides a dynamic simulation of the controlled environment system in that the temperature and flow conditions of the growing environment are estimated on an hourly basis in response to the weather data and the plant growth parameters. The flow energy balance considers the incident solar flux; incoming air temperature, humidity, and flow rate; heat exchange with the roof and floor; and heat and moisture exchange with the plants. A plant transpiration subroutine was developed based plant growth research facility, intended for the study of bioregenerative life support theories. The results of a performance analysis of the plant growth module are given. The estimated energy requirements of the module components and the total energy are given.

  14. 40 CFR 1065.514 - Cycle-validation criteria for operation over specified duty cycles.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... § 1065.512 to the corresponding feedback values recorded during the test. You may compare reference duty cycle points recorded during the test to the corresponding feedback values recorded during the test as... the regression will have up to 1199 pairs of reference and feedback values at the...

  15. Life cycle assessment of coal-fired power plants and sensitivity analysis of CO2 emissions from power generation side

    NASA Astrophysics Data System (ADS)

    Yin, Libao; Liao, Yanfen; Zhou, Lianjie; Wang, Zhao; Ma, Xiaoqian

    2017-05-01

    The life cycle assessment and environmental impacts of a 1000MW coal-fired power plant were carried out in this paper. The results showed that the operation energy consumption and pollutant emission of the power plant are the highest in all sub-process, which accounts for 93.93% of the total energy consumption and 92.20% of the total emission. Compared to other pollutant emissions from the coal-fired power plant, CO2 reached up to 99.28%. Therefore, the control of CO2 emission from the coal-fired power plants was very important. Based on the BP neural network, the amount of CO2 emission from the generation side of coal-fired power plants was calculated via carbon balance method. The results showed that unit capacity, coal quality and unit operation load had great influence on the CO2 emission from coal-fired power plants in Guangdong Province. The use of high volatile and high heat value of coal also can reduce the CO2 emissions. What’s more, under higher operation load condition, the CO2 emissions of 1 kWh electric energy was less.

  16. Galois-unitary operators that cycle mutually-unbiased bases

    NASA Astrophysics Data System (ADS)

    Dang, Hoan; Appleby, Marcus; Bengtsson, Ingemar

    2015-03-01

    Wigner's theorem states that probability-preserving transformations of quantum states must be either unitary or anti-unitary. However, if we restrict ourselves to a subspace of a Hilbert space, it is possible to generalize the notion of anti-unitaries. Such transformations were recently constructed in search of Symmetric Informationally-Complete (SIC) states. They are called Galois-unitaries (g-unitaries for short), as they are unitaries composed with Galois automorphisms of a chosen number field extension. Despite certain bizarre behaviors of theirs, we show that g-unitaries are indeed useful in the theory of Mutually-Unbiased Bases (MUBs), as they help solve the MUB-cycling problem and provide a construction of MUB-balanced states. HD was supported by the Natural Sciences and Engineering Research Council of Canada and the Vanier Canada Graduate Scholarship

  17. Using Plant Phylogenetic Relatedness as a Predictor for Plants' Control on Soil Microbial Communities and Nitrogen Cycling

    NASA Astrophysics Data System (ADS)

    Potter, T.; Bowman, W. D.

    2016-12-01

    Despite the known importance of soil microbes and their influence on soil processes, a mechanistic understanding is still needed to predict how plants and soil microbes interact at scales that are relevant to community and ecosystem-scale processes. Closely related plant species have similar traits aboveground, but we don't know whether this is also true for belowground traits that affect soil microbial community structure and function. Determining how tightly plant phylogeny and plant functional traits are linked to soil microbial communities is a useful approach for discovering plant-microbe associations that are generalizable across plant species (a limitation of studies that employ a single or few plant species). Using this approach, we conducted a greenhouse study with seven congeneric grasses (genus Poa) and their native soils to examine whether plants' influences on microbial community structure were consistent with plant phylogenetic relatedness and/or plant functional traits. Seeds of each Poa species were planted in native soil (from the seed source population) as well as a homogenized soil from all seven populations. Additionally, a nitrogen treatment was added to address how an environmental change (such as nitrogen deposition) alters plant-microbe associations. Rhizosphere community composition of bacteria and fungi was obtained via marker gene sequencing to compare community composition across plant species. Patterns in plant-microbe associations across plant species reveal plant control on nutrient cycling via plant species' influence on microbial community structure. These results determine if we are ready to generalize about plant-microbe interactions at the genus level, an important stepping-stone to applying knowledge of plant-microbe interactions to larger ecological scales.

  18. Design and operating guidelines for nuclear power plant condensers

    SciTech Connect

    Not Available

    1991-09-01

    Recommendations and associated technical justifications are provided for the design and operation of condensate polishing systems. Both deep bed and powdered resin system are addressed. The objective of the guidelines is to ensure that impurity levels in the PWR secondary cycle are reduced to the minimum achievable levels through proper design and operation of the condensate polisher system. Reduction of the condensate polisher to the steam generators has been demonstrated to improve steam generator reliability and limit corrosion of steam generator materials. 19 refs., 12 figs., 4 tabs.

  19. Altered ecosystem carbon and nitrogen cycles by plant invasion: a meta-analysis.

    PubMed

    Liao, Chengzhang; Peng, Ronghao; Luo, Yiqi; Zhou, Xuhui; Wu, Xiaowen; Fang, Changming; Chen, Jiakuan; Li, Bo

    2008-01-01

    Plant invasion potentially alters ecosystem carbon (C) and nitrogen (N) cycles. However, the overall direction and magnitude of such alterations are poorly quantified. Here, 94 experimental studies were synthesized, using a meta-analysis approach, to quantify the changes of 20 variables associated with C and N cycles, including their pools, fluxes, and other related parameters in response to plant invasion. Pool variables showed significant changes in invaded ecosystems relative to native ecosystems, ranging from a 5% increase in root carbon stock to a 133% increase in shoot C stock. Flux variables, such as above-ground net primary production and litter decomposition, increased by 50-120% in invaded ecosystems, compared with native ones. Plant N concentration, soil NH+4 and NO-3 concentrations were 40, 30 and 17% higher in invaded than in native ecosystems, respectively. Increases in plant production and soil N availability indicate that there was positive feedback between plant invasion and C and N cycles in invaded ecosystems. Invasions by woody and N-fixing plants tended to have greater impacts on C and N cycles than those by herbaceous and nonN-fixing plants, respectively. The responses to plant invasion are not different among forests, grasslands, and wetlands. All of these changes suggest that plant invasion profoundly influences ecosystem processes.

  20. Proceedings: Fourth international conference on fossil plant cycle chemistry

    SciTech Connect

    Dooley, R.B.; Pate, S.R.

    1995-01-01

    The objectives of the conference were to review, document and transfer technology on all aspects of cycle chemistry. To meet these objectives, papers were presented and are included in these proceedings in ten technical areas: Boiler Related Chemistry; Feedwater Related Chemistry; International Cycle Chemistry; Instrumentation and Diagnostics; Steam; Ion Exchange and Condensate Polishing; Chemical Cleaning; Oxygenated Treatment; Cycle Effects; and Cycle Chemistry Improvement and Management Programs. Each topic at the conference was discussed in a separate session and these discussions are also included in the proceedings following each paper. The mix of international and domestic papers were chosen to indicate the marked differences in practices and to stimulate discussion. The working group summaries provided some of this flavor; they also indicate the current needs and deficiencies and outline R and D required to improve/upgrade cycle chemistry. The results of a comprehensive survey conducted at the conference are also included. Selected papers are indexed separately for inclusion in the Energy Science and Technology Database.

  1. Fast-cycling unit of root turnover in perennial herbaceous plants in a cold temperate ecosystem.

    PubMed

    Sun, Kai; McCormack, M Luke; Li, Le; Ma, Zeqing; Guo, Dali

    2016-01-21

    Roots of perennial plants have both persistent portion and fast-cycling units represented by different levels of branching. In woody species, the distal nonwoody branch orders as a unit are born and die together relatively rapidly (within 1-2 years). However, whether the fast-cycling units also exist in perennial herbs is unknown. We monitored root demography of seven perennial herbs over two years in a cold temperate ecosystem and we classified the largest roots on the root collar or rhizome as basal roots, and associated finer laterals as secondary, tertiary and quaternary roots. Parallel to woody plants in which distal root orders form a fast-cycling module, basal root and its finer laterals also represent a fast-cycling module in herbaceous plants. Within this module, basal roots had a lifespan of 0.5-2 years and represented 62-87% of total root biomass, thus dominating annual root turnover (60%-81% of the total). Moreover, root traits including root length, tissue density, and biomass were useful predictors of root lifespan. We conclude that both herbaceous and woody plants have fast-cycling modular units and future studies identifying the fast-cycling module across plant species should allow better understanding of how root construction and turnover are linked to whole-plant strategies.

  2. Fast-cycling unit of root turnover in perennial herbaceous plants in a cold temperate ecosystem

    PubMed Central

    Sun, Kai; Luke McCormack, M.; Li, Le; Ma, Zeqing; Guo, Dali

    2016-01-01

    Roots of perennial plants have both persistent portion and fast-cycling units represented by different levels of branching. In woody species, the distal nonwoody branch orders as a unit are born and die together relatively rapidly (within 1–2 years). However, whether the fast-cycling units also exist in perennial herbs is unknown. We monitored root demography of seven perennial herbs over two years in a cold temperate ecosystem and we classified the largest roots on the root collar or rhizome as basal roots, and associated finer laterals as secondary, tertiary and quaternary roots. Parallel to woody plants in which distal root orders form a fast-cycling module, basal root and its finer laterals also represent a fast-cycling module in herbaceous plants. Within this module, basal roots had a lifespan of 0.5–2 years and represented 62–87% of total root biomass, thus dominating annual root turnover (60%–81% of the total). Moreover, root traits including root length, tissue density, and biomass were useful predictors of root lifespan. We conclude that both herbaceous and woody plants have fast-cycling modular units and future studies identifying the fast-cycling module across plant species should allow better understanding of how root construction and turnover are linked to whole-plant strategies. PMID:26791578

  3. Fast-cycling unit of root turnover in perennial herbaceous plants in a cold temperate ecosystem

    NASA Astrophysics Data System (ADS)

    Sun, Kai; Luke McCormack, M.; Li, Le; Ma, Zeqing; Guo, Dali

    2016-01-01

    Roots of perennial plants have both persistent portion and fast-cycling units represented by different levels of branching. In woody species, the distal nonwoody branch orders as a unit are born and die together relatively rapidly (within 1-2 years). However, whether the fast-cycling units also exist in perennial herbs is unknown. We monitored root demography of seven perennial herbs over two years in a cold temperate ecosystem and we classified the largest roots on the root collar or rhizome as basal roots, and associated finer laterals as secondary, tertiary and quaternary roots. Parallel to woody plants in which distal root orders form a fast-cycling module, basal root and its finer laterals also represent a fast-cycling module in herbaceous plants. Within this module, basal roots had a lifespan of 0.5-2 years and represented 62-87% of total root biomass, thus dominating annual root turnover (60%-81% of the total). Moreover, root traits including root length, tissue density, and biomass were useful predictors of root lifespan. We conclude that both herbaceous and woody plants have fast-cycling modular units and future studies identifying the fast-cycling module across plant species should allow better understanding of how root construction and turnover are linked to whole-plant strategies.

  4. Optimised heat recovery steam generators for integrated solar combined cycle plants

    NASA Astrophysics Data System (ADS)

    Peterseim, Jürgen H.; Huschka, Karsten

    2017-06-01

    The cost of concentrating solar power (CSP) plants is decreasing but, due to the cost differences and the currently limited value of energy storage, implementation of new facilities is still slow compared to photovoltaic systems. One recognized option to lower cost instantly is the hybridization of CSP with other energy sources, such as natural gas or biomass. Various references exist for the combination of CSP with natural gas in combined cycle plants, also known as Integrated Solar Combined Cycle (ISCC) plants. One problem with current ISCC concepts is the so called ISCC crisis, which occurs when CSP is not contributing and cycle efficiency falls below efficiency levels of solely natural gas only fired combined cycle plants. This paper analyses current ISCC concepts and compares them with two optimised designs. The comparison is based on a Kuraymat type ISCC plant and shows that cycle optimization enables a net capacity increase of 1.4% and additional daily generation of up to 7.9%. The specific investment of the optimised Integrated Solar Combined Cycle plant results in a 0.4% cost increase, which is below the additional net capacity and daily generation increase.

  5. Optimization and Comparison of Direct and Indirect Supercritical Carbon Dioxide Power Plant Cycles for Nuclear Applications

    SciTech Connect

    Edwin A. Harvego; Michael G. McKellar

    2011-11-01

    There have been a number of studies involving the use of gases operating in the supercritical mode for power production and process heat applications. Supercritical carbon dioxide (CO2) is particularly attractive because it is capable of achieving relatively high power conversion cycle efficiencies in the temperature range between 550 C and 750 C. Therefore, it has the potential for use with any type of high-temperature nuclear reactor concept, assuming reactor core outlet temperatures of at least 550 C. The particular power cycle investigated in this paper is a supercritical CO2 Recompression Brayton Cycle. The CO2 Recompression Brayton Cycle can be used as either a direct or indirect power conversion cycle, depending on the reactor type and reactor outlet temperature. The advantage of this cycle when compared to the helium Brayton cycle is the lower required operating temperature; 550 C versus 850 C. However, the supercritical CO2 Recompression Brayton Cycle requires an operating pressure in the range of 20 MPa, which is considerably higher than the required helium Brayton cycle operating pressure of 8 MPa. This paper presents results of analyses performed using the UniSim process analyses software to evaluate the performance of both a direct and indirect supercritical CO2 Brayton Recompression cycle for different reactor outlet temperatures. The direct supercritical CO2 cycle transferred heat directly from a 600 MWt reactor to the supercritical CO2 working fluid supplied to the turbine generator at approximately 20 MPa. The indirect supercritical CO2 cycle assumed a helium-cooled Very High Temperature Reactor (VHTR), operating at a primary system pressure of approximately 7.0 MPa, delivered heat through an intermediate heat exchanger to the secondary indirect supercritical CO2 Brayton Recompression cycle, again operating at a pressure of about 20 MPa. For both the direct and indirect cycles, sensitivity calculations were performed for reactor outlet temperature

  6. Dynamic modelling and simulation of CSP plant based on supercritical carbon dioxide closed Brayton cycle

    NASA Astrophysics Data System (ADS)

    Hakkarainen, Elina; Sihvonen, Teemu; Lappalainen, Jari

    2017-06-01

    Supercritical carbon dioxide (sCO2) has recently gained a lot of interest as a working fluid in different power generation applications. For concentrated solar power (CSP) applications, sCO2 provides especially interesting option if it could be used both as the heat transfer fluid (HTF) in the solar field and as the working fluid in the power conversion unit. This work presents development of a dynamic model of CSP plant concept, in which sCO2 is used for extracting the solar heat in Linear Fresnel collector field, and directly applied as the working fluid in the recuperative Brayton cycle; these both in a single flow loop. We consider the dynamic model is capable to predict the system behavior in typical operational transients in a physically plausible way. The novel concept was tested through simulation cases under different weather conditions. The results suggest that the concept can be successfully controlled and operated in the supercritical region to generate electric power during the daytime, and perform start-up and shut down procedures in order to stay overnight in sub-critical conditions. Besides the normal daily operation, the control system was demonstrated to manage disturbances due to sudden irradiance changes.

  7. Cost versus life cycle assessment-based environmental impact optimization of drinking water production plants.

    PubMed

    Capitanescu, F; Rege, S; Marvuglia, A; Benetto, E; Ahmadi, A; Gutiérrez, T Navarrete; Tiruta-Barna, L

    2016-07-15

    Empowering decision makers with cost-effective solutions for reducing industrial processes environmental burden, at both design and operation stages, is nowadays a major worldwide concern. The paper addresses this issue for the sector of drinking water production plants (DWPPs), seeking for optimal solutions trading-off operation cost and life cycle assessment (LCA)-based environmental impact while satisfying outlet water quality criteria. This leads to a challenging bi-objective constrained optimization problem, which relies on a computationally expensive intricate process-modelling simulator of the DWPP and has to be solved with limited computational budget. Since mathematical programming methods are unusable in this case, the paper examines the performances in tackling these challenges of six off-the-shelf state-of-the-art global meta-heuristic optimization algorithms, suitable for such simulation-based optimization, namely Strength Pareto Evolutionary Algorithm (SPEA2), Non-dominated Sorting Genetic Algorithm (NSGA-II), Indicator-based Evolutionary Algorithm (IBEA), Multi-Objective Evolutionary Algorithm based on Decomposition (MOEA/D), Differential Evolution (DE), and Particle Swarm Optimization (PSO). The results of optimization reveal that good reduction in both operating cost and environmental impact of the DWPP can be obtained. Furthermore, NSGA-II outperforms the other competing algorithms while MOEA/D and DE perform unexpectedly poorly. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Microgravity effects on different stages of higher plant life cycle and completion of the seed-to-seed cycle.

    PubMed

    De Micco, V; De Pascale, S; Paradiso, R; Aronne, G

    2014-01-01

    Human inhabitation of Space requires the efficient realisation of crop cultivation in bioregenerative life-support systems (BLSS). It is well known that plants can grow under Space conditions; however, perturbations of many biological phenomena have been highlighted due to the effect of altered gravity and its possible interactions with other factors. The mechanisms priming plant responses to Space factors, as well as the consequences of such alterations on crop productivity, have not been completely elucidated. These perturbations can occur at different stages of plant life and are potentially responsible for failure of the completion of the seed-to-seed cycle. After brief consideration of the main constraints found in the most recent experiments aiming to produce seeds in Space, we focus on two developmental phases in which the plant life cycle can be interrupted more easily than in others also on Earth. The first regards seedling development and establishment; we discuss reasons for slow development at the seedling stage that often occurs under microgravity conditions and can reduce successful establishment. The second stage comprises gametogenesis and pollination; we focus on male gamete formation, also identifying potential constraints to subsequent fertilisation. We finally highlight how similar alterations at cytological level can not only be common to different processes occurring at different life stages, but can be primed by different stress factors; such alterations can be interpreted within the model of 'stress-induced morphogenic response' (SIMR). We conclude by suggesting that a systematic analysis of all growth and reproductive phases during the plant life cycle is needed to optimise resource use in plant-based BLSS.

  9. Flexible operation of thermal plants with integrated energy storage technologies

    NASA Astrophysics Data System (ADS)

    Koytsoumpa, Efthymia Ioanna; Bergins, Christian; Kakaras, Emmanouil

    2017-08-01

    The energy system in the EU requires today as well as towards 2030 to 2050 significant amounts of thermal power plants in combination with the continuously increasing share of Renewables Energy Sources (RES) to assure the grid stability and to secure electricity supply as well as to provide heat. The operation of the conventional fleet should be harmonised with the fluctuating renewable energy sources and their intermittent electricity production. Flexible thermal plants should be able to reach their lowest minimum load capabilities while keeping the efficiency drop moderate as well as to increase their ramp up and down rates. A novel approach for integrating energy storage as an evolutionary measure to overcome many of the challenges, which arise from increasing RES and balancing with thermal power is presented. Energy storage technologies such as Power to Fuel, Liquid Air Energy Storage and Batteries are investigated in conjunction with flexible power plants.

  10. Nitrogen cycling and water pulses in semiarid grasslands: Are microbial and plant processes temporarily asynchronous?

    USDA-ARS?s Scientific Manuscript database

    Precipitation pulses in arid ecosystems can lead to temporal asynchrony in microbial and plant processing of nitrogen (N) during drying/wetting cycles causing increased N loss. In contrast, more consistent availability of soil moisture in mesic ecosystems can synchronize microbial and plant processe...

  11. New functions for parts of the Krebs cycle in procyclic Trypanosoma brucei, a cycle not operating as a cycle.

    PubMed

    van Weelden, Susanne W H; van Hellemond, Jaap J; Opperdoes, Fred R; Tielens, Aloysius G M

    2005-04-01

    We investigated whether substrate availability influences the type of energy metabolism in procyclic Trypanosoma brucei. We show that absence of glycolytic substrates (glucose and glycerol) does not induce a shift from a fermentative metabolism to complete oxidation of substrates. We also show that glucose (and even glycolysis) is not essential for normal functioning and proliferation of pleomorphic procyclic T. brucei cells. Furthermore, absence of glucose did not result in increased degradation of amino acids. Variations in availability of glucose and glycerol did result, however, in adaptations in metabolism in such a way that the glycosome was always in redox balance. We argue that it is likely that, in procyclic cells, phosphoglycerate kinase is located not only in the cytosol, but also inside glycosomes, as otherwise an ATP deficit would occur in this organelle. We demonstrate that procyclic T. brucei uses parts of the Krebs cycle for purposes other than complete degradation of mitochondrial substrates. We suggest that citrate synthase plus pyruvate dehydrogenase and malate dehydrogenase are used to transport acetyl-CoA units from the mitochondrion to the cytosol for the biosynthesis of fatty acids, a process we show to occur in proliferating procyclic cells. The part of the Krebs cycle consisting of alpha-ketoglutarate dehydrogenase and succinyl-CoA synthetase was used for the degradation of proline and glutamate to succinate. We also demonstrate that the subsequent enzymes of the Krebs cycle, succinate dehydrogenase and fumarase, are most likely used for conversion of succinate into malate, which can then be used in gluconeogenesis.

  12. Diagnosis of Thermal Efficiency of Advanced Combined Cycle Power Plants Using Optical Torque Sensors

    NASA Astrophysics Data System (ADS)

    Umezawa, Shuichi

    A new optical torque measurement method was applied to diagnosis of thermal efficiency of advanced combined cycle, i.e. ACC, plants. Since the ACC power plant comprises a steam turbine and a gas turbine and both of them are connected to the same generator, it is difficult to identify which turbine in the plant deteriorates the performance when the plant efficiency is reduced. The sensor measures axial distortion caused by power transmission by use of He-Ne laser beams, small stainless steel reflectors having bar-code patterns, and a technique of signal processing featuring high frequency. The sensor was applied to the ACC plants of TOKYO ELECTRIC POWER COMPANY, TEPCO, following the success in the application to the early combined cycle plants of TEPCO. The sensor performance was inspected over a year. After an improvement related to the signal process, it is considered that the sensor performance has reached a practical use level.

  13. Scale Resistant Heat Exchanger for Low Temperature Geothermal Binary Cycle Power Plant

    SciTech Connect

    Hays, Lance G.

    2014-11-18

    Phase 1 of the investigation of improvements to low temperature geothermal power systems was completed. The improvements considered were reduction of scaling in heat exchangers and a hermetic turbine generator (eliminating seals, seal system, gearbox, and lube oil system). A scaling test system with several experiments was designed and operated at Coso geothermal resource with brine having a high scaling potential. Several methods were investigated at the brine temperature of 235 ºF. One method, circulation of abradable balls through the brine passages, was found to substantially reduce scale deposits. The test heat exchanger was operated with brine outlet temperatures as low as 125 ºF, which enables increased heat input available to power conversion systems. For advanced low temperature cycles, such as the Variable Phase Cycle (VPC) or Kalina Cycle, the lower brine temperature will result in a 20-30% increase in power production from low temperature resources. A preliminary design of an abradable ball system (ABS) was done for the heat exchanger of the 1 megawatt VPC system at Coso resource. The ABS will be installed and demonstrated in Phase 2 of this project, increasing the power production above that possible with the present 175 ºF brine outlet limit. A hermetic turbine generator (TGH) was designed and manufacturing drawings produced. This unit will use the working fluid (R134a) to lubricate the bearings and cool the generator. The 200 kW turbine directly drives the generator, eliminating a gearbox and lube oil system. Elimination of external seals eliminates the potential of leakage of the refrigerant or hydrocarbon working fluids, resulting in environmental improvement. A similar design has been demonstrated by Energent in an ORC waste heat recovery system. The existing VPC power plant at Coso was modified to enable the “piggyback” demonstration of the TGH. The existing heat exchanger, pumps, and condenser will be operated to provide the required

  14. Interim Report: Air-Cooled Condensers for Next Generation Geothermal Power Plants Improved Binary Cycle Performance

    SciTech Connect

    Daniel S. Wendt; Greg L. Mines

    2010-09-01

    As geothermal resources that are more expensive to develop are utilized for power generation, there will be increased incentive to use more efficient power plants. This is expected to be the case with Enhanced Geothermal System (EGS) resources. These resources will likely require wells drilled to depths greater than encountered with hydrothermal resources, and will have the added costs for stimulation to create the subsurface reservoir. It is postulated that plants generating power from these resources will likely utilize the binary cycle technology where heat is rejected sensibly to the ambient. The consumptive use of a portion of the produced geothermal fluid for evaporative heat rejection in the conventional flash-steam conversion cycle is likely to preclude its use with EGS resources. This will be especially true in those areas where there is a high demand for finite supplies of water. Though they have no consumptive use of water, using air-cooling systems for heat rejection has disadvantages. These systems have higher capital costs, reduced power output (heat is rejected at the higher dry-bulb temperature), increased parasitics (fan power), and greater variability in power generation on both a diurnal and annual basis (larger variation in the dry-bulb temperature). This is an interim report for the task ‘Air-Cooled Condensers in Next- Generation Conversion Systems’. The work performed was specifically aimed at a plant that uses commercially available binary cycle technologies with an EGS resource. Concepts were evaluated that have the potential to increase performance, lower cost, or mitigate the adverse effects of off-design operation. The impact on both cost and performance were determined for the concepts considered, and the scenarios identified where a particular concept is best suited. Most, but not all, of the concepts evaluated are associated with the rejection of heat. This report specifically addresses three of the concepts evaluated: the use of

  15. Optimization of automotive Rankine cycle waste heat recovery under various engine operating condition

    NASA Astrophysics Data System (ADS)

    Punov, Plamen; Milkov, Nikolay; Danel, Quentin; Perilhon, Christelle; Podevin, Pierre; Evtimov, Teodossi

    2017-02-01

    An optimization study of the Rankine cycle as a function of diesel engine operating mode is presented. The Rankine cycle here, is studied as a waste heat recovery system which uses the engine exhaust gases as heat source. The engine exhaust gases parameters (temperature, mass flow and composition) were defined by means of numerical simulation in advanced simulation software AVL Boost. Previously, the engine simulation model was validated and the Vibe function parameters were defined as a function of engine load. The Rankine cycle output power and efficiency was numerically estimated by means of a simulation code in Python(x,y). This code includes discretized heat exchanger model and simplified model of the pump and the expander based on their isentropic efficiency. The Rankine cycle simulation revealed the optimum value of working fluid mass flow and evaporation pressure according to the heat source. Thus, the optimal Rankine cycle performance was obtained over the engine operating map.

  16. System studies of coal fired-closed cycle MHD for central station power plants

    NASA Technical Reports Server (NTRS)

    Zauderer, B.

    1976-01-01

    This paper presents a discussion of the closed-cycle MHD results obtained in a recent study of various advanced energy-conversion power systems. The direct coal-fired MHD topping-steam bottoming cycle was established as the current choice for central station power generation. Emphasis is placed on the background assumptions and the conclusions that can be drawn from the closed-cycle MHD analysis. It is concluded that closed-cycle MHD has efficiencies comparable to that of open-cycle MHD. Its cost will possibly be slightly higher than that of the open-cycle MHD system. Also, with reasonable fuel escalation assumptions, both systems can produce lower-cost electricity than conventional steam power plants. Suggestions for further work in closed-cycle MHD components and systems are made.

  17. System studies of coal fired-closed cycle MHD for central station power plants

    NASA Technical Reports Server (NTRS)

    Zauderer, B.

    1976-01-01

    This paper presents a discussion of the closed-cycle MHD results obtained in a recent study of various advanced energy-conversion power systems. The direct coal-fired MHD topping-steam bottoming cycle was established as the current choice for central station power generation. Emphasis is placed on the background assumptions and the conclusions that can be drawn from the closed-cycle MHD analysis. It is concluded that closed-cycle MHD has efficiencies comparable to that of open-cycle MHD. Its cost will possibly be slightly higher than that of the open-cycle MHD system. Also, with reasonable fuel escalation assumptions, both systems can produce lower-cost electricity than conventional steam power plants. Suggestions for further work in closed-cycle MHD components and systems are made.

  18. Synchrony of plant cellular circadian clocks with heterogeneous properties under light/dark cycles.

    PubMed

    Okada, Masaaki; Muranaka, Tomoaki; Ito, Shogo; Oyama, Tokitaka

    2017-03-22

    Individual cells in a plant can work independently as circadian clocks, and their properties are the basis of various circadian phenomena. The behaviour of individual cellular clocks in Lemna gibba was orderly under 24-h light/dark cycles despite their heterogeneous free-running periods (FRPs). Here, we reveal the entrainment habits of heterogeneous cellular clocks using non-24-h light/dark cycles (T-cycles). The cellular rhythms of AtCCA1::LUC under T = 16 h cycles showed heterogeneous entrainment that was associated with their heterogeneous FRPs. Under T = 12 h cycles, most cells showed rhythms having ~24-h periods. This suggested that the lower limit of entrainment to the light/dark cycles of heterogeneous cellular circadian clocks is set to a period longer than 12 h, which enables them to be synchronous under ~24-h daily cycles without being perturbed by short light/dark cycles. The entrainment habits of individual cellular clocks are likely to be the basis of the circadian behaviour of plant under the natural day-night cycle with noisy environmental fluctuations. We further suggest that modifications of EARLY FLOWERING3 (ELF3) in individual cells deviate the entrainability to shorter T-cycles possibly by altering both the FRPs and light responsiveness.

  19. Development of a plant growth unit for growing plants over a long-term life cycle under microgravity conditions.

    PubMed

    Kitaya, Y; Tani, A; Goto, E; Saito, T; Takahashi, H

    2000-01-01

    To study the effect of the space environment on plant growth including the reproductive growth and genetic aberration for a long-term plant life cycle, we have initiated development of a new type of facility for growing plants under microgravity conditions. The facility is constructed with subsystems for controlling environmental elements. In this paper, the concept of the facility design is outlined. Subsystems controlling air temperature, humidity, CO2 concentration, light and air circulation around plants and delivering recycled water and nutrients to roots are the major concerns. Plant experiments for developing the facility and future plant experiments with the completed facility are also overviewed. We intend to install this facility in the Japan Experiment Facility (JEM) boarded on the International Space Station.

  20. 40 CFR 1065.514 - Cycle-validation criteria for operation over specified duty cycles.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS ENGINE-TESTING PROCEDURES Performing an Emission Test... part specifies otherwise. This section describes how to determine if the engine's operation during the... from the engine's primary output shaft. Other work inputs and outputs are not subject to...

  1. 40 CFR 1065.514 - Cycle-validation criteria for operation over specified duty cycles.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS ENGINE-TESTING PROCEDURES Performing an Emission Test... part specifies otherwise. This section describes how to determine if the engine's operation during the... from the engine's primary output shaft. Other work inputs and outputs are not subject to...

  2. 40 CFR 1065.514 - Cycle-validation criteria for operation over specified duty cycles.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS ENGINE-TESTING PROCEDURES Performing an Emission Test... part specifies otherwise. This section describes how to determine if the engine's operation during the... from the engine's primary output shaft. Other work inputs and outputs are not subject to...

  3. 40 CFR 1065.514 - Cycle-validation criteria for operation over specified duty cycles.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS ENGINE-TESTING PROCEDURES Performing an Emission Test... part specifies otherwise. This section describes how to determine if the engine's operation during the... from the engine's primary output shaft. Other work inputs and outputs are not subject to...

  4. Increased efficiency of topping cycle PCFB power plants

    SciTech Connect

    Robertson, A.; Domeracki, W.; Horazak, D.

    1996-05-01

    Pressurized circulating fluidized bed (PCFB) power plants offer the power industry significantly increased efficiencies with reduced costs of electricity and lower emissions. When topping combustion is incorporated in the plant, these advantages are enhanced. In the plant, coal is fed to a pressurized carbonizer that produces a low-Btu fuel gas and char. After passing through a cyclone and ceramic barrier filter to remove gas-entrained particulates and a packed bed of emathelite pellets to remove alkali vapors. the fuel gas is burned in a topping combustor to produce the energy required to drive a gas turbine. The gas turbine drives a generator combustor, and a fluidized bed heat exchanger (FBHE). The carbonizer char is burned in the PCFB and the exhaust gas passes through its own cyclone, ceramic barrier filter, and alkali getter and supports combustion of the fuel gas in the topping combustor. Steam generated in a heat-recovery steam generator (HRSG) downstream of the gas turbine and in the FBHE associated with the PCFB drives the steam turbine generator that furnishes the balance of electric power delivered by the plant.

  5. Operating regimes of covalent modification cycles at high enzyme concentrations.

    PubMed

    Straube, Ronny

    2017-10-27

    The Goldbeter-Koshland model has been a paradigm for ultrasensitivity in biological networks for more than 30 years. Despite its simplicity the validity of this model is restricted to conditions when the substrate is in excess over the converter enzymes - a condition that is easy to satisfy in vitro, but which is rarely satisfied in vivo. Here, we analyze the Goldbeter-Koshland model by means of the total quasi-steady state approximation which yields a comprehensive classification of the steady state operating regimes under conditions when the enzyme concentrations are comparable to or larger than that of the substrate. Where possible we derive simple expressions characterizing the input-output behavior of the system. Our analysis suggests that enhanced sensitivity occurs if the concentration of at least one of the converter enzymes is smaller (but not necessarily much smaller) than that of the substrate and if that enzyme is saturated. Conversely, if both enzymes are saturated and at least one of the enzyme concentrations exceeds that of the substrate the system exhibits concentration robustness with respect to changes in that enzyme concentration. Also, depending on the enzyme's saturation degrees and the ratio between their maximal reaction rates the total fraction of phosphorylated substrate may increase, decrease or change nonmonotonically as a function of the total substrate concentration. The latter finding may aid the interpretation of experiments involving genetic perturbations of enzyme and substrate abundances. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Drought regulates the C and N cycling in soil depending on plant community composition

    NASA Astrophysics Data System (ADS)

    Sanaullah, Muhammad; Chabbi, Abad; Rumpel, Cornelia

    2015-04-01

    Drought consequences on carbon (C) and nutrients cycling have been well explored, but little is known about interactions in the rhizosphere under various plant community composition. We compared drought effects on microbial biomass carbon (MBC) and on enzyme activities in the rhizosphere of three plants grown individually or in mixture: two grasses (Lolium perenne and Festuca arundinacea) and one legume (Medicago sativa). The activities of extracellular enzymes involved in C cycle (xylanase, β-cellobiosidase and β-glucosidase) and nitrogen (N) cycle (chitinase and Leucine-aminopeptidase) were compared to MBC changes. The MBC was highly correlated with root biomass. MBC increased in response to drought in soil under the plant mixture, whereas it showed variable trends under monocultures. Drought and plant species composition were responsible for more than 90% of the variation of enzyme activities. Most enzyme activities decreased in unplanted soil in response to drought. The activity of the enzyme involved in the N cycle increased strongly under mixture and two out of three monocultures, indicating an increased N demand under drought conditions. The activities of enzymes involved in the C cycle in soil under mixture (1) generally were lower during drought compared to soil under monocultures and (2) were unchanged or tended to decrease, while they were more likely to increase under monocultures. This has an important ecological consequence: the decomposition of plant residues and soil organic matter will be slower under drought when plants are grown in mixture compared to monocultures.

  7. Geothermal plant efficiency enhancement by means of the use of Kalina cycle

    SciTech Connect

    Lazzeri, L.; Bruzzone, M.

    1995-12-31

    This paper presents a study on the increase in geothermal plant efficiency that can be obtained by using a Kalina cycle. After a brief overview on flash plant and organic binary plant performances and a description of the working principle of Kalina cycle geothermal plants, comparison shall be made between the efficiency of Kalina cycle plants and the one of flash plants on a representative case for medium-high enthalpy resource. Kalina cycle efficiency will also be calculated for a representative case for a low enthalpy resource and this result will be discuss with reference to organic binary cycle efficiencies reported in technical literature. Thermodynamic functions such as specific enthalpy (h) and specific enthropy (s) have been supposed to be known to the readers. The exergy function, being its use is somewhat more recent, is here redefined for the reader`s ease: the specific exergy (e) of a stream in steady flow is: e = (h{minus}h{sub o}){minus}T{sub o}{center_dot}(s{minus}s{sub o}) where the ``o`` subscript refers to environmental conditions. The energetic content of a stream in steady flow represents the maximum power output that can be obtained from the stream.

  8. Effect of operational cycle time length on nitrogen removal in an alternating oxidation ditch system.

    PubMed

    Mantziaras, I D; Stamou, A; Katsiri, A

    2011-06-01

    This paper refers to nitrogen removal optimization of an alternating oxidation ditch system through the use of a mathematical model and pilot testing. The pilot system where measurements have been made has a total volume of 120 m(3) and consists of two ditches operating in four phases during one cycle and performs carbon oxidation, nitrification, denitrification and settling. The mathematical model consists of one-dimensional mass balance (convection-dispersion) equations based on the IAWPRC ASM 1 model. After the calibration and verification of the model, simulation system performance was made. Optimization is achieved by testing operational cycles and phases with different time lengths. The limits of EU directive 91/271 for nitrogen removal have been used for comparison. The findings show that operational cycles with smaller time lengths can achieve higher nitrogen removals and that an "equilibrium" between phase time percentages in the whole cycle, for a given inflow, must be achieved.

  9. Nitrogen cycling and water pulses in semiarid grasslands: are microbial and plant processes temporally asynchronous?

    PubMed

    Dijkstra, Feike A; Augustine, David J; Brewer, Paul; von Fischer, Joseph C

    2012-11-01

    Precipitation pulses in arid ecosystems can lead to temporal asynchrony in microbial and plant processing of nitrogen (N) during drying/wetting cycles causing increased N loss. In contrast, more consistent availability of soil moisture in mesic ecosystems can synchronize microbial and plant processes during the growing season, thus minimizing N loss. We tested whether microbial N cycling is asynchronous with plant N uptake in a semiarid grassland. Using (15)N tracers, we compared rates of N cycling by microbes and N uptake by plants after water pulses of 1 and 2 cm to rates in control plots without a water pulse. Microbial N immobilization, gross N mineralization, and nitrification dramatically increased 1-3 days after the water pulses, with greatest responses after the 2-cm pulse. In contrast, plant N uptake increased more after the 1-cm than after the 2-cm pulse. Both microbial and plant responses reverted to control levels within 10 days, indicating that both microbial and plant responses were short lived. Thus, microbial and plant processes were temporally synchronous following a water pulse in this semiarid grassland, but the magnitude of the pulse substantially influenced whether plants or microbes were more effective in acquiring N. Furthermore, N loss increased after both small and large water pulses (as shown by a decrease in total (15)N recovery), indicating that changes in precipitation event sizes with future climate change could exacerbate N losses from semiarid ecosystems.

  10. Life cycle assessment of introducing an anaerobic digester in a municipal wastewater treatment plant in Spain.

    PubMed

    Blanco, David; Collado, Sergio; Laca, Adriana; Díaz, Mario

    2016-01-01

    Anaerobic digestion (AD) is being established as a standard technology to recover some of the energy contained in the sludge in wastewater treatment plants (WWTPs) as biogas, allowing an economy in electricity and heating and a decrease in climate gas emission. The purpose of this study was to quantify the contributions to the total environmental impact of the plant using life cycle assessment methodology. In this work, data from real operation during 2012 of a municipal WWTP were utilized as the basis to determine the impact of including AD in the process. The climate change human health was the most important impact category when AD was included in the treatment (Scenario 1), especially due to fossil carbon dioxide emissions. Without AD (Scenario 2), increased emissions of greenhouse gases, mostly derived from the use of electricity, provoked a rise in the climate change categories. Biogas utilization was able to provide 47% of the energy required in the WWTP in Scenario 1. Results obtained make Scenario 1 the better environmental choice by far, mainly due to the use of the digested sludge as fertilizer.

  11. Population cycles produced by delayed density dependence in an annual plant.

    PubMed

    Gonzalez-Andujar, J L; Fernandez-Quintanilla, C; Navarrete, L

    2006-09-01

    In contrast to insect and animal populations, little attention has been directed to the study of cycles in plant populations. It has been argued on theoretical grounds that plants present stable dynamics. Nevertheless, there are examples where plant populations appear to exhibit oscillatory dynamics, but the oscillatory signal is variable and comes from very short time series data. Using a combination of time series, models, and empirical results, we present evidence of population cycles for Descurania sophia in a 16-year field experiment. Endogenous and exogenous causal mechanisms were studied to identify processes underlying this temporal dynamic. Our results show a 4-year cycle produced by delayed density dependence. We suggest that high nutrient levels might be responsible for the observed dynamics of D. sophia. Our results suggest that although plant population dynamics may be stabilized by direct density dependence, delayed density dependence could destabilize dynamics.

  12. Assess How Changes in Fuel Cycle Operation Impact Safeguards

    SciTech Connect

    Tobin, Stephen Joseph; Adigun, Babatunde John; Fugate, Michael Lynn; Trellue, Holly Renee; Sprinkle, James K.

    2016-10-31

    Since the beginning of commercial nuclear power generation in the 1960s, the ability of researchers to understand and control the isotopic content of spent fuel has improved. It is therefore not surprising that both fuel assembly design and fuel assembly irradiation optimization have improved over the past 50+ years. It is anticipated that the burnup and isotopics of the spent fuel should exhibit less variation over the decades as reactor operators irradiate each assembly to the optimum amount. In contrast, older spent fuel is anticipated to vary more in burnup and resulting isotopics for a given initial enrichment. Modern fuel therefore should be more uniform in composition, and thus, measured safeguards results should be easier to interpret than results from older spent fuel. With spent fuel ponds filling up, interim and long-­term storage of spent fuel will need to be addressed. Additionally after long periods of storage, spent fuel is no longer self-­protecting and, as such, the IAEA will categorize it as more attractive; in approximately 20 years many of the assemblies from early commercial cores will no longer be considered self-­protecting. This study will assess how more recent changes in the reactor operation could impact the interpretation of safeguards measurements. The status quo for spent fuel assay in the safeguards context is that the overwhelming majority of spent fuel assemblies are not measured in a quantitative way except for those assemblies about to be loaded into a difficult or impossible to access location (dry storage or, in the future, a repository). In other words, when the assembly is still accessible to a state actor, or an insider, when it is cooling in a pool, the inspectorate does not have a measurement database that could assist them in re-­verifying the integrity of that assembly. The spent fuel safeguards regime would be strengthened if spent fuel assemblies were measured from discharge to loading into a difficult or impossible

  13. The organization and operation of the Savannah River Plant`s groundwater monitoring program. Revision 3

    SciTech Connect

    Olson, C.M.; Heffner, J.D.

    1988-09-01

    The Savannah River Plant (SRP) is operated by Du Pont for the Department of Energy. The plant has been operating since 1952 and is one of the largest industrial facilities in the nation. Its function is to produce nuclear materials for the national defense. This paper describes the organization and operation of the Groundwater Monitoring Program (GMP) at the SRP. Groundwater has been actively monitored for radiological parameters at the SRP since the commencement of site operations in the 1950s. More recently, monitoring expanded to include chemical parameters and numerous additional facilities. The GMP is a large monitoring program. Over 700 wells monitor more than 70 facilities which are spread over 300 square miles. The program includes both Du Pont personnel and contractors and is responsible for all phases of groundwater monitoring: the installation (or abandonment) of monitoring wells, the determination of water quality (sample collection, analysis, data review, etc.), and the generation of reports.

  14. Recovering Sturm-Liouville operators from spectra on a graph with a cycle

    SciTech Connect

    Yurko, Vyacheslav A

    2009-10-31

    An inverse problem of spectral analysis is studied for Sturm-Liouville differential operators on a graph with a cycle and with generalized matching conditions at the internal vertex. Theorems on the unique recovery of operators from a system of spectra are proved, and a constructive solution is obtained for this class of inverse problems. Bibliography: 26 titles.

  15. Operation results of the first commercial PFBC plant with high temperature ceramic filters

    SciTech Connect

    Suga, Nobuyuki; Ishioka, Hidekazu; Ohnishi, Takashi; Kaneko, Shozo; Kinoshita, Masaaki; Katoh, Makoto

    1998-12-31

    In this paper the authors introduce the 85MWe Tomatoh-Atsuma Unit No. 3 of the Hokkaido Electric Power Company, Inc. (HEPCO), first commercial Pressurized Fluidized Bed Combustion (PFBC) Combined Cycle Plant in Japan. In recent years, coal is recognized as the most important fossil fuel for power generation, by the abundance and world-wide distribution of resources and by its economical advantages. On the other hand, superior environmental performances in particulate matters, sulfur oxides and nitrogen oxides are required and high efficiency is strongly desirable to minimize the CO{sub 2} emission to prevent the global warming effect. HEPCO decided to adopt PFBC Combined Cycle to its Tomatoh-Atsuma Unit No. 3, evaluating the high efficiency and environmental superiority of PFBC C/C. Mitsubishi Heavy Industries, LTD. (MHI) supplied the whole system as a package, including PFBC, coal handling system, ceramic fibers, steam turbine, gas turbine, heat recovery steam generator, selective catalytic reduction (SCR) system of NOx and direct digital control system. MHI developed the ceramic filter and gas turbine technology based on its own research and development program, and to establish the final specification of the commercial plant, HEPCO and MHI did a joint R and D program since 1990. The Tomatoh-Atsuma Unit No. 3 started its trial operation in May 1995, and finishing a variety of test programs during the trial operation, is scheduled to start its commercial operation in March, 1998.

  16. Unit operations used to treat process and/or waste streams at nuclear power plants. [R

    SciTech Connect

    Godbee, H.W.; Kibbey, A.H.

    1980-01-01

    Estimates are given of the annual amounts of each generic type of LLW (i.e., Government and commerical (fuel cycle and non-fuel cycle)) that is generated at LWR plants. Many different chemical engineering unit operations used to treat process and/or waste streams at LWR plants include adsorption, evaporation, calcination, centrifugation, compaction, crystallization, drying, filtration, incineration, reverse osmosis, and solidification of waste residues. The treatment of these various streams and the secondary wet solid wastes thus generated is described. The various treatment options for concentrates or solid wet wastes, and for dry wastes are discussed. Among the dry waste treatment methods are compaction, baling, and incineration, as well as chopping, cutting and shredding. Organic materials (liquids (e.g., oils or solvents) and/or solids), could be incinerated in most cases. The filter sludges, spent resins, and concentrated liquids (e.g., evaporator concentrates) are usually solidified in cement, or urea-formaldehyde or unsaturated polyester resins prior to burial. Incinerator ashes can also be incorporated in these binding agents. Asphalt has not yet been used. This paper presents a brief survey of operational experience at LWRs with various unit operations, including a short discussion of problems and some observations on recent trends.

  17. Reliability engineering for plant design and life cycle performance

    SciTech Connect

    Elgohary, K.B.; Delgado, A.; Ostrofsky, B.

    1998-12-31

    This paper describes a simplified approach to determining the probability density function (PDF) for both scheduled and unscheduled plant maintenance. Illustrative data is also provided showing the results of the approach for a specific installation. This simpler approach includes nine number sets of values generated to cover the historic data range for each equipment item including the mean, maximum, and minimum for the data elements covering failures and repairs used in calculating the availability of a system.

  18. The pitcher plant Sarracenia purpurea can directly acquire organic nitrogen and short-circuit the inorganic nitrogen cycle.

    PubMed

    Karagatzides, Jim D; Butler, Jessica L; Ellison, Aaron M

    2009-07-07

    Despite the large stocks of organic nitrogen in soil, nitrogen availability limits plant growth in many terrestrial ecosystems because most plants take up only inorganic nitrogen, not organic nitrogen. Although some vascular plants can assimilate organic nitrogen directly, only recently has organic nitrogen been found to contribute significantly to the nutrient budget of any plant. Carnivorous plants grow in extremely nutrient-poor environments and carnivory has evolved in these plants as an alternative pathway for obtaining nutrients. We tested if the carnivorous pitcher plant Sarracenia purpurea could directly take up intact amino acids in the field and compared uptake of organic and inorganic forms of nitrogen across a gradient of nitrogen deposition. We hypothesized that the contribution of organic nitrogen to the nitrogen budget of the pitcher plant would decline with increasing nitrogen deposition. At sites in Canada (low nitrogen deposition) and the United States (high nitrogen deposition), individual pitchers were fed two amino acids, glycine and phenylalanine, and inorganic nitrogen (as ammonium nitrate), individually and in mixture. Plants took up intact amino acids. Acquisition of each form of nitrogen provided in isolation exceeded uptake of the same form in mixture. At the high deposition site, uptake of organic nitrogen was higher than uptake of inorganic nitrogen. At the low deposition site, uptake of all three forms of nitrogen was similar. Completeness of the associated detritus-based food web that inhabits pitcher-plant leaves and breaks down captured prey had no effect on nitrogen uptake. By taking up intact amino acids, Sarracenia purpurea can short-circuit the inorganic nitrogen cycle, thus minimizing potential bottlenecks in nitrogen availability that result from the plant's reliance for nitrogen mineralization on a seasonally reconstructed food web operating on infrequent and irregular prey capture.

  19. Nevada Renewable Energy Training Project: Geothermal Power Plant Operators

    SciTech Connect

    Jim, Nichols

    2014-04-29

    The purpose of this project was to develop and institute a training program for certified geothermal power plant operators (GPO). An advisory board consisting of subject matter experts from the geothermal energy industry and academia identified the critical skill sets required for this profession. A 34-credit Certificate of Achievement (COA), Geothermal Power Plant Operator, was developed using eight existing courses and developing five new courses. Approval from the Nevada System of Higher Education Board of Regents was obtained. A 2,400 sq. ft. geothermal/fluid mechanics laboratory and a 3,000 sq. ft. outdoor demonstration laboratory were constructed for hands-on training. Students also participated in field trips to geothermal power plants in the region. The majority of students were able to complete the program in 2-3 semesters, depending on their level of math proficiency. Additionally the COA allowed students to continue to an Associate of Applied Science (AAS), Energy Technologies with an emphasis in Geothermal Energy (26 additional credits), if they desired. The COA and AAS are stackable degrees, which provide students with an ongoing career pathway. Articulation agreements with other NSHE institutions provide students with additional opportunities to pursue a Bachelor of Applied Science in Management or Instrumentation. Job placement for COA graduates has been excellent.

  20. A microbial avenue to cell cycle control in the plant superkingdom.

    PubMed

    Tulin, Frej; Cross, Frederick R

    2014-10-01

    Research in yeast and animals has resulted in a well-supported consensus model for eukaryotic cell cycle control. The fit of this model to early diverging eukaryotes, such as the plant kingdom, remains unclear. Using the green alga Chlamydomonas reinhardtii, we developed an efficient pipeline, incorporating robotics, semiautomated image analysis, and deep sequencing, to molecularly identify >50 genes, mostly conserved in higher plants, specifically required for cell division but not cell growth. Mutated genes include the cyclin-dependent kinases CDKA (resembling yeast and animal Cdk1) and the plant-specific CDKB. The Chlamydomonas cell cycle consists of a long G1 during which cells can grow >10-fold, followed by multiple rapid cycles of DNA replication and segregation. CDKA and CDKB execute nonoverlapping functions: CDKA promotes transition between G1 and entry into the division cycle, while CDKB is essential specifically for spindle formation and nuclear division, but not for DNA replication, once CDKA-dependent initiation has occurred. The anaphase-promoting complex is required for similar steps in the Chlamydomonas cell cycle as in Opisthokonts; however, the spindle assembly checkpoint, which targets the APC in Opisthokonts, appears severely attenuated in Chlamydomonas, based on analysis of mutants affecting microtubule function. This approach allows unbiased integration of the consensus cell cycle control model with innovations specific to the plant lineage.

  1. A Microbial Avenue to Cell Cycle Control in the Plant Superkingdom[C][W][OPEN

    PubMed Central

    Tulin, Frej; Cross, Frederick R.

    2014-01-01

    Research in yeast and animals has resulted in a well-supported consensus model for eukaryotic cell cycle control. The fit of this model to early diverging eukaryotes, such as the plant kingdom, remains unclear. Using the green alga Chlamydomonas reinhardtii, we developed an efficient pipeline, incorporating robotics, semiautomated image analysis, and deep sequencing, to molecularly identify >50 genes, mostly conserved in higher plants, specifically required for cell division but not cell growth. Mutated genes include the cyclin-dependent kinases CDKA (resembling yeast and animal Cdk1) and the plant-specific CDKB. The Chlamydomonas cell cycle consists of a long G1 during which cells can grow >10-fold, followed by multiple rapid cycles of DNA replication and segregation. CDKA and CDKB execute nonoverlapping functions: CDKA promotes transition between G1 and entry into the division cycle, while CDKB is essential specifically for spindle formation and nuclear division, but not for DNA replication, once CDKA-dependent initiation has occurred. The anaphase-promoting complex is required for similar steps in the Chlamydomonas cell cycle as in Opisthokonts; however, the spindle assembly checkpoint, which targets the APC in Opisthokonts, appears severely attenuated in Chlamydomonas, based on analysis of mutants affecting microtubule function. This approach allows unbiased integration of the consensus cell cycle control model with innovations specific to the plant lineage. PMID:25336509

  2. Geminiviruses: models for plant DNA replication, transcription, and cell cycle regulation.

    PubMed

    Hanley-Bowdoin, L; Settlage, S B; Orozco, B M; Nagar, S; Robertson, D

    2000-01-01

    Geminiviruses have small, single-stranded DNA genomes that replicate through double-stranded intermediates in the nuclei of infected plant cells. Viral double-stranded DNA also assembles into minichromosomes and is transcribed in infected cells. Geminiviruses encode only a few proteins for their replication and transcription and rely on host enzymes for these processes. However, most plant cells, which have exited the cell cycle and undergone differentiation, do not contain the replicative enzymes necessary for viral DNA synthesis. To overcome this barrier, geminiviruses induce the accumulation of DNA replication machinery in mature plant cells, most likely by modifying cell cycle and transcriptional controls. In animals, several DNA viruses depend on host replication and transcription machinery and can alter their hosts to create an environment that facilitates efficient viral replication. Analysis of these viruses and their proteins has contributed significantly to our understanding of DNA replication, transcription, and cell cycle regulation in mammalian cells. Geminiviruses have the same potential for plant systems. Plants offer many advantages for these types of studies, including ease of transformation, well-defined cell populations and developmental programs, and greater tolerance of cell cycle perturbation and polyploidy. Our knowledge of the molecular and cellular events that mediate geminivirus infection has increased significantly during recent years. The goal of this review is to summarize recent research addressing geminivirus DNA replication and its integration with transcriptional and cell cycle regulatory processes.

  3. Cognitive skill training for nuclear power plant operational decision making

    SciTech Connect

    Mumaw, R.J.; Swatzler, D.; Roth, E.M.; Thomas, W.A.

    1994-06-01

    Training for operator and other technical positions in the commercial nuclear power industry traditionally has focused on mastery of the formal procedures used to control plant systems and processes. However, decisionmaking tasks required of nuclear power plant operators involve cognitive skills (e.g., situation assessment, planning). Cognitive skills are needed in situations where formal procedures may not exist or may not be as prescriptive, as is the case in severe accident management (SAM). The Westinghouse research team investigated the potential cognitive demands of SAM on the control room operators and Technical Support Center staff who would be most involved in the selection and execution of severe accident control actions. A model of decision making, organized around six general cognitive processes, was developed to identify the types of cognitive skills that may be needed for effective performance. Also, twelve SAM scenarios were developed to reveal specific decision-making difficulties. Following the identification of relevant cognitive skills, 19 approaches for training individual and team cognitive skills were identified. A review of these approaches resulted in the identification of general characteristics that are important in effective training of cognitive skills.

  4. Cesium isotope ratios as indicators of nuclear power plant operations.

    PubMed

    Delmore, James E; Snyder, Darin C; Tranter, Troy; Mann, Nick R

    2011-11-01

    There are multiple paths by which radioactive cesium can reach the effluent from reactor operations. The radioactive (135)Cs/(137)Cs ratios are controlled by these paths. In an effort to better understand the origin of this radiation, these (135)Cs/(137)Cs ratios in effluents from three power reactor sites have been measured in offsite samples. These ratios are different from global fallout by up to six fold and as such cannot have a significant component from this source. A cesium ratio for a sample collected outside of the plant boundary provides integration over the operating life of the reactor. A sample collected inside the plant at any given time can be much different from this lifetime ratio. The measured cesium ratios vary significantly for the three reactors and indicate that the multiple paths have widely varying levels of contributions. There are too many ways these isotopes can fractionate to be useful for quantitative evaluations of operating parameters in an offsite sample, although it may be possible to obtain limited qualitative information for an onsite sample.

  5. Cesium Isotope Ratios as Indicators of Nuclear Power Plant Operations

    SciTech Connect

    Darin Snyder; James Delmore; Troy Tranter; Nick Mann; Michael Abbott; John Olson

    2011-11-01

    There are multiple paths by which radioactive cesium can reach the effluent from reactor operations. The radioactive 135Cs/137Cs ratios are controlled by these paths. In an effort to better understand the origin of this radiation, these 135Cs/137Cs ratios in effluents from three power reactor sites have been measured in offsite samples. These ratios are different from global fallout by up to six fold and as such cannot have a significant component from this source. A cesium ratio for a sample collected outside of the plant boundary provides integration over the operating life of the reactor. A sample collected inside the plant at any given time can be much different from this lifetime ratio. The measured cesium ratios vary significantly for the three reactors and indicate that the multiple paths have widely varying levels of contributions. There are too many ways these isotopes can fractionate to be useful for quantitative evaluations of operating parameters in an offsite sample, although it may be possible to obtain limited qualitative information for an onsite sample.

  6. Simulated first operating campaign for the Integral Fast Reactor fuel cycle demonstration

    SciTech Connect

    Goff, K.M.; Mariani, R.D.; Benedict, R.W.; Park, K.H.; Ackerman, J.P.

    1993-09-01

    This report discusses the Integral Fast Reactor (IFR) which is an innovative liquid-metal-cooled reactor concept that is being developed by Argonne National Laboratory. It takes advantage of the properties of metallic fuel and liquid-metal cooling to offer significant improvements in reactor safety, operation, fuel cycle-economics, environmental protection, and safeguards. Over the next few years, the IFR fuel cycle will be demonstrated at Argonne-West in Idaho. Spent fuel from the Experimental Breeder Reactor II (EBR-II) win be processed in its associated Fuel Cycle Facility (FCF) using a pyrochemical method that employs molten salts and liquid metals in an electrorefining operation. As part of the preparation for the fuel cycle demonstration, a computer code, PYRO, was developed at Argonne to model the electrorefining operation using thermodynamic and empirical data. This code has been used extensively to evaluate various operating strategies for the fuel cycle demonstration. The modeled results from the first operating campaign are presented. This campaign is capable of processing more than enough material to refuel completely the EBR-II core.

  7. Budgeting for Solar PV Plant Operations & Maintenance: Practices and Pricing.

    SciTech Connect

    Enbar, Nadav; Weng, Dean; Klise, Geoffrey Taylor

    2015-12-01

    With rising grid interconnections of solar photovoltaic (PV) systems, greater attention is being trained on lifecycle performance, reliability, and project economics. Expected to meet production thresholds over a 20-30 year timeframe, PV plants require a steady diet of operations and maintenance (O&M) oversight to meet contractual terms. However, industry best practices are only just beginning to emerge, and O&M budgets—given the arrangement of the solar project value chain—appear to vary widely. Based on insights from in-depth interviews and survey research, this paper presents an overview of the utility-scale PV O&M budgeting process along with guiding rationales, before detailing perspectives on current plant upkeep activities and price points largely in the U.S. It concludes by pondering potential opportunities for improving upon existing O&M budgeting approaches in ways that can benefi t the industry at-large.

  8. Budgeting for Solar PV Plant Operations & Maintenance: Practices and Pricing.

    SciTech Connect

    Enbar, Nadav; Weng, Dean; Klise, Geoffrey Taylor

    2016-01-01

    With rising grid interconnections of solar photovoltaic (PV) systems, greater attention is being trained on lifecycle performance, reliability, and project economics. Expected to meet production thresholds over a 20-30 year timeframe, PV plants require a steady diet of operations and maintenance (O&M) oversight to meet contractual terms. However, industry best practices are only just beginning to emerge, and O&M budgets—given the arrangement of the solar project value chain—appear to vary widely. Based on insights from in-depth interviews and survey research, this paper presents an overview of the utility-scale PV O&M budgeting process along with guiding rationales, before detailing perspectives on current plant upkeep activities and price points largely in the U.S. It concludes by pondering potential opportunities for improving upon existing O&M budgeting approaches in ways that can benefit the industry at-large.

  9. Pre-operational radio-environmental studies of Plant Vogtle

    SciTech Connect

    Winn, W.G.; Sigg, R.A.

    1989-05-01

    This baseline study evaluates radioactivity in the environment near Plant Vogtle before initial reactor startup in 1987. These data will distinguish between any future radio-environmental effects from SRS and Plant Vogtle. Alpha, beta, and gamma-spectrometric methods analyzed river, stream, sediment, and soil samples. The study detected manmade radionuclides {sup 3}H, {sup 60}Co, {sup 134}Cs, {sup 137}Cs, {sup 239}Pu, {sup 240}Pu, and {sup 241}Pu. However, all concentration levels are extremely low and are consistent with levels expected from fallout and from SRS operations in its early years. The measurements begun in this study continue to be used to monitor Vogtle post-startup effluents. 12 refs., 6 figs., 7 tabs.

  10. Catalytic combustor for integrated gasification combined cycle power plant

    DOEpatents

    Bachovchin, Dennis M.; Lippert, Thomas E.

    2008-12-16

    A gasification power plant 10 includes a compressor 32 producing a compressed air flow 36, an air separation unit 22 producing a nitrogen flow 44, a gasifier 14 producing a primary fuel flow 28 and a secondary fuel source 60 providing a secondary fuel flow 62 The plant also includes a catalytic combustor 12 combining the nitrogen flow and a combustor portion 38 of the compressed air flow to form a diluted air flow 39 and combining at least one of the primary fuel flow and secondary fuel flow and a mixer portion 78 of the diluted air flow to produce a combustible mixture 80. A catalytic element 64 of the combustor 12 separately receives the combustible mixture and a backside cooling portion 84 of the diluted air flow and allows the mixture and the heated flow to produce a hot combustion gas 46 provided to a turbine 48. When fueled with the secondary fuel flow, nitrogen is not combined with the combustor portion.

  11. Feasibility and operating costs of an air cycle for CCHP in a fast food restaurant

    DOE PAGES

    Perez-Blanco, Horacio; Vineyard, Edward

    2016-05-06

    This work considers the possibilities of an air-based Brayton cycle to provide the power, heating and cooling needs of fast-food restaurants. A model of the cycle based on conventional turbomachinery loss coefficients is formulated. The heating, cooling and power capabilities of the cycle are extracted from simulation results. Power and thermal loads for restaurants in Knoxville, TN and in International Falls, MN, are considered. It is found that the cycle can meet the loads by setting speed and mass flow-rate apportionment between the power and cooling functional sections. The associated energy costs appear elevated when compared to the cost ofmore » operating individual components or a more conventional, absorption-based CHP system. Lastly, a first-order estimate of capital investments is provided. Suggestions for future work whereby the operational costs could be reduced are given in the conclusions.« less

  12. Feasibility and operating costs of an air cycle for CCHP in a fast food restaurant

    SciTech Connect

    Perez-Blanco, Horacio; Vineyard, Edward

    2016-05-06

    This work considers the possibilities of an air-based Brayton cycle to provide the power, heating and cooling needs of fast-food restaurants. A model of the cycle based on conventional turbomachinery loss coefficients is formulated. The heating, cooling and power capabilities of the cycle are extracted from simulation results. Power and thermal loads for restaurants in Knoxville, TN and in International Falls, MN, are considered. It is found that the cycle can meet the loads by setting speed and mass flow-rate apportionment between the power and cooling functional sections. The associated energy costs appear elevated when compared to the cost of operating individual components or a more conventional, absorption-based CHP system. Lastly, a first-order estimate of capital investments is provided. Suggestions for future work whereby the operational costs could be reduced are given in the conclusions.

  13. Feasibility and operating costs of an air cycle for CCHP in a fast food restaurant

    SciTech Connect

    Perez-Blanco, Horacio; Vineyard, Edward

    2016-05-06

    This work considers the possibilities of an air-based Brayton cycle to provide the power, heating and cooling needs of fast-food restaurants. A model of the cycle based on conventional turbomachinery loss coefficients is formulated. The heating, cooling and power capabilities of the cycle are extracted from simulation results. Power and thermal loads for restaurants in Knoxville, TN and in International Falls, MN, are considered. It is found that the cycle can meet the loads by setting speed and mass flow-rate apportionment between the power and cooling functional sections. The associated energy costs appear elevated when compared to the cost of operating individual components or a more conventional, absorption-based CHP system. Lastly, a first-order estimate of capital investments is provided. Suggestions for future work whereby the operational costs could be reduced are given in the conclusions.

  14. Leak before break application in French PWR plants under operation

    SciTech Connect

    Faidy, C.

    1997-04-01

    Practical applications of the leak-before break concept are presently limited in French Pressurized Water Reactors (PWR) compared to Fast Breeder Reactors. Neithertheless, different fracture mechanic demonstrations have been done on different primary, auxiliary and secondary PWR piping systems based on similar requirements that the American NUREG 1061 specifications. The consequences of the success in different demonstrations are still in discussion to be included in the global safety assessment of the plants, such as the consequences on in-service inspections, leak detection systems, support optimization,.... A large research and development program, realized in different co-operative agreements, completes the general approach.

  15. Hybrid sulfur cycle operation for high-temperature gas-cooled reactors

    DOEpatents

    Gorensek, Maximilian B

    2015-02-17

    A hybrid sulfur (HyS) cycle process for the production of hydrogen is provided. The process uses a proton exchange membrane (PEM) SO.sub.2-depolarized electrolyzer (SDE) for the low-temperature, electrochemical reaction step and a bayonet reactor for the high-temperature decomposition step The process can be operated at lower temperature and pressure ranges while still providing an overall energy efficient cycle process.

  16. Performance comparison of different thermodynamic cycles for an innovative central receiver solar power plant

    NASA Astrophysics Data System (ADS)

    Reyes-Belmonte, Miguel A.; Sebastián, Andrés; González-Aguilar, José; Romero, Manuel

    2017-06-01

    The potential of using different thermodynamic cycles coupled to a solar tower central receiver that uses a novel heat transfer fluid is analyzed. The new fluid, named as DPS, is a dense suspension of solid particles aerated through a tubular receiver used to convert concentrated solar energy into thermal power. This novel fluid allows reaching high temperatures at the solar receiver what opens a wide range of possibilities for power cycle selection. This work has been focused into the assessment of power plant performance using conventional, but optimized cycles but also novel thermodynamic concepts. Cases studied are ranging from subcritical steam Rankine cycle; open regenerative Brayton air configurations at medium and high temperature; combined cycle; closed regenerative Brayton helium scheme and closed recompression supercritical carbon dioxide Brayton cycle. Power cycle diagrams and working conditions for design point are compared amongst the studied cases for a common reference thermal power of 57 MWth reaching the central cavity receiver. It has been found that Brayton air cycle working at high temperature or using supercritical carbon dioxide are the most promising solutions in terms of efficiency conversion for the power block of future generation by means of concentrated solar power plants.

  17. Seabrook, N.H. Wastewater Treatment Plant Chief Operator Recognized for Outstanding Service

    EPA Pesticide Factsheets

    Dustin Price, a resident of Berwick Maine and the Chief Operator of the Seabrook, N.H. Wastewater Treatment Plant, was honored by EPA with a 2016 Regional Wastewater Treatment Plant Operator of the Year Excellence Award.

  18. Nutrient cycling and plant dynamics in estuaries: A brief review

    NASA Astrophysics Data System (ADS)

    Flindt, Mogens R.; Pardal, Miguel Ângelo; Lillebø, Ana Isabel; Martins, Irene; Marques, João Carlos

    1999-07-01

    Eutrophication of European estuaries due to massive nutrient loading from urban areas and diffuse runoff from extensively cultivated land areas is analysed. Consequences for the ecology of estuaries, namely changes in plant species composition, which also affects heterotrophic organisms, are approached based on examples showing that the result is often a fundamental structural change of the ecosystem, from a grazing and/or nutrient controlled stable systems to unstable detritus/mineralisation systems, where the turnover of oxygen and nutrients is much more dynamic and oscillations between aerobic and anaerobic states frequently occur. Several relevant aspects are examined, namely the influence of rooted macrophytes on nutrient dynamics, by comparing bare bottom sediments with eelgrass covered sediments, primary production and the development of organic detritus, and hydrodynamics and its relations to the spatial distribution of macrophytes in estuarine systems.

  19. Recovery Act: Johnston Rhode Island Combined Cycle Electric Generating Plant Fueled by Waste Landfill Gas

    SciTech Connect

    Galowitz, Stephen

    2013-06-30

    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 Central Landfill in Johnston, Rhode Island. 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. 1) Meet environmental and regulatory requirements, particularly the compliance obligations imposed on the landfill to collect, process and destroy landfill gas. 2) Utilize proven and reliable technology and equipment. 3) Maximize electrical efficiency. 4) Maximize electric generating capacity, consistent with the anticipated quantities of landfill gas generated and collected at the Central Landfill. 5) Maximize equipment uptime. 6) Minimize water consumption. 7) Minimize post-combustion emissions. To achieve the Project Objective the project consisted of several components. 1) The landfill gas collection system was modified and upgraded. 2) A State-of-the Art gas clean up and compression facility was constructed. 3) A high pressure pipeline was constructed to convey cleaned landfill gas from the clean-up and compression facility to the power plant. 4) A combined cycle electric generating facility was constructed consisting of combustion turbine generator sets, heat recovery steam generators and a steam turbine. 5) The voltage of the electricity produced was increased at a newly constructed transformer/substation and the electricity was delivered to the local transmission system. The Project produced a myriad of beneficial impacts. 1) The Project created 453 FTE construction and manufacturing jobs and 25 FTE permanent jobs associated with the operation and maintenance of the plant and equipment. 2) By combining state-of-the-art gas clean up systems with post combustion emissions control

  20. Selecting the process arrangement for preparing the gas turbine working fluid for an integrated gasification combined-cycle power plant

    NASA Astrophysics Data System (ADS)

    Ryzhkov, A. F.; Gordeev, S. I.; Bogatova, T. F.

    2015-11-01

    Introduction of a combined-cycle technology based on fuel gasification integrated in the process cycle (commonly known as integrated gasification combined cycle technology) is among avenues of development activities aimed at achieving more efficient operation of coal-fired power units at thermal power plants. The introduction of this technology is presently facing the following difficulties: IGCC installations are characterized by high capital intensity, low energy efficiency, and insufficient reliability and availability indicators. It was revealed from an analysis of literature sources that these drawbacks are typical for the gas turbine working fluid preparation system, the main component of which is a gasification plant. Different methods for improving the gasification plant chemical efficiency were compared, including blast air high-temperature heating, use of industrial oxygen, and a combination of these two methods implying limited use of oxygen and moderate heating of blast air. Calculated investigations aimed at estimating the influence of methods for achieving more efficient air gasification are carried out taking as an example the gasifier produced by the Mitsubishi Heavy Industries (MHI) with a thermal capacity of 500 MW. The investigation procedure was verified against the known experimental data. Modes have been determined in which the use of high-temperature heating of blast air for gasification and cycle air upstream of the gas turbine combustion chamber makes it possible to increase the working fluid preparation system efficiency to a level exceeding the efficiency of the oxygen process performed according to the Shell technology. For the gasification plant's configuration and the GTU working fluid preparation system be selected on a well-grounded basis, this work should be supplemented with technical-economic calculations.

  1. Study of Indonesia low rank coal utilization on modified fixed bed gasification for combined cycle power plant

    NASA Astrophysics Data System (ADS)

    Hardianto, T.; Amalia, A. R.; Suwono, A.; Riauwindu, P.

    2015-09-01

    Gasification is a conversion process converting carbon-based solid fuel into gaseous products that have considerable amount of calorific value. One of the carbon-based solid fuel that serves as feed for gasification is coal. Gasification gaseous product is termed as syngas (synthetic gas) that is composed of several different gases. Syngas produced from gasification vary from one process to another, this is due to several factors which are: feed characteristics, operation condition, gasified fluid condition, and gasification method or technology. One of the utilization of syngas is for combined cycle power plant fuel. In order to meet the need to convert carbon-based solid fuel into gaseous fuel for combined cycle power plant, engineering adjustment for gasification was done using related software to create the syngas with characteristics of natural gas that serve as fuel for combined cycle power plant in Indonesia. Feed used for the gasification process in this paper was Indonesian Low Rank Coal and the method used to obtain syngas was Modified Fixed Bed Gasifier. From the engineering adjustment process, the yielded syngas possessed lower heating value as much as 31828.32 kJ/kg in gasification condition of 600°C, 3.5 bar, and steam to feed ratio was 1 kg/kg. Syngas characteristics obtained from the process was used as a reference for the adjustment of the fuel system modification in combined cycle power plant that will have the same capacity with the conversion of the system's fuel from natural gas to syngas.

  2. COMPUTERIZATION OF NUCLEAR POWER PLANT EMERGENCY OPERATING PROCEDURES.

    SciTech Connect

    OHARA,J.M.; HIGGINS,J.; STUBLER,W.

    2000-07-30

    Emergency operating procedures (EOPs) in nuclear plants guide operators in handling significant process disturbances. Historically these procedures have been paper-based. More recently, computer-based procedure (CBP) systems have been developed to improve the usability of EOPs. The objective of this study was to establish human factors review guidance for CBP systems based on a technically valid methodology. First, a characterization of CBPs was developed for describing their key design features, including both procedure representation and functionality. Then, the research on CBPs and related areas was reviewed. This information provided the technical basis on which the guidelines were developed. For some aspects of CBPs the technical basis was insufficient to develop guidance; these aspects were identified as issues to be addressed in future research.

  3. Fuel and Core Design for Long Operating Cycle Simplified BWR (LSBWR)

    SciTech Connect

    Noriyuki Yoshida; Kouji Hiraiwa; Mikihide Nakamaru; Hideaki Heki

    2002-07-01

    This paper describes an innovative core concept currently being developed for long operating cycle simplified BWR (LSBWR). The LSBWR adopts the long cycle operation (15 years) for the elimination of the fuel pool and the refueling machines and for the capacity usage ratio improvement. To achieve long cycle operation, a combination of enriched gadolinium and 0.7- times sized small bundle with peripheral-positioned gadolinium rod is adopted as a key design concept. A nuclear design for fuel bundle has been determined based on three dimensional nuclear and thermal hydraulic calculation. A core performance has been evaluated based on this bundle design and thermal performance and reactivity characteristics indicated preferable value. (authors)

  4. Tightly-Coupled Plant-Soil Nitrogen Cycling: Comparison of Organic Farms across an Agricultural Landscape.

    PubMed

    Bowles, Timothy M; Hollander, Allan D; Steenwerth, Kerri; Jackson, Louise E

    2015-01-01

    How farming systems supply sufficient nitrogen (N) for high yields but with reduced N losses is a central challenge for reducing the tradeoffs often associated with N cycling in agriculture. Variability in soil organic matter and management of organic farms across an agricultural landscape may yield insights for improving N cycling and for evaluating novel indicators of N availability. We assessed yields, plant-soil N cycling, and root expression of N metabolism genes across a representative set of organic fields growing Roma-type tomatoes (Solanum lycopersicum L.) in an intensively-managed agricultural landscape in California, USA. The fields spanned a three-fold range of soil carbon (C) and N but had similar soil types, texture, and pH. Organic tomato yields ranged from 22.9 to 120.1 Mg ha-1 with a mean similar to the county average (86.1 Mg ha-1), which included mostly conventionally-grown tomatoes. Substantial variability in soil inorganic N concentrations, tomato N, and root gene expression indicated a range of possible tradeoffs between yields and potential for N losses across the fields. Fields showing evidence of tightly-coupled plant-soil N cycling, a desirable scenario in which high crop yields are supported by adequate N availability but low potential for N loss, had the highest total and labile soil C and N and received organic matter inputs with a range of N availability. In these fields, elevated expression of a key gene involved in root N assimilation, cytosolic glutamine synthetase GS1, confirmed that plant N assimilation was high even when inorganic N pools were low. Thus tightly-coupled N cycling occurred on several working organic farms. Novel combinations of N cycling indicators (i.e. inorganic N along with soil microbial activity and root gene expression for N assimilation) would support adaptive management for improved N cycling on organic as well as conventional farms, especially when plant-soil N cycling is rapid.

  5. Optimization of the weekly operation of a multipurpose hydroelectric development, including a pumped storage plant

    NASA Astrophysics Data System (ADS)

    Popa, R.; Popa, F.; Popa, B.; Zachia-Zlatea, D.

    2010-08-01

    It is presented an optimization model based on genetic algorithms for the operation of a multipurpose hydroelectric power development consisting in a pumped storage plant (PSP) with weekly operation cycle. The lower reservoir of the PSP is supplied upstream from a peak hydropower plant (HPP) with a large reservoir and supplies the own HPP which provides the required discharges towards downstream. Under these conditions, the optimum operation of the assembly consisting in 3 reservoirs and hydropower plants becomes a difficult problem if there are considered the restrictions as regards: the gradients allowed for the reservoirs filling/emptying, compliance with of a long-term policy of the upper reservoir from the hydroelectric development and of the weekly cycle for the PSP upper reservoir, correspondence between the power output/consumption in the weekly load schedule, turning to account of the water resource at maximum overall efficiencies, etc. Maximization of the net energy value (generated minus consumed) was selected as performance function of the model, considering the differentiated price of the electric energy over the week (working or weekend days, peak, half-peak or base hours). The analysis time step was required to be of 3 hours, resulting a weekly horizon of 56 steps and 168 decision variables, respectively, for the 3 HPPs of the system. These were allowed to be the flows turbined at the HPP and the number of working hydrounits at PSP, on each time step. The numerical application has considered the guiding data of Fantanele-Tarnita-Lapustesti hydroelectric development. Results of various simulations carried out proved the qualities of the proposed optimization model, which will allow its use within a decisional support program for such a development.

  6. Examination of oxygen release from plants in constructed wetlands in different stages of wetland plant life cycle.

    PubMed

    Zhang, Jian; Wu, Haiming; Hu, Zhen; Liang, Shuang; Fan, Jinlin

    2014-01-01

    The quantification of oxygen release by plants in different stages of wetland plant life cycle was made in this study. Results obtained from 1 year measurement in subsurface wetland microcosms demonstrated that oxygen release from Phragmites australis varied from 108.89 to 404.44 mg O₂/m(2)/d during the different periods from budding to dormancy. Plant species, substrate types, and culture solutions had a significant effect on the capacity of oxygen release of wetland plants. Oxygen supply by wetland plants was estimated to potentially support a removal of 300.37 mg COD/m(2)/d or 55.87 mg NH₄-N/m(2)/d. According to oxygen balance analysis, oxygen release by plants could provide 0.43-1.12% of biochemical oxygen demand in typical subsurface-flow constructed wetlands (CWs). This demonstrates that oxygen release of plants may be a potential source for pollutants removal especially in low-loaded CWs. The results make it possible to quantify the role of plants in wastewater purification.

  7. Method and system to estimate variables in an integrated gasification combined cycle (IGCC) plant

    DOEpatents

    Kumar, Aditya; Shi, Ruijie; Dokucu, Mustafa

    2013-09-17

    System and method to estimate variables in an integrated gasification combined cycle (IGCC) plant are provided. The system includes a sensor suite to measure respective plant input and output variables. An extended Kalman filter (EKF) receives sensed plant input variables and includes a dynamic model to generate a plurality of plant state estimates and a covariance matrix for the state estimates. A preemptive-constraining processor is configured to preemptively constrain the state estimates and covariance matrix to be free of constraint violations. A measurement-correction processor may be configured to correct constrained state estimates and a constrained covariance matrix based on processing of sensed plant output variables. The measurement-correction processor is coupled to update the dynamic model with corrected state estimates and a corrected covariance matrix. The updated dynamic model may be configured to estimate values for at least one plant variable not originally sensed by the sensor suite.

  8. Southern Company Services' study of a Kellogg Rust Westinghouse (KRW)-based gasification-combined-cycle (GCC) power plant

    SciTech Connect

    Gallaspy, D.T.; Johnson, T.W.; Sears, R.E. )

    1990-07-01

    A site-specific evaluation of an integrated-gasification-combined- cycle (IGCC) unit was conducted by Southern Company Services, Inc. (SCS) to determine the effect of such a plant would have on electricity cost, load response, and fuel flexibility on the Southern electric system (SES). The design of the Plant Wansley IGCC plant in this study was configured to utilize three oxygen-blown Kellogg Rust Westinghouse (KRW) gasifiers integrated with two General Electric (GE) MS7001F combustion turbines. The nominal 400-MW IGCC plant was based on a nonphased construction schedule, with an operational start date in the year 2007. Illinois No. 6 bituminous coal was the base coal used in the study. Alabama lignite was also investigated as a potential low-cost feedstock for the IGCC plant, but was found to be higher in cost that the Illinois No. 6 coal when shipped to the Wansley site. The performance and cost results for the nominal 400-MW plant were used in an economic assessment that compared the replacement of a 777-MW pulverized-coal-fired unit with 777-MW of IGCC capacity based on the Southern electric system's expansion plans of installing 777-MW of baseload capacity in the year 2007. The economic analysis indicated that the IGCC plant was competitive compared to a baseload pulverized-coal-fired unit. Capital costs of the IGCC unit were approximately the same as a comparably sized pulverized-coal-fired plant, but the IGCC plant had a lower production cost due to its lower heat rate. 10 refs., 34 figs., 18 tabs.

  9. High-potential Working Fluids for Next Generation Binary Cycle Geothermal Power Plants

    SciTech Connect

    Zia, Jalal; Sevincer, Edip; Chen, Huijuan; Hardy, Ajilli; Wickersham, Paul; Kalra, Chiranjeev; Laursen, Anna Lis; Vandeputte, Thomas

    2013-06-29

    A thermo-economic model has been built and validated for prediction of project economics of Enhanced Geothermal Projects. The thermo-economic model calculates and iteratively optimizes the LCOE (levelized cost of electricity) for a prospective EGS (Enhanced Geothermal) site. It takes into account the local subsurface temperature gradient, the cost of drilling and reservoir creation, stimulation and power plant configuration. It calculates and optimizes the power plant configuration vs. well depth. Thus outputs from the model include optimal well depth and power plant configuration for the lowest LCOE. The main focus of this final report was to experimentally validate the thermodynamic properties that formed the basis of the thermo-economic model built in Phase 2, and thus build confidence that the predictions of the model could be used reliably for process downselection and preliminary design at a given set of geothermal (and/or waste heat) boundary conditions. The fluid and cycle downselected was based on a new proprietary fluid from a vendor in a supercritical ORC cycle at a resource condition of 200°C inlet temperature. The team devised and executed a series of experiments to prove the suitability of the new fluid in realistic ORC cycle conditions. Furthermore, the team performed a preliminary design study for a MW-scale turbo expander that would be used for a supercritical ORC cycle with this new fluid. The following summarizes the main findings in the investigative campaign that was undertaken: 1. Chemical compatibility of the new fluid with common seal/gasket/Oring materials was found to be problematic. Neoprene, Viton, and silicone materials were found to be incompatible, suffering chemical decomposition, swelling and/or compression set issues. Of the materials tested, only TEFLON was found to be compatible under actual ORC temperature and pressure conditions. 2. Thermal stability of the new fluid at 200°C and 40 bar was found to be acceptable after 399

  10. Operations of a spaceflight experiment to investigate plant tropisms

    NASA Astrophysics Data System (ADS)

    Kiss, John Z.; Kumar, Prem; Millar, Katherine D. L.; Edelmann, Richard E.; Correll, Melanie J.

    2009-10-01

    Plants will be an important component in bioregenerative systems for long-term missions to the Moon and Mars. Since gravity is reduced both on the Moon and Mars, studies that identify the basic mechanisms of plant growth and development in altered gravity are required to ensure successful plant production on these space colonization missions. To address these issues, we have developed a project on the International Space Station (ISS) to study the interaction between gravitropism and phototropism in Arabidopsis thaliana. These experiments were termed TROPI (for tropisms) and were performed on the European Modular Cultivation System (EMCS) in 2006. In this paper, we provide an operational summary of TROPI and preliminary results on studies of tropistic curvature of seedlings grown in space. Seed germination in TROPI was lower compared to previous space experiments, and this was likely due to extended storage in hardware for up to 8 months. Video downlinks provided an important quality check on the automated experimental time line that also was monitored with telemetry. Good quality images of seedlings were obtained, but the use of analog video tapes resulted in delays in image processing and analysis procedures. Seedlings that germinated exhibited robust phototropic curvature. Frozen plant samples were returned on three space shuttle missions, and improvements in cold stowage and handing procedures in the second and third missions resulted in quality RNA extracted from the seedlings that was used in subsequent microarray analyses. While the TROPI experiment had technical and logistical difficulties, most of the procedures worked well due to refinement during the project.

  11. Air storage requirements for a 220 MWe CAES plant as a function of turbomachinery selection and operation

    SciTech Connect

    Karalis, A.J.; Sosnowicz, E.J.; Stys, Z.S.

    1985-04-01

    This paper examines the effects of compressor train selection, turbine operation and the generation/compression cycle for a 220 MWe CAES plant which operates with a HP turbine inlet pressure of 44 bar (638 psia). The required air storage mass for a particular CAES generation/compression cycle is a function of both the total air mass withdrawn (during generation) and the total air mass added (during compression). Thus, the air storage mass is dependent upon both the air mass flow rates and daily operating times for the individual turbine and compressor selected. The volumetric requirements of the underground cavities are examined as a function of geologic formation and inlet pressure. While constant volume air storage in a salt formation is emphasized, air storage in a variable volume compensated rock cavern and variable pressure storage in an aquifer are also discussed. Both a daily and weekly compression cycle are addressed and the affect of duty cycle on the compressor train selection is shown. For a given turbine design the effect of constant vs. variable pressure operation on overall plant performance is noted.

  12. Evaluation of catalyst for closed cycle operation of high energy pulsed CO2 lasers

    NASA Technical Reports Server (NTRS)

    Rogowski, R. S.; Miller, I. M.; Wood, G.; Schryer, D. R.; Hess, R. V.; Upchurch, B. T.

    1983-01-01

    Several catalyst materials have been tested for efficiency of converting CO and O2 to CO2 for use in a high energy CO2 laser. The composition of the gas mixtures was monitored by mass spectrometry and gas chromatography. A copper/copper oxide catalyst and a platinum/tin oxide catalyst were used for closed cycle operation of a CO2 laser (0.7 joules/pulse), operating at 10 pulses/sec.

  13. Determining Reliability Parameters for a Closed-Cycle Small Combined Heat and Power Plant

    NASA Astrophysics Data System (ADS)

    Vysokomorny, Vladimir S.; Vysokomornaya, Olga V.; Piskunov, Maxim V.

    2016-02-01

    The paper provides numerical values of the reliability parameters for independent power sources within the ambient temperature and output power range corresponding to the operation under the climatic conditions of Eastern Siberia and the Far East of the Russian Federation. We have determined the optimal values of the parameters necessary for the reliable operation of small CHP plants (combined heat and power plants) providing electricity for isolated facilities.

  14. The Zwilag interim storage plasma plant technology to handle operational waste from nuclear plants

    SciTech Connect

    Heep, Walter

    2007-07-01

    The first processing of low level radioactive wastes from Swiss nuclear power plants marks the successful completion of commissioning in March 2004 of a treatment facility for low and intermediate level radioactive wastes, which is operated with the help of plasma technology. The theoretical principles of this metallurgy-derived process technology are based on plasma technology, which has already been used for a considerable period outside of nuclear technology for the production of highly pure metal alloys and for the plasma synthesis of acetylene. The commercial operation of the Plasma Plant owned by Zwischenlager Wuerenlingen AG (ZWILAG) has also enabled this technology to be used successfully for the first time in the nuclear field, especially in compliance with radiation protection aspects. In addition to a brief presentation of the technology used in the plant, the melting process under operating conditions will be explained in more detail. The separation factors attained and volume reductions achieved open interesting perspectives for the further optimisation of the entire process in the future. (author)

  15. Model operating permits for natural gas processing plants

    SciTech Connect

    Arend, C.

    1995-12-31

    Major sources as defined in Title V of the Clean Air Act Amendments of 1990 that are required to submit an operating permit application will need to: Evaluate their compliance status; Determine a strategic method of presenting the general and specific conditions of their Model Operating Permit (MOP); Maintain compliance with air quality regulations. A MOP is prepared to assist permitting agencies and affected facilities in the development of operating permits for a specific source category. This paper includes a brief discussion of example permit conditions that may be applicable to various types of Title V sources. A MOP for a generic natural gas processing plant is provided as an example. The MOP should include a general description of the production process and identify emission sources. The two primary elements that comprise a MOP are: Provisions of all existing state and/or local air permits; Identification of general and specific conditions for the Title V permit. The general provisions will include overall compliance with all Clean Air Act Titles. The specific provisions include monitoring, record keeping, and reporting. Although Title V MOPs are prepared on a case-by-case basis, this paper will provide a general guideline of the requirements for preparation of a MOP. Regulatory agencies have indicated that a MOP included in the Title V application will assist in preparation of the final permit provisions, minimize delays in securing a permit, and provide support during the public notification process.

  16. Quantum image encryption scheme with iterative generalized Arnold transforms and quantum image cycle shift operations

    NASA Astrophysics Data System (ADS)

    Zhou, Nanrun; Hu, Yiqun; Gong, Lihua; Li, Guangyong

    2017-06-01

    A new quantum image encryption scheme is suggested by using the iterative generalized Arnold transforms and the quantum image cycle shift operations. The times of the quantum image cycle shift operations are controlled by a hyper-chaotic sequence generated by a new 4D hyper-chaotic system. The image pixels are scrambled by the iterative generalized Arnold transform, and the values of the pixels are altered by the quantum image cycle shift operations. The four initial conditions of the new 4D hyper-chaotic system are exploited to control the two parameters, the iterative rounds of the generalized Arnold transform and the times of the quantum image cycle shift operations, respectively. Thus, the main keys of the proposed quantum image encryption scheme are the four initial conditions of the new 4D hyper-chaotic system and the key space is relatively large enough. Simulation results and theoretical analyses demonstrate that the proposed quantum image encryption scheme outperforms its classical counterparts apparently.

  17. Power and Efficiency Analysis of a Solar Central Receiver Combined Cycle Plant with a Small Particle Heat Exchanger Receiver

    NASA Astrophysics Data System (ADS)

    Virgen, Matthew Miguel

    Two significant goals in solar plant operation are lower cost and higher efficiencies. To achieve those goals, a combined cycle gas turbine (CCGT) system, which uses the hot gas turbine exhaust to produce superheated steam for a bottoming Rankine cycle by way of a heat recovery steam generator (HRSG), is investigated in this work. Building off of a previous gas turbine model created at the Combustion and Solar Energy Laboratory at SDSU, here are added the HRSG and steam turbine model, which had to handle significant change in the mass flow and temperature of air exiting the gas turbine due to varying solar input. A wide range of cases were run to explore options for maximizing both power and efficiency from the proposed CSP CCGT plant. Variable guide vanes (VGVs) were found in the earlier model to be an effective tool in providing operational flexibility to address the variable nature of solar input. Combined cycle efficiencies in the range of 50% were found to result from this plant configuration. However, a combustor inlet temperature (CIT) limit leads to two distinct Modes of operation, with a sharp drop in both plant efficiency and power occurring when the air flow through the receiver exceeded the CIT limit. This drawback can be partially addressed through strategic use of the VGVs. Since system response is fully established for the relevant range of solar input and variable guide vane angles, the System Advisor Model (SAM) from NREL can be used to find what the actual expected solar input would be over the course of the day, and plan accordingly. While the SAM software is not yet equipped to model a Brayton cycle cavity receiver, appropriate approximations were made in order to produce a suitable heliostat field to fit this system. Since the SPHER uses carbon nano-particles as the solar absorbers, questions of particle longevity and how the particles might affect the flame behavior in the combustor were addressed using the chemical kinetics software Chemkin

  18. Steam turbines produced by the Ural Turbine Works for combined-cycle plants

    NASA Astrophysics Data System (ADS)

    Valamin, A. E.; Kultyshev, A. Yu.; Shibaev, T. L.; Gol'dberg, A. A.; Bilan, V. N.; Paneque Aguilera, H. C.; Sakhnin, Yu. A.; Shekhter, M. V.; Stepanov, M. Yu.; Polyaeva, E. N.

    2013-08-01

    The most interesting and innovative solutions adopted in the projects of steam turbines for combined-cycle plants with capacities from 115 to 900 MW are pointed out. The development of some ideas and components from the first projects to subsequent ones is shown.

  19. Does cell cycle arrest occur in plant under solar UV-B radiation?

    PubMed

    Jiang, Lei; Wang, Yan; Björn, Lars Olof; Li, Shaoshan

    2011-06-01

    UV-B radiation (280-315 nm) is an integral part of solar radiation and has many harmful effects on plant growth and development. However, the molecular mechanism for the inhibition of plant growth by UV-B remains largely unknown. UV-B radiation induces various responses such as growth inhibition, DNA damage and changes of gene expression. Recently, by using synchronous root tip culture, we found that UV-B modulates the expression of cell cycle regulatory genes through DNA damage. Western blotting analysis revealed that UV-B induced G1-to-S arrest did not correlate with the protein abundance of CDKB1;1 and CYCD3;1 gene regulating proteins, but may with the posttranslational control. We extended the expression analysis of cell cycle related genes based on the published microarray data and the results strengthen our assumption that cell cycle arrest could occur in plant under solar UV-B radiation. Further study is needed to elucidate the relationship between cell cycle regulation and protective pathway induced by low dose of UV-B radiation fundamental molecular mechanism for how plants respond to solar UV-B radiation.

  20. 76 FR 73720 - Knowledge and Abilities Catalog for Nuclear Power Plant Operators: Westinghouse AP1000...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-29

    ... COMMISSION Knowledge and Abilities Catalog for Nuclear Power Plant Operators: Westinghouse AP1000 Pressurized..., NUREG-2103, Revision 0, ``Knowledge and Abilities Catalog for Nuclear Power Plant Operators... operators (ROs) and senior reactor operators (SROs). The examinations developed using this Catalog along...

  1. Diagnosis of Thermal Efficiency of Combined Cycle Power Plants Using Optical Torque Sensors

    NASA Astrophysics Data System (ADS)

    Umezawa, Shuichi

    A new optical torque measurement method is proposed for diagnosis of thermal efficiency of combined cycle power plants. In the case that the plant comprises a steam turbine and a gas turbine, both of which are connected to the same generator, it is difficult to identify which turbine causes deterioration of performance when the plant efficiency is reduced. Therefore, an optical torque sensor has been developed to measure the output of each turbine, which are important data to analyze performance of each machineries in a plant. The sensor measures axial distortion caused by power transmission by use of He-Ne laser beams, small stainless steel reflectors having bar-code patterns, and a technique of signal processing featuring high frequency. It was applied to TOKYO ELECTRIC POWER COMPANY (TEPCO) commercial plants. Following system improvements, it is concluded that error factors can be eliminated and sensor performance can reach a practical use level.

  2. System studies of coal fired-closed cycle MHD for central station power plants

    NASA Technical Reports Server (NTRS)

    Zauderer, B.

    1976-01-01

    This paper presents a discussion of the closed cycle MHD results obtained in a recent study of various advanced energy conversion (ECAS) power systems. The study was part of the first phase of this ECAS study. Since this was the first opportunity to evaluate the coal fired closed cycle MHD system, a number of iterations were required to partially optimize the system. The present paper deals with the latter part of the study in which the direct coal fired, MHD topping-steam bottoming cycle was established as the current choice for central station power generation. The emphasis of the paper is on the background assumptions and the conclusions that can be drawn from the closed cycle MHD analysis. The author concludes that closed cycle MHD has efficiencies comparable to that of open cycle MHD and that both systems are considerably more efficient than the other system studies in Phase 1 of the GE ECAS. Its cost will possibly be slightly higher than that of the open cycle MHD system. Also, with reasonable fuel escalation assumptions, both systems can produce lower cost electricity than conventional steam power plants. Suggestions for further work in closed cycle MHD components and systems is made.

  3. System studies of coal fired-closed cycle MHD for central station power plants

    NASA Technical Reports Server (NTRS)

    Zauderer, B.

    1976-01-01

    This paper presents a discussion of the closed cycle MHD results obtained in a recent study of various advanced energy conversion (ECAS) power systems. The study was part of the first phase of this ECAS study. Since this was the first opportunity to evaluate the coal fired closed cycle MHD system, a number of iterations were required to partially optimize the system. The present paper deals with the latter part of the study in which the direct coal fired, MHD topping-steam bottoming cycle was established as the current choice for central station power generation. The emphasis of the paper is on the background assumptions and the conclusions that can be drawn from the closed cycle MHD analysis. The author concludes that closed cycle MHD has efficiencies comparable to that of open cycle MHD and that both systems are considerably more efficient than the other system studies in Phase 1 of the GE ECAS. Its cost will possibly be slightly higher than that of the open cycle MHD system. Also, with reasonable fuel escalation assumptions, both systems can produce lower cost electricity than conventional steam power plants. Suggestions for further work in closed cycle MHD components and systems is made.

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

    SciTech Connect

    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.

  5. Operation and maintenance results from ISFOC CPV plants

    NASA Astrophysics Data System (ADS)

    Gil, Eduardo; Martinez, María; de la Rubia, Oscar

    2017-09-01

    The analysis of field operation and maintenance data collected during a period of over eight years, from CPV installations consisting of three different CPV technologies (including second generation of one of these technologies), has allowed us to get valuable information about the long-term degradation of the CPV systems. Through the study of the maintenance control ratio previously defined and by applying the root cause analysis methodology, the components responsible for the most unplanned interventions for each technology were identified. Focusing maintenance efforts on these components, a reduction of the unplanned interventions and the total cost of maintenance has been achieved over the years. Therefore, the deployment of an effective maintenance plan, identifying critical components, is essential to minimize the risk for investors and maximize the CPV power plants lifetime and energy output, increasing the availability of CPV installations, boosting market confidence in CPV systems.

  6. Implications of plant acclimation for future climate-carbon cycle feedbacks

    NASA Astrophysics Data System (ADS)

    Mercado, Lina; Kattge, Jens; Cox, Peter; Sitch, Stephen; Knorr, Wolfgang; Lloyd, Jon; Huntingford, Chris

    2010-05-01

    The response of land ecosystems to climate change and associated feedbacks are a key uncertainty in future climate prediction (Friedlingstein et al. 2006). However global models generally do not account for the acclimation of plant physiological processes to increased temperatures. Here we conduct a first global sensitivity study whereby we modify the Joint UK land Environment Simulator (JULES) to account for temperature acclimation of two main photosynthetic parameters, Vcmax and Jmax (Kattge and Knorr 2007) and plant respiration (Atkin and Tjoelker 2003). The model is then applied over the 21st Century within the IMOGEN framework (Huntingford et al. 2004). Model simulations will provide new and improved projections of biogeochemical cycling, forest resilience, and thus more accurate projections of climate-carbon cycle feedbacks and the future evolution of the Earth System. Friedlingstein P, Cox PM, Betts R et al. (2006) Climate-carbon cycle feedback analysis, results from the C4MIP model intercomparison. Journal of Climate, 19, 3337-3353. Kattge J and Knorr W (2007): Temperature acclimation in a biochemical model of photosynthesis: a reanalysis of data from 36 species. Plant, Cell and Environment 30, 1176-1190 Atkin O.K and Tjoelker, M. G. (2003): Thermal acclimation and the dynamic response of plant respiration to temperature. Trends in Plant Science 8 (7), 343-351 Huntingford C, et al. (2004) Using a GCM analogue model to investigate the potential for Amazonian forest dieback. Theoretical and Applied Climatology, 78, 177-185.

  7. USA National Phenology Network: Plant and Animal Life-Cycle Data Related to Climate Change

    DOE Data Explorer

    Phenology refers to recurring plant and animal life cycle stages, such as leafing and flowering, maturation of agricultural plants, emergence of insects, and migration of birds. It is also the study of these recurring plant and animal life cycle stages, especially their timing and relationships with weather and climate. Phenology affects nearly all aspects of the environment, including the abundance and diversity of organisms, their interactions with one another, their functions in food webs, and their seasonable behavior, and global-scale cycles of water, carbon, and other chemical elements. Phenology records can help us understand plant and animal responses to climate change; it is a key indicator. The USA-NPN brings together citizen scientists, government agencies, non-profit groups, educators, and students of all ages to monitor the impacts of climate change on plants and animals in the United States. The network harnesses the power of people and the Internet to collect and share information, providing researchers with far more data than they could collect alone.[Extracts copied from the USA-NPN home page and from http://www.usanpn.org/about].

  8. Advanced steam power plant concepts with optimized life-cycle costs: A new approach for maximum customer benefit

    SciTech Connect

    Seiter, C.

    1998-07-01

    The use of coal power generation applications is currently enjoying a renaissance. New highly efficient and cost-effective plant concepts together with environmental protection technologies are the main factors in this development. In addition, coal is available on the world market at attractive prices and in many places it is more readily available than gas. At the economical leading edge, standard power plant concepts have been developed to meet the requirements of emerging power markets. These concepts incorporate the high technological state-of-the-art and are designed to achieve lowest life-cycle costs. Low capital cost, fuel costs and operating costs in combination with shortest lead times are the main assets that make these plants attractive especially for IPPs and Developers. Other aspects of these comprehensive concepts include turnkey construction and the willingness to participate in BOO/BOT projects. One of the various examples of such a concept, the 2 x 610-MW Paiton Private Power Project Phase II in Indonesia, is described in this paper. At the technological leading edge, Siemens has always made a major contribution and was pacemaker for new developments in steam power plant technology. Modern coal-fired steam power plants use computer-optimized process and plant design as well as advanced materials, and achieve efficiencies exceeding 45%. One excellent example of this high technology is the world's largest lignite-fired steam power plant Schwarze Pumpe in Germany, which is equipped with two 800 MW Siemens steam turbine generators with supercritical steam parameters. The world's largest 50-Hz single-shaft turbine generator with supercritical steam parameters rated at 1025 MW for the Niederaussem lignite-fired steam power plant in Germany is a further example of the sophisticated Siemens steam turbine technology and sets a new benchmark in this field.

  9. Remote Sensing and Modeling for Improving Operational Aquatic Plant Management

    NASA Technical Reports Server (NTRS)

    Bubenheim, Dave

    2016-01-01

    The California Sacramento-San Joaquin River Delta is the hub for California’s water supply, conveying water from Northern to Southern California agriculture and communities while supporting important ecosystem services, agriculture, and communities in the Delta. Changes in climate, long-term drought, water quality changes, and expansion of invasive aquatic plants threatens ecosystems, impedes ecosystem restoration, and is economically, environmentally, and sociologically detrimental to the San Francisco Bay/California Delta complex. NASA Ames Research Center and the USDA-ARS partnered with the State of California and local governments to develop science-based, adaptive-management strategies for the Sacramento-San Joaquin Delta. The project combines science, operations, and economics related to integrated management scenarios for aquatic weeds to help land and waterway managers make science-informed decisions regarding management and outcomes. The team provides a comprehensive understanding of agricultural and urban land use in the Delta and the major water sheds (San Joaquin/Sacramento) supplying the Delta and interaction with drought and climate impacts on the environment, water quality, and weed growth. The team recommends conservation and modified land-use practices and aids local Delta stakeholders in developing management strategies. New remote sensing tools have been developed to enhance ability to assess conditions, inform decision support tools, and monitor management practices. Science gaps in understanding how native and invasive plants respond to altered environmental conditions are being filled and provide critical biological response parameters for Delta-SWAT simulation modeling. Operational agencies such as the California Department of Boating and Waterways provide testing and act as initial adopter of decision support tools. Methods developed by the project can become routine land and water management tools in complex river delta systems.

  10. The contribution of plant-soil interactions to biogeochemical cycles in a changing world

    NASA Astrophysics Data System (ADS)

    Pregitzer, K.

    2005-12-01

    In terrestrial ecosystems, plants are the transducers that provide the energy for microbial metabolism through root exudation, cell sloughing, and the turnover of leaves and roots. Changes in the Earth's atmosphere such as increasing concentrations of atmospheric carbon dioxide, tropospheric ozone, and the atmospheric deposition of nitrogen, will modify plant net primary productivity (NPP) and plant carbon (C) allocation. These changes will, in turn, initiate a series of biochemical alterations in dead leaves and fine roots, responses which move through the soil to structure food webs and control rates of biogeochemical cycling. In our conceptual framework, plant physiology, plant tissue biochemistry, and the production and mortality of plant modules (leaves and roots) are pivotal control points in the soil for the regulation of ecosystem biogeochemistry. In other words, understanding how plant form and function as well as the associated microbial dynamics respond to changes in the Earth's atmosphere is important to understanding the biogeochemical feedbacks which may ultimately constrain long-term ecosystem responses. We will review examples of how changes in the Earth's atmosphere directly modify plant growth and C allocation, which initiates a series of physiological and biochemical changes in live and dead leaves and fine roots. We will then examine how these plant responses structure rhizosphere food webs and control rates of microbial metabolism. Microbial enzyme activity regulates many of the transformation and weathering processes in the soil, thus changes in the microbial community can strongly alter ecosystem biogeochemistry. For example, we will explore how plants and microbes are linked to ecosystem-level feedbacks between soil respiration, dissolved inorganic carbon (DIC), and dissolved organic carbon (DOC) leaching. The basic premise of our conceptual model is that altered atmospheric chemistry directly impacts plant form and function. Theses human

  11. Steady-state simulation and optimization of an integrated gasification combined cycle power plant with CO2 capture

    SciTech Connect

    Bhattacharyya, D.; Turton, R.; Zitney, S.

    2011-01-01

    Integrated gasification combined cycle (IGCC) plants are a promising technology option for power generation with carbon dioxide (CO2) capture in view of their efficiency and environmental advantages over conventional coal utilization technologies. This paper presents a three-phase, top-down, optimization-based approach for designing an IGCC plant with precombustion CO2 capture in a process simulator environment. In the first design phase, important global design decisions are made on the basis of plant-wide optimization studies with the aim of increasing IGCC thermal efficiency and thereby making better use of coal resources and reducing CO2 emissions. For the design of an IGCC plant with 90% CO2 capture, the optimal combination of the extent of carbon monoxide (CO) conversion in the water-gas shift (WGS) reactors and the extent of CO2 capture in the SELEXOL process, using dimethylether of polyethylene glycol as the solvent, is determined in the first phase. In the second design phase, the impact of local design decisions is explored considering the optimum values of the decision variables from the first phase as additional constraints. Two decisions are made focusing on the SELEXOL and Claus unit. In the third design phase, the operating conditions are optimized considering the optimum values of the decision variables from the first and second phases as additional constraints. The operational flexibility of the plant must be taken into account before taking final design decisions. Two studies on the operational flexibility of the WGS reactors and one study focusing on the operational flexibility of the sour water stripper (SWS) are presented. At the end of the first iteration, after executing all the phases once, the net plant efficiency (HHV basis) increases to 34.1% compared to 32.5% in a previously published study (DOE/NETL-2007/1281; National Energy Technology Laboratory, 2007). The study shows that the three-phase, top-down design approach presented is very

  12. Coordinated optimization of the parameters of the cooled gas-turbine flow path and the parameters of gas-turbine cycles and combined-cycle power plants

    NASA Astrophysics Data System (ADS)

    Kler, A. M.; Zakharov, Yu. B.; Potanina, Yu. M.

    2014-06-01

    In the present paper, we evaluate the effectiveness of the coordinated solution to the optimization problem for the parameters of cycles in gas turbine and combined cycle power plants and to the optimization problem for the gas-turbine flow path parameters within an integral complex problem. We report comparative data for optimizations of the combined cycle power plant at coordinated and separate optimizations, when, first, the gas turbine and, then, the steam part of a combined cycle plant is optimized. The comparative data are presented in terms of economic indicators, energy-effectiveness characteristics, and specific costs. Models that were used in the present study for calculating the flow path enable taking into account, as a factor influencing the economic and energy effectiveness of the power plant, the heat stability of alloys from which the nozzle and rotor blades of gas-turbine stages are made.

  13. A novel life cycle arising from leaf segments in plants regenerated from horseradish hairy roots.

    PubMed

    Mano, Y; Matsuhashi, M

    1995-03-01

    Horseradish (Armoracia rusticana) hairy root clones were established from hairy roots which were transformed with the Ri plasmid in Agrobacterium rhizogenes 15834. The transformed plants, which were regenerated from hairy root clones, had thicker roots with extensive lateral branches and thicker stems, and grew faster compared with non-transformed horseradish plants. Small sections of leaves of the transformed plants generated adventitious roots in phytohormone-free G (modified Gamborg's) medium. Root proliferation was followed by adventitious shoot formation and plant regeneration. Approximately twenty plants were regenerated per square centimeter of leaf. The transformed plants were easily transferable from sterile conditions to soil. When leaf segments of the transformed plants were cultured in a liquid fertilizer under non-sterile conditions, adventitious roots were generated at the cut ends of the leaves. Adventitious shoots were generated at the boundary between the leaf and the adventitious roots and developed into complete plants. This novel life cycle arising from leaf segments is a unique property of the transformed plants derived from hairy root clones.

  14. Analysing how plants in coastal wetlands respond to varying tidal regimes throughout their life cycles.

    PubMed

    Xie, Tian; Cui, Baoshan; Li, Shanze

    2017-09-13

    Important to conserve plant species in coastal wetlands throughout their life cycle. All life stages in these habitats are exposed to varying tidal cycles. It is necessary to investigate all life stages as to how they respond to varying tidal regimes. We examine three wetlands containing populations of an endangered halophyte species, each subjected to different tidal regimes: (1). wetlands completely closed to tidal cycles; (2). wetlands directly exposed to tidal cycles (3). wetlands exposed to a partially closed tidal regime. Our results showed that the most threatened stage varied between wetlands subjected to these varying tidal regimes. We hypothesis that populations of this species have adapted to these different tidal regimes. Such information is useful in developing management options for coastal wetlands and modifying future barriers restricting tidal flushing. Copyright © 2017. Published by Elsevier Ltd.

  15. Nuclear plant operations: The U.S. experience

    SciTech Connect

    Lang, J.

    1996-12-31

    Over the past 20 years, electricity has taken on an increasingly important role in the U.S. energy mix and an increasing fraction of that electricity has been generated by nuclear power plants. However, producing electricity with nuclear energy is not an end in itself for electric utilities. Nuclear power is attractive only in so far as it is a safe and economical means of producing electricity. Safety has been and will remain a priority with the nuclear industry-it`s part of the culture. However, during the 1980`s, the economy of nuclear power was called into question. Nuclear production costs (operations, maintenance and fuel) grew at a rate greater than inflation, led by the costs of operations and maintenance. The production costs peaked in 1987 at which time several factors responding to competition from other forms of generation combined to bring them down. The decline in costs is continuing, yielding the positive experience discussed in this paper. 1 ref., 11 figs.

  16. Selenium cycling across soil-plant-atmosphere interfaces: a critical review.

    PubMed

    Winkel, Lenny H E; Vriens, Bas; Jones, Gerrad D; Schneider, Leila S; Pilon-Smits, Elizabeth; Bañuelos, Gary S

    2015-05-29

    Selenium (Se) is an essential element for humans and animals, which occurs ubiquitously in the environment. It is present in trace amounts in both organic and inorganic forms in marine and freshwater systems, soils, biomass and in the atmosphere. Low Se levels in certain terrestrial environments have resulted in Se deficiency in humans, while elevated Se levels in waters and soils can be toxic and result in the death of aquatic wildlife and other animals. Human dietary Se intake is largely governed by Se concentrations in plants, which are controlled by root uptake of Se as a function of soil Se concentrations, speciation and bioavailability. In addition, plants and microorganisms can biomethylate Se, which can result in a loss of Se to the atmosphere. The mobilization of Se across soil-plant-atmosphere interfaces is thus of crucial importance for human Se status. This review gives an overview of current knowledge on Se cycling with a specific focus on soil-plant-atmosphere interfaces. Sources, speciation and mobility of Se in soils and plants will be discussed as well as Se hyperaccumulation by plants, biofortification and biomethylation. Future research on Se cycling in the environment is essential to minimize the adverse health effects associated with unsafe environmental Se levels.

  17. Selenium Cycling Across Soil-Plant-Atmosphere Interfaces: A Critical Review

    PubMed Central

    Winkel, Lenny H.E.; Vriens, Bas; Jones, Gerrad D.; Schneider, Leila S.; Pilon-Smits, Elizabeth; Bañuelos, Gary S.

    2015-01-01

    Selenium (Se) is an essential element for humans and animals, which occurs ubiquitously in the environment. It is present in trace amounts in both organic and inorganic forms in marine and freshwater systems, soils, biomass and in the atmosphere. Low Se levels in certain terrestrial environments have resulted in Se deficiency in humans, while elevated Se levels in waters and soils can be toxic and result in the death of aquatic wildlife and other animals. Human dietary Se intake is largely governed by Se concentrations in plants, which are controlled by root uptake of Se as a function of soil Se concentrations, speciation and bioavailability. In addition, plants and microorganisms can biomethylate Se, which can result in a loss of Se to the atmosphere. The mobilization of Se across soil-plant-atmosphere interfaces is thus of crucial importance for human Se status. This review gives an overview of current knowledge on Se cycling with a specific focus on soil-plant-atmosphere interfaces. Sources, speciation and mobility of Se in soils and plants will be discussed as well as Se hyperaccumulation by plants, biofortification and biomethylation. Future research on Se cycling in the environment is essential to minimize the adverse health effects associated with unsafe environmental Se levels. PMID:26035246

  18. Measurement of Local Frequencies of Filter Regeneration and their Effect on Successive Operating Cycles

    SciTech Connect

    Dittler, A.; Kasper, G.

    2002-09-19

    Stable operation, characterized by a succession of uniform filtration cycles with acceptable duration and pressure increase, remains a key issue in high temperature gas filtration. Ceramic filters are known to sometimes become instable. This is somehow related to ''patchy cleaning'', but cause-and-effect relationships have been difficult to identify. The objective of this contribution is to investigate incomplete regeneration patterns in detail, to try to classify them, and to identify relationships between the residual cake patterns and the form of successive filtration cycles. The work comprises both modeling and experiments at room temperature and high temperature conditions on ceramic media using quartz dust and bark ash.

  19. Thermal analysis of heat and power plant with high temperature reactor and intermediate steam cycle

    NASA Astrophysics Data System (ADS)

    Fic, Adam; Składzień, Jan; Gabriel, Michał

    2015-03-01

    Thermal analysis of a heat and power plant with a high temperature gas cooled nuclear reactor is presented. The main aim of the considered system is to supply a technological process with the heat at suitably high temperature level. The considered unit is also used to produce electricity. The high temperature helium cooled nuclear reactor is the primary heat source in the system, which consists of: the reactor cooling cycle, the steam cycle and the gas heat pump cycle. Helium used as a carrier in the first cycle (classic Brayton cycle), which includes the reactor, delivers heat in a steam generator to produce superheated steam with required parameters of the intermediate cycle. The intermediate cycle is provided to transport energy from the reactor installation to the process installation requiring a high temperature heat. The distance between reactor and the process installation is assumed short and negligable, or alternatively equal to 1 km in the analysis. The system is also equipped with a high temperature argon heat pump to obtain the temperature level of a heat carrier required by a high temperature process. Thus, the steam of the intermediate cycle supplies a lower heat exchanger of the heat pump, a process heat exchanger at the medium temperature level and a classical steam turbine system (Rankine cycle). The main purpose of the research was to evaluate the effectiveness of the system considered and to assess whether such a three cycle cogeneration system is reasonable. Multivariant calculations have been carried out employing the developed mathematical model. The results have been presented in a form of the energy efficiency and exergy efficiency of the system as a function of the temperature drop in the high temperature process heat exchanger and the reactor pressure.

  20. 40 CFR 60.106a - Monitoring of emissions and operations for sulfur recovery plants.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... for sulfur recovery plants. 60.106a Section 60.106a Protection of Environment ENVIRONMENTAL PROTECTION... Commenced After May 14, 2007 § 60.106a Monitoring of emissions and operations for sulfur recovery plants. (a) The owner or operator of a sulfur recovery plant that is subject to the emissions limits in §...

  1. 40 CFR 60.106a - Monitoring of emissions and operations for sulfur recovery plants.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... for sulfur recovery plants. 60.106a Section 60.106a Protection of Environment ENVIRONMENTAL PROTECTION... Commenced After May 14, 2007 § 60.106a Monitoring of emissions and operations for sulfur recovery plants. (a) The owner or operator of a sulfur recovery plant that is subject to the emissions limits in §...

  2. 40 CFR 60.106a - Monitoring of emissions and operations for sulfur recovery plants.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... for sulfur recovery plants. 60.106a Section 60.106a Protection of Environment ENVIRONMENTAL PROTECTION... Commenced After May 14, 2007 § 60.106a Monitoring of emissions and operations for sulfur recovery plants. (a) The owner or operator of a sulfur recovery plant that is subject to the emissions limits in §...

  3. Pilot plant operation of the Uranium Chip Oxidation Facility at the Y-12 Plant

    SciTech Connect

    Childs, Y.C.

    1987-01-16

    Due to changing environmental regulations, the current practice of depleted uranium chip (machine turning) disposal via shallow land burial has become environmentally objectionable. The chips are pyrophoric and oxidize rapidly when exposed to air; therefore, long-term storage of the uranium chips presents a major fire hazard. The Oak Ridge Y-12 Plant Development Division was contacted to devise a disposal method that would eliminate chip burial and minimize storage space requirements. The proposed method of accomplishing this task was oxidizing the uranium chips to uranium oxide (U/sub 3/O/sub 8/) under controlled conditions. Pilot plant operation of the Uranium Chip Oxidation Facility (UCOF) was initiated on May 20, 1985, by the Y-12 Development Division. The purpose of this initial development testing was to evaluate the equipment, determine operating parameters, and provide on-the-job training for Waste Treatment Operations (WTO) personnel. Startup of the UCOF began with the check-out of the equipment using only the No. 1 oxidizer. Following the verification stage, the oxidizer was loaded with an initial charge of cold uranium oxide (U/sub 3/O/sub 8/) in preparation for test burning. Results of the test are given.

  4. State estimation of an acid gas removal (AGR) plant as part of an integrated gasification combined cycle (IGCC) plant with CO2 capture

    SciTech Connect

    Paul, P.; Bhattacharyya, D.; Turton, R.; Zitney, S.

    2012-01-01

    An accurate estimation of process state variables not only can increase the effectiveness and reliability of process measurement technology, but can also enhance plant efficiency, improve control system performance, and increase plant availability. Future integrated gasification combined cycle (IGCC) power plants with CO2 capture will have to satisfy stricter operational and environmental constraints. To operate the IGCC plant without violating stringent environmental emission standards requires accurate estimation of the relevant process state variables, outputs, and disturbances. Unfortunately, a number of these process variables cannot be measured at all, while some of them can be measured, but with low precision, low reliability, or low signal-to-noise ratio. As a result, accurate estimation of the process variables is of great importance to avoid the inherent difficulties associated with the inaccuracy of the data. Motivated by this, the current paper focuses on the state estimation of an acid gas removal (AGR) process as part of an IGCC plant with CO2 capture. This process has extensive heat and mass integration and therefore is very suitable for testing the efficiency of the designed estimators in the presence of complex interactions between process variables. The traditional Kalman filter (KF) (Kalman, 1960) algorithm has been used as a state estimator which resembles that of a predictor-corrector algorithm for solving numerical problems. In traditional KF implementation, good guesses for the process noise covariance matrix (Q) and the measurement noise covariance matrix (R) are required to obtain satisfactory filter performance. However, in the real world, these matrices are unknown and it is difficult to generate good guesses for them. In this paper, use of an adaptive KF will be presented that adapts Q and R at every time step of the algorithm. Results show that very accurate estimations of the desired process states, outputs or disturbances can be

  5. Differences in Plant Traits among N-fixing Trees in Hawaii Affect Understory Nitrogen Cycling

    NASA Astrophysics Data System (ADS)

    August-Schmidt, E.; D'Antonio, C. M.

    2016-12-01

    Nitrogen (N) fixing trees are frequently used to restore soil functions to degraded ecosystems because they can increase soil organic matter and N availability. Although N-fixers are lumped into a single functional group, the quality and quantity of the plant material they produce and the rate at which they accrete and add N to the cycling pool likely vary. This talk will focus on the questions: (1) How does N-cycling differ among N-fixing tree species? And (2) Which plant traits are most important in distinguishing the soil N environment? To address these questions, we investigated planted stands of two Hawaiian native N-fixing trees (Acacia koa and Sophora chrysophylla) and `natural' stands of an invasive N-fixing tree (Morella faya) in burned seasonal submontane woodlands in Hawaii Volcanoes National Park. We measured the relative availability of nitrogen in the soil pool and understory plant community as well as characterizing the rate and amount of N cycling in these stands both in the field and using long term soil incubations in the laboratory. We found that N is cycled very differently under these three N-fixers and that this correlates with differences in their leaf traits. S. chrysophylla had the highest foliar %N and highest specific leaf area, and stands of these trees are associated with faster N-cycling, resulting in greater N availability compared to all other site types. Incubated S. chrysophylla soils mineralized almost twice as much N as any other soil type over the course of the experiment. The comparatively high-N environment under S. chrysophylla suggests that litter quality may be more important than litter quantity in determining nitrogen availability to the understory community.

  6. The cost of carbon capture and storage for natural gas combined cycle power plants.

    PubMed

    Rubin, Edward S; Zhai, Haibo

    2012-03-20

    This paper examines the cost of CO(2) capture and storage (CCS) for natural gas combined cycle (NGCC) power plants. Existing studies employ a broad range of assumptions and lack a consistent costing method. This study takes a more systematic approach to analyze plants with an amine-based postcombustion CCS system with 90% CO(2) capture. We employ sensitivity analyses together with a probabilistic analysis to quantify costs for plants with and without CCS under uncertainty or variability in key parameters. Results for new baseload plants indicate a likely increase in levelized cost of electricity (LCOE) of $20-32/MWh (constant 2007$) or $22-40/MWh in current dollars. A risk premium for plants with CCS increases these ranges to $23-39/MWh and $25-46/MWh, respectively. Based on current cost estimates, our analysis further shows that a policy to encourage CCS at new NGCC plants via an emission tax or carbon price requires (at 95% confidence) a price of at least $125/t CO(2) to ensure NGCC-CCS is cheaper than a plant without CCS. Higher costs are found for nonbaseload plants and CCS retrofits.

  7. The life history of the plant pathogen Pseudomonas syringae is linked to the water cycle.

    PubMed

    Morris, Cindy E; Sands, David C; Vinatzer, Boris A; Glaux, Catherine; Guilbaud, Caroline; Buffière, Alain; Yan, Shuangchun; Dominguez, Hélène; Thompson, Brian M

    2008-03-01

    Pseudomonas syringae is a plant pathogen well known for its capacity to grow epiphytically on diverse plants and for its ice-nucleation activity. The ensemble of its known biology and ecology led us to postulate that this bacterium is also present in non-agricultural habitats, particularly those associated with water. Here, we report the abundance of P. syringae in rain, snow, alpine streams and lakes and in wild plants, in addition to the previously reported abundance in epilithic biofilms. Each of these substrates harbored strains that corresponded to P. syringae in terms of biochemical traits, pathogenicity and pathogenicity-related factors and that were ice-nucleation active. Phylogenetic comparisons of sequences of four housekeeping genes of the non-agricultural strains with strains of P. syringae from disease epidemics confirmed their identity as P. syringae. Moreover, strains belonging to the same clonal lineage were isolated from snow, irrigation water and a diseased crop plant. Our data suggest that the different substrates harboring P. syringae modify the structure of the associated populations. Here, we propose a comprehensive life cycle for P. syringae--in agricultural and non-agricultural habitats--driven by the environmental cycle of water. This cycle opens the opportunity to evaluate the importance of non-agricultural habitats in the evolution of a plant pathogen and the emergence of virulence. The ice-nucleation activity of all strains from snow, unlike from other substrates, strongly suggests that P. syringae plays an active role in the water cycle as an ice nucleus in clouds.

  8. SImbol Materials Lithium Extraction Operating Data From Elmore and Featherstone Geothermal Plants

    DOE Data Explorer

    Stephen Harrison

    2015-07-08

    The data provided in this upload is summary data from its Demonstration Plant operation at the geothermal power production plants in the Imperial Valley. The data provided is averaged data for the Elmore Plant and the Featherstone Plant. Included is both temperature and analytical data (ICP_OES). Provide is the feed to the Simbol Process, post brine treatment and post lithium extraction.

  9. Tightly-Coupled Plant-Soil Nitrogen Cycling: Comparison of Organic Farms across an Agricultural Landscape

    PubMed Central

    Bowles, Timothy M.; Hollander, Allan D.; Steenwerth, Kerri; Jackson, Louise E.

    2015-01-01

    How farming systems supply sufficient nitrogen (N) for high yields but with reduced N losses is a central challenge for reducing the tradeoffs often associated with N cycling in agriculture. Variability in soil organic matter and management of organic farms across an agricultural landscape may yield insights for improving N cycling and for evaluating novel indicators of N availability. We assessed yields, plant-soil N cycling, and root expression of N metabolism genes across a representative set of organic fields growing Roma-type tomatoes (Solanum lycopersicum L.) in an intensively-managed agricultural landscape in California, USA. The fields spanned a three-fold range of soil carbon (C) and N but had similar soil types, texture, and pH. Organic tomato yields ranged from 22.9 to 120.1 Mg ha-1 with a mean similar to the county average (86.1 Mg ha-1), which included mostly conventionally-grown tomatoes. Substantial variability in soil inorganic N concentrations, tomato N, and root gene expression indicated a range of possible tradeoffs between yields and potential for N losses across the fields. Fields showing evidence of tightly-coupled plant-soil N cycling, a desirable scenario in which high crop yields are supported by adequate N availability but low potential for N loss, had the highest total and labile soil C and N and received organic matter inputs with a range of N availability. In these fields, elevated expression of a key gene involved in root N assimilation, cytosolic glutamine synthetase GS1, confirmed that plant N assimilation was high even when inorganic N pools were low. Thus tightly-coupled N cycling occurred on several working organic farms. Novel combinations of N cycling indicators (i.e. inorganic N along with soil microbial activity and root gene expression for N assimilation) would support adaptive management for improved N cycling on organic as well as conventional farms, especially when plant-soil N cycling is rapid. PMID:26121264

  10. Microplate quantification of enzymes of the plant ascorbate-glutathione cycle.

    PubMed

    Murshed, Ramzi; Lopez-Lauri, Félicie; Sallanon, Huguette

    2008-12-15

    Here, we describe microplate assays for determining the specific activities of four enzymes that constitute the ascorbate-glutathione cycle: APX, MDHAR, DHAR, and GR. In plants, these enzymes play a major role in detoxifying reactive oxygen species produced in cells under environmental stress. This work presents the development of plate reader assays to allow rapid analysis of the ascorbate-glutathione cycle activity using tomato fruits subjected to salt stress as a model. With this method, it is possible to analyze easily in one day the activities of the four enzymes for 30 experimental samples, all in triplicate and with blanks.

  11. Performance Diagnosis using Optical Torque Sensor for Selection of a Steam Supply Plant among Advanced Combined Cycle Power Plants

    NASA Astrophysics Data System (ADS)

    Umezawa, Shuichi

    A newly developed optical torque sensor was applied to select a steam supply plant among advanced combined cycle, i.e. ACC, power plants of the Tokyo Electric Power Company. The sensor uses laser beams focused on small stainless steel reflectors having bar-code patterns attached on the surface of the rotating shaft, and a technique of signal processing using a correlation function featuring high frequency. The plant that supplied steam was selected on the basis of diagnosis of each steam turbine performance of the plants. Heat balance program was developed to analyze steam turbine performance using data of turbine output measured by the torque sensor and data measured by existing instruments of the power station. The steam turbine that supplied steam was determined by the present method using the optical torque sensor. The accuracy of the method to determine the steam supply plant was analyzed. It was then confirmed that the accuracy was greatly improved as compared with that of existing method.

  12. 9 CFR 590.124 - Schedule of operation of official plants.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 9 Animals and Animal Products 2 2014-01-01 2014-01-01 false Schedule of operation of official plants. 590.124 Section 590.124 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE... INSPECTION ACT) Performance of Service § 590.124 Schedule of operation of official plants. Operating...

  13. 9 CFR 590.124 - Schedule of operation of official plants.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 9 Animals and Animal Products 2 2012-01-01 2012-01-01 false Schedule of operation of official plants. 590.124 Section 590.124 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE... INSPECTION ACT) Performance of Service § 590.124 Schedule of operation of official plants. Operating...

  14. Mathematics for Water and Wastewater Treatment Plant Operators. Water and Wastewater Training Program.

    ERIC Educational Resources Information Center

    South Dakota Dept. of Environmental Protection, Pierre.

    This booklet is intended to aid the prospective waste treatment plant operator or drinking water plant operator in learning to solve mathematical problems, which is necessary for Class I certification. It deals with the basic mathematics which a Class I operator may require in accomplishing day-to-day tasks. The book also progresses into problems…

  15. 77 FR 3009 - Knowledge and Abilities Catalog for Nuclear Power Plant Operators: Advanced Boiling Water Reactors

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-20

    ... COMMISSION Knowledge and Abilities Catalog for Nuclear Power Plant Operators: Advanced Boiling Water Reactors..., ``Knowledge and Abilities Catalog for Nuclear Power Plant Operators: Advanced Boiling Water Reactors.'' DATES... developed using this Catalog along with the Operator Licensing Examination Standards for Power Reactors...

  16. Operation and Maintenance Manual for the Central Facilities Area Sewage Treatment Plant

    SciTech Connect

    Norm Stanley

    2011-02-01

    This Operation and Maintenance Manual lists operator and management responsibilities, permit standards, general operating procedures, maintenance requirements and monitoring methods for the Sewage Treatment Plant at the Central Facilities Area at the Idaho National Laboratory. The manual is required by the Municipal Wastewater Reuse Permit (LA-000141-03) the sewage treatment plant.

  17. Mathematics for Water and Wastewater Treatment Plant Operators. Water and Wastewater Training Program.

    ERIC Educational Resources Information Center

    South Dakota Dept. of Environmental Protection, Pierre.

    This booklet is intended to aid the prospective waste treatment plant operator or drinking water plant operator in learning to solve mathematical problems, which is necessary for Class I certification. It deals with the basic mathematics which a Class I operator may require in accomplishing day-to-day tasks. The book also progresses into problems…

  18. 7 CFR 70.110 - Requirements for sanitation, facilities, and operating procedures in official plants.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 3 2013-01-01 2013-01-01 false Requirements for sanitation, facilities, and operating... Requirements for sanitation, facilities, and operating procedures in official plants. (a) The requirements for sanitation, facilities, and operating procedures in official plants shall be the applicable provisions...

  19. 7 CFR 70.110 - Requirements for sanitation, facilities, and operating procedures in official plants.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 3 2014-01-01 2014-01-01 false Requirements for sanitation, facilities, and operating... Requirements for sanitation, facilities, and operating procedures in official plants. (a) The requirements for sanitation, facilities, and operating procedures in official plants shall be the applicable provisions...

  20. 7 CFR 70.110 - Requirements for sanitation, facilities, and operating procedures in official plants.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Requirements for sanitation, facilities, and operating... Requirements for sanitation, facilities, and operating procedures in official plants. (a) The requirements for sanitation, facilities, and operating procedures in official plants shall be the applicable provisions...

  1. 7 CFR 70.110 - Requirements for sanitation, facilities, and operating procedures in official plants.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 3 2011-01-01 2011-01-01 false Requirements for sanitation, facilities, and operating... Requirements for sanitation, facilities, and operating procedures in official plants. (a) The requirements for sanitation, facilities, and operating procedures in official plants shall be the applicable provisions...

  2. Development of a smart type motor operated valve for nuclear power plants

    NASA Astrophysics Data System (ADS)

    Kim, Chang-Hwoi; Park, Joo-Hyun; Lee, Dong-young; Koo, In-Soo

    2005-12-01

    In this paper, the design concept of the smart type motor operator valve for nuclear power plant was described. The development objective of the smart valve is to achieve superior accuracy, long-term reliability, and ease of use. In this reasons, developed smart valve has fieldbus communication such as deviceNet and Profibus-DP, auto-tuning PID controller, self-diagnostics, and on-line calibration capabilities. And also, to achieve pressure, temperature, and flow control with internal PID controller, the pressure sensor and transmitter were included in this valve. And, temperature and flow signal acquisition port was prepared. The developed smart valve will be performed equipment qualification test such as environment, EMI/EMC, and vibration in Korea Test Lab. And, the valve performance is tested in a test loop which is located in Seoul National University Lab. To apply nuclear power plant, the software is being developed according to software life cycle. The developed software is verified by independent software V and V team. It is expected that the smart valve can be applied to an existing NPPs for replacing or to a new nuclear power plants. The design and fabrication of smart valve is now being processed.

  3. Predictive control strategy of a gas turbine for improvement of combined cycle power plant dynamic performance and efficiency.

    PubMed

    Mohamed, Omar; Wang, Jihong; Khalil, Ashraf; Limhabrash, Marwan

    2016-01-01

    This paper presents a novel strategy for implementing model predictive control (MPC) to a large gas turbine power plant as a part of our research progress in order to improve plant thermal efficiency and load-frequency control performance. A generalized state space model for a large gas turbine covering the whole steady operational range is designed according to subspace identification method with closed loop data as input to the identification algorithm. Then the model is used in developing a MPC and integrated into the plant existing control strategy. The strategy principle is based on feeding the reference signals of the pilot valve, natural gas valve, and the compressor pressure ratio controller with the optimized decisions given by the MPC instead of direct application of the control signals. If the set points for the compressor controller and turbine valves are sent in a timely manner, there will be more kinetic energy in the plant to release faster responses on the output and the overall system efficiency is improved. Simulation results have illustrated the feasibility of the proposed application that has achieved significant improvement in the frequency variations and load following capability which are also translated to be improvements in the overall combined cycle thermal efficiency of around 1.1 % compared to the existing one.

  4. 9 CFR 355.19 - Inspector to be informed when plant operates.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... OF AGRICULTURE AGENCY ORGANIZATION AND TERMINOLOGY; MANDATORY MEAT AND POULTRY PRODUCTS INSPECTION... Procedure § 355.19 Inspector to be informed when plant operates. The management of an inspected plant...

  5. Interactions Among Water, Carbon, And Nutrient Cycles With Woody Plant Encroachment Into Grasslands

    NASA Astrophysics Data System (ADS)

    Jackson, R. B.; Engel, V.; Jobbagy, E. G.; McElrone, A. J.; Pockman, W. T.

    2003-12-01

    The expansion of woody plants into deserts, grasslands, and savannas alters water and nutrient cycling, affecting some one-fifth of the world's population. In this talk, research along precipitation gradients in North and South America will be used to examine interactions among water, carbon and nutrients in the southwestern U.S. and in grasslands of Argentina and Uruguay. Those interactions include groundwater uptake, carbon sequestration, changes in salinity and pH, and new evidence for the direct uptake of nutrients at depth using stable isotopes. The talk will end with a discussion of key unanswered research questions at the boundary of hydrology, biology, and geochemistry associated with woody plant encroachment.

  6. Improved cycling behavior of ZEBRA battery operated at intermediate temperature of 175 °C

    SciTech Connect

    Li, Guosheng; Lu, Xiaochuan; Kim, Jin Y.; Lemmon, John P.; Sprenkle, Vincent L.

    2014-03-01

    Operation of the sodium-nickel chloride battery at temperatures below 200°C reduces cell degradation and improves cyclability. One of the main technical issues with operating this battery at intermediate temperatures such as 175°C is the poor wettability of molten sodium on β”-alumina solid electrolyte (BASE), which causes reduced active area and limits charging. In order to overcome the poor wettability of molten sodium on BASE at 175°C, a Pt grid was applied on the anode side of the BASE using a screen printing technique. Cells with their active area increased by metallized BASEs exhibited deeper charging and stable cycling behavior.

  7. Improved cycling behavior of ZEBRA battery operated at intermediate temperature of 175 °C

    NASA Astrophysics Data System (ADS)

    Li, Guosheng; Lu, Xiaochuan; Kim, Jin Y.; Lemmon, John P.; Sprenkle, Vincent L.

    2014-03-01

    Operation of the sodium-nickel chloride battery at temperatures below 200 °C reduces cell degradation and improves cyclability. One of the main technical issues with operating this battery at intermediate temperatures such as 175 °C is the poor wettability of molten sodium on β″-alumina solid electrolyte (BASE), which causes reduced active area and limits charging. In order to overcome the poor wettability of molten sodium on BASE at 175 °C, a Pt grid was applied on the anode side of the BASE using a screen printing technique. Cells with their active area increased by metallized BASEs exhibited deeper charging and stable cycling behavior.

  8. Dehumidification Performance of Organic Powder Sorbent in a Fluidized Bed during Batch Cycle Operation

    NASA Astrophysics Data System (ADS)

    Horibe, Akihiko; Inaba, Hideo; Haruki, Naoto; Fujita, Naotoshi

    The air conditioning system with organic sorbent is able to utilize the low temperature waste heat. This paper has dealt with dynamic sorption of powder organic sorbent in a fluidized bed during batch cycle operation. The experiments were carried out under the various conditions such as cycle time, inlet air flow velocity, temperature of the heat exchanger, amount of sorbent. As a result, the cycle time which maximizes the amount of dehumidification became clear. The most suitable cycle time was decided by the balance of the speed of sorption reaction and the effects of heating and cooling. The heating effect and the cooling effect were controlled by the temperature of the heat exchanger. With a rise of the desorption temperature, the most suitable cycle time became short and the amount of dehumidification increased but heat efficiency dropped. On the other hand, with a rise of the sorption temperature, the amount of dehumidification decreased but this system showed an enough dehumidification performance when the sorption temperature is 30°C.

  9. Combined Heat and Power: Coal-Fired Air Turbine (CAT)-Cycle Plant

    SciTech Connect

    Recca, L.

    1999-01-29

    By combining an integrated system with a gas turbine, coal-fired air turbine cycle technology can produce energy at an efficiency rate of over 40%, with capital and operating costs below those of competing conventional systems. Read this fact sheet to discover the additional benefits of this exciting new technology.

  10. Method and apparatus for optimizing operation of a power generating plant using artificial intelligence techniques

    SciTech Connect

    Wroblewski, David; Katrompas, Alexander M.; Parikh, Neel J.

    2009-09-01

    A method and apparatus for optimizing the operation of a power generating plant using artificial intelligence techniques. One or more decisions D are determined for at least one consecutive time increment, where at least one of the decisions D is associated with a discrete variable for the operation of a power plant device in the power generating plant. In an illustrated embodiment, the power plant device is a soot cleaning device associated with a boiler.

  11. Teaching about citric acid cycle using plant mitochondrial preparations: Some assays for use in laboratory courses*.

    PubMed

    Vicente, Joaquim A F; Gomes-Santos, Carina S S; Sousa, Ana Paula M; Madeira, Vítor M C

    2005-03-01

    Potato tubers and turnip roots were used to prepare purified mitochondria for laboratory practical work in the teaching of the citric acid cycle (TCA cycle). Plant mitochondria are particularly advantageous over the animal fractions to demonstrate the TCA cycle enzymatic steps, by using simple techniques to measure O(2) consumption and transmembrane potential (ΔΨ). The several TCA cycle intermediates induce specific enzyme activities, which can be identified by respiratory parameters. Such a strategy is also used to evidence properties of the TCA cycle enzymes: ADP stimulation of isocitrate dehydrogenase and α-ketoglutarate dehydrogenase; activation by citrate of downstream oxidation steps, e.g. succinate dehydrogenase; and regulation of the activity of isocitrate dehydrogenase by citrate action on the citrate/isocitrate carrier. Furthermore, it has been demonstrated that, in the absence of exogenous Mg(2+) , isocitrate-dependent respiration favors the alternative oxidase pathway, as judged by changes of the ADP/O elicited by the inhibitor n-propyl galate. These are some examples of assays related with TCA cycle intermediates we can use in laboratory courses. Copyright © 2005 International Union of Biochemistry and Molecular Biology, Inc.

  12. Investigation of plant control strategies for the supercritical C0{sub 2}Brayton cycle for a sodium-cooled fast reactor using the plant dynamics code.

    SciTech Connect

    Moisseytsev, A.; Sienicki, J.

    2011-04-12

    The development of a control strategy for the supercritical CO{sub 2} (S-CO{sub 2}) Brayton cycle has been extended to the investigation of alternate control strategies for a Sodium-Cooled Fast Reactor (SFR) nuclear power plant incorporating a S-CO{sub 2} Brayton cycle power converter. The SFR assumed is the 400 MWe (1000 MWt) ABR-1000 preconceptual design incorporating metallic fuel. Three alternative idealized schemes for controlling the reactor side of the plant in combination with the existing automatic control strategy for the S-CO{sub 2} Brayton cycle are explored using the ANL Plant Dynamics Code together with the SAS4A/SASSYS-1 Liquid Metal Reactor (LMR) Analysis Code System coupled together using the iterative coupling formulation previously developed and implemented into the Plant Dynamics Code. The first option assumes that the reactor side can be ideally controlled through movement of control rods and changing the speeds of both the primary and intermediate coolant system sodium pumps such that the intermediate sodium flow rate and inlet temperature to the sodium-to-CO{sub 2} heat exchanger (RHX) remain unvarying while the intermediate sodium outlet temperature changes as the load demand from the electric grid changes and the S-CO{sub 2} cycle conditions adjust according to the S-CO{sub 2} cycle control strategy. For this option, the reactor plant follows an assumed change in load demand from 100 to 0 % nominal at 5 % reduction per minute in a suitable fashion. The second option allows the reactor core power and primary and intermediate coolant system sodium pump flow rates to change autonomously in response to the strong reactivity feedbacks of the metallic fueled core and assumed constant pump torques representing unchanging output from the pump electric motors. The plant behavior to the assumed load demand reduction is surprising close to that calculated for the first option. The only negative result observed is a slight increase in the intermediate

  13. Operating Characteristics of Expander/Compressor Combination for Carbon Dioxide Refrigeration Cycle

    NASA Astrophysics Data System (ADS)

    Fukuta, Mitsuhiro; Yanagisawa, Tadashi; Nakaya, Seiji

    An expander can improve the performance of CO2 refrigeration cycles by recovering a throttling loss. One way to utilize the recovered work is to drive an additional compressor by the expander, and it is effective to use an intercooler between a first-stage compressor and a second-stage compressor. An expander/compressor combination, in which the second-stage compressor is driven by the expander autonomously, is developed and the operating characteristics of the achine are discussed. It is operated at a balance point of mass flow rate and shaft torque between the compressor and the expander, and the balance point can be estimated using performance data of the compressor and expander. Although the expander/compressor combination improves the cycle performance, a heat rejection pressure is not maintained at an optimum pressure under off-design operating conditions. A control that keeps the heat rejection pressure optimum by a pre-expansion or a bypass is effective to obtain good performance of the CO2 refrigeration cycle with the expander/compressor combination.

  14. Rainfall variability, carbon cycling, and plant species diversity in a mesic grassland.

    PubMed

    Knapp, Alan K; Fay, Philip A; Blair, John M; Collins, Scott L; Smith, Melinda D; Carlisle, Jonathan D; Harper, Christopher W; Danner, Brett T; Lett, Michelle S; McCarron, James K

    2002-12-13

    Ecosystem responses to increased variability in rainfall, a prediction of general circulation models, were assessed in native grassland by reducing storm frequency and increasing rainfall quantity per storm during a 4-year experiment. More extreme rainfall patterns, without concurrent changes in total rainfall quantity, increased temporal variability in soil moisture and plant species diversity. However, carbon cycling processes such as soil CO2 flux, CO2 uptake by the dominant grasses, and aboveground net primary productivity (ANPP) were reduced, and ANPP was more responsive to soil moisture variability than to mean soil water content. Our results show that projected increases in rainfall variability can rapidly alter key carbon cycling processes and plant community composition, independent of changes in total precipitation.

  15. Steam generator tube degradation at the Doel 4 plant influence on plant operation and safety

    SciTech Connect

    Scheveneels, G.

    1997-02-01

    The steam generator tubes of Doel 4 are affected by a multitude of corrosion phenomena. Some of them have been very difficult to manage because of their extremely fast evolution, non linear evolution behavior or difficult detectability and/or measurability. The exceptional corrosion behavior of the steam generator tubes has had its drawbacks on plant operation and safety. Extensive inspection and repair campaigns have been necessary and have largely increased outage times and radiation exposure to personnel. Although considerable effort was invested by the utility to control corrosion problems, non anticipated phenomena and/or evolution have jeopardized plant safety. The extensive plugging and repairs performed on the steam generators have necessitated continual review of the design basis safety studies and the adaptation of the protection system setpoints. The large asymmetric plugging has further complicated these reviews. During the years many preventive and recently also defence measures have been implemented by the utility to manage corrosion and to decrease the probability and consequences of single or multiple tube rupture. The present state of the Doel 4 steam generators remains troublesome and further examinations are performed to evaluate if continued operation until June `96, when the steam generators will be replaced, is justified.

  16. Large scale softwood planting operations in New Brunswick

    Treesearch

    M. K. Barteaux

    1977-01-01

    New Brunswick is presently planting 20,000 ac. per year and expects to be planting nearly 60,000 ac. per year by 1979. Total productive forest area is 15,000,000 acres. The program is directly related to projected industrial demand and other forest uses. Plantations are established by scarification and planting of paper pot containers and bare root stock.

  17. Mechanized Red Pine Tree Planting Operation -- A Time Study

    Treesearch

    Joseph B. Sturos; Edwin S. Miyata

    1984-01-01

    Projected softwood shortages and high costs of mechanized tree planting indicate that more efficient planting equipment and systems are needed. This paper presents cost and productivity data for mechanically planting red pine seelings on a site previously occupied by hardwoods in northern Wisconsin

  18. Evaluation of a mechanized tree-planting operation.

    Treesearch

    Michael A. Thompson

    1984-01-01

    A continuous-furrow, bareroot-stock, mechanical planter was used to plant red pine tree seedlings on five sites in northern Michigan. Several indicators of planting efficiency were analyzed including utilization of the available land area, productivity as related to site conditions and planting pattern, cost, and effectiveness of the V-blade.

  19. POPCYCLE: a computer code for calculating nuclear and fossil plant levelized life-cycle power costs

    SciTech Connect

    Hardie, R.W.

    1982-02-01

    POPCYCLE, a computer code designed to calculate levelized life-cycle power costs for nuclear and fossil electrical generating plants is described. Included are (1) derivations of the equations and a discussion of the methodology used by POPCYCLE, (2) a description of the input required by the code, (3) a listing of the input for a sample case, and (4) the output for a sample case.

  20. Development and Use of the Coal-Fired Central Energy Plant Operations Expert System (CEPES)

    DTIC Science & Technology

    1993-08-01

    development of the Coal-Fired Central Energy Plant Operations Expert System (CEPES), which analyzes and recommends solutions to coal-fired boiler operational...problems. This phase included selection of the hardware and software platforms, and development and coding of the expert system . Later phases will...expand and beta test the present system, and develop a comprehensive technology transfer plan. Central heating plants, Artificial intelligence, Coal-fired energy plant operations expert system (CEPES).

  1. Plant origin and ploidy influence gene expression and life cycle characteristics in an invasive weed.

    PubMed

    Broz, Amanda K; Manter, Daniel K; Bowman, Gillianne; Müller-Schärer, Heinz; Vivanco, Jorge M

    2009-03-23

    Ecological, evolutionary and physiological studies have thus far provided an incomplete picture of why some plants become invasive; therefore we used genomic resources to complement and advance this field. In order to gain insight into the invasive mechanism of Centaurea stoebe we compared plants of three geo-cytotypes, native Eurasian diploids, native Eurasian tetraploids and introduced North American tetraploids, grown in a common greenhouse environment. We monitored plant performance characteristics and life cycle habits and characterized the expression of genes related to constitutive defense and genome stability using quantitative PCR. Plant origin and ploidy were found to have a significant effect on both life cycle characteristics and gene expression, highlighting the importance of comparing appropriate taxonomic groups in studies of native and introduced plant species. We found that introduced populations of C. stoebe exhibit reduced expression of transcripts related to constitutive defense relative to their native tetraploid counterparts, as might be expected based on ideas of enemy release and rapid evolution. Measurements of several vegetative traits were similar for all geo-cytotypes; however, fecundity of tetraploids was significantly greater than diploids, due in part to their polycarpic nature. A simulation of seed production over time predicts that introduced tetraploids have the highest fecundity of the three geo-cytotypes. Our results suggest that characterizing gene expression in an invasive species using populations from both its native and introduced range can provide insight into the biology of plant invasion that can complement traditional measurements of plant performance. In addition, these results highlight the importance of using appropriate taxonomic units in ecological genomics investigations.

  2. Plant origin and ploidy influence gene expression and life cycle characteristics in an invasive weed

    PubMed Central

    Broz, Amanda K; Manter, Daniel K; Bowman, Gillianne; Müller-Schärer, Heinz; Vivanco, Jorge M

    2009-01-01

    Background Ecological, evolutionary and physiological studies have thus far provided an incomplete picture of why some plants become invasive; therefore we used genomic resources to complement and advance this field. In order to gain insight into the invasive mechanism of Centaurea stoebe we compared plants of three geo-cytotypes, native Eurasian diploids, native Eurasian tetraploids and introduced North American tetraploids, grown in a common greenhouse environment. We monitored plant performance characteristics and life cycle habits and characterized the expression of genes related to constitutive defense and genome stability using quantitative PCR. Results Plant origin and ploidy were found to have a significant effect on both life cycle characteristics and gene expression, highlighting the importance of comparing appropriate taxonomic groups in studies of native and introduced plant species. We found that introduced populations of C. stoebe exhibit reduced expression of transcripts related to constitutive defense relative to their native tetraploid counterparts, as might be expected based on ideas of enemy release and rapid evolution. Measurements of several vegetative traits were similar for all geo-cytotypes; however, fecundity of tetraploids was significantly greater than diploids, due in part to their polycarpic nature. A simulation of seed production over time predicts that introduced tetraploids have the highest fecundity of the three geo-cytotypes. Conclusion Our results suggest that characterizing gene expression in an invasive species using populations from both its native and introduced range can provide insight into the biology of plant invasion that can complement traditional measurements of plant performance. In addition, these results highlight the importance of using appropriate taxonomic units in ecological genomics investigations. PMID:19309502

  3. Soil Salinity Controls on Water and Carbon Cycling by Sunflower Plants

    NASA Astrophysics Data System (ADS)

    Runkle, B.; Liang, X.; Dracup, J.; Hao, F.; Zeng, A.; Zhang, J.; He, B.; Oki, T.

    2007-12-01

    Agricultural effects on water cycling are of great importance for regional water resources management. These effects vary based on local soil and climate conditions, and are particularly modulated by high soil salinity levels, which stress plant growth and change their water use efficiency. Increasing salinization is predicted under hotter, drier conditions resulting from global climate change and from increased societal pressure on agricultural lands. This increased ionic presence creates a higher soil osmotic pressure that increases the resistance to water flow through the plant. This change also impacts the assimilation of carbon dioxide through the stomatal opening, and so affects rates of both photosynthesis and transpiration. Current agricultural and land-surface models that account for salinity do so in an overly empirical manner that cannot account for changes at different time scales in meteorological conditions. They tend to be ill equipped to examine how changing carbon dioxide levels may modify a plant's response to soil salinity. As a result, we present a new model of soil-vegetation- atmosphere water transfer that explicitly incorporates the role of soil salinity in changing this system's behavior. This model will allow for much greater flexibility in examining how vegetation may change the local water cycle under the joint impacts of both salinity and climate change. This model is supported by field research on the effects of salinity on sunflower plants in a large irrigation district in Inner Mongolia, China. Results presented include the role of salinity in changing stomatal regulation of water use efficiency, sub-canopy changes in leaf pressure, and changes in root activity. Modeling at sub-hourly time scales allows for a more precise understanding of how soil salinity changes the diurnal cycle of plant water use.

  4. Differences in wetland nitrogen cycling between the invasive grass Microstegium vimineum and a diverse plant community.

    PubMed

    DeMeester, Julie E; DeB Richter, Daniel

    2010-04-01

    Wetlands are valuable for buffering waterways from excess nitrogen, yet these habitats are often dominated by invasive plant species. There is little understanding as to how various invasive species alter ecosystem nitrogen cycling, especially if one invasive overtakes an entire community of plants. Microstegium vimineum is a nonnative annual grass from Asia that is dominating riparian wetlands in the southeastern United States. To evaluate M. vimineum impacts on the N cycle, we used six paired plots, one invaded by M. vimineum and the other carefully weeded of M. vimineum; removal allowed the establishment of a diverse plant community consisting of Polygonum, Juncus, and Carex species. In the paired plots, we estimated (1) N uptake and accumulation in vegetation biomass, (2) rates of decomposition and N release from plant detritus, (3) mineral soil N mineralization and nitrification, (4) root zone redox potential, and (5) soil water concentrations of inorganic N. The M. vimineum community accumulated approximately half the annual N biomass of the diverse community, 5.04 vs. 9.36 g N x m(-2) x yr(-1), respectively (P = 0.05). Decomposition and release of N from M. vimineum detritus was much less than in the diverse community, 1.19 vs. 5.24 g N x m(-2) x yr(-1). Significantly higher inorganic soil N persisted beneath M. vimineum during the dormant season, although rates of soil N mineralization estimated by in situ incubations were relatively similar in all plots. Microstegium vimineum invasion thus appears to greatly diminish within-ecosystem circulation of N through the understory plants of these wetlands, whereas invasion effects on ecosystem N losses may derive more from enhanced denitrification (due to lower redox potential under M. vimineum plots) than due to leaching. Microstegium vimineum's dominance and yet slower internal cycling of N are counterintuitive to conventional thinking that ecosystems with high N contain vegetation that quickly uptake and

  5. Organic Rankine-cycle turbine power plant utilizing low temperature heat sources

    NASA Astrophysics Data System (ADS)

    Maizza, V.

    1980-03-01

    Utilizing and converting of existing low temperature and waste heat sources by the use of a high efficiency bottoming cycle is attractive and should be possible for many locations. This paper presents a theoretical study on possible combination of an organic Rankine-cycle turbine power plate with the heat pump supplied by waste energy sources. Energy requirements and system performances are analyzed using realistic design operating condition for a middle town. Some conversion systems employing working fluids other than water are being studied for the purpose of proposed application. Thermodynamic efficiencies, with respect to available resource, have been calculated by varying some system operating parameters at various reference temperature. With reference to proposed application equations and graphs are presented which interrelate the turbine operational parameters for some possible working fluids with computation results.

  6. Plant impact on the coupled terrestrial biogeochemical cycles of silicon and carbon: Implications for biogeochemical carbon sequestration

    NASA Astrophysics Data System (ADS)

    Song, Zhaoliang; Wang, Hailong; Strong, P. James; Li, Zimin; Jiang, Peikun

    2012-12-01

    The coupled terrestrial biogeochemical cycles of silicon (Si) and carbon (C) that are driven by plant action play a crucial role in the regulation of atmospheric CO2. Generally, the processes involved in the coupled cycles of Si and C include plant-enhanced silicate weathering, phytolith formation and solubilization, secondary aluminosilicate accumulation, phytolith occlusion of C as well as physico-chemical protection of organic C in soils. There is increasing evidence of biological pumping of Si in terrestrial ecosystems, suggesting that complex feedbacks exist amongst the processes within the coupled Si and C cycles. Recent advances in the coupled Si and C cycles offer promising new possibilities for enhancing atmospheric CO2 sequestration. Organic mulching, rock powder amendment, cultivating Si-accumulating plants and partial plant harvesting are potential measures that may allow for long-term manipulation and biogeochemical sequestration of atmospheric CO2 in soil-plant systems.

  7. Changes in Plant-Parasitic Nematode Populations in Pineapple Fields Following Inter-Cycle Cover Crops

    PubMed Central

    Ko, M. P.; Schmitt, D. P.

    1996-01-01

    The use of plant-covers oat (Arena sativa L.), rhodesgrass (Chloris gayana Kunth), soybean (Glycine max [L.] Merr.), and marigold (Tagetes patula L.) during pineapple inter-cycle planting periods was investigated at two sites (Kunia and Whitmore, Oahu, HI) as a potential means to reduce population densities of Rotylenchulus reniformis, Helicotylenchus dihystera, and Paratylenchus spp. Clean fallow and fallow covered with pineapple-plant residues (mulch) were the controls without plant-cover. Regardless of treatments, population densities of R. reniformis declined with time at both sites to low residue levels by the end of the 6-month period. Treatment means of R. reniformis population densities in the plant-cover treatments were lower than the controls' (P = 0.05). The plant-cover treatments also effected higher rates of R. reniformis population decline at both sites during the period, being 2.0 to 2.2 times that of the mulch control and 1.2 to 1.4 times that of the fallow control. Plant-covers' effect on H. dihystera during the same period at both sites was variable, resulting in decreased, unchanged, or increased population densities. The change was especially obvious in the oat-cover treatment, where H. dihystera population densities increased 9 to 15-fold at both sites. Population of Paratylenchus spp. was absent or present at low levels at the sites throughout the period. Biological activities antagonistic to R. reniformis at Kunia were estimated at the end of 6 months by comparing the extent of nematode's reproduction (on cowpea seedlings) in the treatment soils that had been subjected to autoclaving or freezing temperature. Although higher indices of antagonistic activities were observed in soils with prior plant-cover treatments than in soils from the controls, none of the treatments resulted in conferring soils the increased ability to suppress re-introduced R. reniformis populations or enhance subsequent pineapple-plant growth. PMID:19277173

  8. Recovery of plant biomass and soil N cycling in Alaskan tundra following an unusual fire

    NASA Astrophysics Data System (ADS)

    Bret-Harte, M. S.; Mack, M. C.; Huebner, D. C.; Johnston, M.; Shaver, G. R.

    2012-12-01

    Climate warming is likely to increase the frequency of disturbances in the Arctic. The Anaktuvuk River fire of 2007 burned 1039 km2 of northern Alaskan tundra; this was unprecedented for this vegetation, which is clonal, slow-growing, and long-lived. We harvested plant biomass and soils from severely and moderately burned areas and controls in 2011 to assess recovery of plant productivity and soil N cycling four years after the fire. Biomass of vascular plants had recovered to nearly control levels in moderately burned areas, due primarily to resprouting by graminoids, particularly Eriophorum vaginatum. Graminoid biomass was actually greater in moderately burned tundra than in unburned tundra. Deciduous shrub and evergreen shrub biomass in moderately burned tundra was approximately half that seen in unburned tundra, but non-vascular plant biomass was much less, so that total aboveground biomass in moderately burned tundra had not returned to control levels. Severely burned tundra had less of all components of the community than in moderately burned tundra, except that there was higher biomass of non-vascular plants, due to colonization by fire-following liverworts and mosses. Productivity of vascular plants was similar in unburned and severely burned tundra plots, and higher in moderately burned plots, due in part to higher soil N availability. Recovery of plant biomass was largely due to resprouting of species that survived the fire, though numerous seedlings were seen. Biomass of vascular plants has recovered rapidly in the moderately burned sites, while severely burned sites and nonvascular plants are recovering more slowly, but the relative abundance of different species differs from unburned tundra. The relationship between spectral indices (NDVI, EVI-2) collected at the plot level and either biomass or NPP varied with burn category, which may complicate assessments of NPP by remote sensing following fire.

  9. Evolution of enzymes involved in the photorespiratory 2-phosphoglycolate cycle from cyanobacteria via algae toward plants.

    PubMed

    Kern, Ramona; Bauwe, Hermann; Hagemann, Martin

    2011-09-01

    The photorespiratory pathway was shown to be essential for organisms performing oxygenic photosynthesis, cyanobacteria, algae, and plants, in the present day O(2)-containing atmosphere. The identification of a plant-like 2-phosphoglycolate cycle in cyanobacteria indicated that not only genes of oxygenic photosynthesis but also genes encoding photorespiratory enzymes were endosymbiotically conveyed from ancient cyanobacteria to eukaryotic oxygenic phototrophs. Here, we investigated the origin of the photorespiratory pathway in photosynthetic eukaryotes by phylogenetic analysis. We found that a mixture of photorespiratory enzymes of either cyanobacterial or α-proteobacterial origin is present in algae and higher plants. Three enzymes in eukaryotic phototrophs clustered closely with cyanobacterial homologs: glycolate oxidase, glycerate kinase, and hydroxypyruvate reductase. On the other hand, the mitochondrial enzymes of the photorespiratory cycle in algae and plants, glycine decarboxylase subunits and serine hydroxymethyltransferase, evolved from proteobacteria. Other than most genes for proteins of the photosynthetic machinery, nearly all enzymes involved in the 2-phosphogylcolate metabolism coexist in the genomes of cyanobacteria and heterotrophic bacteria.

  10. Heterogeneity of cellular circadian clocks in intact plants and its correction under light-dark cycles.

    PubMed

    Muranaka, Tomoaki; Oyama, Tokitaka

    2016-07-01

    Recent advances in single-cell analysis have revealed the stochasticity and nongenetic heterogeneity inherent to cellular processes. However, our knowledge of the actual cellular behaviors in a living multicellular organism is still limited. By using a single-cell bioluminescence imaging technique on duckweed, Lemna gibba, we demonstrate that, under constant conditions, cells in the intact plant work as individual circadian clocks that oscillate with their own frequencies and respond independently to external stimuli. Quantitative analysis uncovered the heterogeneity and instability of cellular clocks and partial synchronization between neighboring cells. Furthermore, we found that cellular clocks in the plant body under light-dark cycles showed a centrifugal phase pattern in which the effect of cell-to-cell heterogeneity in period lengths was almost masked. The inherent heterogeneity in the properties of cellular clocks observed under constant conditions is corrected under light-dark cycles to coordinate the daily rhythms of the plant body. These findings provide a novel perspective of spatiotemporal architectures in the plant circadian system.

  11. Massachusetts Maritime Academy Wastewater Treatment Plant Chief Operator Recognized for Outstanding Service

    EPA Pesticide Factsheets

    A resident of Fairhaven, Daniel Freitas, the Chief Operator of the Massachusetts Maritime Academy Wastewater Treatment Plant, was recently honored with a 2015 Regional WWTP Operator of the Year Excellence Award by the US EPA's New England regional office

  12. Life-cycle energy and greenhouse gas emission impacts of different corn ethanol plant types.

    SciTech Connect

    Wang, M.; Wu, M.; Huo, H.; Energy Systems

    2007-04-01

    Since the United States began a program to develop ethanol as a transportation fuel, its use has increased from 175 million gallons in 1980 to 4.9 billion gallons in 2006. Virtually all of the ethanol used for transportation has been produced from corn. During the period of fuel ethanol growth, corn farming productivity has increased dramatically, and energy use in ethanol plants has been reduced by almost by half. The majority of corn ethanol plants are powered by natural gas. However, as natural gas prices have skyrocketed over the last several years, efforts have been made to further reduce the energy used in ethanol plants or to switch from natural gas to other fuels, such as coal and wood chips. In this paper, we examine nine corn ethanol plant types--categorized according to the type of process fuels employed, use of combined heat and power, and production of wet distiller grains and solubles. We found that these ethanol plant types can have distinctly different energy and greenhouse gas emission effects on a full fuel-cycle basis. In particular, greenhouse gas emission impacts can vary significantly--from a 3% increase if coal is the process fuel to a 52% reduction if wood chips are used. Our results show that, in order to achieve energy and greenhouse gas emission benefits, researchers need to closely examine and differentiate among the types of plants used to produce corn ethanol so that corn ethanol production would move towards a more sustainable path.

  13. Optimization of the oxidant supply system for combined cycle MHD power plants

    NASA Technical Reports Server (NTRS)

    Juhasz, A. J.

    1982-01-01

    An in-depth study was conducted to determine what, if any, improvements could be made on the oxidant supply system for combined cycle MHD power plants which could be reflected in higher thermal efficiency and a reduction in the cost of electricity, COE. A systematic analysis of air separation process varitions which showed that the specific energy consumption could be minimized when the product stream oxygen concentration is about 70 mole percent was conducted. The use of advanced air compressors, having variable speed and guide vane position control, results in additional power savings. The study also led to the conceptual design of a new air separation process, sized for a 500 MW sub e MHD plant, referred to a internal compression is discussed. In addition to its lower overall energy consumption, potential capital cost savings were identified for air separation plants using this process when constructed in a single large air separation train rather than multiple parallel trains, typical of conventional practice.

  14. Differentiating moss from higher plants is critical in studying the carbon cycle of the boreal biome.

    PubMed

    Yuan, Wenping; Liu, Shuguang; Dong, Wenjie; Liang, Shunlin; Zhao, Shuqing; Chen, Jingming; Xu, Wenfang; Li, Xianglan; Barr, Alan; Andrew Black, T; Yan, Wende; Goulden, Mike L; Kulmala, Liisa; Lindroth, Anders; Margolis, Hank A; Matsuura, Yojiro; Moors, Eddy; van der Molen, Michiel; Ohta, Takeshi; Pilegaard, Kim; Varlagin, Andrej; Vesala, Timo

    2014-06-26

    The satellite-derived normalized difference vegetation index (NDVI), which is used for estimating gross primary production (GPP), often includes contributions from both mosses and vascular plants in boreal ecosystems. For the same NDVI, moss can generate only about one-third of the GPP that vascular plants can because of its much lower photosynthetic capacity. Here, based on eddy covariance measurements, we show that the difference in photosynthetic capacity between these two plant functional types has never been explicitly included when estimating regional GPP in the boreal region, resulting in a substantial overestimation. The magnitude of this overestimation could have important implications regarding a change from a current carbon sink to a carbon source in the boreal region. Moss abundance, associated with ecosystem disturbances, needs to be mapped and incorporated into GPP estimates in order to adequately assess the role of the boreal region in the global carbon cycle.

  15. Differentiating moss from higher plants is critical in studying the carbon cycle of the boreal biome

    USGS Publications Warehouse

    Yuan, Wenping; Liu, Shuguang; Dong, Wenjie; Liang, Shunlin; Zhao, Shuqing; Chen, Jingming; Xu, Wenfang; Li, Xianglan; Barr, Alan; Black, T. Andrew; Yan, Wende; Goulden, Michael; Kulmala, Liisa; Lindroth, Anders; Margolis, Hank A.; Matsuura, Yojiro; Moors, Eddy; van der Molen, Michiel; Ohta, Takeshi; Pilegaard, Kim; Varlagin, Andrej; Vesala, Timo

    2014-01-01

    The satellite-derived normalized difference vegetation index (NDVI), which is used for estimating gross primary production (GPP), often includes contributions from both mosses and vascular plants in boreal ecosystems. For the same NDVI, moss can generate only about one-third of the GPP that vascular plants can because of its much lower photosynthetic capacity. Here, based on eddy covariance measurements, we show that the difference in photosynthetic capacity between these two plant functional types has never been explicitly included when estimating regional GPP in the boreal region, resulting in a substantial overestimation. The magnitude of this overestimation could have important implications regarding a change from a current carbon sink to a carbon source in the boreal region. Moss abundance, associated with ecosystem disturbances, needs to be mapped and incorporated into GPP estimates in order to adequately assess the role of the boreal region in the global carbon cycle.

  16. CHALLENGES AND OPPORTUNITIES--INTEGRATED LIFE-CYCLE OPTIMIZATION INITIATIVES FOR THE HANFORD RIVER PROTECTION PROJECT--WASTE TREATMENT PLANT

    SciTech Connect

    Auclair, K. D.

    2002-02-25

    of issues across contract boundaries is a more difficult matter. This aspect, one of a seamless systems approach to the treatment of tank wastes at the Hanford site, is the focus of the Optimization Studies. This ''big O''Optimization of Life-Cycle operations is what is meant when the term ''optimization'' is used on the River Protection Project and initiatives cited in this paper. From the early contractor centric methods and processes used to move toward an integrated solution, through extensive partnering approaches, to the current quality initiatives with multi-organizational participation, significant progress is being made towards achieving the goal of truly integrated life-cycle optimization for the Department of Energy's River Protection Project and Waste Treatment Plant.

  17. Sodium Recycle Economics for Waste Treatment Plant Operations

    SciTech Connect

    Sevigny, Gary J.; Poloski, Adam P.; Fountain, Matthew S.

    2008-08-31

    Sodium recycle at the Hanford Waste Treatment Plant (WTP) would reduce the number of glass canisters produced, and has the potential to significantly reduce the cost to the U.S. Department of Energy (DOE) of treating the tank wastes by hundreds of millions of dollars. The sodium, added in the form of sodium hydroxide, was originally added to minimize corrosion of carbon-steel storage tanks from acidic reprocessing wastes. In the baseline Hanford treatment process, sodium hydroxide is required to leach gibbsite and boehmite from the high level waste (HLW) sludge. In turn, this reduces the amount of HLW glass produced. Currently, a significant amount of additional sodium hydroxide will be added to the process to maintain aluminate solubility at ambient temperatures during ion exchange of cesium. The vitrification of radioactive waste is limited by sodium content, and this additional sodium mass will increase low-activity waste-glass mass. An electrochemical salt-splitting process, based on sodium-ion selective ceramic membranes, is being developed to recover and recycle sodium hydroxide from high-salt radioactive tank wastes in DOE’s complex. The ceramic membranes are from a family of materials known as sodium (Na)—super-ionic conductors (NaSICON)—and the diffusion of sodium ions (Na+) is allowed, while blocking other positively charged ions. A cost/benefit evaluation was based on a strategy that involves a separate caustic-recycle facility based on the NaSICON technology, which would be located adjacent to the WTP facility. A Monte Carlo approach was taken, and several thousand scenarios were analyzed to determine likely economic results. The cost/benefit evaluation indicates that 10,000–50,000 metric tons (MT) of sodium could be recycled, and would allow for the reduction of glass production by 60,000–300,000 MT. The cost of the facility construction and operation was scaled to the low-activity waste (LAW) vitrification facility, showing cost would be

  18. Plant Cuticle: A Geochemical and Biophysical Sensor of the Carbon Cycle

    NASA Astrophysics Data System (ADS)

    Upchurch, G. R.; Marino, B. D.

    2007-12-01

    compounds. In addition, fossil leaf cuticle can be analyzed for Stomatal Index by light microscopy prior to its combustion for isotopic analysis, so that the same piece of cuticle can potentially provide information on levels of atmospheric CO2 and the isotopic composition of the atmosphere. Because dispersed plant cuticles can be analyzed with stratigraphic resolution close to that of pollen and spores, they can provide a high-resolution record of changes in the carbon cycle.

  19. Analysis of a Rocket Based Combined Cycle Engine during Rocket Only Operation

    NASA Technical Reports Server (NTRS)

    Smith, T. D.; Steffen, C. J., Jr.; Yungster, S.; Keller, D. J.

    1998-01-01

    The all rocket mode of operation is a critical factor in the overall performance of a rocket based combined cycle (RBCC) vehicle. However, outside of performing experiments or a full three dimensional analysis, there are no first order parametric models to estimate performance. As a result, an axisymmetric RBCC engine was used to analytically determine specific impulse efficiency values based upon both full flow and gas generator configurations. Design of experiments methodology was used to construct a test matrix and statistical regression analysis was used to build parametric models. The main parameters investigated in this study were: rocket chamber pressure, rocket exit area ratio, percent of injected secondary flow, mixer-ejector inlet area, mixer-ejector area ratio, and mixer-ejector length-to-inject diameter ratio. A perfect gas computational fluid dynamics analysis was performed to obtain values of vacuum specific impulse. Statistical regression analysis was performed based on both full flow and gas generator engine cycles. Results were also found to be dependent upon the entire cycle assumptions. The statistical regression analysis determined that there were five significant linear effects, six interactions, and one second-order effect. Two parametric models were created to provide performance assessments of an RBCC engine in the all rocket mode of operation.

  20. Operation reliability analysis of independent power plants of gas-transmission system distant production facilities

    NASA Astrophysics Data System (ADS)

    Piskunov, Maksim V.; Voytkov, Ivan S.; Vysokomornaya, Olga V.; Vysokomorny, Vladimir S.

    2015-01-01

    The new approach was developed to analyze the failure causes in operation of linear facilities independent power supply sources (mini-CHP-plants) of gas-transmission system in Eastern part of Russia. Triggering conditions of ceiling operation substance temperature at condenser output were determined with mathematical simulation use of unsteady heat and mass transfer processes in condenser of mini-CHP-plants. Under these conditions the failure probability in operation of independent power supply sources is increased. Influence of environmental factors (in particular, ambient temperature) as well as output electric capability values of power plant on mini-CHP-plant operation reliability was analyzed. Values of mean time to failure and power plant failure density during operation in different regions of Eastern Siberia and Far East of Russia were received with use of numerical simulation results of heat and mass transfer processes at operation substance condensation.

  1. CP12 provides a new mode of light regulation of Calvin cycle activity in higher plants.

    PubMed

    Wedel, N; Soll, J; Paap, B K

    1997-09-16

    CP12 is a small nuclear encoded chloroplast protein of higher plants, which was recently shown to interact with NAD(P)H-glyceraldehyde-3-phosphate dehydrogenase (GAPDH; EC 1.2.1. 13), one of the key enzymes of the reductive pentosephosphate cycle (Calvin cycle). Screening of a pea cDNA library in the yeast two-hybrid system for proteins that interact with CP12, led to the identification of a second member of the Calvin cycle, phosphoribulokinase (PRK; EC 2.7.1.19), as a further specific binding partner for CP12. The exchange of cysteines for serines in CP12 demonstrate that interaction with PRK occurs at the N-terminal peptide loop of CP12. Size exclusion chromatography and immunoprecipitation assays reveal the existence of a stable 600-kDa PRK/CP12/GAPDH complex in the stroma of higher plant chloroplasts. Its stoichiometry is proposed to be of two N-terminally dimerized CP12 molecules, each carrying one PRK dimer on its N terminus and one A2B2 complex of GAPDH subunits on the C-terminal peptide loop. Incubation of the complex with NADP or NADPH, in contrast to NAD or NADH, causes its dissociation. Assays with the stromal 600-kDa fractions in the presence of the four different nicotinamide-adenine dinucleotides indicate that PRK activity depends on complex dissociation and might be further regulated by the accessible ratio of NADP/NADPH. From these results, we conclude that light regulation of the Calvin cycle in higher plants is not only via reductive activation of different proteins by the well-established ferredoxin/thioredoxin system, but in addition, by reversible dissociation of the PRK/CP12/GAPDH complex, mediated by NADP(H).

  2. Oxygen isotopes and P cycle in the soil/plant system: where are we heading?

    NASA Astrophysics Data System (ADS)

    Tamburini, Federica; Pfahler, Verena; von Sperber, Christian; Bernasconi, Stefano; Frossard, Emmanuel

    2014-05-01

    Phosphorus (P) is a major nutrient for all living organisms. In the terrestrial environment, P is a double-edged sword. For this reason, a better understanding of P cycling in the soil/plant system and the processes influencing its transfers and transformations is needed to provide agricultural and environmental managers with better concepts for P use. In fact, whereas the effect of abiotic reactions on the P concentration in the soil solution are well understood, we still know too little about the forms of soil organic P, and about the importance of soil biological processes (e.g. on organic matter mineralization-immobilization, or on the role of microorganisms) in controlling P availability. Together with more traditional and routine analysis for P, in the last 20 years researchers have started using the ratio of stable oxygen isotopes in phosphate (δ18O-P) to investigate P cycle in the soil/plant system. The scientific community interested in using this isotopic tracer is expanding because δ18O-P has proven to provide important information on biological processes. A large part of the published studies has shown how δ18O-P can be used to track P in the environment, providing information on P transfer from one pool and/or sink to the other. The other part has used this tool as a tracer of biological activity, clarifying how P is cycled through the microbial biomass or by plants. Together with a short review of the most relevant published results, we will discuss whether, and under which conditions, the δ18O-P can be applied to study P cycling and transformations from the process to the ecosystem level.

  3. [Results of operator's work during space flight (experiment "pilot") under different work-and-rest cycles].

    PubMed

    Sal'nitskiĭ, V P; Dudukin, A V; Savchenko, É G; Stepanova, S I; Nesterov, V F; Saraev, I F

    2012-01-01

    The correlation between operator's job quality and crew work-rest cycle (WRC) aboard the International space station was studied. The experiment involved 10 Russian members of ISS missions 17-24 at the age of 35 to 51 yrs. Mission duration varied from 163 to 200 days, averaging 180 days. Each cosmonaut carried out several "pilot" test sessions. The number of sessions per mission ranged from 4 to 6. The procedure consisted of simulating manual operation of transport vehicle Soyuz on the stages of hang-up, berthing and docking with the ISS. Objective job quality parameters were accuracy of the Soyuz and ISS relative motion control and time for completion which actually characterized work rate. WRC intensity was judged by the data of monitoring at the Moscow Mission Control Center. The results lend support to the dependence of operator's efficiency on WRC. In operators aimed at the highest accuracy this dependence manifested itself in work rate parameters; work accuracy but not rate was more WRC-dependent in operators aimed at doing their job fast. In other words, WRC intensity impacted mostly those job qualities that operator considered to be of secondary importance.

  4. Keeping the rhythm: light/dark cycles during postharvest storage preserve the tissue integrity and nutritional content of leafy plants.

    PubMed

    Liu, John D; Goodspeed, Danielle; Sheng, Zhengji; Li, Baohua; Yang, Yiran; Kliebenstein, Daniel J; Braam, Janet

    2015-03-27

    The modular body structure of plants enables detached plant organs, such as postharvest fruits and vegetables, to maintain active responsiveness to environmental stimuli, including daily cycles of light and darkness. Twenty-four hour light/darkness cycles entrain plant circadian clock rhythms, which provide advantage to plants. Here, we tested whether green leafy vegetables gain longevity advantage by being stored under light/dark cycles designed to maintain biological rhythms. Light/dark cycles during postharvest storage improved several aspects of plant tissue performance comparable to that provided by refrigeration. Tissue integrity, green coloration, and chlorophyll content were generally enhanced by cycling of light and darkness compared to constant light or darkness during storage. In addition, the levels of the phytonutrient glucosinolates in kale and cabbage remained at higher levels over time when the leaf tissue was stored under light/dark cycles. Maintenance of the daily cycling of light and dark periods during postharvest storage may slow the decline of plant tissues, such as green leafy vegetables, improving not only appearance but also the health value of the crops through the maintenance of chlorophyll and phytochemical content after harvest.

  5. An analysis of problems arising during operation of the perm district power plant 800-MW power unit at sliding pressure

    NASA Astrophysics Data System (ADS)

    Avrutsky, G. D.; Zakharov, A. E.; Sargsyan, V. A.; Frolov, M. S.; Schwartz, A. L.; Adamov, A. S.

    2015-09-01

    The occurrence of cracks at locations in which bottoms are welded to the high-pressure heaters' headers was revealed during planned repairs of the Perm district power plant units. Specialists of the All-Russia Thermal Engineering Institute carried out investigations aimed at obtaining more detailed data on the effect the loading cyclicity and sliding-pressure operating modes have on the reliability of power-generating equipment. Another aim of those investigations was to elaborate recommendations for achieving more reliable operation of power-generating equipment under the conditions of cyclic variation of its load. The state of the main and auxiliary equipment of the Perm district power plant units is analyzed for determining the possibility and advisability of their further operation in sliding-pressure modes. The results obtained from calculating the permissible number of load variation cycles for the headers used in the Perm district power plant units operating under the conditions of startup-shutdown modes are analyzed, and the headers' residual cyclic service life is estimated. The results obtained from a metallographic investigation of the high-pressure header's bottom in the welded joint of which a through crack was revealed are presented. Recommendations for examining the header bottoms and for modifying their design in order to improve their operational reliability are given.

  6. Study and Development of an Air Conditioning System Operating on a Magnetic Heat Pump Cycle

    NASA Technical Reports Server (NTRS)

    Wang, Pao-Lien

    1991-01-01

    This report describes the design of a laboratory scale demonstration prototype of an air conditioning system operating on a magnetic heat pump cycle. Design parameters were selected through studies performed by a Kennedy Space Center (KSC) System Simulation Computer Model. The heat pump consists of a rotor turning through four magnetic fields that are created by permanent magnets. Gadolinium was selected as the working material for this demonstration prototype. The rotor was designed to be constructed of flat parallel disks of gadolinium with very little space in between. The rotor rotates in an aluminum housing. The laboratory scale demonstration prototype is designed to provide a theoretical Carnot Cycle efficiency of 62 percent and a Coefficient of Performance of 16.55.

  7. Plant operation report and daily evaluation summary. SSPS monthly data, April 1984

    SciTech Connect

    Not Available

    1984-01-01

    Operation and maintenance highlights and test and evaluation highlights are presented for the Small Solar Power Systems (SSPS) Central Receiver System (CRS) and Distributed Collector System (DCS). The major portion of this report consists of the following plant statistics; monthly operation summary for April 1984; CRS daily operation summary; DCS daily operation summary.

  8. Solid-tumor mortality in the vicinity of uranium cycle facilities and nuclear power plants in Spain.

    PubMed Central

    López-Abente, G; Aragonés, N; Pollán, M

    2001-01-01

    To ascertain solid tumor mortality in towns near Spain's four nuclear power plants and four nuclear fuel facilities from 1975 to 1993, we conducted a mortality study based on 12,245 cancer deaths in 283 towns situated within a 30-km radius of the above installations. As nonexposed areas, we used 275 towns lying within a 50- to 100-km radius of each installation, matched by population size and sociodemographic characteristics (income level, proportion of active population engaged in farming, proportion of unemployed, percentage of illiteracy, and province). Using log-linear models, we examined relative risk for each area and trends in risk with increasing proximity to an installation. The results reveal a pattern of solid-tumor mortality in the vicinity of uranium cycle facilities, basically characterized by excess lung [relative risk (RR) 1.12, 95% confidence interval (CI), 1.02-1.25] and renal cancer mortality (RR 1.37, 95% CI, 1.07-1.76). Besides the effects of natural radiation, these results could well be evincing the influence on public health exerted by the environmental impact of mining. No such well-defined pattern appeared in the vicinity of nuclear power plants. Monitoring of cancer incidence and mortality is recommended in areas surrounding nuclear fuel facilities and nuclear power plants, and more specific studies are called for in areas adjacent to installations that have been fully operational for longer periods. In this regard, it is important to use dosimetric information in all future studies. PMID:11485872

  9. Proposed BMPs for Invasive Plant Mitigation during Timber Harvesting Operations

    Treesearch

    Chris B. LeDoux; Danielle K. Martin

    2013-01-01

    The invasion and spread of invasive plants is a major problem in forested ecosystems. Invasive plants can displace existing vegetation and in some cases take over the site. With the displacement of native vegetation come major ecosystem changes that may jeopardize ecological processes and functions as well as habitat for wildlife. The disturbance caused during timber...

  10. 75 FR 73135 - Southern Nuclear Operating Company, Inc. Joseph M. Farley Nuclear Plant, Environmental Assessment...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-29

    ... effect radiation exposures to plant workers and members of the public. The proposed action does not... are needed. No effects on the aquatic or terrestrial habitat in the vicinity of the plant, or to... COMMISSION Southern Nuclear Operating Company, Inc. Joseph M. Farley Nuclear Plant, Environmental Assessment...

  11. 75 FR 14638 - FirstEnergy Nuclear Operating Company; Perry Nuclear Power Plant; Environmental Assessment and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-26

    ...). There will be no change to radioactive effluents that effect radiation exposures to plant workers and... would not significantly affect plant safety and would not have a significant adverse effect on the... COMMISSION FirstEnergy Nuclear Operating Company; Perry Nuclear Power Plant; Environmental Assessment and...

  12. 78 FR 46255 - Revisions to Environmental Review for Renewal of Nuclear Power Plant Operating Licenses; Correction

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-31

    ... COMMISSION 10 CFR Part 51 RIN 3150-AI42 Revisions to Environmental Review for Renewal of Nuclear Power Plant... environmental effect of renewing the operating license of a nuclear power plant. Compliance with the provisions... nuclear power plant. This document is necessary to clarify and correct the revisions made to the...

  13. Manipulation of the Xanthophyll Cycle Increases Plant Susceptibility to Sclerotinia sclerotiorum

    PubMed Central

    Zhou, Jun; Zeng, Lizhang; Liu, Jian; Xing, Da

    2015-01-01

    The xanthophyll cycle is involved in dissipating excess light energy to protect the photosynthetic apparatus in a process commonly assessed from non-photochemical quenching (NPQ) of chlorophyll fluorescence. Here, it is shown that the xanthophyll cycle is modulated by the necrotrophic pathogen Sclerotinia sclerotiorum at the early stage of infection. Incubation of Sclerotinia led to a localized increase in NPQ even at low light intensity. Further studies showed that this abnormal change in NPQ was closely correlated with a decreased pH caused by Sclerotinia-secreted oxalate, which might decrease the ATP synthase activity and lead to a deepening of thylakoid lumen acidification under continuous illumination. Furthermore, suppression (with dithiothreitol) or a defect (in the npq1-2 mutant) of violaxanthin de-epoxidase (VDE) abolished the Sclerotinia-induced NPQ increase. HPLC analysis showed that the Sclerotinia-inoculated tissue accumulated substantial quantities of zeaxanthin at the expense of violaxanthin, with a corresponding decrease in neoxanthin content. Immunoassays revealed that the decrease in these xanthophyll precursors reduced de novo abscisic acid (ABA) biosynthesis and apparently weakened tissue defense responses, including ROS induction and callose deposition, resulting in enhanced plant susceptibility to Sclerotinia. We thus propose that Sclerotinia antagonizes ABA biosynthesis to suppress host defense by manipulating the xanthophyll cycle in early pathogenesis. These findings provide a model of how photoprotective metabolites integrate into the defense responses, and expand the current knowledge of early plant-Sclerotinia interactions at infection sites. PMID:25993128

  14. 75 FR 16869 - Entergy Nuclear Operations, LLC; Palisades Nuclear Plant; Exemption

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-02

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Entergy Nuclear Operations, LLC; Palisades Nuclear Plant; Exemption 1.0 Background Entergy Nuclear... operation of Palisades Nuclear Plant (PNP). The license provides, among other things, that the facility...

  15. Operation of Wastewater Treatment Plants: A Field Study Training Program. Volume I. Second Edition.

    ERIC Educational Resources Information Center

    California State Univ., Sacramento. Dept. of Civil Engineering.

    This manual was prepared by experienced wastewater collection system workers to provide a home study course to develop new qualified workers and expand the abilities of existing workers. This volume is directed primarily towards entry-level operators and the operators of ponds, package plants, or small treatment plants. Ten chapters examine the…

  16. 75 FR 38564 - Advisory Committee on Reactor Safeguards (ACRS) Meeting of the Subcommittee on Plant Operations...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-02

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Advisory Committee on Reactor Safeguards (ACRS) Meeting of the Subcommittee on Plant Operations and Fire Protection The ACRS Subcommittee on Plant Operations and Fire Protection will hold a...

  17. Operation of Wastewater Treatment Plants: A Field Study Training Program. Volume I. Second Edition.

    ERIC Educational Resources Information Center

    California State Univ., Sacramento. Dept. of Civil Engineering.

    This manual was prepared by experienced wastewater collection system workers to provide a home study course to develop new qualified workers and expand the abilities of existing workers. This volume is directed primarily towards entry-level operators and the operators of ponds, package plants, or small treatment plants. Ten chapters examine the…

  18. 9 CFR 354.26 - Schedule of operation of official plants.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... plants. 354.26 Section 354.26 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT... AND VOLUNTARY INSPECTION AND CERTIFICATION VOLUNTARY INSPECTION OF RABBITS AND EDIBLE PRODUCTS THEREOF Performance of Services § 354.26 Schedule of operation of official plants. Inspection operating schedules for...

  19. 9 CFR 354.26 - Schedule of operation of official plants.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... plants. 354.26 Section 354.26 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT... AND VOLUNTARY INSPECTION AND CERTIFICATION VOLUNTARY INSPECTION OF RABBITS AND EDIBLE PRODUCTS THEREOF Performance of Services § 354.26 Schedule of operation of official plants. Inspection operating schedules for...

  20. 9 CFR 354.26 - Schedule of operation of official plants.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... plants. 354.26 Section 354.26 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT... AND VOLUNTARY INSPECTION AND CERTIFICATION VOLUNTARY INSPECTION OF RABBITS AND EDIBLE PRODUCTS THEREOF Performance of Services § 354.26 Schedule of operation of official plants. Inspection operating schedules for...

  1. 9 CFR 354.210 - Minimum standards for sanitation, facilities, and operating procedures in official plants.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 9 Animals and Animal Products 2 2013-01-01 2013-01-01 false Minimum standards for sanitation, facilities, and operating procedures in official plants. 354.210 Section 354.210 Animals and Animal Products... sanitation, facilities, and operating procedures in official plants. The provisions of §§ 354.210 to...

  2. 9 CFR 354.210 - Minimum standards for sanitation, facilities, and operating procedures in official plants.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 9 Animals and Animal Products 2 2012-01-01 2012-01-01 false Minimum standards for sanitation, facilities, and operating procedures in official plants. 354.210 Section 354.210 Animals and Animal Products... sanitation, facilities, and operating procedures in official plants. The provisions of §§ 354.210 to...

  3. 9 CFR 354.210 - Minimum standards for sanitation, facilities, and operating procedures in official plants.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 9 Animals and Animal Products 2 2014-01-01 2014-01-01 false Minimum standards for sanitation, facilities, and operating procedures in official plants. 354.210 Section 354.210 Animals and Animal Products... sanitation, facilities, and operating procedures in official plants. The provisions of §§ 354.210 to...

  4. 9 CFR 354.210 - Minimum standards for sanitation, facilities, and operating procedures in official plants.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Minimum standards for sanitation, facilities, and operating procedures in official plants. 354.210 Section 354.210 Animals and Animal Products... sanitation, facilities, and operating procedures in official plants. The provisions of §§ 354.210 to...

  5. 9 CFR 354.210 - Minimum standards for sanitation, facilities, and operating procedures in official plants.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 9 Animals and Animal Products 2 2011-01-01 2011-01-01 false Minimum standards for sanitation, facilities, and operating procedures in official plants. 354.210 Section 354.210 Animals and Animal Products... sanitation, facilities, and operating procedures in official plants. The provisions of §§ 354.210 to...

  6. Rapid nutrient cycling in leaf litter from invasive plants in Hawai'i.

    PubMed

    Allison, Steven D; Vitousek, Peter M

    2004-12-01

    Physiological traits that contribute to the establishment and spread of invasive plant species could also have impacts on ecosystem processes. The traits prevalent in many invasive plants, such as high specific leaf areas, rapid growth rates, and elevated leaf nutrient concentrations, improve litter quality and should increase rates of decomposition and nutrient cycling. To test for these ecosystem impacts, we measured initial leaf litter properties, decomposition rates, and nutrient dynamics in 11 understory plants from the Hawaiian islands in control and nitrogen + phosphorus fertilized plots. These included five common native species, four of which were ferns, and six aggressive invasive species, including five angiosperms and one fern. We found a 50-fold variation in leaf litter decay rates, with natives decaying at rates of 0.2-2.3 year(-1) and invaders at 1.4-9.3 year(-1). This difference was driven by very low decomposition rates in native fern litter. Fertilization significantly increased the decay rates of leaf litter from two native and two invasive species. Most invasive litter types lost nitrogen and phosphorus more rapidly and in larger quantities than comparable native litter types. All litter types except three native ferns lost nitrogen after 100 days of decomposition, and all litter types except the most recalcitrant native ferns lost >50% of initial phosphorus by the end of the experiment (204-735 days). If invasive understory plants displace native species, nutrient cycling rates could increase dramatically due to rapid decomposition and nutrient release from invasive litter. Such changes are likely to cause a positive feedback to invasion in Hawai'i because many invasive plants thrive on nutrient-rich soils.

  7. Consequential environmental life cycle assessment of a farm-scale biogas plant.

    PubMed

    Van Stappen, Florence; Mathot, Michaël; Decruyenaere, Virginie; Loriers, Astrid; Delcour, Alice; Planchon, Viviane; Goffart, Jean-Pierre; Stilmant, Didier

    2016-06-15

    Producing biogas via anaerobic digestion is a promising technology for meeting European and regional goals on energy production from renewable sources. It offers interesting opportunities for the agricultural sector, allowing waste and by-products to be converted into bioenergy and bio-based materials. A consequential life cycle assessment (cLCA) was conducted to examine the consequences of the installation of a farm-scale biogas plant, taking account of assumptions about processes displaced by biogas plant co-products (power, heat and digestate) and the uses of the biogas plant feedstock prior to plant installation. Inventory data were collected on an existing farm-scale biogas plant. The plant inputs are maize cultivated for energy, solid cattle manure and various by-products from surrounding agro-food industries. Based on hypotheses about displaced electricity production (oil or gas) and the initial uses of the plant feedstock (animal feed, compost or incineration), six scenarios were analyzed and compared. Digested feedstock previously used in animal feed was replaced with other feed ingredients in equivalent feed diets, designed to take account of various nutritional parameters for bovine feeding. The displaced production of mineral fertilizers and field emissions due to the use of digestate as organic fertilizer was balanced against the avoided use of manure and compost. For all of the envisaged scenarios, the installation of the biogas plant led to reduced impacts on water depletion and aquatic ecotoxicity (thanks mainly to the displaced mineral fertilizer production). However, with the additional animal feed ingredients required to replace digested feedstock in the bovine diets, extra agricultural land was needed in all scenarios. Field emissions from the digestate used as organic fertilizer also had a significant impact on acidification and eutrophication. The choice of displaced marginal technologies has a huge influence on the results, as have the

  8. The simulation of organic rankine cycle power plant with n-pentane working fluid

    NASA Astrophysics Data System (ADS)

    Nurhilal, Otong; Mulyana, Cukup; Suhendi, Nendi; Sapdiana, Didi

    2016-02-01

    In the steam power plant in Indonesia the dry steam from separator directly used to drive the turbin. Meanwhile, brine from the separator with low grade temperature reinjected to the earth. The brine with low grade temperature can be converted indirectly to electrical power by organic Rankine cycle (ORC) methods. In ORC power plant the steam are released from vaporization of organic working fluid by brine. The steam released are used to drive an turbine which in connected to generator to convert the mechanical energy into electric energy. The objective of this research is the simulation ORC power plant with n-pentane as organic working fluid. The result of the simulation for brine temperature around 165°C and the pressure 8.001 bar optained the net electric power around 1173 kW with the cycle thermal efficiency 14.61% and the flow rate of n-pentane around 15.51 kg/s. This result enable to applied in any geothermal source in Indonesia.

  9. Intraspecific genetic diversity modulates plant-soil feedback and nutrient cycling.

    PubMed

    Semchenko, Marina; Saar, Sirgi; Lepik, Anu

    2017-10-01

    Plant genetic diversity can affect ecosystem functioning by enhancing productivity, litter decomposition and resistance to natural enemies. However, the mechanisms underlying these effects remain poorly understood. We hypothesized that genetic diversity may influence ecosystem processes by eliciting functional plasticity among individuals encountering kin or genetically diverse neighbourhoods. We used soil conditioned by groups of closely related (siblings) and diverse genotypes of Deschampsia cespitosa - a species known to exhibit kin recognition via root exudation - to investigate the consequences of kin interactions for root litter decomposition and negative feedback between plants and soil biota. Genetically diverse groups produced root litter that had higher nitrogen (N) content, decomposed faster and resulted in greater N uptake by the next generation of seedlings compared with litter produced by sibling groups. However, a similar degree of negative soil feedback on plant productivity was observed in soil conditioned by siblings and genetically diverse groups. This suggests that characteristics of roots produced by sibling groups slow down N cycling but moderate the expected negative impact of soil pathogens in low-diversity stands. These findings highlight interactions between neighbouring genotypes as an overlooked mechanism by which genetic diversity can affect biotic soil feedback and nutrient cycling. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

  10. Tracing entire operation cycles of molecular motor hepatitis C virus helicase in structurally resolved dynamical simulations

    PubMed Central

    Flechsig, Holger; Mikhailov, Alexander S.

    2010-01-01

    Hepatitis C virus helicase is a molecular motor that splits duplex DNA while actively moving over it. An approximate coarse-grained dynamical description of this protein, including its interactions with DNA and ATP, is constructed. Using such a mechanical model, entire operation cycles of an important protein machine could be followed in structurally resolved dynamical simulations. Ratcheting inchworm translocation and spring-loaded DNA unwinding, suggested by experimental data, were reproduced. Thus, feasibility of coarse-grained simulations, bridging a gap between full molecular dynamics and reduced phenomenological theories of molecular motors, has been demonstrated. PMID:21081697

  11. 99 W mid-IR operation of a ZGP OPO at 25% duty cycle.

    PubMed

    Hemming, Alexander; Richards, Jim; Davidson, Alan; Carmody, Neil; Bennetts, Shayne; Simakov, Nikita; Haub, John

    2013-04-22

    We have demonstrated the highest reported output power from a mid-IR ZGP OPO. The laser is a cascaded hybrid system consisting of a thulium fibre laser, Ho:YAG solid state laser and a Zinc Germanium Phosphide parametric oscillator. The system produces 27 W of output power in the 3-5 μm wavelength range with an M(2) = 4.0 when operating in a repetitively q-switched mode, and a modulated peak output power of 99 W at a reduced duty cycle of 25%.

  12. The thermodynamic cycle models for geothermal power plants by considering the working fluid characteristic

    NASA Astrophysics Data System (ADS)

    Mulyana, Cukup; Adiprana, Reza; Saad, Aswad H.; M. Ridwan, H.; Muhammad, Fajar

    2016-02-01

    The scarcity of fossil energy accelerates the development of geothermal power plant in Indonesia. The main issue is how to minimize the energy loss from the geothermal working fluid so that the power generated can be increased. In some of geothermal power plant, the hot water which is resulted from flashing is flown to injection well, and steam out from turbine is condensed in condenser, while the temperature and pressure of the working fluid is still high. The aim of this research is how the waste energy can be re-used as energy source to generate electric power. The step of the research is started by studying the characteristics of geothermal fluid out from the well head. The temperature of fluid varies from 140°C - 250°C, the pressure is more than 7 bar and the fluid phase are liquid, gas, or mixing phase. Dry steam power plant is selected for vapor dominated source, single or multiple flash power plant is used for dominated water with temperature > 225°C, while the binary power plant is used for low temperature of fluid < 160°C. Theoretically, the process in the power plant can be described by thermodynamic cycle. Utilizing the heat loss of the brine and by considering the broad range of working fluid temperature, the integrated geothermal power plant has been developed. Started with two ordinary single flash power plants named unit 1 and unit 2, with the temperature 250°C resulting power is W1'+W2'. The power is enhanced by utilizing the steam that is out from first stage of the turbine by inputting the steam to the third stage, the power of the plant increase with W1''+W2" or 10% from the original power. By using flasher, the water from unit 1 and 2 is re-flashed at 200°C, and the steam is used to drive the turbine in unit 3, while the water is re-flashed at the temperature170°C and the steam is flown to the same turbine (unit 3) resulting the power of W3+W4. Using the fluid enthalpy, the calculated power of these double and triple flash power plant

  13. MYB3Rs, plant homologs of Myb oncoproteins, control cell cycle-regulated transcription and form DREAM-like complexes.

    PubMed

    Kobayashi, Kosuke; Suzuki, Toshiya; Iwata, Eriko; Magyar, Zoltán; Bögre, László; Ito, Masaki

    2015-01-01

    Plant MYB3R transcription factors, homologous to Myb oncoproteins, regulate the genes expressed at G2 and M phases in the cell cycle. Recent studies showed that MYB3Rs constitute multiprotein complexes that may correspond to animal complexes known as DREAM or dREAM. Discovery of the putative homologous complex in plants uncovered their significant varieties in structure, function, dynamics, and heterogeneity, providing insight into conserved and diversified aspects of cell cycle-regulated gene transcription.

  14. Organic Rankine Cycle for Residual Heat to Power Conversion in Natural Gas Compressor Station. Part II: Plant Simulation and Optimisation Study

    NASA Astrophysics Data System (ADS)

    Chaczykowski, Maciej

    2016-06-01

    After having described the models for the organic Rankine cycle (ORC) equipment in the first part of this paper, this second part provides an example that demonstrates the performance of different ORC systems in the energy recovery application in a gas compressor station. The application shows certain specific characteristics, i.e. relatively large scale of the system, high exhaust gas temperature, low ambient temperature operation, and incorporation of an air-cooled condenser, as an effect of the localization in a compressor station plant. Screening of 17 organic fluids, mostly alkanes, was carried out and resulted in a selection of best performing fluids for each cycle configuration, among which benzene, acetone and heptane showed highest energy recovery potential in supercritical cycles, while benzene, toluene and cyclohexane in subcritical cycles. Calculation results indicate that a maximum of 10.4 MW of shaft power can be obtained from the exhaust gases of a 25 MW compressor driver by the use of benzene as a working fluid in the supercritical cycle with heat recuperation. In relation to the particular transmission system analysed in the study, it appears that the regenerative subcritical cycle with toluene as a working fluid presents the best thermodynamic characteristics, however, require some attention insofar as operational conditions are concerned.

  15. The Importance of the Microbial N Cycle in Soil for Crop Plant Nutrition.

    PubMed

    Hirsch, Penny R; Mauchline, Tim H

    2015-01-01

    Nitrogen is crucial for living cells, and prior to the introduction of mineral N fertilizer, fixation of atmospheric N2 by diverse prokaryotes was the primary source of N in all ecosystems. Microorganisms drive the N cycle starting with N2 fixation to ammonia, through nitrification in which ammonia is oxidized to nitrate and denitrification where nitrate is reduced to N2 to complete the cycle, or partially reduced to generate the greenhouse gas nitrous oxide. Traditionally, agriculture has relied on rotations that exploited N fixed by symbiotic rhizobia in leguminous plants, and recycled wastes and manures that microbial activity mineralized to release ammonia or nitrate. Mineral N fertilizer provided by the Haber-Bosch process has become essential for modern agriculture to increase crop yields and replace N removed from the system at harvest. However, with the increasing global population and problems caused by unintended N wastage and pollution, more sustainable ways of managing the N cycle in soil and utilizing biological N2 fixation have become imperative. This review describes the biological N cycle and details the steps and organisms involved. The effects of various agricultural practices that exploit fixation, retard nitrification, and reduce denitrification are presented, together with strategies that minimize inorganic fertilizer applications and curtail losses. The development and implementation of new technologies together with rediscovering traditional practices are discussed to speculate how the grand challenge of feeding the world sustainably can be met. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. Dynamics and control modeling of the closed-cycle gas turbine (GT-HTGR) power plant

    SciTech Connect

    Bardia, A.

    1980-02-01

    The simulation if presented for the 800-MW(e) two-loop GT-HTGR plant design with the REALY2 transient analysis computer code, and the modeling of control strategies called for by the inherently unique operational requirements of a multiple loop GT-HTGR is described. Plant control of the GT-HTGR is constrained by the nature of its power conversion loops (PCLs) in which the core cooling flow and the turbine flow are directly related and thus changes in flow affect core cooling as well as turbine power. Additionally, the high thermal inertia of the reactor core precludes rapid changes in the temperature of the turbine inlet flow.

  17. Monitoring of Plant Light/Dark Cycles Using Air-coupled Ultrasonic Spectroscopy

    NASA Astrophysics Data System (ADS)

    Fariñas, M. D.; Sancho-Knapik, D.; Peguero-Pina, J.; Gil-Pelegrín, E.; Álvarez-Arenas, T. E. G.

    This work presents the application of a technique based on the excitation, sensing and spectral analysis of leaves thickness resonances using air-coupled and wide-band ultrasound to monitor variations in leaves properties due to the plant response along light/dark cycles. The main features of these resonances are determined by the tautness of the cells walls in such a way that small modifications produced by variations in the transpiration rate, stomata aperture or water potential have a direct effect on the thickness resonances that can be measured in a completely non-invasive and contactless way. Results show that it is possible to monitor leaves changes due to variations in light intensity along the diurnal cycle, moreover, the technique reveals differences in the leaf response for different species and also within the same species but for specimens grown under different conditions that present different cell structures at the tissue level.

  18. Theoretical operational life study of the closed-cycle transversely excited atmospheric CO2 laser

    NASA Astrophysics Data System (ADS)

    Hokazono, Hirokazu; Obara, Minoru; Midorikawa, Katsumi; Tashiro, Hideo

    1991-05-01

    The operational characteristics of a high-power closed-cycle transversely excited atmospheric CO2 laser are investigated kinetically. The fractional CO2/N2, molecules decomposition, and concentration of minor impurities accumulated in the laser gas mixture are calculated theoretically as a function of shots and number of repetitive discharge pulses. It is shown that the laser output peak power decreases in proportion to the fractional CO2 decomposition, while nitrogen oxides are found to show little effect on the operational E/N. The theoretical model employed specifies that a trace of water vapor in the laser chamber suppresses the CO2 decomposition due to fact that CO2 reforming is enhanced by OH radicals. As far as ultraviolet preionization is concerned, its absorption depth of the laser gas mixture decreases as the CO2 decomposition increases.

  19. STS-1 operational flight profile. Volume 5: Descent, cycle 3. Appendix C: Monte Carlo dispersion analysis

    NASA Technical Reports Server (NTRS)

    1980-01-01

    The results of three nonlinear the Monte Carlo dispersion analyses for the Space Transportation System 1 Flight (STS-1) Orbiter Descent Operational Flight Profile, Cycle 3 are presented. Fifty randomly selected simulation for the end of mission (EOM) descent, the abort once around (AOA) descent targeted line are steep target line, and the AOA descent targeted to the shallow target line are analyzed. These analyses compare the flight environment with system and operational constraints on the flight environment and in some cases use simplified system models as an aid in assessing the STS-1 descent flight profile. In addition, descent flight envelops are provided as a data base for use by system specialists to determine the flight readiness for STS-1. The results of these dispersion analyses supersede results of the dispersion analysis previously documented.

  20. Improved cycling behavior of ZEBRA battery operated at intermediate temperature of 175°C

    SciTech Connect

    Li, Guosheng; Lu, Xiaochuan; Kim, Jin Yong; Lemmon, John P.; Sprenkle, Vincent L.

    2014-03-01

    Operation of sodium-nickel chloride battery at temperatures lower than 200°C reduces cell degradation and improves the cyclability. One of the main technical issues in terms of operating this battery at intermediate temperatures such as 175°C is the poor wettability of molten sodium on β”-alumina solid electrolyte (BASE) causing reduced active area and limited charging . In order to overcome the problem related to poor wettability of Na melt on BASE at 175°C, Pt grid was applied on the anode side of BASE using a screen printing technique. Deeper charging and improved cycling behavior was observed on the cells with metalized BASEs due to extended active area.

  1. Influence of data collection schemes on the Life Cycle Assessment of a municipal wastewater treatment plant.

    PubMed

    Yoshida, Hiroko; Clavreul, Julie; Scheutz, Charlotte; Christensen, Thomas H

    2014-06-01

    A Life Cycle Assessment (LCA) of a municipal wastewater treatment plant (WWTP) was conducted to illustrate the effect of an emission inventory data collection scheme on the outcomes of an environmental impact assessment. Due to their burden in respect to data collection, LCAs often rely heavily on existing emission and operational data, which are gathered under either compulsory monitoring or reporting requirements under law. In this study, an LCA was conducted using three input data sources: Information compiled under compulsory disclosure requirements (the European Pollutant Release and Transfer Registry), compliance with national discharge limits, and a state-of-the-art emission data collection scheme conducted at the same WWTP. Parameter uncertainty for each collection scheme was assessed through Monte Carlo simulation. The comparison of the results confirmed that LCA results depend heavily on input data coverage. Due to the threshold on reporting value, the E-PRTR did not capture the impact for particulate matter emission, terrestrial acidification, or terrestrial eutrophication. While the current practice can capture more than 90% of non-carcinogenic human toxicity and marine eutrophication, an LCA based on the data collection scheme underestimates impact potential due to limitations of substance coverage. Besides differences between data collection schemes, the results showed that 3-13,500% of the impacts came from background systems, such as from the provisioning of fuel, electricity, and chemicals, which do not need to be disclosed currently under E-PRTR. The incidental release of pollutants was also assessed by employing a scenario-based approach, the results of which demonstrated that these non-routine emissions could increase overall WWTP greenhouse gas emissions by between 113 and 210%. Overall, current data collection schemes have the potential to provide standardized data collection and form the basis for a sound environmental impact assessment, but

  2. Operational results of an agricultural biogas plant equipped with modern instrumentation and automation.

    PubMed

    Wiese, J; Kujawski, O

    2008-01-01

    Agricultural biogas plants based on energy crops gain more and more importance because of numerous energetic, environmental and agricultural benefits. In contrast to older biogas plants, the newest generation of biogas plants is equipped with modern ICA equipment and reliable machines/engines. In this paper, the authors present technical details and operational results of a modern full-scale agricultural biogas plant using energy crops.

  3. Thermal analysis of a solar pond power plant operated with a direct contact boiler

    NASA Astrophysics Data System (ADS)

    Sonn, A.; Letan, R.

    1981-11-01

    A solar pond power plant operated with a direct contact boiler was thermally analyzed. A binary cycle system of concentrated brine, and an organic working fluid were considered. Brine temperature of 80 C, condensation at 30 C, a 75 percent efficient turbine, and 70 percent efficient pumps were specified for the analysis. The current study involved six working fluids: butane, pentane, hexane, and freons R113, R114, R12. Each of these fluids exhibited a maximum efficiency of the system at characteristic operating conditions of the boiler. The system efficiency increased as the boiler pressure approached that of the pond. Net electrical outputs of 7-9 percent of the heat inputs were obtained for the low pressure fluids, such as pentane, hexane, and R113. Gravity flow of brine to boiler increased these values to 8-11 percent. Solute losses in brine by direct contact in boiler were estimated for pentane, as 125 kg per year per sq km of pond, or 63 kg/MWe-year. Similar orders of magnitude are obtained for the other fluids.

  4. Water chemistry of a combined-cycle power plant's auxiliary equipment cooling system

    NASA Astrophysics Data System (ADS)

    Larin, B. M.; Korotkov, A. N.; Oparin, M. Yu.; Larin, A. B.

    2013-04-01

    Results from an analysis of methods aimed at reducing the corrosion rate of structural metal used in heat-transfer systems with water coolant are presented. Data from examination of the closed-circuit system for cooling the auxiliary mechanisms of a combined-cycle plant-based power unit and the results from adjustment of its water chemistry are given. A conclusion is drawn about the possibility of using a reagent prepared on the basis of sodium sulfite for reducing the corrosion rate when the loss of coolant is replenished with nondeaerated water.

  5. Value as a parameter to consider in operational strategies for CSP plants

    NASA Astrophysics Data System (ADS)

    de Meyer, Oelof; Dinter, Frank; Govender, Saneshan

    2017-06-01

    This paper introduced a value parameter to consider when analyzing operational strategies for CSP plants. The electric system in South Africa, used as case study, is severely constrained with an influx of renewables in the early phase of deployment. The energy demand curve for the system is analyzed showing the total wind and solar photovoltaic contributions for winter and summer. Due to the intermittent nature and meteorological operating conditions of wind and solar photovoltaic plants, the value of CSP plants within the electric system is introduced. Analyzing CSP plants based on the value parameter alone will remain only a philosophical view. Currently there is no quantifiable measure to translate the philosophical view or subjective value and it solely remains the position of the stakeholder. By introducing three other parameters, Cost, Plant and System to a holistic representation of the Operating Strategies of generation plants, the Value parameter can be translated into a quantifiable measure. Utilizing the country's current procurement program as case study, CSP operating under the various PPA within the Bid Windows are analyzed. The Value Cost Plant System diagram developed is used to quantify the value parameter. This paper concluded that no value is obtained from CSP plants operating under the Bid Window 1 & 2 Power Purchase Agreement. However, by recognizing the dispatchability potential of CSP plants in Bid Window 3 & 3.5, the value of CSP in the electric system can be quantified utilizing Value Added Relationship VCPS-diagram. Similarly ancillary services to the system were analyzed. One of the relationships that have not yet been explored within the industry is an interdependent relationship. It was emphasized that the cost and value structure is shared between the plant and system. Although this relationship is functional when the plant and system belongs to the same entity, additional value is achieved by marginalizing the cost structure. A

  6. Optimization of wastewater treatment plant operation for greenhouse gas mitigation.

    PubMed

    Kim, Dongwook; Bowen, James D; Ozelkan, Ertunga C

    2015-11-01

    This study deals with the determination of optimal operation of a wastewater treatment system for minimizing greenhouse gas emissions, operating costs, and pollution loads in the effluent. To do this, an integrated performance index that includes three objectives was established to assess system performance. The ASMN_G model was used to perform system optimization aimed at determining a set of operational parameters that can satisfy three different objectives. The complex nonlinear optimization problem was simulated using the Nelder-Mead Simplex optimization algorithm. A sensitivity analysis was performed to identify influential operational parameters on system performance. The results obtained from the optimization simulations for six scenarios demonstrated that there are apparent trade-offs among the three conflicting objectives. The best optimized system simultaneously reduced greenhouse gas emissions by 31%, reduced operating cost by 11%, and improved effluent quality by 2% compared to the base case operation.

  7. Enterprise SRS: leveraging ongoing operations to advance nuclear fuel cycles research and development programs

    SciTech Connect

    Murray, A.M.; Marra, J.E.; Wilmarth, W.R.; McGuire, P.W.; Wheeler, V.B.

    2013-07-01

    The Savannah River Site (SRS) is re-purposing its vast array of assets (including H Canyon - a nuclear chemical separation plant) to solve issues regarding advanced nuclear fuel cycle technologies, nuclear materials processing, packaging, storage and disposition. The vehicle for this transformation is Enterprise SRS which presents a new, radical view of SRS as a united endeavor for 'all things nuclear' as opposed to a group of distinct and separate entities with individual missions and organizations. Key among the Enterprise SRS strategic initiatives is the integration of research into SRS facilities but also in other facilities in conjunction with on-going missions to provide researchers from other national laboratories, academic institutions, and commercial entities the opportunity to demonstrate their technologies in a relevant environment and scale prior to deployment. To manage that integration of research demonstrations into site facilities, a center for applied nuclear materials processing and engineering research has been established in SRS.

  8. Cycle-time equations for five small tractors operating in low-volume small-diameter hardwood stands

    Treesearch

    Chris B. LeDoux; Neil K. Huyler; Neil K. Huyler

    1992-01-01

    Prediction equations for estimating cycle time were developed for five small tractors studied under various silvicultural treatments and operating conditions. The tractors studied included the Pasquali 933, a Holder A60F, a Forest Ant Forwarder (Skogsman), a Massey-Ferguson, and a Sam4 Minitarus. Skidding costs were estimated based on the cycle-time equations. Using...

  9. Changes in vascular plant functional types drive carbon cycling in peatlands

    NASA Astrophysics Data System (ADS)

    Zeh, Lilli; Bragazza, Luca; Erhagen, Björn; Limpens, Juul; Kalbitz, Karsten

    2016-04-01

    Northern peatlands store a large organic carbon (C) pool that is highly exposed to future environmental changes with consequent risk of releasing enormous amounts of C. Biotic changes in plant community structure and species abundance might have an even stronger impact on soil organic C dynamics in peatlands than the direct effects of abiotic changes. Therefore, a sound understanding of the impact of vegetation dynamics on C cycling will help to better predict the response of peatlands to environmental changes. Here, we aimed to assess the role of plant functional types (PFTs) in affecting peat decomposition in relation to climate warming. To this aim, we selected two peatlands at different altitude (i.e. 1300 and 1700 m asl) on the south-eastern Alps of Italy. The two sites represent a contrast in temperature, overall vascular plant biomass and relative ericoids abundance, with the highest biomass and ericoids occurrence at the low latitude. Within the sites we selected 20 plots of similar microtopographical position and general vegetation type (hummocks). All plots contained both graminoids and ericoids and had a 100% cover of Sphagnum mosses. The plots were subjected to four treatments (control, and three clipping treatments) in which we selectively removed aboveground biomass of ericoids, graminoids or both to explore the contribution of the different PFTs for soil respiration (n=5) and peat chemistry. Peat chemical composition was determined by the analysis of C and N and their stable isotopes in association with pyrolysis GC/MS. Soil respiration was measured after clipping with a Licor system. Preliminary findings suggest that peat decomposition pathway and rate depend on plant species composition and particularly on differences in root activity between PFTs. Finally, this study underlines the importance of biotic drivers to predict the effects of future environmental changes on peatland C cycling.

  10. An RF energy harvesting power management circuit for appropriate duty-cycled operation

    NASA Astrophysics Data System (ADS)

    Shirane, Atsushi; Ito, Hiroyuki; Ishihara, Noboru; Masu, Kazuya

    2015-04-01

    In this study, we present an RF energy harvesting power management unit (PMU) for battery-less wireless sensor devices (WSDs). The proposed PMU realizes a duty-cycled operation that is divided into the energy charging time and discharging time. The proposed PMU detects two types of timing, thus, the appropriate timing for the activation can be recognized. The activation of WSDs at the proper timing leads to energy efficient operation and stable wireless communication. The proposed PMU includes a hysteresis comparator (H-CMP) and an RF signal detector (RF-SD) to detect the timings. The proposed RF-SD can operate without the degradation of charge efficiency by reusing the RF energy harvester (RF-EH) and H-CMP. The PMU fabricated in a 180 nm Si CMOS demonstrated the charge operation using the RF signal at 915 MHz and the two types of timing detection with less than 124 nW in the charge phase. Furthermore, in the active phase, the PMU generates a 0.5 V regulated power supply from the charged energy.

  11. Scenarios for low carbon and low water electric power plant operations: implications for upstream water use

    EPA Science Inventory

    In the water-energy nexus, water use for the electric power sector is critical. Currently, the operational phase of electric power production dominates the electric sector's life cycle withdrawal and consumption of fresh water resources. Water use associated with the fuel cycle a...

  12. Scenarios for low carbon and low water electric power plant operations: implications for upstream water use

    EPA Science Inventory

    In the water-energy nexus, water use for the electric power sector is critical. Currently, the operational phase of electric power production dominates the electric sector's life cycle withdrawal and consumption of fresh water resources. Water use associated with the fuel cycle a...

  13. Carbon dioxide control costs for gasification combined-cycle plants in the United States

    SciTech Connect

    Brown, D.R.; Humphreys, K.K.; Vail, L.W.

    1993-06-01

    This study focused on evaluating the cost of recovering CO{sub 2} from coal gasification, combined-cycle (GCC) power plants and transporting the CO{sub 2} in pipelines for disposal in deep ocean water, depleted oil and gas reservoirs, or aquifers. Other fuels and conversion technologies were not evaluated. Technical feasibility, environmental acceptability, and other implementation issues were not addressed in detail. Ocean disposal of CO{sub 2} offers essentially unlimited capacity, but is distant from most US coal-fired power plants and presents environmental concerns at the disposal point. Depleted oil and gas reservoirs are also distant from most US coal-fired power plants and have a more limited disposal capacity,, but were calculated to have a potential capacity more than double that required to dispose of all CO{sub 2} from 830 GCC power plants (380-mwe each) for a period of 40 years. The existence of oil and gas reservoirs provides ``proof`` of the long-term CO{sub 2} confinement potential in these formations. In contrast, aquifer disposal is believed to be significantly riskier. Key concerns are lack of geologic knowledge at depths adequate for CO{sub 2} disposal; uncertainty about geochemical impacts from decreased water pH; and long-term confinement, which is unproven for non-petroleum formations. Carbon dioxide recovery at GCC plants increased the levelized energy cost (LEC) by about one third relative to a reference GCC plant without CO{sub 2} recovery. The transmission distance is the key factor affecting total CO{sub 2} control costs.

  14. Remote detection of forest C and N cycling and the convergent properties of plants

    NASA Astrophysics Data System (ADS)

    Ollinger, S. V.; Lepine, L. C.; Wicklein, H. F.; Sullivan, F. B.

    2011-12-01

    How plants interact with sunlight is central to the existence of life and provides a window to the biogeochemical functioning of ecosystems. Although relationships between leaf reflectance, leaf chemistry and photosynthetic efficiency have been known for decades, interpreting canopy-level spectra is more challenging because leaf-level effects are complicated by a host of stem- and canopy-level traits. Progress has been made through empirical analyses and models, although both methods have been hampered by a series of persistent challenges. Here, we review current understanding of plant spectral properties with respect to carbon and nitrogen dynamics at leaf to canopy scales. We also discuss the role of evolutionary convergence in plant functioning and the difficulty of identifying individual properties related to C and N cycling among a suite of interrelated traits. A pattern that emerges suggests a synergy among the scattering effects of leaf-, stem- and canopy-level traits that becomes most apparent in the near-infrared (NIR) region. This explains the widespread and well-known importance of the NIR region in vegetation remote sensing, but presents an interesting paradox that has yet to be fully explored: that we can often gain more insight about the functioning of plants by examining wavelengths that are not used in photosynthesis than by examining those that are.

  15. Uncovering the abilities of Agaricus bisporus to degrade plant biomass throughout its life cycle.

    PubMed

    Patyshakuliyeva, Aleksandrina; Post, Harm; Zhou, Miaomiao; Jurak, Edita; Heck, Albert J R; Hildén, Kristiina S; Kabel, Mirjam A; Mäkelä, Miia R; Altelaar, Maarten A F; de Vries, Ronald P

    2015-08-01

    The economically important edible basidiomycete mushroom Agaricus bisporus thrives on decaying plant material in forests and grasslands of North America and Europe. It degrades forest litter and contributes to global carbon recycling, depolymerizing (hemi-)cellulose and lignin in plant biomass. Relatively little is known about how A. bisporus grows in the controlled environment in commercial production facilities and utilizes its substrate. Using transcriptomics and proteomics, we showed that changes in plant biomass degradation by A. bisporus occur throughout its life cycle. Ligninolytic genes were only highly expressed during the spawning stage day 16. In contrast, (hemi-)cellulolytic genes were highly expressed at the first flush, whereas low expression was observed at the second flush. The essential role for many highly expressed plant biomass degrading genes was supported by exo-proteome analysis. Our data also support a model of sequential lignocellulose degradation by wood-decaying fungi proposed in previous studies, concluding that lignin is degraded at the initial stage of growth in compost and is not modified after the spawning stage. The observed differences in gene expression involved in (hemi-)cellulose degradation between the first and second flushes could partially explain the reduction in the number of mushrooms during the second flush. © 2015 Society for Applied Microbiology and John Wiley & Sons Ltd.

  16. Peatland carbon cycling at a Scottish wind farm: the role of plant-soil interactions

    NASA Astrophysics Data System (ADS)

    Richardson, Harriett; Whitaker, Jeanette; Waldron, Susan; Ostle, Nick

    2013-04-01

    Peatlands play a fundamental role in the terrestrial carbon cycle by storing 1/3 of the world's soil carbon (Limpens et al. 2008). In the UK, peatlands are often located in areas with potential for electricity generation by harvesting wind energy. Concerns have been raised, however, over the stability of these carbon stocks when large scale wind developments are sited upon them. This project aims to improve understanding of the impact of wind farms on carbon sequestration in peatlands. Wind turbine 'wake-effects' can alter microclimatic conditions, as a result of significant differences in air temperature, humidity, wind speed and turbulence (Baidya Roy and Traiteur 2010). These changes are likely to have a significant impact on above and below ground abiotic conditions and biotic properties, together with the processes they regulate that govern peatland carbon cycling. Specifically, the effects of interactions between typical peatland plant functional types (graminoids, bryophytes and shrubs) (Ward et al. 2009) and peat microbial community composition and function are poorly resolved. We examined a spatial gradient across an area of blanket bog at Black Law wind farm (Lanarkshire, Scotland) and executed a series of controlled mesocosm experiments to examine the impacts of potential microclimatic changes on plant-soil interactions and carbon sequestration processes. In particular we focused on the form and function of plant and microbial communities as determinants of decomposition (Ward et al. 2010) and greenhouse gas (GHG) emissions (Artz 2009). Measurements of plant-litter-soil carbon, nitrogen, microbial community composition (i.e. phospholipid fatty acid biomarkers) and litter mass loss have been made across the wind farm peatland to attribute spatial variance in biotic and biogeochemical properties. In addition, multi-factorial mesocosm experiments have been made to determine how abiotic and biotic changes caused by wind farm effects could influence peat GHG

  17. Insights into deep-time terrestrial carbon cycle processes from modern plant isotope ecology

    NASA Astrophysics Data System (ADS)

    Sheldon, N. D.; Smith, S. Y.

    2012-12-01

    While the terrestrial biosphere and soils contain much of the readily exchangeable carbon on Earth, how those reservoirs function on long time scales and at times of higher atmospheric CO2 and higher temperatures is poorly understood, which limits our ability to make accurate future predictions of their response to anthropogenic change. Recent data compilation efforts have outlined the response of plant carbon isotope compositions to a variety of environmental factors including precipitation amount and timing, elevation, and latitude. The compilations involve numerous types of plants, typically only found at a limited number of climatic conditions. Here, we expand on those efforts by examining the isotopic response of specific plant groups found both globally and across environmental gradients including: 1) ginkgo, 2) conifers, and 3) C4 grasses. Ginkgo is presently widely distributed as a cultivated plant and the ginkgoalean fossil record spans from the Permian to the present, making it an ideal model organism to understand climatic influence on carbon cycling both in modern and ancient settings. Ginkgo leaves have been obtained from a range of precipitation conditions (400-2200 mm yr-1), including dense sampling from individuals and populations in both Mediterranean and temperate climate areas and samples of different organs and developmental stages. Ginkgo carbon isotope results plot on the global C3 plant array, are consistent among trees at single sites, among plant organs, and among development stages, making ginkgo a robust recorder of both climatic conditions and atmospheric δ13C. In contrast, a climate-carbon isotope transect in Arizona highlights that conifers (specifically, pine and juniper) record large variability between organs and have a very different δ13C slope as a function of climate than the global C3 plant array, while C4 plants have a slope with the opposite sign as a function of climate. This has a number of implications for paleo

  18. A Method to Teach Age-Specific Demography with Field Grown Rapid Cycling "Brassica rapa" (Wisconsin Fast Plants)

    ERIC Educational Resources Information Center

    Kelly, Martin G.; Terrana, Sebastian

    2004-01-01

    In this paper, we demonstrate that rapid cycling "Brassica rapa" (Wisconsin Fast Plants) can be used in inquiry-based, student ecological fieldwork. We are the first to describe age-specific survival for field-grown Fast Plants and identify life history traits associated with individual survival. This experiment can be adapted by educators as a…

  19. Fast Plants for Finer Science--An Introduction to the Biology of Rapid-Cycling Brassica Campestris (rapa) L.

    ERIC Educational Resources Information Center

    Tomkins, Stephen P.; Williams, Paul H.

    1990-01-01

    Rapid-cycling brassicas can be used in the classroom to teach concepts such as plant growth, tropisms, floral reproduction, pollination, embryonic development, and plant genetics. Directions on how to obtain them for classroom use and how they may be grown are included. Practical physiology and genetics exercises are listed. (KR)

  20. A Method to Teach Age-Specific Demography with Field Grown Rapid Cycling "Brassica rapa" (Wisconsin Fast Plants)

    ERIC Educational Resources Information Center

    Kelly, Martin G.; Terrana, Sebastian

    2004-01-01

    In this paper, we demonstrate that rapid cycling "Brassica rapa" (Wisconsin Fast Plants) can be used in inquiry-based, student ecological fieldwork. We are the first to describe age-specific survival for field-grown Fast Plants and identify life history traits associated with individual survival. This experiment can be adapted by educators as a…

  1. Optimizing modes of a small-scale combined-cycle power plant with atmospheric-pressure gasifier

    NASA Astrophysics Data System (ADS)

    Donskoi, I. G.; Marinchenko, A. Yu.; Kler, A. M.; Ryzhkov, A. F.

    2015-09-01

    The scheme of an integrated coal gasification combined-cycle power plant with small capacity is proposed. Using the built mathematical model a feasibility study of this unit was performed, taking into account the kinetics of physical and chemical transformations in the fuel bed. The estimates of technical and economic efficiency of the plant have been obtained and compared with the alternative options.

  2. Fast Plants for Finer Science--An Introduction to the Biology of Rapid-Cycling Brassica Campestris (rapa) L.

    ERIC Educational Resources Information Center

    Tomkins, Stephen P.; Williams, Paul H.

    1990-01-01

    Rapid-cycling brassicas can be used in the classroom to teach concepts such as plant growth, tropisms, floral reproduction, pollination, embryonic development, and plant genetics. Directions on how to obtain them for classroom use and how they may be grown are included. Practical physiology and genetics exercises are listed. (KR)

  3. Wind farm and solar park effects on plant-soil carbon cycling: uncertain impacts of changes in ground-level microclimate.

    PubMed

    Armstrong, Alona; Waldron, Susan; Whitaker, Jeanette; Ostle, Nicholas J

    2014-06-01

    Global energy demand is increasing as greenhouse gas driven climate change progresses, making renewable energy sources critical to future sustainable power provision. Land-based wind and solar electricity generation technologies are rapidly expanding, yet our understanding of their operational effects on biological carbon cycling in hosting ecosystems is limited. Wind turbines and photovoltaic panels can significantly change local ground-level climate by a magnitude that could affect the fundamental plant-soil processes that govern carbon dynamics. We believe that understanding the possible effects of changes in ground-level microclimates on these phenomena is crucial to reducing uncertainty of the true renewable energy carbon cost and to maximize beneficial effects. In this Opinions article, we examine the potential for the microclimatic effects of these land-based renewable energy sources to alter plant-soil carbon cycling, hypothesize likely effects and identify critical knowledge gaps for future carbon research.

  4. Design and operation of the Sandia Pilot Plant

    SciTech Connect

    Morris, M.E.

    1980-01-01

    An 8 ton/day dry sewage sludge irradiator was designed and constructed at Sandia National Laboratories in the last half of 1977 and in 1978; and was charged with /sup 137/Cs and made operational in the spring of 1979. The design of the major subsystems of the irradiator is described. Subsequent operational experiences are also summarized.

  5. STATISTICS-BASED APPROACH TO WASTEWATER TREATMENT PLANT OPERATIONS

    EPA Science Inventory

    This paper describes work toward development of a convenient decision support system to improve everyday operation and control of the wastewater treatment process. The goal is to help the operator detect problems in the process and select appropriate control actions. The system...

  6. Large CFB power plant design and operating experience: Texas-New Mexico Power Company 150 MWe (net) CFB power plant

    SciTech Connect

    Riley, K.; Cleve, K.; Tanca, M.

    1995-12-31

    The first unit of the TNP One CFB power plant was successfully put on line by Texas-New Mexico Power Company (TNP) in Robertson County, Texas, US in 1990. Unit 2 came on line one year later. This grassroots plant fires Texas lignite. The two identical CFB units were each designed for 150 MWe net electrical generation. The units have operated at 155 MWe net for extended periods of time without modifications. The boilers have additional capacity but are limited by the balance of plant. The TNP One plant was awarded the Power Plant of the Year Award by Power magazine in 1991 advancing CFB technology in large generating facilities. The plant was designed for maximum fuel flexibility with guaranteed full load operation on either Texas lignite, western coal or natural gas. The plant has fired the following fuels, to date: lignite (base fuel), natural gas (0--100% with lignite), delayed petroleum coke (0--100% with lignite), plant generated waste oils (small amounts), oil filter fluff (small amounts) and a waste product of pelletized reflective tape. Future testing is planned to test burn shredded tires. While firing all fuels, the plant could attain full load and meet all environmentally permitted emissions without any boiler modifications or compromises in boiler efficiency. This high flexibility of the plant can be attributed to the two large fluidized bed heat exchangers (FBHEs) for steam temperature and combustor temperature control. The facility is a mine mouth operation burning the local Texas lignite. The delayed petroleum cokes fired originated from various supply sources from the Texas/Louisiana area.

  7. Operation of Wastewater Treatment Plants. Volume 1. A Field Study Training Program. Third Edition. Revised.

    ERIC Educational Resources Information Center

    California State Univ., Sacramento. Dept. of Civil Engineering.

    The purpose of this wastewater treatment field study training program is to: (1) develop new qualified wastewater treatment plant operators; (2) expand the abilities of existing operators, permitting better service both to employers and public; and (3) prepare operators for civil service and certification examinations (examinations administered by…

  8. Water Treatment Plant Operation. Volume I. A Field Study Training Program.

    ERIC Educational Resources Information Center

    California State Univ., Sacramento. School of Engineering.

    The purpose of this water treatment field study training program is to: (1) develop new qualified water treatment plant operators; (2) expand the abilities of existing operators, permitting better service both to employers and public; and (3) prepare operators for civil service and certification examinations (examinations administered by…

  9. Operation of Wastewater Treatment Plants. Volume 1. A Field Study Training Program. Third Edition. Revised.

    ERIC Educational Resources Information Center

    California State Univ., Sacramento. Dept. of Civil Engineering.

    The purpose of this wastewater treatment field study training program is to: (1) develop new qualified wastewater treatment plant operators; (2) expand the abilities of existing operators, permitting better service both to employers and public; and (3) prepare operators for civil service and certification examinations (examinations administered by…

  10. 76 FR 50767 - Southern Nuclear Operating Co., et al.; Combined Licenses for Vogtle Electric Generating Plant...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-16

    ... COMMISSION Southern Nuclear Operating Co., et al.; Combined Licenses for Vogtle Electric Generating Plant... approval to construct and operate new nuclear power generation facilities at the Vogtle Electric Generating... (10 CFR) part 52 combined licenses (COLs), seeking approval to construct and operate new nuclear power...

  11. 75 FR 16524 - FirstEnergy Nuclear Operating Company, Perry Nuclear Power Plant; Exemption

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-01

    ... COMMISSION FirstEnergy Nuclear Operating Company, Perry Nuclear Power Plant; Exemption 1.0 Background FirstEnergy Nuclear Operating Company (FENOC, the licensee) is the holder of Facility Operating License No... compliance date (Reference: June 4, 2009, letter from R. W. Borchardt, NRC, to M. S. Fertel, Nuclear...

  12. Water Treatment Plant Operation Volume 2. A Field Study Training Program. Revised.

    ERIC Educational Resources Information Center

    California State Univ., Sacramento. School of Engineering.

    The purpose of this water treatment field study training program is to: (1) develop new qualified water treatment plant operators; (2) expand the abilities of existing operators, permitting better service both to employers and public; and (3) prepare operators for civil service and certification examinations (examinations administered by…

  13. Water Treatment Plant Operation. Volume II. A Field Study Training Program.

    ERIC Educational Resources Information Center

    California State Univ., Sacramento. School of Engineering.

    The purpose of this water treatment field study training program is to: (1) develop new qualified water treatment plant operators; (2) expand the abilities of existing operators, permitting better service both to employers and public; and (3) prepare operators for civil service and certification examinations (examinations administered by…

  14. Water Treatment Plant Operation. Volume II. A Field Study Training Program.

    ERIC Educational Resources Information Center

    California State Univ., Sacramento. School of Engineering.

    The purpose of this water treatment field study training program is to: (1) develop new qualified water treatment plant operators; (2) expand the abilities of existing operators, permitting better service both to employers and public; and (3) prepare operators for civil service and certification examinations (examinations administered by…

  15. Water Treatment Plant Operation. Volume I. A Field Study Training Program.

    ERIC Educational Resources Information Center

    California State Univ., Sacramento. School of Engineering.

    The purpose of this water treatment field study training program is to: (1) develop new qualified water treatment plant operators; (2) expand the abilities of existing operators, permitting better service both to employers and public; and (3) prepare operators for civil service and certification examinations (examinations administered by…

  16. Coevolution and Life Cycle Specialization of Plant Cell Wall Degrading Enzymes in a Hemibiotrophic Pathogen

    PubMed Central

    Brunner, Patrick C.; Torriani, Stefano F.F.; Croll, Daniel; Stukenbrock, Eva H.; McDonald, Bruce A.

    2013-01-01

    Zymoseptoria tritici is an important fungal pathogen on wheat that originated in the Fertile Crescent. Its closely related sister species Z. pseudotritici and Z. ardabiliae infect wild grasses in the same region. This recently emerged host–pathogen system provides a rare opportunity to investigate the evolutionary processes shaping the genome of an emerging pathogen. Here, we investigate genetic signatures in plant cell wall degrading enzymes (PCWDEs) that are likely affected by or driving coevolution in plant-pathogen systems. We hypothesize four main evolutionary scenarios and combine comparative genomics, transcriptomics, and selection analyses to assign the majority of PCWDEs in Z. tritici to one of these scenarios. We found widespread differential transcription among different members of the same gene family, challenging the idea of functional redundancy and suggesting instead that specialized enzymatic activity occurs during different stages of the pathogen life cycle. We also find that natural selection has significantly affected at least 19 of the 48 identified PCWDEs. The majority of genes showed signatures of purifying selection, typical for the scenario of conserved substrate optimization. However, six genes showed diversifying selection that could be attributed to either host adaptation or host evasion. This study provides a powerful framework to better understand the roles played by different members of multigene families and to determine which genes are the most appropriate targets for wet laboratory experimentation, for example, to elucidate enzymatic function during relevant phases of a pathogen’s life cycle. PMID:23515261

  17. The plant cell cycle: Pre-Replication complex formation and controls.

    PubMed

    Brasil, Juliana Nogueira; Costa, Carinne N Monteiro; Cabral, Luiz Mors; Ferreira, Paulo C G; Hemerly, Adriana S

    2017-03-16

    The multiplication of cells in all living organisms requires a tight regulation of DNA replication. Several mechanisms take place to ensure that the DNA is replicated faithfully and just once per cell cycle in order to originate through mitoses two new daughter cells that contain exactly the same information from the previous one. A key control mechanism that occurs before cells enter S phase is the formation of a pre-replication complex (pre-RC) that is assembled at replication origins by the sequential association of the origin recognition complex, followed by Cdt1, Cdc6 and finally MCMs, licensing DNA to start replication. The identification of pre-RC members in all animal and plant species shows that this complex is conserved in eukaryotes and, more importantly, the differences between kingdoms might reflect their divergence in strategies on cell cycle regulation, as it must be integrated and adapted to the niche, ecosystem, and the organism peculiarities. Here, we provide an overview of the knowledge generated so far on the formation and the developmental controls of the pre-RC mechanism in plants, analyzing some particular aspects in comparison to other eukaryotes.

  18. The plant cell cycle: Pre-Replication complex formation and controls

    PubMed Central

    Brasil, Juliana Nogueira; Costa, Carinne N. Monteiro; Cabral, Luiz Mors; Ferreira, Paulo C. G.; Hemerly, Adriana S.

    2017-01-01

    Abstract The multiplication of cells in all living organisms requires a tight regulation of DNA replication. Several mechanisms take place to ensure that the DNA is replicated faithfully and just once per cell cycle in order to originate through mitoses two new daughter cells that contain exactly the same information from the previous one. A key control mechanism that occurs before cells enter S phase is the formation of a pre-replication complex (pre-RC) that is assembled at replication origins by the sequential association of the origin recognition complex, followed by Cdt1, Cdc6 and finally MCMs, licensing DNA to start replication. The identification of pre-RC members in all animal and plant species shows that this complex is conserved in eukaryotes and, more importantly, the differences between kingdoms might reflect their divergence in strategies on cell cycle regulation, as it must be integrated and adapted to the niche, ecosystem, and the organism peculiarities. Here, we provide an overview of the knowledge generated so far on the formation and the developmental controls of the pre-RC mechanism in plants, analyzing some particular aspects in comparison to other eukaryotes. PMID:28304073

  19. Completing the cycle: maternal effects as the missing link in plant life histories

    PubMed Central

    Donohue, Kathleen

    2009-01-01

    Maternal effects on seed traits such as germination are important components of the life histories of plants because they represent the pathway from adult to offspring: the pathway that completes the life cycle. Maternal environmental effects on germination influence basic life-history expression, natural selection on germination, the expression of genetic variation for germination and even the genes involved in germination. Maternal effects on seed traits can even influence generation time and projected population growth rates. Whether these maternal environmental effects are imposed by the maternal genotype, the endosperm genotype or the embryonic genotype, however, is as yet unknown. Patterns of gene expression and protein synthesis in seeds indicate that the maternal genotype has the opportunity to influence its progeny's germination behaviour. Investigation of the phenotypic consequences of maternal environmental effects, regardless of its genetic determination, is relevant for understanding the variation in plant life cycles. Distinguishing the genotype(s) that control them is relevant for predicting the evolutionary trajectories and patterns of selection on progeny phenotypes and the genes underlying them. PMID:19324611

  20. Technical and economic evaluation of a Brayton-Rankine combined-cycle solar-thermal power plant

    SciTech Connect

    Wright, J. D.

    1981-05-01

    The objective of this study is to conduct an assessment of gas-liquid direct-contact heat exchange and of a new storage-coupled system (the open-cycle Brayton/steam Rankine combined cycle). Both technical and economic issues are evaluated. Specifically, the storage-coupled combined cycle is compared with a molten salt system. The open Brayton cycle system is used as a topping cycle, and the reject heat powers the molten salt/Rankine system. In this study the molten salt system is left unmodified, the Brayton cycle is integrated on top of a Martin Marietta description of an existing molten salt plant. This compares a nonoptimized combined cycle with an optimized molten salt system.